Unfinished journey (27)

BUS in Compressed Gas Station

Unfinished journey (27)

(Part twenty seven, Depok, West Java, Indonesia, 1 September 2014, 20:50 pm)

In 1995 I was on duty with a senior journalist from Radio Republik Indonesia (RRI) Ahmad Parembahan to covering Energy World Conference held in the city of Madrid, Spain,

The conference, which opened the King of Spain Juan Carlos who was accompanied by queen Sofia was attended by thousands of delegates from over 100 countries who discuss energy problems of the world, such as petroleum, coal, natural gas, and alternative energy such as geothermal energy, solar energy, hydropower, wave and various other alternative energy such as bio diesel.

From Indonesia Prof.Dr.Zuhal represented at the conference, and the expert staff of the Minister of Mines and Energy Ermansyah Yamin.

In the conference illustrated how much consumption, and the availability of energy reserves such as oil, coal, natural gas and other alternative energy.

As well as how to maintain a balance between consumption and exploration of search for available resources, as well as discuss the use of new technology that allows the use of coal for power generation, but using technology to filter the smoke does not cause environmental pollution (acid rain).

Petroleum

From Wikipedia, the free encyclopedia

"Crude Oil" redirects here. For the 2008 film, see Crude Oil (film). For the fuel referred to outside of North America as "petrol", see Gasoline. For other uses, see Petroleum (disambiguation).

Proven world oil reserves, 2013

Pumpjack pumping an oil well near Lubbock, Texas

An oil refinery in Mina-Al-Ahmadi, Kuwait

Natural petroleum spring in Korňa, Slovakia

Petroleum (L. petroleum, from early 15c. "petroleum, rock oil" (mid-14c. in Anglo-French), from Medieval Latin petroleum, from Latin petra rock(see petrous) + Latin: oleum oil (see oil (n.)).[1][2][3]) is a naturally occurring, yellow-to-black liquid found in geologic formations beneath the Earth's surface, which is commonly refined into various types of fuels. It consists of hydrocarbons of various molecular weights and other liquid organic compounds.[4] The name petroleum covers both naturally occurring unprocessed crude oil and petroleum products that are made up of refined crude oil. A fossil fuel, petroleum is formed when large quantities of dead organisms, usually zooplankton and algae, are buried underneath sedimentary rock and subjected to intense heat and pressure.

Petroleum is recovered mostly through oil drilling (natural petroleum springs are rare). This comes after the studies of structural geology (at the reservoir scale), sedimentary basin analysis, reservoir characterization (mainly in terms of the porosity and permeability of geologic reservoir structures).[5][6] It is refined and separated, most easily by distillation, into a large number of consumer products, from gasoline (petrol) and kerosene to asphalt and chemical reagents used to make plastics and pharmaceuticals.[7] Petroleum is used in manufacturing a wide variety of materials,[8] and it is estimated that the world consumes about 90 million barrels each day.

The use of fossil fuels, such as petroleum, has a negative impact on Earth's biosphere, releasing pollutants and greenhouse gases into the air and damaging ecosystems through events such as oil spills. Concern over the depletion of the earth's finite reserves of oil, and the effect this would have on a society dependent on it, is a concept known as peak oil.

Queen Sofia and King Juan Carlos

Contents  [hide]

1 Etymology

2 History

2.1 Early history

2.2 Modern history

3 Composition

4 Chemistry

5 Empirical equations for thermal properties

5.1 Heat of combustion

5.2 Thermal conductivity

5.3 Specific heat

5.4 Latent heat of vaporization

6 Formation

7 Reservoirs

7.1 Crude oil reservoirs

7.2 Unconventional oil reservoirs

8 Classification

9 Petroleum industry

9.1 Shipping

10 Price

11 Uses

11.1 Fuels

11.2 Other derivatives

11.3 Agriculture

12 Petroleum by country

12.1 Consumption statistics

12.2 Consumption

12.3 Production

12.4 Export

12.5 Import

12.6 Import to the USA by country 2010

12.7 Non-producing consumers

13 Environmental effects

13.1 Ocean acidification

13.2 Global warming

13.3 Extraction

13.4 Oil spills

13.5 Tarballs

13.6 Whales

14 Alternatives to petroleum

14.1 Alternatives to petroleum-based vehicle fuels

14.2 Alternatives to using oil in industry

14.3 Alternatives to burning petroleum for electricity

15 Future of petroleum production

15.1 Peak oil

15.2 Unconventional Production

16 See also

17 Notes

18 References

19 Further reading

20 External links

Etymology[edit]

The word petroleum comes from Greek: πέτρα (petra) for rocks and Greek: ἔλαιον (elaion) for oil. The term was found (in the spelling "petraoleum") in 10th-century Old English sources.[9] It was used in the treatise De Natura Fossilium, published in 1546 by the German mineralogist Georg Bauer, also known as Georgius Agricola.[10] In the 19th century, the term petroleum was frequently used to refer to mineral oils produced by distillation from mined organic solids such as cannel coal (and later oil shale), and refined oils produced from them; in the United Kingdom, storage (and later transport) of these oils were regulated by a series of Petroleum Acts, from the Petroleum Act 1863 onwards.

History[edit]

Main article: History of petroleum

Early history[edit]

Oil derrick in Okemah, Oklahoma, 1922.

Petroleum, in one form or another, has been used since ancient times, and is now important across society, including in economy, politics and technology. The rise in importance was due to the invention of the internal combustion engine, the rise in commercial aviation, and the importance of petroleum to industrial organic chemistry, particularly the synthesis of plastics, fertilizers, solvents, adhesives and pesticides.

More than 4000 years ago, according to Herodotus and Diodorus Siculus, asphalt was used in the construction of the walls and towers of Babylon; there were oil pits near Ardericca (near Babylon), and a pitch spring on Zacynthus.[11] Great quantities of it were found on the banks of the river Issus, one of the tributaries of the Euphrates. Ancient Persian tablets indicate the medicinal and lighting uses of petroleum in the upper levels of their society. By 347 AD, oil was produced from bamboo-drilled wells in China.[12] Early British explorers to Myanmar documented a flourishing oil extraction industry based in Yenangyaung that, in 1795, had hundreds of hand-dug wells under production.[13] The mythological origins of the oil fields at Yenangyaung, and its hereditary monopoly control by 24 families, indicate very ancient origins.

Modern history[edit]

In 1847, the process to distill kerosene from petroleum was invented by James Young. He noticed a natural petroleum seepage in the Riddings colliery at Alfreton, Derbyshire from which he distilled a light thin oil suitable for use as lamp oil, at the same time obtaining a thicker oil suitable for lubricating machinery. In 1848 Young set up a small business refining the crude oil.

Young eventually succeeded, by distilling cannel coal at a low heat, in creating a fluid resembling petroleum, which when treated in the same way as the seep oil gave similar products. Young found that by slow distillation he could obtain a number of useful liquids from it, one of which he named "paraffine oil" because at low temperatures it congealed into a substance resembling paraffin wax.[14]

The production of these oils and solid paraffin wax from coal formed the subject of his patent dated 17 October 1850. In 1850 Young & Meldrum and Edward William Binney entered into partnership under the title of E.W. Binney & Co. at Bathgate in West Lothian and E. Meldrum & Co. at Glasgow; their works at Bathgate were completed in 1851 and became the first truly commercial oil-works in the world with the first modern oil refinery, using oil extracted from locally-mined torbanite, shale, and bituminous coal to manufacture naphtha and lubricating oils; paraffin for fuel use and solid paraffin were not sold until 1856.[15]

Shale bings near Broxburn, 3 of a total of 19 in West Lothian

Another early refinery was built by Ignacy Łukasiewicz, providing a cheaper alternative to whale oil. The demand for petroleum as a fuel for lighting in North America and around the world quickly grew.[16] Edwin Drake's 1859 well near Titusville, Pennsylvania, is popularly considered the first modern well. Drake's well is probably singled out because it was drilled, not dug; because it used a steam engine; because there was a company associated with it; and because it touched off a major boom.[17] However, there was considerable activity before Drake in various parts of the world in the mid-19th century. A group directed by Major Alexeyev of the Bakinskii Corps of Mining Engineers hand-drilled a well in the Baku region in 1848.[18] There were engine-drilled wells in West Virginia in the same year as Drake's well.[19] An early commercial well was hand dug in Poland in 1853, and another in nearby Romania in 1857. At around the same time the world's first, small, oil refinery was opened at Jasło in Poland, with a larger one opened at Ploiești in Romania shortly after. Romania is the first country in the world to have had its annual crude oil output officially recorded in international statistics: 275 tonnes for 1857.[20][21]

The first commercial oil well in Canada became operational in 1858 at Oil Springs, Ontario (then Canada West).[22] Businessman James Miller Williams dug several wells between 1855 and 1858 before discovering a rich reserve of oil four metres below ground.[23] Williams extracted 1.5 million litres of crude oil by 1860, refining much of it into kerosene lamp oil.[22] William's well became commercially viable a year before Drake's Pennsylvania operation and could be argued to be the first commercial oil well in North America.[22] The discovery at Oil Springs touched off an oil boom which brought hundreds of speculators and workers to the area. Advances in drilling continued into 1862 when local driller Shaw reached a depth of 62 metres using the spring-pole drilling method.[24] On January 16, 1862, after an explosion of natural gas Canada's first oil gusher came into production, shooting into the air at a recorded rate of 3,000 barrels per day.[25] By the end of the 19th century the Russian Empire, particularly the Branobel company in Azerbaijan, had taken the lead in production.[26]

Access to oil was and still is a major factor in several military conflicts of the twentieth century, including World War II, during which oil facilities were a major strategic asset and were extensively bombed.[27] The German invasion of the Soviet Union included the goal to capture the Baku oilfields, as it would provide much needed oil-supplies for the German military which was suffering from blockades.[28] Oil exploration in North America during the early 20th century later led to the US becoming the leading producer by mid-century. As petroleum production in the US peaked during the 1960s, however, the United States was surpassed by Saudi Arabia and the Soviet Union.

Today, about 90 percent of vehicular fuel needs are met by oil. Petroleum also makes up 40 percent of total energy consumption in the United States, but is responsible for only 1 percent of electricity generation. Petroleum's worth as a portable, dense energy source powering the vast majority of vehicles and as the base of many industrial chemicals makes it one of the world's most important commodities. Viability of the oil commodity is controlled by several key parameters, number of vehicles in the world competing for fuel, quantity of oil exported to the world market (Export Land Model), Net Energy Gain (economically useful energy provided minus energy consumed), political stability of oil exporting nations and ability to defend oil supply lines.

The top three oil producing countries are Russia, Saudi Arabia and the United States.[29] About 80 percent of the world's readily accessible reserves are located in the Middle East, with 62.5 percent coming from the Arab 5: Saudi Arabia, UAE, Iraq, Qatar and Kuwait. A large portion of the world's total oil exists as unconventional sources, such as bitumen in Canada and oil shale in Venezuela. While significant volumes of oil are extracted from oil sands, particularly in Canada, logistical and technical hurdles remain, as oil extraction requires large amounts of heat and water, making its net energy content quite low relative to conventional crude oil. Thus, Canada's oil sands are not expected to provide more than a few million barrels per day in the foreseeable future.

Composition[edit]

In its strictest sense, petroleum includes only crude oil, but in common usage it includes all liquid, gaseous, and solid hydrocarbons. Under surface pressure and temperature conditions, lighter hydrocarbons methane, ethane, propane and butane occur as gases, while pentane and heavier ones are in the form of liquids or solids. However, in an underground oil reservoir the proportions of gas, liquid, and solid depend on subsurface conditions and on the phase diagram of the petroleum mixture.[30]

An oil well produces predominantly crude oil, with some natural gas dissolved in it. Because the pressure is lower at the surface than underground, some of the gas will come out of solution and be recovered (or burned) as associated gas or solution gas. A gas well produces predominantly natural gas. However, because the underground temperature and pressure are higher than at the surface, the gas may contain heavier hydrocarbons such as pentane, hexane, and heptane in the gaseous state. At surface conditions these will condense out of the gas to form natural gas condensate, often shortened to condensate. Condensate resembles petrol in appearance and is similar in composition to some volatile light crude oils.

The proportion of light hydrocarbons in the petroleum mixture varies greatly among different oil fields, ranging from as much as 97 percent by weight in the lighter oils to as little as 50 percent in the heavier oils and bitumens.

The hydrocarbons in crude oil are mostly alkanes, cycloalkanes and various aromatic hydrocarbons while the other organic compounds contain nitrogen, oxygen and sulfur, and trace amounts of metals such as iron, nickel, copper and vanadium. The exact molecular composition varies widely from formation to formation but the proportion of chemical elements vary over fairly narrow limits as follows:[31]

Most of the world's oils are non-conventional.[32]

Composition by weight

Element     Percent range

Carbon      83 to 85%

Hydrogen  10 to 14%

Nitrogen     0.1 to 2%

Oxygen      0.05 to 1.5%

Sulfur         0.05 to 6.0%

Metals        < 0.1%

Four different types of hydrocarbon molecules appear in crude oil. The relative percentage of each varies from oil to oil, determining the properties of each oil.[30]

Composition by weight

Hydrocarbon      Average     Range

Alkanes (paraffins)      30%  15 to 60%

Naphthenes        49%  30 to 60%

Aromatics  15%  3 to 30%

Asphaltics 6%    remainder

Crude oil varies greatly in appearance depending on its composition. It is usually black or dark brown (although it may be yellowish, reddish, or even greenish). In the reservoir it is usually found in association with natural gas, which being lighter forms a gas cap over the petroleum, and saline water which, being heavier than most forms of crude oil, generally sinks beneath it. Crude oil may also be found in semi-solid form mixed with sand and water, as in the Athabasca oil sands in Canada, where it is usually referred to as crude bitumen. In Canada, bitumen is considered a sticky, black, tar-like form of crude oil which is so thick and heavy that it must be heated or diluted before it will flow.[33] Venezuela also has large amounts of oil in the Orinoco oil sands, although the hydrocarbons trapped in them are more fluid than in Canada and are usually called extra heavy oil. These oil sands resources are called unconventional oil to distinguish them from oil which can be extracted using traditional oil well methods. Between them, Canada and Venezuela contain an estimated 3.6 trillion barrels (570×109 m3) of bitumen and extra-heavy oil, about twice the volume of the world's reserves of conventional oil.[34]

Petroleum is used mostly, by volume, for producing fuel oil and petrol, both important "primary energy" sources.[35] 84 percent by volume of the hydrocarbons present in petroleum is converted into energy-rich fuels (petroleum-based fuels), including petrol, diesel, jet, heating, and other fuel oils, and liquefied petroleum gas.[36] The lighter grades of crude oil produce the best yields of these products, but as the world's reserves of light and medium oil are depleted, oil refineries are increasingly having to process heavy oil and bitumen, and use more complex and expensive methods to produce the products required. Because heavier crude oils have too much carbon and not enough hydrogen, these processes generally involve removing carbon from or adding hydrogen to the molecules, and using fluid catalytic cracking to convert the longer, more complex molecules in the oil to the shorter, simpler ones in the fuels.

Due to its high energy density, easy transportability and relative abundance, oil has become the world's most important source of energy since the mid-1950s. Petroleum is also the raw material for many chemical products, including pharmaceuticals, solvents, fertilizers, pesticides, and plastics; the 16 percent not used for energy production is converted into these other materials. Petroleum is found in porous rock formations in the upper strata of some areas of the Earth's crust. There is also petroleum in oil sands (tar sands). Known oil reserves are typically estimated at around 190 km3 (1.2 trillion (short scale) barrels) without oil sands,[37] or 595 km3 (3.74 trillion barrels) with oil sands.[38] Consumption is currently around 84 million barrels (13.4×106 m3) per day, or 4.9 km3 per year. Which in turn yields a remaining oil supply of only about 120 years, if current demand remain static.

Chemistry[edit]

Octane, a hydrocarbon found in petroleum. Lines represent single bonds; black spheres represent carbon; white spheres represent hydrogen.

Petroleum is a mixture of a very large number of different hydrocarbons; the most commonly found molecules are alkanes (paraffins), cycloalkanes (naphthenes), aromatic hydrocarbons, or more complicated chemicals like asphaltenes. Each petroleum variety has a unique mix of molecules, which define its physical and chemical properties, like color and viscosity.

The alkanes, also known as paraffins, are saturated hydrocarbons with straight or branched chains which contain only carbon and hydrogen and have the general formula CnH2n+2. They generally have from 5 to 40 carbon atoms per molecule, although trace amounts of shorter or longer molecules may be present in the mixture.

The alkanes from pentane (C5H12) to octane (C8H18) are refined into petrol, the ones from nonane (C9H20) to hexadecane (C16H34) into diesel fuel, kerosene and jet fuel. Alkanes with more than 16 carbon atoms can be refined into fuel oil and lubricating oil. At the heavier end of the range, paraffin wax is an alkane with approximately 25 carbon atoms, while asphalt has 35 and up, although these are usually cracked by modern refineries into more valuable products. The shortest molecules, those with four or fewer carbon atoms, are in a gaseous state at room temperature. They are the petroleum gases. Depending on demand and the cost of recovery, these gases are either flared off, sold as liquified petroleum gas under pressure, or used to power the refinery's own burners. During the winter, butane (C4H10), is blended into the petrol pool at high rates, because its high vapor pressure assists with cold starts. Liquified under pressure slightly above atmospheric, it is best known for powering cigarette lighters, but it is also a main fuel source for many developing countries. Propane can be liquified under modest pressure, and is consumed for just about every application relying on petroleum for energy, from cooking to heating to transportation.

The cycloalkanes, also known as naphthenes, are saturated hydrocarbons which have one or more carbon rings to which hydrogen atoms are attached according to the formula CnH2n. Cycloalkanes have similar properties to alkanes but have higher boiling points.

The aromatic hydrocarbons are unsaturated hydrocarbons which have one or more planar six-carbon rings called benzene rings, to which hydrogen atoms are attached with the formula CnHn. They tend to burn with a sooty flame, and many have a sweet aroma. Some are carcinogenic.

These different molecules are separated by fractional distillation at an oil refinery to produce petrol, jet fuel, kerosene, and other hydrocarbons. For example, 2,2,4-trimethylpentane (isooctane), widely used in petrol, has a chemical formula of C8H18 and it reacts with oxygen exothermically:[39]

2 C

8H

18(l) + 25 O

2(g) → 16 CO

2(g) + 18 H

2O(g) (ΔH = −5.51 MJ/mol of octane)

The number of various molecules in an oil sample can be determined in laboratory. The molecules are typically extracted in a solvent, then separated in a gas chromatograph, and finally determined with a suitable detector, such as a flame ionization detector or a mass spectrometer.[40] Due to the large number of co-eluted hydrocarbons within oil, many cannot be resolved by traditional gas chromatography and typically appear as a hump in the chromatogram. This unresolved complex mixture (UCM) of hydrocarbons is particularly apparent when analysing weathered oils and extracts from tissues of organisms exposed to oil.

Incomplete combustion of petroleum or petrol results in production of toxic byproducts. Too little oxygen results in carbon monoxide. Due to the high temperatures and high pressures involved, exhaust gases from petrol combustion in car engines usually include nitrogen oxides which are responsible for creation of photochemical smog.

Empirical equations for thermal properties[edit]

Heat of combustion[edit]

At a constant volume the heat of combustion of a petroleum product can be approximated as follows:

Q_v = 12400, - 2,100d^2.

where Q_v is measured in cal/gram and d is the specific gravity at 60 °F (16 °C).

Thermal conductivity[edit]

The thermal conductivity of petroleum based liquids can be modeled as follows:[41]

K = \frac{1.62}{API}[1-0.0003(t-32)]

where K is measured in BTU · °F−1hr−1ft−1 , t is measured in °F and API is degrees API gravity.

Specific heat[edit]

The specific heat of a petroleum oils can be modeled as follows:[42]

c = \frac{1}{d} [0.388+0.00046t],

where c is measured in BTU/lbm-°F, t is the temperature in Fahrenheit and d is the specific gravity at 60 °F (16 °C).

In units of kcal/(kg·°C), the formula is:

c = \frac{1}{d} [0.4024+0.00081t],

where the temperature t is in Celsius and d is the specific gravity at 15 °C.

Latent heat of vaporization[edit]

The latent heat of vaporization can be modeled under atmospheric conditions as follows:

L = \frac{1}{d}[110.9 - 0.09t],

where L is measured in BTU/lbm, t is measured in °F and d is the specific gravity at 60 °F (16 °C).

In units of kcal/kg, the formula is:

L = \frac{1}{d}[194.4 - 0.162t],

where the temperature t is in Celsius and d is the specific gravity at 15 °C.[43]

Formation[edit]

Structure of a vanadium porphyrin compound (left) extracted from petroleum by Alfred E. Treibs, father of organic geochemistry. Treibs noted the close structural similarity of this molecule and chlorophyll a (right).[44][45]

Petroleum is a fossil fuel derived from ancient fossilized organic materials, such as zooplankton and algae.[46] Vast quantities of these remains settled to sea or lake bottoms, mixing with sediments and being buried under anoxic conditions. As further layers settled to the sea or lake bed, intense heat and pressure build up in the lower regions. This process caused the organic matter to change, first into a waxy material known as kerogen, which is found in various oil shales around the world, and then with more heat into liquid and gaseous hydrocarbons via a process known as catagenesis. Formation of petroleum occurs from hydrocarbon pyrolysis in a variety of mainly endothermic reactions at high temperature and/or pressure.[47]

There were certain warm nutrient-rich environments such as the Gulf of Mexico and the ancient Tethys Sea where the large amounts of organic material falling to the ocean floor exceeded the rate at which it could decompose. This resulted in large masses of organic material being buried under subsequent deposits such as shale formed from mud. This massive organic deposit later became heated and transformed under pressure into oil.[48]

Geologists often refer to the temperature range in which oil forms as an "oil window"[49]—below the minimum temperature oil remains trapped in the form of kerogen, and above the maximum temperature the oil is converted to natural gas through the process of thermal cracking. Sometimes, oil formed at extreme depths may migrate and become trapped at a much shallower level. The Athabasca Oil Sands are one example of this.

An alternative mechanism was proposed by Russian scientists in the mid-1850s, the Abiogenic petroleum origin, but this is contradicted by the geological and geochemical evidence.[citation needed]

Reservoirs[edit]

Crude oil reservoirs[edit]

Hydrocarbon trap.

Three conditions must be present for oil reservoirs to form: a source rock rich in hydrocarbon material buried deep enough for subterranean heat to cook it into oil, a porous and permeable reservoir rock for it to accumulate in, and a cap rock (seal) or other mechanism that prevents it from escaping to the surface. Within these reservoirs, fluids will typically organize themselves like a three-layer cake with a layer of water below the oil layer and a layer of gas above it, although the different layers vary in size between reservoirs. Because most hydrocarbons are less dense than rock or water, they often migrate upward through adjacent rock layers until either reaching the surface or becoming trapped within porous rocks (known as reservoirs) by impermeable rocks above. However, the process is influenced by underground water flows, causing oil to migrate hundreds of kilometres horizontally or even short distances downward before becoming trapped in a reservoir. When hydrocarbons are concentrated in a trap, an oil field forms, from which the liquid can be extracted by drilling and pumping.

LNG Tanker

The reactions that produce oil and natural gas are often modeled as first order breakdown reactions, where hydrocarbons are broken down to oil and natural gas by a set of parallel reactions, and oil eventually breaks down to natural gas by another set of reactions. The latter set is regularly used in petrochemical plants and oil refineries.

Wells are drilled into oil reservoirs to extract the crude oil. "Natural lift" production methods that rely on the natural reservoir pressure to force the oil to the surface are usually sufficient for a while after reservoirs are first tapped. In some reservoirs, such as in the Middle East, the natural pressure is sufficient over a long time. The natural pressure in most reservoirs, however, eventually dissipates. Then the oil must be extracted using "artificial lift" means. Over time, these "primary" methods become less effective and "secondary" production methods may be used. A common secondary method is "waterflood" or injection of water into the reservoir to increase pressure and force the oil to the drilled shaft or "wellbore." Eventually "tertiary" or "enhanced" oil recovery methods may be used to increase the oil's flow characteristics by injecting steam, carbon dioxide and other gases or chemicals into the reservoir. In the United States, primary production methods account for less than 40 percent of the oil produced on a daily basis, secondary methods account for about half, and tertiary recovery the remaining 10 percent. Extracting oil (or "bitumen") from oil/tar sand and oil shale deposits requires mining the sand or shale and heating it in a vessel or retort, or using "in-situ" methods of injecting heated liquids into the deposit and then pumping out the oil-saturated liquid.

Unconventional oil reservoirs[edit]

See also: Unconventional oil, Oil sands and Oil shale reserves

Oil-eating bacteria biodegrade oil that has escaped to the surface. Oil sands are reservoirs of partially biodegraded oil still in the process of escaping and being biodegraded, but they contain so much migrating oil that, although most of it has escaped, vast amounts are still present—more than can be found in conventional oil reservoirs. The lighter fractions of the crude oil are destroyed first, resulting in reservoirs containing an extremely heavy form of crude oil, called crude bitumen in Canada, or extra-heavy crude oil in Venezuela. These two countries have the world's largest deposits of oil sands.

On the other hand, oil shales are source rocks that have not been exposed to heat or pressure long enough to convert their trapped hydrocarbons into crude oil. Technically speaking, oil shales are not always shales and do not contain oil, but are fined-grain sedimentary rocks containing an insoluble organic solid called kerogen. The kerogen in the rock can be converted into crude oil using heat and pressure to simulate natural processes. The method has been known for centuries and was patented in 1694 under British Crown Patent No. 330 covering, "A way to extract and make great quantities of pitch, tar, and oil out of a sort of stone." Although oil shales are found in many countries, the United States has the world's largest deposits.[50]

Classification[edit]

Some marker crudes with their sulfur content (horizontal) and API gravity (vertical) and relative production quantity.

See also: Benchmark (crude oil)

The petroleum industry generally classifies crude oil by the geographic location it is produced in (e.g. West Texas Intermediate, Brent, or Oman), its API gravity (an oil industry measure of density), and its sulfur content. Crude oil may be considered light if it has low density or heavy if it has high density; and it may be referred to as sweet if it contains relatively little sulfur or sour if it contains substantial amounts of sulfur.

The geographic location is important because it affects transportation costs to the refinery. Light crude oil is more desirable than heavy oil since it produces a higher yield of petrol, while sweet oil commands a higher price than sour oil because it has fewer environmental problems and requires less refining to meet sulfur standards imposed on fuels in consuming countries. Each crude oil has unique molecular characteristics which are understood by the use of crude oil assay analysis in petroleum laboratories.

Barrels from an area in which the crude oil's molecular characteristics have been determined and the oil has been classified are used as pricing references throughout the world. Some of the common reference crudes are:

West Texas Intermediate (WTI), a very high-quality, sweet, light oil delivered at Cushing, Oklahoma for North American oil

Brent Blend, comprising 15 oils from fields in the Brent and Ninian systems in the East Shetland Basin of the North Sea. The oil is landed at Sullom Voe terminal in Shetland. Oil production from Europe, Africa and Middle Eastern oil flowing West tends to be priced off this oil, which forms a benchmark

Dubai-Oman, used as benchmark for Middle East sour crude oil flowing to the Asia-Pacific region

Tapis (from Malaysia, used as a reference for light Far East oil)

Minas (from Indonesia, used as a reference for heavy Far East oil)

The OPEC Reference Basket, a weighted average of oil blends from various OPEC (The Organization of the Petroleum Exporting Countries) countries

Midway Sunset Heavy, by which heavy oil in California is priced[51]

There are declining amounts of these benchmark oils being produced each year, so other oils are more commonly what is actually delivered. While the reference price may be for West Texas Intermediate delivered at Cushing, the actual oil being traded may be a discounted Canadian heavy oil delivered at Hardisty, Alberta, and for a Brent Blend delivered at Shetland, it may be a Russian Export Blend delivered at the port of Primorsk.[52]

Petroleum industry[edit]

Crude Oil Export Treemap (2012) from Harvard Atlas of Economic Complexity[53]

New York Mercantile Exchange prices ($/bbl) for West Texas Intermediate since 2000

Main article: Petroleum industry

The petroleum industry is involved in the global processes of exploration, extraction, refining, transporting (often with oil tankers and pipelines), and marketing petroleum products. The largest volume products of the industry are fuel oil and petrol. Petroleum is also the raw material for many chemical products, including pharmaceuticals, solvents, fertilizers, pesticides, and plastics. The industry is usually divided into three major components: upstream, midstream and downstream. Midstream operations are usually included in the downstream category.

Petroleum is vital to many industries, and is of importance to the maintenance of industrialized civilization itself, and thus is a critical concern to many nations. Oil accounts for a large percentage of the world's energy consumption, ranging from a low of 32 percent for Europe and Asia, up to a high of 53 percent for the Middle East, South and Central America (44%), Africa (41%), and North America (40%). The world at large consumes 30 billion barrels (4.8 km³) of oil per year, and the top oil consumers largely consist of developed nations. In fact, 24 percent of the oil consumed in 2004 went to the United States alone,[54] though by 2007 this had dropped to 21 percent of world oil consumed.[55]

In the US, in the states of Arizona, California, Hawaii, Nevada, Oregon and Washington, the Western States Petroleum Association (WSPA) represents companies responsible for producing, distributing, refining, transporting and marketing petroleum. This non-profit trade association was founded in 1907, and is the oldest petroleum trade association in the United States.[56]

Shipping[edit]

In the 1950s, shipping costs made up 33 percent of the price of oil transported from the Persian Gulf to USA,[57] but due to the development of supertankers in the 1970s, the cost of shipping dropped to only 5 percent of the price of Persian oil in USA.[57] Due to the increase of the value of the crude oil during the last 30 years, the share of the shipping cost on the final cost of the delivered commodity was less than 3% in 2010. For example, in 2010 the shipping cost from the Persian Gulf to the USA was in the range of 20 $/t and the cost of the delivered crude oil around 800 $/t.[citation needed]

Price[edit]

Main article: Price of petroleum

After the collapse of the OPEC-administered pricing system in 1985, and a short lived experiment with netback pricing, oil-exporting countries adopted a market-linked pricing mechanism.[58] First adopted by PEMEX in 1986, market-linked pricing was widely accepted, and by 1988 became and still is the main method for pricing crude oil in international trade.[58] The current reference, or pricing markers, are Brent, WTI, and Dubai/Oman.[58]

Uses[edit]

Further information: Petroleum products

The chemical structure of petroleum is heterogeneous, composed of hydrocarbon chains of different lengths. Because of this, petroleum may be taken to oil refineries and the hydrocarbon chemicals separated by distillation and treated by other chemical processes, to be used for a variety of purposes. See Petroleum products.

Fuels[edit]

A poster used to promote carpooling as a way to ration gasoline during World War II.

The most common distillation fractions of petroleum are fuels. Fuels include (by increasing boiling temperature range):[59]

Common fractions of petroleum as fuels

Fraction     Boiling range oC

Liquefied petroleum gas (LPG)     −40

Butane       −12 to −1

Petrol         −1 to 110

Jet fuel       150 to 205

Kerosene  205 to 260

Fuel oil       205 to 290

Diesel fuel 260 to 315

Other derivatives[edit]

Certain types of resultant hydrocarbons may be mixed with other non-hydrocarbons, to create other end products:

Alkenes (olefins), which can be manufactured into plastics or other compounds

Lubricants (produces light machine oils, motor oils, and greases, adding viscosity stabilizers as required)

Wax, used in the packaging of frozen foods, among others

Sulfur or Sulfuric acid. These are useful industrial materials. Sulfuric acid is usually prepared as the acid precursor oleum, a byproduct of sulfur removal from fuels.

Bulk tar

Asphalt

Petroleum coke, used in speciality carbon products or as solid fuel

Paraffin wax

Aromatic petrochemicals to be used as precursors in other chemical production

Agriculture[edit]

Since the 1940s, agricultural productivity has increased dramatically, due largely to the increased use of energy-intensive mechanization, fertilizers and pesticides.

Petroleum by country[edit]

Consumption statistics[edit]

Global fossil carbon emissions, an indicator of consumption, for 1800–2007. Total is black, Oil is in blue.

Rate of world energy usage per day, from 1970 to 2010. 1000TWh=1PWh.[60]

daily oil consumption from 1980 to 2006

oil consumption by percentage of total per region from 1980 to 2006: red=USA, blue=Europe, yellow=Asia+Oceania

Oil consumption 1980 to 2007 by region.

Consumption[edit]

According to the US Energy Information Administration (EIA) estimate for 2011, the world consumes 87.421 million barrels of oil each day.

Oil consumption per capita (darker colors represent more consumption, gray represents no data).

This table orders the amount of petroleum consumed in 2011 in thousand barrels (1000 bbl) per day and in thousand cubic metres (1000 m3) per day:[61][62][63]

Consuming Nation 2011      (1000 bbl/

day)  (1000 m3/

day)  population

in millions  bbl/year

per capita  m3/year

per capita  national production/

consumption

United States 1  18,835.5    2,994.6      314   21.8  3.47  0.51

China         9,790.0      1,556.5      1345 2.7    0.43  0.41

Japan 2     4,464.1      709.7         127   12.8  2.04  0.03

India 2        3,292.2      523.4         1198 1       0.16  0.26

Russia 1    3,145.1      500.0         140   8.1    1.29  3.35

Saudi Arabia (OPEC)  2,817.5      447.9         27     40     6.4    3.64

Brazil          2,594.2      412.4         193   4.9    0.78  0.99

Germany 2          2,400.1      381.6         82     10.7  1.70  0.06

Canada     2,259.1      359.2         33     24.6  3.91  1.54

South Korea 2    2,230.2      354.6         48     16.8  2.67  0.02

Mexico 1    2,132.7      339.1         109   7.1    1.13  1.39

France 2    1,791.5      284.8         62     10.5  1.67  0.03

Iran (OPEC)        1,694.4      269.4         74     8.3    1.32  2.54

United Kingdom 1        1,607.9      255.6         61     9.5    1.51  0.93

Italy 2         1,453.6      231.1         60     8.9    1.41  0.10

Source: US Energy Information Administration

Population Data:[64]

1 peak production of oil already passed in this state

2 This country is not a major oil producer

Production[edit]

For oil reserves by country, see List of countries by proven oil reserves.

Oil producing countries

Graph of Top Oil Producing Countries 1960–2006, including Soviet Union[65]

In petroleum industry parlance, production refers to the quantity of crude extracted from reserves, not the literal creation of the product.

#       Producing Nation         103bbl/d (2006)  103bbl/d (2007)  103bbl/d (2008)  103bbl/d (2009)        Present Share

1       Saudi Arabia (OPEC)  10,665       10,234       10,782       9,760         11.8%

2       Russia 1    9,677         9,876         9,789         9,934         12.0%

3       United States 1  8,331         8,481         8,514         9,141         11.1%

4       Iran (OPEC)        4,148         4,043         4,174         4,177         5.1%

5       China         3,846         3,901         3,973         3,996         4.8%

6       Canada 2  3,288         3,358         3,350         3,294         4.0%

7       Mexico 1    3,707         3,501         3,185         3,001         3.6%

8       United Arab Emirates (OPEC)       2,945         2,948         3,046         2,795          3.4%

9       Kuwait (OPEC)   2,675         2,613         2,742         2,496         3.0%

10     Venezuela (OPEC) 1  2,803         2,667         2,643         2,471         3.0%

11     Norway 1   2,786         2,565         2,466         2,350         2.8%

12     Brazil          2,166         2,279         2,401         2,577         3.1%

13     Iraq (OPEC) 3     2,008         2,094         2,385         2,400         2.9%

14     Algeria (OPEC)  2,122         2,173         2,179         2,126         2.6%

15     Nigeria (OPEC)  2,443         2,352         2,169         2,211         2.7%

16     Angola (OPEC)  1,435         1,769         2,014         1,948         2.4%

17     Libya (OPEC)     1,809         1,845         1,875         1,789         2.2%

18     United Kingdom 1,689         1,690         1,584         1,422         1.7%

19     Kazakhstan         1,388         1,445         1,429         1,540         1.9%

20     Qatar (OPEC)     1,141         1,136         1,207         1,213         1.5%

21     Indonesia  1,102         1,044         1,051         1,023         1.2%

22     India 854   881   884   877   1.1%

23     Azerbaijan 648   850   875   1,012         1.2%

24     Argentina   802   791   792   794   1.0%

25     Oman         743   714   761   816   1.0%

26     Malaysia    729   703   727   693   0.8%

27     Egypt         667   664   631   678   0.8%

28     Colombia   544   543   601   686   0.8%

29     Australia    552   595   586   588   0.7%

30     Ecuador (OPEC)         536   512   505   485   0.6%

31     Sudan        380   466   480   486   0.6%

32     Syria 449   446   426   400   0.5%

33     Equatorial Guinea       386   400   359   346   0.4%

34     Thailand    334   349   361   339   0.4%

35     Vietnam     362   352   314   346   0.4%

36     Yemen       377   361   300   287   0.3%

37     Denmark    344   314   289   262   0.3%

38     Gabon       237   244   248   242   0.3%

39     South Africa        204   199   195   192   0.2%

40     Turkmenistan     No data      180   189   198   0.2%

41     Trinidad and Tobago  181   179   176   174   0.1%

Source: U.S. Energy Information Administration

1 Peak production of conventional oil already passed in this state

2 Although Canada's conventional oil production is declining, its total oil production is increasing as oil sands production grows. When oil sands are included, Canada has the world's second largest oil reserves after Saudi Arabia.

3 Trinidad and Tobago has the worlds third largest pitch lake situated La Brea south Trinidad

4 Though still a member, Iraq has not been included in production figures since 1998

In 2013, the United States will produce an average of 11.4 million barrels a day, which would make it the second largest producer of hydrocarbons,[66] and is expected to overtake Saudi Arabia before 2020.[67]

Export[edit]

See also: Fossil fuel exporters and Organization of Petroleum Exporting Countries

Oil exports by country.

In order of net exports in 2011, 2009 and 2006 in thousand bbl/d and thousand m³/d:

#       Exporting Nation          103bbl/d (2011)  103m3/d (2011) 103bbl/d (2009)  103m3/d (2009)        103bbl/d (2006)  103m3/d (2006)

1       Saudi Arabia (OPEC)  8,336         1,325         7,322         1,164         8,651          1,376

2       Russia 1    7,083         1,126         7,194         1,144         6,565         1,044

3       Iran (OPEC)        2,540         403   2,486         395   2,519         401

4       United Arab Emirates (OPEC)       2,524         401   2,303         366   2,515          400

5       Kuwait (OPEC)   2,343         373   2,124         338   2,150         342

6       Nigeria (OPEC)  2,257         359   1,939         308   2,146         341

7       Iraq (OPEC)        1,915         304   1,764         280   1,438         229

8       Angola (OPEC)  1,760         280   1,878         299   1,363         217

9       Norway 1   1,752         279   2,132         339   2,542         404

10     Venezuela (OPEC) 1  1,715         273   1,748         278   2,203         350

11     Algeria (OPEC) 1         1,568         249   1,767         281   1,847         297

12     Qatar (OPEC)     1,468         233   1,066         169   –       –

13     Canada 2  1,405         223   1,168         187   1,071         170

14     Kazakhstan         1,396         222   1,299         207   1,114         177

15     Azerbaijan 1       836   133   912   145   532   85

16     Trinidad and Tobago 1         177   112   167   160   155   199

Source: US Energy Information Administration

1 peak production already passed in this state

2 Canadian statistics are complicated by the fact it is both an importer and exporter of crude oil, and refines large amounts of oil for the U.S. market. It is the leading source of U.S. imports of oil and products, averaging 2,500,000 bbl/d (400,000 m3/d) in August 2007. [1].

Total world production/consumption (as of 2005) is approximately 84 million barrels per day (13,400,000 m3/d).

Import[edit]

Oil imports by country.

In order of net imports in 2011, 2009 and 2006 in thousand bbl/d and thousand m³/d:

#       Importing Nation 103bbl/day (2011)       103m3/day (2011)       103bbl/day (2009)          103m3/day (2009)       103bbl/day (2006)       103m3/day (2006)

1       United States 1  8,728         1,388         9,631         1,531         12,220       1,943

2       China 2      5,487         872   4,328         688   3,438         547

3       Japan        4,329         688   4,235         673   5,097         810

4       India 2,349         373   2,233         355   1,687         268

5       Germany   2,235         355   2,323         369   2,483         395

6       South Korea       2,170         345   2,139         340   2,150         342

7       France       1,697         270   1,749         278   1,893         301

8       Spain         1,346         214   1,439         229   1,555         247

9       Italy   1,292         205   1,381         220   1,558         248

10     Singapore 1,172         186   916   146   787   125

11     Republic of China (Taiwan) 1,009         160   944   150   942   150

12     Netherlands        948   151   973   155   936   149

13     Turkey       650   103   650   103   576   92

14     Belgium     634   101   597   95     546   87

15     Thailand    592   94     538   86     606   96

Source: US Energy Information Administration

1 peak production of oil expected in 2020[68]

2 Major oil producer whose production is still increasing[citation needed]

Import to the USA by country 2010[edit]

oil imports to US 2010

Non-producing consumers[edit]

Countries whose oil production is 10% or less of their consumption.

#       Consuming Nation      (bbl/day)    (m³/day)

1       Japan        5,578,000  886,831

2       Germany   2,677,000  425,609

3       South Korea       2,061,000  327,673

4       France       2,060,000  327,514

5       Italy   1,874,000  297,942

6       Spain         1,537,000  244,363

7       Netherlands        946,700     150,513

8       Turkey       575,011     91,663

Source: CIA World Factbook[not in citation given]

Environmental effects[edit]

Diesel fuel spill on a road

Main article: Environmental issues with petroleum

Because petroleum is a naturally occurring substance, its presence in the environment need not be the result of human causes such as accidents and routine activities (seismic exploration, drilling, extraction, refining and combustion). Phenomena such as seeps[69] and tar pits are examples of areas that petroleum affects without man's involvement. Regardless of source, petroleum's effects when released into the environment are similar.

Ocean acidification[edit]

Seawater Acidification

Ocean acidification is the increase in the acidity of the Earth's oceans caused by the uptake of carbon dioxide (CO

2) from the atmosphere. This increase in acidity inhibits life such as scallops.[70]

Global warming[edit]

When burned, petroleum releases carbon dioxide; a greenhouse gas. Along with the burning of coal, petroleum combustion is the largest contributor to the increase in atmospheric CO2. Atmospheric CO2 has risen steadily since the industrial revolution to current levels of over 390 ppmv, from the 180 – 300 ppmv of the prior 800 thousand years, driving global warming.[71][72][73] The unbridled use of petroleum could potentially cause a runaway greenhouse effect on Earth.[citation needed] Use of oil as an energy source has caused Earth's temperature to increase by nearly one degree Celsius. This raise in temperature has reduced the Arctic ice cap to 1,100,000 sq mi (2,800,000 km2), smaller than ever recorded.[74] Because of this melt, more oil reserves have been revealed. It is estimated by the International Energy Agency that about 13 percent of the world's undiscovered oil resides in the Arctic.[75]

Extraction[edit]

Oil extraction is simply the removal of oil from the reservoir (oil pool). Oil is often recovered as a water-in-oil emulsion, and specialty chemicals called demulsifiers are used to separate the oil from water. Oil extraction is costly and sometimes environmentally damaging, although Dr. John Hunt of the Woods Hole Oceanographic Institution pointed out in a 1981 paper that over 70 percent of the reserves in the world are associated with visible macroseepages, and many oil fields are found due to natural seeps. Offshore exploration and extraction of oil disturbs the surrounding marine environment.[76]

Oil spills[edit]

Further information: Oil spill and List of oil spills

Kelp after an oil spill

Oil Sick from the Montara oil spill in the Timor Sea, September, 2009

Volunteers cleaning up the aftermath of the Prestige oil spill

Crude oil and refined fuel spills from tanker ship accidents have damaged natural ecosystems in Alaska, the Gulf of Mexico, the Galapagos Islands, France and many other places.

The quantity of oil spilled during accidents has ranged from a few hundred tons to several hundred thousand tons (e.g., Deepwater Horizon Oil Spill, Atlantic Empress, Amoco Cadiz). Smaller spills have already proven to have a great impact on ecosystems, such as the Exxon Valdez oil spill

Oil spills at sea are generally much more damaging than those on land, since they can spread for hundreds of nautical miles in a thin oil slick which can cover beaches with a thin coating of oil. This can kill sea birds, mammals, shellfish and other organisms it coats. Oil spills on land are more readily containable if a makeshift earth dam can be rapidly bulldozed around the spill site before most of the oil escapes, and land animals can avoid the oil more easily.

Control of oil spills is difficult, requires ad hoc methods, and often a large amount of manpower. The dropping of bombs and incendiary devices from aircraft on SS Torrey Canyon wreck produced poor results;[77] modern techniques would include pumping the oil from the wreck, like in the Prestige oil spill or the Erika oil spill.[78]

Though crude oil is predominantly composed of various hydrocarbons, certain nitrogen heterocylic compounds, such as pyridine, picoline, and quinoline are reported as contaminants associated with crude oil, as well as facilities processing oil shale or coal, and have also been found at legacy wood treatment sites. These compounds have a very high water solubility, and thus tend to dissolve and move with water. Certain naturally occurring bacteria, such as Micrococcus, Arthrobacter, and Rhodococcus have been shown to degrade these contaminants.[79]

Tarballs[edit]

A tarball is a blob of crude oil (not to be confused with tar, which is typically derived from pine trees rather than petroleum) which has been weathered after floating in the ocean. Tarballs are an aquatic pollutant in most environments, although they can occur naturally, for example, in the Santa Barbara Channel of California.[80][81] Their concentration and features have been used to assess the extent of oil spills. Their composition can be used to identify their sources of origin,[82][83] and tarballs themselves may be dispersed over long distances by deep sea currents.[81] They are slowly decomposed by bacteria, including Chromobacterium violaceum, Cladosporium resinae, Bacillus submarinus, Micrococcus varians, Pseudomonas aeruginosa, Candida marina and Saccharomyces estuari.[80]

Whales[edit]

James S. Robbins has argued that the advent of petroleum-refined kerosene saved some species of great whales from extinction by providing an inexpensive substitute for whale oil, thus eliminating the economic imperative for open-boat whaling.[84]

Alternatives to petroleum[edit]

Further information: Renewable energy

In the United States in 2007 about 70 percent of petroleum was used for transportation (e.g. petrol, diesel, jet fuel), 24 percent by industry (e.g. production of plastics), 5 percent for residential and commercial uses, and 2 percent for electricity production.[85] Outside of the US, a higher proportion of petroleum tends to be used for electricity.[86]

Alternatives to petroleum-based vehicle fuels[edit]

Brazilian fuel station with four alternative fuels for sale: diesel (B3), gasohol (E25), neat ethanol (E100), and compressed natural gas (CNG).

Main articles: Alternative fuel vehicle, Hydrogen economy and Green vehicle

Alternative fuel vehicles refers to both:

Vehicles that use alternative fuels used in standard or modified internal combustion engines such as natural gas vehicles, neat ethanol vehicles, flexible-fuel vehicles, biodiesel-powered vehicles, and hydrogen vehicles.

Vehicles with advanced propulsion systems that reduce or substitute petroleum use such as battery electric vehicles, plug-in hybrid electric vehicles, hybrid electric vehicles, and hydrogen fuel cell vehicles.

Alternatives to using oil in industry[edit]

[icon] This section requires expansion. (July 2008)

Biological feedstocks do exist for industrial uses such as Bioplastic production.[87]

Alternatives to burning petroleum for electricity[edit]

Main articles: Alternative energy, Nuclear power and Renewable energy

In oil producing countries with little refinery capacity, oil is sometimes burned to produce electricity. Renewable energy technologies such as solar power, wind power, micro hydro, biomass and biofuels are used, but the primary alternatives remain large-scale hydroelectricity, nuclear and coal-fired generation.

Future of petroleum production[edit]

US oil production and imports, 1910-2012.

Consumption in the twentieth and twenty-first centuries has been abundantly pushed by automobile growth; the 1985–2003 oil glut even fueled the sales of low economy vehicles in OECD countries. The 2008 economic crisis seems to have had some impact on the sales of such vehicles; still, the 2008 oil consumption shows a small increase. The BRIC countries might also kick in, as China briefly was the first automobile market in December 2009.[88] The immediate outlook still hints upwards. In the long term, uncertainties linger; the OPEC believes that the OECD countries will push low consumption policies at some point in the future; when that happens, it will definitely curb oil sales, and both OPEC and EIA kept lowering their 2020 consumption estimates during the past 5 years.[89] Oil products are more and more in competition with alternative sources, mainly coal and natural gas, both cheaper sources. Production will also face an increasingly complex situation; while OPEC countries still have large reserves at low production prices, newly found reservoirs often lead to higher prices; offshore giants such as Tupi, Guara and Tiber demand high investments and ever-increasing technological abilities. Subsalt reservoirs such as Tupi were unknown in the twentieth century, mainly because the industry was unable to probe them. Enhanced Oil Recovery (EOR) techniques (example: DaQing, China[90] ) will continue to play a major role in increasing the world's recoverable oil.

Peak oil[edit]

Main article: Peak oil

Global Peak Oil forecast

Peak oil is the projection that future petroleum production (whether for individual oil wells, entire oil fields, whole countries, or worldwide production) will eventually peak and then decline at a similar rate to the rate of increase before the peak as these reserves are exhausted. The peak of oil discoveries was in 1965, and oil production per year has surpassed oil discoveries every year since 1980.[91]

Hubbert applied his theory to accurately predict the peak of U.S. conventional oil production at a date between 1966 and 1970. This prediction was based on data available at the time of his publication in 1956. In the same paper, Hubbert predicts world peak oil in "half a century" after his publication, which would be 2006.[92]

It is difficult to predict the oil peak in any given region, due to the lack of knowledge and/or transparency in accounting of global oil reserves.[93] Based on available production data, proponents have previously predicted the peak for the world to be in years 1989, 1995, or 1995–2000. Some of these predictions date from before the recession of the early 1980s, and the consequent reduction in global consumption, the effect of which was to delay the date of any peak by several years. Just as the 1971 U.S. peak in oil production was only clearly recognized after the fact, a peak in world production will be difficult to discern until production clearly drops off.[94] The peak is also a moving target as it is now measured as "liquids", which includes synthetic fuels, instead of just conventional oil.[95]

The International Energy Agency (IEA) said in 2010 that production of conventional crude oil had peaked in 2006 at 70 MBBL/d, then flattened at 68 or 69 thereafter.[96][97] Since virtually all economic sectors rely heavily on petroleum, peak oil, if it were to occur, could lead to a "partial or complete failure of markets".[98]

Unconventional Production[edit]

The calculus for peak oil has changed with the introduction of unconventional production methods. In particular, the combination of horizontal drilling and hydraulic fracturing has resulted in a significant increase in production from previously uneconomic plays.[99] Certain rock strata contain hydrocarbons but have low permeability and are not thick from a vertical perspective. Conventional vertical wells would be unable to economically retrieve these hydrocarbons. Horizontal drilling, extending horizontally through the strata, permits the well to access a much greater volume of the strata. Hydraulic fracturing creates greater permeability and increases hydrocarbon flow to the wellbore.

Coal

From Wikipedia, the free encyclopedia

For other uses, see Coal (disambiguation).

Coal

Sedimentary rock

Coal anthracite.jpg

Anthracite coal

Composition

Primary      carbon

Secondary hydrogen,

sulfur,

oxygen,

nitrogen

Bituminous coal

Coal (from the Old English term col, which has meant "mineral of fossilized carbon" since the 13th century)[1] is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure. Coal is composed primarily of carbon along with variable quantities of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.[2]

Throughout history, coal has been used as an energy resource, primarily burned for the production of electricity and/or heat, and is also used for industrial purposes, such as refining metals. A fossil fuel, coal forms when dead plant matter is converted into peat, which in turn is converted into lignite, then sub-bituminous coal, after that bituminous coal, and lastly anthracite. This involves biological and geological processes that take place over a long period. The Energy Information Administration estimates coal reserves at 948×109 short tons (860 Gt).[3] One estimate for resources is 18 000 Gt.[4]

Coal is the largest source of energy for the generation of electricity worldwide, as well as one of the largest worldwide anthropogenic sources of carbon dioxide releases. In 1999, world gross carbon dioxide emissions from coal usage were 8,666 million tonnes of carbon dioxide.[5] In 2011, world gross emissions from coal usage were 14,416 million tonnes.[6] Coal-fired electric power generation emits around 2,000 pounds of carbon dioxide for every megawatt-hour generated, which is almost double the approximately 1100 pounds of carbon dioxide released by a natural gas-fired electric plant per megawatt-hour generated. Because of this higher carbon efficiency of natural gas generation, as the market in the United States has changed to reduce coal and increase natural gas generation, carbon dioxide emissions have fallen. Those measured in the first quarter of 2012 were the lowest of any recorded for the first quarter of any year since 1992.[7] In 2013, the head of the UN climate agency advised that most of the world's coal reserves should be left in the ground to avoid catastrophic global warming.[8]

Coal is extracted from the ground by coal mining, either underground by shaft mining, or at ground level by open pit mining extraction. Since 1983 the world top coal producer has been China.[9] In 2011 China produced 3,520 millions of tonnes of coal – 49.5% of 7,695 millions tonnes world coal production. In 2011 other large producers were United States (993 millions tonnes), India (589), European Union (576) and Australia (416).[9] In 2010 the largest exporters were Australia with 328 million tonnes (27.1% of world coal export) and Indonesia with 316 millions tonnes (26.1%),[10] while the largest importers were Japan with 207 million tonnes (17.5% of world coal import), China with 195 million tonnes (16.6%) and South Korea with 126 million tonnes (10.7%).[11]

Contents  [hide]

1 Formation

2 Types

2.1 Hilt's law

3 Content

4 Early uses as fuel

5 Uses today

5.1 Coal as fuel

5.2 Coking coal and use of coke

5.3 Gasification

5.4 Liquefaction

5.5 Refined coal

5.6 Industrial processes

5.7 Production of chemicals[67]

6 Cultural usage

7 Coal as a traded commodity

8 Environmental effects

9 Bioremediation

10 Economic aspects

11 Energy density and carbon impact

12 Underground fires

13 Production trends

13.1 World coal reserves

13.2 Major coal producers

13.3 Major coal consumers

13.4 Major coal exporters

13.5 Major coal importers

14 See also

15 References

16 Further reading

17 External links

Formation[edit]

Example chemical structure of coal

At various times in the geologic past, the Earth had dense forests in low-lying wetland areas. Due to natural processes such as flooding, these forests were buried underneath soil. As more and more soil deposited over them, they were compressed. The temperature also rose as they sank deeper and deeper. As the process continued the plant matter was protected from biodegradation and oxidation, usually by mud or acidic water. This trapped the carbon in immense peat bogs that were eventually covered and deeply buried by sediments. Under high pressure and high temperature, dead vegetation was slowly converted to coal. As coal contains mainly carbon, the conversion of dead vegetation into coal is called carbonization.[12]

The wide, shallow seas of the Carboniferous Period provided ideal conditions for coal formation, although coal is known from most geological periods. The exception is the coal gap in the Permian–Triassic extinction event, where coal is rare. Coal is known from Precambrian strata, which predate land plants — this coal is presumed to have originated from residues of algae.[13][14]

Types[edit]

Coastal exposure of the Point Aconi Seam (Nova Scotia)

As geological processes apply pressure to dead biotic material over time, under suitable conditions it is transformed successively into:

Peat, considered to be a precursor of coal, has industrial importance as a fuel in some regions, for example, Ireland and Finland. In its dehydrated form, peat is a highly effective absorbent for fuel and oil spills on land and water. It is also used as a conditioner for soil to make it more able to retain and slowly release water.

Lignite, or brown coal, is the lowest rank of coal and used almost exclusively as fuel for electric power generation. Jet, a compact form of lignite, is sometimes polished and has been used as an ornamental stone since the Upper Palaeolithic.

Sub-bituminous coal, whose properties range from those of lignite to those of bituminous coal, is used primarily as fuel for steam-electric power generation and is an important source of light aromatic hydrocarbons for the chemical synthesis industry.

Bituminous coal is a dense sedimentary rock, usually black, but sometimes dark brown, often with well-defined bands of bright and dull material; it is used primarily as fuel in steam-electric power generation, with substantial quantities used for heat and power applications in manufacturing and to make coke.

"Steam coal" is a grade between bituminous coal and anthracite, once widely used as a fuel for steam locomotives. In this specialized use, it is sometimes known as "sea-coal" in the US.[15] Small steam coal (dry small steam nuts or DSSN) was used as a fuel for domestic water heating.

Anthracite, the highest rank of coal, is a harder, glossy black coal used primarily for residential and commercial space heating. It may be divided further into metamorphically altered bituminous coal and "petrified oil", as from the deposits in Pennsylvania.

Graphite, technically the highest rank, is difficult to ignite and is not commonly used as fuel — it is mostly used in pencils and, when powdered, as a lubricant.

The classification of coal is generally based on the content of volatiles. However, the exact classification varies between countries. According to the German classification, coal is classified as follows:[16]

German Classification English Designation    Volatiles %          C Carbon %        H Hydrogen %       O Oxygen %       S Sulfur % Heat content kJ/kg

Braunkohle         Lignite (brown coal)     45–65        60–75        6.0–5.8      34-17          0.5-3 <28,470

Flammkohle        Flame coal          40-45         75-82         6.0-5.8       >9.8  ~1     <32,870

Gasflammkohle  Gas flame coal   35-40         82-85         5.8-5.6       9.8-7.3       ~1          <33,910

Gaskohle   Gas coal    28-35         85-87.5      5.6-5.0       7.3-4.5       ~1     <34,960

Fettkohle   Fat coal     19-28         87.5-89.5   5.0-4.5       4.5-3.2       ~1     <35,380

Esskohle   Forge coal 14-19         89.5-90.5   4.5-4.0       3.2-2.8       ~1     <35,380

Magerkohle         Nonbaking coal  10-14         90.5-91.5   4.0-3.75     2.8-3.5       ~1          35,380

Anthrazit    Anthracite  7-12  >91.5         <3.75         <2.5  ~1     <35,300

Percent by weight

The middle six grades in the table represent a progressive transition from the English-language sub-bituminous to bituminous coal, while the last class is an approximate equivalent to anthracite, but more inclusive (US anthracite has < 6% volatiles).

Cannel coal (sometimes called "candle coal") is a variety of fine-grained, high-rank coal with significant hydrogen content. It consists primarily of "exinite" macerals, now termed "liptinite".

Hilt's law[edit]

Main article: Hilt's law

Hilt's law is a geological term that states that, in a small area, the deeper the coal, the higher its rank (grade). The law holds true if the thermal gradient is entirely vertical, but metamorphism may cause lateral changes of rank, irrespective of depth.

Content[edit]

Average content

Substance Content

Mercury (Hg)      0.10±0.01 ppm[17]

Arsenic (As)        1.4 – 71 ppm[18]

Selenium (Se)    3 ppm[19]

Early uses as fuel[edit]

Further information: History of coal mining

Chinese coal miners in an illustration of the Tiangong Kaiwu encyclopedia, published in 1637

Coal from the Fushun mine in northeastern China was used to smelt copper as early as 1000 BCE.[20] Marco Polo, the Italian who traveled to China in the 13th century, described coal as "black stones ... which burn like logs", and said coal was so plentiful, people could take three hot baths a week.[21] In Europe, the earliest reference to the use of coal as fuel is from the geological treatise On stones (Lap. 16) by the Greek scientist Theophrastus (circa 371–287 BC):[22][23]

Among the materials that are dug because they are useful, those known as anthrakes [coals] are made of earth, and, once set on fire, they burn like charcoal. They are found in Liguria ... and in Elis as one approaches Olympia by the mountain road; and they are used by those who work in metals.

—Theophrastus, On Stones (16) translation

Outcrop coal was used in Britain during the Bronze Age (3000–2000 BC), where it has been detected as forming part of the composition of funeral pyres.[24][25] In Roman Britain, with the exception of two modern fields, "the Romans were exploiting coals in all the major coalfields in England and Wales by the end of the second century AD".[26] Evidence of trade in coal (dated to about AD 200) has been found at the Roman settlement at Heronbridge, near Chester, and in the Fenlands of East Anglia, where coal from the Midlands was transported via the Car Dyke for use in drying grain.[27] Coal cinders have been found in the hearths of villas and Roman forts, particularly in Northumberland, dated to around AD 400. In the west of England, contemporary writers described the wonder of a permanent brazier of coal on the altar of Minerva at Aquae Sulis (modern day Bath), although in fact easily accessible surface coal from what became the Somerset coalfield was in common use in quite lowly dwellings locally.[28] Evidence of coal's use for iron-working in the city during the Roman period has been found.[29] In Eschweiler, Rhineland, deposits of bituminous coal were used by the Romans for the smelting of iron ore.[26]

Coal miner in Britain, 1942

No evidence exists of the product being of great importance in Britain before the High Middle Ages, after about AD 1000.[30] Mineral coal came to be referred to as "seacoal" in the 13th century; the wharf where the material arrived in London was known as Seacoal Lane, so identified in a charter of King Henry III granted in 1253.[31] Initially, the name was given because much coal was found on the shore, having fallen from the exposed coal seams on cliffs above or washed out of underwater coal outcrops,[30] but by the time of Henry VIII, it was understood to derive from the way it was carried to London by sea.[32] In 1257–59, coal from Newcastle upon Tyne was shipped to London for the smiths and lime-burners building Westminster Abbey.[30] Seacoal Lane and Newcastle Lane, where coal was unloaded at wharves along the River Fleet, are still in existence.[33] (See Industrial processes below for modern uses of the term.)

These easily accessible sources had largely become exhausted (or could not meet the growing demand) by the 13th century, when underground extraction by shaft mining or adits was developed.[24] The alternative name was "pitcoal", because it came from mines. It was, however, the development of the Industrial Revolution that led to the large-scale use of coal, as the steam engine took over from the water wheel. In 1700, five-sixths of the world's coal was mined in Britain. Britain would have run out of suitable sites for watermills by the 1830s if coal had not been available as a source of energy.[34] In 1947, there were some 750,000 miners in Britain,[35] but by 2004, this had shrunk to some 5,000 miners working in around 20 collieries.[36]

Uses today[edit]

Castle Gate Power Plant near Helper, Utah, USA

Coal rail cars

Coal as fuel[edit]

Further information: Electricity generation, Clean coal technology, Coal electricity and Global warming

Coal is primarily used as a solid fuel to produce electricity and heat through combustion. World coal consumption was about 7.25 billion tonnes in 2010[37] (7.99 billion short tons) and is expected to increase 48% to 9.05 billion tonnes (9.98 billion short tons) by 2030.[38] China produced 3.47 billion tonnes (3.83 billion short tons) in 2011. India produced about 578 million tonnes (637.1 million short tons) in 2011. 68.7% of China's electricity comes from coal. The USA consumed about 13% of the world total in 2010, i.e. 951 million tonnes (1.05 billion short tons), using 93% of it for generation of electricity.[39] 46% of total power generated in the USA was done using coal.[40]

When coal is used for electricity generation, it is usually pulverized and then combusted (burned) in a furnace with a boiler.[41] The furnace heat converts boiler water to steam, which is then used to spin turbines which turn generators and create electricity.[42] The thermodynamic efficiency of this process has been improved over time; some older coal-fired power stations have thermal efficiencies in the vicinity of 25%[43] whereas the newest supercritical and "ultra-supercritical" steam cycle turbines, operating at temperatures over 600 °C and pressures over 27 MPa (over 3900 psi), can practically achieve thermal efficiencies in excess of 45% (LHV basis) using anthracite fuel,[44][45] or around 43% (LHV basis) even when using lower-grade lignite fuel.[46] Further thermal efficiency improvements are also achievable by improved pre-drying (especially relevant with high-moisture fuel such as lignite or biomass) and cooling technologies.[47]

An alternative approach of using coal for electricity generation with improved efficiency is the integrated gasification combined cycle (IGCC) power plant. Instead of pulverizing the coal and burning it directly as fuel in the steam-generating boiler, the coal can be first gasified (see coal gasification) to create syngas, which is burned in a gas turbine to produce electricity (just like natural gas is burned in a turbine). Hot exhaust gases from the turbine are used to raise steam in a heat recovery steam generator which powers a supplemental steam turbine. Thermal efficiencies of current IGCC power plants range from 39-42%[48] (HHV basis) or ~42-45% (LHV basis) for bituminous coal and assuming utilization of mainstream gasification technologies (Shell, GE Gasifier, CB&I). IGCC power plants outperform conventional pulverized coal-fueled plants in terms of pollutant emissions, and allow for relatively easy carbon capture.

At least 40% of the world's electricity comes from coal,[41][49] and in 2012, about one-third of the United States' electricity came from coal, down from approximately 49% in 2008.[50][51] As of 2012 in the United States, use of coal to generate electricity was declining, as plentiful supplies of natural gas obtained by hydraulic fracturing of tight shale formations became available at low prices.[50]

In Denmark, a net electric efficiency of > 47% has been obtained at the coal-fired Nordjyllandsværket CHP Plant and an overall plant efficiency of up to 91% with cogeneration of electricity and district heating.[52] The multifuel-fired Avedøreværket CHP Plant just outside Copenhagen can achieve a net electric efficiency as high as 49%. The overall plant efficiency with cogeneration of electricity and district heating can reach as much as 94%.[53]

An alternative form of coal combustion is as coal-water slurry fuel (CWS), which was developed in the Soviet Union. CWS significantly reduces emissions, improving the heating value of coal.[citation needed] Other ways to use coal are combined heat and power cogeneration and an MHD topping cycle.

The total known deposits recoverable by current technologies, including highly polluting, low-energy content types of coal (i.e., lignite, bituminous), is sufficient for many years.[quantify] However, consumption is increasing and maximal production could be reached within decades (see world coal reserves, below). On the other hand much may have to be left in the ground to avoid climate change.[54][55]

Coking coal and use of coke[edit]

Main article: Coke (fuel)

Coke oven at a smokeless fuel plant in Wales, United Kingdom

Coke is a solid carbonaceous residue derived from low-ash, low-sulfur bituminous coal from which the volatile constituents are driven off by baking in an oven without oxygen at temperatures as high as 1,000 °C (1,832 °F), so the fixed carbon and residual ash are fused together. Metallurgical coke is used as a fuel and as a reducing agent in smelting iron ore in a blast furnace.[56] The result is pig iron, and is too rich in dissolved carbon, so it must be treated further to make steel. The coking coal should be low in sulfur and phosphorus, so they do not migrate to the metal.

The coke must be strong enough to resist the weight of overburden in the blast furnace, which is why coking coal is so important in making steel using the conventional route. However, the alternative route is direct reduced iron, where any carbonaceous fuel can be used to make sponge or pelletised iron. Coke from coal is grey, hard, and porous and has a heating value of 24.8 million Btu/ton (29.6 MJ/kg). Some cokemaking processes produce valuable byproducts, including coal tar, ammonia, light oils, and coal gas.

Petroleum coke is the solid residue obtained in oil refining, which resembles coke, but contains too many impurities to be useful in metallurgical applications.

Gasification[edit]

Main articles: Coal gasification and Underground coal gasification

Coal gasification can be used to produce syngas, a mixture of carbon monoxide (CO) and hydrogen (H2) gas. Often syngas is used to fire gas turbines to produce electricity, but the versatility of syngas also allows it to be converted into transportation fuels, such as gasoline and diesel, through the Fischer-Tropsch process; alternatively, syngas can be converted into methanol, which can be blended into fuel directly or converted to gasoline via the methanol to gasoline process.[57] Gasification combined with Fischer-Tropsch technology is currently used by the Sasol chemical company of South Africa to make motor vehicle fuels from coal and natural gas. Alternatively, the hydrogen obtained from gasification can be used for various purposes, such as powering a hydrogen economy, making ammonia, or upgrading fossil fuels.

During gasification, the coal is mixed with oxygen and steam while also being heated and pressurized. During the reaction, oxygen and water molecules oxidize the coal into carbon monoxide (CO), while also releasing hydrogen gas (H2). This process has been conducted in both underground coal mines and in the production of town gas.

C (as Coal) + O2 + H2O → H2 + CO

If the refiner wants to produce gasoline, the syngas is collected at this state and routed into a Fischer-Tropsch reaction. If hydrogen is the desired end-product, however, the syngas is fed into the water gas shift reaction, where more hydrogen is liberated.

CO + H2O → CO2 + H2

In the past, coal was converted to make coal gas (town gas), which was piped to customers to burn for illumination, heating, and cooking.

Liquefaction[edit]

Main article: Coal liquefaction

Coal can also be converted into synthetic fuels equivalent to gasoline or diesel by several different direct processes (which do not intrinsically require gasification or indirect conversion).[58] In the direct liquefaction processes, the coal is either hydrogenated or carbonized. Hydrogenation processes are the Bergius process,[59] the SRC-I and SRC-II (Solvent Refined Coal) processes, the NUS Corporation hydrogenation process[60][61] and several other single-stage and two-stage processes.[62] In the process of low-temperature carbonization, coal is coked at temperatures between 360 and 750 °C (680 and 1,380 °F). These temperatures optimize the production of coal tars richer in lighter hydrocarbons than normal coal tar. The coal tar is then further processed into fuels. An overview of coal liquefaction and its future potential is available.[63]

Coal liquefaction methods involve carbon dioxide (CO

2) emissions in the conversion process. If coal liquefaction is done without employing either carbon capture and storage (CCS) technologies or biomass blending, the result is lifecycle greenhouse gas footprints that are generally greater than those released in the extraction and refinement of liquid fuel production from crude oil. If CCS technologies are employed, reductions of 5–12% can be achieved in Coal to Liquid (CTL) plants and up to a 75% reduction is achievable when co-gasifying coal with commercially demonstrated levels of biomass (30% biomass by weight) in coal/biomass-to-liquids plants.[64] For future synthetic fuel projects, carbon dioxide sequestration is proposed to avoid releasing CO

2 into the atmosphere. Sequestration adds to the cost of production.

Refined coal[edit]

Main article: Refined coal

Refined coal is the product of a coal-upgrading technology that removes moisture and certain pollutants from lower-rank coals such as sub-bituminous and lignite (brown) coals. It is one form of several precombustion treatments and processes for coal that alter coal's characteristics before it is burned. The goals of precombustion coal technologies are to increase efficiency and reduce emissions when the coal is burned. Depending on the situation, precombustion technology can be used in place of or as a supplement to postcombustion technologies to control emissions from coal-fueled boilers.

Industrial processes [edit]

Finely ground bituminous coal, known in this application as sea coal, is a constituent of foundry sand. While the molten metal is in the mould, the coal burns slowly, releasing reducing gases at pressure, and so preventing the metal from penetrating the pores of the sand. It is also contained in 'mould wash', a paste or liquid with the same function applied to the mould before casting.[65] Sea coal can be mixed with the clay lining (the "bod") used for the bottom of a cupola furnace. When heated, the coal decomposes and the bod becomes slightly friable, easing the process of breaking open holes for tapping the molten metal.[66]

Production of chemicals[67][edit]

Production of Chemicals from Coal

Coal is an important feedstock in production of a wide range of chemical fertilizers and other chemical products. The main route to these products is coal gasification to produce syngas. Primary chemicals that are produced directly from the syngas include methanol, hydrogen and carbon monoxide, which are the chemical building blocks from which a whole spectrum of derivative chemicals are manufactured, including olefins, acetic acid, formaldehyde, ammonia, urea and others. The versatility of syngas as a precursor to primary chemicals and high-value derivative products provides the option of using relatively inexpensive coal to produce a wide range of valuable commodities.

Historically, production of chemicals from coal has been used since the 1950s and has become established in the market. According to the 2010 Worldwide Gasification Database,[68] a survey of current and planned gasifiers, from 2004 to 2007 chemical production increased its gasification product share from 37% to 45%. From 2008 to 2010, 22% of new gasifier additions were to be for chemical production.

Because the slate of chemical products that can be made via coal gasification can in general also use feedstocks derived from natural gas and petroleum, the chemical industry tends to use whatever feedstocks are most cost-effective. Therefore, interest in using coal tends to increase for higher oil and natural gas prices and during periods of high global economic growth that may strain oil and gas production. Also, production of chemicals from coal is of much higher interest in countries like South Africa, China, India and the United States where there are abundant coal resources. The abundance of coal combined with lack of natural gas resources in China is strong inducement for the coal to chemicals industry pursued there. In the United States, the best example of the industry is Eastman Chemical Company which has been successfully operating a coal-to-chemicals plant at its Kingsport, Tennessee, site since 1983. Similarly, Sasol has built and operated coal-to-chemicals facilities in South Africa.

Coal to chemical processes do require substantial quantities of water. As of 2013 much of the coal to chemical production was in the People's Republic of China[69][70] where environmental regulation and water management[71] was weak.[72]

Cultural usage[edit]

Coal is the official state mineral of Kentucky.[73] and the official state rock of Utah;[74] both U.S. states have a historic link to coal mining.

Some cultures hold that children who misbehave will receive only a lump of coal from Santa Claus for Christmas in their christmas stockings instead of presents.

It is also customary and considered lucky in Scotland and the North of England to give coal as a gift on New Year's Day. This occurs as part of First-Footing and represents warmth for the year to come.

Coal as a traded commodity[edit]

In North America, Central Appalachian coal futures contracts are currently traded on the New York Mercantile Exchange (trading symbol QL). The trading unit is 1,550 short tons (1,410 t) per contract, and is quoted in U.S. dollars and cents per ton. Since coal is the principal fuel for generating electricity in the United States, coal futures contracts provide coal producers and the electric power industry an important tool for hedging and risk management.[75]

In addition to the NYMEX contract, the IntercontinentalExchange (ICE) has European (Rotterdam) and South African (Richards Bay) coal futures available for trading. The trading unit for these contracts is 5,000 tonnes (5,500 short tons), and are also quoted in U.S. dollars and cents per ton.[76]

The price of coal increased from around $30.00 per short ton in 2000 to around $150.00 per short ton as of September 2008. As of October 2008, the price per short ton had declined to $111.50. Prices further declined to $71.25 as of October 2010.[77]

Environmental effects[edit]

Main article: Environmental effects of coal

Aerial photograph of Kingston Fossil Plant coal fly ash slurry spill site taken the day after the event

A number of adverse health,[78] and environmental effects of coal burning exist,[79] especially in power stations, and of coal mining, including:

Coal-fired power plants cause nearly 24,000 premature deaths annually in the United States, including 2,800 from lung cancer.[80] Annual health costs in Europe from use of coal to generate electricity are €42.8 billion, or $55 billion.[81]

Generation of hundreds of millions of tons of waste products, including fly ash, bottom ash, and flue-gas desulfurization sludge, that contain mercury, uranium, thorium, arsenic, and other heavy metals

Acid rain from high sulfur coal

Interference with groundwater and water table levels due to mining

Contamination of land and waterways and destruction of homes from fly ash spills. such as the Kingston Fossil Plant coal fly ash slurry spill

Impact of water use on flows of rivers and consequential impact on other land uses

Dust nuisance

Subsidence above tunnels, sometimes damaging infrastructure

Uncontrollable coal seam fire which may burn for decades or centuries

Coal-fired power plants without effective fly ash capture systems are one of the largest sources of human-caused background radiation exposure.

Coal-fired power plants emit mercury, selenium, and arsenic, which are harmful to human health and the environment.[82]

Release of carbon dioxide, a greenhouse gas, causes climate change and global warming, according to the IPCC and the EPA. Coal is the largest contributor to the human-made increase of CO2 in the atmosphere.[83]

Approximately 75 Tg/S per year of sulfur dioxide (SO2) is released from burning coal. After release, the sulfur dioxide is oxidized to gaseous H2SO2 which scatters solar radiation, hence its increase in the atmosphere exerts a cooling effect on climate that masks some of the warming caused by increased greenhouse gases. Release of SO2 also contributes to the widespread acidification of ecosystems.[84]

Bioremediation[edit]

The white rot fungus C. versicolor can grow on and metabolize naturally occcuring coal.[85] The bacteria Diplococcus has been found to degrade coal, raising its temperature.[86]

Economic aspects[edit]

Coal (by liquefaction technology) is one of the backstop resources that could limit escalation of oil prices and mitigate the effects of transportation energy shortage that will occur under peak oil. This is contingent on liquefaction production capacity becoming large enough to satiate the very large and growing demand for petroleum. Estimates of the cost of producing liquid fuels from coal suggest that domestic U.S. production of fuel from coal becomes cost-competitive with oil priced at around $35 per barrel,[87] with the $35 being the break-even cost. With oil prices as low as around $40 per barrel in the U.S. as of December 2008, liquid coal lost some of its economic allure in the U.S., but will probably be re-vitalized, similar to oil sand projects, with an oil price around $70 per barrel.

In China, due to an increasing need for liquid energy in the transportation sector, coal liquefaction projects were given high priority even during periods of oil prices below $40 per barrel.[88] This is probably because China prefers not to be dependent on foreign oil, instead utilizing its enormous domestic coal reserves. As oil prices were increasing during the first half of 2009, the coal liquefaction projects in China were again boosted, and these projects are profitable with an oil barrel price of $40.[89]

China is the largest producer of coal in the world. It is the world's largest energy consumer, and relies on coal to supply 69% of its energy needs.[90] An estimated 5 million people worked in China's coal-mining industry in 2007.[91]

Coal pollution costs the EU €43 billion each year.[92] Measures to cut air pollution may have beneficial long-term economic impacts for individuals.[93]

Energy density and carbon impact[edit]

See also: Energy value of coal

The energy density of coal, i.e. its heating value, is roughly 24 megajoules per kilogram[94] (approximately 6.7 kilowatt-hours per kg). For a coal power plant with a 40% efficiency, it takes an estimated 325 kg (717 lb) of coal to power a 100 W lightbulb for one year.[95]

As of 2006, the average efficiency of electricity-generating power stations was 31%; in 2002, coal represented about 23% of total global energy supply, an equivalent of 3.4 billion tonnes of coal, of which 2.8 billion tonnes were used for electricity generation.[96]

The US Energy Information Agency's 1999 report on CO2 emissions for energy generation quotes an emission factor of 0.963 kg CO2/kWh for coal power, compared to 0.881 kg CO2/kWh (oil), or 0.569 kg CO2/kWh (natural gas).[97]

Underground fires[edit]

Main article: Coal seam fire

Thousands of coal fires are burning around the world.[98] Those burning underground can be difficult to locate and many cannot be extinguished. Fires can cause the ground above to subside, their combustion gases are dangerous to life, and breaking out to the surface can initiate surface wildfires. Coal seams can be set on fire by spontaneous combustion or contact with a mine fire or surface fire. Lightning strikes are an important source of ignition. The coal continues to burn slowly back into the seam until oxygen (air) can no longer reach the flame front. A grass fire in a coal area can set dozens of coal seams on fire.[99][100] Coal fires in China burn an estimated 120 million tons of coal a year, emitting 360 million metric tons of CO2, amounting to 2–3% of the annual worldwide production of CO2 from fossil fuels.[101][102] In Centralia, Pennsylvania (a borough located in the Coal Region of the United States), an exposed vein of anthracite ignited in 1962 due to a trash fire in the borough landfill, located in an abandoned anthracite strip mine pit. Attempts to extinguish the fire were unsuccessful, and it continues to burn underground to this day. The Australian Burning Mountain was originally believed to be a volcano, but the smoke and ash comes from a coal fire that has been burning for some 6,000 years.[103]

At Kuh i Malik in Yagnob Valley, Tajikistan, coal deposits have been burning for thousands of years, creating vast underground labyrinths full of unique minerals, some of them very beautiful. Local people once used this method to mine ammoniac. This place has been well-known since the time of Herodotus, but European geographers misinterpreted the Ancient Greek descriptions as the evidence of active volcanism in Turkestan (up to the 19th century, when the Russian army invaded the area).[citation needed]

The reddish siltstone rock that caps many ridges and buttes in the Powder River Basin in Wyoming and in western North Dakota is called porcelanite, which resembles the coal burning waste "clinker" or volcanic "scoria".[104] Clinker is rock that has been fused by the natural burning of coal. In the Powder River Basin approximately 27 to 54 billion tons of coal burned within the past three million years.[105] Wild coal fires in the area were reported by the Lewis and Clark Expedition as well as explorers and settlers in the area.[106]

Production trends[edit]

Continental United States coal regions

Coal output in 2005

A coal mine in Wyoming, United States. The United States has the world's largest coal reserves.

In 2006, China was the top producer of coal with 38% share followed by the United States and India, according to the British Geological Survey. As of 2012 coal production in the United States was falling at the rate of 7% annually[107] with many power plants using coal shut down or converted to natural gas; however, some of the reduced domestic demand was taken up by increased exports[108] with five coal export terminals being proposed in the Pacific Northwest to export coal from the Powder River Basin to China and other Asian markets;[109] however, as of 2013, environmental opposition was increasing.[110] High-sulfur coal mined in Illinois which was unsaleable in the United States found a ready market in Asia as exports reached 13 million tons in 2012.[111]

World coal reserves[edit]

The 948 billion short tons of recoverable coal reserves estimated by the Energy Information Administration are equal to about 4,196 BBOE (billion barrels of oil equivalent).[3] The amount of coal burned during 2007 was estimated at 7.075 billion short tons, or 133.179 quadrillion BTU's.[112] This is an average of 18.8 million BTU per short ton. In terms of heat content, this is about 57,000,000 barrels (9,100,000 m3) of oil equivalent per day. By comparison in 2007, natural gas provided 51,000,000 barrels (8,100,000 m3) of oil equivalent per day, while oil provided 85,800,000 barrels (13,640,000 m3) per day.

British Petroleum, in its 2007 report, estimated at 2006 end that there were 147 years reserves-to-production ratio based on proven coal reserves worldwide. This figure only includes reserves classified as "proven"; exploration drilling programs by mining companies, particularly in under-explored areas, are continually providing new reserves. In many cases, companies are aware of coal deposits that have not been sufficiently drilled to qualify as "proven". However, some nations haven't updated their information and assume reserves remain at the same levels even with withdrawals. Energy Watch Group predicted in 2007 that peak coal production may occur sometime around 2025, depending on future coal production rates.[113]

Of the three fossil fuels, coal has the most widely distributed reserves; coal is mined in over 100 countries, and on all continents except Antarctica. The largest reserves are found in the United States, Russia, China, Australia and India. Note the table below.

Proved recoverable coal reserves at end-2008 (million tons (teragrams))[114]

Country      Anthracite & Bituminous       SubBituminous   Lignite        Total Percentage of World Total

 United States     108,501     98,618       30,176       237,295     22.6

 Russia      49,088       97,472       10,450       157,010     14.4

 China        62,200       33,700       18,600       114,500     12.6

 Australia   37,100       2,100         37,200       76,400       8.9

 India          56,100       0       4,500         60,600       7.0

 Germany  99     0       40,600       40,699       4.7

 Ukraine     15,351       16,577       1,945         33,873       3.9

 Kazakhstan        21,500       0       12,100       33,600       3.9

 South Africa       30,156       0       0       30,156       3.5

 Serbia       9       361   13,400       13,770       1.6

 Colombia  6,366         380   0       6,746         0.8

 Canada    3,474         872   2,236         6,528         0.8

 Poland      4,338         0       1,371         5,709         0.7

 Indonesia 1,520         2,904         1,105         5,529         0.6

 Brazil         0       4,559         0       4,559         0.5

 Greece     0       0       3,020         3,020         0.4

 Bosnia and Herzegovina     484   0       2,369         2,853         0.3

 Mongolia  1,170         0       1,350         2,520         0.3

 Bulgaria    2       190   2,174         2,366         0.3

 Pakistan   0       166   1,904         2,070         0.3

 Turkey      529   0       1,814         2,343         0.3

 Uzbekistan         47     0       1,853         1,900         0.2

 Hungary   13     439   1,208         1,660         0.2

 Thailand   0       0       1,239         1,239         0.1

 Mexico      860   300   51     1,211         0.1

 Iran  1,203         0       0       1,203         0.1

 Czech Republic 192   0       908   1,100         0.1

 Kyrgyzstan         0       0       812   812   0.1

 Albania     0       0       794   794   0.1

 North Korea       300   300   0       600   0.1

 New Zealand     33     205   333-7,000  571–15,000[115]         0.1

 Spain        200   300   30     530   0.1

 Laos          4       0       499   503   0.1

 Zimbabwe          502   0       0       502   0.1

 Argentina  0       0       500   500   0.1

All others   3,421         1,346         846   5,613         0.7

World Total         404,762     260,789     195,387     860,938     100

Major coal producers[edit]

See also: List of countries by coal production

The reserve life is an estimate based only on current production levels and proved reserves level for the countries shown, and makes no assumptions of future production or even current production trends. Countries with annual production higher than 100 million tonnes are shown. For comparison, data for the European Union is also shown. Shares are based on data expressed in tonnes oil equivalent.

Production of Coal by Country and year (million tonnes) [9]

Country      2003 2004 2005 2006 2007 2008 2009 2010 2011 Share         Reserve Life (years)

 China        1834.9       2122.6       2349.5       2528.6       2691.6       2802.0       2973.0          3235.0       3520.0       49.5%        35

 United States     972.3         1008.9       1026.5       1054.8       1040.2       1063.0          975.2         983.7         992.8         14.1%        239

 India          375.4         407.7         428.4         449.2         478.4         515.9         556.0          573.8         588.5         5.6% 103

 European Union         637.2         627.6         607.4         595.1         592.3         563.6          538.4         535.7         576.1         4.2% 97

 Australia   350.4         364.3         375.4         382.2         392.7         399.2         413.2          424.0         415.5         5.8% 184

 Russia      276.7         281.7         298.3         309.9         313.5         328.6         301.3          321.6         333.5         4.0% 471

 Indonesia 114.3         132.4         152.7         193.8         216.9         240.2         256.2          275.2         324.9         5.1% 17

 South Africa       237.9         243.4         244.4         244.8         247.7         252.6          250.6         254.3         255.1         3.6% 118

 Germany  204.9         207.8         202.8         197.1         201.9         192.4         183.7          182.3         188.6         1.1% 216

 Poland      163.8         162.4         159.5         156.1         145.9         144.0         135.2          133.2         139.2         1.4% 41

 Kazakhstan        84.9  86.9  86.6  96.2  97.8  111.1         100.9         110.9         115.9          1.5% 290

World Total         5,301.3      5,716.0      6,035.3      6,342.0      6,573.3      6,795.0          6,880.8      7,254.6      7,695.4      100%         112

Major coal consumers[edit]

Countries with annual consumption higher than 20 million tonnes are shown.

Consumption of Coal by Country and year (million short tons)[116]

Country      2008 2009 2010 2011 Share

 China        2,966         3,188         3,695         4,053         50.7%

 United States     1,121         997   1,048         1,003         12.5%

 India          641   705   722   788   9.9%

 Russia      250   204   256   262   3.3%

 Germany  268   248   256   256   3.3%

 South Africa       215   204   206   210   2.6%

 Japan       204   181   206   202   2.5%

 Poland      149   151   149   162   2.0%

World Total         7,327         7,318         7,994         N/A   100%

Major coal exporters[edit]

Countries with annual gross export higher than 10 million tonnes are shown. In terms of net export the largest exporters are still Australia (328.1 millions tonnes), Indonesia (316.2) and Russia (100.2).

Exports of Coal by Country and year (million short tons)[10][117][118]

Country      2003 2004 2005 2006 2007 2008 2009 2010 Share

 Australia   238.1         247.6         255.0         255.0         268.5         278.0         288.5          328.1         27.1%

 Indonesia 107.8         131.4         142.0         192.2         221.9         228.2         261.4          316.2         26.1%

 Russia      41.0  55.7  98.6  103.4         112.2         115.4         130.9         122.1          10.1%

 United States     43.0  48.0  51.7  51.2  60.6  83.5  60.4  83.2  6.9%

 South Africa       78.7  74.9  78.8  75.8  72.6  68.2  73.8  76.7  6.3%

 Colombia  50.4  56.4  59.2  68.3  74.5  74.7  75.7  76.4  6.3%

 Canada    27.7  28.8  31.2  31.2  33.4  36.5  31.9  36.9  3.0%

 Kazakhstan        30.3  27.4  28.3  30.5  32.8  47.6  33.0  36.3  3.0%

 Vietnam    6.9    11.7  19.8  23.5  35.1  21.3  28.2  24.7  2.0%

 China        103.4         95.5  93.1  85.6  75.4  68.8  25.2  22.7  1.9%

 Mongolia  0.5    1.7    2.3    2.5    3.4    4.4    7.7    18.3  1.5%

 Poland      28.0  27.5  26.5  25.4  20.1  16.1  14.6  18.1  1.5%

Total 713.9         764.0         936.0         1,000.6      1,073.4      1,087.3      1,090.8          1,212.8      100%

Major coal importers[edit]

Countries with annual gross import higher than 20 million tonnes are shown. In terms of net import the largest importers are still Japan (206.0 millions tonnes), China (172.4) and South Korea (125.8).[119]

Imports of Coal by Country and year (million short tons)[11]

Country      2006 2007 2008 2009 2010 Share

 Japan       199.7         209.0         206.0         182.1         206.7         17.5%

 China        42.0  56.2  44.5  151.9         195.1         16.6%

 South Korea      84.1  94.1  107.1         109.9         125.8         10.7%

 India          52.7  29.6  70.9  76.7  101.6         8.6%

 Taiwan      69.1  72.5  70.9  64.6  71.1  6.0%

 Germany  50.6  56.2  55.7  45.9  55.1  4.7%

 Turkey      22.9  25.8  21.7  22.7  30.0  2.5%

 United Kingdom          56.8  48.9  49.2  42.2  29.3  2.5%

 Italy  27.9  28.0  27.9  20.9  23.7  1.9%

 Netherlands       25.7  29.3  23.5  22.1  22.8  1.9%

 Russia      28.8  26.3  34.6  26.8  21.8  1.9%

 France      24.1  22.1  24.9  18.3  20.8  1.8%

 United States     40.3  38.8  37.8  23.1  20.6  1.8%

Total 991.8         1,056.5      1,063.2      1,039.8      1,178.1      100%

[show] v t e

Lists of countries by energy rankings

Compressed natural gas

From Wikipedia, the free encyclopedia

"CNG" redirects here. For other uses, see CNG (disambiguation).

Blue diamond symbol used on CNG-powered vehicles in North America

Green bordered white diamond symbol used on CNG-powered vehicles in China

A CNG powered high-floor Neoplan AN440A, operated by ABQ RIDE in Albuquerque, New Mexico.

Compressed natural gas (CNG) (Methane stored at high pressure) can be used in place of gasoline (petrol), Diesel fuel and propane/LPG. CNG combustion produces fewer undesirable gases than the fuels mentioned above. It is safer than other fuels in the event of a spill, because natural gas is lighter than air and disperses quickly when released. CNG may be found above oil deposits, or may be collected from landfills or wastewater treatment plants where it is known as biogas.

CNG is made by compressing natural gas (which is mainly composed of methane, CH4), to less than 1 percent of the volume it occupies at standard atmospheric pressure. It is stored and distributed in hard containers at a pressure of 20–25 MPa (2,900–3,600 psi), usually in cylindrical or spherical shapes.

CNG is used in traditional gasoline/internal combustion engine automobiles that have been modified or in vehicles which were manufactured for CNG use, either alone ('dedicated'), with a segregated gasoline system to extend range (dual fuel) or in conjunction with another fuel such as diesel (bi-fuel). Natural gas vehicles are increasingly used in Iran, the Asia-Pacific region (especially Pakistan[1] and the Indian capital of Delhi), and other large cities like Ahmedabad, Mumbai, Kolkata, Chennai—as well as cities such as Lucknow, Kanpur, etc. Its use is also increasing in South America, Europe and North America because of rising gasoline prices.[2] In response to high fuel prices and environmental concerns, CNG is starting to be used also in tuk-tuks and pickup trucks, transit and school buses, and trains.

The cost and placement of fuel storage tanks is the major barrier to wider/quicker adoption of CNG as a fuel. It is also why municipal government, public transportation vehicles were the most visible early adopters of it, as they can more quickly amortize the money invested in the new (and usually cheaper) fuel. In spite of these circumstances, the number of vehicles in the world using CNG has grown steadily (30 percent per year).[3] Now, as a result of industry's steady growing, the cost of such fuel storage tanks have been brought down to a much acceptable level. Especially for the CNG Type 1 and Type 2 tanks, many countries are able to make reliable and cost effective tanks for conversion need.[4]

CNG's volumetric energy density is estimated to be 42 percent that of liquefied natural gas (because it is not liquefied), and 25 percent that of diesel fuel.[5]

Contents  [hide]

1 Uses

1.1 Cars

1.2 Locomotives

2 Drawbacks

3 Codes and standards

4 Comparison with other natural gas fuels

5 Worldwide

5.1 South America

5.2 Asia

5.3 Africa

5.4 Europe

5.5 North America

5.5.1 Canada

5.5.2 United States

5.6 Oceania

6 Deployments

7 DNG

8 See also

9 References

10 External links

Uses[edit]

Cars[edit]

CNG pumps at a Brazilian gasoline fueling station

Main article: Natural gas vehicle

Worldwide, there were 14.8 million natural gas vehicles by 2011, led by Iran with 2.86 million, Pakistan (2.85 million), Argentina (2.07 million), Brazil (1.7 million) and India (1.1 million).[6] with the Asia-Pacific region leading with 5.7 million NGVs, followed by Latin America with almost four million vehicles.[2]

Several manufacturers (Fiat, Opel/General Motors, Peugeot, Volkswagen, Toyota, Honda and others) sell bi-fuel cars. In 2006, Fiat introduced the Siena Tetrafuel in the Brazilian market, equipped with a 1.4L FIRE engine that runs on E100, E25 (Standard Brazilian Gasoline), Gasoline and CNG.

Any existing gasoline vehicle can be converted to a dual-fuel (gasoline/CNG) vehicle. Authorized shops can do the retrofitting and involves installing a CNG cylinder, plumbing, a CNG injection system and the electronics. The cost of installing a CNG conversion kit[7] can often reach $8,000 on passenger cars and light trucks and is usually reserved for vehicles that travel many miles each year.

Locomotives[edit]

CNG locomotives are operated by several railroads. The Napa Valley Wine Train successfully retrofit a diesel locomotive to run on compressed natural gas before 2002.[8] This converted locomotive was upgraded to utilize a computer controlled fuel injection system in May 2008, and is now the Napa Valley Wine Train's primary locomotive.[9] Ferrocarril Central Andino in Peru, has run a CNG locomotive on a freight line since 2005.[10] CNG locomotives are usually diesel locomotives that have been converted to use compressed natural gas generators instead of diesel generators to generate the electricity that drives the traction motors. Some CNG locomotives are able to fire their cylinders only when there is a demand for power, which, theoretically, gives them a higher fuel efficiency than conventional diesel engines. CNG is also cheaper than petrol or diesel.

* Increased life of lubricating oils, as CNG does not contaminate and dilute the crankcase oil.

Being a gaseous fuel, CNG mixes easily and evenly in air.

CNG is less likely to ignite on hot surfaces, since it has a high auto-ignition temperature (540 °C), and a narrow range (5–15 percent) of flammability.[11]

Less pollution and more efficiency: CNG emits significantly fewer pollutants (e.g., carbon dioxide (CO

2), unburned hydrocarbons (UHC), carbon monoxide (CO), nitrogen oxides (NOx), sulfur oxides (SOx) and PM (particulate matter) than petrol. For example, an engine running on petrol for 100 km emits 22 kilograms of CO

2, while covering the same distance on CNG emits only 16.3 kilograms of CO

2.[12]

CNG fuel system are sealed.

Carbon monoxide emissions are reduced even further. Due to lower carbon dioxide and nitrogen oxides emissions, switching to CNG can help mitigate greenhouse gas emissions.[11] The ability of CNG to reduce greenhouse gas emissions over the entire fuel lifecycle will depend on the source of the natural gas and the fuel it is replacing.

The lifecycle greenhouse gas emissions for CNG compressed from California's pipeline natural gas is given a value of 67.70 grams of CO

2-equivalent per megajoule (gCO2e/MJ) by CARB (the California Air Resources Board), approximately 28 percent lower than the average gasoline fuel in that market (95.86 gCO2e/MJ).

CNG produced from landfill biogas was found by CARB to have the lowest greenhouse gas emissions of any fuel analyzed, with a value of 11.26 gCO2e/MJ (more than 88 percent lower than conventional gasoline) in the low-carbon fuel standard that went into effect on January 12, 2010.[13]

CNG-powered vehicles are considered to be safer than gasoline-powered vehicles.[14][15][16]

Drawbacks[edit]

Compressed natural gas vehicles require a greater amount of space for fuel storage than conventional gasoline powered vehicles. Since it is a compressed gas, rather than a liquid like gasoline, CNG takes up more space for each GGE (gasoline gallon equivalent). Therefore, the tanks used to store the CNG usually take up additional space in the trunk of a car or bed of a pickup truck which runs on CNG. This problem is solved in factory-built CNG vehicles that install the tanks under the body of the vehicle, leaving the trunk free (e.g., Fiat Multipla, New Fiat Panda, Volkswagen Touran Ecofuel, Volkswagen Caddy Ecofuel, Chevy Taxi - which sold in countries such as Peru). Another option is installation on roof (typical on buses), requiring, however, solution of structural strength issues.

Codes and standards[edit]

The lack of harmonized codes and standards across international jurisdictions is an additional barrier to NGV market penetration.[17] The International Organization for Standardization has an active technical committee working on a standard for natural gas fuelling stations for vehicles.[18]

Despite the lack of harmonized international codes, natural gas vehicles have an excellent global safety record. Existing international standards include ISO 14469-2:2007 which applies to CNG vehicle nozzles and receptacle[19] and ISO 15500-9:2012 specifies tests and requirements for the pressure regulator.[20]

NFPA-52 covers natural gas vehicle safety standards in the US.

Comparison with other natural gas fuels[edit]

Compressed natural gas is often confused with LNG (liquefied natural gas). While both are stored forms of natural gas, the key difference is that CNG is gas that is stored (as a gas) at high pressure, while LNG is stored at very low temperature, becoming liquid in the process. CNG has a lower cost of production and storage compared to LNG as it does not require an expensive cooling process and cryogenic tanks. CNG requires a much larger volume to store the same mass of gasoline or petrol and the use of very high pressures (3000 to 4000 psi, or 205 to 275 bar). As a consequence of this, LNG is often used for transporting natural gas over large distances, in ships, trains or pipelines, and the gas is then converted into CNG before distribution to the end user.

CNG is being experimentally stored at lower pressure in a form known as an ANG (adsorbed natural gas) tank, at 35 bar (500 psi, the pressure of gas in natural gas pipelines) in various sponge like materials, such as activated carbon[21] and MOFs (metal-organic frameworks).[22] The fuel is stored at similar or greater energy density than CNG. This means that vehicles can be refueled from the natural gas network without extra gas compression, the fuel tanks can be slimmed down and made of lighter, weaker materials.

Compressed natural gas is sometimes mixed with hydrogen (HCNG) which increases the H/C ratio (heat capacity ratio) of the fuel and gives it a flame speed about eight times higher than CNG.[23]

Worldwide[edit]

Iran, Pakistan, Argentina, Brazil and India have the highest number of CNG run vehicles in the world.[6]

Top ten countries

with the largest NGV vehicle fleets - 2013[24][25]

(millions)

Rank Country      Registered

fleet  Rank Country      Registered

fleet

1       Iran  3.50  6       India          1.50

2       Pakistan   2.79  7       Italy  0.82

3       Argentina  2.28  8       Colombia  0.46

4       Brazil         1.75  9       Uzbekistan         0.45

5       China        1.58  10     Thailand   0.42

World Total = 18.09 million NGV vehicles

South America[edit]

CNG station in Rosario, Argentina.

CNG vehicles are commonly used in South America, where these vehicles are mainly used as taxicabs in main cities of Argentina and Brazil.[26] Normally, standard gasoline vehicles are retrofitted in specialized shops, which involve installing the gas cylinder in the trunk and the CNG injection system and electronics. Argentina and Brazil are the two countries with the largest fleets of CNG vehicles,[26] with a combined total fleet of more than 3.4 million vehicles by 2009.[2] Conversion has been facilitated by a substantial price differential with liquid fuels, locally produced conversion equipment and a growing CNG-delivery infrastructure.

As of 2009 Argentina had 1,807,186 NGV's with 1,851 refueling stations across the nation,[2] or 15 percent of all vehicles;[26] and Brazil had 1,632,101 vehicles and 1,704 refueling stations,[2] with a higher concentration in the cities of Rio de Janeiro and São Paulo.[26][27]

Colombia had an NGV fleet of 300,000 vehicles, and 460 refueling stations, as of 2009.[2] Bolivia has increased its fleet from 10,000 in 2003 to 121,908 units in 2009, with 128 refueling stations.[2] Peru had 81,024 NGVs and 94 fueling stations as 2009,[2] but that number is expected to skyrocket as Peru sits on South America's largest gas reserves.[26] In Peru several factory-built NGVs have the tanks installed under the body of the vehicle, leaving the trunk free. Among the models built with this feature are the Fiat Multipla, the newFiat Panda, the Volkswagen Touran Ecofuel, the Volkswagen Caddy Ecofuel and the Chevy Taxi. Other countries with significant NGV fleets are Venezuela (15,000) and Chile (8,064) as of 2009.[2]

Asia[edit]

A CNG powered Volvo B10BLE bus, operated by SBS Transit in Singapore.

A CNG powered Hino bus, operated by BMTA in Thailand.

In Singapore, CNG is increasingly being used by public transport vehicles like buses and taxis, as well as goods vehicles. However, according to Channel NewsAsia on April 18, 2008, more owners of private cars in this country are converting their petrol-driven vehicles to also run on CNG – motivated no doubt by rising petrol prices. The initial cost of converting a regular vehicle to dual fuel at the German conversion workshop of C. Melchers, for example, is around S$3,800 (US$2,500); with the promise of real cost-savings that dual-fuel vehicles bring over the long term.

Singapore currently has five operating filling stations for natural gas. SembCorp Gas Pte Ltd. runs the station on Jurong Island and, jointly with Singapore Petroleum Company, the filling station at Jalan Buroh. Both these stations are in the western part of the country. Another station on the mainland is in Mandai Link to the north and is operated by SMART Energy. SMART also own a second station on Serangoon North Ave 5 which was set up end of March 2009; The fifth and largest station in the world was opened by the UNION Group in September 2009. This station is recognized by the Guniness World Records as being the largest in the world with 46 refuelling hoses. This station is located in Toh Tuck. The Union Group, which operates 1000 CNG Toyota Wish taxis plan to introduce another three daughter stations and increase the CNG taxi fleet to 8000 units.

CNG scooters (autorickshaws) in Dhaka, Bangladesh.

As a key incentive for using this eco-friendly fuel Singapore has a green vehicle rebate for users of CNG technology. First introduced in January 2001, the GVR grants a 40 percent discount on the OMV (open market value) cost of newly registered green passenger vehicles. This initiative will end at the end of 2012 as the government believes the 'critical mass' of CNG vehicles would then have been built up.

The Ministry of Transport of Myanmar passed a law in 2005 which required that all public transport vehicles - buses, trucks and taxis, be converted to run on CNG. The Government permitted several private companies to handle the conversion of existing diesel and petrol cars, and also to begin importing CNG variants of buses and taxis. Accidents and rumours of accidents, partly fueled by Myanmar's position in local hydrocarbon politics,[28] has discouraged citizens from using CNG vehicles, although now almost every taxi and public bus in Yangon, Myanmar's largest city, run on CNG. CNG stations have been set up around Yangon and other cities, but electricity shortages mean that vehicles may have to queue up for hours to fill their gas containers.[29] The Burmese opposition movements are against the conversion to CNG, as they accuse the companies as being proxies of the junta, and also that the petrodollars earned by the regime would go towards the defense sector, rather than towards improving the infrastructure or welfare of the people.

In Malaysia, the use of CNG was originally introduced for taxicabs and airport limousines during the late-1990s, when new taxis were launched with CNG engines while taxicab operators were encouraged to send in existing taxis for full engine conversions. The practice of using CNG remained largely confined to taxicabs predominantly in the Klang Valley and Penang due to a lack of interest. No incentives were offered for those besides taxicab owners to use CNG engines, while government subsidies on petrol and diesel made conventional road vehicles cheaper to use in the eyes of the consumers. Petronas, Malaysia's state-owned oil company, also monopolises the provision of CNG to road users. As of July 2008, Petronas only operates about 150 CNG refueling stations, most of which are concentrated in the Klang Valley. At the same time, another 50 were expected by the end of 2008.[30]

As fuel subsidies were gradually removed in Malaysia starting June 5, 2008, the subsequent 41 percent price hike on petrol and diesel led to a 500 percent increase in the number of new CNG tanks installed.[31][32] National car maker Proton considered fitting its Waja, Saga and Persona models with CNG kits from Prins Autogassystemen by the end of 2008,[33] while a local distributor of locally assembled Hyundai cars offers new models with CNG kits.[34] Conversion centres, which also benefited from the rush for lower running costs, also perform partial conversions to existing road vehicles, allowing them to run on both petrol or diesel and CNG with a cost varying between RM3,500 to RM5,000 for passenger cars.[31][35]

A CNG powered bus in Beijing. CNG buses in Beijing were introduced in late 1998.

In China, companies such as Sino-Energy are active in expanding the footprint of CNG filling stations in medium-size cities across the interior of the country, where at least two natural gas pipelines are operational.[citation needed]

A CNG powered car being filled in a filling station in Delhi

In India, the Delhi government under the order of Supreme Court in 2004 made it mandatory for all city buses and auto rickshaws to run on CNG with the intention of reducing air pollution.

The Delhi Transport Corporation operates the world's largest fleet of CNG powered buses.[36]

In Pakistan in 2012, the federal government announced plans to gradually phase out CNG over a period of approximately three years given natural gas shortages which have been negatively affecting the manufacturing sector.[37] Aside from limiting electricity generation capacity, gas shortages in Pakistan have also raised the costs of business for key industries including the fertilizer, cement and textile sectors.[38]

Iran has one of the largest fleets of CNG vehicles and CNG distribution networks in the world. There are 1800 CNG fueling stations, with a total of 10352 CNG nozzles. The number of CNG burning vehicles in Iran is about 2.6 million.[39]

Africa[edit]

Egypt is amongst the top 10 countries in CNG adoption, with 128,754 CNG vehicles and 124 CNG fueling stations. Egypt was also the first nation in Africa and the Middle East to open a public CNG fueling station in January 1996.[40]

The vast majority 780000 have been produced as dual fuel vehicles by the auto manufacturer in the last two years, and the remainder have been converted utilizing after market conversion kits in workshops. There are 750 active refueling stations country wide with an additional 660 refueling stations under construction and expected to come on stream. Currently the major problem facing the industry as a whole is the building of refueling stations that is lagging behind dual fuel vehicle production, forcing many to use petrol instead.

Nigeria CNG started with a pilot project in Benin City Edo State in 2010 by Green Gas Limited. Green Gas Limited is a Joint Venture Company of NGC (Nigerian Gas Company Ltd.) & NIPCO PLC. As at October 2012 about seven CNG stations have been built in Benin City Edo State, with about 1,000 cars running on CNG in Benin City Edo state. In Benin City Edo state, major companies such as Coca-cola are using CNG to power their fork-lifts/trucks while Edo City Transport Ltd (ECTS) is also running some of its busus on CNG.

Europe[edit]

CNG powered bus in Italy

In Italy, there are more than 1173 CNG stations.[41] The use of methane for vehicles, started in the 1930s and has continued off and on until today. Since 2008 there have been a large market expansion for natural gas vehicles (CNG and LPG) caused by the rise of gasoline prices and by the need to reduce air pollution emissions.[42] Before 1995 the only way to have a CNG-powered car was by having it retrofitted with an after-market kit. A large producer was Landi Renzo, Tartarini Auto, Prins Autogassystemen, OMVL, BiGAs,... and AeB for electronic parts used by the most part of kit producer. Landi Renzo and Tartarini selling vehicles in Asia and South America. After 1995 bi-fuel cars (gasoline/CNG) became available from several major manufacturers. Currently Fiat, Opel, Volkswagen, Citroën, Renault, Volvo and Mercedes sell various car models and small trucks that are gasoline/CNG powered. Usually CNG parts used by major car manufacturers are actually produced by automotive aftermarket kit manufacturers, e.g. Fiat use Tartarini Auto components, Volkswagen use Teleflex GFI[43] and Landi Renzo components.

In Germany, CNG-generated vehicles are expected to increase to two million units of motor-transport by the year 2020. The cost for CNG fuel is between 1/3 and 1/2 compared to other fossil fuels in Europe.[citation needed] in 2008 there are around 800 CNG stations in Germany[citation needed]

In Portugal there are four CNG refueling stations but three of them do not sell to the public. Only in Braga, can you find public access to CNG refueling—at the local city bus station (TUB).[citation needed]

In Turkey, Ankara has 1050 CNG buses.[44]

In Hungary there are four public CNG refueling stations in the cities Budapest, Szeged, Pécs and Győr. The public transportation company of Szeged runs buses mainly on CNG.[citation needed]

In Bulgaria, there are 96 CNG refueling stations as of July 2011. One can be found in most of Bulgaria's big towns.[45] In the capital Sofia there are 22 CNG stations making it possibly the city with the most publicly available CNG stations in Europe. There are also quite a few in Plovdiv, Ruse, Stara Zagora and Veliko Tarnovo as well as in the towns on the Black Sea – Varna, Burgas, Nesebar and Kavarna. CNG vehicles are becoming more and more popular in the country. The fuel is mostly used by taxi drivers because of its much lower price compared to petrol.

In Macedonia, there is one CNG station located in the capital Skopje, but it is not for public use. Only twenty buses of the local Public Transport Company have been fitted to use a mixture of diesel and CNG. The first commercial CNG station in Skopje is in the advanced stage of development and is expected to start operation in July 2011.[citation needed]

In Serbia, there are four public CNG refuelling stations in the capital Belgrade and in the towns of Pančevo, Kruševac and Čačak.[citation needed]

In Slovenia, there is only one public CNG refuelling station in the capital Ljubljana.[citation needed]

In Croatia, there is only one CNG station situated close to the center of Zagreb.[46] At least 60 CNG buses are in use as a form of a public transport (Zagreb public transport services).

In Estonia, there are two public CNG refuelling stations - one in the country's capital Tallinn and the other one in Tartu.[47] From 2011, Tartu has five Scania manufactured CNG buses operating its inner-city routes.[48]

In Sweden there are currently 90 CNG filling stations available to the public (as compared to about 10 LPG filling stations), primarily located in the southern and western parts of the country as well the Mälardalen region[49] Another 70-80 CNG filling stations are under construction or in a late stage of planning (completions 2009-2010). Several of the planned filling stations are located in the northern parts of the country, which will greatly improve the infrastructure for CNG car users.[50] There are approx. 14,500 CNG vehicles in Sweden (2007), of which approx. 13,500 are passenger cars and the remainder includes buses and trucks.[51] In Stockholm, the public transportation company SL currently operates 50 CNG buses but have a capacity to operate 500.[52] The Swedish government recently prolonged its subsidies for the development of CNG filling stations, from 2009-12-31 to 2010-12-31.[53]

In Spain the EMT Madrid bus service use CNG motors in 672 regular buses. Is rare to see another kind of CNG vehicle, and there are no CNG refueling stations.[citation needed]

As of 2013, there are 47 public CNG filling stations in the Czech Republic, mainly in the big cities.[54] Local bus manufacturers SOR Libchavy and Tedom produce CNG versions of their vehicles, with roof-mounted tanks.

North America[edit]

The Honda Civic GX is factory-built to run on CNG and it is available in several U.S. regional markets.

Buses powered with CNG are common in the United States such as the New Flyer Industries C40LF bus shown here.

Canada[edit]

Natural gas has been used as a motor fuel in Canada for over 20 years.[55] With assistance from federal and provincial research programs, demonstration projects and NGV market deployment programs during the 1980s and 1990s, the population of light-duty NGVs grew to over 35,000 by the early 1990s. This assistance resulted in a significant adoption of natural gas transit buses as well.[56]

The NGV market started to decline after 1995, eventually reaching today’s vehicle population of about 12,000.[56]

This figure includes 150 urban transit buses, 45 school buses, 9,450 light-duty cars and trucks, and 2,400 forklifts and ice-resurfacers. The total fuel use in all NGV markets in Canada was 1.9 PJs (petajoules) in 2007 (or 54.6 million litres of gasoline litres equivalent), down from 2.6 PJs in 1997. Public CNG refuelling stations have declined in quantity from 134 in 1997 to 72 today. There are 22 in British Columbia, 12 in Alberta, 10 in Saskatchewan, 27 in Ontario and two in Québec. There are only 12 private fleet stations.[17]

Canadian industry has developed CNG-fueled truck and bus engines, CNG-fueled transit buses, and light trucks and taxis.

Fuelmaker Corporation of Toronto, the Honda-owned manufacturer of CNG auto refueling units, was forced into bankruptcy by parent Honda USA for an unspecified reason in 2009.[57] The various assets of Fuelmaker were subsequently acquired by Fuel Systems Corporation of Santa Ana, California.

United States[edit]

Similar to Canada, the United States has implemented various NGV initiatives and programs since 1980, but has had limited success in sustaining the market. There were 105,000 NGVs in operation in 2000; this figure peaked at 121,000 in 2004, and decreased to 110,000 in 2009.[58]

In the United States, federal tax credits are available for buying a new CNG vehicle. Use of CNG varies from state to state; only 34 states have at least one CNG fueling site.[59]

In Athens, Ala., the city and its Gas Department installed a public CNG station on the Interstate 65 Corridor, making it the only public CNG station between Birmingham and Nashville as of February 2014. The city's larger fleet vehicles such as garbage trucks also use this public station for fueling. The city also has two slow-fill non-public CNG stations for its fleet. Athens has added CNG/gasoline Tahoes for police and fire, a CNG Honda Civic, CNG Heil garbage trucks, and CNG/gasoline Dodge pickup trucks to its fleet.

In California, CNG is used extensively in local city and county fleets, as well as public transportation (city/school buses). There are 90 public fueling stations in southern California alone, and travel from San Diego so the Bay Area to Las Vegas and Utah is routine with the advent of online station maps such as www.cngprices.com. Compressed natural gas is typically available for 30-60 percent less than the cost of gasoline in much of California.

The 28 buses running the Gwinnett County Transit local routes run on 100 percent CNG. Additionally, about half of the Georgia Regional Transportation Authority express fleet, which runs and refuels out of the Gwinnett County Transit facility, uses CNG.[60]

The Massachusetts Bay Transportation Authority was running 360 CNG buses as early as in 2007, and is the largest user in the state.[61]

The Metropolitan Transportation Authority (MTA) of New York City currently has over 900 buses powered by compressed natural gas with CNG bus depots located in Brooklyn, The Bronx and Queens.

The Nassau Inter-County Express (or NICE Bus) runs a 100% Orion CNG-fueled bus fleet for fixed route service consisting of 360 buses for service in Nassau County, parts of Queens, New York, and the western sections of Suffolk County.

The City of Harrisburg, Pennsylvania has switched some of the city's vehicles to compressed natural gas in an effort to save money on fuel costs. Trucks used by the city's street and water, sewer and gas departments have been converted from gasoline to CNG.[62]

Personal use of CNG is a small niche market currently, though with current tax incentives and a growing number of public fueling stations available, it is experiencing unprecedented growth. The state of Utah offers a subsidised statewide network of CNG filling stations at a rate of $1.57/gge,[63] while gasoline is above $4.00/gal. Elsewhere in the nation, retail prices average around $2.50/gge, with home refueling units compressing gas from residential gas lines for under $1/gge. Other than aftermarket conversions, and government used vehicle auctions, the only currently[when?] produced CNG vehicle in the United States is the Honda Civic GX sedan, which is made in limited numbers and available only in states with retail fueling outlets.

An initiative, known as Pickens Plan, calls for the expansion of the use of CNG as a standard fuel for heavy vehicles has been recently started by oilman and entrepreneur T. Boone Pickens. California voters defeated Proposition 10 in the 2008 General Election by a significant (59.8 percent to 40.2 percent) margin. Proposition 10 was a $5 billion bond measure that, among other things, would have given rebates to state residents that purchase CNG vehicles.

On February 21, 2013, T. Boone Pickens and New York Mayor, Michael Bloomberg unveiled a CNG powered mobile pizzeria. The company, Neapolitan Express uses alternative energy to run the truck as well as 100 percent recycled and compostable materials for their carryout boxes.[64]

Congress has encouraged conversion of cars to CNG with a tax credits of up to 50 percent of the auto conversion cost and the CNG home filling station cost. However, while CNG is much cleaner fuel, the conversion requires a type certificate from the EPA. Meeting the requirements of a type certificate can cost up to $50,000. Other non-EPA approved kits are available. A complete and safe aftermarket conversion using a non-EPA approved kit can be achieved for as little as $400 without the cylinder.[65]

Oceania[edit]

K230UB CNG bus currently used as part of the "Scania Koala CNG Bus Trial" at ACTION in Canberra.

During the 1970s and 1980s, CNG was commonly used in New Zealand in the wake of the oil crises, but fell into decline after petrol prices receded. At the peak of natural gas use, 10 percent of New Zealand's cars were converted, around 110,000 vehicles.[66]

A Mercedes-Benz OC500LE (with Custom Coaches bodywork) running on CNG, operated by Sydney Buses in Sydney, Australia.

Brisbane Transport in Australia has adopted a policy of purchasing only CNG buses in future. Brisbane Transport has 215 Scania L94UB and 324 MAN 18.310 models as well as 30 MAN NG 313 articulated CNG buses. The State Transit Authority of New South Wales (operating under the name "Sydney Buses") operates 100 Scania L113CRB buses, 299 Mercedes-Benz O405NH buses and 254 Euro 5-compliant Mercedes-Benz OC500LE buses.[67]

In the 1990s Benders Busways of Geelong, Victoria trialled CNG buses for the Energy Research and Development Corporation.[68]

Martin Ferguson, Ollie Clark and Noel Childs featured on ABC 7.30 Report raised the issue of CNG as an overlooked transport fuel option in Australia, highlighting the large volumes of LNG currently being exported from the North West Shelf in light of the cost of importing crude oil to Australia.[69]

Deployments[edit]

AT&T ordered 1,200 CNG-powered cargo vans from General Motors in 2012. It is the largest-ever order of CNG vehicles from General Motors to date.[70] AT&T has announced its intention to invest up to $565 million to deploy approximately 15,000 alternative fuel vehicles over a 10-year period through 2018, will use the vans to provide and maintain communications, high-speed Internet and television services for AT&T customers.[71]

DNG[edit]

DNG, or diesel natural gas, is a retrofit system which can be installed on trucks. It mixes diesel fuel with up to 70 percent natural gas.[72]

Liquefied natural gas

From Wikipedia, the free encyclopedia

Not to be confused with Natural gas processing or Liquefied petroleum gas.

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Liquefied natural gas (LNG) is natural gas (predominantly methane, CH4) that has been converted to liquid form for ease of storage or transport. It takes up about 1/600th the volume of natural gas in the gaseous state. It is odorless, colorless, non-toxic and non-corrosive. Hazards include flammability after vaporization into a gaseous state, freezing and asphyxia. The liquefaction process involves removal of certain components, such as dust, acid gases, helium, water, and heavy hydrocarbons, which could cause difficulty downstream. The natural gas is then condensed into a liquid at close to atmospheric pressure by cooling it to approximately −162 °C (−260 °F); maximum transport pressure is set at around 25 kPa (4 psi).

A typical LNG process. The gas is first extracted and transported to a processing plant where it is purified by removing any condensates such as water, oil, mud, as well as other gases such as CO2 and H2S. An LNG process train will also typically be designed to remove trace amounts of mercury from the gas stream to prevent mercury amalgamizing with aluminium in the cryogenic heat exchangers. The gas is then cooled down in stages until it is liquefied. LNG is finally stored in storage tanks and can be loaded and shipped.

LNG achieves a higher reduction in volume than compressed natural gas (CNG) so that the (volumetric) energy density of LNG is 2.4 times greater than that of CNG or 60 percent of that of diesel fuel.[1] This makes LNG cost efficient to transport over long distances where pipelines do not exist. Specially designed cryogenic sea vessels (LNG carriers) or cryogenic road tankers are used for its transport. LNG is principally used for transporting natural gas to markets, where it is regasified and distributed as pipeline natural gas. It can be used in natural gas vehicles, although it is more common to design vehicles to use compressed natural gas. Its relatively high cost of production and the need to store it in expensive cryogenic tanks have hindered widespread commercial use.

Contents  [hide]

1 Energy density and other physical properties

2 History [5]

3 Production

3.1 LNG plant production

3.2 World total production

4 Commercial aspects

4.1 Global Trade

4.2 Use of LNG to fuel large over the road trucks

5 Trade

5.1 Imports

5.2 Cargo diversion

5.3 Cost of LNG plants

5.3.1 Small-scale liquefaction plants

6 LNG pricing

6.1 Oil parity

6.2 S-curve

6.2.1 JCC and ICP

6.2.2 Brent and other energy carriers

6.3 Price review

7 Quality of LNG

8 Liquefaction technology

8.1 Storage

8.2 Transportation

8.2.1 Terminals

8.3 Refrigeration

9 Environmental concerns

9.1 Safety and accidents

10 See also

11 References

12 Other sources

13 References

14 External links

Energy density and other physical properties[edit]

The heating value depends on the source of gas that is used and the process that is used to liquefy the gas. The range of heating value can span +/- 10 to 15 percent. A typical value of the higher heating value of LNG is approximately 50 MJ/kg or 21,500 Btu/lb.[2] A typical value of the lower heating value of LNG is 45 MJ/kg or 19,350 BTU/lb.

For the purpose of comparison of different fuels the heating value may be expressed in terms of energy per volume which is known as the energy density expressed in MJ/liter. The density of LNG is roughly 0.41 kg/liter to 0.5 kg/liter, depending on temperature, pressure, and composition,[3] compared to water at 1.0 kg/liter. Using the median value of 0.45 kg/liter, the typical energy density values are 22.5 MJ/liter (based on higher heating value) or 20.3 MJ/liter (based on lower heating value).

The (volume-based) energy density of LNG is approximately 2.4 times greater than that of CNG which makes it economical to transport natural gas by ship in the form of LNG. The energy density of LNG is comparable to propane and ethanol but is only 60 percent that of diesel and 70 percent that of gasoline.[4]

History [5][edit]

Experiments on the properties of gases started early in the seventeenth century. By the middle of the seventeenth century Robert Boyle had derived the inverse relationship between the pressure and the volume of gases. About the same time, Guillaume Amontons started looking into temperature effects on gas. Various gas experiments continued for the next 200 years. During that time there were efforts to liquefy gases. Many new facts on the nature of gases had been discovered. For example, early in the nineteenth century Cagniard de la Tours had shown there was a temperature above which a gas could not be liquefied. There was a major push in the mid to late nineteenth century to liquefy all gases. A number of scientists including Michael Faraday, James Joule, and William Thomson (Lord Kelvin), did experiments in this area. In 1886 Karol Olszewski liquefied methane, the primary constituent of natural gas. By 1900 all gases had been liquefied except helium which was liquefied in 1908.

The first large scale liquefaction of natural gas in this country was in 1918 when the U.S. government liquefied natural gas as a way to extract helium, which is a small component of some natural gas. This helium was intended for use in British dirigibles for World War I. The liquid natural gas (LNG) was not stored, but regasified and immediately put into the gas mains.

The key patents having to do with natural gas liquefaction were in 1915 and the mid-1930s. In 1915 Godfrey Cabot patented a method for storing liquid gases at very low temperatures. It consisted of a Thermos bottle type design which included a cold inner tank within an outer tank; the tanks being separated by insulation. In 1937 Lee Twomey received patents for a process for large scale liquefaction of natural gas. The intention was to store natural gas as a liquid so it could be used for shaving peak energy loads during cold snaps. Because of large volumes it is not practical to store natural gas, as a gas, near atmospheric pressure. However, if it can be liquefied it can be stored in a volume 600 times smaller. This is a practical way to store it but the gas must be stored at -260 °F.

There are basically two processes for liquefying natural gas in large quantities. One is a cascade process in which the natural gas is cooled by another gas which in turn has been cooled by still another gas, hence a cascade. There are usually two cascade cycles prior to the liquid natural gas cycle. The other method is the Linde process. (A variation of the Linde process, called the Claude process, is sometimes used.) In this process the gas is cooled regeneratively by continually passing it through an orifice until it is cooled to temperatures at which it liquefies. The cooling of gas by expanding it through an orifice was developed by James Joule and William Thomson and is known as the Joule-Thomson effect. Lee Twomey used the cascade process for his patents.

The East Ohio Gas Company built a full-scale commercial liquid natural gas (LNG) plant in Cleveland, Ohio, in 1940 just after a successful pilot plant built by its sister company, Hope Natural Gas Company of West Virginia. This was the first such plant in the world. Originally it had three spheres, approximately 63 feet in diameter containing LNG at -260 °F. Each sphere held the equivalent of about 50 million cubic feet of natural gas. A fourth tank, a cylinder, was added in 1942. It had an equivalent capacity of 100 million cubic feet of gas. The plant operated successfully for three years. The stored gas was regasified and put into the mains when cold snaps hit and extra capacity was needed. This precluded the denial of gas to some customers during a cold snap.

The plant failed on October 20, 1944 when the cylindrical tank ruptured spilling thousands of gallons of LNG over the plant and nearby neighborhood. The gas evaporated and caught fire, which caused 130 fatalities. The fire delayed further implementation of LNG facilities for several years. However, over the next 15 years new research on low-temperature alloys, and better insulation materials, set the stage for a revival of the industry. It restarted in 1959 when a U.S. World War II Liberty ship, the Methane Pioneer, converted to carry LNG, made a delivery of LNG from the U.S. Gulf coast to energy starved Great Britain. In June 1964, the world's first purpose-built LNG carrier, the "Methane Princess" entered service.[6] Soon after that a large natural gas field was discovered in Algeria. International trade in LNG quickly followed as LNG was shipped to France and Great Britain from the Algerian fields. One more important attribute of LNG had now been exploited. Once natural gas was liquefied it could not only be stored more easily, but it could be transported. Thus energy could now be shipped over the oceans via LNG the same way it was shipped by oil.

The domestic LNG industry restarted in 1965 when a series of new plants were built in the U.S. The building continued through the 1970s. These plants were not only used for peak-shaving, as in Cleveland, but also for base-load supplies for places that never had natural gas prior to this. A number of import facilities were built on the East Coast in anticipation of the need to import energy via LNG. However, a recent boom in U.S. natural production (2010-2014), enabled by the new hydraulic fracturing technique (“fracking”), has many of these import facilities being considered as export facilities. The U.S. Energy Information Administration predicts, with present knowledge, that the U.S. will become an LNG exporting country in the next few years.

Production[edit]

The natural gas fed into the LNG plant will be treated to remove water, hydrogen sulfide, carbon dioxide and other components that will freeze (e.g., benzene) under the low temperatures needed for storage or be destructive to the liquefaction facility. LNG typically contains more than 90 percent methane. It also contains small amounts of ethane, propane, butane, some heavier alkanes, and nitrogen. The purification process can be designed to give almost 100 percent methane. One of the risks of LNG is a rapid phase transition explosion (RPT), which occurs when cold LNG comes into contact with water.[7]

The most important infrastructure needed for LNG production and transportation is an LNG plant consisting of one or more LNG trains, each of which is an independent unit for gas liquefaction. The largest LNG train now in operation is in Qatar. These facilities recently reached a safety milestone, completing 12 years of operations on its offshore facilities without a Lost Time Incident.[8] Until recently it was the Train 4 of Atlantic LNG in Trinidad and Tobago with a production capacity of 5.2 million metric ton per annum (mmtpa),[9] followed by the SEGAS LNG plant in Egypt with a capacity of 5 mmtpa. In July 2014, Atlantic LNG celebrated its 3000th cargo of LNG at the company’s liquefaction facility in Trinidad.[10] The Qatargas II plant has a production capacity of 7.8 mmtpa for each of its two trains. LNG sourced from Qatargas II will be supplied to Kuwait, following the signing of an agreement in May 2014 between Qatar Liquefied Gas Company and Kuwait Petroleum Corp.[10] LNG is loaded onto ships and delivered to a regasification terminal, where the LNG is allowed to expand and reconvert into gas. Regasification terminals are usually connected to a storage and pipeline distribution network to distribute natural gas to local distribution companies (LDCs) or independent power plants (IPPs).

LNG plant production[edit]

Information for the following table is derived in part from publication by the U.S. Energy Information Administration.[11]

Plant Name         Location    Country      Startup Date       Capacity (mmtpa)          Corporation

Qatargas II          Ras Laffan          Qatar          2009 7.8   

Arzew GL4Z                 Algeria       1964 0.90 

Arzew GL1Z                 Algeria       1978         

Arzew GL1Z                 Algeria       1997 7.9   

Skikda GL1K                Algeria       1972         

Skikda GL1K                Algeria       1981         

Skikda GL1K                Algeria       1999 6.0   

Angola LNG        Soyo Angola       2013 5.2    Chevron

Lumut 1               Brunei        1972 7.2   

Badak NGL A-B Bontang     Indonesia  1977 4       Pertamina

Badak NGL C-D Bontang     Indonesia  1986 4.5    Pertamina

Badak NGL E     Bontang     Indonesia  1989 3.5    Pertamina

Badak NGL F     Bontang     Indonesia  1993 3.5    Pertamina

Badak NGL G     Bontang     Indonesia  1998 3.5    Pertamina

Badak NGL H     Bontang     Indonesia  1999 3.7    Pertamina

Donggi Senoro LNG   Luwuk        Indonesia  2014 2.2    Mitsubishi

Sengkang LNG  Sengkang  Indonesia  2014 5       Energy World Corp.

Atlantic LNG       Point Fortin         Trinidad and Tobago  1999          Atlantic LNG

[Atlantic LNG]     [Point Fortin]       Trinidad and Tobago  2003 9.9    Atlantic LNG

Damietta    Egypt         2004 5.5    Segas LNG

Idku  Egypt         2005 7.2   

Bintulu MLNG 1            Malaysia    1983 7.6   

Bintulu MLNG 2           Malaysia    1994 7.8   

Bintulu MLNG 3           Malaysia    2003 3.4   

Nigeria LNG                 Nigeria       1999 23.5 

Northwest Shelf Venture      Karratha    Australia    2009 16.3 

Withnell Bay       Karratha    Australia    1989         

Withnell Bay       Karratha    Australia    1995 (7.7) 

Sakhalin II           Russia       2009 9.6.[12]     

Yemen LNG       Balhaf        Yemen       2008 6.7   

Tangguh LNG Project Papua Barat       Indonesia  2009 7.6   

Qatargas I Ras Laffan          Qatar          1996 (4.0) 

Qatargas I Ras Laffan          Qatar          2005 10.0 

Qatargas III                  Qatar          2010 7.8   

Rasgas I, II and III       Ras Laffan          Qatar          1999 36.3 

Qalhat                 Oman         2000 7.3   

Das Island I                  United Arab Emirates  1977         

Das Island I and II                 United Arab Emirates  1994 5.7   

Melkøya     Hammerfest        Norway      2007 4.2    Statoil

Equatorial Guinea                           2007 3.4    Marathon Oil

World total production[edit]

Global LNG import trends, by volume (in red), and as a percentage of global natural gas imports (in black) (US EIA data)

Trends in the top five LNG-importing nations as of 2009 (US EIA data)

Year Capacity (Mtpa)  Notes

1990 50[13]       

2002 130[14]     

2007 160[13]     

The LNG industry developed slowly during the second half of the last century because most LNG plants are located in remote areas not served by pipelines, and because of the large costs to treat and transport LNG. Constructing an LNG plant costs at least $1.5 billion per 1 mmtpa capacity, a receiving terminal costs $1 billion per 1 bcf/day throughput capacity and LNG vessels cost $200 million–$300 million.

In the early 2000s, prices for constructing LNG plants, receiving terminals and vessels fell as new technologies emerged and more players invested in liquefaction and regasification. This tended to make LNG more competitive as a means of energy distribution, but increasing material costs and demand for construction contractors have put upward pressure on prices in the last few years. The standard price for a 125,000 cubic meter LNG vessel built in European and Japanese shipyards used to be USD 250 million. When Korean and Chinese shipyards entered the race, increased competition reduced profit margins and improved efficiency—reducing costs by 60 percent. Costs in US dollars also declined due to the devaluation of the currencies of the world's largest shipbuilders: the Japanese yen and Korean won.

Since 2004, the large number of orders increased demand for shipyard slots, raising their price and increasing ship costs. The per-ton construction cost of an LNG liquefaction plant fell steadily from the 1970s through the 1990s. The cost reduced by approximately 35 percent. However, recently the cost of building liquefaction and regasification terminals doubled due to increased cost of materials and a shortage of skilled labor, professional engineers, designers, managers and other white-collar professionals.

Due to energy shortage concerns, many new LNG terminals are being contemplated in the United States. Concerns about the safety of such facilities created controversy in some regions where they were proposed. One such location is in the Long Island Sound between Connecticut and Long Island. Broadwater Energy, an effort of TransCanada Corp. and Shell, wishes to build an LNG terminal in the sound on the New York side. Local politicians including the Suffolk County Executive raised questions about the terminal. In 2005, New York Senators Chuck Schumer and Hillary Clinton also announced their opposition to the project.[15] Several terminal proposals along the coast of Maine were also met with high levels of resistance and questions. On Sep. 13, the U.S. Department of Energy approved Dominion Cove Point's application to export up to 770 million cubic feet per day of LNG to countries that do not have a free trade agreement with the U.S.[16] In May 2014, the FERC concluded its environmental assessment of the Cove Point LNG project, which found that the proposed natural gas export project could be built and operated safely.[17] Another LNG terminal is currently proposed for Elba Island, Ga.[18] Plans for three LNG export terminals in the U.S. Gulf Coast region have also received conditional Federal approval.[16][19] In Canada, an LNG export terminal is under construction near Guysborough, Nova Scotia.[20]

Commercial aspects[edit]

Global Trade[edit]

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In the commercial development of an LNG value chain, LNG suppliers first confirm sales to the downstream buyers and then sign long-term contracts (typically 20–25 years) with strict terms and structures for gas pricing. Only when the customers are confirmed and the development of a greenfield project deemed economically feasible, could the sponsors of an LNG project invest in their development and operation. Thus, the LNG liquefaction business has been limited to players with strong financial and political resources. Major international oil companies (IOCs) such as ExxonMobil, Royal Dutch Shell, BP, BG Group, Chevron, and national oil companies (NOCs) such as Pertamina and Petronas are active players.

LNG is shipped around the world in specially constructed seagoing vessels. The trade of LNG is completed by signing an SPA (sale and purchase agreement) between a supplier and receiving terminal, and by signing a GSA (gas sale agreement) between a receiving terminal and end-users. Most of the contract terms used to be DES or ex ship, holding the seller responsible for the transport of the gas. With low shipbuilding costs, and the buyers preferring to ensure reliable and stable supply, however, contract with the term of FOB increased. Under such term, the buyer, who often owns a vessel or signs a long-term charter agreement with independent carriers, is responsible for the transport.

LNG purchasing agreements used to be for a long term with relatively little flexibility both in price and volume. If the annual contract quantity is confirmed, the buyer is obliged to take and pay for the product, or pay for it even if not taken, in what is referred to as the obligation of take-or-pay contract (TOP).

In the mid-1990s, LNG was a buyer's market. At the request of buyers, the SPAs began to adopt some flexibilities on volume and price. The buyers had more upward and downward flexibilities in TOP, and short-term SPAs less than 16 years came into effect. At the same time, alternative destinations for cargo and arbitrage were also allowed. By the turn of the 21st century, the market was again in favor of sellers. However, sellers have become more sophisticated and are now proposing sharing of arbitrage opportunities and moving away from S-curve pricing. There has been much discussion regarding the creation of an "OGEC" as a natural gas equivalent of OPEC. Russia and Qatar, countries with the largest and the third largest natural gas reserves in the world, have finally supported such move.[citation needed]

Until 2003, LNG prices have closely followed oil prices. Since then, LNG prices in Europe and Japan have been lower than oil prices, although the link between LNG and oil is still strong. In contrast, prices in the US and the UK have recently skyrocketed, then fallen as a result of changes in supply and storage.[citation needed] In late 1990s and in early 2000s, the market shifted for buyers, but since 2003 and 2004, it has been a strong seller's market, with net-back as the best estimation for prices.[citation needed].

Research from QNB Group in 2014 shows that robust global demand is likely to keep LNG prices high for at least the next few years.[21]

The current surge in unconventional oil and gas in the U.S. has resulted in lower gas prices in the U.S. This has led to discussions in Asia' oil linked gas markets to import gas based on Henry Hub index.[22] Recent high level conference in Vancouver, the Pacific Energy Summit 2013 Pacific Energy Summit 2013 convened policy makers and experts from Asia and the U.S. to discuss LNG trade relations between these regions.

Receiving terminals exist in about 18 countries, including India, Japan, Korea, Taiwan, China, Greece, Belgium, Spain, Italy, France, the UK, the US, Chile, and the Dominican Republic, among others. Plans exist for Argentina, Brazil, Uruguay, Canada, Ukraine and others to also construct new receiving (gasification) terminals.

Use of LNG to fuel large over the road trucks[edit]

LNG is in the early stages of becoming a mainstream fuel for transportation needs. It is being evaluated and tested for over-the-road trucking,[23] off-road,[24] marine, and train applications.[25] There are known problems with the fuel tanks and delivery of gas to the engine,[26] but despite these concerns the move to LNG as a transportation fuel has begun.

In the United States the beginnings of a public LNG Fueling capability is being put in place. An alternative fuel fueling center tracking site shows 56 public truck LNG fuel centers as of July 2014.[27] The 2013 National Trucker's Directory lists approximately 7,000 truckstops,[28] thus approximately 1% of US truckstops have LNG available as of July 2014.

In May 2013 Dillon Transport announced they were putting 25 LNG large trucks into service in Dallas Texas. They are refueling at a public LNG fuel center.[29]

In Oct 2013 Raven Transportation announced they were buying 36 LNG large trucks to be fueled by Clean Energy Fuels locations.[30]

In fall 2013, Lowe's finished converting one of its dedicated fleets to LNG fueled trucks.[31]

UPS is planning to have over 900 LNG fueled trucks on the roads by the end of 2014.[32] UPS has 16,000 tractor trucks in its fleet and will be buying more LNG vehicles next year. 60 of the new for 2014 large trucks will be placed in service in the Houston, Texas area alone where UPS is building its own private LNG fuel center despite the availability of retail LNG capability. They state they need their own LNG fueling capacity to avoid the lines at a retail fuel center. UPS states the NGVs (natural gas vehicles) are no longer in the testing phase for them, they are vehicles they depend on.[33] In other cities such as Amarillo, Texas and Oklahoma City, Oklahoma they are using public fuel centers.[34]

Clean Energy Fuels has opened several public LNG Fuel Lanes along I-10 and claims that as of June 2014 LNG fueled trucks can use the route from Los Angeles, California to Houston, Texas by refueling exclusively at Clean Energy Fuels public facilities.[35]

In the spring of 2014 Shell and Travel Centers of America opened the first of a planned network of U.S. truck stop LNG stations in Ontario, California.[36] Per the alternative fuel fueling center tracking site there are 9 LNG capable public fuel stations in the greater Los Angeles area, making it the single most penetrated metro market.

As of August 2014, Blu LNG has at least 18 operational LNG capable fuel centers across 8 states.[37]

Clean Energy maintains a list of their existing and planned LNG fuel centers.[38] As of July 2014 they had 30 operational public LNG facilities.

Trade[edit]

In 1970, global LNG trade was of 3 billion cubic metres (bcm).[39] In 2011, it was 331 bcm.[39]

In 2004, LNG accounted for 7 percent of the world’s natural gas demand.[40] The global trade in LNG, which has increased at a rate of 7.4 percent per year over the decade from 1995 to 2005, is expected to continue to grow substantially.[41] LNG trade is expected to increase at 6.7 percent per year from 2005 to 2020.[41]

Until the mid-1990s, LNG demand was heavily concentrated in Northeast Asia: Japan, South Korea and Taiwan. At the same time, Pacific Basin supplies dominated world LNG trade.[41] The world-wide interest in using natural gas-fired combined cycle generating units for electric power generation, coupled with the inability of North American and North Sea natural gas supplies to meet the growing demand, substantially broadened the regional markets for LNG. It also brought new Atlantic Basin and Middle East suppliers into the trade.[41]

By the end of 2011, there were 18 LNG exporting countries and 25 LNG importing countries. The three biggest LNG exporters in 2011 were Qatar (75.5 MT), Malaysia (25 MT) and Indonesia (21.4 MT). The three biggest LNG importers in 2011 were Japan (78.8 MT), South Korea (35 MT) and UK (18.6 MT).[42] LNG trade volumes increased from 140 MT in 2005 to 158 MT in 2006, 165 MT in 2007, 172 MT in 2008.[43] IT was forecasted to be increased to about 200 MT in 2009, and about 300 MT in 2012. During the next several years there would be significant increase in volume of LNG Trade: about 82 MTPA of new LNG supply will come to the market between 2009 and 2011. For example, about 59 MTPA of new LNG supply from six new plants comes to the market just in 2009, including:

Northwest Shelf Train 5: 4.4 MTPA

Sakhalin II: 9.6 MTPA

Yemen LNG: 6.7 MTPA

Tangguh: 7.6 MTPA

Qatargas: 15.6 MTPA

Rasgas Qatar: 15.6 MTPA

In 2006, Qatar became the world's biggest exporter of LNG.[39] As of 2012, Qatar is the source of 25 percent of the world's LNG exports.[39]

Investments in U.S. export facilities were increasing by 2013—such as the plant being built in Hackberry, Louisiana by Sempra Energy. These investments were spurred by increasing shale gas production in the United States and a large price differential between natural gas prices in the U.S. and those in Europe and Asia. However, general exports had not yet been authorized by the United States Department of Energy because the United States had only recently moved from an importer to self-sufficiency status. When U.S. exports are authorized, large demand for LNG in Asia was expected to mitigate price decreases due to increased supplies from the U.S.[44]

Imports[edit]

In 1964, the UK and France made the first LNG trade, buying gas from Algeria, witnessing a new era of energy.

Today, only 19 countries export LNG.[39]

Compared with the crude oil market, the natural gas market is about 60 percent of the crude oil market (measured on a heat equivalent basis), of which LNG forms a small but rapidly growing part. Much of this growth is driven by the need for clean fuel and some substitution effect due to the high price of oil (primarily in the heating and electricity generation sectors).

Japan, South Korea, Spain, France, Italy and Taiwan import large volumes of LNG due to their shortage of energy. In 2005, Japan imported 58.6 million tons of LNG, representing some 30 percent of the LNG trade around the world that year. Also in 2005, South Korea imported 22.1 million tons, and in 2004 Taiwan imported 6.8 million tons. These three major buyers purchase approximately two-thirds of the world's LNG demand. In addition, Spain imported some 8.2 mmtpa in 2006, making it the third largest importer. France also imported similar quantities as Spain.[citation needed] Following the Fukushima Daiichi nuclear disaster in March 2011 Japan became a major importer accounting for one third of the total.[44] European LNG imports fell by 30 percent in 2012, and are expected to fall further by 24 percent in 2013, as South American and Asian importers pay more.[45]

Cargo diversion[edit]

Based on the LNG SPAs, LNG is destined for pre-agreed destinations, and diversion of that LNG is not allowed. However if Seller and Buyer make a mutual agreement, then the diversion of the cargo is permitted—subject to sharing the additional profit created by such a diversion. In the European Union and some other jurisdictions, it is not permitted to apply the profit-sharing clause in LNG SPAs.

Cost of LNG plants[edit]

For an extended period of time, design improvements in liquefaction plants and tankers had the effect of reducing costs.

In the 1980s, the cost of building an LNG liquefaction plant cost $350 per tpa (tonne per year). In 2000s, it was $200/tpa. In 2012, the costs can go as high as $1,000/tpa, partly due to the increase in the price of steel.[39]

As recently as 2003, it was common to assume that this was a “learning curve” effect and would continue into the future. But this perception of steadily falling costs for LNG has been dashed in the last several years.[41]

The construction cost of greenfield LNG projects started to skyrocket from 2004 afterward and has increased from about $400 per ton per year of capacity to $1,000 per ton per year of capacity in 2008.

The main reasons for skyrocketed costs in LNG industry can be described as follows:

Low availability of EPC contractors as result of extraordinary high level of ongoing petroleum projects world wide.[12]

High raw material prices as result of surge in demand for raw materials.

Lack of skilled and experienced workforce in LNG industry.[12]

Devaluation of US dollar.

The 2007–2008 global financial crisis caused a general decline in raw material and equipment prices, which somewhat lessened the construction cost of LNG plants. However, by 2012 this was more than offset by increasing demand for materials and labor for the LNG market.

Small-scale liquefaction plants[edit]

Small-scale liquefaction plants are advantageous because their compact size enables the production of LNG close to the location where it will be used. This proximity decreases transportation and LNG product costs for consumers. It also avoids the additional greenhouse gas emissions generated during long transportation.

The small-scale LNG plant also allows localized peakshaving to occur—balancing the availability of natural gas during high and low periods of demand. It also makes it possible for communities without access to natural gas pipelines to install local distribution systems and have them supplied with stored LNG.[46]

LNG pricing[edit]

There are three major pricing systems in the current LNG contracts:

Oil indexed contract used primarily in Japan, Korea, Taiwan and China;

Oil, oil products and other energy carriers indexed contracts used primarily in Continental Europe;[47] and

Market indexed contracts used in the US and the UK.;

The formula for an indexed price is as follows:

CP = BP + β X

BP: constant part or base price

β: gradient

X: indexation

The formula has been widely used in Asian LNG SPAs, where base price refers to a term that represents various non-oil factors, but usually a constant determined by negotiation at a level which can prevent LNG prices from falling below a certain level. It thus varies regardless of oil price fluctuation.

Oil parity[edit]

Oil parity is the LNG price that would be equal to that of crude oil on a Barrel of oil equivalent basis. If the LNG price exceeds the price of crude oil in BOE terms, then the situation is called broken oil parity. A coefficient of 0.1724 results in full oil parity. In most cases the price of LNG is less the price of crude oil in BOE terms. In 2009, in several spot cargo deals especially in East Asia, oil parity approached the full oil parity or even exceeds oil parity.[48]

S-curve[edit]

Many formulae include an S-curve, where the price formula is different above and below a certain oil price, to dampen the impact of high oil prices on the buyer, and low oil prices on the seller.

JCC and ICP[edit]

In most of the East Asian LNG contracts, price formula is indexed to a basket of crude imported to Japan called the Japan Crude Cocktail (JCC). In Indonesian LNG contracts, price formula is linked to Indonesian Crude Price (ICP).

Brent and other energy carriers[edit]

In continental Europe, the price formula indexation does not follow the same format, and it varies from contract to contract. Brent crude price (B), heavy fuel oil price (HFO), light fuel oil price (LFO), gas oil price (GO), coal price, electricity price and in some cases, consumer and producer price indexes are the indexation elements of price formulas.

Price review[edit]

Usually there exists a clause allowing parties to trigger the price revision or price reopening in LNG SPAs. In some contracts there are two options for triggering a price revision. regular and special. Regular ones are the dates that will be agreed and defined in the LNG SPAs for the purpose of price review.

Quality of LNG[edit]

LNG quality is one of the most important issues in the LNG business. Any gas which does not conform to the agreed specifications in the sale and purchase agreement is regarded as “off-specification” (off-spec) or “off-quality” gas or LNG. Quality regulations serve three purposes:[49]

1 - to ensure that the gas distributed is non-corrosive and non-toxic, below the upper limits for H2S, total sulphur, CO2 and Hg content;

2 - to guard against the formation of liquids or hydrates in the networks, through maximum water and hydrocarbon dewpoints;

3 - to allow interchangeability of the gases distributed, via limits on the variation range for parameters affecting combustion: content of inert gases, calorific value, Wobbe index, Soot Index, Incomplete Combustion Factor, Yellow Tip Index, etc.

In the case of off-spec gas or LNG the buyer can refuse to accept the gas or LNG and the seller has to pay liquidated damages for the respective off-spec gas volumes.

The quality of gas or LNG is measured at delivery point by using an instrument such as a gas chromatograph.

The most important gas quality concerns involve the sulphur and mercury content and the calorific value. Due to the sensitivity of liquefaction facilities to sulfur and mercury elements, the gas being sent to the liquefaction process shall be accurately refined and tested in order to assure the minimum possible concentration of these two elements before entering the liquefaction plant, hence there is not much concern about them.

However, the main concern is the heating value of gas. Usually natural gas markets can be divided in three markets in terms of heating value:[49]

Asia (Japan, Korea, Taiwan) where gas distributed is rich, with a gross calorific value (GCV) higher than 43 MJ/m3(n), i.e. 1,090 Btu/scf,

the UK and the US, where distributed gas is lean, with a GCV usually lower than 42 MJ/m3(n), i.e. 1,065 Btu/scf,

Continental Europe, where the acceptable GCV range is quite wide: approx. 39 to 46 MJ/m3(n), i.e. 990 to 1,160 Btu/scf.

There are some methods to modify the heating value of produced LNG to the desired level. For the purpose of increasing the heating value, injecting propane and butane is a solution. For the purpose of decreasing heating value, nitrogen injecting and extracting butane and propane are proved solutions. Blending with gas or LNG can be a solutions; however all of these solutions while theoretically viable can be costly and logistically difficult to manage in large scale.

Liquefaction technology[edit]

Currently there are four Liquefaction processes available:

C3MR (sometimes referred to as APCI): designed by Air Products & Chemicals, Incorporation.

Cascade: designed by ConocoPhillips.

Shell DMR

Linde

It was expected that by the end of 2012, there will be 100 liquefaction trains on stream with total capacity of 297.2 MMTPA.

The majority of these trains use either APCI or Cascade technology for the liquefaction process. The other processes, used in a small minority of some liquefaction plants, include Shell's DMR (double-mixed refrigerant) technology and the Linde technology.

APCI technology is the most-used liquefaction process in LNG plants: out of 100 liquefaction trains onstream or under-construction, 86 trains with a total capacity of 243 MMTPA have been designed based on the APCI process. Philips Cascade process is the second most-used, used in 10 trains with a total capacity of 36.16 MMTPA. The Shell DMR process has been used in three trains with total capacity of 13.9 MMTPA; and, finally, the Linde/Statoil process is used in the Snohvit 4.2 MMTPA single train.

Floating liquefied natural gas (FLNG) facilities float above an offshore gas field, and produce, liquefy, store and transfer LNG (and potentially LPG and condensate) at sea before carriers ship it directly to markets. The first FLNG facility is now in development by Shell,[50] due for completion in around 2017.[51]

Storage[edit]

LNG storage tank at EG LNG

Modern LNG storage tanks are typically full containment type, which has a prestressed concrete outer wall and a high-nickel steel inner tank, with extremely efficient insulation between the walls. Large tanks are low aspect ratio (height to width) and cylindrical in design with a domed steel or concrete roof. Storage pressure in these tanks is very low, less than 10 kPa (1.45 psig). Sometimes more expensive underground tanks are used for storage. Smaller quantities (say 700 m3 (190,000 US gallons) and less), may be stored in horizontal or vertical, vacuum-jacketed, pressure vessels. These tanks may be at pressures anywhere from less than 50 kPa to over 1,700 kPa (7 psig to 250 psig).

LNG must be kept cold to remain a liquid, independent of pressure. Despite efficient insulation, there will inevitably be some heat leakage into the LNG, resulting in vaporisation of the LNG. This boil-off gas acts to keep the LNG cold. The boil-off gas is typically compressed and exported as natural gas, or it is reliquefied and returned to storage.

Transportation[edit]

Main article: LNG carrier

Tanker LNG Rivers, LNG capacity of 135,000 cubic metres

LNG is transported in specially designed ships with double hulls protecting the cargo systems from damage or leaks. There are several special leak test methods available to test the integrity of an LNG vessel's membrane cargo tanks.[52]

The tankers cost around USD 200 million each.[39]

Transportation and supply is an important aspect of the gas business, since natural gas reserves are normally quite distant from consumer markets. Natural gas has far more volume than oil to transport, and most gas is transported by pipelines. There is a natural gas pipeline network in the former Soviet Union, Europe and North America. Natural gas is less dense, even at higher pressures. Natural gas will travel much faster than oil through a high-pressure pipeline, but can transmit only about a fifth of the amount of energy per day due to the lower density. Natural gas is usually liquefied to LNG at the end of the pipeline, prior to shipping.

Short LNG pipelines for use in moving product from LNG vessels to onshore storage are available. Longer pipelines, which allow vessels to offload LNG at a greater distance from port facilities are under development. This requires pipe in pipe technology due to requirements for keeping the LNG cold.[53]

LNG is transported using both tanker truck,[54] railway tanker, and purpose built ships known as LNG carriers. LNG will be sometimes taken to cryogenic temperatures to increase the tanker capacity. The first commercial ship-to-ship transfer (STS) transfers were undertaken in February 2007 at the Flotta facility in Scapa Flow[55] with 132,000 m3 of LNG being passed between the vessels Excalibur and Excelsior. Transfers have also been carried out by Exmar Shipmanagement, the Belgian gas tanker owner in the Gulf of Mexico, which involved the transfer of LNG from a conventional LNG carrier to an LNG regasification vessel (LNGRV). Prior to this commercial exercise LNG had only ever been transferred between ships on a handful of occasions as a necessity following an incident.[citation needed]

Terminals[edit]

Main articles: List of LNG terminals and Liquefied natural gas terminal

Liquefied natural gas is used to transport natural gas over long distances, often by sea. In most cases, LNG terminals are purpose-built ports used exclusively to export or import LNG.

Refrigeration[edit]

Question book-new.svg

This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (April 2008)

The insulation, as efficient as it is, will not keep LNG cold enough by itself. Inevitably, heat leakage will warm and vapourise the LNG. Industry practice is to store LNG as a boiling cryogen. That is, the liquid is stored at its boiling point for the pressure at which it is stored (atmospheric pressure). As the vapour boils off, heat for the phase change cools the remaining liquid. Because the insulation is very efficient, only a relatively small amount of boil off is necessary to maintain temperature. This phenomenon is also called auto-refrigeration.

Boil off gas from land based LNG storage tanks is usually compressed and fed to natural gas pipeline networks. Some LNG carriers use boil off gas for fuel.

Environmental concerns[edit]

Natural gas could be considered the most environmentally friendly fossil fuel, because it has the lowest CO2 emissions per unit of energy and because it is suitable for use in high efficiency combined cycle power stations. For an equivalent amount of heat, burning natural gas produces about 30 per cent less carbon dioxide than burning petroleum and about 45 per cent less than burning coal. [56] On a per kilometre transported basis, emissions from LNG are lower than piped natural gas, which is a particular issue in Europe, where significant amounts of gas are piped several thousand kilometres from Russia. However, emissions from natural gas transported as LNG are higher than for natural gas produced locally to the point of combustion as emissions associated with transport are lower for the latter.[citation needed]

However, on the West Coast of the United States, where up to three new LNG importation terminals have been proposed, environmental groups, such as Pacific Environment, Ratepayers for Affordable Clean Energy (RACE), and Rising Tide have moved to oppose them.[57] They claim that, while natural gas power plants emit approximately half the carbon dioxide of an equivalent coal power plant, the natural gas combustion required to produce and transport LNG to the plants adds 20 to 40 percent more carbon dioxide than burning natural gas alone.[58]

Green bordered white diamond symbol used on LNG-powered vehicles in China

Safety and accidents[edit]

Natural gas is a fuel and a combustible substance. To ensure safe and reliable operation, particular measures are taken in the design, construction and operation of LNG facilities.

In its liquid state, LNG is not explosive and can not burn. For LNG to burn, it must first vaporize, then mix with air in the proper proportions (the flammable range is 5 percent to 15 percent), and then be ignited. In the case of a leak, LNG vaporizes rapidly, turning into a gas (methane plus trace gases), and mixing with air. If this mixture is within the flammable range, there is risk of ignition which would create fire and thermal radiation hazards.

Gas venting from vehicles powered by LNG may create a flammability hazard if parked indoors for longer than a week. Additionally, due to its low temperature, refueling a LNG-powered vehicle requires training to avoid the risk of frostbite.[59]

LNG tankers have sailed over 100 million miles without a shipboard death or even a major accident.[60]

Several on-site accidents involving or related to LNG are listed below:

1944, Oct. 20. The East Ohio Natural Gas Co. experienced a failure of an LNG tank in Cleveland, Ohio.[61] 128 people perished in the explosion and fire. The tank did not have a dike retaining wall, and it was made during World War II, when metal rationing was very strict. The steel of the tank was made with an extremely low amount of nickel, which meant the tank was brittle when exposed to the cryogenic nature of LNG. The tank ruptured, spilling LNG into the city sewer system. The LNG vaporized and turned into gas, which exploded and burned.

1979, Oct. 6, Lusby, Maryland, at the Cove Point LNG facility a pump seal failed, releasing natural gas vapors (not LNG), which entered and settled in an electrical conduit.[61] A worker switched off a circuit breaker, which ignited the gas vapors. The resulting explosion killed a worker, severely injured another and caused h 

Unfinished journey (27)

(Part twenty seven, Depok, West Java, Indonesia, 1 September 2014, 20:50 pm)

In 1995 I was on duty with a senior journalist from Radio Republik Indonesia (RRI) Ahmad Parembahan to covering Energy World Conference held in the city of Madrid, Spain,

The conference, which opened the King of Spain Juan Carlos who was accompanied by queen Sofia was attended by thousands of delegates from over 100 countries who discuss energy problems of the world, such as petroleum, coal, natural gas, and alternative energy such as geothermal energy, solar energy, hydropower, wave and various other alternative energy such as bio diesel.

From Indonesia Prof.Dr.Zuhal represented at the conference, and the expert staff of the Minister of Mines and Energy Ermansyah Yamin.

In the conference illustrated how much consumption, and the availability of energy reserves such as oil, coal, natural gas and other alternative energy.

As well as how to maintain a balance between consumption and exploration of search for available resources, as well as discuss the use of new technology that allows the use of coal for power generation, but using technology to filter the smoke does not cause environmental pollution (acid rain).

Petroleum

From Wikipedia, the free encyclopedia

"Crude Oil" redirects here. For the 2008 film, see Crude Oil (film). For the fuel referred to outside of North America as "petrol", see Gasoline. For other uses, see Petroleum (disambiguation).

Proven world oil reserves, 2013

Pumpjack pumping an oil well near Lubbock, Texas

An oil refinery in Mina-Al-Ahmadi, Kuwait

Natural petroleum spring in Korňa, Slovakia

Petroleum (L. petroleum, from early 15c. "petroleum, rock oil" (mid-14c. in Anglo-French), from Medieval Latin petroleum, from Latin petra rock(see petrous) + Latin: oleum oil (see oil (n.)).[1][2][3]) is a naturally occurring, yellow-to-black liquid found in geologic formations beneath the Earth's surface, which is commonly refined into various types of fuels. It consists of hydrocarbons of various molecular weights and other liquid organic compounds.[4] The name petroleum covers both naturally occurring unprocessed crude oil and petroleum products that are made up of refined crude oil. A fossil fuel, petroleum is formed when large quantities of dead organisms, usually zooplankton and algae, are buried underneath sedimentary rock and subjected to intense heat and pressure.

Petroleum is recovered mostly through oil drilling (natural petroleum springs are rare). This comes after the studies of structural geology (at the reservoir scale), sedimentary basin analysis, reservoir characterization (mainly in terms of the porosity and permeability of geologic reservoir structures).[5][6] It is refined and separated, most easily by distillation, into a large number of consumer products, from gasoline (petrol) and kerosene to asphalt and chemical reagents used to make plastics and pharmaceuticals.[7] Petroleum is used in manufacturing a wide variety of materials,[8] and it is estimated that the world consumes about 90 million barrels each day.

The use of fossil fuels, such as petroleum, has a negative impact on Earth's biosphere, releasing pollutants and greenhouse gases into the air and damaging ecosystems through events such as oil spills. Concern over the depletion of the earth's finite reserves of oil, and the effect this would have on a society dependent on it, is a concept known as peak oil.

Contents  [hide]

1 Etymology

2 History

2.1 Early history

2.2 Modern history

3 Composition

4 Chemistry

5 Empirical equations for thermal properties

5.1 Heat of combustion

5.2 Thermal conductivity

5.3 Specific heat

5.4 Latent heat of vaporization

6 Formation

7 Reservoirs

7.1 Crude oil reservoirs

7.2 Unconventional oil reservoirs

8 Classification

9 Petroleum industry

9.1 Shipping

10 Price

11 Uses

11.1 Fuels

11.2 Other derivatives

11.3 Agriculture

12 Petroleum by country

12.1 Consumption statistics

12.2 Consumption

12.3 Production

12.4 Export

12.5 Import

12.6 Import to the USA by country 2010

12.7 Non-producing consumers

13 Environmental effects

13.1 Ocean acidification

13.2 Global warming

13.3 Extraction

13.4 Oil spills

13.5 Tarballs

13.6 Whales

14 Alternatives to petroleum

14.1 Alternatives to petroleum-based vehicle fuels

14.2 Alternatives to using oil in industry

14.3 Alternatives to burning petroleum for electricity

15 Future of petroleum production

15.1 Peak oil

15.2 Unconventional Production

16 See also

17 Notes

18 References

19 Further reading

20 External links

Etymology[edit]

The word petroleum comes from Greek: πέτρα (petra) for rocks and Greek: ἔλαιον (elaion) for oil. The term was found (in the spelling "petraoleum") in 10th-century Old English sources.[9] It was used in the treatise De Natura Fossilium, published in 1546 by the German mineralogist Georg Bauer, also known as Georgius Agricola.[10] In the 19th century, the term petroleum was frequently used to refer to mineral oils produced by distillation from mined organic solids such as cannel coal (and later oil shale), and refined oils produced from them; in the United Kingdom, storage (and later transport) of these oils were regulated by a series of Petroleum Acts, from the Petroleum Act 1863 onwards.

History[edit]

Main article: History of petroleum

Early history[edit]

Oil derrick in Okemah, Oklahoma, 1922.

Petroleum, in one form or another, has been used since ancient times, and is now important across society, including in economy, politics and technology. The rise in importance was due to the invention of the internal combustion engine, the rise in commercial aviation, and the importance of petroleum to industrial organic chemistry, particularly the synthesis of plastics, fertilizers, solvents, adhesives and pesticides.

More than 4000 years ago, according to Herodotus and Diodorus Siculus, asphalt was used in the construction of the walls and towers of Babylon; there were oil pits near Ardericca (near Babylon), and a pitch spring on Zacynthus.[11] Great quantities of it were found on the banks of the river Issus, one of the tributaries of the Euphrates. Ancient Persian tablets indicate the medicinal and lighting uses of petroleum in the upper levels of their society. By 347 AD, oil was produced from bamboo-drilled wells in China.[12] Early British explorers to Myanmar documented a flourishing oil extraction industry based in Yenangyaung that, in 1795, had hundreds of hand-dug wells under production.[13] The mythological origins of the oil fields at Yenangyaung, and its hereditary monopoly control by 24 families, indicate very ancient origins.

Modern history[edit]

In 1847, the process to distill kerosene from petroleum was invented by James Young. He noticed a natural petroleum seepage in the Riddings colliery at Alfreton, Derbyshire from which he distilled a light thin oil suitable for use as lamp oil, at the same time obtaining a thicker oil suitable for lubricating machinery. In 1848 Young set up a small business refining the crude oil.

Young eventually succeeded, by distilling cannel coal at a low heat, in creating a fluid resembling petroleum, which when treated in the same way as the seep oil gave similar products. Young found that by slow distillation he could obtain a number of useful liquids from it, one of which he named "paraffine oil" because at low temperatures it congealed into a substance resembling paraffin wax.[14]

The production of these oils and solid paraffin wax from coal formed the subject of his patent dated 17 October 1850. In 1850 Young & Meldrum and Edward William Binney entered into partnership under the title of E.W. Binney & Co. at Bathgate in West Lothian and E. Meldrum & Co. at Glasgow; their works at Bathgate were completed in 1851 and became the first truly commercial oil-works in the world with the first modern oil refinery, using oil extracted from locally-mined torbanite, shale, and bituminous coal to manufacture naphtha and lubricating oils; paraffin for fuel use and solid paraffin were not sold until 1856.[15]

Shale bings near Broxburn, 3 of a total of 19 in West Lothian

Another early refinery was built by Ignacy Łukasiewicz, providing a cheaper alternative to whale oil. The demand for petroleum as a fuel for lighting in North America and around the world quickly grew.[16] Edwin Drake's 1859 well near Titusville, Pennsylvania, is popularly considered the first modern well. Drake's well is probably singled out because it was drilled, not dug; because it used a steam engine; because there was a company associated with it; and because it touched off a major boom.[17] However, there was considerable activity before Drake in various parts of the world in the mid-19th century. A group directed by Major Alexeyev of the Bakinskii Corps of Mining Engineers hand-drilled a well in the Baku region in 1848.[18] There were engine-drilled wells in West Virginia in the same year as Drake's well.[19] An early commercial well was hand dug in Poland in 1853, and another in nearby Romania in 1857. At around the same time the world's first, small, oil refinery was opened at Jasło in Poland, with a larger one opened at Ploiești in Romania shortly after. Romania is the first country in the world to have had its annual crude oil output officially recorded in international statistics: 275 tonnes for 1857.[20][21]

The first commercial oil well in Canada became operational in 1858 at Oil Springs, Ontario (then Canada West).[22] Businessman James Miller Williams dug several wells between 1855 and 1858 before discovering a rich reserve of oil four metres below ground.[23] Williams extracted 1.5 million litres of crude oil by 1860, refining much of it into kerosene lamp oil.[22] William's well became commercially viable a year before Drake's Pennsylvania operation and could be argued to be the first commercial oil well in North America.[22] The discovery at Oil Springs touched off an oil boom which brought hundreds of speculators and workers to the area. Advances in drilling continued into 1862 when local driller Shaw reached a depth of 62 metres using the spring-pole drilling method.[24] On January 16, 1862, after an explosion of natural gas Canada's first oil gusher came into production, shooting into the air at a recorded rate of 3,000 barrels per day.[25] By the end of the 19th century the Russian Empire, particularly the Branobel company in Azerbaijan, had taken the lead in production.[26]

Access to oil was and still is a major factor in several military conflicts of the twentieth century, including World War II, during which oil facilities were a major strategic asset and were extensively bombed.[27] The German invasion of the Soviet Union included the goal to capture the Baku oilfields, as it would provide much needed oil-supplies for the German military which was suffering from blockades.[28] Oil exploration in North America during the early 20th century later led to the US becoming the leading producer by mid-century. As petroleum production in the US peaked during the 1960s, however, the United States was surpassed by Saudi Arabia and the Soviet Union.

Today, about 90 percent of vehicular fuel needs are met by oil. Petroleum also makes up 40 percent of total energy consumption in the United States, but is responsible for only 1 percent of electricity generation. Petroleum's worth as a portable, dense energy source powering the vast majority of vehicles and as the base of many industrial chemicals makes it one of the world's most important commodities. Viability of the oil commodity is controlled by several key parameters, number of vehicles in the world competing for fuel, quantity of oil exported to the world market (Export Land Model), Net Energy Gain (economically useful energy provided minus energy consumed), political stability of oil exporting nations and ability to defend oil supply lines.

The top three oil producing countries are Russia, Saudi Arabia and the United States.[29] About 80 percent of the world's readily accessible reserves are located in the Middle East, with 62.5 percent coming from the Arab 5: Saudi Arabia, UAE, Iraq, Qatar and Kuwait. A large portion of the world's total oil exists as unconventional sources, such as bitumen in Canada and oil shale in Venezuela. While significant volumes of oil are extracted from oil sands, particularly in Canada, logistical and technical hurdles remain, as oil extraction requires large amounts of heat and water, making its net energy content quite low relative to conventional crude oil. Thus, Canada's oil sands are not expected to provide more than a few million barrels per day in the foreseeable future.

Composition[edit]

In its strictest sense, petroleum includes only crude oil, but in common usage it includes all liquid, gaseous, and solid hydrocarbons. Under surface pressure and temperature conditions, lighter hydrocarbons methane, ethane, propane and butane occur as gases, while pentane and heavier ones are in the form of liquids or solids. However, in an underground oil reservoir the proportions of gas, liquid, and solid depend on subsurface conditions and on the phase diagram of the petroleum mixture.[30]

An oil well produces predominantly crude oil, with some natural gas dissolved in it. Because the pressure is lower at the surface than underground, some of the gas will come out of solution and be recovered (or burned) as associated gas or solution gas. A gas well produces predominantly natural gas. However, because the underground temperature and pressure are higher than at the surface, the gas may contain heavier hydrocarbons such as pentane, hexane, and heptane in the gaseous state. At surface conditions these will condense out of the gas to form natural gas condensate, often shortened to condensate. Condensate resembles petrol in appearance and is similar in composition to some volatile light crude oils.

The proportion of light hydrocarbons in the petroleum mixture varies greatly among different oil fields, ranging from as much as 97 percent by weight in the lighter oils to as little as 50 percent in the heavier oils and bitumens.

The hydrocarbons in crude oil are mostly alkanes, cycloalkanes and various aromatic hydrocarbons while the other organic compounds contain nitrogen, oxygen and sulfur, and trace amounts of metals such as iron, nickel, copper and vanadium. The exact molecular composition varies widely from formation to formation but the proportion of chemical elements vary over fairly narrow limits as follows:[31]

Most of the world's oils are non-conventional.[32]

Composition by weight

Element     Percent range

Carbon      83 to 85%

Hydrogen  10 to 14%

Nitrogen     0.1 to 2%

Oxygen      0.05 to 1.5%

Sulfur         0.05 to 6.0%

Metals        < 0.1%

Four different types of hydrocarbon molecules appear in crude oil. The relative percentage of each varies from oil to oil, determining the properties of each oil.[30]

Composition by weight

Hydrocarbon      Average     Range

Alkanes (paraffins)      30%  15 to 60%

Naphthenes        49%  30 to 60%

Aromatics  15%  3 to 30%

Asphaltics 6%    remainder

Crude oil varies greatly in appearance depending on its composition. It is usually black or dark brown (although it may be yellowish, reddish, or even greenish). In the reservoir it is usually found in association with natural gas, which being lighter forms a gas cap over the petroleum, and saline water which, being heavier than most forms of crude oil, generally sinks beneath it. Crude oil may also be found in semi-solid form mixed with sand and water, as in the Athabasca oil sands in Canada, where it is usually referred to as crude bitumen. In Canada, bitumen is considered a sticky, black, tar-like form of crude oil which is so thick and heavy that it must be heated or diluted before it will flow.[33] Venezuela also has large amounts of oil in the Orinoco oil sands, although the hydrocarbons trapped in them are more fluid than in Canada and are usually called extra heavy oil. These oil sands resources are called unconventional oil to distinguish them from oil which can be extracted using traditional oil well methods. Between them, Canada and Venezuela contain an estimated 3.6 trillion barrels (570×109 m3) of bitumen and extra-heavy oil, about twice the volume of the world's reserves of conventional oil.[34]

Petroleum is used mostly, by volume, for producing fuel oil and petrol, both important "primary energy" sources.[35] 84 percent by volume of the hydrocarbons present in petroleum is converted into energy-rich fuels (petroleum-based fuels), including petrol, diesel, jet, heating, and other fuel oils, and liquefied petroleum gas.[36] The lighter grades of crude oil produce the best yields of these products, but as the world's reserves of light and medium oil are depleted, oil refineries are increasingly having to process heavy oil and bitumen, and use more complex and expensive methods to produce the products required. Because heavier crude oils have too much carbon and not enough hydrogen, these processes generally involve removing carbon from or adding hydrogen to the molecules, and using fluid catalytic cracking to convert the longer, more complex molecules in the oil to the shorter, simpler ones in the fuels.

Due to its high energy density, easy transportability and relative abundance, oil has become the world's most important source of energy since the mid-1950s. Petroleum is also the raw material for many chemical products, including pharmaceuticals, solvents, fertilizers, pesticides, and plastics; the 16 percent not used for energy production is converted into these other materials. Petroleum is found in porous rock formations in the upper strata of some areas of the Earth's crust. There is also petroleum in oil sands (tar sands). Known oil reserves are typically estimated at around 190 km3 (1.2 trillion (short scale) barrels) without oil sands,[37] or 595 km3 (3.74 trillion barrels) with oil sands.[38] Consumption is currently around 84 million barrels (13.4×106 m3) per day, or 4.9 km3 per year. Which in turn yields a remaining oil supply of only about 120 years, if current demand remain static.

Chemistry[edit]

Octane, a hydrocarbon found in petroleum. Lines represent single bonds; black spheres represent carbon; white spheres represent hydrogen.

Petroleum is a mixture of a very large number of different hydrocarbons; the most commonly found molecules are alkanes (paraffins), cycloalkanes (naphthenes), aromatic hydrocarbons, or more complicated chemicals like asphaltenes. Each petroleum variety has a unique mix of molecules, which define its physical and chemical properties, like color and viscosity.

The alkanes, also known as paraffins, are saturated hydrocarbons with straight or branched chains which contain only carbon and hydrogen and have the general formula CnH2n+2. They generally have from 5 to 40 carbon atoms per molecule, although trace amounts of shorter or longer molecules may be present in the mixture.

The alkanes from pentane (C5H12) to octane (C8H18) are refined into petrol, the ones from nonane (C9H20) to hexadecane (C16H34) into diesel fuel, kerosene and jet fuel. Alkanes with more than 16 carbon atoms can be refined into fuel oil and lubricating oil. At the heavier end of the range, paraffin wax is an alkane with approximately 25 carbon atoms, while asphalt has 35 and up, although these are usually cracked by modern refineries into more valuable products. The shortest molecules, those with four or fewer carbon atoms, are in a gaseous state at room temperature. They are the petroleum gases. Depending on demand and the cost of recovery, these gases are either flared off, sold as liquified petroleum gas under pressure, or used to power the refinery's own burners. During the winter, butane (C4H10), is blended into the petrol pool at high rates, because its high vapor pressure assists with cold starts. Liquified under pressure slightly above atmospheric, it is best known for powering cigarette lighters, but it is also a main fuel source for many developing countries. Propane can be liquified under modest pressure, and is consumed for just about every application relying on petroleum for energy, from cooking to heating to transportation.

The cycloalkanes, also known as naphthenes, are saturated hydrocarbons which have one or more carbon rings to which hydrogen atoms are attached according to the formula CnH2n. Cycloalkanes have similar properties to alkanes but have higher boiling points.

The aromatic hydrocarbons are unsaturated hydrocarbons which have one or more planar six-carbon rings called benzene rings, to which hydrogen atoms are attached with the formula CnHn. They tend to burn with a sooty flame, and many have a sweet aroma. Some are carcinogenic.

These different molecules are separated by fractional distillation at an oil refinery to produce petrol, jet fuel, kerosene, and other hydrocarbons. For example, 2,2,4-trimethylpentane (isooctane), widely used in petrol, has a chemical formula of C8H18 and it reacts with oxygen exothermically:[39]

2 C

8H

18(l) + 25 O

2(g) → 16 CO

2(g) + 18 H

2O(g) (ΔH = −5.51 MJ/mol of octane)

The number of various molecules in an oil sample can be determined in laboratory. The molecules are typically extracted in a solvent, then separated in a gas chromatograph, and finally determined with a suitable detector, such as a flame ionization detector or a mass spectrometer.[40] Due to the large number of co-eluted hydrocarbons within oil, many cannot be resolved by traditional gas chromatography and typically appear as a hump in the chromatogram. This unresolved complex mixture (UCM) of hydrocarbons is particularly apparent when analysing weathered oils and extracts from tissues of organisms exposed to oil.

Incomplete combustion of petroleum or petrol results in production of toxic byproducts. Too little oxygen results in carbon monoxide. Due to the high temperatures and high pressures involved, exhaust gases from petrol combustion in car engines usually include nitrogen oxides which are responsible for creation of photochemical smog.

Empirical equations for thermal properties[edit]

Heat of combustion[edit]

At a constant volume the heat of combustion of a petroleum product can be approximated as follows:

Q_v = 12400, - 2,100d^2.

where Q_v is measured in cal/gram and d is the specific gravity at 60 °F (16 °C).

Thermal conductivity[edit]

The thermal conductivity of petroleum based liquids can be modeled as follows:[41]

K = \frac{1.62}{API}[1-0.0003(t-32)]

where K is measured in BTU · °F−1hr−1ft−1 , t is measured in °F and API is degrees API gravity.

Specific heat[edit]

The specific heat of a petroleum oils can be modeled as follows:[42]

c = \frac{1}{d} [0.388+0.00046t],

where c is measured in BTU/lbm-°F, t is the temperature in Fahrenheit and d is the specific gravity at 60 °F (16 °C).

In units of kcal/(kg·°C), the formula is:

c = \frac{1}{d} [0.4024+0.00081t],

where the temperature t is in Celsius and d is the specific gravity at 15 °C.

Latent heat of vaporization[edit]

The latent heat of vaporization can be modeled under atmospheric conditions as follows:

L = \frac{1}{d}[110.9 - 0.09t],

where L is measured in BTU/lbm, t is measured in °F and d is the specific gravity at 60 °F (16 °C).

In units of kcal/kg, the formula is:

L = \frac{1}{d}[194.4 - 0.162t],

where the temperature t is in Celsius and d is the specific gravity at 15 °C.[43]

Formation[edit]

Structure of a vanadium porphyrin compound (left) extracted from petroleum by Alfred E. Treibs, father of organic geochemistry. Treibs noted the close structural similarity of this molecule and chlorophyll a (right).[44][45]

Petroleum is a fossil fuel derived from ancient fossilized organic materials, such as zooplankton and algae.[46] Vast quantities of these remains settled to sea or lake bottoms, mixing with sediments and being buried under anoxic conditions. As further layers settled to the sea or lake bed, intense heat and pressure build up in the lower regions. This process caused the organic matter to change, first into a waxy material known as kerogen, which is found in various oil shales around the world, and then with more heat into liquid and gaseous hydrocarbons via a process known as catagenesis. Formation of petroleum occurs from hydrocarbon pyrolysis in a variety of mainly endothermic reactions at high temperature and/or pressure.[47]

There were certain warm nutrient-rich environments such as the Gulf of Mexico and the ancient Tethys Sea where the large amounts of organic material falling to the ocean floor exceeded the rate at which it could decompose. This resulted in large masses of organic material being buried under subsequent deposits such as shale formed from mud. This massive organic deposit later became heated and transformed under pressure into oil.[48]

Geologists often refer to the temperature range in which oil forms as an "oil window"[49]—below the minimum temperature oil remains trapped in the form of kerogen, and above the maximum temperature the oil is converted to natural gas through the process of thermal cracking. Sometimes, oil formed at extreme depths may migrate and become trapped at a much shallower level. The Athabasca Oil Sands are one example of this.

An alternative mechanism was proposed by Russian scientists in the mid-1850s, the Abiogenic petroleum origin, but this is contradicted by the geological and geochemical evidence.[citation needed]

Reservoirs[edit]

Crude oil reservoirs[edit]

Hydrocarbon trap.

Three conditions must be present for oil reservoirs to form: a source rock rich in hydrocarbon material buried deep enough for subterranean heat to cook it into oil, a porous and permeable reservoir rock for it to accumulate in, and a cap rock (seal) or other mechanism that prevents it from escaping to the surface. Within these reservoirs, fluids will typically organize themselves like a three-layer cake with a layer of water below the oil layer and a layer of gas above it, although the different layers vary in size between reservoirs. Because most hydrocarbons are less dense than rock or water, they often migrate upward through adjacent rock layers until either reaching the surface or becoming trapped within porous rocks (known as reservoirs) by impermeable rocks above. However, the process is influenced by underground water flows, causing oil to migrate hundreds of kilometres horizontally or even short distances downward before becoming trapped in a reservoir. When hydrocarbons are concentrated in a trap, an oil field forms, from which the liquid can be extracted by drilling and pumping.

The reactions that produce oil and natural gas are often modeled as first order breakdown reactions, where hydrocarbons are broken down to oil and natural gas by a set of parallel reactions, and oil eventually breaks down to natural gas by another set of reactions. The latter set is regularly used in petrochemical plants and oil refineries.

Wells are drilled into oil reservoirs to extract the crude oil. "Natural lift" production methods that rely on the natural reservoir pressure to force the oil to the surface are usually sufficient for a while after reservoirs are first tapped. In some reservoirs, such as in the Middle East, the natural pressure is sufficient over a long time. The natural pressure in most reservoirs, however, eventually dissipates. Then the oil must be extracted using "artificial lift" means. Over time, these "primary" methods become less effective and "secondary" production methods may be used. A common secondary method is "waterflood" or injection of water into the reservoir to increase pressure and force the oil to the drilled shaft or "wellbore." Eventually "tertiary" or "enhanced" oil recovery methods may be used to increase the oil's flow characteristics by injecting steam, carbon dioxide and other gases or chemicals into the reservoir. In the United States, primary production methods account for less than 40 percent of the oil produced on a daily basis, secondary methods account for about half, and tertiary recovery the remaining 10 percent. Extracting oil (or "bitumen") from oil/tar sand and oil shale deposits requires mining the sand or shale and heating it in a vessel or retort, or using "in-situ" methods of injecting heated liquids into the deposit and then pumping out the oil-saturated liquid.

Unconventional oil reservoirs[edit]

See also: Unconventional oil, Oil sands and Oil shale reserves

Oil-eating bacteria biodegrade oil that has escaped to the surface. Oil sands are reservoirs of partially biodegraded oil still in the process of escaping and being biodegraded, but they contain so much migrating oil that, although most of it has escaped, vast amounts are still present—more than can be found in conventional oil reservoirs. The lighter fractions of the crude oil are destroyed first, resulting in reservoirs containing an extremely heavy form of crude oil, called crude bitumen in Canada, or extra-heavy crude oil in Venezuela. These two countries have the world's largest deposits of oil sands.

On the other hand, oil shales are source rocks that have not been exposed to heat or pressure long enough to convert their trapped hydrocarbons into crude oil. Technically speaking, oil shales are not always shales and do not contain oil, but are fined-grain sedimentary rocks containing an insoluble organic solid called kerogen. The kerogen in the rock can be converted into crude oil using heat and pressure to simulate natural processes. The method has been known for centuries and was patented in 1694 under British Crown Patent No. 330 covering, "A way to extract and make great quantities of pitch, tar, and oil out of a sort of stone." Although oil shales are found in many countries, the United States has the world's largest deposits.[50]

Classification[edit]

Some marker crudes with their sulfur content (horizontal) and API gravity (vertical) and relative production quantity.

See also: Benchmark (crude oil)

The petroleum industry generally classifies crude oil by the geographic location it is produced in (e.g. West Texas Intermediate, Brent, or Oman), its API gravity (an oil industry measure of density), and its sulfur content. Crude oil may be considered light if it has low density or heavy if it has high density; and it may be referred to as sweet if it contains relatively little sulfur or sour if it contains substantial amounts of sulfur.

The geographic location is important because it affects transportation costs to the refinery. Light crude oil is more desirable than heavy oil since it produces a higher yield of petrol, while sweet oil commands a higher price than sour oil because it has fewer environmental problems and requires less refining to meet sulfur standards imposed on fuels in consuming countries. Each crude oil has unique molecular characteristics which are understood by the use of crude oil assay analysis in petroleum laboratories.

Barrels from an area in which the crude oil's molecular characteristics have been determined and the oil has been classified are used as pricing references throughout the world. Some of the common reference crudes are:

West Texas Intermediate (WTI), a very high-quality, sweet, light oil delivered at Cushing, Oklahoma for North American oil

Brent Blend, comprising 15 oils from fields in the Brent and Ninian systems in the East Shetland Basin of the North Sea. The oil is landed at Sullom Voe terminal in Shetland. Oil production from Europe, Africa and Middle Eastern oil flowing West tends to be priced off this oil, which forms a benchmark

Dubai-Oman, used as benchmark for Middle East sour crude oil flowing to the Asia-Pacific region

Tapis (from Malaysia, used as a reference for light Far East oil)

Minas (from Indonesia, used as a reference for heavy Far East oil)

The OPEC Reference Basket, a weighted average of oil blends from various OPEC (The Organization of the Petroleum Exporting Countries) countries

Midway Sunset Heavy, by which heavy oil in California is priced[51]

There are declining amounts of these benchmark oils being produced each year, so other oils are more commonly what is actually delivered. While the reference price may be for West Texas Intermediate delivered at Cushing, the actual oil being traded may be a discounted Canadian heavy oil delivered at Hardisty, Alberta, and for a Brent Blend delivered at Shetland, it may be a Russian Export Blend delivered at the port of Primorsk.[52]

Petroleum industry[edit]

Crude Oil Export Treemap (2012) from Harvard Atlas of Economic Complexity[53]

New York Mercantile Exchange prices ($/bbl) for West Texas Intermediate since 2000

Main article: Petroleum industry

The petroleum industry is involved in the global processes of exploration, extraction, refining, transporting (often with oil tankers and pipelines), and marketing petroleum products. The largest volume products of the industry are fuel oil and petrol. Petroleum is also the raw material for many chemical products, including pharmaceuticals, solvents, fertilizers, pesticides, and plastics. The industry is usually divided into three major components: upstream, midstream and downstream. Midstream operations are usually included in the downstream category.

Petroleum is vital to many industries, and is of importance to the maintenance of industrialized civilization itself, and thus is a critical concern to many nations. Oil accounts for a large percentage of the world's energy consumption, ranging from a low of 32 percent for Europe and Asia, up to a high of 53 percent for the Middle East, South and Central America (44%), Africa (41%), and North America (40%). The world at large consumes 30 billion barrels (4.8 km³) of oil per year, and the top oil consumers largely consist of developed nations. In fact, 24 percent of the oil consumed in 2004 went to the United States alone,[54] though by 2007 this had dropped to 21 percent of world oil consumed.[55]

In the US, in the states of Arizona, California, Hawaii, Nevada, Oregon and Washington, the Western States Petroleum Association (WSPA) represents companies responsible for producing, distributing, refining, transporting and marketing petroleum. This non-profit trade association was founded in 1907, and is the oldest petroleum trade association in the United States.[56]

Shipping[edit]

In the 1950s, shipping costs made up 33 percent of the price of oil transported from the Persian Gulf to USA,[57] but due to the development of supertankers in the 1970s, the cost of shipping dropped to only 5 percent of the price of Persian oil in USA.[57] Due to the increase of the value of the crude oil during the last 30 years, the share of the shipping cost on the final cost of the delivered commodity was less than 3% in 2010. For example, in 2010 the shipping cost from the Persian Gulf to the USA was in the range of 20 $/t and the cost of the delivered crude oil around 800 $/t.[citation needed]

Price[edit]

Main article: Price of petroleum

After the collapse of the OPEC-administered pricing system in 1985, and a short lived experiment with netback pricing, oil-exporting countries adopted a market-linked pricing mechanism.[58] First adopted by PEMEX in 1986, market-linked pricing was widely accepted, and by 1988 became and still is the main method for pricing crude oil in international trade.[58] The current reference, or pricing markers, are Brent, WTI, and Dubai/Oman.[58]

Uses[edit]

Further information: Petroleum products

The chemical structure of petroleum is heterogeneous, composed of hydrocarbon chains of different lengths. Because of this, petroleum may be taken to oil refineries and the hydrocarbon chemicals separated by distillation and treated by other chemical processes, to be used for a variety of purposes. See Petroleum products.

Fuels[edit]

A poster used to promote carpooling as a way to ration gasoline during World War II.

The most common distillation fractions of petroleum are fuels. Fuels include (by increasing boiling temperature range):[59]

Common fractions of petroleum as fuels

Fraction     Boiling range oC

Liquefied petroleum gas (LPG)     −40

Butane       −12 to −1

Petrol         −1 to 110

Jet fuel       150 to 205

Kerosene  205 to 260

Fuel oil       205 to 290

Diesel fuel 260 to 315

Other derivatives[edit]

Certain types of resultant hydrocarbons may be mixed with other non-hydrocarbons, to create other end products:

Alkenes (olefins), which can be manufactured into plastics or other compounds

Lubricants (produces light machine oils, motor oils, and greases, adding viscosity stabilizers as required)

Wax, used in the packaging of frozen foods, among others

Sulfur or Sulfuric acid. These are useful industrial materials. Sulfuric acid is usually prepared as the acid precursor oleum, a byproduct of sulfur removal from fuels.

Bulk tar

Asphalt

Petroleum coke, used in speciality carbon products or as solid fuel

Paraffin wax

Aromatic petrochemicals to be used as precursors in other chemical production

Agriculture[edit]

Since the 1940s, agricultural productivity has increased dramatically, due largely to the increased use of energy-intensive mechanization, fertilizers and pesticides.

Petroleum by country[edit]

Consumption statistics[edit]

Global fossil carbon emissions, an indicator of consumption, for 1800–2007. Total is black, Oil is in blue.

Rate of world energy usage per day, from 1970 to 2010. 1000TWh=1PWh.[60]

daily oil consumption from 1980 to 2006

oil consumption by percentage of total per region from 1980 to 2006: red=USA, blue=Europe, yellow=Asia+Oceania

Oil consumption 1980 to 2007 by region.

Consumption[edit]

According to the US Energy Information Administration (EIA) estimate for 2011, the world consumes 87.421 million barrels of oil each day.

Oil consumption per capita (darker colors represent more consumption, gray represents no data).

This table orders the amount of petroleum consumed in 2011 in thousand barrels (1000 bbl) per day and in thousand cubic metres (1000 m3) per day:[61][62][63]

Consuming Nation 2011      (1000 bbl/

day)  (1000 m3/

day)  population

in millions  bbl/year

per capita  m3/year

per capita  national production/

consumption

United States 1  18,835.5    2,994.6      314   21.8  3.47  0.51

China         9,790.0      1,556.5      1345 2.7    0.43  0.41

Japan 2     4,464.1      709.7         127   12.8  2.04  0.03

India 2        3,292.2      523.4         1198 1       0.16  0.26

Russia 1    3,145.1      500.0         140   8.1    1.29  3.35

Saudi Arabia (OPEC)  2,817.5      447.9         27     40     6.4    3.64

Brazil          2,594.2      412.4         193   4.9    0.78  0.99

Germany 2          2,400.1      381.6         82     10.7  1.70  0.06

Canada     2,259.1      359.2         33     24.6  3.91  1.54

South Korea 2    2,230.2      354.6         48     16.8  2.67  0.02

Mexico 1    2,132.7      339.1         109   7.1    1.13  1.39

France 2    1,791.5      284.8         62     10.5  1.67  0.03

Iran (OPEC)        1,694.4      269.4         74     8.3    1.32  2.54

United Kingdom 1        1,607.9      255.6         61     9.5    1.51  0.93

Italy 2         1,453.6      231.1         60     8.9    1.41  0.10

Source: US Energy Information Administration

Population Data:[64]

1 peak production of oil already passed in this state

2 This country is not a major oil producer

Production[edit]

For oil reserves by country, see List of countries by proven oil reserves.

Oil producing countries

Graph of Top Oil Producing Countries 1960–2006, including Soviet Union[65]

In petroleum industry parlance, production refers to the quantity of crude extracted from reserves, not the literal creation of the product.

#       Producing Nation         103bbl/d (2006)  103bbl/d (2007)  103bbl/d (2008)  103bbl/d (2009)        Present Share

1       Saudi Arabia (OPEC)  10,665       10,234       10,782       9,760         11.8%

2       Russia 1    9,677         9,876         9,789         9,934         12.0%

3       United States 1  8,331         8,481         8,514         9,141         11.1%

4       Iran (OPEC)        4,148         4,043         4,174         4,177         5.1%

5       China         3,846         3,901         3,973         3,996         4.8%

6       Canada 2  3,288         3,358         3,350         3,294         4.0%

7       Mexico 1    3,707         3,501         3,185         3,001         3.6%

8       United Arab Emirates (OPEC)       2,945         2,948         3,046         2,795          3.4%

9       Kuwait (OPEC)   2,675         2,613         2,742         2,496         3.0%

10     Venezuela (OPEC) 1  2,803         2,667         2,643         2,471         3.0%

11     Norway 1   2,786         2,565         2,466         2,350         2.8%

12     Brazil          2,166         2,279         2,401         2,577         3.1%

13     Iraq (OPEC) 3     2,008         2,094         2,385         2,400         2.9%

14     Algeria (OPEC)  2,122         2,173         2,179         2,126         2.6%

15     Nigeria (OPEC)  2,443         2,352         2,169         2,211         2.7%

16     Angola (OPEC)  1,435         1,769         2,014         1,948         2.4%

17     Libya (OPEC)     1,809         1,845         1,875         1,789         2.2%

18     United Kingdom 1,689         1,690         1,584         1,422         1.7%

19     Kazakhstan         1,388         1,445         1,429         1,540         1.9%

20     Qatar (OPEC)     1,141         1,136         1,207         1,213         1.5%

21     Indonesia  1,102         1,044         1,051         1,023         1.2%

22     India 854   881   884   877   1.1%

23     Azerbaijan 648   850   875   1,012         1.2%

24     Argentina   802   791   792   794   1.0%

25     Oman         743   714   761   816   1.0%

26     Malaysia    729   703   727   693   0.8%

27     Egypt         667   664   631   678   0.8%

28     Colombia   544   543   601   686   0.8%

29     Australia    552   595   586   588   0.7%

30     Ecuador (OPEC)         536   512   505   485   0.6%

31     Sudan        380   466   480   486   0.6%

32     Syria 449   446   426   400   0.5%

33     Equatorial Guinea       386   400   359   346   0.4%

34     Thailand    334   349   361   339   0.4%

35     Vietnam     362   352   314   346   0.4%

36     Yemen       377   361   300   287   0.3%

37     Denmark    344   314   289   262   0.3%

38     Gabon       237   244   248   242   0.3%

39     South Africa        204   199   195   192   0.2%

40     Turkmenistan     No data      180   189   198   0.2%

41     Trinidad and Tobago  181   179   176   174   0.1%

Source: U.S. Energy Information Administration

1 Peak production of conventional oil already passed in this state

2 Although Canada's conventional oil production is declining, its total oil production is increasing as oil sands production grows. When oil sands are included, Canada has the world's second largest oil reserves after Saudi Arabia.

3 Trinidad and Tobago has the worlds third largest pitch lake situated La Brea south Trinidad

4 Though still a member, Iraq has not been included in production figures since 1998

In 2013, the United States will produce an average of 11.4 million barrels a day, which would make it the second largest producer of hydrocarbons,[66] and is expected to overtake Saudi Arabia before 2020.[67]

Export[edit]

See also: Fossil fuel exporters and Organization of Petroleum Exporting Countries

Oil exports by country.

In order of net exports in 2011, 2009 and 2006 in thousand bbl/d and thousand m³/d:

#       Exporting Nation          103bbl/d (2011)  103m3/d (2011) 103bbl/d (2009)  103m3/d (2009)        103bbl/d (2006)  103m3/d (2006)

1       Saudi Arabia (OPEC)  8,336         1,325         7,322         1,164         8,651          1,376

2       Russia 1    7,083         1,126         7,194         1,144         6,565         1,044

3       Iran (OPEC)        2,540         403   2,486         395   2,519         401

4       United Arab Emirates (OPEC)       2,524         401   2,303         366   2,515          400

5       Kuwait (OPEC)   2,343         373   2,124         338   2,150         342

6       Nigeria (OPEC)  2,257         359   1,939         308   2,146         341

7       Iraq (OPEC)        1,915         304   1,764         280   1,438         229

8       Angola (OPEC)  1,760         280   1,878         299   1,363         217

9       Norway 1   1,752         279   2,132         339   2,542         404

10     Venezuela (OPEC) 1  1,715         273   1,748         278   2,203         350

11     Algeria (OPEC) 1         1,568         249   1,767         281   1,847         297

12     Qatar (OPEC)     1,468         233   1,066         169   –       –

13     Canada 2  1,405         223   1,168         187   1,071         170

14     Kazakhstan         1,396         222   1,299         207   1,114         177

15     Azerbaijan 1       836   133   912   145   532   85

16     Trinidad and Tobago 1         177   112   167   160   155   199

Source: US Energy Information Administration

1 peak production already passed in this state

2 Canadian statistics are complicated by the fact it is both an importer and exporter of crude oil, and refines large amounts of oil for the U.S. market. It is the leading source of U.S. imports of oil and products, averaging 2,500,000 bbl/d (400,000 m3/d) in August 2007. [1].

Total world production/consumption (as of 2005) is approximately 84 million barrels per day (13,400,000 m3/d).

Import[edit]

Oil imports by country.

In order of net imports in 2011, 2009 and 2006 in thousand bbl/d and thousand m³/d:

#       Importing Nation 103bbl/day (2011)       103m3/day (2011)       103bbl/day (2009)          103m3/day (2009)       103bbl/day (2006)       103m3/day (2006)

1       United States 1  8,728         1,388         9,631         1,531         12,220       1,943

2       China 2      5,487         872   4,328         688   3,438         547

3       Japan        4,329         688   4,235         673   5,097         810

4       India 2,349         373   2,233         355   1,687         268

5       Germany   2,235         355   2,323         369   2,483         395

6       South Korea       2,170         345   2,139         340   2,150         342

7       France       1,697         270   1,749         278   1,893         301

8       Spain         1,346         214   1,439         229   1,555         247

9       Italy   1,292         205   1,381         220   1,558         248

10     Singapore 1,172         186   916   146   787   125

11     Republic of China (Taiwan) 1,009         160   944   150   942   150

12     Netherlands        948   151   973   155   936   149

13     Turkey       650   103   650   103   576   92

14     Belgium     634   101   597   95     546   87

15     Thailand    592   94     538   86     606   96

Source: US Energy Information Administration

1 peak production of oil expected in 2020[68]

2 Major oil producer whose production is still increasing[citation needed]

Import to the USA by country 2010[edit]

oil imports to US 2010

Non-producing consumers[edit]

Countries whose oil production is 10% or less of their consumption.

#       Consuming Nation      (bbl/day)    (m³/day)

1       Japan        5,578,000  886,831

2       Germany   2,677,000  425,609

3       South Korea       2,061,000  327,673

4       France       2,060,000  327,514

5       Italy   1,874,000  297,942

6       Spain         1,537,000  244,363

7       Netherlands        946,700     150,513

8       Turkey       575,011     91,663

Source: CIA World Factbook[not in citation given]

Environmental effects[edit]

Diesel fuel spill on a road

Main article: Environmental issues with petroleum

Because petroleum is a naturally occurring substance, its presence in the environment need not be the result of human causes such as accidents and routine activities (seismic exploration, drilling, extraction, refining and combustion). Phenomena such as seeps[69] and tar pits are examples of areas that petroleum affects without man's involvement. Regardless of source, petroleum's effects when released into the environment are similar.

Ocean acidification[edit]

Seawater Acidification

Ocean acidification is the increase in the acidity of the Earth's oceans caused by the uptake of carbon dioxide (CO

2) from the atmosphere. This increase in acidity inhibits life such as scallops.[70]

Global warming[edit]

When burned, petroleum releases carbon dioxide; a greenhouse gas. Along with the burning of coal, petroleum combustion is the largest contributor to the increase in atmospheric CO2. Atmospheric CO2 has risen steadily since the industrial revolution to current levels of over 390 ppmv, from the 180 – 300 ppmv of the prior 800 thousand years, driving global warming.[71][72][73] The unbridled use of petroleum could potentially cause a runaway greenhouse effect on Earth.[citation needed] Use of oil as an energy source has caused Earth's temperature to increase by nearly one degree Celsius. This raise in temperature has reduced the Arctic ice cap to 1,100,000 sq mi (2,800,000 km2), smaller than ever recorded.[74] Because of this melt, more oil reserves have been revealed. It is estimated by the International Energy Agency that about 13 percent of the world's undiscovered oil resides in the Arctic.[75]

Extraction[edit]

Oil extraction is simply the removal of oil from the reservoir (oil pool). Oil is often recovered as a water-in-oil emulsion, and specialty chemicals called demulsifiers are used to separate the oil from water. Oil extraction is costly and sometimes environmentally damaging, although Dr. John Hunt of the Woods Hole Oceanographic Institution pointed out in a 1981 paper that over 70 percent of the reserves in the world are associated with visible macroseepages, and many oil fields are found due to natural seeps. Offshore exploration and extraction of oil disturbs the surrounding marine environment.[76]

Oil spills[edit]

Further information: Oil spill and List of oil spills

Kelp after an oil spill

Oil Sick from the Montara oil spill in the Timor Sea, September, 2009

Volunteers cleaning up the aftermath of the Prestige oil spill

Crude oil and refined fuel spills from tanker ship accidents have damaged natural ecosystems in Alaska, the Gulf of Mexico, the Galapagos Islands, France and many other places.

The quantity of oil spilled during accidents has ranged from a few hundred tons to several hundred thousand tons (e.g., Deepwater Horizon Oil Spill, Atlantic Empress, Amoco Cadiz). Smaller spills have already proven to have a great impact on ecosystems, such as the Exxon Valdez oil spill

Oil spills at sea are generally much more damaging than those on land, since they can spread for hundreds of nautical miles in a thin oil slick which can cover beaches with a thin coating of oil. This can kill sea birds, mammals, shellfish and other organisms it coats. Oil spills on land are more readily containable if a makeshift earth dam can be rapidly bulldozed around the spill site before most of the oil escapes, and land animals can avoid the oil more easily.

Control of oil spills is difficult, requires ad hoc methods, and often a large amount of manpower. The dropping of bombs and incendiary devices from aircraft on SS Torrey Canyon wreck produced poor results;[77] modern techniques would include pumping the oil from the wreck, like in the Prestige oil spill or the Erika oil spill.[78]

Though crude oil is predominantly composed of various hydrocarbons, certain nitrogen heterocylic compounds, such as pyridine, picoline, and quinoline are reported as contaminants associated with crude oil, as well as facilities processing oil shale or coal, and have also been found at legacy wood treatment sites. These compounds have a very high water solubility, and thus tend to dissolve and move with water. Certain naturally occurring bacteria, such as Micrococcus, Arthrobacter, and Rhodococcus have been shown to degrade these contaminants.[79]

Tarballs[edit]

A tarball is a blob of crude oil (not to be confused with tar, which is typically derived from pine trees rather than petroleum) which has been weathered after floating in the ocean. Tarballs are an aquatic pollutant in most environments, although they can occur naturally, for example, in the Santa Barbara Channel of California.[80][81] Their concentration and features have been used to assess the extent of oil spills. Their composition can be used to identify their sources of origin,[82][83] and tarballs themselves may be dispersed over long distances by deep sea currents.[81] They are slowly decomposed by bacteria, including Chromobacterium violaceum, Cladosporium resinae, Bacillus submarinus, Micrococcus varians, Pseudomonas aeruginosa, Candida marina and Saccharomyces estuari.[80]

Whales[edit]

James S. Robbins has argued that the advent of petroleum-refined kerosene saved some species of great whales from extinction by providing an inexpensive substitute for whale oil, thus eliminating the economic imperative for open-boat whaling.[84]

Alternatives to petroleum[edit]

Further information: Renewable energy

In the United States in 2007 about 70 percent of petroleum was used for transportation (e.g. petrol, diesel, jet fuel), 24 percent by industry (e.g. production of plastics), 5 percent for residential and commercial uses, and 2 percent for electricity production.[85] Outside of the US, a higher proportion of petroleum tends to be used for electricity.[86]

Alternatives to petroleum-based vehicle fuels[edit]

Brazilian fuel station with four alternative fuels for sale: diesel (B3), gasohol (E25), neat ethanol (E100), and compressed natural gas (CNG).

Main articles: Alternative fuel vehicle, Hydrogen economy and Green vehicle

Alternative fuel vehicles refers to both:

Vehicles that use alternative fuels used in standard or modified internal combustion engines such as natural gas vehicles, neat ethanol vehicles, flexible-fuel vehicles, biodiesel-powered vehicles, and hydrogen vehicles.

Vehicles with advanced propulsion systems that reduce or substitute petroleum use such as battery electric vehicles, plug-in hybrid electric vehicles, hybrid electric vehicles, and hydrogen fuel cell vehicles.

Alternatives to using oil in industry[edit]

[icon] This section requires expansion. (July 2008)

Biological feedstocks do exist for industrial uses such as Bioplastic production.[87]

Alternatives to burning petroleum for electricity[edit]

Main articles: Alternative energy, Nuclear power and Renewable energy

In oil producing countries with little refinery capacity, oil is sometimes burned to produce electricity. Renewable energy technologies such as solar power, wind power, micro hydro, biomass and biofuels are used, but the primary alternatives remain large-scale hydroelectricity, nuclear and coal-fired generation.

Future of petroleum production[edit]

US oil production and imports, 1910-2012.

Consumption in the twentieth and twenty-first centuries has been abundantly pushed by automobile growth; the 1985–2003 oil glut even fueled the sales of low economy vehicles in OECD countries. The 2008 economic crisis seems to have had some impact on the sales of such vehicles; still, the 2008 oil consumption shows a small increase. The BRIC countries might also kick in, as China briefly was the first automobile market in December 2009.[88] The immediate outlook still hints upwards. In the long term, uncertainties linger; the OPEC believes that the OECD countries will push low consumption policies at some point in the future; when that happens, it will definitely curb oil sales, and both OPEC and EIA kept lowering their 2020 consumption estimates during the past 5 years.[89] Oil products are more and more in competition with alternative sources, mainly coal and natural gas, both cheaper sources. Production will also face an increasingly complex situation; while OPEC countries still have large reserves at low production prices, newly found reservoirs often lead to higher prices; offshore giants such as Tupi, Guara and Tiber demand high investments and ever-increasing technological abilities. Subsalt reservoirs such as Tupi were unknown in the twentieth century, mainly because the industry was unable to probe them. Enhanced Oil Recovery (EOR) techniques (example: DaQing, China[90] ) will continue to play a major role in increasing the world's recoverable oil.

Peak oil[edit]

Main article: Peak oil

Global Peak Oil forecast

Peak oil is the projection that future petroleum production (whether for individual oil wells, entire oil fields, whole countries, or worldwide production) will eventually peak and then decline at a similar rate to the rate of increase before the peak as these reserves are exhausted. The peak of oil discoveries was in 1965, and oil production per year has surpassed oil discoveries every year since 1980.[91]

Hubbert applied his theory to accurately predict the peak of U.S. conventional oil production at a date between 1966 and 1970. This prediction was based on data available at the time of his publication in 1956. In the same paper, Hubbert predicts world peak oil in "half a century" after his publication, which would be 2006.[92]

It is difficult to predict the oil peak in any given region, due to the lack of knowledge and/or transparency in accounting of global oil reserves.[93] Based on available production data, proponents have previously predicted the peak for the world to be in years 1989, 1995, or 1995–2000. Some of these predictions date from before the recession of the early 1980s, and the consequent reduction in global consumption, the effect of which was to delay the date of any peak by several years. Just as the 1971 U.S. peak in oil production was only clearly recognized after the fact, a peak in world production will be difficult to discern until production clearly drops off.[94] The peak is also a moving target as it is now measured as "liquids", which includes synthetic fuels, instead of just conventional oil.[95]

The International Energy Agency (IEA) said in 2010 that production of conventional crude oil had peaked in 2006 at 70 MBBL/d, then flattened at 68 or 69 thereafter.[96][97] Since virtually all economic sectors rely heavily on petroleum, peak oil, if it were to occur, could lead to a "partial or complete failure of markets".[98]

Unconventional Production[edit]

The calculus for peak oil has changed with the introduction of unconventional production methods. In particular, the combination of horizontal drilling and hydraulic fracturing has resulted in a significant increase in production from previously uneconomic plays.[99] Certain rock strata contain hydrocarbons but have low permeability and are not thick from a vertical perspective. Conventional vertical wells would be unable to economically retrieve these hydrocarbons. Horizontal drilling, extending horizontally through the strata, permits the well to access a much greater volume of the strata. Hydraulic fracturing creates greater permeability and increases hydrocarbon flow to the wellbore.

Coal

From Wikipedia, the free encyclopedia

For other uses, see Coal (disambiguation).

Coal

Sedimentary rock

Coal anthracite.jpg

Anthracite coal

Composition

Primary      carbon

Secondary hydrogen,

sulfur,

oxygen,

nitrogen

Bituminous coal

Coal (from the Old English term col, which has meant "mineral of fossilized carbon" since the 13th century)[1] is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure. Coal is composed primarily of carbon along with variable quantities of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.[2]

Throughout history, coal has been used as an energy resource, primarily burned for the production of electricity and/or heat, and is also used for industrial purposes, such as refining metals. A fossil fuel, coal forms when dead plant matter is converted into peat, which in turn is converted into lignite, then sub-bituminous coal, after that bituminous coal, and lastly anthracite. This involves biological and geological processes that take place over a long period. The Energy Information Administration estimates coal reserves at 948×109 short tons (860 Gt).[3] One estimate for resources is 18 000 Gt.[4]

Coal is the largest source of energy for the generation of electricity worldwide, as well as one of the largest worldwide anthropogenic sources of carbon dioxide releases. In 1999, world gross carbon dioxide emissions from coal usage were 8,666 million tonnes of carbon dioxide.[5] In 2011, world gross emissions from coal usage were 14,416 million tonnes.[6] Coal-fired electric power generation emits around 2,000 pounds of carbon dioxide for every megawatt-hour generated, which is almost double the approximately 1100 pounds of carbon dioxide released by a natural gas-fired electric plant per megawatt-hour generated. Because of this higher carbon efficiency of natural gas generation, as the market in the United States has changed to reduce coal and increase natural gas generation, carbon dioxide emissions have fallen. Those measured in the first quarter of 2012 were the lowest of any recorded for the first quarter of any year since 1992.[7] In 2013, the head of the UN climate agency advised that most of the world's coal reserves should be left in the ground to avoid catastrophic global warming.[8]

Coal is extracted from the ground by coal mining, either underground by shaft mining, or at ground level by open pit mining extraction. Since 1983 the world top coal producer has been China.[9] In 2011 China produced 3,520 millions of tonnes of coal – 49.5% of 7,695 millions tonnes world coal production. In 2011 other large producers were United States (993 millions tonnes), India (589), European Union (576) and Australia (416).[9] In 2010 the largest exporters were Australia with 328 million tonnes (27.1% of world coal export) and Indonesia with 316 millions tonnes (26.1%),[10] while the largest importers were Japan with 207 million tonnes (17.5% of world coal import), China with 195 million tonnes (16.6%) and South Korea with 126 million tonnes (10.7%).[11]

Contents  [hide]

1 Formation

2 Types

2.1 Hilt's law

3 Content

4 Early uses as fuel

5 Uses today

5.1 Coal as fuel

5.2 Coking coal and use of coke

5.3 Gasification

5.4 Liquefaction

5.5 Refined coal

5.6 Industrial processes

5.7 Production of chemicals[67]

6 Cultural usage

7 Coal as a traded commodity

8 Environmental effects

9 Bioremediation

10 Economic aspects

11 Energy density and carbon impact

12 Underground fires

13 Production trends

13.1 World coal reserves

13.2 Major coal producers

13.3 Major coal consumers

13.4 Major coal exporters

13.5 Major coal importers

14 See also

15 References

16 Further reading

17 External links

Formation[edit]

Example chemical structure of coal

At various times in the geologic past, the Earth had dense forests in low-lying wetland areas. Due to natural processes such as flooding, these forests were buried underneath soil. As more and more soil deposited over them, they were compressed. The temperature also rose as they sank deeper and deeper. As the process continued the plant matter was protected from biodegradation and oxidation, usually by mud or acidic water. This trapped the carbon in immense peat bogs that were eventually covered and deeply buried by sediments. Under high pressure and high temperature, dead vegetation was slowly converted to coal. As coal contains mainly carbon, the conversion of dead vegetation into coal is called carbonization.[12]

The wide, shallow seas of the Carboniferous Period provided ideal conditions for coal formation, although coal is known from most geological periods. The exception is the coal gap in the Permian–Triassic extinction event, where coal is rare. Coal is known from Precambrian strata, which predate land plants — this coal is presumed to have originated from residues of algae.[13][14]

Types[edit]

Coastal exposure of the Point Aconi Seam (Nova Scotia)

As geological processes apply pressure to dead biotic material over time, under suitable conditions it is transformed successively into:

Peat, considered to be a precursor of coal, has industrial importance as a fuel in some regions, for example, Ireland and Finland. In its dehydrated form, peat is a highly effective absorbent for fuel and oil spills on land and water. It is also used as a conditioner for soil to make it more able to retain and slowly release water.

Lignite, or brown coal, is the lowest rank of coal and used almost exclusively as fuel for electric power generation. Jet, a compact form of lignite, is sometimes polished and has been used as an ornamental stone since the Upper Palaeolithic.

Sub-bituminous coal, whose properties range from those of lignite to those of bituminous coal, is used primarily as fuel for steam-electric power generation and is an important source of light aromatic hydrocarbons for the chemical synthesis industry.

Bituminous coal is a dense sedimentary rock, usually black, but sometimes dark brown, often with well-defined bands of bright and dull material; it is used primarily as fuel in steam-electric power generation, with substantial quantities used for heat and power applications in manufacturing and to make coke.

"Steam coal" is a grade between bituminous coal and anthracite, once widely used as a fuel for steam locomotives. In this specialized use, it is sometimes known as "sea-coal" in the US.[15] Small steam coal (dry small steam nuts or DSSN) was used as a fuel for domestic water heating.

Anthracite, the highest rank of coal, is a harder, glossy black coal used primarily for residential and commercial space heating. It may be divided further into metamorphically altered bituminous coal and "petrified oil", as from the deposits in Pennsylvania.

Graphite, technically the highest rank, is difficult to ignite and is not commonly used as fuel — it is mostly used in pencils and, when powdered, as a lubricant.

The classification of coal is generally based on the content of volatiles. However, the exact classification varies between countries. According to the German classification, coal is classified as follows:[16]

German Classification English Designation    Volatiles %          C Carbon %        H Hydrogen %       O Oxygen %       S Sulfur % Heat content kJ/kg

Braunkohle         Lignite (brown coal)     45–65        60–75        6.0–5.8      34-17          0.5-3 <28,470

Flammkohle        Flame coal          40-45         75-82         6.0-5.8       >9.8  ~1     <32,870

Gasflammkohle  Gas flame coal   35-40         82-85         5.8-5.6       9.8-7.3       ~1          <33,910

Gaskohle   Gas coal    28-35         85-87.5      5.6-5.0       7.3-4.5       ~1     <34,960

Fettkohle   Fat coal     19-28         87.5-89.5   5.0-4.5       4.5-3.2       ~1     <35,380

Esskohle   Forge coal 14-19         89.5-90.5   4.5-4.0       3.2-2.8       ~1     <35,380

Magerkohle         Nonbaking coal  10-14         90.5-91.5   4.0-3.75     2.8-3.5       ~1          35,380

Anthrazit    Anthracite  7-12  >91.5         <3.75         <2.5  ~1     <35,300

Percent by weight

The middle six grades in the table represent a progressive transition from the English-language sub-bituminous to bituminous coal, while the last class is an approximate equivalent to anthracite, but more inclusive (US anthracite has < 6% volatiles).

Cannel coal (sometimes called "candle coal") is a variety of fine-grained, high-rank coal with significant hydrogen content. It consists primarily of "exinite" macerals, now termed "liptinite".

Hilt's law[edit]

Main article: Hilt's law

Hilt's law is a geological term that states that, in a small area, the deeper the coal, the higher its rank (grade). The law holds true if the thermal gradient is entirely vertical, but metamorphism may cause lateral changes of rank, irrespective of depth.

Content[edit]

Average content

Substance Content

Mercury (Hg)      0.10±0.01 ppm[17]

Arsenic (As)        1.4 – 71 ppm[18]

Selenium (Se)    3 ppm[19]

Early uses as fuel[edit]

Further information: History of coal mining

Chinese coal miners in an illustration of the Tiangong Kaiwu encyclopedia, published in 1637

Coal from the Fushun mine in northeastern China was used to smelt copper as early as 1000 BCE.[20] Marco Polo, the Italian who traveled to China in the 13th century, described coal as "black stones ... which burn like logs", and said coal was so plentiful, people could take three hot baths a week.[21] In Europe, the earliest reference to the use of coal as fuel is from the geological treatise On stones (Lap. 16) by the Greek scientist Theophrastus (circa 371–287 BC):[22][23]

Among the materials that are dug because they are useful, those known as anthrakes [coals] are made of earth, and, once set on fire, they burn like charcoal. They are found in Liguria ... and in Elis as one approaches Olympia by the mountain road; and they are used by those who work in metals.

—Theophrastus, On Stones (16) translation

Outcrop coal was used in Britain during the Bronze Age (3000–2000 BC), where it has been detected as forming part of the composition of funeral pyres.[24][25] In Roman Britain, with the exception of two modern fields, "the Romans were exploiting coals in all the major coalfields in England and Wales by the end of the second century AD".[26] Evidence of trade in coal (dated to about AD 200) has been found at the Roman settlement at Heronbridge, near Chester, and in the Fenlands of East Anglia, where coal from the Midlands was transported via the Car Dyke for use in drying grain.[27] Coal cinders have been found in the hearths of villas and Roman forts, particularly in Northumberland, dated to around AD 400. In the west of England, contemporary writers described the wonder of a permanent brazier of coal on the altar of Minerva at Aquae Sulis (modern day Bath), although in fact easily accessible surface coal from what became the Somerset coalfield was in common use in quite lowly dwellings locally.[28] Evidence of coal's use for iron-working in the city during the Roman period has been found.[29] In Eschweiler, Rhineland, deposits of bituminous coal were used by the Romans for the smelting of iron ore.[26]

Coal miner in Britain, 1942

No evidence exists of the product being of great importance in Britain before the High Middle Ages, after about AD 1000.[30] Mineral coal came to be referred to as "seacoal" in the 13th century; the wharf where the material arrived in London was known as Seacoal Lane, so identified in a charter of King Henry III granted in 1253.[31] Initially, the name was given because much coal was found on the shore, having fallen from the exposed coal seams on cliffs above or washed out of underwater coal outcrops,[30] but by the time of Henry VIII, it was understood to derive from the way it was carried to London by sea.[32] In 1257–59, coal from Newcastle upon Tyne was shipped to London for the smiths and lime-burners building Westminster Abbey.[30] Seacoal Lane and Newcastle Lane, where coal was unloaded at wharves along the River Fleet, are still in existence.[33] (See Industrial processes below for modern uses of the term.)

These easily accessible sources had largely become exhausted (or could not meet the growing demand) by the 13th century, when underground extraction by shaft mining or adits was developed.[24] The alternative name was "pitcoal", because it came from mines. It was, however, the development of the Industrial Revolution that led to the large-scale use of coal, as the steam engine took over from the water wheel. In 1700, five-sixths of the world's coal was mined in Britain. Britain would have run out of suitable sites for watermills by the 1830s if coal had not been available as a source of energy.[34] In 1947, there were some 750,000 miners in Britain,[35] but by 2004, this had shrunk to some 5,000 miners working in around 20 collieries.[36]

Uses today[edit]

Castle Gate Power Plant near Helper, Utah, USA

Coal rail cars

Coal as fuel[edit]

Further information: Electricity generation, Clean coal technology, Coal electricity and Global warming

Coal is primarily used as a solid fuel to produce electricity and heat through combustion. World coal consumption was about 7.25 billion tonnes in 2010[37] (7.99 billion short tons) and is expected to increase 48% to 9.05 billion tonnes (9.98 billion short tons) by 2030.[38] China produced 3.47 billion tonnes (3.83 billion short tons) in 2011. India produced about 578 million tonnes (637.1 million short tons) in 2011. 68.7% of China's electricity comes from coal. The USA consumed about 13% of the world total in 2010, i.e. 951 million tonnes (1.05 billion short tons), using 93% of it for generation of electricity.[39] 46% of total power generated in the USA was done using coal.[40]

When coal is used for electricity generation, it is usually pulverized and then combusted (burned) in a furnace with a boiler.[41] The furnace heat converts boiler water to steam, which is then used to spin turbines which turn generators and create electricity.[42] The thermodynamic efficiency of this process has been improved over time; some older coal-fired power stations have thermal efficiencies in the vicinity of 25%[43] whereas the newest supercritical and "ultra-supercritical" steam cycle turbines, operating at temperatures over 600 °C and pressures over 27 MPa (over 3900 psi), can practically achieve thermal efficiencies in excess of 45% (LHV basis) using anthracite fuel,[44][45] or around 43% (LHV basis) even when using lower-grade lignite fuel.[46] Further thermal efficiency improvements are also achievable by improved pre-drying (especially relevant with high-moisture fuel such as lignite or biomass) and cooling technologies.[47]

An alternative approach of using coal for electricity generation with improved efficiency is the integrated gasification combined cycle (IGCC) power plant. Instead of pulverizing the coal and burning it directly as fuel in the steam-generating boiler, the coal can be first gasified (see coal gasification) to create syngas, which is burned in a gas turbine to produce electricity (just like natural gas is burned in a turbine). Hot exhaust gases from the turbine are used to raise steam in a heat recovery steam generator which powers a supplemental steam turbine. Thermal efficiencies of current IGCC power plants range from 39-42%[48] (HHV basis) or ~42-45% (LHV basis) for bituminous coal and assuming utilization of mainstream gasification technologies (Shell, GE Gasifier, CB&I). IGCC power plants outperform conventional pulverized coal-fueled plants in terms of pollutant emissions, and allow for relatively easy carbon capture.

At least 40% of the world's electricity comes from coal,[41][49] and in 2012, about one-third of the United States' electricity came from coal, down from approximately 49% in 2008.[50][51] As of 2012 in the United States, use of coal to generate electricity was declining, as plentiful supplies of natural gas obtained by hydraulic fracturing of tight shale formations became available at low prices.[50]

In Denmark, a net electric efficiency of > 47% has been obtained at the coal-fired Nordjyllandsværket CHP Plant and an overall plant efficiency of up to 91% with cogeneration of electricity and district heating.[52] The multifuel-fired Avedøreværket CHP Plant just outside Copenhagen can achieve a net electric efficiency as high as 49%. The overall plant efficiency with cogeneration of electricity and district heating can reach as much as 94%.[53]

An alternative form of coal combustion is as coal-water slurry fuel (CWS), which was developed in the Soviet Union. CWS significantly reduces emissions, improving the heating value of coal.[citation needed] Other ways to use coal are combined heat and power cogeneration and an MHD topping cycle.

The total known deposits recoverable by current technologies, including highly polluting, low-energy content types of coal (i.e., lignite, bituminous), is sufficient for many years.[quantify] However, consumption is increasing and maximal production could be reached within decades (see world coal reserves, below). On the other hand much may have to be left in the ground to avoid climate change.[54][55]

Coking coal and use of coke[edit]

Main article: Coke (fuel)

Coke oven at a smokeless fuel plant in Wales, United Kingdom

Coke is a solid carbonaceous residue derived from low-ash, low-sulfur bituminous coal from which the volatile constituents are driven off by baking in an oven without oxygen at temperatures as high as 1,000 °C (1,832 °F), so the fixed carbon and residual ash are fused together. Metallurgical coke is used as a fuel and as a reducing agent in smelting iron ore in a blast furnace.[56] The result is pig iron, and is too rich in dissolved carbon, so it must be treated further to make steel. The coking coal should be low in sulfur and phosphorus, so they do not migrate to the metal.

The coke must be strong enough to resist the weight of overburden in the blast furnace, which is why coking coal is so important in making steel using the conventional route. However, the alternative route is direct reduced iron, where any carbonaceous fuel can be used to make sponge or pelletised iron. Coke from coal is grey, hard, and porous and has a heating value of 24.8 million Btu/ton (29.6 MJ/kg). Some cokemaking processes produce valuable byproducts, including coal tar, ammonia, light oils, and coal gas.

Petroleum coke is the solid residue obtained in oil refining, which resembles coke, but contains too many impurities to be useful in metallurgical applications.

Gasification[edit]

Main articles: Coal gasification and Underground coal gasification

Coal gasification can be used to produce syngas, a mixture of carbon monoxide (CO) and hydrogen (H2) gas. Often syngas is used to fire gas turbines to produce electricity, but the versatility of syngas also allows it to be converted into transportation fuels, such as gasoline and diesel, through the Fischer-Tropsch process; alternatively, syngas can be converted into methanol, which can be blended into fuel directly or converted to gasoline via the methanol to gasoline process.[57] Gasification combined with Fischer-Tropsch technology is currently used by the Sasol chemical company of South Africa to make motor vehicle fuels from coal and natural gas. Alternatively, the hydrogen obtained from gasification can be used for various purposes, such as powering a hydrogen economy, making ammonia, or upgrading fossil fuels.

During gasification, the coal is mixed with oxygen and steam while also being heated and pressurized. During the reaction, oxygen and water molecules oxidize the coal into carbon monoxide (CO), while also releasing hydrogen gas (H2). This process has been conducted in both underground coal mines and in the production of town gas.

C (as Coal) + O2 + H2O → H2 + CO

If the refiner wants to produce gasoline, the syngas is collected at this state and routed into a Fischer-Tropsch reaction. If hydrogen is the desired end-product, however, the syngas is fed into the water gas shift reaction, where more hydrogen is liberated.

CO + H2O → CO2 + H2

In the past, coal was converted to make coal gas (town gas), which was piped to customers to burn for illumination, heating, and cooking.

Liquefaction[edit]

Main article: Coal liquefaction

Coal can also be converted into synthetic fuels equivalent to gasoline or diesel by several different direct processes (which do not intrinsically require gasification or indirect conversion).[58] In the direct liquefaction processes, the coal is either hydrogenated or carbonized. Hydrogenation processes are the Bergius process,[59] the SRC-I and SRC-II (Solvent Refined Coal) processes, the NUS Corporation hydrogenation process[60][61] and several other single-stage and two-stage processes.[62] In the process of low-temperature carbonization, coal is coked at temperatures between 360 and 750 °C (680 and 1,380 °F). These temperatures optimize the production of coal tars richer in lighter hydrocarbons than normal coal tar. The coal tar is then further processed into fuels. An overview of coal liquefaction and its future potential is available.[63]

Coal liquefaction methods involve carbon dioxide (CO

2) emissions in the conversion process. If coal liquefaction is done without employing either carbon capture and storage (CCS) technologies or biomass blending, the result is lifecycle greenhouse gas footprints that are generally greater than those released in the extraction and refinement of liquid fuel production from crude oil. If CCS technologies are employed, reductions of 5–12% can be achieved in Coal to Liquid (CTL) plants and up to a 75% reduction is achievable when co-gasifying coal with commercially demonstrated levels of biomass (30% biomass by weight) in coal/biomass-to-liquids plants.[64] For future synthetic fuel projects, carbon dioxide sequestration is proposed to avoid releasing CO

2 into the atmosphere. Sequestration adds to the cost of production.

Refined coal[edit]

Main article: Refined coal

Refined coal is the product of a coal-upgrading technology that removes moisture and certain pollutants from lower-rank coals such as sub-bituminous and lignite (brown) coals. It is one form of several precombustion treatments and processes for coal that alter coal's characteristics before it is burned. The goals of precombustion coal technologies are to increase efficiency and reduce emissions when the coal is burned. Depending on the situation, precombustion technology can be used in place of or as a supplement to postcombustion technologies to control emissions from coal-fueled boilers.

Industrial processes [edit]

Finely ground bituminous coal, known in this application as sea coal, is a constituent of foundry sand. While the molten metal is in the mould, the coal burns slowly, releasing reducing gases at pressure, and so preventing the metal from penetrating the pores of the sand. It is also contained in 'mould wash', a paste or liquid with the same function applied to the mould before casting.[65] Sea coal can be mixed with the clay lining (the "bod") used for the bottom of a cupola furnace. When heated, the coal decomposes and the bod becomes slightly friable, easing the process of breaking open holes for tapping the molten metal.[66]

Production of chemicals[67][edit]

Production of Chemicals from Coal

Coal is an important feedstock in production of a wide range of chemical fertilizers and other chemical products. The main route to these products is coal gasification to produce syngas. Primary chemicals that are produced directly from the syngas include methanol, hydrogen and carbon monoxide, which are the chemical building blocks from which a whole spectrum of derivative chemicals are manufactured, including olefins, acetic acid, formaldehyde, ammonia, urea and others. The versatility of syngas as a precursor to primary chemicals and high-value derivative products provides the option of using relatively inexpensive coal to produce a wide range of valuable commodities.

Historically, production of chemicals from coal has been used since the 1950s and has become established in the market. According to the 2010 Worldwide Gasification Database,[68] a survey of current and planned gasifiers, from 2004 to 2007 chemical production increased its gasification product share from 37% to 45%. From 2008 to 2010, 22% of new gasifier additions were to be for chemical production.

Because the slate of chemical products that can be made via coal gasification can in general also use feedstocks derived from natural gas and petroleum, the chemical industry tends to use whatever feedstocks are most cost-effective. Therefore, interest in using coal tends to increase for higher oil and natural gas prices and during periods of high global economic growth that may strain oil and gas production. Also, production of chemicals from coal is of much higher interest in countries like South Africa, China, India and the United States where there are abundant coal resources. The abundance of coal combined with lack of natural gas resources in China is strong inducement for the coal to chemicals industry pursued there. In the United States, the best example of the industry is Eastman Chemical Company which has been successfully operating a coal-to-chemicals plant at its Kingsport, Tennessee, site since 1983. Similarly, Sasol has built and operated coal-to-chemicals facilities in South Africa.

Coal to chemical processes do require substantial quantities of water. As of 2013 much of the coal to chemical production was in the People's Republic of China[69][70] where environmental regulation and water management[71] was weak.[72]

Cultural usage[edit]

Coal is the official state mineral of Kentucky.[73] and the official state rock of Utah;[74] both U.S. states have a historic link to coal mining.

Some cultures hold that children who misbehave will receive only a lump of coal from Santa Claus for Christmas in their christmas stockings instead of presents.

It is also customary and considered lucky in Scotland and the North of England to give coal as a gift on New Year's Day. This occurs as part of First-Footing and represents warmth for the year to come.

Coal as a traded commodity[edit]

In North America, Central Appalachian coal futures contracts are currently traded on the New York Mercantile Exchange (trading symbol QL). The trading unit is 1,550 short tons (1,410 t) per contract, and is quoted in U.S. dollars and cents per ton. Since coal is the principal fuel for generating electricity in the United States, coal futures contracts provide coal producers and the electric power industry an important tool for hedging and risk management.[75]

In addition to the NYMEX contract, the IntercontinentalExchange (ICE) has European (Rotterdam) and South African (Richards Bay) coal futures available for trading. The trading unit for these contracts is 5,000 tonnes (5,500 short tons), and are also quoted in U.S. dollars and cents per ton.[76]

The price of coal increased from around $30.00 per short ton in 2000 to around $150.00 per short ton as of September 2008. As of October 2008, the price per short ton had declined to $111.50. Prices further declined to $71.25 as of October 2010.[77]

Environmental effects[edit]

Main article: Environmental effects of coal

Aerial photograph of Kingston Fossil Plant coal fly ash slurry spill site taken the day after the event

A number of adverse health,[78] and environmental effects of coal burning exist,[79] especially in power stations, and of coal mining, including:

Coal-fired power plants cause nearly 24,000 premature deaths annually in the United States, including 2,800 from lung cancer.[80] Annual health costs in Europe from use of coal to generate electricity are €42.8 billion, or $55 billion.[81]

Generation of hundreds of millions of tons of waste products, including fly ash, bottom ash, and flue-gas desulfurization sludge, that contain mercury, uranium, thorium, arsenic, and other heavy metals

Acid rain from high sulfur coal

Interference with groundwater and water table levels due to mining

Contamination of land and waterways and destruction of homes from fly ash spills. such as the Kingston Fossil Plant coal fly ash slurry spill

Impact of water use on flows of rivers and consequential impact on other land uses

Dust nuisance

Subsidence above tunnels, sometimes damaging infrastructure

Uncontrollable coal seam fire which may burn for decades or centuries

Coal-fired power plants without effective fly ash capture systems are one of the largest sources of human-caused background radiation exposure.

Coal-fired power plants emit mercury, selenium, and arsenic, which are harmful to human health and the environment.[82]

Release of carbon dioxide, a greenhouse gas, causes climate change and global warming, according to the IPCC and the EPA. Coal is the largest contributor to the human-made increase of CO2 in the atmosphere.[83]

Approximately 75 Tg/S per year of sulfur dioxide (SO2) is released from burning coal. After release, the sulfur dioxide is oxidized to gaseous H2SO2 which scatters solar radiation, hence its increase in the atmosphere exerts a cooling effect on climate that masks some of the warming caused by increased greenhouse gases. Release of SO2 also contributes to the widespread acidification of ecosystems.[84]

Bioremediation[edit]

The white rot fungus C. versicolor can grow on and metabolize naturally occcuring coal.[85] The bacteria Diplococcus has been found to degrade coal, raising its temperature.[86]

Economic aspects[edit]

Coal (by liquefaction technology) is one of the backstop resources that could limit escalation of oil prices and mitigate the effects of transportation energy shortage that will occur under peak oil. This is contingent on liquefaction production capacity becoming large enough to satiate the very large and growing demand for petroleum. Estimates of the cost of producing liquid fuels from coal suggest that domestic U.S. production of fuel from coal becomes cost-competitive with oil priced at around $35 per barrel,[87] with the $35 being the break-even cost. With oil prices as low as around $40 per barrel in the U.S. as of December 2008, liquid coal lost some of its economic allure in the U.S., but will probably be re-vitalized, similar to oil sand projects, with an oil price around $70 per barrel.

In China, due to an increasing need for liquid energy in the transportation sector, coal liquefaction projects were given high priority even during periods of oil prices below $40 per barrel.[88] This is probably because China prefers not to be dependent on foreign oil, instead utilizing its enormous domestic coal reserves. As oil prices were increasing during the first half of 2009, the coal liquefaction projects in China were again boosted, and these projects are profitable with an oil barrel price of $40.[89]

China is the largest producer of coal in the world. It is the world's largest energy consumer, and relies on coal to supply 69% of its energy needs.[90] An estimated 5 million people worked in China's coal-mining industry in 2007.[91]

Coal pollution costs the EU €43 billion each year.[92] Measures to cut air pollution may have beneficial long-term economic impacts for individuals.[93]

Energy density and carbon impact[edit]

See also: Energy value of coal

The energy density of coal, i.e. its heating value, is roughly 24 megajoules per kilogram[94] (approximately 6.7 kilowatt-hours per kg). For a coal power plant with a 40% efficiency, it takes an estimated 325 kg (717 lb) of coal to power a 100 W lightbulb for one year.[95]

As of 2006, the average efficiency of electricity-generating power stations was 31%; in 2002, coal represented about 23% of total global energy supply, an equivalent of 3.4 billion tonnes of coal, of which 2.8 billion tonnes were used for electricity generation.[96]

The US Energy Information Agency's 1999 report on CO2 emissions for energy generation quotes an emission factor of 0.963 kg CO2/kWh for coal power, compared to 0.881 kg CO2/kWh (oil), or 0.569 kg CO2/kWh (natural gas).[97]

Underground fires[edit]

Main article: Coal seam fire

Thousands of coal fires are burning around the world.[98] Those burning underground can be difficult to locate and many cannot be extinguished. Fires can cause the ground above to subside, their combustion gases are dangerous to life, and breaking out to the surface can initiate surface wildfires. Coal seams can be set on fire by spontaneous combustion or contact with a mine fire or surface fire. Lightning strikes are an important source of ignition. The coal continues to burn slowly back into the seam until oxygen (air) can no longer reach the flame front. A grass fire in a coal area can set dozens of coal seams on fire.[99][100] Coal fires in China burn an estimated 120 million tons of coal a year, emitting 360 million metric tons of CO2, amounting to 2–3% of the annual worldwide production of CO2 from fossil fuels.[101][102] In Centralia, Pennsylvania (a borough located in the Coal Region of the United States), an exposed vein of anthracite ignited in 1962 due to a trash fire in the borough landfill, located in an abandoned anthracite strip mine pit. Attempts to extinguish the fire were unsuccessful, and it continues to burn underground to this day. The Australian Burning Mountain was originally believed to be a volcano, but the smoke and ash comes from a coal fire that has been burning for some 6,000 years.[103]

At Kuh i Malik in Yagnob Valley, Tajikistan, coal deposits have been burning for thousands of years, creating vast underground labyrinths full of unique minerals, some of them very beautiful. Local people once used this method to mine ammoniac. This place has been well-known since the time of Herodotus, but European geographers misinterpreted the Ancient Greek descriptions as the evidence of active volcanism in Turkestan (up to the 19th century, when the Russian army invaded the area).[citation needed]

The reddish siltstone rock that caps many ridges and buttes in the Powder River Basin in Wyoming and in western North Dakota is called porcelanite, which resembles the coal burning waste "clinker" or volcanic "scoria".[104] Clinker is rock that has been fused by the natural burning of coal. In the Powder River Basin approximately 27 to 54 billion tons of coal burned within the past three million years.[105] Wild coal fires in the area were reported by the Lewis and Clark Expedition as well as explorers and settlers in the area.[106]

Production trends[edit]

Continental United States coal regions

Coal output in 2005

A coal mine in Wyoming, United States. The United States has the world's largest coal reserves.

In 2006, China was the top producer of coal with 38% share followed by the United States and India, according to the British Geological Survey. As of 2012 coal production in the United States was falling at the rate of 7% annually[107] with many power plants using coal shut down or converted to natural gas; however, some of the reduced domestic demand was taken up by increased exports[108] with five coal export terminals being proposed in the Pacific Northwest to export coal from the Powder River Basin to China and other Asian markets;[109] however, as of 2013, environmental opposition was increasing.[110] High-sulfur coal mined in Illinois which was unsaleable in the United States found a ready market in Asia as exports reached 13 million tons in 2012.[111]

World coal reserves[edit]

The 948 billion short tons of recoverable coal reserves estimated by the Energy Information Administration are equal to about 4,196 BBOE (billion barrels of oil equivalent).[3] The amount of coal burned during 2007 was estimated at 7.075 billion short tons, or 133.179 quadrillion BTU's.[112] This is an average of 18.8 million BTU per short ton. In terms of heat content, this is about 57,000,000 barrels (9,100,000 m3) of oil equivalent per day. By comparison in 2007, natural gas provided 51,000,000 barrels (8,100,000 m3) of oil equivalent per day, while oil provided 85,800,000 barrels (13,640,000 m3) per day.

British Petroleum, in its 2007 report, estimated at 2006 end that there were 147 years reserves-to-production ratio based on proven coal reserves worldwide. This figure only includes reserves classified as "proven"; exploration drilling programs by mining companies, particularly in under-explored areas, are continually providing new reserves. In many cases, companies are aware of coal deposits that have not been sufficiently drilled to qualify as "proven". However, some nations haven't updated their information and assume reserves remain at the same levels even with withdrawals. Energy Watch Group predicted in 2007 that peak coal production may occur sometime around 2025, depending on future coal production rates.[113]

Of the three fossil fuels, coal has the most widely distributed reserves; coal is mined in over 100 countries, and on all continents except Antarctica. The largest reserves are found in the United States, Russia, China, Australia and India. Note the table below.

Proved recoverable coal reserves at end-2008 (million tons (teragrams))[114]

Country      Anthracite & Bituminous       SubBituminous   Lignite        Total Percentage of World Total

 United States     108,501     98,618       30,176       237,295     22.6

 Russia      49,088       97,472       10,450       157,010     14.4

 China        62,200       33,700       18,600       114,500     12.6

 Australia   37,100       2,100         37,200       76,400       8.9

 India          56,100       0       4,500         60,600       7.0

 Germany  99     0       40,600       40,699       4.7

 Ukraine     15,351       16,577       1,945         33,873       3.9

 Kazakhstan        21,500       0       12,100       33,600       3.9

 South Africa       30,156       0       0       30,156       3.5

 Serbia       9       361   13,400       13,770       1.6

 Colombia  6,366         380   0       6,746         0.8

 Canada    3,474         872   2,236         6,528         0.8

 Poland      4,338         0       1,371         5,709         0.7

 Indonesia 1,520         2,904         1,105         5,529         0.6

 Brazil         0       4,559         0       4,559         0.5

 Greece     0       0       3,020         3,020         0.4

 Bosnia and Herzegovina     484   0       2,369         2,853         0.3

 Mongolia  1,170         0       1,350         2,520         0.3

 Bulgaria    2       190   2,174         2,366         0.3

 Pakistan   0       166   1,904         2,070         0.3

 Turkey      529   0       1,814         2,343         0.3

 Uzbekistan         47     0       1,853         1,900         0.2

 Hungary   13     439   1,208         1,660         0.2

 Thailand   0       0       1,239         1,239         0.1

 Mexico      860   300   51     1,211         0.1

 Iran  1,203         0       0       1,203         0.1

 Czech Republic 192   0       908   1,100         0.1

 Kyrgyzstan         0       0       812   812   0.1

 Albania     0       0       794   794   0.1

 North Korea       300   300   0       600   0.1

 New Zealand     33     205   333-7,000  571–15,000[115]         0.1

 Spain        200   300   30     530   0.1

 Laos          4       0       499   503   0.1

 Zimbabwe          502   0       0       502   0.1

 Argentina  0       0       500   500   0.1

All others   3,421         1,346         846   5,613         0.7

World Total         404,762     260,789     195,387     860,938     100

Major coal producers[edit]

See also: List of countries by coal production

The reserve life is an estimate based only on current production levels and proved reserves level for the countries shown, and makes no assumptions of future production or even current production trends. Countries with annual production higher than 100 million tonnes are shown. For comparison, data for the European Union is also shown. Shares are based on data expressed in tonnes oil equivalent.

Production of Coal by Country and year (million tonnes) [9]

Country      2003 2004 2005 2006 2007 2008 2009 2010 2011 Share         Reserve Life (years)

 China        1834.9       2122.6       2349.5       2528.6       2691.6       2802.0       2973.0          3235.0       3520.0       49.5%        35

 United States     972.3         1008.9       1026.5       1054.8       1040.2       1063.0          975.2         983.7         992.8         14.1%        239

 India          375.4         407.7         428.4         449.2         478.4         515.9         556.0          573.8         588.5         5.6% 103

 European Union         637.2         627.6         607.4         595.1         592.3         563.6          538.4         535.7         576.1         4.2% 97

 Australia   350.4         364.3         375.4         382.2         392.7         399.2         413.2          424.0         415.5         5.8% 184

 Russia      276.7         281.7         298.3         309.9         313.5         328.6         301.3          321.6         333.5         4.0% 471

 Indonesia 114.3         132.4         152.7         193.8         216.9         240.2         256.2          275.2         324.9         5.1% 17

 South Africa       237.9         243.4         244.4         244.8         247.7         252.6          250.6         254.3         255.1         3.6% 118

 Germany  204.9         207.8         202.8         197.1         201.9         192.4         183.7          182.3         188.6         1.1% 216

 Poland      163.8         162.4         159.5         156.1         145.9         144.0         135.2          133.2         139.2         1.4% 41

 Kazakhstan        84.9  86.9  86.6  96.2  97.8  111.1         100.9         110.9         115.9          1.5% 290

World Total         5,301.3      5,716.0      6,035.3      6,342.0      6,573.3      6,795.0          6,880.8      7,254.6      7,695.4      100%         112

Major coal consumers[edit]

Countries with annual consumption higher than 20 million tonnes are shown.

Consumption of Coal by Country and year (million short tons)[116]

Country      2008 2009 2010 2011 Share

 China        2,966         3,188         3,695         4,053         50.7%

 United States     1,121         997   1,048         1,003         12.5%

 India          641   705   722   788   9.9%

 Russia      250   204   256   262   3.3%

 Germany  268   248   256   256   3.3%

 South Africa       215   204   206   210   2.6%

 Japan       204   181   206   202   2.5%

 Poland      149   151   149   162   2.0%

World Total         7,327         7,318         7,994         N/A   100%

Major coal exporters[edit]

Countries with annual gross export higher than 10 million tonnes are shown. In terms of net export the largest exporters are still Australia (328.1 millions tonnes), Indonesia (316.2) and Russia (100.2).

Exports of Coal by Country and year (million short tons)[10][117][118]

Country      2003 2004 2005 2006 2007 2008 2009 2010 Share

 Australia   238.1         247.6         255.0         255.0         268.5         278.0         288.5          328.1         27.1%

 Indonesia 107.8         131.4         142.0         192.2         221.9         228.2         261.4          316.2         26.1%

 Russia      41.0  55.7  98.6  103.4         112.2         115.4         130.9         122.1          10.1%

 United States     43.0  48.0  51.7  51.2  60.6  83.5  60.4  83.2  6.9%

 South Africa       78.7  74.9  78.8  75.8  72.6  68.2  73.8  76.7  6.3%

 Colombia  50.4  56.4  59.2  68.3  74.5  74.7  75.7  76.4  6.3%

 Canada    27.7  28.8  31.2  31.2  33.4  36.5  31.9  36.9  3.0%

 Kazakhstan        30.3  27.4  28.3  30.5  32.8  47.6  33.0  36.3  3.0%

 Vietnam    6.9    11.7  19.8  23.5  35.1  21.3  28.2  24.7  2.0%

 China        103.4         95.5  93.1  85.6  75.4  68.8  25.2  22.7  1.9%

 Mongolia  0.5    1.7    2.3    2.5    3.4    4.4    7.7    18.3  1.5%

 Poland      28.0  27.5  26.5  25.4  20.1  16.1  14.6  18.1  1.5%

Total 713.9         764.0         936.0         1,000.6      1,073.4      1,087.3      1,090.8          1,212.8      100%

Major coal importers[edit]

Countries with annual gross import higher than 20 million tonnes are shown. In terms of net import the largest importers are still Japan (206.0 millions tonnes), China (172.4) and South Korea (125.8).[119]

Imports of Coal by Country and year (million short tons)[11]

Country      2006 2007 2008 2009 2010 Share

 Japan       199.7         209.0         206.0         182.1         206.7         17.5%

 China        42.0  56.2  44.5  151.9         195.1         16.6%

 South Korea      84.1  94.1  107.1         109.9         125.8         10.7%

 India          52.7  29.6  70.9  76.7  101.6         8.6%

 Taiwan      69.1  72.5  70.9  64.6  71.1  6.0%

 Germany  50.6  56.2  55.7  45.9  55.1  4.7%

 Turkey      22.9  25.8  21.7  22.7  30.0  2.5%

 United Kingdom          56.8  48.9  49.2  42.2  29.3  2.5%

 Italy  27.9  28.0  27.9  20.9  23.7  1.9%

 Netherlands       25.7  29.3  23.5  22.1  22.8  1.9%

 Russia      28.8  26.3  34.6  26.8  21.8  1.9%

 France      24.1  22.1  24.9  18.3  20.8  1.8%

 United States     40.3  38.8  37.8  23.1  20.6  1.8%

Total 991.8         1,056.5      1,063.2      1,039.8      1,178.1      100%

[show] v t e

Lists of countries by energy rankings

Compressed natural gas

From Wikipedia, the free encyclopedia

"CNG" redirects here. For other uses, see CNG (disambiguation).

Blue diamond symbol used on CNG-powered vehicles in North America

Green bordered white diamond symbol used on CNG-powered vehicles in China

A CNG powered high-floor Neoplan AN440A, operated by ABQ RIDE in Albuquerque, New Mexico.

Compressed natural gas (CNG) (Methane stored at high pressure) can be used in place of gasoline (petrol), Diesel fuel and propane/LPG. CNG combustion produces fewer undesirable gases than the fuels mentioned above. It is safer than other fuels in the event of a spill, because natural gas is lighter than air and disperses quickly when released. CNG may be found above oil deposits, or may be collected from landfills or wastewater treatment plants where it is known as biogas.

CNG is made by compressing natural gas (which is mainly composed of methane, CH4), to less than 1 percent of the volume it occupies at standard atmospheric pressure. It is stored and distributed in hard containers at a pressure of 20–25 MPa (2,900–3,600 psi), usually in cylindrical or spherical shapes.

CNG is used in traditional gasoline/internal combustion engine automobiles that have been modified or in vehicles which were manufactured for CNG use, either alone ('dedicated'), with a segregated gasoline system to extend range (dual fuel) or in conjunction with another fuel such as diesel (bi-fuel). Natural gas vehicles are increasingly used in Iran, the Asia-Pacific region (especially Pakistan[1] and the Indian capital of Delhi), and other large cities like Ahmedabad, Mumbai, Kolkata, Chennai—as well as cities such as Lucknow, Kanpur, etc. Its use is also increasing in South America, Europe and North America because of rising gasoline prices.[2] In response to high fuel prices and environmental concerns, CNG is starting to be used also in tuk-tuks and pickup trucks, transit and school buses, and trains.

The cost and placement of fuel storage tanks is the major barrier to wider/quicker adoption of CNG as a fuel. It is also why municipal government, public transportation vehicles were the most visible early adopters of it, as they can more quickly amortize the money invested in the new (and usually cheaper) fuel. In spite of these circumstances, the number of vehicles in the world using CNG has grown steadily (30 percent per year).[3] Now, as a result of industry's steady growing, the cost of such fuel storage tanks have been brought down to a much acceptable level. Especially for the CNG Type 1 and Type 2 tanks, many countries are able to make reliable and cost effective tanks for conversion need.[4]

CNG's volumetric energy density is estimated to be 42 percent that of liquefied natural gas (because it is not liquefied), and 25 percent that of diesel fuel.[5]

Contents  [hide]

1 Uses

1.1 Cars

1.2 Locomotives

2 Drawbacks

3 Codes and standards

4 Comparison with other natural gas fuels

5 Worldwide

5.1 South America

5.2 Asia

5.3 Africa

5.4 Europe

5.5 North America

5.5.1 Canada

5.5.2 United States

5.6 Oceania

6 Deployments

7 DNG

8 See also

9 References

10 External links

Uses[edit]

Cars[edit]

CNG pumps at a Brazilian gasoline fueling station

Main article: Natural gas vehicle

Worldwide, there were 14.8 million natural gas vehicles by 2011, led by Iran with 2.86 million, Pakistan (2.85 million), Argentina (2.07 million), Brazil (1.7 million) and India (1.1 million).[6] with the Asia-Pacific region leading with 5.7 million NGVs, followed by Latin America with almost four million vehicles.[2]

Several manufacturers (Fiat, Opel/General Motors, Peugeot, Volkswagen, Toyota, Honda and others) sell bi-fuel cars. In 2006, Fiat introduced the Siena Tetrafuel in the Brazilian market, equipped with a 1.4L FIRE engine that runs on E100, E25 (Standard Brazilian Gasoline), Gasoline and CNG.

Any existing gasoline vehicle can be converted to a dual-fuel (gasoline/CNG) vehicle. Authorized shops can do the retrofitting and involves installing a CNG cylinder, plumbing, a CNG injection system and the electronics. The cost of installing a CNG conversion kit[7] can often reach $8,000 on passenger cars and light trucks and is usually reserved for vehicles that travel many miles each year.

Locomotives[edit]

CNG locomotives are operated by several railroads. The Napa Valley Wine Train successfully retrofit a diesel locomotive to run on compressed natural gas before 2002.[8] This converted locomotive was upgraded to utilize a computer controlled fuel injection system in May 2008, and is now the Napa Valley Wine Train's primary locomotive.[9] Ferrocarril Central Andino in Peru, has run a CNG locomotive on a freight line since 2005.[10] CNG locomotives are usually diesel locomotives that have been converted to use compressed natural gas generators instead of diesel generators to generate the electricity that drives the traction motors. Some CNG locomotives are able to fire their cylinders only when there is a demand for power, which, theoretically, gives them a higher fuel efficiency than conventional diesel engines. CNG is also cheaper than petrol or diesel.

* Increased life of lubricating oils, as CNG does not contaminate and dilute the crankcase oil.

Being a gaseous fuel, CNG mixes easily and evenly in air.

CNG is less likely to ignite on hot surfaces, since it has a high auto-ignition temperature (540 °C), and a narrow range (5–15 percent) of flammability.[11]

Less pollution and more efficiency: CNG emits significantly fewer pollutants (e.g., carbon dioxide (CO

2), unburned hydrocarbons (UHC), carbon monoxide (CO), nitrogen oxides (NOx), sulfur oxides (SOx) and PM (particulate matter) than petrol. For example, an engine running on petrol for 100 km emits 22 kilograms of CO

2, while covering the same distance on CNG emits only 16.3 kilograms of CO

2.[12]

CNG fuel system are sealed.

Carbon monoxide emissions are reduced even further. Due to lower carbon dioxide and nitrogen oxides emissions, switching to CNG can help mitigate greenhouse gas emissions.[11] The ability of CNG to reduce greenhouse gas emissions over the entire fuel lifecycle will depend on the source of the natural gas and the fuel it is replacing.

The lifecycle greenhouse gas emissions for CNG compressed from California's pipeline natural gas is given a value of 67.70 grams of CO

2-equivalent per megajoule (gCO2e/MJ) by CARB (the California Air Resources Board), approximately 28 percent lower than the average gasoline fuel in that market (95.86 gCO2e/MJ).

CNG produced from landfill biogas was found by CARB to have the lowest greenhouse gas emissions of any fuel analyzed, with a value of 11.26 gCO2e/MJ (more than 88 percent lower than conventional gasoline) in the low-carbon fuel standard that went into effect on January 12, 2010.[13]

CNG-powered vehicles are considered to be safer than gasoline-powered vehicles.[14][15][16]

Drawbacks[edit]

Compressed natural gas vehicles require a greater amount of space for fuel storage than conventional gasoline powered vehicles. Since it is a compressed gas, rather than a liquid like gasoline, CNG takes up more space for each GGE (gasoline gallon equivalent). Therefore, the tanks used to store the CNG usually take up additional space in the trunk of a car or bed of a pickup truck which runs on CNG. This problem is solved in factory-built CNG vehicles that install the tanks under the body of the vehicle, leaving the trunk free (e.g., Fiat Multipla, New Fiat Panda, Volkswagen Touran Ecofuel, Volkswagen Caddy Ecofuel, Chevy Taxi - which sold in countries such as Peru). Another option is installation on roof (typical on buses), requiring, however, solution of structural strength issues.

Codes and standards[edit]

The lack of harmonized codes and standards across international jurisdictions is an additional barrier to NGV market penetration.[17] The International Organization for Standardization has an active technical committee working on a standard for natural gas fuelling stations for vehicles.[18]

Despite the lack of harmonized international codes, natural gas vehicles have an excellent global safety record. Existing international standards include ISO 14469-2:2007 which applies to CNG vehicle nozzles and receptacle[19] and ISO 15500-9:2012 specifies tests and requirements for the pressure regulator.[20]

NFPA-52 covers natural gas vehicle safety standards in the US.

Comparison with other natural gas fuels[edit]

Compressed natural gas is often confused with LNG (liquefied natural gas). While both are stored forms of natural gas, the key difference is that CNG is gas that is stored (as a gas) at high pressure, while LNG is stored at very low temperature, becoming liquid in the process. CNG has a lower cost of production and storage compared to LNG as it does not require an expensive cooling process and cryogenic tanks. CNG requires a much larger volume to store the same mass of gasoline or petrol and the use of very high pressures (3000 to 4000 psi, or 205 to 275 bar). As a consequence of this, LNG is often used for transporting natural gas over large distances, in ships, trains or pipelines, and the gas is then converted into CNG before distribution to the end user.

CNG is being experimentally stored at lower pressure in a form known as an ANG (adsorbed natural gas) tank, at 35 bar (500 psi, the pressure of gas in natural gas pipelines) in various sponge like materials, such as activated carbon[21] and MOFs (metal-organic frameworks).[22] The fuel is stored at similar or greater energy density than CNG. This means that vehicles can be refueled from the natural gas network without extra gas compression, the fuel tanks can be slimmed down and made of lighter, weaker materials.

Compressed natural gas is sometimes mixed with hydrogen (HCNG) which increases the H/C ratio (heat capacity ratio) of the fuel and gives it a flame speed about eight times higher than CNG.[23]

Worldwide[edit]

Iran, Pakistan, Argentina, Brazil and India have the highest number of CNG run vehicles in the world.[6]

Top ten countries

with the largest NGV vehicle fleets - 2013[24][25]

(millions)

Rank Country      Registered

fleet  Rank Country      Registered

fleet

1       Iran  3.50  6       India          1.50

2       Pakistan   2.79  7       Italy  0.82

3       Argentina  2.28  8       Colombia  0.46

4       Brazil         1.75  9       Uzbekistan         0.45

5       China        1.58  10     Thailand   0.42

World Total = 18.09 million NGV vehicles

South America[edit]

CNG station in Rosario, Argentina.

CNG vehicles are commonly used in South America, where these vehicles are mainly used as taxicabs in main cities of Argentina and Brazil.[26] Normally, standard gasoline vehicles are retrofitted in specialized shops, which involve installing the gas cylinder in the trunk and the CNG injection system and electronics. Argentina and Brazil are the two countries with the largest fleets of CNG vehicles,[26] with a combined total fleet of more than 3.4 million vehicles by 2009.[2] Conversion has been facilitated by a substantial price differential with liquid fuels, locally produced conversion equipment and a growing CNG-delivery infrastructure.

As of 2009 Argentina had 1,807,186 NGV's with 1,851 refueling stations across the nation,[2] or 15 percent of all vehicles;[26] and Brazil had 1,632,101 vehicles and 1,704 refueling stations,[2] with a higher concentration in the cities of Rio de Janeiro and São Paulo.[26][27]

Colombia had an NGV fleet of 300,000 vehicles, and 460 refueling stations, as of 2009.[2] Bolivia has increased its fleet from 10,000 in 2003 to 121,908 units in 2009, with 128 refueling stations.[2] Peru had 81,024 NGVs and 94 fueling stations as 2009,[2] but that number is expected to skyrocket as Peru sits on South America's largest gas reserves.[26] In Peru several factory-built NGVs have the tanks installed under the body of the vehicle, leaving the trunk free. Among the models built with this feature are the Fiat Multipla, the newFiat Panda, the Volkswagen Touran Ecofuel, the Volkswagen Caddy Ecofuel and the Chevy Taxi. Other countries with significant NGV fleets are Venezuela (15,000) and Chile (8,064) as of 2009.[2]

Asia[edit]

A CNG powered Volvo B10BLE bus, operated by SBS Transit in Singapore.

A CNG powered Hino bus, operated by BMTA in Thailand.

In Singapore, CNG is increasingly being used by public transport vehicles like buses and taxis, as well as goods vehicles. However, according to Channel NewsAsia on April 18, 2008, more owners of private cars in this country are converting their petrol-driven vehicles to also run on CNG – motivated no doubt by rising petrol prices. The initial cost of converting a regular vehicle to dual fuel at the German conversion workshop of C. Melchers, for example, is around S$3,800 (US$2,500); with the promise of real cost-savings that dual-fuel vehicles bring over the long term.

Singapore currently has five operating filling stations for natural gas. SembCorp Gas Pte Ltd. runs the station on Jurong Island and, jointly with Singapore Petroleum Company, the filling station at Jalan Buroh. Both these stations are in the western part of the country. Another station on the mainland is in Mandai Link to the north and is operated by SMART Energy. SMART also own a second station on Serangoon North Ave 5 which was set up end of March 2009; The fifth and largest station in the world was opened by the UNION Group in September 2009. This station is recognized by the Guniness World Records as being the largest in the world with 46 refuelling hoses. This station is located in Toh Tuck. The Union Group, which operates 1000 CNG Toyota Wish taxis plan to introduce another three daughter stations and increase the CNG taxi fleet to 8000 units.

CNG scooters (autorickshaws) in Dhaka, Bangladesh.

As a key incentive for using this eco-friendly fuel Singapore has a green vehicle rebate for users of CNG technology. First introduced in January 2001, the GVR grants a 40 percent discount on the OMV (open market value) cost of newly registered green passenger vehicles. This initiative will end at the end of 2012 as the government believes the 'critical mass' of CNG vehicles would then have been built up.

The Ministry of Transport of Myanmar passed a law in 2005 which required that all public transport vehicles - buses, trucks and taxis, be converted to run on CNG. The Government permitted several private companies to handle the conversion of existing diesel and petrol cars, and also to begin importing CNG variants of buses and taxis. Accidents and rumours of accidents, partly fueled by Myanmar's position in local hydrocarbon politics,[28] has discouraged citizens from using CNG vehicles, although now almost every taxi and public bus in Yangon, Myanmar's largest city, run on CNG. CNG stations have been set up around Yangon and other cities, but electricity shortages mean that vehicles may have to queue up for hours to fill their gas containers.[29] The Burmese opposition movements are against the conversion to CNG, as they accuse the companies as being proxies of the junta, and also that the petrodollars earned by the regime would go towards the defense sector, rather than towards improving the infrastructure or welfare of the people.

In Malaysia, the use of CNG was originally introduced for taxicabs and airport limousines during the late-1990s, when new taxis were launched with CNG engines while taxicab operators were encouraged to send in existing taxis for full engine conversions. The practice of using CNG remained largely confined to taxicabs predominantly in the Klang Valley and Penang due to a lack of interest. No incentives were offered for those besides taxicab owners to use CNG engines, while government subsidies on petrol and diesel made conventional road vehicles cheaper to use in the eyes of the consumers. Petronas, Malaysia's state-owned oil company, also monopolises the provision of CNG to road users. As of July 2008, Petronas only operates about 150 CNG refueling stations, most of which are concentrated in the Klang Valley. At the same time, another 50 were expected by the end of 2008.[30]

As fuel subsidies were gradually removed in Malaysia starting June 5, 2008, the subsequent 41 percent price hike on petrol and diesel led to a 500 percent increase in the number of new CNG tanks installed.[31][32] National car maker Proton considered fitting its Waja, Saga and Persona models with CNG kits from Prins Autogassystemen by the end of 2008,[33] while a local distributor of locally assembled Hyundai cars offers new models with CNG kits.[34] Conversion centres, which also benefited from the rush for lower running costs, also perform partial conversions to existing road vehicles, allowing them to run on both petrol or diesel and CNG with a cost varying between RM3,500 to RM5,000 for passenger cars.[31][35]

A CNG powered bus in Beijing. CNG buses in Beijing were introduced in late 1998.

In China, companies such as Sino-Energy are active in expanding the footprint of CNG filling stations in medium-size cities across the interior of the country, where at least two natural gas pipelines are operational.[citation needed]

A CNG powered car being filled in a filling station in Delhi

In India, the Delhi government under the order of Supreme Court in 2004 made it mandatory for all city buses and auto rickshaws to run on CNG with the intention of reducing air pollution.

The Delhi Transport Corporation operates the world's largest fleet of CNG powered buses.[36]

In Pakistan in 2012, the federal government announced plans to gradually phase out CNG over a period of approximately three years given natural gas shortages which have been negatively affecting the manufacturing sector.[37] Aside from limiting electricity generation capacity, gas shortages in Pakistan have also raised the costs of business for key industries including the fertilizer, cement and textile sectors.[38]

Iran has one of the largest fleets of CNG vehicles and CNG distribution networks in the world. There are 1800 CNG fueling stations, with a total of 10352 CNG nozzles. The number of CNG burning vehicles in Iran is about 2.6 million.[39]

Africa[edit]

Egypt is amongst the top 10 countries in CNG adoption, with 128,754 CNG vehicles and 124 CNG fueling stations. Egypt was also the first nation in Africa and the Middle East to open a public CNG fueling station in January 1996.[40]

The vast majority 780000 have been produced as dual fuel vehicles by the auto manufacturer in the last two years, and the remainder have been converted utilizing after market conversion kits in workshops. There are 750 active refueling stations country wide with an additional 660 refueling stations under construction and expected to come on stream. Currently the major problem facing the industry as a whole is the building of refueling stations that is lagging behind dual fuel vehicle production, forcing many to use petrol instead.

Nigeria CNG started with a pilot project in Benin City Edo State in 2010 by Green Gas Limited. Green Gas Limited is a Joint Venture Company of NGC (Nigerian Gas Company Ltd.) & NIPCO PLC. As at October 2012 about seven CNG stations have been built in Benin City Edo State, with about 1,000 cars running on CNG in Benin City Edo state. In Benin City Edo state, major companies such as Coca-cola are using CNG to power their fork-lifts/trucks while Edo City Transport Ltd (ECTS) is also running some of its busus on CNG.

Europe[edit]

CNG powered bus in Italy

In Italy, there are more than 1173 CNG stations.[41] The use of methane for vehicles, started in the 1930s and has continued off and on until today. Since 2008 there have been a large market expansion for natural gas vehicles (CNG and LPG) caused by the rise of gasoline prices and by the need to reduce air pollution emissions.[42] Before 1995 the only way to have a CNG-powered car was by having it retrofitted with an after-market kit. A large producer was Landi Renzo, Tartarini Auto, Prins Autogassystemen, OMVL, BiGAs,... and AeB for electronic parts used by the most part of kit producer. Landi Renzo and Tartarini selling vehicles in Asia and South America. After 1995 bi-fuel cars (gasoline/CNG) became available from several major manufacturers. Currently Fiat, Opel, Volkswagen, Citroën, Renault, Volvo and Mercedes sell various car models and small trucks that are gasoline/CNG powered. Usually CNG parts used by major car manufacturers are actually produced by automotive aftermarket kit manufacturers, e.g. Fiat use Tartarini Auto components, Volkswagen use Teleflex GFI[43] and Landi Renzo components.

In Germany, CNG-generated vehicles are expected to increase to two million units of motor-transport by the year 2020. The cost for CNG fuel is between 1/3 and 1/2 compared to other fossil fuels in Europe.[citation needed] in 2008 there are around 800 CNG stations in Germany[citation needed]

In Portugal there are four CNG refueling stations but three of them do not sell to the public. Only in Braga, can you find public access to CNG refueling—at the local city bus station (TUB).[citation needed]

In Turkey, Ankara has 1050 CNG buses.[44]

In Hungary there are four public CNG refueling stations in the cities Budapest, Szeged, Pécs and Győr. The public transportation company of Szeged runs buses mainly on CNG.[citation needed]

In Bulgaria, there are 96 CNG refueling stations as of July 2011. One can be found in most of Bulgaria's big towns.[45] In the capital Sofia there are 22 CNG stations making it possibly the city with the most publicly available CNG stations in Europe. There are also quite a few in Plovdiv, Ruse, Stara Zagora and Veliko Tarnovo as well as in the towns on the Black Sea – Varna, Burgas, Nesebar and Kavarna. CNG vehicles are becoming more and more popular in the country. The fuel is mostly used by taxi drivers because of its much lower price compared to petrol.

In Macedonia, there is one CNG station located in the capital Skopje, but it is not for public use. Only twenty buses of the local Public Transport Company have been fitted to use a mixture of diesel and CNG. The first commercial CNG station in Skopje is in the advanced stage of development and is expected to start operation in July 2011.[citation needed]

In Serbia, there are four public CNG refuelling stations in the capital Belgrade and in the towns of Pančevo, Kruševac and Čačak.[citation needed]

In Slovenia, there is only one public CNG refuelling station in the capital Ljubljana.[citation needed]

In Croatia, there is only one CNG station situated close to the center of Zagreb.[46] At least 60 CNG buses are in use as a form of a public transport (Zagreb public transport services).

In Estonia, there are two public CNG refuelling stations - one in the country's capital Tallinn and the other one in Tartu.[47] From 2011, Tartu has five Scania manufactured CNG buses operating its inner-city routes.[48]

In Sweden there are currently 90 CNG filling stations available to the public (as compared to about 10 LPG filling stations), primarily located in the southern and western parts of the country as well the Mälardalen region[49] Another 70-80 CNG filling stations are under construction or in a late stage of planning (completions 2009-2010). Several of the planned filling stations are located in the northern parts of the country, which will greatly improve the infrastructure for CNG car users.[50] There are approx. 14,500 CNG vehicles in Sweden (2007), of which approx. 13,500 are passenger cars and the remainder includes buses and trucks.[51] In Stockholm, the public transportation company SL currently operates 50 CNG buses but have a capacity to operate 500.[52] The Swedish government recently prolonged its subsidies for the development of CNG filling stations, from 2009-12-31 to 2010-12-31.[53]

In Spain the EMT Madrid bus service use CNG motors in 672 regular buses. Is rare to see another kind of CNG vehicle, and there are no CNG refueling stations.[citation needed]

As of 2013, there are 47 public CNG filling stations in the Czech Republic, mainly in the big cities.[54] Local bus manufacturers SOR Libchavy and Tedom produce CNG versions of their vehicles, with roof-mounted tanks.

North America[edit]

The Honda Civic GX is factory-built to run on CNG and it is available in several U.S. regional markets.

Buses powered with CNG are common in the United States such as the New Flyer Industries C40LF bus shown here.

Canada[edit]

Natural gas has been used as a motor fuel in Canada for over 20 years.[55] With assistance from federal and provincial research programs, demonstration projects and NGV market deployment programs during the 1980s and 1990s, the population of light-duty NGVs grew to over 35,000 by the early 1990s. This assistance resulted in a significant adoption of natural gas transit buses as well.[56]

The NGV market started to decline after 1995, eventually reaching today’s vehicle population of about 12,000.[56]

This figure includes 150 urban transit buses, 45 school buses, 9,450 light-duty cars and trucks, and 2,400 forklifts and ice-resurfacers. The total fuel use in all NGV markets in Canada was 1.9 PJs (petajoules) in 2007 (or 54.6 million litres of gasoline litres equivalent), down from 2.6 PJs in 1997. Public CNG refuelling stations have declined in quantity from 134 in 1997 to 72 today. There are 22 in British Columbia, 12 in Alberta, 10 in Saskatchewan, 27 in Ontario and two in Québec. There are only 12 private fleet stations.[17]

Canadian industry has developed CNG-fueled truck and bus engines, CNG-fueled transit buses, and light trucks and taxis.

Fuelmaker Corporation of Toronto, the Honda-owned manufacturer of CNG auto refueling units, was forced into bankruptcy by parent Honda USA for an unspecified reason in 2009.[57] The various assets of Fuelmaker were subsequently acquired by Fuel Systems Corporation of Santa Ana, California.

United States[edit]

Similar to Canada, the United States has implemented various NGV initiatives and programs since 1980, but has had limited success in sustaining the market. There were 105,000 NGVs in operation in 2000; this figure peaked at 121,000 in 2004, and decreased to 110,000 in 2009.[58]

In the United States, federal tax credits are available for buying a new CNG vehicle. Use of CNG varies from state to state; only 34 states have at least one CNG fueling site.[59]

In Athens, Ala., the city and its Gas Department installed a public CNG station on the Interstate 65 Corridor, making it the only public CNG station between Birmingham and Nashville as of February 2014. The city's larger fleet vehicles such as garbage trucks also use this public station for fueling. The city also has two slow-fill non-public CNG stations for its fleet. Athens has added CNG/gasoline Tahoes for police and fire, a CNG Honda Civic, CNG Heil garbage trucks, and CNG/gasoline Dodge pickup trucks to its fleet.

In California, CNG is used extensively in local city and county fleets, as well as public transportation (city/school buses). There are 90 public fueling stations in southern California alone, and travel from San Diego so the Bay Area to Las Vegas and Utah is routine with the advent of online station maps such as www.cngprices.com. Compressed natural gas is typically available for 30-60 percent less than the cost of gasoline in much of California.

The 28 buses running the Gwinnett County Transit local routes run on 100 percent CNG. Additionally, about half of the Georgia Regional Transportation Authority express fleet, which runs and refuels out of the Gwinnett County Transit facility, uses CNG.[60]

The Massachusetts Bay Transportation Authority was running 360 CNG buses as early as in 2007, and is the largest user in the state.[61]

The Metropolitan Transportation Authority (MTA) of New York City currently has over 900 buses powered by compressed natural gas with CNG bus depots located in Brooklyn, The Bronx and Queens.

The Nassau Inter-County Express (or NICE Bus) runs a 100% Orion CNG-fueled bus fleet for fixed route service consisting of 360 buses for service in Nassau County, parts of Queens, New York, and the western sections of Suffolk County.

The City of Harrisburg, Pennsylvania has switched some of the city's vehicles to compressed natural gas in an effort to save money on fuel costs. Trucks used by the city's street and water, sewer and gas departments have been converted from gasoline to CNG.[62]

Personal use of CNG is a small niche market currently, though with current tax incentives and a growing number of public fueling stations available, it is experiencing unprecedented growth. The state of Utah offers a subsidised statewide network of CNG filling stations at a rate of $1.57/gge,[63] while gasoline is above $4.00/gal. Elsewhere in the nation, retail prices average around $2.50/gge, with home refueling units compressing gas from residential gas lines for under $1/gge. Other than aftermarket conversions, and government used vehicle auctions, the only currently[when?] produced CNG vehicle in the United States is the Honda Civic GX sedan, which is made in limited numbers and available only in states with retail fueling outlets.

An initiative, known as Pickens Plan, calls for the expansion of the use of CNG as a standard fuel for heavy vehicles has been recently started by oilman and entrepreneur T. Boone Pickens. California voters defeated Proposition 10 in the 2008 General Election by a significant (59.8 percent to 40.2 percent) margin. Proposition 10 was a $5 billion bond measure that, among other things, would have given rebates to state residents that purchase CNG vehicles.

On February 21, 2013, T. Boone Pickens and New York Mayor, Michael Bloomberg unveiled a CNG powered mobile pizzeria. The company, Neapolitan Express uses alternative energy to run the truck as well as 100 percent recycled and compostable materials for their carryout boxes.[64]

Congress has encouraged conversion of cars to CNG with a tax credits of up to 50 percent of the auto conversion cost and the CNG home filling station cost. However, while CNG is much cleaner fuel, the conversion requires a type certificate from the EPA. Meeting the requirements of a type certificate can cost up to $50,000. Other non-EPA approved kits are available. A complete and safe aftermarket conversion using a non-EPA approved kit can be achieved for as little as $400 without the cylinder.[65]

Oceania[edit]

K230UB CNG bus currently used as part of the "Scania Koala CNG Bus Trial" at ACTION in Canberra.

During the 1970s and 1980s, CNG was commonly used in New Zealand in the wake of the oil crises, but fell into decline after petrol prices receded. At the peak of natural gas use, 10 percent of New Zealand's cars were converted, around 110,000 vehicles.[66]

A Mercedes-Benz OC500LE (with Custom Coaches bodywork) running on CNG, operated by Sydney Buses in Sydney, Australia.

Brisbane Transport in Australia has adopted a policy of purchasing only CNG buses in future. Brisbane Transport has 215 Scania L94UB and 324 MAN 18.310 models as well as 30 MAN NG 313 articulated CNG buses. The State Transit Authority of New South Wales (operating under the name "Sydney Buses") operates 100 Scania L113CRB buses, 299 Mercedes-Benz O405NH buses and 254 Euro 5-compliant Mercedes-Benz OC500LE buses.[67]

In the 1990s Benders Busways of Geelong, Victoria trialled CNG buses for the Energy Research and Development Corporation.[68]

Martin Ferguson, Ollie Clark and Noel Childs featured on ABC 7.30 Report raised the issue of CNG as an overlooked transport fuel option in Australia, highlighting the large volumes of LNG currently being exported from the North West Shelf in light of the cost of importing crude oil to Australia.[69]

Deployments[edit]

AT&T ordered 1,200 CNG-powered cargo vans from General Motors in 2012. It is the largest-ever order of CNG vehicles from General Motors to date.[70] AT&T has announced its intention to invest up to $565 million to deploy approximately 15,000 alternative fuel vehicles over a 10-year period through 2018, will use the vans to provide and maintain communications, high-speed Internet and television services for AT&T customers.[71]

DNG[edit]

DNG, or diesel natural gas, is a retrofit system which can be installed on trucks. It mixes diesel fuel with up to 70 percent natural gas.[72]

Liquefied natural gas

From Wikipedia, the free encyclopedia

Not to be confused with Natural gas processing or Liquefied petroleum gas.

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (February 2008)

Liquefied natural gas (LNG) is natural gas (predominantly methane, CH4) that has been converted to liquid form for ease of storage or transport. It takes up about 1/600th the volume of natural gas in the gaseous state. It is odorless, colorless, non-toxic and non-corrosive. Hazards include flammability after vaporization into a gaseous state, freezing and asphyxia. The liquefaction process involves removal of certain components, such as dust, acid gases, helium, water, and heavy hydrocarbons, which could cause difficulty downstream. The natural gas is then condensed into a liquid at close to atmospheric pressure by cooling it to approximately −162 °C (−260 °F); maximum transport pressure is set at around 25 kPa (4 psi).

A typical LNG process. The gas is first extracted and transported to a processing plant where it is purified by removing any condensates such as water, oil, mud, as well as other gases such as CO2 and H2S. An LNG process train will also typically be designed to remove trace amounts of mercury from the gas stream to prevent mercury amalgamizing with aluminium in the cryogenic heat exchangers. The gas is then cooled down in stages until it is liquefied. LNG is finally stored in storage tanks and can be loaded and shipped.

LNG achieves a higher reduction in volume than compressed natural gas (CNG) so that the (volumetric) energy density of LNG is 2.4 times greater than that of CNG or 60 percent of that of diesel fuel.[1] This makes LNG cost efficient to transport over long distances where pipelines do not exist. Specially designed cryogenic sea vessels (LNG carriers) or cryogenic road tankers are used for its transport. LNG is principally used for transporting natural gas to markets, where it is regasified and distributed as pipeline natural gas. It can be used in natural gas vehicles, although it is more common to design vehicles to use compressed natural gas. Its relatively high cost of production and the need to store it in expensive cryogenic tanks have hindered widespread commercial use.

Contents  [hide]

1 Energy density and other physical properties

2 History [5]

3 Production

3.1 LNG plant production

3.2 World total production

4 Commercial aspects

4.1 Global Trade

4.2 Use of LNG to fuel large over the road trucks

5 Trade

5.1 Imports

5.2 Cargo diversion

5.3 Cost of LNG plants

5.3.1 Small-scale liquefaction plants

6 LNG pricing

6.1 Oil parity

6.2 S-curve

6.2.1 JCC and ICP

6.2.2 Brent and other energy carriers

6.3 Price review

7 Quality of LNG

8 Liquefaction technology

8.1 Storage

8.2 Transportation

8.2.1 Terminals

8.3 Refrigeration

9 Environmental concerns

9.1 Safety and accidents

10 See also

11 References

12 Other sources

13 References

14 External links

Energy density and other physical properties[edit]

The heating value depends on the source of gas that is used and the process that is used to liquefy the gas. The range of heating value can span +/- 10 to 15 percent. A typical value of the higher heating value of LNG is approximately 50 MJ/kg or 21,500 Btu/lb.[2] A typical value of the lower heating value of LNG is 45 MJ/kg or 19,350 BTU/lb.

For the purpose of comparison of different fuels the heating value may be expressed in terms of energy per volume which is known as the energy density expressed in MJ/liter. The density of LNG is roughly 0.41 kg/liter to 0.5 kg/liter, depending on temperature, pressure, and composition,[3] compared to water at 1.0 kg/liter. Using the median value of 0.45 kg/liter, the typical energy density values are 22.5 MJ/liter (based on higher heating value) or 20.3 MJ/liter (based on lower heating value).

The (volume-based) energy density of LNG is approximately 2.4 times greater than that of CNG which makes it economical to transport natural gas by ship in the form of LNG. The energy density of LNG is comparable to propane and ethanol but is only 60 percent that of diesel and 70 percent that of gasoline.[4]

History [5][edit]

Experiments on the properties of gases started early in the seventeenth century. By the middle of the seventeenth century Robert Boyle had derived the inverse relationship between the pressure and the volume of gases. About the same time, Guillaume Amontons started looking into temperature effects on gas. Various gas experiments continued for the next 200 years. During that time there were efforts to liquefy gases. Many new facts on the nature of gases had been discovered. For example, early in the nineteenth century Cagniard de la Tours had shown there was a temperature above which a gas could not be liquefied. There was a major push in the mid to late nineteenth century to liquefy all gases. A number of scientists including Michael Faraday, James Joule, and William Thomson (Lord Kelvin), did experiments in this area. In 1886 Karol Olszewski liquefied methane, the primary constituent of natural gas. By 1900 all gases had been liquefied except helium which was liquefied in 1908.

The first large scale liquefaction of natural gas in this country was in 1918 when the U.S. government liquefied natural gas as a way to extract helium, which is a small component of some natural gas. This helium was intended for use in British dirigibles for World War I. The liquid natural gas (LNG) was not stored, but regasified and immediately put into the gas mains.

The key patents having to do with natural gas liquefaction were in 1915 and the mid-1930s. In 1915 Godfrey Cabot patented a method for storing liquid gases at very low temperatures. It consisted of a Thermos bottle type design which included a cold inner tank within an outer tank; the tanks being separated by insulation. In 1937 Lee Twomey received patents for a process for large scale liquefaction of natural gas. The intention was to store natural gas as a liquid so it could be used for shaving peak energy loads during cold snaps. Because of large volumes it is not practical to store natural gas, as a gas, near atmospheric pressure. However, if it can be liquefied it can be stored in a volume 600 times smaller. This is a practical way to store it but the gas must be stored at -260 °F.

There are basically two processes for liquefying natural gas in large quantities. One is a cascade process in which the natural gas is cooled by another gas which in turn has been cooled by still another gas, hence a cascade. There are usually two cascade cycles prior to the liquid natural gas cycle. The other method is the Linde process. (A variation of the Linde process, called the Claude process, is sometimes used.) In this process the gas is cooled regeneratively by continually passing it through an orifice until it is cooled to temperatures at which it liquefies. The cooling of gas by expanding it through an orifice was developed by James Joule and William Thomson and is known as the Joule-Thomson effect. Lee Twomey used the cascade process for his patents.

The East Ohio Gas Company built a full-scale commercial liquid natural gas (LNG) plant in Cleveland, Ohio, in 1940 just after a successful pilot plant built by its sister company, Hope Natural Gas Company of West Virginia. This was the first such plant in the world. Originally it had three spheres, approximately 63 feet in diameter containing LNG at -260 °F. Each sphere held the equivalent of about 50 million cubic feet of natural gas. A fourth tank, a cylinder, was added in 1942. It had an equivalent capacity of 100 million cubic feet of gas. The plant operated successfully for three years. The stored gas was regasified and put into the mains when cold snaps hit and extra capacity was needed. This precluded the denial of gas to some customers during a cold snap.

The plant failed on October 20, 1944 when the cylindrical tank ruptured spilling thousands of gallons of LNG over the plant and nearby neighborhood. The gas evaporated and caught fire, which caused 130 fatalities. The fire delayed further implementation of LNG facilities for several years. However, over the next 15 years new research on low-temperature alloys, and better insulation materials, set the stage for a revival of the industry. It restarted in 1959 when a U.S. World War II Liberty ship, the Methane Pioneer, converted to carry LNG, made a delivery of LNG from the U.S. Gulf coast to energy starved Great Britain. In June 1964, the world's first purpose-built LNG carrier, the "Methane Princess" entered service.[6] Soon after that a large natural gas field was discovered in Algeria. International trade in LNG quickly followed as LNG was shipped to France and Great Britain from the Algerian fields. One more important attribute of LNG had now been exploited. Once natural gas was liquefied it could not only be stored more easily, but it could be transported. Thus energy could now be shipped over the oceans via LNG the same way it was shipped by oil.

The domestic LNG industry restarted in 1965 when a series of new plants were built in the U.S. The building continued through the 1970s. These plants were not only used for peak-shaving, as in Cleveland, but also for base-load supplies for places that never had natural gas prior to this. A number of import facilities were built on the East Coast in anticipation of the need to import energy via LNG. However, a recent boom in U.S. natural production (2010-2014), enabled by the new hydraulic fracturing technique (“fracking”), has many of these import facilities being considered as export facilities. The U.S. Energy Information Administration predicts, with present knowledge, that the U.S. will become an LNG exporting country in the next few years.

Production[edit]

The natural gas fed into the LNG plant will be treated to remove water, hydrogen sulfide, carbon dioxide and other components that will freeze (e.g., benzene) under the low temperatures needed for storage or be destructive to the liquefaction facility. LNG typically contains more than 90 percent methane. It also contains small amounts of ethane, propane, butane, some heavier alkanes, and nitrogen. The purification process can be designed to give almost 100 percent methane. One of the risks of LNG is a rapid phase transition explosion (RPT), which occurs when cold LNG comes into contact with water.[7]

The most important infrastructure needed for LNG production and transportation is an LNG plant consisting of one or more LNG trains, each of which is an independent unit for gas liquefaction. The largest LNG train now in operation is in Qatar. These facilities recently reached a safety milestone, completing 12 years of operations on its offshore facilities without a Lost Time Incident.[8] Until recently it was the Train 4 of Atlantic LNG in Trinidad and Tobago with a production capacity of 5.2 million metric ton per annum (mmtpa),[9] followed by the SEGAS LNG plant in Egypt with a capacity of 5 mmtpa. In July 2014, Atlantic LNG celebrated its 3000th cargo of LNG at the company’s liquefaction facility in Trinidad.[10] The Qatargas II plant has a production capacity of 7.8 mmtpa for each of its two trains. LNG sourced from Qatargas II will be supplied to Kuwait, following the signing of an agreement in May 2014 between Qatar Liquefied Gas Company and Kuwait Petroleum Corp.[10] LNG is loaded onto ships and delivered to a regasification terminal, where the LNG is allowed to expand and reconvert into gas. Regasification terminals are usually connected to a storage and pipeline distribution network to distribute natural gas to local distribution companies (LDCs) or independent power plants (IPPs).

LNG plant production[edit]

Information for the following table is derived in part from publication by the U.S. Energy Information Administration.[11]

Plant Name         Location    Country      Startup Date       Capacity (mmtpa)          Corporation

Qatargas II          Ras Laffan          Qatar          2009 7.8   

Arzew GL4Z                 Algeria       1964 0.90 

Arzew GL1Z                 Algeria       1978         

Arzew GL1Z                 Algeria       1997 7.9   

Skikda GL1K                Algeria       1972         

Skikda GL1K                Algeria       1981         

Skikda GL1K                Algeria       1999 6.0   

Angola LNG        Soyo Angola       2013 5.2    Chevron

Lumut 1               Brunei        1972 7.2   

Badak NGL A-B Bontang     Indonesia  1977 4       Pertamina

Badak NGL C-D Bontang     Indonesia  1986 4.5    Pertamina

Badak NGL E     Bontang     Indonesia  1989 3.5    Pertamina

Badak NGL F     Bontang     Indonesia  1993 3.5    Pertamina

Badak NGL G     Bontang     Indonesia  1998 3.5    Pertamina

Badak NGL H     Bontang     Indonesia  1999 3.7    Pertamina

Donggi Senoro LNG   Luwuk        Indonesia  2014 2.2    Mitsubishi

Sengkang LNG  Sengkang  Indonesia  2014 5       Energy World Corp.

Atlantic LNG       Point Fortin         Trinidad and Tobago  1999          Atlantic LNG

[Atlantic LNG]     [Point Fortin]       Trinidad and Tobago  2003 9.9    Atlantic LNG

Damietta    Egypt         2004 5.5    Segas LNG

Idku  Egypt         2005 7.2   

Bintulu MLNG 1            Malaysia    1983 7.6   

Bintulu MLNG 2           Malaysia    1994 7.8   

Bintulu MLNG 3           Malaysia    2003 3.4   

Nigeria LNG                 Nigeria       1999 23.5 

Northwest Shelf Venture      Karratha    Australia    2009 16.3 

Withnell Bay       Karratha    Australia    1989         

Withnell Bay       Karratha    Australia    1995 (7.7) 

Sakhalin II           Russia       2009 9.6.[12]     

Yemen LNG       Balhaf        Yemen       2008 6.7   

Tangguh LNG Project Papua Barat       Indonesia  2009 7.6   

Qatargas I Ras Laffan          Qatar          1996 (4.0) 

Qatargas I Ras Laffan          Qatar          2005 10.0 

Qatargas III                  Qatar          2010 7.8   

Rasgas I, II and III       Ras Laffan          Qatar          1999 36.3 

Qalhat                 Oman         2000 7.3   

Das Island I                  United Arab Emirates  1977         

Das Island I and II                 United Arab Emirates  1994 5.7   

Melkøya     Hammerfest        Norway      2007 4.2    Statoil

Equatorial Guinea                           2007 3.4    Marathon Oil

World total production[edit]

Global LNG import trends, by volume (in red), and as a percentage of global natural gas imports (in black) (US EIA data)

Trends in the top five LNG-importing nations as of 2009 (US EIA data)

Year Capacity (Mtpa)  Notes

1990 50[13]       

2002 130[14]     

2007 160[13]     

The LNG industry developed slowly during the second half of the last century because most LNG plants are located in remote areas not served by pipelines, and because of the large costs to treat and transport LNG. Constructing an LNG plant costs at least $1.5 billion per 1 mmtpa capacity, a receiving terminal costs $1 billion per 1 bcf/day throughput capacity and LNG vessels cost $200 million–$300 million.

In the early 2000s, prices for constructing LNG plants, receiving terminals and vessels fell as new technologies emerged and more players invested in liquefaction and regasification. This tended to make LNG more competitive as a means of energy distribution, but increasing material costs and demand for construction contractors have put upward pressure on prices in the last few years. The standard price for a 125,000 cubic meter LNG vessel built in European and Japanese shipyards used to be USD 250 million. When Korean and Chinese shipyards entered the race, increased competition reduced profit margins and improved efficiency—reducing costs by 60 percent. Costs in US dollars also declined due to the devaluation of the currencies of the world's largest shipbuilders: the Japanese yen and Korean won.

Since 2004, the large number of orders increased demand for shipyard slots, raising their price and increasing ship costs. The per-ton construction cost of an LNG liquefaction plant fell steadily from the 1970s through the 1990s. The cost reduced by approximately 35 percent. However, recently the cost of building liquefaction and regasification terminals doubled due to increased cost of materials and a shortage of skilled labor, professional engineers, designers, managers and other white-collar professionals.

Due to energy shortage concerns, many new LNG terminals are being contemplated in the United States. Concerns about the safety of such facilities created controversy in some regions where they were proposed. One such location is in the Long Island Sound between Connecticut and Long Island. Broadwater Energy, an effort of TransCanada Corp. and Shell, wishes to build an LNG terminal in the sound on the New York side. Local politicians including the Suffolk County Executive raised questions about the terminal. In 2005, New York Senators Chuck Schumer and Hillary Clinton also announced their opposition to the project.[15] Several terminal proposals along the coast of Maine were also met with high levels of resistance and questions. On Sep. 13, the U.S. Department of Energy approved Dominion Cove Point's application to export up to 770 million cubic feet per day of LNG to countries that do not have a free trade agreement with the U.S.[16] In May 2014, the FERC concluded its environmental assessment of the Cove Point LNG project, which found that the proposed natural gas export project could be built and operated safely.[17] Another LNG terminal is currently proposed for Elba Island, Ga.[18] Plans for three LNG export terminals in the U.S. Gulf Coast region have also received conditional Federal approval.[16][19] In Canada, an LNG export terminal is under construction near Guysborough, Nova Scotia.[20]

Commercial aspects[edit]

Global Trade[edit]

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In the commercial development of an LNG value chain, LNG suppliers first confirm sales to the downstream buyers and then sign long-term contracts (typically 20–25 years) with strict terms and structures for gas pricing. Only when the customers are confirmed and the development of a greenfield project deemed economically feasible, could the sponsors of an LNG project invest in their development and operation. Thus, the LNG liquefaction business has been limited to players with strong financial and political resources. Major international oil companies (IOCs) such as ExxonMobil, Royal Dutch Shell, BP, BG Group, Chevron, and national oil companies (NOCs) such as Pertamina and Petronas are active players.

LNG is shipped around the world in specially constructed seagoing vessels. The trade of LNG is completed by signing an SPA (sale and purchase agreement) between a supplier and receiving terminal, and by signing a GSA (gas sale agreement) between a receiving terminal and end-users. Most of the contract terms used to be DES or ex ship, holding the seller responsible for the transport of the gas. With low shipbuilding costs, and the buyers preferring to ensure reliable and stable supply, however, contract with the term of FOB increased. Under such term, the buyer, who often owns a vessel or signs a long-term charter agreement with independent carriers, is responsible for the transport.

LNG purchasing agreements used to be for a long term with relatively little flexibility both in price and volume. If the annual contract quantity is confirmed, the buyer is obliged to take and pay for the product, or pay for it even if not taken, in what is referred to as the obligation of take-or-pay contract (TOP).

In the mid-1990s, LNG was a buyer's market. At the request of buyers, the SPAs began to adopt some flexibilities on volume and price. The buyers had more upward and downward flexibilities in TOP, and short-term SPAs less than 16 years came into effect. At the same time, alternative destinations for cargo and arbitrage were also allowed. By the turn of the 21st century, the market was again in favor of sellers. However, sellers have become more sophisticated and are now proposing sharing of arbitrage opportunities and moving away from S-curve pricing. There has been much discussion regarding the creation of an "OGEC" as a natural gas equivalent of OPEC. Russia and Qatar, countries with the largest and the third largest natural gas reserves in the world, have finally supported such move.[citation needed]

Until 2003, LNG prices have closely followed oil prices. Since then, LNG prices in Europe and Japan have been lower than oil prices, although the link between LNG and oil is still strong. In contrast, prices in the US and the UK have recently skyrocketed, then fallen as a result of changes in supply and storage.[citation needed] In late 1990s and in early 2000s, the market shifted for buyers, but since 2003 and 2004, it has been a strong seller's market, with net-back as the best estimation for prices.[citation needed].

Research from QNB Group in 2014 shows that robust global demand is likely to keep LNG prices high for at least the next few years.[21]

The current surge in unconventional oil and gas in the U.S. has resulted in lower gas prices in the U.S. This has led to discussions in Asia' oil linked gas markets to import gas based on Henry Hub index.[22] Recent high level conference in Vancouver, the Pacific Energy Summit 2013 Pacific Energy Summit 2013 convened policy makers and experts from Asia and the U.S. to discuss LNG trade relations between these regions.

Receiving terminals exist in about 18 countries, including India, Japan, Korea, Taiwan, China, Greece, Belgium, Spain, Italy, France, the UK, the US, Chile, and the Dominican Republic, among others. Plans exist for Argentina, Brazil, Uruguay, Canada, Ukraine and others to also construct new receiving (gasification) terminals.

Use of LNG to fuel large over the road trucks[edit]

LNG is in the early stages of becoming a mainstream fuel for transportation needs. It is being evaluated and tested for over-the-road trucking,[23] off-road,[24] marine, and train applications.[25] There are known problems with the fuel tanks and delivery of gas to the engine,[26] but despite these concerns the move to LNG as a transportation fuel has begun.

In the United States the beginnings of a public LNG Fueling capability is being put in place. An alternative fuel fueling center tracking site shows 56 public truck LNG fuel centers as of July 2014.[27] The 2013 National Trucker's Directory lists approximately 7,000 truckstops,[28] thus approximately 1% of US truckstops have LNG available as of July 2014.

In May 2013 Dillon Transport announced they were putting 25 LNG large trucks into service in Dallas Texas. They are refueling at a public LNG fuel center.[29]

In Oct 2013 Raven Transportation announced they were buying 36 LNG large trucks to be fueled by Clean Energy Fuels locations.[30]

In fall 2013, Lowe's finished converting one of its dedicated fleets to LNG fueled trucks.[31]

UPS is planning to have over 900 LNG fueled trucks on the roads by the end of 2014.[32] UPS has 16,000 tractor trucks in its fleet and will be buying more LNG vehicles next year. 60 of the new for 2014 large trucks will be placed in service in the Houston, Texas area alone where UPS is building its own private LNG fuel center despite the availability of retail LNG capability. They state they need their own LNG fueling capacity to avoid the lines at a retail fuel center. UPS states the NGVs (natural gas vehicles) are no longer in the testing phase for them, they are vehicles they depend on.[33] In other cities such as Amarillo, Texas and Oklahoma City, Oklahoma they are using public fuel centers.[34]

Clean Energy Fuels has opened several public LNG Fuel Lanes along I-10 and claims that as of June 2014 LNG fueled trucks can use the route from Los Angeles, California to Houston, Texas by refueling exclusively at Clean Energy Fuels public facilities.[35]

In the spring of 2014 Shell and Travel Centers of America opened the first of a planned network of U.S. truck stop LNG stations in Ontario, California.[36] Per the alternative fuel fueling center tracking site there are 9 LNG capable public fuel stations in the greater Los Angeles area, making it the single most penetrated metro market.

As of August 2014, Blu LNG has at least 18 operational LNG capable fuel centers across 8 states.[37]

Clean Energy maintains a list of their existing and planned LNG fuel centers.[38] As of July 2014 they had 30 operational public LNG facilities.

Trade[edit]

In 1970, global LNG trade was of 3 billion cubic metres (bcm).[39] In 2011, it was 331 bcm.[39]

In 2004, LNG accounted for 7 percent of the world’s natural gas demand.[40] The global trade in LNG, which has increased at a rate of 7.4 percent per year over the decade from 1995 to 2005, is expected to continue to grow substantially.[41] LNG trade is expected to increase at 6.7 percent per year from 2005 to 2020.[41]

Until the mid-1990s, LNG demand was heavily concentrated in Northeast Asia: Japan, South Korea and Taiwan. At the same time, Pacific Basin supplies dominated world LNG trade.[41] The world-wide interest in using natural gas-fired combined cycle generating units for electric power generation, coupled with the inability of North American and North Sea natural gas supplies to meet the growing demand, substantially broadened the regional markets for LNG. It also brought new Atlantic Basin and Middle East suppliers into the trade.[41]

By the end of 2011, there were 18 LNG exporting countries and 25 LNG importing countries. The three biggest LNG exporters in 2011 were Qatar (75.5 MT), Malaysia (25 MT) and Indonesia (21.4 MT). The three biggest LNG importers in 2011 were Japan (78.8 MT), South Korea (35 MT) and UK (18.6 MT).[42] LNG trade volumes increased from 140 MT in 2005 to 158 MT in 2006, 165 MT in 2007, 172 MT in 2008.[43] IT was forecasted to be increased to about 200 MT in 2009, and about 300 MT in 2012. During the next several years there would be significant increase in volume of LNG Trade: about 82 MTPA of new LNG supply will come to the market between 2009 and 2011. For example, about 59 MTPA of new LNG supply from six new plants comes to the market just in 2009, including:

Northwest Shelf Train 5: 4.4 MTPA

Sakhalin II: 9.6 MTPA

Yemen LNG: 6.7 MTPA

Tangguh: 7.6 MTPA

Qatargas: 15.6 MTPA

Rasgas Qatar: 15.6 MTPA

In 2006, Qatar became the world's biggest exporter of LNG.[39] As of 2012, Qatar is the source of 25 percent of the world's LNG exports.[39]

Investments in U.S. export facilities were increasing by 2013—such as the plant being built in Hackberry, Louisiana by Sempra Energy. These investments were spurred by increasing shale gas production in the United States and a large price differential between natural gas prices in the U.S. and those in Europe and Asia. However, general exports had not yet been authorized by the United States Department of Energy because the United States had only recently moved from an importer to self-sufficiency status. When U.S. exports are authorized, large demand for LNG in Asia was expected to mitigate price decreases due to increased supplies from the U.S.[44]

Imports[edit]

In 1964, the UK and France made the first LNG trade, buying gas from Algeria, witnessing a new era of energy.

Today, only 19 countries export LNG.[39]

Compared with the crude oil market, the natural gas market is about 60 percent of the crude oil market (measured on a heat equivalent basis), of which LNG forms a small but rapidly growing part. Much of this growth is driven by the need for clean fuel and some substitution effect due to the high price of oil (primarily in the heating and electricity generation sectors).

Japan, South Korea, Spain, France, Italy and Taiwan import large volumes of LNG due to their shortage of energy. In 2005, Japan imported 58.6 million tons of LNG, representing some 30 percent of the LNG trade around the world that year. Also in 2005, South Korea imported 22.1 million tons, and in 2004 Taiwan imported 6.8 million tons. These three major buyers purchase approximately two-thirds of the world's LNG demand. In addition, Spain imported some 8.2 mmtpa in 2006, making it the third largest importer. France also imported similar quantities as Spain.[citation needed] Following the Fukushima Daiichi nuclear disaster in March 2011 Japan became a major importer accounting for one third of the total.[44] European LNG imports fell by 30 percent in 2012, and are expected to fall further by 24 percent in 2013, as South American and Asian importers pay more.[45]

Cargo diversion[edit]

Based on the LNG SPAs, LNG is destined for pre-agreed destinations, and diversion of that LNG is not allowed. However if Seller and Buyer make a mutual agreement, then the diversion of the cargo is permitted—subject to sharing the additional profit created by such a diversion. In the European Union and some other jurisdictions, it is not permitted to apply the profit-sharing clause in LNG SPAs.

Cost of LNG plants[edit]

For an extended period of time, design improvements in liquefaction plants and tankers had the effect of reducing costs.

In the 1980s, the cost of building an LNG liquefaction plant cost $350 per tpa (tonne per year). In 2000s, it was $200/tpa. In 2012, the costs can go as high as $1,000/tpa, partly due to the increase in the price of steel.[39]

As recently as 2003, it was common to assume that this was a “learning curve” effect and would continue into the future. But this perception of steadily falling costs for LNG has been dashed in the last several years.[41]

The construction cost of greenfield LNG projects started to skyrocket from 2004 afterward and has increased from about $400 per ton per year of capacity to $1,000 per ton per year of capacity in 2008.

The main reasons for skyrocketed costs in LNG industry can be described as follows:

Low availability of EPC contractors as result of extraordinary high level of ongoing petroleum projects world wide.[12]

High raw material prices as result of surge in demand for raw materials.

Lack of skilled and experienced workforce in LNG industry.[12]

Devaluation of US dollar.

The 2007–2008 global financial crisis caused a general decline in raw material and equipment prices, which somewhat lessened the construction cost of LNG plants. However, by 2012 this was more than offset by increasing demand for materials and labor for the LNG market.

Small-scale liquefaction plants[edit]

Small-scale liquefaction plants are advantageous because their compact size enables the production of LNG close to the location where it will be used. This proximity decreases transportation and LNG product costs for consumers. It also avoids the additional greenhouse gas emissions generated during long transportation.

The small-scale LNG plant also allows localized peakshaving to occur—balancing the availability of natural gas during high and low periods of demand. It also makes it possible for communities without access to natural gas pipelines to install local distribution systems and have them supplied with stored LNG.[46]

LNG pricing[edit]

There are three major pricing systems in the current LNG contracts:

Oil indexed contract used primarily in Japan, Korea, Taiwan and China;

Oil, oil products and other energy carriers indexed contracts used primarily in Continental Europe;[47] and

Market indexed contracts used in the US and the UK.;

The formula for an indexed price is as follows:

CP = BP + β X

BP: constant part or base price

β: gradient

X: indexation

The formula has been widely used in Asian LNG SPAs, where base price refers to a term that represents various non-oil factors, but usually a constant determined by negotiation at a level which can prevent LNG prices from falling below a certain level. It thus varies regardless of oil price fluctuation.

Oil parity[edit]

Oil parity is the LNG price that would be equal to that of crude oil on a Barrel of oil equivalent basis. If the LNG price exceeds the price of crude oil in BOE terms, then the situation is called broken oil parity. A coefficient of 0.1724 results in full oil parity. In most cases the price of LNG is less the price of crude oil in BOE terms. In 2009, in several spot cargo deals especially in East Asia, oil parity approached the full oil parity or even exceeds oil parity.[48]

S-curve[edit]

Many formulae include an S-curve, where the price formula is different above and below a certain oil price, to dampen the impact of high oil prices on the buyer, and low oil prices on the seller.

JCC and ICP[edit]

In most of the East Asian LNG contracts, price formula is indexed to a basket of crude imported to Japan called the Japan Crude Cocktail (JCC). In Indonesian LNG contracts, price formula is linked to Indonesian Crude Price (ICP).

Brent and other energy carriers[edit]

In continental Europe, the price formula indexation does not follow the same format, and it varies from contract to contract. Brent crude price (B), heavy fuel oil price (HFO), light fuel oil price (LFO), gas oil price (GO), coal price, electricity price and in some cases, consumer and producer price indexes are the indexation elements of price formulas.

Price review[edit]

Usually there exists a clause allowing parties to trigger the price revision or price reopening in LNG SPAs. In some contracts there are two options for triggering a price revision. regular and special. Regular ones are the dates that will be agreed and defined in the LNG SPAs for the purpose of price review.

Quality of LNG[edit]

LNG quality is one of the most important issues in the LNG business. Any gas which does not conform to the agreed specifications in the sale and purchase agreement is regarded as “off-specification” (off-spec) or “off-quality” gas or LNG. Quality regulations serve three purposes:[49]

1 - to ensure that the gas distributed is non-corrosive and non-toxic, below the upper limits for H2S, total sulphur, CO2 and Hg content;

2 - to guard against the formation of liquids or hydrates in the networks, through maximum water and hydrocarbon dewpoints;

3 - to allow interchangeability of the gases distributed, via limits on the variation range for parameters affecting combustion: content of inert gases, calorific value, Wobbe index, Soot Index, Incomplete Combustion Factor, Yellow Tip Index, etc.

In the case of off-spec gas or LNG the buyer can refuse to accept the gas or LNG and the seller has to pay liquidated damages for the respective off-spec gas volumes.

The quality of gas or LNG is measured at delivery point by using an instrument such as a gas chromatograph.

The most important gas quality concerns involve the sulphur and mercury content and the calorific value. Due to the sensitivity of liquefaction facilities to sulfur and mercury elements, the gas being sent to the liquefaction process shall be accurately refined and tested in order to assure the minimum possible concentration of these two elements before entering the liquefaction plant, hence there is not much concern about them.

However, the main concern is the heating value of gas. Usually natural gas markets can be divided in three markets in terms of heating value:[49]

Asia (Japan, Korea, Taiwan) where gas distributed is rich, with a gross calorific value (GCV) higher than 43 MJ/m3(n), i.e. 1,090 Btu/scf,

the UK and the US, where distributed gas is lean, with a GCV usually lower than 42 MJ/m3(n), i.e. 1,065 Btu/scf,

Continental Europe, where the acceptable GCV range is quite wide: approx. 39 to 46 MJ/m3(n), i.e. 990 to 1,160 Btu/scf.

There are some methods to modify the heating value of produced LNG to the desired level. For the purpose of increasing the heating value, injecting propane and butane is a solution. For the purpose of decreasing heating value, nitrogen injecting and extracting butane and propane are proved solutions. Blending with gas or LNG can be a solutions; however all of these solutions while theoretically viable can be costly and logistically difficult to manage in large scale.

Liquefaction technology[edit]

Currently there are four Liquefaction processes available:

C3MR (sometimes referred to as APCI): designed by Air Products & Chemicals, Incorporation.

Cascade: designed by ConocoPhillips.

Shell DMR

Linde

It was expected that by the end of 2012, there will be 100 liquefaction trains on stream with total capacity of 297.2 MMTPA.

The majority of these trains use either APCI or Cascade technology for the liquefaction process. The other processes, used in a small minority of some liquefaction plants, include Shell's DMR (double-mixed refrigerant) technology and the Linde technology.

APCI technology is the most-used liquefaction process in LNG plants: out of 100 liquefaction trains onstream or under-construction, 86 trains with a total capacity of 243 MMTPA have been designed based on the APCI process. Philips Cascade process is the second most-used, used in 10 trains with a total capacity of 36.16 MMTPA. The Shell DMR process has been used in three trains with total capacity of 13.9 MMTPA; and, finally, the Linde/Statoil process is used in the Snohvit 4.2 MMTPA single train.

Floating liquefied natural gas (FLNG) facilities float above an offshore gas field, and produce, liquefy, store and transfer LNG (and potentially LPG and condensate) at sea before carriers ship it directly to markets. The first FLNG facility is now in development by Shell,[50] due for completion in around 2017.[51]

Storage[edit]

LNG storage tank at EG LNG

Modern LNG storage tanks are typically full containment type, which has a prestressed concrete outer wall and a high-nickel steel inner tank, with extremely efficient insulation between the walls. Large tanks are low aspect ratio (height to width) and cylindrical in design with a domed steel or concrete roof. Storage pressure in these tanks is very low, less than 10 kPa (1.45 psig). Sometimes more expensive underground tanks are used for storage. Smaller quantities (say 700 m3 (190,000 US gallons) and less), may be stored in horizontal or vertical, vacuum-jacketed, pressure vessels. These tanks may be at pressures anywhere from less than 50 kPa to over 1,700 kPa (7 psig to 250 psig).

LNG must be kept cold to remain a liquid, independent of pressure. Despite efficient insulation, there will inevitably be some heat leakage into the LNG, resulting in vaporisation of the LNG. This boil-off gas acts to keep the LNG cold. The boil-off gas is typically compressed and exported as natural gas, or it is reliquefied and returned to storage.

Transportation[edit]

Main article: LNG carrier

Tanker LNG Rivers, LNG capacity of 135,000 cubic metres

LNG is transported in specially designed ships with double hulls protecting the cargo systems from damage or leaks. There are several special leak test methods available to test the integrity of an LNG vessel's membrane cargo tanks.[52]

The tankers cost around USD 200 million each.[39]

Transportation and supply is an important aspect of the gas business, since natural gas reserves are normally quite distant from consumer markets. Natural gas has far more volume than oil to transport, and most gas is transported by pipelines. There is a natural gas pipeline network in the former Soviet Union, Europe and North America. Natural gas is less dense, even at higher pressures. Natural gas will travel much faster than oil through a high-pressure pipeline, but can transmit only about a fifth of the amount of energy per day due to the lower density. Natural gas is usually liquefied to LNG at the end of the pipeline, prior to shipping.

Short LNG pipelines for use in moving product from LNG vessels to onshore storage are available. Longer pipelines, which allow vessels to offload LNG at a greater distance from port facilities are under development. This requires pipe in pipe technology due to requirements for keeping the LNG cold.[53]

LNG is transported using both tanker truck,[54] railway tanker, and purpose built ships known as LNG carriers. LNG will be sometimes taken to cryogenic temperatures to increase the tanker capacity. The first commercial ship-to-ship transfer (STS) transfers were undertaken in February 2007 at the Flotta facility in Scapa Flow[55] with 132,000 m3 of LNG being passed between the vessels Excalibur and Excelsior. Transfers have also been carried out by Exmar Shipmanagement, the Belgian gas tanker owner in the Gulf of Mexico, which involved the transfer of LNG from a conventional LNG carrier to an LNG regasification vessel (LNGRV). Prior to this commercial exercise LNG had only ever been transferred between ships on a handful of occasions as a necessity following an incident.[citation needed]

Terminals[edit]

Main articles: List of LNG terminals and Liquefied natural gas terminal

Liquefied natural gas is used to transport natural gas over long distances, often by sea. In most cases, LNG terminals are purpose-built ports used exclusively to export or import LNG.

Refrigeration[edit]

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The insulation, as efficient as it is, will not keep LNG cold enough by itself. Inevitably, heat leakage will warm and vapourise the LNG. Industry practice is to store LNG as a boiling cryogen. That is, the liquid is stored at its boiling point for the pressure at which it is stored (atmospheric pressure). As the vapour boils off, heat for the phase change cools the remaining liquid. Because the insulation is very efficient, only a relatively small amount of boil off is necessary to maintain temperature. This phenomenon is also called auto-refrigeration.

Boil off gas from land based LNG storage tanks is usually compressed and fed to natural gas pipeline networks. Some LNG carriers use boil off gas for fuel.

Environmental concerns[edit]

Natural gas could be considered the most environmentally friendly fossil fuel, because it has the lowest CO2 emissions per unit of energy and because it is suitable for use in high efficiency combined cycle power stations. For an equivalent amount of heat, burning natural gas produces about 30 per cent less carbon dioxide than burning petroleum and about 45 per cent less than burning coal. [56] On a per kilometre transported basis, emissions from LNG are lower than piped natural gas, which is a particular issue in Europe, where significant amounts of gas are piped several thousand kilometres from Russia. However, emissions from natural gas transported as LNG are higher than for natural gas produced locally to the point of combustion as emissions associated with transport are lower for the latter.[citation needed]

However, on the West Coast of the United States, where up to three new LNG importation terminals have been proposed, environmental groups, such as Pacific Environment, Ratepayers for Affordable Clean Energy (RACE), and Rising Tide have moved to oppose them.[57] They claim that, while natural gas power plants emit approximately half the carbon dioxide of an equivalent coal power plant, the natural gas combustion required to produce and transport LNG to the plants adds 20 to 40 percent more carbon dioxide than burning natural gas alone.[58]

Green bordered white diamond symbol used on LNG-powered vehicles in China

Safety and accidents[edit]

Natural gas is a fuel and a combustible substance. To ensure safe and reliable operation, particular measures are taken in the design, construction and operation of LNG facilities.

In its liquid state, LNG is not explosive and can not burn. For LNG to burn, it must first vaporize, then mix with air in the proper proportions (the flammable range is 5 percent to 15 percent), and then be ignited. In the case of a leak, LNG vaporizes rapidly, turning into a gas (methane plus trace gases), and mixing with air. If this mixture is within the flammable range, there is risk of ignition which would create fire and thermal radiation hazards.

Gas venting from vehicles powered by LNG may create a flammability hazard if parked indoors for longer than a week. Additionally, due to its low temperature, refueling a LNG-powered vehicle requires training to avoid the risk of frostbite.[59]

LNG tankers have sailed over 100 million miles without a shipboard death or even a major accident.[60]

Several on-site accidents involving or related to LNG are listed below:

1944, Oct. 20. The East Ohio Natural Gas Co. experienced a failure of an LNG tank in Cleveland, Ohio.[61] 128 people perished in the explosion and fire. The tank did not have a dike retaining wall, and it was made during World War II, when metal rationing was very strict. The steel of the tank was made with an extremely low amount of nickel, which meant the tank was brittle when exposed to the cryogenic nature of LNG. The tank ruptured, spilling LNG into the city sewer system. The LNG vaporized and turned into gas, which exploded and burned.

1979, Oct. 6, Lusby, Maryland, at the Cove Point LNG facility a pump seal failed, releasing natural gas vapors (not LNG), which entered and settled in an electrical conduit.[61] A worker switched off a circuit breaker, which ignited the gas vapors. The resulting explosion killed a worker, severely injured another and caused heavy damage to the building. A safety analysis was not required at the time, and none was performed during the planning, design or construction of the facility.[62] National fire codes were changed as a result of the accident.

2004, Jan. 19, Skikda, Algeria. Explosion at Sonatrach LNG liquefaction facility.[61] 27 killed, 56 injured, three LNG trains destroyed, a marine berth was damaged and 2004 production was down 76 percent for the year. Total loss was USD 900 million. A steam boiler that was part of an LNG liquefaction train exploded triggering a massive hydrocarbon gas explosion. The explosion occurred where propane and ethane refrigeration storage were located. Site distribution of the units caused a domino effect of explosions.[63][64] It remains unclear if LNG or LNG vapour, or other hydrocarbon gases forming part of the liquefaction process initiated the explosions. One report, of the US Government Team Site Inspection of the Sonatrach Skikda LNG Plant in Skikda, Algeria, March 12–16, 2004, has cited it was a leak of hydrocarbons from the refrigerant (liquefaction) process system. (Continue)eavy damage to the building. A safety analysis was not required at the time, and none was performed during the planning, design or construction of the facility.[62] National fire codes were changed as a result of the accident.

2004, Jan. 19, Skikda, Algeria. Explosion at Sonatrach LNG liquefaction facility.[61] 27 killed, 56 injured, three LNG trains destroyed, a marine berth was damaged and 2004 production was down 76 percent for the year. Total loss was USD 900 million. A steam boiler that was part of an LNG liquefaction train exploded triggering a massive hydrocarbon gas explosion. The explosion occurred where propane and ethane refrigeration storage were located. Site distribution of the units caused a domino effect of explosions.[63][64] It remains unclear if LNG or LNG vapour, or other hydrocarbon gases forming part of the liquefaction process initiated the explosions. One report, of the US Government Team Site Inspection of the Sonatrach Skikda LNG Plant in Skikda, Algeria, March 12–16, 2004, has cited it was a leak of hydrocarbons from the refrigerant (liquefaction) process system. (Continue)