coal shortage

The impact of the coal shortage is already being felt. There have been record power shortfalls in Shanxi Province, where the government had to ration power supplies, hurting energy-intensive plants such as aluminium smelters. China's top 20 aluminium smelters, including Aluminium Corp of China Ltd (Chalco), will cut production by up to 10% to reduce power consumption. Other industrial provinces, such as Shandong in the north and Guangdong in the south, have forecast deep power deficits. “Beijing froze the price miners are paid for thermal coal until the end of the year as it seeks to cap power prices.” Henan, another big aluminium producing province and one of the nation's most popular, has started to restrict power to industrial users in eight regions and cities, while Shanxi province on Thursday said it had begun to ration power supplies as power plants ran short of coal. Some of the power shortfall can be met by diesel generators, and in fact during the last major power crisis in 2004 China's diesel demand surged by 15%, helping oil prices' first ascent above $50 a barrel. The ultimate solution, though, would be to allow markets to set power tariffs, but Beijing would be reluctant to make such a move when inflation is already near a 12-year high. "If the power tariff is opened up, all problems will be solved but its possible impact on the economy is still in question," said Lin of Xiamen University. ($1=6.860 Yuan).

Expand Image Miners understand if they don't dig out all the coal now, they can sell later for a better price.

Expand Image Chinese producer prices for coal and power since the start of 2007.

china small coal

China has failed to meet demand to reopen thousands small coal mines, which has worsened the country’s current power shortage. Also, local officials still fear Beijing's wrath if they suffer more high-profile disasters.

Weeks after the central government urged miners to reopen the mines, effectively reversing a years-old policy of shutting them in order to improve safety in the world's deadliest coal industry, local officials are proving reluctant. And Beijing's freeze on coal prices has lowered the incentive for miners.

failure to boost domestic coal supplies spells trouble for coal-fired electricity generators who produce four fifths of China's power, and could add to this summer's emerging power crisis, which has already forced aluminium smelters to cut output by up to a tenth and could stoke demand for oil.

"Local government officials are more concerned about personal interest. They are afraid of the punishment a mine accident could bring to them," said Li Chaolin, a coal analyst at an industry body based in Beijing.

“China's small coal mines are eight times more deadly per ton of coal than larger mines.”

They are right to be concerned. Six government officials in the Luliang region of Shanxi were sacked after a blast at a small mine, approved to re-open just a month earlier, killed 34 in June, the state-run Xinhua news agency reported.

China has been pushing forward a safety campaign for three years, shutting down the kind of small, inefficient and often dangerous mines that provided 38% of its coal last year.

Around 90% of China's coal mines are classified as small, but they are eight times more deadly per ton of coal produced than the larger mines.

From 1995 to early 2008, the number of coal mines in China had fallen around 80% to about 16,000. Over the same period the death toll is down 40% to 3,786 in 2007, according to the State Administration of Coal Mine Safety.

Beijing's goal is to reduce the number of small mines to under 10,000 by 2010, and to eliminate them by 2015.

But in late May, when coal stocks in the country's key power plants had fallen to critical levels and summer power shortages loomed, China's premier Wen Jiabao called for an increase in coal output, while the country's cabinet asked local governments to speed up approvals for restarting small coal mines.

Some have returned to production in Shanxi, China's top coal producing province, but many are still closed or performing maintenance, traders and analysts said.

And in late June, the Shanxi provincial government ordered local governments to shut down illegal coal mines, highlighting the conflicting signals that have kept officials cautious.

"How can local officials re-open small mines? They want to keep their jobs," said a trader based in Shanxi, who declined to be named.

Diamonds in China

Resources

Diamonds in China

China Diamond Corp., reported a 108 percent increase in production results from the 701 Changma Diamond Mine located in Shandong Province, China. China Diamond is headquartered in London, Ontario, Canada, and is engaged in mining for diamonds and the exploration and advancement of diamond and gold prospects in China.

The 701 Changma Diamond Mine is the company’s principal mining operation the company said in a press release on July 14. Total carats produced from January through March 2005 were 9,240.50, but from April through June total carats produced hit 19,221.20.

Operations were carried out in a higher grade area of the deposit, namely the Small Pipe, which returned an average monthly grade of 1.23 carats per ton. This area is expected to continue to be in production well into August 2005.

More .......

china coal

A gas explosion at a coal mine in China's central Henan province early on Tuesday killed 35 people and 44 others were missing, the government's work safety watchdog said.

Another 14 workers had escaped the mine, which was a small, locally operated venture, at the time of the accident, the State Administration of Work Safety said in a statement on its website (www.chinasafety.gov.cn).

The report said rescue teams were still searching for the missing miners and safety officials would investigate the cause of the blast, but it gave no further details.

The official Xinhua news agency said the pit was being upgraded, and the local government had not given permission to resume production there.

Lax safety standards and strong demand for resources have made China's mines the deadliest in the world, despite a government drive to clamp down on the tiny, unsafe operations that are the site of most accidents.

More than 3,000 people died in mine floods, explosions, collapses and other accidents in 2008 alone.

History

History

Please help improve this article by expanding it. Further information might be found on the talk page. (October 2008)
Main article: History of coal mining
The oldest continuously worked deep-mine in the United Kingdom and possibly in the world is Tower Colliery in South Wales valleys in the heart of the South Wales coalfield. This colliery was first developed in 1805, and its miners bought it out at the end of the 20th century, to prevent it from being closed. Tower Colliery was finally closed on January 25, 2008, although production continues at the Aberpergwym drift mine nearby.
Coal was mined in colonial America in the early 1700s, and commercial mining first occurred around 1730 in Midlothian, Virginia.[3]
Coal-cutting machines were invented in the 1880s. Before the invention, coal was mined from underground with a pick and shovel.
By 1912, surface mining was conducted with steam shovels designed for coal mining.

Major coal producers

Major coal producers
The reserve life is an estimate based only on current production levels for the countries shown, and makes no assumptions of future production or even current production trends.
Production of Coal by Country and year (million tonnes)[55]
Country
2003
2004
2005
2006
Share
Reserve Life (years)
China
1722.0
1992.3
2204.7
2380.0
38.4 %
48
USA
972.3
1008.9
1026.5
1053.6
17.0 %
234
India
375.4
407.7
428.4
447.3
7.2 %
207
Australia
351.5
366.1
378.8
373.8
6.0 %
210
Russia
276.7
281.7
298.5
309.2
5.0 %
508
South Africa
237.9
243.4
244.4
256.9
4.1 %
190
Germany
204.9
207.8
202.8
197.2
3.2 %
34
Indonesia
114.3
132.4
146.9
195.0
3.1 %
25
Poland
163.8
162.4
159.5
156.1
2.5 %
90
Total World
5187.6
5585.3
5886.7
6195.1
100 %
142

Production trends

Production trends

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 USA and India, reports the British Geological Survey.
World coal reserves
At the end of 2006 the recoverable coal reserves amounted around 800 or 900 gigatons. The United States Energy Information Administration gives world reserves as 930 billion short tons[50] (equal to 843 gigatons) as of 2006. At the current extraction rate, this would last 132 years.[51] However, the rate of coal consumption is annually increasing at 2-3% per year and, setting the growth rate to 2.5% yields an exponential depletion time of 56 years (in 2065).[52] At the current global total energy consumption of 15.7 terawatts,[53] there is enough coal to provide the entire planet with all of its energy for 37 years (assuming 0% growth in demand and ignoring transportation's need for liquid fuels).[original research?]
The 930 billion short tons of recoverable coal reserves estimated by the Energy Information Administration are equal to about 4,116 BBOE (billion barrels of oil equivalent).[citation needed] The amount of coal burned during 2007 was estimated at 7.075 billion short tons, or 133.179 quadrillion BTU's.[54] In terms of heat content, this is about 57 million barrels of oil equivalent per day. By comparison in 2007, natural gas provided 51 million barrels of oil equivalent per day, while oil provided 85.8 million barrels per day.
British Petroleum, in its annual report 2007, estimated at 2006 end, there were 909,064 million tons of proven coal reserves worldwide, or 147 years reserves-to-production ratio. 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.

Underground fires

Underground fires
Main article: Coal seam fire
Most underground fires are caused by the mineral marcasite.[citation needed] chemical formula FeS2, it is chemically, the same as pyrite (fool's gold) but structurally complex. Marcasite and pyrite very commonly occur in association with coal beds. these minerals form the source of the sulphur which occurs within the coal. Marcasite is highly unstable at pressures and temperatures close to the earths surface. due to its unstable nature, it may react spontaneously, consuming itself and releasing heat. In the event that sufficient heat is generated and coal occurs close by, the coal may be set alight underground and such a blaze may go on burning for tens to hundreds of years.
There are hundreds of coal fires burning around the world.[41] 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. A grass fire in a coal area can set dozens of coal seams on fire.[42][43] Coal fires in China burn 109 million tons of coal a year, emitting 360 million metric tons of CO2. This contradicts the ratio of 1:1.83 given earlier, but it amounts to 2-3% of the annual worldwide production of CO2 from fossil fuels, or as much as emitted from all of the cars and light trucks in the United States.[44][45] In Centralia, Pennsylvania (a borough located in the Coal Region of the United States) an exposed vein of coal 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 which may have been burning for over 5,500 years.[46]
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).
The reddish siltstone rock that caps many ridges and buttes in the Powder River Basin (Wyoming), and in western North Dakota is called porcelanite, which also may resemble the coal burning waste "clinker" or volcanic "scoria".[47] 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.[48] Wild coal fires in the area were reported by the Lewis and Clark Expedition as well as explorers and settlers in the area.[49]

Energy density

] Energy density
Main article: Energy value of coal
The energy density of coal, i.e. its heating value, is roughly 24 megajoules per kilogram.[38]
The energy density of coal can also be expressed in kilowatt-hours for some unit of mass, the units that electricity is most commonly sold in, to estimate how much coal is required to power electrical appliances. One kilowatt-hour is 3.6 MJ, so the energy density of coal is 6.67 kW·h/kg. The typical thermodynamic efficiency of coal power plants is about 30%, so of the 6.67 kW·h of energy per kilogram of coal, 30% of that—2.0 kW·h/kg—can successfully be turned into electricity; the rest is waste heat. So coal power plants obtain approximately 2.0 kW·h per kilogram of burned coal.
As an example, running one 100 watt lightbulb for one year requires 876 kW·h (100 W × 24 h/day × 365 {days in a year} = 876000 W·h = 876 kW·h). Converting this power usage into physical coal consumption:

It takes 438 kg (966 lb) of coal to power a computer for one full year.[39] One should also take into account transmission and distribution losses caused by resistance and heating in the power lines, which is in the order of 5–10%, depending on distance from the power station and other factors.

Environmental

Environmental effects
Main article: Environmental effects of coal

Aerial photograph of Kingston Fossil Plant coal fly ash slurry spill site taken the day after the event
There are a number of adverse environmental effects of coal mining and burning, specially in power stations.
These effects include:
Release of carbon dioxide, a greenhouse gas, which causes climate change and global warming according to the IPCC. Coal is the largest contributor to the human-made increase of CO2 in the air.[32]
Generation of hundred of millions of tons of waste products, including fly ash, bottom ash, 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
Contamination of land and waterways and destruction of homes from fly ash spills such as 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[citation needed]
Coal-fired power plants without effective fly ash capture are one of the largest sources of human-caused background radiation exposure
Coal-fired power plants shorten nearly 24,000 lives a year in the United States, including 2,800 from lung cancer.[33]
Coal-fired power plant releases emissions including mercury, selenium, and arsenic which are harmful to human health and the environment.[34]
article: Environmental effects of coal

Aerial photograph of Kingston Fossil Plant coal fly ash slurry spill site taken the day after the event
There are a number of adverse environmental effects of coal mining and burning, specially in power stations.
These effects include:
Release of carbon dioxide, a greenhouse gas, which causes climate change and global warming according to the IPCC. Coal is the largest contributor to the human-made increase of CO2 in the air.[32]
Generation of hundred of millions of tons of waste products, including fly ash, bottom ash, 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
Contamination of land and waterways and destruction of homes from fly ash spills such as 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[citation needed]
Coal-fired power plants without effective fly ash capture are one of the largest sources of human-caused background radiation exposure
Coal-fired power plants shorten nearly 24,000 lives a year in the United States, including 2,800 from lung cancer.[33]
Coal-fired power plant releases emissions including mercury, selenium, and arsenic which are harmful to human health and the environment.[34]
Economic aspects
Environmental effects
Main article: Environmental effects of coal

Aerial photograph of Kingston Fossil Plant coal fly ash slurry spill site taken the day after the event
There are a number of adverse environmental effects of coal mining and burning, specially in power stations.
These effects include:
Release of carbon dioxide, a greenhouse gas, which causes climate change and global warming according to the IPCC. Coal is the largest contributor to the human-made increase of CO2 in the air.[32]
Generation of hundred of millions of tons of waste products, including fly ash, bottom ash, 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
Contamination of land and waterways and destruction of homes from fly ash spills such as 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[citation needed]
Coal-fired power plants without effective fly ash capture are one of the largest sources of human-caused background radiation exposure
Coal-fired power plants shorten nearly 24,000 lives a year in the United States, including 2,800 from lung cancer.[33]
Coal-fired power plant releases emissions including mercury, selenium, and arsenic which are harmful to human health and the environment.[34]
] Economic aspects] Environmental effects
Main article: Environmental effects of coal

Aerial photograph of Kingston Fossil Plant coal fly ash slurry spill site taken the day after the event
There are a number of adverse environmental effects of coal mining and burning, specially in power stations.
These effects include:
Release of carbon dioxide, a greenhouse gas, which causes climate change and global warming according to the IPCC. Coal is the largest contributor to the human-made increase of CO2 in the air.[32]
Generation of hundred of millions of tons of waste products, including fly ash, bottom ash, 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
Contamination of land and waterways and destruction of homes from fly ash spills such as 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[citation needed]
Coal-fired power plants without effective fly ash capture are one of the largest sources of human-caused background radiation exposure
Coal-fired power plants shorten nearly 24,000 lives a year in the United States, including 2,800 from lung cancer.[33]
Coal-fired power plant releases emissions including mercury, selenium, and arsenic which are harmful to human health and the environment.[34]
[Economic aspects
Environmental effects
Main article: Environmental effects of coal

Aerial photograph of Kingston Fossil Plant coal fly ash slurry spill site taken the day after the event
There are a number of adverse environmental effects of coal mining and burning, specially in power stations.
These effects include:
Release of carbon dioxide, a greenhouse gas, which causes climate change and global warming according to the IPCC. Coal is the largest contributor to the human-made increase of CO2 in the air.[32]
Generation of hundred of millions of tons of waste products, including fly ash, bottom ash, 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
Contamination of land and waterways and destruction of homes from fly ash spills such as 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[citation needed]
Coal-fired power plants without effective fly ash capture are one of the largest sources of human-caused background radiation exposure
Coal-fired power plants shorten nearly 24,000 lives a year in the United States, including 2,800 from lung cancer.[33]
Coal-fired power plant releases emissions including mercury, selenium, and arsenic which are harmful to human health and the environment.[34]

Gasification

[Gasification
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. This syngas can then be converted into transportation fuels like gasoline and diesel through the Fischer-Tropsch process. Currently, this technology is being used by the Sasol chemical company of South Africa to make gasoline 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 (water vapor) while also being heated and pressurized. During the reaction, oxygen and water molecules oxidize the coal into carbon monoxide (CO) while also releasing hydrogen (H2) gas. This process has been conducted in both underground coal mines and in coal refineries.
(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
High prices of oil and natural gas are leading to increased interest in "BTU Conversion" technologies such as gasification, methanation and liquefaction. The Synthetic Fuels Corporation was a U.S. government-funded corporation established in 1980 to create a market for alternatives to imported fossil fuels (such as coal gasification). The corporation was discontinued in 1985.
In the past, coal was converted to make coal gas, which was piped to customers to burn for illumination, heating, and cooking. At present, the safer natural gas is used instead.

Ethanol production

Ethanol production
The reaction of coal and natural gas was used by a German manufacturer for Buna rubber: Chemische Werke Huls, at Marl, Germany, and AVCO Corp in the US. Consequently several references had described both Huls Arc Process and AVCO rotating arc reactor.[18][19] Both reactors are of cylindrical shape and have a rotating electric arc. The cathode is at the cylinder axis, while the anode is on the circumference. As methane gas provided the highest yield, then it is forced with coal powder into a vortex passing through the electric arc for few milliseconds.
Huls Arc Process[20] produced a mixture of acetylene and ethylene gases. The reaction conditions can be varied to determine the needed product. Increasing the Specific Energy Requirement (SER) favor acetylene production, and lower SER is for ethylene:
Enthalpy Change for Ethylene:[21] = 127.34 kJ/mol, while for acetylene: = 301.4 kJ/mol. As a consequence, recent production processes are using conventional heating instead of electric arc.
Hydration of ethylene gas producing ethanol is the most important process for ethanol production. Vapor phase process is the preferred one[22] in which ethylene and steam pass over a catalyst. One of the most accepted catalyst is diatomite impregnated with phosphoric acid.

cooking

Coking and use of coke
Main article: Coke (fuel)

Coke oven at smokeless fuel plant, South Wales
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 that 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. The product is too rich in dissolved carbon, and must be treated further to make steel. 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 by the conventional route. However, the alternative route to 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 by-products that include 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

coal of use

[edit] Coal as fuel
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 6,743,786,000 short tons in 2006[10] and is expected to increase 48% to 9.98 billion short tons by 2030.[11] China produced 2.38 billion tons in 2006. India produced about 447.3 million tons in 2006. 68.7% of China's electricity comes from coal. The USA consumes about 14% of the world total, using 90% of it for generation of electricity.[12]
When coal is used for electricity generation, it is usually pulverized and then burned in a furnace with a boiler. The furnace heat converts boiler water to steam, which is then used to spin turbines which turn generators and create electricity. The thermodynamic efficiency of this process has been improved over time. "Standard" steam turbines have topped out with some of the most advanced reaching about 35% thermodynamic efficiency for the entire process, although newer combined cycle plants can reach efficiencies as high as 58%. Increasing the combustion temperature can boost this efficiency even further.[13] Old coal power plants, especially "grandfathered" plants, are significantly less efficient and produce higher levels of waste heat. About 40% of the world's electricity comes from coal,[14] and approximately 49% of the United States electricity comes from coal.[15]
Fuels for heating
Heating oilWood pelletKerosenePropaneNatural gasElectricityWoodCoal
The emergence of the supercritical turbine concept envisions running a boiler at extremely high temperatures and pressures with projected efficiencies of 46%, with further theorized increases in temperature and pressure perhaps resulting in even higher efficiencies.[16]
Other efficient ways to use coal are combined cycle power plants, combined heat and power cogeneration, and an MHD topping cycle.
Approximately 40% of the world electricity production uses coal. 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. However, consumption is increasing and maximal production could be reached within decades (see World Coal Reserves, below).
A more energy-efficient way of using coal for electricity production would be via solid-oxide fuel cells or molten-carbonate fuel cells (or any oxygen ion transport based fuel cells that do not discriminate between fuels, as long as they consume oxygen), which would be able to get 60%–85% combined efficiency (direct electricity + waste heat steam turbine).[citation needed] Currently these fuel cell technologies can only process gaseous fuels, and they are also sensitive to sulfur poisoning, issues which would first have to be worked out before large scale commercial success is possible with coal. As far as gaseous fuels go, one idea is pulverized coal in a gas carrier, such as nitrogen. Another option is coal gasification with water, which may lower fuel cell voltage by introducing oxygen to the fuel side of the electrolyte, but may also greatly simplify carbon sequestration. However, this technology has been criticised as being inefficient, slow, risky and costly, while doing nothing about total emissions from mining, processing and combustion.[17] Another efficient and clean

type of coal

As geological processes apply pressure to dead biotic matter 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.
Lignite, also referred to as brown coal, is the lowest rank of coal and used almost exclusively as fuel for electric power generation. Jet is a compact form of lignite that is sometimes polished and has been used as an ornamental stone since the Iron Age.
Sub-bituminous coal, whose properties range from those of lignite to those of bituminous coal are used primarily as fuel for steam-electric power generation. Additionally, it is an important source of light aromatic hydrocarbons for the chemical synthesis industry.
Bituminous coal, dense mineral, black but sometimes dark brown, often with well-defined bands of bright and dull material, used primarily as fuel in steam-electric power generation, with substantial quantities also used for heat and power applications in manufacturing and to make coke.
Anthracite, the highest rank; 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, but difficult to ignite and is not so 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:[2]
Name
Volatiles %
C Carbon %
H Hydrogen %
O Oxygen %
S Sulfur %
Heat content kJ/kg
Braunkohle (Lignite)
45-65
60-75
6.0-5.8
34-17
0.5-3
<28470
Flammkohle (Flame coal)
40-45
75-82
6.0-5.8
>9.8
~1
<32870
Gasflammkohle (Gas flame coal)
35-40
82-85
5.8-5.6
9.8-7.3
~1
<33910
Gaskohle (Gas coal)
28-35
85-87.5
5.6-5.0
7.3-4.5
~1
<34960
Fettkohle (Fat coal)
19-28
87.5-89.5
5.0-4.5
4.5-3.2
~1
<35380
Esskohle (Forge coal)
14-19
89.5-90.5
4.5-4.0
3.2-2.8
~1
<35380
Magerkohle (Non baking coal)
10-14
90.5-91.5
4.0-3.75
2.8-3.5
~1
35380
Anthrazit (Anthracite)
7-12
>91.5
<3.75
<2.5
~1
<35300
Percent by weight