Coal
Example chemical structure of coal

Coal is a fossil fuel formed in ecosystems where plant remains were preserved by water and mud from oxidization and biodegradation, thus sequestering atmospheric carbon. Fossil fuels or mineral fuels are fossil source Fuels that is Hydrocarbons found within the top layer of the Earth’s crust. An ecosystem is a natural unit consisting of all plants animals and micro-organisms( Biotic factors in an area functioning together with all of the non-living physical ( Plants are living Organisms belonging to the kingdom Plantae. Water is a common Chemical substance that is essential for the survival of all known forms of Life. In computer gaming, a MUD ( Multi-User Dungeon, Domain or Dimension) is a multi-player computer game that combines elements of Beta oxidation is the process by which Fatty acids in the form of Acyl-CoA molecules are broken down in Mitochondria and/or in Peroxisomes to Biodegradation is the process by which organic substances are broken down by the enzymes produced by living organisms Coal is a readily combustible black or brownish-black rock. Combustion or burning is a complex sequence of Exothermic chemical reactions between a Fuel and an Oxidant accompanied by the production of It is a sedimentary rock, but the harder forms, such as anthracite coal, can be regarded as metamorphic rocks because of later exposure to elevated temperature and pressure. Sedimentary rock is one of the three main rock types (the others being igneous and Metamorphic rock) Anthracite ( Greek Ανθρακίτης literally "a type of coal" from Anthrax, coal is a hard compact variety of mineral Coal that has a high Metamorphic rock is the result of the transformation of an existing rock type the protolith, in a process called Metamorphism, which means "change It is composed primarily of carbon and hydrogen along with small quantities of other elements, notably including sulfur. Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Sulfur or sulphur (ˈsʌlfɚ see spelling below) is the Chemical element that has the Atomic number 16 It is the largest source of fuel for generation of electricity world-wide, as well as the largest world-wide source of carbon dioxide emissions, which according to the IPCC, contribute to climate change and global warming. Electricity generation is the process of converting non-electrical Energy to Electricity. Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single Climate change is any long-term significant change in the “average weather” that a given region experiences Global warming is the increase in the average measured temperature of the In terms of carbon dioxide emissions, coal is slightly ahead of petroleum and about double that of natural gas. Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single Petroleum ( L petroleum, from Greek πετρέλαιον, lit Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane, [1] Coal is extracted from the ground by coal mining, either underground mining or open pit mining (surface mining). Coal mining is the extraction or removal of Coal from the Earth by Mining. Mining is the extraction of valuable Minerals or other geological materials from the earth usually (but not always from an Ore body Open-pit mining, also known as opencast mining and open-cut mining and strip mining, refers to a method of extracting rock or Minerals Surface mining is a type of Mining in which soil and rock overlying the mineral deposit are removed

## Types 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. Pressure (symbol 'p' is the force per unit Area applied to an object in a direction perpendicular to the surface Peat is an accumulation of partially Decayed Vegetation matter. It has industrial importance as a fuel in some countries, 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 steam-electric power generation. Lignite, often referred to as brown coal, or Rosebud coal by Northern Pacific Railroad, is a soft brown fuel with characteristics that put it somewhere Jet is a compact form of lignite that is sometimes polished and has been used as an ornamental stone since the Iron Age. Jet is a geological material and is considered to be a minor gemstone An ornamental stone is a stone used as a decoration They differ from Gemstones in that they are not only used for Jewelry. This article is about the archaeological period known as the Iron Age for the mythological Iron Age see Ages of Man.
• Sub-bituminous coal, whose properties range from those of lignite to those of bituminous coal and are used primarily as fuel for steam-electric power generation. Sub-bituminous coal is a type of Coal whose properties range from those of Lignite to those of Bituminous coal and are used primarily as fuel for steam-electric Additionally, it is an important source of light aromatic hydrocarbons for the chemical synthesis industry.
• Bituminous coal, a 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. Bituminous coal is a relatively soft Coal containing a tarlike substance called Bitumen. Coke is a solid Carbonaceous material derived from Destructive distillation of low-ash low-sulfur Bituminous coal.
• Anthracite, the highest rank; a harder, glossy, black coal used primarily for residential and commercial space heating. Anthracite ( Greek Ανθρακίτης literally "a type of coal" from Anthrax, coal is a hard compact variety of mineral Coal that has a high It may be divided further in to 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 Mineral graphite, as with Diamond and Fullerene, is one of the Allotropes of carbon. A lubricant (sometimes referred to as a "Lube" is a substance (often a liquid introduced between two moving surfaces to reduce the Friction between them improving

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]

NameVolatiles %C Carbon %H Hydrogen %O Oxygen %S Sulfur %Heat content kJ/kg
Braunkohle (Lignite)45-6560-756. 0-5. 834-170. 5-3<28470
Flammkohle (Flame coal)40-4575-826. 0-5. 8>9. 8~1<32870
Gasflammkohle (Gas flame coal)35-4082-855. 8-5. 69. 8-7. 3~1<33910
Gaskohle (Gas coal)28-3585-87. 55. 6-5. 07. 3-4. 5~1<34960
Fettkohle (Fat coal)19-2887. 5-89. 55. 0-4. 54. 5-3. 2~1<35380
Esskohle (Forge coal)14-1989. 5-90. 54. 5-4. 03. 2-2. 8~1<35380
Magerkohle (Non baking coal)10-1490. 5-91. 54. 0-3. 752. 8-3. 5~135380
Anthrazit (Anthracite)7-12>91. 5<3. 75<2. 5~1<35300

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 (the U. S. anthracite has < 8% volatiles).

## Early use

However, there is no evidence that the product was of great importance in Britain before the High Middle Ages, after about AD 1000. The High Middle Ages was the period of European history in the 11th 12th and 13th centuries (AD 1000&ndash1299 Mineral coal came to be referred to as "seacoal," probably because it came to many places in eastern England, including London, by sea. A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific London ( ˈlʌndən is the capital and largest urban area in the United Kingdom. This is accepted as the more likely explanation for the name than that it was found on beaches, having fallen from the exposed coal seams above or washed out of underwater coal seam outcrops. Coal mining is the extraction or removal of Coal from the Earth by Mining. These easily accessible sources had largely become exhausted (or could not meet the growing demand) by the 13th century, when underground mining from shafts or adits was developed. Shaft mining or Shaft sinking refers to the method of excavating a vertical or near-vertical tunnel from the top down where there is initially no access to the bottom An adit is a type of entrance to an Underground mine which is horizontal or nearly horizontal [4] In London there is still a Seacoal Lane (off the north side of Ludgate Hill) where the coal merchants used to conduct their business. Ludgate Hill is a hill in the City of London, near the old Ludgate, a gate to the City that was taken down with its attached jail in 1780 An 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. The Industrial Revolution was a period in the late 18th and early 19th centuries when major changes in agriculture manufacturing and transportation had a profound effect on the A steam engine is a Heat engine that performs Mechanical work using Steam as its Working fluid. A water wheel is a means of extracting power from the flow (or fall of water otherwise known as Hydropower.

## Uses today

Coal rail cars in Ashtabula, Ohio. Ashtabula is a City in Ashtabula County, Ohio, United States, and the center of the Ashtabula Micropolitan Statistical Area (as defined

### Coal as fuel

Coal is primarily used as a solid fuel to produce electricity and heat through combustion. Clean coal is an Umbrella term used in the promotion of the use of Coal as an energy source by emphasizing methods being developed to reduce its environmental impact A fossil fuel power plant burns Fossil fuels such as Coal, Natural gas or Petroleum (oil to produce Electricity. Fuel is any material that is burned or altered in order to obtain energy World coal consumption is about 6. 2 billion tons annually, of which about 75% is used for the production of electricity. China produced 2. The People's Republic of China is the largest consumer of Coal in the world and is about to become the largest user of coal-derived electicity getting 38 billion tonnes in 2006 and India produced about 447. India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country 3 million tonnes in 2006. 83. 2% of China's electricity comes from coal. The USA consumes about 1. 053 billion tonnes of coal each year, using 90% of it for generation of electricity. The world in total produced 6. 19 billion tonnes of coal in 2006.

When coal is used for electricity generation, it is usually pulverized and then burned in a furnace with a boiler. Electricity generation is the process of converting non-electrical Energy to Electricity. A furnace is a device used for Heating The name derives from Latin fornax, Oven. A boiler is a closed vessel in which Water or other Fluid is heated The furnace heat converts boiler water to steam, which is then used to spin turbines which turn generators and create electricity. Uses A Steam engine uses the expansion of steam in order to drive a Piston or Turbine to perform Mechanical work. A turbine is a rotary Engine that extracts Energy from a Fluid flow In Electricity generation, an electrical generator is a device that converts Mechanical energy to Electrical energy, generally using Electromagnetic The thermodynamic efficiency of this process has been improved over time. In Thermodynamics, the thermal efficiency (\eta_{th} \ is a dimensionless performance measure of a thermal device such as an Internal combustion "Standard" steam turbines have topped out with some of the most advanced reaching about 35% thermodynamic efficiency for the entire process, which means 65% of the coal energy is waste heat released into the surrounding environment. Old coal power plants, especially "grandfathered" plants, are significantly less efficient and produce higher levels of waste heat.

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. A steam turbine is a mechanical device that extracts Thermal energy from pressurized Steam, and converts it into useful mechanical work [7]

Other efficient ways to use coal are combined cycle power plants, combined heat and power cogeneration, and an MHD topping cycle. A combined cycle is characteristic of a power producing engine or plant that employs more than one Thermodynamic cycle. Energy recycling Cogeneration (also combined heat and power, CHP) is the use of a Heat engine or a Power station to simultaneously generate both The MHD ( magnetohydrodynamic) generator or dynamo transforms Thermal energy or Kinetic energy directly into Electricity

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), might be sufficient for 300 years' use at current consumption levels, although maximal production could be reached within decades (see World Coal Reserves, below). Lignite, often referred to as brown coal, or Rosebud coal by Northern Pacific Railroad, is a soft brown fuel with characteristics that put it somewhere Bituminous coal is a relatively soft Coal containing a tarlike substance called Bitumen.

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). A solid oxide fuel cell ( SOFC) is an electrochemical conversion device that produces electricity directly from oxidizing a fuel Molten-carbonate fuel cells ( MCFCs) are high-temperature Fuel cells that operate at temperatures of 600°C and above 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. Coal dust is a fine powdered form of Coal, which is created by the crushing grinding or pulverizing of coal 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.

### Coking and use of coke

Main article: Coke (fuel)
Coke burning

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. Coke is a solid Carbonaceous material derived from Destructive distillation of low-ash low-sulfur Bituminous coal. Coke is a solid Carbonaceous material derived from Destructive distillation of low-ash low-sulfur Bituminous coal. Bituminous coal is a relatively soft Coal containing a tarlike substance called Bitumen. Metallurgic coke is used as a fuel and as a reducing agent in smelting iron ore in a blast furnace. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 A blast furnace is a type of metallurgical Furnace used for Smelting to produce metals generally 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 that include coal tar, ammonia, light oils, and "coal gas". Coal tar is a brown or black liquid of high Viscosity, which smells of Naphthalene and Aromatic hydrocarbons Coal tar is among the by-products when coal Ammonia is a compound with the formula N[[hydrogen H3]] It is normally encountered as a Gas with a characteristic pungent Odor

Petroleum coke is the solid residue obtained in oil refining, which resembles coke but contains too many impurities to be useful in metallurgical applications. Petroleum coke (often abbreviated petcoke) is a Carbonaceous solid derived from Oil refinery Coker units or other cracking processes An oil refinery is an industrial Process plant where Crude oil is processed and refined into more useful Petroleum products, such as Gasoline

#### Gasification

High prices of oil and natural gas are leading to increased interest in "BTU Conversion" technologies such as gasification, methanation and liquefaction. Underground coal gasification (UCG is an in-situ Gasification process carried out in non-mined coal seams using injection and production wells drilled from the surface Gasification is a process that converts carbonaceous materials such as Coal, Petroleum, or Biomass, into Carbon monoxide and Hydrogen

Coal gasification breaks down the coal into smaller molecular weight molecules, usually by subjecting it to high temperature and pressure, using steam and measured amounts of oxygen. This leads to the production of syngas, a mixture mainly consisting of carbon monoxide (CO) and hydrogen (H2). Syngas (from syn thesis gas) is the name given to a gas mixture that contains varying amounts of Carbon monoxide and Hydrogen. Carbon monoxide, with the chemical formula CO is a colorless odorless tasteless yet highly toxic Gas. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1

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. Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane, South Africa still uses gasification of coal for much of its petrochemical needs. The Republic of South Africa (also known by other official names) is a country located at the southern tip of the continent of Africa

The Synthetic Fuels Corporation was a U. The Synthetic Fuels Corporation was a US government -funded corporation established in 1980 by the Synthetic Fuels Corporation Act to create a market for alternatives 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.

Gasification is also a possibility for future energy use, as the produced syngas can be cleaned-up relatively easily leading to cleaner burning than burning coal directly (the conventional way). The cleanliness of the cleaned-up syngas is comparable to natural gas enabling to burn it in a more efficient gas turbine rather than in a boiler used to drive a steam turbine. A gas turbine, also called a combustion turbine, is a rotary Engine that extracts energy from a flow of Combustion gas Syngas produced by gasification can be CO-shifted meaning that the combustible CO in the syngas is transferred into carbon dioxide (CO2) using water as a reactant. The CO-shift reaction also produces an amount of combustible hydrogen (H2) equal to the amount of CO converted into CO2. The CO2 concentrations (or rather CO2 partial pressures) obtained by using coal gasification followed by a CO-shift reaction are much higher than in case of direct combustion of coal in air (which is mostly nitrogen). Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five These higher concentrations of carbon dioxide make carbon capture and storage much more economical than it otherwise would be. Carbon capture and storage ( CCS) is an approach to mitigating Global warming based on capturing Carbon dioxide (CO2 from large

#### Liquefaction - Coal-To-Liquids (CTL)

Coals can also be converted into liquid fuels like gasoline or diesel by several different processes. Synthetic fuel or synfuel is any Liquid fuel obtained from Coal, Natural gas, or Biomass. Diesel or Diesel fuel (ˈdiːzəl in general is any Fuel used in Diesel engines The most common is a specific fractional distillate of petroleum The Fischer-Tropsch process of indirect synthesis of liquid hydrocarbons was used in Nazi Germany for many years and is today used by Sasol in South Africa. The Fischer-Tropsch process (or Fischer-Tropsch Synthesis is a catalyzed chemical reaction in which synthesis gas ( Syngas) a mixture of Carbon monoxide In Organic chemistry, a hydrocarbon is an Organic compound consisting entirely of Hydrogen and Carbon. Nazi Germany and the Third Reich are the common English names for Germany under the regime of Adolf Hitler and the National Socialist German Workers Sasol (originally Afrikaans for Suid-Afrikaanse Steenkool en Olie - South African Coal and Oil is a South African company involved in mining energy chemicals Coal would be gasified to make syngas (a balanced purified mixture of CO and H2 gas) and the syngas condensed using Fischer-Tropsch catalysts to make light hydrocarbons which are further processed into gasoline and diesel. Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst Syngas can also be converted to methanol, which can be used as a fuel, fuel additive, or further processed into gasoline via the Mobil M-gas process. Methanol, also known as methyl alcohol, carbinol, wood alcohol, wood naphtha or wood spirits, is a Chemical compound Gasoline additives increase Gasoline 's Octane rating or act as Corrosion inhibitors or lubricators, thus allowing the use of higher Compression Mobil Gas Station by David Shankbonejpg|thumb|Mobil gas station East Village section of New York City]] Mobil was a major American oil company

A direct liquefaction process Bergius process [8] (liquefaction by hydrogenation) is also available but has not been used outside Germany, where such processes were operated both during World War I and World War II. The Bergius Process is a method of production of liquid Hydrocarbons for use as Synthetic fuel by Hydrogenation of high-volatile bituminous coal at high Hydrogenation is the Chemical reaction that results in addition of Hydrogen (H2 Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. World War I (abbreviated WWI; also known as the First World War, the Great War, and the War to End All World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including SASOL in South Africa has experimented with direct hydrogenation. Several other direct liquefaction processes have been developed, among these being the SRC-I and SRC-II (Solvent Refined Coal) processes developed by Gulf Oil and implemented as pilot plants in the United States in the 1960s and 1970s. Gulf Oil was a major global oil company from the 1900s to the 1980s [9]

Another direct hydrogenation process was explored by the NUS Corporation in 1976 and patented by Wilburn C. Schroeder. The process involved dried, pulverized coal mixed with roughly 1wt% molybdenum catalysts. Molybdenum (məˈlɪbdənəm from the Greek word for the metal " Lead " is a Group 6 Chemical element with the symbol Mo Hydrogenation occurred by use of high temperature and pressure synthesis gas produced in a separate gasifier. Syngas (from syn thesis gas) is the name given to a gas mixture that contains varying amounts of Carbon monoxide and Hydrogen. The process ultimately yielded a synthetic crude product, Naphtha, a limited amount of C3/C4 gas, light-medium weight liquids (C5-C10) suitable for use as fuels, small amounts of NH3 and significant amounts of CO2. Naphtha normally refers to a number of different flammable liquid mixtures of hydrocarbons i [10]

Yet another process to manufacture liquid hydrocarbons from coal is low temperature carbonization (LTC). Carbonization or Carbonisation is the term for the conversion of an Organic substance into Carbon or a carbon-containing residue through Pyrolysis Coal is coked at temperatures between 450 and 700°C compared to 800 to 1000°C for metallurgical coke. 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. The Karrick process was developed by Lewis C. The Karrick process is a low-temperature Carbonization (LTC of Coal, shale, Lignite or any carbonaceous materials Karrick, an oil shale technologist at the U.S. Bureau of Mines in the 1920s. For most of the 20th century the US Bureau of Mines (USBM was the primary United States Government agency conducting scientific research and disseminating information on

All of these liquid fuel production methods release carbon dioxide (CO2) in the conversion process, far more than is released in the extraction and refinement of liquid fuel production from petroleum. If these methods were adopted to replace declining petroleum supplies, carbon dioxide emissions would be greatly increased on a global scale. For future liquefaction projects, Carbon dioxide sequestration is proposed to avoid releasing it into the atmosphere, though no pilot projects have confirmed the feasibility of this approach on a wide scale. As CO2 is one of the process streams, sequestration is easier than from flue gases produced in combustion of coal with air, where CO2 is diluted by nitrogen and other gases. Combustion or burning is a complex sequence of Exothermic chemical reactions between a Fuel and an Oxidant accompanied by the production of Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14 Sequestration will, however, add to the cost.

The reaction of coal and water using high temperature heat from a nuclear reactor offers promise of liquid transport fuels that could prove carbon-neutral compared to petroleum use. Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature The development of a reliable nuclear reactor that could provide 900 to 1000 deg C process heat, such as the pebble bed reactor, would be necessary.

Coal liquefaction is one of the backstop technologies that could potentially limit escalation of oil prices and mitigate the effects of transportation energy shortage that some authors have suggested could occur under peak oil. Backstop resources theory states that as a heavily utilized limited resources becomes expensive alternative resources will become cheap by comparison therefore making the alternatives 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 USD per barrel,[11] (break-even cost). This price, while above historical averages, is well below current oil prices. This article is about the price of crude oil see Gasoline usage and pricing for information about derivative motor fuels This makes coal a viable financial alternative to oil for the time being, although current production is small. [12]

Among commercially mature technologies, advantage for indirect coal liquefaction over direct coal liquefaction are reported by Williams and Larson (2003). Estimates are reported for sites in China where break-even cost for coal liquefaction may be in the range between 25 to 35 USD/barrel of oil. '

Intensive research and project developments have been implemented from 2001. The World CTL Award is granted to personalities having brought eminent contribution to the understanding and development of Coal liquefaction. The 2008 presentation ceremony took place at the World CTL 2008 Conference (3 & 4 April, 2008).

### Coal as a traded commodity

The price of coal has gone up from around $30 per short ton in 2000 to around$130 per short ton in 2008. The short ton ( S/T) is a unit of mass equal to 2000 lb (around 907

In North America, a Central Appalachian coal futures contract is currently traded on the New York Mercantile Exchange (trading symbol QL). The Appalachian Mountains ( often called the Appalachians, are a vast system of mountains in eastern North America. In Finance, a futures contract is a standardized Contract, traded on a Futures exchange, to buy or sell a certain Underlying instrument The New York Mercantile Exchange (NYMEX is the World 's largest physical Commodity Futures exchange, located in New York City. The trading unit is 1,550 short tons 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, the futures contract provides coal producers and the electric power industry an important tool for hedging and risk management. In Finance, a hedge is an investment that is taken out specifically to reduce or cancel out the Risk in another investment [13]

In addition to the NYMEX contract, the IntercontinentalExchange (ICE) has European (Rotterdam) and South African (Richards Bay) coal futures available for trading. IntercontinentalExchange ( is an American financial company that operates Internet-based marketplaces which trade futures and over-the-counter The trading unit for these contracts is 5,000 tonnes, and are also quoted in U. S. dollars and cents per tonne. [14]

### Cultural usage

Coal is the official state mineral of Kentucky and the official state rock of Utah. Not every state has an official state mineral rock stone or gemstone The Commonwealth of Kentucky ( is a state located in the East Central United States of America. Not every state has an official state mineral rock stone or gemstone The State of Utah (ˈjuːtɔː or) is a western state of the United States. Both U.S. states have a historic link to coal mining. A US state is any one of the fifty subnational entities of the United States of America that share Sovereignty with the federal government

Some cultures uphold that children who misbehave will receive coal from Santa Claus for Christmas in their stockings instead of presents. Santa Claus, also known as Saint Nicholas, Father Christmas, Kris Kringle, or simply " Santa " is the ChristmasStockingjpg|thumb|A Christmas stocking hung on a bedpost

It is also customary and lucky in Scotland to give coal as a gift on New Year's Day. It happens as part of First-Footing and represents warmth for the year to come. First-Footing, in British Folklore, especially that of the north and Scotland, is the first person who crosses the threshold after midnight at the end of

## Environmental effects

There are a number of adverse environmental effects of coal mining and burning. There are a number of adverse environmental effects of coal mining and burning

These effects include:

• release of carbon dioxide and methane, both of which are greenhouse gases, which are causing climate change and global warming according to the IPCC. Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single Methane is a Chemical compound with the molecular formula. It is the simplest Alkane, and the principal component of Natural gas. Greenhouse gases are gaseous constituents of the atmosphere bothnatural and anthropogenic that absorb and emit radiation at specific wavelengths within the spectrum of thermal infrared Climate change is any long-term significant change in the “average weather” that a given region experiences Global warming is the increase in the average measured temperature of the Coal is the largest contributor to the human-made increase of CO2 in the air. [15]
• waste products including uranium, thorium, and other heavy metals
• acid rain
• interference with groundwater and water table levels
• impact of water use on flows of rivers and consequential impact on other land-uses
• dust nuisance
• subsidence above tunnels, sometimes damaging infrastructure
• rendering land unfit for other uses. Uranium (jʊˈreɪniəm is a silvery-gray Metallic Chemical element in the Thorium (ˈθɔːriəm is a Chemical element with the symbol Th and Atomic number 90 Acid rain is Rain or any other form of precipitation that is unusually Acidic It has harmful effects on plants aquatic animals and infastructure Groundwater is Water located beneath the Ground surface in Soil pore spaces and in the Fractures of lithologic formations
• coal-fired power plants without effective fly ash capture are one of the largest sources of human-caused background radiation exposure. Background radiation is the Ionizing radiation emitted from a variety of natural and artificial Radiation sources

## Energy density

Main article: Energy value of coal

The energy density of coal, i. The energy value of coal, or the fuel content, is the amount of Potential energy in Coal that can be converted into actual heating ability. e. its heating value, is roughly 24 megajoules per kilogram. The heat of combustion (ΔHc0 is the Energy released as Heat when a compound undergoes complete Combustion with Oxygen The joule (written in lower case ˈdʒuːl or /ˈdʒaʊl/ (symbol J) is the SI unit of Energy measuring heat, Electricity [16]

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. The energy density of coal is 6. 67 kW·h/kg and the typical thermodynamic efficiency of coal power plants is about 30%. In Thermodynamics, the thermal efficiency (\eta_{th} \ is a dimensionless performance measure of a thermal device such as an Internal combustion Of the 6. 67 kW·h of energy per kilogram of coal, about 30% of that can successfully be turned into electricity—the rest is waste heat. Coal power plants obtain approximately 2. 0 kW·h per kg of burned coal.

As an example, running one 100 watt computer 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:

$\frac{876 \ \mathrm{kW \cdot h}}{2.0 \ \mathrm{kW} \cdot \mathrm{h/kg}} = 438 \ \mathrm{kg \ of \ coal} = 966 \ \mathrm{pounds \ of \ coal}$

It takes 438 kg (966 pounds) of coal to power a computer for one full year. [17] 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. Electric power transmission, a process in the delivery of Electricity to consumers is the bulk transfer of electrical power

## Relative carbon cost

Because coal is at least 50% carbon (by mass), then 1 kg of coal contains at least 0. 5 kg of carbon, which is

$\frac{0.5 \ \mathrm{kg}}{\mathrm{12} \cdot \mathrm{kg/kmol}} = \frac{1}{24} \ \mathrm{kmol}$ where 1 mol is equal to NA (Avogadro Number) particles. The mole (symbol mol) is a unit of Amount of substance: it is an SI base unit, and almost the only unit to be used to measure this

This combines with oxygen in the atmosphere during combustion, producing carbon dioxide, with an atomic weight of (12 + 16 × 2 = mass(CO2) = 44 kg/kmol), so 124 kmol of CO2 is produced from the 124 kmol present in every kilogram of coal, which once trapped in CO2 weighs approximately

$\frac{1}{24} \ \mathrm{kmol} \cdot \frac{44 \ \mathrm{kg}}{\mathrm{kmol}} = \frac{11}{6} \ \mathrm{kg} \approx 1.83 \ \mathrm{kg}$.

This can be used to put a carbon-cost of energy on the use of coal power. Since the useful energy output of coal is about 30% of the 6. 67 kW·h/kg(coal), we can say about 2 kW·h/kg(coal) of energy is produced. Since 1 kg coal roughly translates as 1. 83 kg of CO2, we can say that using electricity from coal produces CO2 at a rate of about 0. 915 kg/(kW·h), or about 0. 254 kg/MJ.

This estimate compares favourably with the U. S. Energy Information Agency's 1999 report on CO2 emissions for energy generation[18], which quotes a specific emission rate of 950 g CO2/(kW·h). By comparison, generation from oil in the U. S. was 890 g CO2/(kW·h), while natural gas was 600 g CO2/(kW·h). Estimates for specific emission from nuclear power, hydro, and wind energy vary, but are about 100 times lower. See environmental effects of nuclear power for estimates. See also Nuclear debate Nuclear power, as with all power sources has an effect on the environment through the Nuclear fuel cycle, through operation and

## Coal fires

There are hundreds of coal fires burning around the world. [19] 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. Spontaneous combustion is a type of Combustion which occurs without an external ignition source A coal seam fire or mine fire is the underground Smouldering of a Coal deposit often a Coal mine. A grass fire in a coal area can set dozens of coal seams on fire. [20][21] Coal fires in China burn 109 million tonnes 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. [22][23] 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. Centralia is a borough in Columbia County Pennsylvania, United States. A borough is an Administrative division of various countries In principle the term borough designates a self-governing Township although in practice The Coal Region is a term used to refer to an area of Northeastern Pennsylvania in the central Appalachian Mountains comprising Lackawanna The United States of America —commonly referred to as the Anthracite ( Greek Ανθρακίτης literally "a type of coal" from Anthrax, coal is a hard compact variety of mineral Coal that has a high 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. For a topic outline on this subject see List of basic Australia topics. Burning Mountain is a feature near Wingen, New South Wales, Australia, approximately 300km north of Sydney just off the New England [24]

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. The Yaghnob River is a tributary of the Zeravshan River of Sughd (at ca Tajikistan (təˈdʒɪkɨstæn or /təˈdʒiːkɨstæn/ Тоҷикистон tɔʤikɪsˈtɔn or, Persian تاجیکستان‎ taajikestaan officially the Republic of Local people once used this method to mine ammoniac. Ammonia is a compound with the formula N[[hydrogen H3]] It is normally encountered as a Gas with a characteristic pungent Odor This place has been well-known since the time of Herodotus, but European geographers mis-interpreted the Ancient Greek descriptions as the evidence of active volcanism in Turkestan (up to the 19th century, when Russian army invaded the area). Herodotus of Halicarnassus ( Greek: Hēródotos Halikarnāsseús) was a Greek Historian who lived in the 5th century BC ( 484 BC&ndash Turkestan (literally meaning "Land of the Turks" is a region in Central Asia, which today is largely inhabited by Turkic peoples.

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". The Powder River Basin is a region in southeast Montana and northeast Wyoming about east to west and north to south known for its Coal deposits The State of Wyoming ( is a sparsely populated state in the western region of the United States. North Dakota ( is a state located in the Midwestern and Western regions of the United States of America. Scoria is a textural term for macrovesicular Volcanic rock. It is commonly but not exclusively Basaltic or andesitic in composition [25] Clinker is rock that has been fused by the natural burning of coal. In the Powder River Basin approximately 27 to 54 billion tonnes of coal burned within the past three million years. [26] Wild coal fires in the area were reported by the Lewis and Clark Expedition as well as explorers and settlers in the area. [27]

## Production trends

Coal output in 2005

In 2006, China was the top producer of coal with 38% share followed by the USA and India, reports the British Geological Survey. The British Geological Survey (BGS is a partly publicly-funded body which aims to advance geoscientific knowledge of the United Kingdom landmass and its Continental

### World coal reserves

The 998 billion tons of recoverable coal reserves estimated by the Energy Information Administration are equal to about 4,417 BBOE (billion barrels of oil equivalent). The barrel of oil equivalent (bboe sometimes BOE is a unit of energy based on the approximate energy released by burning one barrel of Crude oil. The amount of coal burned during 2001 was calculated as 2. 337 GTOE (gigatonnes of oil equivalent), which is about 46 million barrels of oil equivalent per day. The tonne of oil equivalent ( toe) is a unit of energy: the amount of energy released by burning one Tonne of Crude oil, approximately 42 Were consumption to continue at that rate those reserves would last about 263 years. As a comparison, natural gas provided 51 million barrels (oil equivalent), and oil 76 million barrels, per day during 2001.

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.

US coal regions

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 USA, Russia, Australia, China, India and South Africa.

Note the table below.

Proved recoverable coal reserves at end-2006 (million tonnes (teragrams))[31]
CountryBituminous & anthraciteSubBituminous & ligniteTOTALShare
USA111,338135,305246,64327. The United States of America —commonly referred to as the 1
Russia49,088107,922157,01017. Russia (Россия Rossiya) or the Russian Federation ( Rossiyskaya Federatsiya) is a transcontinental Country extending 3
China62,20052,300114,50012. Talk People's Republic of China) PEOPLE'S REPUBLIC OF CHINA ARTICLE GUIDELINES 6
India90,0852,36092,44510. India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country 2
Australia38,60039,90078,5008. For a topic outline on this subject see List of basic Australia topics. 6
South Africa48,750048,7505. The Republic of South Africa (also known by other official names) is a country located at the southern tip of the continent of Africa 4
Ukraine16,27417,87934,1533. Ukraine (Україна Ukrayina, /ukrɑˈjinɑ/ is a country in Eastern Europe. 8
Kazakhstan28,1513,12831,2793. Kazakhstan, also Kazakstan ( Қазақстан, Qazaqstan, qɑzɑqˈstɑn Казахстан, Kazakhstán,) officially the 4
Poland14,000014,0001. Poland (Polska officially the Republic of Poland 5
Brazil010,11310,1131. |utc_offset = -2 to -4 |time_zone_DST = BRST |utc_offset_DST = -2 to -5 |cctld 1
Germany1836,5566,7390. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. 7
Colombia6,2303816,6110. Colombia (kəˈlʌmbɪə officially the Republic of Colombia () is a country in northwestern South America. 7
Czech Republic2,0943,4585,5520. The Czech Republic ( ˈt͡ʃɛskaː ˈrɛpuˌblɪka short form in Česko ˈt͡ʃɛskɔ also called Czechia, 6
Indonesia7404,2284,9680. The Republic of Indonesia ( (Republik Indonesia is a Country in Southeast Asia. 5
Turkey2783,9084,1860. Turkey (Türkiye known officially as the Republic of Turkey ( is a Eurasian Country that stretches 5
Greece03,9003,9000. Greece (Ελλάδα transliterated: Elláda, historically, Ellás,) officially the Hellenic Republic (Ελληνική Δημοκρατία 4
Hungary1983,1593,3570. Hungary (Magyarország 'mɔɟɔrorsaːg) officially in English the Republic of Hungary ( Magyar Köztársaság, literally Magyar (Hungarian Republic 4
Pakistan03,0503,0500. Pakistan () officially the Islamic Republic of Pakistan, is a country located in South Asia, Southwest Asia, Middle East and 3
Bulgaria42,1832,1870. The state of Bulgaria (България transliterated bg-Latn ''Balgaria'' The country preserves the traditions (in ethnic name language and alphabet of the First Bulgarian 2
Thailand01,3541,3540. The Kingdom of Thailand (ˈtaɪlænd ราชอาณาจักรไทย, râːtɕʰa-ʔaːnaːtɕɑ̀k-tʰɑj 1
North Korea3003006000. North Korea is the commonly used short form name for the Democratic People's Republic of Korea (or DPRK) a State located in East Asia, 1
New Zealand335385710. New Zealand is an Island country in the south-western Pacific Ocean comprising two main landmasses (the North Island and the South Island 1
Spain2003305300. Spain () or the Kingdom of Spain (Reino de España is a country located mostly in southwestern Europe on the Iberian Peninsula. 1
Zimbabwe50205020. See also Great Zimbabwe National Monument. For information about the March and June 2008 presidential elections see Zimbabwean presidential election 1
Romania224724940. Romania ( dated: Rumania, Roumania 1
Venezuela47904790. Venezuela (ˌvɛnəˈzweɪlə) officially the Bolivarian Republic of Venezuela (Spanish República Bolivariana de Venezuela) is a country on the 1
TOTAL478,771430,293909,064100. 0

### Major coal producers

Production of Coal by Country and year (million tonnes)[31]
Country2003200420052006
PR China1722. China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National 01992. 32204. 72380. 0
United States972. The United States of America —commonly referred to as the 31008. 91026. 51053. 6
India375. India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country 4407. 7428. 4447. 3
Australia351. For a topic outline on this subject see List of basic Australia topics. 5366. 1378. 8373. 8
Russian Federation276. Russia (Россия Rossiya) or the Russian Federation ( Rossiyskaya Federatsiya) is a transcontinental Country extending 7281. 7298. 5309. 2
South Africa237. The Republic of South Africa (also known by other official names) is a country located at the southern tip of the continent of Africa 9243. 4244. 4256. 9
Germany204. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. 9207. 8202. 8197. 2
Indonesia114. The Republic of Indonesia ( (Republik Indonesia is a Country in Southeast Asia. 3132. 4146. 9195. 0
Poland163. Poland (Polska officially the Republic of Poland 8162. 4159. 5156. 1
Total World5187. "The world " is a proper noun for the planet Earth envisioned from an Anthropocentric or Human Worldview, as a place 65585. 35886. 76195. 1

### Major coal exporters

Exports of Coal by Country and year (million tonnes)[32][33]
Country200320042005
Australia238. For a topic outline on this subject see List of basic Australia topics. 1247. 6257. 6
United States43. The United States of America —commonly referred to as the 048. 049. 9
South Africa78. The Republic of South Africa (also known by other official names) is a country located at the southern tip of the continent of Africa 774. 977. 5
CIS (Former Soviet Union)41. The Union of Soviet Socialist Republics (USSR was a constitutionally Socialist state that existed in Eurasia from 1922 to 1991 055. 762. 3
Poland16. Poland (Polska officially the Republic of Poland 416. 316. 4
China103. China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National 495. 579. 0
South America57. South America is a Continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a 865. 968. 8
Indonesia107. The Republic of Indonesia ( (Republik Indonesia is a Country in Southeast Asia. 8131. 4147. 6
VietnamN/A10. Vietnam (ˌviːɛtˈnɑːm Việt Nam) officially 314. 1
Total713. 9764. 0804. 2

## References

1. ^ The EIA reports the following emissions in million metric tons of carbon dioxide:
• Nat gas: 5,840. The hypothesis of abiogenic petroleum origin is an alternative hypothesis to the biological origin theory which was popular in Russia and Ukraine between Asphaltenes are molecular substances that are found in Crude oil, along with Resins, Aromatic hydrocarbons and Alkanes (i The Australian Coal Alliance is a Community action group formed to oppose the Wallarah 2 Coal Project proposal in Wyong hinterland Central Coast by Kores Carbochemistry is the branch of Chemistry that studies the transformation of Coals ( Bituminous coal, Anthracite, Lignite, Graphite Charcoal' is the blackish residue consisting of impure Carbon obtained by removing water and other volatile constituents from Animal and Vegetation Clean coal is an Umbrella term used in the promotion of the use of Coal as an energy source by emphasizing methods being developed to reduce its environmental impact Coal assay techniques are specific analytical methods designed to measure the particular physical and chemical properties of coals Coal dust is a fine powdered form of Coal, which is created by the crushing grinding or pulverizing of coal The People's Republic of China is the largest consumer of Coal in the world and is about to become the largest user of coal-derived electicity getting The Coal Measures is a lithostratigraphical term used mainly in the British Isles for the coal-bearing part of the Upper Carboniferous System The Federal Coal Mine Health and Safety Act of 1969, United States Public Law 91-173 generally referred to as the Coal Act, created the Mining Enforcement and Safety Administration Coal mining is the extraction or removal of Coal from the Earth by Mining. The Wallarah 2 Coal Project (W2CP is a proposal by Korea Resources Corporation (owned by the South Korean government to construct a longwall mine near A coal phase-out is a type of Fossil fuels phase out policy that dictates the gradual shutdown of operating Coal-fired power plants while prohibiting construction Coal tar is a brown or black liquid of high Viscosity, which smells of Naphthalene and Aromatic hydrocarbons Coal tar is among the by-products when coal Energy development is the ongoing effort to provide sufficient Primary energy sources and secondary Energy forms to meet civilization's needs The energy value of coal, or the fuel content, is the amount of Potential energy in Coal that can be converted into actual heating ability. Fluidized bed combustion (FBC is a combustion technology used in power plants FutureGen is a US government project announced by President George W Gasification is a process that converts carbonaceous materials such as Coal, Petroleum, or Biomass, into Carbon monoxide and Hydrogen A granular material is a conglomeration of discrete Solid, macroscopic particles characterized by a loss of energy whenever the particles interact (the most common example would Large-scale coal mining developed during the Industrial Revolution, and coal provided the main source of Primary energy The Natural environment, commonly referred to simply as the environment, is all living and non-living things that occur naturally on Earth or some part China is the largest producer of coal in the world while the United States contains the world's largest coal reserves Mountaintop removal mining ( MTR) often referred to in the industry as mountaintop mining/valley fills (MTM/VF is a form of Surface mining that involves an The Udston mining disaster occurred in Hamilton, Scotland on Saturday 28 May 1887 when 73 miners died in a Firedamp Underground coal gasification (UCG is an in-situ Gasification process carried out in non-mined coal seams using injection and production wells drilled from the surface The World Coal Institute (WCI is a non-profit non-governmental association funded by coal enterprises and stakeholders 07
• Petroleum: 10,995. 47
• Coal: 11,357. 19
For 2005 as the official energy statistics of the US Government. [1]
2. ^ Eberhard Lindner; Chemie für Ingenieure; Lindner Verlag Karlsruhe, S. 258
3. ^ Around the Markets: Future for coal brighter Herald Tribune 2007-04-16 accessed 2007-11-29
4. ^ a b Britannica 2004: Coal mining: ancient use of outcropping coal. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1178 BC - A Solar eclipse may have marked the return of Odysseus, legendary King of Ithaca, to his kingdom Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1777 - San Jose California, is founded as el Pueblo de San José de Guadalupe
5. ^ Salway, Peter (2001): A History of Roman Britain. Oxford University Press.
6. ^ Forbes, R J (1966): Studies in Ancient Technology. Brill Academic Publishers, Boston.
7. ^ Balancing economics and environmental friendliness - the challenge for supercritical coal-fired power plants with highest steam parameters in the future (PDF). Retrieved on 2006-10-23. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 4004 BC - Creation of the world begins according to the calculations of Archbishop James Ussher 42 BC -
8. ^ Robert Haul: Friedrich Bergius (1884-1949), p. 62 in 'Chemie in unserer Zeit', VCH-Verlagsgesellschaft mbH, 19. Jahrgang, April 1985, Weinheim Germany
9. ^ Cleaner Coal Technology Programme (October 1999). "Technology Status Report 010: Coal Liquefaction". . Department of Trade and Industry (UK) Retrieved on November 23. Events 800 - Charlemagne arrives at Rome to investigate the alleged crimes of
10. ^ Phillip A. Lowe, Wilburn C. Schroeder, Anthony L. Liccardi (1976). "Technical Economies, Synfuels and Coal Energy Symposium, Solid-Phase Catalytic Coal Liquefaction Process". . The American Society of Mechanical Engineers
11. ^ Diesel Fuel News: Ultra-clean fuels from coal liquefaction: China about to launch big projects - Brief Article. Retrieved on September 9, 2005.
12. ^ Welcome to Coal People Magazine. Retrieved on September 9, 2005.
13. ^ NYMEX.com: Coal. Retrieved on January 16, 2008.
14. ^ ICE: Coal Futures. Retrieved on January 16, 2008.
15. ^ http://www.columbia.edu/~jeh1/2007/IowaCoal_20071105.pdf
16. ^ Fisher, Juliya (2003). Energy Density of Coal. The Physics Factbook. Retrieved on 2006-08-25. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1248 - The Dutch city of Ommen receives city rights and fortification rights from Otto III the
17. ^ A similar result, using a light bulb instead, see
How much coal is required to run a 100-watt light bulb 24 hours a day for a year?. Howstuffworks. Retrieved on 2006-08-25. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1248 - The Dutch city of Ommen receives city rights and fortification rights from Otto III the
18. ^ CO2 Emissions Report
19. ^ Sino German Coal fire project. Retrieved on September 9, 2005.
20. ^ Committee on Resources-Index. Retrieved on September 9, 2005.
21. ^ http://www.fire.blm.gov/textdocuments/6-27-03.pdf. Retrieved on September 9, 2005.
22. ^ EHP 110-5, 2002: Forum. Retrieved on September 9, 2005.
23. ^ Overview about ITC's activities in China. Retrieved on September 9, 2005.
24. ^ Burning Mountain Nature Reserve. Retrieved on September 9, 2005.
25. ^ North Dakota's Clinker. Retrieved on September 9, 2005.
26. ^ BLM-Environmental Education- The High Plains. Retrieved on September 9, 2005.
27. ^ http://www.wsgs.uwyo.edu/Coal/CR01-1.pdf. Retrieved on September 9, 2005.
28. ^ International Energy Annual 2005: Reserves. Retrieved on March 22, 2008.
29. ^ International Energy Outlook 2007 Chapter 5 Coal
30. ^ BP2006 energy report, and US EIA 2006 overview
31. ^ a b BP Statistical review of world energy June 2007 (XLS). British Petroleum (June 2007). Retrieved on 2007-10-22. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 202 BC - Hannibal Barca, leader of the Carthaginians, is defeated by the Roman legions under Scipio Africanus
32. ^ World Steam Coal Flows
33. ^ World Coal Flows by Importing and Exporting Regions