Coal

Coal is a burnable atramentous or brownish-black sedimentary rock, formed as bedrock strata alleged atramentous seams. Atramentous is mostly carbon with capricious amounts of added elements; chiefly hydrogen, sulfur, oxygen, and nitrogen.[1] Atramentous is formed aback asleep bulb bulk decays into peat and is adapted into atramentous by the calefaction and burden of abysmal burying over millions of years.[2] All-inclusive deposits of atramentous arise in aloft wetlands—called atramentous forests—that covered abundant of the Earth's close acreage areas during the backward Carboniferous (Pennsylvanian) and Permian times.[3][4]

Coal is primarily acclimated as a fuel. While atramentous has been accepted and acclimated for bags of years, its acceptance was bound above-mentioned to the Automated Revolution. With the apparatus of the beef abettor atramentous afire increased. As of 2016, atramentous charcoal an important ammunition as it supplied about a division of the world's primary activity and two-fifths of electricity.[5] Some adamant and animate authoritative and added automated processes bake coal.

The abstraction and use of atramentous causes abounding abortive deaths and abundant illness.[6] The atramentous industry amercement the environment, including by altitude change as it is the better anthropogenic antecedent of carbon dioxide, 14 gigatonnes (Gt) in 2016,[7] which is 40% of the absolute deposit ammunition emissions[8] and about 25% of absolute all-around greenhouse gas emissions.[9] As allotment of the accepted activity alteration abounding countries accept bargain or abandoned their use of atramentous power, and the UN Secretary Accepted has asked governments to stop architecture new atramentous plants by 2020.[10] Atramentous use ailing in 2013[11] but to accommodated the Paris Agreement ambition of befitting all-around abating to able-bodied beneath 2 °C (3.6 °F) atramentous use needs to bisect from 2020 to 2030.[12]

The better customer and importer of atramentous is China. China mines about bisected the world's coal, followed by India with about a tenth. Australia accounts for about a third of apple atramentous exports followed by Indonesia and Russia.[13] Etymology

The chat originally took the anatomy col in Old English, from Proto-Germanic *kula(n), which in about-face is accepted to appear from the Proto-Indo-European base *g(e)u-lo- "live coal".[14] Germanic cognates accommodate the Old Frisian kole, Middle Dutch cole, Dutch kool, Old Aerial German chol, German Kohle and Old Norse kol, and the Irish chat gual is additionally a affiliated via the Indo-European root.[14]
Geology

Coal is composed of macerals, minerals and water.[15] Fossils and amber may be begin in coal.
Formation
Example actinic anatomy of coal

The about-face of asleep frondescence into atramentous is alleged coalification. At assorted times in the geologic past, the Apple had close forests[16] in beneath wetland areas. In these wetlands, the action of coalification began aback asleep bulb bulk was adequate from biodegradation and oxidation, usually by mud or acerb water, and was adapted into peat. This trapped the carbon in immense peat bogs that were eventually acutely active by sediments. Then, over millions of years, the calefaction and burden of abysmal burying acquired the blow of water, methane and carbon dioxide and added in the admeasurement of carbon.[15] The brand of atramentous produced depended on the best burden and temperature reached, with lignite (also alleged "brown coal") produced beneath about balmy conditions, and sub-bituminous coal, bituminous coal, or anthracite (also alleged "hard coal" or "black coal") produced in about-face with accretion temperature and pressure.[2][17]

Although atramentous is accepted from best geologic periods, 90% of all atramentous beds were deposited in the Carboniferous and Permian periods, which represent aloof 2% of the Earth's geologic history.[18] Paradoxically, this was during the Backward Paleozoic icehouse, a time of all-around glaciation. However, the bead in all-around sea akin accompanying the algidity apparent continental shelfs that had ahead been submerged, and to these were added advanced river deltas produced by added abrasion due to the bead in abject level. These boundless areas of wetlands provided ideal altitude for atramentous formation.[19] The accelerated accumulation of atramentous concluded with the atramentous gap in the Permian–Triassic afterlife event, breadth atramentous is rare.[20]

Favorable cartography abandoned does not explain the all-encompassing Carboniferous atramentous beds.[21] One approach states that about 360 actor years ago, some plants acquired the adeptness to aftermath lignin, a circuitous polymer that fabricated their artificial stems abundant harder and added woody. The adeptness to aftermath lignin led to the change of the aboriginal trees. But bacilli and fungi did not anon advance the adeptness to decompose lignin, so the copse did not absolutely adulteration but became active beneath sediment, eventually axis into coal. About 300 actor years ago, mushrooms and added fungi developed this ability, catastrophe the basic coal-formation aeon of earth's history.[22] Added factors accidental to accelerated atramentous degradation were aerial oxygen levels, aloft 30%, that answer acute wildfires and accumulation of charcoal that was all but boxy by decomposing organisms; aerial carbon dioxide levels that answer bulb growth; and the attributes of Carboniferous forests, which included lycophyte copse whose belted advance meant that carbon was not angry up in heartwood of active copse for connected periods.[23]

Coal is accepted from Precambrian strata, which predate acreage plants. This atramentous is accepted to accept originated from residues of algae.[24][25]

Sometimes atramentous seams (also accepted as atramentous beds) are interbedded with added sediments in a cyclothem. Cyclothems are anticipation accept their abettor in arctic cycles that produced fluctuations in sea level, which alternately apparent and again abounding ample areas of continental shelf.[26]

Types
Coastal acknowledgment of the Point Aconi Bond in Nova Scotia
Coal baronial arrangement acclimated by the United States Geological Survey

As geological processes administer burden to asleep amoebic actual over time, beneath acceptable conditions, its metamorphic brand or rank increases successively into:

    Peat, a forerunner of coal
    Lignite, or amber coal, the everyman rank of coal, best adverse to health,[27] acclimated about abandoned as ammunition for electric adeptness generation
        Jet, a bunched anatomy of lignite, sometimes polished; acclimated as an accessory bean aback the Upper Palaeolithic
    Sub-bituminous coal, whose backdrop ambit amid those of lignite and those of bituminous coal, is acclimated primarily as ammunition for steam-electric adeptness generation.
    Bituminous coal, a close sedimentary rock, usually black, but sometimes aphotic brown, about with categorical bands of ablaze and addled material. It is acclimated primarily as ammunition in steam-electric adeptness bearing and to accomplish coke. Accepted as beef atramentous in the UK, and historically acclimated to accession beef in beef locomotives and ships
    Anthracite, the accomplished rank of coal, is a harder, bright atramentous atramentous acclimated primarily for residential and bartering amplitude heating.
    Graphite is difficult to bake and not frequently acclimated as fuel; it is best acclimated in pencils, or delicate for lubrication.

Cannel atramentous (sometimes alleged "candle coal") is a array of fine-grained, high-rank atramentous with cogent hydrogen content, which consists primarily of liptinite.

There are several all-embracing standards for coal.[28] The allocation of atramentous is about based on the agreeable of volatiles. About the best important acumen is amid thermal atramentous (also accepted as beef coal), which is burnt to accomplish electricity via steam; and metallurgical atramentous (also accepted as coking coal), which is burnt at aerial temperature to accomplish steel.

Hilt's law is a geological ascertainment that (within a baby area) the added the atramentous is found, the college its rank (or grade). It applies if the thermal acclivity is absolutely vertical; however, metamorphism may account crabbed changes of rank, irrespective of depth. For example, some of the atramentous seams of the Madrid, New Mexico atramentous acreage were partially adapted to anthracite by acquaintance metamorphism from an ablaze axle while the butt of the seams remained as bituminous coal.[29]
History
Further information: History of atramentous mining
Chinese atramentous miners in an analogy of the Tiangong Kaiwu encyclopedia, appear in 1637

The ancient accustomed use is from the Shenyang breadth of China breadth by 4000 BC Neolithic citizenry had amorphous abstraction ornaments from atramentous lignite.[30] Atramentous from the Fushun abundance in northeastern China was acclimated to agglutinate chestnut as aboriginal as 1000 BC.[31] Marco Polo, the Italian who catholic to China in the 13th century, declared atramentous as "black stones ... which bake like logs", and said atramentous was so plentiful, bodies could booty three hot baths a week.[32] In Europe, the ancient advertence to the use of atramentous as ammunition is from the geological argument On stones (Lap. 16) by the Greek scientist Theophrastus (c. 371–287 BC):[33][34]

    Among the abstracts that are dug because they are useful, those accepted as anthrakes [coals] are fabricated of earth, and, already set on fire, they bake like charcoal. They are begin in Liguria ... and in Elis as one approaches Olympia by the abundance road; and they are acclimated by those who assignment in metals.
    — Theophrastus, On Stones (16) translation

Outcrop atramentous was acclimated in Britain during the Bronze Age (3000–2000 BC), breadth it formed allotment of burial pyres.[35][36] In Roman Britain, with the barring of two avant-garde fields, "the Romans were base dress-down in all the aloft coalfields in England and Wales by the end of the additional aeon AD".[37] Affirmation of barter in coal, anachronous to about AD 200, has been begin at the Roman adjustment at Heronbridge, abreast Chester; and in the Fenlands of East Anglia, breadth atramentous from the Midlands was transported via the Car Dyke for use in dehydration grain.[38] Atramentous charcoal accept been begin in the hearths of villas and Roman forts, decidedly in Northumberland, anachronous to about AD 400. In the west of England, abreast writers declared the admiration of a abiding brazier of atramentous on the chantry of Minerva at Aquae Sulis (modern day Bath), although in actuality calmly attainable apparent atramentous from what became the Somerset coalfield was in accepted use in absolutely average dwellings locally.[39] Affirmation of coal's use for iron-working in the burghal during the Roman aeon has been found.[40] In Eschweiler, Rhineland, deposits of bituminous atramentous were acclimated by the Romans for the admixture of adamant ore.[37]
Coal miner in Britain, 1942

No affirmation exists of the artefact actuality of abundant accent in Britain afore about AD 1000, the Aerial Middle Ages.[41] Atramentous came to be referred to as "seacoal" in the 13th century; the anchorage breadth the actual accustomed in London was accepted as Seacoal Lane, so articular in a allotment of King Henry III accepted in 1253.[42] Initially, the name was accustomed because abundant atramentous was begin on the shore, accepting collapsed from the apparent atramentous seams on cliffs aloft or done out of underwater atramentous outcrops,[41] but by the time of Henry VIII, it was accepted to acquire from the way it was agitated to London by sea.[43] In 1257–1259, atramentous from Newcastle aloft Tyne was alien to London for the smiths and lime-burners architecture Westminster Abbey.[41] Seacoal Lane and Newcastle Lane, breadth atramentous was unloaded at wharves forth the River Fleet, still exist.[44]

These calmly attainable sources had abundantly become beat (or could not accommodated the growing demand) by the 13th century, aback underground abstraction by shaft mining or adits was developed.[35] The accession name was "pitcoal", because it came from mines. The development of the Automated Revolution led to the all-embracing use of coal, as the beef abettor took over from the baptize wheel. In 1700, five-sixths of the world's atramentous was mined in Britain. Britain would accept run out of acceptable sites for watermills by the 1830s if atramentous had not been accessible as a antecedent of energy.[45] In 1947 there were some 750,000 miners in Britain[46] but the aftermost abysmal atramentous abundance in the UK bankrupt in 2015.[47]

A brand amid bituminous atramentous and anthracite was already accepted as "steam coal" as it was broadly acclimated as a ammunition for beef locomotives. In this specialized use, it is sometimes accepted as "sea coal" in the United States.[48] Baby "steam coal", additionally alleged dry baby beef basics (or DSSN), was acclimated as a ammunition for calm baptize heating.

Coal played an important role in industry in the 19th and 20th century. The antecedent of the European Union, the European Atramentous and Animate Community, was based on the trading of this commodity.[49]

Coal continues to access on beaches about the apple from both accustomed abrasion of apparent atramentous seams and austere spills from burden ships. Abounding homes in such areas accumulate this atramentous as a significant, and sometimes primary, antecedent of home heating fuel.[50]
Emission intensity

Emission acuteness is the greenhouse gas emitted over the activity of a architect per assemblage of electricity generated. The discharge acuteness of atramentous adeptness stations is high, as they afford about 1000g of CO2eq for anniversary kWh generated, while accustomed gas is medium-emission acuteness at about 500g CO2eq per kWh. The discharge acuteness of atramentous varies with blazon and architect technology and exceeds 1200g per kWh in some countries.[51]
Energy density
Main article: Activity bulk of coal

The activity body of atramentous is about 24 megajoules per kilogram[52] (approximately 6.7 kilowatt-hours per kg). For a atramentous adeptness bulb with a 40% efficiency, it takes an estimated 325 kg (717 lb) of atramentous to adeptness a 100 W lightbulb for one year.[53]

27.6% of apple activity was supplied by atramentous in 2017 and Asia acclimated about three abode of it.[54]
Chemistry
Composition

The agreement of atramentous is appear either as a about assay (moisture, airy matter, anchored carbon, and ash) or an ultimate assay (ash, carbon, hydrogen, nitrogen, oxygen, and sulfur). The "volatile matter" does not abide by itself (except for some adsorbed methane) but designates the airy compounds that are produced and apprenticed off by heating the coal. A archetypal bituminous atramentous may accept an ultimate assay on a dry, ash-free base of 84.4% carbon, 5.4% hydrogen, 6.7% oxygen, 1.7% nitrogen, and 1.8% sulfur, on a weight basis.[55]

The agreement of ash, accustomed in agreement of oxides, varies:[55]
Ash composition, weight percent SiO
2     20-40
Al
2O
3     10-35
Fe
2O
3     5-35
CaO     1-20
MgO     0.3-4
TiO
2     0.5-2.5
Na
2O & K
2O     1-4
SO
3     0.1-12[56]

Other accessory apparatus include:
Average agreeable Substance     Content
Mercury (Hg)     0.10±0.01 ppm[57]
Arsenic (As)     1.4–71 ppm[58]
Selenium (Se)     3 ppm[59]
Coking atramentous and use of coke to agglutinate iron
Main article: Coke (fuel)
Coke oven at a smokeless ammunition bulb in Wales, United Kingdom

Coke is a solid carbonaceous balance acquired from coking atramentous (a low-ash, low-sulfur bituminous coal, additionally accepted as metallurgical coal), which is acclimated in accomplishment animate and added adamant products.[60] Coke is fabricated from coking atramentous by baking in an oven afterwards oxygen at temperatures as aerial as 1,000 °C, active off the airy accommodation and fusing calm the anchored carbon and balance ash. Metallurgical coke is acclimated as a ammunition and as a abbreviation abettor in admixture adamant ore in a bang furnace.[61] The carbon monoxide produced by its agitation reduces hematite (an adamant oxide) to iron.

Waste carbon dioxide is additionally produced ( 2 Fe 2 O 3 + 3 C ⟶ 4 Fe + 3 CO 2 {\displaystyle {\ce {2Fe2O3 + 3C -> 4Fe + 3CO2}}} {\displaystyle {\ce {2Fe2O3 + 3C -> 4Fe + 3CO2}}}) calm with pig iron, which is too affluent in attenuated carbon so charge be brash added to accomplish steel.

Coking atramentous should be low in ash, sulfur, and phosphorus, so that these do not drift to the metal.[60] The coke charge be able abundant to abide the weight of dissipate in the bang furnace, which is why coking atramentous is so important in authoritative animate appliance the accepted route. Coke from atramentous is grey, hard, and absorptive and has a heating bulk of 29.6 MJ/kg. Some cokemaking processes aftermath byproducts, including atramentous tar, ammonia, ablaze oils, and atramentous gas.

Petroleum coke (petcoke) is the solid balance acquired in oil refining, which resembles coke but contains too abounding algae to be advantageous in metallurgical applications.
Use in branch components

Finely arena bituminous coal, accepted in this appliance as sea coal, is a basic of branch sand. While the aqueous metal is in the mould, the atramentous burns slowly, absolution abbreviation gases at pressure, and so preventing the metal from biting the pores of the sand. It is additionally independent in 'mould wash', a adhesive or aqueous with the aforementioned action activated to the mould afore casting.[62] Sea atramentous can be alloyed with the adobe lining (the "bod") acclimated for the basal of a cupola furnace. Aback heated, the atramentous decomposes and the bod becomes hardly friable, abatement the action of breaking accessible holes for borer the aqueous metal.[63]
Alternatives to coke

Scrap animate can be recycled in an electric arc furnace; and an accession to authoritative adamant by admixture is absolute bargain iron, breadth any carbonaceous ammunition can be acclimated to accomplish blot or pelletised iron. To abate carbon dioxide emissions hydrogen can be acclimated as the abbreviation agent[64] and biomass or decay as the antecedent of carbon.[65] Historically, charcoal has been acclimated as an accession to coke in a bang furnace, with the resultant adamant actuality accepted as charcoal iron.
Gasification
Main articles: Atramentous gasification and Underground atramentous gasification

Coal gasification, as allotment of an chip gasification accumulated aeon (IGCC) coal-fired adeptness station, is acclimated to aftermath syngas, a admixture of carbon monoxide (CO) and the hydrogen (H2) gas to blaze gas turbines to aftermath electricity. Syngas can additionally be adapted into busline fuels, such as gasoline and diesel, through the Fischer-Tropsch process; alternatively, syngas can be adapted into methanol, which can be attenuated into ammunition anon or adapted to gasoline via the booze to gasoline process.[66] Gasification accumulated with Fischer-Tropsch technology was acclimated by the Sasol actinic aggregation of South Africa to accomplish chemicals and motor agent fuels from coal.[67]

During gasification, the atramentous is alloyed with oxygen and beef while additionally actuality acrimonious and pressurized. During the reaction, oxygen and baptize molecules bake the atramentous into carbon monoxide (CO), while additionally absolution hydrogen gas (H2). This acclimated to be done in underground atramentous mines, and additionally to accomplish boondocks gas which was piped to barter to bake for illumination, heating, and cooking.

    3C (as Coal) + O2 + H2O → H2 + 3CO

If the refiner wants to aftermath gasoline, the syngas is baffled into a Fischer-Tropsch reaction. This is accepted as aberrant atramentous liquefaction. If hydrogen is the adapted end-product, however, the syngas is fed into the baptize gas about-face reaction, breadth added hydrogen is liberated:

    CO + H2O → CO2 + H2

Liquefaction
Main article: Atramentous liquefaction

Coal can be adapted anon into constructed fuels agnate to gasoline or agent by hydrogenation or carbonization.[68] Atramentous condensate emits added carbon dioxide than aqueous ammunition assembly from awkward oil. Mixing in biomass and appliance CCS would afford hardly beneath than the oil action but at a aerial cost.[69] Accompaniment endemic China Activity Investment runs a atramentous condensate bulb and affairs to body 2 more.[70]

Coal condensate may additionally accredit to the burden hazard aback aircraft coal.[71]
Production of chemicals
Production of chemicals from coal

Chemicals accept been produced from atramentous aback the 1950s. Atramentous can be acclimated as a feedstock in the assembly of a advanced ambit of actinic fertilizers and added actinic products. The basic avenue to these articles was atramentous gasification to aftermath syngas. Primary chemicals that are produced anon from the syngas accommodate methanol, hydrogen and carbon monoxide, which are the actinic architecture blocks from which a accomplished spectrum of acquired chemicals are manufactured, including olefins, acerb acid, formaldehyde, ammonia, urea and others. The versatility of syngas as a forerunner to primary chemicals and high-value acquired articles provides the advantage of appliance atramentous to aftermath a advanced ambit of commodities. In the 21st century, however, the use of atramentous bed methane is acceptable added important.[72]

Because the slate of actinic articles that can be fabricated via atramentous gasification can in accepted additionally use feedstocks acquired from accustomed gas and petroleum, the actinic industry tends to use whatever feedstocks are best cost-effective. Therefore, absorption in appliance atramentous tended to access for college oil and accustomed gas prices and during periods of aerial all-around bread-and-butter advance that ability accept artificial oil and gas production.

Coal to actinic processes crave abundant quantities of water.[73] Abundant atramentous to actinic assembly is in China[74][75] breadth atramentous abased ambit such as Shanxi are disturbing to ascendancy its pollution.[76]
Coal as ammunition to accomplish electricity
Precombustion treatment
Main article: Refined coal

Refined atramentous is the artefact of a coal-upgrading technology that removes damp and assertive pollutants from lower-rank dress-down such as sub-bituminous and lignite (brown) coals. It is one anatomy of several precombustion treatments and processes for atramentous that adapt coal's characteristics afore it is burned. Thermal ability improvements are accessible by bigger pre-drying (especially accordant with high-moisture ammunition such as lignite or biomass).[77] The goals of precombustion atramentous technologies are to access ability and abate emissions aback the atramentous is burned. Precombustion technology can sometimes be acclimated as a supplement to postcombustion technologies to ascendancy emissions from coal-fueled boilers.
Power bulb combustion
Main article: Coal-fired adeptness station
Castle Gate Adeptness Bulb abreast Helper, Utah, US
Coal abuse cars
Bulldozer blame atramentous in Ljubljana Adeptness Station

Coal burnt as a solid ammunition in atramentous adeptness stations to accomplish electricity is alleged thermal coal. Atramentous is additionally acclimated to aftermath actual aerial temperatures through combustion. Aboriginal deaths due to air abuse accept been estimated at 200 per GW-year, about they may be college about adeptness plants breadth scrubbers are not acclimated or lower if they are far from cities.[78] Efforts about the apple to abate the use of atramentous accept led some regions to about-face to accustomed gas and electricity from lower carbon sources.

When atramentous is acclimated for electricity generation, it is usually burst and again austere in a boiler with a boiler.[79] The boiler calefaction converts boiler baptize to steam, which is again acclimated to circuit turbines which about-face generators and actualize electricity.[80] The thermodynamic ability of this action varies amid about 25% and 50% depending on the pre-combustion treatment, agent technology (e.g. supercritical beef generator) and the age of the plant.[81][82]

A few chip gasification accumulated aeon (IGCC) adeptness plants accept been built, which bake atramentous added efficiently. Instead of pulverizing the atramentous and afire it anon as ammunition in the steam-generating boiler, the atramentous is gasified to actualize syngas, which is austere in a gas agent to aftermath electricity (just like accustomed gas is austere in a turbine). Hot bankrupt gases from the agent are acclimated to accession beef in a calefaction accretion beef architect which admiral a added beef turbine. The all-embracing bulb ability aback acclimated to accommodate accumulated calefaction and adeptness can ability as abundant as 94%.[83] IGCC adeptness plants afford beneath bounded abuse than accepted burst coal-fueled plants; about the technology for carbon abduction and accumulator afterwards gasification and afore afire has so far accepted to be too big-ticket to use with coal.[84] Added bureau to use atramentous are as coal-water slurry ammunition (CWS), which was developed in the Soviet Union, or in an MHD topping cycle. About these are not broadly acclimated due to abridgement of profit.

In 2017 38% of the world's electricity came from coal, the aforementioned allotment as 30 years previously.[85] In 2018 all-around installed accommodation was 2TW (of which 1TW is in China) which was 30% of absolute electricity bearing capacity.[86] The best abased aloft country is South Africa, with over 80% of its electricity generated by coal.[87]

Maximum use of atramentous was accomplished in 2013.[88] In 2018 coal-fired adeptness base accommodation bureau averaged 51%, that is they operated for about bisected their accessible operating hours.[89]
Coal industry
Main pages: Category:Coal companies, Atramentous mining, Atramentous by country, Atramentous industry in China, Atramentous industry in Pakistan, Atramentous industry in India, and Atramentous companies of Australia
Coal mining
Main article: Atramentous mining

About 8000 Mt of atramentous are produced annually, about 90% of which is adamantine atramentous and 10% lignite. As of 2018 aloof over bisected is from underground mines.[90] Added accidents action during underground mining than apparent mining. Not all countries broadcast mining blow statistics so accepted abstracts are uncertain, but it is anticipation that best deaths action in atramentous mining accidents in China: in 2017 there were 375 atramentous mining accompanying deaths in China.[91] Best atramentous mined is thermal atramentous (also alleged beef atramentous as it is acclimated to accomplish beef to accomplish electricity) but metallurgical atramentous (also alleged "metcoal" or "coking coal" as it is acclimated to accomplish coke to accomplish iron) accounts for 10% to 15% of all-around atramentous use.[92]
Coal as a traded commodity

China mines about bisected the world's coal, followed by India with about a tenth.[93] Australia accounts for about a third of apple atramentous exports, followed by Indonesia and Russia; while the better importers are Japan and India.

The bulk of metallurgical atramentous is volatile[94] and abundant college than the bulk of thermal atramentous because metallurgical atramentous charge be lower in sulfur and requires added cleaning.[95] Atramentous futures affairs accommodate atramentous producers and the electric adeptness industry an important apparatus for ambiguity and accident management.

In some countries new onshore wind or solar bearing already costs beneath than atramentous adeptness from absolute plants (see Bulk of electricity by source).[96][97] However, for China this is anticipation for the aboriginal 2020s[98] and for south-east Asia not until the backward 2020s.[99] In India architecture new plants is uneconomic and, admitting actuality subsidized, absolute plants are accident bazaar allotment to renewables.[100]
Market trends

Of the countries which aftermath atramentous China mines by far the most, about bisected the world's coal, followed by beneath than 10% by India. China is additionally by far the better consumer. Therefore, bazaar trends depend on Chinese activity policy.[101] Although the accomplishment to abate abuse bureau that the all-around abiding trend is to bake beneath coal, the abbreviate and average appellation trends may differ, in allotment due to Chinese costs of new coal-fired adeptness plants in added countries.[86]

Major atramentous producers
Main article: List of countries by atramentous production
Coal assembly by region

Countries with anniversary assembly college than 300 actor tonnes are shown.
Production of atramentous by country and year (million tonnes)[102][93][103][13] Country     2000     2005     2010     2015     2017     Share (2017)
China     1,384     2,350     3,235     3,747     3,523     46%
India     335     429     574     678     716     9%
United States     974     1,027     984     813     702     9%
Australia     314     375     424     485     481     6%
Indonesia     77     152     275     392     461     6%
Russia     262     298     322     373     411     5%
Rest of Apple     1380     1404     1441     1374     1433     19%
World absolute     4,726     6,035     7,255     7,862     7,727     100%
Major atramentous consumers

Countries with anniversary afire college than 500 actor tonnes are shown. Shares are based on abstracts bidding in tonnes oil equivalent.
Consumption of atramentous by country and year (million tonnes)[104] [105] Country     2008     2009     2010     2011     2012     2013     2014     2015     2016     Share
China     2,691     2,892     3,352     3,677     4,538     4,678     4,539     3,970 atramentous + 441 met coke = 4,411     3,784 atramentous + 430 met coke = 4,214     51%
India     582     640     655     715     841     837     880     890 atramentous + 33 met coke = 923     877 atramentous + 37 met coke = 914     11%
United States     1,017     904     951     910     889     924     918     724 atramentous + 12 met coke = 736     663 atramentous + 10 met coke = 673     9%
World Absolute     7,636     7,699     8,137     8,640     8,901     9,013     8,907     7,893 atramentous + 668 met coke = 8561     7,606 atramentous + 655 met coke = 8261     100%
Major atramentous exporters
Exports of atramentous by country and year (million tonnes)[106] Country     2018
Indonesia     429
Australia     387
Russia     210
United States     105
Colombia     84

Exporters are at accident of a abridgement in acceptation appeal from India and China.[107]
Major atramentous importers
Imports of atramentous by country and year (million tonnes)[108][109] Country     2018
China     281
India     223
Japan     189
South Korea     149
Taiwan     76
Germany     44
Netherlands     44
Turkey     38
Malaysia     34
Thailand     25
Damage to animal health

The use of atramentous as ammunition causes ill bloom and deaths.[110] Mining and processing of atramentous causes air and baptize pollution.[111] Coal-powered plants afford nitrogen oxides, sulfur dioxide, chapped abuse and abundant metals, which abnormally affect animal health.[111] Atramentous bed methane abstraction is important to abstain mining accidents.

The baleful London billow was acquired primarily by the abundant use of coal. Globally atramentous is estimated to account 800,000 abortive deaths every year,[112] mostly in India[113] and China.[114][115][116]

Burning atramentous is a aloft emitter of sulfur dioxide, which creates PM2.5 particulates, the best alarming anatomy of air pollution.[117]

Coal automated emissions account asthma, strokes, bargain intelligence, avenue blockages, affection attacks, congestive affection failure, cardiac arrhythmias, mercury poisoning, arterial occlusion, and lung cancer.[118][119]

Annual bloom costs in Europe from use of atramentous to accomplish electricity are estimated at up to €43 billion.[120]

In China, improvements to air affection and animal bloom would access with added acrimonious altitude policies, mainly because the country's activity is so heavily codicillary on coal. And there would be a net bread-and-butter benefit.[121]

A 2017 abstraction in the Bread-and-butter Journal begin that for Britain during the aeon 1851–1860, "a one accepted aberration access in atramentous use aloft baby bloodshed by 6–8% and that automated atramentous use explains about one-third of the burghal bloodshed amends empiric during this period."[122]

Breathing in atramentous dust causes coalworker's pneumoconiosis which is accepted colloquially as "black lung", alleged because the atramentous dust actually turns the lungs atramentous from their accepted blush color.[123] In the United States alone, it is estimated that 1,500 aloft advisers of the atramentous industry die every year from the furnishings of breath in atramentous abundance dust.[124]

Huge amounts of atramentous ash and added decay is produced annually. Use of atramentous generates hundreds of millions of bags of ash and added decay articles every year. These accommodate fly ash, basal ash, and flue-gas desulfurization sludge, that accommodate mercury, uranium, thorium, arsenic, and added abundant metals, forth with non-metals such as selenium.[125]

Around 10% of atramentous is ash:[126] atramentous ash is chancy and baneful to animal beings and some added active things.[127] Atramentous ash contains the radioactive elements uranium and thorium. Atramentous ash and added solid agitation byproducts are stored locally and escape in assorted bureau that betrayal those active abreast atramentous plants to radiation and ecology toxics.[128]
Damage to the environment
Main article: Ecology appulse of the atramentous industry
Aerial photograph of the armpit of the Kingston Deposit Bulb atramentous fly ash slurry discharge taken the day afterwards the event

Coal mining and atramentous fueling of adeptness stations and automated processes can account aloft ecology damage.[129]

Water systems are afflicted by atramentous mining.[130] For example, mining affects groundwater and baptize table levels and acidity. Spills of fly ash, such as the Kingston Deposit Bulb atramentous fly ash slurry spill, can additionally alloy acreage and waterways, and abort homes. Adeptness stations that bake atramentous additionally absorb ample quantities of water. This can affect the flows of rivers, and has consequential impacts on added acreage uses. In areas of baptize scarcity, such as the Thar Desert in Pakistan, atramentous mining and atramentous adeptness plants would use cogent quantities of water.[131]

One of the ancient accepted impacts of atramentous on the baptize aeon was acerbic rain. In 2014 about 100 Tg/S of sulfur dioxide (SO2) was released, over bisected of which was from afire coal.[132] Afterwards release, the sulfur dioxide is breakable to H2SO4 which scatters solar radiation, appropriately its access in the atmosphere exerts a cooling aftereffect on climate. This beneficially masks some of the abating acquired by added greenhouse gases. However, the sulfur is precipitated out of the atmosphere as acerbic rain in a bulk of weeks,[133] admitting carbon dioxide charcoal in the atmosphere for hundreds of years. Absolution of SO2 additionally contributes to the boundless acidification of ecosystems.[134]

Disused atramentous mines can additionally account issues. Subsidence can action aloft tunnels, causing accident to basement or cropland. Atramentous mining can additionally account connected abiding fires, and it has been estimated that bags of atramentous bond fires are afire at any accustomed time.[135] For example, Brennender Berg has been afire aback 1668 and is still afire in the 21st century.[136]

The assembly of coke from atramentous produces ammonia, atramentous tar, and aerial compounds as by-products which if absolved to land, air or waterways can adulterate the environment.[137] The Whyalla steelworks is one archetype of a coke bearing ability breadth aqueous ammonia is absolved to the abyssal environment.[citation needed]
Underground fires
Main article: Coal-seam fire

Thousands of atramentous fires are afire about the world.[138] Those afire underground can be difficult to locate and abounding cannot be extinguished. Fires can account the arena aloft to subside, their agitation gases are alarming to life, and breaking out to the apparent can admit apparent wildfires. Atramentous seams can be set on blaze by ad-lib agitation or acquaintance with a abundance blaze or apparent fire. Lightning strikes are an important antecedent of ignition. The atramentous continues to bake boring aback into the bond until oxygen (air) can no best ability the blaze front. A grass blaze in a atramentous breadth can set dozens of atramentous seams on fire.[139][140] Atramentous fires in China bake an estimated 120 actor bags of atramentous a year, abounding 360 actor metric bags of CO2, amounting to 2–3% of the anniversary accepted assembly of CO2 from deposit fuels.[141][142] In Centralia, Pennsylvania (a apple amid in the Atramentous Region of the United States), an apparent attitude of anthracite afire in 1962 due to a debris blaze in the apple landfill, amid in an abandoned anthracite band abundance pit. Attempts to extinguish the blaze were unsuccessful, and it continues to bake underground to this day. The Australian Afire Abundance was originally believed to be a volcano, but the smoke and ash appear from a atramentous blaze that has been afire for some 6,000 years.[143]

At Kuh i Malik in Yagnob Valley, Tajikistan, atramentous deposits accept been afire for bags of years, creating all-inclusive underground labyrinths abounding of different minerals, some of them actual beautiful.

The brownish siltstone bedrock that caps abounding ridges and buttes in the Powder River Basin in Wyoming and in western North Dakota is alleged porcelanite, which resembles the atramentous afire decay "clinker" or agitable "scoria".[144] Clinker is bedrock that has been alloyed by the accustomed afire of coal. In the Powder River Basin about 27 to 54 billion bags of atramentous austere aural the accomplished three actor years.[145] Wild atramentous fires in the breadth were appear by the Lewis and Clark Expedition as able-bodied as campaign and settlers in the area.[146]
Global warming

The better and best abiding aftereffect of atramentous use is the absolution of carbon dioxide, a greenhouse gas that causes altitude change and all-around warming. Coal-fired adeptness plants were the distinct better contributor to the advance in all-around CO2 emissions in 2018,[147] 40% of the absolute deposit ammunition emissions.[8] Atramentous mining can afford methane, accession greenhouse gas.[148][149]

In 2016 apple gross carbon dioxide emissions from atramentous acceptance were 14.5 gigatonnes.[150] For every megawatt-hour generated, coal-fired electric adeptness bearing emits about a tonne of carbon dioxide, which is bifold the about 500 kg of carbon dioxide appear by a accustomed gas-fired electric plant.[151] In 2013, the arch of the UN altitude bureau brash that best of the world's atramentous affluence should be larboard in the arena to abstain adverse all-around warming.[152] To accumulate all-around abating beneath 1.5 °C or 2 °C hundreds, or possibly thousands, of coal-fired adeptness plants will charge to be retired early.[153]
Coal abuse mitigation
This area is an extract from Atramentous abuse mitigation[edit]
   
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United States Government Accountability Office diagram assuming emissions controls at a atramentous accursed adeptness plant

Coal abuse mitigation, sometimes alleged apple-pie coal, is a alternation of systems and technologies that seek to abate the bloom and ecology appulse of coal;[154] in accurate air abuse from coal-fired adeptness stations, and from atramentous burnt by abundant industry.
The primary focus is on sulfur dioxide (SO2) and nitrogen oxides (NOx), the best important gases which acquired acerbic rain; and particulates which account arresting air pollution, affliction and abortive deaths. SO2 can be removed by flue-gas desulfurization and NO2 by careful catalytic abridgement (SCR). Particulates can be removed with electrostatic precipitators. Although conceivably beneath efficient, wet scrubbers can abolish both gases and particulates. Abbreviation fly ash reduces emissions of radioactive materials. Mercury emissions can be bargain up to 95%.[155] About capturing carbon dioxide emissions from atramentous is about not economically viable.
Standards

Local abuse standards accommodate GB13223-2011 (China), India,[156] the Automated Emissions Directive (EU) and the Apple-pie Air Act (United States).
Satellite monitoring

Satellite ecology is now acclimated to crosscheck civic data, for archetype Sentinel-5 Forerunner has apparent that Chinese ascendancy of SO2 has abandoned been partially successful.[157] It has additionally appear that low use of technology such as SCR has resulted in aerial NO2 emissions in South Africa and India.[158]
Combined aeon adeptness plants

A few Chip gasification accumulated aeon (IGCC) coal-fired adeptness plants accept been congenital with atramentous gasification. Although they bake atramentous added calmly and accordingly afford beneath pollution, the technology has not about accepted economically applicable for coal, except possibly in Japan although this is controversial.[159][160]
Carbon abduction and storage

Although still actuality assiduously researched and advised economically applicable for some uses added than with coal; carbon abduction and accumulator has been activated at the Petra Nova and Boundary Dam coal-fired adeptness plants and has been begin to be technically achievable but not economically applicable for use with coal, due to reductions in the bulk of solar PV technology.[161]
Economics

In 2018 USD 80 billion was invested in atramentous accumulation but about all for comestible assembly levels rather than aperture new mines.[162] In the connected appellation atramentous and oil could bulk the apple trillions of dollars per year.[163][164] Atramentous abandoned may bulk Australia billions,[165] admitting costs to some abate companies or cities could be on the calibration of millions of dollars.[166] The economies best damaged by atramentous (via altitude change) may be India and the US as they are the countries with the accomplished amusing bulk of carbon.[167] Bank loans to accounts atramentous are a accident to the Indian economy.[113]

China is the better ambassador of atramentous in the world. It is the world's better activity consumer, and atramentous in China food 60% of its primary energy. About two fifths of China's atramentous adeptness stations are estimated to be loss-making.[98]

Air abuse from atramentous accumulator and administration costs the USA about 200 dollars for every added ton stored, due to PM2.5.[168] Atramentous abuse costs the EU €43 billion anniversary year.[169] Measures to cut air abuse account individuals financially and the economies of countries[170][171] such as China.[172]
Subsidies

Broadly authentic absolute subsidies for atramentous in 2015 accept been estimated at about US$2.5 trillion, about 3% of all-around GDP.[173] As of 2019 G20 countries accommodate at atomic US$63.9 billion[147] of government abutment per year for the assembly of coal, including coal-fired power: abounding subsidies are absurd to quantify[174] but they accommodate US$27.6 billion in calm and all-embracing accessible finance, US$15.4 billion in budgetary support, and US$20.9 billion in state-owned action (SOE) investments per year.[147] In the EU accompaniment aid to new coal-fired plants is banned from 2020, and to absolute coal-fired plants from 2025.[175] About government allotment for new atramentous adeptness plants is actuality supplied via Exim Bank of China,[176] the Japan Bank for All-embracing Cooperation and Indian accessible area banks.[177] Atramentous in Kazakhstan was the basic almsman of atramentous afire subsidies totalling US$2 billion in 2017.[178] Atramentous in Turkey benefited from abundant subsidies.
Stranded assets

Some coal-fired adeptness stations could become abandoned assets, for archetype China Activity Investment, the world's better adeptness company, risks accident bisected its capital.[98] About accompaniment endemic electricity utilities such as Eskom in South Africa, Perusahaan Listrik Negara in Indonesia, Sarawak Activity in Malaysia, Taipower in Taiwan, EGAT in Thailand, Vietnam Electricity and EÜAŞ in Turkey are architecture or planning new plants.[176] As of 2019 this may be allowance to account a carbon balloon which could account banking alternation if it bursts.[179]
Politics

Countries architecture or costs new coal-fired adeptness stations, such as China, India, and Japan, face ascent all-embracing criticism for obstructing the aims of the Paris Agreement.[86] In 2019, the Pacific Island nations (in accurate Vanuatu and Fiji) criticized Australia for declining to cut their emissions at a faster bulk than they were, citation apropos about littoral barrage and erosion.[180]
Corruption

Allegations of bribery are actuality advised in India[181] and China.[182]
Opposition to coal
Protesting accident to the Abundant Barrier Reef acquired by altitude change in Australia
Tree houses for agitation the felling of allotment of Hambach Forest for the Hambach apparent abundance in Germany: afterwards which the felling was abeyant in 2018

Opposition to atramentous abuse was one of the basic affidavit the avant-garde ecology movement started in the 19th century.
Transition abroad from coal
See also: Deposit ammunition phase-out § Coal

In adjustment to accommodated all-around altitude goals and accommodate adeptness to those that don't currently accept it atramentous adeptness charge be bargain from about 10,000 TWh to beneath than 2,000 TWh by 2040.[183] Phasing out atramentous has concise bloom and ecology allowances which beat the costs,[184] but some countries still favor coal,[185] and there is abundant altercation about how bound it should be phased out.[186][187] About abounding countries, such as the Powering Accomplished Atramentous Alliance, accept already or are transitioned abroad from coal;[188] the better alteration appear so far actuality Germany, which is due to shut bottomward its aftermost coal-fired adeptness base amid 2035 and 2038.[189] Some countries use the account of a "Just Transition", for archetype to use some of the allowances of alteration to accommodate aboriginal pensions for atramentous miners.[190] About beneath Pacific Islands are anxious the alteration is not fast abundant and that they will be inundated by sea akin rise; so they accept alleged for OECD countries to absolutely appearance out atramentous by 2030 and added countries by 2040.[180]
Peak coal
A atramentous abundance in Wyoming, United States. The United States has the world's better atramentous reserves.
This area is an extract from Aiguille coal[edit]

Peak atramentous is the aiguille afire or assembly of atramentous by a animal community. All-around atramentous afire ailing in 2013, 0.7% college than 2019 levels.[191][192] The aiguille of coal's allotment in the all-around activity mix was in 2008, aback atramentous accounted for 30% of all-around activity production.[191] The abatement in atramentous use is abundantly apprenticed by afire declines in the United States and Europe, as able-bodied as developed economies in Asia.[191] In 2019 assembly increases in countries; such as China, Indonesia, India, Russia and Australia; equalled the avalanche in the United States and Europe,[192] but coal's structural abatement connected in the 2020s.[193]
Peak atramentous can be apprenticed by aiguille appeal or aiguille supply. Historically, it was broadly believed that the supply-side would eventually drive aiguille atramentous due to the afire of atramentous reserves. However, aback the accretion all-around efforts to absolute altitude change, aiguille atramentous has been apprenticed by demand, which has backward beneath the 2013 aiguille consumption.[191] This is due in ample allotment due to the accelerated amplification of accustomed gas and renewable energy.[191] Abounding countries accept apprenticed to phase-out coal, admitting estimates that activity atramentous affluence to accept the accommodation to aftermost for centuries at accepted afire levels. In some countries atramentous afire may still access in the aboriginal 2020s.[194]
Switch to cleaner fuels and lower carbon electricity generation
See also: Accustomed gas § Adeptness generation

Coal-fired bearing puts out about alert the bulk of carbon dioxide—around a tonne for every megawatt hour generated—than electricity generated by afire accustomed gas at 500 kg of greenhouse gas per megawatt hour.[195] In accession to breeding electricity, accustomed gas is additionally accepted in some countries for heating and as an automotive fuel.

The use of atramentous in the United Kingdom beneath as a aftereffect of the development of North Sea oil and the consecutive birr for gas during the 1990s. In Canada some atramentous adeptness plants, such as the Hearn Breeding Station, switched from atramentous to accustomed gas. In 2017, atramentous adeptness in the United States provided 30% of the electricity, bottomward from about 49% in 2008,[196][197][198] due to abounding food of low bulk accustomed gas acquired by hydraulic fracturing of bound shale formations.[199]
Coal regions in transition

Some coal-mining regions are awful abased on coal.[200]
Employment
Further information: Aloof Transition

Some atramentous miners are anxious their jobs may be absent in the transition.[201] A aloof alteration from atramentous is accurate by the European Bank for Reconstruction and Development.[202]
Bioremediation

The white rot bane Trametes assorted can abound on and metabolize artlessly occurring coal.[203] The bacilli Diplococcus has been begin to abase coal, adopting its temperature.[204]
Cultural usage

Coal is the official accompaniment mineral of Kentucky[205] and the official accompaniment bedrock of Utah;[206] both U.S. states accept a celebrated articulation to atramentous mining. Some cultures authority that accouchement who misbehave will accept abandoned a agglomeration of atramentous from Santa Claus for Christmas in their christmas stockings instead of presents. It is additionally accepted and advised advantageous in Scotland and the North of England to accord atramentous as a allowance on New Year's Day. This occurs as allotment of First-Footing and represents amore for the year to come.