590:
gas to allow for leak monitoring, corrosion prevention and heat transfer. A series of horizontally drilled lateral oxidant delivery lines into the coal and a single or multiple syngas recovery pipeline(s) allow for a larger area of coal to be combusted at one time. The developers claim this method will increase syngas production by up to ten (10) times above earlier design approaches. The single well design means development costs are significantly lower and the facilities and wellheads are concentrated at a single point reducing surface access roads, pipelines and facilities footprint. The UK patent office have advised that the full patent application GB2501074 by
Portman Energy be published 16 October 2013.
335:. The experiments at Gorgas continued for seven years until 1953, at which point the US Bureau of Mines withdrew its support for them after the US Congress withdrew funding. In total 6,000 tons of coal were combusted by 1953 in these experiments. The experiments succeeded in producing combustible synthetic gas. The experiments were reactivated after 1954, this time with hydrofracturing using a mixture of oil and sand, but finally discontinued in 1958 as uneconomical. From 1973–1989, extensive testing was carried out. The
817:) emissions. For comparison, the ash content of UCG syngas is estimated to be approximately 10 mg/m compared to smoke from traditional coal burning where ash content may be up to 70 mg/m. However, UCG operations cannot be controlled as precisely as surface gasifiers. Variables include the rate of water influx, the distribution of reactants in the gasification zone, and the growth rate of the cavity. These can only be estimated from temperature measurements, and analyzing product gas quality and quantity.
423:
899:
Energy's pilot
Underground Coal Gasification plant near Chinchilla in the Queensland's foodbowl of the Darling Downs. When UCG was banned in April, 2016 the Queensland Mines Minister Dr Anthony Lynham stated "The potential risks to Queensland's environment and our valuable agricultural industries far outweigh any potential economic benefits. UCG activity simply doesn't stack up for further use in Queensland."
2377:
926:) in the chamber. The chamber was later flushed and the site successfully rehabilitated. Some research has shown that the persistence of minor quantities of these contaminants in groundwater is short-lived and that ground water recovers within two years. Even so, proper practice, supported by regulatory requirements, should be to flush and decommission each chamber and to rehabilitate UCG sites.
930:
decommissioning. Another important practice is maintaining the pressure of the underground gasifier below that of the surrounding groundwater. The pressure difference forces groundwater to flow continuously into the gasifier and no chemical from the gasifier can escape into the surrounding strata. The pressure is controlled by the operator using pressure valves at the surface.
574:
the two vertical wells. UCG with simple vertical wells, inclined wells, and long deflected wells was used in the Soviet Union. The Soviet UCG technology was further developed by Ergo Exergy and tested at Linc's
Chinchilla site in 1999–2003, in Majuba UCG plant (2007) and in Cougar Energy's failed UCG pilot in Australia (2010).
910:) could remain in the underground chamber after gasification if the chamber is not decommissioned. Site decommissioning and rehabilitation are standard requirements in resources development approvals whether that be UCG, oil and gas, or mining, and decommissioning of UCG chambers is relatively straightforward. Phenol
898:
However, as of late 2013, CCS had never been successfully implemented on a commercial scale as it was not within the scope of UCG projects and some had also resulted in environmental concerns. In
Australia in 2014 the Government filed charges over alleged serious environmental harm stemming from Linc
769:
in preparation for supplying commercial quantities of syngas for commercial production of electricity. African Carbon Energy has received environmental approval for a 50 MW power station near
Theunissen in the Free State province and is bid-ready to participate in the DOE's Independent Power Producer
397:
abandoned the gasification scheme in summer 1959. During the 1960s, European work stopped, due to an abundance of energy and low oil prices, but recommenced in the 1980s. Field tests were conducted in 1981 at Bruay-en-Artois, in 1983–1984 at La Haute Deule, France, in 1982–1985 at Thulin, Belgium and
655:
Underground coal gasification allows access to coal resources that are not economically recoverable by other technologies, e.g., seams that are too deep, low grade, or that have a thin stratum profile. By some estimates, UCG will increase economically recoverable reserves by 600 billion tonnes.
589:
A new technology has been announced in May 2012 by developer
Portman Energy wherein a method called SWIFT (Single Well Integrated Flow Tubing) uses a single vertical well for both oxidant delivery and syngas recovery. The design has a single casing of tubing strings enclosed and filled with an inert
573:
The simplest design uses two vertical wells: one injection and one production. Sometimes it is necessary to establish communication between the two wells, and a common method is to use reverse combustion to open internal pathways in the coal. Another alternative is to drill a lateral well connecting
585:
Carbon Energy was the first to adopt a system which uses a pair of lateral wells in parallel. This system allows a consistent separation distance between the injection and production wells, while progressively mining the coal between the two wells. This approach is intended to provide access to the
902:
Meanwhile, as an article in the
Bulletin of Atomic Sciences pointed out in March 2010 that UCG could result in massive carbon emissions. "If an additional 4 trillion tonnes were extracted without the use of carbon capture or other mitigation technologies atmospheric carbon-dioxide levels could
776:
In addition, there are companies developing projects in
Australia, UK, Hungary, Pakistan, Poland, Bulgaria, Canada, US, Chile, China, Indonesia, India, South Africa, Botswana, and other countries. According to the Zeus Development Corporation, more than 60 projects are in development around the
929:
Newer UCG technologies and practices claim to address environmental concerns, such as issues related to groundwater contamination, by implementing the "Clean Cavern" concept. This is the process whereby the gasifier is self-cleaned via the steam produced during operation and also after
914:
is the most significant environmental hazard due to its high water solubility and high reactiveness to gasification. The US Dept of Energy's
Lawrence Livermore Institute conducted an early UCG experiment at very shallow depth and without hydrostatic pressure at Hoe Creek,
185:. Ratios vary depending upon formation pressure, depth of coal and oxidant balance. Gas output may be combusted for electricity production. Alternatively, the gas output can be used to produce synthetic natural gas, or hydrogen and carbon monoxide can be used as a
389:, United Kingdom, in 1949–1950. A few years later, a first attempt was made to develop a commercial pilot plan, the P5 Trial, at Newman Spinney Derbyshire in 1958–1959. The Newman Spinney project was authorised in 1957 and comprised a steam boiler and a 3.75 MW
741:
conducted pilot projects in
Queensland, Australia based on UCG technology provided by Ergo Exergy until their activities were banned in 2016. Yerostigaz, a subsidiary of Linc Energy, produces about 1 million cubic metres (35 million cubic feet) of
561:
and possibly steam into the reaction zone, and also provide a path for production gases to flow in a controlled manner to the surface. As coal varies considerably in its resistance to flow, depending on its age, composition and geological history, the
582:. This method uses a vertical production well and an extended lateral well drilled directionally in the coal. The lateral well is used for injection of oxidants and steam, and the injection point can be changed by retracting the injector.
601:
may be successfully gasified. A great many factors are taken into account in selecting appropriate locations for UCG, including surface conditions, hydrogeology, lithology, coal quantity, and quality. According to Andrew Beath of
820:
Subsidence is a common issue with all forms of extractive industry. While UCG leaves the ash behind in the cavity, the depth of the void left after UCG is typically greater than that with other methods of coal extraction.
717:
Underground product gas is an alternative to natural gas and potentially offers cost savings by eliminating mining, transport, and solid waste. The expected cost savings could increase given higher coal prices driven by
413:
In New Zealand, a small scale trial was operated in 1994 in the Huntly Coal Basin. In Australia, tests were conducted starting in 1999. China has operated the largest program since the late 1980s, including 16 trials.
577:
In the 1980s and 1990s, a method known as CRIP (controlled retraction and injection point) was developed (but not patented) by the Lawrence Livermore National Laboratory and demonstrated in the United States and
229:
In 1909–1910, American, Canadian, and British patents were granted to American engineer Anson G. Betts for "a method of using unmined coal". The first experimental work on UCG was planned to start in 1912 in
326:
After World War II, the shortage in energy and the diffusion of the Soviets' results provoked new interest in Western Europe and the United States. In the United States, tests were conducted in 1947–1958 in
785:
Eliminating mining eliminates mine safety issues. Compared to traditional coal mining and processing, the underground coal gasification eliminates surface damage and solid waste discharge, and reduces
670:(CCGT) power plants, with some studies suggesting power island efficiencies of up to 55%, with a combined UCG/CCGT process efficiency of up to 43%. CCGT power plants using UCG product gas instead of
1429:
1747:
306:, the Soviet activities culminated in the operation of five industrial-scale UCG plants in the early 1960s. However, Soviet activities subsequently declined due to the discovery of extensive
1972:
1359:
1986:
603:
133:
294:, Donetsk Basin. Production gradually increased, and, in 1937–1938, the local chemical plant began using the produced gas. In 1940, experimental plants were built in
446:) and steam to ignite and fuel the underground combustion process. Separate production wells are used to bring the product gas to the surface. The high pressure
129:
1937:
Shu-qin, L., Jun-hua, Y. (2002). Environmental Benefits of underground coal gasification. Journal of Environmental Sciences (China), vol. 12, no. 2, pp.284-288
1070:
89:
1436:
1835:
1481:
1233:
2110:
1582:
762:
1724:
1719:
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on-site into the highly permeable rock created during the burning process, i.e. the cavity where the coal used to be. Contaminants, such as
554:) are produced. As the coal face burns and the immediate area is depleted, the volumes of oxidants injected are controlled by the operator.
268:
an article "Great Victory of Technology" promising to liberate workers from hazardous work in coal mines by underground coal gasification.
1363:
71:
279:
coal basin at Krutova mine. This test and several following tests failed. The first successful test was conducted on 24 April 1934 in
656:
Lawrence Livermore National Laboratory estimates that UCG could increase recoverable coal reserves in the US by 300%. Livermore and
1996:
2515:
1414:
1330:
2023:
1806:
1531:
1077:
340:
1956:
1919:
1500:
1188:
1776:
1904:"The underground coal gasification is the technology which answers o conditions of sustainable development of coal regions"
1081:
868:
766:
192:
The technique can be applied to coal resources that are otherwise unprofitable or technically complicated to extract by
2155:
1222:
903:
quadruple", the article stated, "resulting in a global mean temperature increase of between 5 and 10 degrees Celsius".
336:
710:
In addition, carbon dioxide produced as a by-product of underground coal gasification may be re-directed and used for
2039:
723:
2119:
2031:
1552:
275:
by the state-owned organization Podzemgaz. The first test using the chamber method started on 3 March 1933 in the
1002:
1973:"Queensland government hits Underground Coal Gasification player Linc Energy with environmental damage charges"
137:
1748:"Linc Energy Limited (ASX:LNC) Technology Update on Chinchilla Underground Coal Gasification (UCG) Operations"
563:
557:
There are a variety of designs for underground coal gasification, all of which provide a means of injecting
2010:
351:
1987:"The Untold Story Of The Dangerous New Experiment Coal Companies Want To Bring To America | ThinkProgress"
1506:
2182:
2024:
National Research Council (U.S.). Committee on Ground-Water Resources in Relation to Coal Mining (1981).
949:
1417:. Vol. 3, no. 2. Cornerstone, The Official Journal of the World Coal Industry. pp. 61–64.
166:
and steam. The product gas is brought to the surface through production wells drilled from the surface.
2520:
2107:
1010:
906:
Aquifer contamination is a potential environmental concern. Organic and often toxic materials (such as
872:
213:
200:
methods for some resources. It has been linked to a number of concerns from environmental campaigners.
586:
greatest quantity of coal per well set and also allows greater consistency in production gas quality.
566:
of the coal to transport the gas is generally not adequate. For high pressure break-up of the coal,
2281:
679:
344:
2328:
189:
feedstock for the production of fuels (e.g. diesel), fertilizer, explosives and other products.
2416:
2311:
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675:
2025:
1903:
1664:
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1174:
2316:
2301:
1466:
711:
355:
208:
The earliest recorded mention of the idea of underground coal gasification was in 1868, when
354:
and Radian Corporation, Livermore conducted experiments in 1981–1982 at the WIDCO Mine near
1693:
1641:
1492:
993:
722:, taxes, and other emissions reduction policies, e.g. the Australian Government's proposed
567:
358:. In 1979–1981, an underground gasification of steeply dipping seams was demonstrated near
209:
111:
98:
37:
8:
2421:
1911:
1783:
407:
394:
660:
claim that UCG capital and operating costs are lower than those for traditional mining.
246:. However, Ramsay was unable to commence the UCG field work before the beginning of the
2431:
2391:
1687:
1635:
747:
399:
332:
311:
193:
1334:
678:
power stations (and associated upstream processes), resulting in a large decrease in
2213:
2196:
2141:
2035:
1952:
1915:
1496:
1184:
1152:
919:. They did not decommission that site and testing showed contaminants (including the
719:
223:
147:
1142:
1014:
892:
538:
434:). Gas is produced and extracted through wells drilled into the unmined coal seam.
359:
1527:
968:
331:. The experiments were carried out in a partnership between Alabama Power and the
2286:
2114:
1389:
1290:
The US Bureau of Mines - Report for the Committee on Interior and Insular Affairs
1138:
939:
490:
430:
Underground coal gasification converts coal to gas while still in the coal seam (
328:
231:
178:
163:
1262:
983:, BBC - Coal gasification: The clean energy of the future?, retrieved 12.07.2014
770:(IPP) gas program where UCG has been earmarked as a domestic gas supply option.
2248:
980:
802:
786:
664:
630:
According to Peter Sallans of Liberty Resources Limited, the key criteria are:
458:
435:
367:
363:
259:
243:
235:
182:
2376:
1863:
2509:
2447:
1991:
1840:
1811:
1156:
998:"On the regenerative gas furnace as applied to the manufacture of cast steel"
734:
593:
A wide variety of coals are amenable to the UCG process and coal grades from
284:
79:
41:
1288:
1237:
216:
suggested the underground gasification of waste and slack coal in the mine.
2472:
2457:
2243:
2228:
2223:
944:
754:
570:, electric-linkage, and reverse combustion may be used in varying degrees.
510:
303:
299:
272:
159:
2494:
2489:
2396:
2273:
2238:
1556:
1394:. 7th Underground Coal Gasification Association (UCGA) Conference. London
1018:
738:
671:
667:
657:
307:
247:
239:
197:
75:
310:
resources. In 1964, the Soviet program was downgraded. As of 2004 only
2477:
2467:
2462:
2452:
2401:
1560:
1147:
1126:
920:
598:
447:
390:
315:
295:
280:
93:
2059:
1949:
Earth: The Sequel: The Race to Reinvent Energy and Stop Global Warming
422:
2484:
2406:
2258:
2027:
Coal mining and ground-water resources in the United States: a report
1583:"Cougar Energy Update on UCG Pilot Project at Kingaroy in Queensland"
1415:"Carbon Energy Delivers Innovations in Underground Coal Gasification"
849:
1331:"Underground Coal Gasification. Current Developments (1990 to date)"
997:
867:, proponents of UCG have argued that the process has advantages for
2426:
2411:
2362:
2263:
2233:
2218:
2191:
2164:
911:
750:. The produced syngas is used as fuel in the Angren Power Station.
703:
509:). In addition, small quantities of various contaminants including
474:
439:
291:
217:
186:
174:
61:
27:
1127:"Early Ideas in Underground Coal Gasification and Their Evolution"
2346:
2336:
1223:"Review of Environmental Issues of Underground Coal Gasification"
923:
916:
888:
693:
623:
594:
558:
494:
382:
374:
343:
conducted three tests in 1976–1979 at the Hoe Creek test site in
339:
and several large oil and gas companies conducted several tests.
226:
further developed Siemens' idea over the next couple of decades.
220:
170:
2108:
Energy & Environmental Research Centre (EERC) - UCG overview
385:, in 1949. The borehole method was tested at Newman Spinney and
162:
process, carried out in non-mined coal seams using injection of
2341:
2253:
2208:
1430:"Underground Coal Gasification Resource Utilisation Efficiency"
1293:. US Government Printing Office. September 1976. pp. 61–62
907:
743:
443:
386:
378:
276:
271:
Between 1928 and 1939, underground tests were conducted in the
264:
2126:
cache in situ Converted Coal Seams - Research Project at the
1888:
758:
579:
403:
2102:
895:, can be removed from product gas at a relatively low cost.
410:
and six European countries formed a European Working Group.
2296:
2133:
1069:
Burton, Elizabeth; Friedmann, Julio; Upadhye, Ravi (2007).
152:
51:
2092:
1179:. Energy Technology Review â„– 14. Noyes Data Corp. p.
373:
In Europe, the stream method was tested at Bois-la-Dame,
290:
The first pilot-scale process started 8 February 1935 in
2097:
454:, but it may reach up to 1,500 °C (2,730 °F).
318:
and Yuzhno-Abinsk site in Russia continued operations.
1068:
773:
ENN has operated a successful pilot project in China.
2011:"Is underground coal gasification a sensible option?"
1836:"Coal gasification demo plant design study under way"
1463:
Choosing the Best Coals in the Best Locations for UCG
2098:
Ergo Exergy Tech - global supplier of UCG technology
1728:. Australian Broadcasting Corporation. 18 April 2016
258:
In 1913, Ramsay's work was noticed by Russian exile
1902:Lazarenko, Sergey N.; Kochetkov, Valery N. (1997).
780:
196:methods. UCG offers an alternative to conventional
1901:
1686:
1634:
1465:. Advanced Coal Technologies Conference. Laramie:
2060:"Best Practices in Underground Coal Gasification"
1412:
2507:
2083:feature article (Fred Pearce), 15 February 2014
1657:
1601:
1435:. CSIRO Exploration & Mining. Archived from
2064:Best Practices in Underground Coal Gasification
1807:"Coal experts search for ways to cut emissions"
1777:"ESKOM's underground coal gasification project"
1236:. COAL R272 DTI/Pub URN 04/1880. Archived from
1071:Best Practices in Underground Coal Gasification
1679:
1627:
1575:
1387:
1323:
287:, by the Donetsk Institute of Coal Chemistry.
151:(UCG) is an industrial process which converts
2149:
1714:
1712:
1487:. In Clarke, A. W.; Trinnaman, J. A. (eds.).
971:, www.clarke-energy.com, retrieved 12.12.2013
875:) technology allows re-injecting some of the
634:Depth of 100–1,400 metres (330–4,590 ft)
103:Chinchilla Demonstration Facility (Australia)
1906:. In Strakos̆, VladimĂr; Farana, R. (eds.).
1827:
1798:
1220:
981:https://www.bbc.co.uk/news/business-26921145
1406:
1221:Sury, Martin; et al. (November 2004).
610:Depth of 100–600 metres (330–1,970 ft)
2156:
2142:
2053:
2051:
1908:Mine Planning and Equipment Selection 1997
1709:
1609:"Cougar To Ramp Up UCG Process Down Under"
1319:. London: Electrical Press. pp. A-79.
1263:"Gasification Tests On Coal Are Completed"
1120:
1118:
1116:
1114:
1112:
1110:
1108:
1106:
1104:
1102:
637:Thickness more than 3 metres (9.8 ft)
457:The process decomposes coal and generates
426:The underground coal gasification process.
1946:
1740:
1521:
1519:
1383:
1381:
1146:
1064:
1062:
1060:
1058:
1056:
1054:
1052:
1050:
1048:
613:Thickness more than 5 metres (16 ft)
1124:
1046:
1044:
1042:
1040:
1038:
1036:
1034:
1032:
1030:
1028:
421:
2048:
1754:. Asia Business News Ltd. 10 March 2009
1460:
1454:
1354:
1352:
1314:
1099:
992:
765:as technology provider) is operating a
321:
2508:
2057:
2017:
1933:
1931:
1833:
1804:
1720:"UCG banned immediately in Queensland"
1532:Lawrence Livermore National Laboratory
1525:
1516:
1479:
1378:
1168:
1166:
1078:Lawrence Livermore National Laboratory
685:UCG product gas can also be used for:
408:Commission of the European Communities
398:in 1992–1999 at the El Tremedal site,
341:Lawrence Livermore National Laboratory
2137:
2093:African Carbon Energy - 50 MW project
1940:
1771:
1769:
1545:
1427:
1421:
1333:. UCG Engineering Ltd. Archived from
1317:Garcke's Manual of Electricity Supply
1310:
1308:
1216:
1214:
1212:
1210:
1208:
1206:
1204:
1202:
1200:
1025:
452:700–900 °C (1,290–1,650 °F)
1895:
1697:. NHST Media Group. 28 November 2007
1349:
1172:
699:Production of synthetic natural gas;
1928:
1645:. NHST Media Group. 14 October 2008
1473:
1163:
855:Regarding emissions of atmospheric
13:
2074:
1951:. New York: Norton & Company.
1947:Krupp, Fred; Horn, Miriam (2009).
1834:Hannah, Jessica (12 August 2011).
1766:
1688:"Linc gears up for Chinchilla GTL"
1665:"Linc Energy Opens CTL Demo Plant"
1305:
1197:
692:Manufacture of chemicals, such as
606:other important criteria include:
337:United States Department of Energy
169:The predominant product gases are
14:
2532:
2086:
1805:Venter, Irma (12 February 2007).
1667:. Downstream Today. 24 April 2009
1636:"Linc pilot flows first GTL fuel"
1615:. Downstream Today. 16 March 2010
1362:. UCG Association. Archived from
724:Carbon Pollution Reduction Scheme
250:, and the project was abandoned.
2375:
2032:United States National Academies
1428:Beath, Andrew (18 August 2006).
1234:Department of Trade and Industry
848:and lowers emissions, including
824:Underground combustion produces
781:Environmental and social impacts
674:can achieve higher outputs than
663:UCG product gas is used to fire
362:. The program culminated in the
253:
2003:
1979:
1965:
1889:"South African IPP Gas Program"
1881:
1864:"Theunissen Project | Africary"
1856:
1553:"Underground Coal Gasification"
1461:Sallans, Peter (23 June 2010).
1125:Klimenko, Alexander Y. (2009).
1080:. W-7405-Eng-48. Archived from
646:Isolation from valued aquifers.
450:is conducted at temperature of
2516:Coal gasification technologies
1315:Garrett, Frederick C. (1959).
1281:
1255:
986:
974:
962:
680:greenhouse gas (GHG) emissions
604:CSIRO Exploration & Mining
138:Skochinsky Institute of Mining
1:
2202:Underground coal gasification
2058:Burton, Elizabeth A. (2019).
1388:Portman Energy (3 May 2012).
1176:Underground coal gasification
955:
393:to generate electricity. The
19:Underground coal gasification
2163:
650:
352:Sandia National Laboratories
155:into product gas. UCG is an
7:
933:
729:
262:who wrote in the newspaper
10:
2537:
1489:Survey of energy resources
1480:Copley, Christine (2007).
1413:Morné Engelbrecht (2015).
1011:Chemical Society of London
873:Carbon capture and storage
871:. Combining UCG with CCS (
689:Synthesis of liquid fuels;
417:
238:, under the leadership of
214:Chemical Society of London
203:
2440:
2384:
2373:
2355:
2327:
2272:
2178:
2171:
1230:WS Atkins Consultants LTD
640:Ash content less than 60%
616:Ash content less than 60%
525:), mono-nitrogen oxides (
125:
117:
107:
85:
67:
57:
47:
33:
23:
2113:16 February 2012 at the
1269:. 6 July 1953. p. 5
1173:Lamb, George H. (1977).
366:trial in 1986–1988 near
345:Campbell County, Wyoming
134:Ergo Exergy Technologies
1267:The Terre Haute Tribune
950:Fischer–Tropsch process
869:geologic carbon storage
643:Minimal discontinuities
619:Minimal discontinuities
438:are used to supply the
2417:Natural-gas processing
2128:RWTH Aachen University
1526:Walter, Katie (2007).
622:Isolation from valued
427:
212:in his address to the
2179:Manufactured fuel gas
1467:University of Wyoming
712:enhanced oil recovery
676:pulverized-coal-fired
425:
356:Centralia, Washington
130:African Carbon Energy
1999:on 13 November 2013.
1914:. pp. 167–168.
1912:Taylor & Francis
1493:World Energy Council
1366:on 12 September 2011
1019:10.1039/JS8682100279
564:natural permeability
350:In cooperation with
322:Post-war experiments
112:Carl Wilhelm Siemens
99:Majuba Power Station
90:Angren Power Station
38:oil and gas industry
34:Industrial sector(s)
2422:Natural gas storage
2079:"Beyond fracking",
1784:European Commission
1337:on 19 November 2007
767:demonstration plant
395:National Coal Board
210:Sir William Siemens
20:
2432:Pipeline transport
2392:Compressor station
1528:"Fire in the Hole"
1148:10.3390/en20200456
748:Angren, Uzbekistan
428:
400:Province of Teruel
333:US Bureau of Mines
194:traditional mining
18:
2521:Thermal treatment
2503:
2502:
2371:
2370:
2214:Blast furnace gas
2197:Coal gasification
1958:978-0-393-33419-7
1921:978-90-5410-915-0
1502:978-0-946121-26-7
1491:(21st ed.).
1442:on 31 August 2007
1190:978-0-8155-0670-6
720:emissions trading
377:, in 1948 and in
224:Dmitri Mendeleyev
148:coal gasification
143:
142:
118:Year of invention
68:Leading companies
2528:
2379:
2176:
2175:
2158:
2151:
2144:
2135:
2134:
2068:
2067:
2055:
2046:
2045:
2021:
2015:
2014:
2013:. 29 March 2010.
2007:
2001:
2000:
1995:. Archived from
1983:
1977:
1976:
1975:. 15 April 2014.
1969:
1963:
1962:
1944:
1938:
1935:
1926:
1925:
1899:
1893:
1892:
1885:
1879:
1878:
1876:
1874:
1868:www.africary.com
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1620:
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1579:
1573:
1572:
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1568:
1559:. Archived from
1549:
1543:
1542:
1540:
1538:
1523:
1514:
1513:
1512:on 9 April 2011.
1511:
1505:. Archived from
1486:
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1451:
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1447:
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1434:
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1122:
1097:
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1094:
1092:
1086:
1075:
1066:
1023:
1022:
990:
984:
978:
972:
966:
893:hydrogen sulfide
886:
885:
884:
866:
865:
864:
847:
846:
845:
835:
834:
833:
816:
815:
814:
800:
799:
798:
696:and fertilizers;
568:hydro-fracturing
553:
551:
550:
539:hydrogen sulfide
536:
535:
534:
524:
523:
522:
508:
507:
506:
488:
487:
486:
472:
471:
470:
453:
391:turbo-alternator
360:Rawlins, Wyoming
21:
17:
2536:
2535:
2531:
2530:
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2527:
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2506:
2505:
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2436:
2380:
2367:
2351:
2323:
2268:
2180:
2167:
2162:
2125:
2115:Wayback Machine
2103:UCG Association
2089:
2077:
2075:Further reading
2072:
2071:
2056:
2049:
2042:
2034:. p. 113.
2022:
2018:
2009:
2008:
2004:
1985:
1984:
1980:
1971:
1970:
1966:
1959:
1945:
1941:
1936:
1929:
1922:
1900:
1896:
1887:
1886:
1882:
1872:
1870:
1862:
1861:
1857:
1847:
1845:
1844:. Creamer Media
1832:
1828:
1818:
1816:
1815:. Creamer Media
1803:
1799:
1789:
1787:
1779:
1775:
1774:
1767:
1757:
1755:
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1698:
1694:Upstream Online
1685:
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1642:Upstream Online
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1607:
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1592:
1590:
1589:. 27 April 2010
1581:
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1459:
1455:
1445:
1443:
1439:
1432:
1426:
1422:
1411:
1407:
1397:
1395:
1391:UCG–the 3rd way
1386:
1379:
1369:
1367:
1360:"How UCG Works"
1358:
1357:
1350:
1340:
1338:
1329:
1328:
1324:
1313:
1306:
1296:
1294:
1287:
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1282:
1272:
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1256:
1246:
1244:
1243:on 11 June 2007
1240:
1225:
1219:
1198:
1191:
1171:
1164:
1139:MDPI Publishing
1123:
1100:
1090:
1088:
1084:
1073:
1067:
1026:
991:
987:
979:
975:
967:
963:
958:
940:Coalbed methane
936:
883:
880:
879:
878:
876:
863:
860:
859:
858:
856:
844:
841:
840:
839:
837:
832:
829:
828:
827:
825:
813:
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809:
808:
806:
797:
794:
793:
792:
790:
783:
732:
653:
549:
546:
545:
544:
542:
533:
530:
529:
528:
526:
521:
518:
517:
516:
514:
505:
502:
501:
500:
498:
491:carbon monoxide
485:
482:
481:
480:
478:
469:
466:
465:
464:
462:
451:
436:Injection wells
420:
406:. In 1988, the
329:Gorgas, Alabama
324:
256:
206:
179:carbon monoxide
136:
132:
102:
97:
86:Main facilities
78:
74:
40:
12:
11:
5:
2534:
2524:
2523:
2518:
2501:
2500:
2498:
2497:
2492:
2487:
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2481:
2480:
2470:
2465:
2460:
2455:
2450:
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2435:
2434:
2429:
2424:
2419:
2414:
2409:
2404:
2399:
2394:
2388:
2386:
2385:Infrastructure
2382:
2381:
2374:
2372:
2369:
2368:
2366:
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2289:
2284:
2278:
2276:
2270:
2269:
2267:
2266:
2261:
2256:
2251:
2249:Regasification
2246:
2241:
2236:
2231:
2226:
2221:
2216:
2211:
2206:
2205:
2204:
2199:
2188:
2186:
2173:
2169:
2168:
2161:
2160:
2153:
2146:
2138:
2132:
2131:
2123:
2117:
2105:
2100:
2095:
2088:
2087:External links
2085:
2076:
2073:
2070:
2069:
2047:
2040:
2016:
2002:
1978:
1964:
1957:
1939:
1927:
1920:
1894:
1880:
1855:
1826:
1797:
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1708:
1678:
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1600:
1574:
1563:on 16 May 2010
1544:
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1420:
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1304:
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1098:
1087:on 6 June 2010
1024:
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952:
947:
942:
935:
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861:
842:
830:
811:
803:nitrogen oxide
795:
787:sulfur dioxide
782:
779:
731:
728:
708:
707:
702:Production of
700:
697:
690:
665:combined cycle
652:
649:
648:
647:
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641:
638:
635:
628:
627:
620:
617:
614:
611:
547:
531:
519:
503:
483:
467:
459:carbon dioxide
419:
416:
368:Hanna, Wyoming
364:Rocky Mountain
323:
320:
260:Vladimir Lenin
255:
252:
244:William Ramsay
236:United Kingdom
205:
202:
183:carbon dioxide
141:
140:
127:
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109:
105:
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101:(South Africa)
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2474:
2471:
2469:
2466:
2464:
2461:
2459:
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2449:
2448:Bunsen burner
2446:
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2090:
2084:
2082:
2081:New Scientist
2065:
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2054:
2052:
2043:
2041:9780309031868
2037:
2033:
2029:
2028:
2020:
2012:
2006:
1998:
1994:
1993:
1992:ThinkProgress
1988:
1982:
1974:
1968:
1960:
1954:
1950:
1943:
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1932:
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1913:
1909:
1905:
1898:
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1869:
1865:
1859:
1843:
1842:
1841:Mining Weekly
1837:
1830:
1814:
1813:
1812:Mining Weekly
1808:
1801:
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1637:
1630:
1614:
1613:Cougar Energy
1610:
1604:
1588:
1584:
1578:
1562:
1558:
1554:
1548:
1533:
1529:
1522:
1520:
1508:
1504:
1498:
1495:. p. 7.
1494:
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1103:
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1037:
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1029:
1020:
1016:
1012:
1008:
1005:
1004:
1003:J. Chem. Soc.
999:
995:
994:Siemens, C.W.
989:
982:
977:
970:
965:
961:
951:
948:
946:
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778:
774:
771:
768:
764:
760:
756:
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749:
745:
740:
736:
735:Cougar Energy
727:
725:
721:
715:
713:
705:
701:
698:
695:
691:
688:
687:
686:
683:
681:
677:
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605:
600:
596:
591:
587:
583:
581:
575:
571:
569:
565:
560:
555:
540:
512:
511:sulfur oxides
496:
492:
476:
460:
455:
449:
445:
441:
437:
433:
424:
415:
411:
409:
405:
401:
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361:
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334:
330:
319:
317:
313:
309:
305:
301:
297:
293:
288:
286:
285:Donetsk Basin
282:
278:
274:
269:
267:
266:
261:
254:Initial tests
251:
249:
245:
241:
237:
233:
227:
225:
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211:
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139:
135:
131:
128:
124:
120:
116:
113:
110:
106:
100:
95:
91:
88:
84:
81:
80:Carbon Energy
77:
73:
70:
66:
63:
60:
56:
53:
50:
46:
43:
42:coal industry
39:
36:
32:
29:
26:
22:
16:
2473:Gas lighting
2458:Gas cylinder
2244:Producer gas
2229:Landfill gas
2224:Gasification
2201:
2080:
2078:
2063:
2026:
2019:
2005:
1997:the original
1990:
1981:
1967:
1948:
1942:
1907:
1897:
1883:
1871:. Retrieved
1867:
1858:
1846:. Retrieved
1839:
1829:
1817:. Retrieved
1810:
1800:
1788:. Retrieved
1786:. 5 May 2008
1756:. Retrieved
1752:ABN Newswire
1751:
1742:
1730:. Retrieved
1723:
1699:. Retrieved
1692:
1681:
1669:. Retrieved
1659:
1647:. Retrieved
1640:
1629:
1617:. Retrieved
1612:
1603:
1591:. Retrieved
1586:
1577:
1565:. Retrieved
1561:the original
1547:
1535:. Retrieved
1507:the original
1488:
1475:
1462:
1456:
1444:. Retrieved
1437:the original
1423:
1408:
1396:. Retrieved
1390:
1368:. Retrieved
1364:the original
1339:. Retrieved
1335:the original
1325:
1316:
1295:. Retrieved
1289:
1283:
1271:. Retrieved
1266:
1257:
1245:. Retrieved
1238:the original
1229:
1175:
1134:
1130:
1089:. Retrieved
1082:the original
1006:
1001:
988:
976:
964:
945:Landfill gas
928:
905:
901:
897:
854:
823:
819:
784:
775:
772:
755:South Africa
752:
733:
716:
709:
684:
662:
654:
629:
592:
588:
584:
576:
572:
556:
456:
431:
429:
412:
372:
349:
325:
304:World War II
289:
273:Soviet Union
270:
263:
257:
228:
207:
191:
168:
160:gasification
156:
146:Underground
145:
144:
126:Developer(s)
24:Process type
15:
2495:Pilot light
2490:Gas turbine
2397:Gas carrier
2274:Natural gas
2239:Pintsch gas
2066:. osti.gov.
1873:12 December
1848:4 September
1819:4 September
1790:4 September
1557:Linc Energy
1446:11 November
1370:11 November
1341:24 November
1141:: 456–476.
1013:: 279–310.
763:Ergo Exergy
746:per day in
739:Linc Energy
672:natural gas
668:gas turbine
658:Linc Energy
597:through to
308:natural gas
248:World War I
242:winner Sir
240:Nobel Prize
198:coal mining
76:Linc Energy
2510:Categories
2478:Gas mantle
2468:Gas heater
2463:Gas engine
2453:Gas burner
2402:Gas holder
1725:ABC Online
1297:5 December
1273:5 December
1076:(Report).
956:References
921:carcinogen
599:bituminous
448:combustion
316:Uzbekistan
296:Lysychansk
281:Lysychansk
94:Uzbekistan
58:Product(s)
2485:Gas stove
2407:Gas meter
2259:Water gas
1537:6 October
1398:1 October
1157:1996-1073
1091:3 January
850:acid rain
651:Economics
493:(CO) and
48:Feedstock
2427:Odorizer
2412:Gasworks
2363:Hydrogen
2264:Wood gas
2234:Mond gas
2219:Blau gas
2192:Coal gas
2165:Fuel gas
2120:CO2SINUS
2111:Archived
1758:8 August
1732:21 April
1701:6 August
1671:6 August
1649:6 August
1587:OilVoice
1131:Energies
996:(1868).
969:Coal Gas
934:See also
912:leachate
730:Projects
704:hydrogen
624:aquifers
475:hydrogen
440:oxidants
314:site in
302:. After
292:Horlivka
187:chemical
175:hydrogen
164:oxidants
108:Inventor
72:Africary
62:coal gas
28:chemical
2347:Propane
2337:Autogas
2317:Bio-SNG
2183:History
1619:31 July
1593:31 July
1567:18 July
1247:18 July
924:benzene
917:Wyoming
889:ammonia
777:world.
694:ammonia
595:lignite
559:oxidant
537:), and
495:methane
432:in-situ
418:Process
383:Morocco
375:Belgium
221:chemist
218:Russian
204:History
171:methane
157:in-situ
2342:Butane
2254:Syngas
2209:Biogas
2038:
1955:
1918:
1499:
1482:"Coal"
1187:
1155:
1009:(21).
908:phenol
801:) and
761:(with
744:syngas
444:oxygen
442:(air,
387:Bayton
379:Jerada
312:Angren
277:Moscow
265:Pravda
234:, the
232:Durham
2356:Other
2172:Types
1780:(PDF)
1510:(PDF)
1485:(PDF)
1440:(PDF)
1433:(PDF)
1241:(PDF)
1226:(PDF)
1137:(2).
1085:(PDF)
1074:(PDF)
759:Eskom
580:Spain
404:Spain
2441:Uses
2297:HCNG
2036:ISBN
1953:ISBN
1916:ISBN
1875:2016
1850:2011
1821:2011
1792:2011
1760:2009
1734:2016
1703:2009
1673:2009
1651:2009
1621:2010
1595:2010
1569:2010
1539:2008
1497:ISBN
1448:2007
1400:2012
1372:2007
1343:2007
1299:2020
1275:2020
1249:2010
1185:ISBN
1153:ISSN
1093:2013
891:and
836:and
737:and
300:Tula
298:and
181:and
153:coal
121:1868
52:coal
2329:LPG
2312:SNG
2307:NGC
2302:LNG
2292:CNG
2287:CBM
2282:APG
1143:doi
1015:doi
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2122:CO
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