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U.S. Department of Energy
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Results from the third LLL underground coal gasification experiment at Hoe Creek

Conference ·
OSTI ID:5280693

A major objective of the US Energy Program is the development of processes to produce clean fuels from coal. Underground coal gasification is one of the most promising of these processes. If successful, underground coal gasification (UCG) would quadruple the proven reserves of the US coal. Cost for products produced from UCG are projected to be 65 to 75% of those from conventional coal conversion. Finally, UCG appears to possess environmental advantages since no mining is involved and there are less solid wastes produced. In this paper we describe results from the Hoe Creek No. 3 underground coal gasification test. The experiment employed a drilled channel between process wells spaced 130' apart. The drilled channel was enlarged by reverse combustion prior to forward gasification. The first week of forward gasification was carried out using air injection, during which 250 tons of coal were consumed yielding an average dry product gas heating value of 114 Btu/scf. Following this phase, steam and oxygen were injected (generally a 50-50 mixture) for 47 days, during which 3945 tons of coal were consumed at an average rate of 84 tons of coal per day and an average dry gas heating value of 217 Btu/scf. The average gas composition during the steam-oxygen phase was 37% H/sub 2/, 5% CH/sub 4/, 11% CO, and 44% CO/sub 2/. Gas recovery was approximately 82% during the test, and the average thermochemical efficiency was near 65%.

Research Organization:
California Univ., Livermore (USA). Lawrence Livermore Lab.
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
5280693
Report Number(s):
UCRL-83961; CONF-800716-3
Country of Publication:
United States
Language:
English