Underground-coal-gasification technical summary

Conference · Mon Mar 14 04:00:00 EST 1983

OSTI ID:6147866

Stephens, D R; Thorsness, C B; Hill, R W; Thompson, D S

There are three basic reasons for the recent emergence of underground coal gasification (UCG) as a leading synfuels candidate: (1) favorable projected economics, (2) ability to use coal seams that are unattractive for mining, and (3) modest environmental impact. The objective of this paper is to list major underground coal gasification results and conclusions, particularly field-oriented results. The twenty field tests and ten years' experience have demonstrated technical feasibility and allow us to make several generalizations concerning underground coal gasification. For example, burns tend to be bowl-shaped after roof collapse, since ash and slag (and high water content in coal) impede downward burning. Burns appear to be symmetrical in plan view, but not in elevation view. Injection and linking at the bottom of the seam can improve performance. Heat losses begin, and heating value of the product gas declines, when the burn reaches the roof and the roof rock begins to collapse. In general, heating value and chemistry appear to be insensitive to operational parameters but are sensitive to process-well geometry and overburden.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6147866
• Report Number(s): UCRL-88339; CONF-830859-1; ON: DE83013043
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
BOREHOLE LINKING
COAL GASIFICATION
ELEMENTS
FIELD TESTS
GASIFICATION
IN-SITU GASIFICATION
IN-SITU PROCESSING
NONMETALS
OXYGEN
PROCESSING
STEAM
TECHNOLOGY ASSESSMENT
TESTING
THERMOCHEMICAL PROCESSES