Coalbed Methane: Scientific, Environmental and Economic Evaluation

Coalbed gas has been considered a hazard since the early 19th century when the first mine gas explosions occurred in the United States in 1810 and France in 1845. In eastern Australia methane-related mine disasters occurred late in the 19th century with hundreds of lives lost in New South Wales, and as recently as 1995 in Queensland's Bowen Basin. Ventilation and gas drainage technologies are now in practice. However, coalbed methane recently is becoming more recognized as a potential source of energy; rather than emitting this gas to the atmosphere during drainage of gassy mines it can be captured and utilized. Both economic and environmental concerns have sparked this impetus to capture coalbed methane. The number of methane utilization projects has increased in the United States in recent years as a result, to a large extent, of development in technology in methane recovery from coal seams. Between 1994 and 1997, the number of mines in Alabama, Colorado, Ohio, Pennsylvania, Virginia, and West Virginia recovering and utilizing methane increased from 1 0 to 17. The Environmental Protection Agency estimates that close to 49 billion cubic feet (Bet) of methane was recovered in 1996, meaning that this amount was not released into the atmosphere. It is estimated that in the same year total emissions of methane equaled 45. 7 Bcf. Other coal mines are being investigated at present, many ofwhich appear to be promising for the development of cost-effective gas recovery.