Utilization of fuel cells to beneficially use coal mine methane. Final report

Abstract

Historically the mining industry has not viewed methane as a resou'rce. The existence. of methane in an underground mine presents a great hazard as mixtures of methane and air are combustible over a wide range of concentrations. Methane has contributed to a large number of serious accidents. To reduce the hazard methane presents, the mining industry has developed systems to remove methane gas from the mine.At this time the only method being employed at the Left Fork Mine to remove methane is the mine ventilation system. Data for the methane content of the ventilation air at the Left Fork Mine, as analyzed by the Department of Labor, was obtained. Consistently, the methane content was measured at one one-hundredth of a percent. We are not aware of any economically viable processes that can effectively recover this small fraction of methane.To prevent this methane from being vented to the atmosphere, degasification wells are proposed. These wells could be drilled into the coal seam prior to the coal being mined. Over a five year period these wells could recover approximately 22% of the methane that exists in the coal. This methane would be of sufficient quality to be used in normal applications or sold to a pipeline.Solutions Engineering, working with information presented by the Bureau of Mines, the United States Geological Survey, the Department of Energy and the Left Fork Mine estimated the methane gas reserves that exist in the mine. This estimate is based on current mine expansion plans. Using this information and a three dimensional dual porosity --single permeability simulator, forecasts of methane production rates for various degasification well arrangements were made. This information indicated that The environmental impacts and benefits of using this technology are summarized in the report. The study indicates the methane emission reduction that could be achieved on a National and Global level. The important point being that this technology is economically viable as is demonstrated in the report.Phase I of this project, the feasibility study, was completed in 60 days. Phase II which will perform the engineering required to install a fuel cell at the mine will be completed over the next twelve months. Phase II will address issues such as which methane source is the most practical, where to locate the fuel cell and how the electrical energy can best be utilized.