Energy Policy Act of 2005 (Ultra-deepwater and Unconventional Resources Program)
Comprehensive Investigation of the Biogeochemical Factors Enhancing Microbially
Generated Methane in Coal Beds
Colorado School of Mines (CSM), Golden, CO 80401
United States Geological Survey, Denver, CO 80202
University of Wyoming, Laramie, WY 82071
Ciris Energy, Centennial, CO 80112
Pioneer Natural Resources, Denver, CO 80202
Pinnacle Gas Resources, Sheridan, WY 82801
Coleman Oil & Gas, Inc., Denver, CO 80202
Research has shown that microorganisms are capable of converting coal to methane, though at widely different rates under controlled laboratory conditions. The methane is produced by methanogenesis, a process in which microorganisms (methanogenic archaea) convert substrates such as acetate or CO2 and hydrogen into methane. The overall objective of the proposed research is to systematically investigate processes involved in methanogenesis from coal to better understand how the process can be enhanced and accelerated. Project activities will include characterizing the following factors that may lead to enhanced methanogenesis: (1) specific chemical constituents of coal, analyzed by methods such as gas chromatography and mass spectrometry, (2) specific microorganisms identified via phospholipid and DNA analyses, (3) culture growth amendments and conditions such as pH, temperature, nutrient and salt levels evaluated by microcosm CH4 production, and (4) chemical pre-treatment of the coal with acids, bases, oxidants, solvents, and/or enzymes to release soluble organic matter that may subsequently stimulate the native methanogens. Additionally, the chemical pathways of methanogenesis from coal, the rate limiting steps and the interactions between microbial communities will be characterized and these dynamics will be captured in a computer model. All of these inquiries will provide a broader understanding of microbial methane production from coal, as a critical first step to ultimately stimulating methanogenesis in situ.
Laboratory experiments have shown that the methane associated with coal can be increased from typical values of 60 SCF/ton to over 300 SCF/ton. As an example of the potential of enhanced methanogenesis, if 1% of the coal in the Powder River Basin could be converted to methane by adding inexpensive nutrients to stimulate existing microorganisms in the coal beds, approximately 30 TCF of gas would be produced, dramatically increasing reserves and profitability. In addition, if sufficient methane could be produced to exceed the solubility of methane in water, the gas could be produced without dewatering the coals, thus avoiding the costly dewatering step and its associated political and environmental complications.
Principal Investigator: Junko Munakata Marr