Reduction of Non-CO2 Greenhouse Gas Emissions Through In Situ Bioconversion of Methane

72593-Methane has a global warming potential 21 times greater than carbon dioxide and a much shorter half-life in the atmosphere. Therefore, on a ton-by-ton basis, technology that targets methane emissions would mitigate global warming at a faster rate than the reduction of carbon dioxide emissions. Because methane recovery from coal mines and landfills is economically driven, and recovery projects are either ceased or not initiated if natural gas prices are low, this greenhouse gas is commonly released to the atmosphere even when it is not present in commercial quantities. This project will identify and cultivate unique microbes that will be used to reduce methane emissions in coal mines, in gob gas systems in front of mining operations, and in biofilters located in mine ventilation systems. Phase I identified methane seep locations that may have persisted for many decades or more, and a unique anaerobic sampling technique was developed that maximized the probability of collecting anaerobic microbes. The microbial research clearly demonstrated that microbes collected at the methane seep locations consumed methane under anaerobic conditions in the presence of sulfate. As a consequence, the feasibility of isolating anaerobic methane oxidizers, so that they can be applied to reducing non-CO2 greenhouse gas emissions in coal mines and coal outcrops, has been demonstrated. Phase II research will lead to the isolation of anaerobic methane oxidizers. Also, multiple samples will be obtained from a few selected sites throughout the year to evaluate the seasonal fluctuations in microbial activity. Commercial Applications and Other Benefits as described by awardee: These unique microorganisms, methanotrophs, would be applied directly to coal in the mine, injected into coal seams in front of mining operations, and utilized in biofilters for mine ventilation systems to reduce methane emissions and prevent explosions. In addition, if these methanotrophs were used in combination with other microbial cultures, they would have the potential of producing cheaper, valuable oxychemicals or energy fuels.