Methane gas, which burns without releasing sulfur contaminants, is becoming increasingly important as a natural gas fuel in the U.S. But the process of recovering methane, which is often trapped within porous, unrecovered or waste coal, produces large amounts of water contaminated with salts, organic compounds, metals, and naturally occurring radioactive elements. "Our idea is to use specially developed bacteria to remove the contaminants from the wastewater, and also help to release the trapped methane," says Brookhaven chemist Mow Lin.
Lin's team has developed several strains of bacteria that can use coal as a nutrient and adsorb or degrade contaminants. They started with natural strains already adapted to extreme conditions, such as the presence of metals or high salinity, then gradually altered the nutrient mix and contaminant levels and selected the most hardy bugs (for more, see: http://www.
In laboratory tests, various strains of these microbes have been shown to absorb contaminant metals, degrade dissolved organics, and break down coal in a way that would release trapped methane. The use of such microbe mixtures in the field could greatly improve the efficiency and lower the associated clean-up costs of coal-bed methane recovery, Lin says.
To learn more about this work, see the talk given by Lin during the Division of Fuel Chemistry's "Synthetic Clean Fuels from Natural Gas and Coalbed Methane: 30 Years Progress Since the First Oil Crisis" session on Thursday, September 11, 2003, at 3:30 p.m. at the Jacob Javits Convention Center, Room 1A13. This research was funded by grants for high-school and undergraduate student research at Brookhaven Lab from Brookhaven Science Associates and DOE's Office of Science.