Release Date: September 14, 2000

Methane, the chief constituent of natural gas, is a potent greenhouse gas, and millions of cubic feet of it escape daily from active coal mines. Now, three projects selected the U.S. Department of Energy propose new ways to capture the gas and convert it to useful energy -- reducing an environmental threat while adding to the nation's supplies of clean natural gas and electric power.

The National Energy Technology Laboratory, the Energy Department's chief field site for its fossil energy research program, has selected:

• Appalachian-Pacific Coal Mine Methane Power Co., LLC, Arlington, VA, to work with West Virginia University Research Corp., Morgantown, WV, and Invitation Energy, Mannington, WV, to convert coal mine methane from mines in Marion County, WV, and surrounding areas into liquefied natural gas (LNG) to fuel heavy trucks.

• Northwest Fuel Development, Inc., Lake Oswego, OR, to build a combination gas- processing/power generation system at a West Virginia coal mine to produce 500 thousand cubic feet per day of pipeline-quality gas and 1.2 megawatts of electricity.

• Fuel Cell Energy, Inc., Danbury, CT, to field test a fuel cell power plant that would produce 250-kilowatts of electricity by capturing and using coal mine methane emissions from a mine in Cadiz, OH.

Coal mine methane refers to methane gas that escapes into the atmosphere when coal is mined (the term coalbed methane is more correctly applied to gas trapped inside unmined coal seams). Data from the Mine Safety and Health Administration indicates that nearly 250 million cubic feet per day of methane is emitted from 400 of the gassiest coal mines in the United States.

Because methane is more than 20 times more potent than carbon dioxide in trapping heat within the Earth's atmosphere, these coal mine emissions are equivalent to the combustion exhausts of roughly a dozen 500-megawatt coal-fired power plants.

Each of the projects is scheduled to run for three years. In each, the private sector participant will contribute at least half the total costs of the project.

Details on the coal mine methane projects follow:

• Appalachian-Pacific Coal Mine Methane Power Co., LLC, Arlington, Va., will work with West Virginia University Research Corp. and Invitation Energy, to convert coal mine methane from mines in Marion County and surrounding West Virginia areas into liquefied natural gas (LNG) to fuel heavy trucks. The coal mine methane will be liquefied using a thermoacoustic refrigeration system known as a TASHER. The TASHER, first developed by DOE's Los Alamos National Laboratory, burns a side stream of coal mine methane to compress and expand helium contained within a specially designed reservoir. During expansion, the helium reservoir and attached heat exchangers absorb heat from the main coal mine methane stream, cooling and liquefying it. The TASHER has no moving parts, which means maintenance is low, and is constructed from low-cost materials. The TASHER-based system is to produce 10,000 gallons/day of LNG.

  The LNG would be sold to heavy vehicle fleets in the Interstate-79 "Clean Corridor" between Pittsburgh, PA, and Sutton, WV, where demonstrations using LNG already exist. By preventing coal mine methane from reaching the atmosphere, the system will avoid emitting the equivalent 69,380 tons of greenhouse gases a year.

  DOE Share: $3.89 million; Participant Share: $7.88 million
  Company Contact: Charles D. Estes, 703-526-7851

• Northwest Fuel Development, Inc., Lake Oswego, OR, will build and demonstrate an integrated gas-processing/power-generation system at a West Virginia coal mine, where it will produce 500 thousand cubic feet a day of pipeline-quality gas and 1.2 megawatts of electricity. The gas-processing technology uses pressure swing adsorption (PSA) to separate a pipeline-quality methane stream for sale from the high-nitrogen coal mine methane. Electricity will be generated by 75-kilowatt modular units. Engines running the generators will use the high-nitrogen methane rejected from the processing unit, along with high-nitrogen methane from the mine. Mine ventilation air, which contains very low concentrations of methane, will also be added. Overall, the system will use 900,000 cubic feet per day of coal mine methane that would otherwise be vented to the atmosphere.

  DOE Share: $600,000; Participant Share: $600,000
  Company Contact: Peet M. Soot, 503-699-9836

• Fuel Cell Energy, Inc., Danbury, CT, will field test a fuel cell power plant designed for capturing and using coal mine methane emissions from a mine in Cadiz, Ohio. The 250-kilowatt plant will use methane to generate power that is to be sold to Harrison Mining Corp., the mine's owner. Sulfur oxide and nitrogen oxide emissions are projected to be significantly below those of other power-generation systems. Fuel Cell Energy plans to operate the plant for 8,000 hours, and use 13.6 million standard cubic feet of methane.

  DOE Share: $2.68 million; Participant Share: $2.68 million
  Company Contact: Ross M. Levine, 203-825-6057