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
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
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
Company Contact: Ross M. Levine, 203-825-6057