430F98080
oEPA
United States
Environmental Protection Agency
Air and Radiation
6202J
Draft
July 1998
         EPA Coalbed Methane Outreach Program Technical Options Series
          COAL MINE METHANE USE IN FUEL CELLS
               200 kW Phosphoric-acid fuel cell (PAFC) with a thermal output of 700,000 Btu/hr
                  Unit dimensions = 1 Oft x 1 Oft x 18ft. (Photo courtesy of International Fuel Cells)
         COAL MINE METHANE POWERED FUEL CELLS CAN. ..
         + Operate on methane from mine pre-drainage and medium quality gob gas
          Use methane at near atmospheric pressure, avoiding compression costs
         * Use methane diluted with air and/or carbon dioxide
         4 Generate electricity for distributed power generation systems
         + Lower NOX and SO2 emissions, and virtually eliminate particulate emissions
         * Reduce emissions of methane (a greenhouse gas)

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 Coal mine methane
 can be used in fuel
cells to generate low
cost power for mining
operations, trimming
   overhead costs
  Powering fuel cells
   with coal mine
  methane provides
economic benefits, as
     well as the
   environmental
   benefits already
   associated with
      fuel cells
WHY CONSIDER COAL MINE METHANE POWERED FUEL CELLS?

At present, tuel cells are economically competitive with conventional  forms  of
electricity generation only in certain cases. Fuel cells are,  however, making steady
progress toward the goal of widespread commercial use. Use of methane in fuel
cells, recovered from gassy coal mines, may be an economical approach to on-site
power generation or local use.

Gob areas (collapsed rock over mined-out areas) release large volumes of gas and
subsequently vent it to the atmosphere.  Much of this gas is of medium quality and
unsuitable for pipeline injection. However, fuel cells can operate on medium-quality
gas, reducing  methane emissions to the atmosphere while producing  electrical
power for on-site use. Because of their high efficiency, the use of fuel cells  for power
generation emits less carbon dioxide per kilowatt-hour of electricity produced than
conventional turbine and internal combustion power generation methods. Sulfur and
NOX emissions are also low, making permitting easier and less expensive.

Several hundred phosphoric-acid fuel cells (PAFCs) are now in use worldwide.  In the
United States, several small commercial and light industrial operations have begun
using PAFCs during the past five years. PAFCs are  reliable and  can  operate  on
conventional natural gas as well as coal mine methane.  PAFCs that produce from
200  kW to 11 MW at 40 percent efficiency are now commercially available from
International Fuel Cells.

Molten-carbonate fuel cells (MCFCs)  are smaller than PAFCs, and testing indicates
that they are more efficient. The US Department of Energy, in conjunction with the City
of Santa Clara, has successfully tested MCFCs with a capacity of 200 kW to 2 MW.
The U.S. Department of Energy  plans to test MCFCs using gas produced from coal
gasification, and coal mine gob gas. Commercial versions of these fuel cells should
be available by 2001,

SOME FACTS ABOUT POWER GENERATION USING FUEL CELLS. .
 Coal mine methane
     lacks heavy
   hydrocarbons,
   making it better
   suited to fuel cell
  power production
   than natural gas
    4  Modular design allows for custom power generation and generation close to
       the load, reducing transmission and distribution losses

    *  Better efficiency than turbine generated power (efficiencies between 40-60%)

    *  A typical gassy mine can drain at least 1 mmcf of methane per day. A 200 kW
       PAFC unit would require about 80 mcf per day of medium  heating value (50%
       methane) gas; a MCFC would require about 62 mcf per day

    *  Ideal power for industries located near coal mines producing medium to high
       heating value coal mine gas

    *  Short permitting and licensing schedules due to clean, quiet, safe operation

    *  Capable of using thermal output for heating (cogeneration), raising potential
       efficiency to over 80 percent

    *  Main by-product is purified water

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     COMPARISON OF PHOSPHORIC ACID AND MOLTEN CARBONATE FUEL CELLS
            Parameter
                                      Phosphoric-acid Fuel
                                          Cells JPAFC}
 Molten-carbonate Fuel
      Cells (MCFC)
 Typical operating costs ($US)
 Typical capital costs ($US)
 Estimated total costs/kWh ($US)2
 Typical efficiency
 Operating temperature (C)
 Thermal output (Btu/kWh)
 Oxidant requirements
 Can use coal mine methane4
 Fuel processor required
 Commercial availability	
                                          $0.0017/kWh
                                        $2,250-3,750/kW
                                       $0.0527-0.0873/kWh
                                            40-45%
                                              200
                                          7,000-8,300
                                            Oxygen
                                              Yes
                                              Yes
                                              Now
$9.8/kW/yr + $0,0017/kWh1
     $1,000-1,500/kW
   $0.0256-0.0370/kWh
         50-60%
           650
       6,000-6,800
Oxygen & Carbon dioxide3
           Yes
           No
          2001
 1 Estimated for commercial operation when available.
 2Based on a 200 kW unit over a five year operation period at maximum capacity. Five years is the minimum
 expected life for the cell stacks. Technology is evolving rapidly and prices are expected to decrease.
 3Fuel cells can use air as an oxygen source. Product gas can be a source of carbon dioxide.
 4Either coal mining operations or "stand-alone" wells can provide coalbed methane for the process. Utilization of
 methane produced during coal mining operations is especially attractive because in most cases, mines vent the
 methane to the atmosphere, which contributes to global warming.  Because mines would otherwise waste coal
 mine methane, it is typically less expensive than conventional natural gas.	
          USING COAL MINE METHANE IN FUEL CELL-POWERED VEHICLES
Proton exchange membrane (PEM) fuel cell technology has been  refined during the
past few years and used in a wide range of stationary and transportation applications.
Since  1997, several urban transit buses in Vancouver, British Columbia and Chicago,
Illinois  have been powered by 275 HP Bollard Fuel Cell  engines.  These zero-emission
engines use hydrogen reformed from natural gas or methanol to create electricity with-
out combustion. The Fuelcell Propulsion Institute is currently developing fuel cells pow-
^                .." .  ..."... ..  ..	               ered by hydrogen produced
                                                     from coal mine methane for
                                                     use  in   underground  mine
                                                     vehicles. Coal mine methane
                                                     can  play a  key role  in the
                                                     production  of  hydrogen  to
                                                     fuel  both stationary  fuel cell
                                                     power  plants and  fuel cell
                                                     engines for vehicles.
m.:
El
                                                        How A Proton Exchange
                                                       Membrane Fuel Cell Works
                                                     The underlying  principle of the
                                                     fuel cell is similar to that of a
                                                     battery.  Operating with a solid
                                                     electrolyte at low temperature
                                                     of approximately  80C, hydro-
                                                     gen (H2) and oxygen (O2) are
                                                     fed into the cell and an  elec-
                                                     trochemical reaction generates
                                                     direct current. The only reaction
                                                     product is water (H2O).

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 For More Information.
 Recent developments in fuel cell technol-
 ogy are  expanding the options for coal
 mine methane  use.  Use  of coal  mine
 methane in fuel cells can  increase  mine
 profits while reducing methane emissions to
 the atmosphere.

 To  obtain more information about  using
 coalbed  methane in  fuel cells  for power
 generation, contact:

 Eric Simpkins
 Energy Research Corporation
 1634 Eye Street Northwest
 Washington, DC 20006
      (202)737-1372
 e-mail: ercc@erols.com

 Fred S. Kemp
 International Fuel Cells
 P.O. Box 739
 South Windsor, CT 06074
      (860)727-2212
 Fax:  (860) 727-2399
 e-mail: kempfs@icf.hsd.utc.com
Arnold R. Miller Ph.D.
President
Fuel Cell Propulsion Institute
PO Box 260130
Denver, CO 80226
      (303) 986-0530
Fax:   (303)986-2184
e-mail: fuelcell@mines.edu
Or contact U.S. EPA's Coalbed Methane Outreach  Program for information about this and
other profitable uses for coal mine methane:
 Coalbed Methane Outreach Program
 U.S. EPA (6202J)
 401 M Street, SW (6202-J)
 Washington, DC 20460 USA
       (202) 564-9468 or (202) 564-9481
 Fax:   (202) 565-2077
 e-mail: fernandez.roger@epa.gov
       schultz.karl@epa.gov

       http://www.epa .gov/coalbed
              C  O  A
              M E  T H A N E
              OUTREACH
              PROGRAM
 The mention of products or services in this case study does not constitute an endorsement by EPA.

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