United States
              Environmental Protection
              Agency	
National Risk Management
Research Laboratory
Research Triangle Park, NC 27711
              Research and Development
EPA/600/SR-95/155    April 1996
EPA       Project  Summary

               Demonstration of Fuel  Cells  to
               Recover Energy from  Landfill
               Gas  -  Phase II.  Pretreatment
               System  Performance
               Measurement
              J.S. Trocciola
                The report describes Phase II of a
              demonstration of the utilization of com-
              mercial phosphoric acid fuel cells to
              recover energy from landfill gas. This
              phase consisted primarily of the con-
              struction and testing of a Gas Pretreat-
              ment Unit (GPU) whose function is to
              remove those impurities from landfill
              gas which are detrimental to the fuel
              cell. The GPU has been successfully
              tested at a landfill-to-energy facility in
              Los Angeles (Sun Valley), California.
              The GPU successfully removed the sul-
              fur and halogen compounds contained
              in the landfill gas to a level signifi-
              cantly below that specified for use with
              the phosphoric acid fuel cell. During a
              challenge test in which dichlorodifluo-
              romethane (Refrigerant 12) was inten-
              tionally injected into the process stream
              during an 8-hour period, the exit con-
              centration of Refrigerant 12 was below
              the limit of  detection and below the
              specified value for the fuel cell.
                This Project Summary was  devel-
              oped by EPA's National Risk Manage-
              ment Research Laboratory's Air Pollu-
              tion Prevention  and Control Division,
              Research Triangle  Park, NC, to an-
              nounce key findings of the research
              project that is fully documented in a
              separate report  of the same title (see
              Project Report ordering at back).

              Overview
                International Fuel Cell Corporation (IFC)
              has completed Phase II of a U.S. Environ-
              mental Protection Agency (EPA) demon-
              stration of the utilization of commercial
              phosphoric acid fuel cells to  recover en-
 ergy from landfill gas. This phase of the
 program consisted  primarily of the con-
 struction and testing of a Gas Pretreat-
 ment Unit (GPU) whose function is to re-
 move those impurities from landfill gas
 which are detrimental to the fuel cell.
  The GPU has been successfully tested
 at a landfill site located in Los  Angeles
 (Sun Valley), California. The site is oper-
 ated by Pacific Energy Corporation as  a
 landfill-to-energy facility. The GPU suc-
 cessfully removed the sulfur and halogen
 compounds contained in the landfill gas to
 a level significantly below that specified
 for use with the phosphoric acid fuel cell.
 During a challenge test in  which dichlo-
 rodifluoromethane (Refrigerant 12) was
 intentionally injected into  the  process
 stream during an 8-hour period, exit con-
 centration of Refrigerant 12 was below
 the limit of detection and below the speci-
 fied value for the fuel cell.
  The GPU was constructed by IFC at its
 facility in South Windsor, Connecticut. Con-
 struction of the unit was completed in Feb-
 ruary 1993. Upon completion of construc-
 tion, the unit was evaluated at the South
 Windsor facility using nitrogen as the test
 gas. The unit successfully completed the
 16-hour control test verifying that rated
 flows, pressure, and temperature were
 achieved. After the test, the unit was
 shipped to the landfill site in Los Angeles,
 California, where it was installed in April
 1993.
  The GPU system is shown schemati-
 cally in Figure 1. The system consists of a
 number of fixed beds and  condensers/
 heat exchangers. A functional description
 of the major elements of the GPU is con-

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tained in Table 1. The unit has been tested
on  landfill  gas at  the  site,  and Table  2
compares the measured  sulfur and halide
contents of the gas produced by the GPU
to the specification value. The data verify
that the GPU reduces  the sulfur and  ha-
lide contents of landfill gas  to a concen-
tration lower than required by the fuel  cell
power plant. The data  also show that liq-
     uids do not condense in the low tempera-
     ture cooler. However, that cooler reduces
     the temperature of the landfill gas prior to
     its  introduction into  the  carbon  bed, in-
     creasing  the  capacity of the  carbon bed
     for  the sulfur and  halogen compounds.
     For system simplification in the future, it
     may be  beneficial  to  eliminate  the low
     temperature cooler and accept any reduc-
                  tion in carbon bed capacity. Based on the
                  favorable results of the GPU testing, the
                  EPA directed IFC to  proceed into Phase
                  III of the program which entails character-
                  izing the performance (i.e., emissions, ef-
                  ficiency, and  power output) of the com-
                  mercial phosphoric acid fuel cell power
                  plant when operating  on landfill gas which
                  has been purified  by the GPU.
        Landfill Gas
                                                                                                         Regeneration
                                                                                                             Gas
                                                                                                                     Clean
                                                                                                                     Landfill
                                                                                                                     Gas to
                                                                                                                     Fuel
                                                                                                                     Cell
Figure 1. Landfill gas pretreatment system.




Table 1. GPU Component Functions

  Component
Function
                        Regenerate
H2S Removal Bed
Cooler/Condenser
Dryer Bed
Low Temperature Cooler
Carbon Bed

Filter
Remove H2S
Remove Water, Hydrocarbons
Remove Water to -50°C Dew Point
Cool Carbon Bed
Remove Organic Sulfur and Halogen
Compounds
Remove Particulates
No
Not Applicable
Yes
Not Applicable
Yes

No
Table 2. GPU Sulfur and Halide Contaminant Removal Performance vs. Specification

                                     GPU Exit (ppmV)           Specified Value (ppmV)
Total Sulfur (as HSf
Total Halides (as Chloride)"
 <_ 0.047
 < 0.032
<3
<3
* Measured by gas chromatography/flame photometric detector by EPA Methods 15, 16, and 18.
b Measured by gas chromatography/mass spectroscopy by EPA Method TO-14.

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  J.S. Trocciola is with International Fuel Cells Corp., South Windsor, CT 06074.
  Ronald J. Spiegel is the EPA Project Officer (see below).
  The complete report, entitled "Demonstration of Fuel Cells to Recover Energy from
    Landfill Gas - Phase II. Pretreatment System Performance Measurement,"
    (Order No. PB96-103 601; Cost: $35.00, subject to change) will be available only
    from:
          National Technical Information Service
          5285 Port Royal Road
          Springfield, VA 22161
          Telephone: 703-487-4650
  The EPA Project Officer can be contacted at:
          Air Pollution Prevention and Control Division
          National Risk Management Research Laboratory
          U.S. Environmental Protection Agency
          Research Triangle Park, NC 27711
United States
Environmental Protection Agency
National Risk Management Research Laboratory (G-72)
Cincinnati, OH 45268

Official Business
Penalty for Private Use $300
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POSTAGE & FEES PAID
         EPA
   PERMIT No. G-35
EPA/600/SR-95/155

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