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-
-------
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
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/600/SR-95/155
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