Electric Power Generation Using A Phosphoric Acid Fuel Cell On A Municipal Solid Waste Landfill Gas Stream

The U.S. Environmental Protection Agency (EPA) and International Fuel Cells Corporation conducted a test to verify the performance of a landfill gas treatment unit and a phosphoric acid fuel cell system. The complete system removes contaminants from landfill gas and produces electricity for on-site use or connection to an electric grid. The verification test was the first use of fuel cell technology at a municipal solid waste facility. The test design was subjected to extensive review and comment by the EPA’s National Risk Management Research Laboratory, landfill test site operators, and the technology developers. Performance data were collected at two sites determined to be representative of the U.S. landfill market. The Penrose facility, located in Los Angeles, California, was the first test site. The landfill gas at this site represented waste gas recovered from four nearby landfills, comprised primarily of industrial waste material. It produced approximately 3,000 standard cubic feet (scf) of gas per minute, and had a higher heating value of 446 BTU/scf at about 44 percent methane concentration. The second test site, Groton Landfill, was located in Groton, Connecticut. This was a relatively small landfill, but with greater heat content gas (methane levels were about 57 percent and average heating value was 585 BTU/scf). The verification test addressed contaminant removal efficiency, flare destruction efficiency, and the operational capability of the clean-up system, and the power production capability of the fuel cell system. The test verified that the clean-up system is capable of reducing total halogen and total sulfur levels to less than 3 ppmv, which are the minimum levels, required to operate the fuel cell. The GPU flare met emission requirements for sulfur, volatile organic compounds, and other hazardous air pollutants. The GPU exceeded the minimum operating requirement and logged more than 6,465 hours between the two sites. Based on the landfill gas quality, it was expected that the PC25 fuel cell would produce a minimum of 140 kW power. The power produced at Penrose was slightly below this value and peaked at 137 kW. The Groton landfill produced a maximum power output of 165 kW due to higher BTU gas. The overall fuel cell efficiency was determined to be 37.1 percent and 38.0 percent at Penrose and Groton, respectively. Additional performance results determined for the fuel cell include adjusted availability of over 96 percent at both sites, and low NOx, SO2, and CO emissions.