Evaluation of Landfill Gas Cleanup Technologies for use with Fuel Cells

摘要

Landfill gas (LFG) cannot be used in today's fuel cells do to contaminants in the gas. We have investigated several LFG cleanup technologies for their ability to sufficiently purify LFG to a level that is suitable for fuel cell use. Landfill gas is produced by the anaerobic decomposition of trash in landfills. LFG is composed primarily of methane and carbon dioxide. Small amounts of nitrogen, oxygen and water are present in LFG as well as numerous compounds in trace quantities. For fuel cells to operate properly on LFG, the total level of compounds containing sulfur, chlorine and silicone must be below one part-per-million by volume (ppmv) in the feedstock gas. Also, any reduction in the level of carbon dioxide, nitrogen, oxygen and water will improve the operating efficiency of the fuel cell. This study characterized the LFG, including trace compounds, at the Burlington County Resource Recovery Complex Landfill in Columbus, New Jersey over a period of one year and compared those results with information available from other landfills in order to establish general cleanup requirements. Through a survey of commercially available gas cleanup systems, a system was identified that could economically clean LFG to levels required for fuel cell use, produce liquid carbon dioxide and concentrate the methane in the gas stream. This study reports the expected reduction in emissions as a result of reduced flaring of LFG and the avoided emissions by fossil fuel displacement. The total CO_2 emission reduction is estimated to be >65,000 tons per year for a complete landfill gas-to-energy project integrating fuel cells with greenhouses at the Burlington County Resource Recovery Complex. The benefits of a landfill gas-to-energy project integrating fuel cells with year-round greenhouse facilities in a modular design are described. Fuel cells are highly modular and can be scaled to match LFG availability. LFG cleanup has the potential to convert a significant environmental problem into valuable commercial products.