Process and apparatus for purification and compression of raw landfill gas for vehicle fuel

摘要

A process and apparatus for purification and compression of raw landfill gas stream in a landfill to produce vehicle grade fuel. After the landfill gas stream is extracted and collected, all solids and significant moisture are removed in a pretreatment system prior to compression of the gas stream. The gas stream is then compressed to enhance the function of a membrane purification system. Additional moisture and compressor oil are removed. The gas stream is then heated to maintain any remaining moisture in vapor form. Volatile organic compounds and the balance of the compressor oil are removed from the gas stream by passing the gas stream across an activated carbon guard bed system. The resultant gas stream is fed to a multi-stage membrane system which separates the methane from the other constituents of the landfill gas stream including any remaining moisture. The resultant vehicle quality gas is then compressed to pressures acceptable for introduction and storage in motor vehicles converted to operate on compressed natural gas.