In a landfill gas application, methane (CH4) and carbon dioxide (CO2) gases are produced during a breakdown of landfill content. The gases are collected and transported through a network of wells and pipelines within the landfill system. The gas is then drawn off the landfill, cleaned, compressed, and processed. Before compression, landfill gas requires filtration to remove numerous particulates that may damage the compression equipment. The captured methane is frequently used as fuel for power turbines driving electrical generators or fuel for natural gas vehicles.
Methane is also captured in other renewable natural gas biodigesters like wastewater treatment or animal waste processing, and a compressor is used to build gas pressure for transmission or fueling. Biogas capture is one of the fastest ways to reduce emissions in transport, with some RNG sources providing negative emissions.