Knowledge Base

Biogas upgrading is the process of purifying raw biogas by removing carbon dioxide and other impurities, turning it into biomethane, also known as renewable natural gas (RNG) or green gas. Raw biogas produced through anaerobic digestion typically consists of 55 to 70% methane and the remainder mostly CO₂, along with trace amounts of hydrogen sulphide (H₂S) and other compounds. Upgrading concentrates the methane content to natural gas quality, around 97%, so the resulting biomethane can be injected directly into the existing gas grid or used anywhere natural gas is used. HoSt applies in-house membrane-based upgrading technology for this step, and its plants have achieved upgrading efficiencies of up to 99.5%, meaning very little methane is lost during the process.