Knowledge Base

Biogas is the raw gas that leaves the digester. It contains methane, CO₂, hydrogen sulphide (H₂S), and water vapour, so it requires treatment before most end uses. Biomethane (also called renewable natural gas or green gas) is biogas from which CO₂ and impurities have been removed through a process called biogas upgrading, raising the methane content to between 90-98%. At that point, it is energy equivalent to fossil natural gas and can be injected directly into the existing gas grid. The fundamental difference between biomethane and natural gas is origin: one is derived from organic waste in a closed biological cycle, the other from fossil carbon that has been locked underground for millions of years.