Biogas and biomethane: Characteristics
What turns raw biogas into a sellable fuel
What this tab covers The physical and chemical properties that set its grade, price and uses, with the commercial grades and the standards that define them.Raw biogas is 50-65% methane with CO2, water and H2S. Its commercial value depends on upgrading to grid or vehicle quality, measured by methane content, Wobbe index and contaminants.
Properties that matter commercially
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Methane content | raw biogas 50-65%; CBG at least 90% CH4 (IS 16087, indicative); grid biomethane usually 95-98% (indicative) | sets energy value and engine compatibility | indicative |
| Hydrogen sulphide | CBG at most about 16 mg/m3 (IS 16087, indicative) | corrodes engines and pipelines | indicative |
| Energy content | about 50 MJ/kg methane; about 10.5 MWh per 1,000 m3 (indicative) | used for unit conversion and pricing | indicative |
| Siloxanes and oxygen | limited by EN 16723 in Europe (indicative) | siloxanes from sewage and landfill gas damage engines | indicative |
Commercial grades
- Raw biogas (power and heat)
- Grid biomethane (EN 16723-1)
- Vehicle biomethane, bio-CNG and CBG (EN 16723-2, IS 16087)
- Bio-LNG