Biogas and natural gas can both contain large amounts of methane and can both be burned for heat or power, but they come from very different sources. Biogas is produced when microorganisms break down organic matter without oxygen. Natural gas is a fossil fuel extracted from underground geological formations.
Raw biogas usually contains more carbon dioxide and trace contaminants, so it often needs upgrading before it can be used like pipeline natural gas.
At a glance
| Point | Biogas | Natural Gas |
|---|---|---|
| Origin | Recent biological decomposition | Ancient geological/fossil formation |
| Renewability | Potentially renewable | Non-renewable on human timescales |
| Raw methane content | Often roughly 50–70%, depending on feedstock/process | Typically much higher methane after processing |
| CO₂ content | Relatively high in raw biogas | Usually removed/limited during gas processing |
| Typical impurities | H₂S, moisture, siloxanes and others can occur | Water, H₂S, CO₂ and heavier hydrocarbons can occur before processing |
| Use | Boilers, CHP, upgraded biomethane, vehicle fuel after treatment | Heating, power, industrial processes, chemical feedstock |
Biogas
A gas mixture produced by anaerobic digestion of materials such as manure, sewage sludge, food waste or agricultural residues.
Natural Gas
A naturally occurring fossil gas mixture extracted from underground reservoirs, composed mainly of methane with varying amounts of other hydrocarbons and gases.
Biomethane bridges the two systems
If raw biogas is cleaned and upgraded so that methane concentration and quality meet pipeline or vehicle-fuel specifications, it can substitute for fossil natural gas in many applications. The exact standards depend on the gas grid or fuel specification.
Climate impact is not just ‘renewable vs fossil’
Biogas can reduce emissions when it captures methane that would otherwise escape from manure or waste, but leaks from digesters and pipelines can undermine benefits because methane is a potent greenhouse gas.
Feedstock, land use, plant energy demand and methane leakage all matter in lifecycle assessments.
Natural gas is not pure methane at the well
Raw natural gas can contain water, hydrogen sulfide, carbon dioxide, nitrogen and natural-gas liquids. Processing removes contaminants and separates valuable components before the gas enters pipelines.
Frequently asked questions
Can biogas be injected into a natural-gas pipeline?
Yes if it is upgraded and meets the local pipeline quality specification.
Is biogas the same as LPG?
No. LPG is mainly propane and butane; biogas is primarily methane plus carbon dioxide.
Does biogas smell?
Raw biogas can contain hydrogen sulfide and other odorous compounds; treated biomethane may be odorized for distribution.
Can food waste make biogas?
Yes. Food waste is a common anaerobic-digestion feedstock.
KnowDifferences Editorial Team
Independent explanations with definitions, practical examples and references. Read our editorial approach.