Content on this page requires a newer version of Adobe Flash Player.

Get Adobe Flash player

What is biomethane?

Biomethane means pipeline-quality gas derived from organic material.
It is identical in properties to natural gas, but it is not derived from fossil fuels. Biomethane can be produced from biogas which
has been cleaned or “upgraded” to meet UK gas pipeline specifications, by the removal of gases such as CO2 and hydrogen
sulphide to leave an almost pure (~98%) methane gas.

Although less commercially viable, biomethane can also be produced by a thermal gasification rather than biological process.
Gasification is a process in which dry biomass (e.g. wood) is thermally decomposed at temperatures of around 850 degrees
centigrade to produce what is known as synthesis gas (often referred to as “syngas”).
This can also be upgraded to pipeline quality biomethane. This pathway allows the recovery of gas from organic materials that
cannot readily be processed by anaerobic digestion.

Biomethane can be injected into the gas network or compressed for use in natural gas vehicles.
Once in the gas network, it can be used in exactly the same way as natural gas (which is a fossil fuel). It can provide domestic
or commercial cooking and heating, or be used as vehicle fuel in locations remote from the source of the gas.

Biomethane injection offers increased scope to maximise the energy contained in biogas by moving it to where it is needed.
Typically this means using it in a location where there is a demand for heat. If there is a local demand for heat, the biogas can
be used most efficiently in CHP mode. However if there is no local heat demand (other than for the AD process itself) then
biomethane is an environmentally superior option, as more energy overall can be extracted from the gas.