Biogas is formed by anaerobic digestion, that is, the microbial degradation of organic material such as farm wastes or energy crops. This process is sometimes referred to as ‘biomethanation’.
Biogas is mainly composed of methane and carbon dioxide, but may also contain small amounts of nitrogen, hydrogen and carbon monoxide, as well water vapour and contaminants such as hydrogen sulphide and siloxanes.
After a relatively striaght-forward clean-up process, biogas (sometimes called biomethane or renewable natural gas (RNG)) can be used as a fuel. Biogas has been used as a fuel for many centuries, and in the UK, the city of Exeter used biogas for street lighting as early as 1895.
The production of biogas not only provides a ‘renewable’ source of energy, it also offers a use for waste products that might otherwise be difficult to dispose of.
The waste products from biogas generation iteslf are water and fermented organic material which can be used as a high-quality fertiliser.
Typically, anaerobic digestion requires a heat source, and so biogas is often used to fuel combined heat and power (CHP) plant that produces both electricity and heat. The heat can be used for the anaerobic digestion process and can also be used to pasteurise animal-derived waste so that it can be used as fertilisers.
Combined heat and power plant can feed electricity into the national grid, and so biogas installations may qualify for payments under the renewable heat incentive (RHI) scheme (other than biogas from landfill).
Biogas can also be cleaned of carbon dioxide and fed into the national grid.
 Related articles on Designing Buildings Wiki
Featured articles and news
5 out of 10 filtering facepieces fail HSE tests.
Eleven Magazine announce the winner and runners-up in their Moontopia competition.
As January is the time for hitting the gym, Designing Buildings Wiki lists the best gym architecture in the world.
London is at the top of the list of global construction megacities, beating Dubai and Abu Dhabi.
What are the innovative business models of the future, and how to incentivise supply chains to work on a whole life basis?
One of the largest churches in the world, the monumental St. Peter's Basilica.
How thermal comfort is quantified and how it can affect wellbeing.
Snøhetta complete a treehouse cabin that allows guests to lie beneath the Northern Lights.
Christiania is an anarchist 'freetown' in Copenhagen where strange and experimental architecture has flourished.
Why buildings crack, how cracks are categorised and what can be done.