Biogas
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.
Net Zero by 2050, A Roadmap for the Global Energy Sector, published by the International Energy Agency in May 2021, defines biogas as: ‘A mixture of methane, carbon dioxide and small quantities of other gases produced by anaerobic digestion of organic matter in an oxygen-free environment.’
Is suggests that biogases: ‘Include biogas and biomethane.’
[edit] Related articles on Designing Buildings Wiki
- Anaerobic digestion (repeats some of the text in this article).
- Biomass.
- Biomaterial.
- Conventional liquid biofuel.
- Environmental impact of biomaterials and biomass (FB 67).
- Feed in tariff.
- Gas Goes Green.
- Liquefied petroleum gas (LPG).
- Mains gas.
- Natural gas.
- Oil - a global perspective.
- Peak oil.
- Renewable energy.
- Renewable heat incentive.
- Shale gas.
- Types of fuel.
- Water vapour.
- Zero carbon homes.
- Zero carbon non-domestic buildings.
Featured articles and news
Excellent Black civil engineers in the UK
Recognising past and present role models for the future.
So why not write something?
Climate Emergency Retrofit Guide
LETI publishes guidance for energy efficient home retrofits.
The new normal for ventilation
Predictions about adequate post-pandemic IAQ in non-domestic buildings.
Government publishes plans to 'build back greener'.
Fire safety exclusions and insurance
The contentious nature of claims associated with cladding, fire safety and EWS1 forms.
ECA comments on low-carbon heating systems initiative and Heat and Buildings Strategy.
Victorian dust heaps of London
Cinders and other forms of domestic rubbish created filth but also generated great wealth.
Young professionals in construction survey
CIC 2050 Group requests input to find out priorities for future industry leaders.