What is biogas and how is it produced?

Biogas is a renewable fuel, which is a mixture of methane, CO2 and small amounts of other gases, such as hydrogen sulphide, nitrogen and water vapor. It is generated through the anaerobic digestion of organic matter by bacteria, which break down biomass fed into a closed drum system. Feedstocks include crops or organic waste, such as animal or food waste.

What is the difference between biogas and biomethane?

Biogas is a mixture of methane (50-70%), CO2 (30-50%) and trace gases. It usually contains impurities and is usually used in smaller-scale applications, such as heating and electricity generation in localised settings. Biomethane is refined biogas. CO2 is removed until the gas is almost pure methane. Biomethane has the same properties as natural gas, so can be injected directly into the national grid or used as a vehicle fuel.

How is biogas used to provide energy?

Biogas can be directly converted into electricity and heat through combined heat and power (CHP) plants , which use combustion engines, fuel cells or gas turbines to generate electricity. If refined and upgraded to become biomethane, it can be compressed or liquefied to use as a vehicle fuel, offering a cleaner alternative to fossil fuels.

How does anaerobic digestion work?

Anaerobic digestion occurs in the absence of oxygen, in a closed drum. It occurs in four stages: hydrolysis, acidogenesis, acetogenesis and methanogenesis. During hydrolysis, complex organic molecules are broken down into simpler sugars and amino acids; in acidogenesis, these are converted into volatile fatty acids and hydrogen; in acetogenesis, these are converted into acetic acid, along with additional hydrogen and carbon dioxide; in methanogenesis, methanogenic microorganisms convert acetic acid and hydrogen into methane and carbon dioxide, resulting in the production of biogas.

What are the biggest challenges to biogas production?

The biogas sector is facing high capital costs for new plants, as well as limited availability of sustainable feedstocks and complications with collecting organic waste at scale. There are also regulatory uncertainties and social obstacles, with biogas see as an unsanitary energy source by some parts of the general public.

All articles by Eve Thomas

Eve Thomas

Eve Thomas is a reporter across Power Technology, Offshore Technology and Mining Technology. With experience in B2B media and podcasting, she covers technology, industry, macro and ESG stories in the sector. Her academic history includes a first class BA in English Literature from the University of Sheffield and an MSt in English from Oxford University.

Powered by pumpkins: how seasonal food waste affects biogas production

Seasonal celebrations cause spikes in certain food waste, which can either rot in landfill or be fed as a slurry…
Microalgae: the biofuel feedstock of the future

Biofuel has been touted as the cornerstone of a decarbonised future, but the complex supply chains and finite availability of…
Why Big Oil has its eye on APAC’s EV charging market

Electric vehicles (EVs) are an established cornerstone of the energy transition, with their increasing global adoption chipping away at a…
Environmental considerations ‘the linchpin’ of new UK government

Ahead of the UK's general election last week, the ultimately triumphant Labour Party promised to work with the private sector…
Will AI help or hinder the energy transition?

AI has been touted as the solution to the energy transition, but its massive energy requirements appear to sit in…

Biden versus Trump: the diverging energy priorities of the US election candidates

The US election will represent a watershed moment for energy policies as the country looks set to embark either on…
Plastic recycling ‘the only way’ of introducing circularity to oil and gas industry

Establishing a circular economy would have a transformative impact on the oil and gas industry – but the only way…
Drones reducing risk in offshore oil and gas inspection

A variety of use cases for drones are materialising across both onshore and offshore oil and gas, many of which…
38% of companies lack an ESG strategy – GlobalData survey

Well over a third (38%) of companies do not have an ESG strategy, and half (50%) of respondents believe that…
“Britain has become more unequal” – Greenpeace on green transition tax

Greenpeace argued earlier this year that some of the measures needed for a just energy transition could be met through…