Biogas

What is biogas, its properties and applications

Biogas is a gas produced as a byproduct of microbial decomposition of biomass in the anaerobic conditions. It consists of methane 50-70% and carbon dioxide 45-30% but also contains some impurities like sulphur and water vapours, which are removed in a gas treatment unit. Biogas is close to natural gas 90-98% methane. It also has no color or smell and is lighter than air. Biogas can be used for burning in boilers, internal combustion engines for power generation without enrichment. Most often, biogas is used to generate electric power or purified to the condition of biomethane and pumped into the gas grid or compressed into cylllinders. Other names for biomethane are bioCNG or CBG

Find out how much biogas is produced out of different substrates

Biogas Outputs

Biogas refers to methane gas. Unlike propane, it does not liquefy at normal temperatures. Biogas is also not suitable for fueling cylinders without enrichment. During freezing and under pressure biogas is stratified into carbon dioxide and methane. An expensive cryogenic technique is required to liquefy methane. Therefore, methane for use as a fuel for automobiles is not liquefied, instead compressed and pumped into cylinders at 200-250 atm.

Biogas can also be cleaned of CO2, adjusted to the properties of natural gas, and fed into the public gas system. Enriched biogas is called biomethane. Typically, such cleaning is carried out by using a water scrubber, membranes or adsorption. After cleaning, drying, odorizing and compressing, the resulting gas does not differ, both in composition and in properties, from natural gas.

The main properties of biogas (with 60% methane)

2.5

kWh electric energy produced by co-generators with gas piston engines per m³ of biogas

2.6

kWh thermal energy produced by co-generators with gas piston engines per m³ of biogas

5133

kcal/m³, Calorific value

1.2

kg/m³, Biogas density

650 – 750

°C, Burning point

Frequently Asked Questions About Biogas

About Biogas

Can biogas be liquefied and filled into cylinders?

Can biogas be accumulated and stored for a long time?

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