Energy recovery from biogas has become more common nowadays. The energy of the biogas is converted into useful energy in the form of electricity, heat or a combination of both (cogeneration) by means of gas engine or (steam/hot water) boiler, ...

Biogas consists of methane (CH₄) and carbon-dioxide (CO₂) along with some trace gases such as water vapour, hydrogen sulphide (H₂S), nitrogen, hydrogen and oxygen.

At some applications trace gas such as H₂S must be removed before the biogas can be used because the hydrogen sulphide gas is corrosive.

H₂S it self has an offensive odour of "rotten eggs" at concentrations as low as 50 ppbv and is toxic at concentrations above 100 ppmv.

H₂S is a health and safety hazard, and when combined with carbon dioxide (CO₂) and water vapour (H₂O), it corrodes plant equipment such as boilers and piping, and can ruin power-generating equipment.

High levels of H₂S can also interfere with other processes such as killing useful bacteria in anaerobic digesters. Reducing H₂S offers cost savings associated with less maintenance, increased process and energy efficiency, and reduced toxic emissions.