Abstract
Biogas is produced during anaerobic digestion of organic substances by a consortium of microorganisms. Biogas consists mainly of methane (CH4) and carbon dioxide (CO2). Other gases such as dinitrogen (N2), water vapour (H2O), ammonia (NH3), hydrogen sulfide (H2S) and other sulfur compounds could also be found therein. Biogas produced by waste biomass has been recognized as one of the most important alternative energy sources in the recent years. In order to be used as a source of energy to generate heat and electricity, biogas should be cleaned. H2S is a colourless, flammable, malodorous and toxic gas. The main issues due to the high concentrations of H2S in biogas are its corrosive action, which damages engines and the production of sulfur oxides (SOx) due to H2S combustion. The best ways to remove H2S from biogas are the biological methods with the use of biofilters, biotrickling filters, bioscrubbers and using of activated sludge.