What is Biogas
Biogas is a gas produced through the anaerobic digestion of organic matter. Biogas from agroindustrial wastes typically consists of CH4 and CO2 with a small amount of H2S.
H2S is corrosive and leads to high SOx emissions and therefore it is typically scrubbed from the biogas.
The CH4 in the gas can be burned to produce heat or to drive an engine or turbine for power generation or for transportation. The ratio of CH4 to CO2 is dependent upon the nature of the wastewater and ususally is irrelevant for power or thermal applications.
Some biogas companies claim to have a superior process due to high CH4 concentration in the biogas, however this is typically due to the process bypassing solids, as solid digestion will typically lead to an increase in CO2 production during hydrolysis. When evaluating a biogas project it is important to evaluate the total gas production and total CH4 production, rather than just focusing on the relative concentration.