The production of biogas is carried out by a process of anaerobic digestion of the biomass. This means that, in an environment without oxygen, methanogenic bacteria that are capable of breaking down organic matter proliferate. In this process of digestion, these bacteria produce fertilizer and biogas, which is composed mainly of methane (CH4) and carbon dioxide (CO2), along with small amounts of other gases such as nitrogen, oxygen, hydrogen sulfide, and water vapor.