Anaerobic digestion and CO2 separation without CCUS (biomethane)

In an anaerobic digestor, bacteria break down to biomass without oxygen and in the process produce biogas, composed mostly of methane (50-75%) and carbon dioxide (25-45%). Biomass can be in the form of animal manure, organic portion of municipal solid waste (MSW), industrial waste such as dry distillers grain (DDG) from ethanol production, agricultural residues and energy crops. The biogas is upgraded by removing CO2 and other impurities such as hydrogen sulphide, producing what is commonly referred to as biomethane. Biomethane can be used directly or injected into the gas grid if it meets the required specifications. In some cases, biomethane needs to be mixed with LPG to increase its calorific potential before being injected.