By burning biogas, heat and electricity can be produced in a cogeneration unit, also called a combined heat and power unit (CHP). Before entering the engine, the biogas goes through a cleanup process in which water, hydrogen sulfide, and impurities are removed to produce clean biomethane. There are many types of technologies that could be used: stirling engines, combustion turbines, steam turbines or combined cycles. The produced heat is mostly used for in-site processes, like digester heating, pasteurization of manure or drying the digestate, but could be also used off-site for domestic heating or industrial processes.
