Two-phase anaerobic digestion of carbonaceous organic materials

摘要

A process for improved methane production by two-phase anaerobic digestion of organic carbonaceous material in which organic carbonaceous material is fermented under anaerobic conditions in an acid phase digester, forming a liquid/solids effluent, the liquid/solids effluent is fermented under anaerobic conditions in a methane phase digester, product gas comprising methane is withdrawn from the methane phase digester, and oxygen is introduced into the methane phase digester. In a preferred embodiment, the methane phase liquid effluent is passed through a CO.sub. 2 stripper resulting in stripping of CO.sub.2 and H.sub. 2 S from the methane phase liquid effluent. The resulting stripper liquid effluent comprising dissolved oxygen is then recycled back to the methane phase digester.