ANAEROBIC DIGESTION SYSTEM FOR PRODUCTION OF BIOGAS WITH A REDUCED HYDROGEN SULPHIDE CONTENT AND METHOD FOR PRODUCTION OF BIOGAS WITH A REDUCED HYDROGEN SULFIDE CONTENT IN AN ANAEROBIC DIGESTION SYSTEM

摘要

the application relates to an anaerobic digestion system for the production of biogas with a reduced hydrogen sulfide content, comprising an airtight reactor vessel comprising a sludge comprising a surface layer; and a volume below the surface layer comprising biomaterial and microorganisms that are capable of anaerobically digesting the biogas producing biomatter, the biogas comprising hydrogen sulfide, a free space above the surface layer of the mud in which the biogas migrates out of the mud, a spray system for spraying an aqueous solution containing nitrate into the free space using a carrier gas stream to form a nitrate-containing interphase layer between the surface layer of the mud and the free space, where the interphase layer comprises the same species of microorganisms such as those present in the mud, and in which at least part of the nitrate from the interphase layer is used by the microorganisms present in the interphase layer to oxidize at least part of the hydrogen sulfide present in the biogas produced to sulfate or sulfur, resulting in the space free being filled with biogas with a reduced content of hi sulfide hydrogen, with the proviso that the reactor vessel does not comprise a membrane or tissue positioned (a) in the free space. the order also refers to a method for producing biogas with a reduced hydrogen sulfide content in an anaerobic digestion system.