Abstract: By acidifying manure, emissions of methane gas and ammonia gas are prevented significantly. The method for the acidification of manure is provided by an acidic flow of an anaerobic digestion device and/or the flow of sulphuric and/or sulphurous acid from a device that removes hydrogen sulphide gas from biogas from an anaerobic digestion device by chemical and/or biological oxidation to sulphuric acid. When manure is digested, acidification has the advantage that more methane is formed in the digestion process by the prevention of the formation of methane by acidification in the storage process, the advantage that the part of ammonia that would be emitted as a gas is now stored as a nitrogen mineral in the digested manure for use as fertilizer, and the advantage is that the manure has a pH value that is more preferable for digestion processes in the case the manure will be digested.

Abstract: The invention relates to a device and method for the anaerobic digestion of organic material to biogas by means of microorganisms. The device and method intensify the anaerobic digestion process by using three separate reactors wherein a hydrolysis process, a first digestion process of a separated solid fraction, and a second digestion process of a separated liquid fraction take place respectively. Membranes and/or mechanical separation means are used to separate the fractions. This keeps the microorganisms, such as microbes, in the reactors. The obtained intensification of the anaerobic digestion process enables to operate with smaller tanks, which leads to lower building costs. The process also makes it possible to precipitate heavy metals for extraction.