Demonstration of cost-effective production of biogas from manure only comprising new pre-separation technology and enzyme liquefaction

The RETROGAS project aims at demonstrating viable production of biogas solely based on animal manure and methods of achieving balance of plant nutrients from animal slurry and manure at farm level. The proposed method is to develop a slurry separation technology which is capable of separating slurry (mainly pig and cattle) into a liquid fraction for irrigation (without phosphorus and very low in nitrogen, less than 300 ppm N) and a solid fraction at ca. 30% dry matter for taking to biogas plants. The technology should also include liquefying the solids in order to be able to transport the material by tanker to the biogas plants whereby the transport will be cheaper and the biogas yield from the solids will increase. The key to the success is the development of a new ultra filtration system for the liquid part and a new enzyme treatment of the solid part. The technology will be demonstrated at farm level and at biogas plant level. Comprehensive reporting and dissemination activities will take place