The competition for cultivable acreage between energy and food crops increases in Germany. One part of the problem are the currently installed biogas plants for energy crops, which use mainly the fruit parts of the plants. To mitigate this problem, cellulose may well be used as a main substrate. For the disintegration of cellulosic indigenous plants the principle of the gastrooesophageal vestibule system of ruminant animals - which nature has honed in millions of years of evolution as the most efficient system of cellulose disintegration - could be used. The implementation of the cellulose digestion of ruminants to a technical concept and the comparison with conventional process technology is the central point for the research project DAUMEN Energy. The objectives are to increase the efficiency of biogas technology and the prevention of food crops being used as energy crops. Laboratory tests showed, that the specific methane yield from wheat straw and spent grains could be increased through the application of rumen microorganisms to a value that was ca. 30% respectively 45% higher than that of the microorganisms of digested sludge. Also test-plants on a pilot-scale, with augmented hydrolysis and methanogenesis are described in this paper.