Aim. To optimize the methane digestion process while using different recipes of substrate components of ag- ricultural origin. Methods. The chemical composition of separate components of the substrate of agricultural by-products, industrial wastes, fats of the agrorefi nery and corn silage was studied. Dry (organic) mass, crude protein (fat) fi ber, loose ash, nitrogen-free exhaust were estimated in the components and the productivity of biogas was determined along with the methane content. These data were used as a basis for daily recipes of the substrate and the analysis of biogas production at the biogas station in Kostkowice. Results. The application of by-products of agricultural production solves the problem of their storage on boards and in open containers, which reduces investment costs, related to the installation of units for their storage. Conclusions. The return on investment for obtaining electric energy out of agricultural biogas depends considerably on the kind of the substrate used and on technological and market conditions.
