Energy Demand and Economy of Nutrient Supply through Distillers Grains with Solubles from Bioethanol Production

Abstract

Two different distillers grains with solubles are analysed for its contents of nitrogen and phosphorus in untreated and processed fraction. Processing includes decanting, heating and anaerobic digestion. Untreated DGS contains approx. 3.3 to 8 g N·l^-1 and 0.2 to 0.5 g P·l^-1. These concentrations can be increased by one order of magnitude through processing. Anaerobic digestion shifts the availability of nutrients from organic fixed forms to inorganic one. Furthermore, anaerobic digestion delivers energy from methane formed rather than the consumption of energy immanent with the other ways of processing.