Thermal pretreatment of cattle manure for enhancing biogas production

The low degradability of waste materials containing lignocellulosic material is one of the factors that hinder the production of biogas. The increased need for advanced techniques in the anaerobic digestion process has led to the use of different pretreatment raw materials prior to the anaerobic digestion process in order to increase the yield of biogas. In order to maximize the yield of biogas from cattle manure in a mixture with waste sludge, the anaerobic digestion process was performed at mesophilic conditions for 54 days. As pretreatment, the thermal treatment of cattle manure at temperatures of 55 and 70 °C was applied. The highest biogas production was obtained in the sample of cattle manure, previously treated at 70 °C (M70), while the lowest was recorded in the control sample M. The specific biogas production in relation to the input quantity of volatile organic matter had the highest value in sample M70 and the lowest in the control sample. Overall results have shown that the thermal treatment of cattle manure before the anaerobic digestion process can increase both yield and biogas quality