PRODUCTION OF BIOGAS FROM ANAEROBIC CO-DIGESTION OF CORN COB WITH COW DUNG

Abstract

Production of biogas through anaerobic digestion of organic waste materials provides an alternative environmentally friendly renewable energy. In this study, biogas production from codigestion of corn cob with cow dung in five mix ratios was evaluated under mesophilic condition (38ºC) using a batch digester for 30 days. In all substrates, VS, organic carbon, pH and C: N ratios were measured before and after digestion. The Parameters studied were total solids (TS), volatile solids (VS), pH and organic carbon. For the experimental design, different mix ratios were adopted for the five digesters employed. All measured physico-chemical parameters of each substrate significantly varied between before and after AD, and also the rate of variation of these parameters between before and after AD varied between substrates. Gas production was measured in all of the substrate types from the first day of digestion experiment and went to zero at about 30 days in all substrates. Assessment of cumulative biogas production revealed that substrate in a mix ratio of 75% CD and 25% CC (2312ml) showed the highest biogas production and the lowest was in 100%CD (1732ml), suggesting this mix ratio of the two substrates is an optimal mix to yield better biogas. Overall the results indicated that biogas yield and VS and TS reduction can be significantly enhanced when CD and CC are co-digested. Corn cob co-digested with cow dung in the ratio of 75% CD+ 25% CC improved biogas production than cow dung or corn cob alone