Comparative study of the optimal ratio of biogas production from various organic wastes and weeds for digester/restarted digester

Abstract

This study carried out a comparative analysis of the rates of production of biogas from various organic wastes and weeds which enabled the determination of optimal ratio of poultry droppings to domestic wastes. Digester was prepared for the anaerobic fermentation of the domestic wastes and weeds. The gas production did not begin until the 7th day and increased steadily at first, and then increased sharply until it reached its peak on the 18th day before declining. The total gas produced within the 22 days of experimentation was 1771 cm3. The maximum volume of gas amounting to 809 cm3 was produced by the sample containing 50% poultry dropping and 50% weeds. This indicates that this sample possesses the best C/N ratio of all the samples prepared. For restarted digester, gas production began on the 2nd day as against the 7th day with no restarted digester and the gas production peaked earlier. Keywords: Digester, Optimal ratio, Biogas production, Organic wastes, C/N ratio