Effect of Total Solids on Biogas Production in a Fixed Dome Laboratory Digester under Mesophilic Temperature

An investigation on the effect of total solids on biogas production was done using a laboratory scale batch reactor of 0.15 m 3 capacity. The feedstock was dung from dairy cows managed under a free-range system. Experiments were done on a substrate having total solids of 6%, 7%, 8%, 9%, and 10% at a constant temperature of 35C; and the mean biogas production was 0.249, 0.304, 0.487, 0.287, and 0.244 m 3 of biogas per m 3 of digester volume per day (m 3 /m 3 d), respectively. It was concluded that the highest average biogas production of 0.487 m 3 /m 3 d is attained at total solids of 8%.