Performance of Cattle Dung at Different Total Solids in Prototype Digesters for Biogas Production

An experiment was conducted to study the performance of cattle dung at different total solids (TS) viz., 10, 12, 15 and 18 per cent in three in prototype digesters of 1:0.5, 1:1 and 1:1.7 (H/D ratio) size for a retention period of 56 days under laboratory conditions. The results indicated that, at 10% TS, the cumulative gas production was maximum (345.8 litres) in 1:1.7 H/D size digester followed by 1:1 size digester (305.2 litres) and 1:0.5 size digester (255.8 litres) at the end of retention period of 56 days. While the maximum cumulative gas production of 393.9 litres was recorded in 1:1.7 H/D size digester followed by 1:1 size digester (358.1 litres) and 1:0.5 size digester (297.0 litres) at the end of retention period of 56 days at 12% TS . Whereas at 15 % TS, the maximum cumulative gas production of 474.5 litres was recorded in 1:1.7 H/D size digester followed by 1:1 size digester (419.3 litres) and 1:0.5 size digester (348.4 litres) at the end of retention period of 56 days. It was observed that the cumulative gas production was maximum in 1:1.7 H/D size digesters followed by 1:1 H/D size digester and 1:0.5 H/D size digester at all the total solids fed. The average percentage of methane content was maximum (57.09 %) in the gas produced from cattle dung at 15 per cent TS in 1:1.7 size (H/D ratio) digester, whereas a minimum of 52.48 percentage of methane content was recorded in the gas produced from cattle dung at 10 per cent TS in 1:0.5 size (H/D ratio) digester.