BIOGAS PRODUCTION FROM CO-DIGESTION OF COW DUNG AND BARLEY STRAW

Abstract

Biogas can be produced from any biodegradable feedstock that is suitable for anaerobic digestion. In present day biogas production from barley straw and cow dung was investigated using the number of small reactors. Barley straw was codigested with Cow dung with the aim of biogas production. Five treatment mixtures of Barley straw and Cow dung in ratio of 100% Barley straw(BS), 70% Barley straw(BS) and 30% Cow dung(CD) , 50% Barley straw(BS) and 50% Cow dung(CD) , 30% Barley straw and 70% Cow dung(CD) and 100% Cow dung(CD) were digested in batch-type anaerobic digesters for about 33 days under mesophilic condition (38oC). The physicochemical parameters for anaerobic digestion (Total solids, volatile solids, pH, organic carbons and C: N ratios) were determined. Produced biogas was measured for about 33 days of retention time. The results showed co-digestion had significant (p < 0.05) effect on the total solids, volatile solids, organic carbons and pH before and after anaerobic digestion within treatments. Cumulative biogas produced from 70% Barley straw (BS) and 30% Cow dung (CD) was the highest (780ml) while the lowest cumulative biogas was measured in Combination of 50% Barley straw (BS) and 50% Cow dung (CD) (481ml) and 100% Barley straw (BS) (440ml). Assessment of cumulative biogas production revealed that substrate in a mix ratio of 70% Barley straw (BS) and 30% Cow dung (CD) showed the highest production, suggesting this mix ratio of the two substrates is the best mix to yield better amount of biogas. Therefore, it can be inferred from the results anaerobic co-digestion of 70% Barley straw (BS) and 30% Cow dung (CD) was a proportion appeared to be the best combination for better biogas production from barley straw and cow dung.