Effect of compost pre-treatment on biogas production from rice straw

The method of compost as a pretreatment of rice straw for anaerobic digestion was used widely. The organic carbon content of the rice straw decreased during compost pretreatment. So it is necessary to understand the influence of the lost organic carbon on the total amount of biogas production, which will help us to objectively evaluate the availability of the pre-treatment of composting. Under the laboratory conditions of 35℃ and the total solids (TS) content of 20%, the composition changes and rate of biodegradation of rice straw between treatments with compost pre-treatment and anaerobic fermentation were studied to determine the effects of compost pre-treatment of rice straw and addition of pig manure on biogas production. Results showed that compost pre-treatment of the rice straw didn’t enhance biogas production and methane content for the hemicellulose content being decreased by more than 12%, consequently reduced the TS gas production. The decomposition rate of hemicellulose was the highest during the anaerobic fermentation, which was the main contributor of biogas production. As a result, method of composting pretreatment can not improve gas production with rice straw.