Effect of temperature and solid concentration on anaerobic digestion of rice straw in South China

Anaerobic digestion (AD) technology for rice straw conversion to biogas was investigated for biomass utilization and bioenergy generation. The effects of solid concentration in different temperatures on AD efficiency were conducted in bottle-tests, these tests showed that higher biogas production was achieved at the mesophilic temperature. Biogas production was inhibited under thermophilic conditions, and lowest biogas production was achieved in dry thermophilic conditions. According to bottle-test results, the dry AD at ambient condition was selected for 1 m3 experiment. For pilot-test, the highest methane content, total methane production and methane yield rate were 62%, 9.5 m3 and 239.7 L/kg VS, respectively. And sour poisoning was effectively avoided by the circulation of leachate. This study could provide useful parameters for the energy utilization of rice straw in South China.