Anaerobic digestion of corn stalk for biogas production: ambient vs. mesophilic temperature

Anaerobic digestion technology for corn stalk conversion to biogas was investigated for corn stalk utilization and pollution reduction. Two temperatures(ambient and thermophilic) and three loading rates of 35, 50, 65 g/L were tested, and their effects on biogas production, total solid(TS) and volatile solid(VS) reduction were compared. The results showed that the loading rate of 50 g/L achieved highest cumulative biogas production for both temperatures. The temperature is one of major factors affecting efficiency and rate of anaerobic digestion of corn stalk. As compared with ambient temperature, mesophilic digestion with the loading rate of 50 g/L was able to achieve 63% higher cumulative biogas production, 33% and 49% more reduction of TS and VS and need 10 days less hydraulic retention time. Therefore, it had favorable economy and is recommended. This study could provide useful parameters for the design of large-scale anaerobic digester for corn stalk conversion for biogas production.