Co-digestion of waste glycerol and glucose to enhance biogas production

Co-digestion in anaerobic fermentation has been widely used to improve biogas production. The biogas production from co-digestion of glucose and glycerol was studied in laboratory-scale batch reactors under mesophilic temperatures, pH 7. The batch experiments involved a variation of glycerol/glucose ratios with initial chemical oxygen demand (COD) for all conditions was fixed at 5,200 mg L-1. The highest yield of biogas production was obtained from glycerol/glucose with 5:5 ratio. The cumulative biogas production was 298.2 mL, and the maximum production rate was 8 mL hr(-1). The findings suggested that co-digestion is a potential method to achieve glycerol waste treatment and energy recovery at the same time. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.