The Study of Slurry Recirculation to Increase Biogas Productivity from Jatropha curcas Linn. Capsule Husk in Two Phase Digestion

The purpose of this study was to obtain the best slurry recirculation treatment for two-phase digester system which produced the highest biogas production in the DH-JcL substrate. The study was conducted in the laboratory using 750 mL and 2 L of plastic digester and biofilter plastic as growth immobilize. The slurry recirculation treatment consisted of the recirculation of 50% slurry to methanogenesis digester, 50% slurry to hydrolysis digester, and 25% slurry to hydrolysis digester combined with 25% to methanogenesis digester. The highest daily biogas production was obtained from the recirculation of 50% slurry to hydrolysis digester. However, the best slurry recirculation treatment, which was more stable in longer period, was 50% slurry to methanogenesis digester.