Biological Hydrogen and Methane Production in from Food Waste in Two-stage CSTR

Total energy recovery from food waste fermentation in a two-stage 5-L CSTR system, in which hydrogen and methane production were sequential setup, was evaluated. The first –stage hydrogen, and the second-stage methane were produced under mesophilic fermentation with the initial pH 6 and 7; and hydraulic retention time of 12 and 24 h, respectively. The results showed that the hydrogen and methane yields were 292.7 and 391.6 mL g-1 VS at the steady stage operation. The methane yield in the one-stage from food waste fermentation were 364.3 mL g-1 VS. The total energy recovery from two-stage process was 6.5x10-2 kW-h, while that from one-stage process was 4.7x10-2 kW-h. The research study found that the total energy recovery from a two-stage fermentation process consisting of hydrogen and methane production potential high energy than one-stage methane production. Clostridium sp. and Lactobacillus are dominant bacteria in the hydrogen fermentation under the steady state operation.