Keywords: anaerobic digestion, heat-treated inoculum, hydrogen gas, kitchen waste, pH control, hydrogen production, biogas plant slurry, biohydrogen
Enhancement of hydrogen production from Kitchen Waste using heat treated anaerobic biogas plant slurry with pH control
Hydrogen is found to be a clean energy source; biohydrogen has been researched in recent years. Anaerobic Digestion of Kitchen Waste (KW) for hydrogen production was performed in lab scale reactors, using heat-treated anaerobically digested biogas plant slurry. The biogas plant slurry was given heat treatment at varying temperatures ranging from 70 to 100 ° C for 15 min. Enhancement of hydrogen production using heat-treated anaerobic biogas plant slurry with pH control was also studied. To study the effect of pH in hydrogen production, the reactors were operated at varying pH ranging from 4.0 to 6.0. The reactor operated with 100 ° C Heat-Treated Inoculum (HTM) was efficient in hydrogen production from KW. The rate of hydrogen production was 176.2 mL kg−1 TS h−1. Methane was not reported in all the operated reactors except that the reactor operated with 70 ° C HTM. A significant difference was found in the production of hydrogen at different pH conditions and the pH 6 at mesophilic condition proved to be effective in enhancing the production of hydrogen. The rate of hydrogen production in the laboratory scale reactor operated with pH 6.0 was 211.20 ml kg−1 TS h−1. The hydrogen concentration was found to be 55-60% and the remaining was CO2. Normal butyrate was the main acid product, and the percentages of butyrate, acetate and propionate at tested conditions were 45-50, 20-25 and 20-25%, respectively.