Methane and hydrogen production from potato wastes and wheat straw under dark fermentation

Abstract

Batch dark fermentation of wheat straw and boiled potato wastes at volatile suspended solids (VSS) 5 g VSS/L are examined and compared. Investigations on dark fermentation of potato wastes and wheat straw were carried out at different pH and OFR (oxygen flow rate) values and inoculum pretreatment. The obtained hydrogen yield from waste potato was 70 mL/g VSS, while for hydrolysed wheat straw it amounted to 80 mL/g VSS. The optimum conditions for potato dark fermentation are acidic pH 6.0 and OFR 1.0 mL/h, while for the wheat straw, optimal conditions are pH 6.4 and OFR 4.6 mL/h. The comparison revealed a significant difference in hydrogen production due to the type of substrate, inoculum stressing and DF conditions applied.