Biohydrogen Production from Hydrolysates of Selected Tropical Biomass Wastes with Clostridium Butyricum

Biohydrogen production has received widespread attention from researchers in industry and academic fields. Response surface methodology (RSM) was applied to evaluate the effects of several key variables in anaerobic fermentation of glucose with Clostridium butyrium, and achieved the highest production rate and yield of hydrogen. Highest H(2) yield of 2.02 mol H(2)/mol-glucose was achieved from 24 h bottle fermentation of glucose at 35 °C, while the composition of medium was (g/L): 15.66 glucose, 6.04 yeast extract, 4 tryptone, 3 K(2)HPO(4), 3 KH(2)PO(4), 0.05 L-cysteine, 0.05 MgSO(4)·7H(2)O, 0.1 MnSO(4)·H(2)O and 0.3 FeSO(4)·7H(2)O, which was very different from that for cell growth. Sugarcane bagasse and Jatropha hulls were selected as typical tropical biomass wastes to produce sugars via a two-step acid hydrolysis for hydrogen production. Under the optimized fermentation conditions, H(2) yield (mol H(2)/mol-total reducing sugar) was 2.15 for glucose, 2.06 for bagasse hydrolysate and 1.95 for Jatropha hull hydrolysate in a 3L fermenter for 24 h at 35 °C, with H(2) purity of 49.7–64.34%. The results provide useful information and basic data for practical use of tropical plant wastes to produce hydrogen.