Biohydrogen production from biomass and molasses wastewater by anaerobic fermentation in continuous stirred-tank reactor

Hydrogen is a clean energy carrier which has a great potential to be an alternative fuel. Abundant biomass from various industries could be a source for biohydrogen production where combination of waste treatment and energy production would be an advantage. A study of biohydrogen production using aerobic-pretreated sludge and molasses by anaerobic fermentation in continuous stirred-tank reactor (CSTR) was investigated. The experimental results indicated the CSTR reactor could achieve continuous biohydrogen production with an initial aerobic-pretreated sludge (VSS) of 17.74 g/L, temperature of 35°C ± 1°C and HRT (hydraulic retention time) of 6 h. The high yield of 11.61 L/d hydrogen was obtained in this study with OLR (organic loading rate) of 24 kg COD/(m³·d). The content of ethanol and acetic acid in liquid fermentation products was 83% which indicated the ethanol-type fermentation formed.