Biohydrogen production from alcohol distillery wastewater using an anaerobic sequencing batch reactor

Abstract

At present, the reserves of fossil fuels become limited, and the excessive utilization of the fossil fuels also subsequently results in global warning. Hydrogen is an interesting renewable energy source for replacing the fossil fuels due to its cleanliness and high-energy yield. In this research, biohydrogen production from alcohol distillery wastewater via dark fermentation was investigated by using an anaerobic sequencing batch reactor (ASBR) with a working volume of 4 liters. The seed sludge taken from an anaerobic tank treating distillery wastewater was boiled for 15 min before feeding to the ASBR. The ASBR system was operated at different chemical oxygen demand (COD) loading rates and different initial feed COD values at a mesophilic temperature of 37 °C, a controlled pH at 5.5, and a cycle time of 6 per/day. The results showed that under the optimum conditions for maximum hydrogen production of a feed COD of 40,000 mg/1, a COD loading rate of 60 kg/m³d, and a hydraulic retention time of 16 h, the produced gas was found to contain 34.7% H₂ and 65.3% CO₂ without methane detected. The specific hydrogen production rate (SHPR) of 270.3 ml H₂/g MLVSS d (or 3,308 ml H₂/I d) and hydrogen yield of 172 ml H₂/g COD removed were obtained. However, when the feed COD exceeded 40,000 mg/1, the process performance in terms of hydrogen Production decreased.