Biohydrogen production from food waste: Current status, limitations, and future perspectives

Among the various biological routes for H₂ production, dark fermentation is considered the most practically applicable owing to its capability to degrade organic wastes and high H₂ production rate. Food waste (FW) has high carbohydrate content and easily hydrolysable in nature, exhibiting higher H₂ production potential than that of other organic wastes. In this review article, first, the current status of H₂ production from FW by dark fermentation and the strategies applied for enhanced performance are briefly summarized. Then, the technical and economic limitations of dark fermentation of FW are thoroughly discussed. Economic assessment revealed that the economic feasibility of H₂ production from FW by dark fermentation is questionable. Current efforts to further increase H₂ yield and waste removal efficiency are also introduced. Finally, future perspectives along with possible routes converting dark fermentation effluent to valuable fuels and chemicals are discussed.