Food waste: A sustainable fuel source for biohydrogen production

The amount of food waste (FW) generated worldwide results in environmental impacts and associated economic costs. Efficient energy conversion and recycling are important in addressing energy shortages and resource depletion. Biomass fermentation is a promising method for FW treatment and sustainable generation of biohydrogen. Therefore, this study first conducted a bibliometrics survey by applying bibliometrics and VOSviewer© software to analyze the research progress and hot topics on hydrogen production from FW in the past 20 years. The characteristics of FW were systematically introduced, followed by a comprehensive overview of the current status and common fermentation techniques for converting food waste into biohydrogen, including dark fermentation, photofermentation, dark-photofermentation, and electro-fermentation. The mechanisms and influence factors (such as diverse raw materials, pretreatment methods, operating parameters, and microbial communities) of different fermentation methods were addressed and elucidated. Then, post-treatment and further utilization of fermentation residues (FRs) into fermentation systems were introduced to achieve their sustainable management while strengthening hydrogen yield. Additionally, this review offered a detailed evaluation of both life-cycle assessment and techno-economic analysis, indicating that hydrogen production by fermentation is economically feasible. Finally, challenges and limitations faced under these methods were presented, and perspectives for future research on platform chemicals production from FW in practice were proposed. Overall, this review aimed to categorize the process of resource hydrogen production from food waste and select more appropriate approaches for FW treatment from the perspective of a green hydrogen economy.