Comprehensive characterization and assessment of biohydrogen production potential of restaurant food waste for scalable dark fermentation systems
Djangbadjoa Gbiete, Elmar Brügging, Satyanarayana Narra, Damgou Mani Kongnine
Abstract
Prevention and recycling of food waste remain priorities to achieving the SDG 12.3, targeting at halving global food waste generation by 2030. This study investigates the potential of food waste as a feedstock for scaling up biohydrogen production, filling the gap in the lack of comprehensive characterization of food waste and analysis of its properties for large-scale dark fermentation systems. Food waste was collected from the university restaurant and characterized for physicochemical, biochemical, elemental and nutritional properties. A biochemical hydrogen potential test of the food waste was then performed in 1 L glass reactors using a digestate pretreated at 80 °C for 24 h. Results showed a TS and VS contents of 19.83 % and 94.17 %TS while carbohydrate, lipid, and protein contents were 65.5 %TS, 8.9 %TS, and 5.7 %TS respectively. The C/N and C/P ratios were 19.6 and 157.5 respectively while light and heavy metals were found in acceptable ranges. The characterized properties of food waste highlight its suitability as a feedstock for large-scale dark fermentation, particularly due to its high carbohydrate content, low lipid and protein fractions that minimize inhibitory effects, and the absence of a need for external nutrient supplementation. The batch fermentation test of the food waste produced 11 mL H 2 /g VS, the yield was affected by the longer inoculum treatment time (24 h). These findings underscore the value of integrating food waste conversion to hydrogen into broader waste management, circular economy and renewable energy frameworks. • Food waste was comprehensively characterized for dark fermentation. • High carbohydrate (65.5 %TS) and balanced C/N (19.6) and C/P (157.5) ratios support H 2 production. • Low lipid and protein contents minimize inhibitory effects by minimizing ammonia and LCFAs formation. • Biochemical hydrogen potential test (BHP) of the food waste produced 11 mL H 2 /g VS. • Food waste shows strong potential for large-scale biohydrogen production.