Biogas production from different food waste using small-scale floating-drum-type anaerobic digester

The generation of food waste poses an escalating societal challenge. Anaerobic digestion emerges as a sustainable and eco-friendly method for valorization and disposal. A small-scale floating-drum-type digester was developed, operating in batch mode to harness biogas from three distinct food waste categories. Potato waste, leftover cooked food, and fish waste were utilized as feedstock, maintained at an average temperature of 21 °C for a retention time of 10 days, with cow manure serving as the inoculum source. The advances of the current work are built upon comparing biogas production volume and methane content from mono-anaerobic digestion of these various wastes. Examining cow manure and different substrate samples offers insights into their composition, encompassing total solids, C/N ratio, and pH. Shredded raw wastes were wet fed into the digester at a 1:1 waste/water ratio. Cumulative production of biogas and the methane fraction from two experiments were monitored. The maximum average cumulative biogas production per kg of total solid was observed for leftover cooked food (up to 261.4 L/kgTS), followed by fish waste (up to 248.5 L/kgTS) and potato waste (up to 137.15 L/kgTS). The maximum methane percentage occurred in fish waste displaying the highest methane percentage (74%), trailed by leftover cooked food (59%) and potato waste (55.8%) from both experiments.