Characterisation and Optimisation of Municipal Solid Waste Composition for Enhanced Biogas Production in Anaerobic Digestion

Abstract

This research investigates optimizing municipal solid waste (MSW) composition to enhance biogas production in anaerobic digestion systems. The study evaluates the influence of various substrate components, specifically food waste (FW), vegetables (V), grass and leaves (GL), and fruits (F), on biogas yield. Factors such as mixing ratios, substrate particle size, retention time, and pH were examined to determine their effects on biogas production. A fractional factorial experimental design was employed, with FW, V, F, and GL mixed at ratios of 100:0, 0:100, 75:25, 50:50, and 25:75, and particle sizes categorized as fine (≤2 mm) or coarse (≥5 mm). Retention time and pH were monitored at 30 days, and a pH ranged between 6.3 and 7.6 across all 16 runs. The highest cumulative biogas yield, 12,000cm 3 , was obtained using a 75:25 FW to GL ratio with fine particle size (≤2 mm), while the lowest yield, 1,690 cm³, was observed at a 0:100 FW to GL ratio with coarse particles (≥5 mm). Overall, co-digestion of FW, V, and F produced higher biogas yield than mono-digestion of GL substrates. The findings offer valuable insights for improving biogas production, promoting sustainable waste management practices and enhancing energy security.