Effects of hydraulic retention time on anaerobic digestion performance of food waste to produce methane as a biofuel

Anaerobic digestion (AD) is a promising technology for treating food waste, as it has high energy recovery and controls environmental problems. The biogasification performance of food waste was observed by changing the process parameters such as hydraulic retention time (HRT) and organic loading rate (OLR). A continuously stirred tank reactor (CSTR) was operated to investigate one-phase anaerobic digestion performance of food waste due to its easy operation and lower cost for industrial application. Two operating conditions R1 (fixed HRT and loading) and R2 (varying HRT and loading concentration) were set for 116 and 92 days respectively. Results showed that the best OLR for R1 was 2.25 g ⋅ L−1 ⋅ d−1 with the biogas yield of 787 mL ⋅ g−1 ⋅ d−1. However, the best OLR for R2 was also 2.25 g ⋅ L−1 ⋅ d−1 with the biogas yield of 724 mL ⋅ g−1 ⋅ d−1. Reactor 1 with fixed HRT showed better performance with higher biogas yield and better stability indicators. The results obtained in this study would be useful for industrial utilization of food waste in the future.