This study investigates the effect of moderate temperature thermal pretreatment on the high-solid anaerobic digestion of organic fraction of municipal solid waste (OFMSW) for enhanced methane production and energy recovery. Batch biomethane potential (BMP) assays were conducted under mesophilic conditions, with pretreatment temperatures of 70, 90, and 110°C for durations of 30, 75, 120, and 180 minutes. A completely randomized factorial experiment was utilized to evaluate the effects of each temperature and time of pretreatment, as well as their interactions on methane yield. The evaluation criteria included methane enhancement and net energy generation (NEG). While all thermal pretreatments led to increased methane yield, energy balance analysis revealed that only certain pretreatments were effective in contributing to a positive energy balance. The best result was achieved by applying pretreatment at 90°C for 120 minutes, which resulted in a 34% increase in methane production compared to untreated OFMSW, with a specific methane production of 342.66±6.11 ml CH4/g VS. Applying this thermal pretreatment also resulted in a net energy generation of 57.26 KWh/ton. These findings suggest that moderate temperature thermal pretreatment can be an effective method for enhancing biogas production and energy recovery from OFMSW AD under high-solid conditions.

Keywords