Modelling and analysis for biogas production process simulation of food waste using Aspen Plus

Researchers around the world are earnestly investigating the production of biogas from food waste as it is rich in organic content, and it has high potential to become a sustainable source for second- generation biofuels. Anaerobic digestion process is used to produce biogas but due to its complex nature the process is still not efficient and productive. Current research on production of biofuel out of food waste using two-stage digesters has shown promising results in increasing the biogas production rate and methane yield. Existing literature demonstrates only a few studies that have simulated a two-stage digester setup at thermophilic conditions for the anaerobic digestion of food waste at different fat concentrations, organic loading rates variation, and hydraulic retention times. Therefore, the purpose of this research was to simulate the anaerobic digestion of food waste using Aspen Plus at increasing Organic Loading Rates and Hydraulic Retentions Time and using 3 different fat concentration levels (20%, 40% and 60%). The simulation used a two-stage digester setup at thermophilic (55°C) conditions. The Aspen Plus simulation results demonstrated that at an Organic Loading Rate of between 2 l/day and 5 l/day and at a fat concentration level of 40%, the highest methane content achieved was 74.82% and 77.10%, respectively. The simulation results provided the data that can be used for future experimental projects for biogas research and development at an industrial level.