Abstract Cleaner energy, particularly biogas, is urgently needed. Biogas is generated via anaerobic digestion (AD), decomposing organic materials without oxygen. AD simulation models are appreciated for their cost-effectiveness and predictive accuracy. This study creates a process model with Aspen Plus to simulate AD and biogas production. Investigations simulated municipal solid waste (MSW), animal manure (AM), and co-digestion feedstock, including hydrolysis equations for carbohydrates, proteins, and fats. MSW includes a water flow of 10°C and 1500 m3/day. The AM enters at 230.4 g/day, while water flows into the mixer at 2300 g/day. The biogas rates for MSW, AM, and co-digestion were 9775.663, 0.25, and 10024.98 m3/day, respectively. Increasing hydraulic retention time (HRT) boosts the biogas production rate. The carbohydrate effect increases biogas rates for MSW and co-digestion feedstock by 65% and 25%, respectively. Carbohydrate content increases from 35% to 55% for AM feedstock, with rising gas production and a linear decrease in methane output. With the increase in protein, the percentage of gas production increases in all cases. Although for MSW, the optimal conditions occurred between 16% and 20% of protein. Gas production drops with fat in MSW but rises in AM. A 50% increase in parameters shows co-digestion is more affected by protein.
