Researchers studied how to make biogas from animal manure and organic waste in Semarang City using anaerobic digestion. They used cow dung, chicken manure, tofu liquid waste, and cabbage waste in a 90-day batch process at 55°C. By using mathematical models, they found that a mix of 70% cow dung, 15% chicken manure, and 15% tofu waste produced the most biogas. The Gompertz model predicted a yield of 3273.20 mL/g of total solid, while the first-order kinetic model predicted 3517.95 mL/g of total solid.