Multi-objective optimization of a regional biogas supply chain using organic waste

The growing volume of agricultural and municipal organic residues presents both a waste-management challenge and an opportunity for low-carbon energy production. This study develops a multi-objective optimization model to support the strategic design of regional biogas supply chains, explicitly accounting for economic, environmental, and system-resilience criteria. The framework is demonstrated using data from a representative biogas plant case study to explore alternative system configurations and trade-offs among total cost, greenhouse gas emissions, energy revenue, resource consumption, and supply reliability. Results indicate that moderate investment levels allow substantial emission reductions, whereas beyond a certain threshold additional expenditure yields progressively smaller environmental benefits. Likewise, increasing plant throughput raises energy revenue, but the incremental financial return declines as capacity limits are approached. Sensitivity analysis shows that feedstock price and biogas yield have the strongest influence on overall system performance, while discount rate and transport-related emissions exert secondary effects. More balanced sourcing from multiple suppliers improves resilience and can enable further emission reductions without increasing capital cost. The proposed framework provides a transparent decision-support tool for designing economically viable and environmentally balanced biogas systems.