Optimization of biomethane production and distribution networks from livestock waste in Northwest Argentina

Abstract

In the current context of climate change and energy transition, biomethane is emerging as a sustainable biofuel with significant potential for transportation and injection into the natural gas grid. This study proposes a mixedinteger linear programming (MILP) model to design the optimal configuration of the biomethane supply chain over a multi-period horizon. The model integrates two objective functions: an economic one (total cost) and an environmental one (global warming potential), incorporating Life Cycle Assessment as a methodology to evaluate environmental impacts. Key constraints are imposed, including livestock waste availability, product demand, and mass balances, allowing the assessment of two strategic approaches: (i) maximizing the use of available feedstock and (ii) partially satisfying the demand for compressed natural gas. Model results include the optimal location, capacity, and number of biomethane production facilities, as well as the annual flows of raw materials to be processed and the product obtained. A trade-off between objectives is observed, as prioritizing cost reduction leads to a higher environmental impact and vice versa. Furthermore, the optimal supply chain configuration varies depending on the strategy adopted and the selected objective function. Finally, in the optimizations performed, the environmental credits outweigh the global warming potential generated by the supply chain, confirming the role of biomethane as a viable solution for climate change mitigation.