Integrated biomass and solar power-to-gas systems for energy storage and freshwater production: A 4E and multicriteria optimization approach

Today, rising concerns about energy shortages and environmental degradation have encouraged innovation in renewable energy sources and cutting-edge technology for capturing their full potential. The adoption of sustainable practices has resulted in the emergence of innovative cogeneration systems that incorporate municipal solid waste as a fuel source. By integrating advanced technologies—including digesters, organic Rankine cycles, multiple effect distillation, methanation, and proton exchange membranes—this system uniquely converts hydrogen and CO2 into methane, enhancing fresh water production through heat recovery in the digestion process. We explore three multiobjective optimization scenarios employing machine learning and Greywolf algorithms to enhance system efficiency. The system has a significant CO2 emission index of 0.1649kg/kWh and total cost products of 12.91$/GJ, with a second-law thermodynamics efficiency of 32.07%. In the second scenario, strategic optimization is centered around the objective of increasing efficiency and net output power, while simultaneously reducing costs. This approach yields significant enhancements, including an exergy efficiency of 39.13% and a net output power of 30366.92 KW. Additionally, the product costs are lowered to 7.2571 $/GJ. These results highlight the system's cost-effectiveness and alignment with sustainability principles, offering meaningful contributions to renewable energy technologies and environmental conservation.