Optimizing a novel biogas-powered multi-generation plant: Thermodynamic, thermo-economic, and environmental evaluations for hydrogen, power, and freshwater production

This study addresses the urgent need for sustainable energy solutions by proposing an innovative multi-generation system that integrates the Cu–Cl cycle, biogas steam reforming (BSR), reverse osmosis (RO) desalination, and gas turbine (GT) technologies. The system simultaneously produces hydrogen, freshwater, and electricity. A comprehensive assessment based on the 5E framework—comprising energetic, exergetic, exergo-economic, environmental, and exergo-environmental analyses—has been conducted. Sensitivity analyses were performed to evaluate the influence of variations in key input parameters on overall system efficiency. The results highlight the system's potential, delivering 50,952 kW of net power, 0.52 kg/s of hydrogen, and 0.96 kg/s of freshwater. An increase in methane molar flow rate was found to enhance the system's techno-economic and environmental performance. In conclusion, the proposed multi-generation system offers a promising and sustainable approach for efficient production of hydrogen, freshwater, and electricity. Moreover, a three-objective optimization further improved the energy and exergy efficiencies, while reducing the specific unit cost of product (SUCP) to 23.29 %, 17.44 %, and 220.57 $/GJ, respectively.