A data-driven multi-criteria optimization of a biogas-fed s-graz cycle combined with biogas steam reforming and Claude cycle for sustainable hydrogen liquefaction

• Biogas steam reforming and Claude cycle combined with biogas-based S-Graz power plant. • Data-driven multi-facet scenario to study a hydrogen production-liquefaction process. • Thermodynamic, exergoeconomic, and sustainability assessments of the proposed system. • Optimum exergy efficiency and liquefied hydrogen output equal 0.5154 and 2.23 lit/s. • Optimum sustainability index and specific cost of products equal 2.06 and 17.88 $/GJ. The purpose of this research is to develop and optimize an innovative trigeneration approach using biogas fuel, focusing on hydrogen production and liquefaction . This approach will increase the long-term sustainability associated with biogas utilization and lower corresponding irreversibility and environmental concerns. The proposed system employs a biogas-powered S-Graz plant enhanced with a carbon capture unit, a biogas steam reforming subsystem for hydrogen production , and a Claude cycle for hydrogen liquefaction. The configuration is modeled and analyzed to determine the system’s feasibility regarding thermodynamic, exergoeconomic, and sustainability factors. Following this, a data-driven optimization method is employed to reduce the optimization time and enhance its accuracy through MATLAB software, utilizing ANN models combined with NSGA-II and TOPSIS methods. The optimization procedure objective functions include total exergy efficiency, liquefied hydrogen production rate, and unit cost of products, yielding their optimal values of 0.5154, 2.23 lit/s, and 17.88 $/GJ, respectively. The optimization also indicates the total exergy destruction at a rate of 18.293 MW and the sustainability index of 2.06. Besides, the total investment cost rate, net present value, and exergoeconomic factor are found at 372.4 $/h, 33.99 M$, and 15.19 %, respectively. These results demonstrate the substantial economic and environmental benefits of integrating hydrogen production into biogas-based multi-generation systems, highlighting the potential for improved exergy efficiency and reduced environmental impact. This work exhibits the way for more sustainable energy solutions, contributing significantly to the development of cleaner technologies considering biogas utilization.