Multi-aspect design and multi-objective optimization of an integrated solar-driven solid oxide electrolysis system for simultaneous hydrogen and ammonia production

This study integrates a solar-driven solid oxide electrolysis cell with a modified organic flash cycle, thermal energy storage, and an ammonia reactor to produce power, hydrogen, and ammonia simultaneously. Energy, exergy, economic, and environmental analyses evaluate system performance. An annual case study compares working fluids, while a parametric analysis identifies decision variables for four multi-objective optimization scenarios. The results identify m-xylene as a suitable working fluid. At the base design, the system generates 129.9 kW of net power, with a total product cost rate of 1.45 $/h and an exergoenvironmental impact rate of 72.69 mPts/h. Under the selected optimal conditions, ammonia and hydrogen production rates reach 12.29 kg/h and 2.18 kg/h, respectively, with an exergy efficiency of 13.59% and an exergoenvironmental impact rate of 70.22 mPts/h.