Numerical Multi-Variable Investigation and Optimization of a High-Temperature Hydrogen Production Process Using Solar-Based Heliostat Field and Supercritical CO2 Utilization

With regard to the sustainability of using carbon dioxide in supercritical processes, this study proposes a novel power/hydrogen cogeneration arrangement consisting of a recompression supercritical carbon dioxide gas turbine cycle and a solid oxide water electrolysis unit in integration with a high-temperature solar-based heliostat field. The steady operation of the system is also guaranteed by means of thermal energy storage tanks. On this path, a numerical multi-variable study and optimization of the entire system are conducted. Hence, four main parameters are viewed to study the sensitivity of the net power output, hydrogen output, energy and exergy efficiencies, and unit cost of products. Hence, a genetic algorithm is applied to investigate the optimum conditions of the entire system considering the maximum energy and exergy efficiencies and the minimum unit cost of products as objective functions. Looking at the results, the sensitivity of the outcomes is further affected by the increase in compressor 1 inlet pressure. Besides, the optimum energy efficiency is 26.81%, optimum exergy efficiency is 21.03%, and optimum unit cost of products is 18.79 $/GJ are attainable.