Experimental Investigation of a Newly Developed Hydrogen Production Cycle for Green Energy Applications

This study introduces a novel hydrogen production system using the three-step copper chlorine (Cu-Cl) cycle. The proposed thermochemical cycle offers an innovative configuration that performs hydrogen production without an electrolysis step, eliminating high-cost components such as membranes, catalysts, and electricity. The Cu-Cl cycle enables large-scale hydrogen production and is examined in various configurations, including two-, three-, four-, and five-step Cu-Cl cycles. Microscale experimental studies are conducted on a novel three-step Cu-Cl thermochemical cycle that works entirely on thermal energy input without electrolysis. In experimental studies, some parameters that directly affect the amount of hydrogen production are investigated. The effects of parameters, such as temperature, steam/copper (S/C) ratio, and reaction time on hydrogen production in the hydrolysis step are evaluated. The investigation also examined the impact of increasing temperature in the hydrolysis reaction on the generation of undesirable byproducts. Additionally, the effect of increased temperatures in the decomposition process on oxygen formation is examined. In the optimization studies, the individual and interactive effects of the parameters are analyzed using the Response Surface Methodology (RSM) and BoxBehnken Design (BBD) of experimental methods. The results of this study further show that the conditions with the highest hydrogen production are a S/C ratio of 55, a temperature of 400 ◦C, and a reaction time between 30 and 40 min. It is also observed that hydrogen concentration increases with the increase in temperature and time and that the maximum level of 134.8 ppm is reached under optimum conditions.