Thermal management of a new integrated copper-chlorine cycle for hydrogen production

This paper develops a thermal management method for the integrated lab-scale copper-chlorine cycle built in the Clean Energy Research Laboratory at the Ontario Tech. University for hydrogen production and studies thermodynamically through energy and exergy approaches. The performance of the system is assessed based on the overall system energy and exergy efficiencies. The approach is further implemented to study the possible options for the highest amount of heat recovery within the cycle. Six different steam and heat recovery configurations are considered in this study based on the various streams recovered within the cycle, with each configuration having a different steam-to-copper molar ratio. The criteria for assessing the performance of each configuration are the exergy destruction of the heater-1 of the system, net thermal exergy, net heat input, and hydrolysis unit heat input, the temperature achieved after heat recovery and the overall system energy and exergy efficiencies. The temperature achieved after heat recovery and the steam-to-copper molar ratio are found to be the key aspects impacting the performance of each configuration. The overall energy and exergy efficiencies of the system without considering heat recovery are evaluated to be 6.8% and 10.4%, respectively while the highest energy and exergy efficiencies obtained after considering heat recovery are found to be 10.7% and 16.3% respectively which shows the influence of heat recovery on the performance of the system.