Hybrid Hydrogen production: Application of CO2 heat pump for the high-temperature water electrolysis process

Hydrogen is considered an energy vector which ensures a pivotal role in the energy market in near future. As a subsequent, the need to provoke novel technologies and investigate the potential layouts rising from hybridization remains on the shoulder of research literature., The current work investigates the potential role of the supercritical CO2 heat pump to contribute to hydrogen production inside a hybrid energy system. The case study is a generic biogas power plant characterized by the combination of diverse hydrogen production technologies such as water electrolysis and the reforming process. Water electrolysis takes place through high (SOEC) and low-temperature(AEC) The role of the heat pump unit is defined to operate between these two technologies to recover heat losses and transfer them to high-temperature electrolysis. The performance of the CO2 cycle in the presented hybrid energy system is simulated via MATLAB SIMULINK and the effective indicators to improve its performance have been carried out.In the end, the result of the simulation shows a production rate of 19.27 kgH2/h. Furthermore, thanks to heat recovery the total thermal efficiency increases by 80%. It also reveals that the heat pump unit operates with COP in the range of 4.5 – 3.3 based on pressure ratios providing temperature in the range of 151-184 °C by fixing the cold sink input temperature and pressure at 70 °C, 75 bar respectively.