Mixed refrigerant as working fluid in Organic Rankine Cycle for hydrogen production driven by geothermal energy

The possibility of utilizing low temperature heat source systems for producing electricity has been significant due to increasing energy demand. In this study, the Organic Rankine Cycle (ORC) integrated with proton exchange membrane (PEM) electrolyzer is analyzed thermodynamically and economically. A mixture of butane, pentane and iso-pentane is selected as working fluid. The results show that utilizing the mixed refrigerant enhances the performance of the system and results in a higher hydrogen production rate because of a glide match of temperature profiles in the heat exchangers. Economic analysis results which are helpful in designing entire the system show that the highest cost component is electrolyzer, followed by the turbine and condenser. © 2018 Hydrogen Energy Publications LLC