Geothermal-based hydrogen production using thermochemical and hybrid cycles: A review and analysis

WOS: 000279971000002Geothermal-based hydrogen production, which basically uses geothermal energy for hydrogen production, appears to be an environmentally conscious and sustainable option for the countries with abundant geothermal energy resources. In this study, four potential methods are identified and proposed for geothermal-based hydrogen production. namely: (i) direct production of hydrogen from the geothermal steam, (ii) through conventional water electrolysis using the electricity generated through geothermal power plant, (iii) by using both geothermal heat and electricity for high temperature steam electrolysis and/or hybrid processes. and (iv) by using the heat available from geothermal resource in thermochemical processes. Nowadays, most researches are focused on high-temperature electrolysis and thermochemical processes. Here we essentially discuss some potential low-temperature thermochemical and hybrid cycles for geothermal-based hydrogen production. due to their wider practicality, and examine them as a sustainable option for hydrogen production using geothermal heat. We also assess their thermodynamic performance through energy and exergy efficiencies. The results show that these cycles have good potential and attractive overall system efficiencies over 50% based on a complete reaction approach. The copper-chlorine cycle is identified as a highly promising cycle for geothermal-hydrogen production. Copyright (C) 2009 John Wiley & Sons, Ltd.Ege UniversityEge University; Aksaray UniversityAksaray University; University of Ontario Institute of Technology; Natural Sciences and Engineering Research Council of CanadaNatural Sciences and Engineering Research Council of CanadaThe authors gratefully acknowledge the support provided by Ege University, Aksaray University, University of Ontario Institute of Technology and the Natural Sciences and Engineering Research Council of Canada. They would also like to thank the reviewers for their invaluable comments, which helped to improve the quality of the paper