Comparative assessment of various chlorine family thermochemical cycles for hydrogen production

Abstract

This study deals with a comparative assessment of various chlorine family cycles namely copper chlorine (CuCl) magnesium-chlorine (MgCl) iron-chlorine (Fe-Cl) and vanadium-chlorine (V-Cl) cycles which are driven by heat and/or electricity. Hydrogen production through thermochemical and/or hybrid cycles can play a significant role in reducing greenhouse gas emissions and hence offering opportunities for better environment and sustainability. In this paper we conduct energy and exergy analyses of the VCl cycle and examine both energy and exergy efficiencies of the cycle. We also undertake a parametric study to investigate how the overall cycle performance is affected by changing the reference environment temperature and cycle operating conditions. The performance of VCl cycle are evaluated and compared with CuCl MgCl and FeCl cycles. Furthermore these cycles are discussed and compared with each other through their advantages and challenges. As a result VCl cycle offers a good potential due to its high efficiency over 40% based on a complete reaction. In this regard VCl cycle appears to be one of the most promising low temperature cycles. It may therefore compete with other low temperature cycles such as copper-chlorine. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.