Journal
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
Volume 40, Issue 28, Pages 8620-8632Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.ijhydene.2015.04.158
Keywords
Hydrogen; Thermochemical reactions; Iron-chlorine cycle; Energy efficiency; Kinetics
Categories
Funding
- Agencia Nacional de Promocion Cientifica y Tecnologica
- Consejo Nacional de Investigaciones Cientificas y Tecnicas
- Universidad Nacional del Comahue
- International Atomic Energy Agency
Ask authors/readers for more resources
In this paper, a theoretical and experimental study on an iron-chlorine thermochemical cycle for hydrogen production is presented. The study was addressed to confirm the occurrence of the thermochemical reactions originally proposed and to investigate the influence of kinetic parameters for improving the overall performance of this cycle. Firstly, a thermodynamic analysis was done for determining whether this cycle is attractive for hydrogen production at reaction temperatures below 1223 K, in terms of both energy efficiency and yield of hydrogen. Following, proof-of-concept experiments using a batch reactor were performed at different reaction temperatures, pressures and holding times. Experimental results showed that the reaction temperature is expected to have a small effect for increasing the hydrogen production, while an increase of the system pressure was observed to raise markedly the conversion degree achieved. Based on experimental results, it was possible to confirm the reaction pathway of thermochemical reactions originally proposed, to identify the rate determining step of the overall process, and to explain the beneficial effect of increasing the system pressure on the hydrogen yield. Finally, a modified cycle is proposed for increasing its overall energy efficiency, by lowering the reaction temperature of two thermochemical reactions from 1198 K to 923 K in order to avoid the phase change of FeCl2 that melts at 950 K. Comparative calculations of enthalpy balance and external heat and work requirements for the original and modified cycles showed that the limiting energy efficiency could be theoretically increased from the range 24-28% to 32-37% and this significant increment appears to be promising for further investigations. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available