Calculation of iodine crystallization process in sulfur-iodine cycle for hydrogen production

The S-I cycle process has been developed for massive hydrogen production coupled to high temperature heat sources. The process is composed of three distinctive sections and HI decomposes into H₂ and I₂ in Section 3. The production of H₂ in Section 3 involved some processes including electrodialysis (EED) for concentrating a product stream from Section 1. Additionally an I₂ crystallization step would be considered to reduce burden by removing certain amount of I₂ out of a process stream prior to EED. In this work we calculated temperature and heat duty of the crystallizer using a developed thermodynamic model and a heat balance equation. We showed relations of liquid phase composition with respect to the temperature and obtained the results presenting relations between heat duty and temperature. The results were expected to be used as operation information in optimizing the whole process and setting up material balance throughout the cycle.