Modelling of westinghouse and sulphur-iodine water splitting cycles for hydrogen production

Abstract

Hydrogen as an ideal energy carrier can play a very important role in future energy systems for hydro-gen production can be used a variety of technologies and sources. One of the most promising methods for large-scale hydrogen production is thermo-chemical water decomposition using heat energy from nuclear, solar and other sources. The water splitting thermo-chemicals cycles are processes where water is decomposed into hydrogen and oxygen via chemical reactions, using intermediate substances which are recycled. Two cycles were retained interesting and chosen for our study: WestingHouse cycle (WH cycle) and Sulphur-Iodine cycle (SI cycle). For both cycles solar energy has been considered as heat source during the endothermic step of the cycle. Detailed simulation models of both cycles were performed using Aspen Plus code and a ther-modynamic analysis was conducted to evaluate the effective plant energetic efficiencies, with respect to their thermodynamic theoretical values. The advantages and disadvantages of both cycles were taken into account. For the WH cycle, an optimization study for SO2/O2 separation process, in order to maximize hydrogen production, was carried out. The obtained results are reported.