Solar hydrogen production via thermochemical metal oxide - Metal sulfate water splitting cycle

Abstract

This paper reports the thermodynamic analysis of solar H2 production via two-step thermochemical iron oxide - iron Sulfate (IO-IS) water splitting cycle. The first step belongs to the exothermic oxidation of FeO via SO2 and H2O producing FeSO4 and H2 and second step corresponds to the endothermic reduction of FeSO4 into FeO, SO2, and O2. The products, FeO and SO2 can be recycled to step 1 and hence, reutilized for the production of H2 via water splitting reaction. Thermodynamic equilibrium compositions of the thermal reduction and water splitting reactions were computed as a function of reaction temperatures. Second law thermodynamic analysis was performed to determine the absorption, Qsolar, Qreactor-net, Qre-radiation Qfeo-oxd and nycyle and nsolar respectively.