Evaluating the Influence of Ar/N2 Flow Rate and Pressure on the Conversion Efficiency of a Solar-Assisted Fe2O3 – FeO WS Cycle for Hydrogen Production: A Thermodynamic Approach

A thermodynamic analysis is carried out to evaluate the effects of oxygen partial pressure (PO2) and molar flow rate of reduction agents (mN2/Ar) on the performance of Fe2O3 -FeO solar thermochemical cycle (STC|Fe2O3-FeO). The chemical equilibrium and efficiency analysis parameters such as enthalpy, Gibbs free energy and entropy are calculated as a function of thermal dissociation temperature (TH). The chemical equilibrium analysis suggests that the thermal dissociation step is feasible above 1250 K while the re-oxidation step is practicable at 550 K. The efficiency analysis revealed that the highest value of conversion efficiency (eta solar-to-fuel) reached up to 44.42% for N2 based cycle and 45.46% for Ar based cycle without using the recuperation technique. However, the conversion efficiency (eta solar-to-fuel) attained the highest value of 57.84% for N2 based cycle and 59.14% for Ar based cycle with 50% heat recuperation.