(80b) Ferrite Based Two-Step Thermochemical Water Splitting Cycle: Solar Reactor Efficiency Analysis

Production of chemical fuel such as H₂ by using solar energy provides a promising path for solar energy conversion and storage. The energy density of H₂ is equal to the summation of the energy densities of oil, gas and coal. H₂ can be used directly as a transportation fuel and can be utilized to produce electricity via fuel cell operation. In addition, H₂ can be mixed with the CO produced from captured CO₂ to make syngas, which can be further converted into liquid transportation fuels.

Ferrite based thermochemical splitting of H₂O is considered as one of the promising options for the production of H₂. A variety of ferrites such as Ni-ferrite, Co-ferrite, Zn-ferrite, Mn-ferrite, Ni-Zn-ferrite, Ni-Mn-ferrite, and others are investigated heavily towards solar thermochemical H₂ generation. Several researchers investigated the effects of synthesis methods, water splitting temperature, thermal reduction temperatures, different reactor arrangements, addition of grain growth inhibitors (mixing and coating approach) and others on ferrite based water-splitting cycle. In addition to the experimental investigations, to compare with other metal oxide based thermochemical cycles, it is highly essential to estimate the solar to fuel conversion efficiency of the ferrite based thermochemical H₂O splitting cycle. In this paper, a thorough thermodynamic scrutiny of solar H₂ production via ferrite based H₂O splitting cycle is performed using HSC Chemistry 7.1. Effect of partial pressure of O₂ in the inert gas (N₂), thermal reduction temperature and water splitting temperature on equilibrium compositions and thermodynamic efficiency of the ferrite based H₂O splitting cycle is investigated.