Concentrated solar power driven water splitting cycle using Zn-ferrite based thermochemical redox reactions

Abstract

A Zn-ferrite based water splitting (ZFWS) cycle is thermodynamically scrutinized by utilizing the data obtained from the HSC Chemistry software. The thermodynamic equilibrium and efficiency evaluation of the ZFWS cycle is carried out by varying the partial pressure of O2 (PO2), thermal reduction (TH), and water splitting temperature (TL). It is understood that the decrease in the PO2 and increase in the TH directly results into higher levels of O2 release i.e. higher ? (degree of nonstiochiometry). As the increases, the solar energy required to run the cycle (Q solar cycle) enhances. Similar to the PO2, the influence of TH and TL on various thermodynamic process parameters of the ZFWS cycle is also investigated. Obtained results indicate that the solar-to-fuel energy conversion efficiency (solar to fuel) of the ZFWS cycle enhances due to the reduction in the PO2, decrease in theTH, increase in the TL, and by employing heat recuperation. The results obtained in case of the ZFWS cycle are compared with the previously studied Ni-ferrite based water splitting (NFWS) cycle. Based on the solar to fuel, the ZFWS cycle seems to be more promising than the NFWS cycle.