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

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 O-2 (P-O2), thermal reduction (T-H), and water splitting temperature (T-L). It is understood that the decrease in the P-O2 and increase in the T-H directly results into higher levels of O-2 release i.e. higher delta (degree of nonstiochiometry). As the delta increases, the solar energy required to run the cycle (<(Q)left right arrow>(solar-cycle)) enhances. Similar to the P-O2, the influence of T-H and T-L on various thermodynamic process parameters of the ZFWS cycle is also investigated. Obtained results indicate that the solar-to-fuel energy conversion efficiency (eta(solar-to-fuel)) of the ZFWS cycle enhances due to the reduction in the P-O2, decrease in the T-H, increase in the T-L, 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 eta(solar-to-fuel), the ZFWS cycle seems to be more promising than the NFWS cycle. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.