Thermodynamic analysis of Ni-ferrite based solar thermochemical H 2 O splitting cycle for H 2 production

Abstract

In this paper, a comprehensive thermodynamic analysis of Ni-ferrite based H 2 O splitting cycle is performed using HSC Chemistry 7.1 software and its thermodynamic database. The influence of partial pressure of O 2 (P O 2 ) in the inert N 2 and thermal reduction temperature (T H ) on (degree of nonstiochiometry) introduced in the Ni-ferrite crystal structure is investigated. With the increase in the P O 2 in the inert N 2 and T H the increases, which results into higher levels of H 2 production via H 2 O splitting reaction. Variations in the other thermodynamic process parameters such as total amount of solar energy required to run the cycle (Q solar-cycle ), total amount of heat energy re-radiated from the cycle (Q re-rad-cycle ), amount of heat energy released by water splitting reactor (Q splitting-reactor ), cycle (cycle ) and solar-to-fuel energy conversion efficiency ( solar to fuel ), and others as a function of P O 2 in the inert N 2 , T H , and water splitting temperature (T L ) are also researched. The cycle and solar to fuel upsurges with the reduction in the P O 2 in the inert N 2 , T H , and T L . For instance, cycle =29.5% and solar to fuel =35.5% can be achieved at P O 2 in the inert N 2 = 10 5 atm, T H =1600K, and T L =1000K.