Transient Three Dimensional Heat Transfer Model of a Solar Thermochemical Reactor for H2O and CO2 Splitting Via Nonstoichiometric Ceria Redox Cycling

Abstract

A transient threedimensional heat transfer model is developed for a 3 kWth solar thermochemical reactor for H2O and CO2 splitting via twostep nonstoichiometric ceria cycling. The reactor consists of a windowed solar receiver cavity, counterrotating reactive and inert cylinders, and insulated reactor walls. The counterrotating cylinders allow for continuous fuel production and heat recovery. The model is developed to solve energy conservation equations accounting for conduction, convection, and radiation heat transfer modes, and chemical reactions. Radiative heat transfer is analyzed using a combination of the Monte Carlo raytracing method, the net radiation method, and the Rosseland diffusion approximation. Steadystate temperatures, heat fluxes, and nonstoichiometry are reported. A temperature swing of up to 401 K, heat recovery effectiveness of up to 95%, and solartofuel efficiency of up to 5% are predicted in parametric studies.