LAUSR

Abstract Induced by promising hydrogen production of CeO2-based solar thermochemical cycle and evident temperature decreasing effect of methane reduction, a moderately high-temperature solar thermochemical ceria-methane cycle is investigated thermodynamically. In this paper, isothermal and non-isothermal solar-to-fuel efficiencies (ηsolar-to-fuel) under different temperatures and reactant ratios are compared carefully. The calculated results indicate that the condition of CH4:CeO2 = 0.5 is favorable for oxygen release, fuel selectivity and methane conversion. The introduction of methane could increase the maximum yield of H2, and more solar energy could be converted to chemical energy as the increase of nH2O:nCeO2. nH2O:nCeO2 = 0.5, Tred = 1400 K and Toxi = 750 K are suggested for the maximum non-isothermal ηsolar-to-fuel of 0.35, which is larger than the maximum isothermal ηsolar-to-fuel of 0.24. The result shows that non-isothermal solar thermochemical ceria-methane cycle is more feasible for fuel production.