Heat transfer and solar absorption analysis of multiscale CeO2 reduction for rapid H2 production prediction

Abstract

The characters of transient heat transfer and solar absorption are analyzed based on the multiscale CeO2 reduction to predict the H2 production, and the results show that the heat absorption of CeO2 is affected by the diameter and the value of concentration ratio. The proportion of energy absorbed by CeO2 increases from 0.55% to 42.73% as the diameter of CeO2 increases from 0.1 to 100 μm. However, the time required for 0.1 and 100 μm CeO2 to reach 1775 K is 0.07 and 0.83 s, respectively. The peak of the solar-to-fuel energy conversion efficiency (ηsolar-fuel) for 1 μm CeO2 is 16.43%, which is the maximum for all selected diameters. After the analysis of the radiation intensity of blackbody and the absorptance of 1 μm CeO2 as a function of wavelength, we find that comparing with no cutoff wavelength coating, the peak of ηsolar-fuel increases from 16.43% to 18.91% as the cutoff wavelength is 600 nm. To reach the same temperature of 1773 K, it takes 0.15 and 0.05 s as C is 50 and 200, and ηsolar-fuel is improved from 14.43% to 17.93%.