Characterization and evaluation of prepared Fe2O3/Al2O3 oxygen carriers for chemical looping process

Abstract

Alumina supported Fe2O3 was prepared to evaluate its feasibility as an oxygen carrier for chemical looping using a thermogravimetric analyzer (TGA) and fixed bed reactor. Fe2O3/Al2O3 particles containing 60 wt% Fe2O3 and sintered at 1300°C demonstrated reasonable oxygen conversion. The reduction mechanism of Fe2O3/Al2O3 oxygen carriers was proposed based on the thermogravimetric analysis and XRD characterization. FeAl2O4 is formed and can serve as a supporting material as well as oxygen carrier in practical operations by using a moving bed reactor. The prepared Fe2O3/Al2O3 oxygen carriers demonstrated high CO2 yields in relation to syngas and methane combustion in the fixed bed reactor operated at temperatures higher than 500 and 850°C, respectively. Moreover, hydrogen generation was demonstrated to be feasible by steam oxidation with reduced Fe2O3/Al2O3 oxygen carriers for experiments conducted at temperatures above 800°C. The crush strength and TGA of Fe2O3/Al2O3 were examined, and the results showed that they had an appropriate crush strength and reasonable reactivity as oxygen carriers for use in a chemical looping process. © Taiwan Association for Aerosol Research.