Characterization and Evaluation of Prepared Fe2O3/Al2O3 Oxygen Carriers for Chemical Looping Process

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 degrees 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 degrees 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 degrees 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.