Experimental and Simulated Investigation of Chemical Looping Combustion of Coal with Fe2O3 based Oxygen Carrier

Abstract Reaction of Fe 2 O 3 oxygen carrier (OC) with a Chinese bituminous coal was experimentally investigated using thermogravimetric (TGA)-differential thermal analysis (DTA) and then thermodynamically simulated based on the minimization of Gibbs free energy, with focuses on the effect of both oxygen excess number Φ and the inclusion of inert support Al 2 O 3 to Fe 2 O 3 . TGA-DTA investigation indicated that sufficient supply of Fe 2 O 3 was beneficial to the full conversion of PDS with its characteristic temperatures shifted to lower temperature, but the inclusion of Al2O3 to Fe 2 O 3 hindered the reaction of Fe 2 O 3 with PDS at the final reaction stage. And thermodynamic simulation of the reaction of PDS with Fe 2 O 3 at Φ=1 revealed that at the temperature of interest for chemical looping combustion (CLC) 900oC, full conversion of PDS was reached and increasing oxygen excess number Φ was beneficial to promote the sufficient conversion of PDS as well as to reduce more Fe 2 O 3 to Fe 3 O 4 . But the inclusion of Al2O3 to Fe2O3 resulted in the interaction between the reduced Fe 2 O 3 with Al 2 O 3 to FeAl 2 O 4 and hindered the full regeneration of the reduced Fe 2 O 3 with air.