Experimental and simulated investigation of chemical looping combustion of coal with Fe 2O 3 based oxygen carrier

Abstract

Reaction of Fe 2O 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 2O 3 to Fe 2O 3. TGA-DTA investigation indicated that sufficient supply of Fe 2O 3 was beneficial to the full conversion of PDS with its characteristic temperatures shifted to lower temperature, but the inclusion of Al 2O 3 to Fe 2O 3 hindered the reaction of Fe 2O 3 with PDS at the final reaction stage. And thermodynamic simulation of the reaction of PDS with Fe 2O 3 at φ=1 revealed that at the temperature of interest for chemical looping combustion (CLC) 900°C, 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 2O 3 to Fe 3O 4. But the inclusion of Al 2O 3 to Fe 2O 3 resulted in the interaction between the reduced Fe 2O 3 with Al 2O 3 to FeAl 2O 4 and hindered the full regeneration of the reduced Fe 2O 3 with air. © 2010 Published by Elsevier Ltd.