Effect of Heating Rate on Chemical Looping Combustion of Coal with Fe2O3 Oxygen Carrier

The reaction of a Chinese bituminous coal PDS with Fe₂O₃ was investigated by such experimental means as thermogravimetric (TGA) coupled with Fourier transform infrared spectroscopy (FTIR) and TGA-difference thermal analysis (DTA) with focus on the effect of the heating rate. It was found that the reaction of PDS with Fe₂O₃ displayed three-staged reaction characteristics, and a higher heating rate facilitated more gaseous products from PDS pyrolysis to react with Fe₂O₃ and was more beneficial to the reaction of PDS with Fe₂O₃; and simultaneously, a higher heating rate made the overall activation energy for the reaction of PDS with Fe₂O₃ decreased from 62.79 kJ/mol at 20k/min to 56.50 kJ/mol at 35k/min, and finally, the heat needed for the reaction of PDS with Fe₂O₃ was less than that of PDS pyrolysis due to the exothermic reaction of Fe₂O₃ with H₂ from PDS pyrolysis, and a higher heating rate made less heat needed for the reaction of PDS with Fe₂O₃.