Integrated CFD and Experimental Analysis of Coke Oxidation in FCC Catalyst Regeneration Under O2/N2 and O2/CO2

This study investigated the combustion profiles and oxidation mechanisms of coke on spent FCC catalysts from two Sinopec refineries and compared the effects of O2/N2 and O2/CO2 atmospheres. Using the Coats–Redfern method combined with nonlinear regression, the kinetics of coke oxidation were analyzed for the activation energies derived from the modified D3 and F2 models. Both these models yielded results that agreed with the previous reports. Selection of the suitable kinetic model was significantly influenced by specific properties of the coke on spent FCC catalysts. Furthermore, a computational model revealed that on an industrial scale, external mass transfer predominated the intrinsic kinetics; the differences observed in the O2/N2 and O2/CO2 environments were primarily due to variations in oxygen diffusion. These findings highlight the potential of optimizing FCC catalyst regeneration processes through alternative oxidation environments and the use of catalytic additives.