REGENERATION OF COKED CATALYST IN ADIABATIC FIXED BEDS AT LOWER TEMPERATURES

Simulation of the adiabatic regeneration process in fixed beds at lower temperatures was studied. At lower temperatures, the burning rate is controlled by the intrinsic chemical kinetics, which has a much higher activation energy than the mass transfer-controlled regime. The higher temperature dependence of the rate constant causes a significant difference in the temperature and concentration profiles compared to the conventional regeneration process, such as the existence of minimum in the coke concentration profile. An implicit semianalytical solution for the quasi-steady-state burning regime was obtained and shown to approach the unsteady-state solution asymptotically for larger times. This semianalytical solution greatly reduces the numerical solution time required for simulating the entire burning period. © 1969, American Chemical Society. All rights reserved.