Regeneration of a Ni-Mo/Al2O3 catalyst experimental and simulated results

Regeneration of a coked Mo-Ni/Al2O3 catalyst in a fixed bed reactor was studied. Several kinetic equations treating the coke burn-off reaction as either non-catalytic or catalytic have been tested in simulating the regeneration of a coked catalyst in a fixed-bed reactor. A modified grain model using a kinetic expression given for an Al2O3/SiO2 catalyst acceptably predicted the temperature rise and residual carbon concentration profiles during the burn-off reaction, as well as the width of reaction zone, thus indicating that the reaction is non-catalytic. Kinetic expressions were similarly considered for the coke oxidation reaction with the aim of studying a possible catalytic effect on the transition metal reaction in the catalyst.