A heterogeneous model is developed for the regeneration of the Cr

2

O

3

/Al

2

O

3

catalyst for the propane dehydrogenation process by considering the internal mass transfer and external mass/heat transfer during the coke combustion.Simulation shows that under practical operating conditions

multi-steady states exist for the catalyst pellets and the catalyst temperature is sensitive to gas temperature.However

at increased mass flow rate or lowered oxygen concentration

multi-steady states will not appear.Under the strong influences of film diffusion

the coke in the packed bed reactor will first be exhausted at the inlet

while if the film diffusion resistance is decreased

the position of first coke exhaustion moves toward the outlet of the reactor.