Patent ID: 7312173

Claim:
A method for improving the oxygen burning efficiency during the combustion of coke in a process for removing coke from catalyst particles in a regeneration zone, said method comprising: (a) providing catalyst particles containing coke deposits in said regeneration zone; (b) forming an elongated bed of said particles having at least one elongated side; (c) heating up said bed by passing an inert gas stream over the particles at an initial inlet temperature of about 200° C. to about 600° C.; (d) measuring a lag time during step (c) for a temperature wave to travel through said bed; (e) passing an oxygen-containing recycle gas stream through said bed to combust coke and produce a flue gas; (f) maintaining the initial inlet temperature until coke combustion approaches completion as determined by measurement of the bulk temperature of the flue gas leaving the bed or by measurement of a change in oxygen concentration of the flue gas; and (g) ramping the inlet temperature to a final inlet temperature greater than the initial inlet temperature by using the lag time determined in step (d) to determine when to start said ramping in combination with a measurement of step (f); and (h) completing coke combustion when the bulk temperature of the flue gas is substantially equal to the final inlet temperature.