Process and vessel for regeneration of a catalyst including monitoring and monitoring and control of combustion completion

In a process for regenerating a used catalyst containing carbonized material, comprising subjecting the used catalyst to at least one designed combustion step in which the catalyst is brought into contact with at least one oxygen-containing gas under designed combustion operating conditions so as to remove carbon from the catalyst, the inprovement comprising subjecting the catalyst which has undergone all of the designed combustion steps to a monitoring and control step, comprising contacting said catalyst in the form of a moving bed with at least one monitoring and control oxygen-containing gas under conditions which are more severe than those of the designed combustion steps and conducting the monitoring and control step with an oxygen consumption of less than 10% of the oxygen entering with said monitoring and control gas, and wherein the temperatures of the gas and/or the catalyst entering and the gas and/or catalyst exiting the monitoring and control step and/or the oxygen contents of the gas entering and the gas exiting the monitoring and control step are measured and compared.