A process for the regeneration of a catalyst, wherein said catalyst comprises a support, at least one noble metal from the platinum family and chlorine, and said catalyst is used in reforming or for the production of aromatic hydrocarbons in at least two reactors in series through which the catalyst and hydrocarbon charge successively circulate, wherein the pressure in the first reactor is between 3 and 8 bars and the pressure in the last reactor is between 2 and 6 bars,
- the process being characterized in that the exhausted catalyst progressively moves downwardly in a regeneration chamber in which it successively encounters a first radial moving bed combustion zone, a second radial moving bed combustion zone, a radial moving bed oxychlorination zone and an axial moving bed calcination zone, and that:
- (a) in the first combustion zone, the catalyst is treated under a pressure of from 3 to 8 bars which is substantially equal to the pressure in the first reactor, at a temperature of between 350.degree. and 450.degree. C., by a combustion gas which comprises an inert gas circulating in co-flow relationship with the catalyst, containing from 0.01 to 1% by volume of oxygen, the combustion gas coming from a washing zone as defined hereinafter,
- (b) in the second combustion zone, the catalyst is treated under a pressure from 3 to 8 bars which is substantially equal to the pressure in the first reactor, at a temperature which is at least 20.degree. C. higher than the temperature in the first combustion zone, in the presence of the gases from the first combustion zone and an inert make-up gas containing up to 20% by volume of oxygen so that the catalyst is in contact with a gas containing from 0.01 to 1% by volume of oxygen, said gases circulating in co-flow relationship with the catalyst,
- (c) the combustion gases are discharged from the second combustion zone and are passed to a washing loop after having been mixed with the gases drawn from the oxychlorination zone and the calcination zone,
- (d) in the oxychlorination zone, the catalyst is treated in co-flow relationship by a mixture of gas from the calcination zone and a gas comprising a compound selected from the group consisting of chlorine and chlorinated compounds, said mixture forming an oxychlorination gas containing 4 to 10% by volume of oxygen, under a pressure of from 3 to 8 bars and at a temperature between 350.degree. and 550.degree. C., and wherein the gases are discharged from the oxychlorination zone to be mixed with the gases drawn from the second combustion zone in order to reach a washing loop which is common to all the gaseous effluent from the regeneration chamber,
- (e) in the calcination zone, the catalyst is treated in counter-flow relationship at between 350.degree. and 550.degree. C. under a pressure of between 3 and 8 bars by at least a part of the gases from the washing loop, which are dried in a drying zone, and, optionally, a make-up amount of fresh air wherein the gases introduced into the calcination zone contain from 1 to 10% by volume of oxygen and no more than 100 ppm of water vapor,
- (f) wherein the other part of the gases from the washing loop are used in step (a) as a combustion gas;
- wherein the gases taken off from the combustion zones are mixed with the gases taken off from the oxychlorination zone, the resulting mixture being passed into a washing zone and then into a drying zone, at the discharge from which the gases pass through a compression zone, and that then a part of the washed and dried gases is heated by indirect contact with the mixture of the gases taken from the combustion zones and is passed to the first combustion zone through which the catalyst passes, that another part of the washed and dried gases has make-up air added thereto, is then heated by indirect contact with the gaseous effluent taken from the calcination zones and the oxychlorination zone and is passed to the calcination zone, that a make-up amount of air or an equivalent gas is passed into the second combustion zone and that a gas containing chlorine or a chlorinated compound is passed into the oxychlorination zone.