Methods and reforming systems for re-dispersing platinum on reforming catalyst

Abstract

Methods and systems for re-dispersing platinum on catalysts used in continuous catalyst regeneration reformer systems are disclosed. Some aspects of the disclosure provide, for example, methods of evaluating the platinum re-dispersion of a reforming catalyst in a small-scale reactor for use in a continuous catalyst regeneration reformer system and methods of improving the activity and selectivity of reforming catalysts for use in a continuous catalyst regeneration reformer system by selection of appropriate reaction parameters in a small-scale reactor for use in a continuous catalyst regeneration reformer system.

1 . A method of operating a continuous catalyst regeneration reformer system, the system having a regeneration section, the regeneration section includes a burn zone, a halogenation zone, and a drying zone, the method comprising:
 (a) transferring catalyst particles comprising a platinum group metal and having coke deposited thereon to the burn zone to contact the catalyst particles with an oxygen-containing regeneration gas thereby to combust the coke from the catalyst particles;   (b) passing the catalyst particles from the burn zone to the halogenation zone to contact the catalyst particles with a halogen-containing gas in the halogenation zone;   (c) re-dispersing the platinum group metal on the catalyst particles;   (d) continuously circulating the halogen-containing gas from a halogenation gas outlet to a halogenation gas inlet in the halogenation zone to maintain a halogen concentration on the surface of the catalyst particles of at least about 1.0 weight percent; and   (e) passing the catalyst particles from the halogenation zone to a drying zone to contact the catalyst particles with a drying gas in the drying zone.   
     
     
         2 . The method of  claim 1 , wherein the burn zone, the halogenation zone, and the drying zone are in a serial arrangement. 
     
     
         3 . The method of  claim 1 , wherein the burn zone, the halogenation zone, and the drying zone are in a stacked arrangement. 
     
     
         4 . The method of  claim 3 , wherein the catalyst particles pass from the burn zone to the halogenation zone under gravity flow. 
     
     
         5 . The method of  claim 3 , wherein the catalyst particles pass from the halogenation zone to the drying zone under gravity flow. 
     
     
         6 . The method of  claim 1 , wherein the halogen concentration on the surface of the catalyst particles is maintained at a concentration above about 1.2 weight percent. 
     
     
         7 . The method of  claim 1 , wherein the halogen concentration on the surface of the catalyst particles is maintained in a range of about 1.0 weight percent to about 1.5 weight percent. 
     
     
         8 . The method of  claim 1 , wherein the halogenation zone further comprises a halogenation recovery system. 
     
     
         9 . The method of  claim 1 , wherein the regeneration section comprises one or more regeneration towers. 
     
     
         10 . The method of  claim 1 , wherein the continuous catalyst regeneration reformer system further comprises a reaction section. 
     
     
         11 . The method of  claim 10 , wherein the catalyst particles are recycled into the reaction section following step (e). 
     
     
         12 . The method of  claim 10 , wherein the platinum group metal is selected from the group consisting of platinum, iridium, rhodium and palladium, and wherein the drying gas comprises an oxygen-containing gas. 
     
     
         13 . The method of  claim 8 , wherein the halogen-containing gas comprises a halogen selected from the group consisting of fluorine, chlorine, bromine and iodine. 
     
     
         14 . A method of operating a continuous catalyst regeneration reformer system, the system having a regeneration section, the regeneration section includes a burn zone, a halogenation zone, and a drying zone, the method comprising:
 (a) transferring catalyst particles comprising a platinum group metal and having coke deposited thereon to the burn zone to contact the catalyst particles with an oxygen-containing regeneration gas thereby to combust the coke from the catalyst particles, the platinum group metal being selected from the group consisting of platinum, iridium, rhodium and palladium;   (b) passing the catalyst particles from the burn zone to the halogenation zone to contact the catalyst particles with a halogen-containing gas in the halogenation zone;   (c) re-dispersing the platinum group metal on the catalyst particles;   (d) continuously circulating the halogen-containing gas from a halogenation gas outlet to a halogenation gas inlet in the halogenation zone to maintain a halogen concentration on the surface of the catalyst particles of at least about 1.0 weight percent; and   (e) passing the catalyst particles from the halogenation zone to a drying zone to contact the catalyst particles with a drying gas in the drying zone.   
     
     
         15 . The method of  claim 14 , wherein the burn zone, the halogenation zone, and the drying zone are in a serial arrangement. 
     
     
         16 . The method of  claim 14 , wherein the burn zone, the halogenation zone, and the drying zone are in a stacked arrangement. 
     
     
         17 . The method of  claim 16 , wherein the catalyst particles pass from the burn zone to the halogenation zone under gravity flow, and wherein the catalyst particles pass from the halogenation zone to the drying zone under gravity flow. 
     
     
         18 . The method of  claim 14 , wherein the halogen concentration on the surface of the catalyst particles is maintained at a concentration above about 1.2 weight percent. 
     
     
         19 . The method of  claim 14 , wherein the halogen concentration on the surface of the catalyst particles is maintained in a range of about 1.0 weight percent to about 1.5 weight percent. 
     
     
         20 . The method of  claim 14 , wherein the halogenation zone further comprises a halogenation recovery system, wherein the regeneration section comprises one or more regeneration towers, wherein the continuous catalyst regeneration reformer system further comprises a reaction section, and wherein the catalyst particles are recycled into the reaction section following step (e).