Processes for reduction of alkylation catalyst deactivation utilizing low silica to alumina ratio catalyst

Abstract

Alkylation systems and methods of minimizing alkylation catalyst regeneration are described herein. The alkylation systems generally include a preliminary alkylation system adapted to receive an input stream including an alkyl aromatic hydrocarbon and contact the input stream with a preliminary alkylation catalyst disposed therein to form a first output stream. The preliminary alkylation catalyst generally includes a zeolite catalyst having a SiO 2 /Al 2 O 3 ratio of less than about 25. The alkylation systems further include a first alkylation system adapted to receive the first output stream and contact the first output stream with a first alkylation catalyst disposed therein and an alkylating agent to form a second output stream.

1 . An alkylation system comprising:
 a preliminary alkylation system adapted to receive an input stream and contact the input stream with a preliminary alkylation catalyst comprising a zeolite catalyst comprising a SiO 2 /Al 2 O 3  ratio of less than about 25 disposed therein to form a first output stream, wherein the input stream comprises an alkyl aromatic hydrocarbon; and   a first alkylation system adapted to receive the first output stream and contact the first output stream with a first alkylation catalyst disposed therein and an alkylating agent to form a second output stream.   
     
     
         2 . The system of  claim 1 , wherein the alkyl aromatic hydrocarbon comprises benzene. 
     
     
         3 . The system of  claim 2 , wherein the alkylating agent comprises ethylene and the second output stream comprises ethylbenzene. 
     
     
         4 . The system of  claim 1 , wherein the first output stream comprises about 100 ppb or less of catalyst poisons. 
     
     
         5 . The system of  claim 1 , wherein the first output stream comprises about 50 ppb or less of catalyst poisons. 
     
     
         6 . The system of  claim 1 , wherein the input stream comprises a first level of catalyst poisons, the first output stream comprises a second level of catalyst poisons and the second level is lower than the first level. 
     
     
         7 . The system of  claim 6 , wherein the second level is at least 20% lower than the first level. 
     
     
         8 . The system of  claim 1 , wherein the first alkylation catalyst comprises a cerium promoted zeolite beta catalyst. 
     
     
         9 . An alkylation system comprising:
 a preliminary alkylation system adapted to receive an input stream comprising an alkyl aromatic hydrocarbon and contact the input stream with a preliminary alkylation catalyst to form a first output stream; and   a first alkylation system adapted to receive the first output stream and contact the first output stream with a first alkylation catalyst disposed therein and an alkylating agent to form a second output stream, wherein the preliminary alkylation catalyst comprises a first SiO 2 /Al 2 O 3  ratio and the first alkylation comprises a second SiO 2 /Al 2 O 3  ratio and wherein the first SiO 2 /Al 2 O 3  ratio is lower than the second SiO 2 /Al 2 O 3  ratio.   
     
     
         10 . The system of  claim 9 , wherein the alkyl aromatic hydrocarbon comprises benzene. 
     
     
         11 . The system of  claim 10 , wherein the alkylating agent comprises ethylene and the second output stream comprises ethylbenzene. 
     
     
         12 . The system of  claim 9 , wherein the first output stream comprises about 100 ppb or less of catalyst poisons. 
     
     
         13 . The system of  claim 9 , wherein the first output stream comprises about 50 ppb or less of catalyst poisons. 
     
     
         14 . The system of  claim 9 , wherein the first alkylation catalyst comprises a cerium promoted zeolite beta catalyst. 
     
     
         15 . The system of  claim 9 , wherein the first SiO 2 /Al 2 O 3  ratio is at least about 50% lower than the second SiO 2 /Al 2 O 3  ratio. 
     
     
         16 . The system of  claim 9 , wherein the first SiO 2 /Al 2 O 3  ratio is at least about 75% lower than the second SiO 2 /Al 2 O 3  ratio. 
     
     
         17 . A method of minimizing alkylation catalyst regeneration comprising:
 contacting an alkyl aromatic hydrocarbon with a preliminary catalyst comprising a zeolite catalyst comprising a SiO 2 /Al 2 O 3  ratio of 25 or less prior to feeding the alkyl aromatic hydrocarbon to an alkylation system;   substantially continuously introducing the alkyl aromatic hydrocarbon and an alkylating agent to the alkylation system comprising an alkylation catalyst disposed therein;   contacting the alkyl aromatic hydrocarbon with the alkylation catalyst to form an output stream; and   withdrawing the output stream from the alkylation system over a period of time substantially equal to a life of the alkylation catalyst, wherein the life of the alkylation catalyst is longer than the life in an absence of contact with the preliminary catalyst.   
     
     
         18 . The method of  claim 17 , wherein the life of the alkylation catalyst is longer than a life of the preliminary catalyst.