Xylene Isomerization Process and Apparatus

Abstract

Xylene isomerization processes, especially those processes in which ethylbenzene is also converted, are beneficially affected by adding benzene to the feed.

1 . An apparatus comprising: 
 a. a reaction assembly having at least one feedstream inlet in communication with a source of a feed of ethylbenzene and xylene in a non-equilibrium mixture and at least one product outlet containing therebetween at least one reaction zone wherein at least one reaction zone contains catalyst suitable for the conversion of ethylbenzene and the same or at least one other reaction zone contains catalyst suitable for the isomerization of xylenes; and    b. a distillation assembly in fluid communication at an inlet with the product outlet of the reaction assembly, said distillation assembly having an outlet adapted to provide a benzene-containing stream, said outlet being in fluid communication with at least one feedstream inlet of the reaction assembly.    
     
     
         2 . The apparatus of  claim 1  wherein the source of a feed of ethylbenzene and xylene is a unit capable of separating para-xylene from a mixture of xylenes.  
     
     
         3 . The apparatus of  claim 2  wherein the distillation assembly has at least one outlet adapted to provide a xylene-containing stream, said outlet being in fluid communication with said unit capable of separating para-xylene from a mixture of xylenes.  
     
     
         4 . The apparatus of  claim 3  wherein the catalyst in said reaction assembly comprises pentasil zeolite.