Patent ID: 7790939
Filing Date: 2010-09-07
Classification: C07C,C10G

Abstract:
1. A process for alkylation of a benzene feed having an amount of reactive impurities with an alkylating agent feed comprising ethylene or propylene to produce a monoalkylated benzene, comprising the steps of: (a) providing a guard bed having a first molecular sieve catalyst located upstream of a reaction zone having a second molecular sieve catalyst; (b) contacting at least a portion of said benzene feed, and at least a portion of said alkylating agent feed with said first molecular sieve catalyst selected from the group consisting of zeolite beta, zeolite Y, Ultrastable Y, Dealuminized Y, rare earth exchanged Y, mordenite, TEA-mordenite, ZSM-3, ZSM-4, ZSM-18, ZSM-20, UHP-Y, and a mixture thereof, in said guard bed under suitable conditions to remove a portion of said reactive impurities which poisons said second molecular sieve catalyst and to alkylate said portion of benzene feed with the alkylating agent feed to form a first effluent comprising monoalkylated benzene, unreacted benzene feed and unreacted alkylating agent feed; (c) contacting said first effluent with said second molecular sieve catalyst selected from the group consisting of ERB-1, ITQ-1, ITQ-2, ITQ-30, PSH-3, SSZ-25, MCM-22, MCM-36, MCM-49, MCM-56, or a mixture thereof in said reaction zone under suitable alkylation conditions to produce additional said monoalkylated benzene, said suitable alkylation conditions comprise a water content in a range from about 1 wppm to about 10 wt. % based on the combined weight of said benzene feed and said alkylating agent; and (d) maintaining said water content in said range in said reaction zone for the majority of the on-oil time; wherein the cycle length of said second molecular sieve catalyst operated inside said water content range is greater than the cycle length of said second molecular sieve catalyst operated outside said water content range when said reaction zone is operated under equivalent alkylation or transalkylation conditions.