Patent ID: 7868215

Claim:
A process for producing cumene which comprises the steps of: i) contacting benzene and propylene with a particulate molecular sieve alkylation catalyst having catalytic activity under at least partial liquid phase alkylating conditions to provide a product containing cumene and a polyisopropylbenzene fraction, said molecular sieve of said alkylation catalyst is selected from the group consisting of zeolite beta; wherein (I) the particles of said alkylation catalyst have a surface to volume ratio of about 100 to about 150 inch −1 ; wherein (II) said catalytic activity of said particulate molecular sieve alkylation catalyst is greater than the catalytic activity of the same alkylation catalyst having a surface to volume ratio less than about 100 inch −1 ; ii) separating the polyisopropylbenzene fraction from the product; and iii) contacting the polyisopropylbenzene fraction and benzene with a particulate molecular sieve transalkylation catalyst under at least partial liquid phase transalkylating conditions to produce additional cumene; wherein said particulate molecular sieve transalkylation catalyst having a surface to volume ratio of about 80 to less than 200 inch −1 is selected from the group consisting of MCM-22, PSH-3, SSZ-25, MCM-36, MCM-49, MCM-56, ZSM-5, faujasite and mordenite.