Process for the preparation of cumene

Claim 1

A process for producing cumene comprising: (A) contacting a molar excess of benzene with propylene in a distillation column reactor containing a fixed bed molecular sieve characterized as acidic catalytic distillation structure in a distillation reaction zone, at a pressure in the range of 0.25 to 40 atmospheres and temperatures in the range of 50° C. to 500° C., thereby concurrently: (i) catalytically reacting said benzene and propylene to form alkylation product comprising cumene and polyalkylated benzene, (ii) concurrently separating said alkylation product and unreacted benzene by fractional distillation whereby there is a liquid phase and a vapor phase in said distillation reaction zone, (iii) withdrawing said alkylation product at a point below said fixed bed, and (iv) withdrawing unreacted benzene at a point above said fixed bed; (B) fractionating said withdrawn alkylation product; (C) recovering cumene as a product from said fractionation; (D) retuning a portion of said withdrawn benzene to said distillation column reactor as reflux, (E) recovering polyalkylated benzenes as bottoms from said fractionation, (F) contacting said polyalkylated benzenes and benzene in liquid phase with a fixed bed molecular sieve catalyst in a linear flow, (G) recovering a transalkylated product comprising cumene, and (H) fractionating said transalkylated product to separate cumene therefrom.