US Patent 7498471 Process for producing cumene

In an alkylation zone, a benzene recycle stream and a propylene feed stream are contacted with an alkylation catalyst to convert the propylene and benzene into cumene. In a transalkylation zone, a polyisopropylbenzene stream and a benzene recycle stream are contacted with a transalkylation catalyst to convert the polyisopropylbenzene and benzene into cumene. The alkylation and transalkylation zone effluents are passed into a dividing wall fractionation column.