Patent ID: 7525004
Filing Date: 2009-04-28
Classification: C07C

Abstract:
1. An ethylbenzene generation process using a dividing wall fractionation zone, said process comprising: contacting, in an alkylation zone, at least ethylene, benzene, and a first benzene recycle stream comprising at least benzene with an alkylation catalyst under alkylation conditions to convert at least a portion of the ethylene and benzene into ethylbenzene and form an alkylation zone effluent comprising benzene and ethylbenzene; contacting, in a transalkylation zone, a polyethylbenzene recycle stream comprising at least polyethylbenzene and a second benzene recycle stream comprising at least benzene with a transalkylation catalyst under transalkylation conditions to convert at least a portion of the polyethylbenzene and benzene into ethylbenzene and form a transalkylation zone effluent comprising benzene and ethylbenzene; passing the alkylation zone effluent and the transalkylation zone effluent into a benzene fractionation column operated at fractionation conditions to recover benzene in an overhead stream and form the first benzene recycle stream, to recover benzene in a side draw to generate the second benzene recycle stream and to recover a benzene column bottoms stream comprising ethylbenzene, polyethylbenzene and flux oil; wherein the transalkylation zone effluent is introduced into the benzene fractionation column at an intermediate height of the benzene fractionation column which is in between the height at which the alkylation zone effluent is introduced and a first end of the benzene fraction column; passing the benzene column bottoms stream into a dividing wall fractionation column operated at fractionation conditions and divided into at least a first and a second parallel fractionation zone by a dividing wall, with the first and the second fractionation zones each having an upper and a lower end located within the fractionation column, with the first and second fractionation zones being in open communication at their upper ends with an undivided upper section of the fractionation column and in open communication at their lower ends with an undivided lower section of the fractionation column, and with the benzene column bottoms stream entering the column at one or more intermediate points of the first fractionation zone; removing a stream comprising polyethylbenzene from an intermediate point of the second fractionation zone of the dividing wall fractionation column to generate the polyethylbenzene recycle stream; removing an ethylbenzene-rich stream from a first end of the dividing wall fractionation column, wherein the dividing wall fractionation column is operated so that the ethylbenzene-rich stream from the first end of the dividing wall fractionation column is at a pressure ranging from 103 to 241 kPa (15 to 35 psia) and a temperature ranging from about 88 to 104° C. (190 to 220° F.); and removing a flux oil-rich stream from a second end of the dividing wall fractionation column.