Patent ID: 6855854

Claim:
A dual transalkylation process for conversion of aromatic hydrocarbons into xylenes comprising: a) providing a stream including benzene and C 9 + alkylaromatics; b) passing the stream of step (a) to a first-transalkylation unit, wherein said stream is contacted with a first-transalkylation catalyst under first-transalkylation conditions to produce a first-transalkylation product stream comprising ethylbenzene; c) combining at least a portion of the first-transalkylation product stream with at least a portion of second-transalkylation product stream; d) separating the combined streams of (c) in a fractionation zone comprising at least one column to produce a fractionated-benzene stream and a xylene-plus stream; e) separating the xylene-plus stream in a xylene column to produce a xylene-enriched stream, which is recovered as a product from the process, and a C 9 + alkylaromatic-enriched stream; f) providing a toluene feed stream; g) combining at least a portion of the C 9 + alkylaromatic-enriched stream of step (e) with at least a portion of the toluene stream; and h) passing at least a portion of the combined streams of step (g) to a second-transalkylation unit, wherein said streams are contacted with a second-transalkylation catalyst under second-transalkylation conditions to produce the second-transalkylation product stream of step (c).