Patent ID: 6958425

Claim:
A process for conversion of aromatic hydrocarbons into para-xylene comprising: a) providing a stream including benzene and C 9 + alkylaromatics; b) passing the stream of step (a) to a liquid-phase transalkylation unit, wherein said streams are contacted with a first transalkylation catalyst under first transalkylation conditions without added hydrogen to produce a first transalkylation product stream comprising ethylbenzene and at least 1 wt-% xylene calculated on a net effluent basis; c) combining at least a portion of the first-transalkylation-product stream with a second-transalkylation-product stream; d) separating the combined streams of step (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 and a C 9 + alkylaromatic-enriched stream; f) passing the xylene enriched stream to a para-xylene production unit to produce para-xylene, which is recovered as a product from the process; g) providing a toluene stream; h) combining the toluene stream with at least part of the C 9 + alkylaromatic-enriched stream of step (e); i) separating the combined streams of step (h) in a heavy aromatics column to produce a stream rich in C 7 , C9 and C 10 alkylaromatics and a stream rich in C 11 + alkylaromatics; j) passing the stream rich in C 7 , C 9 and C 10 alkylaromatics to a gas-phase transalkylation unit, wherein said stream is contacted with a second transalkylation catalyst under second transalkylation conditions to produce ar unstabilized transalkylation stream; and k) separating the unstabilized transalkylation stream in a transalkylation stabilizer column to produce a gas stream and the second transalkylation product stream of step (c).