Process for the Production of Xylenes

Patent metadata

Field	Value
Publication number	US-2016101405-A1
Application number	US-201514972223-A
Country	US
Kind code	A1
Filing date	Dec 17, 2015
Priority date	Jun 30, 2014
Publication date	Apr 14, 2016
Grant date	—

Abstract

In a process for producing para-xylene, a feed stream comprising C 6+ aromatic hydrocarbons is separated into a C 7— aromatic hydrocarbon-containing stream, a C 8 aromatic hydrocarbon-containing stream, and a C 9+ aromatic hydrocarbon-containing stream. The C 7− aromatic hydrocarbon-containing stream is contacted with a methylating agent to convert toluene to xylenes and produce a methylated effluent stream. Ethylbenzene is removed from the C 8 aromatic hydrocarbon-containing stream, para-xylene is recovered from the ethylbenzene-depleted C 8 aromatic hydrocarbon-containing stream and the methylated effluent stream in a para-xylene recovery section to produce a para-xylene depleted stream, which is then contacted with a xylene isomerization catalyst under liquid phase conditions effective to isomerize xylenes in the para-xylene depleted stream and produce an isomerized stream. The C 9+ -containing stream with a transalkylation catalyst under conditions effective to convert C 9+ -aromatics to C 8− -aromatics and produce a transalkylated stream, which is recycled together with the isomerized stream to the para-xylene recovery section.

First claim

1 - 13 . (canceled)

14 . Apparatus for producing para-xylene, the apparatus comprising:
(a) a first separation system for separating a reformate stream comprising C 6+ aromatic hydrocarbons into at least a C 7− aromatic hydrocarbon-containing stream, a C 8 aromatic hydrocarbon-containing stream, and a C 9+ aromatic hydrocarbon-containing stream; (b) a toluene methylation unit for converting toluene in the C 7− aromatic hydrocarbon-containing stream to xylenes and produce a methylated effluent stream; (c) an ethylbenzene removal unit for converting ethylbenzene in the C 8 aromatic hydrocarbon-containing stream to benzene and produce an ethylbenzene-depleted C 8 aromatic hydrocarbon-containing stream; (d) a transalkylation unit for converting C 9+ aromatics in the C 9+ aromatic hydrocarbon-containing stream to C 8− aromatics and produce a transalkylation effluent stream; (e) a para-xylene recovery system for recovering para-xylene from the ethylbenzene-depleted C 8 aromatic hydrocarbon-containing stream, the methylated effluent stream and a transalkylation effluent stream to produce at least one para-xylene depleted stream; (f) a liquid phase xylene isomerization unit for isomerizing xylenes in the at least one para-xylene depleted stream to produce a first isomerized stream; and (g) a recycle system for recycling at least part of the first isomerized stream to the a para-xylene recovery system.

15 . The apparatus of claim 14 and further comprising:
(h) an extractive distillation unit for removing the non-aromatics from the C 7− aromatic hydrocarbon-containing stream and produce a toluene-containing aromatic stream; and
(i) a second separation system for separating the toluene-containing aromatic stream into a benzene stream and a toluene stream.

16 . The apparatus of claim 14 and further comprising:
(j) a third separation system for recovering ortho-xylene from one or more of the C 8 aromatic hydrocarbon-containing stream, the methylated effluent stream, and a transalkylation effluent stream.

17 . The apparatus of claim 14 and further comprising:
(k) a catalytic reformer for producing the reformate stream of (a).

18 . The apparatus of claim 14 , wherein the first separation system is a dividing wall column.

Assignees

• Exxonmobil Chem Patents Inc

Inventors

• Tinger Robert G
• Andrews Jeffrey L
• Molinier Michel

Classifications

• C10G35/04

  Catalytic reforming · CPC title

• C07C5/2732

  Catalytic processes · CPC title

• B01J19/245 Primary

  placed in series · CPC title

• C07C6/123

  of only one hydrocarbon · CPC title

• C07C6/126

  of more than one hydrocarbon · CPC title