Xylene isomerization

Patent metadata

Field	Value
Publication number	US-2017362143-A1
Application number	US-201515536596-A
Country	US
Kind code	A1
Filing date	Dec 16, 2015
Priority date	Dec 17, 2014
Publication date	Dec 21, 2017
Grant date	—

Abstract

A process for producing xylenes, in particular para-xylene that is less energy intensive than conventional processes is provided. In an embodiment the process comprises contacting a feed mixture in an isomerization zone with a catalyst at isomerization conditions and producing an isomerized product comprising a higher proportion of p-xylene than in the feed mixture, wherein the catalyst comprises an acidic sulfonated catalytic membrane. Xylene isomerization can also be coupled with a p-xylene extraction process, where the raffinate (p-xylene deprived stream) from the extraction process is fed to an isomerization reactor to produce p-xylene. In an embodiment, the process can comprise: a) providing a feed stream comprising a mixture of xylene isomers including p-xylene; b) extracting p-xylene from the feed stream using a separator to separate the feed stream into a p-xylene rich stream and a p-xylene deprived stream; and c) delivering the p-xylene deprived stream to an isomerization unit, the isomerization unit including an acidic sulfonated catalytic membrane, and using the isomerization unit to produce an isomerized product comprising a higher proportion of p-xylene than in the p-xylene deprived stream delivered to the isomerization unit. In any one or more aspects, the isomerization unit can be operated at a temperature in the range of less than 350°, for example about 20° C. to about 200° C.

First claim

1 . A process for removing p-xylene from a feed stream, comprising the steps of:
a) providing a feed stream comprising a mixture of xylene isomers including p-xylene; b) extracting p-xylene from the feed stream using an extractor to separate the feed stream into a p-xylene rich stream and a p-xylene deprived stream; c) delivering the p-xylene deprived stream to an isomerization unit, the isomerization unit including an acidic sulfonated catalytic membrane, and using the isomerization unit to produce an isomerized product comprising a higher proportion of p-xylene than in the p-xylene deprived stream delivered to the isomerization unit; and d) admixing the isomerized product with the feed stream for delivery to the separator.

2 . The process of claim 1 , wherein the isomerization unit is operated at a temperature in the range of about 20° C. to about 200° C.

3 . The process of claim 1 , wherein the acidic sulfonated catalytic membrane is comprised of sulfonated polymers and/or copolymers.

4 . The process of claim 3 , wherein the acidic sulfonated catalytic membrane is comprised of Nafion-H.

5 . The process of claim 1 , wherein the feed stream comprises aromatics used to isolate xylenes.

6 . The process of claim 5 , wherein the feed stream includes one or more of catalytically reformed naphthas, aromatics from a stream reforming process, and/or aromatics from biomass refineries.

7 . The process of claim 1 , wherein the isomerization unit is a catalytic membrane reactor.

8 . The process of claim 1 , wherein the isomerization unit is used to carry out a pervaporation process using the membrane to produce the isomerized product under partial vacuum.

9 . A process for isomerizing a feed mixture comprising xylenes, the process comprising contacting the feed mixture in an isomerization zone with a catalyst at isomerization conditions and producing an isomerized product comprising a higher proportion of p-xylene than in the feed mixture, wherein the catalyst comprises an acidic sulfonated catalytic membrane.

10 . The process of claim 9 , wherein the isomerization zone is operated at a temperature in the range of about 20° C. to about 200° C.

11 . The process of claim 9 , wherein the acidic sulfonated catalytic membrane is comprised of sulfonated polymers and/or copolymers.

12 . The process of claim 11 , wherein the acidic sulfonated catalytic membrane is comprised of Nafion-H.

13 . The process of claim 9 , wherein the feed stream aromatics used to isolate xylenes.

14 . The process of claim 13 , wherein the feed stream includes one or more of catalytically reformed naphthas, aromatics from a stream reforming process, and/or aromatics from biomass refineries.

15 . The process of claim 9 , wherein the isomerization zone is located within a catalytic membrane reactor.

16 . The process of claim 15 , wherein a pervaporation process using the membrane is carried out within the isomerization zone under partial vacuum.

17 . The process of claim 1 , wherein the isomerization unit is operated at a temperature in the range of about 70° C. to about 80° C.

18 . The process of claim 2 , wherein the acidic sulfonated catalytic membrane is comprised of sulfonated polymers and/or copolymers.

19 . The process of claim 9 , wherein the isomerization unit is operated at a temperature in the range of about 70° C. to about 80° C.

20 . The process of claim 10 , wherein the acidic sulfonated catalytic membrane is comprised of sulfonated polymers and/or copolymers.

Assignees

• Univ King Abdullah Sci & Tech

Inventors

• Bilaus Rakan Sulaiman
• Pinnau Ingo

Classifications

• C07C2531/10

  sulfonated · CPC title

• B01J35/065

  Operations & Transport · mapped topic

• C07C5/2797

  with ion-exchange resins · CPC title

• C07C5/2756 Primary

  with hydrides or organic compounds (C07C5/2748 takes precedence) · CPC title

• B01J31/10

  sulfonated · CPC title