Systems and processes for alkane aromatization

Patent metadata

Field	Value
Publication number	US-10676410-B2
Application number	US-201815960221-A
Country	US
Kind code	B2
Filing date	Apr 23, 2018
Priority date	Jun 22, 2017
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

Embodiments disclosed herein related to processes and systems for alkane aromatization. In some embodiments, the process includes merging a benzene-containing stream into an ethane containing stream to form a feed stream. The feed stream has at least 5 wt. % benzene based on the total weight of the feed stream. In addition, the process includes contacting the feed stream with an aromatization catalyst to produce an effluent stream comprising C7+ aromatic hydrocarbons. Less than 5 wt. % net benzene is produced during the contacting, based on a total weight of the feed stream.

First claim

The invention claimed is:

1. A process for producing C7+ aromatic hydrocarbons, the process comprising:
a) providing an ethane-containing stream comprising at least 50 wt. % ethane based on a total weight of the ethane-containing stream;
b) merging the ethane-containing stream with a benzene-containing stream to produce a merged stream comprising a first benzene content of at least 14 wt. % benzene and a first C 7+ aromatic content; and
c) contacting the merged stream with an aromatization catalyst at a temperature in a range from about 640° C. to about 750° C. to produce an effluent stream comprising a second benzene content and a second C 7+ aromatic content,
wherein the second benzene content is less than the first benzene content, and
wherein the second C 7+ aromatic content is greater than the first C 7+ aromatic content.

2. The process of claim 1 , further comprising separating at least some benzene from the effluent stream.

3. The process of claim 2 , wherein the benzene-containing stream is provided from outside the process.

4. The process of claim 3 , wherein the benzene-containing stream comprises greater than 50 wt. % benzene based on a total weight of the benzene-containing stream.

5. The process of claim 4 , wherein the merged stream has 14 wt. % to about 30 wt. % benzene based on a total weight of the merged stream.

6. The process of claim 5 , wherein the merged stream has about 14 wt. % to about 20 wt. % benzene based on the total weight of the merged stream.

7. The process of claim 6 , further comprising:
(c) separating a C 7+ aromatic hydrocarbon-containing stream from the effluent stream; and
(d) providing the C 7+ aromatic hydrocarbon-containing stream to a para-xylene production unit.

8. The process of claim 7 , wherein
greater than 40%, by volume, of the ethane in the merged stream is converted into C 7+ aromatic hydrocarbons during the contacting in (c).

9. The process of claim 8 , wherein
greater than 90%, by volume, of the ethane in the merged stream is converted into C 7+ aromatic hydrocarbons during the contacting in (c).

10. The process of claim 9 , wherein the aromatization catalyst comprises ZSM-5.

11. The process of claim 10 , wherein the aromatization catalyst includes Gallium.

12. A process for producing C 7+ aromatic hydrocarbons, the process comprising:
a) flowing a feed stream to an aromatization reactor, wherein the feed stream comprises a first benzene content of at least 14 wt. % and an ethane content of at least 50 wt. %, based on a total weight of the feed stream;
b) contacting the feed stream with an aromatization catalyst at a temperature in a range from about 640° C. to about 750° C. to produce an effluent stream comprising a second benzene content and C 7+ aromatics;
c) separating the effluent stream to obtain an aromatic-containing stream comprising benzene and C 2 -C 6 hydrocarbons; and
d) recycling the aromatic-containing stream to the aromatization reactor,
wherein the second benzene content is less than the first benzene content.

13. The process of claim 12 , wherein 14 wt. % to about 30 wt. % benzene is provided to the aromatization reactor, based on a total weight of the feed stream and the aromatic-containing stream.

14. The process of claim 13 , wherein about 14 wt. % to about 20 wt. % benzene is provided to the aromatization reactor, based on a total weight of the feed stream and the aromatic-containing stream.

15. The process of claim 14 , wherein
greater than 40%, by volume, of the ethane in the feed stream is converted into C 7+ aromatic hydrocarbons during the contacting in (b).

16. The process of claim 15 , wherein
greater than 90%, by volume, of the ethane in the feed stream is converted into C 7+ aromatic hydrocarbons during the contacting in (b).

17. The process of claim 16 , wherein the aromatization catalyst comprises ZSM-5.

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Knaeble William J

Classifications

• C07C2/42 Primary

  homo- or co-oligomerisation with ring formation, not being a Diels-Alder conversion · CPC title

• C07C2/66

  Catalytic processes · CPC title

• C07C2529/40

  of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11 · CPC title

• C07C2/76 Primary

  by condensation of hydrocarbons with partial elimination of hydrogen · CPC title