Efficient downstream process for n-butane dehydrogenation technology for the production of high purity butylenes

Patent metadata

Field	Value
Publication number	US-11168041-B2
Application number	US-201917263265-A
Country	US
Kind code	B2
Filing date	Jun 19, 2019
Priority date	Aug 6, 2018
Publication date	Nov 9, 2021
Grant date	Nov 9, 2021

Abstract

A method for producing butenes by the dehydrogenation of n-butane includes dehydrogenating the n-butane in a dehydrogenation zone and contacting material from the dehydrogenation zone with a solvent that is more selective to dissolve n-butane than butenes. The resulting fluid from the contacting is subjected to extractive distillation to produce (1) a stream comprising a solution of the n-butane and solvent and (2) a stream comprising the butenes.

First claim

The invention claimed is:

1. A method of producing butene, the method comprising:
dehydrogenating, in a dehydrogenation reactor, a feed stream comprising primarily n-butane to produce an intermediate product stream comprising n-butane and one or more butenes;
contacting the intermediate product stream with a solvent that is more selective for dissolving the n-butane than for dissolving the one or more butenes to form a fluid that comprises (1) a first portion comprising primarily the solvent and the n-butane, collectively, and (2) a second portion comprising primarily the one or more butenes;
separating the fluid to produce a stream comprising primarily the solvent and the n-butane, collectively, and a product stream comprising primarily the one or more butenes;

wherein the solvent comprises soya bean oil.

2. The method of claim 1 , further comprising:
flowing the intermediate product stream to an extractive distillation column in which the solvent is disposed.

3. The method of claim 2 , wherein the separating comprises:
distilling the fluid in the extractive distillation column under conditions sufficient to produce an extractor overhead stream comprising primarily the solvent and the n-butane, collectively, and an extractor bottom stream comprising primarily the one or more butenes.

4. The method of claim 3 , further comprising:
separating the extractor overhead stream into a n-butane recycle stream comprising primarily n-butane and a recovered solvent stream comprising primarily solvent.

5. The method of claim 4 , wherein the recovered solvent stream is recycled to the extractive distillation column.

6. The method of claim 5 further comprising:
feeding the n-butane recycle stream to the dehydrogenation reactor.

7. The method of claim 6 , further comprising:
processing the extractor bottom stream to form a product comprising at least 92 wt. % 2-butene.

8. The method of claim 6 , further comprising:
processing the extractor bottom stream to form a product comprising at least to 99.7 wt. % 1-butene.

9. The method of claim 3 , wherein the one or more butenes comprise 1-butene, 2-butene, trans butene, or combinations thereof.

10. The method of claim 4 , wherein the one or more butenes comprise 1-butene, 2-butene, trans butene, or combinations thereof.

11. The method of claim 5 , wherein the one or more butenes comprise 1-butene, 2-butene, trans butene, or combinations thereof.

12. The method of claim 2 , wherein conditions in the extractive distillation column include a temperature in a range of 10 to 50° C.

13. The method of claim 2 , wherein conditions in the extractive distillation column include a pressure in a range of 0.01 to 1 MPa.

14. The method of claim 2 , wherein the one or more butenes comprise 1-butene, 2-butene, trans butene, or combinations thereof.

15. The method of claim 1 , wherein the solvent dissolves 10 to 100 wt. % of the n-butane of the intermediate product stream and only 0.001 to 0.002 wt. % of the one or more butenes of the intermediate product stream is dissolved in the solvent.

16. The method of claim 1 , wherein the feed stream comprises 50 to 60 wt. % n-butane and 40 to 50 wt. % butenes.

17. The method of claim 1 , wherein the one or more butenes comprise 1-butene, 2-butene, trans butene, or combinations thereof.

18. A method of producing butene, the method comprising:
dehydrogenating, in a dehydrogenation reactor, a feed stream comprising primarily n-butane to produce an intermediate product stream comprising n-butane and one or more butenes;
flowing the intermediate product stream to an extractive distillation column in which soya bean oil is disposed;
contacting the intermediate product stream with the soya bean oil, the soya bean oil being more selective for dissolving the n-butane than for dissolving the one or more butenes, the contacting forming a fluid that comprises (1) a first portion comprising primarily the soya bean oil and the n-butane, collectively, and (2) a second portion comprising primarily the one or more butenes; and
distilling the fluid in the extractive distillation column under conditions sufficient to produce an extractor overhead stream comprising primarily the soya bean oil and the n-butane, collectively, and an extractor bottom stream comprising primarily the one or more butenes.

19. A method of producing butene, the method comprising:
dehydrogenating, in a dehydrogenation reactor, a feed stream comprising primarily n-butane to produce an intermediate product stream comprising n-butane and one or more butenes;
flowing the intermediate product stream to an extractive distillation column in which soya bean oil is disposed;
contacting the intermediate product stream with the soya bean oil, the soya bean oil being more selective for dissolving the n-butane than for dissolving the one or more butenes, the contacting forming a fluid that comprises (1) a first portion comprising primarily the soya bean oil and the n-butane, collectively, and (2) a second portion comprising primarily the one or more butenes;
distilling the fluid in the extractive distillation column under conditions sufficient to produce an extractor overhead stream comprising primarily the soya bean oil and the n-butane, collectively, and an extractor bottom stream comprising primarily the one or more butenes;
separating the extractor overhead stream into a n-butane recycle stream comprising primarily n-butane and a recovered soybean oil stream comprising primarily soybean oil;
feeding the n-butane recycle stream to the dehydrogenation reactor; and
processing the extractor bottom stream to form a product comprising 92 wt. % to 99.7 wt. % butene.

Assignees

• Sabic Global Technologies Bv

Inventors

• Haider Muhammad H
• Al-Zahrani Abdulaziz
• Al-Zenaidi Ahmed S

Classifications

• C07C7/08 Primary

  by extractive distillation · CPC title

• C07C5/333

  Catalytic processes · CPC title

• C07C7/005

  Processes comprising at least two steps in series · CPC title

• C07C7/10

  by extraction, i.e. purification or separation of liquid hydrocarbons with the aid of liquids · CPC title

• B01D3/40

  Extractive distillation · CPC title