Process for the recovery of paraffins from an isomerization effluent

Patent metadata

Field	Value
Publication number	US-9567271-B2
Application number	US-201414476256-A
Country	US
Kind code	B2
Filing date	Sep 3, 2014
Priority date	Sep 3, 2014
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

A process for the recovery of C 4 hydrocarbons from a C 5 /C 6 isomerization zone. A portion of the effluent stream from the C 5 /C 6 isomerization zone comprising C 4 hydrocarbons is combined in a stabilizer section with an effluent from a C 4 isomerization zone. In order to increase the C 4 hydrocarbons in the effluent stream from the C 5 /C 6 isomerization zone, a chilling zone may be used.

First claim

What is claimed is:

1. A process for the recovery of C 4 hydrocarbons comprising:
stabilizing and separating a first effluent stream in a first stabilization zone into an overhead stream, a C 4− liquid stream, and a bottoms stream, wherein the first effluent stream is from a first isomerization zone;
stabilizing a second effluent stream from a second isomerization zone in a second stabilization zone;
passing at least a portion of the C 4− liquid stream to the second stabilization zone; and,
separating the second effluent stream and the at least a portion of the C 4− liquid stream into a C 4 stream and a C 3− stream.

2. The process of claim 1 further comprising:
separating the C 4 stream into an iC 4 stream and a nC 4 stream.

3. The process of claim 2 further comprising:
passing the iC4 stream to the second isomerization zone.

4. The process of claim 1 wherein the first stabilization zone comprises a stabilizer, a receiving zone and a chilling zone.

5. The process of claim 4 further comprising:
passing a C 4− stream from the stabilizer to the receiver;
separating the C 4− stream in the receiver into a vapor stream and a liquid stream, the liquid stream comprising the C 4− liquid stream.

6. The process of claim 5 further comprising:
cooling the vapor stream from the receiver in the chilling zone.

7. The process of claim 5 further comprising:
combining a portion of the vapor stream from the receiver and the C 3− stream of the second stabilization zone.

8. The process of claim 1 further comprising:
operating the first isomerization zone under isomerization conditions, in the presence of a catalyst, to convert iso-paraffins into normal paraffins.

9. The process of claim 8 wherein the iso-paraffins comprise iso-pentane and iso-hexane.

10. The process of claim 9 further comprising:
operating the second isomerization zone under isomerization conditions, in the presence of a catalyst, to convert iso-butane into normal butane.

11. A process for the recovery of C 4 hydrocarbons comprising:
passing a C 4− liquid stream to a stabilization zone, the liquid C 4− stream comprising at least a portion of an effluent from a first isomerization zone for isomerization of C 5+ hydrocarbons operated under isomerization conditions to convert iso-paraffins into normal paraffins, wherein the C 4− liquid stream is generated by separation of the effluent from the first isomerization zone;
passing at least a portion of a second effluent stream from a second isomerization zone for isomerization of C 4 hydrocarbons to the stabilization zone, the second effluent stream comprising C 4− hydrocarbons, wherein the second isomerization zone is operated under isomerization conditions to convert iso-butane into normal butane; and
separating the at least a portion of the second effluent stream and the C 4− liquid stream into a C 4 stream and a C 3− stream in the stabilization zone.

12. The process of claim 11 wherein the iso-paraffins comprise iso-pentane and iso-hexane.

13. The process of claim 12 further comprising:
cooling a portion of the effluent from the first isomerization zone to increase an amount of C 4 hydrocarbons in the liquid C 4− stream.

14. The process of claim 11 further comprising:
combining a first vapor stream from the stabilization zone comprising a C 3− stream with a second vapor stream comprising a second C 3— stream wherein the second C 3− stream is generated by separation of the effluent of the first isomerization zone.

15. The process of claim 14 wherein the second C 3− stream comprises a portion of the effluent from the first isomerization zone.

16. The process of claim 11 further comprising:
separating the C 4 stream from the stabilization zone into an iC 4 stream and an nC 4 stream.

17. The process of claim 16 further comprising:
passing the iC 4 stream to the second isomerization zone.

18. The process of claim 11 further comprising:
separating the effluent from the first isomerization zone into a C 4− stream and a C 5+ stream; and,
separating the C 4− liquid stream from at least a portion of the C 4— stream.

19. The process of claim 18 , further comprising:
separating the C 4− stream into the C 4− liquid stream and a C 3− vapor stream.

20. The process of claim 19 further comprising:
increasing an amount of C 4 in the C 4− liquid stream by cooling the C 4− stream.

Assignees

• Uop Llc

Inventors

• Kumar Manoj
• Shecterle David James

Classifications

• C07C5/277 Primary

  Catalytic processes · CPC title

• C10G65/043

  at least one step being a change in the structural skeleton · CPC title

• C10G7/02

  Stabilising gasoline by removing gases by fractioning · CPC title

• C07C7/00

  Purification; Separation; Use of additives (working-up undefined gaseous mixtures obtained by cracking hydrocarbon oils C10G70/00) · CPC title

• C07C9/15

  Straight-chain hydrocarbons · CPC title