Process for the isomerisation of C3-7 (hydro)(halo)fluoroalkenes

Patent metadata

Field	Value
Publication number	US-10179754-B2
Application number	US-201415030940-A
Country	US
Kind code	B2
Filing date	Oct 24, 2014
Priority date	Oct 25, 2013
Publication date	Jan 15, 2019
Grant date	Jan 15, 2019

Abstract

The present invention relates to a process for isomerizing a C 3-7 (hydro)(halo)fluoroalkene comprising (a) providing a reactor feed stream comprising the C 3-7 (hydro)(halo)fluoroalkene; and (b) contacting the C 3-7 (hydro)(halo)fluoroalkene with a catalyst comprising alumina to isomerize the C 3-7 (hydro)(halo)fluoroalkene, wherein the catalyst has a sodium content of less than about 800 ppm.

First claim

The invention claimed is:

1. A process for isomerising a C 3-7 (hydro) (halo)fluoroalkene comprising:
a) providing a reactor feed stream comprising the C 3-7 (hydro)(halo)fluoroalkene; and
b) contacting the C 3-7 (hydro)(halo)fluoroalkene with a catalyst comprising alumina to isomerise the C 3-7 hydro(halo)fluoroalkene, wherein the catalyst has a sodium content of less than about 200 ppm, wherein the catalyst comprises a metal oxide supported on the alumina, and wherein the metal is Zr or Cr.

2. The process according to claim 1 , wherein the catalyst has a sodium content of less than about 150 ppm.

3. The process according to claim 2 , wherein the catalyst has a sodium content of less than about 100 ppm.

4. The process according to claim 3 , wherein the catalyst has a sodium content of less than about 80 ppm.

5. The process according to claim 4 , wherein the catalyst has a sodium content of less than about 60 ppm.

6. The process according to claim 5 , wherein the catalyst has a sodium content of less than about 40 ppm.

7. The process according to claim 6 , wherein the catalyst has a sodium content of less than about 30 ppm.

8. The process according to claim 7 , wherein the catalyst has a sodium content of less than about 20 ppm.

9. The process according to claim 8 , wherein the catalyst has a sodium content of less than about 10 ppm.

10. The process according to claim 1 , wherein the catalyst comprises at least 60% by weight of alumina support based on the total weight of the catalyst.

11. The process according to claim 10 , wherein the catalyst comprises at least 70% by weight of alumina support based on the total weight of the catalyst.

12. The process according to claim 1 , wherein the catalyst comprises up to about 40% by weight of the metal oxide based on the total weight of the catalyst.

13. The process according to claim 12 , wherein the catalyst comprises up to about 30% by weight of the metal oxide based on the total weight of the catalyst.

14. The process according to claim 1 , wherein the catalyst further comprises at least one additional metal or a compound of the additional metal.

15. The process according to claim 14 , wherein the additional metal is selected from the group consisting of Zn, Zr, Cr, In, Co, Ni and mixtures thereof.

16. The process according to claim 14 , wherein the catalyst comprises up to about 20% by weight of the at least one additional metal or a compound of the additional metal, based on the total weight of the catalyst.

17. The process according to claim 16 , wherein the catalyst comprises up to about 10% by weight of the at least one additional metal or compound of the additional metal.

18. The process according to claim 1 , wherein the C 3-7 (hydro)(halo)fluoroalkene exists as geometric isomers and the isomerising results in a change in a ratio of E and Z isomers of the C 3-7 (hydro)(halo)fluoroalkene.

19. The process according to claim 1 carried out at a temperature of from 50 to 400° C. and a pressure of up to 30 bara.

20. The process according to claim 19 carried out at a temperature of from 120° C. to 360° C.

21. The process according to claim 1 , wherein the C 3-7 (hydro)(halo)fluoroalkene is isomerised with a conversion of at least about 5%.

22. The process according to claim 1 , wherein the C 3-7 (hydro)(halo)fluoroalkene is a C (hydro) (halo)fluoroalkene.

23. The process according to claim 22 , wherein the CF 3-6 (hydro)(halo)fluoroalkene is a C 3-4 (hydro)(halo)fluoroalkene.

24. The process according to claim 23 , wherein the C 3-4 (hydro)(halo)fluoroalkene is a (hydro)(halo)fluoropropene.

25. The process according to claim 24 , wherein the (hydro)(halo)fluoropropene is a hydrofluoropropene.

26. The process according to claim 25 , wherein the hydrofluoropropene is selected from tetrafluoropropenes and pentafluoropropenes.

27. The process according to claim 26 , wherein the tetrafluoropropene is 1,3,3,3-tetrafluoropropene (1234ze) and the process comprises isomerising cis-1,3,3,3-tetrafluoropropene (1234ze(Z)) to trans-1,3,3,3-tetrafluoropropene (1234ze(E)).

28. The process according to claim 26 , wherein the pentafluoropropene is 1,2,3,3,3-pentafluoropropene (1225ye) and the process comprises isomerising E-1,2,3,3,3-pentafluoropropene (1225ye(E)) to Z-1,2,3,3,3-pentafluoropropene (1225ye(Z)).

29. The process according to claim 24 , wherein the (hydro)(halo)fluoropropene is a hydrohalofluoropropene.

30. The process according to claim 29 , wherein the hydrohalofluoropropene is 1-chloro-3,3,3-trifluoropropene (1233zd) and the process comprises isomerising cis-1-chloro-3,3,3-trifluoropropene (1233zd(Z)) to trans-1-chloro-3,3,3-trifluoropropene (1233zd(E)).

31. The process according to claim 24 , wherein the C 3-7 (hydro)(halo)fluoroalkene is a hydrohalofluorobutene, a halofluorobutene or a hydrofluorobutene.

32. The process according to claim 31 , wherein the hydrofluorobutene is 1,1,1,4,4,4-hexafluorobut-2-ene (1336mzz) and the process comprises isomerising cis-1,1,1,4,4,4-hexafluorobut-2-ene (1336mzz(Z)) to trans-1,1,1,4,4,4-hexafluorobut-2-ene (1336mzz(E)).

33. A process for preparing a C 3-7 (hydro)(halo)fluoroalkene by dehydrohalogenation of a reactor feed comprising a C 3-7 hydro(halo)fluoroalkane to produce the C 3-7 (hydro)(halo)fluoroalkene, and isomerising the C 3-7 (hydro)(halo)fluoroalkene as defined in claim 1 .

34. The process according to claim 33 , wherein the reactor feed comprises 1,1,1,3,3-pentafluoropropane (245fa) and the process comprises the following steps:
(a) dehydrofluorinating 245fa to produce a dehydrohalogenation stream comprising 1234ze(Z), 1234ze(E), HF and, optionally, unreacted 245fa;
(b) optionally recovering the HF from the dehydrohalogenation stream;
(c) optionally recovering 1234ze(E) from the dehydrohalogenation stream; and
(d) contacting the dehydrohalogenation stream with the catalyst comprising a metal oxide supported on alumina to isomerise the 1234ze(Z) to 1234ze(E), wherein the catalyst has a sodium content of less than about 200 ppm.

Assignees

• Mexichem Amanco Holding Sa

Inventors

• Mcguinness Claire E
• Sharratt Andrew P

Classifications

• C07C17/25

  by splitting-off hydrogen halides from halogenated hydrocarbons · CPC title

• C07B2200/09

  Geometrical isomers · CPC title

• C01F7/02

  Aluminium oxide; Aluminium hydroxide; Aluminates · CPC title

• B01J23/26

  Chromium · CPC title

• C07C17/358 Primary

  by isomerisation · CPC title