Vapor phase process for making 1,1,1,3,3-pentafluoropropane and 1-chloro-3,3,3-trifluoropropene

• US 5,710,352 A
• Filed: 09/19/1996
• Issued: 01/20/1998
• Est. Priority Date: 09/19/1996
• Status: Expired due to Term

• Current Assignee: Alliedsignal Inc.
• Original Assignee: Alliedsignal Inc.
• Inventors: Tung, Hsueh Sung
• Primary Examiner(s): Siegel, Alan
• Application Number:
  US08/716,013
• Time in Patent Office: 488 Days
• Field of Search: 570/166, 570/167, 570/168, 570/169
• US Class Current: 570/166
• CPC Class Codes: C07C 17/00 Preparation of halogenated hydrocarbons
• CPC Class Codes: C07C 17/087 to unsaturated halogenated hydrocarbons
• CPC Class Codes: C07C 17/206 the other compound being HX
• CPC Class Codes: C07C 17/21 with simultaneous increase of the number of halogen atoms
• CPC Class Codes: C07C 19/08 containing fluorine
• CPC Class Codes: C07C 21/18 containing fluorine

Abstract

A method for the preparation of 1,1,1,3,3-pentafluoropropane (HFC-245fa) and 1-chloro-3,3,3-trifluoropropene (HCFC-1233). 1,1,1,3,3-pentachloropropane (HCC-240fa) is fluorinated with HF in a vapor phase in the presence of a vapor phase catalyst. The HCFC-1233 and any co-produced 1,3,3,3-tetrafluoropropene (HFC-1234) are recycled for further fluorination by HF for a greater than 99% HCC-240fa conversion.

Claims

1. A process for the preparation of 1,1,1,3,3-pentafluoropropane comprising the steps of:

(a) conducting a fluorination reaction by reacting 1,1,1,3,3-pentachloropropane with hydrogen fluoride in a reactor in the vapor phase and in the presence of a fluorination catalyst, thereby forming a reaction product comprising HCl, 1,1,1,3,3-pentafluoropropane, 1-chloro-3,3,3-trifluoropropene and 1,3,3,3-tetrafluoropropene;

(b) separating 1,1,1,3,3-pentafluoropropane from said reaction product; and

(c) subsequently recycling the 1-chloro-3,3,3-trifluoropropene and/or 1,3,3,3-tetrafluoropropene to a liquid phase reactor for reaction with HF to thereby produce additional 1,1,1,3,3 -pentafluoropropane.

2. The process of claim 1 wherein the liquid phase reaction is conducted with a fluorination catalyst selected from the group consisting of transition metal halides, Group IVb metal halides, Group Vb metal halides and mixtures thereof.

3. The process of claim 1 wherein the liquid phase reaction is conducted with a fluorination catalyst selected from the group consisting of SbCl₅, SbCl₃, TaCl₅, SnCl₄, NbCl₅, TICl₄, MoCl₅ and mixtures thereof.

4. A process for the preparation of 1,1,1,3,3-pentafluoropropane comprising the steps of:

(a) conducting a fluorination reaction by reacting 1,1,1,3,3-pentachloropropane with hydrogen fluoride in a reactor in the vapor phase and in the presence of a fluorination catalyst, thereby forming a reaction product comprising HCl, 1,1,1,3,3-pentafluoropropane, 1-chloro-3,3,3-trifluoropropene and 1,3,3,3-tetrafluoropropene; and

(b) separating 1,1,1,3,3-pentafluoropropane from said reaction product wherein said fluorination reaction is conducted with a fluorination catalyst selected from the group consisting of, chromium, aluminum, cobalt, manganese, nickel and iron oxides, hydroxides, halides, oxyhalides and inorganic salts thereof.

5. The process of claim 4 further comprising subsequently removing said HCl from said reaction product.

6. The process of claim 4 further comprising additionally removing HCl from said reaction product before said separation.

7. The process of claim 4 further comprising subsequently recovering any unreacted HF present after said separation and recycling it back for said reaction with 1,1,3,3,3-pentachloropropane.

8. The process of claim 4 wherein said 1,1,1,3,3-pentachloropropane is pre-vaporized.

9. The process of claim 4 wherein said HF is pre-vaporized.

10. The process of claim 4 wherein said 1,1,1,3,3-pentachloropropane and said HF are pre-vaporized.

11. The process of claim 4 wherein the 1,1,1,3,3-pentachloropropane and HF are vaporized in the reactor.

12. The process of claim 4 wherein said fluorination reaction is conducted at a temperature of from about 80°

C. to about 400°

C.

13. The process of claim 4 wherein said fluorination reaction is conducted at atmospheric pressure or under a vacuum.

14. The process of claim 4 wherein the fluorination catalyst is a chromium catalyst selected from the group consisting of, Cr₂ O₃ /Al₂ O₃, Cr₂ O₃ /AlF₃, Cr₂ O₃ /carbon, CoCl₂ /Cr₂ O₃ /Al₂ O₃, NiCl₂ /Cr₂ O₃ /Al₂ O₃, CoCl₂ /AlF₃ and NiCl₂ /AlF₃.

15. The process of claim 4 further comprising subsequently recycling the 1-chloro-3,3,3-trifluoropropene and/or 1,3,3,3-tetrafluoropropene and reacting the 1-chloro-3,3,3-trifluoropropene and/or 1,3,3,3-tetrafluoropropene with HF.

16. The process of claim 4 wherein said fluorination catalyst is chromium (III) oxide.

17. The process of claim 4 wherein said separation is conducted by distillation.

18. The process of claim 17 wherein the distillation is conducted at a pressure of from less than about 300 psig.

19. The process of claim 4 wherein the fluorination catalyst contact time is from about 1 second to about 120 seconds.

20. The process of claim 4 wherein the mole ratio of HF to 1,1,1,3,3-pentachloropropane ranges from about 3:

1 to about 100;

1.

21. The process of claim 4 wherein the conversion of 1,1,1,3,3-pentachloropropane is at least about 99%.

22. A process for the preparation of 1-chloro-3,3,3-trifluoropropene which comprises:

(a) conducting a fluorination reaction by reacting 1,1,1,3,3-pentachloropropane with hydrogen fluoride in a reactor in the vapor phase and in the presence of a fluorination catalyst, thereby forming a reaction product comprising HCl, 1,1,1,3,3-pentafluoropropane, 1-chloro-3,3,3-trifluoropropene and 1,3,3,3-tetrafluoropropene, and

(b) separating 1-chloro-3,3,3-trifluoropropene from said reaction product.

23. A process for the preparation of 1,1,1,3,3-pentafluoropropane which comprises:

(a) conducting a fluorination reaction by reacting one or more components comprised of 1,1-dichloro-3,3,3-trifluoropropane, 1-chloro-1,3,3,3,-tetrafluoropropane or 1,1,3-trichloro-3,3-difluoropropane with hydrogen fluoride in a reactor in the vapor phase and in the presence of a fluorination catalyst, thereby forming a reaction product comprising HCl, 1,1,1,3,3-pentafluoropropane, 1-chloro-3,3,3-trifluoropropene and 1,3,3,3-tetrafluoropropene, and

(b) separating 1,1,1,3,3-pentafluoropropane from said reaction product wherein said fluorination reaction is conducted with a fluorination catalyst selected from the group consisting of, chromium, aluminum, cobalt, manganese, nickel and iron oxides, hydroxides, halides, oxyhalides and inorganic salts thereof.

24. A process for the preparation of 1-chloro-3,3,3-trifluoropropene which comprises:

(a) conducting a fluorination reaction by reacting one or more components comprised of 1,1-dichloro-3,3,3-trifluoropropane, 1-chloro-1,3,3,3,-tetrafluoropropane or 1,1,3-trichloro-3,3-difluoropropane with hydrogen fluoride in a reactor in the vapor phase and in the presence of a fluorination catalyst, thereby forming a reaction product comprising HCl, 1,1,1,3,3-pentafluoropropane, 1-chloro-3,3,3-trifluoropropene and 1,3,3,3-tetrafluoropropene, and

(b) separating 1-chloro-3,3,3-trifluoropropene from said reaction product.