PROCESS FOR MAKING TETRAFLUOROPROPENE

• US 20130211155A1
• Filed: 02/04/2013
• Published: 08/15/2013
• Est. Priority Date: 02/14/2012
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Nair, Haridasan K., Singh, Rajiv Ratna, Nalewajek, David, Poss, Andrew Joseph
• Granted Patent: US 8,829,254 B2
• Time in Patent Office: Days
• US Class Current: 570/157
• CPC Class Codes: C07C 17/206 the other compound being HX
• CPC Class Codes: C07C 17/23 by dehalogenation
• CPC Class Codes: C07C 17/25 by splitting-off hydrogen halides from halogenated hydrocarbons
• CPC Class Codes: C07C 17/278 of only halogenated hydrocarbons
• CPC Class Codes: C07C 19/01 containing chlorine
• CPC Class Codes: C07C 19/10 and chlorine
• CPC Class Codes: C07C 21/04 Chloro-alkenes
• CPC Class Codes: C07C 21/18 containing fluorine

Abstract

The present invention describes a process for making CF₃CH═CHF (HFO-1234ze). The process involves the addition of carbon tetrachloride (CCl₄) to 1,2-dichloroethylene to form CCl₃CHClCHCl₂. The compound CCl₃CHClCHCl₂ thus can then either be treated with HF to produce CF₃CHClCHClF as the main product, or it can be converted to CCl₂═CHCHCl₂ (1230za) by dechlorination. CCl₂═CHCHCl₂ can be treated with HF such that the main product obtained is CF₃CHClCHClF. CF₃CH═CHCl may be produced as a by-product, but upon treatment with HF, it affords the compound CF₃CHClCHClF. The desired compound, CF₃CH═CHF (HFO-1234ze), is obtained as a trans/cis mixture by dehydrochlorination of CF₃CH₂CHClF or by dechlorination of CF₃CHClCHClF.

Claims

1. A process for making CF₃CH═

CHF comprising the steps of;

(a) converting 1,2-dichloroethylene to the compound CCl₃CHClCHCl₂;

(b) converting CCl₃CHClCHCl₂ to the compound CCl₂═

CHCHCl₂;

(c) fluorinating the product of step (b) to form the compound CF₃CH₂CHClF; and

(d) dehydrochlorinating the product of step (c) to form the compound CF₃CH═

CHF.

2. The process of claim 1, wherein the reaction of step (a) is conducted with a catalyst.

3. The process of claim 2, wherein the catalyst comprises a copper catalyst.

4. The process of claim 2, wherein the catalyst comprises a ruthenium catalyst.

5. The process of claim 1, wherein the dechlorination reaction of step (b) is conducted using zinc.

6. The process of claim 1, wherein the fluorination reaction of step (c) is conducted with hydrogen fluoride and a fluorination catalyst.

7. The process of claim 6, wherein the hydrogen fluoride is anhydrous.

8. The process of claim 6, wherein the fluorination catalyst has the formula SbCl_xF_y, where x+y=5.

9. The process of claim 6, wherein the fluorination catalyst comprises SbCl₅.

10. The process of claim 6, wherein the fluorination catalyst comprises SbF₅.

11. The process of claim 6, wherein the fluorination catalyst is supported on activated carbon.

12. The process of claim 1, wherein the dehydrochlorination reaction of step (d) is conducted in either the liquid phase or the gas phase, with a dehydrochlorination catalyst.

13. The process of claim 12, wherein the dehydrochlorination reaction is conducted in the liquid phase.

14. The process of claim 13, wherein the catalyst comprises an alkali metal hydroxide with a phase transfer catalyst.

15. The process of claim 13, wherein the alkali metal hydroxide comprises sodium hydroxide.

16. The process of claim 13, wherein the alkali metal hydroxide comprises potassium hydroxide.

17. The process of claim 12, wherein the dehydrochlorination reaction is conducted in the gas phase.

18. The process of claim 17, wherein the catalyst comprises acid treated activated carbon.

19. The process of claim 18, wherein the acid treatment is selected from HCl and HNO₃.

20. The process of claim 17, wherein the dehydrochlorination reaction is conducted at a temperature range of from about 300°

C. to 500°

C.

21. The process of claim 17, wherein the dehydrochlorination reaction is conducted at a temperature range of from about 350°

C. to 370°

C.

34. The process of claim 1, wherein the reactions are conducted in a continuous manner.

22. A process for making CF₃CH═

CHF comprising the steps of;

(a) reacting carbon tetrachloride with 1,2-dichloroethylene to form the compound CCl₃CHClCHCl₂;

(b) fluorinating the compound CCl₃CHClCHCl₂ with HF to produce the compound CF₃CHClCHClF; and

(c) dechlorinating CF₃CHClCHClF to produce the compound CF₃CH═

CHF.

23. The process of claim 22, wherein the dechlorination reaction is conducted with zinc.

24. The process of claim 22, wherein a portion of the compound CCl₃CHClCHCl₂ is converted to the compound CCl₂═

CHCHCl₂ (HCC-1230za) by dehydrochlorination.

25. The process of claim 22, wherein a portion of the compound CCl₃CHClCHCl₂ is fluorinated with HF and a fluorination catalyst to afford the compound CF₃CHClCHClF.

26. The process of claim 25, wherein the fluorination catalyst has the formula SbCl_xF_y, where x+y=5.

27. The process of claim 26, wherein the fluorination catalyst comprises SbCl₅.

28. The process of claim 26, wherein the fluorination catalyst comprises SbF₅.

29. The process of claim 26, wherein the fluorination catalyst is supported on activated carbon.

30. The process of claim 22, further comprising the step wherein the compound CCl₂═

CHCHCl₂ is fluorinated with HF and a fluorination catalyst to produce the compound CF₃CHClCHClF.

31. The process of claim 30, further comprising the step wherein the dechlorination of CF₃CHClCHClF affords the compound CF₃CH═

HF (HFO-1234ze).

32. The process of claim 22, wherein the dechlorination reaction also produces the compound CF₃CH═

CHCl as a by-product.

33. The process of claim 22, further comprising the step wherein the by-product compound CF₃CH═

CHCl is fluorinated with hydrogen fluoride and a fluorination catalyst to produce the compound CF₃CHClCHClF.

35. The process of claim 22, wherein the reactions are conducted in a continuous manner.