Method for producing 2-chloro-3,3,3,-trifluoropropene (HCFC-1233xf)
View Patent ↗The present invention relates to an improved method for manufacturing 2-chloro-3,3,3-trifluoropropene, (HCFC-1233xf) by reacting 1,1,2,3-tetrachloropropene, 1,1,1,2,3-pentachloropropane, and/or 2,3,3,3-tetrachloropropene with hydrogen fluoride, in a vapor phase reaction vessel in the presence of a vapor phase fluorination catalyst and stabilizer. HCFC-1233xf is an intermediate in the production of 2,3,3,3-tetrafluoropropene (HFO-1234yf) which is a refrigerant with low global warming potential.
1. A method of preparing a tetrahalopropene comprising contacting at least one chlorocarbon selected from the group consisting of hydrofluortetrachloropropene and pentachloropropane with a halogenating agent in the presence of at least one catalyst and at least one stabilizer under conditions effective to produce a tetrahalopropene wherein the stabilizer is selected from the group consisting of an amine stabilizer, a hydroquinone stabilizer, a methoxy-hydroquinone, a triethylamine, a di-isopropyl amine, a butylated hydroxyl anisole (BHA), and combinations thereof and wherein said reaction mixture produces a tetrahalopropene.
2. The method of claim 1 wherein said tetrahalopropene comprises 2-chloro-3,3,3,-trifluoropropene.
3. The method of claim 2 wherein said chlorocarbon is at least one compound selected from the group consisting of 1,1,2,3-tetrachloropropene, 2,3,3,3-tetrachloropropene, 1,1,1,2,3-pentachloropropane and combinations of any two or more of these.
4. The method of claim 1 wherein said halogenating agent is a fluorinating agent.
5. The method of claim 4 wherein said fluorinating agent comprises hydrogen fluoride.
6. The method of claim 1 wherein at least a portion of said contacting step is conducted at a temperature of from about 80° C. to about 400° C.
7. The method of claim 1 wherein at least a portion of said contacting step is conducted at a pressure of from about 5 torr to about 150 psig.
8. The method of claim 1 wherein said contacting step comprises conducting at least a portion of said contacting step in the gas phase.
9. The method of claim 1 wherein said catalyst comprises at least one fluorination catalyst.
10. The method of claim 9 where the at least one fluorination catalyst is selected from the group consisting of Cr 2 O 3 , FeCl 3 /C, Cr 2 O 3 , Cr 2 O 3 /Al 2 O 3 , Cr 2 O 3 /AlF 3 , Cr 2 O 3 /carbon, CoCl 2 /Cr 2 O 3 /Al 2 O 3 , NiCl 2 /Cr 2 O 3 /Al 2 O 3 , CoCl 2 /AlF 3 , NiCl 2 /AlF 3 and combinations thereof.
11. The method of claim 9 wherein at least one fluorination catalyst comprises Cr 2 O 3 .
12. The method of claim 1 wherein said stabilizer comprises an amine stabilizer.
13. The method of claim 1 wherein said stabilizer comprises a hydroquinone stabilizer.
14. The method of claim 1 wherein said stabilizer is selected from the group consisting of p-tap(4-tert-Amylphenol), methoxy-hydroquinone, 4-methoxyphenol (HQMME), triethylamine, di-isopropyl amine, butylated hydroxy anisole (BHA), thymol and combinations thereof.
15. The method of claim 12 wherein said stabilizer comprises triethylamine.
16. The method of claim 12 wherein said stabilizer comprises di-isopropyl amine.
17. The method of claim 13 wherein said stabilizer comprises methoxy-hydroquinone.
18. The method of claim 13 wherein said stabilizer comprises 4-methoxyphenol (HQMME).
19. The method of claim 14 wherein said stabilizer comprises p-tap.
20. The method of claim 1 wherein the concentration of said stabilizer is less than about 300 ppm.
21. The method of claim 20 wherein the concentration of said stabilizer is less than about 100 ppm.
22. The method of claim 21 wherein the concentration of said stabilizer is about 10 ppm or less.