NOVEL METHOD FOR FLUORINATING CHLOROALKANES

1 . A method for fluorinating an alkane substrate comprising contacting in the vapor phase said alkane substrate with a fluoroalkane in the presence of a fluorination catalyst at an elevated temperature to effect fluorination of said alkane substrate in the absence of HF or other fluorinating agent in the presence or absence of oxygen.

2 . The method of claim 1 wherein the catalyst is selected from chrome oxide, fluorinated chrome oxide, aluminum oxide, fluorinated aluminum oxide and chrome halide.

3 . The method of claim 2 wherein the catalyst is supported on carbon or on aluminum fluoride.

4 . The method of claim 1 wherein the catalyst is chrome oxide or fluorinated chrome oxide.

5 . The method of claim 1 wherein the catalyst is chrome halide and the catalyst is supported on aluminum oxide or carbon.

6 . The method of claim 1 , wherein said catalyst is Cr 2 O 3 , Cr 2 O 3 /Al 2 O 3 , Cr 2 O 3 /AlF 3 , CrCl 3 karbon, 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 , or mixtures thereof.

7 . The method of claim 5 wherein one or more alkali metal, alkaline earth metal, transition metal or a combination thereof are additionally present.

8 . The method of claim 1 wherein the catalyst is a chrome catalyst that is optionally doped with sodium.

9 . The method of claim 1 , wherein the fluorocarbon has the formula: (R1)CF(R3)(R2), where R1 and R2 are independently fluorinated alkyl having 1 to 8 carbon atoms or hydrogen, and R3 is hydrogen or fluorine.

10 . The method of claim 8 , wherein R1 and R2 have 1-3 carbon atoms.

11 . The method of claim 1 , wherein the fluorocarbon is R1CF 2 H, or R1CH 2 F, or R1CF 2 R2, R1CHFR2, or R1CHFCH 2 R2, or R1CHFCHFR2, or R1CHFCF 2 R2, or R1CF2CH2R2, or R1CF 2 CHFR2, or R1CF 2 CF 2 R2, or R1CH 2 CHFR2 or R1CH 2 CF 2 R2.

12 . The method of claim 1 , wherein the molar ratio of alkane substrate to fluoroalkane ranges from about 0.1 to about 10.

13 . The method of claim 1 , wherein the molar ratio of alkane substrate to fluoroalkane ranges from about 0.5 to about 5.

14 . The method of claim 1 , wherein the temperature for the fluorination ranges from about 150° C. to about 400° C.

15 . The method of claim 9 , wherein the fluorination is effected at a temperature in the range of from about 200° C. to about 350° C.

16 . The method of claim 1 , wherein an inert gas is additionally present.

17 . The method of claim 15 , wherein the inert gas is nitrogen, helium or argon.

18 . The method according to claim 1 , wherein the fluorination is conducted at a pressure ranging from about 0 to about 100 psig.

19 . The method according to claim 13 , wherein the fluorination is conducted at a pressure ranging from about 10 to about 80 psig.

20 . The method of claim 1 , wherein the alkane substrate is 1,1,1-trifluoro-2,3-dichloropropane, 1,1,1-trifluoro-3,3-dichloropropane, 1,1,1-trifluoro-2,2-dichloropropane or 1,1-difluoro-1,2,3-trichloropropane.

21 . The method of claim 1 having a contact time of said fluorination catalyst with said alkane substrate and said fluoroalkane ranges from about 1 second to about 20 min.

22 . The method of claim 20 wherein the contact time ranges from about 2 seconds to about 15 minutes.

23 . The method of claim 21 wherein the contact time ranges from about 5 seconds to about 10 minutes.

24 . The method of claim 4 wherein the chrome oxide or fluorinated chrome oxide is mixed with zinc.

25 . A method of preparing 2,3,3,3-tetrafluoropropene which comprises (a) fluorinating 1,1,1-trifluoro-2,3-dichloropropane with a fluorocarbon in accordance with the method of any one of claims 1 - 14 and isolating the 1,1,1,2-tetrafluoro-3-chloropropane produced therefrom and (b) dehydrochlorinating the 1,1,1,2-tetrafluoro-3-chloropropane to produce 2,3,3,3-tetrafluoropropene.