Processes for selective dehydrohalogenation of halogenated alkanes
Disclosed are processes for producing halogenated olefins, and preferably tetrafluorinated propene(s), from one or more alkanes having both fluorine substituents and non-fluorine substituents, preferably with a high degree of conversion and selectivity. Preferably the process comprises the use of a catalyzed reaction in which the catalyst is selected from the group consisting of activated carbons halogenated mono- and di-valent metal oxides, mono- and di-valent Lewis acid metal halides, zero-valent metals, and combinations of these.
1. A process for the production fluorinated olefin having from three to six carbon atoms, a degree of non-fluorine halogen substitution of a N−1 and a degree of fluorine substitution of M, the process comprising:
exposing a fluorinated and chlorinated alkane having from two to six carbon atoms and a degree of non-fluorine halogen substitution of N and a degree of fluorine substitution of M to conditions effective to convert at least about 20% by weight of said alkane to said fluorinated olefin wherein the process is carried out in the presence of a catalyst comprising activated carbon having a total concentration of Al 3+ of greater than zero to less than 8000 ppm and a total concentration of Fe 3+ of greater than zero to less than 8000 ppm.
2. The process of claim 1 wherein said fluorinated olefins has the same number of carbon atoms as said alkane.
3. The process of claim 1 wherein said exposing step comprises conditions effective to convert at least about 50% by weight of said alkane to one or more olefins having a degree of non-fluorine halogen substitution of a N−1 and a degree of fluorine substitution of M.
4. The process of claim 1 wherein said exposing step comprises conditions effective to convert at least about 70% by weight of said alkane to one or more olefins having a degree of non-fluorine halogen substitution of a N−1 and a degree of fluorine substitution of M.
5. The process of claim 1 wherein said exposing step comprises conditions effective to convert at least about 80% by weight of said alkane to one or more olefins having a degree of non-fluorine halogen substitution of a N−1 and a degree of fluorine substitution of M.
6. The process of claim 1 wherein said exposing step comprises conditions effective to convert at least about 90% by weight of said alkane to one or more olefins having a degree of non-fluorine halogen substitution of a N−1 and a degree of fluorine substitution of M.
7. The process of claim 1 wherein said alkane is a compound in accordance with Formula (I) below:
CF 3 CHYCHFY (I),
where Y is H or a halogen other than F, provided that at least one of said Y is H.
8. The process of claim 7 wherein said one or more olefins comprises a compound of Formula (II):
CF 3 CX═CHX (II)
where one of said X is H and the other of said X is F.
9. The process of claim 8 wherein said exposing step comprises conditions effective to convert at least about 20% by weight of said compounds of Formula (I) to one or more compounds of Formula (II).
10. The process of claim 8 wherein said exposing step comprises conditions effective to convert at least about 50% by weight of said compounds of Formula (I) to one or more compounds of Formula (II).
11. The process of claim 8 wherein said exposing step comprises conditions effective to convert at least about 70% by weight of said compounds of Formula (I) to one or more compounds of Formula (II).
12. The process of claim 8 wherein said exposing step comprises conditions effective to convert at least about 80% by weight of said compounds of Formula (I) to one or more compounds of Formula (II).
13. The process of claim 8 wherein said exposing step comprises conditions effective to convert at least about 90% by weight of said compounds of Formula (I) to one or more compounds of Formula (II).
14. The process of claim 1 wherein said fluorinated olefin comprises a fluoropropene having from three to six fluorine substituents.
15. The process of claim 14 wherein said fluorinated olefin comprises hexafluorpropene.
16. The process of claim 14 wherein said fluorinated olefin comprises pentafluorpropene.
17. The process of claim 14 wherein said alkane comprises chlorotrifluorpropane (HCFC-244).
18. The process of claim 1 wherein said at least one or more fluorinated olefins comprises CFH═CFCF 3 .
19. The process of claim 1 wherein said alkane comprises HCFC-244fa.
20. The process of claim 19 wherein said at least one or more olefins comprises HFO-1234ze.
21. The process of claim 1 wherein said catalyst further comprises a metal-based catalyst.
22. The process of claim 21 wherein said metal-based catalyst is selected from the group consisting of halogentated mono- and di-valent metal oxides, mono- and di-valent Lewis acid metal halides, zero-valent metals, and combinations of these.
23. The process of claim 21 wherein said metal-based catalyst comprises a catalyst containing at least one transition metal contained in one or more of Group VIIIB, Group IB and Group IIB of the periodic table.
24. The process of claim 21 wherein said metal-based catalyst comprises a catalyst containing at least one alkali metal having an atomic number of from about 3 to about 56.
25. The process of claim 21 wherein said metal-based catalyst comprises a catalyst containing at least one alkali metal having an atomic number of from about 12 to about 56.
26. The process of claim 21 wherein said metal-based catalyst comprises a catalyst containing at least one transition metal having an atomic number of from about 26 to about 30.
27. The process of claim 21 wherein said metal-based catalyst is a zero valent metal based catalyst.
28. The process of claim 27 wherein said zero valent metal based catalyst comprises a catalyst containing at least one transition metal.
29. The process of claim 28 wherein said at least one transition metal comprises at least one transition metal contained in Group VIIIA and Group IB of the periodic table.
30. The process of claim 28 wherein said at least one transition metal comprises at least one transition metal having an atomic number of from about 26 to about 29.
31. The process of claim 28 wherein said at least one transition metal comprises at least one transition metal contained in Group VIII and Group IB of the periodic table and having an atomic number of from about 26 to about 29.
32. The process of claim 21 wherein said exposing step comprises exposing said alkane to catalyst selected from the group consisting of activated carbons and/or metal-based catalyst in which the metal(s) are in an oxidation state of 0, +1 or +2.