Conversion of 2-chloro-1,1,1,2-tetrafluoropropane to 2,3,3,3-tetrafluoropropene
View Patent ↗Described is a method for producing fluoropropenes of formula CF 3 CX═CX 2 wherein each X is F or H, at least one X is H, and at least one X is F, comprising pyrolyzing a hydrofluorochloropropane of formula CF 3 CXYCX 2 Y, wherein each X is F or H, at least one X is H, and at least one X is F, and one Y is Cl and the other Y is H, in the gas-phase in a reaction vessel, maintained at a temperature high enough to effect the pyrolysis of said hydrofluorochloropropane to said fluoropropene, wherein the selectivity for the production of the fluoropropene is at least 80%, in he absence of a catalyst.
1. A method for producing a fluoropropene of formula CF 3 CX═CX 2 wherein each X is F or H, at least one X is H, and at least one X is F, comprising:
pyrolyzing a hydrofluorochloropropane of formula CF 3 CXYCX 2 Y, wherein each X is F or H, at least one X is H, and at least one X is F, and one Y is Cl and the other Y is H, and where the hydrofluorochloropropane is not CF 3 CFClCH 3 , in the gas-phase in a reaction vessel, maintained at a temperature high enough to effect the pyrolysis of said hydrofluorochloropropane to said fluoropropene, wherein the selectivity for the production of the fluoropropene is at least 80%, in the absence of a catalyst.
2. The method of claim 1 wherein, said selectivity for the production of said fluoropropene is at least 80% after about 4 hours of continuous operation.
3. The method of claim 1 wherein, said selectivity for the production of said fluoropropene is at least 70% after about 12 hours of continuous operation.
4. The method of claim 1 wherein, the temperature of the reaction vessel is maintained in the range from about 500° C. to about 700° C.
5. The method of claim 1 , wherein said selectivity for the production of said fluoropropene is at least 85%.
6. The method of claim 1 , wherein the said hydrofluorochloropropane is preheated in a vaporizer at a temperature of from about 30° C. to about 100° C.
7. The method of claim 1 , wherein the said hydrofluorochloropropane fed to the reaction vessel further comprises an inert carrier gas.
8. The method of claim 7 wherein the inert carrier gas is chosen from nitrogen, argon, helium or carbon dioxide.
9. The method of claim 1 , wherein the temperature of the reaction vessel is maintained in the range from about 500° C. to about 650° C.
10. The method of claim 1 , wherein the hydrofluorochloropropane is selected from the group consisting of 1,1,1,2-tetrafluoro-3-chloropropane, 1,1,1,3-tetrafluoro-2-chloropropane, 1,1,1,3-tetrafluoro-3-chloropropane, 1,1,1,2,3-pentafluoro-2-chloropropane, 1,1,1,2,3-pentafluoro-3-chloropropane, 1,1,1,3,3-pentafluoro-2-chloropropane and 1,1,1,3,3-pentafluoro-3-chloropropane.
11. The method of claim 1 , wherein the hydrofluorochloropropane is 1,1,1,3-tetrafluoro-3-chloropropane.