Dehydrofluorination of 245FA to 1234ZE

Abstract

A method of producing a fluoropropane fluoropropene of formula CF3CH═CHF, comprising contacting a mixture of 1,1,1,3,3-pentafluoropropane and Z-1,3,3,3-tetrafluoropropene in the gas phase with a catalyst comprising at least one catalyst selected from the group consisting of fluorinated Cr2O3 or Cr/Ni on fluoride alumina, in the presence of an oxygen containing gas, to form a mixture comprising Z-1,3,3,3-tetrafluoropropane Z-1,3,3,3-tetrafluoropropene, E-1,3,3,3,-tetrafluoropropene, hydrogen fluoride, and optionally unreacted 1,1,1,3,3-pentafluoropropane, separating the E-1,3,3,3-tetrafluoropropene from the Z-isomer and any unreacted 1,1,1,3,3-pentafluoropropane, if present, and recovering said E-1,3,3,3-tetrafluoropropene.

What is claimed is: 
     
       1. A method of producing a fluoropropane fluoropropene of formula CF 3 CH═CHF while suppressing additional production of Z-1,3,3,3-tetrafluoropropene, comprising: a) providing and contacting a starting feed mixture of 1,1,1,3,3-pentafluoropropane and at least 10% by weight Z-1,3,3,3-tetrafluoropropene to suppress its production in the gas phase with a catalyst comprising at least one catalyst selected from the group consisting of fluorinated Cr 2 O 3  or Cr/Ni on fluorided alumina, in the presence of an oxygen containing gas, to form a product mixture comprising Z-1,3,3,3-tetrafluoropropane Z-1,3,3,3-tetrafluoropropene, E-1,3,3,3,-tetrafluoropropene, hydrogen fluoride, and optionally unreacted 1,1,1,3,3-pentafluoropropane, b) separating the E-1,3,3,3-tetrafluoropropene from the Z-isomer and any unreacted 1,1,1,3,3-pentafluoropropane, if present, and c) recovering said E-1,3,3,3-tetrafluoropropene. 
     
     
       2. The method of  claim 1 , wherein said mixture of 1,1,1,3,3-pentafluoropropane and Z-1,3,3,3-tetrafluoropropene comprises at least 7% by weight Z-1,3,3,3-tetrafluoropropene. 
     
     
       3. The method of  claim 1 , wherein said mixture of 1,1,1,3,3-pentafluoropropane and Z-1,3,3,3-tetrafluoropropene comprises at least 10% by weight Z-1,3,3,3-tetrafluoropropene. 
     
     
       4. The method of  claim 1 , wherein at least 94% the isomeric selectivity of the conversion of the 1,1,1,3,3-pentafluoropropane is converted to E-isomer of 1,3,3,3-tetrafloropropene 1,3,3,3-tetrafluoropropene is at least 94 mol %. 
     
     
       5. The method of  claim 1 , wherein at least 98% the isomeric selectivity of the conversion of the 1,1,1,3,3-pentafluoropropane is converted to E-isomer of 1,3,3,3-tetrafloropropene 1,3,3,3-tetrafluoropropene is at least 98 mol %. 
     
     
       6. The method of  claim 1 , further comprising recovering Z-1,3,3,3-tetrafluoropropene, or a mixture of Z-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane, and recycling Z-1,3,3,3-tetrafluoropropene, or a mixture of Z-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane back to step a). 
     
     
       7. The process method of  claim 1 , wherein said hydrogen fluoride produced in step a) is separated and recovered. 
     
     
       8. The process method of step claim  1 , wherein said oxygen containing gas is oxygen, or air. 
     
     
       9. The method of claim 8, wherein said oxygen containing gas is oxygen. 
     
     
       10. The method of claim 9, further providing the E-1,3,3,3-tetrafluoropropene to a refrigerant system. 
     
     
       11. A method comprising: a) contacting a starting feed mixture of 1,1,1,3,3-pentafluoropropane and at least 10% by weight Z-1,3,3,3-tetrafluoropropene in the gas phase with a catalyst comprising at least one catalyst selected from the group consisting of fluorinated Cr 2 O 3  or Cr/Ni on fluorided alumina, in the presence of an oxygen containing gas in a reactor, to suppress additional formation of the Z-1,3,3,3-tetrafluoropropene and form a reactor product mixture comprising Z-1,3,3,3-tetrafluoropropene, E-1,3,3,3-tetrafluoropropene, hydrogen fluoride, and optionally unreacted 1,1,1,3,3-pentafluoropropane, b) separating the E-1,3,3,3-tetrafluoropropene from the Z-isomer and any unreacted 1,1,1,3,3-pentafluoropropane, if present, and c) recovering said E-1,3,3,3-tetrafluoropropene and providing the E-1,3,3,3-tetrafluoropropene to a refrigerant system. 
     
     
       12. The method of claim 11, the method including operating the refrigerant system, wherein the refrigerant system comprises the E-1,3,3,3-tetrafluoropropene. 
     
     
       13. The method of claim 1, wherein said mixture of 1,1,1,3,3-pentafluoropropane and Z-1,3,3,3-tetrafluoropropene comprises at least 11% by weight Z-1,3,3,3-tetrafluoropropene. 
     
     
       14. The method of claim 12, wherein the isomeric selectivity of the conversion of the 1,1,1,3,3-pentafluoropropane to E-isomer of 1,3,3,3-tetrafluoropropene is at least 94 mol %. 
     
     
       15. The method of claim 12, wherein the isomeric selectivity of the conversion of the 1,1,1,3,3-pentafluoropropane to E-isomer of 1,3,3,3-tetrafluoropropene is at least 98 mol %. 
     
     
       16. The method of claim 12, further comprising recovering Z-1,3,3,3-tetrafluoropropene, or a mixture of Z-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane, and recycling Z-1,3,3,3-tetrafluoropropene, or a mixture of Z-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane back to step a). 
     
     
       17. The process of claim 12, wherein said hydrogen fluoride produced in step a) is separated and recovered. 
     
     
       18. The process of claim 12, wherein said oxygen containing gas is oxygen, or air. 
     
     
       19. The method of claim 10, further comprising operating the refrigerant system, the refrigerant system comprising said E-1,3,3,3-tetrafluoropropene recovered. 
     
     
       20. The method of claim 1, wherein the isomeric selectivity of the 1,3,3,3-tetrafluoropropene as directly formed from the 1,1,1,3,3-pentafluoropropane is at least 99.7 mol % E-isomer. 
     
     
       21. The method of claim 11, wherein the isomeric selectivity of the 1,3,3,3-tetrafluoropropene as directly formed from the 1,1,1,3,3-pentafluoropropane is at least 99.7 mol % E-isomer. 
     
     
       22. The method of claim 1, wherein the contacting is conducted at a temperature held between 275° C. and 350° C. 
     
     
       23. The method of claim 11, wherein the contacting is conducted at a temperature held between 275° C. and 350° C. 
     
     
       24. The method of claim 1, wherein the product mixture includes a mole ratio of E-1,3,3,3-tetrafluoropropene to Z-1,3,3,3-tetrafluoropropene of about 5.7 to about 6. 
     
     
       25. The method of claim 11, wherein the product mixture includes a mole ratio of E-1,3,3,3-tetrafluoropropene to Z-1,3,3,3-tetrafluoropropene of about 5.7 to about 6.