Integrated process to co-produce trans-1-chloro-3,3,3-trifluoropropene and trans-1,3,3,3-tetrafluoropropene
View Patent ↗The disclosed integrated manufacturing process includes a combined liquid phase reaction and purification operation which directly produces trans-1-chloro-3,3,3-trifluoropropene and 3-chloro-1,1,1,3-tetrafluoropropane which is a precursor to the manufacture of trans-1,3,3,3-tetrafluoropropene. The mixture of co-products is easily separated by conventional distillation and 3-chloro-1,1,1,3-tetrafluoropropane is then dehydrochlorinated to produce trans-1,3,3,3-tetrafluoropropene by contacting in the liquid phase with a caustic solution or in the vapor phase using a dehydrochlorination catalyst.
1. A process for the formation of trans-1-chloro-3,3,3-trifluoropropene and trans-1,3,3,3-tetrafluoropropene comprising the steps of:
(a) reacting 1,1,1,3,3-pentachloropropane, 1,1,3,3-tetrachloropropene, or 1,3,3,3-tetrachloropropene, alone or in combination, with hydrogen fluoride in the presence of a fluorination catalyst to co-produce greater than about 50% yield of trans-1-chloro-3,3,3-trifluoropropene and 3-chloro-1,1,1,3-tetrafluoropropane; and
(b) dehydrohalogenating the 3-chloro-1,1,1,3-tetrafluoropropane formed in step (a) to produce greater than about 50% yield of trans-1,3,3,3-tetrafluoropropene and/or trans-1-chloro-3,3,3-trifluoropropene.
2. The process of claim 1 , wherein dehydrohalogenation reaction is dehydrochlorination reaction.
3. The process of claim 1 , wherein dehydrohalogenation reaction is dehydrofluorination reaction.
4. The process of claim 1 , wherein the dehydrohalogenation reactions of step (b) take place in the liquid phase by contact with a caustic solution.
5. The process of claim 1 , wherein the dehydrohalogenation reactions of step (b) occur in the vapor phase using a dehydrohalogenation catalyst.
6. The process of claim 1 , wherein the dehydrohalogenation step (b) further produces hydrogen chloride and hydrogen fluoride.
7. The process of claim 1 , wherein the dehydrohalogenation catalyst is selected from metal halides, halogenated metal oxides, neutral (or zero oxidation state) metals or metal alloys, or activated carbon in bulk or supported form or mixtures of thereof.
8. The process of claim 7 , wherein the dehydrohalogenation catalyst is selected from mono-, bi-, or tri-valent metal oxides, halogenated metal oxides supported or bulk or mixtures of thereof.
9. The process of claim 7 , wherein dehydrohalogenation catalyst is selected from the list of CsCl/MgF 2 , KCl/MgF 2 , CsCl/MgO, KCl/MgO, CsCl/MgCl 2 , KCl/MgCl 2 , Al 2 O 3 , AlCl 3 , FeCl 3 , Cr 2 O 3 , CrO x F 3-2x .
10. The process of claim 1 , wherein the reactions of step (a) take place in a liquid phase reactor with excess hydrogen fluoride.
11. The process of claim 10 , wherein the reactions are run using a relatively weak fluorination catalyst selected from the group consisting of TiCl 4 , SnCl 4 , TaCl 5 , SbCl 3 , AlCl 3 , SbCl 5 , and mixtures thereof.
12. The process of claim of claim 11 , wherein the catalyst is partially fluorinated.
13. The process of claim of claim 11 , wherein the catalyst is totally fluorinated.
14. The process of claim 1 , wherein the process allows for flexibility in producing different amounts of each compound, simply by adjusting one or more of the following; operating conditions; concentrations of reactants; and catalyst employed in the steps (a) and/or (b).
15. An integrated manufacturing process comprising combined liquid phase reaction and purification operation for the production of trans-1-chloro-3,3,3-trifluoropropene and 3-chloro-1,1,1,3-tetrafluoropropane comprising the steps of:
(a) reacting 1,1,1,3,3-pentachloropropane, 1,1,3,3-tetrachloropropene, or 1,3,3,3-tetrachloropropene, alone or in combination, with anhydrous HF in excess in a liquid-phase catalyzed reactor, thereby producing greater than about 50% yield of trans-1-chloro-3,3,3-trifluoropropene and 3-chloro-1,1,1,3-tetrafluoropropane; and
(b) separating the compounds produced in step (a).
16. The process of claim 15 , which further comprises the step of dehydrohalogenating the 3-chloro-1,1,1,3-tetrafluoropropane to produce trans-1,3,3,3-tetrafluoropropene and 1-chloro-3,3,3-trifluoropropene.
17. The process of claim 16 , wherein the dehydrohalogenation step further produces hydrogen chloride and hydrogen fluoride.
18. The process of claim 17 , wherein the dehydrohalogenation step occurs in the liquid phase by contact with a caustic solution.
19. The process of claim 17 , wherein the dehydrohalogenation step occurs in the vapor phase using a dehydrohalogenation catalyst.
20. The process of claim 1 , wherein at least 50% 3-chloro-1,1,1,3-tetrafluoropropane is formed in step (a).
21. The process of claim 1 , wherein at least 40% trans-1-chloro-3,3,3-trifluoropropane is formed in step (a).
22. The process of claim 1 , wherein at least 50% trans-1-chloro-3,3,3-trifluoropropene is formed in step (b).
23. The process of claim 1 , wherein at least 50% trans-1,3,3,3-tetra-fluoropropene is formed in step (b).