Process for catalytic conversion of mixtures of HCFO-1233zd(Z) and HCFC-244fa into HCFO-1233zd(E)
A method for conversion of a composition containing HCFO-1233zd(Z) and HCFC-244fa to form HCFO-1233zd(E) by reacting a mixture including HCFO-1233zd(Z) and HCFC-244fa in a vapor phase in the presence of a catalyst to simultaneously isomerize HCFO-1233zd(Z) to form HCFO-1233zd(E) and dehydrohalogenate HCFC-244fa to form HCFO-1233zd(E). The catalyst may be a chromium-based catalyst such as chromium trifluoride, chromium oxyfluoride, or chromium oxide, for example.
1. A method for the simultaneous conversion of a composition containing (Z)-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(Z)) and 1 chloro-1,3,3,3-tetrafluoropropane (HCFC-244fa) to form (E)-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E)), comprising the steps of:
providing a composition including HCFO-1233zd(Z) and HCFC-244fa; and
reacting the composition in a vapor phase in a reactor in the presence of a chromium trifluoride (CrF 3 ) catalyst at a temperature between 80° C. and 250° C. and at a pressure above 0 psig to simultaneously isomerize HCFO-1233zd(Z) to form HCFO-1233zd(E) and dehydrohalogenate HCFC-244fa to form HCFO-1233zd(E).
2. The method of claim 1 , wherein the reacting step is conducted at a temperature between between 100° C. and 200° C.
3. The method of claim 2 , wherein the reacting step is conducted at a temperature between between 125° C. and 175° C.
4. The method of claim 1 , wherein a contact time between the composition and the catalyst is between 1 second and 150 seconds.
5. The method of claim 4 , wherein a contact time between the composition and the catalyst is between 25 seconds and 125 seconds.
6. The method of claim 1 , wherein a pressure in the reactor is between 0 psig and 100 psig.
7. The method of claim 1 , wherein during the reacting step, the reactor includes less than 50 ppm water.
8. The method of claim 1 , wherein the reacting step achieves a conversion of HCFO-1233zd(Z) to HCFO-1233zd(E) between 88% and 96%.
9. The method of claim 1 , wherein the reacting step achieves a conversion of HCFC-244fa to HCFO-1233zd(E) between 90% and 99%.
10. The method of claim 1 , wherein the reacting step achieves a selectivity to HCFO-1233zd(E) between 90% and 97%.
11. The method of claim 1 , wherein in the providing step, any compounds other than HCFO-1233zd(Z) and HCFC-244fa are present in an amount less than 10 wt. %, based on the total weight of the composition.
12. The method of claim 1 , wherein in the providing step, any compounds other than HCFO-1233zd(Z) and HCFC-244fa are present in an amount less than 6 wt. %, based on the total weight of the composition.
13. The method of claim 1 , wherein in the providing step, any compounds other than HCFO-1233zd(Z) and HCFC-244fa are present in an amount less than 1.5 wt. %, based on the total weight of the composition.
14. The method of claim 1 , wherein any of HCFC-243fa or HCFC-243db, if present in the composition, is present in an amount less than 3 wt. % based on the total weight of the composition.
15. The method of claim 1 , further comprising, after the reacting step, the additional steps of:
distilling the composition in a distillation column;
removing an overhead stream from the distillation column, the overhead stream concentrated in HCFO-1233zd(E); and
removing a bottoms stream from the distillation column, the bottoms stream concentrated in HCFO-1233zd(Z) and HCFC-244fa.
16. The method of claim 15 , further comprising, after the second removing step, the additional step of recycling the bottoms stream back to the reactor.