Selective catalytical dehydrochlorination of hydrochlorofluorocarbons
View Patent ↗A dehydrochlorination process is disclosed. The process involves contacting R f CHClCH 2 Cl with a chromium oxyfluoride catalyst in a reaction zone to produce a product mixture comprising R f CCl═CH 2 , wherein R f is a perfluorinated alkyl group.
1. A dehydrochlorination process comprising contacting R f CHClCH 2 Cl with a dehydrochlorination catalyst in a reaction zone to produce a product mixture comprising R f CCl═CH 2 , wherein R f is a perfluorination alkyl group and wherein the dehydrochlorination catalyst is chromium oxyfluoride having the formula Cr 2 O x F y , wherein x+y/2=3, optionally in the presence of HF.
2. The dehydrochlorination process of claim 1 wherein the dehydrochlorination process is conducted in the presence of HF.
3. The dehydrochlorination process of claim 1 wherein R f is CF 3 .
4. The dehydrochlorination process of claim 1 wherein the temperature in the reaction zone is from about 200° C. to about 500° C.
5. The dehydrochlorination process of claim 4 wherein the temperature in the reaction zone is from about 275° C. to about 450° C.
6. The dehydrochlorination process of claim 1 wherein the product selectivity to R f CCl═CH 2 is at least 90 mole %.
7. The dehydrochlorination process of claim 1 wherein the product selectivity to R f CCl═CH 2 is at least 95 mole %.
8. The dehydrochlorination process of claim 1 wherein an inert gas is additionally present.
9. The dehydrochlorination process according to claim 2 wherein the mole ratio of HF to R f CHClCH 2 Cl in the reaction zone is no more than 0.9.
10. The dehydrochlorination process of claim 9 conducted in the presence of HF, wherein the mole ratio of HF to R f CHClCH 2 Cl in the reaction zone is no more than 0.5.
11. The dehydrochlorination process of claim 10 wherein the mole ratio of HF to R f CHClCH 2 Cl in the reaction zone is no more than 0.1.
12. The dehydrochlorination process of claim 1 wherein the dehydrochlorination process is conducted in the absence of HF.
13. The dehydrochlorination process according to claim 1 wherein the chromium oxyfluoride catalyst has a surface area of about 10 m 2 /g to about 800 m 2 /g.
14. The dehydrochlorination process according to claim 13 wherein the chromium oxyfluoride catalyst has a surface area of about 20 m 2 /g to about 400 m 2 /g.
15. The dehydrochlorination process according to claim 14 wherein the chromium oxyfluoride catalyst has a surface area of about 40 m 2 /g to about 300 m 2 /g.