Selective catalytic dehydrochlorination of hydrochlorofluorocarbons
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 catalyst consisting of chromium oxyfluoride catalyst in a reaction zone at a temperature of about 200° C. to about 500° C. for a contact time of about 5 seconds to about 150 seconds to produce a product mixture comprising R f CCl═CH 2 , wherein R f is a perfluorination alkyl group.
2. The dehydrochlorination process of claim 1 , wherein the temperature is about 275° C. to about 450° C.
3. The dehydrochlorination process of claim 2 , wherein the temperature is about 300° C. to about 400° C.
4. The dehydrochlorination process of claim 1 , wherein the contact time is about 10 seconds to about 100 seconds.
5. The dehydrochlorination process of claim 1 further comprising feeding the R f CHClCH 2 Cl to a reactor containing the chromium oxyfluoride in the reaction zone.
6. The dehydrochlorination process of claim 5 further comprising feeding HF to the reactor.
7. The dehydrochlorination process of claim 6 , wherein a mole ratio of feeding HF to feeding R f CHClCH 2 Cl is about 5:1 to about 25:1.
8. The dehydrochlorination process of claim 6 , wherein a mole ratio of feeding HF to feeding R f CHClCH 2 Cl is about 0.9:1 or less.
9. The dehydrochlorination process of claim 5 further comprising feeding an inert gas to the reactor.
10. The dehydrochlorination process of claim 5 , wherein the reactor comprises a reactor tube.
11. The dehydrochlorination process of claim 1 , wherein R f is CF 3 .
12. The dehydrochlorination process of claim 1 , wherein the product selectivity to R f CCl═CH 2 is at least 90 mole %.
13. The dehydrochlorination process of claim 12 , wherein the product selectivity to R f CCl═CH 2 is at least 95 mole %.
14. The dehydrochlorination process of claim 1 , wherein the dehydrochlorination selectivity to R f CCl═CH 2 is at least 95 mole %.
15. The dehydrochlorination process of claim 14 , wherein the dehydrochlorination selectivity to R f CCl═CH 2 is at least 99 mole %.
16. The dehydrochlorination process of claim 1 , wherein the chromium oxyfluoride has the formula Cr 2 O x F y , wherein x+y/2=3.
17. The dehydrochlorination process of claim 1 , wherein the chromium oxyfluoride comprises an alkali metal content of about 2000 ppm or less and a surface area of from about 10 m 2 /g to about 800 m 2 /g.