Catalytic dehydrochlorination of hydrochlorofluorocarbons
View Patent ↗A dehydrochlorination process is disclosed. The process involves contacting R f CFClCH 2 X with a catalyst in a reaction zone to produce a product mixture comprising R f CF═CHX, wherein said catalyst comprises MY supported on carbon, and wherein R f is a perfluorinated alkyl group, X ═H, F, Cl, Br or I, M=K, Na or Cs, and Y═F, Cl or Br.
1. A dehydrochlorination process comprising contacting R f CFClCH 2 X with a catalyst in a reaction zone to produce a product mixture comprising R f CF═CHX, wherein said catalyst comprises an alkali metal halide salt represented by the formula MY which is supported on carbon, and wherein R f is a perfluorinated alkyl group, X═H, F, Cl, Br or I, M=K, Na or Cs, and Y═F, Cl or Br, and wherein the catalyst contains from about 5 wt % to about 40 wt % of alkali metal halide salt based on the total amount of alkali metal halide salt and carbon.
2. The dehydrochlorination process of claim 1 wherein the carbon is an activated carbon.
3. The dehydrochlorination process of claim 2 wherein the carbon is an acid washed activated carbon.
4. The dehydrochlorination process of claim 1 wherein M is K and Y is F or Cl.
5. The dehydrochlorination process of claim 1 wherein the temperature in the reaction zone is from about 200° C. to about 500° C.
6. The dehydrochlorination process of claim 5 wherein the temperature in the reaction zone is from about 320° C. to about 380° C.
7. The dehydrochlorination process of claim 1 wherein the product selectivity to R f CF═CHX is at least 90 mole %.
8. The dehydrochlorination process of claim 1 wherein the product selectivity to R f CF═CHX is at least 96 mole %.
9. The dehydrochlorination process of claim 1 wherein R f CFClCH 2 X is CF 3 CFClCH 2 Cl, and R f CF═CHX is CF 3 CF═CHCl.
10. The dehydrochlorination process of claim 1 wherein R f CFClCH 2 X is CF 3 CFClCH 3 , and R f CF═CHX is CF 3 CF═CH 2 .
11. The dehydrochlorination process of claim 1 , further comprising regenerating said catalyst by purging the catalyst with an inert gas.
12. The dehydrochlorination process of claim 11 wherein the inert gas is N 2 .
13. The dehydrochlorination process according to claim 1 where in the catalyst contains from about 10 wt % to about 30 wt % alkali metal halide salt based on the total amount of alkali metal halide salt and carbon.