Preparation of halo-olefin
View Patent ↗A process for preparing a halo-olefin to minimize one or more side reactions which form at least one impurity, said process comprising contacting a halogenated hydrocarbon with a metal dehalogenating agent dissolved in a solvent under conditions sufficient to dehalogenate said halogenated hydrocarbon to produce a product stream comprising said halo-olefin and at least one impurity, said metal dehalogenating agent having an average particle size within a range of average particle sizes, said impurity concentration of said product stream being essentially constant within said range and increasing significantly below said range.
1. A process for preparing a halo-olefin to minimize one or more side reactions which form at least one impurity, said process comprising: contacting a halogenated hydrocarbon with a metal dehalogenating agent dissolved in a solvent under conditions sufficient to dehalogenate said halogenated hydrocarbon to produce a product stream comprising said halo-olefin and at least one impurity, said metal dehalogenating agent having an average particle size within a range of average particle sizes, said impurity concentration of said product stream being essentially constant within said range and increasing significantly below said range.
2. The process of claim 1 , wherein the percentage yield of said halo-olefin in said product stream is essentially constant within said range and decreases substantially above said range.
3. The process of claim 1 , wherein an average particle size about 25% below the lower limit of said range increases the impurity concentration by at least a factor of 1.5 compared to the impurity concentration for said range.
4. The process of claim 1 , wherein an average particle size about 25% below the lower limit of said range results in essentially no increase in the formation of said halo-olefin.
5. The process of claim 2 , wherein an average particle size greater than about 25% above the upper limit of said range decreases the yield of said halo-olefin in said product stream by at least about 5%.
6. The process of claim 1 , wherein said impurity is formed in a multi-step side reaction.
7. The process of claim 1 , wherein the lower limit of said range is greater than about 5 microns.
8. The process of claim 2 , wherein the upper limit of said range is about 9 microns.
9. The process of claim 1 , wherein said range is about 7 to about 8 microns.
10. The process of claim 1 , wherein said halogenated starting material is selected from the group consisting of trichlorotrifluoroethane (CFC-113), trichloroethane, dichlorodifluoroethane, and dichlorotetrafluoroethane.
11. The process of claim 1 , wherein said halogenated starting material is trichlorotrifluoroethane.
12. The process of claim 1 , wherein said halo-olefin is selected from the group consisting of chlorotrifluoroethylene, vinyl chloride, difluoroethylene, and tetrafluoroethylene.
13. The process of claim 1 , wherein said halo-olefin is chlorotrifluoroethylene.
14. The process of claim 1 , wherein said dehalogenating agent is selected from the group consisting of tin, magnesium, iron, zinc, and aluminum.
15. The process of claim 1 , wherein said dehalogenating agent is zinc.
16. The process of claim 1 , wherein said impurity is HFC-1123.
17. A process for preparing CFC 113 to minimize one or more side reactions producing at least HFC-1123, said process comprising: contacting a CFC 113 with zinc particles dissolved in a solvent under conditions sufficient to dehalogenate said CFC 113 to produce CTFE 1113, said zinc particles having an average particle size of greater than about 5 microns to about 9 microns.
18. The process of claim 17 , wherein said zinc particles have an average particle size of about 7 to about 8 microns.