Process for the production of chlorinated and/or fluorinated propenes
View Patent ↗The present invention provides one-step processes for the production of chlorinated and/or fluorinated propenes. The processes provide good product yield with low, e.g., less than about 20%, or even less than 10%, concentrations of residues/by-products. Advantageously, the processes may be conducted at low temperatures than 500° C. so that energy savings are provided, and/or at higher pressures so that high throughputs may also be realized. The use of catalysts or initiators may provide additional enhancements to conversion rates and selectivity, as may adjustments to the molar ratio of the reactants.
1. A one-step process for the production of chlorinated and/or fluorinated propenes comprising: reacting i) a chloroethylene or a chlorofluoroethylene having the formula CHCl═CX 2 wherein each X is independently Cl or F; and ii) a methane, chloromethane, fluoromethane or chlorofluoromethane having the formula CH 4-a-b Cl a F b , wherein a is 0-3 and b is 0-3 and 4-a-b is greater than 0, to provide at least one chlorinated and/or fluorinated propene, provided that when the chloroethylene is of the formula CHCl═CCl 2 and the chloromethane or fluoromethane is of the formula CH 3 Cl or CH 3 F, the process is carried out at a temperature of less than 400° C.
2. The process of claim 1 , wherein the chlorinated and/or fluorinated propene has the formula CCl c F 2-c ═CH—CH 3-e-f Cl e F f wherein c is 0-2, e is 0-3, and f is 0-3, and 3-e-f>=0.
3. The process of claim 1 , provided that when the chloroethylene or chlorofluoroethylene is of the formula CHCl═CClF or CHCl═CF 2 or the chloromethane or fluoromethane is not CHCl 3 or CH 3 F, the process carried out at a temperature of less than 500° C.
4. The process of claim 1 , wherein the process is carried out at ambient pressure or greater.
5. The process of claim 1 , wherein the reaction is carried out in the presence of one or more catalyst(s) and/or initiator(s).
6. The process of claim 5 , wherein the initiator comprises carbon tetrachloride, chlorine, hexachloroethane, benzotrichloride, hexachloroacetone or combinations of these.
7. The process of claim 1 , wherein the methane, chloromethane, fluoromethane or chlorofluoromethane and the chloroethylene or chlorofluoroethylene are provided in a ratio of CH 4-a-b Cl a F b /CHCl═CX 2 of greater than or equal to 0.5.
8. The process of claim 4 , wherein the CH 4-a-b Cl a F b /CHCl═CX 2 ratio is greater than or equal to 2.5.
9. The process of claim 1 , wherein the process is conducted in an adiabatic tubular reactor.
10. The process of claim 9 , wherein the reactor further makes use of a diluent to reduce the temperature within the reactor, wherein the diluent comprises an inert diluent, CH 4-a-b Cl a F b or combinations of these.
11. The process of claim 1 or 3 , wherein the pressure is at least 200 psig.
12. The process of claim 1 , wherein the pressure is greater than 15 psig and the process is carried out in the presence of a catalyst/initiator, and the catalyst/initiator comprises chlorine or carbon tetrachloride, utilized in amounts of from 50 ppm to 100000 ppm.
13. The process of claim 11 , the molar ratio of CH 4-a-b Cl a F b /CHCl═CX 2 is greater than 0.5, and the process is carried out in the presence of a catalyst or initiator.
14. The process of claim 13 , wherein the pressure is at least 300 psig, the molar ratio of CH 4-a-b Cl a F b /CHCl═CX 2 is greater than 2 and the catalyst or initiator comprises chlorine or carbon tetrachloride.
15. The process of claim 14 , wherein the pressure is at least 400 psig, the molar ratio of CH 4-a-b Cl a F b /CHCl═CX 2 is greater than about 2.5 and the catalyst or initiator comprises chlorine gas, hexachloroethane, benzotrichloride, hexachloroacetone, and/or carbon tetrachloromethane in an amount of from 5 ppm to 200000 ppm.
16. The process of claim 1 , further comprising exposing the reaction to pulse laser, UV/visible light and/or microwave discharge.
17. A process for preparing 1,3,3,3-tetrafluoroprop-1-ene (HFO-1234ze) comprising converting a chlorinated and/or fluorinated propene prepared by the process of claim 1 into 1,3,3,3-tetrafluoroprop-1-ene (HFO-1234ze).