Process for the production of chlorinated propenes
Processes for the production of chlorinated propenes are provided. The processes make use of 1,2-dichloropropane as a starting material and subject a feedstream comprising the same to an ionic chlorination process. At least a portion of any tri- and tetrachlorinated propanes not amenable to ionic chlorination conditions are removed from the ionic chlorination product stream, or, are subjected to chemical base dehydrochlorination step. In this way, recycle of intermediates not amenable to ionic chlorination reactions is reduced or avoided, as is the buildup of these intermediates within the process. Selectivity and, in some embodiments, yield of the process is thus enhanced.
1. A process for the production of chlorinated propanes and/or propenes from a feedstream comprising 1,2-dichloropropane and comprising an ionic chlorination step, wherein the ionic chlorination step produces a product stream comprising 1,2,3-trichloropropane that is subjected to a separation step to provide a second product stream comprising at least a portion of the 1,2,3-trichloropropane and either removing the second product stream from the process or subjecting the second product stream to a first chemical base dehydrochlorination step.
2. The process of claim 1 , wherein the ionic chlorination step is conducted in the presence of a catalyst comprising aluminum chloride, ferric chloride, iodine, sulfur, iron, antimony pentachloride, boron trichloride, one or more lanthanum halides, and one or more metal triflates or a combination of these.
3. The process of claim 1 , wherein the ionic chlorination product stream further comprises 1,2,2,3-tetrachloropropane.
4. The process of claim 1 , wherein the ionic chlorination product stream comprises trichloropropanes, tetrachloropropanes, and pentachloropropanes.
5. The process of claim 4 , wherein the ionic chlorination product stream and second product stream further comprise 1,2,2,3-tetrachloropropane.
6. The process of claim 1 , wherein the first chemical base dehydrochlorination step produces a mixture comprising di- and trichloropropenes.
7. The process of claim 6 , wherein the chloropropenes are subjected to a further chlorination step to provide a mixture comprising tetra- and pentachloropropanes.
8. The process of claim 7 , wherein the further chlorination step is conducted in the same reactor as the ionic chlorination step.
9. The process of claim 7 , wherein the further chlorination step is conducted in a separate reactor without a catalyst or with a free radical initiator comprising one or more azo compounds and/or peroxide compounds, UV light, or combinations of these.
10. The process of claim 4 , wherein the pentachloropropanes are separated, purified and subjected to a second dehydrochlorination step.
11. The process of claim 10 , wherein the second dehydrochlorination step is conducted using one or more basic chemicals comprising caustic soda, pottasium hydroxide, calcium hydroxide or a combination of these.
12. The process of claim 11 , wherein the process comprises a further dehydrochlorination step, conducted catalytically.
13. The process of claim 12 , wherein the catalyst comprises a Lewis acid catalyst.
14. The process of claim 12 , wherein the catalyst comprises aluminum chloride, ferric chloride, iodine, sulphur, iron, antimony pentachloride, boron trichloride, one or more lanthanum halids, and one or more metal triflates or a combination of these.
15. The process of claim 1 , further comprising the use of C 12 , SO 2 C 12 or combinations of these as a chlorinating agent.
16. The process of claim 1 , wherein one or more components of the feedstream is generated for use in the process.
17. A process for preparing 2,3,3,3-tetrafluoroprop-1-ene or 1,3,3,3-tetrafluoroprop-1-ene comprising converting a chlorinated propene prepared by the process of claim 1 into 2,3,3,3-tetrafluoroprop-1-ene or 1,3,3,3-tetrafluoroprop-1-ene.