E-1-chloro-3,3,3-trifluoropropene production process from 1,1,3,3-tetrachloropropene
View Patent ↗A production process for the production of E-1-chloro-3,3,3-trifluoropropene, the process including at least one stage during which 1,3,3,3-tetrachloropropene reacts with anhydrous hydrofluoric acid in the liquid phase, in the absence of a catalyst, with an HF/1,1,3,3-tetrachloropropene molar ratio between 3 and 20 inclusive, at a temperature between 50° C. and 150° C. inclusive and an absolute pressure of between 1 and 20 bar inclusive.
1. A production process for the production of E-1-chloro-3,3,3-trifluoropropene, the process comprising:
(i) at least one stage during which 1,1,3,3-tetrachloropropene reacts with anhydrous hydrofluoric acid in the liquid phase in a reactor equipped with a drain and an effluent outlet; wherein HF and recoverable organic compounds are collected in the reactor drain, treated by at least one of decantation and azeotropic distillation, and recycled back to the same reactor;
(ii) at least one stage for treating the effluent from the reactor in order to provide a flow A that comprises E-1-chloro-3,3,3-trifluoropropene, HCl, HF and Z-1-chloro-3,3,3-trifluoropropene and a flow B that comprises at least 50% HF in weight;
(iii) at least one stage for recovering the hydrochloric acid from flow A, the hydrochloric acid being in flow C and flow D that includes E-1-chloro-3,3,3-trifluoropropene, HCl, HF and Z-1-chloro-3,3,3-trifluoropropene;
(iv) at least one stage for purifying flow D from stage (iii) in order to purify the E-1233zd to a level higher than or equal to 98% in weight.
2. The production process of claim 1 , wherein before the purification stage (iv), the flow D from stage (iii) is subjected to at least one separation phase in order to provide a flow E that comprises at least 50% HF in weight that can be recycled to the reactor and a flow F that comprises E-1-chloro-3,3,3-trifluoropropene, HCl, HF and Z-1-chloro-3,3,3-trifluoropropene.
3. The production process of claim 2 , wherein the separation stage is by decantation, initiated at a temperature between −50° C. and 50° C.
4. The production process of claim 1 , wherein the treatment stage (ii) involves a reflux column, initiated at a temperature between 30° C. and 120° C. in order to provide the flow B which is recycled to the reactor.
5. The production process of claim 1 , wherein the recovery of HCl in stage (iii) is obtained using a distillation column equipped with a reboiler at the bottom and a reflux system at the top.
6. The production process of claim 5 , wherein the temperature at the bottom is between 20° C. and 110° C. and the temperature at the top is between −50 and 0° C.
7. The production process of claim 1 , wherein the purification stage (iv) comprises at least one distillation stage.
8. The production process of claim 1 , wherein, in the reactor, the HF/1,1,3,3-tetrachloropropene molar ratio is between 5 and 15.
9. The production process of claim 1 , wherein reaction temperature is between 80° C. and 120° C.
10. The production process of claim 1 , wherein the fluorination reaction is initiated at a pressure between 5 and 15 bar.
11. The production process of claim 1 , wherein the fluorination reaction is initiated in an unstirred reactor.
12. The production process of claim 1 , wherein 1,1,3,3-tetrachloropropene reacts with anhydrous hydrofluoric acid in the liquid phase in a single reactor equipped with a drain and an effluent outlet.