| 主权项 |
1. A method for preparing 1,1,3-Tetrafluorontopene (HFO-1234ze), characterized in that the method comprises the following steps:
(1) charging a reactor with a fluorination catalyst in two sections, wherein the first section of the fluorination catalyst is controlled at a temperature of 200-300° C., and the second section of the fluorination catalyst is controlled at a temperature of 350-450° C.; and (2) introducing a gasified HF with 1,1,1,3,3-pentachloropropane (HCC-240fa) and/or 1,1,3,3-tetrachloro-prop-1-ene (HCO- 1230za) into the reactor, passing through the first section of the fluorination catalyst and then through the second section of the fluorination catalyst, wherein a molar ratio of HF to the total organic phase is from 5:1 to 20:1, a contact time for the reaction is 1-30 seconds, and a reaction pressure is 0.1-1.2 MPa, forming a product stream; and (3) passing the product stream through a distillation tower; wherein:
a stream containing HFO-1234ze and HCl is formed at the top of the distillation tower and the stream is further treated to remove acid and water and distilled to produce HFO-1234ze;a material stream containing 1-chloro-3,3,3-trifluoropropene (HCFC-1233zd), 1,1,1,3,3-pentafluoropropane(HFC-245fa) and HF is formed in a pot at the bottom of the distillation tower; andthe pressure in the distillation tower is 0.1 -0.6 MPa, a temperature at the top of the tower is −30-10° C. and the temperature in the pot at the bottom of the distillation tower 40-80° C. |
