Method for co-production of 1-chloro-3,3,3-trifluoropropene, 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene

A method for co-production of 1-chloro-3,3,3-trifluoropropene, 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene, the method comprising:

• (a) preheating and then directing hydrogen fluoride and 1,1,1,3,3-pentachloropropane into a first reactor in a molar ratio of 9:1-15:1, wherein the first reactor comprises an upper section filled with an aluminum oxide supported chromium metal catalyst and a lower section filled with a chromic oxide supported indium metal catalyst, wherein the hydrogen fluoride and the 1,1,1,3,3-pentachloropropane are reacted in the upper section of the first reactor at a temperature of 200-400° C. and at an air flow rate of 300-1,000 h−1, and a product from the upper section enters the lower section of the first reactor to continuously react with the 1,1,2,3-tetrachloropropane to obtain a first reaction product of the first reactor, wherein a molar ratio of the 1,1,2,3-tetrachloropropane to the hydrogen fluoride in the lower section of the first reactor is 3:9-5:9;
• (b) directly directing the first reaction product of the first reactor into a second reactor to perform a reaction catalysed by a catalyst at a temperature of 250-450° C. and at an air flow rate of 500-1,500 h−1 to obtain a second reaction product of the second reactor;
• (c) separating the second reaction product of the second reactor in a hydrogen chloride tower to obtain a first tower bottom fraction and a first tower top fraction, which is hydrogen chloride that is refined to obtain hydrochloric acid;
• (d) removing hydrogen fluoride and hydrogen chloride from the first tower bottom fraction of the hydrogen chloride tower by sequentially passing the first tower bottom fraction through a water washing tower, an alkaline washing tower and a drying tower to obtain a substance;
• (e) directing the substance into a first rectifying tower to obtain a second tower bottom fraction and a second tower top fraction;
• (f) directing the second tower bottom fraction of the first rectifying tower into a second rectifying tower to obtain 1-chloro-3,3,3-trifluoropropene and a third tower top fraction;
• and
• (g) directing the second tower top fraction of the first rectifying tower into a third rectifying tower to obtain 2,3,3,3-tetrafluoropropene at the top of the third rectifying tower and 1,3,3,3-tetrafluoropropene at the bottom of the third rectifying tower.