Device and method for continuously rectifying and purifying trifluoromethanesulfonyl fluoride

Abstract

The invention provides a device for continuously rectifying and purifying trifluoromethanesulfonyl fluoride. The device comprises a first fluid conveying device, the discharge port of the first fluid conveying device is connected with a light component removal tower, the upper part of the light component removal tower is connected with a hydrogen fluoride cooler, the bottom of the light component removal tower is connected with a heavy component removal tower, and the discharge port of the heavy component removal tower is connected with a fine product tank; the invention also provides a method for continuously rectifying and purifying trifluoromethanesulfonyl fluoride by adopting the device, which comprises the following steps: introducing an electrolytic product of methanesulfonyl fluoride and cooled hydrogen fluoride into the light component removal tower for rectification, producing light component impurities at the top of the light component removal tower, and producing a bottom product at the bottom of the light component removal tower; one part of the bottom product flows back to the light component removal tower, the rest part of the bottom product is introduced into the heavy component removal tower, methylsulfonyl fluoride is introduced into the heavy component removal tower, fine trifluoromethylsulfonyl fluoride is produced at the top of the heavy component removal tower, and impurities are produced at the bottom of the heavy component removal tower. The trifluoromethanesulfonyl fluoride obtained through the method has high purity, the method is easy to operate, industrial stable production is facilitated, high production efficiency is achieved, and the production cost is greatly reduced.

Description

technical field [0001] The invention belongs to the technical field of purification of trifluoromethanesulfonyl fluoride, in particular to a device and method for continuous rectification and purification of trifluoromethanesulfonyl fluoride. Background technique [0002] Trifluoromethanesulfonyl fluoride is an important intermediate in the field of fine chemicals, and can be used as an important raw material for organic synthesis, pesticide medicine, ionic liquid and lithium ion electrolyte. Trifluoromethanesulfonyl fluoride has a boiling point of -21.7°C under normal pressure. It has a weak odor and is easily liquefied at room temperature. It does not react with hydrogen, and is insoluble in cold water and hydrogen fluoride. [0003] Trifluoromethanesulfonyl fluoride has photolysis method, chemical direct fluorination method, electrolysis method and the method of fluorination of trifluoromethanesulfonyl chloride with potassium fluoride, but the electrolytic method is the m...

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Problems solved by technology

[0007] In the above-mentioned data, the purification method of trifluoromethanesulfonyl fluoride using electrolytic methanesulfonyl fluoride (or methanesulfonyl chloride) product as raw material all includes the following steps: condensation Remove part of the hydrogen fluoride, wash with carbonated water to remove most of the hydrogen fluoride, use a dehydrating agent to remove the moisture brought in the process of removing hydrogen fluoride, and then remove the hydrogen through cryogenic cooling to obtain relatively pure trifluoromethanesulfonyl fluoride. This type of purification method has the following problems : (1) There are many purification steps, and more equipment is needed, and multi-step gas-liquid separation equipment and water removal equipment are required; (2) The safety of the process, due to the long process route adopted, and the hydrogen is at the end It is removed in one step, and hydrogen leakage and explosion accidents are prone to occur, so the sealing requirements for all purification equipment are relatively high; (3) trifluoromethanesulfonyl fluoride can be hydrolyzed in alkaline solution, and hydrogen fluoride can be absorbed and removed by carbonate solution. Can absorb a part of trifluoromethanesulfonyl fluoride simultaneously, cause the loss of product, simultaneously trifluoromethanesulfonyl sulfonyl fluoride and carbonate reaction can produce carbon dioxide, bring new impurity, influence the purity of product; (4) adopt to introduce moisture first , and then through the method of dehydrating agent to remove water, activating the dehydrating agent needs to consume inert gas and electric energy, which increases the energy consumption of purification; (5) the product is finally obtained by simple gas-liquid separation to remove hydrogen, light component impurities such as tetrafluoroethylene Carbon dioxide (CF4), sulfoxide difluoride (SOF2), carbon dioxide (CO2) and oxygen difluoride (OF2) have not been removed through effective measures, and the final purity of the product trifluoromethanesulfonyl fluoride has not been mentioned in the literature

[0008] The trifluoromethanesulfonyl fluoride purification method using the electrolytic methanesulfonyl fluoride (or methanesulfonyl chloride) product as a raw material all includes the following steps: in a rectification tower The internal removal of light components and heavy components of impurities is divided into multiple stages. This type of purification method has the following problems: (1) There are many purification steps, the equipment involves multiple state switching, and the energy utilization rate is low; (2) Hydrogen fluoride and three The separation effect of fluoromethanesulfonyl fluoride is poor, and the purity of the product is not high; (3) the production efficiency is low, and the same production capacity requires more equipment; (4) the product content discharged from the light discharge process is higher, and the yield is lower

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