Apparatus and method for continuous preparation of triflate salts

Abstract

This application specifically relates to an apparatus and method for the continuous preparation of trifluoromethanesulfonate. The continuous preparation apparatus includes synthesis and separation units. The synthesis unit includes primary and secondary reactors, with built-in PTFE spiral channels and sieves, and equipped with PTFE distributors to form a gas-liquid circulation path. Various components are made of materials such as steel-lined PTFE or S31603, depending on the medium. The separation unit includes a scraped centrifuge, an intermediate buffer tank, and a thin-film evaporator, with material transport achieved through different pumps. The preparation method involves introducing alkali solution into the reactor, where trifluoromethanesulfonyl fluoride gas undergoes a counter-current reaction. Unreacted gas is recycled, and calcium oxide is added simultaneously. The clarified liquid undergoes separation, heat exchange, and circulation. After reaching a pH of 6-9, a portion is sent to the evaporator for drying. Controlling the alkali solution flow rate, excess gas, and evaporator temperature enables continuous production. This application establishes a continuous process, improving efficiency and reducing costs, achieving a product purity of 99.9%. The reactor flow coupling promotes reaction and prevents clogging.

Description

Technical Field

[0001] This application belongs to the field of trifluoromethanesulfonate preparation technology, specifically relating to an apparatus and method for continuous preparation of trifluoromethanesulfonates. Background Technology

[0002] Trifluoromethanesulfonates, including sodium trifluoromethanesulfonate, potassium trifluoromethanesulfonate, and barium trifluoromethanesulfonate, play an important role in various fields such as lithium battery electrolytes, acidic catalysts in organic synthesis, functional group modification of pharmaceutical intermediates, and surface modification of functional materials due to their strong acidity, high chemical stability, good solubility, and electrochemical activity. Therefore, their efficient and high-purity production processes and industrial applications have become current research hotspots.

[0003] The existing methods for preparing trifluoromethanesulfonates include the following: JP2005232040A discloses a method for producing lithium trifluoromethanesulfonate. First, methanesulfonate chloride reacts with potassium fluoride to produce methanesulfonyl fluoride. Then, methanesulfonyl fluoride and liquid hydrogen fluoride are added to an electrolytic cell for electrolysis. The resulting trifluoromethanesulfonyl fluoride reacts with an aqueous solution or suspension of lithium carbonate to produce a crude lithium trifluoromethanesulfonate solution. This method produces a product with high impurities such as lithium carbonate, resulting in low purity.

[0004] US4925975A discloses a method for preparing high-purity alkali metal fluoroalkyl sulfonates: The US patent reports the reaction of trifluoromethanesulfonic acid with lithium carbonate or lithium hydroxide monohydrate, controlling the pH value of the reaction at 3-6, and then drying the lithium trifluoromethanesulfonate to obtain the product. The product obtained by this method contains excessive trifluoromethanesulfonic acid, which can affect the characteristics of the battery and reduce its stability.

[0005] CN200710185143.4 A method for producing trifluoromethanesulfonic acid metal salts by reacting trifluoromethanesulfonic acid with metal alkoxides, and its use as an esterification catalyst and / or transesterification catalyst for the production of hydroxycarboxylic acid esters, including the use of a trifluoromethanesulfonic acid metal salt having at least one trifluoromethanesulfonic acid group as an esterification catalyst for reacting one or more hydroxycarboxylic acids with one or more alcohols to prepare hydroxycarboxylic acid esters, wherein the metal salt of trifluoromethanesulfonic acid includes Mg, Ca, Al, Sn, Ti, Zr, Fe, Cu or Zn as a metal.

[0006] CN202011631435.8 discloses a method and apparatus for preparing lithium trifluoromethanesulfonate. The method of this application includes: adding lithium carbonate and methyl ethyl ketone (MEK) into a reactor; controlling the reflux temperature and reactor temperature; adding trifluoromethanesulfonyl chloride from the bottom of the reactor; vaporizing the trifluoromethanesulfonyl chloride and reacting it with lithium carbonate after passing through a gas disperser; discharging the carbon dioxide generated in the reaction; filtering the resulting lithium trifluoromethanesulfonyl solution; and drying the solution to obtain the lithium trifluoromethanesulfonate product.

[0007] CN 202310476143.9 discloses a method for preparing trifluoromethanesulfonate, which uses methanesulfonyl chloride, potassium fluoride, liquid hydrogen fluoride, and an aqueous carbonate solution to prepare a crude trifluoromethanesulfonate solution; then, the crude trifluoromethanesulfonate is purified by filtration, concentration, and drying to obtain high-quality trifluoromethanesulfonate. However, this method cannot guarantee complete removal of carbonate, resulting in lower product purity.

[0008] CN 201911135622.4 discloses a method for preparing lithium trifluoromethanesulfonate. Under nitrogen protection, trifluoromethane halide is introduced into a suspension of zinc powder and tetrahydrofuran, followed by the addition of an appropriate amount of elemental iodine. The mixture is then slowly heated to generate trifluoromethyl zinc halide. Sulfur trioxide is added to the trifluoromethyl zinc halide to form a trifluoromethanesulfonate zinc halide reaction solution. This solution is then neutralized with lithium hydroxide, filtered, and the filtrate is evaporated to obtain lithium trifluoromethanesulfonate. This method involves multiple steps and makes it difficult to obtain a high-purity product.

[0009] CN 202011253895.1 discloses a process for preparing zinc trifluoromethanesulfonate. Carbon disulfide reacts with trifluoroiodomethane and sulfur to generate (CF3-SS-CF3). (CF3-SS-CF3) is then reacted with mercury under light to obtain trifluoromethylthiomercuric acid. This trifluoromethylthiomercuric acid is further oxidized with an oxidant to generate trifluoromethanesulfonic acid monohydrate. The trifluoromethanesulfonic acid monohydrate is filtered to obtain an aqueous solution of trifluoromethanesulfonic acid. Sufficient zinc is added to the aqueous solution of trifluoromethanesulfonic acid, and the solution is heated under reflux until it becomes neutral. This method involves complex steps and requires strict control of reaction conditions.

[0010] CN 202311177151.X describes a method that involves adding trifluoromethanesulfonic acid to a non-protic, non-polar organic solvent, followed by the partial addition of cuprous oxide powder. The mixture undergoes a heterogeneous reflux reaction, with the resulting water condensed in a reflux condenser. The solution is then cooled to room temperature, filtered, and vacuum dried to obtain high-purity cuprous trifluoromethanesulfonic acid. However, this method is ineffective in handling the generated waste residue, making it unsuitable for industrial production.

[0011] In summary, the current methods for preparing trifluoromethanesulfonates still have the following problems: One issue is that the purity of the product is difficult to meet the standards, either due to the residue of raw materials such as lithium carbonate and carbonates, or the excessive residue of trifluoromethanesulfonic acid, or the introduction of byproducts due to redundant steps, which cannot meet the purity requirements of high-end application scenarios. Secondly, the process is not practical enough. Some methods and steps are cumbersome and the reaction conditions are strictly controlled, which increases the difficulty of operation and also increases production energy consumption and cost. Thirdly, it has poor industrial adaptability, and there are problems such as difficulty in waste disposal, waste of raw materials, and environmental risks brought about by highly toxic reagents.

[0012] Therefore, there is an urgent need to propose a simple and controllable process for preparing trifluoromethanesulfonate, which produces high-purity products and is suitable for large-scale industrial production, in order to solve the aforementioned core problems of the existing technology. Summary of the Invention

[0013] To address the problems of substandard purity, high process cost, and difficulty in industrial-scale mass production of trifluoromethanesulfonates in existing technologies, this application proposes a device and method for the continuous preparation of trifluoromethanesulfonates that features a simple and controllable process, high product purity, and suitability for large-scale industrial production.

[0014] The technical solution of this application is as follows: On the one hand, this application proposes an apparatus for the continuous preparation of trifluoromethanesulfonate, including a synthesis unit and a separation unit; The synthesis unit includes a primary reactor, a secondary reactor, a heat exchanger, a gas buffer tank, a screw conveyor, and a tail gas treatment tank. Both the primary reactor and the secondary reactor are equipped with spiral channels inside, and sieve holes are evenly arranged on the spiral channels. The primary reactor is equipped with a liquid phase distributor at the top and a gas phase distributor at the bottom; the secondary reactor is equipped with a liquid phase distributor at the top and a gas phase distributor at the bottom. The bottom of the primary reactor is connected to the top liquid phase distributor of the secondary reactor, and the top of the secondary reactor is connected to the gas phase distributor of the primary reactor. The outlet pipe of the heat exchanger is connected to the upper part of the primary reactor; The inlet of the gas buffer tank is connected to the trifluoromethanesulfonyl fluoride inlet pipe, and the outlet of the gas buffer tank is connected to the bottom gas phase distributor of the secondary reactor. The screw conveyor is connected to the top of the primary reactor; The exhaust gas treatment tank is connected to the top of the primary reactor via an exhaust pipe; The separation unit includes a scraped centrifuge, an intermediate buffer tank, and a thin-film evaporator; The inlet of the scraped centrifuge is connected to the bottom of the secondary reactor, and the liquid phase outlet of the scraped centrifuge is connected to the intermediate buffer tank; the outlet of the intermediate buffer tank is connected to the inlet of the thin film evaporator and the inlet of the heat exchanger, respectively.

[0015] Preferably, the primary reactor, secondary reactor, gas buffer tank, and intermediate buffer tank are made of steel lined with PTFE; the scraped centrifuge and thin-film evaporator are made of S31603; and the heat exchanger is made of silicon carbide.

[0016] Preferably, the spiral channels inside the primary and secondary reactors are made of PTFE, the diameter of the sieve holes is 5~20mm, and the spiral channels are fixed by PTFE support plates.

[0017] Preferably, the second gas phase distributor and the first gas phase distributor are made of PTFE and have their openings facing downwards, while the second liquid phase distributor and the first liquid phase distributor are made of PTFE and have their openings facing upwards.

[0018] Preferably, a third pump is provided on the pipeline connecting the bottom outlet of the primary reactor to the top of the secondary reactor; a first pump is provided on the pipeline connecting the inlet of the scraped centrifuge to the bottom of the secondary reactor; and a second pump is provided on the pipeline connecting the outlet of the intermediate buffer tank to the inlet of the thin-film evaporator and the inlet of the heat exchanger.

[0019] Preferably, the third pump and the first pump are mud pumps; the second pump is a centrifugal pump.

[0020] On the other hand, this application provides a method for the continuous preparation of trifluoromethanesulfonate, comprising the following steps: Step S1: The alkaline solution is introduced into the primary reactor through the liquid phase distributor at the top of the primary reactor; Step S2: The alkaline solution at the bottom of the primary reactor is introduced into the secondary reactor through the liquid phase distributor at the top of the secondary reactor; Step S3: Pass the solution at the bottom of the secondary reactor into a scraped centrifuge for solid-liquid separation, and collect the separated clear liquid into an intermediate buffer tank; Step S4: The clear liquid in the intermediate buffer tank is returned to the primary reactor after heat exchange through a heat exchanger; at the same time, calcium oxide is added to the primary reactor through a screw device. Step S5: After passing the trifluoromethanesulfonyl fluoride gas through the gas buffer tank, it then passes through the bottom gas phase distributor II of the secondary reactor to react counter-currently with the alkaline solution in the secondary reactor; the unreacted trifluoromethanesulfonyl fluoride is passed into the primary reactor to continue the reaction, and the residual trifluoromethanesulfonyl fluoride is discharged to the tail gas treatment tank through the exhaust pipe at the top of the primary reactor. Step S6: After the pH value of the clear liquid reaches 6-9, a portion of the clear liquid is transferred to a thin-film evaporator for drying.

[0021] Preferably, in step S1, the mass fraction of the alkaline solution is 30-50%, the temperature is room temperature, and the flow rate is controlled at 80-100 kg / h; the alkaline solution is any one of sodium hydroxide, barium hydroxide, and potassium hydroxide.

[0022] Preferably, in steps S3-S4, the liquid level in the intermediate buffer tank is controlled to be ≥300mm, the filter cloth used in the scraper centrifuge has a mesh size of 400~600 mesh, the temperature of the solution after heat exchange in the heat exchanger is controlled to be ≤90℃, and the amount of calcium oxide added is 200g / h.

[0023] Preferably, in step S5, the inlet pressure of trifluoromethanesulfonyl fluoride is controlled at 0.1~0.2MPa, and the inlet flow rate is 1~2% excess. Preferably, in step S6, the amount of clear liquid delivered to the thin-film evaporator is 0.5 to 0.8 times the amount of circulating clear liquid, the drying temperature of the thin-film evaporator is 130 to 190°C, the vacuum degree is -0.1 to -0.08 MPa, and the residence time of the clear liquid in the thin-film evaporator is 10 to 30 seconds.

[0024] The beneficial effects of this application are as follows: The apparatus designed in this application includes a reaction unit and a separation unit, which are tightly connected by pipelines and valves to form a continuous production process, continuously purifying and obtaining trifluoromethanesulfonate powder. This design greatly improves production efficiency, reduces manual intervention, and lowers raw material consumption and production costs. The final product, trifluoromethanesulfonate, has a purity of over 99.9%, a moisture content of less than 100 ppm, and F... - and SO4 2- The content of impurities is also far below the industry standard, so it can be used directly without further purification.

[0025] This application incorporates a spiral channel and sieve holes within the reactor, enabling the fluid to undergo a coupling of two flow regimes: swirling and perforated flow. This allows for sufficient contact and reaction between the gas and liquid phases, resolving issues such as incomplete conversion and long reaction times. Simultaneously, controlling the sieve hole diameter prevents clogging during operation. This application uses a clear liquid circulation method for heat exchange. The reactor and internal spiral channel are made of PTFE material, which avoids material corrosion of the equipment and extends the service life of the equipment. Attached Figure Description

[0026] Figure 1 This is a diagram of the apparatus for the continuous preparation of trifluoromethanesulfonate according to this application; Figure 2 This is a schematic diagram of the spiral channel set inside the reactor of this application.

[0027] The markings in the diagram are as follows: 1. Gas buffer tank; 2. Secondary reactor; 3. Primary reactor; 4. Scraped centrifuge; 5. Intermediate buffer tank; 6. Heat exchanger; 7. Thin-film evaporator; 8. Spiral device; 9. First pump; 10. Second pump; 11. Liquid phase distributor II; 12. Gas phase distributor II; 13. Liquid phase distributor I; 14. Gas phase distributor I; 15. Flow meter I; 16. Flow meter II; 17. Flow meter III; 18. Control valve I; 19. Control valve II; 20. Control valve III; 21. Shut-off valve; 22. Control valve IV; 23. Cold source inlet; 24. Cold source outlet; 25. Vacuum outlet; 26. Heat source inlet; 27. Heat source outlet; 28. Control valve V; 29. ​​Control valve VI; 30. Control valve VII; 31. Control valve VIII; 32. Third pump; 33. Tail gas treatment tank; 34. Control valve IX; 35. pH meter. Detailed Implementation

[0028] To further illustrate the technical means and effects adopted by this application in order to achieve the intended purpose of the invention, the following detailed description of the specific implementation methods, structures, features and effects of this application is provided in conjunction with the accompanying drawings and preferred embodiments.

[0029] Device Examples See Figure 1 This embodiment provides an apparatus for the continuous preparation of trifluoromethanesulfonate, specifically including a synthesis unit and a separation unit. The connection and configuration of each component are as follows: The synthesis unit includes a reactor assembly, a buffer tank and air intake assembly, a screw conveyor and exhaust gas treatment assembly, and a heat exchanger assembly.

[0030] The reactor assembly includes a primary reactor 3 and a secondary reactor 2. Both reactors have PTFE spiral channels inside, with sieve holes of 5-20 mm in diameter evenly distributed on the spiral channels, which are fixed by PTFE plates. The top of the primary reactor 3 is equipped with a liquid distributor 13 made of PTFE with the opening facing downwards, and the bottom of the primary reactor 3 is equipped with a gas distributor 14 made of PTFE with the opening facing upwards. The top of the secondary reactor 2 is equipped with a liquid distributor 11 made of PTFE with the opening facing upwards, and the bottom of the secondary reactor 2 is equipped with a gas distributor 12 made of PTFE with the opening facing downwards.

[0031] The bottom outlet of the primary reactor 3 is connected to the upper liquid distributor of the secondary reactor 2, namely the liquid distributor 11. The pipeline is sequentially equipped with a third pump 32 (slurry pump) and a regulating valve 20. The top outlet of the secondary reactor 2 is connected to the gas distributor 13 of the primary reactor 3. The pipeline is equipped with a regulating valve 28.

[0032] In the buffer tank and air intake assembly, the gas buffer tank 1 is made of steel lined with PTFE. Its inlet is connected to the trifluoromethanesulfonyl fluoride air intake pipe, and a regulating valve 18 is installed on the pipe. The outlet of the buffer tank 1 is connected to the gas distributor 12 of the secondary reactor 2, and a flow meter 15 is installed on the pipe.

[0033] In the screw conveyor and exhaust gas treatment assembly, the screw conveyor 8 is connected to the top of the primary reactor 3, and a shut-off valve 21 is installed on the pipeline; the exhaust gas treatment device 33 is connected to the exhaust pipe at the top of the primary reactor 3, and a regulating valve 34 is installed on the pipeline.

[0034] In the heat exchanger assembly, heat exchanger 6 is made of silicon carbide. Its inlet pipe is connected to the second pump 10 (centrifugal pump) for clear liquid transportation, and its outlet pipe is connected to the upper part of the first-stage reactor 3. Heat exchanger 6 is equipped with cold source inlet 23 and cold source outlet 24 interfaces. A regulating valve 29 is installed on the cold source inlet 23 pipe.

[0035] The separation unit includes a scraped centrifuge 4, an intermediate buffer tank assembly, and a thin-film evaporator assembly.

[0036] In the assembly of scraped centrifuge 4 and intermediate buffer tank, scraped centrifuge 4 is made of S31603 steel, and its inlet is connected to the bottom of the secondary reactor 2. The pipeline is sequentially equipped with a first mud pump 9 (mud pump) and a second regulating valve 19. The liquid phase outlet of scraped centrifuge 4 is connected to intermediate buffer tank 5, which is made of steel lined with PTFE. The solid outlet of scraped centrifuge 4 is equipped with a fluoride salt collection container. The outlet of intermediate buffer tank 5 is divided into two paths, one connected to the inlet of thin film evaporator 7 and the other connected to the inlet of heat exchanger 6. The outlet pipeline is sequentially equipped with a second centrifuge pump 10 (centrifuge pump), a fourth regulating valve 22, and a pH meter 35.

[0037] In the thin-film evaporator assembly, the thin-film evaporator 7 is made of S31603, and a flow meter 317 is installed on its inlet pipe; the top of it is connected to a vacuum pipe, which corresponds to the vacuum outlet 25 interface, and a regulating valve 831 is installed on the pipe; the outer jacket of the thin-film evaporator 7 is equipped with a heat source inlet 26 and a heat source outlet 27 interface, and a regulating valve 730 is installed on the heat source outlet 27 pipe.

[0038] Device Implementation Principle Check the sealing status of each component of the device, confirm that the scraper centrifuge 4 is equipped with 400-600 mesh filter cloth, and that the vacuum system of the thin film evaporator 7 is in a standby state. Open the feed valve of the 35% sodium hydroxide solution, so that the solution is evenly fed into the primary reactor 3 through the liquid distributor 13 at the top of the primary reactor 3, and control the feed flow rate through the flow meter 16.

[0039] Turn on the third pump 32 (mud pump) and open the regulating valve 3 20 to evenly feed the solution at the bottom of the first-stage reactor 3 into the second-stage reactor 2 through the liquid distributor 2 11 at the top of the second-stage reactor 2.

[0040] Start the first pump 9 (slurry pump), open the regulating valve 19, and transport the mixed solution at the bottom of the secondary reactor 2 to the scraped centrifuge 4 for solid-liquid separation; the separated liquid phase solution flows into the intermediate buffer tank 5 by gravity, and the solid outlet of the scraped centrifuge 4 collects the separated fluoride impurities through the fluoride collection container.

[0041] When the liquid level in the intermediate buffer tank 5 reaches ≥300mm, start the second pump 10 (centrifugal pump) and open the regulating valve 22 to deliver the clear liquid in the intermediate buffer tank 5 in two ways: one way is sent to the inlet of the heat exchanger 6 for circulation, and the other way is used as dry clear liquid for drying. The mass of the dry clear liquid is controlled to be 0.5~0.8 times that of the circulating clear liquid. At the same time, the pH value of the clear liquid is monitored in real time through the pH meter 35 on the outlet pipeline.

[0042] Open the cold source inlet valve 23 of heat exchanger 6, open the regulating valve 29 to introduce circulating water, and adjust the circulating water flow rate so that the temperature of the clear liquid at the outlet of heat exchanger 6 is ≤90℃; the clear liquid after heat exchange is transported to the upper part of the primary reactor 3 through the outlet pipe of heat exchanger 6.

[0043] Open regulating valve 18 to introduce trifluoromethanesulfonyl fluoride gas into buffer tank 1 for pressure stabilization; then open the pipeline valve corresponding to flow meter 15 to evenly introduce trifluoromethanesulfonyl fluoride into secondary reactor 2 through gas distributor 12 at the bottom of secondary reactor 2, controlling the inlet pressure to 0.1~0.2MPa, and trifluoromethanesulfonyl fluoride reacts with the alkaline solution in secondary reactor 2 in a counter-current contact.

[0044] Open the shut-off valve 21 and start the screw conveyor 8 to add calcium oxide to the primary reactor 3 at a rate of 200 g / h. The calcium oxide reacts with the residual fluoride ions in the system to generate insoluble calcium fluoride.

[0045] Open regulating valve 28 to send the unreacted trifluoromethanesulfonyl fluoride gas from the secondary reactor 2 to the gas distributor 14 of the primary reactor 3, and let it continue to react in the primary reactor 3; at the same time, open regulating valve 34 to send the residual trifluoromethanesulfonyl fluoride gas from the primary reactor 3 to the tail gas treatment device 33 for treatment before being discharged.

[0046] When the pH meter 35 shows that the pH value of the clear liquid reaches 6~9, open the corresponding pipeline valve at the inlet of the thin film evaporator 7, and control the flow rate of the clear liquid through the flow meter 317 to deliver this portion of the clear liquid to the thin film evaporator 7; then open the heat source inlet valve 26 of the outer jacket of the thin film evaporator 7, open the regulating valve 730 to introduce the heat source medium, and control the drying temperature to 130~190℃; open the regulating valve 831 to start the vacuum system, control the vacuum degree inside the thin film evaporator 7 to -0.1~-0.08MPa, so that the clear liquid stays in the equipment for 10~30s, and finally dries to obtain sodium trifluoromethanesulfonate product.

[0047] Examples 1-3 use the apparatus from the device examples, wherein the scraper centrifuge filter cloth is 500 mesh, and the spiral channel is uniformly provided with sieve holes with a diameter of 15 mm.

[0048] Example 1 Step S1: 35% sodium hydroxide solution is evenly introduced into the primary reactor through the top distributor of the primary reactor, and the influent flow rate is controlled at 80 kg / h. Step S2: Turn on the third pump to evenly introduce the solution from the bottom of the primary reactor into the secondary reactor through the distributor at the top of the secondary reactor. Step S3: Turn on the first pump to pass the solution at the bottom of the secondary reactor into the scraped centrifuge for separation. After separation, the solution flows into the intermediate buffer tank by gravity. Step S4: Once the liquid level in the intermediate buffer tank reaches 300mm, start the second pump to deliver the clean liquid to the heat exchanger. Adjust the circulating water temperature so that the clean liquid temperature at the heat exchanger outlet is 90℃. Step S5: After the operation is stable, trifluoromethanesulfonyl fluoride is introduced, with an inlet pressure of 0.1~0.2MPa through the inlet control valve and a flow rate of 53.7kg / h controlled by the flow meter; calcium oxide is added to the primary reactor through a screw feeder at a rate of 200g / h. The reaction formulas involved are: CF3SO2F+2Na(OH)→(CF3SO3)Na+NaF+H2O After step S5 and pH 7, the clarified liquid at a flow rate of 133.7 kg / h is delivered to the membrane evaporator for drying via a flow meter. The drying process is set at a temperature of 150~160℃, a vacuum of -0.1~-0.08 MPa, and a residence time of 20~25 s, yielding 62.84 kg / h of sodium trifluoromethanesulfonate.

[0049] After testing, the overall yield was 95.8%, the purity was 99.9%, and the moisture content was 95 ppm. - The content is 3 ppm, SO4 2- The content is 3 ppm.

[0050] Example 2 Step S1: 50% potassium hydroxide solution is evenly introduced into the primary reactor through the top distributor of the primary reactor, and the influent flow rate is controlled at 100 kg / h. Step S2: Turn on the third pump to evenly introduce the solution from the bottom of the primary reactor into the secondary reactor through the distributor at the top of the secondary reactor. Step S3: Turn on the first pump to pass the solution at the bottom of the secondary reactor into the scraped centrifuge for separation. After separation, the solution flows into the intermediate buffer tank by gravity. Step S4: Once the liquid level in the intermediate buffer tank reaches 320mm, start the second pump to deliver the clean liquid to the heat exchanger. Adjust the circulating water temperature to 85℃ at the heat exchanger outlet. Step S5: After the operation is stable, trifluoromethanesulfonyl fluoride is introduced, with an inlet pressure of 0.1~0.2MPa through the inlet control valve and a flow rate of 110.6kg / h controlled by the flow meter; calcium oxide is added to the primary reactor through a screw feeder at a rate of 200g / h. After step S5 and pH 6, the clarified liquid at a flow rate of 151.24 kg / h is delivered to the membrane evaporator for drying via a flow meter. The drying process is set at a temperature of 130~150℃, a vacuum of -0.1~-0.08 MPa, and a residence time of 10~20 s, yielding 67.86 kg / h of potassium trifluoromethanesulfonate.

[0051] After testing, the overall yield was 96.1%, the purity was 99.9%, and the moisture content was 100 ppm. - The content is 6 ppm, SO4 2- The content is 3 ppm.

[0052] Example 3 Step S1: 30% barium hydroxide solution is evenly introduced into the primary reactor through the top distributor of the primary reactor, and the influent flow rate is controlled at 80 kg / h. Step S2: Turn on the third pump to evenly introduce the solution from the bottom of the primary reactor into the secondary reactor through the distributor at the top of the secondary reactor. Step S3: Turn on the first pump to pass the solution at the bottom of the secondary reactor into the scraped centrifuge for separation. After separation, the solution flows into the intermediate buffer tank by gravity. Step S4: When the liquid level reaches 310mm, start the second pump to deliver the clear liquid to the heat exchanger. Adjust the circulating water temperature to achieve a clear liquid temperature of 89℃ at the heat exchanger outlet. Step S5: After the operation is stable, trifluoromethanesulfonyl fluoride is introduced, with an inlet pressure of 0.1~0.2MPa through the inlet control valve and a flow rate of 43.01kg / h controlled by the flow meter; calcium oxide is added to the primary reactor through a screw feeder at a rate of 200g / h. After step S5 and pH 9, the clear liquid with a flow rate of 122.61 kg / h is delivered to the membrane evaporator for drying via a flow meter. The drying process is set at a temperature of 160~190℃, a vacuum of -0.1~-0.08 MPa, and a residence time of 25~30 s, yielding 46.22 kg / h of barium trifluoromethanesulfonate.

[0053] After testing, the overall yield was 95.9%, the purity was 99.9%, and the moisture content was 85 ppm. - The content is 2 ppm, SO4 2- The content is 1 ppm.

[0054] Comparative Example 1 The difference between this comparative example and Example 1 is that in this comparative example, neither the primary nor secondary reactor has a sieve hole uniformly set on the spiral channel. Testing showed an overall yield of 82.1%, purity of 99.1%, and moisture content of 98 ppm. - The content is 10 ppm, SO4 2- The content is 6 ppm.

[0055] The above description is merely a preferred embodiment of this application and is not intended to limit this application in any way. Although this application has been disclosed above with reference to preferred embodiments, it is not intended to limit this application. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of this application. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. An apparatus for the continuous preparation of trifluoromethanesulfonate, characterized in that, Includes synthesis units and separation units; The synthesis unit includes a primary reactor (3), a secondary reactor (2), a heat exchanger (6), a gas buffer tank (1), a screw conveyor (8), and a tail gas treatment tank (33). Both the primary reactor (3) and the secondary reactor (2) are equipped with spiral channels, and the spiral channels are uniformly arranged with sieve holes. The primary reactor (3) is equipped with a liquid phase distributor (13) at the top and a gas phase distributor (14) at the bottom; the secondary reactor (2) is equipped with a liquid phase distributor (11) at the top and a gas phase distributor (12) at the bottom. The bottom of the primary reactor (3) is connected to the top liquid phase distributor II (11) of the secondary reactor (2), and the top of the secondary reactor (2) is connected to the gas phase distributor I (14) of the primary reactor (3). The outlet pipe of the heat exchanger (6) is connected to the upper part of the primary reactor (3); The inlet of the gas buffer tank (1) is connected to the trifluoromethanesulfonyl fluoride inlet pipe, and the outlet of the gas buffer tank (1) is connected to the bottom gas phase distributor (12) of the secondary reactor (2). The screw conveyor (8) is connected to the top of the primary reactor (3); The exhaust gas treatment tank (33) is connected to the top of the primary reactor (3) via an exhaust pipe; The separation unit includes a scraped centrifuge (4), an intermediate buffer tank (5), and a thin film evaporator (7); The inlet of the scraped centrifuge (4) is connected to the bottom of the secondary reactor (2), and the liquid phase outlet of the scraped centrifuge (4) is connected to the intermediate buffer tank (5); the outlet of the intermediate buffer tank (5) is connected to the inlet of the thin film evaporator (7) and the inlet of the heat exchanger (6).

2. The apparatus for continuous preparation of trifluoromethanesulfonate according to claim 1, characterized in that, The primary reactor (3), secondary reactor (2), gas buffer tank (1), and intermediate buffer tank are made of steel lined with PTFE; the scraped centrifuge (4) and thin film evaporator (7) are made of S31603; and the heat exchanger (6) is made of silicon carbide.

3. The apparatus for continuous preparation of trifluoromethanesulfonate according to claim 1, characterized in that, The spiral channels inside the primary reactor (3) and the secondary reactor (2) are made of PTFE, the diameter of the sieve holes is 5~20mm, and the spiral channels are fixed by PTFE plates.

4. The apparatus for continuous preparation of trifluoromethanesulfonate according to claim 1, characterized in that, The gas phase distributor 2 (12) and the gas phase distributor 1 (14) are made of PTFE and have their openings facing downwards, while the liquid phase distributor 2 (11) and the liquid phase distributor 1 (13) are made of PTFE and have their openings facing upwards.

5. The apparatus for continuous preparation of trifluoromethanesulfonate according to claim 1, characterized in that, A third pump (32) is installed on the pipeline connecting the bottom outlet of the primary reactor (3) to the top of the secondary reactor (2); a first pump (9) is installed on the pipeline connecting the inlet of the scraped centrifuge (4) to the bottom of the secondary reactor (2); a second pump (10) is installed on the pipeline connecting the outlet of the intermediate buffer tank (5) to the inlet of the thin film evaporator (7) and the inlet of the heat exchanger (6).

6. The apparatus for continuous preparation of trifluoromethanesulfonate according to claim 5, characterized in that, The third pump (32) and the first pump (9) are mud pumps; the second pump (10) is a centrifugal pump.

7. A method for continuous preparation of trifluoromethanesulfonate, based on the apparatus for continuous preparation of trifluoromethanesulfonate according to any one of claims 1 to 6, characterized in that, Includes the following steps: Step S1: The alkaline solution is introduced into the primary reactor (3) through the top liquid phase distributor (13); Step S2: The alkaline solution at the bottom of the primary reactor (3) is introduced into the secondary reactor (2) through the liquid phase distributor II (11) at the top of the secondary reactor (2); Step S3: Pass the solution at the bottom of the secondary reactor (2) into a scraped centrifuge (4) for solid-liquid separation, and collect the separated clear liquid into an intermediate buffer tank (5). Step S4: The clear liquid in the intermediate buffer tank (5) is returned to the primary reactor (3) after heat exchange through the heat exchanger (6); at the same time, calcium oxide is added to the primary reactor (3) through the screw device (8). Step S5: After passing the trifluoromethanesulfonyl fluoride gas through the gas buffer tank (1), it is then passed through the bottom gas phase distributor (12) of the secondary reactor (2) to react with the alkaline solution in the secondary reactor (2) in a counter-current manner; the unreacted trifluoromethanesulfonyl fluoride is passed into the primary reactor (3) to continue the reaction, and the residual trifluoromethanesulfonyl fluoride is discharged to the tail gas treatment tank (33) through the exhaust pipe at the top of the primary reactor (3). Step S6: After the pH value of the clear liquid reaches 6-9, a portion of the clear liquid is transferred to the thin film evaporator (7) for drying.

8. The method for continuous preparation of trifluoromethanesulfonate according to claim 7, characterized in that, In step S1, the mass fraction of the alkaline solution is 30-50%, the temperature is room temperature, and the flow rate is controlled at 80-100 kg / h; the alkaline solution is any one of sodium hydroxide, barium hydroxide, and potassium hydroxide.

9. The method for continuous preparation of trifluoromethanesulfonate according to claim 7, characterized in that, In steps S3-S4, the liquid level of the intermediate buffer tank (5) is controlled to be ≥300mm, the filter cloth used in the scraper centrifuge (4) has a mesh size of 400~600 mesh, the temperature of the solution after heat exchange in the heat exchanger (6) is controlled to be ≤90℃, and the amount of calcium oxide added is 200g / h.

10. The method for continuous preparation of trifluoromethanesulfonate according to claim 7, characterized in that, In steps S5-S6, the inlet pressure of trifluoromethanesulfonyl fluoride is controlled at 0.1~0.2MPa and the inlet flow rate is 1~2% excess; the amount of clear liquid delivered to the thin film evaporator (7) is 0.5~0.8 times the amount of circulating clear liquid; the drying temperature of the thin film evaporator (7) is 130~190℃ and the vacuum degree is -0.1~-0.08MPa; the residence time of the clear liquid in the thin film evaporator (7) is 10~30s.

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