Preparation device and preparation method of high-purity perfluorotripropylamine
By combining electrolysis-fluorination coupling technology with electrolytic fluorination and secondary fluorine gas recycling fluorination reaction, the problems of low efficiency and high cost in the preparation of perfluorotripropylamine have been solved, and high-purity, high-yield perfluorotripropylamine has been achieved, which has good potential for industrial application.
Patent Information
- Application Number
- CN202511493523.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-20
- Publication Date
- 2026-01-23
AI Technical Summary
Existing methods for preparing perfluorotripropylamine suffer from problems such as low reaction efficiency, numerous byproducts, difficulty in separation and purification, high energy consumption, stringent requirements for equipment materials, and high costs, which limit its large-scale industrial application.
By employing electrolysis-fluorination coupling technology, combining electrolytic fluorination with secondary fluorine gas recycling fluorination reaction, and through process optimization and reaction synergy, a novel composite process was designed, including equipment such as an electrolytic fluorination tank, a crude fluorination tower, and a washing tower, to achieve the efficient preparation of perfluorotripropylamine.
It improves the yield and purity of perfluorotripropylamine, reduces production costs, enhances process safety, simplifies operating procedures, and has broad prospects for industrial application.
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Figure CN121372231A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of preparation technology of perfluorotripropylamine, specifically to an apparatus and method for preparing high-purity perfluorotripropylamine. Background Technology
[0002] Perfluorotripropylamine is a perfluoro tertiary amine compound with a series of unique physical and chemical properties. At room temperature, it is a colorless, transparent liquid with almost no characteristic amine odor. This substance is insoluble in water and ethanol, and also has low solubility in common organic solvents such as acetone, diethyl ether, chloroform, dioxane, ethyl acetate, benzene, and petroleum ether, but it is miscible with chlorofluorocarbons.
[0003] Perfluorotripropylamine is non-toxic to humans and can efficiently dissolve and carry large amounts of oxygen and carbon dioxide, thus it is widely used in modern medicine and is one of the key components of artificial blood plasma. In addition, it is also used as an anti-corrosion transmission fluid for instruments, a dielectric insulating fluid, and a leak detection fluid for electronic components.
[0004] Currently, perfluorotripropylamine can be prepared by methods such as electrolytic fluorination, direct fluorination with fluorine gas, and fluorine reagent method.
[0005] Electrolytic fluorination is the mainstream process for preparing perfluorotripropylamine. This method involves electrolyzing anhydrous hydrogen fluoride in an electrolytic cell under mild conditions to generate active fluorine atoms, which then undergo a substitution reaction with the raw material tripropylamine to ultimately produce perfluorotripropylamine. This process has significant advantages such as low equipment cost, simple process, flexible equipment, and regular molecular structure. However, electrolytic fluorination also has several significant drawbacks, such as low reaction efficiency, numerous byproducts (mostly partial fluorides), difficulty in separation and purification, high energy consumption, and stringent requirements for equipment materials. These factors, to some extent, restrict the large-scale industrial application of this technology.
[0006] While the direct fluorination method uses fluorine gas (F2) as the fluorinating agent and reacts directly with tripropylamine, the process faces significant challenges due to the extremely high oxidizing and reactivity of fluorine itself. The reaction readily leads to carbon chain breakage and the release of substantial amounts of heat. These factors collectively result in a wide variety of byproducts, poor selectivity for the target product, and a low final yield. Therefore, considering reaction control, safety, and economic factors, the industrial application potential of this method is relatively limited.
[0007] The fluorine reagent method uses metal fluorides (such as CoF3, AgF2, etc.) as fluorinating agents to react with tripropylamine. A significant advantage of this method is that the reaction conditions are mild and easily controlled, thus avoiding the safety risks and engineering challenges associated with directly using fluorine gas. However, its limitations are also prominent: the reaction process is usually quite complex, and the high cost of preparing the metal fluoride reagents, and the fact that most are not recyclable, leads to a sharp increase in production costs. Therefore, the economic viability of this process is the main constraint on its large-scale industrial application.
[0008] In summary, all current methods, including electrolytic fluorination, direct fluorination with fluorine gas, and fluorine reagent methods, have inherent technical defects that severely restrict the efficient and large-scale production of perfluorotripropylamine. Summary of the Invention
[0009] To address the aforementioned problems (numerous byproducts in direct fluorination, low efficiency in electrolytic fluorination, and high cost in fluorine reagent methods), this invention aims to provide a device and method for preparing high-purity perfluorotripropylamine. It employs a novel composite process, an electrolysis-fluorination coupling technology, combining electrolytic fluorination with a secondary fluorine gas recycling fluorination reaction. This innovative process integrates two different fluorination technologies (electrolytic fluorination and direct fluorination) into a complete process system through ingenious process design, enabling them to work synergistically and complement each other's advantages. Through process optimization and reaction synergy, this process achieves complementarity and improvement over the shortcomings of traditional technologies. It not only successfully overcomes the limitations of existing methods but also exhibits significant advantages such as high yield and purity of perfluorobutane, good process safety, and simple operation.
[0010] The process of this invention begins with an electrolytic fluorination step: in an electrolytic fluorination tank, anhydrous hydrogen fluoride is used as the electrolytic medium to generate active fluorine atoms (F) through electrolysis; these active fluorine atoms then react with tripropylamine molecules to achieve preliminary fluorination, yielding crude perfluorotripropylamine. Subsequently, the crude product is collected in a collection tank and then pumped to a crude product fluorination tower. Inside the crude product fluorination tower, a fluorine-nitrogen mixture is introduced to carry out a secondary cyclic fluorination reaction on the crude product, aiming to completely eliminate residual CH bonds and purify the product, ultimately obtaining high-purity perfluorotripropylamine. The reaction equation is as follows: The present invention provides an apparatus for preparing high-purity perfluorotripropylamine, comprising a mixing vessel, the inlet of which is connected to both the raw material HF pipeline and the tripropylamine pipeline; the outlet of the mixing vessel is connected to the inlet A of an electrolytic fluorination cell; the outlet at the bottom of the electrolytic fluorination cell is connected to the inlet at the top of a collecting tank; the outlet at the bottom of the collecting tank is connected to the top inlet of a first crude fluorination tower via a first magnetic pump; the outlet at the bottom of the first crude fluorination tower is connected to the top inlet of a second crude fluorination tower via a second magnetic pump; the outlet at the bottom of the second crude fluorination tower is connected to the inlet of a finished product tank via a third magnetic pump; and the outlet of the finished product tank is connected to a distillation and purification system; fluorine and nitrogen pipelines are respectively connected to the lower inlets of the first and second crude fluorination towers.
[0011] Furthermore, a product sampling port is provided at the bottom outlet of the second crude fluorination tower; a connection port is provided between the bottom outlet of the collection tank and the first magnetic pump, and a return valve is provided on the pipeline connecting the connection port and the product sampling port.
[0012] Furthermore, the outlet and inlet B at the top of the electrolytic fluorination cell are both connected to the HF condenser. The gas outlet of the HF condenser is connected to the inlet at the bottom of the buffer tank. The outlet at the top of the buffer tank is connected to the inlet at the bottom of the first scrubbing tower. The outlet at the top of the first scrubbing tower is connected to the inlet at the bottom of the second scrubbing tower. The outlet at the top of the second scrubbing tower is connected to the inlet at the bottom of the third scrubbing tower. The outlet at the top of the third scrubbing tower is connected to the inlet at the bottom of the activated adsorption tower. The outlet at the top of the activated adsorption tower is connected to the venting pipeline.
[0013] Furthermore, the outlets of the collection tank at the top, the first crude fluorination tower at the top, and the second crude fluorination tower at the top are all connected to the inlet of the buffer tank.
[0014] Furthermore, the alkali pipelines are connected to the inlets at the top of the first, second, and third washing towers via alkali pumps; the outlets at the bottom of the first, second, and third washing towers are connected to the waste liquid tank via pipelines.
[0015] Furthermore, the inlet at the top of the return tank is also connected to the outlet at the bottom of the electrolytic fluorination tank. When the electrolytic fluorination tank malfunctions (such as failing to electrolyze normally and requiring material return for maintenance), the material in the electrolytic fluorination tank enters the return tank, and the outlet at the top of the return tank is connected to the inlet of the buffer tank.
[0016] Furthermore, the HF pipeline is also connected to inlet A of the electrolytic fluorination cell.
[0017] Furthermore, the electrolytic fluorination tank is equipped with a level gauge.
[0018] The present invention provides a method for preparing high-purity perfluorotripropylamine, which uses the above-mentioned preparation apparatus and specifically includes the following steps: Nitrogen gas was introduced into the apparatus for evacuation and replacement. Then, liquid hydrogen fluoride and liquid tripropylamine were introduced into the mixing vessel and stirred for 2-3 hours at -20℃ to -10℃. The resulting mixture was then transferred to an electrolytic fluorination tank and subjected to electrolytic fluorination at -5℃ to 5℃, 0-101 kPa, and 0-6.5V (excluding the left endpoint 0). After the reaction, the material at the bottom of the stratified masterbatch was transferred to a collection tank using the level gauge of the electrolytic fluorination tank. Then, a first magnetic pump was used to transfer the material from the collection tank to the first... In the crude fluorination tower, the fluorine and nitrogen gas entering from the lower inlet of the first crude fluorination tower undergoes secondary fluorination with the aforementioned material. After secondary fluorination, the material is discharged from the bottom outlet of the first crude fluorination tower and transported to the second crude fluorination tower via a second magnetic pump. The material entering the second crude fluorination tower undergoes further fluorination with the fluorine and nitrogen gas entering from the lower inlet of the second crude fluorination tower. The product obtained from the bottom outlet of the second crude fluorination tower is sent to the finished product tank via a third magnetic pump, and then enters the distillation and purification system from the finished product tank. After distillation and purification, the final product is obtained.
[0019] Furthermore, when the volume of material collected in the collection tank is 1 / 2 to 2 / 3 of the collection tank volume, the first magnetic pump is used to transfer the material into the first crude fluorination tower.
[0020] Furthermore, the fluorinated product is collected and tested through a product sampling port set at the bottom outlet of the second crude fluorination tower. If the test fails, the obtained product is pumped into the pipeline between the collection tank and the first magnetic pump by the first magnetic pump, and then sent back into the first crude fluorination tower for cyclic fluorination by the first magnetic pump. If the test passes, the product is sent into the finished product tank by the third magnetic pump, and then enters the distillation and purification system from the finished product tank. After distillation and purification, the final product is obtained.
[0021] Furthermore, if the purity of perfluorotripropylamine is less than 95% after testing the fluorinated product at the sampling port, the test is considered unqualified; if the purity of perfluorotripropylamine is greater than or equal to 95%, the test is considered qualified.
[0022] Furthermore, the electrolytic fluorination reaction ends when the current is ≤1A.
[0023] Furthermore, the mass fraction of the raw material tripropylamine is 5% to 20% of the mass of the raw material hydrogen fluoride.
[0024] Furthermore, the height-to-diameter ratio of the first and second crude fluorination towers is 10:1 to 20:1; the fluorine gas fraction in the fluorine-nitrogen gas is 0 to 5% (excluding the zero at the left end); the rates of the first, second, and third magnetic pumps are set to 0 to 2.5 mol / h (excluding the zero at the left end), and the fluorine-nitrogen gas flow rate is set to 0 to 1 mol / h (excluding the zero at the left end). Fluorination causes a secondary fluorination reaction in some of the fluorination products containing H.
[0025] Furthermore, the HF gas volatilized in the electrolytic fluorination tank and the gaseous impurities from electrolytic fluorination enter the HF condenser. The HF gas is condensed and then returned to the electrolytic fluorination tank, while the other gases after passing through the HF condenser enter the buffer tank.
[0026] Furthermore, the gas in the return tank or collection tank is introduced into the buffer tank through pipelines, and the gas located in the upper part of the first crude fluorination tower and the second crude fluorination tower is also introduced into the buffer tank through pipelines.
[0027] Furthermore, the gas in the buffer tank is sequentially introduced into the first, second, and third washing towers from the bottom. Alkali solution is introduced into the top of the first, second, and third washing towers for washing. The washing liquid after washing is introduced into the waste liquid tank. The washed gas is purified into H2 and discharged after being treated by the activated adsorption tower.
[0028] The features of this invention are: (1) This invention designs and develops a novel composite process, namely, electrolysis-fluorination coupling technology. High-purity perfluorotripropylamine can be efficiently and continuously prepared by combining two different fluorination technologies (electrolytic fluorination and direct fluorination) through an ingenious process; (2) The concentration of fluorine in the fluorine nitrogen gas of the fluorine gas cycle fluorination reaction is ≤5%. A high concentration of fluorine gas can easily destroy the structure of perfluorotripropylamine. (3) The first crude fluorination tower and the second crude fluorination tower of this process have a tower height to tower diameter ratio of 10:1 to 20:1. Fluorination reaction is carried out in this parameter range, and the reaction efficiency, conversion rate and selectivity are optimal.
[0029] Compared with the prior art, the present invention has the following beneficial effects: (1) The process of this invention is simple, highly operable, low in cost, low in impurities, high in product yield, easy to collect, and has great potential for industrial scale-up. It provides a brand-new solution for the large-scale, low-cost production of perfluorotripropylamine and has broad application prospects. (2) The process of this invention integrates electrolytic fluorination and secondary fluorination into a complete process system through ingenious process design, enabling them to work synergistically and complement each other's advantages. This not only improves the safety factor of the process but also increases the product yield; (3) In the first crude fluorination tower and the second crude fluorination tower, the ratio of tower height to tower diameter can enable the material to fully contact with fluorine gas, prolong the residence time in the reaction zone, and ensure that the reactants have a greater probability of being completely fluorinated into the target product perfluorotripropylamine, thereby improving the yield. Attached Figure Description
[0030] Figure 1 This is a schematic flowchart of a method for preparing high-purity perfluorotripropylamine in Examples 1-2; Figure 2 This is the gas chromatogram of the product obtained in Example 1; Figure 3 This is the gas chromatogram of the product obtained in Example 2.
[0031] Figure Labels 1-Mixing kettle, 2-Electrolytic fluorination tank, 3-HF condenser, 4-Buffer tank, 5-First washing tower, 6-Second washing tower, 7-Third washing tower, 8-Activated adsorption tower, 9-Return tank, 10-Collection tank, 11-First crude fluorination tower, 12-Second crude fluorination tower, 13-Finished product tank, 14-First magnetic pump, 15-Second magnetic pump, 16-Third magnetic pump. Detailed Implementation
[0032] To better understand the content of this invention, it will be further described below with reference to specific embodiments and accompanying drawings. The following embodiments are based on the technology of this invention and provide detailed implementation methods and operating steps, but the scope of protection of this invention is not limited to the following embodiments.
[0033] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0034] In Examples 1-2, the direction of medium flow along the pipeline is specified as "before" and "after".
[0035] Please combine Figure 1The apparatus for preparing high-purity perfluorotripropylamine in Examples 1-2 includes a mixing vessel 1. The inlet of the mixing vessel 1 is connected to both the raw material HF pipeline and the tripropylamine pipeline. The outlet of the mixing vessel 1 is connected to the inlet A of the electrolytic fluorination tank 2. The outlet at the bottom of the electrolytic fluorination tank 2 is connected to the inlet at the top of the collecting tank 10. The outlet at the bottom of the collecting tank 10 is connected to the top inlet of the first crude fluorination tower 11 via a first magnetic pump 14. The outlet at the bottom of the first crude fluorination tower 11 is connected to the top inlet of the second crude fluorination tower 12 via a second magnetic pump 15. The outlet at the bottom of the second crude fluorination tower 12 is connected to the inlet of the finished product tank 13 via a third magnetic pump 16. The outlet of the finished product tank 13 is connected to a distillation purification system (the distillation purification system is prior art and will not be described in detail here).
[0036] Fluorine and nitrogen gas pipelines are connected to the lower inlets of the first crude fluorination tower 11 and the second crude fluorination tower 12, respectively, so that fluorine and nitrogen gas are introduced into the first crude fluorination tower 11 and the second crude fluorination tower 12, respectively.
[0037] The outlet at the bottom of the second crude fluorination tower 12 is also equipped with a product sampling port; the outlet at the bottom of the collection tank 10 is connected to the first magnetic pump 14 through a pipeline, and a return valve is provided on the pipeline between the connection port and the product sampling port. If the product sampling port fails the test, the return valve is opened, and the material at the bottom outlet of the second crude fluorination tower 12 is drawn to the connection port by the first magnetic pump 14, and then re-enters the first crude fluorination tower 11 through the first magnetic pump 14.
[0038] The outlet and inlet B at the top of the electrolytic fluorination tank 2 are both connected to the HF condenser 3. Specifically, the outlet is connected to the inlet of the HF condenser 3, and inlet B is connected to the liquid outlet of the HF condenser 3. The volatilized HF and the gaseous impurities from the electrolytic fluorination enter the HF condenser 3 through the outlet. After being condensed by the HF condenser 3, the volatilized HF flows back to the electrolytic fluorination tank 2 through inlet B. The gas outlet of the HF condenser 3 is connected to the inlet at the bottom of the buffer tank 4. The non-condensable tail gas after passing through the HF condenser 3 enters the buffer tank 4. The outlet at the top of the buffer tank 4 is connected to the inlet at the bottom of the first scrubbing tower 5. The outlet at the top of the first scrubbing tower 5 is connected to the inlet at the bottom of the second scrubbing tower 6. The outlet at the top of the second scrubbing tower 6 is connected to the inlet at the bottom of the third scrubbing tower 7. The outlet at the top of the third scrubbing tower 7 is connected to the inlet at the bottom of the activated adsorption tower 8. The outlet at the top of the activated adsorption tower is connected to the venting pipeline.
[0039] The outlets at the top of the collection tank 10, the first crude fluorination tower 11, and the second crude fluorination tower 12 are all connected to the inlet of the buffer tank 4.
[0040] The alkali solution pipelines are connected to the inlets at the top of the first washing tower 5, the second washing tower 6, and the third washing tower 7 via alkali solution pumps. The outlets at the bottom of the first washing tower 5, the second washing tower 6, and the third washing tower 7 are connected to the waste liquid tank via pipelines.
[0041] The inlet at the top of the return tank 9 is also connected to the outlet at the bottom of the electrolytic fluorination tank 2. When the electrolytic fluorination tank 2 malfunctions (e.g., it cannot electrolyze normally and needs to be returned for maintenance), the material in the electrolytic fluorination tank 2 enters the return tank 9. The outlet at the top of the return tank 9 is connected to the inlet of the buffer tank 4.
[0042] In other embodiments, the HF pipeline is also connected to the inlet A of the electrolytic fluorination tank 2. If the amount of HF used during the reaction is insufficient, the HF liquid can be directly added to the electrolytic fluorination tank 2 through the pipeline.
[0043] In Examples 1-2, when preparing high-purity perfluorotripropylamine, before introducing the raw materials, high-purity nitrogen gas was introduced into the mixing tank 1, collecting tank 10, electrolytic fluorination tank 2, first crude fluorination tower 11, second crude fluorination tower 12, finished product tank 13, unloading tank 9, and the corresponding pipelines for evacuation and replacement.
[0044] Example 1: 800 mL of HF liquid and 50 g of tripropylamine were introduced into mixing vessel 1, and stirred for 2 hours at -10°C and 100 r / min. The resulting mixture was then introduced into electrolytic fluorination tank 2 (in other embodiments, if the amount of HF liquid used is insufficient, the HF liquid can be directly added to electrolytic fluorination tank 2 through a pipeline). Electrolytic fluorination was then carried out at -5°C to 0°C, standard atmospheric pressure (i.e., 101 kPa), and a constant voltage of 5.5 V until the current was ≤1 A, at which point electrolysis was completed. After electrolysis, the material at the bottom of the stratified masterbatch was introduced into collection tank 10, where approximately 136.36 g of material was collected. The material was then transported from collection tank 10 to the top of the first crude fluorination tower 11 using a first magnetic pump 14 and introduced into the first crude fluorination tower 11. Fluorine and nitrogen gas entering from the lower inlet of the first crude fluorination tower 11 reacted with the material. A second fluorination process is performed. After the second fluorination, the material is discharged from the bottom outlet of the first crude fluorination tower 11 and transported to the top of the second crude fluorination tower 12 via the second magnetic pump 15. The material entering the second crude fluorination tower 12 is further fluorinated with fluorine and nitrogen gas entering from the lower inlet of the second crude fluorination tower 12. Afterward, the fluorinated product is collected and tested through a product sampling port set at the bottom outlet of the second crude fluorination tower 12. If the test is qualified (i.e., the purity of perfluorotripropylamine is greater than or equal to 95%), the product is sent to the finished product tank 13 via the third magnetic pump 16, and then enters the distillation purification system from the finished product tank 13. After distillation purification, the final product is obtained with a purity of 98.3%. If the test is unqualified, the obtained product is drawn into the pipeline between the collection tank 10 and the first magnetic pump 14 via the first magnetic pump 14, and then sent back to the first crude fluorination tower 11 via the first magnetic pump 14 for cyclic fluorination. In this embodiment, the height of the first crude fluorination tower 11 and the second crude fluorination tower 12 are both 10 meters and the diameter of the towers is 1 meter.
[0045] Of these, the fluorine gas component in fluorine nitrogen gas is 3%.
[0046] In this embodiment, a total of 141.92g of the final product was collected, and the purity of perfluorotripropylamine was found to be 98.3%.
[0047] Among them, the gas in the discharge tank 9 or the collection tank 10 is introduced into the buffer tank 4 through pipelines, and the gas located in the upper part of the first crude fluorination tower 11 and the second crude fluorination tower 12 is also introduced into the buffer tank 4 through pipelines.
[0048] The HF gas volatilized in the electrolytic fluorination tank 2 and the gaseous impurities from electrolytic fluorination enter the HF condenser. The HF gas is condensed and then returned to the electrolytic fluorination tank 2. The other gases after passing through the HF condenser enter the buffer tank 4.
[0049] The gas in buffer tank 4 is sequentially introduced into the first washing tower 5, the second washing tower 6, and the third washing tower 7 from the bottom. Alkali solution is introduced into the top of the first washing tower 5, the second washing tower 6, and the third washing tower 7 for washing. The washing liquid after washing is introduced into the waste liquid pool. The washed gas is purified into H2 after being treated by the activated adsorption tower 8 and then discharged into the air.
[0050] Figure 2 This is the gas chromatogram of the final product obtained in this embodiment, by Figure 2 It can be seen that the peak of perfluorotripropylamine is at 2.061 min, and its purity is 98.3%.
[0051] Example 2: 800 mL of HF liquid and 50 g of tripropylamine were introduced into mixing vessel 1, and stirred for 2 hours at -10℃ and 100 r / min. The resulting mixture was then introduced into electrolytic fluorination tank 2, and electrolytic fluorination was carried out at 0℃~5℃, standard pressure, and a constant voltage of 5.5V until the current was ≤1A, at which point electrolysis was completed. After electrolysis, the bottom layer of the stratified masterbatch was transferred to collection tank 10, where approximately 147.21 g of material was collected. This material was then transported from collection tank 10 to the top of the first crude product reaction tower 11 using a first magnetic pump 14 and introduced into the first crude product fluorination tower 11. Fluorine and nitrogen gas entering from the lower inlet of the first crude product fluorination tower 11 reacted with the material for secondary fluorination. After secondary fluorination, the material was discharged from the bottom of the first crude product fluorination tower 11. The material is discharged from the outlet and transported to the top of the second crude fluorination tower 12 via the second magnetic pump 15. The material entering the second crude fluorination tower 12 is further fluorinated with fluorine and nitrogen gas entering from the lower inlet of the second crude fluorination tower 12. Afterwards, the fluorinated product is collected and tested through the product sampling port set at the bottom outlet of the second crude fluorination tower 12. If the test is qualified (the purity of perfluorotripropylamine is greater than or equal to 95%), the product is sent to the finished product tank 13 via the third magnetic pump 16, and then enters the distillation purification system from the finished product tank 13. After distillation purification, the final product is obtained with a purity of 99.43%. If the test is unqualified, the obtained product is drawn into the pipeline between the collection tank 10 and the first magnetic pump 14 via the first magnetic pump 14, and then sent back to the first crude fluorination tower 11 via the first magnetic pump 14 for cyclic fluorination. In this embodiment, the height of the first crude fluorination tower 11 and the second crude fluorination tower 12 are both 15 meters and the diameter of the towers is 1 meter.
[0052] Of these, the fluorine gas component in fluorine nitrogen gas is 5%.
[0053] In this embodiment, a total of 158.36g of the final product was collected, and the purity of perfluorotripropylamine was found to be 99.43%.
[0054] Figure 3This is the gas chromatogram of the final product obtained in this embodiment, by Figure 3 It can be seen that the peak of perfluorotripropylamine is at 2.124 min, and its purity is 99.43%.
[0055] The above description is merely an embodiment of the present invention and is not intended to limit the present invention in any way. The present invention can also have other embodiments based on the above structure and function, which will not be listed hereafter. Therefore, any simple modifications, equivalent changes, and alterations made by those skilled in the art to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.
Claims
1. An apparatus for preparing high-purity perfluorotripropylamine, characterized in that, The system includes a mixing vessel, whose inlet is connected to both the HF pipeline and the tripropylamine pipeline. The outlet of the mixing vessel is connected to inlet A of the electrolytic fluorination tank. The outlet at the bottom of the electrolytic fluorination tank is connected to the inlet at the top of the collection tank. The outlet at the bottom of the collection tank is connected to the top inlet of the first crude fluorination tower via a first magnetic pump. The outlet at the bottom of the first crude fluorination tower is connected to the top inlet of the second crude fluorination tower via a second magnetic pump. The outlet at the bottom of the second crude fluorination tower is connected to the inlet of the finished product tank via a third magnetic pump. The outlet of the finished product tank is connected to the distillation and purification system. Fluorine and nitrogen pipelines are connected to the lower inlets of the first and second crude fluorination towers, respectively.
2. The apparatus for preparing high-purity perfluorotripropylamine as described in claim 1, characterized in that, The outlet at the bottom of the second crude fluorination tower is also equipped with a product sampling port; the outlet of the collection tank at the bottom is connected to the first magnetic pump, and a return valve is provided on the pipeline connecting the connection port and the product sampling port.
3. The apparatus for preparing high-purity perfluorotripropylamine as described in claim 1, characterized in that, The outlet and inlet B of the electrolytic fluorination tank at the top are both connected to the HF condenser. The gas outlet of the HF condenser is connected to the inlet of the buffer tank at the bottom. The outlet of the buffer tank at the top is connected to the inlet of the first scrubbing tower at the bottom. The outlet of the first scrubbing tower at the top is connected to the inlet of the second scrubbing tower at the bottom. The outlet of the second scrubbing tower at the top is connected to the inlet of the third scrubbing tower at the bottom. The outlet of the third scrubbing tower at the top is connected to the inlet of the activated adsorption tower at the bottom. The outlet at the top of the activated adsorption tower is connected to the vent pipeline.
4. The apparatus for preparing high-purity perfluorotripropylamine as described in claim 1, characterized in that, The outlets at the top of the collection tank, the first crude fluorination tower, and the second crude fluorination tower are all connected to the inlet of the buffer tank; the alkali pipelines are connected to the inlets at the top of the first, second, and third washing towers via alkali pumps; and the outlets at the bottom of the first, second, and third washing towers are connected to the waste liquid pool via pipelines.
5. The apparatus for preparing high-purity perfluorotripropylamine as described in claim 1, characterized in that, The inlet at the top of the return tank is also connected to the outlet at the bottom of the electrolytic fluorination tank; the HF pipeline is also connected to inlet A of the electrolytic fluorination tank.
6. A method for preparing high-purity perfluorotripropylamine, using the preparation apparatus described in any one of claims 1-5, specifically comprising the following steps: Nitrogen gas was introduced into the apparatus for evacuation and replacement. Then, liquid hydrogen fluoride and tripropylamine were introduced into the mixing vessel and stirred for 2-3 hours at -20℃ to -10℃. The resulting mixture was then transferred to an electrolytic fluorination tank and subjected to electrolytic fluorination at -5℃ to 5℃, 0-101 kPa, and 0-6.5 V. After the reaction, the bottom layer of the stratified masterbatch was transferred to a collection tank. A first magnetic pump was then used to transfer the material from the collection tank to the first crude fluorination tower. The fluorine and nitrogen gas entering at the lower inlet of the first crude fluorination tower undergoes secondary fluorination with the aforementioned material. After secondary fluorination, the material is discharged from the bottom outlet of the first crude fluorination tower and transported to the second crude fluorination tower via a second magnetic pump. The material entering the second crude fluorination tower undergoes further fluorination with the fluorine and nitrogen gas entering from the lower inlet of the second crude fluorination tower. The product obtained from the bottom outlet of the second crude fluorination tower is sent to the finished product tank via a third magnetic pump, and then enters the distillation and purification system from the finished product tank. After distillation and purification, the final product is obtained.
7. The method for preparing high-purity perfluorotripropylamine as described in claim 6, characterized in that, The fluorinated product is collected and tested through a sampling port set at the bottom outlet of the second crude fluorination tower. If the test fails, the product is pumped into the pipeline between the collection tank and the first magnetic pump by the first magnetic pump, and then sent back into the first crude fluorination tower for cyclic fluorination by the first magnetic pump. If the test passes, the product is sent into the finished product tank by the third magnetic pump, and then enters the distillation and purification system from the finished product tank. After distillation and purification, the final product is obtained.
8. The method for preparing high-purity perfluorotripropylamine as described in claim 6, characterized in that, When the current is ≤1A, the electrolytic fluorination reaction ends; the mass fraction of the raw material tripropylamine is 5%~20% of the mass of hydrogen fluoride; the ratio of the height to the diameter of the first crude fluorination tower and the second crude fluorination tower is 10:1~20:1; the fluorine gas fraction in the fluorine nitrogen gas is 0~5%.
9. The method for preparing high-purity perfluorotripropylamine as described in claim 7, characterized in that, The rates of the first, second, and third magnetic pumps are set to 0~2.5 mol / h, and the rate of fluorine and nitrogen gas introduction is set to 0~1 mol / h. If the purity of perfluorotripropylamine is less than 95% after the fluorinated product is collected and tested at the product sampling port, the test is considered unqualified. If the purity of perfluorotripropylamine is greater than or equal to 95%, the test is considered qualified.
10. The method for preparing high-purity perfluorotripropylamine as described in claim 6, characterized in that, The HF gas volatilized in the electrolytic fluorination cell and the gaseous impurities from electrolytic fluorination enter the HF condenser. The HF gas is condensed and then returned to the electrolytic fluorination cell. The other gases after passing through the HF condenser enter the buffer tank. The gas in the buffer tank is sequentially fed into the first, second, and third scrubbing towers from the bottom. Alkali solution is fed into the top of the first, second, and third scrubbing towers for scrubbing. The scrubbing liquid is then fed into the waste liquid tank. The scrubbing gas is purified into H2 and discharged into the air after being treated by the activated adsorption tower.