Solvent drying device and method for drying organic solvent through potassium-sodium alloy and capable of being recycled for multiple times

Abstract

The invention discloses a solvent drying device and method for drying an organic solvent through a potassium-sodium alloy and capable of being used repeatedly, the solvent water and oxygen removal device comprises a reaction bottle for distillation and a collection bottle arranged above the reaction bottle, the upper end of the reaction bottle is communicated with the upper end of the collection bottle through a distillation neck, and the lower end of the collection bottle is communicated with the potassium-sodium alloy. A liquid nitrogen cold trap for cooling is arranged on the distillation neck; the collecting bottle is provided with a second high-vacuum throttle, the reaction bottle is provided with a first high-vacuum throttle, and the pressure in the bottle can be adjusted through the first high-vacuum throttle and the second high-vacuum throttle, so that a solvent and metal can be fed and taken out under the protection of inert gas; a stirrer is arranged in the reaction bottle. According to the method, an extremely sensitive chemical reaction system can be met, a glass firing process does not need to be mastered, the experiment threshold of a conventional potassium-sodium alloy drying solvent method is reduced, the potassium-sodium alloy drying solvent can be recycled for multiple times, and potential safety hazards caused by residual metal after each time of drying in the common potassium-sodium alloy drying solvent method are avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of solvent purification, and in particular relates to a solvent drying method which uses a potassium-sodium alloy to dry an organic solvent and can be recycled for multiple times. Background Art

[0002] In chemical synthesis, the raw materials and products of the reaction are often sensitive to air, that is, they are unstable to water and oxygen in the air, so it is necessary to remove water and oxygen from the organic solvent. In particular, some particularly sensitive reaction systems, such as carbon anions / carbon cations, carbenes / carbynes, organometallic reagents, metal organic catalysts, rare earth complexes, and multiple free radicals, have higher requirements for anhydrous and oxygen-free solvents. In order to avoid surface passivation or inactivation in reactions with alkali metals, strong oxidants, and other active initiators, the water and oxygen content (ppm) of the organic solvent is usually required to be less than 0.1 (ppm means one part per million).

[0003] At present, there are four main methods for dehydrating and deoxygenating organic solvents in laboratories: 1. Molecular sieve-assisted double-row tube high vacuum line operation: that is, first use the activated molecular sieve to dehydrate the organic solvent, and then the dehydrated organic solvent is repeatedly evacuated and filled with inert gas on the double-row tube high vacuum line with liquid nitrogen; 2. Solvent purification device: that is, the solvent purification device sold on the market, which is achieved by purifying with a filter column; 3. Sodium metal plus benzophenone (indicator) reflux method: that is, add sodium metal and benzophenone to the organic solvent, and then use a common distillation device to heat and reflux for a long time; 4. Potassium-sodium alloy drying: use potassium-sodium alloy to dry the organic solvent, and then use a common distillation transfer device to distill and transfer after drying; or use a homemade integrated glass tool to react and transfer.

[0004] However, each of the above methods has its own limitations: the organic solvent obtained by drying in method 1 has a high oxygen content and can only be applied to general anhydrous and oxygen-free reaction systems. It is not applicable to some sensitive reactions, such as nanocarbon reduction reaction, preparation of rare earth complexes, metal organic complexes, and stabilization of multiple free radicals; the solvent purification device described in method 2 is generally expensive, up to hundreds of thousands, and will be exposed to air for a short time after collection, and the use of filter column purification will cause the anhydrous and oxygen-free organic solvent to contain trace metal ions, thereby reducing the success rate of the reaction; method 3 often requires heating and reflux for dozens of hours. If it is not supervised, the long-term heating and reflux of the heating jacket is prone to safety hazards, causing serious The consequences of this method are that the distillation of the solvent often needs to be much greater than the boiling point of the solvent, which is not suitable for some organic solvents with strong coordination and high boiling points, such as diethylene glycol dimethyl ether (boiling point is 159.76°); the drying effect of the potassium-sodium alloy in method 4 is very good, but the several parts of the common distillation transfer device are not integrated, but spliced ​​together by vacuum silicone grease, which will cause the quality of the anhydrous and oxygen-free solvent to deteriorate during the distillation transfer process, which is not suitable for extremely sensitive reaction systems. The self-made integrated glass tool is used for reaction and transfer, and it needs to be re-glassed after each use. Moreover, these two methods cannot be recycled. After each use, the large amount of potassium-sodium alloy remaining needs to be quenched, which is very dangerous. Therefore, a solvent drying device and method that uses potassium-sodium alloy to dry organic solvents and can be recycled for multiple times are developed. Summary of the invention

[0005] Due to the above-mentioned defects in the prior art, the present invention provides a solvent drying device and method for drying organic solvents with potassium-sodium alloy and being recyclable for multiple times. The device and method have an integrated glass system, low operating requirements, low cost, and excellent sealing performance. The potassium-sodium alloy can be used for purification, and the purification effect is good, which can meet the needs of sensitive reaction systems; the device can be reused multiple times, so there is no need to frequently treat a large amount of residual potassium-sodium alloy, which is safer; and because the pressure of the system is adjustable, purification can be performed under negative pressure, and the temperature required for the operation is much lower than the boiling point of the solvent, which can meet the drying needs of some strongly coordinated and high-boiling-point organic solvents, such as diethylene glycol dimethyl ether (boiling point is 159.76°). The present invention provides a solvent drying device and method for drying an organic solvent using a potassium-sodium alloy and capable of being recycled and reused multiple times. The dried anhydrous and oxygen-free solvent has high quality, can meet the requirements of extremely sensitive chemical reaction systems, has low operation requirements, has low heating requirements, and reduces safety risks; it has the characteristics of high efficiency, economy, recyclability and safety, can meet the requirements of extremely sensitive chemical reaction systems (such as carbon anions / carbon cations, carbenes / carbynes, organic metal reagents, metal organic catalysts, rare earth complexes, multiple free radicals, etc.), does not require the mastery of glass firing technology, has low operation requirements, and can avoid the safety hazards of conventional potassium-sodium alloy drying organic solvent methods.

[0006] To achieve the above-mentioned purpose, in a first aspect, the present invention provides a solvent drying device that uses potassium-sodium alloy to dry organic solvents and can be recycled for multiple times, comprising an integrally sintered glass purification device and a high vacuum valve; the glass purification device comprises a reaction bottle for distillation and a collecting bottle arranged above the reaction bottle, the upper end of the collecting bottle is connected to the reaction bottle through a distillation neck, and a liquid nitrogen cold trap for cooling is arranged between the distillation neck and the collecting bottle; a connecting pipe is arranged between the collecting bottle and the reaction bottle, and the connecting pipe connects the collecting bottle and the reaction bottle; the high vacuum valve comprises a first high vacuum valve arranged on the connecting pipe and a second high vacuum valve arranged on the collecting bottle; the first high vacuum valve can control the connecting pipe by closing or partially opening a valve core, thereby selectively controlling the connection between the collecting bottle and the reaction bottle; the second high vacuum valve is provided with an exhaust port, and the reaction bottle is provided with a sodium-potassium alloy and a stirrer.

[0007] By adopting the above technical scheme, the overall structure of the recyclable solvent dehydration and deoxygenation device provided by the present invention is composed of integrated glass, and the vacuum sealing is better, and potassium-sodium alloy can be used to quickly dehydrate and deoxygenate various organic solvents; it can be quickly dried at room temperature, avoiding safety accidents caused by long-term heating; after an organic solvent is distilled, the remaining organic solvent can be stored in a reaction bottle, and the solvent or potassium-sodium alloy can be directly added after it is used up, so as to achieve the purpose of reuse, so it is not necessary to process the potassium-sodium alloy after each use, avoiding safety hazards; in addition, the pressure in the reaction bottle can be adjusted by a high vacuum valve, and the temperature required for the operation is much lower than the boiling point of the solvent, so it is safer. And the unused solvent in the collection bottle can be refluxed into the reaction bottle through the Unicom pipe, avoiding the waste of solvent, which is more economical.

[0008] In some embodiments, the liquid nitrogen cold trap includes a condensation cup with a hollow interior and a liquid nitrogen pool formed by the depression of the condensation cup; the interior of the condensation cup is connected to the distillation neck and the collecting bottle respectively, and the liquid nitrogen pool can store liquid nitrogen.

[0009] With such a design, liquid nitrogen can be directly added to the liquid nitrogen pool, which is convenient to add. The liquid nitrogen pool is wrapped by the condensation cup, and the liquid nitrogen can cool the gas inside the condensation cup. The structure is simple, the contact surface is large during the cooling process, and the cooling effect is good.

[0010] In some embodiments, the high vacuum valves are all high vacuum Schlenk-type glass valves that are thread-sealed with a plug fully covered with perfluoroethylene, and the first high vacuum valve and the second high vacuum valve can be used to load and discharge materials under inert gas;

[0011] The gas extraction port can be connected to a double-row tube, and with the cooperation of the double-row tube, the gas pressure inside the device can be adjusted under inert gas. The stirrer is configured as a magnetic stirrer fully covered by glass.

[0012] The double row of tubes is used to provide an inert environment and a vacuum condition.

[0013] In some embodiments, for safety reasons, the wall thickness of all glass equipment used needs to be greater than or equal to 1 mm, the reaction bottle is set to a round-bottom flask with a volume of 150 mL to 2000 mL; the collecting bottle is set to a round-bottom flask with a volume not greater than half of the volume of the reaction bottle; the shortest distance between the distillation neck and the collecting bottle is greater than 1 cm; the shortest distance between the liquid nitrogen cold trap and the collecting bottle is greater than 1 cm; the glass thickness at the liquid nitrogen cold trap is not less than 1 mm.

[0014] This design is used to meet the overall strength requirements.

[0015] In a second aspect, the present invention further provides a solvent drying method for drying an organic solvent using a potassium-sodium alloy and being recyclable for multiple uses, comprising the following steps:

[0016] S1. After the entire solvent dehydration and deoxygenation device is baked in an oven, a double-row pipe is used to repeatedly evacuate and fill with inert gas three times through the exhaust port to construct an anhydrous and oxygen-free internal environment of the device, and then the stirrer, potassium-sodium alloy and organic solvent are put into the reaction bottle through the first high vacuum valve; during this period, the device always needs to be kept at a slightly positive pressure.

[0017] In some embodiments, the stirrer and potassium-sodium alloy are put into the reaction bottle through the first high vacuum valve in the glove box, and then the vacuum is repeatedly evacuated and filled with inert gas three times using a double-row tube, and then the required organic solvent is put into the reaction bottle through the first high vacuum valve.

[0018] S2. Stirring the organic solvent in the reaction flask by using the stirrer.

[0019] S3. After repeatedly decompressing the device on the double-row pipes through the second high vacuum valve for at least 2 times, pouring liquid nitrogen into the liquid nitrogen cold trap, and then repeating the decompression for at least 2 times.

[0020] S4, baking the reaction bottle to distill the organic solvent, condensing it in a liquid nitrogen cold trap and storing it in the collection bottle.

[0021] S5. The treated organic solvent is extracted under the protection of inert gas through the second high vacuum valve. During this process, the device is kept at a slightly positive pressure.

[0022] S6. After use, the second high vacuum valve can be opened to allow the unused residual organic solvent in the collection bottle to be recovered into the reaction bottle.

[0023] In some embodiments, in order to meet the needs of sensitive reaction systems, in step S1, the solvent dehydration and deoxygenation device is baked at a temperature of 80° or above for 30 minutes or more to remove the residual moisture on the surface of the glass. In order to ensure the anhydrous and oxygen-free environment of the system, the vacuum degree of the above-mentioned repeated vacuuming needs to be evacuated to less than 100 mbar on the vacuum gauge, and each decompression is evacuated to 600 mbar or less on the vacuum gauge. At the same time, in order to avoid oxygen inflow when entering and exiting the material, it is necessary to ensure that the speed of inert gas flowing into the device is not less than 70 ml / min to ensure that the pressure of the glass device is always kept positive. The above-mentioned inert gas refers to a gas that is chemically inactive and relatively stable, including but not limited to helium, nitrogen, argon, etc. with a purity of not less than 99.999%. For reactions involving alkali metals, argon is usually used as an inert gas for safety and cost considerations, and high-purity argon with a purity of not less than 99.999% is required. For safety, in step S4, the baking temperature should be greater than or equal to the boiling point of the organic solvent, but should be less than 500°C to prevent the glass from melting.

[0024] Compared with the prior art, the above invention has the following advantages or beneficial effects: the solvent drying method of drying organic solvents with potassium-sodium alloy and being recyclable multiple times can meet the needs of extremely sensitive chemical reaction systems (such as carbon anions / carbon cations, carbenes / carbynes, organic metal reagents, metal organic catalysts, rare earth complexes, multiple free radicals, etc.), does not require mastering the glass firing process, has low operating requirements, can avoid the safety hazards of conventional potassium-sodium alloy drying organic solvents, and is low-cost, and has great application value and commercial value in the field of organic solvent purification. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention and its features, appearance and advantages will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings. The same reference numerals indicate the same parts in all the drawings. The drawings are not drawn to scale, and emphasis is placed on illustrating the subject matter of the present invention.

[0026] Figure 1 A schematic diagram of a recyclable solvent dehydration and deoxygenation device provided in an embodiment of the present invention;

[0027] Figure 2 A schematic diagram of a second high vacuum valve provided in an embodiment of the present invention.

[0028] Among them, 1. reaction bottle; 1-1. first high vacuum valve; 2. collecting bottle; 2-1. second high vacuum valve; 3. distillation neck; 4. liquid nitrogen cold trap; 4-1. condensation cup; 4-2. liquid nitrogen pool; 5. stirring bar; 6. connecting pipe; 7. vacuum port. DETAILED DESCRIPTION

[0029] The structure of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but is not intended to limit the present invention.

[0030] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be noted that the terms "first" and "second" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0032] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0033] Example

[0034] See also Figure 1 The present embodiment provides a solvent drying device that uses potassium-sodium alloy to dry organic solvents and can be recycled for multiple times, including an integrally formed glass purification device and a high vacuum valve; the glass purification device includes a reaction bottle 1 for distillation and a collecting bottle 2 arranged above the reaction bottle 1, the upper end of the collecting bottle 2 is connected to the upper end of the reaction bottle 1 through a distillation neck 3, and a liquid nitrogen cold trap 4 for cooling is arranged between the distillation neck 3 and the collecting bottle 2; a connecting pipe 6 is arranged between the collecting bottle 2 and the reaction bottle 1, and the connecting pipe 6 connects the collecting bottle 2 and the reaction bottle 1; the high vacuum valve includes a first high vacuum valve 1-1 arranged on the connecting pipe and a second high vacuum valve 2-1 arranged on the collecting bottle; the first high vacuum valve 1-1 can close or open the connection between the collecting bottle 2 and the reaction bottle 1 through a valve core; the reaction bottle 1 is provided with a sodium-potassium alloy and a stirrer 5.

[0035] It is worth noting that the distillation and condensation device in the prior art is not integrated. When it is needed, multiple glasswares are assembled, and silicone grease is used at the joints to prevent air from entering. The solvent dried by this system can only be used for general anhydrous and oxygen-free reactions, and cannot be used for some particularly sensitive reaction systems, such as carbon anions / carbon cations, carbenes / carbynes, organic metal reagents, metal organic catalysts, rare earth complexes, and multiple free radicals. Although some advanced laboratory staff abroad have mastered the glass firing process and used a self-made sintered integrated glass transfer system to use potassium-sodium alloy to dry solvents, it is necessary to re-fire the glass after each use, and the large amount of potassium-sodium alloy remaining after each use needs to be quenched, which is very dangerous.

[0036] The present invention not only uses an integrally formed glass system, but also has better sealing performance, and can safely use potassium-sodium alloy to remove water and oxygen, and can meet the needs of sensitive chemical systems. Compared with the method of drying solvents with metallic sodium, it can be dried quickly at room temperature, does not require long-term heating, and avoids safety accidents caused by long-term heating; and can be recycled, and the potassium-sodium alloy does not need to be processed after each use, which is safer.

[0037] The general distillation and condensation device in the prior art has insufficient air tightness and needs to continuously pass inert gas into the system, which is a great waste of inert gas; and under positive pressure, liquid nitrogen cannot be used for cooling, and only water condensation can be used, which increases the difficulty of distillation. In addition, it is in a positive pressure environment, which makes it almost impossible to distill high-boiling point solvents. In this embodiment, since the entire solvent dehydration and deoxygenation device has good sealing properties, air can be extracted through a high vacuum valve to make the interior of the solvent dehydration and deoxygenation device under negative pressure, the melting point of the solvent is lower, and the high-boiling point solvent is easy to distill. In addition, since the solvent used for purification itself already has a high purity, a lot of impurities will not accumulate in the reaction bottle, and it only needs to be cleaned once at intervals.

[0038] Specifically, sodium-potassium alloy and stirrer 5 can be added into reaction bottle 1 through first high vacuum valve 1-1 via connecting pipe 6, and the purified organic solvent can be extracted from second high vacuum valve 2-1 disposed on collecting bottle 2 through needle.

[0039] It should be noted that the water content in this example was measured by a Karl Fischer apparatus, i.e., about 3.0 mL (the exact amount added was accurately determined by weighing the filled syringe and the empty syringe after injecting the sample into the cell on a three-decimal balance inside the glove box and calculating the difference) of sample was injected into the anode chamber of the measuring cell of the Karl Fischer apparatus (N=6).

[0040] Laboratory glass solvent purification used in the prior art generally uses sodium as a desiccant, and the residual water content (ppm) is generally about 43.4, and the residual oxygen content (ppm) is generally about 32.5. This treatment method requires long-term high-temperature reflux and has poor safety; the glass needs to be sealed with grease, and the airtightness is poor; the purification effect is not as good as potassium-sodium alloy; in addition, commercial solvent purification systems use molecular sieves, activated aluminum and activated copper as desiccants, and the residual water content (ppm) is about 1, and the residual oxygen content (ppm) is about 1, but this device is expensive, all of which are more than hundreds of thousands, and the purification column is disposable and requires maintenance; Filtration purification will introduce trace amounts of metal ions to contaminate the solvent.

[0041] The recyclable solvent dehydration and deoxygenation device disclosed in the present application uses potassium-sodium alloy to quickly dehydrate and deoxygenate various organic solvents, and processes them in an integrated glass device. After the treatment, high-quality anhydrous and oxygen-free organic solvents can be obtained, and the water-oxygen content ppm is less than 0.1. This solvent dehydration and deoxygenation equipment is simple to operate, low in cost, high in efficiency, adjustable in pressure, and recyclable, avoiding the safety problems faced by long-term heating and frequent handling of residual potassium-sodium alloy, as well as the problem of impurity generation caused by long-term drying or heating.

[0042] In some embodiments, the liquid nitrogen cold trap 4 includes a condensation cup 4-1 with a hollow interior and a liquid nitrogen pool 4-2 formed by the depression of the condensation cup 4-1; the interior of the condensation cup 4-1 is connected to the distillation neck 3 and the collecting bottle 2 respectively, and the liquid nitrogen pool 4-2 stores liquid nitrogen and cools the condensation cup 4-1. With such a design, the liquid nitrogen pool of such a shape is more convenient for adding liquid nitrogen, and at the same time, the liquid nitrogen has a larger contact surface with the vaporized solvent, and the cooling effect is good. At the same time, compared with conventional multiple cooling tubes, the structure is simpler, and the manufacturing is simpler in the integrated molding manufacturing process of the entire solvent dehydration and deoxygenation device.

[0043] The high vacuum valves are all high vacuum Schlenk type glass valves with threaded seals using plugs fully covered with all-tetrafluoroethylene, and can be partially or fully opened when inert gas is introduced.

[0044] With such a design, before the reaction, the sodium-potassium alloy, the stirrer 5 and the solvent can be added to the reaction bottle 1 under the protection of inert gas by fully opening the first high vacuum valve 1-1; after the reaction, the first high vacuum valve 1-1 can be partially opened to heat the solution for reflux and rinse the glass system; after reflux, the first high vacuum valve 1-1 can be completely closed to collect the purified solvent in the collection bottle 2; after collection, the second high vacuum valve 2-1 can be fully opened to extract the purified liquid with a syringe under the protection of inert gas; after use, the first high vacuum valve 1-1 can be partially opened to allow the solvent to flow back to the reaction bottle 1. Since the solvent dehydration and deoxygenation device has excellent sealing performance, the solvent can be stored in the reaction bottle and taken at any time as needed.

[0045] In some embodiments, the reaction bottle 1 is set as a round-bottom flask with a volume of 150 mL to 2000 mL; the collecting bottle 2 is set as a round-bottom flask with a volume not greater than half of the volume of the reaction bottle 1; the shortest distance between the distillation neck 3 and the collecting bottle 2 is greater than 1 cm; the shortest distance between the liquid nitrogen cold trap 4 and the collecting bottle 2 is greater than 1 cm; the glass thickness at the liquid nitrogen cold trap 4 is not less than 1 mm. In some embodiments, the second high vacuum valve 2-1 and the first high vacuum valve 1-1 are both set as valves with a sealed stopper fully covered with tetrafluoroethylene. The stirrer 5 is set as a magnetic stirrer fully covered with glass.

[0046] In general, the present invention can meet the needs of extremely sensitive chemical reaction systems, does not require the mastery of glass firing technology, lowers the experimental threshold of the conventional potassium-sodium alloy drying solvent method, and can be recycled multiple times, avoiding the safety hazard caused by residual metal after each drying in the common potassium-sodium alloy drying solvent method.

[0047] Example 1

[0048] Taking the organic solvent tetrahydrofuran as an example, the specific process of using the purification method of the present application is: first, the purification equipment is baked in an oven at 110° or above for more than 30 minutes; after baking, it is then transferred to a glove box, and the glass stirrer 5 and the potassium-sodium alloy are put into the reaction bottle 1 through the first high vacuum valve 1-1 in the glove box; the double-row pipe is repeatedly evacuated and filled with high-purity (99.999%) argon gas 3 times through the second high vacuum valve 2-1, and the vacuum degree is drawn to 100 mba each time. Then, the second high vacuum valve 2-1 is partially opened to allow argon gas to flow into the device at a rate of not less than 70 ml / min to ensure that the device is used at a slightly positive pressure; the first high vacuum valve 1-1 is fully opened, and tetrahydrofuran (anhydrous grade) is put into the reaction bottle 1 through the first high vacuum valve 1-1, and the two high vacuum valves are closed to stir the solution and the potassium-sodium alloy for 3 hours. After stirring for 3 hours, the second high vacuum valve 2-1 was repeatedly evacuated and filled with high-purity (99.999%) argon gas for 3 times, and the vacuum degree was 100 mba each time. The pressure was reduced for more than 2 times, and liquid nitrogen was introduced into the liquid nitrogen cold trap, and then the pressure was reduced for more than 2 times, and it was noted that the vacuum degree was reduced to 600 mba each time; then the reaction bottle 1 was baked with a hot air gun, and the organic solvent was distilled and stored in the collection bottle 2 through the liquid nitrogen cold trap 4; finally, the purified tetrahydrofuran could be extracted with a syringe in an argon environment through the first high vacuum valve 2-1.

[0049] In order to better clarify the quality of the anhydrous and oxygen-free organic solvent obtained by the solvent purification device disclosed in this patent, the reaction rate of cyclopentene and metallic lithium (Li) in tetrahydrofuran solvent is used as a measure to compare the quality of tetrahydrofuran obtained by different purification methods. (Cyclopentene will undergo a reduction reaction with metallic lithium to gradually gain electrons, and the gain of electrons will cause the absorption spectrum to red-shift with the change of the degree of molecular conjugation, and the color will change from light yellow to dark green, dark purple, reddish brown, and dark brown. Since cyclopentene anions are extremely sensitive to water and oxygen, the time for the large-scale generation of their first reduced state can be used as a criterion for judging the quality of the solvent.)

[0050] Table 1 Results of different purification methods for tetrahydrofuran

[0051]

[0052] Referring to Table 1, the following results can be obtained by comparing the effects of this example with those after purification by the prior art: molecular sieve-assisted double-row tube high vacuum line operation is indeed not suitable for particularly sensitive chemical reaction systems; the time required for purifying tetrahydrofuran by sodium plus benzophenone is 48 hours, the residual water content (ppm) is 43.4, the residual oxygen content (ppm) is 32.5, and the solvent color change time during the reduction of cyclopentene is 10 minutes; the time required for purifying tetrahydrofuran by a commercial solvent purification system is 72 hours, the residual water content (ppm) is 0.8, the residual oxygen content (ppm) is 0.9, and the solvent color change time during the reduction of cyclopentene is 5 minutes; while the time required for this example is 3 hours, the residual water content (ppm) is 0.05, the residual oxygen content (ppm) is 0.08, and the solvent color change time during the reduction of cyclopentene is 10 seconds.

[0053] Example 2

[0054] Taking n-hexane as an example, the specific process of using the purification method of the present application is: first, the purification equipment is baked in an oven at 110° or above for more than 30 minutes; after baking, it is then transferred to a glove box, and the glass stirrer 5 and the potassium-sodium alloy are put into the reaction bottle 1 through the first high vacuum valve 1-1 in the glove box; the double-row pipe is repeatedly evacuated and filled with high-purity (99.999%) argon gas 3 times through the second high vacuum valve 2-1, and the vacuum degree is drawn to 100 mba each time. Then, the second high vacuum valve 2-1 is partially opened to allow argon gas to flow into the device at a rate of not less than 70 liters / minute to ensure that the device is used at a slightly positive pressure; the first high vacuum valve 1-1 is fully opened, and n-hexane (anhydrous grade) is put into the reaction bottle 1 through the first high vacuum valve 1-1, and the two high vacuum valves are closed to stir the solution and the potassium-sodium alloy for 12 hours. After stirring for 12 hours, the second high vacuum valve 2-1 was repeatedly evacuated and filled with high-purity (99.999%) argon gas for 3 times, and the vacuum degree was 100 mba each time. The pressure was reduced for more than 2 times, and liquid nitrogen was introduced into the liquid nitrogen cold trap, and then the pressure was reduced for more than 2 times, and it was noted that the vacuum degree was reduced to 600 mba each time; then the reaction bottle 1 was baked with a hot air gun, and the organic solvent was distilled and stored in the collection bottle 2 through the liquid nitrogen cold trap 4; finally, the purified n-hexane could be extracted with a syringe in an argon environment through the first high vacuum valve 2-1.

[0055] Table 2 Results of different purification methods for treating n-hexane

[0056]

[0057] Referring to Table 2, the following results can be obtained by comparing the effects of this example with those of the prior art after purification: the time required for the molecular sieve-assisted double-row tube high vacuum line operation is 100 h, the residual water content (ppm) is 0.88, and the residual oxygen content (ppm) is 102; the time required for sodium plus benzophenone is 48 h, the residual water content (ppm) is 27.8, and the residual oxygen content (ppm) is 33.4; the time required for the commercial solvent purification system is 72 h, the residual water content (ppm) is 0.7, and the residual oxygen content (ppm) is 0.8; while the time required for this example is 12 h, the residual water content (ppm) is 0.05, and the residual oxygen content (ppm) is 0.1.

[0058] Example 3

[0059] Taking diethylene glycol dimethyl ether as an example, the specific process of using the purification method of the present application is: first, the purification equipment is baked in an oven at 110° or above for more than 30 minutes; after baking, it is then transferred to a glove box, and the glass stirring rod 5 and the potassium-sodium alloy are put into the reaction bottle 1 through the first high vacuum valve 1-1 in the glove box; the double-row pipe is repeatedly evacuated and filled with high-purity (99.999%) argon gas 3 times through the second high vacuum valve 2-1, and the vacuum degree is drawn to 100 mba each time. Then, the second high vacuum valve 2-1 is partially opened to allow argon gas to flow into the device at a rate of not less than 70 ml / min to ensure that the device is used at a slightly positive pressure; the first high vacuum valve 1-1 is fully opened, and diethylene glycol dimethyl ether (anhydrous grade) is put into the reaction bottle 1 through the first high vacuum valve 1-1, and the two high vacuum valves are closed to stir the solution and the potassium-sodium alloy for 12 hours. After stirring for 12 hours, the second high vacuum valve 2-1 was repeatedly evacuated and filled with high-purity (99.999%) argon gas for 3 times, and the vacuum degree was 100 mba each time. The pressure was reduced for more than 2 times, and liquid nitrogen was introduced into the liquid nitrogen cold trap, and then the pressure was reduced for more than 2 times, and it was noted that the vacuum degree was reduced to 600 mba each time; then the reaction bottle 1 was baked with a hot air gun, and the organic solvent was distilled and stored in the collection bottle 2 through the liquid nitrogen cold trap 4; finally, the purified diethylene glycol dimethyl ether was extracted with a syringe in an argon environment through the first high vacuum valve 2-1.

[0060] Table 3 Results of different purification methods for diethylene glycol dimethyl ether

[0061]

[0062] Referring to Table 3, by comparing the effects of this example with those of the prior art after purification, the following results can be obtained: the time required for the commercial glass solvent purification system is 72 h, the residual water content (ppm) is 2, and the residual oxygen content (ppm) is 2; while the time required for this example is 3 h, the residual water content (ppm) is 0.1, and the residual oxygen content (ppm) is 0.09.

[0063] In summary, the present application provides a recyclable solvent dehydration and deoxygenation device and method, which has a higher efficiency of rapid deoxygenation and dehydration using the device, and can be better applied to sensitive chemical reaction systems. It should be noted here that high purification efficiency is a characteristic of potassium-sodium alloy, but the present invention provides a recyclable drying device and method that can solve the problems of potassium-sodium alloy drying solvents, such as the treatment of residual potassium-sodium alloy and the need for an integrated high-airtightness device, etc., with the advantages of low cost, simple operation and high safety.

[0064] Those skilled in the art should understand that those skilled in the art can implement variations by combining the prior art and the above embodiments, which will not be described in detail here. Such variations do not affect the essential content of the present invention, and will not be described in detail here.

[0065] The above describes the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and the devices and structures that are not described in detail should be understood to be implemented in a common manner in the art; any technician familiar with the art can use the above-disclosed methods and technical contents to make many possible changes and modifications to the technical solutions of the present invention without departing from the scope of the technical solutions of the present invention, or modify them into equivalent embodiments of equivalent changes, which does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention are still within the scope of protection of the technical solutions of the present invention.

Claims

1. A solvent drying device for drying organic solvents with potassium-sodium alloy and capable of being recycled for multiple times, characterized in that: It comprises an integrally fired glass purification device and a high vacuum valve; the glass purification device comprises a reaction bottle (1) for distillation and a collecting bottle (2) arranged above the reaction bottle (1); the upper end of the collecting bottle (2) is connected to the upper end of the reaction bottle (1) via a distillation neck (3); a liquid nitrogen cold trap (4) for condensation is arranged between the distillation neck (3) and the collecting bottle (2); a connecting pipe (6) is arranged between the collecting bottle (2) and the reaction bottle (1); the connecting pipe (6) connects the collecting bottle (2) with the reaction bottle (1); The high vacuum valve comprises a second high vacuum valve (2-1) arranged on the collecting bottle (2), and a first high vacuum valve (1-1) arranged on the connecting pipe (6) and the collecting bottle (1); the first high vacuum valve (1-1) can control the connecting pipe (6) by closing or partially opening the valve core, thereby selectively controlling the connection between the collecting bottle (2) and the reaction bottle (1); The second high vacuum valve (2-1) is provided with a vacuum port (7); The reaction bottle (1) is provided with a sodium-potassium alloy and a stirrer (5).

2. The solvent drying device for drying organic solvents with potassium-sodium alloy and capable of being recycled multiple times according to claim 1, characterized in that: The liquid nitrogen cold trap (4) comprises a condensation cup (4-1) with a hollow interior and a liquid nitrogen pool (4-2) formed by the depression of the condensation cup (4-1); the interior of the condensation cup (4-1) is respectively connected to the distillation neck (3) and the collection bottle (2), and the liquid nitrogen pool (4-2) can store liquid nitrogen.

3. The solvent drying device for drying organic solvents with potassium-sodium alloy and capable of being recycled multiple times according to claim 1, characterized in that: The reaction bottle (1) is configured as a round-bottom flask with a volume of 150 mL to 2000 mL; the collecting bottle (2) is configured as a round-bottom flask with a volume not greater than one-half of the volume of the reaction bottle (1); the shortest distance between the distillation neck (3) and the collecting bottle (2) is greater than 1 cm; the shortest distance between the liquid nitrogen cold trap (4) and the collecting bottle (2) is greater than 1 cm; and the glass thickness at the liquid nitrogen cold trap (4) is not less than 1 mm.

4. The solvent drying device for drying organic solvents with potassium-sodium alloy and capable of being recycled multiple times according to claim 1, characterized in that: The first high vacuum valve (1-1) and the second high vacuum valve (2-1) are both high vacuum Schlenk-type glass valves that are thread-sealed with a plug fully covered with perfluoroethylene; The first high vacuum valve (1-1) and the second high vacuum valve (2-1) are used for feeding and discharging materials under an inert gas; The gas extraction port (7) is connected to a double-row tube, and with the cooperation of the double-row tube, the gas pressure inside the device is adjusted under inert gas. The stirrer (5) is configured as a magnetic stirrer fully covered with glass.

5. A solvent drying method for drying an organic solvent using a potassium-sodium alloy and being recyclable for multiple uses, characterized in that: The solvent dehydration and deoxygenation device according to any one of claims 1 to 4 comprises the following steps: S1. After the entire solvent dehydration and deoxygenation device is baked in an oven, a double-row pipe is used to repeatedly evacuate and fill the device with inert gas three times through the exhaust port (7) to create an anhydrous and oxygen-free internal environment of the device; Putting the stirrer (5), the potassium-sodium alloy and the organic solvent into the reaction bottle (1) through the first high vacuum valve (1-1); During this period, it is always necessary to maintain a slight positive pressure in the device; S2, stirring the organic solvent in the reaction bottle (1) by means of the stirrer (5); S3, using a double-row pipe to repeatedly depressurize the interior of the device through the second high vacuum valve (2-1) for at least 2 times, pouring liquid nitrogen into the liquid nitrogen cold trap (4), and then repeating the depressurization for at least 2 times; S4, baking the reaction bottle (1) to distill the organic solvent, condense it in the liquid nitrogen cold trap (4) and store it in the collection bottle (2); S5, extracting the treated organic solvent under the protection of inert gas through the second high vacuum valve (2-1), during which the inside of the device is kept at a slightly positive pressure; S6. After use, the first high vacuum valve (1-1) is opened to allow the unused residual organic solvent in the collection bottle (2) to be recovered into the reaction bottle (1).

6. The solvent drying method of claim 5, wherein the method comprises: In step S1, the stirrer (5) and the potassium-sodium alloy are first introduced into the reaction bottle (1) through the first high vacuum valve (1-1) in the glove box, and then the double-row tube is repeatedly evacuated and filled with inert gas three times, and then the required organic solvent is introduced into the reaction bottle (1) through the first high vacuum valve (1-1).

7. The solvent drying method of claim 5, wherein the method comprises: In step S1, the solvent dehydration and deoxygenation device is baked at a temperature of not less than 80° for not less than 30 minutes to remove residual moisture on the glass surface.

8. The solvent drying method of claim 5, wherein the method comprises: Inert gas refers to a chemically inactive and relatively stable gas, including but not limited to helium, nitrogen, and argon with a purity of not less than 99.999%.

9. The solvent drying method of claim 6, wherein the organic solvent is dried by using potassium-sodium alloy and can be recycled for multiple times, characterized in that: The vacuum degree of repeated evacuation and decompression is each time evacuated to a value not greater than 100 mbar on the vacuum gauge.

10. The solvent drying device and method for drying organic solvents with potassium-sodium alloy and capable of being recycled multiple times according to claim 6, characterized in that: In steps S1 and S5, the speed at which the inert gas flows into the device is not less than 70 ml / min, so as to ensure that the pressure of the glass device always maintains a slight positive pressure.

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