Method and device for preparing organic alkali salt of imidodisulfuryl fluoride

Abstract

The invention relates to a method and a device for preparing an organic alkali salt of bis (fluorosulfonyl) imide. Ammonia gas, sulfuryl fluoride and liquid organic alkali are adopted as reaction raw materials, and under the condition that no solvent is added or a small amount of solvent is added, the raw materials react through pressurization to generate the organic alkali salt of the bis (fluorosulfonyl) imide. As no solvent is used or only a small amount of solvent is used in the reaction, the chroma of the obtained product is relatively low, and subsequent preparation of lithium bis (fluorosulfonyl) imide as a precursor is facilitated. The invention provides a simple and effective method for reducing the chromaticity of the imidodisulfuryl fluoride salt.

Description

Technical Field

[0001] The present application relates to the field of chemical engineering technology, and particularly relates to a method and device for preparing an organic base salt of bis(fluorosulfonyl)imide. Background Art

[0002] Lithium bis(fluorosulfonyl)imide has high solubility and stability, can improve the dissolution performance of the electrolyte of a lithium-ion battery, increase the conductivity and ion transport rate of the battery, and thus improve the electrochemical performance of the battery. At present, the main precursors for preparing lithium bis(fluorosulfonyl)imide are bis(fluorosulfonyl)imide salts, bis(chlorosulfonyl)imide, and bis(fluorosulfonyl)imide. Among them, bis(fluorosulfonyl)imide salts are important precursors for preparing lithium bis(fluorosulfonyl)imide. At present, the chromaticity of bis(fluorosulfonyl)imide salts prepared by traditional methods is relatively large, the color is yellowish, or even brownish or blackish, which means that the impurity content is relatively high and is not conducive to subsequent use. Summary of the Invention

[0003] In view of the problems in the background art, the present application provides a method for preparing an organic base salt of bis(fluorosulfonyl)imide, which can reduce the chromaticity of the prepared organic base salt of bis(fluorosulfonyl)imide.

[0004] The method for preparing an organic base salt of bis(fluorosulfonyl)imide provided in the first aspect of the present application includes the following steps:

[0005] Ammonia, sulfuryl fluoride, a liquid organic base, and a solvent are introduced into a reactor, and the pressure at the discharge end of the reactor is controlled to be above 0.5 MPa. After the reaction is completed, an organic base salt of bis(fluorosulfonyl)imide is obtained. Among them, the molar ratio of ammonia to the solvent is 1:(0 - 5).

[0006] The present application uses ammonia, sulfuryl fluoride, and a liquid organic base as reaction raw materials. Without adding a solvent or adding a small amount of solvent, the raw materials are reacted under pressure to generate an organic base salt of bis(fluorosulfonyl)imide. Since the reaction does not use a solvent or only uses a small amount of solvent, the chromaticity of the obtained product is relatively low, which is conducive to subsequent use as a precursor for preparing lithium bis(fluorosulfonyl)imide. The present application provides a simple and effective method for reducing the chromaticity of bis(fluorosulfonyl)imide salts.

[0007] In some embodiments, according to the first aspect, a first example of the first aspect is proposed. The pressure at the discharge end of the reactor is 0.8 - 2.0 MPa, preferably 1.0 - 2.0 MPa.

[0008] By optimizing the reaction pressure, it is beneficial to promote the efficient reaction of the reaction raw materials and improve the conversion rate of sulfuryl fluoride. When the pressure is relatively low, ammonia and sulfuryl fluoride are likely to volatilize from the reaction system, which is not conducive to the full progress of the reaction.

[0009] In some embodiments, according to the first aspect, a second example of the first aspect is proposed, where the temperature of the reactor is controlled to be 35 - 80 °C, preferably 50 - 80 °C.

[0010] By optimizing the reaction temperature, it is beneficial to increase the collisions between molecules, promote the efficient reaction of reaction raw materials, and improve the conversion rate of sulfuryl fluoride. When the reaction temperature is relatively low, the reaction rate is slow. Within a certain period of time, the reaction raw materials cannot fully react, resulting in low product purity and waste of raw materials.

[0011] In some embodiments, according to the first aspect, a third example of the first aspect is proposed. Passing ammonia gas, sulfuryl fluoride, liquid organic base, and solvent into the reactor includes:

[0012] Dissolving ammonia gas in the liquid organic base and solvent to obtain a first solution, where the molar ratio of ammonia gas to the solvent is 1:(0 - 5);

[0013] Dissolving sulfuryl fluoride in the liquid material to obtain a second solution, where the liquid material includes one or more of hydrofluoride salts of organic bases, bis(fluorosulfonyl)imide, and organic base salts of bis(fluorosulfonyl)imide;

[0014] Mixing the first solution and the second solution in the reactor.

[0015] Ammonia gas and sulfuryl fluoride are gases under normal temperature and pressure. To promote the effective reaction among ammonia gas, sulfuryl fluoride, and the liquid organic base, in this application, ammonia gas is dissolved in the liquid organic base or a mixture of the liquid organic base and a small amount of solvent, and sulfuryl fluoride is dissolved in the liquid material, and the reaction is carried out under pressure. The liquid materials in this application, such as hydrofluoride salts of organic bases, bis(fluorosulfonyl)imide acid, and organic base salts of bis(fluorosulfonyl)imide, can promote the rapid progress of the reaction and play a role similar to that of a catalyst. These liquid materials are either reaction products or reaction by-products, and their introduction will not lead to an increase in the types of by-products, which is beneficial for subsequent separation and purification.

[0016] In some embodiments, according to the first aspect, a fourth example of the first aspect is proposed. Dissolution is carried out in a static mixer; the reactor is a screw reactor.

[0017] Carrying out the dissolution of ammonia gas and sulfuryl fluoride in the static mixer is beneficial to achieving the full mixing of gas and liquid, reducing the occurrence of uneven dispersion of gas in the liquid, and improving the reaction efficiency. The material mixed by the static mixer enters the screw reactor, where it is further mixed and compressed, increasing the collision probability between reaction raw materials, improving the reaction rate, reducing the generation of by-products, and realizing the reaction of ammonia gas, sulfuryl fluoride, and liquid organic base under high pressure.

[0018] In some embodiments, according to the first aspect, a fifth example of the first aspect is provided. After the reaction in the screw reactor, the obtained mixed material is introduced into the reaction kettle for continuous reaction. Preferably, the reaction pressure in the reaction kettle is above 0.5 MPa, and the reaction temperature is 35 - 80 °C.

[0019] After the mixed material is discharged from the screw reactor and enters the reaction kettle for continuous reaction, the contact time of the unreacted raw materials can be increased, enabling the unreacted raw materials to continue reacting, improving the conversion rate of the raw materials, and increasing the yield of the product.

[0020] In some embodiments, according to the first aspect, a sixth example of the first aspect is provided. The molar ratio of ammonia to sulfuryl fluoride is 1:(2 - 3). The molar ratio of ammonia to liquid organic base is 1:(2 - 5).

[0021] By optimizing the molar ratio of the reaction raw materials, it is beneficial to promote the full progress of the reaction, improve the reaction efficiency, raw material conversion rate, and product purity, etc.

[0022] In some embodiments, according to the first aspect, a seventh example of the first aspect is provided. The liquid organic base includes one or more of pyridine, methylpyridine, N-methylpyrrolidone, triethylamine, tri-n-propylamine, and tri-n-butylamine.

[0023] By optimizing the type of liquid organic base, it is beneficial to better dissolve ammonia and promote the full progress of the reaction.

[0024] The second aspect of the present application provides a device for preparing an organic base salt of bis(fluorosulfonyl)imide, including a first premixing unit, a second premixing unit, a screw reactor, and a reaction kettle. The screw reactor is respectively connected to the first premixing unit and the second premixing unit. The reaction kettle is connected to the discharge port of the screw reactor.

[0025] This device can be used to prepare an organic base salt of bis(fluorosulfonyl)imide. The specific working principle is as follows: First, the dissolution of ammonia and the dissolution of sulfuryl fluoride are respectively carried out in the first premixing unit and the second premixing unit; then the two obtained solutions are introduced into the screw reactor for mixing and reaction. As the screw rotates, it pushes the material forward continuously, thus realizing the reaction under pressure; after the reaction, the mixed material is discharged from the screw reactor and enters the reaction kettle for continuous reaction to improve the conversion rate of the reaction raw materials. The above device for preparing an organic base salt of bis(fluorosulfonyl)imide can not add a solvent or only add a small amount of solvent, thereby reducing the product chromaticity.

[0026] In some embodiments, according to the second aspect, a first example of the second aspect is provided. The lower part of the reaction kettle is provided with a feed port. The feed port is connected to the discharge port of the screw reactor.

[0027] The mixed material from the screw reactor enters from the lower part of the reaction kettle, which is beneficial to increasing the contact time of the unreacted raw materials and reducing the possibility of being directly discharged after feeding from the upper part of the reaction kettle.

[0028] In some embodiments, according to the second aspect, a second example of the second aspect is proposed. The interior of the reaction kettle is provided with a stirrer and a feed pipe. The stirrer includes a rotating shaft and stirring rods connected thereto. The stirring rods are located in the lower part of the reaction kettle. The feed pipe includes a first end and a second end. The first end is connected to the feed port of the reaction kettle. The second end is arranged above and close to the stirring rods. Preferably, the stirring rods are horizontally arranged, and the port of the second end is 2-5 cm away from the stirring rods in the vertical direction.

[0029] The mixed material from the screw reactor is fed above the stirring rods in the reaction kettle, which is beneficial to rapidly dispersing the unreacted raw materials in the mixed material and reducing the generation of by-products due to local excess of ammonia.

[0030] In some embodiments, according to the second aspect, a third example of the second aspect is proposed. The first premixing unit includes a first gas distributor and a first static mixer. The first gas distributor includes a first pipeline and a first gas distribution structure arranged in the first pipeline. The first static mixer is connected to the first gas distributor. The second premixing unit includes a second gas distributor and a second static mixer. The second gas distributor includes a second pipeline and a second gas distribution structure arranged in the second pipeline. The second static mixer is connected to the second gas distributor.

[0031] The gas distributor is arranged upstream of the static mixer. After the gas is evenly distributed by the gas distributor, it enters the static mixer for mixing, which is beneficial to improving the mixing uniformity of the gas and the liquid material.

[0032] In some embodiments, according to the second aspect, a fourth example of the second aspect is proposed. The first premixing unit further includes: a first Venturi ejector. The first Venturi ejector includes a first reduced-diameter section and a first equal-diameter section connected thereto. The first reduced-diameter section is connected to the first static mixer. The second premixing unit further includes: a second Venturi ejector. The second Venturi ejector includes a second reduced-diameter section and a second cylindrical section connected thereto. The second reduced-diameter section is connected to the second static mixer.

[0033] The gas distributor is arranged upstream of the static mixer, and the Venturi ejector is arranged downstream of the static mixer. The liquid mixed by the static mixer enters the Venturi ejector. After being pressurized by the reduced-diameter section and stabilized by the cylindrical section, the undissolved gas can be completely dissolved in the liquid material, improving the conversion rate of the reaction raw materials.

[0034] In some embodiments, according to the second aspect, a fifth example of the second aspect is proposed. The device of the present application further includes a first gas storage tank, a first liquid storage tank, and a second gas storage tank. The first gas storage tank is connected to the first gas distribution structure of the first gas distributor. The first liquid storage tank is connected to the first pipeline of the first gas distributor. The second gas storage tank is connected to the second gas distribution structure of the second gas distributor.

[0035] The gas in the gas storage tank and the liquid in the liquid storage tank are introduced into the premixing unit for mixing, so as to achieve gas dissolution.

[0036] In some embodiments, according to the second aspect, a sixth example of the second aspect is proposed. A first discharge port is provided at the upper part of the reaction kettle. A second discharge port is provided at the bottom of the reaction kettle. The second discharge port is connected to the second pipeline of the second gas distributor.

[0037] The materials in the reaction kettle are introduced into the second pipeline of the second gas distributor for dissolving sulfuryl fluoride, which can achieve continuous production.

[0038] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the following specifically gives the specific implementation manners of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. And throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0040] Figure 1 It is a schematic structural diagram of a device for preparing an organic base salt of bis(fluorosulfonyl)imide in an embodiment of the present application.

[0041] Figure 2 It is a schematic structural diagram of a reaction kettle in an embodiment of the present application.

[0042] Figure 3 It is a schematic structural diagram of a first premixing unit in an embodiment of the present application.

[0043] Figure 4 It is a schematic structural diagram of a first gas distributor in an embodiment of the present application.

[0044] Figure 5 It is a schematic structural diagram of a first static mixer in an embodiment of the present application.

[0045] Figure 6 It is a schematic structural diagram of a first Venturi injector in an embodiment of the present application.

[0046] Figure 7 It is a schematic structural diagram of a screw reactor in an embodiment of the present application.

[0047] Description of the reference numerals:

[0048] 100 is the first premixing unit, 110 is the first gas distributor, 111 is the first pipeline, 112 is the first gas distribution structure, 113 is the gas pipeline, 120 is the first static mixer, 121 is the cylindrical section, 122 is the conical section, 130 is the first Venturi injector, 131 is the first reduced-diameter section, 132 is the first equal-diameter section, 200 is the second premixing unit, 300 is the screw reactor, 301 is the screw, 302 is the feeding port, 303 is the discharging port, 304 is the heat-insulating jacket, 305 is the inlet of the heat-insulating medium, 400 is the reaction kettle, 401 is the feeding pipe, 402 is the first discharging port, 403 is the second discharging port, 404 is the feeding tube, 405 is the rotating shaft, 406 is the stirring rod. Detailed Embodiments

[0049] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solutions of the present application more clearly, so they are only examples and cannot be used to limit the protection scope of the present application.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion.

[0051] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present application, "a plurality of" means more than two unless otherwise specifically defined.

[0052] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various positions in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0053] In the description of the embodiments of the present application, the orientation or positional relationship indicated by technical terms such as "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the embodiments of the present application.

[0054] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0055] Lithium bis(fluorosulfonyl)imide has high solubility and stability, which can improve the dissolution performance of the electrolyte of lithium-ion batteries, increase the conductivity and ion transport rate of the batteries, and thus improve the electrochemical performance of the batteries. At present, the main precursors for preparing lithium bis(fluorosulfonyl)imide are bis(fluorosulfonyl)imide salts, bis(chlorosulfonyl)imide, and bis(fluorosulfonyl)imide. Among them, bis(fluorosulfonyl)imide salts are important precursors for preparing lithium bis(fluorosulfonyl)imide. At present, bis(fluorosulfonyl)imide salts are usually prepared in a solvent system, with a large amount of solvent used. The obtained bis(fluorosulfonyl)imide salts have a large chromaticity, usually above 150 Hazen, with a yellowish color, even tending to brown or black, which also means a high impurity content. Therefore, before using it to prepare lithium bis(fluorosulfonyl)imide, it usually needs to be decolorized to reduce the adverse effects on the chromaticity and purity of lithium bis(fluorosulfonyl)imide, which leads to a complex process. Therefore, a method for preparing bis(fluorosulfonyl)imide salts with low chromaticity needs to be developed.

[0056] For this reason, the present application proposes a method for preparing an organic base salt of bis(fluorosulfonyl)imide. The method includes the following steps:

[0057] Ammonia, sulfuryl fluoride, a liquid organic base, and a solvent are introduced into a reactor, and the pressure at the discharge end of the reactor is controlled to be above 0.5 MPa. After the reaction is completed, an organic base salt of bis(fluorosulfonyl)imide is obtained. Among them, the molar ratio of ammonia to the solvent is 1:(0 - 5).

[0058] In this application, ammonia, sulfuryl fluoride, and a liquid organic base are used as reaction raw materials. Without adding a solvent or adding a small amount of solvent, the raw materials react under pressure to form an organic base salt of bis(fluorosulfonyl)imide. Since the reaction does not use a solvent or only uses a small amount of solvent, the chromaticity of the obtained product is low, which is beneficial for subsequent preparation of lithium bis(fluorosulfonyl)imide as a precursor. This application provides a simple and effective method for reducing the chromaticity of bis(fluorosulfonyl)imide salts.

[0059] In addition, this method does not use a solvent or only uses a small amount of solvent, which can reduce production costs and is environmentally friendly. The by-products of this method are mainly hydrofluorides of organic bases. During post-treatment, the organic base can be recovered by alkalization, reducing production costs, and continuous production can be achieved.

[0060] In addition, this method does not require the use of dangerous raw materials such as hydrofluoric acid and has high safety. Compared with other industrial production methods, the equipment required for the method of this application is simple and the operation is convenient.

[0061] In this application, the reaction general formula of the reaction chemistry is as follows:

[0062] NH3 + SF2O2 + R → NH(SFO2)2·R + R(HF) n

[0063] Wherein R is a liquid organic base. The liquid organic base can combine with at least one HF.

[0064] In some specific embodiments, the solvent includes one or more of acetonitrile, propionitrile, isopropyl cyanide, diethyl ether, dipropyl ether, diisopropyl ether, tetrahydrofuran, acetone, butanone, methyl isobutyl ketone, and N-methylpyrrolidone.

[0065] In some specific embodiments, the molar ratio of ammonia to the solvent can be 1:0, 1:1, 1:2, 1:3, 1:4, or 1:5. This application can achieve the reaction of ammonia, sulfuryl fluoride, and organic base without adding a solvent or only adding a small amount or trace amount of solvent, reducing the chromaticity of the product.

[0066] In some embodiments, the pressure at the discharge end of the reactor can be 0.8 - 2.0 MPa, preferably 1.0 - 2.0 MPa.

[0067] By optimizing the reaction pressure, it is beneficial to promote the efficient reaction of reaction raw materials and improve the conversion rate of sulfuryl fluoride. When the pressure is low, ammonia and sulfuryl fluoride are likely to volatilize from the reaction system, which is not conducive to the full progress of the reaction.

[0068] In some specific embodiments, the pressure at the discharge end of the reactor may be 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, 1.0 MPa, 1.1 MPa, 1.2 MPa, 1.3 MPa, 1.4 MPa, 1.5 MPa, 1.6 MPa, 1.7 MPa, 1.8 MPa, 1.9 MPa or 2.0 MPa.

[0069] When the reactor is a screw reactor 300, the pressure exerted on the reaction material in the reactor is constantly changing. As the screw rotates, the reaction material continuously advances and is compressed, and the reaction pressure usually gradually increases. In this application, the pressure at the discharge end of the screw reactor 300 is controlled to be below 2.0 MPa, which can not only enable the reaction to proceed fully but also reduce the safety hazards of production equipment. When the reactor is a reaction kettle 400, the pressure inside the reaction kettle 400 is uniform. Controlling the pressure at the discharge end of the reactor to be below 2.0 MPa is equivalent to controlling the pressure inside the entire reaction kettle 400 to be below 2.0 MPa, which can not only enable the reaction to proceed fully but also reduce the safety hazards of production equipment.

[0070] In some embodiments, the temperature of the reactor is controlled to be 35 - 80 °C, preferably 50 - 80 °C.

[0071] By optimizing the reaction temperature, it is beneficial to increase the collision between molecules, promote the efficient reaction of reaction raw materials, and improve the conversion rate of sulfuryl fluoride. When the reaction temperature is low, the reaction rate is slow. Within a certain period of time, the reaction raw materials cannot fully react, resulting in low product purity and waste of raw materials.

[0072] In some specific embodiments, the temperature of the reactor is controlled to be 35 °C, 40 °C, 45 °C, 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, 75 °C or 80 °C.

[0073] In some embodiments, introducing ammonia, sulfuryl fluoride, liquid organic base and solvent into the reactor includes:

[0074] Dissolving ammonia in the liquid organic base and solvent to obtain a first solution, where the molar ratio of ammonia to the solvent is 1:(0 - 5);

[0075] Dissolving sulfuryl fluoride in the liquid material to obtain a second solution, where the liquid material includes one or more of hydrofluoride salts of organic bases, bis(fluorosulfonyl)imide, and organic base salts of bis(fluorosulfonyl)imide;

[0076] Mixing the first solution and the second solution in the reactor.

[0077] Ammonia and sulfuryl fluoride are gases at normal temperature and pressure. To promote an effective reaction among ammonia, sulfuryl fluoride, and a liquid organic base, in this application, ammonia is dissolved in a liquid organic base or a mixture of a liquid organic base and a small amount of solvent, and sulfuryl fluoride is dissolved in a liquid material, and the reaction is carried out under pressure. The liquid materials in this application, such as hydrofluorides of organic bases, bis(fluorosulfonyl)imide, and organic base salts of bis(fluorosulfonyl)imide, can promote the reaction to proceed rapidly and play a role similar to that of a catalyst. Before the reaction starts, the liquid material can be added to the reactor and drained to the premixing unit to be mixed with sulfuryl fluoride; alternatively, during the reaction process, a part of the material from the outlet of the reactor can be drained to the premixing unit to be mixed with sulfuryl fluoride. These liquid materials are either reaction products or reaction by-products, and their introduction will not increase the types of by-products, which is beneficial to later separation and purification.

[0078] In some specific embodiments, when the liquid material is a single compound, the molar ratio of sulfuryl fluoride to the liquid material can be 1:10 - 1:20, such as 1:10 - 1:15. When the liquid material is a mixture of multiple compounds, the ratio of the molar amount of sulfuryl fluoride to the total molar amount of all compounds in the liquid material can be 1:10 - 1:20, such as 1:10 - 1:15.

[0079] In some embodiments, the dissolution is carried out in a static mixer; the reactor is a screw reactor 300.

[0080] Dissolving ammonia and sulfuryl fluoride in a static mixer is conducive to achieving full mixing of gas and liquid, reducing the occurrence of uneven dispersion of gas in the liquid, and improving the reaction efficiency. The material mixed by the static mixer enters the screw reactor 300, where it is further mixed and compressed, increasing the collision probability between reaction raw materials, improving the reaction rate, reducing the generation of by-products, and realizing the reaction of ammonia, sulfuryl fluoride, and liquid organic base under high pressure.

[0081] In some embodiments, after the reaction in the screw reactor 300, the obtained mixed material is introduced into the reaction kettle 400 to continue the reaction. Preferably, the reaction pressure of the reaction kettle 400 can be above 0.5 MPa. The reaction temperature of the reaction kettle 400 can be 35 - 80 °C, preferably 50 - 80 °C.

[0082] After the mixed material is discharged from the screw reactor 300 and enters the reaction kettle 400 to continue the reaction, the contact time of unreacted raw materials can be increased, enabling the unreacted raw materials to continue to react, improving the conversion rate of raw materials, and increasing the yield of products.

[0083] In some specific embodiments, the reaction pressure of the reactor 400 can be 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, 1.0 MPa, 1.1 MPa, 1.2 MPa, 1.3 MPa, 1.4 MPa, 1.5 MPa, 1.6 MPa, 1.7 MPa, 1.8 MPa, 1.9 MPa or 2.0 MPa.

[0084] The pressure of the reactor 400 can be the same as the pressure at the discharge end of the screw reactor 300 to maintain the balance of feed and discharge.

[0085] In some specific embodiments, the temperature of the reactor 400 is controlled to be 35 °C, 40 °C, 45 °C, 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, 75 °C or 80 °C.

[0086] In some embodiments, the molar ratio of ammonia to sulfuryl fluoride can be 1:(2 - 3). The molar ratio of ammonia to liquid organic base can be 1:(2 - 5).

[0087] By optimizing the molar ratio of the reaction raw materials, it is beneficial to promote the full progress of the reaction, improve the reaction efficiency, raw material conversion rate and product purity, etc.

[0088] In some specific embodiments, the molar ratio of ammonia to sulfuryl fluoride can be 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5, 1:2.6, 1:2.7, 1:2.8, 1:2.9 or 1:3.

[0089] In some specific embodiments, the molar ratio of ammonia to liquid organic base can be 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5 or 1:5.

[0090] In some embodiments, the liquid organic base includes one or more of pyridine, methylpyridine, N-methylpyrrolidone, triethylamine, tri-n-propylamine, and tri-n-butylamine.

[0091] By optimizing the type of liquid organic base, it is beneficial to better dissolve ammonia and promote the full progress of the reaction.

[0092] The second aspect of the present application provides a device for preparing an organic base salt of bis(fluorosulfonyl)imide, including a first premixing unit 100, a second premixing unit 200, a screw reactor 300 and a reactor 400. The screw reactor 300 is respectively connected to the first premixing unit 100 and the second premixing unit 200. The reactor 400 is connected to the discharge port 303 of the screw reactor 300.

[0093] The device prepares an organic base salt of bis(fluorosulfonyl)imide. The specific working principle is as follows: First, the dissolution of ammonia gas and the dissolution of sulfuryl fluoride are carried out in the first premixing unit 100 and the second premixing unit 200 respectively; then the two obtained solutions are introduced into the screw reactor 300 for mixing reaction. As the screw rotates, it pushes the materials forward continuously, thus realizing the reaction under pressure to generate the organic base salt of bis(fluorosulfonyl)imide; after the mixed materials after the reaction are discharged from the screw reactor 300, they enter the reaction kettle 400 to continue the reaction, improving the conversion rate of the reaction raw materials. The above device for preparing the organic base salt of bis(fluorosulfonyl)imide can avoid adding solvents or only add a small amount of solvents, thereby reducing the chromaticity of the product.

[0094] Figure 1 The structural schematic diagram of the device for preparing the organic base salt of bis(fluorosulfonyl)imide in an embodiment of the present application is given. As Figure 1 shown, the screw reactor 300 is provided with two feeding ports 302, and the first premixing unit 100 and the second premixing unit 200 are respectively connected to the two feeding ports 302. The materials from the first premixing unit 100 and the second premixing unit 200 enter the screw reactor 300 through the two feeding ports 302, are further compressed and mixed, and the reaction of ammonia gas, sulfuryl fluoride and liquid organic base is realized under pressure. The mixed materials after the reaction are discharged into the reaction kettle 400 and discharged after further reaction.

[0095] In some embodiments, referring to Figure 2 , a feeding port 401 is provided at the lower part of the reaction kettle 400. The feeding port 401 is connected to the discharge port 303 of the screw reactor 300.

[0096] The mixed materials from the screw reactor 300 enter from the lower part of the reaction kettle 400, which is beneficial to increasing the contact time of the unreacted raw materials and reducing the possibility of being directly discharged after feeding from the upper part of the reaction kettle 400.

[0097] In some specific embodiments, the reaction kettle 400 can be of a cylindrical structure. The reaction kettle 400 can include a cylinder body and a cover body. The feeding port 401 is arranged at the lower part of the side wall of the reaction kettle 400.

[0098] In some embodiments, continuing to refer to Figure 2 , a stirrer and a feeding pipe 404 are arranged inside the reaction kettle 400. The stirrer includes a rotating shaft 405 and a stirring rod 406 connected thereto. The stirring rod 406 is located at the lower part of the reaction kettle 400. The feeding pipe 404 includes a first end and a second end. The first end is connected to the feeding port 401 of the reaction kettle 400. The second end is arranged above and close to the stirring rod 406. Preferably, the distance between the port of the second end and the stirring rod 406 is 2 - 5 cm.

[0099] The mixed material from the screw reactor 300 is fed above the stirring rod 406 in the reaction kettle 400, which is beneficial to quickly disperse the unreacted raw materials in the mixed material and reduce the local excess of ammonia to produce by-products.

[0100] In some specific embodiments, the stirring rod 406 is horizontally arranged. The port of the second end is 2 cm, 2.5 cm, 3 cm, 3.5 cm, 4 cm, 4.5 cm or 5 cm away from the stirring rod in the vertical direction. The mixed material from the screw reactor enters the reaction kettle from above the stirring rod, and the unreacted raw materials are quickly dispersed, prolonging the reaction time without generating solids.

[0101] In some embodiments, referring to Figures 3 - 5 , the first premixing unit 100 includes a first gas distributor 110 and a first static mixer 120. The first gas distributor 110 includes a first pipeline 111 and a first gas distribution structure 112 arranged in the first pipeline 111. The first static mixer 120 is connected to the first gas distributor 110. The second premixing unit 200 includes a second gas distributor and a second static mixer. The second gas distributor includes a second pipeline and a second gas distribution structure arranged in the second pipeline. The second static mixer is connected to the second gas distributor.

[0102] The gas distributor is arranged upstream of the static mixer. The gas enters the gas distributor and is dispersed into tiny bubbles (less than 20 microns) for easy dissolution; then the gas and the liquid enter the static mixer together for further uniform mixing, which is beneficial to improving the mixing uniformity of the gas and liquid materials.

[0103] In some specific embodiments, the first premixing unit 100 has the same structure as the second premixing unit 200, as shown in Figures 3 - 6 .

[0104] In some specific embodiments, referring to Figure 4 , the first gas distributor 110 further includes a first gas pipeline 113. The second gas distributor further includes a second gas pipeline.

[0105] In some specific embodiments, continuing to refer to Figure 4 , the first gas pipeline 113 is detachably connected to the first gas distribution structure 112. For example, the outer wall of the first gas pipeline 113 and the inner wall of the first gas distribution structure 112 are provided with threads that can be used in cooperation, so that the first gas pipeline 113 is threadedly connected to the first gas distribution structure 112. When it is necessary to replace the gas distributor, it can be removed and updated.

[0106] In some specific embodiments, referring to Figure 5, the first static mixer 120 includes a connected cylindrical section 121 and a conical section 122. The cylindrical section 121 is filled with packing material, where the gas and liquid can be further dispersed and mixed. Through the pressure increase caused by the diameter reduction of the conical section 122, the undissolved gas can be further dissolved.

[0107] In some embodiments, referring to Figure 3 and Figure 6 , the first premixing unit 100 further includes: a first Venturi ejector 130. The first Venturi ejector 130 includes a first diameter reduction section 131 and a first equal-diameter section 132 connected thereto. The first diameter reduction section 131 is connected to the first static mixer 120. The second premixing unit 200 further includes: a second Venturi ejector. The second Venturi ejector includes a second diameter reduction section and a second equal-diameter section connected thereto. The second diameter reduction section is connected to the second static mixer.

[0108] The gas distributor is arranged upstream of the static mixer, and the Venturi ejector is arranged downstream of the static mixer. The liquid mixed by the static mixer enters the Venturi ejector. After being pressurized by the diameter reduction section and stabilized by the equal-diameter section, the undissolved gas can be completely dissolved in the liquid material, improving the conversion rate of the reaction raw materials.

[0109] In some embodiments, the device of the present application further includes a first gas storage tank (not shown in the figure), a first liquid storage tank, and a second gas storage tank (not shown in the figure). The first gas storage tank is connected to the first gas distribution structure 112 of the first gas distributor 110. The first liquid storage tank is connected to the first pipeline 111 of the first gas distributor 110. The second gas storage tank is connected to the second gas distribution structure of the second gas distributor.

[0110] Ammonia can be stored in the first gas storage tank. Liquid organic base or a mixture of liquid organic base and a small amount or trace amount of solvent can be stored in the first liquid storage tank. Sulfuryl fluoride gas can be stored in the second gas storage tank. By introducing the gas and liquid materials in the gas storage tank and the liquid storage tank into the premixing unit for mixing, gas dissolution can be achieved.

[0111] In some embodiments, referring to Figure 2 , a first discharge port 402 is provided at the upper part of the reaction kettle 400. A second discharge port 403 is provided at the bottom of the reaction kettle 400. The second discharge port 403 is connected to the second pipeline of the second gas distributor.

[0112] Part of the product is continuously discharged above the reaction kettle 400 to achieve continuous reaction, and part of the product is discharged below the reaction kettle 400 and introduced into the second pipeline of the second gas distributor for dissolving sulfuryl fluoride to achieve circulation.

[0113] In some embodiments, referring to Figure 7, a screw reactor 300 is provided with a screw 301 inside. There are 2 feeding ports 302 and 1 discharging port 303 on the side wall of the screw reactor 300. The outer wall of the screw reactor 300 is provided with a heat preservation jacket 304. There is an inlet 305 for the heat preservation medium on the heat preservation jacket.

[0114] Example

[0115] Hereinafter, examples of the present application will be described. The examples described below are exemplary and are only used to explain the present application and should not be construed as a limitation of the present application. For those techniques or conditions not specified in the examples, they shall be carried out according to the techniques or conditions described in the literature in the field or according to the product specifications. For the reagents or instruments whose manufacturers are not indicated, they are all conventional products that can be obtained through commercial purchase.

[0116] Example 1

[0117] In Figure 1 the device shown, the organic base salt of bis(fluorosulfonyl)imide is produced. The specific production process is as follows.

[0118] (1) Premixing stage: After ammonia gas is dispersed through the first gas distributor, it is dissolved in triethylamine in the first static mixer, and ammonia and triethylamine are fed in a molar ratio of 1:3.

[0119] Commercially available triethylamine salt of bis(fluorosulfonyl)imide is pre-added into the reaction kettle, and it is pumped back into the second static mixer at the front end through the second discharge port at the bottom of the reaction kettle for dissolving sulfuryl fluoride. After sulfuryl fluoride is dispersed through the second gas distributor, it is dissolved in the triethylamine salt of bis(fluorosulfonyl)imide in the second static mixer, and ammonia and sulfuryl fluoride are fed in a molar ratio of 1:2.05.

[0120] (2) Reaction stage: The pre-mixed materials in step (1) are introduced into a screw reactor at a temperature of 55 °C for reaction. By adjusting the discharge valve at the end of the screw reactor, the pressure at the discharge end of the screw reactor is controlled to be 1.8 MPa, and the temperature of the reaction kettle is controlled to be 55 °C, 1.8 MPa.

[0121] (3) Discharge stage: When the materials in the reaction kettle cover the first discharge port (i.e., the upper discharge port) of the reaction kettle, the triethylamine salt of bis(fluorosulfonyl)imide is continuously discharged from the upper part of the reaction kettle, and is continuously discharged from the second discharge port at the bottom of the reaction kettle and pumped back into the second static mixer at the front end for dissolving sulfuryl fluoride.

[0122] Examples 2 - 5

[0123] It is carried out according to the method described in Example 1, except that the pressure at the discharge end of the screw reactor and the pressure of the reaction kettle are different from those in Example 1, as shown in Table 1 below.

[0124] Table 1

[0125] Number Pressure at the discharge end of the screw reactor / MPa Pressure in the reaction kettle / MPa Example 1 1.8 1.8 Example 2 2 2 Example 3 1 1 Example 4 0.8 0.8 Example 5 0.5 0.5

[0126] Examples 6 - 9

[0127] It is carried out according to the method described in Example 1, except that the temperature of the screw reactor and the temperature of the reaction kettle are different from those in Example 1, as shown in Table 2 below.

[0128] Table 2

[0129] Number Temperature of the screw reactor / °C Temperature in the reaction kettle / °C Example 1 55 55 Example 6 80 80 Example 7 50 50 Example 8 35 35 Example 9 25 25

[0130] Examples 10 - 12

[0131] It is carried out according to the method described in Example 1, except that the molar ratio of ammonia to triethylamine is different from that in Example 1, as shown in Table 3 below.

[0132] Table 3

[0133] Number Molar ratio of ammonia to triethylamine Example 1 1:3 Example 10 1:5 Example 11 1:2 Example 12 1:1

[0134] Examples 13 - 17

[0135] It is carried out according to the method described in Example 1, except that the molar ratio of ammonia to sulfuryl fluoride is different from that in Example 1, as shown in Table 4 below.

[0136] Table 4

[0137]

[0138]

[0139] Examples 18 - 19

[0140] It is carried out according to the method described in Example 1, except that the type of liquid organic base is different from that in Example 1, as shown in Table 5 below.

[0141] Table 5

[0142] Number Type of liquid organic base Example 1 Triethylamine Example 18 Pyridine Example 19 N - Methylpyrrolidone

[0143] Example 20

[0144] It is carried out according to the method described in Example 1, except that in the premixing stage of step (1): after ammonia gas is dispersed through the first gas distributor, it is dissolved in triethylamine and acetonitrile in the first static mixer, and ammonia gas is fed in a molar ratio of 1:3 to triethylamine and in a molar ratio of 1:2 to acetonitrile.

[0145] Example 21

[0146] It is carried out according to the method described in Example 20, except that ammonia and acetonitrile are fed in a molar ratio of 1:5.

[0147] Comparative Example 1

[0148] It is carried out according to the method described in Example 1, except that the pressure at the discharge end of the screw reactor and the pressure in the reaction kettle are different from those in Example 1, as shown in Table 6 below.

[0149] Table 6

[0150] Number Pressure at the discharge end of the screw reactor / MPa Pressure in the reaction kettle / MPa Example 1 1.8 1.8 Comparative Example 1 0.2 0.2

[0151] Comparative Example 2

[0152] It is carried out according to the method described in Example 20, except that ammonia and acetonitrile are fed in a molar ratio of 1:7.

[0153] The organic base salts of bis(fluorosulfonyl)imide prepared in the above examples and comparative examples are analyzed to detect the chromaticity of the obtained product, the residual amount of the organic base in the obtained product, and the conversion rate of sulfuryl fluoride.

[0154] 1. Chromaticity of triethylamine salt of bis(fluorosulfonyl)imide

[0155] The product is added to a colorimetric cell with a pipette, and then put into a colorimeter together with a blank sample, and the instrument directly reads out the data. The results are shown in Table 7 below.

[0156] Table 7

[0157]

[0158]

[0159] 2. Test for residual amount of organic base

[0160] Take 30 μL of the reacted liquid from the reaction kettle, vaporize it in a headspace, and then inject it into a gas chromatograph to directly obtain the conversion rate of triethylamine. The results are shown in Table 8 below.

[0161] 3. Conversion rate of sulfuryl fluoride

[0162] Take 0.1 g of the reacted liquid from the reaction kettle, make up the volume to 250 mL, and measure the concentration of bis(fluorosulfonyl)imide anions by anion chromatography, and then convert it to the conversion rate of sulfuryl fluoride. The calculation formula is: Conversion rate of sulfuryl fluoride % = 0.7234 × c × v × m 总 / (m1 × m2). Where c is the concentration of bis(fluorosulfonyl)imide anions measured by ion chromatography, μg / mL; v is the made-up volume, mL (here it is 250 mL); m1 is the weight of the reacted liquid taken from the reaction kettle, g (here it is 0.1 g); m2 is the weight of the fed sulfuryl fluoride, g; m 总is the total weight of the reaction solution, in g. The results are shown in Table 8 below.

[0163] Table 8

[0164]

[0165]

[0166] By comparing Example 1, Examples 20 - 21 and Comparative Example 2, it can be seen that in Example 1, no solvent was used, in Examples 20 - 21, a small amount of solvent was used, and in Comparative Example 2, a large amount of solvent was used. The chromaticity of the products in Example 1 and Examples 20 - 21 was significantly lower than that in Comparative Example 2, and the chromaticity of the products decreased with the decrease in the amount of solvent used. Thus, it can be seen that in the method of the present application, without adding a solvent or adding a small amount of solvent, the raw materials react under pressure, reducing the chromaticity of the organic base salt of bis(fluorosulfonyl)imide.

[0167] By comparing Example 1 and Comparative Example 1, it can be seen that controlling the pressure at the discharge end of the screw reactor and the pressure in the reaction kettle above 0.5 MPa can promote the full reaction of ammonia, sulfuryl fluoride and liquid organic base. However, in Comparative Example 1, the pressure was too low, making it difficult for the gas to dissolve fully, resulting in volatilization and thus making the reaction almost impossible to proceed.

[0168] By comparing Examples 1 - 5, it can be seen that as the pressure increases, the residual amount of triethylamine decreases and the conversion rate of sulfuryl fluoride increases, indicating that pressurization is beneficial to the full reaction of ammonia, sulfuryl fluoride and liquid organic base. However, too high a pressure requires higher requirements for production equipment, so the pressure generally does not exceed 2 MPa.

[0169] By comparing Example 1 and Examples 6 - 9, it can be seen that controlling the reaction temperature in the range of 35 - 80 °C is more conducive to reducing the residual amount of triethylamine and increasing the conversion rate of sulfuryl fluoride.

[0170] The theoretical molar ratio of ammonia to triethylamine is 1:2. An appropriate excess of triethylamine is beneficial to increasing the conversion rate of sulfuryl fluoride and promoting the full progress of the reaction. By comparing Example 1 and Examples 10 - 12, it can be seen that controlling the molar ratio of ammonia to triethylamine in the range of 1:(2 - 5) is more conducive to increasing the conversion rate of sulfuryl fluoride.

[0171] By comparing Example 1 and Examples 13 - 17, it can be seen that controlling the molar ratio of ammonia to sulfuryl fluoride in the range of 1:(2 - 3) is more conducive to the full progress of the reaction and reducing the residual amount of triethylamine. Since too much excess of sulfuryl fluoride will cause waste of raw materials, generally, the molar ratio of ammonia to sulfuryl fluoride does not exceed 1:3.

[0172] In Example 1 and Examples 18 - 19, different types of liquid organic bases were used, and the reactions could all proceed fully.

[0173] As described above, it is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for preparing an organic base salt of bis(fluorosulfonyl)imide, characterized in that, It includes the following steps: Introduce ammonia gas, sulfuryl fluoride, liquid organic base and solvent into a reactor, and control the pressure at the discharge end of the reactor to be above 0.5 MPa. After the reaction is completed, the organic base salt of bis(fluorosulfonyl)imide is obtained. Among them, the molar ratio of the ammonia gas to the solvent is 1:(0 - 5).

2. The method according to claim 1, wherein, The pressure at the discharge end of the reactor is 0.8 - 2.0 MPa, preferably 1.0 - 2.0 MPa.

3. The method according to claim 1 or 2, characterized in that, Control the temperature of the reactor to be 35 - 80 °C, preferably 50 - 80 °C.

4. The method according to any one of claims 1 to 3, characterized in that Introducing ammonia gas, sulfuryl fluoride, liquid organic base and solvent into the reactor includes: Dissolve the ammonia gas in the liquid organic base and the solvent to obtain a first solution, where the molar ratio of the ammonia gas to the solvent is 1:(0 - 5). Dissolve the sulfuryl fluoride in the liquid material to obtain a second solution, where the liquid material includes one or more of the hydrofluoride salt of the organic base, bis(fluorosulfonyl)imide, and the organic base salt of bis(fluorosulfonyl)imide. Mix the first solution and the second solution in the reactor.

5. The method according to claim 4, wherein The dissolution is carried out in a static mixer; the reactor is a screw reactor.

6. The method according to claim 5, characterized in that, After the reaction in the screw reactor, the obtained mixed material is introduced into a reaction kettle for continuous reaction. Preferably, the reaction pressure of the reaction kettle is above 0.5 MPa, and the reaction temperature is 35 - 80 °C.

7. The method according to any one of claims 1-6, characterized in that, The molar ratio of the ammonia gas to the sulfuryl fluoride is 1:(2 - 3), and the molar ratio of the ammonia gas to the liquid organic base is 1:(2 - 5).

8. The method according to any one of claims 1 - 7, characterized in that, The liquid organic base includes one or more of pyridine, methylpyridine, N - methylpyrrolidone, triethylamine, tri - n - propylamine, and tri - n - butylamine.

9. An apparatus for preparing an organic base salt of bis(fluorosulfonyl)imide, characterized in that, It includes: A first premixing unit; A second premixing unit; A screw reactor, which is respectively connected to the first premixing unit and the second premixing unit; And A reaction kettle, which is connected to the discharge port of the screw reactor.

10. The device according to claim 9, characterized in that, The lower part of the reaction kettle is provided with a feed port, and the feed port is connected to the discharge port of the screw reactor.

11. The device according to claim 10, characterized in that, Inside the reaction kettle, there are: A stirrer, which includes a rotating shaft and stirring rods connected thereto, and the stirring rods are located at the lower part of the reaction kettle; A feed pipe, which includes a first end and a second end. The first end is connected to the feed port of the reaction kettle, and the second end is arranged above and close to the stirring rods. Preferably, the stirring rods are horizontally arranged, and the port of the second end is 2 - 5 cm away from the stirring rods in the vertical direction.

12. The device according to any one of claims 9 - 11, wherein The first premixing unit includes: A first gas distributor, which includes a first pipe and a first gas distribution structure arranged in the first pipe; and A first static mixer, which is connected to the first gas distributor; The second premixing unit includes: A second gas distributor, which includes a second pipe and a second gas distribution structure arranged in the second pipe; and A second static mixer, which is connected to the second gas distributor.

13. The device according to claim 12, characterized in that, The first premixing unit further includes: a first Venturi ejector, the first Venturi ejector includes a first reduced-diameter section and a first equal-diameter section connected thereto, and the first reduced-diameter section is connected to the first static mixer; The second premixing unit further includes: a second Venturi ejector, the second Venturi ejector includes a second reduced-diameter section and a second cylindrical section connected thereto, and the second reduced-diameter section is connected to the second static mixer.

14. The device according to claim 12, characterized in that, It further includes: a first gas storage tank, the first gas storage tank is connected to the first gas distribution structure of the first gas distributor; a first liquid storage tank, the first liquid storage tank is connected to the first pipeline of the first gas distributor; a second gas storage tank, the second gas storage tank is connected to the second gas distribution structure of the second gas distributor.

15. The device according to claim 12, wherein A first discharge port is provided at the upper part of the reaction kettle, a second discharge port is provided at the bottom of the reaction kettle, and the second discharge port is connected to the second pipeline of the second gas distributor.

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