Dichlorosulfimide as well as preparation method and reaction device thereof

Abstract

The invention provides bis (chlorosulfonyl) imide as well as a preparation method and a reaction device thereof, the preparation method comprises the following steps: 1) preparing mixed slurry containing sulfamic acid and chlorosulfonic acid, pumping the mixed slurry into a continuous micro-channel reactor by using a metering pump, and carrying out amination reaction, so as to obtain an aminated slurry; an intermediate is obtained; 2) carrying out a chlorination reaction on a mixed system containing the intermediate and thionyl chloride in a tubular reactor to obtain a reaction product; and 3) carrying out separation treatment on the reaction product to obtain the bis (chlorosulfonyl) imide. The preparation method provided by the invention can be used for preparing the bis (chlorosulfonyl) imide with high purity, and the preparation method is simple in process and easy to operate.

Description

Technical Field

[0001] This invention relates to a dichlorosulfonylimide belonging to the field of chemical material preparation technology, and particularly to a dichlorosulfonylimide, its preparation method, and reaction apparatus. Background Technology

[0002] With the rapid development of the new energy industry, especially the lithium battery market, the demand for lithium bisfluorosulfonylimide, a common electrolyte lithium salt, is increasing. Currently, the common preparation method for lithium bisfluorosulfonylimide involves reacting bischlorosulfonylimide with a fluorine-containing substance to generate bisfluorosulfonylimide, and then reacting the bisfluorosulfonylimide with lithium fluoride to obtain lithium bisfluorosulfonylimide.

[0003] However, in the industrial production of bischlorosulfonylimide, although the batch reaction route of aminosulfonic acid, chlorosulfonic acid and thionyl chloride has been widely studied and applied, the purity of the bischlorosulfonylimide prepared by this process is not high enough, and the content of acidic substances such as sulfur dioxide and hydrogen chloride is high. This may lead to high impurity content in subsequent bisfluorosulfonylimide and lithium bisfluorosulfonylimide, resulting in side reactions such as the oxidation and decomposition of electrolyte by acidic substances in battery applications, thereby degrading the electrochemical performance of the battery.

[0004] Therefore, those skilled in the art urgently need to develop a high-purity dichlorosulfonyl imide. Summary of the Invention

[0005] This invention provides a method for preparing dichlorosulfonylimide, which can produce dichlorosulfonylimide with high purity. The method is simple, easy to operate, and has high production efficiency.

[0006] The present invention also provides a dichlorosulfonamide, which has high purity and low content of impurities such as sulfur dioxide and hydrogen chloride, which is beneficial to the widespread application of subsequent products.

[0007] The present invention also provides a reaction apparatus that provides excellent conditions for the preparation of dichlorosulfonylimide, which is beneficial for achieving high-purity dichlorosulfonylimide.

[0008] In a first aspect, the present invention provides a method for preparing dichlorosulfonylimide, comprising the following steps:

[0009] 1) Prepare a mixed slurry containing aminosulfonic acid and chlorosulfonic acid, wherein the particle size of aminosulfonic acid is not greater than 200 micrometers, and then pump the mixed slurry into a continuous microchannel reactor to carry out an amination reaction to obtain an intermediate;

[0010] The tail back pressure of the continuous microchannel reactor is 0-3 MPa.

[0011] 2) The mixture including the intermediate and thionyl chloride is subjected to chlorination in a tubular reactor to obtain the reaction product;

[0012] The Reynolds number of the mixed system is not less than 5000, and the back pressure at the tail of the tubular reactor is 0-2 MPa.

[0013] 3) The reaction product is separated to obtain the dichlorosulfonamide.

[0014] In the preparation method of dichlorosulfonylimide as described above, the molar ratio of aminosulfonic acid to chlorosulfonic acid in the mixed slurry is 1:1.01-2.

[0015] In the preparation method of dichlorosulfonylimide as described above, the molar ratio of the intermediate to thionyl chloride is 1:2-2.5.

[0016] The method for preparing dichlorosulfonylimide as described above, wherein step 1) includes controlling the reaction temperature of the amination reaction using a heat-conducting medium, wherein the temperature difference between the heat-conducting medium after heat exchange and the heat-conducting medium before heat exchange is 0-2℃.

[0017] The method for preparing dichlorosulfonylimide as described above, wherein the separation process includes the following steps:

[0018] The reaction product was distilled at 0-1.5 MPa and 30-60 °C to obtain the dichlorosulfonamide.

[0019] In a second aspect, the present invention provides a dichlorosulfonyl imide, wherein the dichlorosulfonyl imide is prepared by the method for preparing dichlorosulfonyl imide described in the first aspect;

[0020] The dichlorosulfonyl imide, by mass percentage, comprises: 85-95% dichlorosulfonyl imide compound, 1-5% sulfur dioxide, 1-5% hydrogen chloride, 1-5% water, ≤4% bis(aminosulfonyl)sulfonamide, 0.1-1% aminosulfonic acid, and 1-10% chlorosulfonylsulfonamide.

[0021] Thirdly, the present invention provides a reaction apparatus comprising a mixing pump, a stirred tank, a continuous microchannel reactor, a tubular reactor, and a flash evaporator connected in sequence by pipelines.

[0022] In the reaction apparatus described above, the diaphragm metering pump is used to deliver a mixed slurry containing aminosulfonic acid and chlorosulfonic acid to a continuous microchannel reactor. The diaphragm metering pump is disposed between the stirred tank and the continuous microchannel reactor. The inlet of the diaphragm metering pump is connected to the outlet of the stirred tank, and the outlet of the diaphragm metering pump is connected to the inlet of the continuous microchannel reactor. The mass flow meter is disposed between the outlet of the diaphragm metering pump and the inlet of the continuous microchannel reactor.

[0023] In the reaction apparatus described above, a first shell is fitted around the outside of the continuous microchannel reactor, wherein the continuous microchannel reactor and the first shell form a cavity for accommodating a heat-conducting medium.

[0024] In the reaction apparatus described above, a second shell is fitted around the outside of the tubular reactor, wherein the tubular reactor and the second shell form a cavity for containing a heat-conducting medium.

[0025] The present invention provides a three-step method for preparing dichlorosulfonylimide. First, chlorosulfonic acid and aminosulfonic acid undergo an amination reaction in a continuous microchannel reactor. This allows for uniform and efficient mixing of the two acids, maintaining a constant local concentration ratio and enabling rapid amination. It also effectively suppresses the formation of byproducts, thereby improving the selectivity of the target dichlorosulfonylimide synthesis. Second, the intermediate is chlorinated with thionyl chloride in a tubular reactor. This increases the conversion rate of the chlorination stage, thereby improving the purity and preparation efficiency of the dichlorosulfonylimide. Finally, the reaction product is separated and purified, further reducing the impurity content and improving the purity of the dichlorosulfonylimide. Furthermore, the preparation method of the present invention significantly improves the production efficiency of dichlorosulfonylimide, facilitating the implementation of large-scale industrial continuous production, while simultaneously reducing the overall production cost of dichlorosulfonylimide.

[0026] The bischlorosulfonylimide provided by this invention has the advantage of high purity. Using this bischlorosulfonylimide as a raw material in the preparation of bisfluorosulfonylimide can improve the purity of the bisfluorosulfonylimide. Furthermore, because the bischlorosulfonylimide of this invention contains a low mass percentage of acidic substances such as sulfur dioxide and hydrogen chloride, when it is used as a raw material to prepare lithium bisfluorosulfonylimide and applied to the electrolyte, the probability of acidic substances such as sulfur dioxide and hydrogen chloride reacting with the electrolyte is low, reducing the likelihood of side reactions such as electrolyte oxidation and decomposition, thereby improving the electrochemical performance of the battery.

[0027] The present invention also provides a reaction apparatus for preparing dichlorosulfonylimide, which can be used for the preparation of dichlorosulfonylimide and helps to achieve the preparation of high-purity dichlorosulfonylimide. Attached Figure Description

[0028] Figure 1 This is a reaction apparatus according to a specific embodiment of the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0030] In a first aspect, the present invention provides a method for preparing dichlorosulfonylimide, comprising the following steps:

[0031] 1) Prepare a mixed slurry containing aminosulfonic acid and chlorosulfonic acid, wherein the particle size of aminosulfonic acid is not greater than 200 micrometers, and then pump the mixed slurry into a continuous microchannel reactor to carry out an amination reaction to obtain an intermediate;

[0032] The tail back pressure of the continuous microchannel reactor is 0-3 MPa.

[0033] 2) The mixture including the intermediate and thionyl chloride is subjected to chlorination in a tubular reactor to obtain the reaction product;

[0034] The Reynolds number of the mixed system is not less than 5000, and the back pressure at the tail of the tubular reactor is 0-2 MPa.

[0035] 3) The reaction product is separated to obtain the dichlorosulfonamide.

[0036] Specifically, in step 1), a mixed slurry containing aminosulfonic acid and chlorosulfonic acid is fed into a continuous microchannel reactor. The back pressure at the tail of the continuous microchannel reactor is controlled within the range of 0-3 MPa, for example, 0, 0.5 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, or 3 MPa, so that chlorosulfonic acid and aminosulfonic acid undergo a rapid amination reaction, that is, the hydrogen on aminosulfonic acid is attacked by chlorosulfonic acid to form a dihydroxysulfonamide intermediate and produce one molecule of hydrogen chloride (chemical reaction formula is shown in Formula 1).

[0037]

[0038] This invention does not limit the specific choice of the internal structure of the continuous microchannel reactor, such as heart-shaped structure, triangular structure, omega-shaped structure, etc., and can be selected according to actual needs.

[0039] Step 2) The intermediate and thionyl chloride are separately introduced into a tubular reactor to obtain a mixed system including the intermediate and thionyl chloride. The Reynolds number of the mixed system is controlled to be not less than 5000, for example, 5000, 5100, 5200, 5300, 5400, 5500, 5600, 5700, 5800, 5900 or 6000, etc., and the back pressure at the tail of the tubular reactor is controlled to be 0-2MPa, for example, 0, 0.2MPa, 0.4MPa, 0.6MPa, 0.8MPa, 1MPa, 1.2MPa, 1.4MPa, 1.6MPa, 1.8MPa or 2MPa, etc., so that the intermediate and thionyl chloride undergo chlorination reaction, that is, the intermediate and thionyl chloride undergo chlorination substitution to obtain reaction products including dichlorosulfonylimide, sulfur dioxide and hydrogen chloride (chemical reaction formula is shown in Equation 2).

[0040]

[0041] Step 3) Separate the reaction product obtained in step 2) to obtain dichlorosulfonamide.

[0042] This invention does not limit the specific parameters of the separation process, as long as sulfur dioxide, hydrogen chloride and dichlorosulfonamide can be separated, and can be selected according to actual needs.

[0043] The preparation method of bischlorosulfonylimide of the present invention involves a three-step process. First, chlorosulfonic acid and aminosulfonic acid undergo an amination reaction in a continuous microchannel reactor. Due to the small channel size, the diffusion distance of molecules is greatly shortened in the microchannels, meaning that molecules can diffuse within a very short time, thus achieving rapid mixing. Furthermore, the complex flow fields generated by the microchannels, such as vortices and shear flows, significantly enhance convective diffusion, resulting in unique hydrodynamic effects within the continuous microchannel reactor. This allows chlorosulfonic acid and aminosulfonic acid to achieve uniform and efficient mixing within a micrometer-scale spatial scale and a microsecond-scale time scale, while maintaining a constant local concentration ratio. The invention employs a specific method to rapidly advance the amination reaction, effectively suppressing the formation of byproducts such as bis(aminosulfonyl)sulfonamides, thereby improving the synthetic selectivity of the target dichlorosulfonylimide and consequently increasing its purity. Secondly, the intermediate is chlorinated with thionyl chloride in a tubular reactor. The heat released during the chlorination reaction accelerates the hydroxyl chlorination reaction rate, increasing the conversion rate of the chlorination stage and thus improving the purity and preparation efficiency of the dichlorosulfonylimide. Finally, the reaction products are separated and purified to obtain dichlorosulfonylimide, further reducing the impurity content and improving its purity. Furthermore, this invention fully utilizes the enhanced mass transfer advantages of continuous microchannel reactors and the efficient heat transfer performance of tubular reactors, combined with high temperature, high pressure, and short residence time, significantly improving the production efficiency of dichlorosulfonylimide. This facilitates the implementation of large-scale continuous industrial production while reducing the overall production cost of dichlorosulfonylimide.

[0044] The preparation of the mixed slurry is not particularly limited in this invention. In one specific embodiment, the mixed slurry can be prepared through the following process:

[0045] At -10 to 20°C, a mixing pump is used to quantitatively add aminosulfonic acid solids to the chlorosulfonic acid liquid phase for mixing. The particle size of the aminosulfonic acid solids is controlled to be below 200 micrometers. The resulting mixture is then fed into a stirred tank for slurrying. The stirred tank is maintained at atmospheric pressure and the temperature is maintained at -10 to 20°C to obtain the mixed slurry.

[0046] In one specific embodiment, the molar ratio of aminosulfonic acid to chlorosulfonic acid in the mixed slurry is 1:1.01-2, for example, a molar ratio of 1:1.01, 1:1.05, 1:1.1, 1:1.15, 1:1.2, 1:1.25, 1:1.3, 1:1.35, 1:1.4, 1:1.45, 1:1.5, 1:1.55, 1:1.6, 1:1.65, 1:1.7, 1:1.75, 1:1.8, 1:1.85, 1:1.9, 1:1.95, or 1:2, etc. When the molar ratio of aminosulfonic acid to chlorosulfonic acid is within the above range, an intermediate is prepared by rationally mixing aminosulfonic acid and chlorosulfonic acid. This avoids the formation of byproducts such as chlorosulfonylsulfonamide and bis(aminosulfonyl)sulfonamide due to excessive chlorosulfonic acid, thereby improving the purity of bischlorosulfonimide. At the same time, it can reduce the waste of raw materials and reduce the difficulty of subsequent purification.

[0047] In one specific embodiment, the molar ratio of the intermediate to thionyl chloride is 1:2-2.5, for example, 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4, or 1:2.5. When the molar ratio of the intermediate to thionyl chloride is within the above range, the intermediate and thionyl chloride can undergo a more complete chlorination reaction, avoiding the formation of reaction byproducts, further improving the purity of dichlorosulfonylimide, while also avoiding raw material waste and simplifying the impurity removal process.

[0048] In one specific embodiment, step 1) includes controlling the reaction temperature of the amination reaction using a heat-conducting medium, wherein the temperature difference between the heat-conducting medium after heat exchange and the heat-conducting medium before heat exchange is 0-2℃. Specifically, in step 1), the continuous microchannel reactor is heated using a heat-conducting medium to ensure the reaction temperature of the amination reaction, and the temperature difference between the heat-conducting medium before and after use is controlled to be ±2℃. This invention does not limit the specific selection of the heat-conducting medium; for example, thermal grease, thermal silicone, thermal oil, etc., can be selected according to actual needs. The heat-conducting medium of this invention provides the thermal conditions for the amination reaction to reach the reaction temperature, while also rapidly removing the reaction heat released by the amination reaction that would cause the reaction to continue to rise in temperature, ensuring a constant temperature for the amination reaction, avoiding temperature-changing reactions, thereby reducing the formation of by-products and improving the purity of dichlorosulfonyl imide.

[0049] In one specific embodiment, the amination reaction temperature is 50-90°C, for example, 50°C, 60°C, 70°C, 80°C, or 90°C, and the reaction time is 2-4 min, for example, 2 min, 2.2 min, 2.4 min, 2.6 min, 2.8 min, 3 min, 3.2 min, 3.4 min, 3.6 min, 3.8 min, or 4 min. When the reaction temperature and reaction time are within the above ranges, chlorosulfonic acid and aminosulfonic acid can undergo a sufficient amination reaction, allowing the hydrogen on the aminosulfonic acid to be attacked by chlorosulfonic acid, forming a dihydroxysulfonylimide intermediate.

[0050] In one specific embodiment, the chlorination reaction temperature is 80-150°C, for example, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, or 150°C, and the reaction time is 2-4 min, for example, 2 min, 2.2 min, 2.4 min, 2.6 min, 2.8 min, 3 min, 3.2 min, 3.4 min, 3.6 min, 3.8 min, or 4 min. When the chlorination reaction temperature and reaction time are within the above ranges, the intermediate and thionyl chloride can undergo a chlorination reaction, causing the hydroxyl groups on the intermediate to be chlorinated and substituted to obtain dichlorosulfonylimide.

[0051] In one specific embodiment, the separation process includes the following steps: distilling the reaction product at -0.1 to 1.5 MPa and 30 to 60 °C to obtain dichlorosulfonamide.

[0052] Specifically, the reaction product is distilled at -0.1 to 1.5 MPa and 30 to 60 °C to obtain a gaseous product and a liquid product. The gaseous product includes volatile byproducts such as sulfur dioxide and hydrogen chloride, while the liquid product includes dichlorosulfonylimide. For the subsequent application of sulfur dioxide and hydrogen chloride, the distilled gaseous product can be condensed. When distillation is performed within the temperature and pressure range described above, byproducts such as sulfur dioxide and hydrogen chloride in the reaction product can be removed, reducing the impurity content in dichlorosulfonylimide and thus further improving its purity.

[0053] This invention provides a dichlorosulfonyl imide, which is prepared by the method described above; wherein the dichlorosulfonyl imide comprises, by weight percentage: 85-95% dichlorosulfonyl imide compound, 1-5% sulfur dioxide, 1-5% hydrogen chloride, 1-5% water, ≤4% bis(aminosulfonyl)sulfonamide, 0.1-1% aminosulfonic acid, and 1-10% chlorosulfonylsulfonamide.

[0054] The bischlorosulfonylimide provided by this invention has high purity. Using this bischlorosulfonylimide as a raw material in the preparation of bisfluorosulfonylimide can improve the purity of bisfluorosulfonylimide. Furthermore, the mass percentage of acidic substances such as sulfur dioxide and hydrogen chloride in this bischlorosulfonylimide is low. When it is used as a raw material to prepare lithium bisfluorosulfonylimide and applied to the electrolyte, the probability of acidic substances such as sulfur dioxide and hydrogen chloride reacting with the electrolyte is low, reducing the probability of side reactions such as electrolyte oxidation and decomposition, thereby improving the electrochemical performance of the battery.

[0055] Specifically, the mass percentage of each component in the dichlorosulfonamide of the present invention is obtained by liquid chromatography.

[0056] The present invention provides a reaction apparatus comprising a mixing pump, a stirred tank, a continuous microchannel reactor, a tubular reactor, and a flash evaporator, which are connected in sequence by pipelines.

[0057] The continuous microchannel reactor of this invention is used for the amination reaction of chlorosulfonic acid and aminosulfonic acid to generate an intermediate; the tubular reactor is used for the chlorination reaction of the intermediate with thionyl chloride to generate a reaction product; and the flash evaporator is used to remove byproducts such as sulfur dioxide and hydrogen chloride from the reaction product to obtain high-purity dichlorosulfonylimide. The outlet of the continuous microchannel reactor is connected to the inlet of the tubular reactor, meaning the intermediate is discharged from the outlet of the continuous microchannel reactor and introduced from the inlet of the tubular reactor; the outlet of the tubular reactor is connected to the inlet of the flash evaporator, meaning the reaction product is discharged from the outlet of the tubular reactor and introduced from the inlet of the flash evaporator.

[0058] The reaction apparatus provided by this invention provides excellent conditions for the preparation of dichlorosulfonylimide, thereby enabling the preparation of dichlorosulfonylimide with high purity, which is beneficial for the subsequent preparation of high-quality products.

[0059] In one specific embodiment, the diaphragm metering pump is used to deliver a mixed slurry containing aminosulfonic acid and chlorosulfonic acid to a continuous microchannel reactor. The diaphragm metering pump is disposed between the stirred tank and the continuous microchannel reactor. The inlet of the diaphragm metering pump is connected to the outlet of the stirred tank, and the outlet of the diaphragm metering pump is connected to the inlet of the continuous microchannel reactor. The mass flow meter is disposed between the outlet of the diaphragm metering pump and the inlet of the continuous microchannel reactor.

[0060] This invention does not limit the number of mass flow meters and can select them according to actual needs. In some embodiments, the mass flow meters can be connected between the outlet of the diaphragm metering pump and the inlet of the continuous microchannel reactor via flanges. This invention controls the feed flow rate of the mixed slurry containing chlorosulfonic acid and aminosulfonic acid by using a diaphragm metering pump and mass flow meters, which can accurately control the reaction rate and reaction degree, so that chlorosulfonic acid and aminosulfonic acid can react fully and avoid the formation of by-products, thereby improving the purity of dichlorosulfonylimide.

[0061] In one specific embodiment, a first shell is fitted around the outside of the continuous microchannel reactor, forming a cavity between the continuous microchannel reactor and the first shell for accommodating the heat-conducting medium. The apparatus of the present invention further includes a first shell disposed outside the continuous microchannel reactor, forming a cavity between the first shell and the continuous microchannel reactor for accommodating the heat-conducting medium. This apparatus provides conditions for an isothermal reaction of the amination reaction, thereby enabling the preparation of dichlorosulfonyl imide with high purity.

[0062] In one specific embodiment, a second shell is fitted around the tubular reactor, forming a cavity between the tubular reactor and the second shell for containing the heat-conducting medium. The apparatus of the present invention further includes a second shell disposed outside the tubular reactor, forming a cavity between the second shell and the tubular reactor for containing the heat-conducting medium. The second shell fitted around the tubular reactor of the present invention ensures that the chlorination reaction proceeds under adiabatic conditions, preventing the heat of reaction generated by the chlorination reaction from diffusing to the external environment and thus avoiding a decrease in the chlorination reaction rate, thereby saving process energy and improving production efficiency.

[0063] The present invention will be further described in detail below through specific embodiments.

[0064] Example 1

[0065] The preparation process of dichlorosulfonyl imide provided in this embodiment includes the following steps:

[0066] 1. At -10℃, solid aminosulfonic acid is added to liquid chlorosulfonic acid using a mixing pump (the molar ratio of solid aminosulfonic acid to chlorosulfonic acid is 1:1.25). The particle size of the solid aminosulfonic acid is controlled to be below 200 micrometers. The resulting mixture is then fed into a stirred tank and further stirred to obtain a mixed slurry. The tank is kept at atmospheric pressure and the temperature is maintained at -10℃. Subsequently, the mixed slurry is pumped into a continuous microchannel reactor using a metering pump to carry out an amination reaction. By setting a first shell outside the continuous microchannel reactor, the amination reaction temperature is controlled at 60℃, the back pressure at the tail of the continuous microchannel reactor is 1MPa, and the reaction time is 3min to obtain an intermediate.

[0067] The temperature difference between the heat transfer medium after heat exchange and the heat transfer medium before heat exchange is 2℃.

[0068] 2. In a tubular reactor with a second shell on the outside, the intermediate and thionyl chloride are subjected to chlorination reaction at a molar ratio of 1:2.1. The chlorination reaction is carried out under adiabatic conditions, the Reynolds number of the mixed system is controlled at 5000, the reaction temperature of the chlorination reaction is 140℃, the reaction time is 3min, and the back pressure at the tail of the tubular reactor is 1MPa to obtain the reaction product.

[0069] 3. The reaction product was distilled at -0.07 MPa and 50 °C to obtain dichlorosulfonamide.

[0070] According to liquid chromatography analysis, the dichlorosulfonylimide composition by mass percentage includes: 91.5% dichlorosulfonylimide compound, 2.5% sulfur dioxide, 2.4% hydrogen chloride, 1.7% water, 0.1% bis(aminosulfonyl)sulfonamide, 0.3% aminosulfonic acid, and 1.5% chlorosulfonylsulfonamide.

[0071] Example 2

[0072] The process is basically the same as in Example 1, except that in step 1), the aminosulfonic acid solid is quantitatively added to the chlorosulfonic acid liquid phase using a mixing pump at 20°C, and the back pressure at the tail of the continuous microchannel reactor is 0 MPa.

[0073] Examples 3-36

[0074] It is basically the same as Example 1, except that the parameters shown in Table 1 are changed.

[0075] Comparative Examples 1-3

[0076] It is basically the same as Example 1, except that the parameters shown in Table 1 are changed.

[0077] Comparative Example 4

[0078] The preparation process of the dichlorosulfonyl imide provided in this comparative example includes the following steps:

[0079] 1. In the first reaction vessel, chlorosulfonic acid and aminosulfonic acid are subjected to an amination reaction at a molar ratio of 1:1.25. The amination reaction temperature is controlled at 60℃, the amination reaction pressure is 1MPa, and the reaction time is 3min to obtain an intermediate.

[0080] 2. In the second reaction vessel, the intermediate and thionyl chloride are subjected to chlorination reaction at a molar ratio of 1:1. The stirring rate of the intermediate and thionyl chloride is controlled at 50 r / min, the reaction temperature of the chlorination reaction is 140°C, and the reaction pressure of the chlorination reaction is 0.1 MPa, until the pressure inside the vessel is atmospheric pressure, and the reaction product is obtained.

[0081] 3. The reaction product was distilled at -0.07 MPa and 50 °C to obtain dichlorosulfonamide.

[0082] Test case

[0083] The components of the dichlorosulfonamides prepared in the above examples and comparative examples were tested by liquid chromatography, and the results are shown in Table 2.

[0084] Table 1:

[0085]

[0086]

[0087] Table 2:

[0088]

[0089] As shown in Table 2, the dichlorosulfonamide prepared by the method in the examples has higher purity than that prepared by the comparative example.

[0090] In summary, the method for preparing dichlorosulfonylimide provided by this invention can produce dichlorosulfonylimide with high purity, wherein the purity of the dichlorosulfonylimide compound in the dichlorosulfonylimide is as high as 91.5%, which is beneficial to the subsequent application of dichlorosulfonylimide.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing dichlorosulfonylimide, characterized in that, Includes the following steps: 1) Prepare a mixed slurry containing aminosulfonic acid and chlorosulfonic acid, wherein the particle size of aminosulfonic acid is not greater than 200 micrometers, and then pump the mixed slurry into a continuous microchannel reactor to carry out an amination reaction to obtain an intermediate; The tail back pressure of the continuous microchannel reactor is 0-3 MPa. 2) The mixture including the intermediate and thionyl chloride is subjected to chlorination in a tubular reactor to obtain the reaction product; The Reynolds number of the mixed system is not less than 5000, and the back pressure at the tail of the tubular reactor is 0-2 MPa. 3) The reaction product is separated to obtain the dichlorosulfonamide.

2. The method for preparing dichlorosulfonylimide according to claim 1, characterized in that, In the mixed slurry, the molar ratio of aminosulfonic acid to chlorosulfonic acid is 1:1.01-2; And / or, the molar ratio of the intermediate to the thionyl chloride is 1:2-2.

5.

3. The method for preparing dichlorosulfonylimide according to claim 1 or 2, characterized in that, Step 1) includes controlling the reaction temperature of the amination reaction using a heat-conducting medium, wherein the temperature difference between the heat-conducting medium after heat exchange and the heat-conducting medium before heat exchange is 0-2℃.

4. The method for preparing dichlorosulfonylimide according to any one of claims 1-3, characterized in that, The amination reaction is carried out at a temperature of 50-90℃ for 2-4 minutes. And / or, the chlorination reaction is carried out at a temperature of 80-150°C for a time of 2-4 minutes.

5. The method for preparing dichlorosulfonylimide according to any one of claims 1-4, characterized in that, The separation process includes the following steps: The reaction product was distilled at -0.1 to 1.5 MPa and 30 to 60 °C to obtain the dichlorosulfonamide.

6. A dichlorosulfonylimide, characterized in that, The dichlorosulfonyl imide is prepared by the method for preparing dichlorosulfonyl imide according to any one of claims 1-5; The dichlorosulfonyl imide, by mass percentage, comprises: 85-95% dichlorosulfonyl imide compound, 1-5% sulfur dioxide, 1-5% hydrogen chloride, 1-5% water, ≤4% bis(aminosulfonyl)sulfonamide, 0.1-1% aminosulfonic acid, and 1-10% chlorosulfonylsulfonamide.

7. A reaction apparatus, characterized in that, It includes a mixing pump, a stirred tank, a continuous microchannel reactor, a tubular reactor, and a flash evaporator, which are connected in sequence by pipelines.

8. The reaction apparatus according to claim 7, characterized in that, The reaction apparatus further includes a diaphragm metering pump and a mass flow meter. The diaphragm metering pump is used to transport a mixed slurry containing aminosulfonic acid and chlorosulfonic acid to a continuous microchannel reactor. The diaphragm metering pump is disposed between the stirred tank and the continuous microchannel reactor. The inlet of the diaphragm metering pump is connected to the outlet of the stirred tank, and the outlet of the diaphragm metering pump is connected to the inlet of the continuous microchannel reactor. The mass flow meter is disposed between the outlet of the diaphragm metering pump and the inlet of the continuous microchannel reactor.

9. The reaction apparatus according to claim 7 or 8, characterized in that, The continuous microchannel reactor is surrounded by a first shell, wherein a cavity for accommodating the heat-conducting medium is formed between the continuous microchannel reactor and the first shell.

10. The reaction apparatus according to any one of claims 7-9, characterized in that, The tubular reactor is fitted with a second shell, wherein a cavity for containing a heat-conducting medium is formed between the tubular reactor and the second shell.

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