A method and system for continuous production of bischlorosulfonamide acid

Abstract

The present application relates to a kind of continuous preparation of dichlorosulfamide acid method and system, belong to the preparation technical field of nitrogen-containing compound.The continuous preparation of dichlorosulfamide acid method of the present application includes the following steps: chlorosulfonic acid, chlorosulfonyl isocyanate is continuously injected into microchannel reactor and circulates liquid and is reacted under the pressure of 0.5-5MPa, and microchannel reactor effluent material is carried out gas-liquid separation;The circulating liquid is part of liquid in the liquid obtained by gas-liquid separation.The method of the present application, by the liquid after gas-liquid separation part of material as circulating liquid continues to participate in the reaction of chlorosulfonic acid and chlorosulfonyl isocyanate, can improve the utilization rate of chlorosulfonic acid in the reaction system, reduce production cost;And can also improve the absorption rate of carbon dioxide, inhibit the generation of gas-liquid two-phase, avoid the continuous gas phase space in microchannel reactor, make the reaction in homogeneous state, ensure HClSI continuous, stable production.

Description

Technical Field

[0001] This invention relates to a method and system for the continuous preparation of dichlorosulfonylimine, belonging to the field of nitrogen-containing compound preparation technology. Background Technology

[0002] With increasing focus on a green and low-carbon economy, lithium batteries have gained popularity and widespread application due to their obvious advantages over traditional chemical batteries, such as high operating voltage, high energy density, long lifespan, and no memory effect. Among these, the electrolyte, as a crucial component of lithium batteries, significantly impacts cycle life, high and low temperature performance, and safety. Currently, lithium hexafluorophosphate (LiPF6) is the most widely used electrolyte lithium salt; however, it suffers from poor thermal stability and the generation of HF upon contact with water, negatively affecting battery performance and safety. Lithium bisfluorosulfonylimide (LiFSI) is a novel lithium salt. Compared to LiPF6, LiFSI has a higher decomposition temperature, better conductivity, and is less prone to hydrolysis, thus possessing promising application prospects.

[0003] Typically, LiFSI is synthesized through three steps: preparation of bischlorosulfonylimide acid (HClSI); fluorination of bischlorosulfonylimide to generate bisfluorosulfonylimide (HFSI) or its salt; and introduction of lithium ions to finally generate LiFSI. The raw materials and process conditions used in each step may vary depending on the specific process route, but the preparation of bischlorosulfonylimide acid is always necessary. In existing technologies, there are numerous process routes for preparing bischlorosulfonylimide acid. For example, using aminosulfonic acid, thionyl chloride, and chlorosulfonic acid as raw materials to produce HClSI generates toxic SO2 waste gas, requiring tail gas treatment and causing environmental harm. This route also has low atom economy and does not meet the requirements of green chemistry. Alternatively, bischlorosulfonylimide acid is often prepared by reacting chlorosulfonic acid and chlorosulfonyl isocyanate. This route does not generate waste gas other than CO2, making it green, economical, and environmentally friendly. However, the generated CO2 gas tends to accumulate in the reaction system, affecting the mass transfer process and hindering the efficient production of bischlorosulfonylimide acid. Summary of the Invention

[0004] The purpose of this invention is to provide a method for the continuous preparation of dichlorosulfonylimide acid, so as to solve the problem of low production efficiency in the preparation of dichlorosulfonylimide acid by existing methods.

[0005] The present invention also provides a system for the continuous preparation of dichlorosulfonylimide acid, in order to solve the problem of low production efficiency in the preparation of dichlorosulfonylimide acid by existing methods.

[0006] To achieve the above objectives, the technical solution adopted by the continuous preparation method of dichlorosulfonylimine acid of the present invention is as follows:

[0007] A method for the continuous preparation of dichlorosulfonylimine includes the following steps: continuously injecting chlorosulfonic acid, chlorosulfonyl isocyanate and circulating liquid into a microchannel reactor to react under a pressure of 0.5 to 5 MPa, and performing gas-liquid separation on the material flowing out of the microchannel reactor; wherein the circulating liquid is a portion of the liquid obtained from the gas-liquid separation.

[0008] The method for continuous preparation of dichlorosulfonyl imide of the present invention improves upon existing methods by using a portion of the liquid material after gas-liquid separation as a circulating liquid to continue participating in the reaction of chlorosulfonic acid and chlorosulfonyl isocyanate. This improves the utilization rate of chlorosulfonic acid within the reaction system and reduces production costs. Furthermore, since dichlorosulfonyl imide has a good absorption capacity for carbon dioxide and the reaction occurs at high pressure, the method of the present invention also improves the system's carbon dioxide absorption rate, suppresses the formation of gas-liquid two-phase mixtures, avoids continuous gas phase space within the microchannel reactor, and ensures the reaction proceeds in a homogeneous state, guaranteeing continuous and stable production of HClSI. In addition, the method of the present invention uses chlorosulfonic acid and chlorosulfonyl isocyanate as raw materials, avoiding the generation of waste gases such as SO2 and HCl, thus better meeting environmental protection requirements. The chemical reactions involved in the continuous preparation of dichlorosulfonyl imide of the present invention are as follows:

[0009]

[0010] Further, injecting chlorosulfonic acid, chlorosulfonyl isocyanate, and the circulating liquid into the microchannel reactor involves injecting a mixture of chlorosulfonic acid, chlorosulfonyl isocyanate, and the circulating liquid into the microchannel reactor. To promote complete conversion of the chlorosulfonyl isocyanate and reduce energy consumption, the molar percentage of chlorosulfonic acid in the mixture is further 31-90%, and the molar percentage of chlorosulfonyl isocyanate is 1-5%. Even further, the molar percentage of chlorosulfonic acid in the mixture is 31-64%, and the molar percentage of chlorosulfonyl isocyanate is 1.1-2%. For example, the molar percentage of chlorosulfonic acid in the mixture is 45-64%.

[0011] Further, the feed molar ratio of chlorosulfonic acid and chlorosulfonyl isocyanate is 0.5–2:1; the ratio of the volumetric flow rate of the circulating liquid to the total volumetric flow rate of chlorosulfonic acid and chlorosulfonyl isocyanate is 5–50:1, preferably 6.49–29.41:1. By controlling the feed ratio within the above range during the reaction process, the conversion of chlorosulfonyl isocyanate to dichlorosulfonylimine can be promoted, and the reaction rate can be significantly improved while shortening the reaction time.

[0012] The circulating liquid and the liquid obtained from gas-liquid separation have identical compositions, mainly consisting of chlorosulfonic acid and dichlorosulfonylimide acid, with a molar ratio of 0.25 to 4:1. For example, the molar ratio of chlorosulfonic acid to dichlorosulfonylimide acid in the circulating liquid is 0.42 to 1.85:1. Further, the molar ratio of chlorosulfonic acid to dichlorosulfonylimide acid in the circulating liquid is 0.79 to 1.85:1.

[0013] To facilitate precise control of the reaction time, more preferably, the chlorosulfonic acid, chlorosulfonyl isocyanate, and circulating liquid are injected into the microchannel reactor as a mixture of the chlorosulfonic acid, chlorosulfonyl isocyanate, and circulating liquid; the mixture is preheated to the reaction temperature before being injected into the microchannel reactor. To prevent the carbon dioxide generated during the preheating stage from escaping and forming a gas phase space that affects subsequent mass transfer, and to achieve rapid mixing of materials, the preheating is further carried out at a pressure of 0.5–5 MPa.

[0014] To improve preparation efficiency while ensuring the raw materials do not decompose, the reaction temperature is further set at 60–200°C; the residence time of the material in the microchannel reactor is 3–240 min. To further ensure rapid and stable reaction, the reaction temperature is set at 100–140°C, for example, 100°C, 120°C, or 140°C; the residence time of the material in the microchannel reactor is 5–240 min. While conducting the reaction at a higher pressure ensures a homogeneous system, to achieve gas-liquid homogeneity while avoiding the danger of excessive pressure, the reaction pressure is further set at 1–3 MPa, for example, 1 MPa or 2 MPa.

[0015] Understandably, during the reaction, the material flows continuously through the microchannel reactor. During gas-liquid separation, CO2 gas is continuously discharged from the system to ensure constant system pressure.

[0016] Furthermore, the gas-liquid separation temperature is controlled at 40–150°C, and the pressure is controlled at 0.5–5 MPa. To facilitate control of the reaction process, the gas-liquid separation temperature and pressure are further aligned with the reaction temperature and pressure.

[0017] To obtain a high-purity dichlorosulfonylimide acid product, the method for continuously preparing dichlorosulfonylimide acid further includes the following step: subjecting the remaining liquid after removing the portion returned as a circulating liquid from the separated liquid to vacuum distillation to obtain dichlorosulfonylimide acid. It is understood that, to maintain reaction stability, the return rate of the circulating liquid remains constant during the reaction process, and the discharge rate of the remaining liquid is the same as the total feed rate of chlorosulfonic acid and chlorosulfonyl isocyanate.

[0018] The fraction collected at 120°C under a vacuum of -0.095 MPa by vacuum distillation is dichlorosulfonylimine.

[0019] The technical solution adopted in the system for continuous preparation of dichlorosulfonylimine of the present invention is as follows:

[0020] A system for the continuous preparation of dichlorosulfonylimine includes a microchannel reactor and a gas-liquid separator arranged sequentially in the material flow direction; the microchannel reactor provides a reaction site for chlorosulfonic acid and chlorosulfonyl isocyanate; the gas-liquid separator separates the material flowing out of the microchannel reactor into gas and liquid components; and a material channel is provided between the gas-liquid separator and the microchannel reactor to allow some of the liquid from the gas-liquid separator to return to the microchannel reactor.

[0021] The continuous dichlorosulfonyl imide system of the present invention has a material channel between the gas-liquid separator and the microchannel reactor for returning part of the liquid obtained from gas-liquid separation to the microchannel reactor. By using part of the material in the liquid after gas-liquid separation as a circulating liquid to continue to participate in the reaction of chlorosulfonic acid and chlorosulfonyl isocyanate, the utilization rate of chlorosulfonic acid in the reaction system can be improved and the production cost can be reduced.

[0022] Furthermore, the system for the continuous preparation of dichlorosulfonylimine also includes a micromixer for providing a portion of the material channel and for mixing chlorosulfonic acid, chlorosulfonyl isocyanate, and a portion of the liquid after gas-liquid separation.

[0023] The microchannel reactor used in this invention is a plug flow reactor, typically constructed from thin tubes, the cross-sectional area of ​​which is preferably 10–15 mm². 2 For example, 12.56mm 2 .

[0024] The present invention uses a mixture of chlorosulfonic acid and dichlorosulfonylimide with the same molar ratio as chlorosulfonic acid and dichlorosulfonylimide in the circulating liquid as the starting circulating liquid at startup. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the system for the continuous preparation of dichlorosulfonylimide acid according to Example 8 of the present invention;

[0026] Figure 2 The image shows the hydrogen nuclear magnetic resonance spectrum of the mixed solution obtained in Example 1 of this invention.

[0027] Figure 3 This is a schematic diagram of the peak separation method in the experimental example of the present invention;

[0028] Among them, 1-micro mixer, 2-microchannel reactor, 3-gas-liquid separator, 4-reduced pressure distillation column, 5-circulating pump, 6-chlorosulfonic acid delivery pump, 7-chlorosulfonyl isocyanate delivery pump. Detailed Implementation

[0029] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0030] The following examples use a mixture of chlorosulfonic acid and dichlorosulfonylimide with the same molar ratio of chlorosulfonic acid and dichlorosulfonylimide in the circulating liquid as in the corresponding examples as the starting circulating liquid. After the reaction is stabilized, the method of each example is obtained.

[0031] Example 1

[0032] The method for continuous preparation of dichlorosulfonylimide acid in this embodiment includes the following steps:

[0033] Chlorosulfonic acid (0.05 mol / min) and chlorosulfonyl isocyanate (0.05 mol / min) were mixed with circulating liquid (all the circulating liquid separated from the liquid phase of gas-liquid separation was returned, with a volumetric flow rate of 50 mL / min) at a flow rate of 4.35 mL / min and a flow rate of 50 mL / min) in a micromixer at 100 °C and 2 MPa. The resulting mixture (45% chlorosulfonic acid and 2% chlorosulfonyl isocyanate) flowed into a microchannel reactor. The residence time of the mixture was controlled at 150 min. After reacting at 100℃ and 2MPa, the mixture flows into a gas-liquid separator for gas-liquid separation at 100℃ and 2MPa. The gas phase (mainly carbon dioxide) produced by the separation is directly discharged from the system, while the liquid phase (mainly chlorosulfonic acid and dichlorosulfonylimide) is divided into two streams. One stream is returned at 50mL / min as a circulating liquid (the molar ratio of chlorosulfonic acid and dichlorosulfonylimide in the circulating liquid is 0.79:1) and enters a micro mixer. The other stream is discharged at 7.7mL / min. The liquid at the discharge point is sampled and subjected to vacuum distillation. The fraction collected at 120℃ under a vacuum of -0.095MPa is used to obtain HClSI liquid.

[0034] Example 2

[0035] The method for continuous preparation of dichlorosulfonylimide acid in this embodiment includes the following steps:

[0036] Chlorosulfonic acid and chlorosulfonyl isocyanate were mixed at a flow rate of 4.35 mL / min and a circulating liquid (all the circulating liquid separated from the liquid phase of the gas-liquid separation was returned, with a flow rate of 50 mL / min) in a micromixer at 120 °C and 2 MPa. The resulting mixture (containing 50% chlorosulfonic acid and 1.9% chlorosulfonyl isocyanate) flowed into a microchannel reactor. The residence time of the mixture was controlled at 90 min, and the mixture was further processed in the microchannel reactor at 120 °C and 2 MPa. After the reaction, the mixture flows into a gas-liquid separator for gas-liquid separation at 120℃ and 2MPa. The gas phase (mainly carbon dioxide) produced by the separation is directly discharged from the system, while the liquid phase (mainly chlorosulfonic acid and dichlorosulfonylimide) is divided into two streams. One stream is returned at 50mL / min as a circulating liquid (the molar ratio of chlorosulfonic acid and dichlorosulfonylimide in the circulating liquid is 1.03:1) and enters a micro mixer. The other stream is discharged at 7.7mL / min. The liquid at the discharge point is sampled and subjected to vacuum distillation. The fraction collected at 120℃ under a vacuum of -0.095MPa is used to obtain HClSI liquid.

[0037] Example 3

[0038] The method for continuous preparation of dichlorosulfonylimide acid in this embodiment includes the following steps:

[0039] Chlorosulfonic acid and chlorosulfonyl isocyanate were mixed at a flow rate of 4.35 mL / min and a circulating liquid (all the circulating liquid separated from the liquid phase of the gas-liquid separation was returned, with a flow rate of 50 mL / min) in a micromixer at 140 °C and 2 MPa. The resulting mixture (containing 47% chlorosulfonic acid and 1.9% chlorosulfonyl isocyanate) flowed into a microchannel reactor. The residence time of the mixture was controlled at 35 min, and the mixture was further processed in the microchannel reactor at 140 °C and 2 MPa. After the reaction, the mixture flows into a gas-liquid separator for gas-liquid separation at 140℃ and 2MPa. The gas phase (mainly carbon dioxide) produced by the separation is directly discharged from the system, while the liquid phase (mainly chlorosulfonic acid and dichlorosulfonylimide) is divided into two streams. One stream is returned at 50mL / min as a circulating liquid (the molar ratio of chlorosulfonic acid and dichlorosulfonylimide in the circulating liquid is 0.83:1) and enters a micro mixer. The other stream is discharged at 7.7mL / min. The liquid at the discharge point is sampled and subjected to vacuum distillation. The fraction collected at 120℃ under a vacuum of -0.095MPa is used to obtain HClSI liquid.

[0040] Example 4

[0041] The method for continuous preparation of dichlorosulfonylimide acid in this embodiment includes the following steps:

[0042] Chlorosulfonic acid (0.66 mL / min, 0.001 mol / min) and chlorosulfonyl isocyanate (0.87 mL / min, 0.001 mol / min) were mixed with circulating liquid (all the circulating liquid separated from the liquid phase of gas-liquid separation was returned, with a volumetric flow rate of 45 mL / min) in a micromixer at 140 °C and 2 MPa pressure. The resulting mixture (containing 64% chlorosulfonic acid and 1.8% chlorosulfonyl isocyanate) flowed into a microchannel reactor. The residence time of the mixture was controlled at 5 min. After the reaction is carried out at 140℃ and 2MPa, the mixture flows into a gas-liquid separator for gas-liquid separation at 140℃ and 2MPa. The gas phase (mainly carbon dioxide) produced by the separation is directly discharged from the system, while the liquid phase (mainly chlorosulfonic acid and dichlorosulfonylimide) produced by the separation is divided into two streams. One stream is returned at 45mL / min as the circulating liquid (the molar ratio of chlorosulfonic acid and dichlorosulfonylimide in the circulating liquid is 1.85:1) and enters the micro mixer. The other stream is discharged at 1.53mL / min. The liquid at the discharge point is sampled and subjected to vacuum distillation. The fraction collected at 120℃ under a vacuum of -0.095MPa is used to obtain HClSI liquid.

[0043] Example 5

[0044] The method for continuous preparation of dichlorosulfonylimide acid in this embodiment includes the following steps:

[0045] Chlorosulfonic acid and chlorosulfonyl isocyanate were mixed at a flow rate of 4.35 mL / min and a circulating liquid (all the circulating liquid separated from the liquid phase of the gas-liquid separation was returned, with a flow rate of 50 mL / min) in a micromixer at 80°C and 2 MPa. The resulting mixture (containing 53% chlorosulfonic acid and 1.1% chlorosulfonyl isocyanate) flowed into a microchannel reactor. The residence time of the mixture was controlled at 240 min, and the mixture was further processed in the microchannel reactor at 80°C and 2 MPa. After the reaction, the mixture flows into a gas-liquid separator for gas-liquid separation at 80℃ and 2MPa. The gas phase (mainly carbon dioxide) produced by the separation is directly discharged from the system, while the liquid phase (mainly chlorosulfonic acid and dichlorosulfonylimide) is divided into two streams. One stream is returned at 50mL / min as the circulating liquid (the molar ratio of chlorosulfonic acid and dichlorosulfonylimide in the circulating liquid is 1.81:1) and enters the micro mixer. The other stream is discharged at 7.7mL / min. The liquid at the discharge point is sampled and subjected to vacuum distillation. The fraction collected at 120℃ under a vacuum of -0.095MPa is used to obtain HClSI liquid.

[0046] Example 6

[0047] The method for continuous preparation of dichlorosulfonylimide acid in this embodiment includes the following steps:

[0048] Chlorosulfonic acid and chlorosulfonyl isocyanate were mixed at a flow rate of 4.35 mL / min and a circulating liquid (all the circulating liquid separated from the liquid phase of the gas-liquid separation was returned, with a flow rate of 50 mL / min) in a micromixer at 90°C and 1 MPa. The resulting mixture (containing 46% chlorosulfonic acid and 2% chlorosulfonyl isocyanate) flowed into a microchannel reactor. The residence time of the mixture was controlled at 210 min, and the mixture was reacted in the microchannel reactor at 90°C and 1 MPa. The product flows into a gas-liquid separator for gas-liquid separation at 90℃ and 1MPa. The gas phase (mainly carbon dioxide) produced by the separation is directly discharged from the system, while the liquid phase (mainly chlorosulfonic acid and dichlorosulfonylimide) is divided into two streams. One stream is returned at 50mL / min as a circulating liquid (the molar ratio of chlorosulfonic acid and dichlorosulfonylimide in the circulating liquid is 0.81:1) and enters a micro mixer. The other stream is discharged at 7.7mL / min. The liquid at the discharge point is sampled and subjected to vacuum distillation. The fraction collected at 120℃ under a vacuum of -0.095MPa is used to obtain HClSI liquid.

[0049] Example 7

[0050] The method for continuous preparation of dichlorosulfonylimide acid in this embodiment includes the following steps:

[0051] Chlorosulfonic acid and chlorosulfonyl isocyanate were mixed at a flow rate of 4.35 mL / min and a circulating liquid (all the circulating liquid separated from the liquid phase of the gas-liquid separation was returned, with a flow rate of 50 mL / min) in a micromixer at 60°C and 2 MPa. The resulting mixture (containing 31% chlorosulfonic acid and 1.9% chlorosulfonyl isocyanate) flowed into a microchannel reactor. The residence time of the mixture was controlled at 150 min, and the mixture was further processed in the microchannel reactor at 60°C and 2 MPa. After the reaction, the mixture flows into a gas-liquid separator for gas-liquid separation at 60℃ and 2MPa. The gas phase (mainly carbon dioxide) produced by the separation is directly discharged from the system, while the liquid phase (mainly chlorosulfonic acid and dichlorosulfonylimide) is divided into two streams. One stream is returned at 50mL / min as a circulating liquid (the molar ratio of chlorosulfonic acid and dichlorosulfonylimide in the circulating liquid is 0.42:1) and enters a micro mixer. The other stream is discharged at 7.7mL / min. The liquid at the discharge point is sampled and subjected to vacuum distillation. The fraction collected at 120℃ under a vacuum of -0.095MPa is used to obtain HClSI liquid.

[0052] The continuous preparation of dichlorosulfonylimide acid in Examples 1 to 7 above was carried out using the system described in Example 8 below.

[0053] Example 8

[0054] The system for the continuous preparation of dichlorosulfonylimine in this embodiment, such as Figure 1 As shown, the system includes a micromixer 1, a microchannel reactor 2, a gas-liquid separator 3, and a vacuum distillation column 4, arranged sequentially in the material flow direction. The micromixer 1 has a chlorosulfonic acid inlet, a chlorosulfonyl isocyanate inlet, and a circulating liquid inlet. The outlet of the micromixer 1 is connected to the inlet of the microchannel reactor 2, and the outlet of the microchannel reactor 2 is connected to the inlet of the gas-liquid separator 3. The gas-liquid separator 3 has a gas phase outlet, a first liquid phase outlet, and a second liquid phase outlet. The first liquid phase outlet is connected to the circulating liquid inlet of the micromixer via a pipeline, and a circulating pump 5 is connected in series on the connecting pipeline. The second liquid phase outlet is connected to the material inlet of the vacuum distillation column 4. The system also includes a chlorosulfonic acid delivery pump 6 for supplying chlorosulfonic acid to the micromixer 1 and a chlorosulfonyl isocyanate delivery pump 7 for supplying chlorosulfonyl isocyanate. In this embodiment, the microchannel reactor has a cross-sectional area of ​​12.56 mm². 2 It is made by winding thin tubes.

[0055] Comparative Example 1

[0056] The comparative example of the continuous preparation method of dichlorosulfonylimide acid includes the following steps:

[0057] Chlorosulfonic acid and chlorosulfonyl isocyanate were fed into a micromixer at a flow rate of 3.35 mL / min and a flow rate of 4.35 mL / min, respectively, and mixed at 100 °C and 2 MPa. The resulting mixture flowed into a microchannel reactor, where the residence time was controlled at 150 min. After reacting in the microchannel reactor at 100 °C and 2 MPa, the mixture flowed into a gas-liquid separator at 100 °C and 2 MPa for gas-liquid separation. The gas phase (mainly carbon dioxide) produced by the separation was directly discharged from the system, while the liquid phase (mainly chlorosulfonic acid and dichlorosulfonyl imide) was completely discharged. The liquid at the discharge point was sampled and subjected to vacuum distillation. The fraction collected at -0.095 MPa vacuum and 120 °C yielded HClSI liquid.

[0058] Experimental Example

[0059] In this experimental example, 1H NMR and 1H NMR spectra were performed on samples of the liquid from the discharge point in each embodiment and the comparative example, using deuterated chloroform as the deuterating reagent and dichloroethane as the internal standard. The specific procedure was as follows: 5 mL of the reaction solution was taken, and 100 μL of dichloroethane was added and mixed thoroughly; then 20 μL of the mixed solution was added to 0.6 mL of deuterated chloroform, and 1H NMR was performed. The results are shown in [Figure number missing]. Figure 2 Then, the contents of dichlorosulfonylimide (HClSI) and chlorosulfonic acid (HClSO3) in the sample mixture are calculated by integrating the peak areas of the characteristic peaks. Since chlorosulfonic acid and dichlorosulfonylimide have similar chemical shifts, their NMR characteristic peaks influence each other and overlap. Therefore, when calculating the contents of dichlorosulfonylimide and chlorosulfonic acid, it is necessary to perform peak separation before integrating the peak areas. The peak separation method is as follows: Figure 3 As shown.

[0060] The calculation formula is as follows:

[0061]

[0062] In the formula, The peak area of ​​chlorosulfonic acid; A HClSI The peak area of ​​dichlorosulfonamide; The mass of dichloroethane is in grams. This represents the peak area of ​​dichloroethane; The molecular weight of dichloroethane is expressed in g / mol. The concentration of chlorosulfonic acid is expressed in mol / mL; n HClSI The values ​​represent the concentration of dichlorosulfonylimide acid, in mol / mL. The peak areas are obtained by integrating the NMR spectra and are dimensionless. The chemical shift for dichloroethane is approximately 3.73 ppm; for chlorosulfonic acid, approximately 9.90 ppm; and for dichlorosulfonylimide, approximately 9.20 ppm.

[0063] After obtaining the composition of the solution after the reaction, it is compared with the composition of the solution before the reaction. Assuming that the solution volume remains unchanged before and after the reaction, the product yield is calculated using the following formula:

[0064]

[0065] In the formula, V1 represents the yield of HClSI; V2 represents the volumetric flow rate of chlorosulfonic acid added, in mL; V3 represents the volumetric flow rate of chlorosulfonyl isocyanate added, in mL. The molar flow rate of chlorosulfonic acid added is expressed in mol.

[0066] The calculated contents of dichlorosulfonamide and chlorosulfonic acid in the samples of the examples and comparative examples, as well as the calculated yields of the products, are shown in Table 1.

[0067] Table 1 Content and yield of dichlorosulfonylimine and chlorosulfonic acid

[0068]

[0069]

Claims

1. A method for the continuous preparation of dichlorosulfonylimine, characterized in that: Includes the following steps: Chlorosulfonic acid, chlorosulfonyl isocyanate, and circulating liquid are continuously injected into a microchannel reactor and reacted under a pressure of 0.5~5MPa. The material flowing out of the microchannel reactor is then subjected to gas-liquid separation. The circulating liquid is a portion of the liquid obtained from the gas-liquid separation. Injecting chlorosulfonic acid, chlorosulfonyl isocyanate, and circulating liquid into a microchannel reactor involves injecting a mixture of chlorosulfonic acid, chlorosulfonyl isocyanate, and circulating liquid into the microchannel reactor; the molar percentage of chlorosulfonic acid in the mixture is 31-90%, and the molar percentage of chlorosulfonyl isocyanate is 1-5%; the reaction temperature is 60-200℃.

2. The method for continuous preparation of dichlorosulfonylimine according to claim 1, characterized in that: The mixture contains 45-64% chlorosulfonic acid in molar percentage.

3. The method for continuous preparation of dichlorosulfonylimine according to claim 1, characterized in that: The mixture contains 31-64% chlorosulfonic acid and 1.1-2% chlorosulfonyl isocyanate.

4. The method for continuous preparation of dichlorosulfonylimine according to any one of claims 1 to 3, characterized in that: The feed molar ratio of chlorosulfonic acid and chlorosulfonyl isocyanate is 0.5~2:1; the ratio of the volumetric flow rate of the circulating liquid to the total volumetric flow rate of chlorosulfonic acid and chlorosulfonyl isocyanate is 5~50:

1.

5. The method for continuous preparation of dichlorosulfonylimine according to claim 4, characterized in that: The molar ratio of chlorosulfonic acid to dichlorosulfonylimine in the circulating liquid is 0.42~1.85:

1.

6. The method for continuous preparation of dichlorosulfonylimine according to any one of claims 1 to 3, characterized in that: The residence time of the material in the microchannel reactor is 3 to 240 minutes.

7. The method for continuous preparation of dichlorosulfonylimine according to claim 6, characterized in that: The reaction is carried out at a temperature of 100-140°C and a pressure of 1-3 MPa.

8. The method for continuous preparation of dichlorosulfonylimine according to any one of claims 1 to 3, characterized in that: Injecting chlorosulfonic acid, chlorosulfonyl isocyanate, and circulating liquid into the microchannel reactor involves injecting a mixture of chlorosulfonic acid, chlorosulfonyl isocyanate, and circulating liquid into the microchannel reactor; before injecting the mixture into the microchannel reactor, the mixture is preheated to the reaction temperature; the preheating is carried out at a pressure of 0.5~5MPa.

9. A system specifically for the continuous preparation of dichlorosulfonyl imide acid using the method of claim 1, comprising a microchannel reactor and a gas-liquid separator arranged sequentially in the material flow direction; the microchannel reactor providing a site for the reaction of chlorosulfonic acid and chlorosulfonyl isocyanate; the gas-liquid separator separating the gas from the material flowing out of the microchannel reactor; characterized in that: A material channel is provided between the gas-liquid separator and the microchannel reactor to provide a portion of the liquid after gas-liquid separation by the gas-liquid separator to return to the microchannel reactor.

10. The system for the continuous preparation of dichlorosulfonylimine according to claim 9, characterized in that: It also includes a micro mixer for providing a portion of the material passage and for mixing chlorosulfonic acid, chlorosulfonyl isocyanate, and a portion of the liquid after gas-liquid separation.

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