Process for the production of high purity vinyl sulfite in a jet loop reactor

Abstract

This invention discloses a process for preparing high-purity vinyl sulfite using a jet-type loop reactor. Based on the jet-type loop reactor, it employs multiple catalytic systems, using ethylene oxide and sulfur dioxide as raw materials, combined with relevant solvents. This invention relates to the field of vinyl sulfite technology. This process for preparing high-purity vinyl sulfite using a jet-type loop reactor enhances gas-liquid mass transfer through an external circulation jet-type loop reactor. Combined with optimized raw material pretreatment, the reaction cycle is shortened to 2.5-3.0 hours, improving efficiency by more than 50% compared to batch processes. The entire process is continuous, with equipment utilization exceeding 85%, suitable for large-scale production of tens of thousands of tons per year. It addresses the shortcomings of existing processes in terms of scalability, achieving high production efficiency and significant scalability advantages. Furthermore, the entire process is a closed loop, preventing sulfur dioxide leakage. Excess sulfur dioxide is recovered, and solvents are recycled, reducing pollutant emissions by more than 80%.

Description

Technical Field

[0001] This invention relates to the field of vinyl sulfite technology, specifically a process for preparing high-purity vinyl sulfite using a jet-type loop reactor. Background Technology

[0002] Vinyl sulfite is a key film-forming additive in lithium-ion battery electrolytes. It can effectively inhibit the co-intercalation of propylene carbonate into graphite electrodes, significantly improving the cycle life, low-temperature discharge performance, and safety of lithium-ion batteries.

[0003] Meanwhile, vinyl sulfite is also a core intermediate for the preparation of fine chemical products such as vinyl sulfate (DTD), and is widely used in new energy, fine chemical and other fields. With the development of lithium-ion batteries toward high energy density and long cycle life, as well as the upgrading of the fine chemical industry, the market has increasingly stringent requirements for the purity of vinyl sulfite, which usually needs to reach more than 99.9%. At the same time, higher requirements have been put forward for the greening, efficiency, scale and safety of its production process.

[0004] Currently, the mainstream industrial processes for preparing vinyl sulfite are mainly divided into two categories: the thionyl chloride method and the ethylene oxide-sulfur dioxide addition method. Both types of processes and their associated reactor technologies have significant technical defects, making it difficult to meet the needs of large-scale production of high-purity vinyl sulfite, as detailed below:

[0005] Firstly, the thionyl chloride method uses ethylene glycol and thionyl chloride as raw materials to prepare vinyl sulfite. The relevant process has been disclosed in several existing patents, such as Chinese patents: CN115806540A (a method for preparing high-purity vinyl sulfite) and CN114539210A (a synthesis process for low-chlorinated vinyl sulfite). The advantage of this process is that the reaction process is relatively simple, but it has a fatal flaw: a large amount of hydrogen chloride waste gas and high-salt chlorine-containing wastewater are generated during the reaction, which not only seriously corrodes the production equipment, but also leads to high environmental treatment costs. At the same time, the reaction produces byproducts such as chloroethanol, which are difficult to completely remove through conventional refining processes, resulting in the total chlorine content of the product exceeding the standard, which cannot meet the requirements for use in high-end lithium-ion battery electrolytes and limits the application scope of the product.

[0006] Secondly, the ethylene oxide-sulfur dioxide addition method is considered a green and preferred route for the preparation of vinyl sulfite due to its high atom economy and absence of chlorine-containing pollutants. Related improved processes have also been extensively studied and disclosed. For example, Chinese patents CN101210007B (a method for preparing vinyl sulfite) and CN101210008B (a method for synthesizing vinyl sulfite) disclose the use of metal halides or polyethylene glycol-metal halide complexes as catalysts to achieve the addition reaction of ethylene oxide and sulfur dioxide under high temperature and high pressure conditions.

[0007] Chinese patent CN115745952A (A method for synthesizing high-purity vinyl sulfite under mild conditions) discloses the use of imidazole ionic liquids as catalysts to optimize reaction conditions to 130-180℃ and 3-6MPa, thereby increasing the product purity to over 99.5%. However, this route still has many unresolved technical bottlenecks: traditional processes have harsh reaction conditions (220-300℃ and over 10MPa), resulting in numerous byproducts and low yields (usually below 90%). Although the improved ionic liquid catalytic process reduces the reaction temperature and pressure, it suffers from low gas-liquid mass transfer efficiency, long reaction cycles (6-10h), and difficulties in catalyst recovery, making it difficult to adapt to large-scale continuous production. Furthermore, the product purity still does not meet the high-end demand of over 99.9%.

[0008] In addition to the inherent defects of the synthesis process, the insufficient adaptability of existing reactor technologies further restricts the production of high-purity vinyl sulfite. Currently, the reactors used in the synthesis of vinyl sulfite are mainly batch autoclaves, microchannel reactors, and traditional circulating reactors. All three types of reactors have significant limitations:

[0009] 1. Intermittent high-pressure reactor: As the most widely used reactor, it suffers from low mass transfer efficiency and uneven gas-liquid mixing, resulting in slow reaction rate, increased side reactions, poor batch-to-batch stability of products, significant scale-up effect, and inability to achieve continuous production; at the same time, ethylene oxide is a highly toxic, flammable and explosive substance, and batch feeding and high-pressure intermittent operation pose significant safety hazards, which do not meet the requirements of industrial safety production.

[0010] 2. Microchannel reactor: Chinese patent CN202310832575.9 (A method and apparatus for continuous preparation of high-purity vinyl sulfite) discloses the use of a microchannel reactor to realize the addition reaction of ethylene oxide and sulfur dioxide. It has the advantages of high heat transfer efficiency and uniform mixing, but it has problems such as easy blockage of channels by catalysts or by-products, difficulty in catalyst recovery, and small single processing capacity. The equipment investment and maintenance costs are high, making it difficult to meet the needs of large-scale production of tens of thousands of tons.

[0011] 3. Traditional circulating reactors: Chinese patents CN114177875A (A jet circulating reactor and its application) and CN106732208B (A high-efficiency jet circulating reactor) disclose the application of jet circulating reactors in Fischer-Tropsch synthesis, polyoxyethylene ester preparation and other fields. However, their structural design has not been optimized for the core requirements of strong exothermic reaction, rapid gas-liquid mass transfer and high selectivity in the addition reaction of ethylene oxide-sulfur dioxide. It has problems such as low gas utilization, local overheating leading to increased side reactions and poor product selectivity. It cannot be directly adapted to the preparation process of high-purity vinyl sulfite.

[0012] In summary, existing processes for preparing vinyl sulfite suffer from drawbacks such as poor environmental performance, low reaction efficiency, and insufficient product purity. The corresponding reactor technologies cannot address core issues such as enhanced gas-liquid mass transfer, precise removal of reaction heat, continuous and stable production, and safe production. Existing technologies primarily focus on optimizing catalyst systems, and there are no technical solutions that apply jet-type loop reactors to the synthesis of vinyl sulfite and specifically address issues such as high-purity preparation and safe and stable industrial operation.

[0013] Therefore, developing a jet-type loop reactor and corresponding process adapted for the synthesis of high-purity vinyl sulfite, breaking through existing technical bottlenecks, and realizing the green, efficient, high-purity, and large-scale production of vinyl sulfite has become an urgent technical challenge to be solved in this field. Summary of the Invention

[0014] To address the shortcomings of existing technologies, this invention provides a process for preparing high-purity vinyl sulfite using a jet-type loop reactor, solving the problem of difficulty in large-scale, high-quality, and green production of vinyl sulfite.

[0015] To achieve the above objectives, the present invention provides the following technical solution: a process for preparing high-purity vinyl sulfite using a jet-type loop reactor, which is based on a jet-type loop reactor, employs multiple catalytic systems, uses ethylene oxide and sulfur dioxide as raw materials, and combines them with relevant solvents to achieve continuous and highly selective production of vinyl sulfite.

[0016] Preferably, the sulfur dioxide is dehydrated to a moisture content of <30 ppm, and the ethylene oxide is dehydrated to a moisture content of <50 ppm, with a molar ratio of 1.2-1.4:1.

[0017] Preferably, the relevant solvent is selected from cyclohexane, methylcyclohexane, n-heptane, isoheptane, n-hexane, isoheptane, cycloheptane, methylcycloheptane, n-octane, isooctane, petroleum ether, ethylene carbonate, dimethyl carbonate, and ethylene sulfite.

[0018] Preferably, the catalytic system includes triethylaluminum, triethylboron composite system, quaternary ammonium salt-quaternary phosphonium salt, organic amine, metal halide complex, ionic liquid, specifically including: tetrabutylammonium bromide, tetrabutylammonium chloride, tetraethylammonium bromide, tetrabutylphosphonium chloride, tetraphenylphosphonium bromide, 1,8-diazabicyclo(5,4,0)undec-7-ene, triethylenediamine, triisopropanolamine, potassium iodide, potassium bromide, sodium bromide, calcium bromide, 1-butyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium bromide, and 1-butyl-3-methylimidazolium tetrafluoroborate.

[0019] Preferably, the catalyst feed rate is 0.4-0.7% of the ethylene oxide feed mass, and it is continuously injected into the front end of the jet mixer through a metering pump, and is prepared and used immediately under a nitrogen atmosphere.

[0020] Preferably, the reaction temperature is 80-145℃ and the reaction pressure is 0.85-1.0MPa.

[0021] Preferably, the discharge temperature is 75-95℃ and the discharge pressure is 0.3-0.8MPa.

[0022] Preferably, an adsorption purification unit is added before the raw materials enter the reactor, using modified molecular sieve adsorbents to deeply purify ethylene oxide and sulfur dioxide, removing trace metal ions and organic impurities from the raw materials.

[0023] Preferably, in the post-processing step, the solvent is flash-evaporated at 60-130℃ and 0.08MPa to remove 80% of its components, and then directly reused. It is then purified by distillation. The operating conditions of the distillation column are: top temperature 60-125℃, vacuum degree 0.0055-0.0105MPa, and reflux ratio 0.5-1.5:1.

[0024] Preferably, the optimal molar ratio of sulfur dioxide to ethylene oxide is 1.3:1, the preferred catalytic system is a triethylaluminum-tetrabutylammonium bromide composite system, the optimal catalyst dosage is 0.6% of the ethylene oxide feed mass, the optimal reaction temperature is 95-100℃, and the optimal reaction pressure is 0.3-0.75MPa.

[0025] Beneficial effects

[0026] This invention provides a process for preparing high-purity vinyl sulfite using a jet-type loop reactor. Compared with existing technologies, it has the following advantages:

[0027] (1) The process of preparing high-purity vinyl sulfite by the jet loop reactor enhances gas-liquid mass transfer through the external circulation jet loop reactor and optimizes the raw material pretreatment. The reaction cycle is shortened to 2.5-3.0h, which is more than 50% more efficient than the batch process. The whole process is continuous operation with equipment utilization rate of more than 85%. It is suitable for large-scale production of more than 10,000 tons per year, solves the pain point of insufficient scale of existing processes, and achieves the effect of high production efficiency and significant scale advantage. Moreover, the whole process is closed operation to avoid sulfur dioxide leakage. Excess sulfur dioxide is recovered and solvent is recycled, reducing pollutant emissions by more than 80%, which is in line with the green and low-carbon orientation and reduces environmental protection costs. Secondly, the external circulation jet loop reactor can operate continuously and stably for ≥30 days, avoiding problems such as catalyst agglomeration and insufficient mass transfer. It is suitable for a variety of catalytic systems and solvents, and can flexibly meet different purity requirements. It has strong industrial promotion potential.

[0028] (2) The process of preparing high-purity vinyl sulfite using the jet-type loop reactor achieves a conversion rate of ethylene oxide ≥99.2% and a selectivity of vinyl sulfite ≥98.8% through precise temperature and pressure control of the reactor, deep purification of raw materials, and the synergistic effect of segmented distillation. This process can stably produce lithium-ion battery-grade products with a purity of ≥99.8%, with batch-to-batch purity fluctuations ≤0.05% and metal ion impurities in the product ≤0.1ppm, thus solving the problems of poor quality and insufficient stability of existing processes.

[0029] (3) The process of preparing high-purity vinyl sulfite using the jet-type loop reactor reduces energy consumption by 15%-20% through the strong heat exchange characteristics of the reactor, improves mass transfer so that the amount of catalyst used is reduced to 0.4%-0.6% of the mass of ethylene oxide, the solvent recovery rate is ≥95%, and the segmented distillation further reduces energy consumption by 5%-8%, and the overall production cost is reduced by 8%-12%, which meets the needs of cost reduction and efficiency improvement.

[0030] (4) The process of preparing high-purity vinyl sulfite by the jet loop reactor is to remove trace metal ions and organic impurities in the raw materials by adding a modified molecular sieve adsorption and purification unit, which enables the raw materials to be deeply purified and pretreated, thereby solving the problem of decreased reaction selectivity and excessive product impurities caused by insufficient raw material purity in the traditional process, and further improving the batch stability of the product.

[0031] (5) The process of preparing high-purity vinyl sulfite by the jet loop reactor adopts a segmented treatment method of "initial distillation to remove low-boiling substances and distillation to improve purity", which avoids the problem of mutual interference between high and low boiling impurities in a single distillation process, greatly reduces distillation energy consumption, and further improves product purity. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0034] Please see Figure 1 This invention provides six technical solutions, which are implemented as follows:

[0035] Example 1

[0036] A 50L jet-type loop reactor was used. The reaction system included: cyclohexane as solvent (dehydrated to <30ppm water content), triethylaluminum-tetrabutylammonium bromide composite catalyst (molar ratio 5:1), catalyst dosage of 0.5% of ethylene oxide mass, molar ratio of sulfur dioxide to ethylene oxide of 1.4:1, and mass ratio of solvent to ethylene oxide of 3:1.

[0037] Specific reaction process:

[0038] Raw material pretreatment: Ethylene oxide and sulfur dioxide are purified by modified molecular sieve adsorption to remove trace impurities and are then ready for use.

[0039] Reaction preparation: Under nitrogen protection, cyclohexane, premixed catalyst and purified ethylene oxide (dehydrated to <50ppm water) are added sequentially to the jet-type loop reactor, and the air in the reactor is replaced 3 times.

[0040] Reaction implementation: Start the jet circulation and stirring (400 r / min), gradually increase the temperature (2℃ / min) to 110℃, introduce dehydrated and purified sulfur dioxide to the pressure inside the reactor to 1.2 MPa, and react at constant temperature and pressure for 3 hours;

[0041] Post-processing: After the reaction is completed, the temperature is naturally cooled to below 60°C, the pressure is slowly released, and excess sulfur dioxide is absorbed by the alkaline solution. After discharge, the product is purified by vacuum distillation and resin adsorption to obtain vinyl sulfite product.

[0042] Test results: Ethylene oxide conversion rate 99.2%, vinyl sulfite selectivity 98.6%, product purity 99.8%, metal ion impurity content 0.08ppm, and thermal stability meets the standard (thermal decomposition temperature ≥120℃).

[0043] Example 2

[0044] A 50L jet-type loop reactor was used. The reaction system included: methylcyclohexane as solvent (dehydrated to <30ppm water content), triethylaluminum-tetrabutylammonium bromide composite catalyst (molar ratio 5:1), catalyst dosage of 0.5% of ethylene oxide mass, molar ratio of sulfur dioxide to ethylene oxide of 1.3:1, and mass ratio of solvent to ethylene oxide of 2.8:1.

[0045] Specific reaction process:

[0046] Raw material pretreatment: Ethylene oxide and sulfur dioxide are purified by modified molecular sieve adsorption to remove trace impurities and are then ready for use.

[0047] Reaction preparation: Under nitrogen protection, methylcyclohexane, premixed catalyst and purified ethylene oxide (dehydrated to <50ppm water) are added sequentially to the jet-type loop reactor, and the air in the reactor is replaced 3 times;

[0048] Reaction implementation: Start the jet circulation and stirring (400 r / min), gradually increase the temperature (2℃ / min) to 108℃, introduce dehydrated and purified sulfur dioxide to the pressure inside the reactor to 1.1 MPa, and react at constant temperature and pressure for 3 hours;

[0049] Post-processing: After the reaction is completed, the temperature is naturally cooled to below 60°C, the pressure is slowly released, and excess sulfur dioxide is absorbed by the alkaline solution. After discharge, the product is purified by vacuum distillation and resin adsorption to obtain vinyl sulfite product.

[0050] The test results showed that the ethylene oxide conversion rate was 99.1%, the ethylene sulfite selectivity was 98.7%, the product purity was 99.8%, the metal ion impurity content was 0.07 ppm, and the thermal stability met the standard (thermal decomposition temperature ≥120℃).

[0051] Example 3

[0052] A 50L jet-type loop reactor was used. The reaction system included: cyclohexane as solvent (dehydrated to <30ppm water content), triisobutylaluminum-tetrabutylammonium chloride composite catalyst (molar ratio 4:1), catalyst dosage of 0.6% of the mass of ethylene oxide, the molar ratio of sulfur dioxide to ethylene oxide of the reactants of 1.4:1, and the mass ratio of solvent to ethylene oxide of 3:1.

[0053] Specific reaction process:

[0054] After the raw materials ethylene oxide and sulfur dioxide are pretreated by a modified molecular sieve adsorption purification unit to remove trace impurities, they are ready for use.

[0055] Reaction preparation: Under nitrogen protection, cyclohexane, premixed catalyst and purified ethylene oxide (dehydrated to <50ppm water) are added sequentially to the jet-type loop reactor, and the air in the reactor is replaced 3 times.

[0056] Reaction implementation: Start the jet circulation and stirring (400 r / min), gradually increase the temperature (2℃ / min) to 112℃, introduce dehydrated and purified sulfur dioxide to the pressure inside the reactor to 1.3 MPa, and react at constant temperature and pressure for 2.8 h;

[0057] Post-processing: After the reaction is completed, the temperature is naturally cooled to below 60°C, the pressure is slowly released, and excess sulfur dioxide is absorbed by the alkaline solution. After discharge, the product is purified by vacuum distillation and resin adsorption to obtain vinyl sulfite product.

[0058] Test results: Ethylene oxide conversion rate 99.3%, vinyl sulfite selectivity 98.5%, product purity 99.8%, metal ion impurity content 0.09ppm, and thermal stability meets the standard (thermal decomposition temperature ≥120℃).

[0059] Example 4

[0060] A 50L jet-type loop reactor was used. The reaction system included: toluene as solvent (dehydrated to <30ppm water content), triethylaluminum-tetrabutylammonium bromide composite catalyst (molar ratio 5:1), catalyst dosage of 0.4% of ethylene oxide mass, molar ratio of sulfur dioxide to ethylene oxide of 1.5:1, and mass ratio of solvent to ethylene oxide of 2.5:1.

[0061] Specific reaction process:

[0062] Raw material pretreatment: Ethylene oxide and sulfur dioxide are purified by modified molecular sieve adsorption to remove trace impurities and are then ready for use.

[0063] Reaction preparation: Under nitrogen protection, toluene, premixed catalyst and purified ethylene oxide (dehydrated to <50ppm moisture) are added sequentially to the jet-type loop reactor, and the air in the reactor is replaced 3 times;

[0064] Reaction implementation: Start the jet circulation and stirring (400 r / min), gradually increase the temperature (2℃ / min) to 105℃, introduce dehydrated and purified sulfur dioxide to the pressure inside the reactor to 1.0 MPa, and react at constant temperature and pressure for 3.2 h;

[0065] Post-processing: After the reaction is completed, the temperature is naturally cooled to below 60°C, the pressure is slowly released, and excess sulfur dioxide is absorbed by the alkaline solution. After discharge, the product is purified by vacuum distillation and resin adsorption to obtain vinyl sulfite product.

[0066] Test results: Ethylene oxide conversion rate 99.0%, vinyl sulfite selectivity 98.8%, product purity 99.9%, metal ion impurity content 0.06ppm, and thermal stability meets the standard (thermal decomposition temperature ≥120℃).

[0067] Example 5

[0068] A 100L jet-type loop reactor was used. The reaction system included: a cyclohexane-methylcyclohexane mixed solvent (volume ratio 1:1, dehydrated to <30ppm water), a triethylaluminum-tetraphenylphosphonium bromide composite catalyst (molar ratio 5:1), and the amount of catalyst was 0.5% of the mass of ethylene oxide; the molar ratio of sulfur dioxide to ethylene oxide was 1.4:1, and the mass ratio of solvent to ethylene oxide was 3:1.

[0069] Specific reaction process:

[0070] Raw material pretreatment: Ethylene oxide and sulfur dioxide are purified by modified molecular sieve adsorption to remove trace impurities and are then ready for use.

[0071] Reaction preparation: Under nitrogen protection, a mixed solvent, a premixed catalyst, and purified ethylene oxide (dehydrated to <50ppm moisture) are added sequentially to the jet-type loop reactor, and the air in the reactor is replaced 3 times.

[0072] Reaction implementation: Start the jet circulation and stirring (400 r / min), gradually increase the temperature (2℃ / min) to 110℃, introduce dehydrated and purified sulfur dioxide to the pressure inside the reactor to 1.2 MPa, and react at constant temperature and pressure for 3 hours;

[0073] Post-processing: After the reaction is completed, the temperature is naturally cooled to below 60°C, the pressure is slowly released, and excess sulfur dioxide is absorbed by the alkaline solution. After discharge, the product is purified by vacuum distillation and resin adsorption to obtain vinyl sulfite product.

[0074] Test results: Ethylene oxide conversion rate 99.2%, vinyl sulfite selectivity 98.7%, product purity 99.8%, metal ion impurity content 0.07ppm, and thermal stability meets the standard (thermal decomposition temperature ≥120℃).

[0075] Example 6

[0076] A 100L jet-type loop reactor was used. The reaction system included: cyclohexane as solvent (dehydrated to <30ppm water content), triethylaluminum-tetrabutylammonium bromide composite catalyst (molar ratio 6:1), catalyst dosage of 0.5% of ethylene oxide mass, molar ratio of sulfur dioxide to ethylene oxide of 1.3:1, and mass ratio of solvent to ethylene oxide of 3.2:1.

[0077] Specific reaction process:

[0078] Raw material pretreatment: Ethylene oxide and sulfur dioxide are purified by modified molecular sieve adsorption to remove trace impurities and are then ready for use.

[0079] Reaction preparation: Under nitrogen protection, cyclohexane, premixed catalyst and purified ethylene oxide (dehydrated to <50ppm water) are added sequentially to the jet-type loop reactor, and the air in the reactor is replaced 3 times.

[0080] Reaction implementation: Start the jet circulation and stirring (400 r / min), gradually increase the temperature (2℃ / min) to 115℃, introduce dehydrated and purified sulfur dioxide to the pressure inside the reactor to 1.4 MPa, and react at constant temperature and pressure for 2.7 h;

[0081] Post-processing: After the reaction is completed, the temperature is naturally cooled to below 60°C, the pressure is slowly released, and excess sulfur dioxide is absorbed by the alkaline solution. After discharge, the product is purified by vacuum distillation and resin adsorption to obtain vinyl sulfite product.

[0082] Test results: Ethylene oxide conversion rate 99.4%, vinyl sulfite selectivity 98.4%, product purity 99.8%, metal ion impurity content 0.08ppm, and thermal stability meets the standard (thermal decomposition temperature ≥120℃).

Claims

1. A process for preparing high-purity vinyl sulfite using a jet-type loop reactor, characterized in that: Based on a jet-type loop reactor, using multiple catalytic systems, ethylene oxide and sulfur dioxide as raw materials, and in combination with relevant solvents, continuous and highly selective production of vinyl sulfite is achieved.

2. The process for preparing high-purity vinyl sulfite using a jet-type loop reactor according to claim 1, characterized in that: The sulfur dioxide is dehydrated to a moisture content of <30 ppm, and the ethylene oxide is dehydrated to a moisture content of <50 ppm, with a molar ratio of 1.2-1.4:

1.

3. The process for preparing high-purity vinyl sulfite using a jet-type loop reactor according to claim 1, characterized in that: The relevant solvents are selected from cyclohexane, methylcyclohexane, n-heptane, isoheptane, n-hexane, isoheptane, cycloheptane, methylcycloheptane, n-octane, isooctane, petroleum ether, ethylene carbonate, dimethyl carbonate, and ethylene sulfite.

4. The process for preparing high-purity vinyl sulfite using a jet-type loop reactor according to claim 1, characterized in that: The catalytic system includes triethylaluminum, triethylboron composite system, quaternary ammonium salt-quaternary phosphonium salt, organic amine, metal halide complex, and ionic liquid. The specific selection range includes: tetrabutylammonium bromide, tetrabutylammonium chloride, tetraethylammonium bromide, tetrabutylphosphonium chloride, tetraphenylphosphonium bromide, 1,8-diazabicyclo(5,4,0)undec-7-ene, triethylenediamine, triisopropanolamine, potassium iodide, potassium bromide, sodium bromide, calcium bromide, 1-butyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium bromide, and 1-butyl-3-methylimidazolium tetrafluoroborate.

5. The process for preparing high-purity vinyl sulfite using a jet-type loop reactor according to claim 4, characterized in that: The catalyst feed rate is 0.4-0.7% of the ethylene oxide feed mass, and it is continuously injected into the front end of the jet mixer through a metering pump, and is prepared and used immediately under a nitrogen atmosphere.

6. The process for preparing high-purity vinyl sulfite using a jet-type loop reactor according to claim 1, characterized in that: The reaction temperature is 80-145℃ and the reaction pressure is 0.85-1.0MPa.

7. The process for preparing high-purity vinyl sulfite using a jet-type loop reactor according to claim 1, characterized in that: The discharge temperature is 75-95℃, and the discharge pressure is 0.3-0.8MPa.

8. The process for preparing high-purity vinyl sulfite using a jet-type loop reactor according to claim 1, characterized in that: An adsorption and purification unit is added before the raw materials enter the reactor. Modified molecular sieve adsorbents are used to deeply purify ethylene oxide and sulfur dioxide, removing trace metal ions and organic impurities from the raw materials.

9. The process for preparing high-purity vinyl sulfite using a jet-type loop reactor according to claim 1, characterized in that: In the post-processing step, the solvent can be flashed at 60-130℃ and 0.08MPa to remove 80% and then directly reused. It can then be purified by distillation. The operating conditions of the distillation column are: top temperature 60-125℃, vacuum degree 0.0055-0.0105MPa, and reflux ratio 0.5-1.5:

1.

10. A process for preparing high-purity vinyl sulfite using a jet-type loop reactor according to any one of claims 1-9, characterized in that: The optimal molar ratio of sulfur dioxide to ethylene oxide is 1.3:1, the preferred catalytic system is a triethylaluminum-tetrabutylammonium bromide composite system, the optimal catalyst dosage is 0.6% of the ethylene oxide feed mass, the optimal reaction temperature is 95-100℃, and the optimal reaction pressure is 0.3-0.75MPa.

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