System and method for synthesizing ethylene sulfate

Abstract

The invention relates to a system and a method for synthesizing ethylene sulfate. Ethylene oxide and sulfur trioxide are used as raw materials, ethylene sulfate is used as a solvent, an imidazolium salt and zinc halide compound is used as a catalyst, and ethylene sulfate is used as a solvent; under the action of a catalyst, ethylene oxide and sulfur trioxide are subjected to an addition reaction to generate ethylene sulfate; the reacted material enters a film evaporator, a concentrated catalyst material is extracted from the bottom of the film evaporator and flows back to an ethylene sulfate storage tank, and ethylene sulfate, unreacted ethylene oxide and sulfur trioxide materials are extracted from the top of the film evaporator and enter a light component removal tower; materials at the top of the light component removal tower are converged into a pipeline connected with a static mixer, materials of ethylene sulfate and a catalyst are extracted from the tower bottom and enter an ethylene sulfate refining tower, high-purity ethylene sulfate is obtained at the top of the tower, and heavy components are obtained at the bottom of the tower. The method is simple and efficient in process, high in production continuity degree, simple in subsequent separation and purification, high in product purity and suitable for large-scale production.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry and environmental protection, and in particular relates to a system and method for synthesizing vinyl sulfate. Background Art

[0002] Electrochemical energy storage systems provide a feasible way to solve energy shortages and environmental problems, and lithium-ion batteries, as the core of electrochemical energy storage, are widely used in electric vehicles, mobile communications, and computers. As an important SEI film-forming additive for lithium-ion batteries, ethylene sulfate (ES, or 1,3,2-Dioxathiolane 2,2-dioxide, DTD) can effectively improve the initial charge and discharge performance of the battery, reduce battery expansion after high-temperature storage, and improve battery cycle stability.

[0003] At present, the industrial method for synthesizing vinyl sulfate is mainly a two-step method, that is, ethylene glycol and dichloride react to obtain vinyl sulfite, and then vinyl sulfite is oxidized to obtain vinyl sulfate, and the process route is relatively complicated. The oxidation reaction in the second step of this process mainly has five pathways depending on the oxidant, and there are certain problems. For example, when sodium hypochlorite is used as an oxidant, the conversion rate of vinyl sulfite is low, and the product is difficult to separate and purify; when sodium periodate is used as an oxidant, a noble metal salt ruthenium trichloride is required as a catalyst, which is costly and difficult to recycle; when potassium persulfate is used as an oxidant, the reaction selectivity is poor, there are many side reactions, the product yield is low, there are more three wastes, and the final product has a high chloride ion content, which is difficult to purify.

[0004] The methods for synthesizing vinyl sulfate reported so far include acylation, substitution, addition, dioxane synthesis, oxidation, etc. Due to the short development time of vinyl sulfate, various synthesis processes are not yet mature, and each has its own advantages and disadvantages. For example, although the raw materials of the acylation method, sulfuryl chloride or sulfuryl fluoride, are cheap and easy to obtain, they are highly corrosive and have a low reaction yield.

[0005] Vinyl sulfate (melting point 95-99°C, boiling point 231°C) is similar in properties and structure to vinyl carbonate (melting point 35-38°C, boiling point 248°C). At present, vinyl carbonate is generally produced by the reaction of carbon dioxide (carbonic anhydride) and ethylene oxide, and sulfur trioxide, as sulfuric anhydride, can theoretically react with ethylene oxide to obtain vinyl sulfate. The 2017 public patent document (application number 201710156378.4) discloses a process for preparing vinyl sulfate from sulfur trioxide and ethylene oxide and the preparation of a catalyst, which mainly solves the problem that the existing process route has many wastes and the product is difficult to purify. The catalyst used in the present invention includes a main catalyst and a co-catalyst; the main catalyst is a metal mixed oxide M a O b / Nc O d ; Wherein, M is selected from at least one of Cu, Mg, Zn, Ca, Co or Ni; N is selected from at least one of Al, Fe, Cr or Zr; the co-catalyst is a quaternary ammonium salt R1R2R3R4N + X. In this patent scheme, the solvents are low-boiling methylene chloride, ethylene dichloride, carbon tetrachloride, chlorobenzene, cyclohexane, n-hexane, acetonitrile, and ethyl acetate. The main catalyst is a metal oxide, the auxiliary catalyst is a quaternary ammonium salt, and the reaction temperature is relatively low. Obviously, this method has the problems of low reaction rate, long reaction time, many by-products, complex and difficult product separation and purification, and it is difficult to obtain high-purity vinyl sulfate suitable for battery applications. The patent document published in 2021 (application number 202111540651.6) discloses a method for synthesizing vinyl sulfate, which is: under the joint action of a catalyst and a co-catalyst, supercritical carbon dioxide is used as a solvent, and the synthesis of vinyl sulfate is achieved in one pot. The raw materials include ethylene oxide, carbon dioxide and sulfur trioxide. This reaction process may undergo a transition state of vinyl carbonate, and then undergo ester exchange with sulfur trioxide to generate the target product vinyl sulfate. In this scheme, in the same reactor, carbon dioxide and ethylene oxide are first introduced to obtain vinyl carbonate (EC), and then sulfur trioxide is introduced to react with EC for ester exchange to obtain ES. Since the physical properties of EC and ES are very similar and both are high-boiling point substances, subsequent separation and purification are also difficult. The patent document published in 2022 (application number 202211477151.7) discloses a production process for electronic-grade vinyl sulfate, in which solution A is used to dissolve sulfur trioxide to prepare a sulfur trioxide solution, and solution B is mixed with ethylene oxide to prepare an ethylene oxide solution. The sulfur trioxide solution and the ethylene oxide solution are pre-cooled and then introduced into a group of microchannel reactors for real-time reaction to obtain a mixed solution containing crude vinyl sulfate, which is then subjected to a post-treatment process to obtain crude vinyl sulfate. This scheme uses a microchannel reactor, passes a sulfur trioxide solution and an ethylene oxide solution, and then obtains ES by spray drying. The catalyst uses a low-boiling point organic amine and the solvent is a low-boiling point ester solvent. There is a problem that the reactor is prone to clogging and difficult to operate continuously and stably, which is not suitable for large-scale industrial production.

[0006] Therefore, there is an urgent need to develop a method for synthesizing vinyl sulfate that is highly atom-economical, safe and reliable, easy to purify and separate, produces less waste, waste gas and has low cost. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention provides a system and method for synthesizing vinyl sulfate.

[0008] The invention utilizes ethylene oxide and sulfur trioxide to synthesize vinyl sulfate. The method has simple process, safe and reliable process, high catalyst activity, and the product is easy to separate and purify with high purity.

[0009] The purpose of the present invention can be achieved by the following technical solutions:

[0010] The present invention first provides a system for synthesizing vinyl sulfate, which comprises a vinyl sulfate storage tank, a sulfur trioxide storage tank, an ethylene oxide storage tank, a static mixer, an adiabatic reactor, a thin film evaporator, a lightness removal tower and a vinyl sulfate refining tower, wherein the vinyl sulfate storage tank, the sulfur trioxide storage tank and the ethylene oxide storage tank are all connected to the static mixer through a pipeline, the static mixer is connected to the adiabatic reactor, the bottom of the adiabatic reactor is connected to the thin film evaporator through a pipeline, the bottom of the thin film evaporator is used to extract concentrated catalyst materials, and the top of the thin film evaporator is used to extract vinyl sulfate The bottom of the thin film evaporator is connected to the vinyl sulfate storage tank through a pipeline, the top of the thin film evaporator is connected to the lightness removal tower through a pipeline, the top of the lightness removal tower is used to produce the unreacted ethylene oxide and sulfur trioxide materials, the bottom of the lightness removal tower is used to produce the vinyl sulfate and catalyst materials, the top of the lightness removal tower is connected to the static mixer through a pipeline, the bottom of the lightness removal tower is connected to the vinyl sulfate refining tower through a pipeline, the top of the vinyl sulfate refining tower is used to obtain high-purity vinyl sulfate, and the bottom of the vinyl sulfate refining tower is used to obtain heavy components.

[0011] In one embodiment of the present invention, the system for synthesizing vinyl sulfate further comprises a heat exchanger, the bottom of the adiabatic reactor is further connected to the heat exchanger via a pipeline, and the heat exchanger is further connected to the static mixer via a pipeline.

[0012] In one embodiment of the present invention, a product circulation pump is provided on the pipeline connecting the bottom of the adiabatic reactor to the heat exchanger.

[0013] In one embodiment of the present invention, a sulfur trioxide delivery pump is provided on the pipeline connecting the sulfur trioxide storage tank and the static mixer.

[0014] In one embodiment of the present invention, an ethylene oxide delivery pump is provided on the pipeline connecting the ethylene oxide storage tank and the static mixer.

[0015] In one embodiment of the present invention, a vinyl sulfate delivery pump is provided on the pipeline connecting the vinyl sulfate storage tank and the static mixer.

[0016] In one embodiment of the present invention, a catalyst circulation pump is provided on the pipeline connecting the bottom of the thin film evaporator with the vinyl sulfate storage tank.

[0017] In one embodiment of the present invention, a raw material circulation pump is provided on the pipeline connecting the top of the light removal tower and the static mixer.

[0018] In one embodiment of the present invention, the thin film evaporator is a falling film evaporator, preferably a multiple-effect falling film evaporator.

[0019] In one embodiment of the present invention, the adiabatic reactor is a tubular reactor or a tower reactor.

[0020] In one embodiment of the present invention, the vinyl sulfate storage tank is used to add a vinyl sulfate solution containing a catalyst.

[0021] In one embodiment of the present invention, the feed inlet of the vinyl sulfate refining tower is arranged in the middle position, and the bottom of the light removal tower is connected to the feed inlet of the vinyl sulfate refining tower through a pipeline.

[0022] The system of the present invention is used, and the method for synthesizing vinyl sulfate specifically includes the following contents: using ethylene oxide and sulfur trioxide as raw materials, vinyl sulfate as solvent, imidazole salt and zinc halide complex as catalyst, and vinyl sulfate as solvent, and dissolving the catalyst in vinyl sulfate; sulfur trioxide, ethylene oxide and vinyl sulfate solution containing the catalyst are input into a static mixer via respective material delivery pumps; after the raw materials are evenly mixed, they are input into an adiabatic reactor for reaction, and under the action of the imidazole salt and zinc halide complex catalysts, ethylene oxide and sulfur trioxide undergo addition reaction to generate vinyl sulfate; two streams of liquid materials are taken out from the bottom of the adiabatic reactor, and one stream of liquid materials is taken out from the bottom of the adiabatic reactor. The material is input into the heat exchanger for cooling via the product circulation pump, and the cooled material is merged into the mixed raw material pipeline. Another stream of material enters the thin film evaporator, and the concentrated catalyst material is taken out from the bottom of the thin film evaporator. The material is input into the vinyl sulfate storage tank via the catalyst circulation pump. The materials of vinyl sulfate, unreacted ethylene oxide and sulfur trioxide are taken out from the top of the thin film evaporator and enter the light-removing tower; the materials of unreacted ethylene oxide and sulfur trioxide are taken out from the top of the light-removing tower and merged into the pipeline connected to the static mixer via the raw material circulation pump. The materials of vinyl sulfate and catalyst are taken out from the bottom of the tower and enter the vinyl sulfate refining tower. High-purity vinyl sulfate is obtained from the top of the tower, and heavy components are obtained from the bottom of the tower.

[0023] The present invention further provides a method for synthesizing vinyl sulfate, comprising the following steps:

[0024] (1) adding the catalyst into the vinyl sulfate storage tank for dissolution and mixing;

[0025] (2) vinyl sulfate solution containing a catalyst, ethylene oxide liquid, and sulfur trioxide liquid are respectively fed into a static mixer via respective material delivery pumps for mixing;

[0026] (3) the mixed materials enter an adiabatic reactor and react to synthesize vinyl sulfate under the action of a catalyst;

[0027] (4) The reacted material is divided into two streams, one of which is fed into a heat exchanger through a product circulation pump, and after being cooled in the heat exchanger, it is merged into the pipeline after the raw material mixing, and the other stream of material enters a thin film evaporator;

[0028] (5) The concentrated catalyst material is taken out from the bottom of the thin film evaporator and fed into the vinyl sulfate storage tank via a catalyst circulation pump; a mixture of vinyl sulfate, unreacted ethylene oxide and sulfur trioxide is taken out from the top of the thin film evaporator and fed into a light-removal tower;

[0029] (6) The unreacted ethylene oxide and sulfur trioxide are taken out from the top of the light-removal tower and introduced into the pipeline connected to the static mixer through the raw material circulation pump; the vinyl sulfate and catalyst taken out from the bottom of the tower are introduced into the vinyl sulfate refining tower;

[0030] (7) High-purity vinyl sulfate is extracted from the top of the vinyl sulfate refining tower, and heavy components are extracted from the bottom of the tower.

[0031] In one embodiment of the present invention, the temperature of the vinyl sulfate storage tank is 100-150°C, preferably 110-140°C, which can ensure the solution state of vinyl sulfate and reduce steam consumption; the temperature of the sulfur trioxide storage tank is 20-40°C, preferably 25-35°C, which can avoid solidification and sublimation of sulfur trioxide; the temperature of the ethylene oxide storage tank is -20-5°C, preferably -10-0°C, which can ensure the liquid state of ethylene oxide and reduce the saturated vapor pressure of ethylene oxide, thereby improving production safety.

[0032] In one embodiment of the present invention, the residence time of the reaction material mixture in the adiabatic reactor is 10-120 min, preferably 30-60 min, and this time setting can simultaneously ensure a high conversion rate and selectivity; the temperature of the adiabatic reactor is 100-150°C, preferably 110-140°C, and this temperature setting ensures liquid phase reaction, avoids clogging of the adiabatic reactor during the reaction, and reduces side reactions; the pressure in the adiabatic reactor is 0.1-6 MPa, preferably 0.2-3 MPa, and this pressure setting ensures that ethylene oxide is well dissolved in vinyl sulfate, thereby improving reaction efficiency and reaction safety.

[0033] In one embodiment of the present invention, the temperature at the outlet of the heat exchanger is 100-150°C, preferably 110-140°C.

[0034] In one embodiment of the present invention, the pressure of the thin film evaporator is 1-20 kPa, preferably 2-10 kPa, and the temperature of the thin film evaporator is 100-150° C., preferably 110-140° C. The limitation of the process conditions can ensure a shorter evaporation time and avoid the occurrence of side reactions.

[0035] In one embodiment of the present invention, the pressure of the lightness removal tower is 1-90 kPa, preferably 10-80 kPa; the temperature of the lightness removal tower is 100-150°C, preferably 110-140°C.

[0036] In one embodiment of the present invention, the pressure of the vinyl sulfate refining tower is 1-20 kPa, preferably 2-10 kPa; the temperature of the vinyl sulfate refining tower is 100-150°C, preferably 110-140°C.

[0037] In one embodiment of the present invention, the catalyst is a complex of an imidazole salt and a zinc halide;

[0038] The imidazolium salt includes at least one of 1,3-dimethylimidazolium bromide, 1,3-dimethylimidazolium chloride, 1-ethyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium bromide, and 1-butyl-3-methylimidazolium bromide;

[0039] The zinc halide is at least one of zinc bromide and zinc chloride;

[0040] The molar ratio of the imidazole salt to the zinc halide is 1:1-12:1, preferably 6:1-10:1.

[0041] In one embodiment of the present invention, the imidazole salt and zinc halide in the catalyst can be directly mixed with vinyl sulfate, or can be pretreated first and then mixed with vinyl sulfate. The pretreatment method is as follows:

[0042] (1) dissolving an imidazole salt in dichloromethane to obtain a solution A, and dissolving a zinc halide in tetrahydrofuran to obtain a solution B, wherein the molar ratio of the imidazole salt to the zinc halide is 2:1;

[0043] (2) Solution A and solution B are mixed and refluxed for a certain period of time. After the reflux is completed, the mixture is cooled to room temperature to obtain a composite ionic liquid precipitate.

[0044] (3) adding the composite ionic liquid precipitate and the imidazole salt into a vinyl sulfate solvent, wherein the molar ratio of the imidazole salt to the zinc halide in the vinyl sulfate solution is 1:1-12:1, preferably 6:1-10:1.

[0045] In one embodiment of the present invention, vinyl sulfate is used as the solvent for ethylene oxide and sulfur trioxide, and the molar ratio of Zn to ethylene oxide in the catalyst is 0.0002:1 to 0.02:1, preferably 0.0005:1 to 0.01:1.

[0046] In one embodiment of the present invention, the raw material molar ratio of ethylene oxide, sulfur trioxide and vinyl sulfate is 5-30:5-30:90-40, and more preferably 10-25:10-25:80-50. This molar ratio can ensure a high conversion rate of ethylene oxide and reaction safety, and has a high reaction efficiency.

[0047] The technical solution of the present invention adopts a composite ionic liquid of imidazole salt and zinc halide as a catalyst, the catalyst has high activity and good stability, and is conducive to the separation and purification of the product.

[0048] The technical solution of the present invention adopts vinyl sulfate as a solvent, does not introduce any foreign components, reduces the burden of side reactions and separation, and can effectively improve the purity of vinyl sulfate and simplify the process flow.

[0049] The technical solution of the present invention adopts an adiabatic reactor to increase the reaction speed and reactor production capacity and reduce energy consumption.

[0050] The technical solution of the present invention adopts a thin film evaporator to achieve product purification and catalyst concentration, and the product separation is simple and the purity is high.

[0051] Compared with the prior art, the present invention has the following advantages:

[0052] The process is simple, energy consumption is low, product separation is simple, and the vinyl sulfate has high purity. The adiabatic reactor is used, the equipment structure is simple, energy consumption is low, the degree of continuity is high, safety and reliability are high, and the production cost is low. The catalyst preparation process is simple, the activity is high, the stability is good, and it can be recycled. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a schematic diagram of a system for synthesizing vinyl sulfate in Example 1 of the present invention.

[0054] 101. Ethylene sulfate storage tank, 102. Sulfur trioxide storage tank, 103. Ethylene oxide storage tank;

[0055] 200. Static mixer;

[0056] 300. Adiabatic reactor;

[0057] 400. Heat exchanger;

[0058] 500. Thin film evaporator;

[0059] 601, light removal tower, 602, vinyl sulfate refining tower,

[0060] 11. Ethylene sulfate delivery pump, 12. Sulfur trioxide delivery pump, 13. Ethylene oxide delivery pump, 14. Product circulation pump, 15. Catalyst circulation pump, 16. Raw material circulation pump. DETAILED DESCRIPTION

[0061] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0062] refer to Figure 1 The present invention provides a system for synthesizing vinyl sulfate, which comprises a vinyl sulfate storage tank 101, a sulfur trioxide storage tank 102, an ethylene oxide storage tank 103, a static mixer 200, an adiabatic reactor 300, a thin film evaporator 500, a lightness removal tower 601 and a vinyl sulfate refining tower 602. The vinyl sulfate storage tank 101, the sulfur trioxide storage tank 102 and the ethylene oxide storage tank 103 are all connected to the static mixer 200 through a pipeline, the static mixer 200 is connected to the adiabatic reactor 300, the bottom of the adiabatic reactor 300 is connected to the thin film evaporator 500 through a pipeline, the bottom of the thin film evaporator 500 is used to extract the concentrated catalyst material, and the top of the thin film evaporator 500 is used to remove the concentrated catalyst material. Used to produce materials of vinyl sulfate, unreacted ethylene oxide and sulfur trioxide, the bottom of the thin film evaporator 500 is connected to the vinyl sulfate storage tank 101 through a pipeline, the top of the thin film evaporator 500 is connected to the light removal tower 601 through a pipeline, the top of the light removal tower 601 is used to produce unreacted ethylene oxide and sulfur trioxide materials, the bottom of the light removal tower 601 is used to produce materials of vinyl sulfate and catalyst, the top of the light removal tower 601 is connected to the static mixer 200 through a pipeline, the bottom of the light removal tower 601 is connected to the vinyl sulfate refining tower 602 through a pipeline, the top of the vinyl sulfate refining tower 602 is used to obtain high-purity vinyl sulfate, and the bottom of the vinyl sulfate refining tower 602 is used to obtain heavy components.

[0063] In an embodiment of the present invention, the system for synthesizing vinyl sulfate further comprises a heat exchanger 400, the bottom of the adiabatic reactor 300 is also connected to the heat exchanger 400 via a pipeline, and the heat exchanger 400 is further connected to the static mixer 200 via a pipeline.

[0064] In an embodiment of the present invention, a vinyl sulfate delivery pump 11 is provided on the pipeline connecting the vinyl sulfate storage tank 101 and the static mixer 200. A sulfur trioxide delivery pump 12 is provided on the pipeline connecting the sulfur trioxide storage tank 102 and the static mixer 200. An ethylene oxide delivery pump 13 is provided on the pipeline connecting the ethylene oxide storage tank 103 and the static mixer 200. A product circulation pump 14 is provided on the pipeline connecting the bottom of the adiabatic reactor 300 and the heat exchanger 400. A catalyst circulation pump 15 is provided on the pipeline connecting the bottom of the thin film evaporator 500 and the vinyl sulfate storage tank 101. A raw material circulation pump 16 is provided on the pipeline connecting the top of the light removal tower 601 and the static mixer 200.

[0065] In an embodiment of the present invention, the thin film evaporator 500 is a falling film evaporator, preferably a multi-effect falling film evaporator.

[0066] In an embodiment of the present invention, the adiabatic reactor 300 is a tubular reactor or a tower reactor.

[0067] In an embodiment of the present invention, the vinyl sulfate storage tank 101 is used to add a vinyl sulfate solution containing a catalyst.

[0068] In an embodiment of the present invention, the feed port of the vinyl sulfate refining tower 602 is arranged in the middle, and the bottom of the light removal tower 601 is connected to the feed port of the vinyl sulfate refining tower 602 through a pipeline.

[0069] The method for synthesizing vinyl sulfate by using the system of the present invention specifically comprises the following contents: using ethylene oxide and sulfur trioxide as raw materials, vinyl sulfate as solvent, imidazole salt and zinc halide complex as catalyst, and vinyl sulfate as solvent, wherein the catalyst is dissolved in vinyl sulfate; sulfur trioxide, ethylene oxide and vinyl sulfate solution containing the catalyst are input into a static mixer via respective material delivery pumps; after the raw materials are evenly mixed, they are input into an adiabatic reactor for reaction, and under the action of the imidazole salt and zinc halide complex catalysts, ethylene oxide and sulfur trioxide undergo addition reaction to generate vinyl sulfate; two streams of liquid materials are taken out from the bottom of the adiabatic reactor, and one stream of liquid materials is taken out from the bottom of the adiabatic reactor. The material is input into the heat exchanger for cooling via the product circulation pump, and the cooled material is merged into the mixed raw material pipeline. Another stream of material enters the thin film evaporator, and the concentrated catalyst material is taken out from the bottom of the thin film evaporator. The material is input into the vinyl sulfate storage tank via the catalyst circulation pump. The materials of vinyl sulfate, unreacted ethylene oxide and sulfur trioxide are taken out from the top of the thin film evaporator and enter the light-removing tower; the materials of unreacted ethylene oxide and sulfur trioxide are taken out from the top of the light-removing tower and merged into the pipeline connected to the static mixer via the raw material circulation pump. The materials of vinyl sulfate and catalyst are taken out from the bottom of the tower and enter the vinyl sulfate refining tower. High-purity vinyl sulfate is obtained from the top of the tower, and heavy components are obtained from the bottom of the tower.

[0070] Specifically, the method for synthesizing vinyl sulfate comprises the following steps:

[0071] (1) adding the catalyst into the vinyl sulfate storage tank for dissolution and mixing;

[0072] (2) vinyl sulfate solution containing a catalyst, ethylene oxide liquid, and sulfur trioxide liquid are respectively fed into a static mixer via respective material delivery pumps for mixing;

[0073] (3) the mixed materials enter an adiabatic reactor and react to synthesize vinyl sulfate under the action of a catalyst;

[0074] (4) The reacted material is divided into two streams, one of which is fed into a heat exchanger through a product circulation pump, and after being cooled in the heat exchanger, it is merged into the pipeline after the raw material mixing, and the other stream of material enters a thin film evaporator;

[0075] (5) The concentrated catalyst material is taken out from the bottom of the thin film evaporator and fed into the vinyl sulfate storage tank via a catalyst circulation pump; a mixture of vinyl sulfate, unreacted ethylene oxide and sulfur trioxide is taken out from the top of the thin film evaporator and fed into a light-removal tower;

[0076] (6) The unreacted ethylene oxide and sulfur trioxide are taken out from the top of the light-removal tower and introduced into the pipeline connected to the static mixer through the raw material circulation pump; the vinyl sulfate and catalyst taken out from the bottom of the tower are introduced into the vinyl sulfate refining tower;

[0077] (7) High-purity vinyl sulfate is extracted from the top of the vinyl sulfate refining tower, and heavy components are extracted from the bottom of the tower.

[0078] refer to Figure 1 , Examples 1-12 are all methods for synthesizing vinyl sulfate, and the specific process conditions of Examples 1-12 are shown in Table 1-3.

[0079] Table 1. Effect of [EMIM]Br-ZnCl2 catalyst on the reaction of ethylene oxide and sulfur trioxide at different reaction temperatures

[0080] Example Reaction temperature (℃) Conversion rate (%) 1 110 12.5 2 120 30.9 3 130 62.8 4 140 80.5

[0081] Reaction conditions of Examples 1-4: the catalyst is [EMIM]Br-ZnCl2, Zn:EO=0.05%, [EMIM]:Zn=10, ES:EO:SO3=80:10:10, and the reaction pressure is 1.5 MPa.

[0082] Examples 1-4

[0083] [EMIM]Br and ZnCl2 are dissolved in vinyl sulfate, the molar ratio of EMIM to Zn is 10, the molar ratio of Zn to EO is 0.05%, and the molar ratio of ES, EO and SO3 raw material liquid is 80:10:10. The materials are fed into a static mixer through respective material delivery pumps, and the mixed materials enter a tubular reactor, where an addition reaction occurs under the action of a catalyst. The obtained product is refined by light removal and then analyzed and detected by offline chromatography. The reaction time is 45 minutes, the reaction temperature is 110-140°C, the conversion rate of SO3 increases from 12.5% ​​to 80.5%, and the purity of vinyl sulfate is 99.9%.

[0084] Example 2 Table 2 Effect of [EMIM]Br-ZnBr2 catalyst on the reaction of ethylene oxide and sulfur trioxide at different reaction temperatures

[0085]

[0086]

[0087] Reaction conditions of Examples 5-8: Catalyst is [EMIM]Br-ZnBr2, Zn:EO=0.05%, EMIM:Zn

[0088] =10, ES:EO:SO3=80:10:10, reaction pressure is 1.5MPa.

[0089] [EMIM]Br and ZnBr2 are dissolved in vinyl sulfate, the molar ratio of EMIM to Zn is 10, the molar ratio of Zn to EO is 0.05%, and the molar ratio of ES, EO and SO3 raw material liquid is 80:10:10. The materials are fed into a static mixer through respective material delivery pumps, and the mixed materials enter a tubular reactor, where an addition reaction occurs under the action of a catalyst. The obtained product is subjected to light removal and refining, and then analyzed and detected by offline chromatography. The reaction time is 45 minutes, the reaction temperature is 110-140°C, the conversion rate of SO3 increases from 42.6% to 93.2%, and the purity of vinyl sulfate is 99.9%.

[0090] Examples 9-12 Table 3 Effect of different reaction times on the reaction of ethylene oxide and sulfur trioxide in the presence of [EMIM]Br-ZnBr2 catalyst

[0091] Example Reaction time (min) Conversion rate (%) 9 15 89.3 10 30 98.2％ 11 45 99.0％ 12 60 99.2％

[0092] Reaction conditions of Examples 9-12: the catalyst is [EMIM]Br-ZnBr2, Zn:EO=0.1%, EMIM:Zn=10, ES:EO:SO3=80:10:10, the reaction temperature is 140°C, and the reaction pressure is 1.5 MPa.

[0093] [EMIM]Br and ZnBr2 are dissolved in vinyl sulfate, the molar ratio of EMIM to Zn is 10, the molar ratio of Zn to EO is 0.1%, and the molar ratio of ES, EO and SO3 raw liquid is 80:10:10. The raw materials are fed into a static mixer through a feed pump, and the mixed materials are fed into a tower reactor. Addition reaction occurs under the action of a catalyst, and the obtained product is refined by light removal and analyzed by offline chromatography. The reaction temperature is 140°C, the reaction time is 15-60min, the conversion rate of SO3 is increased from 89.3% to 99.2%, and the purity of vinyl sulfate is 99.9%.

[0094] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A system for synthesizing vinyl sulfate, characterized in that: The invention comprises a vinyl sulfate storage tank (101), a sulfur trioxide storage tank (102), an ethylene oxide storage tank (103), a static mixer (200), an adiabatic reactor (300), a thin film evaporator (500), a lightness removal tower (601) and a vinyl sulfate refining tower (602), wherein the vinyl sulfate storage tank (101), the sulfur trioxide storage tank (102) and the ethylene oxide storage tank (103) are all connected to the static mixer (200) through a pipeline, the static mixer (200) is connected to the adiabatic reactor (300), the bottom of the adiabatic reactor (300) is connected to the thin film evaporator (500) through a pipeline, the bottom of the thin film evaporator (500) is used to extract the concentrated catalyst material, and the top of the thin film evaporator (500) is used to extract the vinyl sulfate , unreacted ethylene oxide and sulfur trioxide materials, the bottom of the thin film evaporator (500) is connected to the vinyl sulfate storage tank (101) through a pipeline, the top of the thin film evaporator (500) is connected to the lightness removal tower (601) through a pipeline, the top of the lightness removal tower (601) is used to produce unreacted ethylene oxide and sulfur trioxide materials, the bottom of the lightness removal tower (601) is used to produce vinyl sulfate and catalyst materials, the top of the lightness removal tower (601) is connected to the static mixer (200) through a pipeline, the bottom of the lightness removal tower (601) is connected to the vinyl sulfate refining tower (602) through a pipeline, the top of the vinyl sulfate refining tower (602) is used to obtain high-purity vinyl sulfate, and the bottom of the vinyl sulfate refining tower (602) is used to obtain heavy components.

2. A method for synthesizing vinyl sulfate, characterized in that: Based on the system of claim 1, the method comprises the following steps: (1) adding the catalyst into the vinyl sulfate storage tank for dissolution and mixing; (2) vinyl sulfate solution containing a catalyst, ethylene oxide liquid, and sulfur trioxide liquid are respectively fed into a static mixer via respective material delivery pumps for mixing; (3) the mixed materials enter an adiabatic reactor and react to synthesize vinyl sulfate under the action of a catalyst; (4) The reacted material is divided into two streams, one of which is fed into a heat exchanger through a product circulation pump, and after being cooled in the heat exchanger, it is merged into the pipeline after the raw material mixing, and the other stream of material enters a thin film evaporator; (5) The concentrated catalyst material is taken out from the bottom of the thin film evaporator and fed into the vinyl sulfate storage tank via a catalyst circulation pump; a mixture of vinyl sulfate, unreacted ethylene oxide and sulfur trioxide is taken out from the top of the thin film evaporator and fed into a light-removal tower; (6) The unreacted ethylene oxide and sulfur trioxide are taken out from the top of the light-removal tower and introduced into the pipeline connected to the static mixer through the raw material circulation pump; the vinyl sulfate and catalyst taken out from the bottom of the tower are introduced into the vinyl sulfate refining tower; (7) High-purity vinyl sulfate is extracted from the top of the vinyl sulfate refining tower, and heavy components are extracted from the bottom of the tower.

3. A method for synthesizing vinyl sulfate according to claim 2, characterized in that: The temperature of the vinyl sulfate storage tank is 100-150°C; the temperature of the sulfur trioxide storage tank is 20-40°C; the temperature of the ethylene oxide storage tank is -20-5°C.

4. A method for synthesizing vinyl sulfate according to claim 2, characterized in that: The residence time of the reaction material mixture in the adiabatic reactor is 10-120 min, the temperature of the adiabatic reactor is 100-150° C., and the pressure in the reactor is 0.1-6 MPa.

5. A method for synthesizing vinyl sulfate according to claim 2, characterized in that: The temperature at the outlet of the heat exchanger is 100-150°C; The pressure of the thin film evaporator is 1-20 kPa, and the temperature of the thin film evaporator is 100-150°C.

6. A method for synthesizing vinyl sulfate according to claim 2, characterized in that: The pressure of the lightness removal tower is 1-90 kPa; the temperature of the lightness removal tower is 100-150°C; The pressure of the vinyl sulfate refining tower is 1-20 kPa, and the temperature of the vinyl sulfate refining tower is 100-150°C.

7. A method for synthesizing vinyl sulfate according to claim 2, characterized in that: The catalyst is a complex of imidazole salt and zinc halide; The imidazolium salt includes at least one of 1,3-dimethylimidazolium bromide, 1,3-dimethylimidazolium chloride, 1-ethyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium bromide, and 1-butyl-3-methylimidazolium bromide; The zinc halide is at least one of zinc bromide and zinc chloride; The molar ratio of the imidazole salt to the zinc halide is 1:1-12:

1.

8. A method for synthesizing vinyl sulfate according to claim 7, characterized in that: The imidazole salt and zinc halide in the catalyst are first pretreated and then mixed with vinyl sulfate. The pretreatment method is as follows: (1) dissolving an imidazole salt in dichloromethane to obtain a solution A, and dissolving a zinc halide in tetrahydrofuran to obtain a solution B, wherein the molar ratio of the imidazole salt to the zinc halide is 2:1; (2) mixing solution A and solution B and refluxing for a certain period of time, and cooling to room temperature to obtain a composite ionic liquid precipitate after the reflux is completed; (3) adding the composite ionic liquid precipitate and the imidazole salt into a vinyl sulfate solvent, wherein the molar ratio of the imidazole salt to the zinc halide in the vinyl sulfate solution is 1:1-12:

1.

9. A method for synthesizing vinyl sulfate according to claim 2, characterized in that: Vinyl sulfate is used as a solvent for ethylene oxide and sulfur trioxide, and the molar ratio of Zn to ethylene oxide in the catalyst is 0.0002:1 to 0.02:

1.

10. A method for synthesizing vinyl sulfate according to claim 2, characterized in that: The raw material molar ratio of ethylene oxide, sulfur trioxide and vinyl sulfate is 5-30:5-30:90-40.

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