A method for the industrial synthesis of vinylsulfate

Abstract

This invention relates to an industrial synthesis method for vinyl sulfate. The method uses ethylene glycol and thionyl chloride as raw materials and innovatively employs aluminum trichloride and silicon dioxide as catalysts, thus avoiding the use of the precious metal ruthenium trichloride as a catalyst. Aluminum trichloride and silicon dioxide are inexpensive and recyclable, greatly reducing costs. Most importantly, it improves catalytic efficiency and yields high results. Furthermore, it uses hydrogen peroxide solution as an oxidant, requiring less hydrogen peroxide and generating less wastewater, enabling industrial-scale production.

Description

Technical Field

[0001] This invention relates to an industrial synthesis method for vinyl sulfate, belonging to the field of fine chemical technology. Background Technology

[0002] Ethyl sulfate, as a film-forming additive, can improve the performance of lithium-ion battery electrolytes. By improving the structure of the "solid electrolyte interface film" in the electrolyte, it can suppress the decline of the initial capacity of lithium batteries, increase the initial discharge capacity, reduce the expansion of batteries after high-temperature storage, and improve the charge-discharge performance and cycle life of batteries.

[0003] Currently, the methods for preparing vinyl sulfate include: 1. One-step synthesis of vinyl sulfate from ethylene oxide and sulfur trioxide in dioxane solvent. This reaction releases a large amount of heat, is violent, and poses significant safety risks, making industrialization difficult; 2. Synthesis of vinyl sulfate via the reaction of dibromoethane and silver sulfate. This reaction has low yield and high cost, making it unsuitable for industrial production; 3. Direct acylation reaction of ethylene glycol with sulfuryl chloride (or sulfuryl fluoride) to produce vinyl sulfate. This method has low yield, is highly corrosive, and causes significant pollution, making it unsuitable for industrial production; 4. Reaction of sulfur trioxide with dioxane under inert gas protection to synthesize crude vinyl sulfate, followed by sublimation under reduced pressure to obtain the final product. This method is highly hazardous and corrosive, and the sublimation process... Pure methods are also unsuitable for industrial production; 5. The reaction of ethylene glycol and thionyl chloride to produce vinyl sulfite, followed by oxidation with sodium hypochlorite to produce vinyl sulfate, is currently the mainstream method. However, this method has a low single-batch conversion rate, generates a large amount of wastewater during the preparation process, the reaction is incomplete, and the process is cumbersome and discontinuous with high energy consumption. This method basically uses the precious metal ruthenium trichloride as a catalyst, which is difficult to recycle and has a low yield. Since ruthenium is an extremely expensive rare precious metal, its price is high, making the cost of vinyl sulfate synthesis process very high.

[0004] Therefore, designing a novel industrial synthesis method for vinyl sulfate with high single-batch conversion rate, low acid wastewater generation, avoidance of precious metal catalysts, high yield, and low cost has significant market value. Summary of the Invention

[0005] To address the shortcomings of existing technologies, especially the problems of low yield and high cost when using ethylene glycol and thionyl chloride as raw materials and ruthenium trichloride as a catalyst, this invention provides an industrial synthesis method for vinyl sulfate.

[0006] The method of the present invention has mild reaction conditions, which solves the technical problems of low yield, high energy consumption, serious environmental pollution and high cost of existing preparation methods.

[0007] This invention is achieved through the following technical solution:

[0008] An industrial synthesis method for vinyl sulfate includes the following steps:

[0009] 1) Adjust the pressure inside the reactor to a slightly negative pressure, and slowly add thionyl chloride and ethylene glycol into the reactor simultaneously to obtain crude vinyl sulfite;

[0010] 2) The crude vinyl sulfite obtained in step 1) is subjected to vacuum distillation to remove hydrogen chloride;

[0011] 3) After removing hydrogen chloride, the crude vinyl sulfite was adjusted to neutral pH with sodium carbonate solution, and the phases were separated to obtain pure vinyl sulfite.

[0012] 4) Add pure vinyl sulfite, dichloroethane, and catalyst to a reaction vessel, and slowly add hydrogen peroxide solution dropwise to carry out the reaction. After the addition is complete, continue the reaction, filter out the catalyst, and perform phase separation. The lower organic phase is a dichloroethane solution of vinyl sulfite. The catalyst is a mixture of aluminum trichloride and silicon dioxide.

[0013] 5) Crystallize the dichloroethane solution of vinyl sulfate obtained in step 4), and centrifuge to obtain crude vinyl sulfate;

[0014] 6) Mix crude vinyl sulfate with dichloroethane, dissolve completely, add a dehydrating agent, dehydrate, filter out the dehydrating agent, and obtain a dichloroethane solution of vinyl sulfate.

[0015] 7) Crystallize the dichloroethane solution of vinyl sulfate, centrifuge to obtain a moist pure vinyl sulfate, and dry it to obtain a pure vinyl sulfate.

[0016] According to a preferred embodiment of the present invention, in step 1), the pressure inside the reactor is -0.03 to -0.01 MPa, and the molar ratio of thionyl chloride to ethylene glycol is 1 to 1.1:1.

[0017] According to a preferred embodiment of the present invention, in step 1), the reaction temperature is 10~30℃ and the dropping time is 3~5h.

[0018] According to a preferred embodiment of the present invention, in step 2), the vacuum distillation temperature is 25~50℃ and the pressure inside the vessel is -0.098~-0.08Mpa.

[0019] According to a preferred embodiment of the present invention, in step 3), the mass concentration of the sodium carbonate solution is 1% to 5%.

[0020] According to a preferred embodiment of the present invention, in step 4), the mass ratio of pure vinyl sulfite to dichloroethane is 1:4; the mass concentration of the hydrogen peroxide solution is 27.5%; and the molar ratio of vinyl sulfite to hydrogen peroxide is 1:1.26.

[0021] According to a preferred embodiment of the present invention, in step 4), the mass ratio of aluminum trichloride to silicon dioxide in the mixture of aluminum trichloride and silicon dioxide is (4-10):(2-6).

[0022] Most preferably, the mass ratio of aluminum trichloride to silicon dioxide in the mixture of aluminum chloride and silicon dioxide is 7:3.

[0023] According to a preferred embodiment of the present invention, in step 4), the mass ratio of the catalyst to the pure vinyl sulfite is (0.02-0.2):1.

[0024] The most preferred mass ratio of catalyst to pure vinyl sulfite is 0.046:1.

[0025] According to a preferred embodiment of the present invention, in step 5), the crystallization temperature is -15~0℃ and the crystallization time is 3h.

[0026] According to a preferred embodiment of the present invention, in step 6), the mass ratio of crude vinyl sulfate to dichloroethane is 1:4.

[0027] According to a preferred embodiment of the present invention, in step 6), the dehydrating agent is one or a combination of several of anhydrous magnesium sulfate, activated carbon, and sodium sulfate.

[0028] According to a preferred embodiment of the present invention, in step 7), the recrystallization temperature is -15~0℃ and the crystallization time is 3h.

[0029] According to a preferred embodiment of the present invention, in step 7), the drying pressure is -0.098 to -0.09 MPa, the drying temperature is 45 to 60°C, and the drying time is 3 hours.

[0030] Technical features and advantages of the present invention:

[0031] 1. The method of this invention innovatively uses aluminum trichloride and silicon dioxide as catalysts, avoiding the use of the precious metal ruthenium trichloride as a catalyst. Aluminum trichloride and silicon dioxide are inexpensive and recyclable, which greatly reduces costs. Most importantly, it improves catalytic efficiency and yields high output. Furthermore, it uses hydrogen peroxide solution as an oxidant, which requires less hydrogen peroxide and generates less wastewater, enabling industrial production.

[0032] 2. In step 1) of this invention, the pressure inside the reactor is slightly negative, which allows the hydrogen chloride generated by the reaction of thionyl chloride and ethylene glycol to be removed in time, making the reaction more complete and reducing the occurrence of side reactions.

[0033] 3. In the method of the present invention, thionyl chloride and ethylene glycol are added dropwise to make the reaction more complete, improve the yield of vinyl sulfite, and reduce the formation of by-products.

[0034] 4. Method of the present invention: The present invention performs vacuum distillation to remove acid from crude vinyl sulfite and alkali washing, thereby reducing the acidity of vinyl sulfite and increasing its purity, which in turn increases the purity of vinyl sulfate.

[0035] 5. The method of the present invention adds a dehydrating agent before recrystallization of vinyl sulfate, which reduces the hydrolysis of vinyl sulfate, improves the purity and yield of vinyl sulfate, and reduces the drying time. Detailed Implementation

[0036] The present invention will be further described below with reference to the embodiments, but the technical content of the present invention is not limited thereto; the raw materials used in the embodiments are all conventional raw materials and commercially available products.

[0037] Example 1

[0038] The industrial synthesis method of vinyl sulfate includes the following steps:

[0039] Step 1: Set the pressure inside the reactor to -0.02 MPa, and slowly add thionyl chloride and ethylene glycol dropwise into the reactor simultaneously to obtain crude vinyl sulfite. The molar ratio of thionyl chloride to ethylene glycol is 1:1. The reaction temperature is 15°C, and the dropwise addition time is 3-5 h.

[0040] Step 2: Transfer the crude vinyl sulfite from Step 1 into a deacidification kettle for vacuum distillation to remove hydrogen chloride. The distillation temperature in the deacidification kettle is 50℃, and the pressure inside the kettle is -0.098~-0.090 MPa.

[0041] Step 3: Transfer the crude vinyl sulfite from Step 2 into an alkaline washing kettle, add sodium carbonate solution to adjust the pH of the material to neutral, and then separate the phases to obtain pure vinyl sulfite, wherein the concentration of sodium carbonate solution is 3%.

[0042] Step 4: Add 1.3 kg of pure vinyl sulfite, dichloroethane, and catalyst from Step 3 to the reactor. Slowly add 27.5% hydrogen peroxide solution dropwise to carry out the reaction. After the addition is complete, continue the reaction for 2 hours. Filter out the catalyst and separate the phases. The lower organic phase is a dichloroethane solution of vinyl sulfite, wherein the mass ratio of pure vinyl sulfite to dichloroethane is 1:4, the molar ratio of vinyl sulfite to hydrogen peroxide is 1:1.1, and the catalyst is a mixture of aluminum trichloride and silicon dioxide, wherein the mass ratio of aluminum trichloride to silicon dioxide is 7:3, and the mass ratio of catalyst to pure vinyl sulfite is 0.046:1.

[0043] Step 5: Add the dichloroethane solution of vinyl sulfate obtained in Step 4 to a crystallization vessel for crystallization. After centrifugation, crude vinyl sulfate is obtained. The temperature of the crystallization vessel is -15~-10℃ and the crystallization time is 3h.

[0044] Step 6: Add the crude vinyl sulfate obtained in Step 5 and fresh dichloroethane to the dissolving vessel. After complete dissolution, add a dehydrating agent. After dehydration is completed, filter out the dehydrating agent to obtain a dichloroethane solution of vinyl sulfate. The mass ratio of crude vinyl sulfate to fresh dichloroethane is 1:4. The dehydrating agent is a combination of anhydrous magnesium sulfate and activated carbon.

[0045] Step 7: Add the dichloroethane solution of vinyl sulfate obtained in Step 6 to a recrystallization vessel for crystallization. After centrifugation, obtain a moist pure vinyl sulfate product. The temperature of the recrystallization vessel is -15~-10℃, and the crystallization time is 3h.

[0046] Step 8: The humid pure vinyl sulfate obtained in Step 7 is dried to obtain pure vinyl sulfate. The pressure inside the drying equipment is -0.098 to -0.09 MPa, the drying temperature is 45 to 60℃, and the drying time is 3 hours.

[0047] The purity of the vinyl sulfate obtained in this example was 99.23%, and the yield of the synthesized vinyl sulfate was 99.18% based on ethylene glycol.

[0048] Example 2:

[0049] The industrial synthesis method of vinyl sulfate includes the following steps:

[0050] Step 1: Set the pressure inside the reactor to -0.02 MPa, and slowly add thionyl chloride and ethylene glycol dropwise into the reactor simultaneously to obtain crude vinyl sulfite. The molar ratio of thionyl chloride to ethylene glycol is 1.05:1. The reaction temperature is 15℃ and the dropwise addition time is 3~5 h.

[0051] Step 2: Transfer the crude vinyl sulfite from Step 1 into a deacidification kettle for vacuum distillation to remove hydrogen chloride. The distillation temperature in the deacidification kettle is 50℃, and the pressure inside the kettle is -0.098~-0.090 MPa.

[0052] Step 3: Transfer the crude vinyl sulfite from Step 2 into an alkaline washing kettle, add sodium carbonate solution to adjust the pH of the material to neutral, and then separate the phases to obtain pure vinyl sulfite, wherein the concentration of sodium carbonate solution is 3%.

[0053] Step 4: Add 1.3 kg of pure vinyl sulfite, dichloroethane, and catalyst from Step 3 to the reactor. Slowly add 27.5% hydrogen peroxide solution dropwise to carry out the reaction. After the addition is complete, continue the reaction for 2 hours. Filter out the catalyst and separate the phases. The lower organic phase is a dichloroethane solution of vinyl sulfite, wherein the mass ratio of pure vinyl sulfite to dichloroethane is 1:4, the molar ratio of vinyl sulfite to hydrogen peroxide is 1:1.1, and the catalyst is a mixture of aluminum trichloride and silicon dioxide, wherein the mass ratio of aluminum trichloride to silicon dioxide is 7:3, and the mass ratio of catalyst to pure vinyl sulfite is 0.046:1.

[0054] Step 5: Add the dichloroethane solution of vinyl sulfate obtained in Step 4 to a crystallization vessel for crystallization. After centrifugation, crude vinyl sulfate is obtained. The temperature of the crystallization vessel is -15~-10℃ and the crystallization time is 3h.

[0055] Step 6: Add the crude vinyl sulfate obtained in Step 5 and fresh dichloroethane to the dissolving vessel. After complete dissolution, add a dehydrating agent. After dehydration is completed, filter out the dehydrating agent to obtain a dichloroethane solution of vinyl sulfate. The mass ratio of crude vinyl sulfate to fresh dichloroethane is 1:4. The dehydrating agent is a combination of anhydrous magnesium sulfate and activated carbon.

[0056] Step 7: Add the dichloroethane solution of vinyl sulfate obtained in Step 6 to a recrystallization vessel for crystallization. After centrifugation, obtain a moist pure vinyl sulfate product. The temperature of the recrystallization vessel is -15~-10℃, and the crystallization time is 3h.

[0057] Step 8: The humid pure vinyl sulfate obtained in Step 7 is dried to obtain pure vinyl sulfate. The pressure inside the drying equipment is -0.098 to -0.09 MPa, the drying temperature is 45 to 60℃, and the drying time is 3 hours.

[0058] The purity of the vinyl sulfate obtained in this example was 99.51%, and the yield of the synthesized vinyl sulfate was 99.49% based on ethylene glycol.

[0059] Example 3:

[0060] The industrial synthesis method of vinyl sulfate includes the following steps:

[0061] Step 1: The pressure inside the reactor is set to -0.02 MPa. Thionyl chloride and ethylene glycol are simultaneously and slowly added dropwise to the reactor to obtain crude vinyl sulfite. The molar ratio of thionyl chloride to ethylene glycol is 1.1:1. The reaction temperature is 15℃ and the dropping time is 3~5h.

[0062] Step 2: Transfer the crude vinyl sulfite from Step 1 into a deacidification kettle for vacuum distillation to remove hydrogen chloride. The distillation temperature in the deacidification kettle is 50℃, and the pressure inside the kettle is -0.098~-0.090 MPa.

[0063] Step 3: Transfer the crude vinyl sulfite from Step 2 into an alkaline washing kettle, add sodium carbonate solution to adjust the pH of the material to neutral, and then separate the phases to obtain pure vinyl sulfite, wherein the concentration of sodium carbonate solution is 3%.

[0064] Step 4: Add 1.3 kg of pure vinyl sulfite, dichloroethane, and catalyst from Step 3 to the reactor. Slowly add 27.5% hydrogen peroxide solution dropwise to carry out the reaction. After the addition is complete, continue the reaction for 2 hours. Filter out the catalyst and separate the phases. The lower organic phase is a dichloroethane solution of vinyl sulfite, wherein the mass ratio of pure vinyl sulfite to dichloroethane is 1:4, the molar ratio of vinyl sulfite to hydrogen peroxide is 1:1.1, and the catalyst is a mixture of aluminum trichloride and silicon dioxide, wherein the mass ratio of aluminum trichloride to silicon dioxide is 7:3, and the mass ratio of catalyst to pure vinyl sulfite is 0.046:1.

[0065] Step 5: Add the dichloroethane solution of vinyl sulfate obtained in Step 4 to a crystallization vessel for crystallization. After centrifugation, crude vinyl sulfate is obtained. The temperature of the crystallization vessel is -15~-10℃ and the crystallization time is 3h.

[0066] Step 6: Add the crude vinyl sulfate obtained in Step 5 and fresh dichloroethane to the dissolving vessel. After complete dissolution, add a dehydrating agent. After dehydration is completed, filter out the dehydrating agent to obtain a dichloroethane solution of vinyl sulfate. The mass ratio of crude vinyl sulfate to fresh dichloroethane is 1:4. The dehydrating agent is a combination of anhydrous magnesium sulfate and activated carbon.

[0067] Step 7: Add the dichloroethane solution of vinyl sulfate obtained in Step 6 to a recrystallization vessel for crystallization. After centrifugation, obtain a moist pure vinyl sulfate product. The temperature of the recrystallization vessel is -15~-10℃, and the crystallization time is 3h.

[0068] Step 8: The humid pure vinyl sulfate obtained in Step 7 is dried to obtain pure vinyl sulfate. The pressure inside the drying equipment is -0.098 to -0.09 MPa, the drying temperature is 45 to 60℃, and the drying time is 3 hours.

[0069] The purity of the vinyl sulfate obtained in this example was 99.68%, and the yield of the synthesized vinyl sulfate was 99.82% based on ethylene glycol.

[0070] Comparing the data from Examples 1-3, it can be seen that the highest purity and yield of synthesized vinyl sulfate were achieved when the molar ratio of thionyl chloride to ethylene glycol was 1.1:1 and the mass ratio of catalyst to vinyl sulfate was 0.046:1.

[0071] Example 4

[0072] The industrial synthesis method of vinyl sulfate described in Example 1 differs from that described in the following aspects:

[0073] In step 4, the catalyst is a mixture of aluminum trichloride and silicon dioxide, with a mass ratio of aluminum trichloride to silicon dioxide of 6:4.

[0074] Example 5

[0075] The industrial synthesis method of vinyl sulfate described in Example 1 differs from that described in the following aspects:

[0076] In step 4, the catalyst is a mixture of aluminum trichloride and silicon dioxide, with a mass ratio of aluminum trichloride to silicon dioxide of 4:1.

[0077] Comparative Example 1

[0078] The industrial synthesis method of vinyl sulfate described in Example 1 differs from that described in the following aspects:

[0079] In step 4, ruthenium trichloride is used to replace the mixture of aluminum trichloride and silicon dioxide.

[0080] Testing showed that the purity of the vinyl sulfate prepared in this comparative example was 98%-98.5%, and the yield of the synthesized vinyl sulfate was 80%-88% based on ethylene glycol.

[0081] By comparing with the present invention, it can be seen that using ruthenium trichloride as a catalyst significantly reduces the yield and generates a large amount of wastewater.

Claims

1. An industrial synthesis method for vinyl sulfate, comprising the following steps: 1) Adjust the pressure inside the reactor to a slightly negative pressure, and slowly add thionyl chloride and ethylene glycol into the reactor simultaneously to obtain crude vinyl sulfite; 2) The crude vinyl sulfite obtained in step 1) is subjected to vacuum distillation to remove hydrogen chloride; 3) After removing hydrogen chloride, the crude vinyl sulfite was adjusted to neutral pH with sodium carbonate solution, and the phases were separated to obtain pure vinyl sulfite. 4) Add pure vinyl sulfite, dichloroethane, and catalyst to a reaction vessel, and slowly add hydrogen peroxide solution dropwise to carry out the reaction. After the addition is complete, continue the reaction, filter out the catalyst, and perform phase separation. The lower organic phase is a dichloroethane solution of vinyl sulfite. The catalyst is a mixture of aluminum trichloride and silicon dioxide. 5) Crystallize the dichloroethane solution of vinyl sulfate obtained in step 4), and centrifuge to obtain crude vinyl sulfate; 6) Mix crude vinyl sulfate with dichloroethane, dissolve completely, add a dehydrating agent, dehydrate, filter out the dehydrating agent, and obtain a dichloroethane solution of vinyl sulfate. 7) Crystallize the dichloroethane solution of vinyl sulfate, centrifuge to obtain a moist pure vinyl sulfate, and dry it to obtain a pure vinyl sulfate.

2. The industrial synthesis method according to claim 1, characterized in that, In step 1), the pressure inside the reactor is -0.03 to -0.01 MPa, and the molar ratio of thionyl chloride to ethylene glycol is 1 to 1.1:

1.

3. The industrial synthesis method according to claim 1, characterized in that, In step 1), the reaction temperature is 10~30℃ and the dropping time is 3~5h.

4. The industrial synthesis method according to claim 1, characterized in that, In step 2), the reduced pressure distillation temperature is 25~50℃, and the pressure inside the vessel is -0.098~-0.08Mpa.

5. The industrial synthesis method according to claim 1, characterized in that, In step 3), the mass concentration of the sodium carbonate solution is 1% to 5%.

6. The industrial synthesis method according to claim 1, characterized in that, In step 4), the mass ratio of pure vinyl sulfite to dichloroethane is 1:4; the mass concentration of hydrogen peroxide solution is 27.5%; and the molar ratio of vinyl sulfite to hydrogen peroxide is 1:1.

26.

7. The industrial synthesis method according to claim 1, characterized in that, In step 4), the mass ratio of aluminum chloride to silicon dioxide in the mixture of aluminum chloride and silicon dioxide is (4-10):(2-6), and the mass ratio of catalyst to pure vinyl sulfite in step 4) is (0.02-0.2):

1.

8. The industrial synthesis method according to claim 1, characterized in that, In step 5), the crystallization temperature is -15~0℃ and the crystallization time is 3h.

9. The industrial synthesis method according to claim 1, characterized in that, In step 6), the mass ratio of crude vinyl sulfate to dichloroethane is 1:4, and the dehydrating agent is one or a combination of anhydrous magnesium sulfate, activated carbon, and sodium sulfate.

10. The industrial synthesis method according to claim 1, characterized in that, In step 7), the crystallization temperature is -15~0℃, the crystallization time is 3h, the drying pressure is -0.098~-0.09MPa, the drying temperature is 45~60℃, and the drying time is 3h.