A continuous purification method and rectification system of ethylene glycol monovinyl ether

Abstract

This invention relates to a continuous purification method and distillation system for ethylene glycol monovinyl ether, belonging to the field of fine chemical technology. The continuous purification method includes the following steps: Ethylene glycol monovinyl ether crude product is fed into a crude product column for distillation, with the crude ether product collected from the top of the column and the potassium alkoxide catalyst collected and recovered from the bottom; the crude ether product is fed into a light-boiling component removal column for distillation, with the light-boiling component collected from the top and the removed light-boiling component collected from the bottom; the removed light-boiling component is fed into a heavy-boiling component removal column for distillation, with the ethylene glycol monovinyl ether product collected from the top side stream and the heavy-boiling component containing ethylene glycol collected from the bottom; the heavy-boiling component containing ethylene glycol is fed into a alcohol removal column for distillation, with the ethylene glycol collected and recovered from the top. This invention solves the problems of existing purification methods, such as complex processes, the need to add extractants or neutralizing agents, low yields due to rearrangement side reactions during distillation, and the difficulty in achieving continuous production.

Description

Technical Field

[0001] This invention relates to the field of fine chemical technology, and in particular to a continuous purification method and distillation system for ethylene glycol monovinyl ether. Background Technology

[0002] Ethylene glycol monovinyl ether (EDGME) is an important fine chemical intermediate characterized by low viscosity, good dilution properties, low toxicity, low volatility, and no irritating odor. This compound can be used as a comonomer to prepare homopolymers and copolymers, and also as a reactive diluent for UV-cured coatings. More broadly, EEGME is a key precursor raw material for the synthesis of polyether monomers used in polycarboxylate superplasticizers. Superplasticizers prepared using EEGME as a monomer show low sensitivity to aggregates and exhibit significantly better performance in concrete than traditional polycarboxylate superplasticizers, demonstrating broad market prospects.

[0003] Industrially, ethylene glycol monovinyl ether is mainly produced by the reaction of acetylene and ethylene glycol in the presence of an alkaline catalyst (such as potassium alkoxide catalyst). However, in addition to the target product, this reaction system usually also produces byproducts such as ethylene glycol divinyl ether and 2-methyl-1,3-dioxolane, as well as unreacted ethylene glycol, catalyst, and a small amount of water. Therefore, efficient purification of crude ethylene glycol monovinyl ether is a key step in realizing its industrial application. The purification process faces the following technical difficulties: (1) The boiling points of ethylene glycol monovinyl ether and ethylene glycol divinyl ether are similar, especially under reduced pressure distillation conditions, the difference in boiling points is further reduced, and conventional distillation is difficult to achieve clear separation between the two; (2) Under reduced pressure heating conditions, ethylene glycol monovinyl ether is prone to intramolecular rearrangement to generate 2-methyl-1,3-dioxolane, resulting in a decrease in product yield; (3) Ethylene glycol divinyl ether and ethylene glycol monovinyl ether may form an azeotrope, further increasing the difficulty of separation.

[0004] To address the aforementioned separation challenges, various purification methods have been reported in previous studies. For example, Chinese invention patent CN112778102A discloses a method that first involves vacuum distillation to collect a mixed fraction of monovinyl ether and divinyl ether, then introducing this mixed fraction into a polyether reactor, adding a catalyst and ethylene oxide, and utilizing the reaction between the terminal hydroxyl groups of the monovinyl ether and ethylene oxide to increase the boiling point difference between the components. Finally, divinyl ether is separated by vacuum distillation again, thus obtaining a high-purity monovinyl ether product. This method involves the coupling of reaction and distillation, making the process relatively complex and increasing the difficulty of process development and industrial scale-up. Chinese invention patent CN118304671A discloses another separation process that uses potassium hydroxide or sodium hydroxide aqueous solution as an extractant to extract and separate the azeotrope of divinyl ether and monovinyl ether. Although it can obtain monovinyl ether and divinyl ether products separately, the entire process involves numerous pieces of equipment and cumbersome operating steps. US Patent 3657360 discloses a method for purifying 4-hydroxybutyl vinyl ether. This method requires the addition of a neutralizing agent such as potassium bicarbonate to the reaction mother liquor before distillation; otherwise, the product purity can only reach approximately 95%. Therefore, existing disclosed ethylene glycol monovinyl ether purification technologies generally suffer from drawbacks such as complex processes, the need for additional extractants or neutralizing agents, and difficulties in industrial scale-up due to their intermittent operation.

[0005] Therefore, there is an urgent need to develop a simple, additive-free, continuous method for purifying ethylene glycol monovinyl ether, along with a matching distillation system, that produces high-purity and high-yield products. Summary of the Invention

[0006] The purpose of this invention is to provide a continuous purification method and distillation system for ethylene glycol monovinyl ether, aiming to solve the technical problems of existing purification processes, such as complex processes, the need for external extractants or neutralizing agents, easy rearrangement of target products to generate by-products, difficulty in separating mono- and diethers, low product purity and yield, inability to efficiently recover catalysts and unreacted ethylene glycol, and difficulty in stable industrial continuous production.

[0007] This invention provides a continuous purification method for ethylene glycol monovinyl ether, employing the following technical solution: A continuous purification method for ethylene glycol monovinyl ether includes the following steps: 1) The crude ethylene glycol monovinyl ether obtained by reacting acetylene with ethylene glycol is sent to a crude product column for distillation. The crude ether is collected from the top of the crude product column, and the potassium alkoxide catalyst is collected from the bottom of the crude product column and recovered. 2) The crude ether obtained in step 1) is fed into a light-boiling component removal column for distillation. The light-boiling component is collected from the top of the light-boiling component removal column, and the light-boiling component is collected from the bottom of the light-boiling component removal column. 3) The light-removed material obtained in step 2) is fed into the heavy-removed column for distillation. Ethylene glycol monovinyl ether product is collected from the upper side stream of the heavy-removed column, and heavy component material containing ethylene glycol is collected from the bottom of the heavy-removed column. 4) The heavy component material containing ethylene glycol obtained in step 3) is fed into a deethanolating tower for distillation. Ethylene glycol is collected from the top of the deethanolating tower and recovered, and high-boiling residue is collected from the bottom of the deethanolating tower.

[0008] Preferably, in step 1), the top pressure of the crude product column is 0.02 MPa, and the reflux ratio is 1-3; The crude product tower is filled with CY-700 structured packing, with a packing height of 8-14m.

[0009] Preferably, in step 2), the pressure at the top of the light-light-removal tower is 0.01 MPa, and the reflux ratio is 2-8; The light-weight removal tower is filled with CY-700 structured packing, with a packing height of 10-15m.

[0010] Preferably, in step 3), the top pressure of the deweight removal tower is 0.01 MPa, and the reflux ratio is 1-4; The deweight removal tower is filled with CY-700 structured packing material, with a packing height of 15-20m.

[0011] Preferably, in step 4), the top pressure of the dealcoholization column is 0.01 MPa, and the reflux ratio is 1-5; The deethanolating tower is filled with CY-700 structured packing, with a packing height of 10-20m.

[0012] Preferably, in step 1), the feed flow rate of the crude product tower is 4.03 m³ / h. 3 / h; In step 2), the feed flow rate of the light-weight removal tower is 1.33 m³ / h. 3 / h; In step 3), the feed flow rate of the deweight removal tower is 1.20 m³ / s. 3 / h.

[0013] Preferably, in step 4), the recovered ethylene glycol is recycled back to the reaction system or returned to the crude ether transfer tank.

[0014] On the other hand, the present invention also provides a continuous purification and distillation system for realizing the above-mentioned continuous purification method of ethylene glycol monovinyl ether, which adopts the following technical solution: A continuous purification and distillation system for ethylene glycol monovinyl ether includes: Crude tower; Ether crude product transfer tank connected to the top of the crude product tower; A light-removal tower connected to the crude ether transfer tank; The heavy removal tower is connected to the reboiler of the light removal tower; The feed tank for the alcohol removal tower is connected to the bottom of the heavy removal tower; The dealcoholization tower is connected to the feed tank of the dealcoholization tower; The crude product column is connected to a potassium alkoxide catalyst transfer tank at its bottom; the upper side of the heavy product removal column is connected to an ethylene glycol monoethylene ether product transfer tank; the top of the alcohol removal column is connected to a recovery alcohol transfer tank, which is connected to the crude ether transfer tank.

[0015] Preferably, the crude product tower, light product removal tower, heavy product removal tower, and alcohol removal tower are any one of packed towers or plate towers. The packing material in the packed tower is CY-700 structured packing.

[0016] Preferably, the top of the light boiling component removal tower is connected to a light boiling component discharge pipeline; The bottom of the dealcoholization tower is connected to a high-boiling tank.

[0017] In summary, the present invention has the following beneficial technical effects: 1. This application adopts a distillation system consisting of four columns connected in series: a crude product column, a light component removal column, a heavy component removal column, and a alcohol removal column. This system can achieve efficient separation of light components, products, heavy components, and unreacted raw materials from crude ethylene glycol monovinyl ether. No extractant or neutralizing agent needs to be added during the entire process, avoiding the introduction of additional substances and the burden of subsequent separation. The process is simple and easy to operate.

[0018] 2. This application sets up a crude product column at the very beginning of the distillation process to first separate and recover the potassium alkoxide catalyst in the crude product, thus avoiding the catalyst from entering the subsequent high-temperature distillation column. This setting eliminates the conditions for intramolecular rearrangement of ethylene glycol monovinyl ether to form 2-methyl-1,3-dioxolane under heating conditions, significantly inhibiting the occurrence of side reactions and thereby improving the yield of the target product.

[0019] 3. This application incorporates a side-stream outlet at the top of the de-weighting tower to precisely extract ethylene glycol monovinyl ether (EDE) product. Example data shows that the EDE product obtained using the method of this invention achieves a purity of 99.63-99.76%, effectively solving the technical challenge of clearly separating EDE and EDE divinyl ether, which have similar boiling points.

[0020] 4. In the purification method of this application, each distillation column adopts a continuous feeding and continuous discharging operation mode, and the entire purification process is a continuous production. Compared with the existing technologies that have some intermittent operation or require step-by-step processing, it has significant advantages such as large processing capacity, good operational stability, and easy industrial scale-up.

[0021] 5. This application recovers the potassium alkoxide catalyst via a crude product tower, which, after appropriate treatment, can be returned to the reaction system for recycling; unreacted ethylene glycol is recovered via a dealcoholization tower and returned to the crude ether transfer tank or the reaction system for reuse. This dual recovery of catalyst and raw materials significantly reduces production costs and waste emissions, aligning with the principles of green chemistry and atom economy. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a continuous purification and distillation system for ethylene glycol monovinyl ether in an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached diagram: 1. Crude product feed line; 2. Crude product tower; 3. Potassium alkoxide catalyst transfer tank; 4. Ether crude product transfer tank; 5. Light product removal tower; 6. Light boiling component discharge pipeline; 7. Heavy product removal tower; 8. Ethylene glycol monoethylene ether finished product transfer tank; 9. De-alcoholization tower feed tank; 10. De-alcoholization tower; 11. Recovered alcohol transfer tank; 12. High boiling tank. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example Example 1 The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings.

[0026] Reference Figure 1A continuous purification and distillation system for ethylene glycol monovinyl ether includes: a crude product column 2, an ether crude product transfer tank 4 connected to the top of the crude product column 2, a light-boiling component removal column 5 connected to the ether crude product transfer tank 4, a heavy-weight component removal column 7 connected to the bottom of the light-weight component removal column 5, a alcohol removal column feed tank 9 connected to the bottom of the heavy-weight component removal column 7, and an alcohol removal column 10 connected to the alcohol removal column feed tank 9. The bottom of the crude product column 2 is connected to a potassium alkoxide catalyst transfer tank 3; the upper side line of the heavy-weight component removal column 7 is connected to an ethylene glycol monovinyl ether product transfer tank 8; the top of the alcohol removal column 10 is connected to a recovery alcohol transfer tank 11, and the bottom of the alcohol removal column 10 is connected to a high-boiling tank 12; the top of the light-boiling component removal column 5 is connected to a light-boiling component discharge line 6; the recovery alcohol transfer tank 11 is connected to the ether crude product transfer tank 4. Among them, the crude product tower 2, light product removal tower 5, heavy product removal tower 7, and alcohol removal tower 10 are all packed towers. In this embodiment, the total height of the crude product tower 2, light product removal tower 5, heavy product removal tower 7, and alcohol removal tower 10 is 34m, with a 2m allowance at the top, a 3.5m allowance at the bottom, a 6m skirt, and a 1.5m allowance for the distributor between each packing section. The towers are all filled with CY-700 structured packing, which has a relatively large porosity and higher efficiency. The packing height of the crude product tower 2 is 12m, the packing height of the light product removal tower 5 is 13.5m, the packing height of the heavy product removal tower 7 is 18m, and the packing height of the alcohol removal tower 10 is 15m.

[0027] The continuous purification method for ethylene glycol monovinyl ether specifically includes the following steps: S1. Add appropriate amounts of corresponding residual liquid to crude product tower 2, light product stripping tower 5, heavy product stripping tower 7, and alcohol stripping tower 10 (in this embodiment, "corresponding residual liquid" refers to a liquid with a composition similar to the bottom material of the tower during normal operation; for crude product tower 2, it is ethylene glycol residual liquid containing catalyst; for light product stripping tower 5, heavy product stripping tower 7, and alcohol stripping tower 10, it is mainly ethylene glycol monovinyl ether or ethylene glycol). Start the reboiler and condenser of crude product tower 2, light product stripping tower 5, heavy product stripping tower 7, and alcohol stripping tower 10, and adjust the top pressure of crude product tower 2, light product stripping tower 5, heavy product stripping tower 7, and alcohol stripping tower 10. The pressure at the top of crude product tower 2 is 0.02 MPa (too low a pressure will result in a low temperature at the top of crude product tower 2, too small a temperature difference in the circulating water heat exchange, and increased energy consumption; too high a pressure will increase side reactions and cause a decrease in yield); the pressure at the top of light product removal tower 5, heavy product removal tower 7, and alcohol removal tower 10 is 0.01 MPa; after the liquids in crude product tower 2, light product removal tower 5, heavy product removal tower 7, and alcohol removal tower 10 boil, total reflux operation is performed for 30 minutes to establish a stable gas-liquid equilibrium state in crude product tower 2, light product removal tower 5, heavy product removal tower 7, and alcohol removal tower 10, ensuring the stability of the separation effect during subsequent continuous feeding; S2. The crude ethylene glycol monovinyl ether product obtained from the reaction of ethylene glycol and acetylene is pumped into crude product tower 2 through crude product feed line 1 at a flow rate of 4.03 m³ / h. 3 / h; The reflux ratio of crude product column 2 is set to 2. The top product (crude ether) of crude product column 2 enters the crude ether transfer tank 4, and the bottom product (residual liquid containing potassium alkoxide catalyst) of crude product column 2 enters the potassium alkoxide catalyst transfer tank 3. The recovered catalyst, after adding an appropriate amount of ethylene glycol and reacting for activation, can be pumped back to the reaction system for recycling. S3. Pump the material in crude ether transfer tank 4 into light product removal tower 5 at a feed flow rate of 1.33 m³ / h. 3 The reflux ratio of the light component removal tower 5 is set to 6 / h. The top discharge from the light component removal tower 5 is led out through the light boiling component discharge pipeline 6. This light boiling component is mainly a mixture of 2-methyl-1,3-dioxolane and ethylene glycol divinyl ether, and is transported off-site in drums. The bottom discharge (removed light component material) from the light component removal tower 5 is pumped into the heavy component removal tower 7 at a feed flow rate of 1.20 m³ / h. 3 / h; S4. The reflux ratio of the heavy component removal tower 7 is set to 2. The material from the upper side stream of the heavy component removal tower 7 enters the ethylene glycol monoethylene ether finished product transfer tank 8, which is the obtained ethylene glycol monoethylene ether product. The material from the bottom of the heavy component removal tower 7 (containing heavy components of ethylene glycol) is pumped into the feed tank 9 of the alcohol removal tower. S5. Pump the material in the feed tank 9 of the dealcoholization tower into the dealcoholization tower 10. The reflux ratio of the dealcoholization tower 10 is set to 5. The top discharge of the dealcoholization tower 10 (recovered ethylene glycol) is pumped into the recovery alcohol transfer tank 11, and further pumped into the crude ether transfer tank 4 to realize the recycling of unreacted ethylene glycol. The bottom discharge of the dealcoholization tower 10 (high boiling residual liquid) is pumped into the high boiling tank 12, and then barrelled and transported for disposal.

[0028] Based on the sampling analysis, the component composition at each sampling location is shown in Table 1.

[0029] Table 1. Component composition at each sampling location

[0030] As can be seen from Table 1, the purity of the ethylene glycol monoethylene ether product obtained in Example 1 is 99.76%.

[0031] Example 2 This embodiment is basically the same as Embodiment 1, except for the adjustment of operating parameters. Specifically, in Embodiment 2, the reflux ratio of the crude product tower 2 is set to 1, the reflux ratio of the light product removal tower 5 is set to 2, and the remaining parameters and operating steps are the same as in Embodiment 1.

[0032] Based on the sampling analysis, the component composition at each sampling location is shown in Table 2.

[0033] Table 2 Component composition at each sampling location

[0034] As can be seen from Table 2, the purity of the ethylene glycol monoethylene ether product obtained in Example 2 is 99.67%.

[0035] Example 3 This embodiment is basically the same as Embodiment 1, except for the adjustment of operating parameters. Specifically, in Embodiment 3, the reflux ratio of the crude product tower 2 is set to 3, the reflux ratio of the light product removal tower 5 is set to 8, and the remaining parameters and operating steps are the same as in Embodiment 1.

[0036] Based on the sampling analysis, the component composition at each sampling location is shown in Table 3.

[0037] Table 3 Component composition at each sampling location

[0038] As can be seen from Table 3, the purity of the ethylene glycol monoethylene ether product obtained in Example 3 is 99.63%.

[0039] Example 4 This embodiment is basically the same as Embodiment 1, except for the adjustment of operating parameters. Specifically, in Embodiment 4, the reflux ratio of the heavy removal tower 7 is set to 1, the reflux ratio of the alcohol removal tower 10 is set to 1, and the remaining parameters and operating steps are the same as in Embodiment 1.

[0040] Based on the sampling analysis, the component composition at each sampling location is shown in Table 4.

[0041] Table 4. Component composition at each sampling location

[0042] As can be seen from Table 4, the purity of the ethylene glycol monoethylene ether product obtained in Example 4 is 99.65%.

[0043] Example 5 This embodiment is basically the same as Embodiment 1, except for the adjustment of operating parameters. Specifically, in Embodiment 5, the reflux ratio of the de-weighting tower 7 is set to 4, and the remaining parameters and operating steps are the same as in Embodiment 1.

[0044] Based on the sampling analysis, the component composition at each sampling location is shown in Table 5.

[0045] Table 5. Component composition at each sampling location

[0046] As can be seen from Table 4, the purity of the ethylene glycol monoethylene ether product obtained in Example 4 is 99.66%.

[0047] Example 6 This embodiment is basically the same as Embodiment 1, except that in Embodiment 6, the finished product outlet of the heavy removal tower 7 is not at the upper side of the heavy removal tower, but at the top of the tower, and the reflux ratio is adjusted to 1.5:1. Under this separation process, in order to ensure that the product content is qualified, the process parameters of the bottom temperature of the light removal tower need to be adjusted to control the pentane ring impurities in the bottom material of the light removal tower below 0.05%. The remaining parameters and operating steps are the same as in Embodiment 1.

[0048] Based on the sampling analysis, the component composition at each sampling location is shown in Table 6.

[0049] Table 6. Component composition at each sampling location

[0050] Comparative Example Comparative Example 1 Comparative Example 1 is used to illustrate the indispensability of the step of "setting up a crude product column at the front end of the distillation process to separate the catalyst" in this invention.

[0051] The same distillation system as in Example 1 was used, but the operating procedure was changed: the crude ethylene glycol monovinyl ether product obtained by reacting ethylene glycol and acetylene was directly pumped into the light product removal tower without being processed by the crude product tower (i.e., skipping the catalyst separation step in step (2)). The subsequent operation was the same as in Example 1. All other operating parameters (feed flow rate, tower pressure, reflux ratio, packing, etc.) were kept the same as in Example 1.

[0052] Sampling analysis revealed that the purity of the product from the side stream of the deweighting tower was 99.24%, with the content of 2-methyl-1,3-dioxolane (pentane) significantly increasing to 0.38%. Meanwhile, the overall yield of ethylene glycol monovinyl ether was calculated to be approximately 4.6% lower than in Example 1.

[0053] The results of Comparative Example 1 show that if the potassium alkoxide catalyst is not removed at the front end of the distillation process, the load on the light alkoxide removal column increases significantly, and the required number of trays also increases, ultimately leading to an increase in the overall column pressure drop, a rise in the reboiler temperature, and an acceleration of the isomerization reaction of 2-methyl-1,3-dioxolane. The catalyst further enters the heavy alkoxide removal column, which also experiences an increase in load and a significant rise in reboiler temperature. Under steam heating conditions, some products ultimately fail to separate from the high-boiling point, resulting in a decrease in yield. Therefore, without a crude product column, product purity decreases, impurity content increases, and product yield decreases. This fully demonstrates the substantial contribution of the present invention's "catalyst pre-separation" technical feature.

[0054] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A continuous purification method for ethylene glycol monovinyl ether, characterized in that, Includes the following steps: 1) The crude ethylene glycol monovinyl ether obtained by reacting acetylene with ethylene glycol is sent to the crude product column (2) for distillation. The crude ether is collected from the top of the crude product column (2), and the potassium alkoxide catalyst is collected and recovered from the bottom of the crude product column (2). 2) The crude ether obtained in step 1) is fed into the light-boiling component removal tower (5) for distillation. The light-boiling component is collected from the top of the light-boiling component removal tower (5), and the light-boiling component is collected from the bottom of the light-boiling component removal tower (5). 3) The light-removed material obtained in step 2) is fed into the heavy-removed tower (7) for distillation. Ethylene glycol monovinyl ether product is collected from the upper side stream of the heavy-removed tower (7), and heavy component material containing ethylene glycol is collected from the bottom of the heavy-removed tower (7). 4) The heavy component material containing ethylene glycol obtained in step 3) is fed into the deethanolating tower (10) for distillation. Ethylene glycol is collected from the top of the deethanolating tower (10) and recovered. High-boiling residual liquid is collected from the bottom of the deethanolating tower (10).

2. The continuous purification method for ethylene glycol monovinyl ether according to claim 1, characterized in that, In step 1), the top pressure of the crude product column (2) is 0.02 MPa, and the reflux ratio is 1-3; The crude product tower (2) is filled with CY-700 structured packing, and the packing height is 8-14m.

3. The continuous purification method for ethylene glycol monovinyl ether according to claim 1, characterized in that, In step 2), the pressure at the top of the light-light tower (5) is 0.01 MPa, and the reflux ratio is 2-8; The light-removal tower (5) is filled with CY-700 structured packing, and the packing height is 10-15m.

4. The continuous purification method for ethylene glycol monovinyl ether according to claim 1, characterized in that, In step 3), the pressure at the top of the deweight removal tower (7) is 0.01 MPa, and the reflux ratio is 1-4; The deweight removal tower (7) is filled with CY-700 structured packing, and the packing height is 15-20m.

5. The continuous purification method for ethylene glycol monovinyl ether according to claim 1, characterized in that, In step 4), the top pressure of the dealcoholization tower (10) is 0.01 MPa, and the reflux ratio is 1-5; The dealcoholization tower (10) is filled with CY-700 structured packing, and the packing height is 10-20m.

6. The continuous purification method for ethylene glycol monovinyl ether according to claim 1, characterized in that, In step 1), the feed flow rate of the crude product tower (2) is 4.03 m³ / s. 3 / h; In step 2), the feed flow rate of the light-weight removal tower (5) is 1.33 m³ / s. 3 / h; In step 3), the feed flow rate of the deweight removal tower (7) is 1.20 m³ / s. 3 / h.

7. The continuous purification method for ethylene glycol monovinyl ether according to claim 1, characterized in that, In step 4), the recovered ethylene glycol is recycled back to the reaction system or returned to the crude ether transfer tank (4).

8. A continuous purification and distillation system for ethylene glycol monovinyl ethers for implementing the continuous purification method as described in any one of claims 1-7, characterized in that, include: Crude tower (2); Ether crude product transfer tank (4) connected to the top of the crude product tower (2); Light removal tower (5) connected to the crude ether transfer tank (4); The heavy removal tower (7) is connected to the bottom of the light removal tower (5); The feed tank (9) of the alcohol removal tower is connected to the bottom of the heavy removal tower (7); A dealcoholization tower (10) connected to the dealcoholization tower feed tank (9); The bottom of the crude product tower (2) is connected to a potassium alkoxide catalyst transfer tank (3); the upper side of the de-heavy product tower (7) is connected to an ethylene glycol monoethylene ether product transfer tank (8); the top of the de-alcoholizing tower (10) is connected to a recovery alcohol transfer tank (11), which is connected to the crude ether transfer tank (4).

9. The continuous purification and distillation system for ethylene glycol monovinyl ether according to claim 8, characterized in that, The crude product tower (2), light product removal tower (5), heavy product removal tower (7), and alcohol removal tower (10) are either packed towers or plate towers. The packing material in the packed tower is CY-700 structured packing.

10. The continuous purification and distillation system for ethylene glycol monovinyl ether according to claim 8, characterized in that, The top of the light boiling component discharge pipeline (6) is connected to the light boiling component. The bottom of the dealcoholization tower (10) is connected to a high-boiling tank (12).

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