Continuous and efficient synthesis method of glycol ketal or acetal and reaction device thereof

Abstract

The invention relates to a continuous and efficient synthesis method of glycol ketal or acetal and a reaction device thereof, and relates to the field of fine chemical production, the continuous and efficient synthesis method of glycol ketal or acetal comprises the following steps: preheating and uniformly mixing raw materials including glycol, ketone or aldehyde; feeding the raw materials into a condensation tower filled with a catalyst for condensation reaction to obtain a product, and enabling the product to flow out of the condensation tower in a liquid form; the product is subjected to oil-water separation, an oil phase and a water phase are formed, the oil phase comprises glycol ketal or acetal, and the water phase comprises water and dihydric alcohol; rectifying and separating the water phase to obtain dihydric alcohol and water, feeding the dihydric alcohol into the condensation tower again, and discharging the water out of the system. According to the method, the ketal or the acetal can be fully subjected to condensation reaction on the premise that an entrainer is not introduced, and the method is continuous in process, low in investment and high in industrial value.

Description

Technical Field

[0001] The present application relates to the field of fine chemical production, and in particular to a continuous and efficient synthesis method of diol ketal or acetal and a reaction device thereof. Background Art

[0002] A series of hydroxy ethers can be generated from glycol ketal or acetal through catalytic hydrogenation. Especially for ketones and aldehydes with high carbon chain branching degree, the corresponding hydroxy ethers can be generated after condensation with glycol and then hydrogenolysis, thus avoiding the use of hazardous raw materials such as ethylene oxide, propylene oxide and butylene oxide. At the same time, it also simplifies the subsequent processing technology of polyether.

[0003] In the related art, the commonly used synthesis methods of ketal and acetal usually use an azeotropic agent to carry water to promote the complete reaction. This method requires the introduction of an additional azeotropic agent, which increases the types of impurities to be separated, and when diols are used as one of the raw materials, it is difficult to carry out the reaction completely by carrying water due to the strong water absorption of diols.

[0004] In view of this, there is an urgent need for a continuous and efficient device for producing diol ketal or acetal, which can promote the condensation reaction of diol ketal or acetal without introducing an azeotropic agent. Summary of the invention

[0005] The present application provides a continuous and efficient synthesis method of diol ketal or acetal and a reaction device thereof, which can promote the diol ketal or acetal to fully undergo condensation reaction without introducing an azeotropic agent, and has a continuous process, low investment, and great industrial value.

[0006] In the first aspect, the present application provides a continuous and efficient synthesis method of diol ketal or acetal using the following technical scheme:

[0007] A continuous and efficient synthesis method of diol ketal or acetal comprises the following steps:

[0008] Preheating and mixing raw materials, wherein the raw materials include diols, ketones or aldehydes;

[0009] The raw materials are fed into a condensation tower filled with a catalyst for condensation reaction to obtain a product, which flows out of the condensation tower in liquid form;

[0010] Separating the product into oil and water to form an oil phase and a water phase, wherein the oil phase comprises diol ketal or acetal, and the water phase comprises water and diol;

[0011] The water phase is separated by distillation to obtain glycol and water. The glycol is fed back into the condensation tower and the water is discharged from the system.

[0012] Furthermore, the molar ratio of the ketone or aldehyde to the diol is set to 1:1.5-3.

[0013] Furthermore, the raw material includes a diol and a ketone, and the ketone is set to be at least one of C10 to C18 ketones, or

[0014] The raw materials include diols and aldehydes, and the aldehyde is set to be at least one of C10-C18 aldehydes.

[0015] Furthermore, the diol is set as an ortho- or meta-diol, and the diol includes at least any one of 1,2-ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,2-butylene glycol, 2,3-butylene glycol, and 1,3-butylene glycol.

[0016] Further, the distillation separation of the water phase to obtain glycol and water comprises:

[0017] The aqueous phase is sent to a distillation tower for distillation to obtain a first separated product and water;

[0018] The first separated product is partially withdrawn and partially refluxed into the distillation tower, and the reflux and withdrawal ratio of the first separated product is set to 1-2:1.

[0019] Furthermore, the distillation separation of the water phase is carried out in a vacuum environment, and the vacuum degree is set to -0.09 to -0.08.

[0020] Furthermore, the first isolate comprises diol, and the diol accounts for at least 99.9% of the first isolate.

[0021] Furthermore, the oil phase is split, part of the oil phase is refluxed into the condensation tower, and part of the oil phase is produced as a product, and the reflux and production ratio of the oil phase is set to 1:1-10.

[0022] Furthermore, the catalyst is at least configured to be any one of A-15 resin or 732 resin.

[0023] A continuous and efficient reaction device for diol ketal or acetal, used to realize the above-mentioned synthesis method, the reaction device comprises a condensation tower, an oil-water separator and a distillation tower arranged in sequence. In summary, the present application includes at least one of the following beneficial technical effects:

[0024] 1. In the present application, the product obtained by the condensation reaction is separated into oil and water to obtain a diol ketal or acetal (i.e., oil phase) and a mixture of diol and water (i.e., water phase), and the water phase is output to a distillation tower. The diol separated after distillation to remove water can be used as a raw material and then re-introduced into the condensation tower for condensation reaction with ketone or aldehyde. The process has the characteristics of continuous process, low investment, and no need to carry water through an azeotropic agent to promote the diol ketal or acetal reaction, and has great industrial value.

[0025] 2. In the present application, the raw materials are fully preheated and mixed before the condensation reaction, and the content of the diol fed into the reaction is set to be greater than that of the ketone or aldehyde, so that the ketone or aldehyde can be fully converted into diol ketal or acetal in a single pass, so as to promote the condensation reaction to be carried out efficiently and further ensure the purity of the obtained diol ketal or acetal.

[0026] 3. In the present application, before the water phase is distilled and separated, the water phase is preheated to make the water phase have a higher initial temperature. The distillation and separation of the water phase is carried out under a vacuum environment, thereby making the distillation and separation more stable and efficient. When the water phase is distilled, most of the first separated product is refluxed into the distillation tower, and the water in the first separated product is continuously removed. The purity of the obtained diol (i.e., the first separated product) is greater than 99.9%. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of a continuous and efficient reaction device for diol ketal or acetal in the present application.

[0028] In the figure, 1. condensation tower; 2. oil-water separator; 21. first discharge port; 22. fourth discharge port; 23. fifth discharge port; 3. distillation tower; 31. second discharge port; 32. third discharge port; 4. cooling recovery structure; 41. heat exchanger; 42. transfer tank; 5. vacuum system; 6. pretreatment structure; 61. mixer; 62. feed pipeline; 7. first heater; 8. second heater. DETAILED DESCRIPTION

[0029] The following will be combined with the attached Figure 1 The technical solution of the present application is described clearly and completely. The following embodiments are exemplary and are only used to explain the present application, and cannot be interpreted as limiting the present application. In the following description, the same symbols are used to represent the same or equivalent elements, and repeated descriptions are omitted.

[0030] In the description of the present application, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the products of the present application are conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0031] In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] It should be further understood that the term “and / or” used in the specification and corresponding claims of this application refers to any and all possible combinations of one or more of the listed items.

[0033] A continuous and efficient synthesis method of diol ketal or acetal comprises the following steps:

[0034] Preheat and mix the raw materials evenly;

[0035] The raw materials are fed into a condensation tower 1 filled with a catalyst for condensation reaction to obtain a product, and the product flows out of the condensation tower 1 in liquid form;

[0036] When preheating the raw materials, the raw materials are preheated to 100-150° C., so that the raw materials have a relatively high temperature before being sent to the condensation tower 1, ensuring that the raw materials can fully and efficiently undergo condensation reaction to obtain products.

[0037] In a specific embodiment, the raw materials can be heated to 100°C. In another specific embodiment, the raw materials can also be heated to 150°C. In other specific embodiments, the order of preheating and mixing can also be adaptively adjusted, that is, mixing can be performed first, then preheating, or mixing and preheating can be performed at the same time to ensure that the raw materials can fully undergo condensation reaction.

[0038] Furthermore, the raw materials include diols, ketones or aldehydes, wherein the ketones or aldehydes are both configured as long carbon chain structures with or without branches.

[0039] The molar ratio of ketone or aldehyde to diol is set to 1:1.5-3 to ensure that the content of diol is slightly higher than that of ketone or aldehyde, so that ketone or aldehyde can be fully converted into diol ketal or acetal in a single pass, and the obtained product mainly includes diol ketal or acetal, water, and remaining diol.

[0040] In a specific embodiment, the molar ratio of ketone or aldehyde to diol is set to 1:1.5. In another specific embodiment, the content of diol can be further increased to set the molar ratio of ketone or aldehyde to diol to 1:2 or 1:3.

[0041] Furthermore, the catalyst can be specifically set according to actual conditions, and it is at least set to any one of A-15 resin or 732 resin. In a specific embodiment, the catalyst is set to A-15 resin, and in another specific embodiment, the catalyst is set to 732 resin, and both catalysts can promote the condensation reaction.

[0042] Furthermore, in a specific embodiment, the raw materials are set to ketones and diols, wherein the ketone is set to a long carbon chain structure (which may or may not contain branches), specifically set to at least one of C10 to C18 ketones, and the ketone and the diol undergo a condensation reaction with the assistance of a catalyst to obtain ketal and water.

[0043] In another specific embodiment, the raw materials are set to aldehyde and diol, wherein the aldehyde is set to a long carbon chain structure (which may or may not contain branches), specifically set to at least one of C10 to C18 aldehydes, and the aldehyde and the diol undergo a condensation reaction with the assistance of a catalyst to obtain acetal and water.

[0044] Among them, the diol is set to an ortho- or meta-diol, and the diol includes at least any one of 1,2-ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,2-butylene glycol, 2,3-butylene glycol, and 1,3-butylene glycol. In a specific embodiment, the diol is set to 1,2-propylene glycol or ethylene glycol.

[0045] Separating the product into oil and water to form an oil phase and an aqueous phase, wherein the oil phase comprises diol ketal or acetal, and the aqueous phase comprises water and diol;

[0046] The oil phase is split, part of the oil phase is refluxed into the condensation tower 1, and part of the oil phase is extracted as a product. The reflux and extraction ratio of the oil phase is set to 1:1-10. By refluxing part of the oil phase, the purity of the product is ensured. In a specific embodiment, the reflux and extraction ratio of the oil phase can be set to 1:1-3, specifically 1:3.

[0047] Furthermore, before the water phase is introduced into the next unit for distillation, the water phase is preheated. The preheating allows the water phase to have a higher initial temperature so that the distillation separation of the water phase is faster.

[0048] Further, the water phase is separated by distillation to obtain glycol and water, the glycol is fed back into the condensation tower 1, and the water is discharged from the system.

[0049] The distillation separation of the water phase is carried out in the distillation tower 3. Specifically, the distillation tower 3 includes a distillation section and a stripping section. The distillation section is provided with 8 to 10 plates, and the stripping section is provided with 3 to 5 plates. After the sequential action of the distillation section and the stripping section, the lighter component (water) exits the distillation tower 3 in the form of steam, while the heavier component (glycol) is collected at the bottom of the distillation tower 3.

[0050] The distillation separation of the aqueous phase to obtain glycol and water comprises the following steps:

[0051] The water phase is sent to a distillation tower 3 for distillation to obtain a first separated product and water;

[0052] Part of the first separated product is produced, and part of it is refluxed into the distillation tower 3, and the reflux and production ratio of the first separated product is set to 1-2:1.

[0053] In a specific embodiment, the reflux and withdrawal ratio of the first separation is set to 1:1. In another specific embodiment, the proportion of the first separation refluxed to the distillation tower 3 can be further increased, so that the reflux and withdrawal ratio of the first separation is set to 2:1. The first separation mainly includes glycols and water. By continuously removing water from the first separation, the proportion of glycols in the first separation is continuously increased.

[0054] According to the test, the purity of the diol obtained after the distillation separation in the distillation tower 3 is greater than 99.9% (ie, the first separated product), and can be re-added to the condensation tower 1 as a raw material to undergo condensation reaction with alcohol or aldehyde.

[0055] It should be noted that during the distillation process, the diol in the distillation tower 3 has reached a relatively high temperature, and the recovered diol does not need to be preheated, but can be directly mixed with the preheated ketone or alcohol and then sent to the condensation tower 1. The recovered diol can also be preheated again to compensate for the heat loss during the process of being sent to the condensation tower 1.

[0056] In addition, during the distillation separation of the water phase, the water vapor is condensed by the heat exchanger 41 and stored in the form of liquid water to facilitate further processing and discharge.

[0057] Furthermore, distillation separation of water phase and condensation of water vapor are carried out in a vacuum environment, wherein the vacuum degree is set to -0.09 to -0.08 to ensure that the distillation process can be carried out more stably and efficiently. In a specific embodiment, the vacuum degree is set to -0.09.

[0058] The raw materials are preheated and fully mixed before being sent to the condensation tower 1. The liquid product formed after the condensation reaction is further sent to the oil-water separator 2. After the action of the oil-water separator 2, an oil phase (located at the upper layer) and a water phase (located at the lower layer) are formed. Part of the produced oil phase is produced as a product, and the water phase is preheated and sent to the distillation tower 3 for distillation to complete the dehydration of the diol. The water flows out of the distillation tower 3 in the form of steam and is collected in the form of liquid water after heat exchange. The dehydrated diol is used as a raw material and is re-added to the condensation tower 1 to undergo a condensation reaction with the alcohol or ketone.

[0059] The whole process does not require the addition of an azeotropic agent (i.e., a water-carrying agent), does not introduce impurities from other materials, has a high conversion rate of diol ketal or acetal, has a simple process, and is applied to the reaction of diol ketal or acetal, and has good industrial value.

[0060] The specific details of the continuous and efficient synthesis method of diol ketal or acetal disclosed in the present invention are described in detail below through specific examples.

[0061] Embodiment 1:

[0062] A continuous and efficient synthesis method of diol ketal comprises the following steps:

[0063] Preheating the raw materials to 120° C. and mixing them to obtain a mixture, wherein the raw materials include 2-tetradecanone and 1,2-propylene glycol, and the molar ratio of 2-tetradecanone to 1,2-propylene glycol is set to 1:3;

[0064] The mixture is sent to a condensation tower 1 filled with A-15 cation exchange resin for condensation reaction to obtain a product. After testing, the proportion of diol ketal in the product is 97.5%;

[0065] The product flows out of the condensation tower 1 in liquid form and enters the oil-water separator 2 to form an upper oil phase and a lower water phase, wherein the oil phase includes diol ketal and the water phase includes water-containing 1,2-propylene glycol;

[0066] Part of the diol ketal is refluxed into the condensation tower 1, and part is withdrawn as a product, and the reflux and withdrawal ratio of the diol ketal is set to 1:1;

[0067] The water-containing 1,2-propylene glycol is sent to the distillation tower 3 for distillation separation, wherein the distillation section of the distillation tower 3 is provided with 8 plates, the stripping section of the distillation tower 3 is provided with 3 plates, and the top reflux ratio of the distillation tower 3 is set to 1:1. After separation, the first separated product and water vapor are obtained, and the water vapor is condensed and sent to the transfer tank 42 in the form of liquid water. The vacuum degree in the distillation tower 3 and the transfer tank 42 is set to -0.09 MPa;

[0068] After testing, the first separated product includes 1,2-propylene glycol and water, the content of 1,2-propylene glycol is 99.9%, and the water content is less than 0.03%. The obtained first separated product enters into the condensation tower 1 for condensation reaction.

[0069] Embodiment 2:

[0070] A continuous and efficient synthesis method of diol acetal is the same as that of Example 1, except that the raw materials include 3-methyl-2-decanone and 1,3-propylene glycol.

[0071] Embodiment 3:

[0072] A continuous and efficient synthesis method of diol ketal is the same as Example 1, except that the raw materials include 6-ethyl-3-undecanone and ethylene glycol.

[0073] Embodiment 4:

[0074] A continuous and efficient synthesis method of diol acetal comprises the following steps:

[0075] Preheating the raw materials to 130° C. and mixing them to obtain a mixture, wherein the raw materials include 2-methylundecane and ethylene glycol, and the molar ratio of 2-methylundecane to ethylene glycol is set to 1:2;

[0076] The mixture is sent to a condensation tower 1 filled with 732 cation exchange resin for condensation reaction to obtain a product. After testing, the proportion of diol acetal in the product is 96%;

[0077] The product flows out of the condensation tower 1 in liquid form and enters the oil-water separator 2 to form an upper oil phase and a lower water phase, wherein the oil phase includes diol acetal and the water phase includes water-containing ethylene glycol;

[0078] Part of the diol acetal is refluxed into the condensation tower 1, and part is taken out as a product, and the reflux and take-out ratio of the diol acetal is set to 1:3;

[0079] The water-containing ethylene glycol is sent to the distillation tower 3 for distillation separation, wherein the distillation section of the distillation tower 3 is set to 10 plates, the stripping section of the distillation tower 3 is set to 5 plates, and the top reflux ratio of the distillation tower 3 is set to 2:1. After separation, the first separated product and water vapor are obtained. After the water vapor is condensed, it is sent to the transfer tank 42 in the form of liquid water. The vacuum degree in the distillation tower 3 and the transfer tank 42 is set to -0.08 MPa;

[0080] After testing, the first separated product includes ethylene glycol and water, the content of ethylene glycol is 99.9%, and the water content is less than 0.05%. The obtained first separated product enters the condensation tower 1 for condensation reaction.

[0081] Embodiment 5:

[0082] A continuous and efficient synthesis method of diol acetal is the same as Example 4, except that the raw materials include 6-methylhexadecanal and ethylene glycol.

[0083] Embodiment 6:

[0084] A continuous and efficient synthesis method of diol acetal is the same as Example 4, except that the raw materials include 2-methyldodecanal and 2,3-butanediol.

[0085] Secondly, the present application also discloses a continuous and efficient reaction device for diol ketal or acetal, comprising a condensation tower 1, an oil-water separator 2 and a distillation tower 3. The condensation tower 1 is filled with a catalyst. During production, raw materials are put into the condensation tower 1 to carry out a condensation reaction to obtain a product.

[0086] Before the raw materials enter the condensation tower 1, they are pretreated. Correspondingly, a pretreatment structure 6 is provided at the input end of the condensation tower 1. The pretreatment structure 6 includes a mixer 61 and a pair of feed pipes 62. The output end of the mixer 61 is connected to the input end of the condensation tower 1, and a pair of feed pipes 62 are both connected to the input end of the mixer 61.

[0087] When the raw materials are fed into the condensation tower 1, the ketone or aldehyde enters the mixer 61 from a feed pipe 62, and the diol enters the mixer 61 from another feed pipe 62. The diol and the ketone or aldehyde are fully mixed in the mixer 61 and finally fed into the condensation tower 1 to ensure that the condensation reaction can be fully carried out in the condensation tower 1.

[0088] Furthermore, a first heater 7 is provided between the pretreatment structure 6 and the condensation tower 1, or a first heater 7 is provided on the pretreatment structure 6, so that the raw material has a higher temperature before entering the condensation tower 1, so as to facilitate the condensation reaction to proceed fully.

[0089] In a specific embodiment, the first heater 7 is arranged between the pretreatment structure 6 and the condensation tower 1. Specifically, the pretreatment structure 6 and the condensation tower 1 are connected by a pipeline, and the first heater 7 is installed on the corresponding pipeline. When the raw material is sent from the pretreatment structure 6 to the condensation tower 1, the raw material is fully heated.

[0090] Furthermore, in another specific embodiment, the first heater 7 is disposed on the pretreatment structure 6. The first heater 7 can be disposed on the feed pipe 62 or in the mixer 61. The raw materials are fully heated before or during mixing.

[0091] That is, the raw materials may be heated first and then mixed, or heated and mixed simultaneously, or mixed first and then heated.

[0092] The oil-water separator 2 is connected to the output end of the condensation tower 1, and can receive and separate the product to form an oil phase and an aqueous phase. The oil phase is a glycol ketal or acetal, and the aqueous phase is water and a diol (diol is easily soluble in water). Correspondingly, the oil-water separator 2 has a first discharge port 21 for outputting the aqueous phase, a fourth discharge port 22 for outputting the oil phase, and a fifth discharge port 23.

[0093] In a specific embodiment, part of the diol ketal or acetal is taken out from the fourth discharge port 22, and the fifth discharge port 23 is connected to the input end of the condensation tower 1, and the remaining part of the diol ketal or acetal re-enters the condensation tower 1 from the fifth discharge port 23 to ensure that the ketone or aldehyde, one of the raw materials, can react completely.

[0094] Furthermore, the distillation tower 3 includes a distillation section and a stripping section arranged in sequence from bottom to top, 8 to 10 plates are arranged in the distillation section, 3 to 5 plates are arranged in the stripping section, the distillation section is connected to the first discharge port 21 of the oil-water separator 2 through a pipeline, and a second heater 8 is arranged on the pipeline.

[0095] Before the water phase enters the distillation tower 3 , it is preheated to accelerate the distillation process. After the stripping section and the distillation section, the heavier components (glycols) are collected at the bottom of the tower, and the lighter components (water) evaporate out of the distillation tower 3 .

[0096] Correspondingly, the distillation tower 3 has a second outlet 31 for outputting diols and a third outlet 32 ​​for outputting water; the third outlet 32 ​​is connected to the output end of the condensation tower 1, and the diols obtained by distillation and purification enter the feed pipe 62 through the second outlet 31, are mixed with ketones or aldehydes after heating, and further undergo condensation reaction in the condensation tower 1.

[0097] Furthermore, the third discharge port 32 is connected to a cooling recovery structure 4, which includes a heat exchanger 41 and a transfer tank 42 connected in sequence. After the water vapor evaporates, it enters the heat exchanger 41 and enters the transfer tank 42 in the form of liquid water to be stored.

[0098] Furthermore, the transfer tank 42 is connected to a vacuum system 5, which can provide a vacuum environment for the distillation tower 3 and the transfer tank 42, that is, the distillation separation process and the condensation process are carried out in a vacuum environment, so that the distillation separation process and the condensation process can be carried out more stably and efficiently.

[0099] The embodiments of this specific implementation are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. The same components are represented by the same figure marks. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A continuous and efficient synthesis method of diol ketal or acetal, characterized in that: The following steps are involved: Preheating and mixing raw materials, wherein the raw materials include diols, ketones or aldehydes; The raw materials are fed into a condensation tower filled with a catalyst for condensation reaction to obtain a product, which flows out of the condensation tower in liquid form; Separating the product into oil and water to form an oil phase and a water phase, wherein the oil phase comprises diol ketal or acetal, and the water phase comprises water and diol; The water phase is separated by distillation to obtain glycol and water. The glycol is fed back into the condensation tower and the water is discharged from the system.

2. The synthesis method according to claim 1, characterized in that The molar ratio of the ketone or aldehyde to the diol is set to 1:1.5-3.

3. The synthesis method according to claim 2, characterized in that The raw materials include diols and ketones, wherein the ketone is at least one of C10 to C18 ketones, or The raw materials include diols and aldehydes, and the aldehyde is set to be at least one of C10-C18 aldehydes.

4. The synthesis method according to claim 1, characterized in that The diol is set as an ortho- or meta-diol, and the diol includes at least any one of 1,2-ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,2-butylene glycol, 2,3-butylene glycol, and 1,3-butylene glycol.

5. The synthesis method according to claim 1, characterized in that The distillation separation of the aqueous phase to obtain glycol and water comprises: The aqueous phase is sent to a distillation tower for distillation to obtain a first separated product and water; The first separated product is partially withdrawn and partially refluxed into the distillation tower, and the reflux and withdrawal ratio of the first separated product is set to 1-2:

1.

6. The synthesis method according to claim 5, characterized in that The distillation separation of the water phase is carried out in a vacuum environment, and the vacuum degree is set to -0.09 to -0.

08.

7. The synthesis method according to claim 5 or 6, characterized in that: The first isolate includes a glycol, the glycol comprising at least 99.9% of the first isolate.

8. The synthesis method according to claim 1, characterized in that The oil phase is split, part of the oil phase is refluxed into the condensation tower, and part of the oil phase is produced as a product, and the reflux and production ratio of the oil phase is set to 1:1-10.

9. The synthesis method according to claim 1, characterized in that The catalyst is at least one of A-15 resin and 732 resin.

10. A continuous and efficient reaction device for diol ketal or acetal, used to implement the synthesis method according to any one of claims 1 to 9, characterized in that: The invention comprises a condensation tower, an oil-water separator and a distillation tower which are arranged in sequence.

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