Preparation method and reaction system of high-purity ethylhexylglycerin and ethylhexylglycerin

Abstract

The invention provides a preparation method of high-purity ethylhexylglycerin, a reaction system and ethylhexylglycerin. According to the method, crude ethylhexylglycerin obtained by a synthesis unit is taken as a raw material, primary separation is realized through a rectifying tower, moisture and most of raw material impurities in the crude ethylhexylglycerin are thoroughly removed, moisture is obtained at the tower top, the raw material intercepted in the tower can be recycled, and an ethylhexylglycerin fraction with the content of 99.5% is obtained at the tower bottom; and the fraction enters a rectification purification tower, and is separated and purified by the rectification purification tower to obtain a colorless and odorless ethylhexylglycerin product with the purity of more than 99.99%. According to the preparation method of the high-purity ethylhexylglycerin, the whole technological process is reasonable, the process is continuous, and the preparation method has the characteristics of low energy consumption, high product quality, no pollution and the like, is an efficient and feasible continuous refining process of the ethylhexylglycerin, and has a good industrial application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of preparation technology of fine chemical products, and in particular to a method for preparing high-purity ethylhexylglycerol, a reaction system and ethylhexylglycerol. Background Art

[0002] Ethylhexylglycerin is a colorless, odorless liquid that can be used as an antibacterial agent, deodorant, emollient, and synergist, etc. Ethylhexylglycerin has antiseptic properties, does not irritate the skin, has a moisturizing effect, and can enhance the synergy of traditional preservatives. Therefore, ethylhexylglycerin will play an important role in the green preservative system.

[0003] As a multifunctional auxiliary agent developed in recent years, there are few reports on the synthesis process of ethylhexyl glycerol. The Chinese invention patent with publication number CN104817436A discloses a method for preparing high-purity ethylhexyl glycerol, which generates an intermediate 4-alkoxymethyl-1,3-dioxoalkane by using 2-ethylhexyl glycidyl ether and acetone under the catalysis of boron trifluoride ether, adds a terminator to stop the reaction, and then hydrolyzes and separates the liquid under the catalysis of formic acid to separate the oil phase, neutralizes and washes with sodium bicarbonate, and then uses molecular distillation to obtain ethylhexyl glycerol, with a product yield of 88% and a purity of 99%. The Chinese invention patent with publication number CN117447315A discloses a method for preparing ethylhexyl glycerol by hydrolyzing 2-ethylhexyl glycidyl ether. The method adopts a water-soluble solvent such as dioxane or dimethyl sulfoxide, and 2-ethylhexyl glycidyl ether is hydrolyzed under the catalysis of sulfuric acid, phosphotungstic acid, etc. The reaction is kept warm for a certain time, and the reaction liquid is heated and decompressed to distill and recover the organic solvent. The concentrated liquid is separated into a water layer, washed with water, and distilled to obtain ethylhexyl glycerol. The hydrolysis yield is 84.9% and the purity is 99%.

[0004] The above two processes are synthesized by traditional reactors, which are purified and refined by general distillation or molecular distillation, and the purity can reach 99%, which meets general applications. According to the introduction of some other patents, literature materials, etc., the purification process of ethylhexyl glycerol is completed by general distillation or molecular distillation technology. The molecular distillation equipment has a small processing capacity, expensive equipment, high requirements for operating conditions, and extremely high operating costs. It is not suitable for industrial mass production. The product content of the general distillation method can reach 99% or more, but the impurities with peculiar smell are not completely removed. The presence of these trace impurities causes the ethylhexyl glycerol product to have a peculiar smell, which does not meet the requirements of high-quality daily chemical product raw materials. This restricts the production and development of ethylhexyl glycerol to a great extent, and limits the promotion and use of ethylhexyl glycerol as a new multifunctional additive in cosmetics and daily chemical industries. Summary of the invention

[0005] The disclosed embodiments provide a method for preparing high-purity ethylhexylglycerol, a reaction system, and ethylhexylglycerol, which can solve the purity and odor problems of products prepared by traditional processes. The technical solution is as follows:

[0006] According to a first aspect of an embodiment of the present disclosure, a method for preparing high-purity ethylhexylglycerol is provided, the method comprising:

[0007] Step S1: pumping the crude ethylhexylglycerol feed liquid in the material storage tank into the distillation tower at a predetermined flow rate for preliminary separation, the light component water after the preliminary separation overflows through the fraction outlet at the top of the distillation tower and enters the first condenser, and after being condensed by the first condenser, a large part of the light component water enters the first light component storage tank, and another small part of the light component water returns to the top of the distillation tower for reflux, and the second light component and the third light component enter the second light component storage tank and the third light component storage tank after being condensed by the second condenser and the third condenser respectively through the two fraction outlets at the middle and upper part of the distillation tower;

[0008] Step S2, introducing the ethylhexylglycerol treated in step S1 into a distillation purification tower through the outlet at the lower middle part of the distillation tower for separation and purification, a small amount of impurities after separation and purification overflow through the fraction outlet at the top of the distillation purification tower and enter the fourth condenser, and after condensation by the fourth condenser, a part of the impurities enter the fourth light component storage tank, and the other part of the impurities return to the top of the distillation purification tower for reflux;

[0009] Step S3, introducing the high-purity ethylhexylglycerol treated in step S2 into a product condenser through the outlet at the lower middle portion of the rectification and purification tower, and then introducing the high-purity ethylhexylglycerol into a product storage tank after being cooled by the product condenser.

[0010] In one embodiment, in step S1, the top pressure of the distillation tower is -0.085 to -0.095 MPa, the top temperature is 35 to 55°C, the reflux ratio is 1:1 to 10, and the bottom temperature is 120 to 150°C.

[0011] In one embodiment, in step S2, the top pressure of the distillation purification tower is -0.090 to -0.099 MPa, the temperature is 80 to 130°C, the reflux ratio is 3:1 to 10, and the bottom temperature is 140 to 210°C.

[0012] In one embodiment, in step S1, the crude ethylhexylglycerol liquid in the material storage tank is pumped into a distillation tower at a flow rate of 40 to 60 mL / min for preliminary separation.

[0013] In one embodiment, the top pressure of the distillation tower is -0.090 to -0.095 MPa, the top temperature is 38 to 48°C, the reflux ratio is 1:6 to 9, and the bottom temperature is 120 to 140°C.

[0014] In one embodiment, in step S2, the top pressure of the distillation purification tower is -0.095 to -0.099 MPa, the top temperature is 80 to 120°C, the reflux ratio is 3:3 to 6, and the bottom temperature is 150 to 200°C.

[0015] According to a second aspect of an embodiment of the present disclosure, a high-purity ethylhexylglycerol is provided, and the high-purity ethylhexylglycerol is prepared by the high-purity ethylhexylglycerol preparation method described above.

[0016] According to a third aspect of an embodiment of the present disclosure, a reaction system for preparing high-purity ethylhexylglycerol is provided, characterized in that the reaction system comprises: a material storage tank, a distillation tower, a first condenser, a first light component storage tank, a second condenser, a third condenser, a second light component storage tank, a third light component storage tank, a distillation purification tower, a fourth condenser, a fourth light component storage tank, a product condenser and a product storage tank; wherein,

[0017] A first outlet pump is provided on the connecting pipeline between the material storage tank and the distillation tower, the fraction outlet at the top of the distillation tower is connected to the first condenser inlet through a pipeline, and the first condenser outlet is connected to the first light component storage tank through a pipeline;

[0018] The two fraction outlets in the upper part of the distillation tower are connected to the second condenser and the third condenser inlet through pipelines, respectively; the second condenser outlet is connected to the second light component storage tank through a pipeline; and the third condenser outlet is connected to the third light component storage tank through a pipeline;

[0019] A second outlet pump is provided on the connecting pipeline between the outlet of the middle and lower part of the distillation tower and the distillation purification tower, the distillate outlet at the top of the distillation purification tower is connected to the inlet of the fourth condenser through a pipeline, and the fourth condenser outlet is connected to the fourth light component storage tank through a pipeline;

[0020] The outlet of the lower part of the rectification and purification tower is connected to the inlet of the product condenser through a pipeline, and the outlet of the product condenser is connected to the product storage tank through a pipeline;

[0021] The reaction system is used to implement the above-mentioned method for preparing high-purity ethylhexylglycerol.

[0022] In one embodiment, the reaction system further comprises: a third outlet pump, a first light component reflux tank, a fourth outlet pump, a cooler and a fourth light component reflux tank; wherein,

[0023] The first condenser outlet is connected to the first light component reflux tank inlet through a pipeline, the first light component reflux tank outlet is connected to the first light component storage tank through a pipeline, and the third outlet pump is arranged on the connecting pipeline between the first light component reflux tank and the first light component storage tank;

[0024] The fourth condenser outlet is connected to the fourth light component reflux tank inlet through a pipeline, the fourth light component reflux tank outlet is connected to the cooler inlet through a pipeline, the cooler outlet is connected to the fourth light component storage tank, and the fourth dewatering pump is arranged on the connecting pipeline between the fourth light component reflux tank and the condenser.

[0025] In one embodiment, the reaction system further comprises: a vacuum cooler, a vacuum buffer tank, a first reboiler and a second reboiler; wherein,

[0026] The inlet of the vacuum cooler is connected to the first light component reflux tank and the fourth light component reflux tank through a pipeline, and the outlet of the vacuum cooler is connected to the vacuum buffer tank through a pipeline;

[0027] The first reboiler is connected to the bottom outlet of the distillation tower through a pipeline, and the second reboiler is connected to the bottom outlet of the distillation purification tower through a pipeline.

[0028] Compared with the prior art, the present invention has the following outstanding effects:

[0029] 1. The refining process is simple and continuous. Through double-tower coupling, it has the characteristics of low energy consumption and no pollution. It is an efficient and feasible process for purifying and refining ethylhexylglycerin.

[0030] 2. The refined product has high purity. The purity of the ethylhexylglycerol prepared by the present invention reaches more than 99.99%.

[0031] 3. The refined product has few trace impurities and removes the influence of small molecule impurities, making it colorless and odorless.

[0032] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The present invention provides a flow chart of a method for preparing high-purity ethylhexylglycerol.

[0034] Figure 2 A schematic diagram of a reaction system for preparing high-purity ethylhexylglycerol provided in an embodiment of the present disclosure.

[0035] In the figure, 1-material storage tank, 2-distillation tower, 3-first condenser, 4-first light component reflux tank, 5-first light component storage tank, 6-second condenser, 7-second light component storage tank, 8-third condenser, 9-third light component storage tank, 10-first reboiler, 11-distillation purification tower, 12-fourth condenser, 13-fourth light component reflux tank, 14-cooler, 15-fourth light component storage tank, 16-product condenser, 17-product storage tank, 18-second reboiler, 19-vacuum cooler, 20-vacuum buffer tank, 21-first export pump, 22-second export pump, 23-third export pump, 24-fourth export pump. DETAILED DESCRIPTION

[0036] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0037] Figure 1 The flowchart of a method for preparing high-purity ethylhexylglycerol provided in this embodiment is as follows. Figure 1 As shown, the method specifically comprises the following steps:

[0038] Step S1: pumping the crude ethylhexylglycerol feed liquid in the material storage tank into the distillation tower at a predetermined flow rate for preliminary separation, the light component water after the preliminary separation overflows through the fraction outlet at the top of the distillation tower and enters the first condenser, and after being condensed by the first condenser, a large part of the light component water enters the first light component storage tank, and another small part of the light component water returns to the top of the distillation tower for reflux, and the second light component and the third light component enter the second light component storage tank and the third light component storage tank after being condensed by the second condenser and the third condenser respectively through the two fraction outlets at the middle and upper part of the distillation tower;

[0039] Preferably, in step S1, the top pressure of the distillation tower is -0.085 to -0.095 MPa, the top temperature is 35 to 55°C, the reflux ratio is 1:1 to 10, and the bottom temperature is 120 to 150°C.

[0040] More preferably, the top pressure of the distillation tower is -0.090 to -0.095 MPa, the top temperature is 38 to 48°C, the reflux ratio is 1:6 to 9, and the bottom temperature is 120 to 140°C.

[0041] In one embodiment, in step S1, the crude ethylhexylglycerol liquid in the material storage tank is pumped into a distillation tower at a flow rate of 40 to 60 mL / min for preliminary separation.

[0042] Step S2, introducing the ethylhexylglycerol treated in step S1 into a distillation purification tower through the outlet at the lower middle part of the distillation tower for separation and purification, a small amount of impurities after separation and purification overflow through the fraction outlet at the top of the distillation purification tower and enter the fourth condenser, and after condensation by the fourth condenser, a part of the impurities enter the fourth light component storage tank, and the other part of the impurities return to the top of the distillation purification tower for reflux;

[0043] Preferably, in step S2, the top pressure of the distillation purification tower is -0.090 to -0.099 MPa, the temperature is 80 to 130°C, the reflux ratio is 3:1 to 10, and the bottom temperature is 140 to 210°C.

[0044] More preferably, the top pressure of the distillation purification tower is -0.095 to -0.099 MPa, the top temperature is 80 to 120°C, the reflux ratio is 3:3 to 6, and the bottom temperature is 150 to 200°C.

[0045] Step S3, introducing the high-purity ethylhexylglycerol treated in step S2 into a product condenser through the outlet at the lower middle portion of the rectification and purification tower, and then introducing the high-purity ethylhexylglycerol into a product storage tank after being cooled by the product condenser.

[0046] The specific process flow of the high-purity ethylhexylglycerol preparation method provided in the embodiments of the present disclosure is as follows:

[0047] The crude ethylhexyl glycerol obtained by the synthesis unit is added to the material storage tank 1, and the crude ethylhexyl glycerol feed liquid is pumped into the distillation tower 2 at a flow rate of 40-60 mL / min, so that the light component water overflows from the top of the distillation tower 2, and a small part of it returns to the top of the distillation tower 2 for reflux after condensation, and most of it enters the first light component storage tank 5. Two fraction outlets are arranged in the upper part of the distillation tower 2, and they enter the second light component storage tank 7 and the third light component storage tank 9 after condensation by the second condenser 6 and the third condenser 8 respectively. The ethylhexyl glycerol flows out from the bottom of the distillation tower 2 and enters the distillation purification tower 11 for separation and purification. A small amount of impurities overflow from the top of the distillation purification tower 11, and a part of them returns to the top of the distillation purification tower 11 for reflux after condensation by the fourth condenser 12, and a part of them enters the fourth light component storage tank 15. The high-purity ethylhexyl glycerol flows out from the bottom of the distillation purification tower 1, and enters the product storage tank 17 after cooling by the product condenser 16.

[0048] The present disclosure provides a method for preparing high-purity ethylhexyl glycerin, which has a simple refining process and a continuous process. Through double-tower coupling, it has the characteristics of low energy consumption and no pollution, and is an efficient and feasible ethylhexyl glycerin purification and refining process. In addition, the refined product prepared by the high-purity ethylhexyl glycerin preparation method provided by the present disclosure has high purity, and the purity of the prepared ethylhexyl glycerin reaches more than 99.99%. Furthermore, the refined product prepared by the high-purity ethylhexyl glycerin preparation method provided by the present disclosure has few trace impurities, and the influence of small molecular impurities is removed, so that it can be colorless and tasteless.

[0049] The present disclosure also provides a high-purity ethylhexyl glycerin, which is prepared by the high-purity ethylhexyl glycerin preparation method described above.

[0050] Figure 2 Schematic diagram of a reaction system for preparing high-purity ethylhexylglycerol provided in an embodiment of the present disclosure. Figure 2 As shown, the reaction system includes: a material storage tank 1, a distillation tower 2, a first condenser 3, a first light component storage tank 5, a second condenser 6, a third condenser 8, a second light component storage tank 7, a third light component storage tank 9, a distillation purification tower 11, a fourth condenser 12, a fourth light component storage tank 15, a product condenser 16 and a product storage tank 17; wherein,

[0051] A first outlet pump 21 is provided on the connecting pipeline between the material storage tank 1 and the distillation tower 2, the distillate outlet at the top of the distillation tower 2 is connected to the inlet of the first condenser 3 through a pipeline, and the outlet of the first condenser 3 is connected to the first light component storage tank 5 through a pipeline;

[0052] The two fraction outlets in the upper part of the distillation tower 2 are connected to the inlets of the second condenser 6 and the third condenser 8 through pipelines, respectively; the outlet of the second condenser 6 is connected to the second light component storage tank 7 through a pipeline, and the outlet of the third condenser 8 is connected to the third light component storage tank 9 through a pipeline;

[0053] A second outlet pump 22 is provided on the connecting pipeline between the outlet of the middle and lower part of the distillation tower 2 and the distillation purification tower 11, the distillate outlet at the top of the distillation purification tower 11 is connected to the inlet of the fourth condenser 12 through a pipeline, and the outlet of the fourth condenser 12 is connected to the fourth light component storage tank 15 through a pipeline;

[0054] The outlet of the lower part of the distillation purification tower 11 is connected to the inlet of the product condenser 16 through a pipeline, and the outlet of the product condenser 16 is connected to the product storage tank 17 through a pipeline;

[0055] The reaction system is used to implement the above-mentioned method for preparing high-purity ethylhexylglycerol.

[0056] In one embodiment, Figure 2 The reaction system further comprises: a third outlet pump 23, a first light component reflux tank 4, a fourth outlet pump 24, a cooler 14 and a fourth light component reflux tank 13; wherein,

[0057] The outlet of the first condenser 3 is connected to the inlet of the first light component reflux tank 4 through a pipeline, the outlet of the first light component reflux tank 4 is connected to the first light component storage tank 5 through a pipeline, and the third outlet pump 23 is arranged on the connecting pipeline between the first light component reflux tank 4 and the first light component storage tank 5;

[0058] The outlet of the fourth condenser 12 is connected to the inlet of the fourth light component reflux tank through a pipeline, the outlet of the fourth light component reflux tank is connected to the inlet of the cooler 14 through a pipeline, the outlet of the cooler 14 is connected to the fourth light component storage tank 15, and the fourth outlet pump 24 is arranged on the connecting pipeline between the fourth light component reflux tank 13 and the condenser.

[0059] In one embodiment, Figure 2 As shown, the reaction system further includes: a vacuum cooler 19, a vacuum buffer tank 20, a first reboiler 10 and a second reboiler 18; wherein,

[0060] The inlet of the vacuum cooler 19 is connected to both the first light component reflux tank 4 and the fourth light component reflux tank 13 through pipelines, and the outlet of the vacuum cooler 19 is connected to the vacuum buffer tank 20 through pipelines;

[0061] The first reboiler 10 is connected to the bottom outlet of the distillation tower 2 through a pipeline, and the second reboiler 18 is connected to the bottom outlet of the distillation purification tower 11 through a pipeline.

[0062] The method for preparing high-purity ethylhexylglycerol provided in the present disclosure will be described in detail with reference to specific examples below.

[0063] Example 1

[0064] The synthesized crude ethylhexyl glycerol was added to the material storage tank 1, and the pump flow rate was adjusted to pump it into the distillation tower 2 at a flow rate of 40 mL / min. The top pressure of the distillation tower 2 was adjusted to -0.090 MPa by using the vacuum system. The feed liquid reached gas-liquid equilibrium in the distillation tower 2, and the top temperature was 45°C. The light component water overflowed from the top of the distillation tower 2. The reflux ratio was set to 1:8. After condensation, a small part returned to the top of the distillation tower 2 for reflux, and most of it entered the first light component storage tank 5. Two fraction outlets were set in the upper part of the distillation tower 2, and they entered the second light component storage tank 7 and the third light component storage tank 9 after passing through the second condenser 6 and the third condenser 8 respectively. At this time, the bottom temperature of the tower was controlled to be 140°C. Ethylhexyl glycerol flows out from the bottom of the tower and enters the distillation purification tower 11 for separation and purification. The top pressure of the distillation purification tower 11 is adjusted to -0.097 MPa, and the top temperature is 115° C. The feed liquid reaches gas-liquid equilibrium in the distillation purification tower 11. A small amount of impurities overflow from the top of the distillation purification tower 11. The reflux ratio is set to 3:5. After condensation in the fourth condenser 12, a part of it returns to the top of the distillation purification tower 11 for reflux, and a part of it enters the fourth light component storage tank 15. At this time, the bottom temperature of the tower is controlled to be 180° C. High-purity ethylhexyl glycerol flows out from the bottom of the tower, and after cooling in the product condenser 16, it enters the product storage tank 17 to obtain a product with a content of 99.99%, and a yield of 98.0%.

[0065] Example 2

[0066] The crude ethylhexyl glycerol material of this embodiment is pumped into the distillation tower 2 at a flow rate of 60 mL / min for preliminary separation. The top operating pressure of the distillation tower 2 is -0.095 MPa, the top temperature is 38° C., the reflux ratio is 1:9, and the bottom temperature is 125° C. The top operating pressure of the distillation purification tower 11 is -0.099 MPa, the top temperature is 100° C., the reflux ratio is 3:7, and the bottom temperature is 160° C. The other operating steps are the same as those in Example 1. The purity of the obtained product ethylhexyl glycerol reaches more than 99.99%, and the yield reaches 98.9%.

[0067] Example 3

[0068] The crude ethylhexylglycerol material of this embodiment is pumped into the distillation tower 2 at a flow rate of 45 mL / min for preliminary separation. The top operating pressure of the distillation tower 2 is -0.091 MPa, the top temperature is 43° C., the reflux ratio is 1:8, and the bottom temperature is 138° C. The top operating pressure of the distillation purification tower 11 is -0.098 MPa, the top temperature is 110° C., the reflux ratio is 3:8, and the bottom temperature is 170° C. The other operating steps are the same as those in Example 1. The purity of the obtained product ethylhexylglycerol reaches more than 99.99%, and the yield is 98.6%.

[0069] Example 4

[0070] The crude ethylhexyl glycerol material of this embodiment is pumped into the distillation tower 2 at a flow rate of 50 mL / min for preliminary separation. The top operating pressure of the distillation tower 2 is -0.093 MPa, the top temperature is 40° C., the reflux ratio is 1:8, and the bottom temperature is 130° C. The top operating pressure of the distillation purification tower 11 is -0.095 MPa, the top temperature is 120° C., the reflux ratio is 3:8, and the bottom temperature is 200° C. The other operating steps are the same as those in Example 1. The purity of the obtained product ethylhexyl glycerol reaches more than 99.99%, and the yield is 96.2%.

[0071] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

Claims

1. A method for preparing high-purity ethylhexylglycerol, characterized in that: The method comprises: Step S1: pumping the crude ethylhexylglycerol feed liquid in the material storage tank into the distillation tower at a predetermined flow rate for preliminary separation, the light component water after the preliminary separation overflows through the fraction outlet at the top of the distillation tower and enters the first condenser, and after being condensed by the first condenser, a large part of the light component water enters the first light component storage tank, and another small part of the light component water returns to the top of the distillation tower for reflux, and the second light component and the third light component enter the second light component storage tank and the third light component storage tank after being condensed by the second condenser and the third condenser respectively through the two fraction outlets at the middle and upper part of the distillation tower; Step S2, introducing the ethylhexylglycerol treated in step S1 into a distillation purification tower through the outlet at the lower middle part of the distillation tower for separation and purification, a small amount of impurities after separation and purification overflow through the fraction outlet at the top of the distillation purification tower and enter the fourth condenser, and after condensation by the fourth condenser, a part of the impurities enter the fourth light component storage tank, and the other part of the impurities return to the top of the distillation purification tower for reflux; Step S3, introducing the high-purity ethylhexylglycerol treated in step S2 into a product condenser through the outlet at the lower middle portion of the rectification and purification tower, and then introducing the high-purity ethylhexylglycerol into a product storage tank after being cooled by the product condenser.

2. The method for preparing high-purity ethylhexylglycerol according to claim 1, characterized in that: In step S1, the top pressure of the distillation tower is -0.085 to -0.095 MPa, the top temperature is 35 to 55°C, the reflux ratio is 1:1 to 10, and the bottom temperature is 120 to 150°C.

3. The method for preparing high-purity ethylhexylglycerol according to claim 1, characterized in that: In step S2, the top pressure of the distillation purification tower is -0.090 to -0.099 MPa, the temperature is 80 to 130°C, the reflux ratio is 3:1 to 10, and the bottom temperature is 140 to 210°C.

4. The method for preparing high-purity ethylhexylglycerol according to any one of claims 1 to 3, characterized in that: In step S1, the crude ethylhexylglycerol liquid in the material storage tank is pumped into a distillation tower at a flow rate of 40 to 60 mL / min for preliminary separation.

5. The method for preparing high-purity ethylhexylglycerol according to claim 2, characterized in that: The top pressure of the distillation tower is -0.090 to -0.095 MPa, the top temperature is 38 to 48°C, the reflux ratio is 1:6 to 9, and the bottom temperature is 120 to 140°C.

6. The method for preparing high-purity ethylhexylglycerol according to claim 3, characterized in that: In step S2, the top pressure of the distillation purification tower is -0.095 to -0.099 MPa, the top temperature is 80 to 120°C, the reflux ratio is 3:3 to 6, and the bottom temperature is 150 to 200°C.

7. A high-purity ethylhexylglycerol, characterized in that: The high-purity ethylhexylglycerol is produced according to the method for producing high-purity ethylhexylglycerol according to any one of claims 1 to 6.

8. A reaction system for preparing high-purity ethylhexylglycerol, characterized in that: The reaction system comprises: a material storage tank, a distillation tower, a first condenser, a first light component storage tank, a second condenser, a third condenser, a second light component storage tank, a third light component storage tank, a distillation purification tower, a fourth condenser, a fourth light component storage tank, a product condenser and a product storage tank; wherein, A first outlet pump is provided on the connecting pipeline between the material storage tank and the distillation tower, the fraction outlet at the top of the distillation tower is connected to the first condenser inlet through a pipeline, and the first condenser outlet is connected to the first light component storage tank through a pipeline; The two fraction outlets in the upper part of the distillation tower are connected to the second condenser and the third condenser inlet through pipelines, respectively; the second condenser outlet is connected to the second light component storage tank through a pipeline; and the third condenser outlet is connected to the third light component storage tank through a pipeline; A second outlet pump is provided on the connecting pipeline between the outlet of the middle and lower part of the distillation tower and the distillation purification tower, the distillate outlet at the top of the distillation purification tower is connected to the inlet of the fourth condenser through a pipeline, and the fourth condenser outlet is connected to the fourth light component storage tank through a pipeline; The outlet of the lower part of the rectification and purification tower is connected to the inlet of the product condenser through a pipeline, and the outlet of the product condenser is connected to the product storage tank through a pipeline; The reaction system is used to implement the method for preparing high-purity ethylhexylglycerol according to any one of claims 1 to 6.

9. The reaction system according to claim 8, characterized in that: The reaction system further comprises: a third outlet pump, a first light component reflux tank, a fourth outlet pump, a cooler and a fourth light component reflux tank; wherein, The first condenser outlet is connected to the first light component reflux tank inlet through a pipeline, the first light component reflux tank outlet is connected to the first light component storage tank through a pipeline, and the third outlet pump is arranged on the connecting pipeline between the first light component reflux tank and the first light component storage tank; The fourth condenser outlet is connected to the fourth light component reflux tank inlet through a pipeline, the fourth light component reflux tank outlet is connected to the cooler inlet through a pipeline, the cooler outlet is connected to the fourth light component storage tank, and the fourth dewatering pump is arranged on the connecting pipeline between the fourth light component reflux tank and the condenser.

10. The reaction system according to claim 9, characterized in that: The reaction system further comprises: a vacuum cooler, a vacuum buffer tank, a first reboiler and a second reboiler; wherein, The inlet of the vacuum cooler is connected to the first light component reflux tank and the fourth light component reflux tank through a pipeline, and the outlet of the vacuum cooler is connected to the vacuum buffer tank through a pipeline; The first reboiler is connected to the bottom outlet of the distillation tower through a pipeline, and the second reboiler is connected to the bottom outlet of the distillation purification tower through a pipeline.

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