阅读说明：本技术 一种乙二醇单丙基醚的制备方法及系统 (Preparation method and system of ethylene glycol monopropyl ether ) 是由 马定连 金一丰 王新荣 余渊荣 王敏 于 2020-07-23 设计创作，主要内容包括：本发明提供一种乙二醇单丙基醚的制备方法及系统,制备方法是采用以下反应方程式：<Image he="76" wi="700" file="DDA0002599057050000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>包括：正丙醇和环氧乙烷在催化剂作用下反应合成乙二醇单丙基醚粗品；粗品再经减压精馏得到乙二醇单丙基醚成品。制备系统包括加成精馏一体化反应釜,加成精馏一体化反应釜包括反应釜主体,反应釜主体上方连接精馏塔；反应釜主体包括反应进料口、反应出料口和物料蒸汽出口,物料蒸汽出口连接精馏塔的精馏进口,精馏塔上设有精馏进口和精馏出口,精馏塔还连接真空装置。采用本发明方法制备的乙二醇单丙基醚,纯度高(≥99.8％),副产物少。(The invention provides a preparation method and a system of ethylene glycol monopropyl ether, wherein the preparation method adopts the following reaction equation: the method comprises the following steps: n-propanol and ethylene oxide react under the action of a catalyst to synthesize a crude product of ethylene glycol monopropyl ether; and carrying out reduced pressure rectification on the crude product to obtain a finished product of the ethylene glycol monopropyl ether. The preparation system comprises an addition and rectification integrated reaction kettle, the addition and rectification integrated reaction kettle comprises a reaction kettle main body, and a rectification tower is connected above the reaction kettle main body; inverse directionThe reactor main body comprises a reaction feed inlet, a reaction discharge outlet and a material steam outlet, the material steam outlet is connected with a rectification inlet of a rectification tower, the rectification tower is provided with a rectification inlet and a rectification outlet, and the rectification tower is also connected with a vacuum device. The ethylene glycol monopropyl ether prepared by the method has high purity (more than or equal to 99.8 percent) and few byproducts.)

1. A preparation system of ethylene glycol monopropyl ether is characterized in that: the device comprises an addition and rectification integrated reaction kettle, wherein the addition and rectification integrated reaction kettle comprises a reaction kettle main body, and a rectification tower is connected above the reaction kettle main body; the reaction kettle main body comprises a reaction feed inlet, a reaction discharge outlet and a material steam outlet, and the material steam outlet is connected with a rectification inlet of the rectification tower; the rectifying tower comprises a rectifying inlet and a rectifying outlet, and is also connected with a vacuum device.

2. The system for preparing ethylene glycol monopropyl ether according to claim 1, wherein: the reaction discharge hole is also connected with the reaction feed hole through a material return pipeline, and a filter and a material conveying pump are arranged on the material return pipeline.

3. The system for preparing ethylene glycol monopropyl ether according to claim 1, wherein: the reaction kettle is provided with an interlayer, and the interlayer is used for introducing a temperature control medium.

4. The system for producing ethylene glycol monopropyl ether according to any one of claims 1 to 3, characterized in that: the preparation system also comprises a raw material storage tank and a product storage tank, wherein the raw material storage tank and the product storage tank are respectively connected with the addition rectification integrated reaction kettle.

5. A preparation method of ethylene glycol monopropyl ether is characterized in that: the preparation system of any one of claims 1 to 4 is used with the following reaction equation:

the method comprises the following steps: n-propanol and ethylene oxide react under the action of a catalyst to synthesize a crude product of ethylene glycol monopropyl ether; and rectifying the crude product to obtain a finished product of the ethylene glycol monopropyl ether.

6. A process according to claim 5The preparation method of the ethylene glycol monopropyl ether is characterized by comprising the following steps: the preparation method comprises the following steps: mixing N-propanol with a catalyst, N₂Adding ethylene oxide under protection to react; separating out the catalyst after the reaction is finished to obtain a crude product of ethylene glycol monopropyl ether; and (2) carrying out reduced pressure rectification on the ethylene glycol monopropyl ether crude product, respectively collecting free n-propanol, an ethylene glycol monopropyl ether finished product and kettle bottom liquid, wherein the separated catalyst and the free n-propanol can be recycled and applied to the reaction process, and the kettle bottom liquid can be directly used for producing an n-propanol polyether surfactant product.

7. The method for preparing ethylene glycol monopropyl ether according to claim 5 or 6, characterized in that: the catalyst is one or a mixture of zinc methanesulfonate and zinc p-toluenesulfonate.

8. The method for preparing ethylene glycol monopropyl ether according to claim 5 or 6, characterized in that: the mass ratio of the n-propanol to the ethylene oxide is as follows: 60: (13.2-44), wherein the dosage of the catalyst is 0.3-5 per mill of the total weight of the n-propanol and the ethylene oxide.

9. The method for preparing ethylene glycol monopropyl ether according to claim 5 or 6, characterized in that: the reaction temperature of the n-propanol and the ethylene oxide under the catalysis of the catalyst is 110-180 ℃, and the reaction pressure is-0.05-0.60 MPa.

10. The method for preparing ethylene glycol monopropyl ether according to claim 5 or 6, characterized in that: the vacuum rectification specific process comprises the following steps: vacuumizing the addition rectification integrated reaction kettle to-0.05 MPa, controlling the vacuum degree to be constant, heating the ethylene glycol monopropyl ether crude product in the reaction kettle, opening rectification for condensation, controlling the temperature of the material at the bottom of the kettle to be 65-80 ℃ and the temperature at the top of the kettle to be 50-65 ℃, carrying out total reflux for 30min, then starting to receive the n-propanol, vacuumizing to improve the vacuum degree in the kettle to be more than or equal to-0.098 MPa when the n-propanol is completely collected and the temperature at the top of the kettle is reduced to normal temperature; kettle capable of raising temperature againControlling the temperature of the inner material at the bottom of the kettle to be 80-100 ℃, controlling the temperature at the top of the kettle to be 50-65 ℃, carrying out total reflux for 30min, and then starting to receive the mixture of ethylene glycol monopropyl ether and n-propanol, wherein the reflux ratio is controlled to be 5: 1, taking liquid during the period to detect the content of ethylene glycol monopropyl ether in the mixture, starting to receive the finished product of ethylene glycol monopropyl ether alone when the content of ethylene glycol monopropyl ether in the receiving liquid is more than or equal to 99.7 percent, stopping receiving when the purity of ethylene glycol monopropyl ether in the fraction is less than or equal to 99.7 percent, and finishing rectification. Cooling the bottom liquid to 40 + -2 deg.C, charging N₂And (3) putting the kettle bottom liquid into a packaging barrel for producing other n-propanol polyether until the pressure of the reaction kettle is 0.00-0.04 MPa.

Technical Field

The invention belongs to the technical field of organic compound synthesis, and particularly relates to a preparation method and a system of ethylene glycol monopropyl ether.

Background

The ethylene glycol monopropyl ether is also called propoxyethanol, is colorless transparent liquid, can be dissolved in organic solvents such as ethanol and acetone, and is miscible with water. The ethylene glycol monopropyl ether has very high dissolving capacity, and has kauri-butanol value (KB value) 5 times that of aromatic hydrocarbon solvent and 17 times that of aliphatic hydrocarbon solvent, so that ethylene glycol monopropyl ether is excellent solvent and may be used widely in nitric acid fiber, industrial paint, etc. Because the evaporation speed of the ethylene glycol monopropyl ether is relatively slow, the ethylene glycol monopropyl ether has obvious effects of improving the gloss of varnish, preventing peeling and the like, and can be used as a diluent in quick-drying paint and enamel paint to increase the adhesion of the paint to wood and metal. Meanwhile, the ethylene glycol monopropyl ether can also be used as a raw material for synthesizing a pesticide herbicide pretilachlor.

The current synthesis process route of ethylene glycol monopropyl ether is polymerization: the catalyst mainly comprises Lewis acid catalyst and alkali metal catalyst. With Lewis acids, e.g. BF₃The catalyst has the characteristics of high catalytic activity and low catalytic temperature, but has more side reactions, high contents of by-products such as dioxane, diethylene glycol and the like, and is not easy to remove. The alkali metal catalyst such as KOH catalyst is easy to produce by-products such as ethylene glycol, diethylene glycol and the like, reaction products are widely distributed, the conversion rate of a target ethylene glycol monopropyl ether product is low, and the content of by-products such as diethylene glycol monopropyl ether, triethylene glycol monopropyl ether and the like is high. Therefore, the existing synthesis process route of ethylene glycol monopropyl ether is necessary to be carried outThe method is optimized to solve the problems of low purity of the synthesized crude product, more byproducts, complex working procedures, high production cost and the like in the existing synthesis process route.

In order to solve the problems of low purity of a synthetic crude product, more byproducts, complex working procedures, high production cost and the like of the existing synthetic process route, the invention provides the preparation method of the ethylene glycol monopropyl ether, which has the advantages of high catalytic selectivity, low production cost, less byproducts, easy operation and high efficiency.

Disclosure of Invention

In order to solve the problems of low purity of a synthesized crude product, more byproducts, complex working procedures, high production cost and the like in the existing synthesis process route of the ethylene glycol monopropyl ether, the invention provides a preparation method and a system of the ethylene glycol monopropyl ether, which have the advantages of high catalytic selectivity, low production cost, less byproducts, easy operation and high efficiency. The technical scheme of the invention is as follows:

the invention provides a preparation system of ethylene glycol monopropyl ether, which comprises an addition rectification integrated reaction kettle, wherein the addition rectification integrated reaction kettle comprises a reaction kettle main body, and a rectification tower is connected above the reaction kettle main body; the reaction kettle main body comprises a reaction feed inlet, a reaction discharge outlet and a material steam outlet, and the material steam outlet is connected with a rectification inlet of the rectification tower; the rectifying tower is provided with the rectifying inlet and the rectifying outlet and is also connected with a vacuum device.

Furthermore, the reaction discharge hole is connected with the reaction feed hole through a material return pipeline, and a filter and a material conveying pump are arranged on the material return pipeline.

Further, a stirring device is also arranged in the reaction kettle main body.

Further, the reaction kettle is provided with an interlayer, and the interlayer is used for introducing a temperature control medium.

Further, the preparation system also comprises a raw material storage tank and a product storage tank, wherein the raw material storage tank and the product storage tank are respectively connected with the addition rectification integrated reaction kettle.

In a second aspect, the present invention provides a method for preparing ethylene glycol monopropyl ether, which uses the above system and the following reaction equation:

the method comprises the following steps: n-propanol and ethylene oxide react under the action of a catalyst to synthesize a crude product of ethylene glycol monopropyl ether; and carrying out reduced pressure rectification on the crude product to obtain a finished product of the ethylene glycol monopropyl ether.

Further, the preparation method comprises the following steps: mixing N-propanol with a catalyst, N₂Adding ethylene oxide under protection to react; separating out the catalyst after the reaction is finished to obtain a crude product of ethylene glycol monopropyl ether; and (2) carrying out reduced pressure rectification on the ethylene glycol monopropyl ether crude product, respectively collecting free n-propanol, an ethylene glycol monopropyl ether finished product and kettle bottom liquid, wherein the separated catalyst and the free n-propanol can be recycled and applied to the reaction process, and the kettle bottom liquid can be directly used for producing an n-propanol polyether surfactant product.

Further, the catalyst is one or a mixture of two of zinc methanesulfonate and zinc p-toluenesulfonate.

Further, the mass ratio of the n-propanol to the ethylene oxide is as follows: 60: (13.2-44), wherein the dosage of the catalyst is 0.3-5 per mill of the total weight of the n-propanol and the ethylene oxide.

Preferably, the reaction temperature of the n-propanol and the ethylene oxide under the catalysis of the catalyst is 110-180 ℃, and the reaction pressure is-0.05-0.60 MPa.

Further, the vacuum rectification specific process comprises the following steps: vacuumizing the addition rectification integrated reaction kettle to-0.05 MPa, controlling the vacuum degree to be constant, heating the ethylene glycol monopropyl ether crude product in the reaction kettle main body, opening rectification and condensation, controlling the temperature of the material at the bottom of the kettle to be 65-80 ℃, controlling the temperature at the top of the kettle to be 50-65 ℃, carrying out total reflux for 30min, then starting to receive the n-propanol, vacuumizing to improve the vacuum degree in the kettle to be more than or equal to-0.098 MPa when the n-propanol is completely collected and the temperature at the top of the kettle is reduced to the normal temperature; heating the materials in the kettle again, controlling the temperature of the materials at the bottom of the kettle to be 80-100 ℃, controlling the temperature at the top of the kettle to be 50-65 ℃, carrying out total reflux for 30min, and then beginning to receive ethylene glycol monopropylEther and n-propanol mixture, controlling reflux ratio at 5: 1, taking liquid during the period to detect the content of ethylene glycol monopropyl ether in the mixture, starting to receive the finished product of ethylene glycol monopropyl ether alone when the content of ethylene glycol monopropyl ether in the receiving liquid is more than or equal to 99.7 percent, stopping receiving when the purity of ethylene glycol monopropyl ether in the fraction is less than or equal to 99.7 percent, and finishing rectification. Cooling the bottom liquid to 40 + -2 deg.C, charging N₂And (3) putting the kettle bottom liquid into a packaging barrel for producing other n-propanol polyether until the pressure of the reaction kettle is 0.00-0.04 MPa.

Compared with the prior art, the method has the following outstanding advantages and positive effects:

1. the ethylene glycol monopropyl ether prepared by the method has high purity (more than or equal to 99.8 percent) and few byproducts.

2. The preparation method has the advantages of simple process, mild reaction conditions, good selectivity, short production period, low energy consumption, repeated utilization of the catalyst and less three wastes.

3. The preparation system integrates the addition reaction and the rectification process, and the rectification step is directly carried out in the same reaction kettle after the addition reaction is finished, so that the equipment requirement is reduced, the cost is reduced, material transfer is not needed, the material pollution probability is avoided, and the product quality can be ensured.

Drawings

FIG. 1 is a schematic view of the structure of a production system of the present invention.

Fig. 2 is a schematic structural view of a rectifying column of the present invention.

In fig. 1 and 2, 1: ethylene oxide storage tank, 2: material transfer pump, 3: catalyst filter, 4: reaction kettle main body, 5: rectifying tower, 6: n-propanol storage tank, 7: ethylene glycol monopropyl ether reservoir, 8: vacuum pipeline, 9, branch pipeline, 10, reaction feed inlet, 11, reaction discharge outlet, 12, temperature-control steam outlet/cooling water inlet, 13, protective gas port, 14, rectification inlet, 15, rectification outlet, 16, stirring device, 17, interlayer, 18, control valve, 19, vacuumizing port on the storage tank, 20, protective gas port on the storage tank, 21, sampling port, 22, storage tank material outlet, 23, material return pipeline, 24, storage tank material inlet, 25 condenser, 26, temperature-control steam inlet/cooling water outlet, 27, check valve, 28 and vacuum device.

Detailed Description

In the description of the present invention, it is to be noted that those whose specific conditions are not specified in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturers. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The present invention will now be described in further detail with reference to the following figures and specific examples, which are intended to be illustrative, but not limiting, of the invention.

Preparation of the reaction kettle before implementation: washing the main body of the reaction kettle, the rectifying tower, the raw material storage tank and the product storage tank with distilled water for several times until the main body, the rectifying tower, the raw material storage tank and the product storage tank are clean, and heating N₂And blowing and drying the reaction kettle main body, the rectifying tower and the storage tank, and cooling to normal temperature for later use.