阅读说明：本技术 一种含氟醇纯化方法 (Method for purifying fluorine-containing alcohol ) 是由 谢伟东 邹灿 吴成英 林登高 谢德兴 张何聪 于 2020-06-15 设计创作，主要内容包括：为克服现有含氟醇纯化方法提纯后的含氟醇存在纯度不足的问题,本发明提供了一种含氟醇纯化方法,包括以下操作步骤：将含有非含氟醇的含氟醇混合物和水作为原料混合物进行一次精馏操作,使含氟醇初产物精馏采出分离,收集含氟醇初产物的馏分,原料混合物分离含氟醇初产物后塔底得到非含氟醇/水混合物；将非含氟醇/水混合物继续进行二次精馏操作,使非含氟醇精馏采出分离,收集非含氟醇的馏分,非含氟醇/水混合物分离非含氟醇后塔底得到水；将分离非含氟醇后的水作为原料混合物中的水连续循环利用。本发明提供的含氟醇纯化方法具有分离度好、操作简单、成本低、易于产业化的优势。(In order to overcome the problem that the purity of the fluorine-containing alcohol purified by the existing fluorine-containing alcohol purification method is insufficient, the invention provides a fluorine-containing alcohol purification method, which comprises the following operation steps: carrying out primary rectification operation on a fluorine-containing alcohol mixture containing non-fluorine-containing alcohol and water serving as a raw material mixture to rectify, extract and separate a fluorine-containing alcohol primary product, collecting fractions of the fluorine-containing alcohol primary product, and obtaining a non-fluorine-containing alcohol/water mixture at the bottom of a tower after the fluorine-containing alcohol primary product is separated from the raw material mixture; continuing to perform secondary rectification operation on the non-fluorine-containing alcohol/water mixture to enable the non-fluorine-containing alcohol to be rectified, extracted and separated, collecting the fraction of the non-fluorine-containing alcohol, and obtaining water at the bottom of the tower after the non-fluorine-containing alcohol/water mixture is separated from the non-fluorine-containing alcohol; and continuously recycling the water after the non-fluorine-containing alcohol is separated as the water in the raw material mixture. The method for purifying the fluorine-containing alcohol has the advantages of good separation degree, simple operation, low cost and easy industrialization.)

1. A method for purifying a fluorine-containing alcohol, comprising the following steps:

carrying out primary rectification operation on a fluorine-containing alcohol mixture containing non-fluorine-containing alcohol and water serving as a raw material mixture to rectify, extract and separate a fluorine-containing alcohol primary product, collecting fractions of the fluorine-containing alcohol primary product, and separating the fluorine-containing alcohol primary product from the raw material mixture to obtain a non-fluorine-containing alcohol/water mixture;

continuing to perform secondary rectification operation on the non-fluorine-containing alcohol/water mixture to separate the non-fluorine-containing alcohol by rectification, collecting the fraction of the non-fluorine-containing alcohol, and separating the non-fluorine-containing alcohol from the non-fluorine-containing alcohol/water mixture to obtain water;

and recycling the water after the non-fluorine-containing alcohol is separated as the water in the raw material mixture.

2. The method for purifying a fluorine-containing alcohol according to claim 1, wherein the primary distillation operation is carried out in a first distillation column, water is fed from an upper part of the first distillation column, a fluorine-containing alcohol mixture containing a non-fluorine-containing alcohol is fed from a lower part of the first distillation column, a fraction of the fluorine-containing alcohol primary product is taken out from the top of the column, and the non-fluorine-containing alcohol/water mixture is taken out from the bottom of the column; the secondary rectification operation is carried out in a second rectification tower, the fraction containing no fluorine alcohol is extracted from the top of the tower, and the water after separating the non-fluorine alcohol is led out from the bottom of the tower.

3. The method for purifying a fluoroalcohol according to claim 2, wherein the first rectifying column is operated at an operating pressure of-0.05 to 0.2MPa, a reflux ratio of 1 to 20, and a theoretical plate number of 20 to 90;

the operating pressure of the second rectifying tower is-0.05-0.2 MPa, the reflux ratio is 0.5-30, and the number of theoretical plates is 10-60.

4. The method for purifying a fluoroalcohol according to claim 1, wherein the obtained fluoroalcohol crude product is dried with a drying agent to remove water, thereby obtaining the fluoroalcohol product.

5. The method of claim 4, wherein the drying agent comprises one or more of a molecular sieve drying agent, anhydrous sodium sulfate, anhydrous magnesium sulfate, anhydrous calcium chloride, concentrated sulfuric acid, fuming sulfuric acid, and phosphorus pentoxide.

6. The method for purifying a fluorinated alcohol according to claim 1, wherein the fluorinated alcohol comprises one or more of 2,2, 2-trifluoroethanol, 2, 2-difluoroethanol, 2-chloro-2, 2-difluoroethanol, 2,2,3,3,3, 3-pentafluoropropanol, 1,1,1,3,3, 3-hexafluoro-2-propanol, 1,1, 1-trifluoro-2-methyl-2-propanol, 2,2,3,3,4,4, 4-heptafluoro-1-butanol, perfluoro-tert-butanol and 2, 2-bis (trifluoromethyl) propanol.

7. The method of purifying a fluoroalcohol according to claim 1 wherein the non-fluoroalcohol comprises one or more of methanol, ethanol, n-propanol, isopropanol and tert-butanol.

8. The method of purifying a fluorinated alcohol according to claim 1, wherein the mixture of fluorinated alcohols containing a non-fluorinated alcohol does not contain water.

9. The method for purifying a fluorinated alcohol according to claim 1, wherein the mixture of the fluorinated alcohols containing the non-fluorinated alcohol further contains water.

10. The method for purifying a fluorinated alcohol according to claim 1, wherein the mass ratio of the fluorinated alcohol mixture containing a non-fluorinated alcohol to water is 1: 3 to 15.

Technical Field

The invention belongs to the technical field of purification of a fluorine-containing alcohol chemical product, and particularly relates to a purification method of fluorine-containing alcohol.

Background

The fluorine-containing alcohol is not flammable, has small surface tension and can clean small parts; the cleaning agent has good cleaning effect on polyethylene glycol, ester oil and water-soluble flux, can be used as a cleaning agent and a solvent, and in addition, the fluorine-containing alcohol is an important fluorine-containing fine chemical and has wide application in the fields of pesticide, medicine, fluoropolymer synthesis and the like.

The synthesis of the fluorine-containing alcohol mainly comprises an addition method, a catalytic hydrogenation method, a catalytic oxidation method and the like, the non-fluorine-containing alcohol is usually used as a solvent in the reaction process or the existing fluorine-containing alcohol which generates a non-fluorine-containing alcohol byproduct is inevitably introduced into the non-fluorine-containing alcohol in the preparation process in the form of a synthetic raw material or a reaction solvent, in the final product of the reaction, the purity of the fluorine-containing alcohol is affected by the existence of the non-fluorine-containing alcohol, so that some performances of the fluorine-containing alcohol as a surfactant or other processing reagents are affected, purification is required to be carried out in the crude product of the fluorine-containing alcohol, the non-fluorine-containing alcohol is removed to obtain the fluorine-containing alcohol with higher purity, the existing purification mode is mainly realized by a common rectification mode, however, there are some fluorine-containing alcohol products in which a small amount of non-fluorine-containing alcohol is mixed and which have a boiling point close to that of the fluorine-containing alcohol, or forms an azeotrope with the fluorine-containing alcohol, and a small amount of non-fluorine-containing alcohol mixed in the fluorine-containing alcohol product is difficult to further separate by ordinary rectification.

Disclosure of Invention

Aiming at the problem that the purity of the fluorine-containing alcohol purified by the existing fluorine-containing alcohol purification method is insufficient, the invention provides a fluorine-containing alcohol purification method.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the invention provides a method for purifying fluorine-containing alcohol, which comprises the following operation steps:

carrying out primary rectification operation on a fluorine-containing alcohol mixture containing non-fluorine-containing alcohol and water serving as a raw material mixture to rectify, extract and separate a fluorine-containing alcohol primary product, collecting fractions of the fluorine-containing alcohol primary product, and separating the fluorine-containing alcohol primary product from the raw material mixture to obtain a non-fluorine-containing alcohol/water mixture;

continuing to perform secondary rectification operation on the non-fluorine-containing alcohol/water mixture to separate the non-fluorine-containing alcohol by rectification, collecting the fraction of the non-fluorine-containing alcohol, and separating the non-fluorine-containing alcohol from the non-fluorine-containing alcohol/water mixture to obtain water;

and recycling the water after the non-fluorine-containing alcohol is separated as the water in the raw material mixture.

Optionally, the primary rectification operation is performed in a first rectification tower, water is added from the upper part of the first rectification tower, a fluorine-containing alcohol mixture containing non-fluorine-containing alcohol is added from the lower part of the first rectification tower, a fraction of the fluorine-containing alcohol primary product is extracted from the top of the tower, and the non-fluorine-containing alcohol/water mixture is extracted from the bottom of the tower; the secondary rectification operation is carried out in a second rectification tower, the fraction containing no fluorine alcohol is extracted from the top of the tower, and the water after separating the non-fluorine alcohol is led out from the bottom of the tower.

Optionally, the operating pressure of the first rectifying tower is-0.05-0.2 MPa, the reflux ratio is 1-20, and the number of theoretical plates is 20-90;

the operating pressure of the second rectifying tower is-0.05-0.2 MPa, the reflux ratio is 0.5-30, and the number of theoretical plates is 10-60.

Optionally, drying and dehydrating the obtained initial product containing the fluorine alcohol by adopting a drying agent to obtain a product containing the fluorine alcohol.

Optionally, the drying agent includes one or more of a molecular sieve drying agent, anhydrous sodium sulfate, anhydrous magnesium sulfate, anhydrous calcium chloride, concentrated sulfuric acid, fuming sulfuric acid, and phosphorus pentoxide.

Optionally, the fluorine-containing alcohol comprises one or more of 2,2, 2-trifluoroethanol, 2, 2-difluoroethanol, 2-chloro-2, 2-difluoroethanol, 2,2,3,3,3, 3-pentafluoropropanol, 1,1,1,3,3, 3-hexafluoro-2-propanol, 1,1, 1-trifluoro-2-methyl-2-propanol, 2,2,3,3,4,4, 4-heptafluoro-1-butanol, perfluoro-tert-butanol, and 2, 2-bis (trifluoromethyl) propanol.

Optionally, the non-fluorine containing alcohol comprises one or more of methanol, ethanol, n-propanol, isopropanol and tert-butanol.

Optionally, the non-fluoroalcohol containing fluoroalcohol mixture does not contain water.

Optionally, the fluorine-containing alcohol mixture containing the non-fluorine-containing alcohol further contains water.

Optionally, the mass ratio of the fluorine-containing alcohol mixture containing non-fluorine-containing alcohol to water is 1: 3 to 15.

According to the method for purifying the fluorine-containing alcohol, water is used as an additive of a fluorine-containing alcohol mixture containing the non-fluorine-containing alcohol, the affinity between the non-fluorine-containing alcohol and the water is high, the affinity between the fluorine-containing alcohol and the water is low, the relative volatility of the fluorine-containing alcohol and the non-fluorine-containing alcohol is improved by utilizing the existence of the water, the rectification separation efficiency is improved, a high-purity fluorine-containing alcohol initial product is obtained, a good technical effect is obtained, and the method can be used for industrial production for continuously separating the fluorine-containing alcohol and the non-fluorine-containing alcohol. The technical scheme of the invention has the advantages of good separation degree, simple operation, low cost and easy industrialization.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects solved by the present invention more apparent, the present invention is further described in detail below with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

An embodiment of the present invention provides a method for purifying a fluorinated alcohol, including the following steps:

carrying out primary rectification operation on a fluorine-containing alcohol mixture containing non-fluorine-containing alcohol and water serving as a raw material mixture to rectify, extract and separate a fluorine-containing alcohol primary product, collecting fractions of the fluorine-containing alcohol primary product, and separating the fluorine-containing alcohol primary product from the raw material mixture to obtain a non-fluorine-containing alcohol/water mixture;

continuing to perform secondary rectification operation on the non-fluorine-containing alcohol/water mixture to separate the non-fluorine-containing alcohol by rectification, collecting the fraction of the non-fluorine-containing alcohol, and separating the non-fluorine-containing alcohol from the non-fluorine-containing alcohol/water mixture to obtain water;

and recycling the water after the non-fluorine-containing alcohol is separated as the water in the raw material mixture.

The method adopts water as the additive of the fluorine-containing alcohol mixture containing the non-fluorine-containing alcohol, because the affinity of the non-fluorine-containing alcohol and the water is higher, and the affinity of the fluorine-containing alcohol and the water is lower, the relative volatility of the fluorine-containing alcohol and the non-fluorine-containing alcohol is improved by utilizing the existence of the water, the rectification separation efficiency is improved to obtain a high-purity fluorine-containing alcohol initial product, the content of the non-fluorine-containing alcohol can be controlled below 1w percent, better technical effect is obtained, and the method can be used in the industrial production for continuously separating the fluorine-containing alcohol and the non-fluorine-containing alcohol. The technical scheme of the invention has the advantages of good separation degree, simple operation, low cost and easy industrialization.

Wherein, the water is separated in the subsequent secondary rectification operation, the water content in the obtained water after the non-fluorine-containing alcohol is separated can be controlled to be more than 99.95wt percent, and the high-temperature water obtained in the secondary rectification operation is added into the primary rectification operation again to be used as a raw material mixture, so that the water required to be consumed in the primary rectification operation and the heat energy consumed by heating can be effectively reduced.

In some embodiments, the primary rectification operation is performed in a first rectification column, water is fed from the upper part of the first rectification column, a fluorine-containing alcohol mixture containing non-fluorine-containing alcohol is fed from the lower part of the first rectification column, a fraction of the fluorine-containing alcohol primary product is withdrawn from the top of the column, and the non-fluorine-containing alcohol/water mixture is withdrawn from the bottom of the column; the secondary rectification operation is carried out in a second rectification tower, the fraction containing no fluorine alcohol is extracted from the top of the tower, and the water after separating the non-fluorine alcohol is led out from the bottom of the tower.

The first rectification column and the second rectification column may each independently be selected from a tray column including a bubble cap column, a sieve plate column and a float valve column, or a packed column, in a preferred embodiment, the tray column is selected from a sieve plate column, the packing in the packed column includes loose packing and structured packing, and in a preferred embodiment, the packing in the packed column is selected from wire mesh structured packing.

The non-fluorine-containing alcohol extracted from the top of the second rectifying tower can be further used industrially or incinerated.

In some embodiments of the present invention, the,

the water after separating the non-fluorine-containing alcohol is guided out by the second rectifying tower and then needs to be subjected to heat preservation treatment, specifically, the water in the tower kettle of the second rectifying tower is guided into the first rectifying tower through a pipeline and a pump, a heat preservation layer is arranged outside the pipeline, the temperature of the water is kept, and the material temperature fluctuation in the first rectifying tower caused by the over-low temperature of the water is avoided.

Specifically, the fluorine-containing alcohol mixture containing the non-fluorine-containing alcohol is fed to the first rectifying column after being preheated to a bubble point, so as to avoid material temperature fluctuation.

In some embodiments, the first rectification column is operated at a pressure of-0.05 to 0.2MPa, a reflux ratio of 1 to 20, and a theoretical plate number of 20 to 90;

the operating pressure of the second rectifying tower is-0.05-0.2 MPa, the reflux ratio is 0.5-30, and the number of theoretical plates is 10-60.

In some embodiments, the obtained initial product containing fluorine alcohol is dried and dewatered by a drying agent to obtain the product containing fluorine alcohol.

The primary product of the fluorine-containing alcohol after being rectified by the first rectifying tower contains certain moisture, and the residual moisture in the primary product of the fluorine-containing alcohol can be removed in a manner of adding a drying agent, so that the purity of the fluorine-containing alcohol product is improved.

In some embodiments, the desiccant comprises one or more of a molecular sieve desiccant, anhydrous sodium sulfate, anhydrous magnesium sulfate, anhydrous calcium chloride, concentrated sulfuric acid, oleum, phosphorus pentoxide.

In some embodiments, the fluorine-containing alcohol comprises one or more of 2,2, 2-trifluoroethanol, 2,2, -difluoroethanol, 2-chloro-2, 2-difluoroethanol, 2,2,3,3,3, 3-pentafluoropropanol, 1,1,1,3,3, 3-hexafluoro-2-propanol, 1,1, 1-trifluoro-2-methyl-2-propanol, 2,2,3,3,4,4, 4-heptafluoro-1-butanol, perfluoro-tert-butanol, and 2, 2-bis (trifluoromethyl) propanol.

In some embodiments, the non-fluorine containing alcohol comprises one or more of methanol, ethanol, n-propanol, isopropanol, and tert-butanol.

It should be noted that the above are merely some specific examples of the present invention, and do not represent limitations of the present invention.

In some embodiments, the non-fluoroalcohol containing fluoroalcohol mixture does not contain additional water.

In some embodiments, the non-fluoroalcohol containing fluoroalcohol mixture further comprises water.

In some embodiments, the mass ratio of the fluorine-containing alcohol mixture containing a non-fluorine-containing alcohol to water is 1: 3 to 15.

The fluorine-containing alcohol mixture containing the non-fluorine-containing alcohol and the water are continuously fed into the first rectification column in the primary rectification operation, and the material ratio is controlled by controlling the flow rate of the fluorine-containing alcohol mixture containing the non-fluorine-containing alcohol and the water.

The present invention will be further illustrated by the following examples.