阅读说明：本技术 一种2-甲基-3-丁炔-2-醇的分离方法 (Separation method of 2-methyl-3-butyne-2-ol ) 是由 鲍元野 杨颖� 刘英俊 张永振 黎源 于 2020-07-20 设计创作，主要内容包括：本发明属于炔属醇类生产的技术领域,尤其涉及一种2-甲基-3-丁炔-2-醇的分离方法,包括：将含有2-甲基-3-丁炔-2-醇的反应液进行预处理,除去其中未反应的丙酮和含有的盐,得到2-甲基-3-丁炔-2-醇粗品；所述含有2-甲基-3-丁炔-2-醇的反应液中,控制2,5-二甲基-3-己炔-2,5-二醇的含量≤0.1wt％；通过膜分离处理和减压精馏处理,对所述2-甲基-3-丁炔-2-醇粗品进行分离和纯化,得到2-甲基-3-丁炔-2-醇产品。本发明方法在投资及能耗降低的情况下可除去产物中的水和降低2,5-二甲基-3-己炔-2,5-二醇的含量,得到纯度和转化率均较高的2-甲基-3-丁炔-2-醇。(The invention belongs to the technical field of acetylene alcohol production, and particularly relates to a separation method of 2-methyl-3-butyne-2-alcohol, which comprises the following steps: pretreating reaction liquid containing 2-methyl-3-butyn-2-ol, and removing unreacted acetone and contained salt to obtain a crude product of 2-methyl-3-butyn-2-ol; in the reaction liquid containing the 2-methyl-3-butyne-2-ol, the content of the 2, 5-dimethyl-3-hexyne-2, 5-diol is controlled to be less than or equal to 0.1 wt%; separating and purifying the crude product of the 2-methyl-3-butyn-2-ol by membrane separation treatment and vacuum rectification treatment to obtain a 2-methyl-3-butyn-2-ol product. The method can remove water in the product and reduce the content of 2, 5-dimethyl-3-hexyne-2, 5-diol under the condition of reducing investment and energy consumption, and obtains the 2-methyl-3-butyne-2-ol with higher purity and conversion rate.)

1. A method for separating 2-methyl-3-butyn-2-ol, comprising:

(1) a pretreatment procedure: pretreating reaction liquid containing 2-methyl-3-butyn-2-ol, and removing unreacted acetone and contained salt to obtain a crude product of 2-methyl-3-butyn-2-ol; in the reaction liquid containing the 2-methyl-3-butyn-2-ol, the content of the 2, 5-dimethyl-3-hexyne-2, 5-diol is controlled to be less than or equal to 0.1wt percent, preferably less than or equal to 0.06wt percent;

(2) separation and purification procedures: separating and purifying the crude product of the 2-methyl-3-butyn-2-ol by membrane separation treatment and vacuum rectification treatment to obtain a 2-methyl-3-butyn-2-ol product.

2. The separation method according to claim 1, characterized in that it comprises the steps of:

(1) a pretreatment procedure: rectifying the reaction liquid containing the 2-methyl-3-butyn-2-ol to remove acetone, and distilling or rectifying to desalt to obtain a crude product of the 2-methyl-3-butyn-2-ol;

in the crude product of the 2-methyl-3-butyn-2-ol, the content of water is 10 to 40 weight percent, the content of acetone is less than or equal to 1 weight percent, and the content of 2, 5-dimethyl-3-hexyne-2, 5-diol is less than or equal to 0.1 weight percent;

(2) separation and purification procedures: performing membrane separation treatment on the crude product of the 2-methyl-3-butyn-2-ol to obtain a mixture containing the 2-methyl-3-butyn-2-ol, wherein the content of water is less than or equal to 5%; then carrying out vacuum rectification treatment on the mixture containing the 2-methyl-3-butyn-2-ol to obtain a 2-methyl-3-butyn-2-ol product, wherein the content of water is less than or equal to 1 wt%;

preferably, the 2-methyl-3-butyn-2-ol product in the step (2) has the content of 2, 5-dimethyl-3-hexyne-2, 5-diol of less than or equal to 0.01 wt%.

3. The separation method according to claim 1 or 2, wherein in the membrane separation treatment of step (2), at least one membrane separator for separating water from 2-methyl-3-butyn-2-ol is used; a hydrophilic membrane is arranged in the membrane separator;

preferably, the hydrophilic membrane is selected from a polyvinyl alcohol membrane, a polyimide membrane or a ceramic membrane, more preferably a polyvinyl alcohol membrane or a polyimide membrane;

preferably, the operating temperature of the membrane separation treatment using the hydrophilic membrane is 0 ℃ or higher and 100 ℃ or lower.

4. The separation method according to any one of claims 1 to 3, wherein the operation process of step (2) comprises:

(i) treating the crude 2-methyl-3-butyn-2-ol product by a membrane separator, and separating an aqueous organic phase stream and an aqueous phase stream; wherein, in the aqueous organic phase stream, the content of water is less than or equal to 5 wt%, and the content of 2-methyl-3-butyn-2-ol is more than or equal to 90 wt%; in the water phase stream, the content of water is more than or equal to 95 wt%, and the content of 2-methyl-3-butyn-2-ol is less than or equal to 1 wt%;

(ii) the organic phase flow strand containing water enters a crude rectifying tower for treatment, and a light component flow is extracted from the top of the crude rectifying tower, wherein the content of water in the light component flow is 5-30 wt%; a heavy component stream to be removed is extracted from the bottom of the crude rectifying tower, and the content of water in the heavy component stream to be removed is less than or equal to 1 wt%;

(iii) the stream of the heavy components to be removed enters a product separation tower for treatment, and a product stream is collected from the top of the product separation tower; in the product stream, the content of 2-methyl-3-butyn-2-ol is more than or equal to 99 wt%, the content of water is less than or equal to 1 wt%, and the content of 2, 5-dimethyl-3-hexyne-2, 5-diol is less than or equal to 0.01 wt%; a heavy component stream is extracted from the bottom of the product separation tower, wherein the content of the 2-methyl-3-butyne-2-ol in the heavy component stream is less than or equal to 70 wt%;

preferably, the stream of the heavy component to be removed enters from the middle of the product separation column.

5. The separation method according to claim 4, wherein the number of theoretical plates of the rectifying section of the crude rectifying tower is more than or equal to 5, preferably 10 to 15;

preferably, the operating pressure of the crude distillation column is 50hPa to 300hPa, more preferably 100hPa to 200 hPa; the operation temperature of the tower kettle of the crude rectifying tower is 100-130 ℃, and more preferably 110-125 ℃.

6. The separation process according to claim 4, wherein the product separation column has a theoretical plate number of 5 or more, preferably 10 to 15;

preferably, the operating pressure of the product separation column is 50hPa to 300hPa, more preferably 100hPa to 200 hPa; the operation temperature of the tower kettle of the product separation tower is 100-130 ℃, and more preferably 110-125 ℃.

7. The separation method according to any one of claims 1 to 6, wherein the obtained 2-methyl-3-butyn-2-ol product has a water content of 1 wt.% or less and a 2, 5-dimethyl-3-hexyn-2, 5-diol content of 0.01 wt.% or less after the separation and purification steps.

8. The separation method according to any one of claims 1 to 7, wherein the reaction liquid containing 2-methyl-3-butyn-2-ol is prepared by a method comprising:

mixing acetone, acetylene and divalent metal salt in liquid ammonia to react by using strong base as a catalyst; after the reaction is finished, adding a weakly acidic aqueous solution to neutralize the catalyst in the system, and preparing a reaction solution containing 2-methyl-3-butyne-2-ol; in the reaction liquid containing the 2-methyl-3-butyne-2-ol, the content of the 2, 5-dimethyl-3-hexyne-2, 5-diol is less than or equal to 0.1 wt%.

9. The separation method according to claim 8, wherein the divalent metal salt is selected from one or more of a divalent zinc salt, a divalent magnesium salt and a divalent cobalt salt, preferably one or more of zinc acetate, magnesium sulfate and cobalt chloride, further preferably zinc acetate and/or magnesium sulfate, more preferably zinc acetate.

10. The separation method according to claim 8 or 9, wherein the divalent metal salt is used in an amount of 0.01% to 0.1%, preferably 0.02% to 0.05% by mass of acetone.

11. The separation process according to any one of claims 8 to 10, wherein the molar ratio of acetylene to acetone is greater than or equal to 1:1 and less than or equal to 3:1, preferably from 1.05:1 to 2: 1.

Technical Field

The invention belongs to the technical field of acetylene alcohol production, and particularly relates to a separation method of high-purity 2-methyl-3-butyne-2-alcohol.

Background

2-methyl-3-butyn-2-ol is one of important acetylene alcohol chemicals and is mainly applied to the fields of corrosion inhibitors, food and medicine, other chemical products and the like. In the application aspect of the corrosion inhibitor, the molecules of the 2-methyl-3-butyn-2-ol have both polar groups and nonpolar groups, so the corrosion inhibitor can be used as an adsorption type corrosion inhibitor and can effectively prevent metal hydrogen embrittlement.

In addition, the downstream product methyl heptenone of 2-methyl-3-butyn-2-ol is an important medical intermediate and food intermediate, and can be used for further preparing linalool, citral and pseudoionone, and further preparing vitamin A, vitamin E, vitamin K1 and various spice essences. Furthermore, the 2-methyl-3-butyn-2-ol can generate tert-amyl alcohol, also called tert-amyl alcohol, after hydrogenation, and is mainly applied to synthetic perfumes, color developing agents of color cinematographic films, plasticizers, pesticides, medicines, dyes, metal flotation agents, organic solvents and the like. The 2-methyl-3-butyn-2-ol is partially hydrogenated to generate methyl butenol, and the prepared monomer can be used for producing 1, 4-cis polyisoprene which can be used for synthesizing rubber.

Disclosure of Invention

Aiming at the problems that the conversion rate and selectivity of products are reduced and the content of 2, 5-dimethyl-3-hexyne-2, 5-diol is higher in the preparation and separation processes of 2-methyl-3-butyne-2-ol in the prior art, the invention aims to provide a separation method of high-purity 2-methyl-3-butyne-2-ol, which can effectively control the content of 2, 5-dimethyl-3-hexyne-2, 5-diol in a reaction liquid containing 2-methyl-3-butyne-2-ol, ensure the separation effect of membrane separation treatment in the separation and purification procedures and the service life of a membrane, further realize effective separation and purification and obtain a high-purity 2-methyl-3-butyne-2-ol product, improve the color number and the refractive index of the 2-methyl-3-butine-2-alcohol product.

In order to achieve the purpose, the technical scheme provided by the invention is as follows:

a method of isolating 2-methyl-3-butyn-2-ol comprising:

(1) a pretreatment procedure: pretreating reaction liquid containing 2-methyl-3-butyn-2-ol, and removing unreacted acetone and contained salt to obtain a crude product of 2-methyl-3-butyn-2-ol; in the reaction liquid containing the 2-methyl-3-butyn-2-ol, the content of the 2, 5-dimethyl-3-hexyne-2, 5-diol is controlled to be less than or equal to 0.1wt percent, preferably less than or equal to 0.06wt percent;

(2) separation and purification procedures: separating and purifying the crude product of the 2-methyl-3-butyn-2-ol by membrane separation treatment and vacuum rectification treatment to obtain a 2-methyl-3-butyn-2-ol product.

According to the separation method provided by the invention, in some examples, the separation method comprises the following steps:

(1) a pretreatment procedure: rectifying the reaction liquid containing the 2-methyl-3-butyn-2-ol to remove acetone, and distilling or rectifying to desalt to obtain a crude product of the 2-methyl-3-butyn-2-ol;

in the crude product of the 2-methyl-3-butyn-2-ol, the content of water is 10 to 40 weight percent, the content of acetone is less than or equal to 1 weight percent, and the content of 2, 5-dimethyl-3-hexyne-2, 5-diol is less than or equal to 0.1 weight percent;

(2) separation and purification procedures: performing membrane separation treatment on the crude product of the 2-methyl-3-butyn-2-ol to obtain a mixture containing the 2-methyl-3-butyn-2-ol, wherein the content of water is less than or equal to 5%; and then carrying out vacuum rectification treatment on the mixture containing the 2-methyl-3-butyn-2-ol to obtain a 2-methyl-3-butyn-2-ol product, wherein the content of water is less than or equal to 1 wt%.

In some examples, the acetone removal and desalination processes performed in the pretreatment step of step (1) are not in sequence, that is, the acetone may be removed first and then desalinated, or the acetone may be desalted first and then desalinated.

For example, the acetone removal can be achieved by means of rectification. Optionally, a rectification column, which may be a tray column or a packed column, is used for acetone removal, as is well known to those skilled in the art. In some examples, the reaction liquid obtained by the alkynylation reaction is subjected to acetone removal treatment by using an atmospheric distillation mode in the process of using the distillation tower. For example, the operation temperature of the bottom of the rectifying tower is 90-93 ℃, the reflux ratio is 3:1, and the acetone content in the reaction liquid after acetone removal treatment can be lower than 0.5 wt%.

Desalination can be achieved, for example, by distillation or rectification, as is well known to those skilled in the art. In some examples, the desalting device can be a thin film evaporator or a short path distiller, preferably a horizontal thin film evaporator, a metal scraper operated at normal pressure, and an external circulating 80-120 ℃ oil bath.

In order to increase the lifetime of the permeable membrane used in the membrane separation process, the content of 2, 5-dimethyl-3-hexyne-2, 5-diol contained in the crude 2-methyl-3-butyn-2-ol needs to be strictly limited to less than 0.1 wt%. The content of 2, 5-dimethyl-3-hexyne-2, 5-diol has a very adverse effect on the service life of the osmotic membrane, and if the content of 2, 5-dimethyl-3-hexyne-2, 5-diol is too high, the pore channels of the osmotic membrane are blocked, so that the flux is reduced, the service life of the membrane is influenced, and the water removal effect is influenced. Therefore, in order to ensure the service life of the permeable membrane used in the membrane separation process and the separation and water removal effects, the content of the byproduct 2, 5-dimethyl-3-hexyne-2, 5-diol in the reaction liquid obtained by the ethynylation reaction can be controlled.

In order to ensure the product quality, the content of 2, 5-dimethyl-3-hexyne-2, 5-diol in the finally obtained 2-methyl-3-butyne-2-ol product can be controlled. In some preferred embodiments, the 2-methyl-3-butyn-2-ol product of step (2) has a 2, 5-dimethyl-3-hexyn-2, 5-diol content of 0.01 wt% or less.

In some examples, in the membrane separation treatment of step (2), at least one membrane separator for separating water from 2-methyl-3-butyn-2-ol is used; the membrane separator is provided with a hydrophilic membrane (or a permeable membrane).

In some preferred embodiments, the hydrophilic membrane is selected from a polyvinyl alcohol membrane, a polyimide membrane, or a ceramic membrane, more preferably a polyvinyl alcohol membrane or a polyimide membrane.

In some examples, the operating temperature of the membrane separation process using the hydrophilic membrane is 0 ℃ or higher and 100 ℃ or lower (e.g., 20 ℃, 40 ℃, 60 ℃, 80 ℃).

Alternatively, the hydrophilic membrane may also be, for example, a ceramic membrane based on zeolite a. The ceramic membrane used for pervaporation comprises a nanoporous layer on a macroporous support. The pores must be large enough to allow the passage of water molecules and small enough to retain 2-methyl-3-butyn-2-ol. The surface may be modified by a specific coating or treatment. Such films have been used to remove water from organic reaction mixtures and are available from FOLEX, switzerland. The material of the hydrophilic membrane is well known to those skilled in the art and will not be described herein.

According to the separation method provided by the invention, in some preferred embodiments, the operation process of the step (2) comprises:

(i) treating the crude 2-methyl-3-butyn-2-ol product by a membrane separator, and separating an aqueous organic phase stream and an aqueous phase stream; wherein, in the aqueous organic phase stream (based on the total weight of all components in the aqueous organic phase stream being 100 wt%), the content of water is less than or equal to 5 wt%, and the content of 2-methyl-3-butyn-2-ol is greater than or equal to 90 wt%; in the water phase stream, the content of water is more than or equal to 95 wt%, and the content of 2-methyl-3-butyn-2-ol is less than or equal to 1 wt% (based on the total weight of all components in the water phase stream as 100 wt%);

(ii) the organic phase flow strand containing water enters a crude distillation column for treatment, a light component flow is extracted from the top of the crude distillation column, and the content of water in the light component flow (calculated by the total weight of all components in the light component flow being 100 wt%) is 5-30 wt%; a stream to be subjected to heavy component removal is extracted from the bottom of the crude rectifying tower, wherein the content of water in the stream to be subjected to heavy component removal is less than or equal to 1 wt% (based on the total weight of all components in the stream to be subjected to heavy component removal being 100 wt%);

(iii) the stream of the heavy components to be removed enters a product separation tower for treatment, and a product stream is collected from the top of the product separation tower; in the product stream (based on the total weight of all components in the product stream being 100 wt%), the content of 2-methyl-3-butyn-2-ol is more than or equal to 99 wt%, the content of water is less than or equal to 1 wt%, and the content of 2, 5-dimethyl-3-hexyne-2, 5-diol is less than or equal to 0.01 wt%; and (3) a heavy component stream is produced at the bottom of the product separation tower, wherein the content of the 2-methyl-3-butyne-2-ol in the heavy component stream (calculated by taking the total weight of all components in the heavy component stream as 100 wt%) is less than or equal to 70 wt%.

The heavy component stream has high molecular weight component ratio and high viscosity, so that a part of 2-methyl-3-butyn-2-ol product is required to be present for ensuring the fluidity of the stream.

The crude distillation column here is such that sufficiently ideal separation conditions can be achieved. In some examples, the number of theoretical plates in the rectifying section of the crude rectifying tower is more than or equal to 5 (for example, 6, 8, 12, 14, 20), and preferably 10 to 15.

In some examples, the crude rectification column is operated at a pressure of 50hPa to 300hPa (e.g., 60hPa, 80hPa, 150hPa, 200hPa, 250hPa), preferably 100hPa to 200 hPa; the operation temperature of the bottom of the crude distillation column is 100 ℃ to 130 ℃ (for example, 115 ℃ and 120 ℃), preferably 110 ℃ to 125 ℃.

In some examples, the heavy component to be removed stream from the bottom of the crude distillation column enters from the middle of the product separation column, and 2-methyl-3-butyn-2-ol is separated from other components in the product separation column.

In some examples, the product separation column has a theoretical plate number of 5 or more (e.g., 6, 8, 12, 14, 20), preferably 10 to 15;

in some examples, the product separation column is operated at a pressure of 50hPa to 300hPa (e.g., 60hPa, 80hPa, 150hPa, 200hPa, 250hPa), preferably 100hPa to 200 hPa; the operating temperature of the bottom of the product separation tower is 100 ℃ to 130 ℃ (for example, 115 ℃ and 120 ℃), and is preferably 110 ℃ to 125 ℃.

The quality of the product 2-methyl-3-butyn-2-ol can be influenced by the content of the byproduct 2, 5-dimethyl-3-hexyne-2, 5-diol contained in the product, namely, the color number and the refractive index of the 2-methyl-3-butyn-2-ol product can be adversely influenced; therefore, the content of the by-product can be further effectively controlled by adjusting the parameters of the process conditions during the process of removing water therefrom. In some examples, after the separation and purification steps, the resulting 2-methyl-3-butyn-2-ol product has a water content of less than or equal to 1 wt.% (e.g., 0.8 wt.%, 0.5 wt.%, 0.3 wt.%, 0.1 wt.%) and a 2, 5-dimethyl-3-hexyne-2, 5-diol content of less than or equal to 0.01 wt.% (e.g., 0.008 wt.%, 0.005 wt.%, 0.003 wt.%, 0.001 wt.%).

According to the separation method provided by the invention, in some preferred embodiments, the reaction liquid containing 2-methyl-3-butyn-2-ol is prepared by a method comprising the following steps:

mixing acetone, acetylene and divalent metal salt in liquid ammonia to react by using strong base as a catalyst; after the reaction is finished, adding a weakly acidic aqueous solution to neutralize the catalyst in the system, and preparing a reaction solution containing 2-methyl-3-butyne-2-ol; the reaction solution containing 2-methyl-3-butyn-2-ol contains 2, 5-dimethyl-3-hexyne-2, 5-diol in an amount of 0.1 wt% or less (for example, in an amount of 0.08 wt%, 0.06 wt%, 0.04 wt%, 0.02 wt%).

In the preparation of the reaction solution, the reaction temperature and time are well known to those skilled in the art and will not be described herein.

Both strong and weak acidic aqueous solutions herein can be routinely selected in the art. For example, the strong base may be selected from sodium hydroxide, potassium hydroxide; the weakly acidic aqueous solution may be selected from aqueous ammonium sulfate solutions. The amount of the strong base to be used in the reaction system is well known to those skilled in the art and will not be described herein. The amount of the weakly acidic aqueous solution to be added is, for example, an amount capable of neutralizing a strong base present in the reaction system just enough.

The reaction solution obtained by the ethynylation reaction contains various other components, such as a by-product of 2, 5-dimethyl-3-hexyne-2, 5-diol, water, unreacted raw material acetone, inorganic salts or other impurities, in addition to 2-methyl-3-butyn-2-ol. In some examples, the reaction liquid containing 2-methyl-3-butyn-2-ol contains 10-40 wt% of water and 1-20 wt% of unreacted raw material acetone (based on 100 wt% of the total weight of the components in the reaction liquid). In the reaction solution, the amount of the inorganic salt contained is related to the amounts of the strong base and the weakly acidic aqueous solution added during the reaction.

According to the separation method provided by the present invention, in some examples, the divalent metal salt is selected from one or more of a divalent zinc salt, a divalent magnesium salt and a divalent cobalt salt, preferably one or more of zinc acetate, magnesium sulfate and cobalt chloride, more preferably zinc acetate and/or magnesium sulfate, and more preferably zinc acetate.

In some examples, the divalent metal salt is used in an amount of 0.01% to 0.1% (e.g., 0.015%, 0.03%, 0.05%, 0.08%, 0.09%) by mass of acetone, preferably 0.02% to 0.05%.

In some examples, the molar ratio of acetylene to acetone is greater than or equal to 1:1 and less than or equal to 3:1 (e.g., 1.1:1, 1.3:1, 1.5:1, 1.8:1, 2.2:1, 2.5:1, 2.8:1), preferably 1.05:1 to 2:1, during the preparation of the reaction solution. Under the condition of proper molar ratio of acetylene to acetone, the divalent metal salt is added into the system, so that the content of 2, 5-dimethyl-3-hexyne-2, 5-diol in the reaction liquid containing the 2-methyl-3-butyn-2-ol can be effectively controlled, and the reaction liquid is ensured to be in a lower content range (less than or equal to 0.1 wt%).

During the reaction, the effect of controlling the molar ratio of acetone to acetylene within this range is: under the condition of ensuring a certain acetylene content, divalent metal salt is introduced to inhibit the generation of byproducts and improve the selectivity of the product; meanwhile, on the premise of ensuring safety, the energy loss can be reduced by reducing the molar ratio of acetylene to acetone, and the cost is saved. In order to integrate the selectivity of the product and the energy consumption, the molar ratio of acetylene to acetone is preferably 1.05: 1-2: 1.

On one hand, the selectivity of the ethynylation reaction product can be improved by adjusting the adding amount of acetylene in the ethynylation reaction and adding divalent metal salt in the system, and the content of the byproduct 2, 5-dimethyl-3-hexyne-2, 5-diol in the prepared reaction liquid can be effectively controlled. The amount of the divalent metal salt added also affects the content of 2, 5-dimethyl-3-hexyne-2, 5-diol in the reaction solution. The content of the 2, 5-dimethyl-3-hexyne-2, 5-diol in the reaction liquid is controlled to be less than or equal to 0.1 weight percent, so that the membrane separation effect in the separation and purification procedures can be ensured, and the service life of the permeable membrane can be prolonged. On the other hand, the content of the 2, 5-dimethyl-3-hexyne-2, 5-diol in the separated product can be controlled in the process of separating the reaction liquid containing the 2-methyl-3-butyne-2-ol, so that the content of the reaction liquid is further reduced, and the quality of the obtained product is ensured.

Compared with the prior art, the technical scheme of the invention has the following beneficial effects:

by the separation method, water in the 2-methyl-3-butyn-2-ol product can be removed and the content of 2, 5-dimethyl-3-hexyne-2, 5-diol can be reduced under the condition of reducing investment and energy consumption, and the 2-methyl-3-butyn-2-ol with higher purity and conversion rate can be prepared.

Under the working condition that the molar ratio of acetylene to acetone is low, by adding divalent metal salt into the system, the generation of byproducts in the reaction process can be effectively inhibited, so that the content of 2, 5-dimethyl-3-hexyne-2, 5-diol in the obtained reaction liquid containing 2-methyl-3-butyne-2-ol is controlled to be in a lower range (for example, less than or equal to 0.1wt percent), and the product selectivity is improved; meanwhile, the energy consumption and the purification difficulty can be reduced.

By strictly controlling the content of the key component 2, 5-dimethyl-3-hexyne-2, 5-diol in the obtained reaction liquid containing 2-methyl-3-butyne-2-ol, the water removal effect in the membrane separation process and the service life of the used permeable membrane can be improved, the replacement frequency of the permeable membrane is obviously reduced, for example, the replacement is changed from monthly replacement to once every half year, and the separation cost is reduced.

By controlling the content of a key component 2, 5-dimethyl-3-hexyne-2, 5-diol in the obtained reaction liquid containing the 2-methyl-3-butyne-2-ol, powerful conditions are provided for further membrane separation treatment and rectification treatment of a crude product of the 2-methyl-3-butyne-2-ol, so that the 2-methyl-3-butyne-2-ol in the product is fully separated from the water, meanwhile, the content of 2, 5-dimethyl-3-hexyne-2, 5-diol (for example, less than or equal to 0.01 wt%) is further reduced, the purpose of controlling the quality of the product 2-methyl-3-butyne-2-ol is achieved, and qualified products with high quality and high purity can be obtained.

The membrane separation process is adopted to replace the original azeotropic distillation process, so that the operation process is simplified, and the industrial controllability is better.

Drawings

FIG. 1 is a process flow diagram of a separation and purification process in one embodiment of the separation method of the present invention.

The reference numerals in the figures are explained below:

1-2-methyl-3-butyn-2-ol crude product, 2-aqueous organic phase stream, 3-aqueous phase stream, 4-light components stream, 5-heavy components to be removed stream, 6-product stream, 7-heavy components stream;

SEP-membrane separator, RAC 1-crude distillation column, COOLER 1-overhead condenser, REBOILER 1-bottom REBOILER;

RAC2 product splitter, COOLER2 overhead condenser, REBOILER2 bottoms REBOILER.

Detailed Description

In order that the technical features and contents of the present invention can be understood in detail, preferred embodiments of the present invention will be described in more detail below. While the preferred embodiments of the present invention have been described in the examples, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein.

< sources of raw materials >

99 wt% of acetone and Shandong vitamin chemical industry;

acetylene, 98 wt%, Qingdao acetylene gas, Inc.;

99 wt% of liquid ammonia, Dongying Hengsheng chemical Co., Ltd;

magnesium sulfate, 99 wt%, carbofuran technologies ltd;

zinc acetate, 99 wt%, welfare technologies ltd;

potassium hydroxide, denna blooms chemical ltd;

ammonium sulfate, 99 wt%, largeway technologies ltd.

< analytical method >

The test methods for each example and comparative example are as follows:

1. the composition of each component in the stream adopts a gas chromatograph: agilent7820A, column HP-5(30 m.times.320. mu.m.times.0.25 μm), injection port temperature: 150 ℃; the split ratio is 50: 1; carrier gas flow: 1.5 ml/min;

temperature rising procedure: keeping at 40 deg.C for 1min, heating to 90 deg.C at 10 deg.C/min for 0min, heating to 160 deg.C at 5 deg.C/min for 0min, heating to 280 deg.C at 30 deg.C/min for 6 min. Detector temperature: 280 ℃.

2. Refractive index test of the product: METTLER TOLEDO refractometer Easy R40 was used.

3. Color number test of the product: a HANNA platinum cobalt (Pt-Co) colorimeter was used.