阅读说明：本技术 一种连续制备1,4-二氯丁烷的方法 (Method for continuously preparing 1, 4-dichlorobutane ) 是由 董亮 陶文平 马凯 王顺利 张驰 郝祥忠 张明 吴发明 孙运林 于 2021-09-16 设计创作，主要内容包括：本发明涉及一种连续制备1,4-二氯丁烷的方法,属于化学产品制备技术领域。本发明公开了一种连续制备1,4-二氯丁烷的方法,将四氢呋喃与氯化氢在装有惰性填料的强化管道反应器中加路易斯酸催化剂强制循环反应得到粗品,经过两次减压精馏得到1,4-二氯丁烷,同时第一精馏塔塔顶主要得到的四氢呋喃可以循环套用,第二精馏塔塔釜的少量催化剂残液作高沸处理。本发明提供的工艺方法物料利用率高、产品纯度高,反应过程容易控制,可以连续化生产。(The invention relates to a method for continuously preparing 1, 4-dichlorobutane, belonging to the technical field of chemical product preparation. The invention discloses a method for continuously preparing 1, 4-dichlorobutane, which comprises the steps of adding Lewis acid catalyst into tetrahydrofuran and hydrogen chloride in a reinforced pipeline reactor filled with inert filler for forced circulation reaction to obtain a crude product, carrying out vacuum rectification twice to obtain 1, 4-dichlorobutane, recycling tetrahydrofuran mainly obtained from the top of a first rectifying tower, and carrying out high-boiling treatment on a small amount of catalyst residual liquid in the bottom of a second rectifying tower. The process method provided by the invention has the advantages of high material utilization rate, high product purity, easy control of reaction process and continuous production.)

1. A method for continuously preparing 1, 4-dichlorobutane is characterized by comprising the following specific preparation steps:

(1) adding tetrahydrofuran containing Lewis acid catalyst into an intensified reactor, and preheating to 93-97 ℃;

(2) introducing hydrogen chloride into a reinforced pipeline reactor to perform forced circulation reaction to obtain reaction liquid;

(3) adding the reaction liquid obtained in the step (2) into a first rectifying tower, carrying out rectification separation under reduced pressure, obtaining a fraction with a main component of tetrahydrofuran at the tower top, obtaining a fraction containing 1, 4-dichlorobutane at the tower bottom, and recycling the fraction with the main component of tetrahydrofuran at the tower top to the step (1) for reuse;

(4) and (3) adding the fraction containing 1, 4-dichlorobutane obtained at the tower bottom in the step (3) into a second rectifying tower for rectification and separation under reduced pressure to obtain 1, 4-dichlorobutane at the tower top, and obtaining tower bottom residual liquid with a main component containing a Lewis acid catalyst at the tower bottom for high-boiling treatment.

2. The process according to claim 1, for the continuous preparation of 1, 4-dichlorobutane, characterized in that: the reinforced pipeline reactor is a pipeline reactor with external pumping circulation, and is filled with one of inert theta ring packing, saddle ring packing or pall ring packing.

3. The process according to claim 1, for the continuous preparation of 1, 4-dichlorobutane, characterized in that: the Lewis acid catalyst is one or a mixture of more of ferric chloride, aluminum chloride and zinc chloride.

4. The process according to claim 1, for the continuous preparation of 1, 4-dichlorobutane, characterized in that: and the hydrogen chloride is fully mixed with tetrahydrofuran in the Venturi mixer and then is sent into the reinforced pipeline reactor.

5. The process according to claim 1, for the continuous preparation of 1, 4-dichlorobutane, characterized in that: the reaction temperature of the forced circulation reaction in the step (2) is 120-150 ℃, the reaction pressure is 1.2-1.5 Mpa, and the molar ratio of tetrahydrofuran to hydrogen chloride is 1:2.05 to 2.1; sampling and analyzing every 0.5h, and stopping the reaction when the conversion rate of the tetrahydrofuran reaches 85-95%.

6. The process according to claim 1, for the continuous preparation of 1, 4-dichlorobutane, characterized in that: in the step (3), the rectification temperature of the first rectification tower is 25-60 ℃, and the rectification pressure is-0.09 to-0.05 MPa.

7. The process according to claim 1, for the continuous preparation of 1, 4-dichlorobutane, characterized in that: in the step (4), the rectification temperature of the second rectification tower is 61-96 ℃, and the rectification pressure is-0.09 to-0.098 MPa.

8. The process according to claim 1, for the continuous preparation of 1, 4-dichlorobutane, characterized in that: and (4) in the step (4), the tower bottom residual liquid discharge system with the main component of the catalyst is obtained at the tower bottom.

Technical Field

The invention relates to a method for continuously preparing 1, 4-dichlorobutane, belonging to the technical field of chemical product preparation.

Background

At present, 1, 4-dichlorobutane is an important fine chemical product, can be used as an organic synthesis raw material and a solvent, and is used for synthesizing adiponitrile, a medicament, tubibenz and the like. The method replaces a large amount of hydrogen chloride byproducts in the chlorination process, is easy to carry a small amount of organic matters when used as a secondary acid, and can be sold as a product only by treating the organic matters in the secondary acid to be below 50ppm, thereby greatly improving the production cost. If the byproduct hydrogen chloride is simply treated and used as a raw material for producing the 1, 4-dichlorobutane to be comprehensively utilized, the waste can be changed into valuable, the process economy can be improved, and the circular economy concept is embodied.

In view of the above-mentioned drawbacks, the present invention is to provide a method for continuously preparing 1, 4-dichlorobutane, which is more industrially applicable.

Disclosure of Invention

In order to solve the above technical problems, the present invention aims to provide a method for continuously preparing 1, 4-dichlorobutane.

The invention relates to a method for continuously preparing 1, 4-dichlorobutane, which comprises the following specific preparation steps:

(1) adding tetrahydrofuran containing Lewis acid catalyst into an intensified reactor, and preheating to 93-97 ℃;

(2) introducing hydrogen chloride into a reinforced pipeline reactor to perform forced circulation reaction to obtain reaction liquid;

(3) adding the reaction liquid obtained in the step (2) into a first rectifying tower, carrying out rectification separation under reduced pressure, obtaining a fraction with a main component of tetrahydrofuran at the tower top, obtaining a fraction containing 1, 4-dichlorobutane at the tower bottom, and recycling the fraction with the main component of tetrahydrofuran at the tower top to the step (1) for reuse;

(4) and (3) adding the fraction containing 1, 4-dichlorobutane obtained at the tower bottom in the step (3) into a second rectifying tower for rectification and separation under reduced pressure to obtain 1, 4-dichlorobutane at the tower top, and obtaining tower bottom residual liquid with a main component containing a Lewis acid catalyst at the tower bottom for high-boiling treatment.

Furthermore, the reinforced pipeline reactor is a pipeline reactor with an external pumping cycle, and one of inert theta ring packing, saddle ring packing or pall ring packing is filled in the reinforced pipeline reactor.

Furthermore, the Lewis acid catalyst is one or a mixture of more of ferric chloride, aluminum chloride and zinc chloride.

Further, the hydrogen chloride is fully mixed with tetrahydrofuran in a Venturi mixer and then is sent into the reinforced pipeline reactor.

Further, the reaction temperature of the forced circulation reaction in the step (2) is 120-150 ℃, the reaction pressure is 1.2-1.5 Mpa, and the molar ratio of tetrahydrofuran to hydrogen chloride is 1:2.05 to 2.1; sampling and analyzing every 0.5h, and stopping the reaction when the conversion rate of the tetrahydrofuran reaches 85-95%.

Further, in the step (3), the rectification temperature of the first rectification tower is 25-60 ℃, and the rectification pressure is-0.09 to-0.05 MPa.

Further, in the step (4), the rectification temperature of the second rectification tower is 61-96 ℃, and the rectification pressure is-0.09 to-0.098 MPa.

Further, in the step (4), the tower bottom residual liquid discharge system with the main component of the catalyst is obtained at the tower bottom.

By the scheme, the invention at least has the following advantages:

1) according to the method for continuously preparing the 1, 4-dichlorobutane, the excessive hydrogen chloride is controlled, the 1, 4-dichlorobutane is prepared in a one-step method with tetrahydrofuran in an enhanced pipeline reactor, the conversion rate of raw materials is high, the side reactions are few, the product yield is high, and the purity of the product obtained by rectification is not lower than 99.5%;

2) in the method for continuously preparing the 1, 4-dichlorobutane, the tower top fraction of the first rectifying tower can be recycled, and the waste is less;

3) the method for continuously preparing the 1, 4-dichlorobutane uses the reinforced reactor, can improve the dispersibility of reaction materials and accelerate the reaction rate.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate a certain embodiment of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic flow diagram of a process for the preparation of 1, 4-dichlorobutane according to the present invention;

in the figure, 1, preheating a kettle; 2. a strengthening reactor; 3. a circulation pump; 4. a gas-liquid mixer; 5. a first rectification column; 6. a second rectifying tower.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

Referring to fig. 1, in a preferred embodiment of the present invention, a pipe reactor with an internal diameter of 100mm and a length of 2.0m and an external pumping cycle is used as an intensive reactor, and the internal packing is one of an inert θ ring packing, a saddle ring packing or a pall ring packing;

the preparation process flow of the 1, 4-dichlorobutane comprises the following steps:

(1) adding tetrahydrofuran into an intensified reactor, and preheating to 93-97 ℃;

(2) heating the strengthening reactor to 120-150 ℃, slowly introducing hydrogen chloride into the strengthening reactor according to the molar ratio of tetrahydrofuran to hydrogen chloride of 1: 2.05-2.1, controlling the pressure of the strengthening reactor to be 1.2-1.5 MPa, forcibly performing a circulating reaction, sampling and analyzing every 0.5h in the reaction process, and stopping the reaction when the conversion rate of tetrahydrofuran reaches 85-95% to obtain a reaction solution;

(3) adding the reaction liquid obtained in the step (2) into a first rectifying tower, controlling the temperature of a tower kettle of the first rectifying tower to be 25-60 ℃, controlling the pressure of the first rectifying tower to be-0.09-0.05 Mpa, recovering hydrogen chloride and tetrahydrofuran fractions obtained at the tower top in the rectifying process, recycling the hydrogen chloride and tetrahydrofuran fractions to the step (1), and feeding the crude 1, 4-dichlorobutane obtained at the tower kettle into a second rectifying tower for high-vacuum rectification;

(4) controlling the temperature of a tower kettle of the second rectifying tower to be 61-96 ℃, the rectifying pressure to be-0.09-0.098 Mpa, rectifying the crude 1, 4-dichlorobutane in the second rectifying tower for 2.0h under high vacuum to obtain the 1, 4-dichlorobutane at the tower top, wherein the yield is 88-93%, the purity is 99.5%, and discharging the catalyst residual liquid at the tower kettle to a system for waste liquid treatment.

Examples

Example 1

A method for continuously preparing 1, 4-dichlorobutane, wherein a pipeline reactor with an internal diameter of phi 100mm and a length of 2.0m and with an external pumping circulation is selected as a strengthening reactor, and an inert theta ring filler is used as an internal filler; the preparation process flow of the 1, 4-dichlorobutane comprises the following steps:

(1) adding tetrahydrofuran into an intensified reactor and preheating to 93 ℃;

(2) heating the enhanced reactor to 120 ℃, slowly introducing hydrogen chloride into the enhanced reactor according to the molar ratio of 1:2.05 of tetrahydrofuran to hydrogen chloride, controlling the pressure of the enhanced reactor to be 1.2MPa, performing forced circulation reaction, sampling and analyzing every 0.5h in the reaction process, and stopping the reaction when the conversion rate of tetrahydrofuran reaches 85% to obtain a reaction solution;

(3) adding the reaction liquid obtained in the step (2) into a first rectifying tower, controlling the temperature of a tower kettle of the first rectifying tower to be 25 ℃, controlling the pressure of the first rectifying tower to be-0.09 Mpa, recovering hydrogen chloride and tetrahydrofuran fractions obtained at the tower top in the rectifying process, and feeding the crude 1, 4-dichlorobutane obtained at the tower kettle into a second rectifying tower for high vacuum rectification;

(4) controlling the temperature of the tower bottom of the second rectifying tower to be 61 ℃, the rectifying pressure to be-0.096 Mpa, rectifying the crude 1, 4-dichlorobutane in the second rectifying tower for 2.0h under high vacuum, obtaining the 1, 4-dichlorobutane at the tower top, the yield is 88%, the purity is 99.5%, and recovering the residual liquid at the tower bottom.

Example 2

A method for continuously preparing 1, 4-dichlorobutane, wherein a pipeline reactor with an internal diameter of phi 100mm and a length of 2.0m and with an external pumping circulation is selected as a strengthening reactor, and an inert theta ring filler is used as an internal filler; the preparation process flow of the 1, 4-dichlorobutane comprises the following steps:

(1) adding tetrahydrofuran into an intensified reactor and preheating to 95 ℃;

(2) heating the enhanced reactor to 136 ℃, slowly introducing hydrogen chloride into the enhanced reactor according to the molar ratio of 1:2.07 of tetrahydrofuran to hydrogen chloride, controlling the pressure of the enhanced reactor to be 1.35MPa, performing forced circulation reaction, sampling and analyzing every 0.5h in the reaction process, and stopping the reaction when the conversion rate of tetrahydrofuran reaches 90% to obtain a reaction solution;

(3) adding the reaction liquid obtained in the step (2) into a first rectifying tower, controlling the temperature of a tower kettle of the first rectifying tower to be 35 ℃, controlling the pressure of the first rectifying tower to be-0.067 Mpa, recovering hydrogen chloride and tetrahydrofuran fractions obtained at the tower top in the rectifying process, and feeding the crude 1, 4-dichlorobutane obtained at the tower kettle into a second rectifying tower for high vacuum rectification;

(4) controlling the temperature of the tower bottom of the second rectifying tower to be 78 ℃, the rectifying pressure to be-0.094 Mpa, rectifying the crude 1, 4-dichlorobutane in the second rectifying tower for 2.0h under high vacuum, obtaining the 1, 4-dichlorobutane at the tower top, the yield is 93 percent, the purity is 99.5 percent, and recovering the residual liquid at the tower bottom.

Example 3

A method for continuously preparing 1, 4-dichlorobutane, wherein a pipeline reactor with an internal diameter of phi 100mm and a length of 2.0m and with an external pumping circulation is selected as a strengthening reactor, and an inert theta ring filler is used as an internal filler; the preparation process flow of the 1, 4-dichlorobutane comprises the following steps:

(1) adding tetrahydrofuran into an intensified reactor and preheating to 97 ℃;

(2) heating the enhanced reactor to 150 ℃, slowly introducing hydrogen chloride into the enhanced reactor according to the molar ratio of 1:2.1 of tetrahydrofuran to hydrogen chloride, controlling the pressure of the enhanced reactor to be 1.5MPa, performing forced circulation reaction, sampling and analyzing every 0.5h in the reaction process, and stopping the reaction when the conversion rate of tetrahydrofuran reaches 95% to obtain a reaction solution;

(3) adding the reaction liquid obtained in the step (2) into a first rectifying tower, controlling the temperature of a tower kettle of the first rectifying tower to be 50 ℃, controlling the pressure of the first rectifying tower to be-0.05 Mpa, recovering hydrogen chloride and tetrahydrofuran fractions obtained at the tower top in the rectifying process, and feeding the crude 1, 4-dichlorobutane obtained at the tower kettle into a second rectifying tower for high vacuum rectification;

(4) controlling the temperature of the tower bottom of the second rectifying tower to be 96 ℃, the rectifying pressure to be-0.098 Mpa, rectifying the crude 1, 4-dichlorobutane in the second rectifying tower for 2.0h under high vacuum, obtaining the 1, 4-dichlorobutane at the tower top, the yield is 95%, the purity is 99.6%, and recovering the residual liquid at the tower bottom.

Compared with the example 1, the differences of the example 2 and the example 3 are that the temperature of the intensified reactor, the ratio of the hydrogen chloride and the tetrahydrofuran, the pressure in the intensified reactor and the conditions of the rectification reaction are changed, and the product yield and the purity of the 1, 4-dichlorobutane are improved on the basis of the example 1, so that the process parameters of the invention also have influence on the process result and have optimized parameters. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, it should be noted that, for those skilled in the art, many modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.