阅读说明：本技术 一种1，3-二氯丙酮的连续流制备方法及微反应系统 (Continuous flow preparation method and micro-reaction system of 1, 3-dichloroacetone ) 是由 陈芬儿 刘敏杰 蒋龙 李鹏飞 于 2021-09-18 设计创作，主要内容包括：本发明属于化学工程技术领域,具体为一种1,3-二氯丙酮的连续流制备方法及微反应系统。本发明将含双乙烯酮的底物液与氯气于第一微混合器内混合后送入第一微通道反应器内进行连续氯化开环反应,接着与水在第二微混合器内混合后送入第二微通道反应器内进行连续水解脱羧反应得到1,3-二氯丙酮。本发明还提供了用于1,3-二氯丙酮连续流制备的微反应系统,包括依次相连的第一微混合器、第一微通道反应器、第二微混合器和第二微通道反应器。与现有技术相比,采用本发明的制备方法及微反应系统,反应时间仅需几分钟,产物1,3-二氯丙酮的收率高,工艺过程连续,效率高,能耗低,本质安全,且操作简便,易于工业化生产。(The invention belongs to the technical field of chemical engineering, and particularly relates to a continuous flow preparation method of 1, 3-dichloroacetone and a micro-reaction system. The method comprises the steps of mixing a substrate solution containing diketene with chlorine in a first micro mixer, sending the mixture into a first micro-channel reactor for continuous chlorination ring-opening reaction, mixing the mixture with water in a second micro mixer, and sending the mixture into a second micro-channel reactor for continuous hydrolysis decarboxylation reaction to obtain the 1, 3-dichloroacetone. The invention also provides a micro-reaction system for the continuous flow preparation of the 1, 3-dichloroacetone, which comprises a first micro-mixer, a first micro-channel reactor, a second micro-mixer and a second micro-channel reactor which are connected in sequence. Compared with the prior art, the preparation method and the micro-reaction system have the advantages that the reaction time is only a few minutes, the yield of the product 1, 3-dichloroacetone is high, the technological process is continuous, the efficiency is high, the energy consumption is low, the essence is safe, the operation is simple and convenient, and the industrial production is easy to realize.)

1. A continuous flow process for the preparation of 1, 3-dichloroacetone comprising the steps of:

(1) respectively and simultaneously conveying substrate liquid containing diketene and chlorine gas into a first micro mixer for mixing to obtain a first reaction mixed material;

(2) directly introducing the first reaction mixed material flowing out of the first micro-mixer in the step (1) into a first micro-channel reactor for continuous chlorination ring-opening reaction to obtain a first reaction mixed solution;

(3) introducing the first reaction mixed liquid flowing out of the first microchannel reactor in the step (2) and water into a second micro mixer for mixing to obtain a second reaction mixed material;

(4) directly introducing the second reaction mixed material flowing out of the second micro-mixer in the step (3) into a second micro-channel reactor for continuous hydrolysis decarboxylation reaction to obtain a second reaction mixed solution;

(5) collecting the second reaction mixed liquid flowing out of the second microchannel reactor, and performing separation and purification treatment to obtain a target product 1, 3-dichloroacetone (I);

wherein the 1, 3-dichloroacetone is a compound shown in a formula (I), and the diketene is a compound shown in a formula (II); the method relates to a chemical reaction formula as follows:

2. the continuous flow preparation method of claim 1, wherein the substrate solution in step (1) is a solution of diketene dissolved in an organic solvent; the organic solvent is any one of straight-chain aliphatic hydrocarbon, branched-chain aliphatic hydrocarbon, alicyclic hydrocarbon, halogenated hydrocarbon and aromatic hydrocarbon;

preferably, the concentration of the diketene in the substrate solution is 0.01-30 mol/L.

3. The continuous flow production process of claim 2, wherein the linear aliphatic hydrocarbon is selected from any one of n-pentane, n-hexane, n-heptane, n-octane, and n-nonane;

the branched aliphatic hydrocarbon is any one selected from the group consisting of 2-methylbutane, 2-methylpentane, 3-methylpentane, 2-dimethylbutane, 2, 3-dimethylbutane, 2-methylhexane, 3-methylhexane, 2, 3-dimethylpentane, 2, 4-dimethylpentane, 2, 4-trimethylpentane, 2,3, 3-trimethylpentane and 2,2, 5-trimethylhexane;

the alicyclic hydrocarbon is selected from any one of cyclopentane, methyl cyclopentane, cyclohexane, methyl cyclohexane, 1, 3-dimethyl cyclohexane, cycloheptane and cyclooctane;

the halogenated hydrocarbon is selected from any one of dichloromethane, 1, 2-dichloroethane, chloroform and carbon tetrachloride;

the aromatic hydrocarbon is selected from any one of benzene, toluene, ethylbenzene, chlorobenzene, xylene and dichlorobenzene.

4. The continuous-flow production process of claim 1, wherein step (1) further comprises the steps of:

adjusting the volume flow ratio of the substrate liquid pumped into the first micro mixer to the chlorine gas so that the molar ratio of the diketene entering the first micro mixer to the chlorine gas is within the range of 1 (0.1-5.0);

controlling the temperature in the first micro mixer within the range of-50 ℃ to 120 ℃;

and controlling the total flow of the substrate liquid and the chlorine gas entering the first micro-mixer, so that the residence time of a first reaction mixed material formed by the substrate liquid and the chlorine gas in the first micro-channel reactor is within the range of 0.1-45 minutes.

5. The method of claim 1, wherein the first and second micromixers are any of static mixers, T-type micromixers, Y-type micromixers, coaxial flow micromixers, flow focusing micromixers, and the like.

6. The method of claim 1, wherein step (2) further comprises the steps of:

controlling the temperature in the first microchannel reactor to be within the range of-50 ℃ to 120 ℃;

preferably, the first microchannel reactor is a tubular microchannel reactor or a plate microchannel reactor;

the inner diameter of the tubular micro-channel reactor is 100 mu m-10 mm;

the plate-type microchannel reactor comprises a first heat exchange layer, a reaction layer and a second heat exchange layer which are sequentially arranged from top to bottom, wherein the reaction layer is provided with a reaction fluid channel, and the hydraulic diameter of the reaction fluid channel is 100-10 mm.

7. The method of claim 1, wherein step (3) further comprises the steps of:

adjusting the volume flow ratio of the first reaction mixed liquid flowing out of the first microchannel reactor to water so that the molar ratio of diketene entering the second microchannel reactor to water is within the range of 0.1-10;

controlling the temperature in the second micro mixer within the range of 5-120 ℃;

and controlling the total flow of the first reaction mixed liquid flowing out of the first microchannel reactor and water entering the second microchannel reactor, so that the retention time of a second reaction mixed material in the second microchannel reactor is within the range of 0.1-45 minutes.

8. The method of claim 1, wherein step (4) further comprises the steps of:

controlling the temperature in the second microchannel reactor to be within the range of 5-120 ℃;

preferably, the second microchannel reactor is a tubular microchannel reactor or a plate microchannel reactor;

the inner diameter of the tubular micro-channel reactor is 100 mu m-10 mm;

the plate-type microchannel reactor comprises a first heat exchange layer, a reaction layer and a second heat exchange layer which are sequentially arranged from top to bottom, wherein the reaction layer is provided with a reaction fluid channel, and the hydraulic diameter of the reaction fluid channel is 100-10 mm.

9. A micro-reaction system for use in the continuous flow production process of any of claims 1 to 8, comprising a first micro-mixer, a first microchannel reactor, a second micro-mixer, and a second microchannel reactor connected in series;

the first micro mixer is respectively connected with a substrate liquid feeding pump and a gas mass flow controller and is respectively used for introducing the substrate liquid and the chlorine;

the second micromixer is connected with a water feed pump and is used for introducing the water.

10. The micro-reaction system according to claim 9, further comprising a first gas-liquid separator, a first back pressure valve, a first nitrogen line, a reaction liquid buffer tank, a second gas-liquid separator, a second back pressure valve, a second nitrogen line, and a reaction liquid collection tank;

the first microchannel reactor is connected with the second micro mixer sequentially through the first gas-liquid separator and the reaction liquid buffer storage tank;

the first inlet of the first micro mixer is connected with the substrate liquid feeding pump, the second inlet of the first micro mixer is connected with the gas mass flow controller, the outlet of the first micro mixer is connected with the inlet of the first microchannel reactor, and the outlet of the first microchannel reactor is connected with the first interface of the first gas-liquid separator;

the second interface of the first gas-liquid separator is connected with the first nitrogen pipeline and used for providing pressure for the first gas-liquid separator; a third interface of the first gas-liquid separator is connected with the first backpressure valve;

an outlet of the first gas-liquid separator is connected with an inlet of the reaction liquid buffer storage tank, an outlet of the reaction liquid buffer storage tank is connected with a first inlet of the second micro mixer through a delivery pump, a second inlet of the second micro mixer is connected with the water feeding pump, an outlet of the second micro mixer is connected with an inlet of the second microchannel reactor, and an outlet of the second microchannel reactor is connected with a first interface of the second gas-liquid separator;

the second interface of the second gas-liquid separator is connected with the second nitrogen pipeline and used for providing pressure for the second gas-liquid separator; a third interface of the second gas-liquid separator is connected with the second backpressure valve; the outlet of the second gas-liquid separator is connected with the reaction liquid collecting storage tank;

preferably, the adjustable ranges of the nitrogen pressure connected into the first nitrogen pipeline and the second nitrogen pipeline are both 0.1-3.0 MPa;

preferably, the backpressure ranges of the first backpressure valve and the second backpressure valve are both 0.1-2.5 MPa;

preferably, the pressure value of the nitrogen gas introduced into the first nitrogen gas pipeline is 0.2-0.5 MPa greater than the backpressure value set by the first backpressure valve, and the pressure value of the nitrogen gas introduced into the second nitrogen gas pipeline is 0.2-0.5 MPa greater than the backpressure value set by the second backpressure valve.

Technical Field

The invention belongs to the technical field of chemical engineering, and particularly relates to a continuous flow preparation method of 1, 3-dichloroacetone and a micro-reaction system.

Background

1, 3-dichloroacetone (I) is an important fine chemical intermediate, has wide application prospect in the industries of medicine, pesticide and the like, and has a chemical structural formula shown as the formula (I):

ro\ 21219Shen et al (J. China pharmaceutical industry, 1990,21,177) and Benzodiac (J. China pharmaceutical chemistry, 1992,2, 43-44) all describe the preparation of compound (I) by oxidation of 1, 3-dichloro-2-propanol with chromium trioxide-sulfuric acid. plum-Bo et al (chemical engineering and development, 2007,36, 11-13) reported a method for preparing compound (I) by oxidizing 1, 3-dichloro-2-propanol with dichromate. These methods all have the disadvantages of long reaction time, complicated operation, low yield and serious environmental pollution. U.S. Pat. No. 4, 2635118 discloses a process for preparing compound (I) by direct reaction of acetone with chlorine, but the process is cumbersome to operate, has poor selectivity, produces large amounts of 1,1, 1-trichloroacetone and 1,1, 3-trichloroacetone, and has difficulty in product isolation and low yield. U.S. Pat. No. 4, 4251467 discloses a method for preparing compound (I) by reacting acetone with iodine reagent, but the method has long reaction time, produces about 24.6-53.8% of monochloroacetone and trichloroacetone as by-products, and has the defects of low yield, poor purity, high cost and the like. Nollet et al (Journal of the Royal Netherlands Chemical Society,1975, 59-60) reported a method for preparing compound (I) by reacting diketene with chlorine, which could produce a target product of higher purity, unfortunately had the disadvantages of long reaction time, low chlorine utilization, low yield, high risk coefficient of the process, and high cost.

Disclosure of Invention

In order to overcome the defects of long reaction time, high danger coefficient, low yield, high energy consumption and low efficiency of the traditional batch kettle type synthesis method of the 1, 3-dichloroacetone, the invention provides a continuous flow preparation method of the 1, 3-dichloroacetone and a micro-reaction system. The method has the advantages of greatly shortening the reaction time, greatly improving the yield, remarkably improving the automation degree and efficiency of the technological process, greatly reducing the energy consumption, greatly improving the safety and easily realizing the industrial application.

In a first aspect, the present invention provides a continuous flow process for the preparation of 1, 3-dichloroacetone, comprising the steps of:

(1) respectively and simultaneously conveying substrate liquid containing diketene and chlorine gas into a first micro mixer for mixing to obtain a first reaction mixed material;

(2) directly introducing the first reaction mixed material flowing out of the first micro-mixer in the step (1) into a first micro-channel reactor for continuous chlorination ring-opening reaction to obtain a first reaction mixed solution;

(3) introducing the first reaction mixed liquid flowing out of the first microchannel reactor in the step (2) and water into a second micro mixer for mixing to obtain a second reaction mixed material;

(4) directly introducing the second reaction mixed material flowing out of the second micro-mixer in the step (3) into a second micro-channel reactor for continuous hydrolysis decarboxylation reaction to obtain a second reaction mixed solution;

(5) collecting the second reaction mixed liquid flowing out of the second microchannel reactor, and performing separation and purification treatment to obtain a target product 1, 3-dichloroacetone (I);

wherein the 1, 3-dichloroacetone is a compound shown in a formula (I), and the diketene is a compound shown in a formula (II); the method relates to a chemical reaction formula as follows:

as a further embodiment of the invention, the substrate solution in step (1) is a solution prepared by dissolving diketene in an organic solvent; the organic solvent is any one of straight-chain aliphatic hydrocarbon, branched-chain aliphatic hydrocarbon, alicyclic hydrocarbon, halogenated hydrocarbon and aromatic hydrocarbon.

Preferably, the linear aliphatic hydrocarbon is selected from any one of n-pentane, n-hexane, n-heptane, n-octane and n-nonane;

the branched aliphatic hydrocarbon is any one selected from the group consisting of 2-methylbutane, 2-methylpentane, 3-methylpentane, 2-dimethylbutane, 2, 3-dimethylbutane, 2-methylhexane, 3-methylhexane, 2, 3-dimethylpentane, 2, 4-dimethylpentane, 2, 4-trimethylpentane, 2,3, 3-trimethylpentane and 2,2, 5-trimethylhexane;

the alicyclic hydrocarbon is selected from any one of cyclopentane, methyl cyclopentane, cyclohexane, methyl cyclohexane, 1, 3-dimethyl cyclohexane, cycloheptane and cyclooctane;

the halogenated hydrocarbon is selected from any one of dichloromethane, 1, 2-dichloroethane, chloroform and carbon tetrachloride;

the aromatic hydrocarbon is selected from any one of benzene, toluene, ethylbenzene, chlorobenzene, xylene and dichlorobenzene.

Preferably, the organic solvent is a halogenated hydrocarbon.

As a further embodiment of the invention, the concentration of diketene in the substrate solution is 0.01-30 mol/L; preferably, the concentration of the diketene in the substrate solution is 0.05-28 mol/L.

As a further embodiment of the present invention, the step (1) further comprises the steps of:

adjusting the volume flow ratio of the substrate liquid pumped into the first micro mixer to the chlorine gas to ensure that the molar ratio of the diketene entering the first micro mixer to the chlorine gas is within the range of 1 (0.1-5.0), and preferably, controlling the molar ratio of the diketene entering the first micro mixer to the chlorine gas to be within the range of 1 (0.2-4.0);

controlling the temperature in the first micro mixer within the range of-50 ℃ to 120 ℃, preferably controlling the temperature in the first micro mixer within the range of-40 ℃ to 110 ℃;

and controlling the total flow of the substrate liquid and the chlorine gas entering the first micro-mixer so that the residence time of a first reaction mixed material formed by the substrate liquid and the chlorine gas in the first micro-channel reactor is within the range of 0.1-45 minutes, and preferably, controlling the residence time of the first reaction mixed material in the first micro-channel reactor to be within the range of 0.5-30 minutes.

As a further embodiment of the present invention, the first and second micromixers may be any one of a static mixer, a T-type micromixer, a Y-type micromixer, a coaxial flow micromixer (coaxial flow micromixer), a flow-focusing micromixer (flow-focusing micromixer), and the like. The first micromixer and the second micromixer may be the same or different mixers.

As a further embodiment of the present invention, the step (2) further comprises the steps of:

controlling the temperature in the first microchannel reactor to be within the range of-50 ℃ to 120 ℃; preferably, the temperature in the first microchannel reactor is controlled within the range of-40 ℃ to 110 ℃.

As a further embodiment of the present invention, the first microchannel reactor is a tubular microchannel reactor or a plate microchannel reactor;

the inner diameter of the tubular micro-channel reactor is 100 mu m-10 mm; preferably, the inner diameter of the tubular microchannel reactor is 120 mu m-5.35 mm;

the plate-type microchannel reactor comprises a first heat exchange layer, a reaction layer and a second heat exchange layer which are sequentially arranged from top to bottom, wherein the reaction layer is provided with a reaction fluid channel, the hydraulic diameter of the reaction fluid channel is 100-10 mm, and preferably, the hydraulic diameter of the reaction fluid channel is 120-5.35 mm.

As a further embodiment of the present invention, the step (3) further comprises the steps of:

adjusting the volume flow ratio of the first reaction mixed liquid flowing out of the first microchannel reactor to water so that the molar ratio of diketene to water entering the second micro mixer is within the range of 0.1-10, and preferably, controlling the molar ratio of diketene to water entering the second micro mixer to be within the range of 0.2-8;

controlling the temperature in the second micro mixer within the range of 5-120 ℃, preferably, controlling the temperature in the second micro mixer within the range of 10-100 ℃;

and controlling the total flow of the first reaction mixed liquid flowing out of the first microchannel reactor and water entering the second microchannel reactor, so that the residence time of a second reaction mixed material in the second microchannel reactor is within the range of 0.1-45 minutes, and preferably, controlling the residence time of the second reaction mixed material in the second microchannel reactor to be within the range of 0.5-30 minutes.

As a further embodiment of the present invention, the step (4) further comprises the steps of:

controlling the temperature in the second microchannel reactor to be within the range of 5-120 ℃; preferably, the temperature in the second microchannel reactor is controlled within the range of 10 ℃ to 100 ℃.

As a further embodiment of the present invention, the second microchannel reactor is a tubular microchannel reactor or a plate microchannel reactor;

the inner diameter of the tubular micro-channel reactor is 100 mu m-10 mm; preferably, the inner diameter of the tubular microchannel reactor is 120 mu m-5.35 mm;

the plate-type microchannel reactor comprises a first heat exchange layer, a reaction layer and a second heat exchange layer which are sequentially arranged from top to bottom, wherein the reaction layer is provided with a reaction fluid channel, the hydraulic diameter of the reaction fluid channel is 100-10 mm, and preferably, the hydraulic diameter of the reaction fluid channel is 120-5.35 mm.

The invention provides a micro-reaction system for the continuous flow preparation method, which comprises a first micro-mixer, a first micro-channel reactor, a second micro-mixer and a second micro-channel reactor which are connected in sequence;

the first micro mixer is respectively connected with a substrate liquid feeding pump and a gas mass flow controller and is respectively used for introducing the substrate liquid and the chlorine;

the second micromixer is connected with a water feed pump and is used for introducing the water.

As a further embodiment of the present invention, the micro-reaction system provided by the second aspect of the present invention further comprises a first gas-liquid separator, a first back-pressure valve, a first nitrogen gas line, a reaction liquid buffer tank, a second gas-liquid separator, a second back-pressure valve, a second nitrogen gas line, and a reaction liquid collection tank;

the first microchannel reactor is connected with the second micro mixer sequentially through the first gas-liquid separator and the reaction liquid buffer storage tank;

the first inlet of the first micro mixer is connected with the substrate liquid feeding pump, the second inlet of the first micro mixer is connected with the gas mass flow controller, the outlet of the first micro mixer is connected with the inlet of the first microchannel reactor, and the outlet of the first microchannel reactor is connected with the first interface of the first gas-liquid separator;

the second interface of the first gas-liquid separator is connected with the first nitrogen pipeline and used for providing pressure for the first gas-liquid separator; a third interface of the first gas-liquid separator is connected with the first backpressure valve;

an outlet of the first gas-liquid separator is connected with an inlet of the reaction liquid buffer storage tank, an outlet of the reaction liquid buffer storage tank is connected with a first inlet of the second micro mixer through a delivery pump, a second inlet of the second micro mixer is connected with the water feeding pump, an outlet of the second micro mixer is connected with an inlet of the second microchannel reactor, and an outlet of the second microchannel reactor is connected with a first interface of the second gas-liquid separator;

the second interface of the second gas-liquid separator is connected with the second nitrogen pipeline and used for providing pressure for the second gas-liquid separator; a third interface of the second gas-liquid separator is connected with the second backpressure valve; and the outlet of the second gas-liquid separator is connected with the reaction liquid collecting storage tank.

Preferably, the adjustable ranges of the nitrogen pressure connected into the first nitrogen pipeline and the second nitrogen pipeline are both 0.1-3.0 MPa;

preferably, the backpressure ranges of the first backpressure valve and the second backpressure valve are both 0.1-2.5 MPa;

preferably, the pressure value of the nitrogen gas connected into the first nitrogen pipeline is 0.2-0.5 MPa greater than the back pressure value set by the first back pressure valve;

preferably, the pressure value of the nitrogen gas connected to the second nitrogen gas pipeline is 0.2-0.5 MPa greater than the back pressure value set by the second back pressure valve.

Compared with the prior art, the continuous flow preparation method and the micro-reaction system provided by the invention have the advantages that the total reaction time is only a few minutes, the yield of the product 1, 3-dichloroacetone is up to more than 93%, the chlorine dosage can be accurately controlled, the complete quantitative conversion of chlorine in the micro-channel reactor is realized, and the problems of low excessive utilization rate of chlorine, serious waste and difficult recovery in an intermittent kettle type synthesis mode are solved. In addition, the method realizes the continuous synthesis from the raw materials to the target product, greatly reduces the number of operators and labor intensity, obviously reduces the production cost, has small online liquid holdup and intrinsically safe technical process.

Drawings

FIG. 1 is a schematic structural diagram of a micro-reaction system according to an embodiment of the present invention.

Description of reference numerals:

1. a chlorine pipeline;

2. a substrate liquid storage tank;

3. a gas mass flow controller;

4. a substrate liquid feed pump;

5. a first micromixer;

6. a first microchannel reactor;

7. a first nitrogen line;

8. a first gas-liquid separator;

9. a reaction liquid buffer storage tank;

10. a first back pressure valve;

11. a delivery pump;

12. a second micromixer;

13. a water feed pump;

14. a water line;

15. a second microchannel reactor;

16. a second nitrogen line;

17. a second gas-liquid separator;

18. a reaction liquid collecting and storing tank;

19. a second back pressure valve.

Detailed Description

To explain technical contents, structural features, and objects and effects of the technical solutions in detail, the following detailed description is given with reference to the accompanying drawings in conjunction with the embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

The experimental procedures in the following examples are conventional unless otherwise specified. For example, the "separation and purification treatment" is a treatment method well known in the art, and is not described herein. Test materials, reagents and the like used in the following examples are commercially available unless otherwise specified. The quantitative tests in the following examples, all set up three replicates and the results averaged.

Referring to fig. 1, a micro-reaction system according to an embodiment of the present invention includes a first micro-mixer 5, a first micro-channel reactor 6, a second micro-mixer 12, and a second micro-channel reactor 15 connected in sequence. The first micromixer 5 is connected to the substrate liquid feed pump 4 and the gas mass flow controller 3, respectively, and is used for introducing the substrate liquid and the chlorine gas, respectively. The second micromixer 12 is connected to a water feed pump 13 for introducing water.

The continuous flow preparation method of 1, 3-dichloroacetone provided by the specific embodiment of the invention comprises the following steps:

(1) respectively and simultaneously conveying the substrate solution containing diketene and chlorine gas into a first micro mixer 5 for mixing to obtain a first reaction mixed material;

(2) directly introducing the first reaction mixed material flowing out of the first micro-mixer 5 in the step (1) into a first micro-channel reactor 6 for continuous chlorination ring-opening reaction to obtain a first reaction mixed solution;

(3) introducing the first reaction mixed liquid flowing out of the first microchannel reactor 6 in the step (2) and water into a second micro mixer 12 for mixing to obtain a second reaction mixed material;

(4) directly introducing the second reaction mixed material flowing out of the second micro mixer 12 in the step (3) into a second micro-channel reactor 15 for continuous hydrolysis decarboxylation reaction to obtain a second reaction mixed solution;

(5) collecting a second reaction mixed solution flowing out of the second microchannel reactor 15, and performing separation and purification treatment to obtain a target product 1, 3-dichloroacetone (I);

wherein, the 1, 3-dichloroacetone is a compound shown in a formula (I), and the diketene is a compound shown in a formula (II); the method relates to a chemical reaction formula as follows:

further, referring to fig. 1, the micro-reaction system according to the embodiment of the present invention further includes a first gas-liquid separator 8, a reaction liquid buffer tank 9, a first back pressure valve 10, a second nitrogen pipeline 16, a second gas-liquid separator 17, a reaction liquid collecting tank 18, and a second back pressure valve 19. The first microchannel reactor 6 is connected with the second micromixer 12 sequentially through the first gas-liquid separator 8 and the reaction liquid buffer storage tank 9. The first inlet of the first micromixer 5 is connected to a substrate liquid feed pump 4, and is connected to a substrate liquid reservoir 2 through the substrate liquid feed pump 4 to pump the diketene substrate liquid into the first micromixer 5. The second inlet of the first micromixer 5 is connected with the gas mass flow controller 3; the gas mass flow controller 3 is connected to the chlorine line 1 for feeding chlorine gas into the first micromixer 5. The outlet of the first micromixer 5 is connected to the inlet of the first microchannel reactor 6, and the outlet of the first microchannel reactor 6 is connected to the first port of the first gas-liquid separator 8. The second interface of the first gas-liquid separator 8 is connected with the first nitrogen pipeline 7 and is used for providing pressure for the first gas-liquid separator 8; the third port of the first gas-liquid separator 8 is connected to a first backpressure valve 10. An outlet of the first gas-liquid separator 8 is connected with an inlet of a reaction liquid buffer storage tank 9, an outlet of the reaction liquid buffer storage tank 9 is connected with a first inlet of a second micromixer 12 through a delivery pump 11, and a second inlet of the second micromixer 12 is connected with a water feeding pump 13; a water feed pump 13 is connected to the water line 14 for pumping water into the second micromixer 12. The outlet of the second micro mixer 12 is connected with the inlet of a second micro-channel reactor 15, and the outlet of the second micro-channel reactor 15 is connected with the first interface of a second gas-liquid separator 17; a second port of the second gas-liquid separator 17 is connected to the second nitrogen gas line 16 for providing pressure to the second gas-liquid separator 17; a third port of the second gas-liquid separator 17 is connected with a second back pressure valve 19; an outlet of the second gas-liquid separator 17 is connected to a reaction liquid collecting tank 18.

The working process of the micro-reaction system used in the embodiment of the invention is as follows:

(A) preparing substrate solution containing diketene, and placing the substrate solution in a substrate solution storage tank 2;

(B) respectively and simultaneously conveying the substrate liquid in the substrate liquid storage tank 2 and the chlorine gas in the chlorine gas pipeline 1 into a first micro mixer 5 by using a substrate liquid feeding pump 4 and a gas mass flow controller 3, mixing the substrate liquid and the chlorine gas by the first micro mixer 5 to form a first reaction mixed material, feeding the first reaction mixed material flowing out of the first micro mixer 5 into a first micro-channel reactor 6, carrying out continuous chlorination ring-opening reaction in the first micro-channel reactor 6, and feeding the first reaction mixed liquid flowing out of the first micro-channel reactor 6 into a reaction liquid buffer storage tank 9 after passing through a first gas-liquid separator 8;

(C) and (2) respectively conveying the first reaction mixed liquid and water in the reaction liquid buffer storage tank 9 to a second micro mixer 12 by using a conveying pump 11 and a water feeding pump 13, feeding the second reaction material mixed by the second micro mixer 12 into a second micro-channel reactor 15 for continuous hydrolysis and decarboxylation, directly feeding the second reaction mixed liquid flowing out of the second micro-channel reactor 15 into a second gas-liquid separator 17 to separate gas components, collecting the gas components in a reaction liquid collecting storage tank 18, and performing separation and purification treatment to obtain the target product 1, 3-dichloroacetone.

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to specific examples.

Example 1

Mixing diketene (84g, 1mol) and carbon tetrachloride (420mL) to prepare a substrate solution, respectively and simultaneously conveying the substrate solution and chlorine gas into a first micro mixer 5 (T-shaped micro mixer), controlling the temperature in the first micro mixer 5 to be-25 ℃, and adjusting the flow ratio of the diketene substrate solution pumped into the first micro mixer 5 to the chlorine gas so that the molar ratio of the diketene to the chlorine gas is 1: 2.0. the first reaction mixture exiting the first micromixer 5 then enters a first microchannel reactor 6 (a Protrix microreactor from Chemtrix, the netherlands) and the residence time of the first reaction mixture in the first microchannel reactor 6 is controlled to 2 minutes. The backpressure value of the first backpressure valve 10 is set to be 0.2MPa, the nitrogen pressure of the first gas-liquid separator 8 connected to the first nitrogen pipeline 7 is adjusted to be 0.5MPa, the temperature in the first microchannel reactor 6 is controlled to be-15 ℃, the first reaction mixed liquid flows out of the outlet of the first microchannel reactor 6, and after gas components are separated by the first gas-liquid separator 8, the reaction mixed liquid is collected in the reaction liquid buffer storage tank 9. Then, the temperature in the second micro-mixer 12 is controlled to 50 ℃, and the flow ratio of the first reaction mixture (i.e., the first reaction mixture subjected to gas-liquid separation and flowing out from the first microchannel reactor 6) collected by the reaction liquid buffer tank 9 to water is adjusted so that the molar ratio of ketene dimer to water is 1: 1.1, respectively and simultaneously conveying the first reaction mixed liquid and water collected by the reaction liquid buffer storage tank 9 to a second micro mixer 12 (T-shaped micro mixer) for mixing. The second reaction mixture flowing out is then conducted directly into a second microchannel reactor 15 (GramFlow microreactor from Chemtrix, the Netherlands). The temperature in the second microchannel reactor 15 is controlled to 70 ℃, and after 5 minutes of reaction (i.e., the residence time of the second reaction mixture in the second microchannel reactor 15 is 5 minutes), the second reaction mixture flows out from the outlet of the second microchannel reactor 15, and after the gas components are separated by the second gas-liquid separator 17, the reaction mixture is collected in the reaction liquid collection tank 18. The back pressure value of the second back pressure valve 19 is set to 0.2MPa, and the nitrogen pressure of the second gas-liquid separator 17 connected to the second nitrogen line 16 is adjusted to 0.5 MPa. Sampling and analyzing, using a gas chromatograph for quantitative detection, and quantifying the concentration of the reaction substrate and the product by peak area. By analysis, the substrate is completely converted, and the yield of the product 1, 3-dichloroacetone is 93 percent (GC) and the purity is more than 99 percent (GC).

Example 2

This example is the same as example 1, except that the first micromixer 5 in this example is a Y-type micromixer, and the yield of 1, 3-dichloroacetone product is 93.2% (GC), and the purity is greater than 99% (GC).

Example 3

This example is the same as example 1, except that the first micromixer 5 in this example is a co-axial flow micromixer, and the product 1, 3-dichloroacetone yield is 94% (GC), and the purity is greater than 99% (GC).

Example 4

This example is the same as example 1, except that the first micromixer 5 in this example is a flow focusing micromixer, the yield of 1, 3-dichloroacetone product is 93.6% (GC), and the purity is greater than 99% (GC).

Example 5

This example is the same as example 1, except that the first micromixer 5 in this example is a static mixer, the yield of 1, 3-dichloroacetone product is 94.2% (GC), and the purity is greater than 99% (GC).

Example 6

This example is the same as example 1, except that the second micromixer 12 in this example is a Y-type micromixer, the yield of 1, 3-dichloroacetone product is 93.2% (GC), and the purity is greater than 99% (GC).

Example 7

This example is the same as example 1, except that the second micromixer 12 in this example is a co-axial flow micromixer, and the product 1, 3-dichloroacetone yield is 94% (GC), and the purity is greater than 99% (GC).

Example 8

This example is the same as example 1, except that the second micromixer 12 in this example is a flow focusing micromixer, the yield of 1, 3-dichloroacetone product is 93.6% (GC), and the purity is greater than 99% (GC).

Example 9

This example is the same as example 1, except that the second micromixer 12 in this example is a static mixer, the product 1, 3-dichloroacetone yield is 94.2% (GC), the purity is greater than 99% (GC).

Example 10

This example is the same as example 1, except that in this example the temperature in the first microchannel reactor 6 was controlled to-10 deg.C, the yield of 1, 3-dichloroacetone product was 93% (GC), and the purity was greater than 99% (GC).

Example 11

This example is the same as example 1, except that in this example the temperature in the first microchannel reactor 6 was controlled to-5 deg.C, the yield of 1, 3-dichloroacetone product was 93% (GC), and the purity was greater than 99% (GC).

Example 12

This example is the same as example 1 except that in this example the temperature in the first microchannel reactor 6 was controlled to 0 deg.C and the product 1, 3-dichloroacetone was produced in 93% (GC) and in greater than 99% (GC).

Example 13

This example is the same as example 1, except that in this example the temperature in the second microchannel reactor 15 was controlled to 75 deg.C, the yield of 1, 3-dichloroacetone product was 93.1% (GC), and the purity was greater than 99% (GC).

Example 14

This example is the same as example 1, except that in this example the temperature in the second microchannel reactor 15 was controlled to 65 ℃, the yield of 1, 3-dichloroacetone product was 93.1% (GC), and the purity was greater than 99% (GC).

Example 15

The present example is the same as example 1, except that the flow ratio of the substrate solution to chlorine gas in the present example was adjusted so that the molar ratio of the substrate diketene to chlorine gas was 1: 1.5, the yield of the product 1, 3-dichloroacetone is 93.2 percent (GC), and the purity is more than 99 percent (GC).

Example 16

The present example is the same as example 1, except that the flow ratio of the substrate solution to chlorine gas in the present example was adjusted so that the molar ratio of the substrate diketene to chlorine gas was 1: 1.2, the yield of the product 1, 3-dichloroacetone is 93.1 percent (GC), and the purity is more than 99 percent (GC).

Example 17

This example is the same as example 1, except that in this example the flow ratio of the first reaction mixture to water was adjusted so that the molar ratio of substrate diketene to water was 1: 1.5, the yield of the product 1, 3-dichloroacetone is 93 percent (GC), and the purity is more than 99 percent (GC).

Example 18

This example is the same as example 1, except that the first microchannel reactor 6 in this example is a teflon tube with an inner diameter of 0.6mm, the yield of 1, 3-dichloroacetone is 93.1% (GC) and the purity is more than 99% (GC).

Example 19

This example is the same as example 1, except that the second microchannel reactor 15 in this example is a teflon tube having an inner diameter of 0.6mm, and the yield of 1, 3-dichloroacetone product is 93.1% (GC) and the purity is greater than 99% (GC).

Example 20

This example is the same as example 1, except that the first microchannel reactor 6 and the second microchannel reactor 15 in this example are polytetrafluoroethylene tubes having an inner diameter of 0.6mm, and the yield of the product 1, 3-dichloroacetone is 93.4% (GC) and the purity is more than 99% (GC).

Example 21

This example is the same as example 1, except that chloroform was used as the solvent in the preparation of the substrate solution in this example, and the yield of the product 1, 3-dichloroacetone was 93.2% (GC) and the purity was more than 99% (GC).

Example 22

This example is the same as example 1, except that the substrate solution in this example was prepared using 1, 2-dichloroethane as the solvent, and the product 1, 3-dichloroacetone was obtained in 93.3% (GC) and in greater than 99% (GC) purity.

Example 23

This example is the same as example 1 except that the concentration of diketene in the substrate solution in this example was 10mol/L, the yield of the product 1, 3-dichloroacetone was 95.6% (GC), and the purity was more than 99% (GC).

Example 24

This example is the same as example 1 except that the concentration of diketene in the substrate solution in this example was 20mol/L, the yield of the product 1, 3-dichloroacetone was 96.1% (GC), and the purity was more than 99% (GC).

Example 25

This example is the same as example 1, except that in this example the temperature in the first micromixer 5 was controlled at-5 ℃, the yield of 1, 3-dichloroacetone product was 93.2% (GC), and the purity was greater than 99% (GC).

Example 26

This example is the same as example 1, except that in this example the temperature in the first micromixer 5 was controlled to 10 ℃, the yield of the product 1, 3-dichloroacetone was 93.0% (GC), and the purity was greater than 99% (GC).

Example 27

This example is the same as example 1, except that the temperature in the second micromixer 12 in this example was controlled to 20 ℃, the yield of the product 1, 3-dichloroacetone was 93.1% (GC), and the purity was greater than 99% (GC).

Example 28

This example is the same as example 1, except that in this example the temperature in the second micromixer 12 was controlled to 80 ℃, the yield of the product 1, 3-dichloroacetone was 93.6% (GC), and the purity was greater than 99% (GC).

Example 29

This example is the same as example 1 except that the residence time of the first reaction mixture in the first microchannel reactor 6 was controlled to be in the range of 5 minutes in this example, resulting in a 1, 3-dichloroacetone yield of 94.7% (GC) and a purity of greater than 99% (GC).

Example 30

This example is the same as example 1 except that the residence time of the second reaction mixture in the second microchannel reactor 15 is controlled to be in the range of 15 minutes in this example, resulting in a 1, 3-dichloroacetone product yield of 95.2% (GC) and a purity of greater than 99% (GC).

Comparative example

The comparative example adopts a batch kettle type reactor to prepare the 1, 3-dichloroacetone, the batch kettle type reactor is a 1500 ml round-bottom flask, and the specific preparation method is as follows: a substrate solution prepared by mixing diketene (84g, 1mol) and carbon tetrachloride (420mL) is added into a round-bottom flask, the round-bottom flask is placed in a constant-temperature bath at-15 ℃, stirring is started, and chlorine is introduced to start the reaction. Sampling and analyzing at regular time, reacting for 1 hour, and ensuring that the conversion rate of a reaction substrate, namely the diketene is about 62%; the reaction time is 2 hours, and the conversion rate of the reaction substrate diketene is about 76%; the reaction time is 3 hours, and the conversion rate of the reaction substrate diketene is about 83 percent; after 8 hours of reaction, the conversion rate of the reaction substrate, namely the diketene, is about 99 percent. Then, 22 ml of water was added to the round-bottom flask, the temperature was raised to 70 ℃ and the reaction was refluxed for 8 hours, and the reaction was monitored to be completed. The yield of the product 1, 3-dichloroacetone was 74% (GC) and the purity was greater than 99% (GC) by gas chromatography analysis.

The charge ratio and reaction conditions were the same for the comparative example and example 1. Compared with the preparation method adopting an intermittent reactor, the method for continuously preparing the 1, 3-dichloroacetone by adopting the micro-reaction system can be completed only by a few minutes of reaction, so that the reaction time is greatly shortened, the process efficiency is greatly improved, and the yield of the product 1, 3-dichloroacetone is obviously improved.

It should be noted that, although the above embodiments have been described herein, the scope of the present invention is not limited thereby, and the technical parameters not described in detail herein may be changed within the range of the listed parameters, so that the technical effects similar to or similar to the above embodiments can be obtained, and still fall within the scope of the present invention. Therefore, based on the innovative concepts of the present invention, the technical solutions of the present invention can be directly or indirectly applied to other related technical fields by making changes and modifications to the embodiments described herein, or by using equivalent structures or equivalent processes performed in the content of the present specification and the attached drawings, which are included in the scope of the present invention.