Refining device of 1,3-dichloro-2-propanol in epichlorohydrin production

Abstract

The utility model belongs to the technical field of organic separation, and specifically relates to a refining device for 1,3-dichloro-2-propanol in the production of epichlorohydrin. The refining device for 1,3-dichloro-2-propanol in the production of epichlorohydrin comprises a chlorination reaction kettle, a crude product buffer tank, a light removal tower, a distillation tower and a deep distillation tower connected in sequence, and the gas phase outlets of the chlorination reaction kettle, the light removal tower, the distillation tower and the deep distillation tower are respectively connected in sequence with a condenser and a gas-liquid separator; it also comprises a condensate buffer tank, a desorption tower and a material temporary storage tank connected in sequence; it also comprises a hydrogen chloride recovery pipeline. The refining device can realize the continuous production and separation and refining of 1,3-dichloro-2-propanol, improve the recycling rate of hydrogen chloride tail gas, have good environmental benefits, and at the same time improve the yield and purity of the 1,3-dichloro-2-propanol product.

Description

Technical Field

[0001] The utility model belongs to the technical field of organic separation, and specifically relates to a refining device for 1,3-dichloro-2-propanol in the production of epichlorohydrin. Background Art

[0002] 1,3-dichloro-2-propanol is an important intermediate in the glycerol process for preparing epichlorohydrin. It is produced by the reaction of glycerol and hydrogen chloride under the action of a catalyst. The reaction also produces water, 2,3-dichloro-1-propanol, 3-chloro-1,2-propanediol and other ester heavy components. During the reaction, due to the excess of hydrogen chloride and its high solubility in water, the generated 1,3-dichloro-2-propanol contains a large amount of water, hydrogen chloride and a small amount of by-products. The 1,3-dichloro-2-propanol generated by this method must be further refined to remove the light component water, hydrogen chloride and ester heavy components before it can be used in the glycerol process for producing epichlorohydrin. In the conventional glycerin method epichlorohydrin production process, 1,3-dichloro-2-propanol separation mainly adopts kettle distillation, which has the disadvantages of high energy consumption, small processing volume and difficulty in continuous production. Therefore, in view of the problems existing in the 1,3-dichloro-2-propanol separation process in the above conventional glycerin method epichlorohydrin production process, it is necessary to provide a device capable of continuously separating 1,3-dichloro-2-propanol, improve the distillation separation processing capacity of 1,3-dichloro-2-propanol, and realize continuous production. Utility Model Content

[0003] In view of the deficiencies in the prior art, the purpose of the utility model is to provide a refining device for 1,3-dichloro-2-propanol in the production of epichlorohydrin, which can realize the continuous production and separation and refining of 1,3-dichloro-2-propanol, improve the recycling rate of hydrogen chloride tail gas, have good environmental benefits, and at the same time improve the yield and purity of the 1,3-dichloro-2-propanol product.

[0004] The utility model is realized by adopting the following technical solutions:

[0005] The refining device of 1,3-dichloro-2-propanol in the production of epichlorohydrin comprises a chlorination reaction kettle, a crude product buffer tank, a light-removing tower, a distillation tower and a deep distillation tower connected in sequence, wherein the gas phase outlets of the chlorination reaction kettle, the light-removing tower, the distillation tower and the deep distillation tower are respectively connected in sequence with a first condenser and a first gas-liquid separator, a second condenser and a second gas-liquid separator, a third condenser and a third gas-liquid separator, and a fourth condenser and a fourth gas-liquid separator; the refining device also comprises a condensate buffer tank, a desorption tower and a material temporary storage tank connected in sequence, wherein the inlet of the condensate buffer tank is connected to the liquid phase outlet of the first gas-liquid separator through a pipeline, and the inlet of the material temporary storage tank is respectively connected to the liquid phase outlet of the third gas-liquid separator and the liquid phase outlet of the fourth gas-liquid separator through a pipeline; the refining device also comprises a hydrogen chloride recovery pipeline, wherein the gas phase outlets of the second gas-liquid separator, the third gas-liquid separator, the fourth gas-liquid separator and the desorption tower are respectively connected to the hydrogen chloride recovery pipeline through pipelines, and the outlet of the hydrogen chloride recovery pipeline is connected to the inlet of the chlorination reaction kettle.

[0006] The bottom and top of the chlorination reaction kettle are respectively connected with a hydrogen chloride feed pipeline and a glycerol feed pipeline, and hydrogen chloride and glycerol enter the chlorination reaction kettle through the pipelines for reaction.

[0007] The gas phase outlet of the first gas-liquid separator is connected to a pipeline to the tail gas treatment system, and the gas phase containing a small amount of hydrogen chloride separated by the first gas-liquid separator is sent to the tail gas treatment system for further treatment.

[0008] The bottom liquid phase outlet of the deep distillation tower is connected to a tar removal tower pipeline, and the heavy components obtained at the bottom of the deep distillation tower are sent to the tar tower for subsequent treatment.

[0009] The outlet of the temporary material storage tank is connected to a pipeline to the finished product storage tank. The material in the temporary material storage tank can be discharged into the finished product storage tank only after it passes the inspection. If the inspection fails, further processing is required.

[0010] The liquid phase outlets of the second gas-liquid separator, the third gas-liquid separator and the fourth gas-liquid separator are also connected to the top inlets of the light removal tower, the distillation tower and the deep distillation tower through reflux lines respectively.

[0011] The working principle of the device is as follows:

[0012] (1) introducing hydrogen chloride and glycerol reaction raw materials into a chlorination reactor to generate a 1,3-dichloro-2-propanol reaction liquid through a catalytic reaction, the reaction temperature is controlled to be 60° C., the reaction pressure is slightly positive, the gas phase generated by the reaction is cooled by a first condenser at the top of the reactor and separated by a first gas-liquid separator, the gas phase material is sent to the tail gas treatment system, and the liquid phase material in the first gas-liquid separator enters a condensate buffer tank for buffering and is then pumped to a desorption tower;

[0013] (2) The operating pressure of the desorption tower is 180-200 kPa, and the hydrogen chloride gas with a purity of more than 98 wt.% is obtained at the top of the tower and returned to the chlorination reaction kettle through the hydrogen chloride recovery pipeline for reaction, and the 1,3-dichloro-2-propanol with a content of not less than 27 wt.% is obtained at the bottom of the tower and enters the material temporary storage tank;

[0014] (3) The feed liquid at the bottom of the chlorination reaction kettle enters the crude product buffer tank, and the feed liquid in the crude product buffer tank is transported to the middle feed port of the light removal tower by a feed pump. The operating pressure of the light removal tower is 30-60 kPa. The gas phase at the top of the tower is cooled to 40-50° C. by a second condenser, and the hydrogen chloride gas with a purity of 98 wt.% is obtained by separation in a second gas-liquid separator and returned to the chlorination reaction kettle for reaction. The small amount of liquid phase obtained by separation is refluxed to the light removal tower through a reflux pipeline, and the 1,3-dichloro-2-propanol mixture with a purity of more than 55 wt.% obtained at the bottom of the tower is sent to a distillation tower for further separation and purification;

[0015] (4) The operating pressure of the distillation tower is 5-10 kPa, the gas phase at the top of the tower is cooled to 40-50° C. by the third condenser, and the 1,3-dichloro-2-propanol liquid phase mixture with a purity of 90 wt.% is obtained after separation by the third gas-liquid separator. Part of it is refluxed, and the rest is sent to the 1,3-dichloro-2-propanol temporary storage tank, and the feed liquid containing a small amount of 1,3-dichloro-2-propanol heavy components obtained at the bottom of the tower is sent to the deep distillation tower for further recovery and treatment;

[0016] (5) The operating pressure of the deep distillation tower is 5-10 kPa, the gas phase at the top of the tower is cooled to 40-50° C. by the fourth condenser, and the 1,3-dichloro-2-propanol component in the heavy component is recovered and sent to the material temporary storage tank, and the heavy component obtained at the bottom of the tower enters the tar tower through the detarring tower pipeline for subsequent treatment;

[0017] (6) After the material in the temporary storage tank passes the inspection, it enters the finished product storage tank through the pipeline to the finished product storage tank.

[0018] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0019] (1) The 1,3-dichloro-2-propanol refining device in the production of epichlorohydrin described in the utility model overcomes the limitation of the traditional production process that the chlorination reaction and distillation process of 1,3-dichloro-2-propanol are limited to intermittent and small-batch production in the same kettle, and realizes the continuous and large-scale production of the chlorination reaction and the refining process, thereby significantly improving the production efficiency and production capacity of 1,3-dichloro-2-propanol;

[0020] (2) The refining device for 1,3-dichloro-2-propanol in the production of epichlorohydrin described in the utility model can significantly improve the recycling efficiency of hydrogen chloride, which not only helps to reduce the waste of hydrogen chloride in the production process, but also significantly reduces the content of hydrogen chloride in the tail gas, thereby achieving higher environmental benefits and bringing dual environmental and economic benefits to enterprises and society;

[0021] (3) The refining device for 1,3-dichloro-2-propanol in the production of epichlorohydrin described in the utility model has an excellent separation effect. By finely controlling the reaction and separation conditions at each stage, the light and heavy components in the reaction liquid can be separated more thoroughly and accurately, which not only greatly improves the yield of 1,3-dichloro-2-propanol in the finished product, but also significantly improves the purity and quality of the product, providing better quality raw materials for production and application in related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a refining device for 1,3-dichloro-2-propanol in the production of epichlorohydrin described in the utility model;

[0023] In the figure: 1, chlorination reaction kettle; 2, crude product buffer tank; 3, light removal tower; 4, distillation tower; 5, deep distillation tower; 6, first condenser; 7, first gas-liquid separator; 8, second condenser; 9, second gas-liquid separator; 10, third condenser; 11, third gas-liquid separator; 12, fourth condenser; 13, fourth gas-liquid separator; 14, condensate buffer tank; 15, desorption tower; 16, material temporary storage tank; 17, hydrogen chloride recovery pipeline; 18, hydrogen chloride feed pipeline; 19, glycerol feed pipeline; 20, to tail gas treatment system pipeline; 21, to tar tower pipeline; 22, to finished product storage tank pipeline. DETAILED DESCRIPTION

[0024] In order to make the purpose and technical solution of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings.

[0025] Example 1

[0026] like Figure 1As shown, the refining device of 1,3-dichloro-2-propanol in the production of epichlorohydrin comprises a chlorination reaction kettle 1, a crude product buffer tank 2, a light removal tower 3, a distillation tower 4 and a deep distillation tower 5 which are connected in sequence, and the gas phase outlets of the chlorination reaction kettle 1, the light removal tower 3, the distillation tower 4 and the deep distillation tower 5 are respectively connected in sequence with a first condenser 6 and a first gas-liquid separator 7, a second condenser 8 and a second gas-liquid separator 9, a third condenser 10 and a third gas-liquid separator 11, a fourth condenser 12 and a fourth gas-liquid separator 13; the refining device also comprises a condensate buffer tank 14, a deionized water separator 15 and a deionized water separator 16 which are connected in sequence. The tower 15 and the material temporary storage tank 16, wherein the inlet of the condensate buffer tank 14 is connected to the liquid phase outlet of the first gas-liquid separator 7 through a pipeline, and the inlet of the material temporary storage tank 16 is connected to the liquid phase outlet of the third gas-liquid separator 11 and the liquid phase outlet of the fourth gas-liquid separator 13 through pipelines respectively; the refining device also includes a hydrogen chloride recovery pipeline 17, and the gas phase outlets of the second gas-liquid separator 9, the third gas-liquid separator 11, the fourth gas-liquid separator 13 and the separation tower 15 are respectively connected to the hydrogen chloride recovery pipeline 17 through pipelines, and the outlet of the hydrogen chloride recovery pipeline 17 is connected to the inlet of the chlorination reaction kettle 1.

[0027] The bottom and top of the chlorination reaction kettle 1 are respectively connected to a hydrogen chloride feed pipeline 18 and a glycerol feed pipeline 19.

[0028] The gas phase outlet of the first gas-liquid separator 7 is connected to a tail gas treatment system pipeline 20 .

[0029] The bottom liquid phase outlet of the deep distillation tower 5 is connected to a detarring tower pipeline 21 .

[0030] The outlet of the temporary material storage tank 16 is connected to a pipeline 22 to a finished product storage tank.

[0031] The liquid phase outlets of the second gas-liquid separator 9, the third gas-liquid separator 11 and the fourth gas-liquid separator 13 are also connected to the top inlets of the lightness removal tower 3, the distillation tower 4 and the deep distillation tower 5 through reflux lines, respectively.

[0032] When working, the specific steps are as follows:

[0033] (1) adding hydrogen chloride and glycerol reaction raw materials into the 1,3-dichloro-2-propanol reaction liquid generated by the catalytic reaction in the chlorination reactor 1 through the hydrogen chloride feed pipeline 18 and the glycerol feed pipeline 19 respectively, the reaction temperature is controlled to be 60° C., the reaction pressure is slightly positive pressure, the reaction is an exothermic reaction, the gas phase generated by the reaction is cooled by the first condenser 6 at the top of the reactor and separated by the first gas-liquid separator 7, and the gas phase material is sent to the tail gas treatment system through the tail gas treatment system pipeline 20 for further treatment, and the liquid phase material in the first gas-liquid separator 7 enters the condensate buffer tank 14 for buffering and is then pumped to the desorption tower 15;

[0034] (2) The operating pressure of the stripping tower 15 is 190 kPa, and the tower top temperature is controlled at 70° C. The hydrogen chloride gas with a purity of 98 wt.% obtained at the tower top is returned to the chlorination reaction kettle 1 through the hydrogen chloride recovery pipeline 17 for reaction, and the 1,3-dichloro-2-propanol with a content of 27 wt.% obtained at the tower bottom enters the material temporary storage tank 16;

[0035] (3) The feed liquid at the bottom of the chlorination reaction kettle 1 enters the crude product buffer tank 2, and the feed liquid in the crude product buffer tank 2 is transported to the middle feed port of the light removal tower 3 by a feed pump. The operating pressure of the light removal tower 3 is 40 kPa, and the tower top temperature is 85° C. The tower top gas phase is cooled to 40° C. by the second condenser 8, and the hydrogen chloride gas with a purity of 98 wt.% is separated by the second gas-liquid separator 9 and returned to the chlorination reaction kettle 1 through the hydrogen chloride recovery pipeline 17 for reaction. The small amount of liquid phase obtained by separation is refluxed to the light removal tower 3 through the reflux pipeline, and the 1,3-dichloro-2-propanol mixture with a purity of 55 wt.% obtained at the bottom of the tower is sent to the distillation tower 4 for further separation and purification;

[0036] (4) The operating pressure of the distillation tower 4 is 5 kPa, and the tower top temperature is 80° C. The tower top gas phase is cooled to 40° C. by the third condenser 10, and is separated by the third gas-liquid separator 11 to obtain a 1,3-dichloro-2-propanol liquid phase mixture with a purity of 90 wt.%. Part of the mixture is refluxed, and the rest is sent to the 1,3-dichloro-2-propanol temporary material storage tank 16. The separated hydrogen chloride gas is returned to the chlorination reactor 1 through the hydrogen chloride recovery pipeline 17 for reaction. The feed liquid containing a small amount of 1,3-dichloro-2-propanol heavy components obtained at the bottom of the tower is sent to the deep distillation tower 5 for further recovery and treatment;

[0037] (5) The operating pressure of the deep distillation tower 5 is 5 kPa, and the tower top temperature is 90° C. The tower top gas phase is cooled to 40° C. by the fourth condenser 12, and the 1,3-dichloro-2-propanol component in the heavy component is recovered after separation by the fourth gas-liquid separator 13 and sent to the material temporary storage tank 16. The separated hydrogen chloride gas is returned to the chlorination reactor 1 through the hydrogen chloride recovery pipeline 17 for reaction, and the heavy component obtained at the bottom of the tower enters the tar tower through the detarring tower pipeline 21 for subsequent treatment;

[0038] (6) After the material in the temporary material storage tank 16 passes the inspection, it enters the finished product storage tank through the finished product storage tank pipeline 22.

Claims

1. A refining device for 1,3-dichloro-2-propanol in the production of epichlorohydrin, characterized in that: The invention comprises a chlorination reaction kettle (1), a crude product buffer tank (2), a light-removing tower (3), a distillation tower (4) and a deep distillation tower (5) which are connected in sequence, wherein the gas phase outlets of the chlorination reaction kettle (1), the light-removing tower (3), the distillation tower (4) and the deep distillation tower (5) are respectively connected in sequence with a first condenser (6) and a first gas-liquid separator (7), a second condenser (8) and a second gas-liquid separator (9), a third condenser (10) and a third gas-liquid separator (11), a fourth condenser (12) and a fourth gas-liquid separator (13); the refining device also comprises a condensate buffer tank (14), a light-removing tower (15) and a material temporary storage tank (16) which are connected in sequence. 6), wherein the inlet of the condensate buffer tank (14) is connected to the liquid phase outlet of the first gas-liquid separator (7) through a pipeline, and the inlet of the material temporary storage tank (16) is connected to the liquid phase outlet of the third gas-liquid separator (11) and the liquid phase outlet of the fourth gas-liquid separator (13) through pipelines respectively; the refining device also includes a hydrogen chloride recovery pipeline (17), and the gas phase outlets of the second gas-liquid separator (9), the third gas-liquid separator (11), the fourth gas-liquid separator (13) and the separation tower (15) are respectively connected to the hydrogen chloride recovery pipeline (17) through pipelines, and the outlet of the hydrogen chloride recovery pipeline (17) is connected to the inlet of the chlorination reaction kettle (1).

2. The refining device for 1,3-dichloro-2-propanol in the production of epichlorohydrin according to claim 1, characterized in that: The bottom and top of the chlorination reaction kettle (1) are respectively connected to a hydrogen chloride feed pipeline (18) and a glycerol feed pipeline (19).

3. The refining device for 1,3-dichloro-2-propanol in the production of epichlorohydrin according to claim 1, characterized in that: The gas phase outlet of the first gas-liquid separator (7) is connected to a tail gas treatment system pipeline (20).

4. The refining device for 1,3-dichloro-2-propanol in the production of epichlorohydrin according to claim 1, characterized in that: The bottom liquid phase outlet of the deep distillation tower (5) is connected to a detarring tower pipeline (21).

5. The refining device for 1,3-dichloro-2-propanol in the production of epichlorohydrin according to claim 1, characterized in that: The outlet of the temporary material storage tank (16) is connected to a pipeline (22) to a finished product storage tank.

6. The device for refining 1,3-dichloro-2-propanol in the production of epichlorohydrin according to claim 1, characterized in that: The liquid phase outlets of the second gas-liquid separator (9), the third gas-liquid separator (11) and the fourth gas-liquid separator (13) are also connected to the top inlets of the lightness removal tower (3), the distillation tower (4) and the deep distillation tower (5) respectively through reflux lines.

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