Equipment for continuously preparing ketazine

Abstract

The utility model discloses equipment for continuously preparing ketazine, which relates to the technical field of azodiisobutyronitrile production and comprises a hydrazine hydrate feeding jacketed pipe, an acetone feeding jacketed pipe, a sectional tubular reactor and a ketazine storage tank, the hydrazine hydrate feeding jacketed pipe and the acetone feeding jacketed pipe are both communicated with a material inlet of the sectional type tubular reactor, a material outlet of the sectional type tubular reactor is communicated with a feeding port of the ketazine storage tank, and the ketazine storage tank comprises a jacket cooling system. Compared with the traditional kettle type reaction method, the reaction time is shortened to 1-1.5 hours, the equipment structure is simple, the utilization efficiency of unit volume is greatly improved, the volume of the reactor is reduced, the safety level is essentially improved, the reaction proportion is more accurate, and the conversion rate is improved by 0.8%-1.5% compared with the traditional method.

Description

Technical Field

[0001] The utility model relates to the technical field of azodiisobutyronitrile production, and more specifically to the technical field of a method and equipment for continuously preparing acetone azine. Background Art

[0002] Azodiisobutyronitrile (AIBN) is a widely used oil-soluble initiator, mainly used as a foaming agent and polymerization initiator for rubber, plastics, etc., and can also be used in organic synthesis.

[0003] Azodiisobutyronitrile can be prepared by reacting acetone, hydrazine hydrate and hydrocyanic acid, or by reacting acetone, hydrazine sulfate and sodium cyanide followed by oxidation, or by condensing acetone cyanohydrin with hydrazine hydrate followed by oxidation. In the preparation method using acetone and hydrazine hydrate as starting materials, acetone azine is first generated by reacting acetone with hydrazine hydrate, and then diisobutyronitrile hydrazine is generated by reacting acetone azine with hydrocyanic acid, and then azodiisobutyronitrile is generated by oxidation, and high-quality products are obtained through recrystallization and drying.

[0004] The existing production method of acetone azine adopts batch kettle reaction. Hydrazine hydrate and acetone are sequentially added to a reaction kettle with a cooling system according to a molar ratio of hydrazine hydrate:acetone = 1:2 - 2.5. Stirring is started, and the reaction temperature is controlled at 30 - 60 °C through a jacket cooling system. The reaction gas phase is refluxed to the reaction kettle through a reflux condenser, and the reaction continues for 12 - 15 hours. Acetone azine and water are generated by the reaction, and the preparation is completed after sampling and analysis are qualified.

[0005] Since the boiling point of acetone is relatively low and it is in excess relative to hydrazine hydrate, when producing acetone azine by batch kettle reaction, the consequences caused by the increase in acetone vapor pressure at a relatively high temperature must be considered. Under atmospheric pressure operation, a large amount of acetone will be lost. The reaction temperature selected in this process is low and the reaction time is long. Once the reaction temperature is increased, the reaction kettle will be under pressure, which significantly improves the requirements for reaction equipment. Moreover, the operation time during the feeding heating, cooling and pressure reduction and discharging processes is greatly extended when using batch production. As a result, the existing method has low production efficiency, long reaction time and high equipment requirements. Summary of the Utility Model

[0006] The purpose of the utility model is to solve the technical problems of low reaction efficiency, long reaction time and high equipment requirements existing in the existing intermittent reaction preparation method of azodiisobutyronitrile. The utility model provides a method and equipment for continuously preparing acetone azine.

[0007] The utility model specifically adopts the following technical solutions to achieve the above purpose:

[0008] The utility model provides an equipment for continuously preparing acetone azine, including a hydrazine hydrate feed jacket pipe, an acetone feed jacket pipe, a segmented tubular reactor, and an acetone azine storage tank;

[0009] The hydrazine hydrate feed jacketed pipe and the acetone feed jacketed pipe are both connected to the material inlet of the segmented tubular reactor, and the material outlet of the segmented tubular reactor is connected to the feed inlet of the acetone azine storage tank.

[0010] The acetone azine storage tank includes a jacket cooling system.

[0011] In one embodiment, a jacket preheating system is provided outside both the hydrazine hydrate feed jacketed pipe and the acetone feed jacketed pipe.

[0012] In one embodiment, the segmented tubular reactor is divided into three sections, which are successively arranged as a front-stage tubular reactor, a middle-stage tubular reactor, and a rear-stage tubular reactor in the fluid direction. A circulating temperature control jacket is sleeved outside each of the front-stage tubular reactor, the middle-stage tubular reactor, and the rear-stage tubular reactor.

[0013] In one embodiment, the front-stage tubular reactor, the middle-stage tubular reactor, and the rear-stage tubular reactor are all serpentine bent pipes;

[0014] The material inlet of the front-stage tubular reactor is connected to the hydrazine hydrate feed jacketed pipe and the acetone feed jacketed pipe, the material outlet of the front-stage tubular reactor is connected to the material inlet of the middle-stage tubular reactor, the material outlet of the middle-stage tubular reactor is connected to the material inlet of the rear-stage tubular reactor, and the material outlet of the rear-stage tubular reactor is connected to the feed inlet of the acetone azine storage tank.

[0015] In one embodiment, the circulating temperature control jackets of the front-stage tubular reactor, the middle-stage tubular reactor, and the rear-stage tubular reactor are independently arranged and independently temperature-controlled.

[0016] In one embodiment, jacket heating systems are provided on both the hydrazine hydrate feed jacketed pipe and the acetone feed jacketed pipe, and a transfer pump, a flow control valve, a flow meter, a thermometer, and a pressure gauge are provided.

[0017] In one embodiment, the acetone azine storage tank includes a tank body, a stirring assembly arranged inside the tank body, a driving motor arranged at the top outside the tank body to drive the stirring assembly to rotate, a discharge port arranged at the bottom of the tank body, and a feed port arranged at the top of the tank body. The jacket cooling system is arranged on the bottom and side walls of the tank body.

[0018] In one embodiment, the jacket cooling system includes an external jacket housing. The jacket housing and the bottom and side walls of the tank body enclose a jacket cavity, and an inlet pipe and an outlet pipe communicating with the inside of the jacket cavity are arranged on the jacket housing.

[0019] In one embodiment, a maintenance manhole, a pressure gauge, a thermometer, an air inlet, and an exhaust port are arranged at the top of the tank body.

[0020] In one embodiment, the tank body includes a cylindrical body in the middle and end heads provided at both ends of the cylindrical body.

[0021] The beneficial effects of the present utility model are as follows:

[0022] The present utility model is reasonably designed and obtains data for quickly completing the reaction under the condition of reaching a relatively high temperature in a short time. By increasing the reaction temperature and pressure and making full use of the good pressure-bearing and heat-exchanging characteristics of the tubular reactor, a device capable of quickly completing the hydrazoic reaction is formed. Compared with the traditional kettle reaction method, the reaction time is shortened to 1 - 1.5 hours, the equipment structure is simple, the utilization efficiency per unit volume is greatly improved, the volume of the reactor becomes smaller, the safety level is essentially enhanced, the reaction ratio is more accurate, and the conversion rate is increased by 0.8% - 1.5% compared with the traditional method. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present utility model and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 is a schematic structural diagram of the present utility model;

[0025] Figure 2 is a schematic structural diagram of the segmented tubular reactor;

[0026] Figure 3 is a schematic structural diagram of the acetone azide storage tank;

[0027] Reference numerals: 1 - hydrazine hydrate feed jacket pipe, 2 - acetone feed jacket pipe, 3 - segmented tubular reactor, 31 - front-segment tubular reactor, 32 - middle-segment tubular reactor, 33 - end-segment tubular reactor, 4 - acetone azide storage tank, 41 - air inlet, 42 - stirring assembly, 43 - water inlet pipe, 44 - discharge port, 45 - jacket housing, 46 - water outlet pipe, 47 - tank body, 48 - drive motor, 49 - feed port. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are some but not all of the embodiments of the present utility model. Usually, the components of the embodiments of the present utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0030] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In addition, the terms "first", "second", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0031] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "inner", "outer", "upper", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation on the present invention.

[0032] Embodiment 1

[0033] As Figures 1 to 3 shown, this embodiment provides a device for continuous preparation of acetone azine, including a hydrazine hydrate feed jacketed pipe 1, an acetone feed jacketed pipe 2, a segmented tubular reactor 3, and an acetone azine storage tank 4;

[0034] Both the hydrazine hydrate feed jacketed pipe 1 and the acetone feed jacketed pipe 2 are connected to the material inlet of the segmented tubular reactor 3, and the material outlet of the segmented tubular reactor 3 is connected to the feed port 49 of the acetone azine storage tank 4;

[0035] The hydrazine hydrate feed jacketed pipe 1 and the acetone feed jacketed pipe 2 include a jacket preheating system.

[0036] The acetone azine storage tank 4 includes a jacket cooling system.

[0037] The segmented tubular reactor 3 is divided into three sections, which are successively arranged as a front-stage tubular reactor 31, a middle-stage tubular reactor 32, and a final-stage tubular reactor 33 in the fluid direction. The outer parts of the front-stage tubular reactor 31, the middle-stage tubular reactor 32, and the final-stage tubular reactor 33 are all sleeved with circulating temperature control jackets.

[0038] The front-stage tubular reactor 31, the middle-stage tubular reactor 32, and the final-stage tubular reactor 33 are all serpentine bent pipes;

[0039] The material inlet of the front-stage tubular reactor 31 is connected to the hydrazine hydrate feed jacket pipe 1 and the acetone feed jacket pipe 2. The material outlet of the front-stage tubular reactor 31 is connected to the material inlet of the middle-stage tubular reactor 32. The material outlet of the middle-stage tubular reactor 32 is connected to the material inlet of the last-stage tubular reactor 33. The material outlet of the last-stage tubular reactor 33 is connected to the inlet 49 of the acetone azine storage tank 4.

[0040] The circulating temperature control jackets of the front-stage tubular reactor 31, the middle-stage tubular reactor 32, and the last-stage tubular reactor 33 are independently arranged and temperature-controlled independently.

[0041] Both the hydrazine hydrate feed jacket pipe 1 and the acetone feed jacket pipe 2 are provided with a jacket preheating system, a transfer pump, a flow control valve, a flow meter, a thermometer, and a pressure gauge.

[0042] The acetone azine storage tank 4 includes a tank body 47, a stirring assembly 42 arranged inside the tank body 47, a driving motor 48 arranged at the outer top of the tank body 47 to drive the stirring assembly 42 to rotate, a discharge port 44 arranged at the bottom of the tank body 47, and an inlet 49 arranged at the top of the tank body 47. A jacket cooling system is arranged on the bottom and side walls of the tank body 47.

[0043] The jacket cooling system includes an outer jacket housing 45. The jacket housing 45 and the bottom and side walls of the tank body 47 enclose a jacket cavity. The jacket housing 45 is provided with a water inlet pipe 43 and a water outlet pipe 46 that communicate with the inside of the jacket cavity.

[0044] The top of the tank body 47 is provided with a maintenance manhole, a pressure gauge, a thermometer, an air inlet 41, and an exhaust port.

[0045] The tank body 47 includes a middle cylinder and end heads arranged at both ends of the cylinder.

[0046] Example 2

[0047] A method for continuously preparing acetone azine includes the following steps:

[0048] S1. Prepare hydrazine hydrate and acetone;

[0049] S2. The hydrazine hydrate and acetone are respectively controlled to enter the segmented tubular reactor 3 through the jacket hot water preheating system and the flow regulating valve. The reaction temperature of the reaction materials in the segmented tubular reactor 3 is controlled by the circulating water regulating valve. The segmented tubular reactor 3 is divided into three sections, which are successively arranged as the front-stage tubular reactor 31, the middle-stage tubular reactor 32, and the last-stage tubular reactor 33 in the fluid direction;

[0050] S3. In the segmented tubular reactor 3, along the fluid flow direction, the reaction temperature in each segment of the tubular reactor gradually decreases, and acetone azine is obtained by reaction.

[0051] For the front - stage tubular reactor 31, the reaction material is controlled at 90 °C through the circulating water regulating valve, the pressure is controlled at 0.12 MPa through the back - pressure control, and the length is controlled at 20 m.

[0052] In the middle - stage tubular reactor 32, the reaction temperature gradually decreases. The reaction material temperature is gradually reduced to 70 °C through the circulating water regulating valve, the pressure is controlled at 0.12 MPa through the outlet pressure regulating valve, and the length is controlled at 40 m.

[0053] For the last - stage tubular reactor 33, the reaction material is controlled at 45 °C through the circulating water regulating valve, the pressure is controlled at 0.12 MPa through the outlet pressure regulating valve, and the length is controlled at 40 m.

[0054] S4. The acetone azine that has reacted in the segmented tubular reactor 3 enters the acetone azine storage tank 4, and the temperature of the acetone azine storage tank 4 is controlled to be less than 40 °C.

[0055] Start the feed pumps of the water - hydrazine feed jacket pipe 1 and the acetone feed jacket pipe 2. Through the jacket hot - water preheating system and the flow control valve, 590 Kg of hydrazine hydrate (at 70 °C) and 1105 Kg of acetone (at 45 °C) enter the multi - stage tubular reactor simultaneously. The two materials start to react. In the front - stage tubular reactor 31, the reaction material is controlled at 90 °C through the 32 °C circulating water regulating valve. The reaction in the rear - stage tubular reactor gradually weakens and the temperature is relatively low. The reaction material is controlled at 45 °C through the 32 °C circulating water. The pressure in the rear - stage tubular reactor is controlled at 0.12 MPa through the outlet pressure regulating valve. The reaction material enters the acetone azine storage tank 4 through the pipeline. A total of 1695 Kg of reactants are obtained, and 1051 Kg of acetone azine products are sampled and analyzed. The yield is 99.5% (calculated based on acetone).

[0056] Example 3

[0057] A method for continuously preparing acetone azine, comprising the following steps:

[0058] S1. Prepare hydrazine hydrate and acetone.

[0059] S2. Hydrazine hydrate and acetone respectively enter the segmented tubular reactor 3 through the jacket hot - water preheating system and the flow control valve. The reaction temperature of the reaction material in the segmented tubular reactor 3 is controlled through the circulating water regulating valve. The segmented tubular reactor 3 is divided into three segments, which are successively arranged as the front - stage tubular reactor 31, the middle - stage tubular reactor 32, and the last - stage tubular reactor 33 in the fluid direction.

[0060] S3. In the segmented tubular reactor 3, along the fluid flow direction, the reaction temperature in each section of the tubular reactor gradually decreases, and acetone azine is obtained through the reaction.

[0061] For the front-section tubular reactor 31, the reaction material is controlled at 92 °C through the circulating water regulating valve, the pressure is controlled at 0.15 MPa through back pressure, and the length is controlled at 40 m.

[0062] In the middle-section tubular reactor 32, the reaction temperature and pressure gradually weaken. The reaction material temperature is gradually reduced to 68 °C through the circulating water regulating valve, the pressure is controlled at 0.15 MPa through the outlet pressure regulating valve, and the length is controlled at 40 m.

[0063] For the last-section tubular reactor 33, the reaction material is controlled at 60 °C through the circulating water regulating valve, the pressure is controlled at 0.15 MPa through the outlet pressure regulating valve, and the length is controlled at 20 m.

[0064] S4. The acetone azine obtained from the reaction in the segmented tubular reactor 3 enters the acetone azine storage tank 4, and the temperature of the acetone azine storage tank 4 is controlled to be less than 40 °C.

[0065] Example 4

[0066] A method for continuously preparing acetone azine includes the following steps:

[0067] S1. Prepare hydrazine hydrate and acetone.

[0068] S2. Hydrazine hydrate and acetone respectively enter the segmented tubular reactor 3 through the jacket hot water preheating system and the flow regulating valve. The reaction temperature of the reaction material in the segmented tubular reactor 3 is controlled through the circulating water regulating valve. The segmented tubular reactor 3 is divided into three sections, which are successively arranged as the front-section tubular reactor 31, the middle-section tubular reactor 32, and the last-section tubular reactor 33 along the fluid direction.

[0069] S3. In the segmented tubular reactor 3, along the fluid flow direction, the reaction temperature in each section of the tubular reactor gradually decreases, and acetone azine is obtained through the reaction.

[0070] For the front-section tubular reactor 31, the reaction material is controlled at 95 °C through the circulating water regulating valve, the pressure is controlled at 0.2 MPa through back pressure, and the length is controlled at 30 m.

[0071] In the middle-section tubular reactor 32, the reaction temperature and pressure gradually weaken. The reaction material temperature is gradually reduced to 65 °C through the circulating water regulating valve, the pressure is controlled at 0.2 MPa through the outlet pressure regulating valve, and the length is controlled at 35 m.

[0072] For the last-stage tubular reactor 33, the reaction materials are controlled at 50°C by the circulating water regulating valve, the pressure is controlled at 0.2 MPa by the outlet pressure regulating valve, and the length is controlled at 35 m.

[0073] S4. The acetone azine that has passed through the segmented tubular reactor 3 enters the acetone azine storage tank 4, and the temperature of the acetone azine storage tank 4 is controlled to be less than 40°C.

[0074] Comparative Example 1

[0075] Add 590 Kg of hydrazine hydrate to the azine reaction kettle. Then put 1105 Kg of acetone into the azine reaction kettle. Use the circulating water in the jacket of the reaction kettle (32°C) to control the reaction temperature at 60°C. The reaction pressure is slightly positive pressure. There is a gas-phase reflux condenser above the reaction kettle. A small amount of gas is condensed by the condenser and then refluxed to the reaction kettle. No gas can pass through the tail gas pipeline to the tail gas treatment system. After reacting for 12 hours, sample and analyze. A total of 1695 Kg of reactants are obtained, and a total of 1041 Kg of acetone azine products are sampled and analyzed. The yield is 98.6% (calculated based on acetone).

[0076] The conclusions of Example 3 and Example 4 are similar to those of Example 2 and will not be elaborated here. Through the above comparative examples, using a continuous tubular reactor in Example 2 to Example 4 to increase the reaction temperature and pressure ratio increases the average conversion rate by 0.8% - 1.5% compared to using a kettle reactor. The reaction time is shortened to 1 - 1.5 hours. If the temperature and pressure of the kettle reaction solution are increased, the equipment investment will increase. Since the boiling points of the reaction raw materials are all relatively low, a large amount will vaporize after heating. If it is vaporized and condensed and then continue to react, the production efficiency will be greatly reduced. Such a production method is not the most preferred for industrial production.

Claims

1. An apparatus for continuously preparing acetone azine, characterized in that, It includes a hydrazine hydrate feed jacketed pipe (1), an acetone feed jacketed pipe (2), a segmented tubular reactor (3), and an acetone azine storage tank (4); Both the hydrazine hydrate feed jacketed pipe (1) and the acetone feed jacketed pipe (2) are connected to the material inlet of the segmented tubular reactor (3), and the material outlet of the segmented tubular reactor (3) is connected to the feed port (49) of the acetone azine storage tank (4). The acetone azine storage tank (4) includes a jacket cooling system.

2. The apparatus for continuously preparing acetone azine according to claim 1, wherein Both the outside of the hydrazine hydrate feed jacketed pipe (1) and the acetone feed jacketed pipe (2) are provided with jacket preheating systems.

3. The device for continuously preparing acetone azine according to claim 2, wherein The segmented tubular reactor (3) is divided into three sections, which are successively arranged as a front-stage tubular reactor (31), a middle-stage tubular reactor (32), and a final-stage tubular reactor (33) in the fluid direction. The outside of the front-stage tubular reactor (31), the middle-stage tubular reactor (32), and the final-stage tubular reactor (33) are all sleeved with circulating temperature control jackets.

4. The apparatus for continuously preparing acetone azine according to claim 3, characterized in that, The front-stage tubular reactor (31), the middle-stage tubular reactor (32), and the final-stage tubular reactor (33) are all serpentine bent pipes; The material inlet of the front-stage tubular reactor (31) is connected to the hydrazine hydrate feed jacketed pipe (1) and the acetone feed jacketed pipe (2), the material outlet of the front-stage tubular reactor (31) is connected to the material inlet of the middle-stage tubular reactor (32), the material outlet of the middle-stage tubular reactor (32) is connected to the material inlet of the final-stage tubular reactor (33), and the material outlet of the final-stage tubular reactor (33) is connected to the feed port (49) of the acetone azine storage tank (4).

5. The device for continuously preparing acetone azine according to claim 1, characterized in that, The circulating temperature control jackets of the front-stage tubular reactor (31), the circulating temperature control jacket of the middle-stage tubular reactor (32), and the circulating temperature control jacket of the final-stage tubular reactor (33) are independently arranged and independently temperature-controlled.

6. The apparatus for continuously preparing acetone azine according to claim 1, characterized in that, Both the hydrazine hydrate feed jacketed pipe (1) and the acetone feed jacketed pipe (2) are provided with jacket heating systems, and are provided with transfer pumps, flow control valves, flow meters, thermometers, and pressure gauges.

7. The apparatus for continuously preparing acetone azine according to claim 6, characterized in that, The acetone azine storage tank (4) includes a tank body (47), a stirring assembly (42) arranged inside the tank body (47), a driving motor (48) arranged at the outer top of the tank body (47) to drive the stirring assembly (42) to rotate, a discharge port (44) arranged at the bottom of the tank body (47), and a feed port (49) arranged at the top of the tank body (47). The jacket cooling system is arranged on the bottom and side walls of the tank body (47).

8. The apparatus for continuously preparing acetone azine according to claim 6, wherein, The jacket cooling system includes an external jacket housing (45). The jacket housing (45) and the bottom and side walls of the tank body (47) enclose a jacket cavity. The jacket housing (45) is provided with a water inlet pipe (43) and a water outlet pipe (46) that are connected to the inside of the jacket cavity.

9. The apparatus for continuously preparing acetone azine according to claim 6, wherein, An inspection manhole, a pressure gauge, a thermometer, an air inlet (41), and an exhaust port are arranged at the top of the tank body (47).

10. The apparatus for continuously preparing acetone azine according to claim 6, wherein, The tank body (47) includes a middle cylinder and heads arranged at both ends of the cylinder.

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