A 2-methyl glutaronitrile hydrogenation three-phase reactor

Abstract

This invention discloses a three-phase reactor for the hydrogenation of 2-methylglutaronitrile, comprising a reaction cylinder, a gas distributor, a heat exchange coil, and catalyst inlet and outlet. The reaction cylinder has a raw material inlet at the bottom and a material outlet and a hydrogen outlet at the top. The gas distributor consists of a main inlet pipe, branch pipes, and a straight outlet hole to achieve uniform hydrogen distribution. A wire mesh demister is installed at the top of the cylinder to reduce catalyst loss. The heat exchange coil is located above the gas distributor to enhance heat transfer efficiency. Vertical and inclined baffles are installed inside the reactor; the baffles have openings to optimize fluid distribution and suppress flow deviation. Unreacted hydrogen is circulated through a reflux pipe at the hydrogen outlet, and the feed liquid circulation outlet is connected to the raw material inlet to improve raw material utilization. The reactor has a height-to-diameter ratio (H / D) of 2~10, suitable for the hydrogenation reaction of 2-methylglutaronitrile, and improves production efficiency through efficient gas-liquid-solid three-phase mass transfer. This invention has a compact structure, flexible operation, and is suitable for continuous production.

Description

Technical Field

[0001] This invention relates to the field of reactor technology, and more specifically, to a three-phase reactor for the hydrogenation of 2-methylglutaronitrile. Background Technology

[0002] Hydrogenation of 2-methylglutaronitrile is an important chemical reaction in the chemical industry, mainly used to produce 2-methylpentanediamine. 2-Methylpentanediamine has wide industrial applications. It can be used to produce polyamide plastics, films, fibers, polyamide adhesives, printing resins, epoxy resin curing agents (such as coatings, flooring, etc.), and organic chemicals (such as pesticides); it can also be used for chain expansion of isocyanates, polyols, etc.; it is also an important chain extender in the production of polyurethane, elastic fiber spandex, and high-modulus fiber aramid, and is an important chemical and pharmaceutical intermediate. It can be used as a polyamide monomer, thus partially replacing hexamethylenediamine in the preparation of nylon 66. 2-Methylglutaronitrile can be catalytically hydrogenated to produce 2-methylpentanediamine, thereby extending the adiponitrile industrial chain and increasing the added value of the byproduct 2-methylglutaronitrile.

[0003] Many methods for manufacturing 2-methylpentanediamine have been disclosed in the prior art. For example, Chinese Patent Publication No. CN111377820A, published on April 23, 2020, entitled "A Method for Preparing 2-Methylpentanediamine," discloses a method for preparing 2-methylpentanediamine. Although the above method can theoretically achieve a relatively fast conversion rate, in actual production, the low mass transfer efficiency between substances during the hydrogenation process of 2-methylpentanedione severely affects the reaction rate. Utility Model Content

[0004] This invention overcomes the problem in the prior art that the low mass transfer efficiency between substances during the hydrogenation of 2-methylglutaronitrile in the preparation of 2-methylpentanediamine severely restricts production efficiency. It provides a three-phase reactor for the hydrogenation of 2-methylglutaronitrile, which can effectively improve the mass transfer efficiency between gas, liquid and solid three-phase reactants, thereby improving the production efficiency of the product.

[0005] To solve the above-mentioned technical problems, this utility model adopts the following technical solution: a three-phase reactor for hydrogenation of 2-methylglutaronitrile, comprising:

[0006] The reaction vessel has a raw material inlet at the bottom and a material outlet at the top.

[0007] A gas distributor is installed inside the reaction cylinder. Hydrogen enters the gas distributor and reacts with the materials inside the reaction cylinder. A hydrogen outlet is provided at the top of the reaction cylinder.

[0008] The catalyst inlet is located on the side wall of the reaction vessel and above the gas distributor;

[0009] Heat exchange coils installed inside the reaction vessel.

[0010] This application relates to the hydrogenation of 2-methylglutaronitrile. By incorporating a gas distributor, hydrogen gas can be uniformly distributed within the reaction vessel, ensuring sufficient contact between the hydrogen and the raw materials and improving reaction efficiency. Simultaneously, the downward-spraying hydrogen gas counteracts the upward-flowing raw materials, allowing for thorough mixing and enhancing reaction efficiency. Furthermore, propelled by hydrogen bubbles, the mixed gas and liquid react with the packed catalyst particles, effectively improving mass transfer efficiency between the gas, liquid, and solid phases of the reactants, thereby increasing product production efficiency.

[0011] Preferably, the gas distributor includes a main inlet pipe that penetrates the side wall of the reaction cylinder and several inlet branch pipes that communicate with the main inlet pipe. The bottom of the inlet branch pipes is provided with a vertically oriented outlet hole.

[0012] Hydrogen gas enters the main inlet pipe sequentially, then enters the branch inlet pipe, and finally enters the reaction chamber through the outlet port on the branch inlet pipe to react. This arrangement allows the hydrogen gas to be evenly distributed in the reaction chamber, ensuring that the hydrogen gas fully contacts the raw materials.

[0013] Preferably, a wire mesh demister is provided at the top of the inside of the reaction cylinder, and hydrogen gas is discharged from the hydrogen outlet after passing through the wire mesh demister.

[0014] The remaining unreacted hydrogen gas passes through a wire mesh demister before being discharged from the hydrogen outlet. The wire mesh demister effectively removes solid dust and reduces catalyst loss.

[0015] Preferably, a hydrogen outlet pipe is connected to the hydrogen outlet, and a hydrogen return pipe is connected to the hydrogen outlet pipe. The end of the hydrogen return pipe away from the hydrogen outlet pipe is connected to a gas distributor.

[0016] The hydrogen reflux pipe enables the recycling of unreacted hydrogen.

[0017] Preferably, a material main pipe is provided at the material inlet, and several material branch pipes connected to the material main pipe are provided in the circumferential direction. Feed nozzles are provided at the ends of the material main pipe and the material branch pipes.

[0018] The feed nozzle can make the gas spray more uniform, increase the contact area between the raw material and hydrogen, and improve the reaction efficiency.

[0019] Preferably, a liquid circulation outlet is provided on the side wall of the reaction vessel, and the liquid circulation outlet is connected to the raw material inlet through a liquid return pipe.

[0020] The feed reflux pipe allows unreacted raw materials to re-enter the reaction vessel and participate in the reaction, improving the utilization rate of the raw materials. A second valve is also installed on the feed reflux pipe to control its opening and closing.

[0021] Preferably, several vertical baffles are provided inside the reaction cylinder along the vertical direction.

[0022] The installation of vertical and inclined baffles can reduce the impact of flow deviation.

[0023] Preferably, an inclined baffle is provided on the circumferential direction of the inner wall of the reaction vessel, and the inclined baffle is positioned above the vertical baffle.

[0024] Inclined baffles can reduce the space at the top and can work in conjunction with vertical baffles to reduce the impact of flow deviation.

[0025] Preferably, the vertical baffle has several holes evenly distributed throughout it.

[0026] Setting holes in the vertical baffles helps to reduce the mass transfer difference between the channels between the vertical baffles 8.

[0027] Preferably, the reactor cylinder has a height of H and a diameter of D, with the H / D ratio between 2 and 10.

[0028] The reaction efficiency is best when the H / D ratio is between 2 and 10.

[0029] Compared with existing technologies, the beneficial effects of this utility model are as follows: Multiple feed nozzles and gas distributors are installed at the bottom of the reaction vessel for thorough mixing of the gas and liquid phases. Vertical baffles with small holes are installed inside the reaction vessel; the combined effect of the vertical baffles and gas distributors reduces the impact of flow deviation. The perforated vertical baffles help to reduce the mass transfer differences between the channels of each vertical baffle; therefore, the openings should not be too large, otherwise it will affect the effect of suppressing flow deviation. A wire mesh demister is installed at the top of the reaction vessel to effectively remove solid dust and reduce catalyst loss. The three-phase reactor provided in this application, used for the hydrogenation of 2-methylglutaronitrile, effectively improves the mass transfer efficiency between the gas, liquid, and solid three-phase reactants, thereby increasing the production efficiency of the product. Attached Figure Description

[0030] Figure 1 This is a simplified structural diagram of the present invention.

[0031] Figure 2 This is a schematic diagram of the gas distributor of this utility model.

[0032] Figure 3 This is a structural schematic diagram of the material main pipe and material branch pipe of this utility model.

[0033] In the diagram: 1. Reaction cylinder, 11. Raw material inlet, 12. Material outlet, 13. Hydrogen outlet, 14. Catalyst inlet, 15. Catalyst outlet, 16. Liquid feed circulation outlet;

[0034] 2. Gas distributor; 21. Main intake pipe; 22. Branch intake pipe; 23. Outlet diameter;

[0035] 3. Heat exchange coils;

[0036] 4. Wire mesh demister,

[0037] 5. Hydrogen outlet pipe; 51. Hydrogen return pipe; 52. First valve;

[0038] 6. Liquid return pipe; 61. Second valve;

[0039] 7. Main material pipe; 71. Branch material pipe; 72. Feed nozzle;

[0040] 8. Vertical baffle; 81. Inclined baffle. Detailed Implementation

[0041] The technical solution of this utility model will be further described in detail below through specific embodiments and with reference to the accompanying drawings:

[0042] Example 1: Refer to Figures 1 to 3 As shown, a three-phase reactor for hydrogenation of 2-methylglutaronitrile includes: a reaction cylinder 1, a gas distributor 2, and a heat exchange coil 3.

[0043] The bottom of the reaction cylinder 1 is provided with a raw material inlet 11 and the top of the reactor is provided with a material outlet 12. The raw material enters the reaction cylinder 1 through the raw material inlet 11, participates in the reaction, and then flows out through the material outlet 12.

[0044] Gas distributor 2 is installed inside reaction cylinder 1. Hydrogen enters gas distributor 2 and reacts with materials inside reaction cylinder 1. Hydrogen outlet 13 is provided at the top of reaction cylinder 1. Hydrogen enters the interior of reaction cylinder 1 after passing through gas distributor 2, so that hydrogen can be evenly distributed inside reaction cylinder 1 for reaction.

[0045] A catalyst inlet 14 is provided on the side wall of the reaction cylinder 1 and above the gas distributor 2; the catalyst enters the reaction cylinder 1 from the catalyst inlet 14, and correspondingly, a catalyst outlet 15 is provided at the bottom of the reaction cylinder 1 to facilitate the removal of the catalyst from the reaction cylinder 1 through the catalyst outlet 15.

[0046] The heat exchange coil 3 is installed inside the reaction cylinder 1 and above the gas distributor 2. The heat exchange coil 3 is used to connect with the external heat exchange medium to exchange heat in a timely manner and achieve a more complete mass transfer reaction.

[0047] In one embodiment, the gas distributor 2 includes an inlet main pipe 21 penetrating the side wall of the reaction cylinder 1 and several inlet branch pipes 22 communicating with the inlet main pipe 21. The bottom of the inlet branch pipes 22 is provided with vertically arranged outlet holes 23. Specifically, the inlet main pipe 21 passes through the reaction cylinder 1, and several neatly arranged inlet branch pipes 22 perpendicular to the inlet main pipe 21 are provided inside the reaction cylinder 1. The inlet branch pipes 22 are communicating with the inlet main pipe 21, and at the bottom of the inlet branch pipes 22, several outlet holes 23 are provided along the length of the inlet branch pipes 22. Hydrogen gas enters the main inlet pipe 21 sequentially, then flows from the main inlet pipe 21 into the inlet branch pipe 22, and finally enters the reaction chamber 1 through the outlet branch pipe 23 on the inlet branch pipe 22 to undergo the reaction. This arrangement allows the hydrogen gas to be evenly distributed within the reaction chamber 1, ensuring sufficient contact between the hydrogen gas and the raw materials, thus improving reaction efficiency. Simultaneously, the hydrogen gas is sprayed downwards, counteracting the upward-flowing raw materials, allowing the hydrogen gas to mix thoroughly with the raw materials, further enhancing reaction efficiency. At the same time, driven by the hydrogen gas bubbles, the mixed gas and liquid react with the packed catalyst particles.

[0048] In one embodiment, a wire mesh demister 4 is provided at the top inside the reaction vessel 1. After passing through the wire mesh demister 4, the hydrogen gas is discharged from the hydrogen outlet 13. The remaining unreacted hydrogen gas passes through the wire mesh demister 4 before being discharged from the hydrogen outlet 13. The wire mesh demister 4 can effectively remove solid dust and reduce catalyst loss.

[0049] In one embodiment, a hydrogen outlet pipe 5 is connected to the hydrogen outlet 13, and the hydrogen outlet pipe 5 is connected to a hydrogen return pipe 51. The end of the hydrogen return pipe 51 away from the hydrogen outlet pipe 5 is connected to the gas distributor 2. Specifically, the end of the hydrogen return pipe 51 away from the hydrogen outlet pipe 5 is connected to the hydrogen outlet pipe 5, and the other end is connected to the main gas inlet pipe 21 located outside the reaction cylinder 1, thereby realizing the recycling of unreacted hydrogen. At the same time, a first valve 52 is provided on the hydrogen return pipe 51, which can control the opening and closing of the hydrogen return pipe 51.

[0050] In one embodiment, a liquid circulation outlet 16 is provided on the side wall of the reaction vessel 1, and the liquid circulation outlet 16 is connected to the raw material inlet 11 through a liquid return pipe 6. Specifically, a material main pipe 7 is provided at the raw material inlet 11, and the liquid return pipe 6 allows unreacted raw materials to re-enter the reaction vessel 1 to participate in the reaction, thereby improving the utilization rate of raw materials. At the same time, a second valve 61 is provided on the liquid return pipe 6, which can control the opening and closing of the liquid return pipe 6.

[0051] In one embodiment, a material main pipe 7 is provided at the material inlet 11, and several material branch pipes 71 connected to the material main pipe 7 are arranged in the circumferential direction. Specifically, inside the reaction cylinder 1, several material branch pipes 71 are connected in the circumferential direction of the material main pipe 7. In this application, the material main pipe 7 is connected to four material branch pipes 71, so that hydrogen can flow out evenly in the reaction cylinder 1.

[0052] In addition, feed nozzles 72 are provided at the ends of both the main material pipe 7 and the branch material pipe 71. The feed nozzles 72 can make the gas spray more uniform, increase the contact area between the raw materials and hydrogen, and improve the reaction efficiency.

[0053] In one embodiment, the reactor cylinder 1 has a height of H and a diameter of D, with the H / D ratio between 2 and 10.

[0054] In this application, multiple feed nozzles 72 and a gas distributor 2 are provided at the bottom of the reaction vessel 1 for thorough mixing of the gas and liquid phases. A wire mesh demister 4 is provided at the top of the reaction vessel 1 to effectively remove solid dust and reduce catalyst loss. The three-phase reactor provided in this application is used for the hydrogenation of 2-methylglutaronitrile, effectively improving the mass transfer efficiency between the gas, liquid, and solid three-phase reactants, thereby increasing the production efficiency of the product.

[0055] Example 2: Refer to 1 to Figure 3 As shown, a three-phase reactor for hydrogenation of 2-methylglutaronitrile includes: a reaction cylinder 1, a gas distributor 2, and a heat exchange coil 3.

[0056] The bottom of the reaction cylinder 1 is provided with a raw material inlet 11 and the top of the reactor is provided with a material outlet 12. The raw material enters the reaction cylinder 1 through the raw material inlet 11, participates in the reaction, and then flows out through the material outlet 12.

[0057] Gas distributor 2 is installed inside reaction cylinder 1. Hydrogen enters gas distributor 2 and reacts with materials inside reaction cylinder 1. Hydrogen outlet 13 is provided at the top of reaction cylinder 1. Hydrogen enters the interior of reaction cylinder 1 after passing through gas distributor 2, so that hydrogen can be evenly distributed inside reaction cylinder 1 for reaction.

[0058] A catalyst inlet 14 is provided on the side wall of the reaction cylinder 1 and above the gas distributor 2; the catalyst enters the reaction cylinder 1 from the catalyst inlet 14, and correspondingly, a catalyst outlet 15 is provided at the bottom of the reaction cylinder 1 to facilitate the removal of the catalyst from the reaction cylinder 1 through the catalyst outlet 15.

[0059] The heat exchange coil 3 is installed inside the reaction cylinder 1 and above the gas distributor 2. The heat exchange coil 3 is used to connect with the external heat exchange medium to exchange heat in a timely manner and achieve a more complete mass transfer reaction.

[0060] In one embodiment, the gas distributor 2 includes an inlet main pipe 21 penetrating the side wall of the reaction cylinder 1 and several inlet branch pipes 22 communicating with the inlet main pipe 21. The bottom of the inlet branch pipes 22 is provided with vertically arranged outlet holes 23. Specifically, the inlet main pipe 21 passes through the reaction cylinder 1, and several neatly arranged inlet branch pipes 22 perpendicular to the inlet main pipe 21 are provided inside the reaction cylinder 1. The inlet branch pipes 22 are communicating with the inlet main pipe 21, and at the bottom of the inlet branch pipes 22, several outlet holes 23 are provided along the length of the inlet branch pipes 22. Hydrogen gas enters the main inlet pipe 21 sequentially, then flows from the main inlet pipe 21 into the inlet branch pipe 22, and finally enters the reaction chamber 1 through the outlet branch pipe 23 on the inlet branch pipe 22 to undergo the reaction. This arrangement allows the hydrogen gas to be evenly distributed within the reaction chamber 1, ensuring sufficient contact between the hydrogen gas and the raw materials, thus improving reaction efficiency. Simultaneously, the hydrogen gas is sprayed downwards, counteracting the upward-flowing raw materials, allowing the hydrogen gas to mix thoroughly with the raw materials, further enhancing reaction efficiency. At the same time, driven by the hydrogen gas bubbles, the mixed gas and liquid react with the packed catalyst particles.

[0061] In one embodiment, a wire mesh demister 4 is provided at the top inside the reaction vessel 1. After passing through the wire mesh demister 4, the hydrogen gas is discharged from the hydrogen outlet 13. The remaining unreacted hydrogen gas passes through the wire mesh demister 4 before being discharged from the hydrogen outlet 13. The wire mesh demister 4 can effectively remove solid dust and reduce catalyst loss.

[0062] In one embodiment, a hydrogen outlet pipe 5 is connected to the hydrogen outlet 13, and the hydrogen outlet pipe 5 is connected to a hydrogen return pipe 51. The end of the hydrogen return pipe 51 away from the hydrogen outlet pipe 5 is connected to the gas distributor 2. Specifically, the end of the hydrogen return pipe 51 away from the hydrogen outlet pipe 5 is connected to the hydrogen outlet pipe 5, and the other end is connected to the main gas inlet pipe 21 located outside the reaction cylinder 1, thereby realizing the recycling of unreacted hydrogen. At the same time, a first valve 52 is provided on the hydrogen return pipe 51, which can control the opening and closing of the hydrogen return pipe 51.

[0063] In one embodiment, a liquid circulation outlet 16 is provided on the side wall of the reaction vessel 1, and the liquid circulation outlet 16 is connected to the raw material inlet 11 through a liquid return pipe 6. Specifically, a material main pipe 7 is provided at the raw material inlet 11, and the liquid return pipe 6 allows unreacted raw materials to re-enter the reaction vessel 1 to participate in the reaction, thereby improving the utilization rate of raw materials. At the same time, a second valve 61 is provided on the liquid return pipe 6, which can control the opening and closing of the liquid return pipe 6.

[0064] In one embodiment, a material main pipe 7 is provided at the material inlet 11, and several material branch pipes 71 connected to the material main pipe 7 are arranged in the circumferential direction. Specifically, inside the reaction cylinder 1, several material branch pipes 71 are connected in the circumferential direction of the material main pipe 7. In this application, the material main pipe 7 is connected to four material branch pipes 71, so that hydrogen can flow out evenly in the reaction cylinder 1.

[0065] In addition, feed nozzles 72 are provided at the ends of both the main material pipe 7 and the branch material pipe 71. The feed nozzles 72 can make the gas spray more uniform, increase the contact area between the raw materials and hydrogen, and improve the reaction efficiency.

[0066] In one embodiment, the reactor cylinder 1 has a height of H and a diameter of D, with the H / D ratio between 2 and 10.

[0067] This application has a similar structure to that in Embodiment 1, except that several vertical baffles 8 are arranged vertically inside the reaction cylinder 1. An inclined baffle 81 is arranged circumferentially on the inner wall of the reaction cylinder 1, forming an inclined ring inside the reactor, and is positioned above the vertical baffles 8. Several holes are evenly distributed through the vertical baffles 8. The vertical baffles 8 are positioned at the top of the heat exchange coil 3. The feed liquid circulation outlet 16 is located below the inclined baffles 81.

[0068] The vertical baffle 8 and the inclined baffle 81 can reduce the influence of flow deviation. At the same time, the holes in the vertical baffle can help reduce the mass transfer difference between the channels of the vertical baffle 8.

[0069] In this application, multiple feed nozzles 72 and a gas distributor 2 are installed at the bottom of the reaction vessel 1 to ensure thorough mixing of the gas and liquid phases. Vertical baffles 8 with small holes are installed inside the reaction vessel 1. The combined action of the vertical baffles 8 and the gas distributor 2 reduces the impact of flow deviation. The perforated vertical baffles 8 help to reduce the mass transfer differences between the channels of each vertical baffle 8; therefore, the perforations should not be too large, otherwise the effect of suppressing flow deviation will be affected. A wire mesh demister 4 is installed at the top of the reaction vessel 1 to effectively remove solid dust and reduce catalyst loss. The three-phase reactor provided in this application is used for the hydrogenation of 2-methylglutaronitrile, effectively improving the mass transfer efficiency between the gas, liquid, and solid three-phase reactants, thereby increasing the production efficiency of the product.

[0070] The embodiments described above are merely preferred solutions of this utility model and are not intended to limit this utility model in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A three-phase reactor for hydrogenation of 2-methylglutaronitrile, characterized in that, include: The reaction vessel has a raw material inlet at the bottom and a material outlet at the top. A gas distributor is installed inside the reaction cylinder. Hydrogen enters the gas distributor and reacts with the materials inside the reaction cylinder. A hydrogen outlet is provided at the top of the reaction cylinder. The catalyst inlet is located on the side wall of the reaction vessel and above the gas distributor; Heat exchange coils installed inside the reaction vessel.

2. The three-phase reactor for hydrogenation of 2-methylglutaronitrile according to claim 1, characterized in that, The gas distributor includes a main inlet pipe that penetrates the side wall of the reaction cylinder and several branch inlet pipes that are connected to the main inlet pipe. The bottom of the branch inlet pipes is provided with a vertically oriented straight outlet hole.

3. The three-phase reactor for hydrogenation of 2-methylglutaronitrile according to claim 1 or 2, characterized in that, A wire mesh demister is installed at the top of the inside of the reaction cylinder. After passing through the wire mesh demister, the hydrogen gas is discharged from the hydrogen outlet.

4. The three-phase reactor for hydrogenation of 2-methylglutaronitrile according to claim 1, characterized in that, A hydrogen outlet pipe is connected to the hydrogen outlet, and a hydrogen return pipe is connected to the hydrogen outlet pipe. The end of the hydrogen return pipe away from the hydrogen outlet pipe is connected to the gas distributor.

5. The three-phase reactor for hydrogenation of 2-methylglutaronitrile according to claim 1, characterized in that, A material main pipe is provided at the raw material inlet, and several material branch pipes connected to it are arranged in the circumferential direction of the material main pipe. Feed nozzles are provided at the ends of the material main pipe and the material branch pipes.

6. The three-phase reactor for hydrogenation of 2-methylglutaronitrile according to claim 1, 2, or 5, characterized in that, A liquid circulation outlet is provided on the side wall of the reaction vessel, and the liquid circulation outlet is connected to the raw material inlet through a liquid return pipe.

7. The three-phase reactor for hydrogenation of 2-methylglutaronitrile according to claim 1, 2, or 5, characterized in that, Several vertical baffles are installed inside the reaction cylinder along the vertical direction.

8. The three-phase reactor for hydrogenation of 2-methylglutaronitrile according to claim 7, characterized in that, An inclined baffle is provided on the circumferential direction of the inner wall of the reaction vessel, and the inclined baffle is positioned above the vertical baffle.

9. The three-phase reactor for hydrogenation of 2-methylglutaronitrile according to claim 7, characterized in that, The vertical baffle has several holes evenly distributed throughout it.

10. The three-phase reactor for hydrogenation of 2-methylglutaronitrile according to claim 1, 2, or 5, characterized in that, The reactor cylinder has a height of H and a diameter of D, with the H / D ratio between 2 and 10.

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