Process for the preparation of amine compounds

Abstract

The present application relates to the field of amine preparation, in particular to a preparation method of amine compounds. The preparation method comprises: mixing a nitrile compound solution and hydrogen to obtain a gas-liquid mixture, and feeding the gas-liquid mixture into a fixed bubble bed reactor as raw material to react with a catalyst in the fixed bubble bed reactor. The present application can improve the content of dissolved hydrogen in the reaction system, reduce the reaction pressure, inhibit the side reaction, avoid the accumulation of heavy components in the reaction process, ensure the activity and service life of the catalyst and the quality of the product, reduce the energy consumption of the production process, improve the conversion rate of nitrile raw materials and the selectivity of amine products, and make the device run more stably by using the fixed bubble bed reactor to prepare m-xylylenediamine from m-xylylenecarbonitrile through hydrogenation.

Description

Technical Field

[0001] This invention relates to the field of amine preparation, and more specifically to a method for preparing amine compounds. Background Technology

[0002] m-Phenylenediamine (MXDA) is an important monomer for the production of high-end materials. Currently, continuous production and R&D of MXDA are still in their early stages. Only batch reactors have achieved small-scale industrial conversion, and the products can only meet the needs of low-end curing agents. In high-end electronic curing agents and high-end barrier nylons, the lack of high-quality MXDA production technology means that production capacity and purity (>99.5%) are far from meeting market demand. Currently, MXDA production technology all uses the continuous hydrogenation method of isophthalonitrile (IPN), and the reaction equation is as follows: Main reaction:

[0003] Main side reactions: (1) Insufficient hydrogenation: produces an intermediate product imine, which is extremely reactive and easily polymerizes.

[0004]

[0005]

[0006]

[0007] (2) Excessive hydrogenation: produces 3-methylbenzamine, m-xylene, etc.

[0008]

[0009] (3) Condensation and deamination: The amino group, as a nucleophile, attacks the imine to generate high-boiling substances such as secondary amines, tertiary amines, and cross-linked amines, which affect the reaction selectivity and yield. The adsorption of high-boiling substances on the catalyst surface further reduces the adsorption of imine, which may lead to catalyst deactivation.

[0010]

[0011]

[0012] As can be seen above, the hydrogenation of nitrile compounds to their corresponding amine compounds, especially the hydrogenation of isophthalonitrile to prepare m-phenylenediamine, involves numerous side reactions, many of which are strongly exothermic. If the heat of reaction cannot be dissipated in time, leading to a significant temperature rise in the bed, not only will the number of side reactions increase, but more seriously, the generated heavy components will directly adhere to the catalyst surface, resulting in a decrease in catalyst activity. This affects the catalyst's lifespan, as well as the quality and yield of the product.

[0013] CN113365975A discloses a process for producing m-phenylenediamine. This method involves contacting an isophthalonitrile solution, hydrogen gas, and a particulate solid catalyst in a three-phase hydrogenation reaction. After solid-liquid separation, the liquid product is crude m-phenylenediamine, and the solid product is the catalyst particles, which are recycled. This method not only consumes a lot of energy and has low production efficiency, but the solid-liquid separation process also causes significant catalyst wear. Furthermore, the design pressure of the reactor, separator, and solid-liquid separator must be kept consistent with the reactor, resulting in high equipment investment and subsequent maintenance costs. Summary of the Invention

[0014] The purpose of this invention is to overcome the problems in the existing technology of preparing amine compounds, especially m-phenylenediamine, where there are many side reactions, most of which are strongly exothermic. If the heat of reaction cannot be removed in time, the temperature rise of the bed will be large, which will not only lead to an increase in side reactions, but more seriously, the generated heavy components will directly adhere to the surface of the catalyst, resulting in a decrease in catalyst activity, affecting the service life of the catalyst, as well as the quality and yield of the product. This invention provides a method for preparing m-phenylenediamine that has the characteristics of suppressing side reactions and avoiding the accumulation of heavy components during the reaction.

[0015] To achieve the above objectives, the present invention provides a method for preparing amine compounds, the method comprising: mixing a nitrile compound solution with hydrogen gas to obtain a gas-liquid mixture, and feeding the gas-liquid mixture as a raw material into a fixed bubble bed reactor for contact reaction with a catalyst in the fixed bubble bed reactor.

[0016] Through the above technical solution, the present invention has the following advantages: This invention utilizes a fixed bubbling bed reactor for the hydrogenation of nitrile compounds to produce amines, such as the hydrogenation of isophthalonitrile to prepare m-phenylenediamine. This method increases the dissolved hydrogen content in the reaction system, reduces reaction pressure, suppresses side reactions, avoids the accumulation of heavy components during the reaction, ensures the activity and lifespan of the catalyst, and maintains product quality. Consequently, it reduces energy consumption in the production process, improves the conversion rate of nitrile feedstock and the selectivity of amine products, and makes the equipment operation more stable. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a reaction apparatus and process according to a preferred embodiment of the present invention; Figure 2 This is a schematic diagram of a gas-liquid mixer according to a preferred embodiment of the present invention; Figure 3 This is a schematic diagram of a gas-liquid redistributor according to a preferred embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures A is a gas-liquid mixer, B is a fixed bubbling bed reactor, a is the feed inlet, b is the gas-liquid redistribution unit, c is the catalyst support unit, d is the catalytic reaction zone, e is the catalyst compaction unit and grid, and f is the reaction product outlet. Detailed Implementation

[0019] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0020] This invention provides a method for preparing amine compounds, the method comprising: mixing a nitrile compound solution with hydrogen gas to obtain a gas-liquid mixture, and feeding the gas-liquid mixture as a raw material into a fixed bubble bed reactor for contact reaction with a catalyst in the fixed bubble bed reactor.

[0021] By employing a fixed bubbling bed reactor for the hydrogenation of nitrile compounds to produce amines, such as the hydrogenation of isophthalonitrile to prepare m-phenylenediamine, the dissolved hydrogen content in the reaction system can be increased, the reaction pressure reduced, side reactions suppressed, and the accumulation of heavy components avoided during the reaction process. This ensures the activity and lifespan of the catalyst and the quality of the product, resulting in reduced energy consumption in the production process, improved conversion rate of nitrile feedstock and selectivity of amine products, and more stable operation of the equipment.

[0022] According to a preferred embodiment of the present invention, such as Figure 1 As shown, the fixed bubbling bed reactor B, from bottom to top, includes a lower head, a cylindrical body, and an upper head. The cylindrical body, from bottom to top, includes a gas-liquid redistribution unit b, a catalyst support unit c, and a catalyst compaction unit e. The gas-liquid redistribution unit b, the cylindrical body, and the lower head together form a pre-distribution zone for pre-distributing the raw material. The gas-liquid redistribution unit b, the cylindrical body, and the catalyst support unit c together form a redistribution zone for redistributing the raw material. The catalyst support unit c, the cylindrical body, and the catalyst compaction unit e together form a catalytic reaction zone d for catalytically reacting the raw material from the redistribution zone. The catalyst compaction unit e, the cylindrical body, and the upper head together form a product enrichment zone for collecting the product from the catalytic reaction zone. By adopting the aforementioned preferred scheme, energy consumption can be further reduced, the conversion rate of nitrile feedstock and the selectivity of amine products can be improved, and the operation of the unit can be made more stable.

[0023] According to a preferred embodiment of the present invention, the ratio of the distance between the gas-liquid redistribution unit and the catalyst support unit in the fixed bubbling bed reactor to the reactor diameter is 0.40-1.20:1, preferably 0.50-1:1. By adopting the aforementioned preferred scheme, energy consumption can be further reduced, the conversion rate of nitrile feedstock and the selectivity of amine products can be improved, and the operation of the device can be made more stable.

[0024] According to a preferred embodiment of the present invention, the diameter of the gas-liquid redistribution unit is equal to the diameter of the reactor.

[0025] According to a preferred embodiment of the present invention, the vertical distance between the catalyst compaction unit and the tangent of the upper end cap of the fixed bubbling bed reactor is not less than 600 mm, preferably 600-1000 mm. By adopting the aforementioned preferred solution, energy consumption can be further reduced, the conversion rate of nitrile feedstock and the selectivity of amine products can be improved, and the operation of the unit can be made more stable.

[0026] In this invention, the range of types of gas-liquid redistribution units is relatively wide, as long as the purpose of this invention can be achieved. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the gas-liquid redistribution unit of the fixed bubbling bed reactor is an orifice plate.

[0027] According to a preferred embodiment of the present invention, the orifice plate has an opening ratio of 20-60%, preferably 30-50%. By adopting the aforementioned preferred embodiment, energy consumption can be further reduced, the conversion rate of nitrile feedstock and the selectivity of amine products can be improved, and the operation of the device can be made more stable.

[0028] According to a preferred embodiment of the present invention, the area of ​​a single opening in the perforated plate is 20-400 mm². 2 Preferably 25-80mm 2 By adopting the aforementioned preferred scheme, energy consumption can be further reduced, the conversion rate of nitrile feedstock and the selectivity of amine products can be improved, and the operation of the unit can be made more stable.

[0029] According to a preferred embodiment of the present invention, the aperture spacing of the orifice plate is 10-100 mm, preferably 25-80 mm. By adopting the aforementioned preferred solution, energy consumption can be further reduced, the conversion rate of nitrile feedstock and the selectivity of amine products can be improved, and the operation of the device can be made more stable.

[0030] In this invention, there are no special requirements for the opening form of the perforated plate. However, to better suit this invention, according to a preferred embodiment, such as... Figure 3 As shown, the opening shape of the perforated plate is selected from at least one of annular, circular and rhomboid, preferably annular and / or circular.

[0031] In this invention, such as Figure 1As shown, the upper head of the fixed bubbling bed reactor is provided with a reaction product outlet f.

[0032] According to a preferred embodiment of the present invention, such as Figure 1 As shown, the fixed bubbling bed reactor B has a raw material inlet a on the cylinder below the gas-liquid redistribution unit b. The inlet pipeline extends to the center of the reactor and then bends downwards at a 60-120° angle, preferably at an 80-100° angle. By adopting the aforementioned preferred scheme, energy consumption can be further reduced, the conversion rate of nitrile feedstock and the selectivity of amine products can be improved, and the operation of the device can be made more stable.

[0033] According to a preferred embodiment of the present invention, such as Figure 1 As shown, the mixing takes place in gas-liquid mixer A, as follows: Figure 2 The gas-liquid mixer A is selected from at least one of the Venturi type, orifice plate type, and cyclone type. By adopting the aforementioned preferred scheme, energy consumption can be further reduced, the conversion rate of nitrile feedstock and the selectivity of amine products can be improved, and the operation of the unit can be made more stable.

[0034] In this invention, the gas-liquid mixer is provided with a gas phase inlet and a liquid phase inlet, with at least two units. By placing the gas-liquid mixer externally, when a mixer becomes blocked, it can be switched in time to ensure stable feeding of the reactor.

[0035] In this invention, the mixing conditions can be selected from a wide range, including the control of the ratio of gas to liquid feed during mixing. The following is an illustrative description, but it does not limit the scope of the invention. The gas-liquid feed volume ratio is 10-500, preferably 20-100.

[0036] In this invention, the mixing conditions also include the control of the gas phase feed rate, which is illustrated below but does not limit the scope of the invention. In a preferred embodiment of the invention, the gas phase feed flow rate is 10-100 m³ / h, preferably 10-50 m³ / h.

[0037] In this invention, the mixing conditions also include the control of the liquid phase feed rate, which is illustrated below but does not limit the scope of the invention. In a preferred embodiment of the invention, the liquid phase feed flow rate is 0.1-20 m³ / h, preferably 0.5-10 m³ / h.

[0038] According to a preferred embodiment of the present invention, during gas-liquid mixing, the gas phase and liquid phase are fed separately, that is, hydrogen gas and nitrile compound solution are fed separately, and the feeding directions intersect at an angle of not less than 90°, preferably 90°-150°. The advantages of the present invention are illustrated by taking an example of two phases being fed perpendicularly at a 90° angle.

[0039] In this invention, the operating temperature range for the fixed bubbling bed is relatively wide. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the operating temperature of the fixed bubbling bed reactor is 60-180℃, preferably 60-120℃.

[0040] In this invention, the operating pressure range for the fixed bubbling bed is relatively wide. The following is an illustrative description, but it does not limit the scope of the invention. The operating pressure of the fixed bubbling bed reactor is 2-25 MPaG, preferably 4-20 MPaG.

[0041] In this invention, the catalyst for the hydrogenation of nitrile compounds to prepare amine compounds can be a conventional catalyst in the art. The following is an illustrative example, but does not limit the scope of the invention. According to a preferred embodiment of the invention, the catalyst is selected from at least one of silicon-based catalysts, nickel-based catalysts, and nickel-cobalt bimetallic catalysts. This invention uses a nickel-based catalyst as an example to illustrate the advantages of the invention.

[0042] In this invention, the method is particularly suitable for the preparation of aromatic amines, preferably arylalkylamines, more preferably C6-C12 m-phenylenedialkylamines. Toluene dimethylamine is used as an example to illustrate the advantages of this invention.

[0043] In this invention, the solvent in the nitrile compound solution can be selected from a wide range, as long as it can solvent the nitrile compound. To improve the preparation effect of amine in the method of this invention, ammonia is selected as the solvent. Preferably, the solvent content in the nitrile compound solution is 80-95 wt%. In this invention, an ammonia content of 90 wt% is used as an example to illustrate the advantages of this invention.

[0044] This invention provides a method for preparing amine compounds, wherein, as in... Figure 1 The process, as shown in the apparatus, includes: introducing a nitrile compound solution and hydrogen gas into a gas-liquid mixer A, with the feed directions intersecting at an angle of not less than 90°; obtaining a gas-liquid mixture after mixing; using the gas-liquid mixture as raw material, introducing it into a fixed bubbling bed reactor B from the raw material inlet a; entering the bottom head for pre-distribution along the downward-bent inlet pipeline; flowing upwards; passing through the gas-liquid redistribution unit b for redistribution; then flowing upwards again through the catalyst support unit c to enter the hydrogenation reaction zone, where it contacts the catalyst to produce a product gas containing amine compounds; the product gas containing amine compounds flows upwards through the catalyst compaction unit e to enter the product enrichment zone; and leaves the system from the reaction product outlet f to collect the product.

[0045] The present invention will be described in detail below through examples. In the following examples, the conversion rate of isophthalonitrile is calculated as: (1 - molar amount of remaining isophthalonitrile after reaction / molar amount of isophthalonitrile before reaction) × 100%.

[0046] The selectivity of m-phenylenediamine is calculated as: (molar amount of m-phenylenediamine produced / molar amount of all products) × 100%; The isophthalonitrile raw material was a commercially available product from Shandong Dacheng Biochemical Co., Ltd. The catalysts used in the examples and comparative examples were the same, and all were nickel-based catalysts.

[0047] Example 1 The preparation of m-phenylenediamine by hydrogenation of isophthalonitrile is carried out using methods such as... Figure 1 The reaction system shown has a reactor diameter of 1500 mm and a height of 9000 mm. The gas phase feed flow rate is 10 m³ / h, and the liquid phase (ammonia solution of isophthalonitrile, where ammonia accounts for 90 wt%) feed flow rate is 0.5 m³ / h. The gas and liquid phases are fed perpendicularly, and the gas-liquid mixer is a Venturi mixer. After the gas and liquid feedstocks are uniformly mixed, they enter the reactor through the material inlet on the bottom side wall. After entering the bottom head for pre-distribution along the 90° downward bend in the inlet pipe, they flow upward and are redistributed through a gas-liquid redistributor. The gas-liquid redistributor is an orifice plate with annular openings. The vertical distance between the orifice plate and the catalyst support grid is 750 mm, the opening ratio is 30%, the opening spacing is 80 mm, and the area of ​​each opening is 25 mm². 2 The vertical distance between the catalyst pressure grid and the tangent of the upper head is 600 mm. The reactor operating pressure is 7.4 MPaG, and the operating temperature is 60℃. The conversion rate of isophthalonitrile is 99.8%, the selectivity of isophthalic diamine is 98.5%, the content of condensed heavy components is less than 300 ppm, and the bed temperature rise is 5℃.

[0048] Example 2 The preparation of m-phenylenediamine by hydrogenation of isophthalonitrile is carried out using methods such as... Figure 1 The reaction system shown has a reactor diameter of 2000 mm and a height of 10000 mm. The gas phase feed flow rate is 50 m³ / h, and the liquid phase (ammonia solution of isophthalonitrile, where ammonia accounts for 90 wt%) feed flow rate is 1 m³ / h. The gas and liquid phases are fed perpendicularly, and the gas-liquid mixer is an orifice plate type mixer. After the gas and liquid feedstocks are uniformly mixed, they enter the reactor through the material inlet on the bottom side wall of the reactor. After entering the bottom head for pre-distribution along the inlet pipe with a 100° bend downwards, they flow upwards and are redistributed by the gas-liquid redistributor. The gas-liquid redistributor is an orifice plate with circular orifice openings. The vertical distance between the orifice plate and the catalyst support grid is 1500 mm, the opening ratio is 40%, the opening spacing is 60 mm, and the area of ​​each individual opening is 60 mm². 2The vertical distance between the catalyst pressure grid and the tangent of the upper head is 800 mm. The reactor operating pressure is 7 MPaG, and the operating temperature is 90℃. The conversion rate of isophthalonitrile is 99.9%, the selectivity of isophthalic diamine is 99.2%, the content of condensed heavy components is less than 200 ppm, and the bed temperature rise is 6℃.

[0049] Example 3 The preparation of m-phenylenediamine by hydrogenation of isophthalonitrile is carried out using methods such as... Figure 1 The reaction system shown has a reactor diameter of 1800 mm and a height of 10000 mm. The gas phase feed flow rate is 50 m³ / h, and the liquid phase (ammonia solution of isophthalonitrile, where ammonia accounts for 90 wt%) feed flow rate is 0.5 m³ / h. The gas and liquid phases are fed perpendicularly, and the gas-liquid mixer is a cyclone mixer. After the gas and liquid feedstocks are uniformly mixed, they enter the reactor through the material inlet on the bottom side wall. After entering the bottom head for pre-distribution along the inlet pipe that bends downwards at 80°, they flow upwards and are redistributed by the gas-liquid redistributor. The gas-liquid redistributor is an orifice plate with annular openings. The vertical distance between the orifice plate and the catalyst support grid is 1800 mm, the opening ratio is 50%, the opening spacing is 25 mm, and the area of ​​each opening is 80 mm². 2 The vertical distance between the catalyst pressure grid and the tangent of the upper head is 1000 mm. The reactor operating pressure is 10 MPaG, and the operating temperature is 120℃. The conversion rate of isophthalonitrile is 99.7%, the selectivity of isophthalic dimethylamine is 98.7%, the content of condensed heavy components is less than 250 ppm, and the bed temperature rise is 5℃.

[0050] Example 4 Same as Example 1, except that the perforation rate of the perforated plate is 60%.

[0051] Reaction results: the conversion rate of isophthalonitrile was 95.1%, the selectivity of isophthalic acid was 88.2%, the content of the condensed heavy component was less than 1000 ppm, and the bed temperature rise was 10℃.

[0052] Example 5 Same as Example 1, except that the vertical distance between the gas-liquid redistributor and the catalyst support grid is 150 mm.

[0053] Reaction results: The conversion rate of isophthalonitrile was 92.6%, the selectivity of isophthalic dimethylamine was 87.3%, the content of the condensed heavy component was less than 1200 ppm, and the bed temperature rise was 13℃.

[0054] Example 6 Same as Example 1, except that the area of ​​a single opening in the gas-liquid redistributor is 200 mm². 2 .

[0055] Reaction results: The conversion rate of isophthalonitrile was 92.6%, the selectivity of isophthalic acid was 90.3%, the content of the condensed heavy component was less than 800 ppm, and the bed temperature rise was 8℃.

[0056] Example 7 Similar to Example 1, except that the liquid phase and gas phase are fed in the same direction in the gas-liquid mixer.

[0057] Reaction results: The conversion rate of isophthalonitrile was 93.4%, the selectivity of isophthalic acid was 89.3%, the content of the condensed heavy component was less than 900 ppm, and the bed temperature rise was 9℃.

[0058] Comparative Example 1 Similar to Example 1, except that the reactor type is a conventional fixed-bed reactor, that is, a raw material inlet is provided at the top, the middle layer is a reaction zone filled with catalyst, there is no distributor in the reactor, and a reactant outlet is provided at the bottom.

[0059] Reaction results: The conversion rate of isophthalonitrile was 84.1%, the selectivity of isophthalic dimethylamine was 80.3%, the content of the condensed heavy component was less than 5000 ppm, and the bed temperature rise was 20℃.

[0060] Comparative Example 2 Similar to Example 1, except that the reactor type is also a bubble bed reactor, but the gas-liquid mixer is built into the pre-distribution zone.

[0061] Reaction results: The conversion rate of isophthalonitrile was 74.1%, and the selectivity of isophthalic dimethylamine was 78.1%. Due to the large amount of heavy components generated, the gas-liquid mixer was blocked, and the machine was shut down urgently after 500 hours of operation.

[0062] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing an amine compound, characterized in that, The preparation method includes: mixing a nitrile compound solution and hydrogen to obtain a gas-liquid mixture, and feeding the gas-liquid mixture as a raw material into a fixed bubble bed reactor to react with the catalyst in the fixed bubble bed reactor.

2. The preparation method according to claim 1, wherein, The fixed bubbling bed reactor includes, from bottom to top, a lower end cap, a cylindrical body, and an upper end cap. The cylindrical body includes, from bottom to top, a gas-liquid redistribution unit, a catalyst support unit, and a catalyst compression unit. The gas-liquid redistribution unit, the cylinder, and the lower end cap together form a pre-distribution zone for the pre-distribution of raw materials. The gas-liquid redistribution unit, the cylinder, and the catalyst support unit together form a redistribution zone for the redistribution of raw materials. The catalyst support unit, the cylinder, and the catalyst pressing unit together form a catalytic reaction zone, which is used to catalyze the reaction of raw materials from the redistribution zone; The catalyst compression unit, the cylinder, and the upper end cap together form a product enrichment zone, which is used to collect products from the catalytic reaction zone.

3. The preparation method according to claim 1 or 2, wherein, The distance between the gas-liquid redistribution unit and the catalyst support unit in the fixed bubbling bed reactor is 0.40-1.20:1, preferably 0.50-1:1, in ratio to the reactor diameter.

4. The preparation method according to any one of claims 1-3, wherein, The vertical distance between the catalyst pressing unit and the tangent of the upper head of the fixed bubbling bed reactor is not less than 600 mm, preferably 600-1000 mm.

5. The preparation method according to any one of claims 1-4, wherein, The gas-liquid redistribution unit of the fixed bubbling bed reactor is an orifice plate; preferably, The perforation rate of the perforated plate is 20-60%, preferably 30-50%; and / or The area of ​​a single opening in the perforated plate is 20-400 mm². 2 Preferably 25-80mm 2 ; and / or The perforation spacing of the perforated plate is 10-100mm, preferably 25-80mm; and / or The perforation pattern of the perforated plate is selected from at least one of annular, circular, and rhomboid shapes, preferably annular and / or circular.

6. The preparation method according to any one of claims 1-5, wherein, The upper head of the fixed bubbling bed reactor is provided with a reaction product outlet; and / or The fixed bubbling bed reactor has a raw material inlet on the cylinder below the gas-liquid redistribution unit. The inlet pipeline extends to the center of the reactor and then bends downward at 60-120°, preferably 80-100°.

7. The preparation method according to any one of claims 1-6, wherein, The mixing is carried out in a gas-liquid mixer, the type of which is selected from at least one of Venturi type, orifice plate type and cyclone type.

8. The preparation method according to any one of claims 1-7, wherein, The mixing conditions include: a gas-liquid phase feed volume ratio of 10-500, preferably 20-100; Preferably, the gas phase feed flow rate is 10-100 m³ / h, more preferably 10-50 m³ / h; and / or the liquid phase feed flow rate is 0.1-20 m³ / h, more preferably 0.5-10 m³ / h; and / or Hydrogen gas and nitrile compound solution are fed separately, and the feed directions intersect at an angle of not less than 90°, preferably 90°-150°.

9. The preparation method according to any one of claims 1-8, wherein, The operating temperature of the fixed bubbling bed reactor is 60-180℃, preferably 60-120℃; and / or The operating pressure of the fixed bubbling bed reactor is 2-25 MPaG, preferably 4-20 MPaG.

10. The preparation method according to any one of claims 1-9, wherein, The catalyst is selected from at least one of silicon-based catalysts, nickel-based catalysts, and nickel-cobalt bimetallic catalysts; and / or The amine compound is an aromatic amine, preferably an arylalkylamine, and more preferably a C6-C12 m-phenylenedialkylamine; The solvent in the nitrile compound solution is ammonia.

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