Hydrogenation method for synthesizing hexamethylenediamine and co-producing hexamethyleneimine

Abstract

The invention relates to a hydrogenation method for synthesizing hexamethylenediamine and co-producing hexamethyleneimine, which comprises the following steps: feeding an adiponitrile-containing raw material and hydrogen into a tube pass of a shell and tube reactor, contacting with an activated adiponitrile hydrogenation catalyst, reacting under the condition of adiponitrile hydrogenation reaction, separating the obtained reaction effluent, and separating the separated reaction effluent to obtain the hexamethyleneimine. At least a hexamethylenediamine product and a hexamethyleneimine product are obtained. The process route is simple and optimized, the operation is simple, convenient and safe, the continuous production can be realized, the cost is low, and the product yield is high.

Description

Technical Field

[0001] The invention relates to the field of preparing hexamethylenediamine by hydrogenation of adiponitrile, and in particular to a hydrogenation method for synthesizing hexamethylenediamine and co-producing cycloheximide. Background Art

[0002] Hexamethylenediamine is an important chemical raw material, which can be used to synthesize nylon 66, nylon 610, hexamethylene diisocyanate, etc. Among them, 90% of hexamethylenediamine is used to synthesize nylon salt and then produce nylon 66. Nylon-66 is mainly used to produce engineering plastics and fiber products. Its plastic products have strong tensile strength and weather resistance, and can replace traditional metal materials for the production of mechanical parts, mechanical force components, etc. At present, the methods for industrial production of hexamethylenediamine mainly include low-pressure fluidized bed method and high-pressure fixed bed method. Patent US3821305 discloses the use of Raney nickel for hydrogenation of adiponitrile to prepare hexamethylenediamine. The reaction device is a three-phase fluidized bed. The catalyst particle size in the reaction is about 20-50μm, which is difficult to separate and has a high degree of wear on the device. At the same time, waste alkali liquid is generated, which is difficult to handle and causes great environmental pollution.

[0003] CN106536476B discloses a method and system for preparing hexamethylenediamine using a high-pressure fixed bed, wherein an iron-based catalyst is used in the process and the pressure is higher than 27 MPa.

[0004] Cycloheximide is also an important intermediate. It can be used as a pesticide intermediate to synthesize a variety of carbamate herbicides, and can also be used to prepare cycloheximide penicillin and anti-neuropathy drugs. There are three main methods for preparing cycloheximide: the first is to use aniline as a raw material and produce cycloheximide through hydrogenation reaction; the second is to use caprolactam as a raw material, and CN112079726B discloses this production method; the third is to use hexamethylenediamine as a raw material, and hexamethylenediamine can be deaminated and cyclized to obtain the target product.

[0005] In the prior art, 1,2-diaminocyclohexane (DCH) and aminomethylcyclopentylamine (AMCPA) are common impurities in hexamethylenediamine products. The content of trans-1,2-diaminocyclohexane is used as one of the important indicators of industrial 1,6-hexamethylenediamine. According to the standard "HG / T 3937-2021", the content of trans-1,2-diaminocyclohexane in superior hexamethylenediamine is ≤10mg / kg, the content of trans-1,2-diaminocyclohexane in first-class hexamethylenediamine is ≤18mg / kg, and the content of trans-1,2-diaminocyclohexane in qualified hexamethylenediamine is ≤30mg / kg. However, diamine impurities have a similar boiling point to hexamethylenediamine, and the diamine impurities produced in the reaction will increase the cost of subsequent product separation. Summary of the invention

[0006] The object of the present invention is to provide a hydrogenation method for synthesizing hexamethylenediamine and producing cycloheximide on the basis of the prior art, comprising: providing a tubular reactor, loading an adiponitrile hydrogenation catalyst in the tube side of the tubular reactor, using a cooling medium in the shell side of the tubular reactor to control the reaction temperature in the tube side within a certain range,

[0007] The raw material containing adiponitrile and hydrogen are introduced into the tube side of the tubular reactor together, contacted with the activated adiponitrile hydrogenation catalyst, and reacted under adiponitrile hydrogenation reaction conditions. After separation of the obtained reaction effluent, at least hexamethylenediamine product and cycloheximide product are obtained.

[0008] The reaction conditions for adiponitrile hydrogenation are: reaction temperature of 65-125°C, hydrogen partial pressure of 2-10 MPa, liquid hourly mass space velocity of adiponitrile of 0.1-10 h -1 , the molar ratio of hydrogen to adiponitrile is 50 to 500,

[0009] The adiponitrile hydrogenation catalyst comprises an active component M, an auxiliary agent 1 and an auxiliary agent 2. Based on the dry weight of the catalyst and calculated as oxide, the content of the active component M is 5 to 90% by weight, the content of the auxiliary agent 1 is 0.1 to 30% by weight, and the content of the auxiliary agent 2 is 5 to 80% by weight. The active component M is selected from at least one of the metal elements of Group VIII, the auxiliary agent 1 is selected from at least one of the metal elements of Group IIA, and the auxiliary agent 2 is selected from at least one of the lanthanide metal elements.

[0010] In a preferred embodiment of the present invention, in the adiponitrile hydrogenation catalyst, the active metal component M is selected from one or more of iron, cobalt, nickel, ruthenium, rhodium and palladium, the auxiliary agent 1 is selected from one or more of magnesium, calcium and barium, and the auxiliary agent 2 is selected from lanthanum and / or cerium.

[0011] In a preferred embodiment of the present invention, in the adiponitrile hydrogenation catalyst, based on the dry weight of the catalyst and calculated as oxide, the content of active component M is 30-80 weight %, the content of auxiliary agent 1 is 0.5-20 weight %, and the content of auxiliary agent 2 is 10-55 weight %.

[0012] The tube side of the shell-and-tube reactor is composed of a plurality of reaction tubes. In one embodiment of the present invention, in the shell-and-tube reactor, the aspect ratio of a single shell-and-tube is in the range of 10 to 200, and the diameter of a single shell-and-tube is in the range of 10 to 100 mm.

[0013] In one embodiment of the present invention, the shape of the adiponitrile hydrogenation catalyst is one or more selected from the group consisting of spherical, annular, cylindrical, butterfly and clover-leaf shapes; preferably spherical.

[0014] In one embodiment of the present invention, the packing ratio of the adiponitrile hydrogenation catalyst is 0.5-1.2 kg / L.

[0015] In one embodiment of the present invention, the cooling medium is at least one of molten salt, heat transfer oil and water. In the present invention, the flow mode of the shell side cooling medium is cross flow or parallel flow.

[0016] In one embodiment of the present invention, the flow direction of the logistics in the tube pass of the tube reactor is that the gas and liquid flow in parallel from top to bottom, and the liquid phase reactants in the tube are in a trickle flow state.

[0017] In one embodiment of the present invention, the raw material containing adiponitrile is an alcohol solution of adiponitrile, the mass concentration of adiponitrile is 10-99%, and the alcohol is selected from one or more of C2 to C12 monohydric saturated alcohols and C2 to C6 dihydric saturated diols.

[0018] In one embodiment of the present invention, the adiponitrile hydrogenation catalyst is activated in a reducing gas atmosphere to obtain an activated adiponitrile hydrogenation catalyst, and the activation treatment conditions are: pressure 0.5-8.0 MPa, temperature 120-450° C., and gas hourly volume space velocity of the reducing gas of 200-20000 h -1 The activation treatment time is 12 to 120 hours, and the reducing gas contains hydrogen and an optional protective gas, wherein the protective gas is nitrogen and / or water vapor.

[0019] In one embodiment of the present invention, the reaction effluent is separated to obtain a gaseous product, and the volume fraction of hydrogen is greater than or equal to 80% based on the entire gaseous product; the gaseous product is circulated to the tube side inlet of the shell-and-tube reactor.

[0020] In one embodiment of the present invention, the reaction effluent is separated to obtain a liquid product, and the liquid product includes hexamethylenediamine and cycloheximide, wherein the mass ratio of hexamethylenediamine to cycloheximide is greater than or equal to 2. At the same time, at normal temperature and pressure (standard atmospheric pressure, 25° C.), 1,2-diaminocyclohexane (DCH) and aminomethylcyclopentylamine (AMCPA) in the obtained liquid product are both less than or equal to 10 ppm.

[0021] In the present invention, the separation method includes but is not limited to flash evaporation, rectification and the like.

[0022] In a preferred embodiment of the present invention, the adiponitrile hydrogenation catalyst is obtained by the following preparation process, comprising:

[0023] (1) using a flame synthesis method to prepare an oxide powder of an active component M, wherein the active component M is selected from at least one metal element of Group VIII,

[0024] (2) mixing the active component M oxide powder obtained in step (1) with the first solvent, and stirring the mixture to obtain a suspension A, wherein the mass ratio of the active component M oxide to the first solvent is 0.01 to 1:1.

[0025] (3) dissolving the precursors of auxiliary agent 1 and auxiliary agent 2 in a first solvent to obtain a solution B containing the precursors of auxiliary agent 1 and auxiliary agent 2, wherein auxiliary agent 1 is selected from at least one metal element of Group IIA, and auxiliary agent 2 is selected from at least one metal element of lanthanide series.

[0026] The first solvent is one or more selected from deionized water, C1-C8 monohydric saturated alcohols and C2-C6 dihydric saturated alcohols.

[0027] (4) The suspension A obtained in step (2) and the solution B obtained in step (3) are fully mixed, dried, calcined, and then molded to obtain an adiponitrile hydrogenation catalyst.

[0028] In one embodiment of the present invention, the flame synthesis method described in step (1) refers to using a gas fuel to provide a high temperature to burn the precursor to generate powder particles, and the gas fuel is selected from at least one of hydrogen, methane, ethane, ethylene, propane or butane, and the high temperature is a temperature sufficient to form an oxide, and the temperature range is 500 to 2000°C.

[0029] In one embodiment of the present invention, the precursor refers to a salt solution of the active component M, and the concentration of the active component M in the solution is 0.01 to 1 mol / L in terms of element;

[0030] The active component M salt solution is obtained by dissolving the active component M salt in a second solvent, wherein the active component M salt is selected from at least one of nitrate, formates, acetates, oxalates, and isooctanoates, and the second solvent is selected from at least one of C1-C8 monohydric saturated alcohols and C1-C8 monohydric saturated carboxylic acids.

[0031] In one embodiment of the present invention, the precursors of additive 1 and additive 2 are independently selected from one or more of nitrate, formates, acetates, oxalates, and isooctanoates of additive 1 and additive 2;

[0032] In solution B, the concentration of additive 1 is 0.001 to 1 mol / L, and the concentration of additive 2 is 0.001 to 1 mol / L, calculated as the element.

[0033] In one embodiment of the present invention, in step (4), the volume ratio of the suspension A obtained in step (2) to the solution B obtained in step (3) is 0.1 to 10:1;

[0034] The temperature for mixing the two is 20 to 80°C, and the mixing time is 1 to 24 hours;

[0035] In step (4), the drying temperature is 50 to 250° C. and the drying time is 2 to 48 hours;

[0036] Preferably, the drying temperature is 60 to 200°C and the drying time is 4 to 24 hours;

[0037] The calcination temperature is 260-1000°C and the calcination time is 1-44h;

[0038] Preferably, the calcination temperature is 300-800° C., and the calcination time is 2-10 hours.

[0039] The present invention is characterized by:

[0040] (1) The present invention provides a hydrogenation method for synthesizing hexamethylenediamine, which can simultaneously continuously and stably produce cycloheximide. The technical scheme of the present invention is simple and optimized, the operation is simple and safe, the cost is low, and the raw material conversion rate is high and the target product selectivity is high.

[0041] (2) The present invention adopts a shell-and-tube reactor and uses a cooling medium to remove the heat released by the reaction and maintain the reaction temperature within a certain range. On the one hand, it is easy to adjust the product ratio by adjusting the reaction temperature. On the other hand, it is also easy to keep the reaction temperature constant during the reaction process, which is conducive to obtaining the target product with high selectivity over a long period of time.

[0042] (3) The present invention does not use alkaline compounds such as sodium hydroxide that are conventionally used in the prior art production of hexamethylenediamine, thereby reducing the wastewater treatment cost of the enterprise.

[0043] (4) The preferred adiponitrile hydrogenation catalyst of the present invention has a synergistic effect between its active component and the auxiliary agent, and the crystals are stable during the activation process. The adiponitrile hydrogenation catalyst has high activity after activation. DETAILED DESCRIPTION

[0044] The following examples will further illustrate the present invention, but should not be construed as limiting the present invention.

[0045] In the present invention,

[0046] ADN means "adiponitrile";

[0047] HMD refers to "hexamethylenediamine";

[0048] ACN refers to "6-aminocapronitrile", also known as "aminocapronitrile";

[0049] HMI refers to "hexamethyleneimine", also known as "cyclohexylimine";

[0050] DCH refers to "1,2-diaminocyclohexane";

[0051] BHMT refers to "bis(hexamethylene)triamine";

[0052] AMCPA stands for "aminomethylcyclopentylamine".

[0053] The heavy component is mainly dihexylenetriamine.

[0054] In the embodiments and comparative examples, the calculation formulas for conversion and selectivity are as follows:

[0055] Reactant conversion rate = (1-mass of adiponitrile remaining after reaction / mass of adiponitrile before reaction) × 100%;

[0056] Product selectivity = mass of adiponitrile required to generate product / mass of adiponitrile consumed in the reaction × 100%.

[0057] In the examples and comparative examples, the products were analyzed using a gas chromatograph (Agilent 7890A) to analyze the components of each substance in the product. The lower limit of the chromatographic analysis was calculated to be 10 ppm based on the chromatographic signal-to-noise ratio.

[0058] In the following examples and comparative examples, the adiponitrile hydrogenation catalysts used are catalyst A and catalyst B, respectively.

[0059] The preparation method of catalyst A is:

[0060] (1) Take 23.26g of nickel nitrate hexahydrate and dissolve it in 400mL of ethanol solution. Stir it for 1h at 25℃ to dissolve it and prepare a mixed metal solution. The solution is atomized by a syringe pump jet, and the feed flow rate of the solution is maintained at 3mL / min and the flow rate of oxygen dispersion gas is maintained at 5L / min. Using methane as the gas fuel, the solution is ignited by a premixed flame and nucleates and grows in the high temperature zone of the flame. The particles are cooled and condensed through a rapid quenching process and finally deposited on the glass fiber filter paper above the device with the help of an auxiliary vacuum pump. In this way, nickel oxide particles are collected and prepared in multiple batches to obtain the required amount.

[0061] (2) 20.0 g of nickel oxide particles were mixed with 400 mL of deionized water to obtain the desired suspension A1;

[0062] (3) 16.68 g of magnesium nitrate hexahydrate and 19.84 g of cerium nitrate hexahydrate were mixed with 600 mL of deionized water, and stirred at 60° C. for 1 h to dissolve, thereby obtaining a solution B1;

[0063] (4) The obtained suspension A1 and solution B1 were mixed and stirred at 60°C for 2 h, and dried at 90°C for 24 h;

[0064] (5) The dried product was calcined at 350° C. for 2 h, and the calcined product was granulated to obtain a 14-20 mesh adiponitrile hydrogenation catalyst A.

[0065] Based on the total dry weight of Catalyst A, the NiO content, calculated as oxides, was 65.6 wt %, the MgO content was 8.6 wt %, and the CeO2 content was 25.8 wt %.

[0066] The preparation method of catalyst B is:

[0067] (1) Take 23.28g of cobalt nitrate hexahydrate and dissolve it in 400mL of ethanol solution. Stir it for 1h at 25℃ to dissolve it and prepare a mixed metal solution. The solution is atomized by a syringe pump jet, and the feed flow rate of the solution is maintained at 3mL / min and the flow rate of oxygen dispersion gas is maintained at 5L / min. Using methane as the gas fuel, the solution is ignited by a premixed flame and nucleates and grows in the high temperature zone of the flame. The particles are cooled and condensed through a rapid quenching process and finally deposited on the glass fiber filter paper above the device with the help of an auxiliary vacuum pump. In this way, cobalt oxide particles are collected and prepared in multiple batches to obtain the required amount.

[0068] (2) 20.0 g of cobalt oxide particles were mixed with 400 mL of deionized water to obtain the desired suspension A2;

[0069] (3) 16.60 g of magnesium nitrate hexahydrate, 19.76 g of cerium nitrate hexahydrate and 600 mL of deionized water were mixed and stirred at 60° C. for 1 h to dissolve to obtain solution B2;

[0070] (4) The obtained suspension A2 and solution B2 were mixed and stirred at 60°C for 2 h, and dried at 90°C for 24 h;

[0071] (5) The dried product was calcined at 350° C. for 2 h, and the calcined product was granulated to obtain a 14-20 mesh adiponitrile hydrogenation catalyst B.

[0072] Based on the total dry weight of Catalyst B, the CoO content, calculated as oxides, was 65.7 wt %, the MgO content was 8.6 wt %, and the CeO2 content was 25.7 wt %.

[0073] Example 1

[0074] After mixing 14-20 mesh spherical particle catalyst A with inert ceramic balls, the mixed volume ratio is catalyst: inert ceramic balls = 1:1, and loaded into a shell-and-tube reactor (the shell-and-tube length is 790 mm, and the inner diameter of a single shell-and-tube is 20 mm). The cooling medium of the shell side of the shell-and-tube reactor is water.

[0075] Activation treatment process: Reducing gas is introduced into the tube side of the tubular reactor. The reducing gas is a mixture of hydrogen and nitrogen, and the volume percentage of hydrogen in the reducing gas is 10%. The activation treatment conditions are: pressure 2.0MPa, temperature 400℃, gas hourly volume space velocity of reducing gas is 4000h-1 , reduction activation for 24h.

[0076] Reaction process: The reaction raw material is adiponitrile / ethanol solution (adiponitrile concentration 50wt%), new hydrogen and circulating hydrogen are mixed to form gaseous feed, the reaction raw material and gaseous feed are mixed and preheated to 75.0℃ and enter the tube side of the shell-and-tube reactor, and contact with the reduced activated catalyst A to react. The reaction conditions are: hydrogen partial pressure of 4.0MPa, average tube side temperature of 80.0℃, hydrogen nitrile molar ratio of 100, adiponitrile liquid mass space velocity of 0.5h -1 .

[0077] After separation of the reaction effluent, a gas phase product and a liquid phase product were obtained. The gas phase product was circulated, and the liquid phase product was analyzed by gas chromatography. The analysis results and calculation results are shown in Table 1.

[0078] Example 2

[0079] The same technical scheme as in Example 1 was used for the reaction, except that the preheating temperature during the reaction was 90.0° C. and the average temperature of the tube was 95.0° C. The liquid product was analyzed by gas chromatography. The analysis results and calculation results are shown in Table 1.

[0080] Example 3

[0081] The same technical scheme as in Example 1 was used for the reaction, except that the preheating temperature during the reaction was 105.0° C. and the average temperature of the tube was 110.0° C. The liquid product was analyzed by gas chromatography. The analysis results and calculation results are shown in Table 1.

[0082] Example 4

[0083] After mixing 14-20 mesh spherical particle catalyst B with inert porcelain balls, the mixed volume ratio is catalyst: inert porcelain balls = 1:1, and loaded into a shell-and-tube reactor (the shell-and-tube length is 790 mm, and the inner diameter of a single shell-and-tube is 20 mm). The cooling medium of the shell side of the shell-and-tube reactor is water.

[0084] Activation treatment process: Reducing gas is introduced into the tube side of the tubular reactor. The reducing gas is a mixture of hydrogen and nitrogen, and the volume percentage of hydrogen in the reducing gas is 10%. The activation treatment conditions are: pressure 2.0MPa, temperature 400℃, gas hourly volume space velocity of reducing gas is 4000h -1 , reduction activation for 24h.

[0085] Reaction process: The reaction raw material is adiponitrile / ethanol solution (adiponitrile concentration 50wt%), new hydrogen and circulating hydrogen are mixed to form gaseous feed, the reaction raw material and gaseous feed are mixed and preheated to 75.0℃ and enter the tube side of the tubular reactor, and contact with the reduced activated catalyst A to react. The reaction conditions are: hydrogen partial pressure of 4.0MPa, average tube side temperature of 80.0℃, hydrogen nitrile molar ratio of 100, adiponitrile liquid mass space velocity of 1.0h -1 .

[0086] After separation of the reaction effluent, a gas phase product and a liquid phase product were obtained. The gas phase product was circulated, and the liquid phase product was analyzed by gas chromatography. The analysis results and calculation results are shown in Table 1.

[0087] Comparative Example 1

[0088] The same technical scheme as in Example 1 was used for the reaction, except that the preheating temperature during the reaction was 55.0° C. and the average temperature of the tube was 62.0° C. The liquid product was analyzed by gas chromatography. The analysis results and calculation results are shown in Table 1.

[0089] Comparative Example 2

[0090] The same technical scheme as in Example 1 was used for the reaction, except that the preheating temperature during the reaction was 125.0° C. and the average temperature of the tube was 132.0° C. The liquid product was analyzed by gas chromatography. The analysis results and calculation results are shown in Table 1.

[0091] Comparative Example 3

[0092] The reaction was carried out according to the same technical scheme as in Example 1, except that there was no cooling medium heat exchange during the reaction, and the material temperature at the tube outlet reached 135.0° C. The liquid product was analyzed by gas chromatography. The analysis results and calculation results of the liquid product are shown in Table 1.

[0093] Comparative Example 4

[0094] The reaction was carried out according to the same technical scheme as in Example 3, except that there was no cooling medium heat exchange during the reaction, and the material temperature at the tube outlet reached 164.2° C. The liquid product was analyzed by gas chromatography. The analysis results and calculation results of the liquid product are shown in Table 1.

[0095] Table 1

[0096]

Claims

1. A hydrogenation method for synthesizing hexamethylenediamine and producing cycloheximide, characterized in that: A tubular reactor is provided, the adiponitrile hydrogenation catalyst is loaded in the tube side of the tubular reactor, and a cooling medium is used in the shell side of the tubular reactor to control the reaction temperature in the tube side within a certain range. The raw material containing adiponitrile and hydrogen are introduced into the tube side of the tubular reactor together, contacted with the activated adiponitrile hydrogenation catalyst, and reacted under adiponitrile hydrogenation reaction conditions. After separation of the obtained reaction effluent, at least hexamethylenediamine product and cycloheximide product are obtained. The reaction conditions for adiponitrile hydrogenation are: reaction temperature of 65-125°C, hydrogen partial pressure of 2-10 MPa, liquid hourly mass space velocity of adiponitrile of 0.1-10 h -1 , the molar ratio of hydrogen to adiponitrile is 50 to 500, The adiponitrile hydrogenation catalyst comprises an active component M, an auxiliary agent 1 and an auxiliary agent 2. Based on the dry weight of the catalyst and calculated as oxide, the content of the active component M is 5 to 90% by weight, the content of the auxiliary agent 1 is 0.1 to 30% by weight, and the content of the auxiliary agent 2 is 5 to 80% by weight. The active component M is selected from at least one of the metal elements of Group VIII, the auxiliary agent 1 is selected from at least one of the metal elements of Group IIA, and the auxiliary agent 2 is selected from at least one of the lanthanide metal elements.

2. The method according to claim 1, characterized in that In the adiponitrile hydrogenation catalyst, the active metal component M is selected from one or more of iron, cobalt, nickel, ruthenium, rhodium and palladium. The auxiliary agent 1 is selected from one or more of magnesium, calcium and barium, The additive 2 is selected from lanthanum and / or cerium.

3. The method according to claim 1 or 2, characterized in that: In the adiponitrile hydrogenation catalyst, based on the dry weight of the catalyst and calculated as oxide, the content of active component M is 30-80 weight %, the content of auxiliary agent 1 is 0.5-20 weight %, and the content of auxiliary agent 2 is 10-55 weight %.

4. The method according to claim 1, characterized in that: In the shell-and-tube reactor, the aspect ratio of a single shell-and-tube is in the range of 10 to 200, and the diameter of a single shell-and-tube is in the range of 10 to 100 mm.

5. The method according to claim 1, characterized in that The adiponitrile hydrogenation catalyst has a shape selected from one or more of spherical, annular, cylindrical, butterfly and clover-shaped; The loading ratio of the adiponitrile hydrogenation catalyst is 0.5 to 1.2 kg / L.

6. The method according to claim 1, characterized in that The cooling medium is at least one of molten salt, heat transfer oil and water.

7. The method according to claim 1, characterized in that The raw material containing adiponitrile is an alcohol solution of adiponitrile, the mass concentration of adiponitrile is 10-99%, and the alcohol is selected from one or more of C2 to C12 monohydric saturated alcohol and C2 to C6 dihydric saturated alcohol.

8. The method according to claim 1, characterized in that The adiponitrile hydrogenation catalyst is activated in a reducing gas atmosphere to obtain an activated adiponitrile hydrogenation catalyst. The activation treatment conditions are: pressure 0.5-8.0 MPa, temperature 120-450° C., and gas hourly volume space velocity of the reducing gas of 200-20000 h -1 The activation treatment time is 12 to 120 hours, and the reducing gas contains hydrogen and an optional protective gas, wherein the protective gas is nitrogen and / or water vapor.

9. The method according to claim 1, characterized in that: The reaction effluent is separated to obtain a gaseous product, wherein the volume fraction of hydrogen is greater than or equal to 80% based on the entire gaseous product; the gaseous product is circulated to the tube side inlet of the tubular reactor.

10. The method according to claim 1, characterized in that The adiponitrile hydrogenation catalyst is obtained by the following preparation process, comprising: (1) using a flame synthesis method to prepare an oxide powder of an active component M, wherein the active component M is selected from at least one metal element of Group VIII, (2) mixing the active component M oxide powder obtained in step (1) with the first solvent, and stirring the mixture to obtain a suspension A, wherein the mass ratio of the active component M oxide to the first solvent is 0.01 to 1:

1. (3) dissolving the precursors of auxiliary agent 1 and auxiliary agent 2 in a first solvent to obtain a solution B containing the precursors of auxiliary agent 1 and auxiliary agent 2, wherein auxiliary agent 1 is selected from at least one metal element of Group IIA, and auxiliary agent 2 is selected from at least one metal element of lanthanide series. The first solvent is one or more selected from deionized water, C1-C8 monohydric saturated alcohols and C2-C6 dihydric saturated alcohols. (4) The suspension A obtained in step (2) and the solution B obtained in step (3) are fully mixed, dried, calcined, and then molded to obtain an adiponitrile hydrogenation catalyst.

11. The method according to claim 10, characterized in that The flame synthesis method described in step (1) refers to using a gas fuel to provide a high temperature to burn the precursor to generate powder particles. The gas fuel is selected from at least one of hydrogen, methane, ethane, ethylene, propane or butane. The high temperature is a temperature sufficient to form an oxide, and the temperature range is 500 to 2000°C.

12. The method according to claim 11, characterized in that The precursor is a salt solution of the active component M, and the concentration of the active component M in the solution is 0.01 to 1 mol / L in terms of element; The active component M salt solution is obtained by dissolving the active component M salt in a second solvent, wherein the active component M salt is selected from at least one of nitrate, formates, acetates, oxalates, and isooctanoates, and the second solvent is selected from at least one of C1-C8 monohydric saturated alcohols and C1-C8 monohydric saturated carboxylic acids.

13. The method according to claim 10, characterized in that The precursors of additive 1 and additive 2 are independently selected from one or more of nitrate, formates, acetates, oxalates and isooctanoates of additive 1 and additive 2; In solution B, the concentration of additive 1 is 0.001 to 1 mol / L, and the concentration of additive 2 is 0.001 to 1 mol / L, calculated as the element.

14. The method according to claim 10, characterized in that In step (4), the volume ratio of the suspension A obtained in step (2) to the solution B obtained in step (3) is 0.1 to 10:1; The temperature for mixing the two is 20 to 80°C, and the mixing time is 1 to 24 hours; In step (4), the drying temperature is 50 to 250° C. and the drying time is 2 to 48 hours; Preferably, the drying temperature is 60 to 200°C and the drying time is 4 to 24 hours; The calcination temperature is 260-1000°C and the calcination time is 1-44h; Preferably, the calcination temperature is 300-800° C., and the calcination time is 2-10 hours.

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