Preparation method of adiponitrile hydrogenation catalyst, catalyst and adiponitrile hydrogenation method

Abstract

The present application relates to a kind of preparation method of adiponitrile hydrogenation catalyst and its catalyst, adiponitrile hydrogenation method, in which the preparation method uses flame synthesis method to prepare active component M oxide powder, and the suspension A containing active component M oxide powder is mixed with the solution B containing the precursors of auxiliary 1 and auxiliary 2, then after drying, calcination, the adiponitrile hydrogenation catalyst is formed by molding.The present application can obtain the adiponitrile hydrogenation catalyst with high active component content, and the active component and the auxiliary form mutual cooperation, the activity of the obtained adiponitrile hydrogenation catalyst is high, and the selectivity of the obtained adiphenine and cyclohexylideneimine by-product is good.

Description

Technical Field

[0001] The present invention relates to the field of preparing hexamethylenediamine by hydrogenating adiponitrile, and in particular to a preparation method of an adiponitrile hydrogenation catalyst, an adiponitrile hydrogenation catalyst and an adiponitrile hydrogenation method using the catalyst. Background Art

[0002] Amines are crucial industrial chemical raw materials, widely used in the production of solvents, pharmaceutical intermediates, resin raw materials, textile auxiliaries, disinfectants, rubber stabilizers, corrosion inhibitors, detergents, and plastics. Their primary production method is the catalytic hydrogenation of nitriles. Similar to most hydrogenation reactions, nitrile hydrogenation has a high atomic efficiency.

[0003] Raney-type catalysts, the most common among nitrile hydrogenation catalysts, include Raney nickel and Raney cobalt catalysts. US Pat. No. 3,821,305A discloses the use of Raney nickel catalysts in the hydrogenation of adiponitrile to produce hexamethylenediamine, demonstrating excellent reactivity and the ability to produce the target product, hexamethylenediamine. US Pat. No. 5,900,511A discloses the use of Raney cobalt catalysts in the hydrogenation of adiponitrile to produce aminocapronitrile and hexamethylenediamine. Raney-type catalysts have high reactivity but are prone to spontaneous combustion, have poor mechanical properties, and are easily broken by interaction with agitators or liquids during the reaction, making subsequent handling difficult.

[0004] Iron-based catalysts are also a common nitrile hydrogenation catalyst. Their main active ingredient is iron oxide, which can exceed 90% by mass. They also contain other oxides such as aluminum oxide, silicon oxide, calcium oxide, and magnesium oxide. Before the catalytic reaction, hydrogen is used to activate the iron oxide into a hydrogenation-active elemental iron, typically at higher pressures. US4587228A discloses a method for preparing an iron-based catalyst. By hydrogenating lepidocrocite, adding graphite, and then pressing the catalyst into tablets, the catalyst's strength and activity are increased, resulting in excellent nitrile hydrogenation performance.

[0005] Another common nitrile hydrogenation catalyst is a noble metal-supported catalyst. Due to the high cost of noble metals, their mass fraction is typically kept below 5%, with the remainder primarily serving as a support. CN1531459A discloses a Ru / SiO2 catalyst, prepared by absorbing an aqueous solution of ruthenium nitrosyl nitrate onto SiO2, followed by drying and activation. Summary of the Invention

[0006] The object of the present invention is to provide a preparation method of an adiponitrile hydrogenation catalyst, an adiponitrile hydrogenation catalyst and an adiponitrile hydrogenation method based on the prior art.

[0007] A first aspect of the present invention provides a method for preparing an adiponitrile hydrogenation catalyst, comprising:

[0008] (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,

[0009] (2) The active component M oxide powder obtained in step (1) is mixed with the first solvent, and the mixture is stirred evenly 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.

[0010] (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 the lanthanide series.

[0011] The first solvent is one or more selected from deionized water, C1-C8 monohydric saturated alcohol and C2-C6 dihydric saturated alcohol.

[0012] (4) The suspension A obtained in step (2) and the solution B obtained in step (3) are fully mixed, dried, calcined, and then formed into an adiponitrile hydrogenation catalyst; wherein,

[0013] Based on the adiponitrile hydrogenation catalyst, the content of the active component M is 5 to 90% by weight, calculated as oxide.

[0014] Calculated on an elemental basis, the molar ratio of the active component M to the additive 1 is 1 to 10:1.

[0015] Calculated on an element basis, the molar ratio of the active component M to the auxiliary agent 2 is 0.1 to 50:1.

[0016] In one embodiment of the present invention, the active metal component M is selected from one or more of iron, cobalt, nickel, ruthenium, rhodium and palladium.

[0017] In one embodiment of the present invention, the auxiliary agent 1 is selected from one or more of magnesium, calcium and barium.

[0018] In one embodiment of the present invention, the auxiliary agent 2 is selected from lanthanum and / or cerium.

[0019] 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; the high temperature is a temperature sufficient to form an oxide, and the temperature range is 500-2000°C.

[0020] In one embodiment of the present invention, 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, calculated as the element;

[0021] The active component M salt solution is obtained by dissolving an active component M salt in a second solvent, wherein the active component M salt is at least one selected from the group consisting of nitrate, formate, acetate, oxalate, iso-octoate, and the second solvent is at least one selected from the group consisting of C1-C8 monohydric saturated alcohols and C1-C8 monohydric saturated carboxylic acids.

[0022] In one embodiment of the present application, the precursors of the auxiliary agent 1 and the auxiliary agent 2 are each independently selected from one or more of the group consisting of nitrate, formate, acetate, oxalate, iso-octoate of the auxiliary agent 1 and the auxiliary agent 2.

[0023] In the solution B, the concentration of the auxiliary agent 1 is 0.001-1 mol / L and the concentration of the auxiliary agent 2 is 0.001-1 mol / L, in terms of elements.

[0024] In one embodiment of the present application, in step (4), the volume ratio of the suspension A obtained in step (2) to the solution B obtained in step (3) is 0.1-10:1.

[0025] The temperature for mixing is 20-80°C and the mixing time is 1-24 h.

[0026] In one embodiment of the present application, in step (4), the drying temperature is 50-250°C and the drying time is 2-48 h.

[0027] Preferably, the drying temperature is 60-200°C and the drying time is 4-24 h.

[0028] In one embodiment of the present application, in step (4), the calcination temperature is 260-1000°C and the calcination time is 1-44 h.

[0029] Preferably, the calcination temperature is 300-800°C and the calcination time is 2-10 h.

[0030] The second aspect of the present application provides the adiponitrile hydrogenation catalyst prepared by any of the above methods, wherein the content of the active component M is 5-90 wt%, the content of the auxiliary agent 1 is 0.1-30 wt%, and the content of the auxiliary agent 2 is 5-80 wt%, based on the dry weight of the catalyst and in terms of oxides.

[0031] In one embodiment of the present application, in the adiponitrile hydrogenation catalyst, the content of the active component M is 30-80 wt%, the content of the auxiliary agent 1 is 0.5-20 wt%, and the content of the auxiliary agent 2 is 10-55 wt%, based on the dry weight of the catalyst and in terms of oxides.

[0032] The third aspect of the present invention provides an adiponitrile hydrogenation method using an adiponitrile hydrogenation catalyst prepared by any of the above methods, wherein the adiponitrile hydrogenation catalyst is activated in a reducing gas atmosphere, and the activation treatment conditions are: pressure 0.5-8.0 MPa, temperature 120-450° C., activation treatment time 12-120 h, and the gas hourly volume space velocity of the reducing gas is 200-20000 h -1 , the reducing gas contains hydrogen and optionally a protective gas, wherein the protective gas is nitrogen and / or water vapor,

[0033] The adiponitrile solution is contacted with the activated adiponitrile hydrogenation catalyst in the presence of hydrogen to react to obtain a reaction product containing hexamethylenediamine. The reaction conditions are: reaction temperature 60-200°C, reaction pressure 1-15 MPa, and liquid hourly volume space velocity of adiponitrile 0.1-10 h -1 , the molar ratio of hydrogen to adiponitrile is 50-500.

[0034] Features of the present invention:

[0035] (1) The preparation method provided by the present invention is simple and produces an adiponitrile hydrogenation catalyst having a high active metal content. The preparation method is not limited by the loading amount, and the active component content can be freely adjusted, with the active component content reaching 90% by weight (calculated as the active metal component on the catalyst dry basis after activation).

[0036] (2) The preparation method provided by the present invention forms a synergistic relationship between the active components of the adiponitrile hydrogenation catalyst prepared and the auxiliary agent, the crystals are stable during the activation process, and the adiponitrile hydrogenation catalyst has high activity after activation.

[0037] (3) The adiponitrile hydrogenation catalyst prepared by the preparation method of the present invention is used for hydrogenating adiponitrile to prepare hexamethylenediamine and co-produce cycloheximide, which has economic advantages and industrial application prospects. DETAILED DESCRIPTION

[0038] The following examples will further illustrate the present invention, but should not be construed as limiting the present invention.

[0039] In the Examples and Comparative Examples, the calculation formulas for conversion and selectivity are as follows:

[0040] Reactant conversion rate = (1-mass of adiponitrile remaining after reaction / mass of adiponitrile before reaction) × 100%;

[0041] Product selectivity = mass of adiponitrile required to generate the product / mass of adiponitrile consumed in the reaction × 100%.

[0042] In the following examples and comparative examples, the adiponitrile hydrogenation method is:

[0043] The adiponitrile hydrogenation method was carried out in a 5 mL high-pressure micro-reactor, using the adiponitrile hydrogenation catalysts prepared in the examples and comparative examples.

[0044] First, the adiponitrile hydrogenation catalyst was activated directly using a temperature-programmed activation method. The catalyst loading was 1 mL. The activation conditions were: an activation pressure of 2.0 MPa, a hydrogen concentration greater than 99% by volume, a hydrogen flow rate of 400 mL / min, an activation temperature of 380°C, and an activation time of 4 hours.

[0045] Secondly, after activation, the adiponitrile hydrogenation reaction was started, and the reaction raw material was an adiponitrile-ethanol solution with an adiponitrile concentration of 10 wt%. The reaction conditions were: pressure of 2 MPa, liquid hourly volume space velocity of the reaction raw material adiponitrile of 1.0 h -1 The molar ratio of hydrogen to adiponitrile was 100, and the reaction temperature was 75°C. After the reaction stabilized, the product composition was analyzed. The product was analyzed using a gas chromatograph (Agilent 7890A). The chromatographic analysis limit was 10 ppm, calculated based on the chromatographic signal-to-noise ratio.

[0046] Example 1

[0047] This example is used to illustrate the preparation method of the adiponitrile hydrogenation catalyst provided by the present invention, the prepared adiponitrile hydrogenation catalyst and its application.

[0048] The preparation method of adiponitrile hydrogenation catalyst is as follows:

[0049] (1) 19.91 g of nickel acetate tetrahydrate was dissolved in 400 mL of a mixed solution of isooctanoic acid and ethanol (volume ratio of isooctanoic acid to ethanol was 1:1), and stirred at 25°C for 1 h to dissolve, thereby preparing a mixed metal solution. The solution was atomized by a syringe pump, and the feed flow rate of the solution was maintained at 3 mL / min and the flow rate of the oxygen dispersion gas was maintained at 5 L / min. Using methane as the gas fuel, the solution was ignited by a premixed flame and nucleated and grew in the high temperature zone of the flame. The particles were 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 were collected.

[0050] (2) 3.0 g of nickel oxide particles were mixed with 50 mL of deionized water to obtain the desired suspension A1;

[0051] (3) 10.00 g of magnesium nitrate hexahydrate, 29.74 g of cerium nitrate hexahydrate, and 150 mL of deionized water were mixed and stirred at 60° C. for 1 h to dissolve to obtain solution B1;

[0052] (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;

[0053] (5) The dried product was calcined at 350° C. for 2 h, and the calcined product was granulated to obtain a 40-60 mesh adiponitrile hydrogenation catalyst C1.

[0054] Based on the total amount of adiponitrile hydrogenation catalyst C1, the contents of the catalyst components, calculated as oxides, are shown in Table 1.

[0055] After activation and adiponitrile hydrogenation reaction of adiponitrile hydrogenation catalyst C1, the raw materials and products in the reaction solution were analyzed by gas chromatography, and the conversion rate of the raw materials and the product selectivity were calculated. The results showed that the adiponitrile conversion rate was 62.53%, the selectivity of hexamethylenediamine was 2.45%, the selectivity of cyclohexaneimine was 4.87%, the selectivity of aminocapronitrile was 54.49%, 2-diaminocyclohexane (DCH) and aminomethylcyclopentylamine (AMCPA) were not detected, and the selectivity of the remaining heavy components (mainly dihexamethylenetriamine, the same below) was 38.19%. The total selectivity of the target products hexamethylenediamine and cyclohexaneimine was 7.32%.

[0056] Example 2

[0057] This example is used to illustrate the preparation method of the adiponitrile hydrogenation catalyst provided by the present invention, the prepared adiponitrile hydrogenation catalyst and its application.

[0058] The preparation method of adiponitrile hydrogenation catalyst is as follows:

[0059] (1) 19.91 g of nickel acetate tetrahydrate was dissolved in 400 mL of a mixed solution of isooctanoic acid and ethanol (volume ratio of isooctanoic acid to ethanol was 1:1), and stirred at 25°C for 1 h to dissolve, thereby preparing a mixed metal solution. The solution was atomized by a syringe pump, and the feed flow rate of the solution was maintained at 3 mL / min and the flow rate of the oxygen dispersion gas was maintained at 5 L / min. Using methane as the gas fuel, the solution was ignited by a premixed flame and nucleated and grew in the high temperature zone of the flame. The particles were 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 were collected.

[0060] (2) 3.0 g of nickel oxide particles were mixed with 50 mL of deionized water to obtain the desired suspension A2;

[0061] (3) Mix 3.75 g of magnesium nitrate hexahydrate, 5.43 g of cerium acetate monohydrate, and 150 mL of deionized water, and stir at 60°C for 1 h to dissolve to obtain solution B2;

[0062] (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;

[0063] (5) The dried product was calcined at 350° C. for 2 h, and the calcined product was granulated to obtain a 40-60 mesh adiponitrile hydrogenation catalyst C2.

[0064] The contents of the catalyst components, calculated as oxides, based on the total amount of adiponitrile hydrogenated C2, are shown in Table 1.

[0065] After activation and adiponitrile hydrogenation reaction of adiponitrile hydrogenation catalyst C2, raw materials and products in the reaction solution were analyzed by gas chromatography, and the conversion rate of raw materials and product selectivity were calculated. The results showed that the adiponitrile conversion rate was 88.48%, the selectivity of hexamethylenediamine was 29.99%, the selectivity of cyclohexaneimine was 35.45%, the selectivity of aminocapronitrile was 25.26%, 2-diaminocyclohexane (DCH) and aminomethylcyclopentylamine (AMCPA) were not detected, and the selectivity of other heavy components was 9.3%. The total selectivity of the target products hexamethylenediamine and cyclohexaneimine was 65.44%.

[0066] Example 3

[0067] This example is used to illustrate the preparation method of the adiponitrile hydrogenation catalyst provided by the present invention, the prepared adiponitrile hydrogenation catalyst and its application.

[0068] The preparation method of adiponitrile hydrogenation catalyst is as follows:

[0069] (1) 23.26 g of nickel nitrate hexahydrate was dissolved in 400 mL of ethanol solution and stirred at 25°C for 1 h to dissolve, thereby preparing a mixed metal solution. The solution was atomized by a syringe pump, and the solution feed rate was maintained at 3 mL / min and the oxygen dispersion gas flow rate was maintained at 5 L / min. Methane was used as the gas fuel, and the solution was ignited by a premixed flame and nucleated and grew in the high temperature zone of the flame. The particles were 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. Nickel oxide particles were thus collected.

[0070] (2) 5.0 g of nickel oxide particles were mixed with 100 mL of deionized water to obtain the desired suspension A3;

[0071] (3) Mix 4.17 g of magnesium nitrate hexahydrate, 4.96 g of cerium nitrate hexahydrate, and 150 mL of deionized water, and stir at 60°C for 1 h to dissolve to obtain solution B3;

[0072] (4) The obtained suspension A3 and solution B3 were mixed and stirred at 60°C for 2 h, and dried at 90°C for 24 h;

[0073] (5) The dried product was calcined at 350° C. for 2 h, and the calcined product was granulated to obtain a 40-60 mesh adiponitrile hydrogenation catalyst C3.

[0074] The contents of the catalyst components, calculated as oxides, based on the total amount of adiponitrile hydrogenated C3, are shown in Table 1.

[0075] After activation and adiponitrile hydrogenation reaction of adiponitrile hydrogenation catalyst C3, raw materials and products in the reaction solution were analyzed by gas chromatography, and the conversion rate of raw materials and product selectivity were calculated. The results showed that the adiponitrile conversion rate was 99.54%, the selectivity of hexamethylenediamine was 89.41%, and the selectivity of cycloheximine was 10.59%. No aminocapronitrile, 2-diaminocyclohexane (DCH), aminomethylcyclopentylamine (AMCPA) and heavy components were detected. The total selectivity of the target products hexamethylenediamine and cycloheximine was 100%.

[0076] Example 4

[0077] This example is used to illustrate the preparation method of the adiponitrile hydrogenation catalyst provided by the present invention, the prepared adiponitrile hydrogenation catalyst and its application.

[0078] The preparation method of adiponitrile hydrogenation catalyst is as follows:

[0079] (1) 23.26 g of nickel nitrate hexahydrate was dissolved in 400 mL of ethanol solution and stirred at 25°C for 1 h to dissolve, thereby preparing a mixed metal solution. The solution was atomized by a syringe pump, and the solution feed rate was maintained at 3 mL / min and the oxygen dispersion gas flow rate was maintained at 5 L / min. Methane was used as the gas fuel, and the solution was ignited by a premixed flame and nucleated and grew in the high temperature zone of the flame. The particles were 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. Nickel oxide particles were thus collected.

[0080] (2) 5.0 g of nickel oxide particles were mixed with 100 mL of deionized water to obtain the desired suspension A4;

[0081] (3) Mix 3.12 g of magnesium nitrate hexahydrate, 1.24 g of cerium nitrate hexahydrate, and 150 mL of deionized water, and stir at 60°C for 1 h to dissolve to obtain solution B4;

[0082] (4) The obtained suspension A4 and solution B4 were mixed and stirred at 60°C for 2 h, and dried at 90°C for 24 h;

[0083] (5) The dried product was calcined at 350° C. for 2 h, and the calcined product was granulated to obtain a 40-60 mesh adiponitrile hydrogenation catalyst C4.

[0084] The contents of the catalyst components, calculated as oxides, based on the total amount of adiponitrile hydrogenated C4, are shown in Table 1.

[0085] After activation of adiponitrile hydrogenation catalyst C4 and adiponitrile hydrogenation reaction, the raw materials and products in the reaction solution were analyzed by gas chromatography, and the conversion rate of the raw materials and the product selectivity were calculated. The results showed that the adiponitrile conversion rate was 98.99%, the selectivity of hexamethylenediamine was 86.54%, the selectivity of cyclohexaneimine was 13.45%, and aminocapronitrile, 2-diaminocyclohexane (DCH), and aminomethylcyclopentylamine (AMCPA) were not detected. The selectivity of other heavy components was 0.01%. The total selectivity of the target products hexamethylenediamine and cyclohexaneimine was 99.99%.

[0086] Example 5

[0087] This example is used to illustrate the preparation method of the adiponitrile hydrogenation catalyst provided by the present invention, the prepared adiponitrile hydrogenation catalyst and its application.

[0088] The preparation method of adiponitrile hydrogenation catalyst is as follows:

[0089] (1) 23.28 g of cobalt nitrate hexahydrate was dissolved in 400 mL of ethanol solution and stirred at 25°C for 1 h to dissolve, thereby preparing a mixed metal solution. The solution was atomized by a syringe pump, and the solution feed rate was maintained at 3 mL / min and the oxygen dispersion gas flow rate was maintained at 5 L / min. Methane was used as the gas fuel, and the solution was ignited by a premixed flame and nucleated and grew in the high temperature zone of the flame. The particles were cooled and condensed through a rapid quenching process, and finally deposited on a glass fiber filter paper above the device with the help of an auxiliary vacuum pump. Cobalt oxide particles were thus collected.

[0090] (2) 5.0 g of cobalt oxide particles were mixed with 100 mL of deionized water to obtain the desired suspension A5;

[0091] (3) Mix 4.15 g of magnesium nitrate hexahydrate, 4.94 g of cerium nitrate hexahydrate, and 150 mL of deionized water, and stir at 60°C for 1 h to dissolve to obtain solution B5;

[0092] (4) The obtained suspension A5 and solution B5 were mixed and stirred at 60°C for 2 h, and dried at 90°C for 24 h;

[0093] (5) The dried product was calcined at 350° C. for 2 h, and the calcined product was granulated to obtain a 40-60 mesh adiponitrile hydrogenation catalyst C5.

[0094] The contents of the catalyst components, calculated as oxides, based on the total amount of C5 adiponitrile hydrogenated, are shown in Table 1.

[0095] After activation and adiponitrile hydrogenation reaction of adiponitrile hydrogenation catalyst C5, the raw materials and products in the reaction solution were analyzed by gas chromatography, and the conversion rate of the raw materials and the product selectivity were calculated. The results showed that the adiponitrile conversion rate was 99.82%, the selectivity of hexamethylenediamine was 87.63%, the selectivity of cycloheximide was 11.24%, and aminocapronitrile, 2-diaminocyclohexane (DCH) and aminomethylcyclopentylamine (AMCPA) were not detected. The selectivity of other heavy components was 1.13%. The total selectivity of the target products hexamethylenediamine and cycloheximide was 98.87%.

[0096] Example 6

[0097] This example is used to illustrate the preparation method of the adiponitrile hydrogenation catalyst provided by the present invention, the prepared adiponitrile hydrogenation catalyst and its application.

[0098] The preparation method of adiponitrile hydrogenation catalyst is as follows:

[0099] (1) 23.26 g of nickel nitrate hexahydrate was dissolved in 400 mL of a mixed solution of isooctanoic acid and ethanol (volume ratio of isooctanoic acid to ethanol was 1:1), and stirred at 25°C for 1 h to dissolve, thereby preparing a mixed metal solution. The solution was atomized by a syringe pump, and the feed flow rate of the solution was maintained at 3 mL / min and the flow rate of the oxygen dispersion gas was maintained at 5 L / min. Using methane as the gas fuel, the solution was ignited by a premixed flame and nucleated and grew in the high temperature zone of the flame. The particles were 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 were collected.

[0100] (2) 5.0 g of cerium oxide particles were mixed with 100 mL of deionized water to obtain the desired suspension A6;

[0101] (3) 1.58 g of barium nitrate hexahydrate, 4.96 g of cerium nitrate hexahydrate, and 150 mL of deionized water were mixed and stirred at 60°C for 1 h to dissolve to obtain solution B6;

[0102] (4) The obtained suspension A6 and solution B6 were mixed and stirred at 60°C for 2 h, and then dried at 90°C for 24 h;

[0103] (5) The dried product was calcined at 350° C. for 2 h, and the calcined product was granulated to obtain a 40-60 mesh adiponitrile hydrogenation catalyst C6.

[0104] Based on the total amount of C6 adiponitrile hydrogenated, the contents of the catalyst components in terms of oxides are shown in Table 1.

[0105] After activation and adiponitrile hydrogenation reaction of adiponitrile, the raw materials and products in the reaction solution were analyzed by gas chromatography, and the conversion rate of the raw materials and the product selectivity were calculated. The results showed that the adiponitrile conversion rate was 90.42%, the selectivity of hexamethylenediamine was 88.36%, and the selectivity of cycloheximine was 11.64%. No aminocapronitrile, 2-diaminocyclohexane (DCH), aminomethylcyclopentylamine (AMCPA) and heavy components were detected. The total selectivity of the target products hexamethylenediamine and cycloheximine was 100%.

[0106] Comparative Example 1

[0107] This comparative example includes a method for preparing an adiponitrile hydrogenation catalyst, the prepared adiponitrile hydrogenation catalyst, and applications.

[0108] The preparation method of adiponitrile hydrogenation catalyst is as follows:

[0109] (1) 22.79 g of cerium 2-ethylhexanoate was dissolved in 400 mL of a mixed solution of 2-ethylhexanoate and ethanol (volume ratio of 1:1), stirred at 25°C for 1 h to dissolve, and a mixed metal solution was prepared. The solution was atomized by a syringe pump, and the feed flow rate of the solution was maintained at 3 mL / min and the flow rate of the oxygen dispersion gas was maintained at 5 L / min. Using methane as the gas fuel, the solution was ignited by a premixed flame and nucleated and grew in the high temperature zone of the flame. The particles were 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. Cerium oxide particles were thus collected.

[0110] (2) Mix 2.0 g of cerium oxide particles with 50 mL of deionized water to obtain the desired suspension A7;

[0111] (3) 4.24 g of magnesium nitrate hexahydrate and 19.82 g of nickel nitrate hexahydrate were mixed with 150 mL of deionized water and stirred at 60° C. for 1 h to dissolve to obtain solution B7;

[0112] (4) The obtained suspension A7 and solution B7 were mixed and stirred at 60°C for 2 h, and dried at 90°C for 24 h;

[0113] (5) The dried product was calcined at 350° C. for 2 h, and the calcined product was granulated to obtain a 40-60 mesh adiponitrile hydrogenation catalyst D1.

[0114] The contents of the catalyst components, calculated as oxides, based on the total amount of adiponitrile hydrogenation D1 are shown in Table 1.

[0115] After activation and adiponitrile hydrogenation reaction of adiponitrile hydrogenation catalyst D1, raw materials and products in the reaction solution were analyzed by gas chromatography, and the conversion rate of raw materials and product selectivity were calculated. The results showed that the adiponitrile conversion rate was 63.73%, the selectivity of hexamethylenediamine was 34.65%, the selectivity of cyclohexaneimine was 21.01%, and the selectivity of aminocapronitrile was 43.52%. No aminocapronitrile, 2-diaminocyclohexane (DCH), or aminomethylcyclopentylamine (AMCPA) were detected. The selectivity of heavy components was 0.82%. The total selectivity of the target products hexamethylenediamine and cyclohexaneimine was 55.66%.

[0116] Comparative Example 2

[0117] This comparative example includes a method for preparing an adiponitrile hydrogenation catalyst, the prepared adiponitrile hydrogenation catalyst, and applications.

[0118] The preparation method of adiponitrile hydrogenation catalyst is as follows:

[0119] (1) Mix 4.17 g of magnesium nitrate hexahydrate, 19.47 g of nickel nitrate hexahydrate, and 4.96 g of cerium nitrate hexahydrate with 300 mL of deionized water and stir at 40°C for 1 h.

[0120] (2) Add 50 mL of 1.0 mol L -1 The precipitate was dried at 90°C for 12 hours, and the dried product was calcined at 350°C for 2 hours. After granulation, a 40-60 mesh adiponitrile hydrogenation catalyst D2 was obtained.

[0121] The contents of the catalyst components, calculated as oxides, based on the total amount of adiponitrile hydrogenated D2 are shown in Table 1.

[0122] After activation and adiponitrile hydrogenation reaction of adiponitrile, the raw materials and products in the reaction solution were analyzed by gas chromatography, and the conversion rate of the raw materials and the product selectivity were calculated. The results showed that the adiponitrile conversion rate was 99.24%, the selectivity of hexamethylenediamine was 49.26%, the selectivity of cyclohexaneimine was 28.18%, the selectivity of aminocapronitrile was 21.68%, and 2-diaminocyclohexane (DCH) and aminomethylcyclopentylamine (AMCPA) were not detected. The selectivity of heavy components was 0.88%; and the total selectivity of the target products hexamethylenediamine and cyclohexaneimine was 77.44%.

[0123] Table 1

[0124]

Claims

1. A method for preparing an adiponitrile hydrogenation catalyst, 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 one or more of iron, cobalt, and nickel. The flame synthesis method 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 methane, ethane, ethylene, propane, or butane. The high temperature is a temperature sufficient to form an oxide, and the temperature range is 500-2000°C. (2) The active component M oxide powder obtained in step (1) is mixed with the first solvent, and the mixture is stirred evenly 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 the lanthanide series. The first solvent is one or more selected from deionized water, C1-C8 monohydric saturated alcohol and C2-C6 dihydric saturated alcohol. (4) The suspension A obtained in step (2) and the solution B obtained in step (3) are fully mixed, dried, calcined, and then formed into an adiponitrile hydrogenation catalyst; wherein, In the adiponitrile hydrogenation catalyst, based on the dry weight of the catalyst and calculated as oxide, the content of the active component M is 30-80 weight %, the content of the auxiliary agent 1 is 0.5-20 weight %, and the content of the auxiliary agent 2 is 10-55 weight %.

2. The method according to claim 1, characterized in that The auxiliary agent 1 is selected from one or more of magnesium, calcium and barium; The auxiliary agent 2 is selected from lanthanum and / or cerium.

3. The method according to claim 1, 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, calculated as the 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.

4. The method according to claim 1, wherein 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.

5. The method according to claim 1, wherein 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 mixing temperature of the two is 20 to 80° C., and the mixing time is 1 to 24 hours.

6. The method according to claim 1, characterized in that In step (4), the drying temperature is 50 to 250° C., and the drying time is 2 to 48 hours.

7. The method according to claim 6, characterized in that The drying temperature is 60-200°C and the drying time is 4-24 hours.

8. The method according to claim 1, characterized in that In step (4), the calcination temperature is 260-1000° C., and the calcination time is 1-44 hours.

9. The method according to claim 8, characterized in that The calcination temperature is 300-800°C, and the calcination time is 2-10 hours.

10. An adiponitrile hydrogenation catalyst prepared by the method according to any one of claims 1 to 9, 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 %.

11. A method for hydrogenating adiponitrile using an adiponitrile hydrogenation catalyst prepared by the method according to any one of claims 1 to 9, characterized in that: The adiponitrile hydrogenation catalyst is activated in a reducing gas atmosphere. The activation conditions are: pressure 0.5-8.0 MPa, temperature 120-450°C, activation time 12-120 h, and gas hourly volume space velocity of the reducing gas 200-20000 h -1 , the reducing gas contains hydrogen and optionally a protective gas, wherein the protective gas is nitrogen and / or water vapor, The adiponitrile solution is contacted with the activated adiponitrile hydrogenation catalyst in the presence of hydrogen to react to obtain a reaction product containing hexamethylenediamine. The solvent of the adiponitrile solution is ethanol. The reaction conditions are: reaction temperature 60-200°C, reaction pressure 1-15 MPa, and liquid hourly volume space velocity of adiponitrile 0.1-10 h -1 , the molar ratio of hydrogen to adiponitrile is 50-500.

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