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

Abstract

The invention relates to a preparation method of an adiponitrile hydrogenation catalyst, the catalyst and an adiponitrile hydrogenation method.The preparation method comprises the steps that oxide powder of an active component M is prepared through a flame synthesis method, and turbid liquid A containing the oxide powder of the active component M is mixed with a solution B containing precursors of an auxiliary 1 and an auxiliary 2; and then drying, roasting and molding to obtain the adiponitrile hydrogenation catalyst. According to the method, the adiponitrile hydrogenation catalyst with high active component content can be obtained, the active components and the auxiliary agent are mutually cooperated, the activity of the obtained adiponitrile hydrogenation catalyst is high, and the selectivity of the obtained hexamethylenediamine and co-production of the hexamethyleneimine is good.

Description

Technical Field

[0001] The 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 very important chemical raw materials in industry and are widely used in the production of solvents, pharmaceutical intermediates, resin raw materials, textile auxiliaries, disinfectants, rubber stabilizers, corrosion inhibitors, detergents and plastics. The main production method is the catalytic hydrogenation of the corresponding nitriles. Similar to most hydrogenation reactions, the nitrile hydrogenation reaction has a high atomic efficiency.

[0003] The most common Raney catalysts among nitrile hydrogenation catalysts include Raney nickel and Raney cobalt catalysts. US3821305A discloses that Raney nickel catalyst is used for the hydrogenation of adiponitrile to prepare hexamethylenediamine, and its reaction performance is good, and the target product hexamethylenediamine can be obtained. US5900511A discloses that Raney cobalt is used for the hydrogenation of adiponitrile to prepare aminocapronitrile and hexamethylenediamine. Raney catalysts have high reaction activity, but are prone to spontaneous combustion, have poor mechanical properties, and are easily broken by interaction with agitators or liquids during the reaction, resulting in difficulties in subsequent processing.

[0004] Iron-based catalyst is also a common nitrile hydrogenation catalyst, the main active ingredient of which is iron oxide, with a mass fraction of more than 90%, and also contains some 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 an iron element with hydrogenation activity, which is generally used at a higher pressure level. US4587228A discloses a method for preparing an iron-based catalyst, which increases the strength and activity of the catalyst by hydrogenating lepidocrocite and adding graphite for tableting, thereby obtaining good nitrile hydrogenation performance.

[0005] In addition, another common nitrile hydrogenation catalyst is a noble metal supported catalyst. Due to the high price of noble metals, the mass fraction is generally controlled to be less than 5% in use, and the rest is mainly a carrier. CN1531459A discloses a Ru / SiO2 catalyst, the preparation method of which is to use SiO2 to absorb an aqueous solution of ruthenium nitrosyl nitrate, followed by drying and activation. Summary of the invention

[0006] The object of the present invention is to provide a method for preparing 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) 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.

[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 lanthanide series.

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

[0012] (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; 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 by elements, the molar ratio of active component M to auxiliary agent 1 is 1 to 10:1.

[0015] Calculated by elements, 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 additive 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 to 2000°C.

[0020] 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;

[0021] 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.

[0022] 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;

[0023] 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.

[0024] 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;

[0025] The mixing temperature of the two is 20 to 80°C, and the mixing time is 1 to 24 hours.

[0026] In one embodiment of the present invention, in step (4), the drying temperature is 50 to 250° C. and the drying time is 2 to 48 hours;

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

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

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

[0030] The second aspect of the present invention provides an adiponitrile hydrogenation catalyst prepared by any of the above methods, wherein, based on the dry weight of the catalyst and calculated as oxide, the content of active component M is 5 to 90 weight%, the content of auxiliary agent 1 is 0.1 to 30 weight%, and the content of auxiliary agent 2 is 5 to 80 weight%.

[0031] In one 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 %.

[0032] The third aspect of the present invention provides a method for hydrogenating adiponitrile 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 and the activated adiponitrile hydrogenation catalyst are contacted and reacted in the presence of hydrogen to obtain a reaction product containing hexamethylenediamine. The reaction conditions are: reaction temperature 60-200°C, reaction pressure 1-15MPa, and liquid hourly volume space velocity of adiponitrile 0.1-10h -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 can obtain a high active metal content adiponitrile hydrogenation catalyst. The preparation method is not limited by the loading amount, and the content of the active component can be freely adjusted, and the active component can reach 90% by weight (calculated based on the active metal component after activation on the catalyst dry basis).

[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 activity of the adiponitrile hydrogenation catalyst after activation is high.

[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 embodiments 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 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 on a 5 mL high pressure micro reactor, using the adiponitrile hydrogenation catalysts prepared in the example and the comparative example.

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

[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: the pressure was 2 MPa, the liquid hourly volume space velocity of the reaction raw material adiponitrile was 1.0 h -1 , the molar ratio of hydrogen to adiponitrile is 100, and the reaction temperature is 75°C. After the reaction is stable, the product composition is analyzed. The product is analyzed using a gas chromatograph (Agilent 7890A) to analyze the components of each substance in the product. According to the chromatographic signal-to-noise ratio, the lower limit of the chromatographic analysis is 10ppm.

[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) Take 19.91g of nickel acetate tetrahydrate and dissolve it in 400mL of a mixed solution of isooctanoic acid and ethanol (volume ratio of isooctanoic acid and ethanol is 1:1), stir for 1h at a temperature of 25°C to dissolve, 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 the oxygen dispersion gas is maintained at 5L / min. Using methane as a 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.

[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 in terms of oxides are shown in Table 1.

[0055] After activation and adiponitrile hydrogenation reaction of adiponitrile hydrogenation catalyst C1, 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, and the adiponitrile conversion rate was 62.53%, the selectivity of hexamethylenediamine was 2.45%, the selectivity of cyclohexylimine was 4.87%, the selectivity of aminocapronitrile was 54.49%, 2-diaminocyclohexane (DCH) and aminomethylcyclopentylamine (AMCPA) were not detected, and the selectivity of other heavy components (mainly dihexamethylenetriamine, the same below) was 38.19%; the total selectivity of the target products hexamethylenediamine and cyclohexylimine 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) Take 19.91g of nickel acetate tetrahydrate and dissolve it in 400mL of a mixed solution of isooctanoic acid and ethanol (volume ratio of isooctanoic acid and ethanol is 1:1), stir for 1h at a temperature of 25°C to dissolve, 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 the oxygen dispersion gas is maintained at 5L / min. Using methane as a 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.

[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) 3.75 g of magnesium nitrate hexahydrate, 5.43 g of cerium acetate monohydrate and 150 mL of deionized water were mixed and stirred 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] Based on the total amount of adiponitrile hydrogenated C2, the contents of the catalyst components in terms of oxides 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, and the adiponitrile conversion rate was 88.48%, the selectivity of hexamethylenediamine was 29.99%, the selectivity of cyclohexylimine 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 target products hexamethylenediamine and cyclohexylimine 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) 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, 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 the 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.

[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) 4.17 g of magnesium 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 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] Based on the total amount of adiponitrile hydrogenated C3, the contents of the catalyst components in terms of oxides are shown in Table 1.

[0075] After activation and adiponitrile hydrogenation reaction of adiponitrile hydrogenation catalyst C3, gas chromatography was used to analyze raw materials and products in the reaction solution, and the conversion rate of raw materials and product selectivity were calculated, and the adiponitrile conversion rate was 99.54%, the hexamethylenediamine selectivity was 89.41%, the cyclohexylimine selectivity was 10.59%, and aminocapronitrile, 2-diaminocyclohexane (DCH), aminomethylcyclopentylamine (AMCPA) and heavy components were not detected; the total selectivity of the target products hexamethylenediamine and cyclohexylimine 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) 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, 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 the 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.

[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) 3.12 g of magnesium nitrate hexahydrate, 1.24 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 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] Based on the total amount of adiponitrile hydrogenated C4, the contents of the catalyst components in terms of oxides are shown in Table 1.

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

[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) 4.15 g of magnesium nitrate hexahydrate, 4.94 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 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] Based on the total amount of adiponitrile hydrogenated C5, the contents of the catalyst components in terms of oxides are shown in Table 1.

[0095] After activation and adiponitrile hydrogenation reaction of adiponitrile hydrogenation catalyst C5, 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, and the adiponitrile conversion rate was 99.82%, the selectivity of hexamethylenediamine was 87.63%, the selectivity of cyclohexylimine was 11.24%, aminocapronitrile, 2-diaminocyclohexane (DCH) and aminomethylcyclopentylamine (AMCPA) were not detected, and the selectivity of other heavy components was 1.13%; the total selectivity of target products hexamethylenediamine and cyclohexylimine 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) Take 23.26g of nickel nitrate hexahydrate and dissolve it in 400mL of a mixed solution of isooctanoic acid and ethanol (volume ratio of isooctanoic acid and ethanol is 1:1), stir for 1h at a temperature of 25°C to dissolve, 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 the oxygen dispersion gas is maintained at 5L / min. Using methane as a 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.

[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 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 adiponitrile hydrogenated C6, the contents of the catalyst components in terms of oxides are shown in Table 1.

[0105] After activation and adiponitrile hydrogenation reaction of adiponitrile hydrogenation catalyst C6, gas chromatography is used to analyze raw materials and products in the reaction solution, and the conversion rate of raw materials and product selectivity are calculated, and the adiponitrile conversion rate is 90.42%, the hexamethylenediamine selectivity is 88.36%, the cyclohexylimine selectivity is 11.64%, and aminocapronitrile, 2-diaminocyclohexane (DCH), aminomethylcyclopentylamine (AMCPA) and heavy components are not detected; the total selectivity of the target products hexamethylenediamine and cyclohexylimine is 100%.

[0106] Comparative Example 1

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

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

[0109] (1) Take 22.79g of cerium isooctanoate and dissolve it in 400mL of a mixed solution of isooctanoic acid and ethanol (volume ratio of isooctanoic acid and ethanol is 1:1), stir for 1h at 25°C to dissolve, 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, cerium oxide particles are collected.

[0110] (2) 2.0 g of cerium oxide particles were mixed 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, thereby obtaining 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] Based on the total amount of adiponitrile hydrogenation D1, the contents of the catalyst components in terms of oxides 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, and the adiponitrile conversion rate was 63.73%, the selectivity of hexamethylenediamine was 34.65%, the selectivity of cyclohexylimine was 21.01%, the selectivity of aminocapronitrile was 43.52%, aminocapronitrile, 2-diaminocyclohexane (DCH) and aminomethylcyclopentylamine (AMCPA) were not detected, the selectivity of heavy components was 0.82%, and the total selectivity of target products hexamethylenediamine and cyclohexylimine 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 its application.

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

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

[0120] (2) Add 50 mL of 1.0 mol﹒ L -1 The sodium carbonate solution was filtered and washed to obtain a precipitate. 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] Based on the total amount of adiponitrile hydrogenated D2, the contents of the catalyst components in terms of oxides are shown in Table 1.

[0122] After activation and adiponitrile hydrogenation reaction of adiponitrile hydrogenation catalyst D2, 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, and the adiponitrile conversion rate was 99.24%, the selectivity of hexamethylenediamine was 49.26%, the selectivity of cyclohexylimine was 28.18%, the selectivity of aminocapronitrile was 21.68%, and 2-diaminocyclohexane (DCH) and aminomethylcyclopentylamine (AMCPA) were not detected, and the selectivity of heavy components was 0.88%; the total selectivity of target products hexamethylenediamine and cyclohexylimine 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 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; wherein: Based on the adiponitrile hydrogenation catalyst, the content of the active component M is 5 to 90% by weight, calculated as oxide. Calculated by elements, the molar ratio of active component M to auxiliary agent 1 is 1 to 10:

1. Calculated by elements, the molar ratio of the active component M to the auxiliary agent 2 is 0.1 to 50:

1.

2. The method according to claim 1, characterized in that 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, 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.

4. The method according to claim 3, 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.

5. The method according to claim 1, 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.

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

7. 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; Preferably, the drying temperature is 60 to 200° C., and the drying time is 4 to 24 hours.

8. The method according to claim 1, characterized in that In step (4), the calcination temperature is 260 to 1000° C. and the calcination time is 1 to 44 hours; Preferably, the calcination temperature is 300-800° C., and the calcination time is 2-10 hours.

9. An adiponitrile hydrogenation catalyst prepared by any method of claims 1-8, 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 5-90 weight %, the content of auxiliary agent 1 is 0.1-30 weight %, and the content of auxiliary agent 2 is 5-80 weight %.

10. The catalyst according to claim 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 of any one of claims 1 to 8, 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 and the activated adiponitrile hydrogenation catalyst are contacted and reacted in the presence of hydrogen 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 1-15MPa, and liquid hourly volume space velocity of adiponitrile 0.1-10h -1 , the molar ratio of hydrogen to adiponitrile is 50-500.

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