Process for the preparation of a hydrogenation catalyst from hexamethylene diamine key intermediate residues, hydrogenation catalyst and use

Abstract

The application provides a method for preparing a hydrogenation catalyst from a hexanediamine key intermediate residue, the hydrogenation catalyst and application, and the method comprises the following steps: (1) forming a solid mixture precursor of the hexanediamine key intermediate residue and a metal salt; (2) carbonizing the solid mixture precursor under a protective gas to obtain a carbon-coated hydrogenation catalyst. The application can solve the problem of low utilization rate of residue solid waste in the prior art, utilize organic residue solid to prepare a high-value-added hydrogenation catalyst, and use the hydrogenation catalyst in a downstream 6-aminocapronitrile hydrogenation process, so that the purposes of carbon reduction and pollution reduction can be achieved, the catalyst use cost of the hydrogenation process is reduced, and the economic competitiveness of a caprolactam method hexanediamine process is improved.

Description

Technical Field

[0001] This invention relates to the field of petrochemical technology, and in particular to a method for preparing a hydrogenation catalyst from hexamethylenediamine key intermediate residue, the hydrogenation catalyst, and its application. Background Technology

[0002] 1,6-Hexanediamine is an important monomer for the synthesis of nylon 66, 6T, 610, 612, etc., and is mainly used in the production of nylon materials and hexamethylene diisocyanate. 1,6-Hexanediamine can also be used as a chemical additive, primarily in aluminum composite panel adhesives, plastic stabilizers, polyamide resin inks, textile printing and dyeing color fixing, epoxy resin coating curing agents, oilfield demulsifiers, water treatment additives, and light stabilizers. The main synthetic methods for 1,6-Hexanediamine include the 1,4-butadiene hydrocyanation method, acrylonitrile electrolytic dimerization method, 1,6-adipic acid ammoniation and dehydration method, caprolactam ammoniation and dehydration method, 1,6-hexanediol ammoniation method, 1,6-adipic ester ammoniation method, and 1,6-hexanedialdehyde ammoniation method. Currently, the synthesis of hexamethylenediamine from key intermediates via caprolactam amination and dehydration has become a research hotspot. The main preparation process involves the catalytic synthesis of crude 6-aminohexanonitrile from caprolactam and ammonia under a high-temperature catalyst atmosphere. High-purity 6-aminohexanonitrile is then obtained through distillation purification, followed by hydrogenation to yield 1,6-hexamethylenediamine. However, polymerization reactions occur during the caprolactam amination and dehydration reaction and the purification of crude 6-aminohexanonitrile, generating residual solid waste. The treatment of this residual solid waste has become a significant challenge for industrial production.

[0003] CN11174877A discloses a method for the resource utilization of key intermediate residues of hexamethylenediamine. The method involves feeding the residue and water into a reaction vessel or fixed-bed reactor to carry out a depolymerization reaction, yielding 6-aminohexanonitrile and caprolactam. The advantage of this method is that it can recover 6-aminohexanonitrile and caprolactam from the residue, reducing production costs. However, the depolymerization process generates wastewater and waste residue, causing secondary pollution.

[0004] Therefore, it is necessary to develop new methods for the resource utilization of key intermediate residues of hexamethylenediamine. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for preparing a hydrogenation catalyst from hexamethylenediamine key intermediate residue, the hydrogenation catalyst itself, and its application. By preparing the hydrogenation catalyst from the hexamethylenediamine key intermediate residue, no additional waste is generated. The utilization rate of the hexamethylenediamine key intermediate residue is high, and the prepared hydrogenation catalyst has excellent performance. It can be applied in the hydrogenation process of amino nitriles, reducing the catalyst usage cost of the hydrogenation process and improving the economic competitiveness of the caprolactam-based hexamethylenediamine process.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for preparing a hydrogenation catalyst from hexamethylenediamine key intermediate residue, the method comprising the following steps:

[0008] (1) Hexamethylenediamine key intermediate residue and metal salt form a solid mixture precursor;

[0009] (2) The solid mixture precursor is carbonized under a protective gas to obtain a carbon-coated hydrogenation catalyst.

[0010] This invention utilizes the residue of a key intermediate of hexamethylenediamine as a carbon and nitrogen source to form a solid mixture precursor with a metal salt, followed by high-temperature carbonization. This process yields a highly efficient carbon-coated transition metal hydrogenation catalyst, enabling high-value utilization of the residue from the production of the key intermediate of hexamethylenediamine, thus avoiding simple incineration. Furthermore, the method of preparing the precursor by mixing first allows the key intermediate residue of hexamethylenediamine and the metal salt to bond together in the early stage, resulting in more uniform dispersion of the residue and the metal salt, and a more uniform carbon coating.

[0011] The carbon content of the hexamethylenediamine key intermediate residue in step (1) is 65% to 75%, for example, it can be 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74% or 75%, etc.

[0012] Preferably, the nitrogen content of the hexamethylenediamine key intermediate residue is 8% to 23%, for example, it can be 8%, 9%, 10%, 12%, 15%, 18%, 20%, 22% or 23%, etc.

[0013] Preferably, the groups of the hexamethylenediamine key intermediate residue include any one or a combination of at least two of amino, primary amine, secondary amine, tertiary amine, quaternary amine or amide, wherein typical but non-limiting combinations are combinations of amino and primary amine, combinations of secondary and primary amine, combinations of amino and secondary amine, and combinations of tertiary and primary amine.

[0014] Preferably, the metal element in the metal salt includes a transition metal.

[0015] Preferably, the transition metal includes any one or a combination of at least two of cobalt, iron, nickel, or copper, wherein typical but non-limiting combinations are combinations of cobalt and iron, combinations of nickel and iron, combinations of cobalt and nickel, combinations of copper and iron, and combinations of cobalt and copper.

[0016] Preferably, the metal salt is a soluble salt.

[0017] Preferably, the anion of the metal salt includes any one or a combination of at least two of nitrate, sulfate, acetate, or chloride ions, wherein typical but non-limiting combinations are combinations of nitrate and sulfate, nitrate and acetate, acetate and sulfate, chloride and sulfate, and nitrate and chloride, with nitrate and / or acetate being the most preferred. The present invention preferably uses nitrate and acetate, which can be completely decomposed at high temperatures, leaving virtually no residue in the catalyst and not affecting its performance.

[0018] Preferably, the solid mixture precursor comprises: mixing hexamethylenediamine key intermediate residue, metal salt and water, and drying to obtain the solid mixture precursor.

[0019] Preferably, the mass ratio of the hexamethylenediamine key intermediate residue, the metal salt, and water is 1:0.01-0.3:0-10, wherein the amount of metal salt can be, for example, 0.01, 0.02, 0.05, 0.08, 0.1, 0.12, 0.13, 0.15, 0.2, 0.22, 0.25, or 0.3; and the amount of water can be, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0020] In this invention, a low metal salt content results in fewer active metal components in the catalyst, leading to poor overall catalyst performance. Conversely, a high metal salt content makes it difficult for metal ions to be reduced to metal atoms, or the reduced metal components struggle to form a carbon-coated structure, resulting in low catalytic hydrogenation activity. Furthermore, during hydrogenation, non-metallic atomic metal components easily leach into the reaction solution, shortening the catalyst's lifespan and negatively impacting the reaction. A low water content leads to insufficient complexation between the metal salt and nitrogen-containing organic functional groups in the residue, resulting in poor uniformity of the metal component distribution in the prepared catalyst and low hydrogenation activity. A high water content requires a longer drying time, and the drying process involves partial hydrolysis of the residue into small molecules, increasing the loss of carbon and nitrogen elements during carbonization, further affecting the catalyst's catalytic hydrogenation activity.

[0021] Preferably, the mixing is carried out by stirring.

[0022] Preferably, the stirring rate is 100 to 800 r / min, for example, it can be 100 r / min, 170 r / min, 250 r / min, 330 r / min, 410 r / min, 480 r / min, 560 r / min, 640 r / min, 720 r / min or 800 r / min, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0023] Preferably, the stirring time is 2 to 12 hours, for example, 2 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours or 12 hours, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0024] Preferably, the drying temperature is 0 to 60°C, for example, it can be 0°C, 7°C, 14°C, 20°C, 27°C, 34°C, 40°C, 47°C, 54°C or 60°C, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0025] Preferably, the drying time is 6 to 72 hours, for example, it can be 6 hours, 14 hours, 21 hours, 28 hours, 36 hours, 43 hours, 50 hours, 58 hours, 65 hours or 72 hours, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0026] Preferably, the protective gas includes any one or a combination of at least two of N2, Ar, He or Kr, wherein typical but non-limiting combinations are combinations of N2 and Ar, He and Ar, N2 and He, Kr and Ar, N2 and Kr, and preferably Ar.

[0027] Preferably, the mass hourly space velocity of the protective gas is 1 to 100 h⁻¹. -1 For example, it could be 1 hour. -1 12h -1 23h -1 34h -1 45h -1 56h -1 67h -1 78h -1 89h -1 or 100h -1 This includes, but is not limited to, the listed values; other unlisted values ​​within this range also apply.

[0028] Preferably, the final carbonization temperature is 500 to 1000°C, for example, it can be 500°C, 550°C, 610°C, 660°C, 720°C, 770°C, 830°C, 880°C, 940°C or 1000°C, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0029] In this invention, when the carbonization temperature is low, it is not conducive to the full reduction and dispersion of metal ions, and the proportion of reduced active metal components is low, which is not conducive to the hydrogenation reaction. When the carbonization temperature is high, it will cause the agglomeration of metal nanoparticles, which will ultimately affect the catalytic hydrogenation reaction effect of the catalyst.

[0030] Preferably, the heating rate of the carbonization is 5 to 30 °C / min, for example, it can be 5 °C / min, 8 °C / min, 11 °C / min, 14 °C / min, 17 °C / min, 19 °C / min, 22 °C / min, 25 °C / min, 28 °C / min or 30 °C / min, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0031] In this invention, when the heating rate is low, the carbon layer formed on the surface of the metal active component has a small particle size and low porosity, resulting in poor hydrogenation performance of the catalyst; when the heating rate is high, the carbon layer formed on the surface of the metal active component has a large particle size, and the carbonization degree inside and outside the carbon layer is different, resulting in low catalyst activity.

[0032] Preferably, the carbonization is carried out at the final temperature for 1 to 24 hours, for example, 1 hour, 4 hours, 7 hours, 9 hours, 12 hours, 14 hours, 17 hours, 19 hours, 22 hours or 24 hours, but not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0033] In a second aspect, the present invention provides a carbon-coated hydrogenation catalyst, wherein the hydrogenation catalyst is prepared by the method described in the first aspect for preparing a hydrogenation catalyst from the residue of a key intermediate of hexamethylenediamine.

[0034] The carbon-coated hydrogenation catalyst provided by the second aspect of the present invention has excellent performance, high catalytic conversion rate and selectivity, and broad application prospects.

[0035] Preferably, the hydrogenation catalyst comprises an active component core, a carbon layer covering the outside of the active component core, and amorphous nitrogen doped with nitrogen.

[0036] In this invention, in addition to carbon coating the outer layer of metal nanoparticles, there is also a large amount of amorphous nitrogen-doped carbon, which forms a carrier for the coated metal particles, thereby improving the overall performance of the carbon-coated hydrogenation catalyst.

[0037] Preferably, the thickness of the carbon layer is 0.34 to 8.5 nm, for example, it can be 0.34 nm, 1.25 nm, 2.16 nm, 3.06 nm, 3.97 nm, 4.88 nm, 5.78 nm, 6.69 nm, 7.6 nm or 8.5 nm, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0038] Preferably, the particle size of the active component core is 1 to 100 nm, for example, it can be 1 nm, 12 nm, 23 nm, 34 nm, 45 nm, 56 nm, 67 nm, 78 nm, 89 nm or 100 nm, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0039] Preferably, the metal content in the carbon-coated hydrogenation catalyst is 0.2 to 5 wt%, for example, it can be 0.2 wt%, 0.8 wt%, 1.3 wt%, 1.8 wt%, 2.4 wt%, 2.9 wt%, 3.4 wt%, 4 wt%, 4.5 wt%, or 5 wt%, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0040] Preferably, the nitrogen content in the carbon-coated hydrogenation catalyst is 0.2 to 5 wt%, for example, it can be 0.2 wt%, 0.8 wt%, 1.3 wt%, 1.8 wt%, 2.4 wt%, 2.9 wt%, 3.4 wt%, 4 wt%, 4.5 wt%, or 5 wt%, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0041] Preferably, the carbon content in the carbon-coated hydrogenation catalyst is 85-98 wt%, for example, it can be 85 wt%, 87 wt%, 88 wt%, 90 wt%, 91 wt%, 93 wt%, 94 wt%, 96 wt%, 97 wt%, or 98 wt%, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0042] Preferably, the active component in the hydrogenation catalyst is a transition metal.

[0043] Preferably, the transition metal includes any one or a combination of at least two of cobalt, iron, nickel, or copper.

[0044] Thirdly, the present invention provides an application of the carbon-coated hydrogenation catalyst described in the second aspect in a hydrogenation reaction.

[0045] The carbon-coated hydrogenation catalyst described in the second aspect of this invention exhibits high conversion and selectivity in hydrogenation processes and has broad application prospects.

[0046] Preferably, the carbon-coated hydrogenation catalyst is used in the hydrogenation reaction of amino nitrile organic compounds to produce organic diamines.

[0047] Preferably, when the carbon-coated hydrogenation catalyst is used in the hydrogenation reaction of amino nitrile organic compounds to produce organic diamines, the catalytic hydrogenation process includes a batch reactor process, a fluidized bed process, or a moving bed process.

[0048] Preferably, when the carbon-coated hydrogenation catalyst is used in the hydrogenation reaction of amino nitrile organic compounds to produce organic diamines, the mass ratio of the catalyst to 6-aminohexanonitrile is 0.01 to 0.5:1, the reaction temperature is 100 to 180°C, the hydrogen pressure is 0.5 to 4 MPa, and the reaction time is 0.5 to 24 h.

[0049] Specifically, the mass ratio of catalyst to 6-aminohexanonitrile is 0.01 to 0.5:1, for example, it can be 0.01:1, 0.07:1, 0.12:1, 0.18:1, 0.23:1, 0.29:1, 0.34:1, 0.4:1, 0.45:1, or 0.5:1, but is not limited to the listed values; other unlisted values ​​within this range are also applicable. The reaction temperature is 100 to 180℃, for example, it can be 100℃, 109℃, 118℃, 127℃, 136℃, 145℃, 154℃, 163℃, 172℃, or 180℃, but is not limited to the listed values; other unlisted values ​​within this range are also applicable. The hydrogen pressure is 0.5–4 MPa, for example, 0.5 MPa, 0.9 MPa, 1.3 MPa, 1.7 MPa, 2.1 MPa, 2.5 MPa, 2.9 MPa, 3.3 MPa, 3.7 MPa, or 4 MPa, but is not limited to the listed values; other unlisted values ​​within this range are also applicable. The reaction time is 0.5–24 h, for example, 0.5 h, 3.2 h, 5.8 h, 8.4 h, 11 h, 13.6 h, 16.2 h, 18.8 h, 21.4 h, or 24 h, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0050] Compared with the prior art, the present invention has at least the following beneficial effects:

[0051] (1) The method for preparing hydrogenation catalyst from hexamethylenediamine key intermediate residue provided by the present invention can effectively solve the problem of low utilization rate of solid waste residue, and use organic residue to prepare high value-added hydrogenation catalyst, which can be used in the hydrogenation process of amino nitrile organic compounds, such as the downstream 6-aminohexanenitrile hydrogenation process.

[0052] (2) The method for preparing hydrogenation catalyst from hexamethylenediamine key intermediate residue provided by the present invention has a simple and quick preparation process, and does not generate wastewater or waste residue in the process. It can achieve the purpose of reducing carbon and pollution, reduce the catalyst usage cost of hydrogenation process, and improve the economic competitiveness of caprolactam hexamethylenediamine process.

[0053] (3) The carbon-coated catalyst provided by the present invention exhibits excellent catalytic activity and selectivity in hydrogenation processes. Under preferred conditions, it has a high conversion rate for organic nitriles, which is above 99.04%, and a selectivity for organic diamines, which is above 99.52%. Moreover, the obtained organic diamines have high purity, all above 99.973 wt%, and have broad application prospects. Attached Figure Description

[0054] Figure 1 This is a TEM image of the carbon-coated catalyst provided in Example 1 of the present invention. Detailed Implementation

[0055] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0056] Example 1

[0057] This embodiment provides a method for preparing a hydrogenation catalyst from hexamethylenediamine key intermediate residue, the method comprising the following steps:

[0058] (1) Mix hexamethylenediamine key intermediate residue (containing 68% carbon, 20% nitrogen, and also containing amino, primary amine, secondary amine, tertiary amine, quaternary amine and amide), nickel nitrate and water at a mass ratio of 1:0.2:5, stir at 600 r / min for 8 h to complete the mixing, and dry at 40 °C for 24 h to obtain the precursor of the solid mixture.

[0059] (2) The solid mixture precursor is placed in a tube furnace and argon gas is introduced as a protective gas with a mass hourly space velocity of 50 h⁻¹. -1 The temperature was increased to a final temperature of 800℃ at a heating rate of 15℃ / min and held at the final temperature for 20h for carbonization. After cooling to room temperature, the catalyst was ground to obtain a carbon-coated hydrogenation catalyst.

[0060] The carbon-coated hydrogenation catalyst prepared in this embodiment is as follows: Figure 1 As shown, from Figure 1 It can be seen that the catalyst prepared by the present invention has excellent performance, with an average particle size of about 16.0 nm and an outer layer coated with a carbon layer.

[0061] Examples 2-19 and Comparative Examples 1-2

[0062] Examples 2-19 and Comparative Examples 1-2 provide a method for preparing a hydrogenation catalyst. Except for adjusting relevant parameters or substances, the method is identical to that of Example 1 and will not be repeated here. See Table 1 for details.

[0063] Table 1

[0064]

[0065] Comparative Example 2 could not produce the relevant product. Test methods: The particle size of the catalyst was measured using a transmission electron microscope (TEM), and the average size of 100 randomly selected particles from the TEM image was taken. Elemental analysis was used to determine the carbon and nitrogen content, and ICP was used to determine the metal content.

[0066] Application method: The catalyst prepared above and 6-aminohexanonitrile were added to a high-pressure reactor at a mass ratio of 0.2:1. Hydrogen gas was introduced into the reactor to purge the air. Hydrogen gas was continued to be introduced until the pressure inside the reactor reached 4 MPa. Simultaneously, the reactor was heated to 120°C. The reaction time was 4 hours. After the hydrogenation reaction was completed, the reaction product was obtained. The reaction product was then subjected to distillation to obtain high-purity hexamethylenediamine. Calculate the conversion rate of 6-aminohexanonitrile, the selectivity of hexamethylenediamine, and the purity of hexamethylenediamine.

[0067] The test results of the above embodiments and comparative examples are shown in Table 2.

[0068] Table 2

[0069]

[0070]

[0071] "-" indicates that there is no relevant data.

[0072] Examples 20-27

[0073] The difference from Example 1 lies in the evaluation of the hydrogenation reaction under different hydrogenation conditions. The results are shown in Table 3.

[0074] Table 3

[0075]

[0076]

[0077] The following points can be observed from Tables 1 to 3:

[0078] (1) As can be seen from Examples 1-8 and Examples 20-27, the method for preparing hydrogenation catalyst from hexamethylenediamine key intermediate residue provided by the present invention can convert hexamethylenediamine key intermediate residue into a catalyst containing carbon, nitrogen and metal. Moreover, the catalyst has a small particle size, with the average core particle size of its active component being 1-100 nm. It has a high conversion rate for aminohexanonitrile, which is above 99.04%, and a selectivity for organic diamines, which is above 99.52%. Furthermore, the obtained organic diamines have high purity, all above 99.973 wt%. Moreover, as can be seen from Examples 28-29, the catalyst prepared by the present invention can be applied to the conversion of similar nitrile substances into organic diamines, all of which have excellent conversion rates and selectivity.

[0079] (2) As can be seen from the combined examples 1 and 9-10, the amount of water added in Example 1 was 5 parts, compared with 0.1 and 15 parts in Examples 9-10, respectively. In Example 1, a carbon-coated catalyst was obtained, and the conversion rate for aminohexanonitrile was as high as 99.97%. In Example 9, due to uneven mixing, it was difficult to obtain a carbon-coated catalyst product. The final product was a non-uniform distribution of carbon and metal, without forming a coating relationship. The conversion rates of the catalysts in Examples 9-10 for aminohexanonitrile were only 54.1% and 89.57%, respectively, and the yields of hexamethylenediamine were also significantly reduced. This shows that the present invention preferably controls the water content in the mixture to further improve the particle size of the metal core of the catalyst and its catalytic activity and selectivity. It can also be seen from Example 20 that dry mixing will lead to a non-uniform distribution of carbon and metal, making it difficult to form a good coating relationship.

[0080] (3) As can be seen from the combined examples 1 and 11-12, the amount of metal salt added in Example 1 is 0.2 parts, compared with 0.5 and 0.005 parts in Examples 11-12, respectively. The average particle size of the active component core in Example 1 is 16.0 nm, and the conversion rate for aminohexanonitrile is as high as 99.97%. In contrast, the average particle size of the active component core in Examples 11 and 12 is 0.8 nm and 187.3 nm, respectively. The conversion rates of the catalysts for aminohexanonitrile in Examples 11-12 are only 79.76% and 82.1%, respectively. The yields of hexamethylenediamine in both examples are also significantly reduced. This indicates that the present invention preferably controls the content of metal salt in the mixture to further improve the particle size of the metal core of the catalyst and its catalytic activity and selectivity.

[0081] (4) As can be seen from the combined results of Examples 1 and 13-14, the heating rate in Example 1 was 15℃ / min, compared with 2℃ / min and 45℃ / min in Examples 13-14, respectively. The average particle size of the active component core in Example 1 was 16.0 nm, and the conversion rate of aminohexanonitrile was as high as 99.97%. In contrast, the conversion rate of aminohexanonitrile and the yield of hexamethylenediamine in Examples 13 and 14 both decreased. This indicates that the present invention preferably controls the heating rate to further improve catalytic activity and selectivity.

[0082] (5) As can be seen from the combined results of Examples 1 and 15-16, the carbonization temperature in Example 1 is 800°C, compared with 350°C and 1200°C in Examples 15 and 16 respectively. The average particle size of the active component core in Example 1 is 16.0 nm, and the conversion rate for aminohexanonitrile is as high as 99.97%. In contrast, the average particle size of the active component core in Examples 15 and 16 is 8.5 nm and 87.4 nm respectively, and the conversion rates for aminohexanonitrile in Examples 15 and 16 are only 25.12% and 49.45% respectively. Furthermore, the yields of hexamethylenediamine in both examples are significantly reduced. This indicates that the present invention preferably controls the carbonization temperature to further improve the particle size of the metal core of the catalyst, as well as its catalytic activity and selectivity.

[0083] (6) It can be seen from the combined examples 1 and 17-19 that the metal salt selected in Example 1 is nickel nitrate. Compared with the metal salts selected in Examples 17-19, nickel sulfate, nickel chloride and palladium nitrate respectively, the catalytic performance of the catalyst obtained in Example 1 is better than that in Examples 17-19. This shows that the preferred use of specific metal salts in the present invention can further improve catalytic activity and selectivity.

[0084] (7) As can be seen from the combined results of Example 1 and Comparative Example 1, the use of hexamethylenediamine key intermediate residue in Example 1 provides both nitrogen and carbon sources. Compared with the use of glucose as carbon source in Comparative Example 1, the particle size of the active component obtained in Example 1 is 16.0 nm and the coating is uniform, resulting in a catalyst with significantly better catalytic performance.

[0085] The present invention has been illustrated with the above embodiments to illustrate its detailed structural features. However, the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the components used in the present invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A process for the preparation of a hydrogenation catalyst for aminonitrile organic compounds from residues of hexamethylenediamine key intermediates, characterized in that, The method comprises the following steps: (1) mixing hexamethylene diamine key intermediate residue, metal salt and water, and drying to obtain a solid mixture precursor; (2) carbonizing the solid mixture precursor under a protective gas to obtain a carbon-coated hydrogenation catalyst, wherein the heating rate of the carbonization is 5-30 ℃ / min, and the final temperature of the carbonization is 500-1000 ℃; The groups of the hexamethylene diamine key intermediate residue include any one or a combination of at least two of primary amine, secondary amine, tertiary amine or amide; The metal element in the metal salt includes a transition metal; the transition metal includes any one or a combination of at least two of cobalt, iron, nickel or copper; The mass ratio of the hexamethylene diamine key intermediate residue, the metal salt and the water is 1:0.01-0.3:1-10.

2. The method of claim 1, wherein, The carbon content of the hexamethylene diamine key intermediate residue in step (1) is 65-75%.

3. The method of claim 1, wherein, The nitrogen content of the hexamethylene diamine key intermediate residue is 8-23%.

4. The method of claim 1, wherein, The metal salt is a soluble salt.

5. The method of claim 1, wherein, The anion of the metal salt includes any one or a combination of at least two of nitrate, sulfate, acetate or chloride.

6. The method of claim 1, wherein, The mixing is performed under stirring.

7. The method of claim 6, wherein, The stirring rate is 100-800 r / min.

8. The method of claim 6, wherein, The stirring time is 2-12 h.

9. The method of claim 1, wherein, The drying temperature is 0-60 ℃.

10. The method of claim 1, wherein, The drying time is 6-72 h.

11. The method of claim 1, wherein, The protective gas includes any one or a combination of at least two of N2, Ar, He or Kr.

12. The method of claim 11, wherein, The protective gas is Ar.

13. The method of claim 1, wherein, The mass space velocity of the protective gas is 1-100 h -1 .

14. The method of claim 1, wherein, The carbonization is kept at the final temperature for 1-24 h.

15. A carbon-coated hydrogenation catalyst, characterized by comprising: The carbon-coated hydrogenation catalyst is prepared by the method for preparing an aminonitrile organic matter hydrogenation catalyst from hexamethylene diamine key intermediate residue according to any one of claims 1-14.

16. The carbon-coated hydrogenation catalyst according to claim 15, wherein The carbon-coated hydrogenation catalyst comprises an active component core, a carbon layer coated outside the active component core and amorphous nitrogen-doped carbon.

17. The carbon-coated hydrogenation catalyst according to claim 16, wherein The thickness of the carbon layer is 0.34-8.5 nm.

18. The carbon-coated hydrogenation catalyst according to claim 16, wherein The particle size of the active component core is 1-100 nm.

19. The carbon-coated hydrogenation catalyst according to claim 16, wherein The metal content in the carbon-coated hydrogenation catalyst is 0.2-5 wt%.

20. The carbon-coated hydrogenation catalyst according to claim 16, wherein The nitrogen content in the carbon-coated hydrogenation catalyst is 0.2-5 wt%.

21. The carbon-coated hydrogenation catalyst according to claim 16, wherein The carbon content in the carbon-coated hydrogenation catalyst is 85-98 wt%.

22. Use of the carbon-coated hydrogenation catalyst according to any one of claims 15-21 in an aminonitrile organic matter hydrogenation reaction to prepare an organic diamine.

Images