Adsorbent and method for preparing the same, method for purifying hexamethylenediamine, method for preparing organic diamine, and apparatus used therefor

Abstract

The present invention provides an adsorbent and its preparation method, a method for purifying hexamethylenediamine, a method for preparing organic diamines, and an apparatus for use. The adsorbent includes a carrier and surface molecules supported on the carrier, and an imprint cavity is formed between the surface molecules, and the imprint cavity matches with azepine compounds. The preparation process of the adsorbent is short, suitable for industrial production, and the adsorbent has a specific adsorption effect on azepine compounds, which can be suitably applied to the adsorption and separation of trace impurities in hexamethylenediamine, and the product purity of hexamethylenediamine is significantly improved.

Description

Cross - reference to related applications

[0001] This application is based on and claims priority to a Chinese application with CN application number 202110881293.9 and filing date August 2, 2021, and a Chinese application with CN application number 202110882630.6 and filing date August 2, 2021. The disclosure content of the CN application is hereby incorporated by reference into this application in its entirety again.

Technical Field

[0002] The present invention relates to the field of organic chemistry, and specifically relates to an adsorbent and its preparation method, a method for purifying hexamethylenediamine, a method for preparing organic diamine, and the apparatus used.

Background Art

[0003] As one of the top five engineering plastics, nylon 66 has extremely wide applications in the fields of machinery and electrical appliances, and is mainly applied to gears, bearings, electronic and electrical appliances, automotive parts, etc. Nylon 66 not only has the characteristics of high mechanical strength, high toughness, and excellent wear resistance compared with other general - purpose plastics, but also has excellent properties such as self - lubricity, flame retardancy, non - toxicity, and environmental friendliness. Nylon 66 is a thermoplastic polymer, a polycrystalline semi - crystalline polymer, and is a kind of polyamide obtained by polycondensation of adipic acid and hexamethylenediamine.

[0004] Hexamethylenediamine is an important intermediate for producing nylon 66 and an important chemical raw material. The purity of hexamethylenediamine greatly affects the product quality of nylon 66, and the high - molecular polycondensation reaction has high requirements for the purity of raw materials. The synthesis methods of hexamethylenediamine mainly include the caprolactam method, adiponitrile method, and hexylene glycol method. None of these methods can avoid purifying hexamethylenediamine by rectification. In the rectification process, hexamethylenediamine undergoes side reactions to produce 3,4,5,6 - tetrahydro - 2H - azepine, and it is difficult to completely remove such impurities by the rectification process.

[0005] CN103936595A discloses a method for purifying crude hexamethylenediamine. The purification method employs fractional distillation in a column to obtain hexamethylenediamine with a content of 99.99%. However, this method has low separation efficiency and high energy consumption.

[0006] CN101939286A discloses a method for purifying hexamethylenediamine. The purification method separates tetrahydroheptane present in hexamethylenediamine by distillation. However, this method does not relate to the separation of 3,4,5,6 - tetrahydro - 2H - azepine in the fractional distillation process, and the separation efficiency of this method decreases.

[0007] CN106810455A discloses a method for producing high - quality finished hexamethylenediamine. The method can obtain high - quality finished hexamethylenediamine by distilling and purifying semi - finished hexamethylenediamine multiple times. By adopting vacuum fractional distillation technology, dehydration, removal of light components, and removal of heavy components are carried out under vacuum conditions according to the boiling points of impurities in semi - finished hexamethylenediamine, and finally, hexamethylenediamine with a purity of ≧99.9% can be obtained. However, this method still has low purity and may have high energy consumption.

[0008] Therefore, there is a need for a mild production method that can remove 3,4,5,6 - tetrahydro - 2H - azepine in the crude hexamethylenediamine product and meet the requirement of producing nylon 66 by downstream polycondensation.

Summary of the Invention

Problems to be Solved by the Invention

[0009] The main object of the present invention is to provide an adsorbent and its preparation method, a method for purifying hexamethylenediamine, a method for preparing organic diamine, and the apparatus used, in order to solve the problems in the prior art of producing caprolactam with many by - products and poor economic effects.

Means for Solving the Problems

[0010] According to one aspect of the present invention, in order to achieve the above object, an adsorbent is provided which includes a carrier and surface molecules supported on the carrier, the surface molecules are molecularly imprinted polymers, an imprint cavity is formed between the surface molecules, and the adsorbent is surface molecule imprint-functionalized such that the imprint cavity matches an azepine compound.

[0011] According to one aspect of the present invention, in order to achieve the above object, a method for preparing the surface molecule imprint-functionalized adsorbent is provided. The preparation method includes: (1) a step of pre-polymerizing a functional monomer and an azepine compound template to obtain a pre-polymerization reaction material; (2) a step of polymerizing the pre-polymerization reaction material with a carrier, a cross-linking agent, and an initiator to obtain polymer particles; and (3) a step of removing the azepine compound template from the polymer particles to obtain the surface molecule imprint-functionalized adsorbent.

[0012] According to another aspect of the present invention, use of the surface molecule imprint-functionalized adsorbent is provided, and the adsorbent is applied to the separation of azepine compounds, preferably to the removal of azepine compound impurities.

[0013] According to another aspect of the present invention, a method for purifying hexamethylenediamine is provided, in which impurity adsorption separation is performed using the surface molecule imprint-functionalized adsorbent.

[0014] According to a further aspect of the present invention, a method for producing an organic diamine is provided, which includes: a step of performing a hydrogenation reaction on an aminonitrile-based organic substance and hydrogen gas under the action of a hydrogenation catalyst to obtain a post-reaction material containing the organic diamine; and a step of obtaining the organic diamine after the post-reaction material undergoes a second purification and a second adsorption, where the second adsorption employs the surface molecule imprint-functionalized adsorbent and the second purification is a second rectification treatment.

[0015] According to a further aspect of the present invention, there is provided an apparatus used in the method for preparing the above-mentioned organic diamine, the apparatus including a vaporization unit, an ammoniation reaction unit, a first purification unit, a first adsorption unit, a hydrogenation reaction unit, a second purification unit, and a second adsorption unit, which are connected in sequence.

Advantages of the Invention

[0016] By applying the technical solution of the present invention, the adsorbent provided by the present invention has an imprint cavity that matches the azepine compound, so it can specifically adsorb the azepine compound and has an excellent selective separation effect in the separation process of the azepine compound.

Brief Description of the Drawings

[0017] The drawings forming a part of this application are for providing a further understanding of the present invention. The schematic embodiments and their descriptions of the present invention are for interpreting the present invention and do not unduly limit the present invention. The drawings are as follows.

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Figure 11

[0018] In the figure: 1 - main body; 2 - protrusion; 3 - second type of pore channel; 10 - vaporization unit; 101 - converging section; 102 - throat section; 103 - diverging section; 104 - first inlet; 105 - first gas outlet; 106 - material conveying device; 20 - ammoniation reaction unit; 30 - first purification unit; 40 - first adsorption unit; 50 - hydrogenation reaction unit; 501 - first heating device; 502 - tubular reactor; 503 - heating member; 504 - third inlet; 505 - first outlet; 506 - fourth inlet; 507 - hydrogen gas inlet; 508 - catalyst inlet; 509 - Helmholtz coil; 5010 - exhaust gas outlet; 5011 - product outlet; 5012 - catalyst outlet; 60 - second purification unit; 70 - second adsorption unit.

Mode for Carrying Out the Invention

[0019] In addition, when there is no contradiction, the examples in this application and the features in the examples can be combined with each other. Hereinafter, the present invention will be described in detail with reference to the drawings by way of examples.

[0020] According to a first aspect, the present invention provides an adsorbent functionalized with surface molecular imprinting. The adsorbent includes a carrier and surface molecules supported on the carrier. The surface molecules are molecularly imprinted polymers, and imprinted cavities are formed between the surface molecules, and the imprinted cavities match an azepine compound.

[0021] Since the adsorbent provided by the present invention has imprinted cavities that match an azepine compound, it can specifically adsorb the azepine compound and has an excellent selective separation effect in the separation process of the azepine compound.

[0022] Preferably, the surface molecule can form a weak chemical bond with the azepine compound. Preferably, the weak chemical bond includes a hydrogen bond. Since the surface molecule of the present invention can form a weak chemical bond such as a hydrogen bond with the azepine compound, it can specifically adsorb to the azepine compound, reducing the difficulty of separation from other substances.

[0023] Preferably, the imprinted cavity matches the molecular space, shape, and groups of the azepine compound. Thereby, biospecific adsorption similar to antibody-antigen is realized, and selective adsorption of trace or trace amounts of azepine compounds is realized.

[0024] Preferably, the carrier includes any one or at least two combinations of aluminum oxide, silica, activated carbon, ZSM-5 molecular sieve, or montmorillonite. Typical but non-limiting combinations thereof are combinations of aluminum oxide and activated carbon, combinations of silica and ZSM-5 molecular sieve, combinations of aluminum oxide and silica, combinations of activated carbon and ZSM-5 molecular sieve, and preferably aluminum oxide. Since the above carrier has a porous structure and a large specific surface area, it provides sufficient loading sites for loading surface molecules and can improve its loading amount.

[0025] Preferably, the particle size of the adsorbent is 50 nm to 5 μm, and may be, for example, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 500 nm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, or 5 μm.

[0026] Preferably, the specific surface area of the adsorbent is 100 to 1000 m 2 / g, for example, 100 m 2 / g, 200 m 2 / g, 300 m 2 / g, 400 m 2 / g, 500 m 2 / g, 600 m 2 / g, 700 m 2 / g, 800 m2 / g, 900 m 2 / g or 1000 m 2 / g etc. may also be used.

[0027] Preferably, the azepine compound is selected from 3,4,5,6 - tetrahydro - 2H - azepine.

[0028] Preferably, the carrier is a carrier having an amino group supported thereon, that is, a carrier modified with amino. The carrier modified with amino may be a known carrier in the prior art or a carrier obtained by a known modification method in the prior art, or may be a carrier obtained by the method described below in the present application.

[0029] The present invention further preferably relates to a carrier having an amino group supported thereon. The amino group on the surface of the carrier can be well - bonded to a cross - linker to link surface molecules, making the performance of the adsorbent more stable.

[0030] Preferably, the surface molecules include a so - called molecularly imprinted polymer obtained by polymerizing a functional monomer, a cross - linker, and an azepine compound and then removing the polymerized molecules of the azepine compound.

[0031] The surface molecules of the present invention are realized by one kind of surface molecular imprinting. First, the azepine compound is polymerized and then removed to empty the imprint cavities between the surface molecules, improving the specificity of adsorption.

[0032] In some embodiments of the present application, the functional monomer is selected from amines and / or pyridines, and includes any one or at least a combination of two of acrylamide, o-phenylenediamine or 2-vinylpyridine. Its typical but non-limiting combinations are the combination of acrylamide and o-phenylenediamine, the combination of 2-vinylpyridine and o-phenylenediamine, the combination of acrylamide and 2-vinylpyridine, and the combination of acrylamide, o-phenylenediamine and 2-vinylpyridine. Both the above functional monomer and the azepine compound contain N atoms, and the N atoms have lone pairs of electrons. In the prepolymerization process, the N atoms in the functional monomer and the azepine compound can form intermolecular hydrogen bonds with the H atoms of each other, and based on the characteristics of the connection by hydrogen bonds, it is convenient to remove the azepine compound subsequently.

[0033] In some embodiments of the present application, the cross-linking agent includes any one or at least a combination of two of ethylene glycol diglycidyl ether, ethylene glycol dimethacrylate or N,N-methylenebisacrylamide. Its typical but non-limiting combinations are the combination of ethylene glycol diglycidyl ether and ethylene glycol dimethacrylate, the combination of ethylene glycol dimethacrylate and N,N-methylenebisacrylamide, and the combination of ethylene glycol diglycidyl ether and N,N-methylenebisacrylamide.

[0034] According to a second aspect, the present invention provides a method for preparing a surface molecular imprinted functionalized adsorbent according to the first aspect. The preparation method includes

[0035] (1) Prepolymerizing a functional monomer and an azepine compound template to obtain a prepolymerization reaction material;

[0036] (2) Reacting the prepolymerization reaction material with a carrier, a cross-linking agent and an initiator to obtain polymer particles;

[0037] (3) After removing the azepine compound template, the polymer particles are surface molecule imprinted and functionalized to obtain an adsorbent.

[0038] According to the method for producing an adsorbent provided in the second aspect of the present invention, first, after pre-polymerizing an azepine compound template and a functional monomer, they are reacted with a cross-linking agent and a carrier and supported on the carrier. Finally, by removing the template molecules therein, an imprint cavity matching the azepine compound template is left between the surface molecules supported on the surface of the carrier, giving the adsorbent specific adsorption performance for the azepine compound when used, and providing an excellent adsorbent by separating the azepine compound template. And the present invention can better ensure the bonding between the azepine compound template and the functional monomer by the method of first pre-polymerizing the azepine compound template and the functional monomer with weak chemical bonds such as hydrogen bonds and then polymerizing, avoiding the adverse reaction between the azepine compound template and the cross-linking agent, and ensuring the matching property between the imprint cavity and the molecules of the azepine compound.

[0039] Preferably, the azepine compound template in step (1) is selected from 3,4,5,6-tetrahydro-2H-azepine. The present invention preferably selects a template for specific impurities in hexamethylenediamine products. The nitrogen-containing group therein can form weak chemical bonds such as hydrogen bonds with the functional monomer, and then the 3,4,5,6-tetrahydro-2H-azepine template can be removed in a relatively mild manner, thereby obtaining an adsorbent having an imprint cavity matching it.

[0040] Preferably, the molar ratio of the functional monomer to the azepine compound template is 1 to 6:1, and may be, for example, 1:1, 1.6:1, 2.2:1, 2.7:1, 3.3:1, 3.8:1, 4.4:1, 4.9:1, 5.5:1 or 6:1, etc., but is not limited to the listed values, and other values not listed in this range are equally applicable.

[0041] In some embodiments, the preliminary polymerization is carried out in a first organic solvent. Preferably, the first organic solvent is alcohols such as methanol, ethanol or propanol, preferably including ethanol. It can achieve sufficient dispersion of the functional monomer and the azepine compound, improve the mass transfer efficiency of both, and further improve the preliminary polymerization efficiency.

[0042] Preferably, the ratio of the azepine compound template to the first organic solvent is 0.5 - 10 g:1 L, for example, it may be 0.5 g:1 L, 1.0 g:1 L, 2.0 g:1 L, 3.0 g:1 L, 4.0 g:1 L, 5.0 g:1 L, 6.5 g:1 L, 7.0 g:1 L, 9.0 g:1 L or 10 g:1 L, etc., but it is not limited to the listed values, and other values not listed in this range are equally applicable.

[0043] Preferably, the reaction temperature of the preliminary polymerization is 10 - 40 °C, for example, it may be 10 °C, 14 °C, 17 °C, 20 °C, 24 °C, 27 °C, 30 °C, 34 °C, 37 °C or 40 °C, etc., but it is not limited to the listed values, and other values not listed in this range are equally applicable, and preferably it is room temperature.

[0044] Preferably, the preliminary polymerization is carried out under stirring conditions. The stirring method in the present invention is not particularly limited, and any method commonly known to those skilled in the art and can be used for stirring can be adopted, and it may be adjusted according to the actual process. For example, it may be magnetic stirring or paddle stirring, etc.

[0045] Preferably, the reaction time of the preliminary polymerization is 1 - 20 h, for example, it may be 1 h, 4 h, 6 h, 8 h, 10 h, 12 h, 14 h, 16 h, 18 h or 20 h, etc., but it is not limited to the listed values, and other values not listed in this range are equally applicable.

[0046] Preferably, in step (2), the ratio of the carrier to the first organic solvent is 5-30 g:1 L, for example, it may be 5 g:1 L, 8 g:1 L, 11 g:1 L, 14 g:1 L, 17 g:1 L, 19 g:1 L, 22 g:1 L, 25 g:1 L, 28 g:1 L or 30 g:1 L, etc., but it is not limited to the listed values, and other values not listed in this range are equally applicable. By controlling the ratio of the carrier to the first organic solvent, sufficient dispersion in the prepolymerization reaction material of the carrier is realized, and sufficient loading space for prepolymerization is provided.

[0047] Preferably, the molar ratio of the crosslinking agent to the azepine-based compound template is 18-22:1, for example, it may be 18.0:1, 18.5:1, 19.0:1, 19.4:1, 19.8:1, 20.0:1, 20.5:1, 21.0:1, 21.5:1 or 22:1, etc., but it is not limited to the listed values, and other values not listed in this range are equally applicable.

[0048] Preferably, the ratio of the initiator to the first organic solvent is 0.1-1 g:1 L, for example, it may be 0.1 g:1 L, 0.2 g:1 L, 0.3 g:1 L, 0.4 g:1 L, 0.5 g:1 L, 0.6 g:1 L, 0.7 g:1 L, 0.8 g:1 L, 0.9 g:1 L or 1 g:1 L, etc., but it is not limited to the listed values, and other values not listed in this range are equally applicable.

[0049] Preferably, the initiator contains azobisisobutyronitrile and / or ammonium persulfate.

[0050] Preferably, the temperature of the polymerization reaction is 40-80 °C, for example, it may be 40 °C, 45 °C, 49 °C, 54 °C, 58 °C, 63 °C, 67 °C, 72 °C, 76 °C or 80 °C, etc., but it is not limited to the listed values, and other values not listed in this range are equally applicable.

[0051] Preferably, the polymerization reaction time is 10 to 48 h, for example, it may be 10 h, 15 h, 19 h, 23 h, 27 h, 32 h, 36 h, 40 h, 44 h, or 48 h, etc., but it is not limited to the listed values, and other values not listed in this range are equally applicable.

[0052] Preferably, the polymerization reaction includes first mixing a prepolymerization reaction material and a carrier, performing a first dispersion, and then adding a crosslinking agent and an initiator to carry out the polymerization reaction.

[0053] Preferably, the first dispersion includes ultrasonic dispersion. Preferably, the time of the first dispersion is 10 to 60 min, for example, it may be 10 min, 16 min, 22 min, 27 min, 33 min, 38 min, 44 min, 49 min, 55 min, or 60 min, etc., but it is not limited to the listed values, and other values not listed in this range are equally applicable.

[0054] Preferably, after the first dispersion, a crosslinking agent and an initiator are further added in a first protective atmosphere.

[0055] Preferably, the first protective atmosphere includes any one or at least a combination of two of nitrogen gas, helium gas, or argon gas. Its typical but non-limiting combinations are the combination of nitrogen gas and helium gas, the combination of argon gas and helium gas, and the combination of nitrogen gas and argon gas.

[0056] Preferably, the method for removing the azepine-based compound template includes any one of solvent washing extraction, solid-phase extraction, supercritical extraction, gas purge, or Soxhlet extraction.

[0057] Preferably, in step (3), the step of removing the azepine-based compound template includes extracting the azepine-based compound template in the polymer particles by using a mixed acid solution. Preferably, the extraction includes Soxhlet extraction.

[0058] Preferably, the mixed acid solution contains formic acid and acetic acid. Preferably, the volume ratio of formic acid to acetic acid is 5 to 10:1, and may be, for example, 5.0:1, 5.5:1, 6.0:1, 7.0:1, 7.3:1, 7.5:1, 8.0:1, 8.5:1, 9.5:1 or 10:1, etc., but is not limited to the listed values, and other values not listed in this range are equally applicable, and preferably 8:1. It has a better solvent removal effect.

[0059] Preferably, it includes the first drying after removing the azepine compound template. Preferably, the temperature of the first drying is 40 to 100 °C, and may be, for example, 40 °C, 47 °C, 54 °C, 60 °C, 67 °C, 74 °C, 80 °C, 87 °C, 94 °C or 100 °C, etc., but is not limited to the listed values, and other values not listed in this range are equally applicable.

[0060] Preferably, after the carrier is modified, it is added to step (2). Preferably, the method for modifying the carrier includes mixing the starting carrier, the second organic solvent, and the amino group-containing organic substance, performing a modification reaction, and sequentially subjecting the obtained modification reaction product to solid-liquid separation, washing, and the second drying to obtain a modified carrier.

[0061] The solid-liquid separation method in the present invention is not particularly limited, and any method commonly known to those skilled in the art and can be used for solid-liquid separation can be adopted, such as filtration, sedimentation separation, or centrifugal separation, etc.

[0062] Preferably, the starting carrier includes any one or at least two combinations of aluminum oxide, silica, activated carbon, ZSM-5 molecular sieve, or montmorillonite, aluminum, or silicon. Its typical but non-limiting combinations are the combination of aluminum oxide and aluminum, the combination of silica and aluminum, the combination of aluminum oxide and silica, the combination of silicon and aluminum, the combination of aluminum oxide and silicon, and preferably aluminum oxide.

[0063] Preferably, the second organic solvent contains toluene.

[0064] Preferably, the amino group-containing organic substance contains an aminosilane, preferably 3-aminopropyltriethoxysilane.

[0065] Preferably, the temperature of the modification reaction is 80 to 100 °C, for example, it may be 80 °C, 83 °C, 85 °C, 87 °C, 89 °C, 92 °C, 94 °C, 96 °C, 98 °C or 100 °C, etc., but it is not limited to the listed values, and other values not listed in this range are equally applicable.

[0066] Preferably, the mass ratio of the amino group-containing organic substance to the starting carrier is 1 to 10:1, for example, it may be 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1, etc., but it is not limited to the listed values, and other values not listed in this range are equally applicable.

[0067] Preferably, the ratio of the starting carrier to the second organic solvent is 15 to 30 g:1 L, for example, it may be 15 g:1 L, 17 g:1 L, 19 g:1 L, 20 g:1 L, 22 g:1 L, 24 g:1 L, 25 g:1 L, 27 g:1 L, 29 g:1 L or 30 g:1 L, etc., but it is not limited to the listed values, and other values not listed in this range are equally applicable.

[0068] In some embodiments, the above order of mixing the starting carrier, the second organic solvent, and the amino group-containing organic substance includes first mixing the starting carrier and the second organic solvent, and after the second dispersion, further adding the amino group-containing organic substance.

[0069] Preferably, the addition method of the amino group-containing organic substance is dropping. It is preferable to adopt the dropping method, which can better improve the uniformity of the modification and improve the adsorption effect of the final adsorbent.

[0070] Preferably, the second dispersion is ultrasonic dispersion.

[0071] The present invention does not have special requirements for the power of ultrasonic dispersion for the first dispersion and the second dispersion, and can be adjusted according to the actual process, and may be, for example, 200W, 300W, 400W, 500W, 550W, 600W or 700W.

[0072] Preferably, the time of the second dispersion is 10 to 60 minutes, and may be, for example, 10 minutes, 16 minutes, 20 minutes, 27 minutes, 30 minutes, 38 minutes, 40 minutes, 45 minutes, 55 minutes or 60 minutes, etc., but is not limited to the listed values, and other values not listed in this range are equally applicable.

[0073] Preferably, after the second dispersion, an amino group-containing organic substance is added under the second protective atmosphere.

[0074] Preferably, the second protective atmosphere contains any one or at least a combination of two of nitrogen gas, argon gas or helium gas, and its typical but non-limiting combinations are the combination of nitrogen gas and argon gas, the combination of helium gas and argon gas, and the combination of nitrogen gas and helium gas.

[0075] Preferably, the washing includes toluene washing and methanol washing performed sequentially to remove amino group-containing organic substances or other small molecules that did not succeed in grafting in the modification process. Preferably, the number of times of toluene washing is at least three times, and may be, for example, 3 times, 4 times, 5 times, 6 times or 8 times, etc.

[0076] Preferably, the number of times of methanol washing is at least three times, and may be, for example, 3 times, 4 times, 5 times, 6 times or 8 times, etc.

[0077] Preferably, the temperature of the second drying is 40 to 100 °C, and may be, for example, 40 °C, 47 °C, 54 °C, 60 °C, 67 °C, 74 °C, 80 °C, 87 °C, 94 °C or 100 °C, etc., but is not limited to the listed values, and other values not listed in this range are equally applicable.

[0078] The methods of the first drying and the second drying in the present invention are not particularly limited, and any method commonly known to those skilled in the art and can be used for drying can be adopted. For example, it may be vacuum drying or air blowing drying, etc., and preferably it is vacuum drying.

[0079] As a preferred technical solution of the present invention, the preparation method is (1) Carry out preliminary polymerization at 10 - 40°C for 1 - 20 h in a first organic solvent with a functional monomer and an azepine compound template in a molar ratio of 1 - 6:1. The ratio of the azepine compound template to the first organic solvent is 0.5 - 10 g:1 L, to obtain a preliminary polymerization reaction material; (2) First, mix the preliminary polymerization reaction material and a modified carrier. The ratio of the modified carrier to the first organic solvent is 5 - 30 g:1 L. After the first dispersion, add a cross-linking agent and an initiator in a first protective atmosphere. The molar ratio of the cross-linking agent to the azepine compound template is 18 - 22:1, and the ratio of the initiator to the first organic solvent is 0.1 - 1 g:1 L. Carry out a polymerization reaction at 40 - 80°C for 10 - 48 h to obtain polymer particles;

[0080] (3) Use a mixed acid solution of formic acid and acetic acid with a volume ratio of 5 - 10:1 to extract the azepine compound template in the polymer particles to obtain a surface molecularly imprinted functionalized adsorbent.

[0081] According to a third aspect, the present invention provides the use of a surface molecularly imprinted functionalized adsorbent according to the first aspect. The adsorbent is used for separating azepine compounds, and preferably, it is used for removing impurities of azepine compounds.

[0082] The adsorbent according to the first aspect of the present invention can specifically adsorb azepine compounds, has strong adsorption selectivity, and has relatively obvious property differences compared with other non-analogous substances. Therefore, it is particularly suitable for removing trace amounts of impurities of azepine compounds and trace amounts of impurities of azepine compounds, and has the advantages of lower energy consumption and higher removal efficiency than other methods.

[0083] The trace amount in the present invention means that the content of the azepine compound is < 0.01%, and the trace amount means that the content of the azepine compound is 0.01 - 1%.

[0084] According to a fourth aspect, the present invention provides a method for purifying hexamethylenediamine, which employs the adsorbent surface molecule imprint functionalized in the first aspect to perform adsorption separation of impurities.

[0085] In the method for purifying hexamethylenediamine provided in the fourth aspect of the present invention, by-products such as azepine compounds are generated in the conventional hexamethylenediamine purification and production processes. However, it is difficult to remove the azepine compounds by rectification, and even after preliminary purification, impurities of azepine compounds still remain. In view of this, the inventor has developed a method for purifying hexamethylenediamine by adsorption separation through extensive exploration. The method of the present invention has the following two inventive points. (1) Although both hexamethylenediamine and azepine compounds are organic substances and both have polar groups, the inventors can still separate the impurities and hexamethylenediamine by adsorption from conventional separation methods such as rectification, adsorption, filtration, extraction, and membrane separation. (2) It has been discovered that conventional adsorbents also have a high adsorption effect on hexamethylenediamine, so it is difficult to achieve selective adsorption of azepine compounds. The surface molecule imprint functionalized adsorbent of the first aspect is selected, which not only specifically adsorbs azepine compounds but also has a relatively low adsorption amount for hexamethylenediamine, and can achieve the removal of impurities in hexamethylenediamine under high yield conditions.

[0086] In addition, the purification method of adsorption separation has the advantages that the adsorbent is recyclable and the energy consumption is low, and the industrial production cost can be significantly reduced.

[0087] In some embodiments, the purification method includes adsorbing azepine compound impurities in crude hexamethylenediamine using an adsorbent.

[0088] Preferably, the mass ratio of the crude hexamethylenediamine to the adsorbent is 300 - 600:1, for example, it may be 300:1, 334:1, 367:1, 400:1, 434:1, 467:1, 500:1, 534:1, 567:1 or 600:1, etc., but it is not limited to the listed values, and other values not listed in this range are equally applicable. From the above mass ratio, it can be seen that the adsorbent of the present invention has a large processing capacity and high processing efficiency.

[0089] The specific adsorption method in the present invention is not particularly limited, and any method that can be used for adsorption well known to those skilled in the art can be adopted, for example, it may be a kettle type, a fixed bed type, a tower type or a moving bed type, etc. The adsorption method may be adjusted according to the actual process.

[0090] Preferably, after the adsorbent is saturated with adsorption, it is regenerated and recycled.

[0091] The regeneration method in the present invention is not particularly limited, and any method that can be used for the regeneration of the adsorbent well known to those skilled in the art can be adopted, for example, it can be any one of solvent washing, Soxhlet extraction, gas purge, solid phase extraction or supercritical extraction.

[0092] According to a fifth aspect, the present invention provides a method for preparing an organic diamine, including the steps of: performing a hydrogenation reaction on an aminonitrile-based organic substance and hydrogen gas under the action of a hydrogenation catalyst to obtain a post-reaction material containing an organic diamine; obtaining an organic diamine after the post-reaction material undergoes a second purification and a second adsorption, wherein the second adsorption employs the surface molecular imprint functionalized adsorbent provided in the first aspect of the present application, and the second purification is a second rectification process.

[0093] According to the manufacturing method provided by the present invention, the post-reaction material purified by using the surface molecular imprinted functionalized adsorbent of the present application is adsorbed. Since the adsorbent has an imprint cavity compatible with azepine compounds, it can specifically adsorb the impurities of azepine compounds therein, greatly reduce the adsorption to organic diamines, realize an excellent selective separation effect of azepine compounds, realize the industrial production of high-purity organic diamine products, and obtain high-purity organic diamine products from raw materials with low energy consumption, high selectivity and high conversion rate, which has high industrial production value.

[0094] The present invention adopts a purification method that combines purification and adsorption, and can further purify a small amount of impurities remaining after purification, thereby reducing the generation of by-products during the reaction, and it can be seen that it is advantageous by reducing the influence on downstream products such as nylon due to the high purity of the obtained organic diamine product.

[0095] Preferably, the above preparation method further includes the preparation process of aminonitrile-based organic substances, and the preparation process includes step A of mixing and vaporizing ammonia gas and organic amide to obtain a vaporized material, and the vaporized material undergoes an ammoniation reaction under the action of an ammoniation catalyst to obtain a first reaction material, and step B of obtaining an aminonitrile-based organic substance after the first reaction material undergoes first purification and first adsorption.

[0096] Preferably, an auxiliary agent is further added to step A, and the auxiliary agent contains any one or a combination of at least two kinds of elements corresponding to the ammoniation catalyst. The corresponding elements include aluminum element, silicon element, boron element, nitrogen element, alkaline earth element, transition metal element, and phosphorus element.

[0097] The present invention preferably reduces the loss of elements in the ammoniation catalyst during the reaction process by adding an auxiliary agent containing elements corresponding to the ammoniation catalyst components in the ammoniation reaction process, maintains the ammoniation catalyst activity from the source, and significantly extends the service life of the ammoniation catalyst. Specifically, during the reaction process, the ammoniation catalyst is prone to the loss of beneficial elements due to physical actions (including material flushing, especially the flushing of generated water, etc.) or chemical actions (including complexation reactions, etc.) between the reactants / products, and further causes the deactivation of the ammoniation catalyst. The present invention introduces elements corresponding to the beneficial elements in the ammoniation catalyst, reduces the loss of beneficial elements from the perspective of chemical equilibrium, stabilizes the performance of the ammoniation catalyst, reduces the phenomena of deactivation due to the loss of beneficial components of the ammoniation catalyst and further coking, carbon accumulation, etc., and realizes the deactivation of the ammoniation catalyst from the source and in situ.

[0098] Preferably, in step A, the auxiliary agent is mixed with ammonia gas and then with the organic amide.

[0099] The auxiliary agent in the present invention can also obtain a service life of the ammoniation catalyst better than that of the prior art even if it contains other elements such as a carrier and co-elements in the ammoniation catalyst. However, it is more preferable that the elements contained in the auxiliary agent correspond to the elements of the active components in the ammoniation catalyst, timely compensate for the loss of the active components, and the service life of the ammoniation catalyst is longer.

[0100] Preferably, the existence form of the aluminum element in the auxiliary agent includes aluminum trichloride and / or isopropoxydistearoyl aluminate.

[0101] Preferably, the existence form of the silicon element in the auxiliary agent includes tetraalkyl silicate.

[0102] Preferably, the existence form of the boron element in the auxiliary agent includes alkyl borate.

[0103] Preferably, the form of existence of the nitrogen element in the auxiliary agent includes any one or at least a combination of two of nitrogen-containing organic substances, ammonium salts or nitrogen-containing complexes, and typical but non-limiting combinations thereof are combinations of nitrogen-containing organic substances and ammonium salts, combinations of nitrogen-containing complexes and ammonium salts, and combinations of nitrogen-containing organic substances and nitrogen-containing complexes.

[0104] Preferably, the nitrogen-containing organic substance includes N,N-dialkyldimethylformyl nitrate and / or N-acetylacetyl aromatic amide copper.

[0105] Preferably, the ammonium salt includes any one or at least a combination of two of ammonium dihydrogen phosphate, ammonium hydrogen phosphate, ammonium phosphate or ammonium polyphosphate, and typical but non-limiting combinations thereof are combinations of ammonium dihydrogen phosphate and ammonium hydrogen phosphate, combinations of ammonium phosphate and ammonium hydrogen phosphate, combinations of ammonium dihydrogen phosphate and ammonium polyphosphate, and combinations of ammonium polyphosphate and ammonium hydrogen phosphate.

[0106] Preferably, the complex includes nickel hexamine bromide complex and / or cobalt hexamine chloride complex.

[0107] Preferably, the form of existence of the alkaline earth metal element in the auxiliary agent includes alkylmagnesium bromide.

[0108] Preferably, the form of existence of the transition metal element in the auxiliary agent includes any one or at least a combination of two of nickel hexamine bromide complex, cobalt hexamine chloride complex, N-acetylacetyl aromatic amide copper or tetraalkyl titanate, and typical but non-limiting combinations thereof are combinations of nickel hexamine bromide complex and cobalt hexamine chloride complex, combinations of cobalt hexamine chloride complex and N-acetylacetyl aromatic amide copper, and combinations of N-acetylacetyl aromatic amide copper and tetraalkyl titanate.

[0109] Preferably, the form of phosphorus element in the auxiliary agent includes any one or at least a combination of two or more of phosphoric acid, hypophosphorous acid, phosphate, hydrogen phosphate, hypophosphite, polyphosphoric acid, polyphosphate or phosphate ester. Its typical but non-limiting combinations are the combination of phosphoric acid and hypophosphorous acid, the combination of phosphate and hypophosphorous acid, the combination of hydrogen phosphate and phosphate ester, the combination of hypophosphite and hypophosphorous acid, the combination of hypophosphite and polyphosphoric acid, and the combination of polyphosphate and phosphate ester. Preferably, the phosphate includes ammonium phosphate.

[0110] Preferably, the hydrogen phosphate includes ammonium hydrogen phosphate. Preferably, the dihydrogen phosphate includes ammonium dihydrogen phosphate.

[0111] Preferably, the polyphosphate includes ammonium polyphosphate. Preferably, the phosphate ester includes any one or at least a combination of two or more of monoalkyl phosphate, dialkyl phosphate or trialkyl phosphate. Its typical but non-limiting combinations are the combination of monoalkyl phosphate and dialkyl phosphate, the combination of trialkyl phosphate and dialkyl phosphate, and the combination of monoalkyl phosphate and trialkyl phosphate.

[0112] Preferably, the addition amount of the auxiliary agent is 0.1 - 100 ppm of the weight of ammonia gas, and it may be, for example, 0.1 ppm, 0.5 ppm, 1 ppm, 5 ppm, 10 ppm, 20 ppm, 30 ppm, 40 ppm, 50 ppm, 60 ppm, 80 ppm, 90 ppm or 100 ppm.

[0113] The promoter can improve the service life of the catalyst to a certain extent when added in any process of the ammoniation reaction. However, in the present invention, it is more preferable to mix the promoter with ammonia gas and add it to the reaction process, which can further avoid the polymerization of the promoter in the vaporization process and the influence of the promoter on the polymerization of the organic amide. After being mixed with ammonia gas, it enters the reaction, and the ammonia gas reduces the partial pressures of the promoter and the organic amide, thereby reducing the temperature required for the vaporization of the organic amide and the situations such as its coking and carbonization amount. Therefore, the promoter effect of extending the service life of the catalyst by mixing the promoter with ammonia gas can be more effectively ensured.

[0114] And in this way, when the promoter is added to the reaction process together with the material, for the catalyst that is more likely to be deactivated at the inlet of the bed layer, it is more remarkable to reduce the loss of its components and its inducing effect, which is beneficial to maintaining the reaction effect, maintaining the stabilization of the organic amide concentration in the catalyst bed layer, suppressing the polymerization caused by the increase in the organic amide concentration due to the deactivation of the catalyst and the generation of polymers, coal tar and carbon accumulation generated thereby, being beneficial to maintaining the active sites of the catalyst, and further extending the service life of the catalyst.

[0115] Preferably, the temperature of the pre-treatment is 300 - 600 °C, and it may also be, for example, 300 °C, 350 °C, 400 °C, 450 °C, 500 °C, 550 °C or 600 °C, etc.

[0116] Preferably, the organic amide is an organic lactam. Preferably, the number of carbon atoms of the organic amide is a natural number from 3 to 18, and it may also be, for example, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18, and preferably it is a natural number from 3 to 10. Preferably, the organic amide is caprolactam.

[0117] Preferably, step A specifically is that after ammonia gas and the first part of the organic amide are mixed and vaporized, they are introduced into the i-th segment fixed-bed reactor, and an ammoniation reaction is carried out under the action of the first reaction temperature, the first reaction pressure and the first catalyst to obtain a first reaction discharge sample.

[0118] The i-th reaction effluent sample and the organic amide of the i+1-th portion are introduced into the (i+1)-th segment fixed bed reactor, where the value range of i is 1≤i≤n-1, and i is a natural number, n is a natural number ≥2. An ammoniation reaction is carried out under the action of the (i+1)-th reaction temperature, the (i+1)-th reaction pressure and the (i+1)-th catalyst to obtain the (i+1)-th reaction effluent sample. Here, the (i+1)-th reaction effluent sample is circulated and used as the i-th reaction effluent sample in the next step to carry out the ammoniation reaction until i+1=n.

[0119] Preferably, by classifying and introducing the organic amide, the problems of organic amide polymerization and the resulting coking on the catalyst surface can be effectively reduced, the generation of by-products can be reduced, and the conversion rate and selectivity of the reaction can be improved. And the present invention combines and adopts the purification method of the product that combines purification and adsorption purification, further purifies the crude aminonitrile-based organic matter by the adsorption method, and improves the economic effect of the whole process.

[0120] Preferably, the (i+1)-th reaction temperature > the i-th reaction temperature. Preferably, the (i+1)-th reaction pressure > the i-th reaction pressure. Preferably, the molar ratio of the active component to the carrier element in the (i+1)-th catalyst > the molar ratio of the active component to the carrier element in the i-th catalyst.

[0121] Due to the above preferred features, as the material is introduced into the fixed bed reactor, the reaction temperature, pressure and the content of the active component of the reaction catalyst are gradually increased. In the previous part, the molar ratio of the organic amide to the ammonia gas is high, the reaction pressure is low, and the problems of polymerization or decomposition, coking of the organic amide, especially organic lactam, and the resulting coking on the catalyst surface can be effectively reduced. In this case, the selectivity of the reaction is high, the generation of by-products is small. As the reaction progresses, the temperature and pressure are increased step by step, the utilization rate of the ammonia gas is effectively improved, the circulation amount of the ammonia gas is reduced, the economy of the whole process is improved, and the effects that both the selectivity and the conversion rate of the reaction are high when the molar ratio of the low ammonia gas to the organic amide are realized.

[0122] Due to its unique characteristics, the present invention preferably adjusts the content of the active component in the catalyst of each segment. As a result, in the early stage, the molar ratio of the active component to the carrier element is low, but a high selectivity for amino nitrile-based organic substances can be obtained with a high ammonia / organic amide molar ratio. At the same time, a relatively low reaction pressure is combined in the early stage, the partial pressure of the organic amide is reduced, there is less polymerization, decomposition or coking of the organic amide, which is beneficial for reducing coking on the catalyst surface and extending the catalyst life; in the later stage, the molar ratio of the active component to the carrier element is high, the conversion rate of the organic amide is high, the utilization rate of ammonia gas is greatly improved, and in accordance with the method of supplementing the organic amide in a multi-stage manner, the partial pressure of the organic amide in the system is controlled to be in a relatively low state, reducing the polymerization, decomposition or coking of the organic amide in the subsequent reaction process, which is beneficial for reducing coking on the catalyst surface and extending the catalyst life.

[0123] Preferably, the active component contains a phosphorus element. Preferably, the carrier element contains silicon. Preferably, the molar ratio of the active component to silicon in the i-th catalyst is (0.1-2):1, and may be, for example, 0.1:1, 0.2:1, 0.4:1, 0.5:1, 0.8:1, 1:1, 1.2:1, 1.5:1, 1.8:1 or 2:1, etc.

[0124] Preferably, the carriers of the first catalyst to the n-th catalyst each independently contain silicon and aluminum. Preferably, the molar ratios of silicon, aluminum and phosphorus in the first catalyst to the n-th catalyst are each independently 1:(0.01-1):(0.1-2), and may be, for example, 1:0.01:0.1, 1:0.01:0.2, 1:0.01:0.5, 1:0.01:0.8, 1:0.01:1, 1:0.01:1.5, 1:0.01:2, 1:0.05:0.1, 1:0.08:0.1, 1:0.1:0.2, 1:0.2:0.8, 1:0.8:0.1, 1:1:0.1, 1:0.01:0.5, 1:0.5:0.1 or 1:0.8:2, etc.

[0125] The phosphorus source of the active ingredient in the present invention is not particularly limited, and a phosphorus source commonly used by those skilled in the art can be adopted. However, adopting the preferred phosphorus source of this application has a better catalytic effect.

[0126] Preferably, the phosphorus source of the active ingredient includes any one or at least two combinations of phosphoric acid, phosphate, or metaphosphate. Typical but non-limiting combinations thereof are combinations of phosphoric acid and phosphate, combinations of phosphate and metaphosphate, and combinations of phosphoric acid and metaphosphate.

[0127] Preferably, the phosphate includes any one or at least two combinations of boron phosphate, calcium phosphate, magnesium phosphate, aluminum phosphate, ammonium phosphate, titanium phosphate, copper phosphate, or nickel phosphate. Typical but non-limiting combinations thereof are combinations of boron phosphate and calcium phosphate, combinations of magnesium phosphate and calcium phosphate, combinations of boron phosphate and magnesium phosphate, combinations of aluminum phosphate and ammonium phosphate, combinations of aluminum phosphate and titanium phosphate, combinations of ammonium phosphate and calcium phosphate, combinations of nickel phosphate and ammonium phosphate, and combinations of aluminum phosphate and copper phosphate. Preferably, the metaphosphate includes any one or at least two combinations of calcium metaphosphate, aluminum metaphosphate, or magnesium metaphosphate. Typical but non-limiting combinations thereof are combinations of calcium metaphosphate and aluminum metaphosphate, combinations of aluminum metaphosphate and magnesium metaphosphate, and combinations of calcium metaphosphate and magnesium metaphosphate.

[0128] Preferably, the carriers of the first catalyst to the nth catalyst are each independently a silicon-aluminum molecular sieve.

[0129] Preferably, the first catalyst to the nth catalyst are silicon-aluminum-phosphorus molecular sieves.

[0130] Catalysts for preparing aminonitrile-based organic substances by conventional gas-phase methods can improve the service life of the catalyst by the preparation method of the present invention. For example, it can be applied to pure silicon molecular sieve, titanium silicon molecular sieve, pure aluminum molecular sieve, phosphorus aluminum molecular sieve, boron phosphorus aluminum catalyst, etc. to improve the yield of aminonitrile-based organic substances and the conversion rate of organic amides. However, the use of silicon-aluminum-phosphorus molecular sieve has a better conversion effect than other ordinary catalysts.

[0131] In the present invention, silicon-aluminum-phosphorus molecular sieve cannot be avoided from coking, carbon accumulation, and even deactivation during the reaction process. By the classification manufacturing method of the present invention, the service life of the catalyst can be effectively improved.

[0132] The preparation method of the silicon-aluminum-phosphorus molecular sieve of the present invention is carried out with reference to CN111659463A.

[0133] The aluminum source and silicon source in the present invention are not particularly limited, and aluminum sources and silicon sources commonly used by those skilled in the art can be adopted. However, adopting the preferred aluminum source and silicon source of the present application has a better catalytic effect. Preferably, the aluminum source in the silicon-aluminum-phosphorus molecular sieve includes any one or at least two combinations of alumina, aluminum isopropoxide, or boehmite. Typical but non-limiting combinations thereof are combinations of alumina and aluminum isopropoxide, combinations of aluminum isopropoxide and boehmite, and combinations of alumina and boehmite. Preferably, the silicon source in the silicon-aluminum-phosphorus molecular sieve includes silica hydrogel.

[0134] Preferably, the ratio of the molar ratio of the active component to the carrier element in the i-th catalyst to the molar ratio of the active component to the carrier element in the (i + 1)-th catalyst is 1:1.2 to 3, and may be, for example, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.8, 1:2, 1:2.2, 1:2.5, 1:2.8, or 1:3.

[0135] In the present invention, it is more preferable that the molar ratio of the active component to the carrier element of the catalyst is configured in the above ratio, which can better improve the selectivity, conversion rate of the reaction, and the utilization rate of ammonia gas, and can extend the service life of the catalyst. Preferably, the ratio of the molar ratio of the active component to silicon in the i-th catalyst to the molar ratio of the active component to silicon in the (i + 1)-th catalyst is 1:1.2 to 3, and may be, for example, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.8, 1:2, 1:2.2, 1:2.5, 1:2.8, or 1:3. Preferably, the amount of caprolactam in the i-th part is the same as the amount of caprolactam in the (i + 1)-th part.

[0136] Preferably, each of the first catalyst to the n-th catalyst independently includes a first type of pore channel. The catalyst further contains a second type of pore channel, and / or the catalyst further includes a protrusion, and the protrusion is closer to the outside of the catalyst.

[0137] Preferably, the length of at least one dimension of the pores of the second type of pore channel occupies 0.15 to 0.6 times the corresponding dimension length of the catalyst, and / or the protruding length of the protrusion occupies 0.1 to 0.6 times the corresponding dimension length of the catalyst. The present invention preferably further relates to a catalyst including a second type of pore channel and / or a protrusion structure, which can better reduce the reduction of the bed stacking compared with a catalyst having a conventional structure and can extend the service life of the catalyst.

[0138] Preferably, the (i + 1)-th reaction temperature is 10 to 50 °C higher than the i-th reaction temperature, and may be, for example, 10 °C, 12 °C, 15 °C, 18 °C, 20 °C, 25 °C, 28 °C, 30 °C, 35 °C, 40 °C, 45 °C, or 50 °C. Preferably, the (i + 1)-th reaction pressure is 0.1 to 0.5 MPa higher than the i-th reaction pressure, and may be, for example, 0.1 MPa, 0.15 MPa, 0.2 MPa, 0.25 MPa, 0.3 MPa, 0.35 MPa, 0.4 MPa, 0.45 MPa, or 0.5 MPa.

[0139] In the present invention, a more preferable increase degree of the reaction temperature and the reaction pressure can better improve the selectivity and conversion rate of the reaction.

[0140] Preferably, the organic amide in the i-th part is the same as the amount of the organic amide in the (i + 1)-th part.

[0141] Preferably, the regeneration methods of the first catalyst to the n-th catalyst are each independently introducing an oxygen-containing gas into a regeneration device containing the deactivated catalyst. The regeneration device is provided with m uniformly distributed inlets, or includes m serially connected regenerators, and introducing a supplementary oxygen-containing gas from the second to the m-th inlets or from inside the second to the m-th regenerators to perform the regeneration of the deactivated catalyst, where m is a natural number greater than or equal to 2.

[0142] A preferred method for regenerating the catalyst of the present invention is that the deactivated catalyst can be regenerated in-situ directly in the reaction device, and the regenerator can be directly applied to the original fixed-bed reaction device where the reaction occurs, realizing the in-situ regeneration of the catalyst, avoiding the complicated catalyst disintegration process and environmental pollution during the process, and it is also possible to load the discharged catalyst into the device for regeneration, improving the safety and reliability during the catalyst regeneration process. The deactivated catalyst of the present invention contains carbon-containing harmful substances, and the carbon-containing harmful substances refer to carbon-containing substances that are adsorbed, adhered, deposited, or coated on the surface of the catalyst in the catalyst, block the pores of the catalyst, cover the active sites of the catalyst, or deactivate the catalyst in other ways. These carbon-containing harmful substances react with oxygen in the front stage of the regeneration device to generate carbon dioxide, and carbon dioxide continuously reacts with carbon-containing harmful substances such as accumulated carbon in the deactivated catalyst at high temperature to generate carbon monoxide, which is prone to explosion accidents. The regeneration method of the present invention replenishes the oxygen-containing gas in multiple stages to maintain a stable oxygen content in the entire regeneration device, reduces the generation of carbon monoxide due to the further reaction of carbon dioxide and carbon-containing harmful substances, significantly reduces the content of carbon monoxide in the system, and further reduces the risk of explosion in the regeneration process and exhaust gas treatment. By adopting the method of gradient temperature increase and gradient increase in oxygen content, the regeneration process is made gentle and slow, the temperature rise of the hot spot in the bed layer is reduced, which is beneficial to maintaining the catalyst structure and reducing pulverization. The regeneration end point is maintained at high temperature and high oxygen, and further removes carbon-containing harmful substances such as carbon accumulation and coal tar in the pores inside the molecular sieve catalyst, fully releases the active sites of the catalyst, and fully restores the catalyst activity. The inventor has discovered that after adopting the preferred regeneration method of the present invention, the catalyst activity of the regenerated catalyst hardly decreases, and the service life is significantly extended.

[0143] Preferably, the deactivated catalyst contains carbon-containing harmful substances. Preferably, the regeneration device is the original reaction device. Preferably, in the regeneration process, the oxygen content of the oxygen-containing gas improves in a gradient with the regeneration time, and the regeneration temperature improves in a gradient with the regeneration time. Preferably, the oxygen content of the oxygen-containing gas is 0.5 to 21 v / v%, and may be, for example, 0.5 v / v%, 2.8 v / v%, 5.1 v / v%, 7.4 v / v%, 9.7 v / v%, 11.9 v / v%, 14.2 v / v%, 16.5 v / v%, 18.8 v / v% or 21 v / v%.

[0144] Preferably, the oxygen-containing gas further contains nitrogen. Preferably, the improvement rate of the oxygen content of the oxygen-containing gas is 0.001 to 5 v / v% / h, and may be, for example, 0.001 v / v% / h, 0.1 v / v% / h, 0.7 v / v% / h, 1.2 v / v% / h, 1.8 v / v% / h, 2.3 v / v% / h, 2.9 v / v% / h, 3.4 v / v% / h, 4 v / v% / h, 4.5 v / v% / h or 5 v / v%, and is preferably 0.001 to 1 v / v% / h.

[0145] The present invention further preferably has an improvement rate of the oxygen content within the above range, and can more effectively realize the regeneration of the catalyst while saving the usage amount of oxygen.

[0146] Preferably, the initial oxygen content in the oxygen-containing gas is 0.5 to 2 v / v%, and may be, for example, 0.5 v / v%, 0.7 v / v%, 0.9 v / v%, 1 v / v%, 1.2 v / v%, 1.4 v / v%, 1.5 v / v%, 1.7 v / v%, 1.9 v / v% or 2 v / v%. Preferably, the final oxygen content in the oxygen-containing gas is 10 to 21 v / v%, and may be, for example, 10 v / v%, 12 v / v%, 13 v / v%, 14 v / v%, 15 v / v%, 17 v / v%, 18 v / v%, 19 v / v%, 20 v / v% or 21 v / v%.

[0147] The present invention further comprehensively controls the initial oxygen content and the final oxygen content, more effectively improves the regeneration effect of the catalyst, and extends the service life of the catalyst.

[0148] Preferably, the regeneration is maintained for 1 to 200 h under the final oxygen content, and may be, for example, 1 h, 5 h, 10 h, 15 h, 20 h, 30 h, 50 h, 80 h, 100 h, 110 h, 150 h, 180 h or 200 h, etc., and preferably 50 to 150 h.

[0149] Preferably, the oxygen-containing gas is introduced from the first inlet or the first regenerator inlet.

[0150] Preferably, the supplementary oxygen-containing gas contains air, oxygen-enriched air and / or oxygen.

[0151] Preferably, the oxygen content of the oxygen-containing gas introduced into each fixed-bed reactor is equivalent, or the oxygen content in the fixed-bed reactor at the inlet for introducing the supplementary oxygen-containing gas is equivalent to the oxygen content of the oxygen-containing gas introduced from the first inlet.

[0152] The present invention makes the oxygen content of the oxygen-containing gas introduced into the previous regenerator equivalent or equivalent to the oxygen content of the oxygen-containing gas introduced from the first inlet by introducing the supplementary oxygen-containing gas, improves the uniformity of the oxygen content of each regeneration segment, and improves the regeneration effect.

[0153] Preferably, the regeneration temperature is 250 to 800 °C, and may be, for example, 250 °C, 312 °C, 373 °C, 434 °C, 495 °C, 556 °C, 617 °C, 678 °C, 739 °C or 800 °C, etc.

[0154] Preferably, the heating rate of the regeneration is 0.01 to 20 °C / h, and may be, for example, 0.01 °C / h, 2.4 °C / h, 5 °C / h, 6.8 °C / h, 8.9 °C / h, 11.2 °C / h, 13.0 °C / h, 15.0 °C / h, 17.0 °C / h or 20 °C / h, etc., and preferably 0.01 to 5 °C / h.

[0155] The present invention further controls the heating rate during regeneration to be within the above range, reduces the hot spot temperature rise and local overheating situation during the regeneration process, significantly reduces the cracking situation of the catalyst, ensures good mechanical strength of the catalyst, has a better regeneration effect of the catalyst, and a longer service life.

[0156] Preferably, the initial temperature of regeneration is 100 - 500 °C, and it may be, for example, 100 °C, 120 °C, 150 °C, 180 °C, 200 °C, 250 °C, 260 °C, 270 °C, 300 °C, 320 °C, 330 °C, 350 °C, 400 °C, 450 °C or 500 °C, etc., and preferably 250 - 350 °C.

[0157] Preferably, the final temperature of regeneration is 300 - 1200 °C, and it may be, for example, 300 °C, 400 °C, 500 °C, 700 °C, 750 °C, 800 °C, 850 °C, 900 °C, 970 °C, 1000 °C or 1200 °C, etc., and preferably 700 - 800 °C.

[0158] Preferably, the regeneration is maintained at the final temperature for 1 - 200 h, and it may be, for example, 1 h, 6 h, 24 h, 50 h, 100 h, 150 h and 200 h, etc., and preferably 50 - 150 h.

[0159] The regeneration includes a pre-regeneration stage and a post-regeneration stage that are carried out sequentially.

[0160] Preferably, in the pre-regeneration stage, the oxygen content of the oxygen-containing gas is fixed as the initial oxygen content, and the temperature of regeneration rises from the initial temperature to the final temperature. In the post-regeneration stage, the temperature of regeneration is fixed as the final temperature, the oxygen content of the oxygen-containing gas is increased to the final oxygen content, and the regeneration is continued at the final oxygen content and the final temperature.

[0161] In the present invention, there is no order between the steps of raising the temperature and improving the oxygen content. The two may be carried out simultaneously, or the temperature may be raised first and then the oxygen content may be improved, or the oxygen content may be improved first and then the temperature may be raised. Preferably, the temperature is raised first and then the oxygen content is improved, which can better reduce the increase in the hot spot temperature, lower the maximum content of carbon monoxide, and extend the life of the catalyst.

[0162] That is, preferably, the regeneration process includes a pre-regeneration stage and a post-regeneration stage that are sequentially performed. The pre-regeneration stage includes fixing the oxygen content of the oxygen-containing gas as the initial oxygen content and raising the temperature of the regeneration from the initial temperature to the final temperature. The post-regeneration stage includes fixing the temperature of the regeneration as the final temperature, improving the oxygen content of the oxygen-containing gas to the final oxygen content, and continuing the regeneration at the final oxygen content and the final temperature.

[0163] Preferably, m is selected from natural numbers from 2 to 6, and may be, for example, 2, 3, 4, 5, or 6.

[0164] As a preferred technical solution of the present invention, the regeneration method includes the following steps:

[0165] An oxygen-containing gas with an initial oxygen content of 0.5 to 2 v / v% is introduced into a regeneration device containing a deactivated catalyst. The regeneration device is provided with m uniformly distributed inlets, or includes m serially connected regenerators, and supplementary oxygen-containing gas is introduced from the second to the mth inlets or regenerators to perform the regeneration of the deactivated catalyst.

[0166] During the regeneration process, the oxygen content of the oxygen-containing gas is improved from 0.001 to 5 v / v% / h to a final oxygen content of 10 to 21 v / v%. The initial temperature of the regeneration is 250 to 350 °C, and the temperature is raised from 0.01 to 20 °C / h to a final temperature of 700 to 800 °C. The regeneration is continued by holding at the final temperature and the final oxygen content for 1 to 200 h. Here, m is a natural number greater than or equal to 2.

[0167] The preferred method for regenerating the catalyst of the present invention can effectively remove partial side reaction centers (such as strong acid centers) because the damage to the catalyst during the regeneration process is small, extend the service life of the catalyst, be widely applicable to the regeneration of deactivated catalysts, and reduce production costs.

[0168] Preferably, the mixing and vaporization in step A is carried out in a Venturi vaporizer.

[0169] The organic amide moiety is a heat-sensitive substance, prone to polymerization, decomposition or charring during the vaporization process, resulting in a decrease in vaporization efficiency, an increased tendency for the vaporizer to char, and it is preferable to promote the vaporization of the organic amide using a Venturi atomizer and reduce the vaporization efficiency of the organic amide.

[0170] Preferably, it is preset in the heating medium in the Venturi vaporizer. Preferably, the heating medium contains molten salt.

[0171] Preferably, before the mixing and vaporization, the temperature of the organic amide in the liquid phase is 0 to 300 °C, and it may be, for example, 0 °C, 10 °C, 20 °C, 50 °C, 69 °C, 70 °C, 100 °C, 120 °C, 140 °C, 150 °C, 180 °C, 200 °C, 220 °C, 250 °C, 280 °C or 300 °C, etc. In the case of caprolactam, 69 to 220 °C is preferable.

[0172] Preferably, the temperature after vaporization is 300 to 500 °C, such as 300 °C, 320 °C, 350 °C, 370 °C, 400 °C, 420 °C, 450 °C, 480 °C, 490 °C or 500 °C, etc.

[0173] Preferably, the weight hourly space velocity of the organic amide passing through the ammoniation catalyst is, independently of each other, 0.1 to 10 h -1 and, for example, 0.1 h -1 , 0.5 h -1 , 1 h -1 , 1.2 h -1 , 1.5 h -1 , 2 h -1 , 2.5 h -1 , 3 h -1 , 4 h -1 , 5 h-1 、6 h -1 、7 h -1 、8 h -1 、9 h -1 or 10 h -1 etc. may be used, preferably 0.5 to 5 h -1 is used.

[0174] Preferably, the temperature range of the ammoniation reaction is 300 to 500 °C, and may be, for example, 300 °C, 320 °C, 350 °C, 380 °C, 400 °C, 420 °C, 450 °C, 480 °C or 500 °C, etc.

[0175] Preferably, the pressure of the ammoniation reaction is 0 to 2 MPaG, and may be, for example, 0 MPaG, 0.5 MPaG, 1 MPaG, 1.2 MPaG, 1.3 MPaG, 1.5 MPaG, 1.8 MPaG or 2 MPaG, etc., preferably 0.2 to 1 MpaG.

[0176] In the present invention, G in MPaG means gauge pressure.

[0177] Preferably, the total molar ratio of ammonia gas to organic amide is 2 to 50:1, and may be, for example, 2:1, 4:1, 5:1, 10:1, 12:1, 15:1, 18:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1 or 50:1, etc.

[0178] Preferably, for the first adsorption, a first adsorbent is used, and the first adsorbent includes an adsorbent carrying a metal element.

[0179] For the amino nitrile-based organic substance containing conventional impurities, an adsorbent carrying a metal element is selected for adsorption, and the metal element is combined with the impurities in the amino nitrile-based organic substance to realize the separation of the amino nitrile-based organic substance from the impurities, thereby improving the purity of the amino nitrile-based organic substance and further improving the purity of the amino nitrile-based organic substance in addition to the conventional purification.

[0180] Preferably, the first adsorbent includes montmorillonite, ZSM-5 zeolite molecular sieve, SiO 2 , Al 2 O 3 or activated carbon, or a combination of any one or at least two of them. Typical but non-limiting combinations thereof include the combination of montmorillonite and ZSM-5 zeolite molecular sieve, the combination of SiO 2 and ZSM-5 zeolite molecular sieve, the combination of montmorillonite and SiO 2 , the combination of Al 2 O 3 and activated carbon.

[0181] Preferably, the metal element includes a transition metal element.

[0182] The present invention further preferably supports a transition metal element. Since the transition metal ions form π-bonding hands of weak chemical reactions with unsaturated hydrocarbons in the impurities, the selectivity of adsorption is improved, and after the purity is improved, the loss rate of 6-aminohexyl nitrile-based organic substances is reduced.

[0183] Preferably, the transition metal element includes any one or a combination of at least two of Ag, Cu, Cd, Cr, Fe, Zn, Ni, Zr, or Mn. Typical but non-limiting combinations thereof include the combination of Ag and Cu, the combination of Ag and Cd, the combination of Cd and Cr, the combination of Fe and Cu, the combination of Fe and Zn, the combination of Zn and Cu, the combination of Ni and Mn, and the combination of Ni and Zr.

[0184] Preferably, the impurities of the first adsorption contain unsaturated bonds.

[0185] Preferably, the impurities of the first adsorption contain carbon-carbon double bonds and / or carbon-carbon triple bonds.

[0186] Preferably, the space velocity of the first adsorption is 0.5~3 h -1 , for example, 0.5 h -1 , 0.8 h -1 , 1.1 h -1 , 1.4 h -1, 1.7 h -1 , 1.9 h -1 , 2.2 h -1 , 2.5 h -1 , 2.8 h -1 or 3 h -1 etc. may also be acceptable. Preferably, the temperature of the first adsorption is 20 - 60 °C, for example, it may be 20 °C, 25 °C, 29 °C, 34 °C, 38 °C, 43 °C, 47 °C, 52 °C, 56 °C or 60 °C etc. Preferably, the pressure of the first adsorption is 0.1 - 1 MPa, for example, it may be 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa or 1 MPa etc.

[0187] Preferably, after purging and regenerating the metal oxide adsorbed to saturation by the first adsorption with a purge gas, the first adsorption is continued.

[0188] The first adsorbent of the present invention can be regenerated by thermal N 2 purging, so it has recyclable use value and is highly economical at low cost. Preferably, the purge gas contains nitrogen gas. Preferably, the temperature of the purge is 300 - 400 °C, for example, it may be 300 °C, 312 °C, 323 °C, 334 °C, 345 °C, 356 °C, 367 °C, 378 °C, 389 °C or 400 °C etc. Preferably, the time of the purge is 2 - 8 h, for example, it may be 2 h, 2.7 h, 3.4 h, 4 h, 4.7 h, 5.4 h, 6 h, 6.7 h, 7.4 h or 8 h etc.

[0189] Preferably, the polymer residues generated in the ammoniation reaction and / or the first purification are sequentially subjected to a depolymerization reaction, vacuum dehydration, and vacuum distillation to obtain aminonitrile-based organic substances and organic amides, respectively. More preferably, the present invention uses the polymer residue solid waste generated in the reaction process as a raw material, and conducts resource utilization of the reaction residue in the processes of depolymerization, separation, etc., recovers aminonitrile-based organic substances and organic amides, reduces the amount of solid waste, and the recovered organic amide can be used again as a raw material for synthesizing aminonitrile-based organic substances, which is advantageous for reducing the production cost of the raw materials and improving the economic benefits. Aminonitriles can cause the ring-opening polymerization reaction of lactam to generate polyamide substances, resulting in an increase in molecular weight and the formation of polymer residues. After depolymerization, aminonitrile-based products and lactam raw materials are obtained, separated by distillation, and the aminonitrile-based substances can be used in the hydrogenation reaction of the next step.

[0190] Preferably, water is added to the depolymerization reaction.

[0191] Preferably, the mass ratio of the polymer residue to water is 1:0.5 to 20, and may be, for example, 1:1, 1:2, 1:4, 1:5, 1:8, 1:10, 1:12, 1:15, 1:18 or 1:20. Preferably, the temperature of the depolymerization reaction is 100 to 400 °C, and may be, for example, 100 °C, 120 °C, 150 °C, 180 °C, 200 °C, 220 °C, 250 °C, 300 °C, 340 °C or 400 °C. Preferably, the pressure of the depolymerization reaction is 0 to 10 MPa, and may be, for example, 0 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa or 10 MPa. Preferably, the time of the depolymerization reaction is 10 s to 10 h, and may be, for example, 10 s, 30 s, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h or 10 h.

[0192] Preferably, the depolymerization reaction is carried out by catalysis. Preferably, the mass ratio of the polymer residue to the catalyst is 1:0.01-0.5, such as 1:0.01, 1:0.02, 1:0.05, 1:0.08, 1:0.1, 1:0.12, 1:0.15, 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.45 or 1:0.5. Preferably, the catalyst comprises titanium silicon molecular sieve, solid acid catalyst or solid base catalyst, wherein the solid acid catalyst is Al 2 O 3 , TiO 2 , ZrO 2 , SiO 2 , B 2 O 3 , SiO 2 -Al 2 O 3 , ZrO 2 -SiO 2 , NiSO 4 and Zr(SO 4 ) 2 The solid base catalyst is KOH, NaOH, Ba(OH) 2 , Cu(OH) 2 , Fe(OH) 3 , CaO-MgO, MgO-ZrO 2 and KF-ZrO 2 Any one or any combination of two or more of the above.

[0193] Preferably, the hydrogenation catalyst is γ-Fe 2 O 3 / SiO 2 , Rh / SiO 2 , Pt-Rh / Al 2 O 3 , Fe 3 O 4 -SiO 2 -Ag, Ru-Fe 2 O 3 -Al 2 O 3 , Raney nickel, amorphous nickel or carbon-based cobalt catalysts, of which exemplary but non-limiting combinations include γ-Fe 2 O3 / SiO 2 and Rh / SiO 2 and the combination with Pt-Rh / Al 2 O 3 and the combination with a carbon-based cobalt catalyst, γ-Fe 2 O 3 / SiO 2 and Pt-Rh / Al 2 O 3 and the combination with Fe 3 O 4 -SiO 2 -Ag and Rh / SiO 2 and the combination with a carbon-based cobalt catalyst and Ru-Fe 2 O 3 -Al 2 O 3 and the combination, preferably a carbon-based cobalt catalyst, preferably a carbon-based cobalt catalyst.

[0194] The present invention preferably employs the above catalyst, and can have the dual advantages of applicability to a magnetically stabilized bed and high catalytic activity.

[0195] Preferably, the carbon-based cobalt catalyst is a nitrogen and phosphorus co-doped carbon-based cobalt catalyst. Preferably, the components of the carbon-based cobalt catalyst include an active component and a main component. The active component includes cobalt: 0.5 to 15%, phosphorus: 0.1 to 5%, nitrogen: 1 to 10%, and the main component includes carbon.

[0196] The nitrogen and phosphorus co-doped carbon-based cobalt catalyst preferably employed in the present invention has the above composition of components, has high selectivity for converting aminonitriles to organic diamine reactions, provides excellent catalytic selectivity for the production of organic diamines. The present invention controls the contents of nitrogen element and phosphorus element within the above ranges, thereby adjusting the catalytic activity and achieving the effect of significantly improving the conversion rate and selectivity.

[0197] Preferably, the particle size of the catalyst is 10 to 1000 μm, and may be, for example, 10 μm, 120 μm, 230 μm, 340 μm, 450 μm, 560 μm, 670 μm, 780 μm, 890 μm, or 1000 μm.

[0198] In the present invention, the cobalt content in the carbon-based cobalt catalyst is 0.5 to 15%, and may be, for example, 0.5%, 2.0%, 3.0%, 5.0%, 7.0%, 8.0%, 10.0%, 11.0%, 13.0%, or 15.0%. The phosphorus content in the carbon-based cobalt catalyst is 0.1 to 5%, and may be, for example, 0.1%, 0.7%, 1.2%, 1.8%, 2.3%, 2.9%, 3.4%, 4%, 4.5%, or 5%. The nitrogen content in the carbon-based cobalt catalyst is 1 to 10%, and may be, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%. In the present invention, the carbon-based cobalt catalyst further contains an oxygen element.

[0199] Preferably, the specific surface area of the carbon-based cobalt catalyst is 50 to 1000 m 2 / g, and may be, for example, 50 m 2 / g, 156 m 2 / g, 262 m 2 / g, 367 m 2 / g, 473 m 2 / g, 578 m 2 / g, 684 m 2 / g, 789 m 2 / g, 895 m 2 / g, or 1000 m 2 / g, etc.

[0200] Preferably, the mass ratio of phosphorus to nitrogen in the carbon-based cobalt catalyst is 1:0.5 to 20, and may be, for example, 1:0.5, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:5, 1:6, 1:7, 1:10, 1:12, 1:15, 1:18, or 1:20.

[0201] Preferably, the carbon-based cobalt catalyst has a carbon layer with a coating structure, and it is preferable that a carbon coating layer is formed centering on cobalt. The carbon layer of the coating structure is a graphitized carbon layer coated on cobalt nanoparticles. The degree of graphitization of the carbon in the main body component is relatively low, and it is partially amorphous. It functions as a carrier, and the nitrogen-doped carbon coating layer and the cobalt nanoparticles as the active component form a strong interaction through coordination bonds, which can improve its activity and stability.

[0202] Preferably, in the present invention, the carbon-based cobalt catalyst preferably forms a structure in which a carbon layer is coated around the active center cobalt. The cycle stability of the catalyst is significantly improved. Moreover, the coated carbon layer is a co-doped carbon layer of phosphorus and nitrogen, and the selectivity of the catalyst is significantly improved.

[0203] Preferably, the hydrogenation reaction is carried out in a magnetic stabilization reactor.

[0204] Preferably, the mass ratio of the aminonitrile-based organic substance to the hydrogenation catalyst is 1:0.001 to 1, and it may be, for example, 1:0.001, 1:0.01, 1:0.02, 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9 or 1:1, etc.

[0205] Preferably, the temperature of the hydrogenation reaction is 25 to 200 °C, and it may be, for example, 25 °C, 45 °C, 64 °C, 84 °C, 103 °C, 123 °C, 142 °C, 162 °C, 181 °C or 200 °C, etc. Preferably, the pressure of the hydrogenation reaction is 0.1 to 5 MPa, and it may be, for example, 0.1 MPa, 0.7 MPa, 1.2 MPa, 1.8 MPa, 2.3 MPa, 2.9 MPa, 3.4 MPa, 4 MPa, 4.5 MPa or 5 MPa, etc. Preferably, the magnetic field strength in the hydrogenation reaction is 1000 to 8000 A·m -1 and, for example, 1000 A·m -1 、2000 A·m -1 、3000 A·m -1 、4000 A·m -1 、5000 A·m -1, 6000 A·m -1 , 7000 A·m -1 , 8000 A·m -1 etc. may be used. Preferably, the space velocity of the aminonitrile-based organic substance is 0.01 - 20 h -1 , for example, 0.01 h -1 , 2.24 h -1 , 4.46 h -1 , 6.68 h -1 , 8.9 h -1 , 11.12 h -1 , 13.34 h -1 , 15.56 h -1 , 17.78 h -1 , 20 h -1 etc. may be used. Preferably, the molar ratio of hydrogen gas to the aminonitrile-based organic substance is 2 - 100:1, and for example, it may be 2:1, 13:1, 24:1, 35:1, 46:1, 57:1, 68:1, 79:1, 90:1 or 100:1, etc.

[0206] Preferably, the hydrogenation reaction is carried out under solvent conditions. Preferably, the solvent contains an alcohol solvent, and preferably any one or at least a combination of two of ethanol, methanol, tert-butanol, isopropanol, n-propanol, isobutanol or n-butanol. Typical but non-limiting combinations thereof are the combination of ethanol and methanol, the combination of tert-butanol and n-propanol, the combination of ethanol and tert-butanol, the combination of tert-butanol and isopropanol, the combination of isopropanol and isobutanol, the combination of n-propanol and methanol, and the combination of n-butanol and methanol.

[0207] Preferably, the number of carbon atoms of the aminonitrile-based organic substance is a natural number from 3 to 18, and for example, it may be 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18. Preferably, it is a natural number from 3 to 10, and more preferably it is 6-aminohexanenitrile.

[0208] Preferably, before performing the hydrogenation reaction, the above preparation method further includes mixing the aminonitrile-based organic substance and a solvent, heating the mixture to 25 to 200 °C, and further introducing the mixture into a magnetic stabilization reactor containing a catalyst. Preferably, a promoter is further added during the mixing. Preferably, the promoter includes an alkali and / or an organic salt of an alkali metal, preferably NaOH, KOH, Ba(OH) 2 , CH 3 CH 2 ONa or CH 3 ONa, including any one or at least a combination of two of them. Its typical but non-limiting combinations include the combination of NaOH and KOH, Ba(OH) 2 and CH 3 CH 2 ONa, the combination of Ba(OH) 2 and CH 3 ONa, the combination of CH 3 CH 2 ONa and KOH.

[0209] Preferably, the mass ratio of the aminonitrile-based organic substance to the promoter is 1:0.001 to 0.1, and it may be, for example, 1:0.001, 1:0.01, 1:0.02, 1:0.03, 1:0.04, 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09 or 1:0.1, etc.

[0210] Preferably, the second purification includes rectification and / or distillation to obtain a crude organic diamine.

[0211] Preferably, the purity of the organic diamine in the crude organic diamine is ≥99%.

[0212] Preferably, the crude organic diamine contains azepine-based compound impurities, preferably 3,4,5,6-tetrahydro-2H-azepine.

[0213] Preferably, the second adsorption involves adsorbing impurities from the second purified crude organic diamine with a second adsorbent to obtain an organic diamine. Preferably, the mass ratio of the crude organic diamine to the surface molecule imprint-functionalized adsorbent is 300-600:1. Preferably, the number of carbon atoms in the organic diamine is a natural number from 3 to 18, preferably a natural number from 3 to 10, and more preferably hexamethylenediamine.

[0214] In the conventional purification and production process of organic diamines, by-products such as azepine compounds are generated. However, azepine compounds are difficult to remove by rectification, and after preliminary purification, impurities of azepine compounds still remain. Although the same certain adsorption effect can be achieved by the usual adsorption method, the adsorption selectivity is relatively poor. The present invention preferably employs a surface molecule imprint-functionalized adsorbent, which not only specifically adsorbs azepine compounds but also has a relatively low adsorption capacity for organic diamines, and can achieve the removal of impurities in organic diamines under high-yield conditions. In addition, the purification method of adsorption separation has the advantages that the adsorbent can be recycled and the energy consumption is low. When applied industrially, the production cost can be significantly reduced.

[0215] Preferably, the second adsorption involves adsorbing impurities from the second purified crude organic diamine with a second adsorbent to obtain an organic diamine product.

[0216] Preferably, the mass ratio of the crude organic diamine to the adsorbent is 300-600:1, and it may be, for example, 300:1, 334:1, 367:1, 400:1, 434:1, 467:1, 500:1, 534:1, 567:1 or 600:1, etc.

[0217] The specific adsorption method of the present invention is not particularly limited, and any method that can be used for any adsorption well-known to those skilled in the art can be adopted. For example, it may be a kettle type, a fixed bed type, a tower type or a moving bed type, etc. The adsorption method may be adjusted according to the actual process.

[0218] Preferably, after the adsorbent is saturated with adsorption, it is regenerated and recycled.

[0219] The regeneration method of the present invention is not particularly limited, and can be carried out by any method used for the regeneration of adsorbents well known to those skilled in the art. For example, it may be any one of solvent washing, Soxhlet extraction, gas purge, solid-phase extraction, or supercritical extraction.

[0220] Preferably, the number of carbon atoms of the organic diamine is a natural number from 3 to 18, and may be, for example, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18. Preferably, it is a natural number from 3 to 10, and more preferably hexamethylenediamine.

[0221] In addition, regarding the steps and parameters not specifically described in the present invention, the present invention is not particularly limited, and may be carried out by steps or parameters well known to those skilled in the art, and may also be adjusted according to process conditions. For the convenience of the paper, the present invention will not be described one by one.

[0222] According to the sixth aspect, the present invention provides an apparatus for implementing a method for preparing an organic diamine according to the fifth aspect. The apparatus includes a vaporization unit, an ammoniation reaction unit, a first purification unit, a first adsorption unit, a hydrogenation reaction unit, a second purification unit, and a second adsorption unit, which are sequentially connected.

[0223] Preferably, the vaporization unit includes a Venturi vaporizer.

[0224] Preferably, the Venturi vaporizer includes a converging section, a throat section, and a diverging section. A first inlet is installed in the converging section, a first gas outlet is installed in the diverging section, and a second inlet is installed in the throat section.

[0225] The present invention preferably atomizes and ejects an organic amide, has a large contact area with hot ammonia, a high flow rate in the throat portion, a strong shearing force, forms a local micro-negative pressure (with respect to the converging portion and the diverging portion) to accelerate vaporization, improves the vaporization efficiency, and is advantageous for the stable operation of the device and the improvement of the reaction effect.

[0226] Preferably, the Venturi vaporizer further includes an external circulation pipeline connecting the diverging portion and the throat portion.

[0227] Preferably, a material conveying device is installed in the external circulation pipeline.

[0228] Preferably, the external circulation pipeline is installed at the lowest point position of the diverging portion.

[0229] Preferably, a turbulence member is installed inside the diverging portion.

[0230] The preferred turbulence member of the present invention further strengthens the vaporization process and reduces the polymerization and coking of the organic amide.

[0231] Preferably, an atomizing nozzle is installed at the second inlet.

[0232] Preferably, the ammoniation reaction unit includes a fixed bed reactor.

[0233] Preferably, the hydrogenation reaction unit includes a magnetically stabilized reactor. Preferably, the magnetically stabilized reactor includes a tubular reactor and at least two Helmholtz coils installed outside the tubular reactor and arranged axially.

[0234] The preferred magnetically stabilized reactor of the present invention can convert the tubular reactor into a magnetically stabilized bed reactor by installing at least two Helmholtz coils to provide a magnetic field, uniformly distribute the magnetic catalyst under the magnetic field, reduce the wear of the catalyst and the mixed flow of the reaction materials, and avoid the loss of the catalyst and the occurrence of channeling in the reaction process.

[0235] Preferably, each Helmholtz coil is independently connected to the transformer device. Preferably, the number of turns of each Helmholtz coil is from 1 to 500, and may be, for example, 1, 2, 4, 10, 50, 100, 200, 300, 400 or 500.

[0236] Preferably, the magnetic stabilization reactor is installed in front of the tubular reactor and further includes a first heating device connected to the tubular reactor. In the present invention, the first heating device is further installed in front of the second tubular reactor to realize preheating of the reaction material before the reaction, and the reaction effect is better.

[0237] Preferably, a heating member is installed outside the first heating device. Preferably, an inert filler is installed in the first heating device, and may be, for example, a quartz filler, a glass filler or a ceramic ball filler. In the present invention, by further adding an inert filler, the heat transfer and preheating efficiency are improved.

[0238] Preferably, a third inlet is installed at the bottom and / or lower side of the first heating device, and a first outlet is installed at the top. Preferably, a fourth inlet is installed at the bottom and / or lower side of the tubular reactor. Preferably, the fourth inlet is connected to the first outlet.

[0239] Preferably, a hydrogen gas inlet is further installed at the bottom and / or lower side of the tubular reactor.

[0240] Preferably, a catalyst inlet is installed at the lower side of the tubular reactor. Preferably, the installation position of the catalyst inlet is on the lower surface of the Helmholtz coil.

[0241] Preferably, a catalyst outlet is installed at the upper side of the tubular reactor. Preferably, the catalyst outlet is installed on the upper surface of the Helmholtz coil. Preferably, a product outlet is installed at the upper side of the tubular reactor. Preferably, an exhaust gas outlet is installed at the top of the tubular reactor. The inner diameter and length of the tubular reactor in the present invention are not particularly limited and can be adjusted according to the production scale.

[0242] Compared with the prior art, the present invention has at least the following beneficial effects.

[0243] (1) The adsorbent functionalized by surface molecular imprinting provided by the present invention can be recycled multiple times. After being regenerated 5 times repeatedly, hexamethylenediamine can be purified to more than 99.98%, and it has the characteristics of low cost, simple operation, high selectivity, and environmental friendliness.

[0244] (2) The preparation method of the adsorbent functionalized by surface molecular imprinting provided by the present invention adopts the surface molecular imprinting technology, has a specific recognition site for azepine compounds, and prepares a molecularly imprinted polymer that specifically adsorbs. The manufacturing process is simple and easy to implement.

[0245] (3) The purification method of hexamethylenediamine provided by the present invention can further purify the hexamethylenediamine obtained by rectification, make the purity of hexamethylenediamine reach the polymerization requirement of nylon 66, improve the purity of hexamethylenediamine to more than 99.98 wt%, and the yield of hexamethylenediamine is more than 98 wt%. The loss rate is low, the content of 3,4,5,6-tetrahydro-2H-azepine is reduced to 0.011 wt% or less, preferably reduced to 0.008 wt% or less under favorable conditions. Moreover, the selective adsorption effect of the adsorbent on azepine compounds is good, and the yield of hexamethylenediamine is high.

[0246] (4) The method for preparing the organic diamine provided by the present invention integrates the gas-phase ammoniation reaction, adsorption purification of intermediate products, hydrogenation reaction, and adsorption purification process of products. The content of purified aminonitrile-based organic impurities is low, and the purity of the aminonitrile-based organic intermediate is more than 99.999 wt%. Then, when preparing the organic diamine product, there are few by-products, the purification of the product is easy, the purity of the obtained organic diamine product is high, and finally the purity of the organic diamine is more than 99.980 wt%, preferably more than 99.99 wt%.

[0247] (5) In the method for preparing the organic diamine provided by the present invention, the heat distribution of the amination reaction and the hydrogenation reaction is uniform, which is advantageous for controlling the degree of the reaction, extending the catalyst life, and it is more preferable to add an auxiliary agent in the ammoniation reaction stage, reducing the loss of beneficial elements of the catalyst, extending the service life of the ammoniation catalyst to 7000 h or more, and reaching 10000 h or more under excellent conditions. At the same time, it can have the advantages of high ammonia gas utilization rate, high organic amide conversion rate, and high selectivity for aminonitrile-based organic substances. The selectivity for aminonitrile-based organic substances is 88% or more, preferably 98 wt% or more, and the conversion rate of the organic amide is 86% or more, and preferably converts to 98% or more under preferable conditions.

[0248] (6) In the method for producing the organic diamine provided by the present invention, the selectivity of the organic diamine in the hydrogenation segment is as high as 92 wt% or more, preferably 99 wt% or more, the conversion rate of aminonitrile-based organic substances is 96 wt% or more, preferably 99 wt% or more, and the abrasion rate of the hydrogenation catalyst is ≦ 3.25 wt%, preferably ≦ 1.1 wt%.

[0249] (7) The process of the method for preparing the organic diamine provided by the present invention can be continuously produced, the process control is easy, and it has excellent future prospects for industrial application.

[0250] Hereinafter, the present application will be described in more detail with reference to specific examples, but these examples should not be understood as limiting the scope of protection required by the present application.

[0251] Examples of the adsorbent functionalized by surface molecular imprinting Example 1 This example provides a method for preparing an adsorbent functionalized by surface molecular imprinting. The flow of the preparation method is shown in Figure 1 and specifically includes the following steps.

[0252] First, 50 g of the carrier Al 2 O 3It was mixed with 2 L of anhydrous toluene, and after ultrasonic dispersion for 30 min, 0.1 L of 3-aminopropyltriethoxysilane was added dropwise under a nitrogen atmosphere, and a modification reaction was carried out at 90 °C for 18 h. The obtained modified reaction material was washed successively three times with toluene and three times with methanol, and then dried at 60 °C in a vacuum drying oven to obtain a modified carrier. (1) 3 g of acrylamide, which is a functional monomer, and 2 g of 3,4,5,6-tetrahydro-2H-azepine, which is an azepine-based compound template, were subjected to preliminary polymerization at room temperature (25 °C) for 10 h with 2 L of ethanol to obtain a preliminary polymerization reaction material containing a preliminary polymerization polymer. (2) First, the preliminary polymerization reaction material of step (1) was mixed with 20 g of the modified carrier, dispersed by ultrasonic waves for 30 min, and then 71.5 g of ethylene glycol dimethacrylate as a cross-linking agent and 0.8 g of azobisisobutyronitrile as an initiator were added under a nitrogen atmosphere, and a polymerization reaction was carried out at 60 °C for 24 h to obtain polymer particles. (3) In a Soxhlet extractor, a mixed acid solution of formic acid and acetic acid with a volume ratio of 8:1 was used to extract the 3,4,5,6-tetrahydro-2H-azepine template in the polymer particles until 3,4,5,6-tetrahydro-2H-azepine could not be detected in the extract. The polymer particles with the 3,4,5,6-tetrahydro-2H-azepine template removed were placed in vacuum drying at 60 °C and dried until a constant weight was obtained to obtain a surface molecular imprint-functionalized adsorbent.

[0253] The surface molecular imprint-functionalized adsorbent obtained in this example has a carrier of Al 2 O 3 and a carrier of Al 2 O 3It includes surface molecules supported thereon, an imprint cavity is formed between the surface molecules, and the imprint cavity matches an azepine compound. The SEM image of the adsorbent is shown in Figure 2. As is clear from Figure 2, the surface of the irregular microspherical carrier is coated with a molecularly imprinted polymer, where the irregular microspherical carrier is shown within the circular frame in the figure, and the polymer has some aggregation as shown within the white rectangular frame therein, indicating the successful production of the molecular imprint composite. The polymer coated outside the carrier has porosity, improving the specific surface area and adsorption performance. The BET adsorption / desorption curve is as shown in Figure 3. The rectangular frame represents the desorption curve, and the circles represent the adsorption curve. Thereby, the adsorbent belongs to the Type IV isothermal adsorption line and also belongs to the type of H3 hysteresis loop, which is a typical porous characteristic, and the surface area was measured to be 100.2 m 2 / g, having a large specific surface area, capable of providing more adsorption sites, and verifying the microscopic features of SEM.

[0254] Example 2 This example provides a method for preparing an adsorbent functionalized with surface molecular imprinting. The preparation method is the same as that of Example 1 except that 0.15 L of 3-aminopropyltriethoxysilane is dropped into the modification reaction, 5.7 g of acrylamide is added as a functional monomer in step (1), and 79.3 g of ethylene glycol dimethacrylate is added as a cross-linking agent in step (2).

[0255] Example 3 This example provides a method for preparing an adsorbent functionalized with surface molecular imprinting. The preparation method is the same as that of Example 1 except that 0.15 L of 3-aminopropyltriethoxysilane is dropped into the modification reaction, 8.4 g of 2-vinylpyridine is added as a functional monomer in step (1), and 61.7 g of N,N-methylenebisacrylamide is added as a cross-linking agent during step (2).

[0256] Example 4 This example provides a method for preparing an adsorbent functionalized with surface molecular imprinting. The preparation method is the same as that of Example 1, except that 0.15 L of 3-aminopropyltriethoxysilane is dropped into the modification reaction, 8.53 g of acrylamide is added as a functional monomer in step (1), and 87.2 g of ethylene glycol dimethacrylate is added as a cross-linking agent in step (2).

[0257] Example 5 This example provides a method for preparing an adsorbent functionalized with surface molecular imprinting. The preparation method is the same as that of Example 1, except that 0.15 L of 3-aminopropyltriethoxysilane is dropped into the modification reaction, 1.42 g of acrylamide is added as a functional monomer in step (1), and 87.1 g of ethylene glycol dimethacrylate is added as a cross-linking agent in step (2).

[0258] Example 6 This example provides a method for preparing an adsorbent functionalized with surface molecular imprinting. The preparation method is the same as that of Example 1, except that 0.15 L of 3-aminopropyltriethoxysilane is dropped into the modification reaction, 7.1 g of acrylamide is added as a functional monomer in step (1), and 71.3 g of ethylene glycol dimethacrylate is added as a cross-linking agent in step (2).

[0259] Example 7 This example provides a method for preparing an adsorbent functionalized with surface molecular imprinting. The preparation method is the same as that of Example 1, except that the carrier Al 2 O 3 is not modified

[0260] Example 8 This example provides a method for preparing an adsorbent functionalized with surface molecular imprinting. The preparation method is the same as that of Example 1, except that the carrier Al 2 O 3 is replaced with a silica carrier

[0261] Example 9 This example provides a method for preparing an adsorbent functionalized with surface molecular imprinting. The preparation method is the same as that of Example 1, except that prepolymerization in step (1) is not performed, and the functional monomer, azepine compound template, crosslinking agent, and initiator are directly polymerized together.

[0262] The specific steps are as follows. (1) 3 g of acrylamide as the functional monomer, 2 g of 3,4,5,6-tetrahydro-2H-azepine as the azepine compound template, and 20 g of the modified carrier were dispersed in 2 L of ethanol by ultrasonic for 30 min, and then 71.5 g of ethylene glycol dimethacrylate as the crosslinking agent and 0.8 g of azobisisobutyronitrile as the initiator were added in a nitrogen atmosphere, and a polymerization reaction was carried out at 60 °C for 24 h to obtain polymer particles. (2) In a Soxhlet extractor, a mixed acid solution of formic acid and acetic acid with a volume ratio of 8:1 was used to extract the 2,3,4,5,6-tetrahydro-2H-azepine template in the polymer particles until 3,4,5,6-tetrahydro-2H-azepine could not be detected in the extract. The polymer particles with the 3,4,5,6-tetrahydro-2H-azepine template removed were placed in vacuum drying at 60 °C and dried until a constant weight was obtained to obtain an adsorbent functionalized with surface molecular imprinting.

[0263] Example 10 This example provides a method for preparing an adsorbent functionalized with surface molecular imprinting. The preparation method includes the following steps.

[0264] First, 15 g of carrier Al 2 O 3 and 1 L of anhydrous toluene were mixed and dispersed by ultrasonic for 45 min, and then 15 mL of 3-aminopropyltriethoxysilane was dropped under a nitrogen atmosphere, and a modification reaction was carried out at 80 °C for 10 h. The obtained modification reaction product was sequentially filtered, washed 4 times with toluene, washed 3 times with methanol, and dried at 40 °C in a vacuum drying oven to obtain a modified carrier.

[0265] (1) 3.2 g of acrylamide, which is a functional monomer, and 1 g of 3,4,5,6-tetrahydro-2H-azepine, which is an azepine-based compound template, were stirred in 1 L of ethanol at 15 °C for 20 h for prepolymerization to obtain a prepolymerization reaction material containing a prepolymer.

[0266] (2) First, the prepolymerization reaction material from step (1) was mixed with 30 g of a modified carrier and dispersed by ultrasonic waves for 60 min. Then, in a nitrogen atmosphere, 78.6 g of ethylene glycol dimethacrylate, which is a cross-linking agent, and 1 g of azobisisobutyronitrile, which is an initiator, were added, and a polymerization reaction was carried out at 40 °C for 48 h to obtain polymer particles.

[0267] (3) In a Soxhlet extractor, a mixed acid solution of formic acid and acetic acid with a volume ratio of 10:1 was used to extract the 2,3,4,5,6-tetrahydro-2H-azepine template in the polymer particles until 3,4,5,6-tetrahydro-2H-azepine could not be detected in the extract. The polymer particles with the 3,4,5,6-tetrahydro-2H-azepine template removed were placed in a vacuum drying at 100 °C and dried until a constant weight was obtained to obtain an adsorbent with surface molecular imprinting functionalization.

[0268] Example 11 This example provides a method for preparing an adsorbent with surface molecular imprinting functionalization, and the preparation method includes the following steps.

[0269] First, 60 g of carrier Al 2 O 3 was mixed with 2 L of anhydrous toluene, ultrasonically dispersed for 60 min, and then 0.1 L of 3-aminopropyltriethoxysilane was dropped under a nitrogen atmosphere, and a modification reaction was carried out at 100 °C for 25 h. The obtained modification reaction material was sequentially filtered, washed 3 times with toluene, washed 4 times with methanol, and dried at 100 °C in a vacuum drying oven to obtain a modified carrier.

[0270] (1) 5.7 g of acrylamide, which is a functional monomer, and 2 g of 3,4,5,6-tetrahydro-2H-azepine, which is an azepine-based compound template, were stirred in 0.5 L of ethanol at room temperature (25 °C) for 10 h for prepolymerization to obtain a prepolymerization reaction material containing a prepolymer.

[0271] (2) First, the prepolymerization reaction material of step (1) and 2.5 g of a modified carrier were mixed and dispersed by ultrasonic waves for 20 min. Then, 79.0 g of ethylene glycol dimethacrylate, which is a cross-linking agent, and 0.05 g of azobisisobutyronitrile, which is an initiator, were added under a nitrogen atmosphere, and a polymerization reaction was carried out at 60 °C for 24 h to obtain polymer particles.

[0272] (3) In a Soxhlet extractor, a mixed acid solution of formic acid and acetic acid with a volume ratio of 5:1 was used to extract the 2,3,4,5,6-tetrahydro-2H-azepine template in the polymer particles until 3,4,5,6-tetrahydro-2H-azepine could not be detected in the extract. The polymer particles with the 3,4,5,6-tetrahydro-2H-azepine template removed were placed in vacuum drying at 40 °C and dried until a constant weight was obtained to obtain an adsorbent with surface molecular imprint functionalization.

[0273] Comparative Example 1 This comparative example provides a method for preparing an adsorbent. The preparation method is the same as that of Example 1 except that 3,4,5,6-tetrahydro-2H-azepine, which is an azepine-based compound template, was not added.

[0274] Application Example 1 This application example provides a method for purifying hexamethylenediamine. The purification method includes adding 1 kg of the adsorbent obtained in Example 1 to a 1 m 3 reaction kettle, further adding 500 kg of rectified hexamethylenediamine, stirring to disperse uniformly, stirring at room temperature (25 °C) for 20 h for adsorption, then filtering to separate the adsorbent, and analyzing the content of the filtrate by gas chromatography.

[0275] Application Examples 2 to 9 Application Examples 2 to 9 each provide a method for purifying hexamethylenediamine. The purification methods are the same as those in Application Example 1, except that the adsorbents provided in Examples 2 to 9 are respectively adopted for regeneration.

[0276] Application Example 10 This application example provides a method for purifying hexamethylenediamine. The purification method includes filling 1 kg of the adsorbent obtained in Example 10 into four serially connected adsorption columns, and further introducing the rectified hexamethylenediamine at a rate of 0.5 h -1 for adsorption at 35°C, and analyzing the content of the liquid phase by gas chromatography after adsorption.

[0277] Application Example 11 This application example provides a method for purifying hexamethylenediamine. The purification method includes adding 2.5 kg of the adsorbent obtained in Example 11 to a 2 m 3 reaction kettle, further adding 500 kg of hexamethylenediamine, stirring to disperse uniformly, shaking for 35 h at room temperature (25°C) for adsorption, filtering to separate the adsorbent, and analyzing the content of the filtrate by gas chromatography.

[0278] Application Comparative Example 1 This application comparative example provides a method for purifying hexamethylenediamine. The purification method is the same as that in Application Example 1, except that the adsorbent provided in Comparative Example 1 is adopted.

[0279] Application Comparative Example 2 This application comparative example provides a method for purifying hexamethylenediamine, and the purification method adopts the purification method provided in Example 1 of CN103936595A. The measurement results of the above application examples and application comparative examples are shown in Table 1.

[0280]

Table 1

[0281] As can be seen from Table 1, first, by comprehensively considering Application Examples 1 to 6 and Application Examples 10 to 11, for hexamethylenediamine with different impurity contents, the purification method according to the present invention can improve the purity of hexamethylenediamine to 99.99 wt% or more, and the yield of hexamethylenediamine is 98 wt% or more, the loss rate is low, and the content of 3,4,5,6-tetrahydro-2H-azepine after adsorption is ≦0.011 wt%.

[0282] Next, by comprehensively considering Application Example 1 and Application Comparative Example 1, the present invention can improve the purity of hexamethylenediamine to 99.98 wt% or more by adopting an adsorbent functionalized with surface molecular imprinting for adsorption purification, and has an excellent effect on further removing trace impurities.

[0283] Again, as can be seen from Application Example 1 and Application Examples 7 to 8, when a modified aluminum oxide carrier is adopted in Application Example 1, compared with the unmodified aluminum oxide carrier in Application Example 7 and the silica carrier in Application Example 8, the purity after adsorption in Application Example 1 is 99.992 wt%, while the purity of hexamethylenediamine after adsorption in Application Examples 7 to 8 is only 99.989 wt% and 99.990 wt% respectively. Thereby, it is shown that the present invention can further improve the impurity removal performance by preferably using the modified aluminum oxide as the carrier.

[0284] Finally, as can be seen from Application Example 1 and Application Example 9, in Application Example 1, an adsorbent was prepared by adopting a prepolymerization method. Compared with the direct total polymerization in Application Example 9, the purity of hexamethylenediamine after adsorption in Application Example 1 was 99.992 wt%, and the content of 3,4,5,6-tetrahydro-2H-azepine after adsorption was only 0.005 wt%. However, the purity of hexamethylenediamine after adsorption in Application Example 9 was 99.988 wt%, and the content of 3,4,5,6-tetrahydro-2H-azepine after adsorption was as high as 0.011 wt%. Therefore, the present invention preferably prepares the adsorbent by the prepolymerization method first, which significantly improves the purification effect of hexamethylenediamine and reduces the content of 3,4,5,6-tetrahydro-2H-azepine after adsorption.

[0285] Taking the adsorbent provided in Example 2 as an example, the adsorption purification of hexamethylenediamine was carried out by the method provided in Application Example 2, and the adsorption effect after the catalyst was regenerated multiple times was considered. Here, the regeneration treatment method was to place the recovered adsorbent in a Soxhlet extractor and continuously extract the template molecules in the adsorbent with a mixed solution of methanol and acetic acid at a ratio of 8:1 until no template molecules could be detected in the extract. Then, the adsorbent was placed in a vacuum drying oven and dried until it reached a constant weight to obtain the regenerated adsorbent. The regenerated adsorbent was used in the method in Application Example 2 for adsorption, and this was repeated 5 times in this way to consider the regeneration performance of the adsorbent. The specific consideration results are shown in Table 2.

[0286]

Table 2

[0287] As can be seen from Table 2, after the regeneration was repeated 4 times, all the adsorbents could purify hexamethylenediamine to more than 99.99%, showing good regeneration performance. After the regeneration was repeated 5 times, the performance of the adsorbent decreased slightly, but still could purify hexamethylenediamine to more than 99.98%. Therefore, the adsorbent of the present invention can be used repeatedly, reducing the use cost.

[0288] As described above, the adsorbent functionalized with surface molecular imprinting provided by the present invention can be recycled multiple times, and has characteristics such as low cost, simple operation, high selectivity, and environmental friendliness. This is applied to the purification process of hexamethylenediamine, and under favorable conditions, the purity of hexamethylenediamine can be improved to 99.99 wt% or more, and the yield of hexamethylenediamine can reach 98 wt% or more. Also, the content of 3,4,5,6-tetrahydro-2H-azepine can be reduced to 0.011 wt% or less, reducing the impact on subsequent nylon products.

[0289] Examples of the ammoniation catalyst Catalyst A1 Catalyst A1 is a hollow cylindrical catalyst. The catalyst contains the first type of pore channels, and the main body of the catalyst further contains the second type of pore channels. The second type of pore channels are cylindrical pore channels with a diameter of 1 mm and a height of 5 mm. The main body of the catalyst is cylindrical with a diameter of 4.2 mm and a height of 5 mm.

[0290] The pore diameter of the first type of pore channels is in the nanoscale, and the pore diameter of the first type of pore channels is 12.61 nm.

[0291] The pore volume of the catalyst is 0.694 cm 3 / g, the specific surface area of the catalyst is 178.23 m 2 / g, and the molar ratio of silicon, aluminum, and phosphorus is 1:0.8:0.2.

[0292] The preparation method of catalyst A1 was carried out with reference to CN111659463A. In the molding step, a mold matching catalyst A1 was used for molding. Except for forming catalyst A1 with a specific structure, the preparation method was carried out with reference to CN111659463A.

[0293] Catalysts A2 to A4 have the same structure and manufacturing method as catalyst A1, and the difference lies in that the molar ratios of silicon, aluminum, and phosphorus are 1:0.8:0.5, 1:0.8:0.8, and 1:0.8:1.6, respectively.

[0294] Catalyst B1 Catalyst B1 is a clover-shaped columnar catalyst having a columnar body 1 with a height of 5 mm and a protruding portion 2. The leaf lobes other than the intersections of the clover circles are taken as the protruding portion 2. As shown in FIG. 4, the interior of the dashed line is the main body portion of the catalyst, and the portion other than the dotted circle is the protruding portion 2. The diameter of the dotted circle is 3 mm, and a marked by the dashed-dotted line is the length of the protruding portion 2, which was 1.6 mm.

[0295] The pore diameter of the first type of pore channels is on the nanoscale, and the pore diameter of the first type of pore channels was 16.29 nm.

[0296] The pore volume of the catalyst is 0.719 cm 3 / g, and the specific surface area of the catalyst is 151.89 m 2 / g, and the molar ratio of silicon, aluminum, and phosphorus was 1:0.8:0.2.

[0297] The preparation method of catalyst B1 was carried out with reference to CN111659463A. In the molding step, molding was carried out using a mold that matches catalyst B1 to form a catalyst B1 with a specific structure. Except for this, the preparation method was carried out with reference to CN111659463A.

[0298] Catalysts B2 to B4 are the same as catalyst B1 in terms of structure and manufacturing method. The difference is that the molar ratios of silicon, aluminum, and phosphorus are 1:0.8:0.3, 1:0.8:0.5, and 1:0.8:1.5, respectively.

[0299] Catalyst C1 Catalyst C1 is a three-hole ball-shaped catalyst. As shown in FIG. 5, the three-hole ball-shaped catalyst includes a spherical main body 1 and a second type of pore channels 3 inside. The second type of pore channels 3 is a single pore that penetrates the main body 1. Three are provided, the diameter of the single pore is 1.0 mm, the three single pores exhibit an equilateral triangle distribution, and the diameter of the spherical main body 1 was 4.5 mm.

[0300] The pore diameter of the first type of pore channels is on the nanoscale, and the pore diameter of the first type of pore channels was 18.43 nm.

[0301] The pore volume of the catalyst is 0.781 cm 3 / g, and the specific surface area of the catalyst is 201.77 m 2 / g. The molar ratio of silicon, aluminum, and phosphorus was 1:0.6:0.3.

[0302] The preparation method of catalyst C1 was carried out with reference to CN111659463A. In the forming step, it was formed using a mold that matches catalyst C1 to form a catalyst C1 with a specific structure. Except for this, the preparation method was carried out with reference to CN111659463A.

[0303] Catalysts C2 to C3 were the same as the structure and manufacturing method of catalyst C1. The difference was that the molar ratios of silicon, aluminum, and phosphorus were 1:0.6:0.7, 1:0.6:0.9, and 1:0.6:1.3, respectively.

[0304] Catalysts D1 to D4 were the same as catalysts A1 to A4, respectively, except that they were solid cylindrical catalysts.

[0305] Examples of the first adsorbent The first adsorbent a The preparation method of the first adsorbent a includes the following steps.

[0306] (1) Mix 1.2 kg of montmorillonite and a hydrochloric acid solution with a concentration of 21% for pretreatment. First, immerse it at room temperature for 2.5 h for the first time, then heat it to 85 °C and filter while it is hot. During the filtration process, wash the montmorillonite with pure water multiple times and dry it until it reaches a constant weight to obtain a precursor.

[0307] (2) Add 250 g of the precursor to 0.8 L of a metal salt solution. The metal salt solution is an aqueous solution with a total concentration of 0.1 mol / L AgNO 3 / Cd(NO 3 ) 2 (n Ag / n Cd= 1:1), and this was placed on a vibrating shaker at a rotation speed of 50 rpm and secondarily immersed for 4 h, dried until a constant weight was achieved, and the dried adsorbent was calcined in a muffle furnace at a heating rate of 6 °C / min, an end point temperature of 550 °C, and the calcination time at the end point temperature was 3 h to obtain the first adsorbent a.

[0308] The first adsorbent b The preparation method of the first adsorbent b includes the following steps.

[0309] (1) 1 kg of ZSM-5 zeolite molecular sieve and a nitric acid solution with a concentration of 50% were mixed for pretreatment, first immersed at room temperature for 10 h, then heated to 50 °C, filtered while hot, and the ZSM-5 zeolite molecular sieve was washed multiple times with pure water during the filtration process, and the ZSM-5 zeolite molecular sieve was dried until a constant weight was achieved to obtain a precursor.

[0310] (2) 250 g of the precursor was added to an aqueous solution of 0.3 L with a total concentration of 0.5 mol / L AgNO 3 / Cd(NO 3 ) 2 (n Ag / n Cd = 1:1), placed on a vibrating shaker at a rotation speed of 50 rpm and secondarily immersed for 0.5 h, dried until a constant weight was achieved, and the dried adsorbent was calcined in a muffle furnace at a heating rate of 5.5 °C / min, an end point temperature of 300 °C, and the calcination time at the end point temperature was 8 h to obtain the first adsorbent b.

[0311] The first adsorbent c The preparation method of the first adsorbent c includes the following steps.

[0312] (1) 1 kg of ZSM-5 zeolite molecular sieve and a hydrogen peroxide solution with a concentration of 12% were mixed for pretreatment, first immersed at room temperature for 15 h, then heated to 65 °C, filtered while hot, and the ZSM-5 zeolite molecular sieve was washed multiple times with pure water during the filtration process, and the ZSM-5 zeolite molecular sieve was dried until a constant weight was achieved to obtain a precursor.

[0313] (2) 500 g of the precursor was added to 1.2 L with a total concentration of 0.08 mol / L AgNO3 It was added to an aqueous solution, placed on a shaking incubator with a rotation speed of 20 rpm, and secondarily immersed for 5 h. It was dried until it reached a constant weight, and the dried adsorbent was calcined in a muffle furnace. The heating rate was 5.5 °C / min, the end point temperature was 250 °C, and the calcination time at the end point temperature was 3.6 h, to obtain the first adsorbent c.

[0314] Examples of hydrogenation catalysts Catalyst I Catalyst I is a nitrogen and phosphorus co-doped carbon-based cobalt catalyst, and its preparation method includes the following steps.

[0315] (I) 100.84 g of activated carbon (carbon content 84.5%, pore volume 9.6 cm 3 / g, specific surface area 273 m 2 / g), 30.72 g of cobalt nitrate hexahydrate, 51.03 g of urea, 9.79 g of triphenylphosphine, and a solvent (100.66 g of water and 101.29 g of ethanol) were mixed, and the stirring and mixing time was 12 h to obtain a mixed material.

[0316] (II) The mixed material was slowly dried at 55 °C for 24 h to remove the solvent, obtaining a solvent-removed material.

[0317] (III) After the solvent-removed material was polished to be uniform, it was placed in a tubular furnace and pyrolyzed in an argon gas atmosphere. The mass space velocity of the argon gas was 1 h -1 , heated to 600 °C at 5 °C / min, and the pyrolysis time was 2 h, obtaining a nitrogen and phosphorus co-doped carbon-based cobalt catalyst.

[0318] The nitrogen adsorption and desorption curve of Catalyst I is shown in Figure 6. As can be seen from Figure 6, Catalyst I has excellent adsorption performance, and the specific surface area is 271 m 2 / g, and as can be seen from Figure 7, Catalyst I contains N, P, Co, and O elements. And as can be seen from the analysis, the catalyst contains 3.11% Co, 4.10% N, and 0.81% P. As can be seen from the transmission electron microscope image in Figure 8, the nitrogen / phosphorus co-doped carbon-based cobalt catalyst has a nitrogen / phosphorus-doped carbon coating layer formed around cobalt, and the distribution of cobalt centers is uniform.

[0319] Catalyst II Catalyst II is a nitrogen / phosphorus co-doped carbon-based cobalt catalyst, and its preparation method includes the following steps.

[0320] (I) Mix 100.56 g of activated carbon (carbon content 91.5%, pore volume 5.6 cm 3 / g, specific surface area 355 m 2 / g), 38.59 g of cobalt oxalate, 27.05 g of ethylenediamine, 83.02 g of diethylphenylphosphine, and a solvent (250.25 g of water and 49.98 g of ethanol), and the stirring and mixing time is 6 h to obtain a mixed material.

[0321] (II) Slowly dry the mixed material at 45 °C for 48 h to remove the solvent and obtain a solvent-removed material.

[0322] (III) After polishing the solvent-removed material to make it uniform, place it in a tubular furnace and pyrolyze it in an argon gas atmosphere. The mass space velocity of the argon gas is 0.2 h -1 and heat it up to 800 °C at a rate of 4 °C / min. The pyrolysis time is 1.5 h to obtain a nitrogen / phosphorus co-doped carbon-based cobalt catalyst.

[0323] Catalyst III Catalyst III is a nitrogen / phosphorus co-doped carbon-based cobalt catalyst, and its preparation method includes the following steps.

[0324] (I) 100.93 g of activated carbon (carbon content 78.7%, pore volume 11.7 cm 3 / g, specific surface area 486 m 2(g), 7.29 g of cobalt acetate tetrahydrate, 78.23 g of ethylenediamine / piperazine (mass ratio 1:1), 10.02 g of triethylphosphine and a solvent (30.36 g of water and 150.14 g of ethanol) were mixed, and the mixing time was 8 h to obtain a mixed material.

[0325] (II) The mixed material was slowly dried at 60 °C for 6 h to remove the solvent, obtaining a solvent-removed material.

[0326] (III) After the solvent-removed material was polished to be uniform, it was placed in a tubular furnace and pyrolyzed in an argon gas atmosphere. The mass space velocity of the argon gas was 3 h -1 and the temperature was raised to 700 °C at 10 °C / min, and the pyrolysis time was 3.5 h to obtain a nitrogen and phosphorus co-doped carbon-based cobalt catalyst.

[0327] Catalyst IV Catalyst IV is a nitrogen-doped carbon-based cobalt catalyst, and its preparation method is the same as that of Catalyst I except that triphenylphosphine is not added in step (I).

[0328] Catalyst V Catalyst V is a phosphorus-doped carbon-based cobalt catalyst, and its preparation method is the same as that of Catalyst I except that urea is not added in step (I).

[0329] Second adsorbent α The preparation method of the second adsorbent α is the same as the preparation method of Example 1.

[0330] Second adsorbent β The second adsorbent β provides a surface molecule imprint-functionalized second adsorbent. The second adsorbent includes a carrier Al 2 O 3 and surface molecules supported on the carrier Al 2 O 3 and imprint cavities are formed between the surface molecules, and the imprint cavities match the azepine compounds.

[0331] The preparation method of the second adsorbent β includes the following steps.

[0332] First, 15 g of the carrier Al 2 O 3 was mixed with 1 L of anhydrous toluene, dispersed by ultrasonic waves for 45 min, and then 15 mL of 3-aminopropyltriethoxysilane was added dropwise under a nitrogen atmosphere, followed by a modification reaction at 80 °C for 10 h. The obtained modified reaction product was sequentially filtered, washed 4 times with toluene, washed 3 times with methanol, and dried at 40 °C in a vacuum drying oven to obtain a modified carrier.

[0333] (1) 3.2 g of acrylamide, which is a functional monomer, and 1 g of 3,4,5,6-tetrahydro-2H-azepine, which is an azepine-based compound template, were stirred in 1 L of ethanol at 15 °C for 20 h for prepolymerization to obtain a prepolymerization reaction material containing a prepolymer.

[0334] (2) First, the prepolymerization reaction material in step (1) was mixed with 30 g of the modified carrier, dispersed by ultrasonic waves for 60 min, and then 78.6 g of ethylene glycol dimethacrylate, which is a cross-linking agent, and 1 g of azobisisobutyronitrile, which is an initiator, were added under a nitrogen atmosphere, followed by a polymerization reaction at 40 °C for 48 h to obtain polymer particles.

[0335] (3) In a Soxhlet extractor, a mixed acid solution of formic acid and acetic acid with a volume ratio of 10:1 was used to extract the 3,4,5,6-tetrahydro-2H-azepine template in the polymer particles until 3,4,5,6-tetrahydro-2H-azepine could not be detected in the extract. The polymer particles with the 3,4,5,6-tetrahydro-2H-azepine template removed were placed in a vacuum drying at 100 °C and dried until a constant weight was obtained to obtain the second adsorbent β with surface molecular imprint functionalization.

[0336] The second adsorbent γ The second adsorbent γ provides a second adsorbent with surface molecular imprint functionalization. The second adsorbent is the carrier Al 2 O 3 and the carrier Al 2 O3 It contains surface molecules supported thereon, an imprint cavity is formed between the surface molecules, and the imprint cavity matches an azepine compound.

[0337] The preparation method of the second adsorbent γ includes the following steps.

[0338] First, 60 g of carrier Al 2 O 3 is mixed with 2 L of anhydrous toluene, dispersed by ultrasonic wave for 60 min, then 0.1 L of 3-aminopropyltriethoxysilane is dropped in under a nitrogen atmosphere, and a modification reaction is carried out at 100 °C for 25 h. The obtained modified reaction product is sequentially filtered, washed three times with toluene, washed four times with methanol, and dried in a vacuum drying oven at 100 °C to obtain a modified carrier.

[0339] (1) 5.7 g of acrylamide, which is a functional monomer, and 2 g of 3,4,5,6-tetrahydro-2H-azepine, which is an azepine compound template, are stirred with 0.5 L of ethanol at room temperature (25 °C) for 10 h of prepolymerization to obtain a prepolymerization reaction material containing a prepolymer.

[0340] (2) First, the prepolymerization reaction material in step (1) and 2.5 g of the modified carrier are mixed, dispersed by ultrasonic wave for 20 min, then 79.0 g of ethylene glycol dimethacrylate, which is a cross-linking agent, and 0.05 g of azobisisobutyronitrile, which is an initiator, are added under a nitrogen atmosphere, and a polymerization reaction is carried out at 60 °C for 24 h to obtain polymer particles.

[0341] (3) In a Soxhlet extractor, a mixed acid solution of formic acid and acetic acid with a volume ratio of 5:1 is adopted. The 3,4,5,6-tetrahydro-2H-azepine template in the polymer particles is extracted until 3,4,5,6-tetrahydro-2H-azepine cannot be detected in the extract. The polymer particles with the 3,4,5,6-tetrahydro-2H-azepine template removed are placed in vacuum drying at 40 °C and dried until a constant weight is obtained to obtain the second adsorbent γ with surface molecular imprint functionalization.

[0342] The second adsorbent δ, i.e., the adsorbent prepared in Comparative Example 1. Example of preparing hexamethylenediamine

[0343] Example 12 This example provides a method for preparing hexamethylenediamine from caprolactam. As shown in FIGS. 9 to 11, the apparatus employed in the method includes a vaporization unit 10, an ammoniation reaction unit 20, a first purification unit 30, a first adsorption unit 40, a hydrogenation reaction unit 50, a second purification unit 60, and a second adsorption unit 70 connected in sequence.

[0344] The vaporization unit 10 includes a Venturi vaporizer. The Venturi vaporizer includes a converging section 101, a throat section 102, and a diverging section 103. A first inlet 104 is installed in the converging section 101, a first gas outlet 105 is installed in the diverging section 103, and a second inlet is installed in the throat section 102. The Venturi vaporizer further includes an external circulation pipeline connecting the diverging section 103 and the throat section 102. A material conveying device 106 is installed in the external circulation pipeline. The external circulation pipeline is installed at the lowest point position of the diverging section 103. A turbulence member is installed inside the diverging section 103. An atomizing nozzle is installed at the second inlet.

[0345] The ammoniation reaction unit 20 includes a fixed bed reactor, and the fixed bed reactor includes four fixed bed reactors connected in series.

[0346] The hydrogenation reaction unit 50 includes a magnetic stabilization reactor. The magnetic stabilization reactor includes a tubular reactor 502 and at least two Helmholtz coils 509 installed outside the tubular reactor 502 and arranged in the axial direction. Each of the Helmholtz coils 509 is independently connected to a transformer device. The number of turns of each Helmholtz coil 509 is 20. The magnetic stabilization reactor further includes a first heating device 501 installed in front of the tubular reactor 502 and connected to the tubular reactor 502. A heating member 503 is installed outside the first heating device 501. A quartz filler is installed inside the first heating device 501. A third inlet 504 is installed on the lower side of the first heating device 501, and a first outlet 505 is installed at the top. A fourth inlet 506 is installed at the bottom of the tubular reactor 502. The fourth inlet 506 is connected to the first outlet 505. A hydrogen gas inlet 507 is further installed at the bottom and / or lower side of the tubular reactor 502. A catalyst inlet 508 is installed on the lower side of the tubular reactor 502. The installation position of the catalyst inlet 508 is on the lower surface of the Helmholtz coil 509. A catalyst outlet 5012 is installed on the upper side of the tubular reactor 502. The catalyst outlet 5012 is installed on the upper surface of the Helmholtz coil 509. A product outlet 5011 is installed on the upper side of the tubular reactor 502. An exhaust gas outlet 5010 is installed at the top of the tubular reactor 502.

[0347] Specifically, the method includes the following steps.

[0348] (1) After mixing trimethyl phosphate (occupying 10 ppm of the weight of ammonia gas) and ammonia gas, the mixture was preheated at 500 °C to superheat the ammonia gas and obtain a mixed gas. The mixed gas was mixed and vaporized at 350 °C in a liquid-phase state of the i-th partial organic amide with a temperature of 120 °C and a Venturi vaporizer, and then introduced into a first segment fixed-bed reactor (a total of 4 fixed-bed reactors connected in series, regarded as a 4-segment fixed-bed reactor, and the same weight of catalyst was filled in each segment fixed-bed reactor), and reacted under the action of a first reaction temperature, a first reaction pressure and a first catalyst to obtain a first reaction discharge sample.

[0349] The i-th reaction discharge sample is introduced into the i+1-th segment fixed bed reactor with the i+1-th partial organic amide, the value range of i is 1≦i≦3, and i is a natural number, and the reaction is carried out under the action of the i+1-th reaction temperature, the i+1-th reaction pressure and the i+1-th catalyst, and the i+1-th reaction discharge sample is obtained, where the i+1-th reaction discharge sample is circulated as the i-th reaction discharge sample of the next step, and the ammonification reaction is carried out until i+1=n (n=4), and the first reaction discharge sample is obtained.

[0350] The first to fourth reaction temperatures are 350° C., 375° C., 400° C., and 425° C., respectively, the first to fourth reaction pressures are 0 MPa, 0.3 MPa, 0.6 MPa, and 0.9 MPa, respectively, the first to fourth catalysts are catalysts A1 to A4, respectively, the amount of caprolactam in the i-th portion is the same as the amount of caprolactam in the i+1-th portion, and the total caprolactam hourly space velocity is 5 h -1 and the total molar ratio of the ammonia gas to the organic amide was 5:1.

[0351] (2) The first reaction discharge sample is rectified to obtain crude 6-aminohexanenitrile, and the crude 6-aminohexanenitrile is condensed at a space velocity of 1 h -1 The product was purified by adsorption through the first adsorbent a at 35°C and 0.5 MPa to obtain 6-aminohexanenitrile.

[0352] The polymer residue produced in step (1) and step (2) is mixed with water, and the mass ratio of the polymer residue to the water is 1:4. The mixture is heated at 200° C., 5 MPa, and Al 2 O 3 The depolymerization reaction was carried out under the action of solid acid catalyst for 3 h, the mass ratio of polymer residue to catalyst was 1:0.4, and then the reaction mixture was subjected to negative pressure dehydration and negative pressure distillation to obtain 6-aminohexanenitrile and caprolactam, respectively.

[0353] (3) Load 50 g of Catalyst I with a particle size D50 = 20 μm into the second tubular reactor in the magnetically stabilized bed reactor. Mix 6-aminohexanenitrile, solvent methanol, and auxiliary agent NaOH, introduce it into the first heating device, preheat it to 100 °C, and then introduce it into the second tubular reactor. React 6-aminohexanenitrile with hydrogen under the conditions of a pressure of 2.0 MP and a magnetic field strength of 1000 A·m -1 to prepare hexamethylenediamine, and obtain the post-reaction material. However, the space velocity of 6-aminohexanenitrile is 20 h -1 . The molar ratio of hydrogen gas to 6-aminohexanenitrile is 5:1, the mass ratio of 6-aminohexanenitrile to the solvent is 1:3, and the mass ratio of 6-aminohexanenitrile to the auxiliary agent is 1:0.001.

[0354] (4) Rectify the post-reaction material at 120 °C and -0.095 MPaG to obtain crude hexamethylenediamine. Add 1 kg of the second adsorbent α to a 1 m 3 reactor, and then add 500 kg of crude hexamethylenediamine, stir to disperse it uniformly, and stir and adsorb it at room temperature (25 °C) for 20 h to obtain hexamethylenediamine.

[0355] The method for regenerating the catalyst for the ammoniation reaction in this example includes the following steps.

[0356] An oxygen-containing gas with an initial oxygen content of 1 v / v% is pumped from the first inlet of the fixed-bed reactor and sequentially introduced into four series-connected fixed-bed reactors containing deactivated silicon-aluminum-phosphorus molecular sieves. Supplementary oxygen-containing gas (air) is introduced from the first side port into the third side port, and the oxygen content at the inlet of each fixed-bed reactor is controlled to be the same as the oxygen content of the oxygen-containing gas at the inlet of the first fixed-bed reactor to regenerate the deactivated catalyst.

[0357] The regeneration process includes a pre-regeneration stage and a post-regeneration stage. In the pre-regeneration stage, the oxygen content of the oxygen-containing gas is fixed at 1 v / v%, the initial temperature of regeneration is 300 °C, and the temperature is raised to the final temperature of 800 °C at a rate of 2 °C / h; when entering the post-regeneration stage, the regeneration temperature is fixed at 800 °C, the oxygen content of the oxygen-containing gas is increased at a rate of 0.1 v / v% / h to the final oxygen content of 10 v / v%, and the regeneration is continued by holding at the final oxygen content and the final temperature for 180 h to obtain a regenerated catalyst.

[0358] Example 13 This example provides a method for preparing hexamethylenediamine from caprolactam, and the method includes the following steps.

[0359] (1) After mixing isopropoxydistearoyl aluminate (occupying 20 ppm of the weight of ammonia gas) with ammonia gas, it is preheated at 600 °C to superheat the ammonia gas to obtain a mixed gas.

[0360] The mixed gas is mixed and vaporized at 500 °C in a first partial organic amide in a liquid phase state with a temperature of 220 °C and a Venturi vaporizer, and then introduced into a first segment fixed bed reactor (a total of 4 fixed bed reactors connected in series, regarded as a 4-segment fixed bed reactor, and the same weight of catalyst is filled in each segment fixed bed reactor), and the reaction is carried out under the action of the first reaction temperature, the first reaction pressure and the first catalyst to obtain a first reaction discharge sample.

[0361] The i-th reaction discharge sample is introduced into the i+1-th segment fixed bed reactor with the i+1-th organic amide, the range of i being 1≦i≦3, and i being a natural number; the reaction is carried out under the action of the i+1-th reaction temperature, the i+1-th reaction pressure and the i+1-th catalyst; the i+1-th reaction discharge sample is obtained; the i+1-th reaction discharge sample is circulated to i+1=n (n=4) as the i-th reaction discharge sample of the next step; the first to fourth reaction temperatures are 300°C, 375°C, 450°C and 500°C, respectively; the first to fourth reaction pressures are 0.2MPa, 0.5MPa, 0.7MPa and 1.0MPa, respectively; the first to fourth catalysts are catalysts B1 to B4, respectively; the amount of caprolactam in the i-th portion is the same as the amount of caprolactam in the i+1-th portion; and the hourly space velocity of the total caprolactam is 10h -1 and the total molar ratio of the ammonia gas to the organic amide was 50:1.

[0362] (2) The reaction discharge sample is rectified to obtain crude 6-aminohexanenitrile, and the crude 6-aminohexanenitrile is rectified at a space velocity of 3 h -1 The product was purified by adsorption using the first adsorbent b at 60°C and 1 MPa to obtain 6-aminohexanenitrile product.

[0363] The polymer residue produced in step (1) and step (2) is mixed with water, the mass ratio of the polymer residue to water is 1:20, and the mixture is heated at 100° C., 10 MPa, and Cu(OH) 2 Depolymerization reaction was carried out for 10 h under the action of solid base catalyst, the mass ratio of polymer residue to catalyst was 1:0.5, and then 6-aminohexanenitrile and caprolactam were obtained through negative pressure dehydration and negative pressure distillation, respectively.

[0364] (3) 60 g of catalyst II having a particle size D50 = 300 μm was loaded into the second tubular reactor in the magnetically stabilized bed reactor, and 6-aminohexanenitrile, isopropanol as a solvent, and Ba(OH) 2 were mixed, introduced into the first heating device and preheated to 200 °C, and then introduced into the second tubular reactor under a pressure of 5.0 MPa and a magnetic field strength of 8000 A m -1Under the following conditions, 6-aminohexanenitrile reacts with hydrogen gas to prepare hexamethylenediamine, and the material after the reaction is obtained. However, the space velocity of 6-aminohexanenitrile is 15 h -1 and the molar ratio of hydrogen gas to 6-aminohexanenitrile is 100:1, the mass ratio of 6-aminohexanenitrile to the solvent is 1:50, and the mass ratio of 6-aminohexanenitrile to the auxiliary agent is 1:0.001.

[0365] (4) The material after the reaction is rectified at 120 °C and -0.095 MPaG to obtain crude hexamethylenediamine. Four adsorption columns filled with 1 kg of the second adsorbent β in series are filled, and 0.3 h -1 The crude hexamethylenediamine is introduced at a rate of, and adsorbed at 35 °C to obtain hexamethylenediamine.

[0366] The method for regenerating the catalyst for the ammoniation reaction in this example includes the following steps.

[0367] The oxygen-containing gas with an initial oxygen content of 2 v / v% is pumped from the first inlet of the fixed-bed reactor and sequentially introduced into four fixed-bed reactors in series containing deactivated silicon-aluminum-phosphorus molecular sieve. Supplementary oxygen-containing gas (air) is introduced from the first side port to the third side port, and the oxygen content at the inlet of each fixed-bed reactor is controlled to be the same as the oxygen content of the oxygen-containing gas at the inlet of the first fixed-bed reactor, and the regeneration of the deactivated catalyst is carried out.

[0368] The regeneration process includes a pre-regeneration stage and a post-regeneration stage. In the pre-regeneration stage, the oxygen content of the oxygen-containing gas is fixed at 2 v / v%, the initial temperature of regeneration is 250 °C, and the temperature is raised to the final temperature of 800 °C at 20 °C / h; entering the post-regeneration stage, the temperature of regeneration is fixed at 800 °C, the oxygen content of the oxygen-containing gas rises at 2 v / v% / h to the final oxygen content of 21 v / v% / h, and the regeneration is continued by holding at the final oxygen content and the final temperature for 100 h to obtain a regenerated catalyst.

[0369] Example 14 This embodiment provides a method for preparing hexamethylenediamine from caprolactam, and the method includes the following steps.

[0370] (1) Ammonia gas is mixed and vaporized with an organic amide to obtain a vaporized material, and the vaporized material undergoes an ammoniation reaction under the action of an ammoniation catalyst to obtain a first reaction material.

[0371] (2) The first reaction material is subjected to first purification and first adsorption to obtain an aminonitrile-based organic substance.

[0372] (3) The aminonitrile-based organic substance undergoes a hydrogenation reaction under the action of hydrogen gas and a hydrogenation catalyst to obtain a post-reaction material containing an organic diamine.

[0373] (4) The post-reaction material is sequentially subjected to second purification and second adsorption to obtain an organic diamine product.

[0374] (5) After mixing nickel hexamine bromide complex (occupying 100 ppm of the weight of ammonia gas) with ammonia gas, it is preheated at 300 °C to superheat the ammonia gas to obtain a mixed gas.

[0375] After the mixed gas is mixed and vaporized at 300 °C with a first partial organic amide in a liquid phase state where the temperature is 69 °C in a Venturi vaporizer, it is introduced into a first segment fixed bed reactor (a total of three fixed bed reactors in series, regarded as a three-segment fixed bed reactor, and the same weight of catalyst is filled in each segment fixed bed reactor), and reacted under the action of a first reaction temperature, a first reaction pressure, and a first catalyst to obtain a first reaction discharge sample.

[0376] The i-th reaction discharge sample is introduced into the (i + 1)-th partial organic amide and the (i + 1)-th segment fixed bed reactor, where the value range of i is 1 ≤ i ≤ 2 and i is a natural number, and the reaction is carried out under the action of the (i + 1)-th reaction temperature, the (i + 1)-th reaction pressure, and the (i + 1)-th catalyst to obtain the (i + 1)-th reaction discharge sample. Here, the (i + 1)-th reaction discharge sample is circulated as the i-th reaction discharge sample in the next step until the ammoniation reaction is carried out up to i + 1 = n (n = 3).

[0377] The first to third reaction temperatures are 360° C., 400° C., and 460° C., respectively, the first to third reaction pressures are 0.3 MPa, 0.7 MPa, and 0.9 MPa, respectively, the first to fourth catalysts are catalysts C1 to C3, respectively, the amount of the i-th partial caprolactam is the same as the amount of the i+1-th partial caprolactam, and the hourly space velocity of the total caprolactam is 1 h -1 and the total molar ratio of the ammonia gas to the organic amide was 15:1.

[0378] (2) The first reaction discharge sample is rectified to obtain crude 6-aminohexanenitrile, and the crude 6-aminohexanenitrile is condensed at a space velocity of 0.5 h -1 The product was purified by adsorption using modified adsorbent c at 20°C and 1 MPa to obtain 6-aminohexanenitrile.

[0379] The polymer residue produced in step (1) and step (2) is mixed with water, and the mass ratio of the polymer residue to water is 1:0.5. The mixture is heated at 400° C., 0.2 MPa, and Al 2 O 3 The depolymerization reaction was carried out under the action of solid acid catalyst for 0.5 h, the mass ratio of polymer residue to catalyst was 1:0.01, and then the mixture was subjected to negative pressure dehydration and negative pressure distillation to obtain 6-aminohexanenitrile and caprolactam, respectively.

[0380] (3) 30 g of catalyst III with a particle size D50 = 900 μm was loaded into the second tubular reactor in the magnetically stabilized bed reactor, mixed with 6-aminohexanenitrile, the solvent n-butanol and the auxiliary KOH, introduced into the first heating device to preheat to 50 °C, and then introduced into the second tubular reactor under a pressure of 1.0 MPa and a magnetic field strength of 2000 A m -1 6-aminohexanenitrile is reacted with hydrogen gas under the conditions to prepare hexamethylenediamine, where the space velocity of 6-aminohexanenitrile is 1h -1The molar ratio of hydrogen gas to 6-aminohexanenitrile was 2:1, the mass ratio of 6-aminohexanenitrile to the solvent was 1:1, and the mass ratio of 6-aminohexanenitrile to the auxiliary agent was 1:0.1. (4) The material after the reaction was rectified at 130 °C and -0.090 MPaG to obtain crude hexamethylenediamine, which was filled into five adsorption columns in series with 1 kg of the second adsorbent γ, and then -1 The crude hexamethylenediamine was introduced at a space velocity and adsorbed at 25 °C to obtain hexamethylenediamine.

[0381] The method for regenerating the catalyst for the ammoniation reaction in this example includes the following steps.

[0382] An oxygen-containing gas with an initial oxygen content of 0.5 v / v% was pumped from the first inlet of the fixed-bed reactor and sequentially introduced into three fixed-bed reactors in series containing the deactivated silicon-aluminum-phosphorus molecular sieve. Supplementary oxygen-containing gas (air) was introduced from the first side port into the second side port, and the oxygen content at the inlet of each fixed-bed reactor was controlled to be the same as the oxygen content of the oxygen-containing gas at the inlet of the first fixed-bed reactor to regenerate the deactivated catalyst.

[0383] The regeneration process includes a pre-regeneration stage and a post-regeneration stage. In the pre-regeneration stage, the oxygen content of the oxygen-containing gas was fixed at 5 v / v%, the initial temperature of regeneration was 350 °C, and the oxygen content of the oxygen-containing gas increased from 0.05 v / v% / h to a final oxygen content of 10 v / v% / h; in the post-regeneration stage, the final oxygen content was fixed at 10 v / v% / h, the temperature was raised at 1 °C / h to a final temperature of 700 °C, and the regeneration was continued by holding for 200 h at the final oxygen content and the final temperature to obtain a regenerated catalyst.

[0384] For Examples 12 to 14, the maximum carbon monoxide content in the regeneration process of the catalyst for the ammoniation reaction was examined, the increase in the hot spot temperature of the catalyst bed layer in the regeneration process was measured, and it was found that the maximum carbon monoxide content in the regeneration process decreased significantly, and the increase in the hot spot temperature decreased significantly compared with the case where the temperature was increased in a gradient manner and the oxygen content was not increased, and the catalyst life after regeneration hardly changed.

[0385] Example 15 This example provides a method for preparing hexamethylenediamine from caprolactam. The method is the same as that of Example 12 except that trimethyl phosphate is not added as an auxiliary agent in step (1).

[0386] Example 16 This example provides a method for preparing hexamethylenediamine from caprolactam. The method is the same as that of Example 12 except that "trimethyl phosphate" is replaced with "aluminum trichloride" in step (1).

[0387] Example 17 This example provides a method for preparing hexamethylenediamine from caprolactam. The method is the same as that of Example 12 except that "Catalysts A1 to A4" are replaced with "Catalysts D1 to D4" in step (1).

[0388] Example 18 This example provides a method for preparing hexamethylenediamine from caprolactam. The method is the same as that of Example 12 except that the venturi vaporizer is replaced with a vaporization kettle in step (1).

[0389] Example 19 This example provides a method for preparing hexamethylenediamine from caprolactam. The method is the same as that of Example 12 except that the temperature and pressure of each segment fixed reactor are maintained the same as those of the first segment fixed bed reactor in step (1).

[0390] Example 20 This example provides a method for preparing hexamethylenediamine from caprolactam. The method is the same as Example 12, except that in step (1), all the catalyst components in each segment fixed reactor are the same as those in the first segment fixed bed reactor.

[0391] Example 21 This example provides a method for preparing hexamethylenediamine from caprolactam. The method is the same as Example 12, except that in step (3), the magnetic field strength is 0.

[0392] Example 22 This example provides a method for preparing hexamethylenediamine from caprolactam. The method is the same as Example 12, except that in step (3), catalyst I is replaced with Ru-Fe 2 O 3 -Al 2 O 3 catalyst (Ru: 5%; Fe 2 O 3 : 40%; Al 2 O 3 : 55%).

[0393] Example 23 This example provides a method for preparing hexamethylenediamine from caprolactam. The method is the same as Example 12, except that in step (3), catalyst I is replaced with catalyst IV.

[0394] Example 24 This example provides a method for preparing hexamethylenediamine from caprolactam. The method is the same as Example 12, except that in step (3), catalyst I is replaced with catalyst V.

[0395] Example 25 This example provides a method for preparing hexamethylenediamine from caprolactam. The method is the same as Example 12, except that in step (4), the second adsorbent α is replaced with the second adsorbent δ.

[0396] Comparative Example 2 This comparative example provides a method for preparing hexamethylenediamine from caprolactam. The method is the same as Example 12 except that adsorption purification was performed in step (2).

[0397] Comparative Example 3 This comparative example provides a method for preparing hexamethylenediamine from caprolactam. The method is the same as Example 12 except that the adsorption step in step (4) was not performed.

[0398] Measurement method: The purity of the product and raw materials was measured by quantitative analysis using gas chromatography. The service life of the catalyst was calculated so that the selectivity of 6-aminohexanenitrile was not less than 98%, and the service life of the catalyst was calculated so that the selectivity of hexamethylenediamine was not less than 97%. The results are shown in Table 3.

[0399]

Table 3

[0400] The following points can be seen from Table 1.

[0401] (1) As can be seen from Examples 12 to 25, the method for preparing hexamethylenediamine from caprolactam provided by the present invention extends the service life of the ammoniation catalyst to 7000 h or more, and under excellent conditions, it is 10000 h or more. The purity of the 6-aminohexanenitrile intermediate is 99.999 wt% or more, the selectivity of 6-aminohexanenitrile is 88% or more, the conversion rate of caprolactam is 86% or more, preferably 96% or more, and finally, under excellent conditions, the purity of hexamethylenediamine is 99.980 wt% or more, preferably 99.99 wt% or more under preferred conditions. The selectivity of hexamethylenediamine is 93 wt% or more, and the selectivity of hexamethylenediamine is 99.2 wt% or more under excellent conditions. The loss rate of the hydrogenation catalyst is ≦3.25 wt%, and preferably the loss rate of the hydrogenation catalyst is ≦1.1 wt% in the magnetic reaction device. Among them, the conversion rate of 6-aminohexanenitrile in the hydrogenation segment is 96 wt% or more, preferably 99 wt% or more.

[0402] (2) As can be seen from Example 12 and Comparative Examples 2 to 3, the present invention realizes the removal of trace impurities of 6-aminohexanenitrile and hexamethylenediamine by a purification method combining adsorption and purification, and the purity of the obtained product is higher.

[0403] Example 26 This example provides a method for preparing n-dodecyldiamine from 12-amino-n-dodecylnitrile. The method is the same as Example 1 except that caprolactam is replaced by 12-amino-n-dodecylnitrile in step (1). In Example 26, the conversion rate of the raw material is 99.9 wt%, the selectivity of the product n-dodecyldiamine is 98.7 wt%, and the purity of the product n-dodecyldiamine is 99.99 wt%.

[0404] As described above, the method for preparing organic diamine from the organic amide provided by the present invention integrates the gas-phase ammoniation reaction, intermediate product adsorption purification, hydrogenation reaction, and product adsorption purification processes. The content of purified aminonitrile-based organic impurities is low. Subsequently, when preparing the organic diamine product, there are few by-products, the purification of the product is easy, the purity of the obtained organic diamine product is high, the service life of the catalyst in this process is long, the regeneration method is reasonable, and the cost of industrial production is reduced.

[0405] As can be understood from the above description, the above embodiments of the present invention have achieved the following technical effects: Since the adsorbent provided by the present invention has an imprint cavity matching the azepine-based compound, it can specifically adsorb the azepine-based compound and is applied to the separation process of the azepine-based compound, having an excellent selective separation effect.

[0406] The above are only preferred embodiments of the present invention and do not limit the present invention. For those skilled in the art, various modifications and changes are possible to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should all be included within the protection scope of the present invention. Some embodiments are shown below. Item 1 It includes a carrier and surface molecules supported on the carrier, and the surface molecules are molecularly imprinted polymers. An adsorbent, characterized in that an imprint cavity is formed between the surface molecules, and the imprint cavity matches an azepine compound. Item 2 The carrier includes any one or at least a combination of two of aluminum oxide, silica, activated carbon, ZSM-5 molecular sieve or montmorillonite. Preferably, the particle size of the adsorbent is 50 nm to 5 μm. Preferably, the specific surface area of the adsorbent is 100 m 2 / g to 1000 m 2 / g. Preferably, the azepine compound is selected from 3,4,5,6-tetrahydro-2H-azepine. Preferably, the carrier is a carrier supported with an amino group. Preferably, the surface molecules include polymerized molecules obtained by polymerizing a functional monomer, a crosslinking agent, and an azepine compound and then removing the azepine compound. Preferably, the functional monomer is selected from amines and / or pyridines, and preferably includes any one or at least a combination of two of acrylamide, o-phenylenediamine or 2-vinylpyridine. Preferably, the crosslinking agent includes any one or at least a combination of two of ethylene glycol diglycidyl ether, ethylene glycol dimethacrylate or N,N-methylenebisacrylamide. The adsorbent according to Item 1 is characterized by this. Item 3 A method for preparing the adsorbent functionalized with surface molecular imprinting according to Item 1 or 2, (1) A step of pre-polymerizing a functional monomer and an azepine compound template to obtain a pre-polymerization reaction material. (2) A step of polymerizing the pre-polymerization reaction material, a carrier, a crosslinking agent, and an initiator to obtain polymer particles. (3) A step of obtaining the adsorbent functionalized with surface molecular imprinting after removing the azepine compound template from the polymer particles. A preparation method characterized by including this. Item 4 In the step (1), the azepine compound template is selected from 3,4,5,6-tetrahydro-2H-azepine. Preferably, the functional monomer is an amine substance and / or a pyridine, preferably including any one or at least a combination of two of acrylamide, o-phenylenediamine or 2-vinylpyridine, Preferably, the molar ratio of the functional monomer to the azepine compound template is 1 to 6:1, Preferably, the preliminary polymerization is carried out in a first organic solvent, Preferably, the ratio of the azepine compound template to the first organic solvent is 0.5 g:1 L to 10 g:1 L, Preferably, the first organic solvent is an alcohol solvent, preferably one or two of methanol, ethanol or propanol, and more preferably ethanol, Preferably, the reaction temperature of the preliminary polymerization is 10°C to 40°C, and the reaction time of the preliminary polymerization is 1 h to 20 h, Preferably, the preliminary polymerization is carried out under stirring conditions, and the preparation method according to item 3 is characterized in that. Item 5 In the step (2), the ratio of the carrier to the first organic solvent is 5 g:1 L to 30 g:1 L, Preferably, the molar ratio of the crosslinking agent to the azepine compound template is 18 to 22:1, Preferably, the ratio of the initiator to the first organic solvent is 0.1 g:1 L to 1 g:1 L, Preferably, the initiator includes azobisisobutyronitrile and / or ammonium persulfate, Preferably, the crosslinking agent includes any one or at least a combination of two of ethylene glycol diglycidyl ether, ethylene glycol dimethacrylate or N,N-methylenebisacrylamide, Preferably, the temperature of the polymerization reaction is 40°C to 80°C, Preferably, the time of the polymerization reaction is 10 h to 48 h, Preferably, the polymerization reaction includes first mixing the preliminary polymerization reaction material and the carrier in a first dispersion, and after the first dispersion, further adding the crosslinking agent and the initiator to carry out the polymerization reaction, Preferably, after the first dispersion, the crosslinking agent and the initiator are further added to a first protective atmosphere, Preferably, the first protective atmosphere includes any one or at least a combination of two of nitrogen gas, helium gas or argon gas, and the preparation method according to item 3 or 4 is characterized in that. Item 6 In the step (3), the step of removing the azepine compound template includes extracting the azepine compound template in the polymer particles by using a mixed acid solution, Preferably, the mixed acid solution contains formic acid and acetic acid, Preferably, the volume ratio of the formic acid to the acetic acid is 5 to 10:1, Preferably, the extraction is Soxhlet extraction, and the preparation method according to any one of Items 3 to 5 is characterized thereby. Item 7 The carrier is modified and added to the step (2). Preferably, the method for modifying the carrier is to mix a starting carrier, a second organic solvent, and an amino group-containing organic substance to perform a modification reaction, and subject the obtained modification reaction product to solid-liquid separation, washing, and second drying in sequence to obtain a modified carrier. Preferably, the starting carrier includes any one or at least two combinations of aluminum oxide, silica, activated carbon, ZSM-5 molecular sieve, or montmorillonite. Preferably, the second organic solvent includes toluene. Preferably, the amino group-containing organic substance is aminosilane, preferably 3-aminopropyltriethoxysilane. Preferably, the temperature of the modification reaction is 80°C to 100°C. Preferably, the mass ratio of the amino group-containing organic substance to the starting carrier is 1 to 10:1. Preferably, the ratio of the starting carrier to the second organic solvent is 15 g:1 L to 30 g:1 L. Preferably, the order of mixing the starting carrier, the second organic solvent, and the amino group-containing organic substance includes first mixing the starting carrier and the second organic solvent by second dispersion, and then further adding the amino group-containing organic substance after the second dispersion. Preferably, after the second dispersion, the amino group-containing organic substance is added under a second protective atmosphere. Preferably, the second protective atmosphere includes any one or at least two combinations of nitrogen gas, argon gas, or helium gas. Preferably, the washing includes toluene washing and methanol washing performed in sequence, and the preparation method according to any one of Items 3 to 6 is characterized thereby. Item 8 Use of the surface molecular imprint-functionalized adsorbent according to Item 1 or 2, characterized in that the adsorbent is applied to the separation of azepine compounds, preferably the removal of azepine compound impurities. Item 9 A method for purifying hexamethylenediamine, characterized by performing adsorption separation of impurities by using the surface molecular imprint-functionalized adsorbent according to Item 1 or 2. Item 10 The purification method includes adsorbing azepine compound impurities in crude hexamethylenediamine by using the adsorbent. Preferably, the purification method according to item 9 is characterized in that the mass ratio of the crude hexamethylenediamine to the adsorbent is 300 to 600:1. Item 11 A step of performing a hydrogenation reaction on an aminonitrile-based organic substance and hydrogen gas under the action of a hydrogenation catalyst to obtain a reaction product containing an organic diamine; The reaction product is subjected to second purification and second adsorption to obtain the organic diamine, the second adsorption employs the surface molecular imprint-functionalized adsorbent according to item 1 or 2, and the second purification is a second rectification treatment step; A method for preparing an organic diamine, characterized by comprising the above steps. Item 12 The hydrogenation catalyst is γ-Fe 2 O 3 / SiO 2 , Rh / SiO 2 , Pt-Rh / Al 2 O 3 , Fe 3 O 4 -SiO 2 -Ag, Ru-Fe 2 O 3 -Al 2 O 3 , Raney nickel, amorphous nickel, or one or more of carbon-based cobalt catalysts. Preferably, the carbon-based cobalt catalyst is a nitrogen and phosphorus co-doped carbon-based cobalt catalyst. Preferably, the components of the carbon-based cobalt catalyst include an active component and a main component. The active component includes cobalt, phosphorus, and nitrogen, and the main component includes carbon. The content of cobalt in the carbon-based cobalt catalyst is 0.5% to 15%, the content of phosphorus is 0.1% to 5%, and the content of nitrogen is 1% to 10%. Preferably, the specific surface area of the carbon-based cobalt catalyst is 50 m 2 / g to 1000 m 2 / g. Preferably, the mass ratio of phosphorus to nitrogen in the carbon-based cobalt catalyst is 1:0.5 to 20. Preferably, the carbon-based cobalt catalyst has a carbon layer with a coating structure. The preparation method according to item 11 is characterized by the above. Item 13 The hydrogenation reaction is carried out in a magnetic stabilization reactor. Preferably, the pressure of the hydrogenation reaction is 0.1 MPa to 5 MPa, the temperature of the hydrogenation reaction is 25°C to 200°C, the magnetic field strength in the hydrogenation reaction is preferably 1000 A·m -1 to 8000 A·m -1 , the space velocity of the aminonitrile-based organic substance is preferably 0.01 h -1 ~20h -1 , and the molar ratio of the hydrogen gas to the aminonitrile-based organic substance is preferably 2 to 100:1. The preparation method according to item 11 or 12 is characterized by the above. Item 14 The second adsorption includes adsorbing impurities from the second purified crude organic diamine with a second adsorbent to obtain the organic diamine. Preferably, the mass ratio of the crude organic diamine to the surface molecule imprint-functionalized adsorbent is 300-600:1. Preferably, the number of carbon atoms of the organic diamine is a natural number from 3 to 18, preferably a natural number from 3 to 10, and more preferably hexamethylenediamine. The preparation method according to any one of items 11 to 13, characterized in that. Item 15 The preparation method includes the preparation process of amino nitrile-based organic substances, and the preparation process is Step A of mixing and vaporizing ammonia gas with an organic amide to obtain a vaporized material, and performing an ammoniation reaction on the vaporized material under the action of an ammoniation catalyst to obtain a first reactant; Step B of obtaining an amino nitrile-based organic substance from the first reactant through first purification and first adsorption; The preparation method according to any one of items 11 to 14, characterized by including. Item 16 The first adsorption employs a first adsorbent, and the first adsorbent is an adsorbent loaded with a metal element. Preferably, the first adsorbent is selected from one or more of montmorillonite, ZSM-5 zeolite molecular sieve, SiO 2 、Al 2 O 3 Or activated carbon, and the metal element includes transition metal elements. Preferably, the transition metal elements are selected from one or more of Ag, Cu, Cd, Cr, Fe, Zn, Ni, Zr or Mn. The preparation method according to item 15, characterized in that. Item 17 The impurities in the first adsorption include carbon-carbon double bonds and / or carbon-carbon triple bonds. Preferably, the space velocity of the first adsorbent is 0.5h -1 ~3h -1 And preferably, the temperature of the first adsorption is 20°C to 60°C, preferably, the pressure of the first adsorption is 0.1MPa to 1MPa. Preferably, the polymer residues generated in the ammoniation reaction and / or the first purification are subjected to depolymerization reaction, negative pressure dehydration and negative pressure distillation in sequence to obtain amino nitrile-based organic substances and organic amides respectively. The preparation method according to item 15 or 16, characterized in that. Item 18 An auxiliary agent is further added to step A, and the auxiliary agent contains one or more of the elements corresponding to the ammoniation catalyst. The corresponding elements include aluminum element, silicon element, boron element, nitrogen element, alkaline earth element, transition metal element, phosphorus element. Preferably, the addition amount of the auxiliary agent is 0.1 ppm to 100 ppm of the weight of ammonia gas. Preferably, the auxiliary agent and ammonia gas are mixed and pre-treated to obtain a mixed gas, and then mixed with the organic amide. Preferably, the organic amide is an organic lactam. Preferably, the number of carbon atoms of the organic amide is a natural number from 3 to 18, more preferably a natural number from 3 to 10. Further preferably, the organic amide contains caprolactam. The preparation method according to any one of items 15 to 17. Item 19 In step A, after ammonia gas and the first part of the organic amide are mixed and vaporized, they are introduced into a first segment fixed bed reactor, and an ammoniation reaction is carried out under the action of a first reaction temperature, a first reaction pressure, and a first ammoniation catalyst to obtain a first reaction discharge sample. The i-th reaction discharge sample and the (i + 1)-th part of the organic amide are introduced into the (i + 1)-th segment fixed bed reactor. The value range of i is 1 ≤ i ≤ n - 1, and i is a natural number. n is selected from natural numbers where n ≥ 2. An ammoniation reaction is carried out under the action of the (i + 1)-th reaction temperature, the (i + 1)-th reaction pressure, and the (i + 1)-th ammoniation catalyst to obtain the (i + 1)-th reaction discharge sample. Here, the (i + 1)-th reaction discharge sample is circulated as the i-th reaction input sample of the next step until ammoniation is carried out until i + 1 = n. Preferably, the (i + 1)-th reaction temperature > the i-th reaction temperature. Preferably, the (i + 1)-th reaction pressure > the i-th reaction pressure. Preferably, the molar ratio of the active ingredient to the carrier element in the (i + 1)-th ammoniation catalyst > the molar ratio of the active ingredient to the carrier element in the i-th ammoniation catalyst. Preferably, the active ingredient contains a phosphorus element. Preferably, the carrier element contains silicon. Preferably, the molar ratio of the active ingredient to silicon in the (i + 1)-th ammoniation catalyst is (0.1 to 2):1. Preferably, the molar ratio of the active ingredient to the carrier element in the i-th ammoniation catalyst is T, and the molar ratio of the active ingredient to the carrier element in the (i + 1)-th ammoniation catalyst is S. The ratio value of T to S is 1:1.2 to 3. Preferably, from the first ammoniation catalyst to the n-th catalyst, each independently contains a first type of pore channel, further contains a second type of pore channel in the catalyst, and / or the catalyst further includes a protrusion. Preferably, in the same dimension, the pore length of the second type of pore channels is 0.15 to 0.6 times the length of the ammoniation catalyst, and / or the protruding length of the protruding portion is 0.1 to 0.6 times the length of the ammoniation catalyst. Preferably, the (i + 1)-th reaction temperature is 10°C to 50°C higher than the i-th reaction temperature. Preferably, the (i + 1)-th reaction pressure is 0.1 MPa to 0.5 MPa higher than the i-th reaction pressure. Preferably, the organic amide in the i-th portion is the same as the amount of the organic amide in the (i + 1)-th portion. Preferably, the regeneration methods of the first catalyst to the n-th catalyst are each independently introducing an oxygen-containing gas into a regeneration device containing a deactivated ammoniation catalyst. The regeneration device is provided with m uniformly distributed inlets, or includes m serially connected regenerators, and supplementary oxygen-containing gas is introduced from the second to the m-th inlets or from the second inlet or from within the second to the m-th regenerators to regenerate the deactivated catalyst, where m is a natural number greater than or equal to 2. Preferably, the oxygen content of the oxygen-containing gas in the regeneration process improves in a gradient with the regeneration time, and the regeneration temperature improves in a gradient with the regeneration time. The preparation method according to any one of items 15 to 18. Item 20 In step A, the mixing and vaporization are carried out in a Venturi vaporization device. Preferably, before the mixing and vaporization, the temperature of the liquid-phase organic amide is 0°C to 300°C, and preferably, the temperature after vaporization is 300°C to 500°C. The preparation method according to any one of items 15 to 19. Item 21 An apparatus used in the preparation method of an organic diamine according to any one of items 11 to 20, comprising a vaporization unit, an ammoniation reaction unit, a first purification unit, a first adsorption unit, a hydrogenation reaction unit, a second purification unit, and a second adsorption unit connected in sequence. Item 22 The vaporization unit includes a Venturi vaporization device. Preferably, the ammoniation reaction unit includes a fixed-bed reaction device. Preferably, the hydrogenation reaction unit includes a magnetic stabilization reaction device. The apparatus according to item 21.

Claims

1. An adsorbent that specifically adsorbs azepine compounds in crude hexamethylenediamine, comprising a carrier and surface molecules supported on the carrier, wherein the surface molecules are molecularly imprinted polymers, the surface molecules include polymerized molecules obtained by polymerizing a functional monomer, a crosslinking agent, and an azepine compound and then removing the azepine compound, the functional monomer is selected from amines and / or pyridines, the carrier includes any one or at least a combination of two of aluminum oxide, silica, activated carbon, ZSM-5 molecular sieve, or montmorillonite, an imprint cavity is formed between the surface molecules, and the imprint cavity matches the azepine compound, the azepine compound is selected from 3,4,5,6-tetrahydro-2H-azepine, the method for preparing the adsorbent is as follows (1) preliminarily polymerizing the functional monomer and the azepine compound template to obtain a preliminary polymerization reaction material; (2) polymerizing the preliminary polymerization reaction material, the carrier, the crosslinking agent, and an initiator to obtain polymer particles; (3) removing the azepine compound template from the polymer particles to obtain the surface molecule imprint-functionalized adsorbent, including the reaction temperature of the preliminary polymerization is 10°C to 40°C, the temperature of the polymerization reaction is 40°C to 80°C, the step of removing the azepine compound template includes extracting the azepine compound template in the polymer particles using a mixed acid solution, the mixed acid solution contains formic acid and acetic acid, and is characterized by the adsorbent.

2. the particle size of the adsorbent is 50 nm to 5 μm, The specific surface area of the adsorbent is 100 m ２ / g to 1000 m ２ / g, and the carrier is a carrier supported with amino groups; the functional monomer includes any one or at least a combination of two of acrylamide, o-phenylenediamine, or 2-vinylpyridine, the crosslinking agent includes any one or at least a combination of two of ethylene glycol diglycidyl ether, ethylene glycol dimethacrylate, or N,N-methylenebisacrylamide, and is characterized by the adsorbent according to Claim 1.

3. A method for preparing a surface molecule imprint-functionalized adsorbent according to Claim 1 or 2, comprising (1) preliminarily polymerizing a functional monomer and an azepine compound template to obtain a preliminary polymerization reaction material; (2) A step of subjecting the prepolymerization reaction material, the carrier, the crosslinking agent, and the initiator to a polymerization reaction to obtain polymer particles; (3) A step of obtaining the surface molecule imprinted adsorbent after removing the azepine compound template from the polymer particles, and The azepine compound template is selected from 3,4,5,6 - tetrahydro - 2H - azepine, The functional monomer is selected from amines and / or pyridines, and a preparation method characterized thereby.

4. In the step (1), The functional monomer includes any one or at least a combination of two or more of acrylamide, o - phenylenediamine, or 2 - vinylpyridine, The molar ratio of the functional monomer to the azepine compound template is 1 to 6:1, The prepolymerization is carried out in a first organic solvent, The ratio of the azepine compound template to the first organic solvent is 0.5 g:1 L to 10 g:1 L, The first organic solvent is an alcohol solvent, The reaction temperature of the prepolymerization is 10°C to 40°C, and the reaction time of the prepolymerization is 1 h to 20 h, The prepolymerization is carried out under stirring conditions, and the preparation method according to claim 3 is characterized thereby.

5. In the step (2), the ratio of the carrier to the first organic solvent is 5 g:1 L to 30 g:1 L, The molar ratio of the crosslinking agent to the azepine compound template is 18 to 22:1, The ratio of the initiator to the first organic solvent is 0.1 g:1 L to 1 g:1 L, The initiator includes azobisisobutyronitrile and / or ammonium persulfate, The crosslinking agent includes any one or at least a combination of two or more of ethylene glycol diglycidyl ether, ethylene glycol dimethacrylate, or N,N - methylenebisacrylamide, The temperature of the polymerization reaction is 40°C to 80°C, The time of the polymerization reaction is 10 h to 48 h, The polymerization reaction includes first mixing the prepolymerization reaction material and the carrier by first dispersion, and after the first dispersion, further adding the crosslinking agent and the initiator to carry out the polymerization reaction, After the first dispersion, the crosslinking agent and the initiator are further added in a first protective atmosphere, The first protective atmosphere includes any one or at least a combination of two or more of nitrogen gas, helium gas, or argon gas, and the preparation method according to claim 4 is characterized thereby.

6. In the step (3), the step of removing the azepine compound template includes extracting the azepine compound template in the polymer particles by using a mixed acid solution. The mixed acid solution contains formic acid and acetic acid. The volume ratio of the formic acid to the acetic acid is 5 to 10:

1. The preparation method according to claim 3, wherein the extraction is Soxhlet extraction.

7. In addition to the step (2), the carrier is modified. The method for modifying the carrier includes mixing a starting carrier, a second organic solvent, and an amino group-containing organic substance, performing a modification reaction, and subjecting the obtained modification reaction product to solid-liquid separation, washing, and second drying in sequence to obtain a modified carrier. The starting carrier includes any one or at least two combinations of aluminum oxide, silica, activated carbon, ZSM-5 molecular sieve, or montmorillonite. The second organic solvent includes toluene. The amino group-containing organic substance is 3-aminopropyltriethoxysilane. The temperature of the modification reaction is 80°C to 100°C. The mass ratio of the amino group-containing organic substance to the starting carrier is 1 to 10:

1. The ratio of the starting carrier to the second organic solvent is 15 g:1 L to 30 g:1 L. The order of mixing the starting carrier, the second organic solvent, and the amino group-containing organic substance includes first mixing the starting carrier and the second organic solvent by second dispersion, and then adding the amino group-containing organic substance after the second dispersion. After the second dispersion, the amino group-containing organic substance is added under a second protective atmosphere. The second protective atmosphere includes any one or at least two combinations of nitrogen gas, argon gas, or helium gas. The preparation method according to claim 3, wherein the washing includes toluene washing and methanol washing performed in sequence.

8. Use of the surface molecular imprint-functionalized adsorbent according to claim 1 or 2, wherein the adsorbent is applied to the removal of azepine compound impurities.

9. A method for purifying hexamethylenediamine, characterized by performing adsorption separation of impurities by using the surface molecular imprint-functionalized adsorbent according to claim 1 or 2.

10. The purification method includes adsorbing azepine compound impurities in crude hexamethylenediamine by using the adsorbent. The purification method according to claim 9, wherein the mass ratio of the crude hexamethylenediamine to the adsorbent is 300 to 600:

1.

11. A step of performing a hydrogenation reaction on an aminonitrile-based organic substance and hydrogen gas under the action of a hydrogenation catalyst to obtain a post-reaction material containing an organic diamine; The post-reaction material is subjected to second purification and second adsorption to obtain the organic diamine. The second adsorption employs the surface molecule imprint-functionalized adsorbent according to claim 1 or 2, and the second purification is a second rectification treatment step; A method for preparing an organic diamine, comprising the above steps.

12. The hydrogenation catalyst is γ-Fe ２ O ３ / SiO ２ , Rh / SiO ２ , Pt-Rh / Al ２ O ３ , Fe ３ O ４ -SiO ２ -Ag, Ru-Fe ２ O ３ -Al ２ O ３ , and contains one or more of Raney nickel, amorphous nickel or a carbon-based cobalt catalyst. The carbon-based cobalt catalyst is a nitrogen / phosphorus co-doped carbon-based cobalt catalyst. The components of the carbon-based cobalt catalyst include an active component and a main component. The active component contains cobalt, phosphorus and nitrogen, and the main component contains carbon. The content of cobalt in the carbon-based cobalt catalyst is 0.5% to 15%, the content of phosphorus is 0.1% to 5%, and the content of nitrogen is 1% to 10%. The specific surface area of the carbon-based cobalt catalyst is 50 m ２ / g to 1000 m ２ / g, and the mass ratio of phosphorus to nitrogen in the carbon-based cobalt catalyst is 1:0.5 to 20. The preparation method according to claim 11, characterized in that the carbon-based cobalt catalyst has a carbon layer with a coating structure.

13. The hydrogenation reaction is carried out in a magnetic stabilization reactor, the pressure of the hydrogenation reaction is 0.1 MPa to 5 MPa, the temperature of the hydrogenation reaction is 25°C to 200°C, and the magnetic field strength in the hydrogenation reaction is 1000 A·m －１ to 8000 A·m －１ and the space velocity of the aminonitrile-based organic substance is 0.01 h －１ to 20 h －１ The preparation method according to claim 11, characterized in that the molar ratio of the hydrogen gas to the aminonitrile-based organic substance is 2 to 100:

1.

14. The second adsorption includes adsorbing impurities from the second-purified crude organic diamine with a second adsorbent to obtain the organic diamine. The mass ratio of the crude organic diamine to the surface molecule imprint-functionalized adsorbent is 300 to 600:1, and the organic diamine is hexamethylenediamine. The preparation method according to claim 11, characterized in that.

15. The preparation method includes the preparation process of the aminonitrile-based organic substance, and the preparation process includes: Step A: Ammonia gas and an organic amide are mixed and vaporized to obtain a vaporized material, and the vaporized material undergoes an ammoniation reaction under the action of an ammoniation catalyst to obtain a first reactant; Step B: The first reactant is subjected to first purification and first adsorption to obtain the aminonitrile-based organic substance. The preparation method according to claim 11, characterized by including the above steps.

16. The first adsorption employs a first adsorbent, the first adsorbent is an adsorbent on which a metal element is supported, and the first adsorbent is selected from one or more of montmorillonite, ZSM-5 zeolite molecular sieve, SiO ２ , Al ２ O ３ or activated carbon, the metal element includes a transition metal element, and the transition metal element is selected from one or more of Ag, Cu, Cd, Cr, Fe, Zn, Ni, Zr or Mn. The preparation method according to claim 15, characterized in that.

17. The impurities of the first adsorption contain carbon-carbon double bonds and / or carbon-carbon triple bonds, and the space velocity of the first adsorption is 0.5 h －１ ~3 h －１ ; the temperature of the first adsorption is 20°C to 60°C, the pressure of the first adsorption is 0.1 MPa to 1 MPa, and the polymer residues generated in the ammoniation reaction and / or the first purification are sequentially subjected to depolymerization reaction, negative pressure dehydration and negative pressure distillation to obtain the aminonitrile-based organic substance and the organic amide respectively. The preparation method according to claim 16, characterized in that.

18. A co-agent is further added in step A. The co-agent contains one or more of the elements corresponding to the ammoniation catalyst. The corresponding elements include aluminum element, silicon element, boron element, nitrogen element, alkaline earth element, transition metal element, and phosphorus element. The addition amount of the co-agent is 0.1 ppm to 100 ppm of the weight of the ammonia gas. The co-agent and the ammonia gas are mixed for pre-treatment to obtain a mixed gas, and then mixed with the organic amide. The organic amide is an organic lactam, and the organic amide is caprolactam. The preparation method according to claim 15, characterized in that.

19. In the step A, after the ammonia gas and the first part of the organic amide are mixed and vaporized, they are introduced into a first-segment fixed-bed reactor, and the ammoniation reaction is carried out under the action of a first reaction temperature, a first reaction pressure, and a first ammoniation catalyst to obtain a first reaction discharge sample. The i-th reaction discharge sample and the (i + 1)-th part of the organic amide are introduced into an (i + 1)-th segment fixed-bed reactor, where the value range of i is 1 ≤ i ≤ n - 1, and i is a natural number, and n is selected from natural numbers where n ≥ 2. The ammoniation reaction is carried out under the action of an (i + 1)-th reaction temperature, an (i + 1)-th reaction pressure, and an (i + 1)-th ammoniation catalyst to obtain an (i + 1)-th reaction discharge sample. Here, the (i + 1)-th reaction discharge sample is circulated as the i-th reaction input sample for the next step until ammoniation is carried out up to i + 1 = n. The (i + 1)-th reaction temperature > the i-th reaction temperature. The (i + 1)-th reaction pressure > the i-th reaction pressure. The molar ratio of the active component to the carrier element in the (i + 1)-th ammoniation catalyst > the molar ratio of the active component to the carrier element in the i-th ammoniation catalyst. The active component contains phosphorus element, and the carrier element contains silicon. The molar ratio of the active component to the silicon in the (i + 1)-th ammoniation catalyst is (0.1 - 2):

1. Let the molar ratio of the active component to the carrier element in the i-th ammoniation catalyst be T, and the molar ratio of the active component to the carrier element in the (i + 1)-th ammoniation catalyst be S. The ratio value of T to S is 1:1.2 - 3. The first ammoniation catalyst to the n-th catalyst each independently contains a first type of pore channel, and further contains a second type of pore channel in the catalyst, and / or the catalyst further includes a protruding part. In the same dimension, the pore length of the second type of pore channel is 0.15 times to 0.6 times the length of the ammoniation catalyst, and / or the protruding length of the protruding part is 0.1 times to 0.6 times the length of the ammoniation catalyst. The (i + 1)-th reaction temperature is 10°C to 50°C higher than the i-th reaction temperature. The (i + 1)-th reaction pressure is 0.1 MPa to 0.5 MPa higher than the i-th reaction pressure. The i-th part of the organic amide is the same in amount as the (i + 1)-th part of the organic amide. The regeneration method of the first to nth catalysts is, independently of each other, introducing an oxygen-containing gas into a regeneration device containing a deactivated ammoniated catalyst. The regeneration device is provided with m uniformly distributed inlets, or includes m serially connected regenerators, and supplementary oxygen-containing gas is introduced from the second to the mth inlets or from the second inlet or from inside the second to the mth regenerators to regenerate the deactivated ammoniated catalyst. Here, m is a natural number greater than or equal to 2. The oxygen content of the oxygen-containing gas in the regeneration process improves in a gradient with the regeneration time, and the regeneration temperature improves in a gradient with the regeneration time. The preparation method according to claim 15 is characterized in that.

20. In step A, the mixing and vaporization are performed in a Venturi vaporization device. Before the mixing and vaporization, the temperature of the organic amide in the liquid phase is 0°C to 300°C, and the temperature of the organic amide after the vaporization is 300°C to 500°C. The preparation method according to claim 15 is characterized in that.

21. An apparatus used in the method for preparing an organic diamine according to claim 11, comprising a vaporization unit, an ammoniation reaction unit, a first purification unit, a first adsorption unit, a hydrogenation reaction unit, a second purification unit, and a second adsorption unit, which are sequentially connected.

22. The vaporization unit includes a Venturi vaporization device, the ammoniation reaction unit includes a fixed-bed reaction device, and the hydrogenation reaction unit includes a magnetic stabilization reaction device. The apparatus according to claim 21 is characterized in that.

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