Method for synthesizing hexamethylenediamine and producing cyclohexylimine

Abstract

This invention relates to the field of synthesis and discloses a method for synthesizing hexamethylenediamine and co-producing cyclohexylimine. The method includes: (1) ammonolysis: bis(hexamethylene)triamine undergoes an ammonolysis reaction in the presence of an ammonolysis catalyst, ammonia, and hydrogen; wherein the ammonolysis catalyst contains active components Ni, La, and In; (2) the material obtained from the ammonolysis reaction is sequentially subjected to cyclohexylimine separation and hexamethylenediamine separation. This method can simultaneously obtain hexamethylenediamine and cyclohexylimine, and exhibits high reactivity, high conversion rate, and high selectivity.

Description

Technical Field

[0001] This invention relates to the field of synthesis, and more specifically to a method for synthesizing hexamethylenediamine and producing cyclohexylimine. Background Technology

[0002] Cycloheximine (HMI), chemical formula C6H 13 Ruthenium (N), soluble in water and readily soluble in ethanol and ether, is an important chemical intermediate and fine organic chemical. It is used not only as a pharmaceutical and pesticide intermediate but also in the production of soda ash, developing agents, and waste treatment. Due to the difficulty in selecting catalysts for its synthesis, only a few countries in the world are capable of producing it. US3830800 discloses that under conditions of reaction temperature 225-250℃ and ruthenium supported on an inert catalyst, the yield of hexamethylenediamine and cyclohexylimine can reach 90%. However, due to unresolved intermolecular condensation issues, this route has not been industrially applied. Research using caprolactam as a raw material has received widespread attention. US4035353 describes a method of mixing several catalyst components tightly together using impregnation, co-precipitation, or aqueous solutions containing molybdenum and rhenium compounds with pre-precipitated cobalt salts. These components are then thoroughly dried at 80-120℃ and reduced in a reducing atmosphere at 350-600℃ for several hours to obtain cobalt-molybdenum, cobalt-rhenium, or cobalt-molybdenum-rhenium bimetallic or trimetallic catalysts. Using this catalyst, along with a self-developed continuous process, can significantly reduce byproducts and extend catalyst life. However, caprolactam polymerizes very easily, resulting in low reaction conversion, and currently, the catalyst life is relatively short and the selectivity is not high.

[0003] Hexamethylenediamine (HMDA), chemical formula C6H 16 Nitrogen dioxide (N2) is primarily used in the synthesis of nylon 66 and 610 resins, polyurethane resins, ion exchange resins, and hexylene diisocyanate. It is also used as a curing agent and organic crosslinking agent for urea-formaldehyde resins and epoxy resins. In the textile and paper industries, it serves as a stabilizer and bleaching agent; an inhibitor of corrosion on aluminum alloys; and as an emulsifier, adhesive, aerospace coating, and rubber vulcanization accelerator for chloroprene rubber. Hexamethylenediamine reacts with hydrochloric acid to form 1,6-hexamethylenediamine hydrochloride, which can be used to produce the bactericide chlorhexidine acetate. In recent years, with the development of the synthetic fiber industry, the global demand for hexamethylenediamine compounds has been continuously increasing.

[0004] The key to the hexamethylenediamine process lies in the synthesis of adiponitrile. CN106397476A describes the preparation of monodentate phosphorus ligands using mixed phenols in the butadiene hydrocyanation reaction. Compared to catalysts prepared from single phenols, this method reduces production costs and increases activity, effectively inhibiting catalyst poisoning and organophosphorus ligand degradation in the secondary hydrocyanation reaction. CN112794948A develops a porous polymer-nickel catalyst for the butadiene hydrocyanation heterogeneous reaction, exhibiting high catalytic activity, high reaction selectivity, and high linearity in the hydrocyanation reaction.

[0005] Monsanto, Inc. of the United States, was the first to propose and implement the acrylonitrile electrolytic dimerization process. US3649511 improved this process by developing a diaphragm-free electrolysis process, simplifying the electrolytic cell structure and allowing the generated adiponitrile to be extracted into the organic phase, resulting in a higher yield. CN111228941A studied the acrylonitrile dimerization process for producing adiponitrile. This process uses a circulating carrier, and the material exiting the electrolytic reactor includes the circulating carrier, the product oil phase, and the gas phase, which are mostly separated using a three-phase separator.

[0006] CN108821997A describes a process that reacts adipic acid with ammonia at 155-200℃ to produce ammonium adipicate, which is then dehydrated under the catalysis of phosphoric acid or ammonium phosphate to produce adiponitrile, increasing the yield by 3-5% and extending the operating cycle by 30-60 days.

[0007] Besides the adiponitrile hydrogenation method for preparing hexamethylenediamine, other methods can be used, such as the caprolactam amination and dehydration to prepare 6-aminohexamethylenediamine followed by hydrogenation, and the direct amination of hexamethylenediamine. CN107739318A describes a liquid-phase method using phosphoric acid or phosphate catalysts in a reactor to produce 6-aminohexamethylenediamine from caprolactam, achieving a caprolactam conversion of 65% and a 6-aminohexamethylenediamine selectivity of 98.2%. US20160326092A1 describes the catalytic amination of 1,6-hexanediol to obtain hexamethylenediamine. The fraction rich in cycloheximine obtained after separation of the amination product is recycled to the amination process. Since aminohexanol and hexamethylenediamine have very similar vapor pressures, the mixture of aminohexanol and hexamethylenediamine obtained by distillation is recycled for amination to obtain pure hexamethylenediamine.

[0008] However, the current processes for preparing hexamethylenediamine and cycloheximine still suffer from poor reactivity and low yield, requiring further improvements to the processes. Summary of the Invention

[0009] The purpose of this invention is to overcome the aforementioned problems of the prior art and provide a method for synthesizing hexamethylenediamine and co-producing cyclohexylimine. This method can simultaneously obtain hexamethylenediamine and cyclohexylimine, and has high reactivity, high conversion rate, and high selectivity.

[0010] To achieve the above objectives, a first aspect of the present invention provides a method for synthesizing hexamethylenediamine and concurrently producing cyclohexylimine, the method comprising:

[0011] (1) Ammonolysis: In the presence of an ammonolysis catalyst, ammonia and hydrogen, bis(hexamethylene)triamine undergoes an ammonolysis reaction;

[0012] The ammonolysis catalyst contains active components Ni, La, and In;

[0013] (2) The material obtained from the ammonolysis reaction is separated by hydrogen and then deammoniated in a deammonilysis tower. Liquid ammonia is obtained at the top of the deammonilysis tower and a lean liquid ammonia stream is obtained at the bottom of the tower.

[0014] (3) The lean ammonia column bottom stream is subjected to cyclohexylimine separation in a cyclohexylimine separation column to obtain cyclohexylimine at the top of the column and lean cyclohexylimine column bottom stream at the bottom of the column.

[0015] (4) The bottom stream of the column with depleted cyclohexylimine is separated into hexamethylenediamine in a hexamethylenediamine separation column to obtain hexamethylenediamine at the top of the column and a bottom stream with depleted hexamethylenediamine at the bottom of the column.

[0016] (5) The hexamethylenediamine-poor bottom stream is separated into C12 in a C12 separation column to obtain a C12-rich top stream at the top of the column.

[0017] A second aspect of the present invention provides a method for synthesizing hexamethylenediamine and co-producing cyclohexylimine, the method comprising:

[0018] (1) Ammonolysis: In the presence of an ammonolysis catalyst, ammonia and hydrogen, bis(hexamethylene)triamine undergoes an ammonolysis reaction;

[0019] The ammonolysis catalyst contains active components Ni, La, and In;

[0020] (2) The materials obtained from the ammonolysis reaction are sequentially separated into cyclohexylimine and hexamethylenediamine.

[0021] The method provided by this invention can simultaneously prepare hexamethylenediamine and cyclohexylimine, exhibiting high reactivity, high conversion rate, and high selectivity. Furthermore, in a preferred embodiment of this invention, the obtained cyclohexylimine stream can be returned to the ammonolysis step for further reaction to generate hexamethylenediamine. This allows for flexible control of the ratio of hexamethylenediamine to cyclohexylimine produced in the reaction, thus adapting to market demands. Detailed Implementation

[0022] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0023] In a first aspect, the present invention provides a method for synthesizing hexamethylenediamine and concurrently producing cyclohexylimine, the method comprising:

[0024] (1) Ammonolysis: In the presence of an ammonolysis catalyst, ammonia and hydrogen, bis(hexamethylene)triamine undergoes an ammonolysis reaction;

[0025] The ammonolysis catalyst contains active components Ni, La, and In;

[0026] (2) The material obtained from the ammonolysis reaction is separated by hydrogen and then deammoniated in a deammonilysis tower. Liquid ammonia is obtained at the top of the deammonilysis tower and a lean liquid ammonia stream is obtained at the bottom of the tower.

[0027] (3) The lean ammonia column bottom stream is subjected to cyclohexylimine separation in a cyclohexylimine separation column to obtain cyclohexylimine at the top of the column and lean cyclohexylimine column bottom stream at the bottom of the column.

[0028] (4) The bottom stream of the column with depleted cyclohexylimine is separated into hexamethylenediamine in a hexamethylenediamine separation column to obtain hexamethylenediamine at the top of the column and a bottom stream with depleted hexamethylenediamine at the bottom of the column.

[0029] (5) The hexamethylenediamine-poor bottom stream is separated into C12 in a C12 separation column to obtain a C12-rich top stream at the top of the column.

[0030] In a second aspect, the present invention provides a method for synthesizing hexamethylenediamine and concurrently producing cyclohexylimine, the method comprising:

[0031] (1) Ammonolysis: In the presence of an ammonolysis catalyst, ammonia and hydrogen, bis(hexamethylene)triamine undergoes an ammonolysis reaction;

[0032] The ammonium hydrolysis catalyst contains active components Ni, La and In, and the ammonium hydrolysis catalyst also includes a support, which includes alumina, silicon oxide and calcium oxide, with the weight ratio of alumina, silicon oxide and calcium oxide being (6-40):(1-20):1;

[0033] (2) The materials obtained from the ammonolysis reaction are sequentially separated into cyclohexylimine and hexamethylenediamine.

[0034] The inventors of this invention discovered in their research that when using an ammonolysis catalyst with the above-described composition to catalyze the ammonolysis reaction of bis(hexamethylene)triamine, the reaction exhibits a high conversion rate and can yield hexamethylenediamine (i.e., HMDA) and cycloheximine (i.e., HMI) with high selectivity. The ammonia can be used in liquid form. The alumina can be γ-Al₂O₃.

[0035] According to the present invention, preferably, the content of Ni is 20-30 wt% (e.g., 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%), the content of La is 1-10 wt% (e.g., 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%), and the content of In is 1-5 wt% (e.g., 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%), based on the total weight of the catalyst. All the above components are expressed by mass of the corresponding element.

[0036] According to the present invention, preferably, the weight ratio of Ni, La and In is (6-25):(1-10):1.

[0037] Within the aforementioned range, it is possible to further ensure high conversion rate and selectivity during ammonolysis, and the catalyst also exhibits high stability with its performance not easily deteriorating over long-term use.

[0038] In the ammonolysis catalyst, Ni can exist primarily in its reduced state (elemental form) and partially in its oxide form. The forms of La and In are also not particularly restricted; they can exist as both oxides and elements.

[0039] In a catalyst, all components other than the active component can be supports.

[0040] According to the present invention, preferably, the ammonia adsorption capacity of the catalyst is 0.05-0.3 mmol / g. Within the above range, the catalyst exhibits better conversion and selectivity in the ammonolysis reaction. The ammonia adsorption capacity of the support can be determined by first saturating the support with ammonia, then using a programmed temperature increase to desorb the ammonia from the support, and finally detecting the amount of desorbed ammonia to obtain the ammonia adsorption capacity.

[0041] In a catalyst, apart from the active component, all other components can be support components.

[0042] The preparation method of the catalyst is not particularly limited, as long as the active component can be loaded onto the support to obtain a catalyst with the above-mentioned composition. The specific operation for preparing the catalyst is not particularly limited, as long as a catalyst with the above-mentioned composition can be obtained. The support can also be modified and controlled in accordance with conventional methods in the art. For example, the pore structure of the support oxide can be adjusted using pore-expanding agents or hydrothermal treatment to improve the overall selectivity and stability of the catalyst; alternatively, suitable acidity and basicity can be controlled by adding compounds that can regulate surface acidity and basicity during the catalyst preparation process to improve catalyst activity and selectivity; alternatively, the stability of the catalyst and its lifetime can be improved by adding a metal that can synergize with the active component such as nickel to the support; alternatively, the catalyst lifetime can be extended by adjusting the surface properties of the catalyst to reduce the deposition of certain compounds or heavy components on the catalyst surface or to improve the surface dispersion of the active component.

[0043] Furthermore, the specific operation of loading the active component can also employ conventional methods in the art, such as impregnation, ion exchange, blending, kneading, co-precipitation, deposition-precipitation, ammonium evaporation precipitation, melt-filtration, ball milling, and sol-gel methods. Preferably, one or more of the impregnation, co-precipitation, and sol-gel methods are used in combination, as these methods for preparing catalysts are mostly well-known to those skilled in the art as existing mature technologies. For example, a support can be weighed, and a precursor of the metal active component can be loaded onto the support using a one-step or multi-step impregnation method, followed by drying, calcination, and reduction to obtain the desired ammonolysis catalyst; alternatively, a spraying method can be used to spray the precursor of the active component onto the support, followed by drying, calcination, and reduction to obtain the desired ammonolysis catalyst; furthermore, a co-precipitation method can be used to prepare the catalyst powder, followed by drying and decomposition, and then granulation, tableting, and reduction steps to obtain the desired catalyst product.

[0044] Furthermore, the shape of the ammonolysis catalyst is not particularly limited; for example, it can be spherical, strip-shaped, columnar, or ring-shaped. The size can be between 0.3-10 mm, especially between 0.5-5 mm. This size requirement is mainly based on the design of the fixed-bed reactor to meet the requirements of catalyst loading and reducing bed pressure. Appropriate shapes and sizes can be selected according to the application requirements. All of the above knowledge is well-known to those skilled in the art.

[0045] For example, a catalyst can be prepared by the following multi-step impregnation method;

[0046] (1) Weigh the alumina precursor, silica precursor and calcium oxide precursor. Place the alumina precursor in a kneader, add the weighed silica precursor and calcium oxide precursor to water to make a solution, add the solution to the alumina precursor in the kneader and stir thoroughly, then add an aqueous solution of water, nitric acid and phosphoric acid, knead and extrude into a clover shape, dry it at 110-120℃ for 4-5h, then calcine it in a muffle furnace at 850-920℃ for 5-8h, and obtain the carrier after cooling.

[0047] (2) Add nickel source, lanthanum source and indium source to water to prepare an aqueous solution. Load the solution onto the carrier obtained in step (1) in two equal-volume impregnation methods. After each impregnation, dry at 120-150℃ for 3-5 hours, and then calcine at 350-400℃ for 3-6 hours. Then reduce.

[0048] The amounts of the above materials are determined based on the required amounts of the active components and support in the target catalyst. Alumina precursors can be pseudoboehmite, silica precursors can be silica sol, and calcium oxide precursors can be calcium nitrate. Nickel sources can be nickel sulfate, lanthanum sources can be lanthanum acetate, and indium sources can be indium nitrate.

[0049] It is understandable that the catalyst needs to be reduced before application in catalysis to ensure that at least some of the active component Ni exists in elemental form. When reducing the catalyst, a mixture of hydrogen and nitrogen is generally used. If pure hydrogen is used for reduction, the heating rate needs to be strictly controlled. Considering the reduction efficiency and control, a nitrogen-hydrogen mixture with a lower hydrogen content is preferred. During reduction, a higher space velocity of the reducing gas is better because a high space velocity can quickly remove the heat generated by the reaction, maintaining a relatively stable catalyst bed temperature and preventing overheating and catalyst damage. For example, a space velocity of 4000-8000 m / s is suitable. 3 / m 3 ·h -1 The reduction temperature can be determined based on the specific catalyst composition. For the catalyst described in this invention, the catalyst bed temperature can be gradually increased at a rate of 10-20°C / h, held at around 200°C for 5-10 hours, and then gradually increased at a rate of 5-20°C / h until reaching 380-480°C, maintained at this temperature for 10-20 hours. Then, it is slowly reduced to room temperature, for example, at a cooling rate of 10-20°C / h. After cooling to room temperature, the system is completely switched to nitrogen gas, and dry air is gradually mixed into the nitrogen gas, gradually increasing the air volume to increase the oxygen content in the mixture to passivate the catalyst. The air volume is adjusted according to changes in the catalyst temperature to avoid the catalyst bed temperature from becoming too high, for example, not exceeding 70°C. If the catalyst is reduced in situ in the corresponding reactor, it can be used after the catalyst temperature drops to the reaction temperature following reduction.

[0050] According to the present invention, the preferred reaction conditions for ammonolysis include: a reaction temperature of 130-280°C, a reaction pressure of 8-28 MPa, and a feed liquid hourly space velocity of 0.005-1.2 h⁻¹ for bis(hexamethylene)triamine. -1 The molar ratio of hydrogen, ammonia, and bis(hexamethylene)triamine is (0.8-18):(40-180):1. The reaction pressure is the pressure of the entire reaction system.

[0051] Preferably, the reaction conditions for ammonolysis include: a reaction temperature of 165-235℃, a reaction pressure of 14-23 MPa, and a feed liquid hourly space velocity of 0.08-0.9 h⁻¹ for bis(hexamethylene)triamine. -1 The molar ratio of hydrogen, ammonia and bis(hexamethylene)triamine is (1.8-12):(70-130):1.

[0052] The bis(hexamethylene)triamine and ammonia can be preheated in hydrogen gas before being introduced into the ammonolysis reactor for reaction.

[0053] Bis(hexamethylene)triamine is generally fed in the form of a solution. The solvent can be water, or organic solvents such as 1,4-epoxybutane or 1,4-dioxane. The mass concentration of bis(hexamethylene)triamine in the solution is not particularly limited, for example, it can be 20-50 wt%. The use of the above solvents can also better cooperate with the catalyst, further improve the conversion rate of the reaction and the selectivity of the target products (hexamethylenediamine and cyclohexylimine), reduce the amount of heavy components formed, and thus extend the catalyst life.

[0054] During the ammonolysis of bis(hexamethylene)triamine to synthesize hexamethylenediamine, some side reactions may occur due to unsuitable catalysts or process conditions. These side reactions include further reaction to generate heavy components, and intramolecular chain scission reactions within the product. These reactions may be caused by the properties or strength of the catalyst itself, or by extreme process conditions. Selecting a catalyst with balanced performance and suitable process conditions is essential for achieving ideal ammonolysis catalytic effects. The inventors of this invention have discovered that, under the aforementioned preferred ammonolysis reaction conditions, heterogeneous catalysis (where reactants and catalyst exist in different states) results in higher reaction conversion rates and higher selectivity for the target product.

[0055] The reactor used for the ammonolysis reaction can be a fixed-bed reactor or other forms useful for the ammonolysis process. The ammonolysis reaction can be carried out under gaseous, liquid, or supercritical conditions. Supercritical ammonia can be used for the ammonolysis reaction.

[0056] According to the present invention, preferably, before the separation of cycloheximine, the method further includes: sequentially performing hydrogen separation and deammoniation on the material obtained from the ammonolysis reaction, and returning the hydrogen obtained after hydrogen separation to the ammonolysis step.

[0057] It is understandable that ammonia is generally used in liquid form, and hydrogen separation can be achieved through gas-liquid separation. The separated hydrogen is then returned to the ammonolysis step for recycling, avoiding material waste.

[0058] According to the present invention, preferably, the deammoniation is carried out in a deammoniation tower, and the deammoniation method is as follows: the material obtained from the ammonolysis reaction is fed into the deammoniation tower from the upper part, and liquid ammonia is obtained at the top of the deammoniation tower, while a lean liquid ammonia stream is obtained at the bottom of the tower. In this way, liquid ammonia can be separated and obtained.

[0059] According to the present invention, the preferred operating conditions in the deammoniation tower include: a theoretical plate number of 50-75, a tower top temperature of 60-75°C, and a tower top pressure of 0.05 MPa to 0.15 MPa.

[0060] The above ammonolysis reaction can yield the target product with high conversion rate and selectivity. Depending on the needs, all or part of the material after the ammonolysis reaction can be subjected to subsequent cyclohexylimine and hexamethylenediamine separation.

[0061] According to the present invention, preferably, the cyclohexylimine separation is carried out in a cyclohexylimine separation tower. The cyclohexylimine separation method is as follows: the material is fed into the cyclohexylimine separation tower from the middle and lower part, and cyclohexylimine is obtained at the top of the tower, while a tower bottom stream leaning towards cyclohexylimine is obtained at the bottom of the tower. In this way, cyclohexylimine can be separated from the material.

[0062] According to the present invention, the preferred operating conditions in the cycloheximine separation tower include: a theoretical plate number of 40-70, a tower top temperature of 110-125°C, and a tower top pressure of -0.2MPa to -0.05MPa.

[0063] According to the present invention, preferably, the hexamethylenediamine separation is carried out in a hexamethylenediamine separation tower. The hexamethylenediamine separation method is as follows: the material is fed into the hexamethylenediamine separation tower from the upper part, and hexamethylenediamine is obtained at the top of the tower, while a tower bottom stream leaning towards hexamethylenediamine is obtained at the bottom of the tower. In this way, hexamethylenediamine can be separated and obtained.

[0064] According to the present invention, the preferred operating conditions in the hexamethylenediamine separation tower include: 40-65 theoretical plates, a tower top temperature of 130-165°C, and a tower top pressure of -0.3MPa to -0.1MPa.

[0065] The method of the present invention can achieve high selectivity, but some byproducts or intermediate products still exist, such as products containing 12 carbon atoms, i.e., C12. According to the present invention, preferably, after the separation of hexamethylenediamine, the method further includes: performing C12 separation on the material.

[0066] Preferably, C12 separation is carried out in a C12 separation tower. The C12 separation method is as follows: the material is fed into the C12 separation tower from the middle and lower part, and a C12-rich overhead stream is obtained at the top of the tower. The stream obtained in the bottom of the tower is mostly composed of C18 and other components.

[0067] Preferably, the operating conditions in the C12 separation column include: a theoretical plate number of 30-60, a column top temperature of 210-240℃, and a column top pressure of -0.2MPa to -0.01MPa.

[0068] All pressures in the above towers are absolute pressures. Furthermore, it is understandable that, given the conditions at the top of the tower, the state of the bottom of the tower can generally be determined.

[0069] Those skilled in the art can also rationally select other operating conditions, such as reflux ratio and the ratio of top product to feed, based on the crude product of the reaction and the feed to each column, as well as the purpose of separation and purification. These conventional technical conditions will not be elaborated here.

[0070] According to the present invention, preferably, the method further includes: returning at least a portion of the liquid ammonia obtained from the top of the deammoniation tower and / or the C12-rich overhead stream obtained from the C12 separation tower to the ammonolysis step. The liquid ammonia obtained after separation by the deammoniation tower can be reused in the ammonolysis step. The C12 component can be an intermediate product for the formation of cyclohexylimine and hexamethylenediamine, which can be further reacted to obtain cyclohexylimine and hexamethylenediamine through ammonolysis. This allows for full utilization of resources and avoids waste.

[0071] According to the present invention, preferably, at least a portion of the cyclohexylimine obtained from the top of the cyclohexylimine separation tower is returned to the ammonolysis step. The obtained cyclohexylimine is then returned to the ammonolysis step, and the reaction yields hexanediamine. Therefore, when a higher proportion of hexanediamine and a lower proportion of cyclohexylimine are desired, the above-mentioned preferred method can be used to return the cyclohexylimine to the reaction, thereby allowing for flexible adjustment of the product ratio to better meet market needs. Alternatively, the cyclohexylimine obtained from the top of the cyclohexylimine separation tower may not be returned to the ammonolysis step, but may be entirely collected for use in downstream processes or directly sold commercially.

[0072] According to a particularly preferred embodiment of the present invention, hexamethylenediamine is synthesized and cyclohexylimine is produced concurrently according to the following catalyst and method:

[0073] Take an ammonolysis catalyst containing active components Ni, La and In, and a support of alumina, silica and calcium oxide. The total weight of the catalyst is 21-23 wt%, the content of La is 2-3 wt%, the content of In is 1.5-2 wt%, and the remainder is the support. The weight ratio of alumina, silica and calcium oxide is (9-15):(2.5-5):1.

[0074] (1) Ammonolysis: Bis(hexamethylene)triamine and ammonia are mixed and preheated under a hydrogen atmosphere and then introduced into an ammonolysis reactor. In the presence of an ammonolysis catalyst, bis(hexamethylene)triamine is ammonolysed to synthesize a crude product containing hexamethylenediamine and cyclohexylimine. The specific ammonolysis reaction conditions are: reaction temperature of 190-198℃, reaction pressure of 19-22MPa, and feed liquid hourly space velocity of bis(hexamethylene)triamine of 0.32-0.4h. -1 The molar ratio of hydrogen, ammonia, and bis(hexamethylene)triamine is (2-3):(90-100):1.

[0075] (2) Deammoniation: The crude product prepared above is subjected to gas-liquid separation to obtain hydrogen. The material after hydrogen separation is fed into a deammoniation tower. Liquid ammonia is obtained at the top of the deammoniation tower, and a lean liquid ammonia stream is obtained at the bottom of the tower. The deammoniation tower has a theoretical number of 66-67 plates, the feed inlet is located in the upper middle part, the top temperature is 68-69℃, and the top pressure is 0.11 to 0.12 MPa.

[0076] (3) HMI separation: The bottom stream of the deammoniation tower is sent to the cyclohexylimine separation tower, where cyclohexylimine is obtained at the top of the tower and a bottom stream of cyclohexylimine-lean is obtained at the bottom of the tower; the theoretical number of plates of the HMI separation tower is 60-61, the feed inlet is located in the middle and lower part, the top temperature of the tower is 116-118℃, and the top pressure of the tower is -0.18MPa to -0.15MPa;

[0077] (4) HMDA separation: The hexamethylenediamine-containing bottom stream is sent to the HMDA separation tower, the hexamethylenediamine product is collected at the top of the tower, and a bottom stream with hexamethylenediamine is obtained at the bottom of the tower; the theoretical number of plates of the HMDA separation tower is 56-58, the feed inlet is located in the middle and upper part, the top temperature of the tower is 156-158℃, and the top pressure of the tower is -0.19MPa to -0.185MPa;

[0078] (5) C12 separation: The bottom stream of the HMDA separation tower is sent to the C12 separation tower. The C12 component is collected from the top of the tower, and the C18 component is collected from the bottom of the tower. The theoretical number of plates of the C12 purification tower is 48-50, the feed inlet is located in the middle and lower part, the top temperature of the tower is 223-225℃, and the top pressure of the tower is -0.09MPa to -0.06MPa.

[0079] The present invention will be described in detail below through preparation examples and embodiments.

[0080] In the following preparation examples, the ammonia adsorption capacity was determined using NH3-TPD, as detailed below:

[0081] Testing instrument: Automated Catalyst Characterization System (Autochem 2920), product of Microlithics, USA.

[0082] Test conditions: Accurately weigh approximately 0.1 g of sample and place it in a sample tube. Under He gas purging conditions, raise the temperature to 600 °C at 10 °C / min, hold for 1 h, lower the temperature to 120 °C, then change the gas to a 10% NH3-He mixture, adsorb for 60 min, then switch back to He gas purging for 1 h. After the baseline stabilizes, start counting, raise the temperature to 600 °C at 10 °C / min, hold for 30 min, stop recording, and complete the experiment. Calculate the ammonia adsorption capacity by integrating the peak area.

[0083] The weights of alumina, silica, and calcium oxide in the carrier were calculated using X-ray fluorescence analysis (XRF) tests.

[0084] The content of metal elements supported on the catalysts was analyzed by X-ray fluorescence analysis (XRF). In each catalyst, apart from the active component, the rest were supports.

[0085] Preparation Example 1

[0086] The following catalyst was prepared by a multi-step impregnation method:

[0087] (1) Weigh the pseudoboehmite (produced by the aluminum sulfate method, with a specific surface area of ​​310 m²). 2 The mixture consisted of 94.20 g of pseudoboehmite (1.19 ml / g pore volume), 72.50 g of silica sol (JN-40), and 25.26 g of calcium nitrate tetrahydrate. The pseudoboehmite was placed in a kneader. The weighed silica sol and calcium nitrate tetrahydrate were added to 24.77 g of water to prepare a solution, which was then added to the pseudoboehmite in the kneader and stirred thoroughly. An aqueous solution of 16.51 g water, 4.71 g nitric acid, and 2.83 g phosphoric acid was added, and the mixture was kneaded and extruded into a clover shape. This was dried at 120°C for 4 hours, followed by calcination at 900°C in a muffle furnace for 6 hours. After cooling, the carrier was obtained.

[0088] (2) 100.77 g of nickel sulfate hexahydrate (industrial grade, 98% purity), 5.69 g of lanthanum acetate monohydrate, and 5.96 g of indium nitrate pentahydrate were added to 134.78 mL of water to prepare an aqueous solution. The solution was loaded onto 73.25 g of the support obtained in step (1) using an equal-volume impregnation method in two separate applications. After each impregnation, the solution was dried at 120 °C for 4 hours and then calcined at 390 °C for 4 hours. Then, reduction was performed to obtain catalyst A-1, which had an ammonia adsorption capacity of 0.21 mmol / g.

[0089] Preparation Example 2

[0090] The following catalyst was prepared by a multi-step impregnation method:

[0091] (1) Weigh the pseudoboehmite (produced by aluminum sulfate method, specific surface area 323m²). 2 The mixture consisted of 101.45 g of pseudoboehmite (1.32 ml / g pore volume), 70.0 g of silica sol (JN-40), and 8.42 g of calcium nitrate tetrahydrate. The pseudoboehmite was placed in a kneader. The weighed silica sol and calcium nitrate tetrahydrate were added to 41.76 g of water to prepare a solution, which was then added to the pseudoboehmite in the kneader and stirred thoroughly. An aqueous solution of 27.84 g water, 5.07 g nitric acid, and 3.04 g phosphoric acid was added, and the mixture was kneaded and extruded into a clover shape. This was dried at 110 °C for 5 h, followed by calcination at 860 °C in a muffle furnace for 8 h. After cooling, the carrier was obtained.

[0092] (2) 128.98 g of nickel sulfate hexahydrate (industrial grade, 98% purity), 12.51 g of lanthanum acetate monohydrate, and 11.91 g of indium nitrate pentahydrate were added to 114.45 mL of water to prepare an aqueous solution. The solution was then loaded onto 62.2 g of the support obtained in step (1) using an equal-volume impregnation method in two separate applications. After each impregnation, the solution was dried at 150 °C for 3 hours and then calcined at 370 °C for 6 hours. Reduction was then carried out to obtain catalyst A-2. The ammonia adsorption capacity of the catalyst was 0.28 mmol / g.

[0093] Preparation Example 3

[0094] The following catalyst was prepared by a multi-step impregnation method:

[0095] (1) Weigh the pseudoboehmite (produced by the aluminum sulfate method, with a specific surface area of ​​305 m²). 2The mixture consisted of 108.70 g of pseudoboehmite (1.27 ml / g pore volume), 40.0 g of silica sol (JN-40), and 37.90 g of calcium nitrate tetrahydrate. The pseudoboehmite was placed in a kneader. The weighed silica sol and calcium nitrate tetrahydrate were added to 50.82 g of water to prepare a solution, which was then added to the pseudoboehmite in the kneader and stirred thoroughly. An aqueous solution of 33.88 g water, 6.52 g nitric acid, and 3.26 g phosphoric acid was added, and the mixture was kneaded and extruded into a clover shape. This was dried at 120°C for 4 hours, followed by calcination at 890°C in a muffle furnace for 5 hours. After cooling, the carrier was obtained.

[0096] (2) 90.47 g of nickel sulfate hexahydrate (industrial grade, 98% purity), 19.57 g of lanthanum acetate monohydrate, and 3.40 g of indium nitrate pentahydrate were added to 129.17 mL of water to prepare an aqueous solution. This solution was then loaded onto 70.20 g of the support obtained in step (1) using an equal-volume impregnation method in two separate applications. After each impregnation, the solution was dried at 130 °C for 4 hours and then calcined at 400 °C for 4 hours. Reduction was then performed to obtain catalyst A-3. The ammonia adsorption capacity of the catalyst was 0.14 mmol / g.

[0097] Comparative Preparation Example 1

[0098] The following catalyst was prepared by a multi-step impregnation method:

[0099] (1) Weigh the pseudoboehmite (produced by the aluminum sulfate method, with a specific surface area of ​​310 m²). 2 The mixture consisted of 102.32 g of a mixture containing 1.19 ml / g of silica sol (JN-40), 62.25 g of silica sol, and 18.95 g of calcium nitrate tetrahydrate. The pseudoboehmite was placed in a kneader. The weighed silica sol and calcium nitrate tetrahydrate were added to 38.98 g of water to prepare a solution, which was then added to the pseudoboehmite in the kneader and stirred thoroughly. An aqueous solution consisting of 25.99 g of water, 5.12 g of nitric acid, and 3.07 g of phosphoric acid was added, and the mixture was kneaded and extruded into a clover shape. This was dried at 100°C for 6 hours, followed by calcination at 960°C in a muffle furnace for 4 hours. After cooling, the carrier was obtained.

[0100] (2) 95.40 g of nickel sulfate hexahydrate (industrial grade, 98% purity) and 4.08 g of indium nitrate pentahydrate were added to 140.39 mL of water to prepare an aqueous solution. The solution was then loaded onto 76.30 g of the support obtained in step (1) using an equal-volume impregnation method in two separate applications. After each impregnation, the substrate was dried at 120 °C for 4 hours and then calcined at 360 °C for 7 hours. Reduction was then carried out to obtain catalyst B-1. The ammonia adsorption capacity of the catalyst was 0.26 mmol / g.

[0101] Comparative Preparation Example 2

[0102] The following catalyst was prepared by a multi-step impregnation method:

[0103] (1) Weigh the pseudoboehmite (produced by the aluminum sulfate method, with a specific surface area of ​​305 m²). 2 The mixture consisted of 108.7g of pseudoboehmite (1.27ml / g pore volume), 40.0g of silica sol (JN-40), and 37.90g of calcium nitrate tetrahydrate. The pseudoboehmite was placed in a kneader. The weighed silica sol and calcium nitrate tetrahydrate were added to 50.82g of water to prepare a solution, which was then added to the pseudoboehmite in the kneader and stirred thoroughly. An aqueous solution of 33.88g water, 5.43g nitric acid, and 3.26g phosphoric acid was added, and the mixture was kneaded and extruded into a clover shape. This was dried at 120℃ for 5 hours, followed by calcination at 990℃ in a muffle furnace for 3 hours. After cooling, the carrier was obtained.

[0104] (2) 122.11 g of nickel sulfate hexahydrate (industrial grade, 98% purity) and 11.38 g of lanthanum acetate monohydrate were added to 121.81 mL of water to prepare an aqueous solution. The solution was then loaded onto 66.20 g of the support obtained in step (1) using an equal-volume impregnation method in two separate applications. After each impregnation, the solution was dried at 120 °C for 4 hours and then calcined at 370 °C for 4 hours. Reduction was then carried out to obtain catalyst B-2. The ammonia adsorption capacity of the catalyst was 0.16 mmol / g.

[0105] Comparative preparation example 3

[0106] The following catalyst was prepared by a multi-step impregnation method:

[0107] (1) Weigh the pseudoboehmite (produced by the aluminum sulfate method, with a specific surface area of ​​298 m²). 2 The mixture consisted of 101.45 g of a mixture containing 1.12 ml / g of silica sol (JN-40) 65.0 g of silica sol and 16.84 g of calcium nitrate tetrahydrate. The pseudoboehmite was placed in a kneader. The weighed silica sol and calcium nitrate tetrahydrate were added to 37.47 g of water to prepare a solution, which was then added to the pseudoboehmite in the kneader and stirred thoroughly. An aqueous solution of 24.98 g of water, 7.10 g of acetic acid, and 3.04 g of phosphoric acid was added, and the mixture was kneaded and extruded into a clover shape. This was dried at 110 °C for 6 h, then calcined in a muffle furnace at 950 °C for 5 h. After cooling, the carrier was obtained.

[0108] (2) 127.20 g of nickel sulfate hexahydrate (industrial grade, 98% purity) was added to 129.72 mL of water to prepare an aqueous solution. The solution was loaded onto 70.50 g of the support obtained in step (1) using an equal-volume impregnation method in two batches. After each impregnation, the solution was dried at 150 °C for 4 hours and then calcined at 430 °C for 4 hours. Then, reduction was performed to obtain catalyst B-3. The ammonia adsorption capacity of the catalyst was 0.23 mmol / g.

[0109] Comparative preparation example 4

[0110] The following catalyst was prepared by a multi-step impregnation method:

[0111] (1) Weigh the pseudoboehmite (produced by the aluminum sulfate method, with a specific surface area of ​​310 m²). 2 The mixture consisted of 65.22 g of pseudoboehmite (1.19 ml / g pore volume), 100.0 g of silica sol (JN-40), and 63.16 g of calcium nitrate tetrahydrate. The pseudoboehmite was placed in a kneader. The weighed silica sol and calcium nitrate tetrahydrate were added to 17.04 g of water to prepare a solution, which was then added to the pseudoboehmite in the kneader and stirred thoroughly. An aqueous solution of 14.70 g water, 3.26 g nitric acid, and 2.94 g phosphoric acid was added, and the mixture was kneaded and extruded into a clover shape. This was dried at 120°C for 3 hours, followed by calcination at 1000°C in a muffle furnace for 4 hours. After cooling, the carrier was obtained.

[0112] (2) 101.76 g of nickel sulfate hexahydrate (industrial grade, 98% purity), 9.10 g of lanthanum acetate monohydrate, and 6.13 g of indium nitrate pentahydrate were added to 129.17 mL of water to prepare an aqueous solution. The solution was then loaded onto 70.2 g of the support obtained in step (1) using an equal-volume impregnation method in two separate applications. After each impregnation, the solution was dried at 120 °C for 4 hours and then calcined at 410 °C for 4 hours. Reduction was then carried out to obtain catalyst B-4. The ammonia adsorption capacity of the catalyst was 0.22 mmol / g.

[0113] Comparative preparation example 5

[0114] The following catalyst was prepared by a multi-step impregnation method:

[0115] (1) Weigh the pseudoboehmite (produced by the aluminum sulfate method, with a specific surface area of ​​310 m²). 2 / g, pore volume 1.19ml / g) 133.33g and silica sol (JN-40) 20.0g. The pseudoboehmite was placed in a kneader. The weighed silica sol and calcium nitrate tetrahydrate were added to 56.80g of water to prepare a solution, which was then added to the pseudoboehmite in the kneader and stirred thoroughly. An aqueous solution of 37.87g water, 6.62g nitric acid, and 4.02g phosphoric acid was added, and the mixture was kneaded and extruded into a clover shape. It was dried at 120℃ for 4h, then calcined in a muffle furnace at 900℃ for 5h. After cooling, the carrier was obtained.

[0116] (2) 95.40 g of nickel sulfate hexahydrate (industrial grade, 98% purity), 5.69 g of lanthanum acetate monohydrate, and 5.96 g of indium nitrate pentahydrate were added to 134.78 mL of water to prepare an aqueous solution. This solution was then loaded onto 73.25 g of the support obtained in step (1) using an equal-volume impregnation method in two separate applications. After each impregnation, the solution was dried at 110 °C for 4 hours and then calcined at 400 °C for 4 hours. Reduction was then performed to obtain catalyst B-5. The ammonia adsorption capacity of the catalyst was 0.41 mmol / g.

[0117] The compositions of the catalysts obtained in Preparation Examples 1-8 are shown in Table 1-2.

[0118] Table 1

[0119]

[0120] Table 2

[0121]

[0122] In the following examples, after the ammonolysis reactor had fully reacted, samples were taken for gas chromatography analysis, and the conversion rate of bis(hexamethylene)triamine and the selectivity of hexamethylenediamine and cycloheximine were calculated. The calculation method is as follows:

[0123] BHT conversion rate:

[0124]

[0125] The selectivity of cyclohexylimine is:

[0126]

[0127] The selectivity of hexamethylenediamine is:

[0128]

[0129] Example 1

[0130] This invention provides a method for synthesizing hexamethylenediamine and simultaneously producing cycloheximine.

[0131] This embodiment uses the ammonolysis catalyst obtained in Preparation Example 1.

[0132] (1) Ammonolysis: Bis(hexamethylene)triamine and ammonia are mixed and preheated under a hydrogen atmosphere and then introduced into an ammonolysis reactor. In the presence of an ammonolysis catalyst, bis(hexamethylene)triamine is ammonolysed to synthesize a crude product containing hexamethylenediamine and cyclohexylimine. The specific ammonolysis reaction conditions are: reaction temperature of 195℃, reaction pressure of 20.0MPa, and feed liquid hourly space velocity of bis(hexamethylene)triamine of 0.35h⁻¹. -1 The molar ratio of hydrogen, ammonia, and bis(hexamethylene)triamine is 3:100:1.

[0133] (2) Deammoniation: The crude product prepared above is subjected to gas-liquid separation to obtain hydrogen. The material after hydrogen separation is fed into a deammoniation tower. Liquid ammonia is obtained at the top of the deammoniation tower, and a lean liquid ammonia stream is obtained at the bottom of the tower. The theoretical number of trays of the deammoniation tower is 66, the feed inlet is located on the 32nd tray (i.e., the middle and upper part of the deammoniation tower, the 32nd tray from top to bottom, and similar descriptions below also refer to counting from top to bottom), the top temperature is 68.3℃, and the top pressure is 0.12MPa.

[0134] (3) HMI separation: The bottom stream of the deammoniation tower is sent to the cyclohexylimine separation tower to obtain cyclohexylimine at the top of the tower and a bottom stream of cyclohexylimine-deficient at the bottom of the tower; the theoretical number of trays of the HMI separation tower is 60, the feed inlet is located on the 35th tray, the temperature at the top of the tower is 116℃, and the pressure at the top of the tower is -0.15MPa.

[0135] (4) HMDA separation: The bottom stream containing hexamethylenediamine is sent to the HMDA separation tower, the hexamethylenediamine product is collected at the top of the tower, and a bottom stream with hexamethylenediamine is obtained at the bottom of the tower; the theoretical number of plates of the HMDA separation tower is 56, the feed inlet is located at the 27th plate, the top temperature of the tower is 156℃, and the top pressure of the tower is -0.19MPa;

[0136] (5) C12 separation: The bottom stream of the HMDA separation tower is sent to the C12 separation tower. The C12 component is collected from the top of the tower, and the C18 component is collected from the bottom of the tower. The theoretical number of plates of the C12 purification tower is 48, the feed inlet is located on the 29th plate, the temperature at the top of the tower is 223℃, and the pressure at the top of the tower is -0.09MPa.

[0137] The conversion rate of bis(hexamethylene)triamine was 94.46%, the selectivity of cycloheximine was 50.54%, and the selectivity of hexamethylenediamine was 20.39%.

[0138] The material input and output details for each step are shown in Table 3.

[0139] Table 3

[0140]

[0141]

[0142] Example 2

[0143] This invention provides a method for synthesizing hexamethylenediamine and simultaneously producing cycloheximine.

[0144] This embodiment uses the ammonolysis catalyst obtained in Preparation Example 2.

[0145] (1) Ammonolysis: Bis(hexamethylene)triamine and ammonia are mixed and preheated under a hydrogen atmosphere and then introduced into an ammonolysis reactor. In the presence of an ammonolysis catalyst, bis(hexamethylene)triamine is ammonolysed to synthesize a crude product containing hexamethylenediamine and cyclohexylimine. The specific ammonolysis reaction conditions are: reaction temperature of 185℃, reaction pressure of 18.0 MPa, and feed liquid hourly space velocity of bis(hexamethylene)triamine of 0.45 h⁻¹. -1 The molar ratio of hydrogen, ammonia, and bis(hexamethylene)triamine is 5:120:1.

[0146] (2) Deammoniation: The crude product prepared above is subjected to gas-liquid separation to obtain hydrogen. The material after hydrogen separation is fed into a deammoniation tower. Liquid ammonia is obtained at the top of the deammoniation tower, and a lean liquid ammonia stream is obtained at the bottom of the tower. The theoretical number of trays of the deammoniation tower is 65, the feed inlet is located on the 30th tray (i.e., the middle and upper part of the deammoniation tower), the top temperature is 67.5℃, and the top pressure is 0.1MPa.

[0147] (3) HMI separation: The bottom stream of the deammoniation tower is sent to the cyclohexylimine separation tower. Cyclohexylimine is obtained at the top of the tower and a bottom stream of cyclohexylimine-deficient is obtained at the bottom of the tower. The theoretical number of plates of the HMI separation tower is 57, the feed inlet is located on the 30th plate, the top temperature is 112.5℃, and the top pressure is -0.14MPa.

[0148] (4) HMDA separation: The bottom stream containing hexamethylenediamine is sent to the HMDA separation tower, the hexamethylenediamine product is collected at the top of the tower, and a bottom stream with hexamethylenediamine is obtained at the bottom of the tower; the theoretical number of plates of the HMDA separation tower is 61, the feed inlet is located at the 30th plate, the top temperature of the tower is 161.2℃, and the top pressure of the tower is -0.21MPa;

[0149] (5) C12 separation: The bottom stream of the HMDA separation tower is sent to the C12 separation tower. The C12 component is collected from the top of the tower, and the C18 component is collected from the bottom of the tower. The theoretical number of plates of the C12 purification tower is 51, the feed inlet is located on the 32nd plate, the temperature at the top of the tower is 228.4℃, and the pressure at the top of the tower is -0.12MPa.

[0150] The conversion rate of bis(hexamethylene)triamine was 95.01%, the selectivity of cycloheximine was 47.30%, and the selectivity of hexamethylenediamine was 23.49%.

[0151] Example 3

[0152] This invention provides a method for synthesizing hexamethylenediamine and simultaneously producing cycloheximine.

[0153] This embodiment uses the ammonolysis catalyst obtained in Preparation Example 3.

[0154] (1) Ammonolysis: Bis(hexamethylene)triamine and ammonia are mixed and preheated under a hydrogen atmosphere and then introduced into an ammonolysis reactor. In the presence of an ammonolysis catalyst, bis(hexamethylene)triamine is ammonolysed to synthesize a crude product containing hexamethylenediamine and cyclohexylimine. The specific ammonolysis reaction conditions are: reaction temperature of 204℃, reaction pressure of 16.5MPa, and feed liquid hourly space velocity of bis(hexamethylene)triamine of 0.52h⁻¹. -1 The molar ratio of hydrogen, ammonia, and bis(hexamethylene)triamine is 7:110:1.

[0155] (2) Deammoniation: The crude product prepared above is subjected to gas-liquid separation to obtain hydrogen. The material after hydrogen separation is fed into a deammoniation tower. Liquid ammonia is obtained at the top of the deammoniation tower, and a lean liquid ammonia stream is obtained at the bottom of the tower. The theoretical number of trays of the deammoniation tower is 68, the feed inlet is located on the 33rd tray (i.e., the middle and upper part of the deammoniation tower), the top temperature is 70.1℃, and the top pressure is 0.13MPa.

[0156] (3) HMI separation: The bottom stream of the deammoniation tower is sent to the cyclohexylimine separation tower, where cyclohexylimine is obtained at the top of the tower and a bottom stream of cyclohexylimine-deficient is obtained at the bottom of the tower; the theoretical number of plates of the HMI separation tower is 59, the feed inlet is located on the 33rd plate, the top temperature is 115.6℃, and the top pressure is -0.14MPa;

[0157] (4) HMDA separation: The bottom stream containing hexamethylenediamine is sent to the HMDA separation tower, the hexamethylenediamine product is collected at the top of the tower, and a bottom stream with hexamethylenediamine is obtained at the bottom of the tower; the theoretical number of plates of the HMDA separation tower is 59, the feed inlet is located at the 28th plate, the top temperature of the tower is 159.8℃, and the top pressure of the tower is -0.18MPa;

[0158] (5) C12 separation: The bottom stream of the HMDA separation tower is sent to the C12 separation tower. The C12 component is collected from the top of the tower, and the C18 component is collected from the bottom of the tower. The theoretical number of plates of the C12 purification tower is 47, the feed inlet is located on the 28th plate, the temperature at the top of the tower is 221.3℃, and the pressure at the top of the tower is -0.14MPa.

[0159] The conversion rate of bis(hexamethylene)triamine was 94.53%, the selectivity of cycloheximine was 48.59%, and the selectivity of hexamethylenediamine was 21.59%.

[0160] Example 4

[0161] The procedure was carried out according to Example 1, except that the catalyst prepared in Preparation Example 4 was used. The conversion of bis(hexamethylene)triamine was 94.67%, the selectivity for cycloheximine was 45.31%, and the selectivity for hexamethylenediamine was 20.85%.

[0162] Example 5

[0163] The procedure was carried out according to Example 1, except that the catalyst prepared in Preparation Example 5 was used. The conversion of bis(hexamethylene)triamine was 93.87%, the selectivity for cycloheximine was 44.38%, and the selectivity for hexamethylenediamine was 19.18%.

[0164] Example 6

[0165] The procedure was carried out according to Example 1, except that the catalyst prepared in Preparation Example 6 was used. The conversion of bis(hexamethylene)triamine was 87.02%, the selectivity for cycloheximine was 36.89%, and the selectivity for hexamethylenediamine was 18.57%.

[0166] Example 7

[0167] The procedure was carried out according to Example 1, except that the catalyst prepared in Preparation Example 7 was used. The conversion of bis(hexamethylene)triamine was 84.93%, the selectivity for cycloheximine was 39.84%, and the selectivity for hexamethylenediamine was 18.92%.

[0168] Example 8

[0169] The procedure was carried out according to Example 1, except that the catalyst prepared in Preparation Example 8 was used. The conversion rate of bis(hexamethylene)triamine was 89.23%, the selectivity for cycloheximine was 43.87%, and the selectivity for hexamethylenediamine was 17.85%.

[0170] As can be seen from Examples 1-4, when using the catalyst containing Ni, La and In as defined in this invention, the selectivity of cycloheximine is better.

[0171] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for synthesizing hexamethylenediamine and concurrently producing cyclohexylimine, characterized in that, The method includes: (1) Ammonolysis: In the presence of an ammonolysis catalyst, ammonia and hydrogen, bis(hexamethylene)triamine undergoes an ammonolysis reaction; The active components of the ammonolysis catalyst are Ni, La, and In; based on the total weight of the catalyst, the content of Ni is 20-30 wt%, the content of La is 1-10 wt%, and the content of In is 1-5 wt%. The support for the ammonolysis catalyst is alumina, silicon dioxide and calcium oxide, and the weight ratio of alumina, silicon dioxide and calcium oxide is (6-40):(1-20):1; (2) After the material obtained from the ammonolysis reaction is separated by hydrogen, it is deaminated in the deammoniation tower. Liquid ammonia is obtained at the top of the deammoniation tower and a lean liquid ammonia stream is obtained at the bottom of the tower. (3) The lean ammonia column bottom stream is subjected to cyclohexylimine separation in a cyclohexylimine separation column to obtain cyclohexylimine at the top of the column and lean cyclohexylimine column bottom stream at the bottom of the column. (4) The lean cyclohexylimine bottom stream is separated into hexamethylenediamine in a hexamethylenediamine separation tower to obtain hexamethylenediamine at the top of the tower and a lean hexamethylenediamine bottom stream at the bottom of the tower. (5) The low-hexamethylenediamine bottom stream is separated into C12 in a C12 separation column to obtain a C12-rich top stream at the top of the column.

2. A method for synthesizing hexamethylenediamine and concurrently producing cyclohexylimine, characterized in that, The method includes: (1) Ammonolysis: Bis(hexamethylene)triamine is subjected to ammonolysis in the presence of an ammonolysis catalyst, ammonia and hydrogen; wherein the active components of the ammonolysis catalyst are Ni, La and In, and the content of Ni is 20-30 wt%, the content of La is 1-10 wt% and the content of In is 1-5 wt% based on the total weight of the catalyst; The support for the ammonolysis catalyst is alumina, silicon dioxide and calcium oxide, and the weight ratio of alumina, silicon dioxide and calcium oxide is (6-40):(1-20):1; (2) The materials obtained from the ammonolysis reaction are subjected to cycloheximine separation and hexamethylenediamine separation in sequence.

3. The method according to claim 2, wherein, The weight ratio of Ni, La and In is (6-25):(1-10):

1.

4. The method according to claim 3, wherein, The ammonia adsorption capacity of the ammonolysis catalyst is 0.05-0.3 mmol / g.

5. The method according to claim 2, wherein, The reaction conditions for ammonolysis include: a reaction temperature of 130-280℃, a reaction pressure of 8-28 MPa, and a feed liquid hourly space velocity (LHSV) of 0.005-1.2 h⁻¹ for bis(hexamethylene)triamine. -1 The molar ratio of hydrogen, ammonia and bis(hexamethylene)triamine is (0.8-18):(40-180):

1.

6. The method according to claim 2 or 5, wherein, The reaction conditions for ammonolysis include: a reaction temperature of 165-235℃, a reaction pressure of 14-23 MPa, and a feed liquid hourly space velocity of 0.08-0.9 h⁻¹ for bis(hexamethylene)triamine. -1 The molar ratio of hydrogen, ammonia and bis(hexamethylene)triamine is (1.8-12):(70-130):

1.

7. The method according to claim 2 or 5, wherein, Before the separation of cycloheximine, the method further includes: sequentially performing hydrogen separation and deammoniation on the material obtained from the ammonolysis reaction, and returning the hydrogen obtained after hydrogen separation to the ammonolysis step.

8. The method according to claim 7, wherein, The deammoniation is carried out in a deammoniation tower. The deammoniation method is as follows: the material obtained from the ammonolysis reaction is fed into the deammoniation tower from the middle and upper part, and liquid ammonia is obtained at the top of the deammoniation tower, and a lean liquid ammonia bottom stream is obtained at the bottom of the tower.

9. The method according to claim 8, wherein, The operating conditions in the ammonia removal tower include: 50-75 theoretical plates, 60-75℃ top temperature, and 0.05MPa to 0.15MPa top pressure.

10. The method according to claim 8, wherein, The cyclohexylimine separation is carried out in a cyclohexylimine separation tower. The cyclohexylimine separation method is as follows: the material is fed into the cyclohexylimine separation tower from the middle and lower part, and cyclohexylimine is obtained at the top of the tower, while a tower bottom stream with cyclohexylimine deficiency is obtained at the bottom of the tower.

11. The method according to claim 10, wherein, The operating conditions in the cycloheximine separation tower include: 40-70 theoretical plates, 110-125℃ top temperature, and -0.2MPa to -0.05MPa top pressure.

12. The method according to claim 2, wherein, The hexamethylenediamine separation is carried out in a hexamethylenediamine separation tower. The hexamethylenediamine separation method is as follows: the material is fed into the hexamethylenediamine separation tower from the middle and upper part, and hexamethylenediamine is obtained at the top of the tower, while a tower bottom stream with depleted hexamethylenediamine is obtained at the bottom of the tower.

13. The method according to claim 12, wherein, The operating conditions in the hexamethylenediamine separation tower include: 40-65 theoretical plates, a top temperature of 130-165℃, and a top pressure of -0.3MPa to -0.1MPa.

14. The method of claim 10, wherein, After the separation of hexamethylenediamine, the method further includes: performing C12 separation on the material.

15. The method according to claim 14, wherein, C12 separation is carried out in a C12 separation tower. The C12 separation method is as follows: the material is fed into the C12 separation tower from the middle and lower part, and a C12-rich top stream is obtained at the top of the tower.

16. The method according to claim 15, wherein, The operating conditions in the C12 separation column include: 30-60 theoretical plates, 210-240℃ top temperature, and -0.2MPa to -0.01MPa top pressure.

17. The method of claim 14, wherein, The method further includes returning at least a portion of the liquid ammonia obtained from the top of the deammoniation tower and / or the C12-rich overhead stream obtained from the C12 separation tower to the ammonolysis step.

18. The method according to claim 10, wherein, At least a portion of the cyclohexylimine obtained from the top of the cyclohexylimine separation column is returned to the ammonolysis step.

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