Method for preparing primary amine by ammonolysis of secondary amine

Abstract

The invention discloses a method for preparing primary amine through secondary amine ammonolysis, and relates to the technical field of primary amine preparation, the method comprises the following steps: in the presence of hydrogen, secondary amine and / or a secondary amine solution and an ammonia source are subjected to ammonolysis reaction under the action of an ammonolysis catalyst to generate primary amine; the ammonolysis catalyst comprises a carrier and an active component loaded on the carrier; the active component comprises a main active component and an auxiliary agent; the main active component is Ni; the auxiliary agent is at least one of IIIB group elements, VIB group elements, VIIB group elements and IIIA group elements; the content of the main active component is 20-45wt% by taking the total weight of the catalyst as 100%; and the content of the auxiliary agent is 0.5-4.0 wt%. According to the method for preparing the primary amine through secondary amine ammonolysis, the primary amine can be efficiently prepared from various secondary amines through reaction, and the ammonolysis catalyst has high conversion rate and selectivity.

Description

Technical Field

[0001] The present invention relates to the technical field of primary amine preparation, and more particularly to a method for preparing primary amine by ammonolysis of secondary amine. Background Art

[0002] Amines refer to products produced when one or more hydrogen atoms in an ammonia molecule are replaced by hydrocarbon groups. Amines can be divided into primary amines, secondary amines, and tertiary amines according to the number of hydrogen atoms replaced in the amine molecule. Amines are widely present in the biological world and have extremely important physiological and biological activities. For example, proteins, nucleic acids, many hormones, antibiotics, and alkaloids are all derivatives of amines. Most of the drugs used clinically are also amines or amine derivatives.

[0003] The properties of amines are very similar to those of ammonia. Low-order aliphatic amines are gases or volatile liquids with an unpleasant odor. High-order amines are solids. Aromatic amines are high-boiling liquids or low-melting solids with a special odor. They are insoluble in water but soluble in organic solvents. Like ammonia, amines are polar compounds. The boiling point of amines is higher than that of hydrocarbons with similar relative molecular mass, but lower than that of alcohols or carboxylic acids with similar relative molecular mass. Tertiary amines have no hydrogen atoms on their nitrogen atoms and cannot form hydrogen bonds between molecules, so their boiling points are lower than those of their isomers, namely, primary and secondary amines. Primary, secondary, and tertiary amines can all form hydrogen bonds with water molecules, so low-order amines are easily soluble in water. The solubility of amines decreases rapidly with the increase of relative molecular mass, and amines with 6 carbon atoms are insoluble in water. Generally, amines are soluble in organic solvents such as ether, alcohol, and benzene.

[0004] Secondary amine is a type of amine, also known as secondary amine, with the general formula R2NH. It reacts with primary amine (RNH2), tertiary amine (R3N), quaternary ammonium salt (R4N + X - ) together constitute the four major categories of organic amines. Generally speaking, alcohols, ketones or aldehydes are usually used to react with ammonia or amines to prepare the corresponding amines. However, in the process of amination or amination, primary amines, secondary amines and even tertiary amines are generally reacted at the same time. In the consumer market, primary amines are mostly the most demanded varieties, such as monoisopropylamine, monoethylamine, ethylenediamine, hexamethylenediamine and other primary amine products.

[0005] Monoethylamine, also known as ethylamine, aminoethane, is a colorless liquid, flammable, volatile and has an ammonia smell. It is miscible with water, alcohol and ether, and is used to make dyes, rubber accelerators, surfactants, and also used to make pesticides such as simazine and atrazine. Chinese patent CN112691677 discloses a catalyst for preparing ethylamine by hydrogenation of ethanol and its application. It can be seen from the data of Example 14 that the product contains monoethylamine, diethylamine and triethylamine, and the proportion of diethylamine is as high as more than 50%, while the proportion of monoethylamine is only 16-17%. Chinese patent CN114315593 discloses a method for producing ethylamine with an adjustable product ratio, wherein the diethylamine produced in the product is further reacted with ethanol, ammonia, etc. to prepare triethylamine, thereby achieving an adjustable product ratio of ethylamine.

[0006] Ethylenediamine, also known as 1,2-diaminoethane, is a colorless, transparent, viscous liquid that is easily soluble in water and miscible with ethanol. It has the characteristics of alkalinity and surface activity. It is an important chemical raw material and fine chemical intermediate. It is widely used in epoxy resin curing agents, pesticides, medicines, low molecular weight polyamide resins, chelating agents and other fields, involving many industries. Chinese patent CN105585501 discloses a method for producing ethylenediamine. In addition to ethylenediamine, its reaction products also include triethylenediamine, diethylenetriamine and piperazine and other by-products. Chinese patent CN110201671 discloses a catalyst for preparing monoethanolamine and liquid ammonia reduction amination synthesis of ethyleneamine using an ammonia complex, and its preparation and use methods. It effectively improves the selectivity of ethanolamine reduction amination synthesis of ethylenediamine under hydrogen conditions, up to 69%, and the rest are by-products such as diethylenetriamine. Patent document CN109908900A discloses a supported catalyst for preparing ethyleneamines by the ethanolamine process, wherein the main active component of the catalyst is Ni, Co or Cu, and the auxiliary agent is at least one of metals or oxides such as Fe, Cr, Re, Ru, B, Mg, Ba, etc.; the carrier is alumina, silica, alumina-silica, H-ZSM-5 or H-β molecular sieve, and the main products of the catalyst are ethylenediamine and piperazine, while diethylenetriamine (DETA), hydroxyethylpiperazine (HEP), N-aminoethylpiperazine (AEP) and hydroxyethylethylenediamine (AEEA) are by-products, and the selectivity of diethylenetriamine in the embodiment is 6.9-18.3%.

[0007] 1,6-Hexanediamine, also known as 1,6-diaminohexane and hexamethylenediamine, has a chemical formula of C6H 16N2 is an important chemical intermediate, mainly used in organic synthesis and polymer production, and can also be used as epoxy resin curing agent and chemical reagent. The literature Science China Chemsitry 2017, 60, 920-926. reported a metal ruthenium-based catalyst for the reductive amination of hexanediol to prepare hexamethylenediamine, with a hexamethylenediamine conversion rate of 100%, a hexamethylenediamine selectivity of only 38.4%, and many by-products. Chinese patent CN116272969 discloses a catalyst for the synthesis of hexamethylenediamine, with a hexamethylenediamine conversion rate of up to 100%, a hexamethylenediamine selectivity of about 50%, and other by-products: cyclohexylimine, 6-aminolysis-1-hexanol, hexylamine, hexanol, dimer (N-(6-aminohexyl)-1,6-hexamethylenediamine and N-(6-aminohexyl) cyclohexylimine.

[0008] It is known from the literature that when alcohols, ketones or aldehydes are used to react with ammonia or amines to prepare corresponding amines, not only primary amines are generated, but secondary amines or even tertiary amines are generally generated in the reaction. In order to increase the yield of primary amines to a greater extent, it is often necessary to return the generated secondary amines or tertiary amines to the reaction inlet and then carry out an amination reaction together with fresh raw materials. This method will cause a large amount of materials to circulate back and forth continuously, which consumes a lot of energy and energy, and will also produce a large amount of secondary amines or even tertiary amines. Therefore, it is of great economic and practical significance to develop a process technology for preparing primary amines by ammonolysis of secondary amines. Summary of the invention

[0009] In order to solve the problems existing in the prior art, the present invention provides a method for preparing primary amines by ammonolysis of secondary amines. The method of the present invention can react to efficiently prepare primary amines from multiple secondary amines, and the ammonolysis catalyst has a high conversion rate and selectivity.

[0010] The object of the present invention is to provide a method for preparing primary amines by aminolysis of secondary amines.

[0011] The method for preparing primary amine by aminolysis of secondary amine comprises:

[0012] In the presence of hydrogen, secondary amine and / or secondary amine solution and ammonia source undergo ammonolysis reaction under the action of an ammonolysis catalyst to generate primary amine;

[0013] The ammonolysis catalyst comprises a carrier and an active component supported on the carrier;

[0014] The active components include main active components and auxiliary agents;

[0015] The main active component is Ni;

[0016] The auxiliary agent is at least one of the elements of Group IIIB, Group VIB, Group VIIB and Group IIIA;

[0017] Taking the total weight of the catalyst as 100%:

[0018] The content of the main active component is 20-45wt%;

[0019] The content of the auxiliary agent is 0.5-4.0wt%.

[0020] Preferably,

[0021] The secondary amine is at least one of diisopropylamine, diethylamine, di-n-propylamine, diethylenetriamine, dipropylenetriamine, and dihexylenetriamine; and / or,

[0022] The solvent of the secondary amine solution is at least one of water, 1,4-dioxane, tetrahydrofuran and phenyl ether; and / or,

[0023] The concentration of the secondary amine solution is 20-100 wt %; and / or,

[0024] The ammonia source is ammonia gas or liquid ammonia; and / or,

[0025] The molar ratio of the hydrogen, the ammonia source and the secondary amine is (0.1-10):(1-100):1, preferably (0.5-5):(5-90):1.

[0026] Preferably,

[0027] The ammonolysis reaction temperature is 150-250°C, preferably 170-220°C, and / or the reaction pressure is 0.1-25.0MPa, preferably 1-20MPa; and / or,

[0028] The feed liquid phase volume space velocity of the secondary amine and / or secondary amine solution is 0.05 to 1.0 m / s. 3 / (m 3 h), preferably 0.06 to 0.8 m 3 / (m 3 h).

[0029] Preferably,

[0030] The auxiliary agent is at least one of La, Mn and Re, preferably Re;

[0031] Taking the total weight of the catalyst as 100%:

[0032] The content of the main active component is 24-42wt%;

[0033] The content of the auxiliary agent is 0.75-3.75wt%.

[0034] Preferably,

[0035] Since zirconium dioxide itself has certain acidic and alkaline sites, its properties vary with the production method, roasting and processing of the carrier raw materials. After research, the inventors found that some other substances can be added artificially to modify it. For example, SiO2, Al2O3, molecular sieves, zeolites and acid-base precursors can be added to ZrO2 to improve certain carrier properties. In the technical scheme of the present invention, the carrier can also be treated with fluorine-containing compounds, phosphorus-containing compounds, sulfur-containing compounds or selenium-containing compounds; the above compounds can also be added during the carrier molding process or the catalyst molding process for modification; in addition, these compounds or other forms of corresponding elements can also be introduced when producing the carrier raw materials. These methods of modifying the carrier are merely illustrative and are not limited to this. The inventors have found through research that adding an appropriate amount of specific silk-denite zeolite is more helpful in improving the catalyst performance;

[0036] The carrier is a modified zirconium dioxide carrier; preferably, the modified zirconium dioxide carrier is zirconium dioxide modified by mordenite; more preferably, the content of zirconium dioxide is 50-80wt% of the total weight of the carrier, preferably 60-75wt%.

[0037] Preferably,

[0038] The modified zirconium dioxide carrier is prepared by fully stirring a zirconium source and mordenite, adding an extrusion aid solution, extruding and molding, and drying and calcining.

[0039] Preferably,

[0040] The zirconium source is at least one of zirconium oxychloride, zirconium acetate, zirconium sulfate, zirconyl nitrate and zirconyl sulfate; and / or,

[0041] The mordenite has a silicon-to-aluminum ratio of 10-20, and / or a grain size of 0.5-1.0 μm, and / or a sodium content of ≤0.1 wt%; and / or,

[0042] The extrusion aid is at least one of citric acid, acetic acid and nitric acid; and / or,

[0043] The solvent of the extrusion aid solution is water. Preferably, the concentration of the extrusion aid solution is 3-10 vol%.

[0044] The extrusion aid solution mainly promotes the extrusion molding of the zirconium source and mordenite. The amount thereof is not particularly limited, and those skilled in the art can adjust it adaptively according to the molding effects of the zirconium source and mordenite.

[0045] Preferably,

[0046] The drying temperature is 70-150° C., and / or the drying time is 5-10 hours; and / or,

[0047] The calcination temperature is 800-1100° C., and / or the calcination time is 2-8 hours.

[0048] Preferably,

[0049] Since the carrier is a porous material, it is filled with micro-channels of different sizes. The pore structure of the carrier has a great influence on the selectivity, life and mechanical strength of the catalyst. According to the classification of the International Union of Pure and Applied Chemistry (IUPAC), the pores of porous materials can be divided into: macropores with a pore size greater than 50nm, mesopores or medium pores with a pore size of 2-50nm, and micropores with a pore size less than 2nm. Different pore structures will cause different specific surface areas and pore size distributions of the catalyst, and the diffusion, adsorption and desorption states of the reactants in the pores and the surface utilization of the pores will all be different, which will in turn affect the performance of the ammonolysis reaction. The pore volume corresponding to the pores of a certain pore size is different for different pore sizes, and the pore volume distribution or pore distribution is also very different. If the catalyst contains more capillaries, although its surface area is large at this time, it does not match the reactants and cannot diffuse into the pores, and this part of the pores cannot be fully utilized. Reasonable control of pore distribution can enable the catalyst to exert the best catalytic performance. In order to obtain a catalyst with better catalytic performance, the inventors have carefully studied that the ratio of the mesopore volume of the catalyst to the total pore volume of the catalyst is greater than 0.70, preferably 0.75-0.95.

[0050] Preferably,

[0051] The catalyst is prepared by heating a main active component precursor solution and an auxiliary agent precursor solution, spraying them onto a carrier, and then drying, roasting and reducing them.

[0052] There is no specific limitation on the preparation method of the catalyst, and a variety of preparation methods can be used, such as precipitation method, impregnation method, etc., which will not be described in detail here.

[0053] Preferably,

[0054] The main active component precursor is a water-soluble salt of the main active component, preferably at least one of sulfate, nitrate and acetate. The concentration of the main active component precursor solution is not particularly limited. Those skilled in the art can adaptively adjust the amount of solvent water according to the amount of the main active component precursor to ensure that the main active component precursor is fully dissolved; and / or,

[0055] The auxiliary agent precursor is a water-soluble salt of the auxiliary agent, preferably an ammonium salt. The concentration of the auxiliary agent precursor solution is not particularly limited. Those skilled in the art can adaptively adjust the amount of solvent water according to the amount of the auxiliary agent precursor to ensure sufficient dissolution of the auxiliary agent precursor.

[0056] Preferably,

[0057] The heating temperature is 70-90° C.; and / or,

[0058] The number of spraying is 1 or more, and the amount of the mixed solution sprayed each time is adaptively adjusted according to the water absorption rate of the carrier. The main active component precursor solution and the auxiliary agent precursor solution can be impregnated into the carrier in any desired order, or the mixed solution containing the main active component precursor and the auxiliary agent precursor can be used for continuous impregnation, and the appropriate solution concentration is selected to load the active component on the carrier; when spraying multiple times, it is best to dry and roast after each spraying; and / or,

[0059] The drying temperature is 80-150° C., preferably 100-150° C., and / or the drying time is 4-8 hours; and / or,

[0060] The calcination temperature is 150-500° C., preferably 300-500° C., and / or the calcination time is 3-8 hours, preferably 4-6 hours; and / or,

[0061] The reduction temperature is 400-550°C, and / or the reduction time is 2-10h, preferably 3-8h, and / or the heating rate of the reduction process does not exceed 20°C / hour; and / or,

[0062] The gas used in the reduction process is hydrogen or nitrogen, preferably hydrogen.

[0063] When the catalyst is prepared by impregnation, the active and auxiliary components required to be loaded on the carrier are preferably used in the form of soluble salt solutions of the components, such as nitrates, formates, oxalates, etc. The impregnation of the carrier with the metal salt solution can be carried out in any desired order, or it can be continuously impregnated with a solution containing one or more metal salts. The appropriate concentration of the solution is selected to load the active metal on the carrier. The impregnated carrier needs to be dried at a certain temperature, preferably 80-150°C. The required drying time can be set according to the specific temperature, material amount and equipment performance. The water content in the dried carrier does not affect the subsequent roasting, and the drying time is not specifically limited. The dried catalyst precursor needs to be roasted at a certain temperature to remove the crystal water in the salt, or to decompose the salt of the required load component into an oxide. The roasting temperature is preferably 150-500°C, and more preferably 300-500°C. When multiple impregnations are performed, it is best to dry and roast after each impregnation. The oxidized catalyst finally obtained needs to be reduced to have catalytic activity. The gas used for reduction can be pure hydrogen or a mixed gas, such as a mixture of hydrogen and nitrogen. The reduction temperature can be gradually increased during reduction, but the temperature increase should not be too fast, for example, not more than 20°C / hour. Of course, other methods can also be selected to reduce the catalyst, such as irradiation reduction and other methods.

[0064] The present invention can specifically adopt the following scheme:

[0065] In order to achieve better reaction effect, the reaction temperature is 150-250°C, the reaction pressure is 0.1-25.0MPa, the feed liquid phase volume space velocity of the secondary amine and / or secondary amine solution is 0.05-1.0m 3 / (m 3 h), hydrogen: ammonia source: secondary amine molar ratio is (0.1-10): (1-100): 1, the secondary amine and the ammonia source undergo an ammonolysis reaction under the catalytic action of the ammonolysis catalyst to generate a primary amine. In order to ensure the smooth progress of the reaction, the secondary amine can be fed alone, or water, 1,4-dioxane, tetrahydrofuran or phenyl ether can be used as a solvent to prepare a mixed solution of a certain concentration for feeding, and the weight percentage of the secondary amine in the mixed solution is 20-100wt%. Studies have found that the use of an appropriate amount of solvent can improve the secondary amine conversion rate and primary amine selectivity, reduce the generation of by-products and thus reduce coking, and extend the service life of the catalyst; at the same time, the inventors have conducted in-depth research on existing amination reaction technologies and proposed a catalyst that can effectively improve the activity and selectivity of the ammonolysis catalyst, the catalyst comprising a carrier and a support The main active component and the auxiliary agent on the carrier, the main active component is Ni, the auxiliary agent is selected from at least one of the elements of group IIIB, group VIB, group VIIB and group IIIA, the carrier is a modified zirconium dioxide carrier, and the content of zirconium dioxide is 50-80wt% of the total weight of the carrier; in order to better balance the different catalytic properties of the ammonolysis catalyst, such as dehydrogenation, ammonolysis and adsorption and desorption capabilities, the total weight of the catalyst is 100%: the content of Ni element is 20-45wt%; in order to further reduce side reactions and improve the selectivity of primary amines, the catalyst contains an auxiliary agent, the auxiliary agent is selected from at least one of La, Mn and Re, more preferably, the auxiliary agent is preferably Re, and the content of the auxiliary agent in the catalyst is 0.5wt% to 4.0wt%.

[0066] The amount of catalyst used is the conventional amount used in the prior art. Since the ammonolysis reaction is a continuous reaction, a certain amount of catalyst is usually loaded into the reactor, and the reaction materials are continuously introduced to react through the catalyst bed. The amount of catalyst is adaptively loaded according to the size of the fixed bed reactor in actual use, and the technicians can adjust it according to the actual situation.

[0067] The method for preparing primary amines by ammonolysis of secondary amines of the present invention can react to efficiently prepare primary amines from multiple secondary amines, and the ammonolysis catalyst has high conversion rate and selectivity. DETAILED DESCRIPTION

[0068] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the contents of the present invention still fall within the scope of protection of the present invention.

[0069] The raw materials used in the examples and comparative examples of the present invention are all commercially available products.

[0070] 1. Preparation of Catalyst

[0071] Example 1

[0072] 281.34 g of zirconium oxynitrate and 50.0 g of commercially available mordenite (Si / Al ratio of 10-20, grain size of 0.5-1.0 μm, sodium content of 0.05 wt%) powders were added into a kneader and mixed thoroughly. The mixture was kneaded and extruded using a dilute acid solution containing 5 vol% nitric acid. The mixture was dried at 110°C for 8 h and then calcined at 950°C for 3 h to prepare the desired modified zirconium dioxide carrier. 275.26g of nickel nitrate hexahydrate (industrial grade, purity 98%) and 4.57g of ammonium perrhenate were dissolved in water to form 162mL of solution, and the solution was heated to 85°C and loaded on the obtained 100g modified zirconium dioxide carrier by spraying method three times, and dried at 110°C for 8h after each spraying, and then calcined at 350°C for 5h; finally, the catalyst A-1 was reduced by gradually increasing the temperature at 15°C / min and reduced at 450°C for 4h to obtain the catalyst A-1, and the specific composition is shown in Table 1. The ratio of the mesopore volume to the total pore volume of the catalyst was 0.88 as determined by the BET method.

[0073] Example 2

[0074] 243.83 g of zirconium oxynitrate and 70.0 g of commercially available silk zeolite (Si / Al ratio of 10-20, grain size of 0.5-1.0 μm, sodium content of 0.05 wt%) powders were added into a kneader and mixed thoroughly. The mixture was kneaded and extruded using a dilute acid solution containing 8 vol% nitric acid. The mixture was dried at 140°C for 4 h and then calcined at 900°C for 8 h to prepare the desired modified zirconium dioxide carrier. 167.61g nickel nitrate hexahydrate (industrial grade, purity 98%) and 2.14g ammonium perrhenate were dissolved in water to form 130mL solution, the solution was heated to 90°C and loaded on the obtained 100g modified zirconium dioxide carrier by spraying twice, and dried at 140°C for 8h after each spraying, and then calcined at 380°C for 4h; finally, the catalyst A-2 was reduced by gradually increasing the temperature at 20°C / min with hydrogen, and reduced at 420°C for 6h to obtain the catalyst A-2, the specific composition of which is shown in Table 1. The ratio of its mesopore volume to the total pore volume of the catalyst was 0.82 as determined by the BET method.

[0075] Example 3

[0076] 262.58 g of zirconium oxynitrate and 44 g of commercially available silk zeolite (Si / Al ratio of 10-20, grain size of 0.5-1.0 μm, sodium content of 0.05 wt%) powders were added into a kneader and mixed thoroughly. The mixture was kneaded and extruded using a dilute acid solution containing 3 vol% nitric acid and 4 vol% citric acid. The mixture was dried at 150°C for 3 h and then calcined at 1000°C for 4 h to prepare the desired modified zirconium dioxide carrier. 333.64g of nickel nitrate hexahydrate (industrial grade, purity 98%) and 1.46g of ammonium perrhenate were dissolved in water to form 178mL of solution, and the solution was heated to 85°C and loaded on the obtained 100g modified zirconium dioxide carrier by spraying method three times, and dried at 130°C for 8h after each spraying, and then calcined at 390°C for 4h; finally, the catalyst A-3 was reduced by gradually increasing the temperature at 10°C / min with hydrogen, and reduced at 490°C for 4h to obtain the catalyst A-3, the specific composition of which is shown in Table 1. The ratio of its mesopore volume to the total pore volume of the catalyst was 0.84 as determined by the BET method.

[0077] Example 4

[0078] 225.07g of zirconium oxynitrate and 80.0g of commercially available mordenite (Si / Al ratio of 10-20, grain size of 0.5-1.0μm, sodium content of 0.05wt%) powders were added into a kneader and mixed thoroughly. The mixture was kneaded and extruded using a dilute acid solution containing 10vol% nitric acid. The mixture was dried at 120°C for 6h and then calcined at 920°C for 6h to prepare the desired modified zirconium dioxide carrier. 209.38g of nickel acetate tetrahydrate (industrial grade, purity 98%) and 7.11g of ammonium perrhenate were dissolved in water to form 142mL of solution, and the solution was heated to 90°C and loaded on the obtained 100g of the modified zirconium dioxide carrier by spraying twice, and dried at 120°C for 8h after each spraying, and then calcined at 400°C for 5h; finally, the catalyst A-4 was reduced by gradually increasing the temperature at 15°C / min with hydrogen, and reduced at 460°C for 5h to obtain the catalyst A-4, the specific composition of which is shown in Table 1. The ratio of the mesopore volume to the total pore volume of the catalyst was 0.79 as determined by the BET method.

[0079] Example 5

[0080] 255.08g of zirconium oxynitrate and 64.0g of commercially available mordenite (Si / Al ratio of 10-20, grain size of 0.5-1.0μm, sodium content of 0.05wt%) powders were added into a kneader and mixed thoroughly. The mixture was kneaded and extruded using a dilute acid solution containing 6vol% nitric acid. The mixture was dried at 100°C for 6h and then calcined at 980°C for 4h to prepare the desired modified zirconium dioxide carrier. 425.49g nickel nitrate hexahydrate (industrial grade, purity 98%) and 7.15g ammonium perrhenate were dissolved in water to form 260mL solution, the solution was heated to 80°C and loaded on the obtained 100g modified zirconium dioxide carrier by spraying method four times, and dried at 130°C for 8h after each spraying, and then calcined at 430°C for 4h; finally, the catalyst A-5 was reduced by gradually increasing the temperature at 15°C / min with hydrogen, and reduced at 460°C for 4h to obtain the catalyst A-5, the specific composition of which is shown in Table 1. The ratio of its mesopore volume to the total pore volume of the catalyst was 0.85 as determined by the BET method.

[0081] Example 6

[0082] 288.84 g of zirconium oxynitrate and 46.0 g of commercially available mordenite (Si / Al ratio of 10-20, grain size of 0.5-1.0 μm, sodium content of 0.05 wt%) powders were added into a kneader and mixed thoroughly. The mixture was kneaded and extruded using a dilute acid solution containing 5 vol% nitric acid. The mixture was dried at 120°C for 8 h and then calcined at 1020°C for 3 h to prepare the desired modified zirconium dioxide carrier. 324.61g nickel nitrate hexahydrate (industrial grade, purity 98%) and 9.93g ammonium perrhenate were dissolved in water to form 165mL solution, the solution was heated to 80°C and loaded on the obtained 100g modified zirconium dioxide carrier by spraying method three times, and dried at 130°C for 8h after each spraying, and then calcined at 390°C for 6h; finally, the catalyst A-6 was reduced by gradually increasing the temperature at 20°C / min with hydrogen, and reduced at 460°C for 4h to obtain the catalyst A-6, the specific composition of which is shown in Table 1. The ratio of its mesopore volume to the total pore volume of the catalyst was 0.91 as determined by the BET method.

[0083] Example 7

[0084] 277.05 g of zirconium sulfate tetrahydrate and 76 g of commercially available mordenite (Si / Al ratio of 10-20, grain size of 0.5-1.0 μm, sodium content of 0.05 wt%) powder were added into a kneader and mixed thoroughly. The mixture was kneaded and extruded using a dilute acid solution containing 7 vol% nitric acid. The mixture was dried at 120°C for 6 h and then calcined at 970°C for 4 h to prepare the desired modified zirconium dioxide carrier. 196.22g nickel nitrate hexahydrate (industrial grade, purity 98%) and 1.84g ammonium perrhenate were dissolved in water to form 122mL solution, the solution was heated to 85°C and loaded on the obtained 100g modified zirconium dioxide carrier by spraying twice, and dried at 130°C for 6h after each spraying, and then calcined at 350°C for 6h; finally, the temperature was gradually increased with hydrogen for reduction, the temperature increase rate was 15°C / h, and the reduction was carried out at 450°C for 6h to obtain the ammonolysis catalyst A-7, the specific composition of which is shown in Table 1. The ratio of its mesopore volume to the total pore volume of the ammonolysis catalyst was 0.90 as determined by the BET method.

[0085] Example 8

[0086] 210.86 g of zirconium oxynitrate and 88.0 g of commercially available mordenite (Si / Al ratio of 10-20, grain size of 0.5-1.0 μm, sodium content of 0.05 wt%) powders were added into a kneader and mixed thoroughly. The mixture was kneaded and extruded using a dilute acid solution containing 10 vol% acetic acid, dried at 110°C for 6 h, and then calcined at 900°C for 7 h to prepare the desired modified zirconium dioxide carrier. 143.23g nickel nitrate hexahydrate (industrial grade, purity 98%) and 3.60g ammonium perrhenate were dissolved in water to form 144mL solution, the solution was heated to 80°C and loaded on the obtained 100g modified zirconium dioxide carrier by spraying twice, and dried at 150°C for 8h after each spraying, and then calcined at 420°C for 4h; finally, the catalyst A-8 was reduced by gradually increasing the temperature at 15°C / min with hydrogen, and reduced at 420°C for 5h to obtain the catalyst A-8, the specific composition of which is shown in Table 1. The ratio of its mesopore volume to the total pore volume of the catalyst was 0.77 as determined by the BET method.

[0087] Table 1

[0088]

[0089] 2. Preparation of primary amines by ammonolysis of secondary amines

[0090] 100 ml of the above catalysts A-1 to A-8 were respectively taken and placed in a fixed bed reactor, and pre-reduced with hydrogen at 250°C for 4 hours, then cooled to 200°C, the system pressure was increased to 17.0 MPa, and then liquid ammonia was metered by a metering pump and mixed with hydrogen after preheating into the reactor, and a mixed solution of 25 wt% dihexyltriamine and 75 wt% tetrahydrofuran was sent into the reactor by a metering pump. The three reacted through the catalyst bed, the molar ratio of hydrogen: ammonia: dihexyltriamine was 0.5:77:1, and the liquid phase volume space velocity of the mixed solution of dihexyltriamine was 0.3 h -1 After the reaction stabilized, samples were taken for analysis. The reaction results are shown in Table 2.

[0091] Table 2

[0092]

[0093] Example 9

[0094] 100 ml of the above catalyst A-4 was loaded into a fixed bed reactor and activated with hydrogen at 250°C for 2 hours. The other conditions were the same as in Example 1, except for the following experimental conditions: temperature, pressure, molar ratio of hydrogen: ammonia: dihexylenetriamine, liquid phase volume space velocity of dihexylenetriamine, etc. The effects of different reaction conditions on the catalyst performance were investigated. The results are shown in Table 3.

[0095] Table 3

[0096]

[0097] Example 10

[0098] 100 ml of each of the above catalysts A-1 to A-7 were placed in a fixed bed reactor, and pre-reduced with hydrogen at 250°C for 2 h. The temperature was then lowered to 190°C, and the system pressure was increased to 12.0 MPa. Liquid ammonia was then metered by a metering pump and mixed with hydrogen before entering the reactor. A mixed solution of 40 wt% diethylenetriamine and 60 wt% tetrahydrofuran was sent into the reactor by a metering pump. The three reacted through the catalyst bed. The molar ratio of hydrogen: ammonia: diethylenetriamine was 1:45:1, and the liquid phase volume space velocity of the mixed solution of diethylenetriamine was 0.25 h -1 After the reaction is stable, samples are taken for analysis. The reaction results are shown in Table 4.

[0099] Table 4

[0100]

[0101] Embodiment 11

[0102] 100 ml of the above catalyst A-3 was loaded into a fixed bed reactor and activated with hydrogen at 250°C for 2 hours. A mixed solution of 35 wt% diethylenetriamine and 65 wt% phenyl ether was fed into the reactor with a metering pump. The rest was the same as in Example 3, except for the experimental conditions such as temperature, pressure, molar ratio of hydrogen: ammonia: diethylenetriamine, liquid phase volume space velocity of the mixed solution of diethylenetriamine, etc. The effects of different reaction conditions on the catalyst performance were investigated. The results are shown in Table 5.

[0103] Table 5

[0104]

[0105] Example 12

[0106] 100 ml of the above catalyst A-4 was loaded into a fixed bed reactor, activated with hydrogen at 250°C for 4 hours, and then cooled to the reaction temperature shown in Table 6. Liquid ammonia was then metered with a metering pump and mixed with hydrogen after preheating and entering the reactor. Diisopropylamine was also sent into the reactor with a metering pump. The three reacted through the catalyst bed. The reaction conditions were changed to examine the catalyst performance. After the reaction was stable, samples were taken for analysis. The results are shown in Table 6.

[0107] Table 6

[0108]

[0109] Example 13

[0110] 100 ml of the above-mentioned catalyst A-1 was loaded into a fixed bed reactor, activated with hydrogen at 250°C for 4 hours, and then cooled to the reaction temperature shown in Table 7. Liquid ammonia was then metered with a metering pump and mixed with hydrogen after preheating and then fed into the reactor. Diethylamine was also fed into the reactor with a metering pump. The three reacted through the catalyst bed. The reaction conditions were changed to examine the catalyst performance. After the reaction was stable, samples were taken for analysis. The results are shown in Table 7.

[0111] Table 7

[0112]

[0113] Embodiment 14

[0114] 100 ml of the above-mentioned catalyst A-4 was taken and placed in a fixed bed reactor, activated with hydrogen at 250°C for 4 hours, and then cooled to the reaction temperature shown in Table 8. Liquid ammonia was then metered with a metering pump and mixed with hydrogen after preheating before entering the reactor. Di-n-propylamine was also sent into the reactor with a metering pump. The three reacted through the catalyst bed. The reaction conditions were changed to examine the catalyst performance. After the reaction was stable, samples were taken for analysis. The results are shown in Table 8.

[0115] Table 8

[0116]

[0117] Embodiment 15

[0118] 100 ml of the above-mentioned catalyst A-3 was measured and placed in a fixed bed reactor, activated with hydrogen at 250°C for 4 hours, and then cooled to the reaction temperature shown in Table 9 below. Liquid ammonia was then metered with a metering pump and mixed with hydrogen after preheating before entering the reactor. Dipropylene triamine was also sent into the reactor with a metering pump. The three reacted through the catalyst bed. The reaction conditions were changed to examine the catalyst performance. After the reaction was stable, samples were taken for analysis. The results are shown in Table 9.

[0119] Table 9

[0120]

[0121] It is not difficult to see from the above examples that the method of the present invention can enable a variety of secondary amines to efficiently prepare primary amines; and within different process conditions, the catalyst of the present invention has a good ammonolysis reaction effect, and the ammonolysis method of the present invention has good process condition stability.

[0122] The above embodiments are merely illustrative, and the secondary amine aminolysis reaction is not limited to the above examples.

Claims

1. A method for preparing primary amines by ammonolysis of secondary amines, characterized in that The method comprises: In the presence of hydrogen, secondary amine and / or secondary amine solution and ammonia source undergo ammonolysis reaction under the action of an ammonolysis catalyst to generate primary amine; The ammonolysis catalyst comprises a carrier and an active component supported on the carrier; The active components include main active components and auxiliary agents; The main active component is Ni; The auxiliary agent is at least one of the elements of Group IIIB, Group VIB, Group VIIB and Group IIIA; Taking the total weight of the catalyst as 100%: The content of the main active component is 20-45wt%; The content of the auxiliary agent is 0.5-4.0wt%.

2. The method according to claim 1, characterized in that: The secondary amine is at least one of diisopropylamine, diethylamine, di-n-propylamine, diethylenetriamine, dipropylenetriamine, and dihexylenetriamine; and / or, The solvent of the secondary amine solution is at least one of water, 1,4-dioxane, tetrahydrofuran and phenyl ether; and / or, The concentration of the secondary amine solution is 20-100 wt %; and / or, The ammonia source is ammonia gas or liquid ammonia; and / or, The molar ratio of the hydrogen, the ammonia source and the secondary amine is (0.1-10):(1-100):1, preferably (0.5-5):(5-90):

1.

3. The method according to claim 1, characterized in that: The ammonolysis reaction temperature is 150-250°C, preferably 170-220°C, and / or the reaction pressure is 0.1-25.0MPa, preferably 1-20MPa; and / or, The feed liquid phase volume space velocity of the secondary amine and / or secondary amine solution is 0.05 to 1.0 m / s. 3 / (m 3 h), preferably 0.06 to 0.8 m 3 / (m 3 h).

4. The method according to claim 1, characterized in that: The auxiliary agent is at least one of La, Mn and Re, preferably Re; Taking the total weight of the catalyst as 100%: The content of the main active component is 24-42wt%; The content of the auxiliary agent is 0.75-3.75wt%.

5. The method according to claim 1, characterized in that: The carrier is a modified zirconium dioxide carrier; preferably, the modified zirconium dioxide carrier is zirconium dioxide modified by mordenite; more preferably, the content of zirconium dioxide is 50-80wt% of the total weight of the carrier, preferably 60-75wt%.

6. The method according to claim 5, characterized in that: The modified zirconium dioxide carrier is prepared by fully stirring a zirconium source and mordenite, adding an extrusion aid solution, extruding and molding, and drying and calcining.

7. The method according to claim 6, characterized in that: The zirconium source is at least one of zirconium oxychloride, zirconium acetate, zirconium sulfate, zirconyl nitrate and zirconyl sulfate; and / or, The mordenite has a silicon-to-aluminum ratio of 10-20, and / or a grain size of 0.5-1.0 μm, and / or a sodium content of ≤0.1 wt%; and / or, The extrusion aid is at least one of citric acid, acetic acid and nitric acid; and / or, The solvent of the extrusion aid solution is water. Preferably, the concentration of the extrusion aid solution is 3-10 vol%.

8. The method according to claim 6, characterized in that: The drying temperature is 70-150° C., and / or the drying time is 5-10 hours; and / or, The calcination temperature is 800-1100° C., and / or the calcination time is 2-8 hours.

9. The method according to any one of claim 1, characterized in that: The ratio of the mesopore volume of the catalyst to the total pore volume of the catalyst is greater than 0.70, preferably 0.75-0.

95.

10. The method according to claim 1, characterized in that: The catalyst is prepared by heating a main active component precursor solution and an auxiliary agent precursor solution, spraying them onto a carrier, and then drying, roasting and reducing them.

11. The method according to claim 10, characterized in that: The main active component precursor is a water-soluble salt of the main active component, preferably at least one of sulfate, nitrate and acetate; and / or, The auxiliary agent precursor is a water-soluble salt of the auxiliary agent, preferably an ammonium salt.

12. The method according to claim 10, characterized in that: The heating temperature is 70-90° C.; and / or, The number of spraying times is 1 or more; and / or, The drying temperature is 80-150° C., preferably 100-150° C., and / or the drying time is 4-8 hours; and / or, The calcination temperature is 150-500° C., preferably 300-500° C., and / or the calcination time is 3-8 hours, preferably 4-6 hours; and / or, The reduction temperature is 400-550°C, and / or the reduction time is 2-10h, preferably 3-8h, and / or the heating rate of the reduction process does not exceed 20°C / hour; and / or, The gas used in the reduction process is hydrogen or nitrogen, preferably hydrogen.

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