Nickel alloy catalyst and preparation method of cyclohexylamine

Abstract

The invention relates to a nickel alloy catalyst and a preparation method of cyclohexylamine. The nickel alloy catalyst comprises the following components in percentage by mass: 70%-85% of Ni, 5%-15% of Cu and 5%-15% of Al. The nickel alloy catalyst comprises the Ni, Cu and Al components in a specific ratio, the three components cooperate with one another, the catalytic activity of the catalyst is improved, the catalyst has good stability, the good catalytic activity can still be kept after multiple times of recycling, and therefore the catalyst has good renewability; when the catalyst is applied to a preparation process of cyclohexylamine, the selectivity of cyclohexylamine can be improved; the nickel alloy catalyst has good renewability, so that the replacement frequency of the nickel alloy catalyst can be reduced, and the production cost of cyclohexylamine can be reduced.

Description

Technical Field

[0001] The invention relates to the field of materials, and in particular to a method for preparing a nickel alloy catalyst and cyclohexylamine. Background Art

[0002] Cyclohexylamine, referred to as CHA, is an organic compound, a colorless to yellow liquid with a strong ammonia smell and strong organic base properties. Cyclohexylamine has a wide range of applications, and can be used to prepare sodium cyclamate, caprolactam, cellulose acetate and nylon, etc. It can also be used to prepare desulfurizers, rubber antioxidants, vulcanization accelerators, plastic and textile chemical additives, boiler feed water treatment agents, metal corrosion inhibitors, emulsifiers, preservatives, antistatic agents, latex coagulants, petroleum additives, fungicides, pesticides and dye intermediates, etc.

[0003] There are many process routes for the preparation of cyclohexylamine, mainly including catalytic hydrogenation of aniline, reduction of nitrocyclohexane, catalytic ammonolysis of chlorocyclohexane, and catalytic ammonolysis of cyclohexanol and cyclohexanone. When cyclohexylamine is prepared by traditional catalytic methods, supported catalysts are often used to load the active components of the catalyst on a carrier with a large specific surface area, such as a carbon or alumina carrier. However, when supported catalysts catalyze the reaction of some carbon-containing compounds, carbon deposits may form on the surface or in the pores of the catalyst, blocking the active sites and pores, hindering the diffusion of reactants and products, and thus causing the catalyst to deactivate. In addition, the regeneration of supported catalysts is usually more complicated, requiring specific conditions and methods to remove the causes of deactivation (such as removing adsorbed impurities, burning off carbon deposits, etc.), and the performance of the regenerated catalyst may not be fully restored to the initial state, requiring frequent replacement of the catalyst, increasing the cost of use and the complexity of operation. Summary of the invention

[0004] Based on this, it is necessary to provide a nickel alloy catalyst with more stable activity and better regenerative properties.

[0005] In a first aspect, the present application provides a nickel alloy catalyst, which comprises, by mass percentage, 70% to 85% Ni, 5% to 15% Cu and 5% to 15% Al.

[0006] The nickel alloy catalyst includes Ni, Cu and Al components in a specific ratio. The three components cooperate with each other to improve the catalytic activity of the catalyst and have good stability. After multiple cycles of use, the catalyst can still maintain good catalytic activity, so it has good renewability. When applied to the preparation process of cyclohexylamine, the selectivity of cyclohexylamine can be improved; because the nickel alloy catalyst has good renewability, the replacement frequency of the nickel alloy catalyst can be reduced, and the production cost of cyclohexylamine can be reduced.

[0007] The second aspect of the present application provides a method for preparing cyclohexylamine, comprising the following steps:

[0008] Cyclohexanone, cyclohexanol, liquid ammonia and hydrogen are subjected to an amination reaction under the action of a catalyst to obtain cyclohexylamine;

[0009] The catalyst is a nickel alloy catalyst, which comprises 70% to 85% Ni, 5% to 15% Cu and 5% to 15% Al in terms of mass percentage.

[0010] In some embodiments, the cyclohexanone and cyclohexanol are added in the form of cyclohexene hydrated light oil as a raw material.

[0011] In some embodiments, the total mass percentage of cyclohexanone and cyclohexanol in the cyclohexene hydration light oil is ≥40%, and can be optionally ≥80%.

[0012] In some embodiments, the molar ratio of the total amount of the cyclohexanone and the cyclohexanol to the liquid ammonia is 1:(1-15).

[0013] In some embodiments, the mass of the catalyst is 5% to 45% of the mass of the cyclohexene hydration light oil.

[0014] In some embodiments, the reaction temperature of the amination reaction is 140°C to 250°C.

[0015] In some embodiments, the step of subjecting cyclohexene hydrated light oil, liquid ammonia and hydrogen to an amination reaction under the action of a catalyst comprises:

[0016] The catalyst is loaded into a reactor, the liquid ammonia and the hydrogen are introduced, the temperature is raised to the reaction temperature of the amination reaction, and then the cyclohexene hydrate light oil is added dropwise.

[0017] In some embodiments, the preparation method satisfies at least one of the following conditions:

[0018] (1) introducing the hydrogen gas so that the initial gas pressure in the reactor reaches 1.0 MPa to 3.0 MPa, and then raising the temperature;

[0019] (2) The dripping time of the cyclohexene hydration light oil is 1h~8h;

[0020] (3) After the cyclohexene hydration light oil is added dropwise, the mixture is kept warm for 3 h to 5 h.

[0021] In some embodiments, before loading the catalyst into the reactor, the step of activating the catalyst is also included;

[0022] The activation treatment step comprises:

[0023] The catalyst is mixed with a strong alkaline solution to perform an activation reaction, and then washed with desalted water to neutrality.

[0024] In some embodiments, the temperature of the activation reaction is 80° C. to 90° C.; the time of the activation reaction is 1 h to 3 h. DETAILED DESCRIPTION

[0025] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively below, and preferred embodiments of the present invention are given. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. It should be understood that the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0028] Cyclohexylamine, referred to as CHA, is an organic compound, a colorless to yellow liquid with a strong ammonia smell and strong organic base properties. Cyclohexylamine has a wide range of applications, and can be used to prepare sodium cyclamate, cyclohexanol, caprolactam, cellulose acetate and nylon, etc. It can also be used to prepare desulfurizers, rubber antioxidants, vulcanization accelerators, plastic and textile chemical additives, boiler feed water treatment agents, metal corrosion inhibitors, emulsifiers, preservatives, antistatic agents, latex coagulants, petroleum additives, fungicides, pesticides and dye intermediates, etc.

[0029] There are many process routes for the preparation of cyclohexylamine, mainly including catalytic hydrogenation of aniline, reduction of nitrocyclohexane, catalytic ammonolysis of chlorocyclohexane, and catalytic ammonolysis of cyclohexanol and cyclohexanone. In the traditional preparation process of cyclohexylamine, supported catalysts are often used to catalyze the preparation of cyclohexylamine, but supported catalysts have the problem that the pores are easily blocked, resulting in a significant decrease in catalytic activity and a low regeneration rate.

[0030] Based on this, in one embodiment of the present application, a nickel alloy catalyst is provided, which, by mass percentage, includes 70% to 85% Ni, 5% to 15% Cu and 5% to 15% Al.

[0031] The nickel alloy catalyst includes Ni, Cu and Al components in a specific ratio. The three components cooperate with each other to improve the catalytic activity of the catalyst and have good stability. After multiple cycles of use, the catalyst can still maintain good catalytic activity, so it has good renewability. When applied to the preparation process of cyclohexylamine, the selectivity of cyclohexylamine can be improved; because the nickel alloy catalyst has good renewability, the replacement frequency of the nickel alloy catalyst can be reduced, and the production cost of cyclohexylamine can be reduced.

[0032] As an example, the mass percentage of Ni in the nickel alloy catalyst can be 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84% or 85%. Further, the mass percentage of Ni in the nickel alloy catalyst can be a range value consisting of any two of the above point values ​​as end values. Preferably, the mass percentage of Ni in the nickel alloy catalyst can be 75% to 80%.

[0033] As an example, the mass percentage of Cu in the nickel alloy catalyst can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14% or 15%. Further, the mass percentage of Cu in the nickel alloy catalyst can be a range value consisting of any two of the above point values ​​as end values. Preferably, the mass percentage of Cu in the nickel alloy catalyst can be 5% to 10%.

[0034] As an example, the mass percentage of Al in the nickel alloy catalyst can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14% or 15%. Further, the mass percentage of Al in the nickel alloy catalyst can be a range value consisting of any two of the above point values ​​as end values. Preferably, the mass percentage of Al in the nickel alloy catalyst can be 10% to 15%.

[0035] In some embodiments, the average particle size of the nickel alloy catalyst is 3 mm to 10 mm. As an example, the average particle size of the nickel alloy catalyst can be 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm or 7 mm. Further, the average particle size of the nickel alloy catalyst can be a range value consisting of any two of the above point values ​​as end values. Controlling the average particle size of the nickel alloy catalyst is beneficial to improving the conversion rate and the service life of the catalyst.

[0036] Cyclohexene hydration light oil is a byproduct of cyclohexene hydration, and cyclohexene hydration light oil includes light oil components such as alkanes, olefins, cyclohexanol, cyclohexanone and dicyclohexyl ether. At present, cyclohexene hydration light oil is mainly used to obtain different products through distillation. However, due to the complex raw material components of cyclohexene hydration light oil, it is difficult to separate, so the purity of the product after distillation is not high, which affects the downstream application.

[0037] Based on this, it is necessary to develop a process for synthesizing cyclohexylamine using hydrated light oil as raw material, broaden the downstream utilization of hydrated light oil, improve the utilization value of by-products, and reduce the production cost of cyclohexylamine.

[0038] In addition, cyclohexene hydration light oil contains cyclohexanol and cyclohexanone, which are easy to generate cyclohexylamine and dicyclohexylamine during amination reaction. In order to obtain the desired cyclohexanol product, it is necessary to further improve the selectivity of cyclohexylamine.

[0039] In another embodiment of the present application, a method for preparing cyclohexylamine is provided, comprising the following steps:

[0040] Cyclohexanone, cyclohexanol, liquid ammonia and hydrogen are subjected to an amination reaction under the action of a catalyst to obtain cyclohexylamine;

[0041] The catalyst is a nickel alloy catalyst, which comprises 70% to 85% of Ni, 5% to 15% of Cu and 5% to 15% of Al in terms of mass percentage.

[0042] In the preparation method of cyclohexylamine, cyclohexanone, cyclohexanol, liquid ammonia and hydrogen are used as raw materials, and a catalytic amination reaction is carried out under the condition of a nickel alloy catalyst of specific components, so that the cyclohexylamine obtained has high selectivity and the purity of the obtained cyclohexylamine product is high and can reach 99% or above.

[0043] In some embodiments, cyclohexanone and cyclohexanol are added in the form of cyclohexene hydration light oil as raw materials. In this way, the cyclohexene hydration light oil can be recycled and the process of synthesizing cyclohexylamine is economical.

[0044] In some embodiments, the total mass percentage of cyclohexanone and cyclohexanol in the cyclohexene hydration light oil is ≥40%. As an example, the total mass percentage of cyclohexanone and cyclohexanol in the cyclohexene hydration light oil can be 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or other mass percentages greater than 40%. Further, the total mass percentage of cyclohexanone and cyclohexanol in the cyclohexene hydration light oil can be a range value consisting of any two of the above point values ​​as end values. Preferably, the total mass percentage of cyclohexanone and cyclohexanol in the cyclohexene hydration light oil is ≥80%.

[0045] In some embodiments, the molar ratio of the total amount of cyclohexanone and cyclohexanol in the cyclohexene hydration light oil to the liquid ammonia is 1:(1-15). As an example, the molar ratio of the total amount of cyclohexanone and cyclohexanol in the cyclohexene hydration light oil to the liquid ammonia can be 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14 or 1:15. Further, the molar ratio of the total amount of cyclohexanone and cyclohexanol in the cyclohexene hydration light oil to the liquid ammonia can be any other ratio within the above range.

[0046] In some embodiments, the mass of the catalyst is 5% to 45% of the mass of the cyclohexene hydration light oil. As an example, the mass of the catalyst can be 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40% or 45% of the mass of the cyclohexene hydration light oil. Further, the mass of the catalyst can be a range value consisting of any two of the above point values ​​as end values.

[0047] In some embodiments, the reaction temperature of the amination reaction is 140°C to 250°C. As an example, the reaction temperature of the amination reaction can be 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C or 250°C. Further, the reaction temperature of the amination reaction can be a range value consisting of any two of the above point values ​​as end values. Preferably, the reaction temperature of the amination reaction is 160°C to 200°C.

[0048] In some embodiments, before the step of subjecting the cyclohexene hydrated light oil, liquid ammonia and hydrogen to an amination reaction under the action of a catalyst, the step of purifying the cyclohexene hydrated light oil is also included.

[0049] The step of purifying the cyclohexene hydrate light oil includes performing a first distillation treatment on the cyclohexene hydrate light oil at normal pressure to obtain a bottom fraction; and performing a second distillation treatment on the bottom fraction at 10KPa to 30KPa. The distillation treatment at normal pressure can remove light components such as cyclohexane, cyclohexene and water, and the second distillation treatment at 10KPa to 30KPa can remove components such as dicyclohexyl ether and N,N-dimethylacetamide.

[0050] In some embodiments, the top temperature of the first distillation treatment is ≤ 155°C.

[0051] In some embodiments, the reflux ratio of the first distillation treatment is (1-3):1.

[0052] In some embodiments, the top temperature of the second distillation treatment is 85°C to 120°C.

[0053] In some embodiments, the reflux ratio of the second distillation process is (1-3):1.

[0054] In some embodiments, the step of subjecting cyclohexene hydrated light oil, liquid ammonia and hydrogen to an amination reaction under the action of a catalyst comprises:

[0055] The catalyst is loaded into the reactor, liquid ammonia and hydrogen are introduced, the temperature is raised to the reaction temperature of the amination reaction, and then cyclohexene hydrated light oil is added dropwise. Compared with the traditional method of preparing cyclohexylamine by vaporizing cyclohexanone and cyclohexanol and reacting with ammonia, this method can only react under low pressure conditions; adding cyclohexene hydrated light oil dropwise can achieve the preparation of cyclohexylamine under high pressure conditions; compared with low-pressure reactions, high-pressure reactions have better selectivity for target products and faster raw material conversion.

[0056] In some embodiments, hydrogen is introduced to make the initial gas pressure in the reactor reach 1.0MPa to 3.0MPa, and then the temperature is increased. As an example, the initial pressure in the reactor can be 1.0MPa, 1.2MPa, 1.5MPa, 1.6MPa, 1.8MPa, 2.0MPa, 2.2MPa, 2.4MPa, 2.5MPa, 2.6MPa, 2.8MPa or 3MPa. Further, the initial pressure in the reactor can be a range value consisting of any two of the above point values ​​as end values. Making the hydrogen pressure in the reactor reach 1.0MPa to 3.0MPa is conducive to improving the activity of the catalyst.

[0057] In some embodiments, the dripping time of the cyclohexene hydration light oil is 1 hour to 8 hours. As an example, the dripping time of the cyclohexene hydration light oil can be 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, 6.5 hours, 7 hours, 7.5 hours or 8 hours. Further, the dripping time of the cyclohexene hydration light oil can be a range value consisting of any two of the above point values ​​as end values.

[0058] In some embodiments, after the cyclohexene hydrate light oil is added dropwise, the temperature is kept for 3 hours to 5 hours. After the cyclohexene hydrate light oil is added dropwise, the temperature is kept for reaction, which is conducive to the reactants to react fully.

[0059] In some embodiments, after the insulation reaction is completed, the reaction solution is separated and purified to obtain cyclohexylamine.

[0060] In some embodiments, the step of separating and purifying the reaction solution comprises:

[0061] The reaction liquid enters the degassing kettle for atmospheric degassing; then enters from the middle of the dehydration tower, and water and light components are extracted from the top of the dehydration tower; the dehydration tower kettle liquid enters from the middle of the product refining tower, and the cyclohexylamine product is extracted from the top of the refining tower.

[0062] In some embodiments, the temperature of the degassing kettle is 60°C to 80°C.

[0063] In some embodiments, the dehydration tower top temperature is < 110°C.

[0064] In some embodiments, the pressure in the refining tower is 10 KPa~30 KPa.

[0065] In some embodiments, the temperature in the refining tower is 100°C to 120°C.

[0066] In some embodiments, before loading the catalyst into the reactor, the step of activating the catalyst is further included.

[0067] In some embodiments, the activation treatment step includes: mixing the catalyst with a strong alkaline solution, performing an activation reaction, and then washing with desalted water until neutral. After the metal aluminum in the catalyst reacts with the strong alkaline solution, the specific surface area of ​​the active components nickel and copper is increased, thereby improving the catalytic activity.

[0068] In some embodiments, the strong alkaline solution includes at least one of an aqueous potassium hydroxide solution and an aqueous sodium hydroxide solution.

[0069] In some embodiments, the strong alkaline solution is a potassium hydroxide aqueous solution with a mass concentration of 5% to 20%.

[0070] In some embodiments, the temperature of the activation reaction is 80°C to 90°C.

[0071] In some embodiments, the activation reaction time is 1 h to 3 h.

[0072] In order to make the purpose, technical solutions and advantages of the present invention more concise and clear, the present invention is described with the following specific embodiments, but the present invention is by no means limited to these embodiments. The embodiments described below are only preferred embodiments of the present invention, which can be used to describe the present invention and cannot be understood as limiting the scope of the present invention. It should be pointed out that any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0073] In order to better illustrate the present invention, the present invention is further described below in conjunction with the embodiments. The following are specific embodiments.

[0074] Example 1

[0075] The cyclohexene hydrated light oil raw material (wherein the total mass content of cyclohexanol and cyclohexanone is 40%) is purified:

[0076] Alkanes and olefins are extracted from the top of the light removal tower of tower 1, with a top temperature of 70℃-100℃ and a reflux ratio of 3:1. The bottom kettle liquid of tower 1 enters from the middle of the refining tower of tower 2, and cyclohexanol and cyclohexanone with a content of ≥80% are extracted from the top of tower 2, with a top temperature of 95-105℃, a reflux ratio of 3:1, and an operating pressure of 10KPa-30KPa. A cyclohexene hydrated light oil with a total mass content of cyclohexanol and cyclohexanone of 85% is obtained.

[0077] Example 2

[0078] Weigh 400g of nickel alloy catalyst with an average particle size of 5mm-8mm (wherein, in terms of mass percentage, the nickel alloy catalyst includes 80% Ni, 5% Cu, and 15% Al), add 400g of 10% potassium hydroxide aqueous solution, heat to 85°C and react for 2h; then wash with deionized water until neutral. Immobilize the activated nickel alloy catalyst in a reactor, introduce nitrogen, replace the air in the reactor until the O2 content in the reactor is ≤0.2%, and stop introducing nitrogen; add 600g of liquid ammonia to the reactor and fill it with hydrogen to make the pressure in the reactor reach 2.5MPa, heat to 170°C, and drop 1370g of purified cyclohexene hydrated light oil (mass content of cyclohexanone + cyclohexanol 85%, molar ratio of total cyclohexanone + cyclohexanol to liquid ammonia 1:3), the dropwise addition time is 4h; after the dropwise addition is completed, keep the reactor warm for 4h.

[0079] Then, a sample was taken from the reaction solution for analysis. With N,N-diformamide as the internal standard, an HP-5 capillary column and an FID detector were used to perform quantitative analysis on the reaction solution. The analysis results are shown in Table 1.

[0080] The reaction liquid is degassed at normal pressure in a degassing kettle at 60°C; then it is dehydrated in a dehydration tower at normal pressure, and the top temperature of the dehydration tower is less than 110°C; then the bottom liquid of the dehydration tower is distilled in a refining tower at a temperature of 120°C and a negative pressure of 20KPa to obtain cyclohexylamine with a purity greater than 99%.

[0081] Example 3

[0082] Weigh 400g of nickel alloy catalyst with an average particle size of 5mm-8mm (wherein, in terms of mass percentage, the nickel alloy catalyst includes 80% Ni, 5% Cu, and 15% Al), add 400g of 10% potassium hydroxide aqueous solution, heat to 85℃ and react for 2h; then wash with desalted water until neutral. Immobilize the activated nickel alloy catalyst in a reactor, introduce nitrogen, replace the air in the reactor until the O2 content in the reactor is ≤0.2%, and stop introducing nitrogen; add 600g of liquid ammonia to the reactor and fill it with hydrogen to make the pressure in the reactor reach 2.5MPa, heat to 170℃, and drop 1028g of purified cyclohexene hydrated light oil (mass content of cyclohexanone + cyclohexanol 85%, molar ratio of total amount of cyclohexanone + cyclohexanol to liquid ammonia 1:4), and the dropwise addition time is 4h; after the dropwise addition is completed, keep the reactor warm for 4h.

[0083] Then, a sample was taken from the reaction solution for analysis. With N,N-diformamide as the internal standard, an HP-5 capillary column and an FID detector were used to perform quantitative analysis on the reaction solution. The analysis results are shown in Table 1.

[0084] The reaction liquid is degassed at normal pressure in a degassing kettle at 60°C; then it is dehydrated in a dehydration tower at normal pressure, and the top temperature of the dehydration tower is less than 110°C; then the bottom liquid of the dehydration tower is distilled in a refining tower at a temperature of 120°C and a negative pressure of 20KPa to obtain cyclohexylamine with a purity greater than 99%.

[0085] Example 4

[0086] Weigh 400g of nickel alloy catalyst with an average particle size of 5mm-8mm (wherein, in terms of mass percentage, the nickel alloy catalyst includes 80% Ni, 5% Cu, and 15% Al), add 400g of 10% potassium hydroxide aqueous solution, heat to 85℃ and react for 2h; then wash with desalted water until neutral. Immobilize the activated nickel alloy catalyst in a reactor, introduce nitrogen, replace the air in the reactor until the O2 content in the reactor is ≤0.2%, and stop introducing nitrogen; add 600g of liquid ammonia to the reactor and fill it with hydrogen to make the pressure in the reactor reach 2.5MPa, heat to 170℃, and drop 822g of purified cyclohexene hydrated light oil (mass content of cyclohexanone + cyclohexanol 85%, molar ratio of total cyclohexanone + cyclohexanol to liquid ammonia 1:5), and the dropwise addition time is 4h; after the dropwise addition is completed, keep the reactor warm for 4h.

[0087] Then, a sample was taken from the reaction solution for analysis. With N,N-diformamide as the internal standard, an HP-5 capillary column and an FID detector were used to perform quantitative analysis on the reaction solution. The analysis results are shown in Table 1.

[0088] The reaction liquid is degassed at normal pressure in a degassing kettle at 60°C; then it is dehydrated in a dehydration tower at normal pressure, and the top temperature of the dehydration tower is less than 110°C; then the bottom liquid of the dehydration tower is distilled in a refining tower at a temperature of 120°C and a negative pressure of 20KPa to obtain cyclohexylamine with a purity greater than 99%.

[0089] Example 5

[0090] Weigh 400g of nickel alloy catalyst with an average particle size of 5mm-8mm (wherein, in terms of mass percentage, the nickel alloy catalyst includes 80% Ni, 5% Cu, and 15% Al), add 400g of 10% potassium hydroxide aqueous solution, heat to 85℃ and react for 2h; then wash with desalted water until neutral. Immobilize the activated nickel alloy catalyst in a reactor, introduce nitrogen, replace the air in the reactor until the O2 content in the reactor is ≤0.2%, and stop introducing nitrogen; add 600g of liquid ammonia to the reactor and fill it with hydrogen to make the pressure in the reactor reach 2.5MPa, heat to 170℃, and drop 685g of purified cyclohexene hydrated light oil (mass content of cyclohexanone + cyclohexanol 85%, molar ratio of total cyclohexanone + cyclohexanol to liquid ammonia 1:6), and the dropwise addition time is 4h; after the dropwise addition is completed, keep the reactor warm for 4h.

[0091] Then, a sample was taken from the reaction solution for analysis. With N,N-diformamide as the internal standard, an HP-5 capillary column and an FID detector were used to perform quantitative analysis on the reaction solution. The analysis results are shown in Table 1.

[0092] The reaction liquid is degassed at normal pressure in a degassing kettle at 60°C; then it is dehydrated in a dehydration tower at normal pressure, and the top temperature of the dehydration tower is less than 110°C; then the bottom liquid of the dehydration tower is distilled in a refining tower at a temperature of 120°C and a negative pressure of 20KPa to obtain cyclohexylamine with a purity greater than 99%.

[0093] Example 6

[0094] Weigh 400g of nickel alloy catalyst with an average particle size of 5mm-8mm (wherein, in terms of mass percentage, the nickel alloy catalyst includes 80% Ni, 5% Cu, and 15% Al), add 400g of 10% potassium hydroxide aqueous solution, heat to 85℃ and react for 2h; then wash with deionized water until neutral. Immobilize the activated nickel alloy catalyst in a reactor, introduce nitrogen, replace the air in the reactor until the O2 content in the reactor is ≤0.2%, and stop introducing nitrogen; add 600g of liquid ammonia to the reactor and fill it with hydrogen to make the pressure in the reactor reach 2.5MPa, heat to 170℃, and drop 587g of purified cyclohexene hydrated light oil (mass content of cyclohexanone + cyclohexanol 85%, molar ratio of total amount of cyclohexanone + cyclohexanol to liquid ammonia 1:7), and the dropwise addition time is 4h; after the dropwise addition is completed, keep the reactor warm for 4h.

[0095] Then, a sample was taken from the reaction solution for analysis. With N,N-diformamide as the internal standard, an HP-5 capillary column and an FID detector were used to perform quantitative analysis on the reaction solution. The analysis results are shown in Table 1.

[0096] The reaction liquid is degassed at normal pressure in a degassing kettle at 60°C; then it is dehydrated in a dehydration tower at normal pressure, and the top temperature of the dehydration tower is less than 110°C; then the bottom liquid of the dehydration tower is distilled in a refining tower at a temperature of 120°C and a negative pressure of 20KPa to obtain cyclohexylamine with a purity greater than 99%.

[0097] Example 7

[0098] Weigh 400g of nickel alloy catalyst with an average particle size of 5mm-8mm (wherein, in terms of mass percentage, the nickel alloy catalyst includes 80% Ni, 5% Cu, and 15% Al), add 400g of 10% potassium hydroxide aqueous solution, heat to 85℃ and react for 2h; then wash with desalted water until neutral. Immobilize the activated nickel alloy catalyst in a reactor, introduce nitrogen, replace the air in the reactor until the O2 content in the reactor is ≤0.2%, and stop introducing nitrogen; add 600g of liquid ammonia to the reactor and fill it with hydrogen to make the pressure in the reactor reach 2.5MPa, heat to 170℃, and drop 513g of purified cyclohexene hydrated light oil (mass content of cyclohexanone + cyclohexanol 85%, molar ratio of total cyclohexanone + cyclohexanol to liquid ammonia 1:8), and the dropwise addition time is 4h; after the dropwise addition is completed, keep the reactor warm for 4h.

[0099] Then, a sample was taken from the reaction solution for analysis. With N,N-diformamide as the internal standard, an HP-5 capillary column and an FID detector were used to perform quantitative analysis on the reaction solution. The analysis results are shown in Table 1.

[0100] The reaction liquid is degassed at normal pressure in a degassing kettle at 60°C; then it is dehydrated in a dehydration tower at normal pressure, and the top temperature of the dehydration tower is less than 110°C; then the bottom liquid of the dehydration tower is distilled in a refining tower at a temperature of 120°C and a negative pressure of 20KPa to obtain cyclohexylamine with a purity greater than 99%.

[0101] Example 8

[0102] Weigh 400g of nickel alloy catalyst with an average particle size of 5mm-8mm (wherein, in terms of mass percentage, the nickel alloy catalyst includes 80% Ni, 5% Cu, and 15% Al), add 400g of 10% potassium hydroxide aqueous solution, heat to 85℃ and react for 2h; then wash with desalted water until neutral. Immobilize the activated nickel alloy catalyst in a reactor, introduce nitrogen, replace the air in the reactor until the O2 content in the reactor is ≤0.2%, and stop introducing nitrogen; add 600g of liquid ammonia to the reactor and fill it with hydrogen to make the pressure in the reactor reach 2.5MPa, heat to 160℃, and drop 685g of purified cyclohexene hydrated light oil (mass content of cyclohexanone + cyclohexanol 85%, molar ratio of total cyclohexanone + cyclohexanol to liquid ammonia 1:6), and the dropwise addition time is 5h; after the dropwise addition is completed, keep the reactor warm for 4h.

[0103] Then, a sample was taken from the reaction solution for analysis. With N,N-diformamide as the internal standard, an HP-5 capillary column and an FID detector were used to perform quantitative analysis on the reaction solution. The analysis results are shown in Table 1.

[0104] The reaction liquid is degassed at normal pressure in a degassing kettle at 60°C; then it is dehydrated in a dehydration tower at normal pressure, and the top temperature of the dehydration tower is less than 110°C; then the bottom liquid of the dehydration tower is distilled in a refining tower at a temperature of 120°C and a negative pressure of 20KPa to obtain cyclohexylamine with a purity greater than 99%.

[0105] Example 9

[0106] Weigh 400g of nickel alloy catalyst with an average particle size of 5mm-8mm (wherein, in terms of mass percentage, the nickel alloy catalyst includes 80% Ni, 5% Cu, and 15% Al), add 400g of 10% potassium hydroxide aqueous solution, heat to 85℃ and react for 2h; then wash with deionized water until neutral. Immobilize the activated nickel alloy catalyst in a reactor, introduce nitrogen, replace the air in the reactor until the O2 content in the reactor is ≤0.2%, and stop introducing nitrogen; add 600g of liquid ammonia to the reactor and fill it with hydrogen to make the pressure in the reactor reach 2.5MPa, heat to 180℃, and drop 685g of purified cyclohexene hydrated light oil (mass content of cyclohexanone + cyclohexanol 85%, molar ratio of total cyclohexanone + cyclohexanol to liquid ammonia 1:6), and the dropwise addition time is 5h; after the dropwise addition is completed, keep the reactor warm for 4h.

[0107] Then, a sample was taken from the reaction solution for analysis. With N,N-diformamide as the internal standard, an HP-5 capillary column and an FID detector were used to perform quantitative analysis on the reaction solution. The analysis results are shown in Table 1.

[0108] The reaction liquid is degassed at normal pressure in a degassing kettle at 60°C; then it is dehydrated in a dehydration tower at normal pressure, and the top temperature of the dehydration tower is less than 110°C; then the bottom liquid of the dehydration tower is distilled in a refining tower at a temperature of 120°C and a negative pressure of 20KPa to obtain cyclohexylamine with a purity greater than 99%.

[0109] Example 10

[0110] Weigh 400g of nickel alloy catalyst with an average particle size of 5mm-8mm (wherein, in terms of mass percentage, the nickel alloy catalyst includes 80% Ni, 5% Cu, and 15% Al), add 400g of 10% potassium hydroxide aqueous solution, heat to 85℃ and react for 2h; then wash with desalted water until neutral. Immobilize the activated nickel alloy catalyst in a reactor, introduce nitrogen, replace the air in the reactor until the O2 content in the reactor is ≤0.2%, and stop introducing nitrogen; add 600g of liquid ammonia to the reactor and fill it with hydrogen to make the pressure in the reactor reach 2.5MPa, heat to 190℃, and drop 685g of purified cyclohexene hydrated light oil (mass content of cyclohexanone + cyclohexanol 85%, molar ratio of total cyclohexanone + cyclohexanol to liquid ammonia 1:6), and the dropwise addition time is 5h; after the dropwise addition is completed, keep the reactor warm for 4h. Then, samples were taken for analysis using an HP-5 capillary column, an FID detector, and N,N-diformamide as an internal standard for quantitative analysis. The analysis results are shown in Table 1.

[0111] The reaction solution is degassed, dehydrated and refined to obtain cyclohexylamine with a purity greater than 99%.

[0112] Embodiment 11

[0113] Weigh 400g of nickel alloy catalyst with an average particle size of 5mm-8mm (wherein, in terms of mass percentage, the nickel alloy catalyst includes 80% Ni, 5% Cu, and 15% Al), add 400g of 10% potassium hydroxide aqueous solution, heat to 85℃ and react for 2h; then wash with deionized water until neutral. Immobilize the activated nickel alloy catalyst in a reactor, introduce nitrogen, replace the air in the reactor until the O2 content in the reactor is ≤0.2%, and stop introducing nitrogen; add 600g of liquid ammonia to the reactor and fill it with hydrogen to make the pressure in the reactor reach 2.5MPa, heat to 200℃, and drop 685g of purified cyclohexene hydrated light oil (mass content of cyclohexanone + cyclohexanol 85%, molar ratio of total cyclohexanone + cyclohexanol to liquid ammonia 1:6), and the dropwise addition time is 5h; after the dropwise addition is completed, keep the reactor warm for 4h.

[0114] Then, a sample was taken from the reaction solution for analysis. With N,N-diformamide as the internal standard, an HP-5 capillary column and an FID detector were used to perform quantitative analysis on the reaction solution. The analysis results are shown in Table 1.

[0115] The reaction liquid is degassed at normal pressure in a degassing kettle at 60°C; then it is dehydrated in a dehydration tower at normal pressure, and the top temperature of the dehydration tower is less than 110°C; then the bottom liquid of the dehydration tower is distilled in a refining tower at a temperature of 120°C and a negative pressure of 20KPa to obtain cyclohexylamine with a purity greater than 99%.

[0116] Example 12

[0117] Weigh 400g of nickel alloy catalyst with an average particle size of 5mm-8mm (wherein, in terms of mass percentage, the nickel alloy catalyst includes 80% Ni, 5% Cu, and 15% Al), add 400g of 10% potassium hydroxide aqueous solution, heat to 85℃ and react for 2h; then wash with desalted water until neutral. Immobilize the activated nickel alloy catalyst in a reactor, introduce nitrogen, replace the air in the reactor until the O2 content in the reactor is ≤0.2%, and stop introducing nitrogen; add 600g of liquid ammonia to the reactor and fill it with hydrogen to make the pressure in the reactor reach 2.5MPa, heat to 190℃, and drop 822g of purified cyclohexene hydrated light oil (mass content of cyclohexanone + cyclohexanol 85%, molar ratio of total cyclohexanone + cyclohexanol to liquid ammonia 1:5), and the dropwise addition time is 3h; after the dropwise addition is completed, keep the reactor warm for 4h.

[0118] Then, a sample was taken from the reaction solution for analysis. With N,N-diformamide as the internal standard, an HP-5 capillary column and an FID detector were used to perform quantitative analysis on the reaction solution. The analysis results are shown in Table 1.

[0119] The reaction liquid is degassed at normal pressure in a degassing kettle at 60°C; then it is dehydrated in a dehydration tower at normal pressure, and the top temperature of the dehydration tower is less than 110°C; then the bottom liquid of the dehydration tower is distilled in a refining tower at a temperature of 120°C and a negative pressure of 20KPa to obtain cyclohexylamine with a purity greater than 99%.

[0120] Embodiment 13

[0121] Weigh 400g of nickel alloy catalyst with an average particle size of 5mm-8mm (wherein, in terms of mass percentage, the nickel alloy catalyst includes 80% Ni, 5% Cu, and 15% Al), add 400g of 10% potassium hydroxide aqueous solution, heat to 85℃ and react for 2h; then wash with deionized water until neutral. Immobilize the activated nickel alloy catalyst in a reactor, introduce nitrogen, replace the air in the reactor until the O2 content in the reactor is ≤0.2%, and stop introducing nitrogen; add 600g of liquid ammonia to the reactor and fill it with hydrogen to make the pressure in the reactor reach 2.5MPa, heat to 190℃, and drop 822g of purified cyclohexene hydrated light oil (mass content of cyclohexanone + cyclohexanol 85%, molar ratio of total cyclohexanone + cyclohexanol to liquid ammonia 1:5), the dropwise addition time is 2h; after the dropwise addition is completed, keep the reactor warm for 4h.

[0122] Then, a sample was taken from the reaction solution for analysis. With N,N-diformamide as the internal standard, an HP-5 capillary column and an FID detector were used to perform quantitative analysis on the reaction solution. The analysis results are shown in Table 1.

[0123] The reaction liquid is degassed at normal pressure in a degassing kettle at 60°C; then it is dehydrated in a dehydration tower at normal pressure, and the top temperature of the dehydration tower is less than 110°C; then the bottom liquid of the dehydration tower is distilled in a refining tower at a temperature of 120°C and a negative pressure of 20KPa to obtain cyclohexylamine with a purity greater than 99%.

[0124] Embodiment 14

[0125] Weigh 400g of nickel alloy catalyst with an average particle size of 5mm-8mm (wherein, in terms of mass percentage, the nickel alloy catalyst includes 80% Ni, 5% Cu, and 15% Al), add 400g of 10% potassium hydroxide aqueous solution, heat to 85℃ and react for 2h; then wash with desalted water until neutral. Immobilize the activated nickel alloy catalyst in a reactor, introduce nitrogen, replace the air in the reactor until the O2 content in the reactor is ≤0.2%, and stop introducing nitrogen; add 600g of liquid ammonia to the reactor and fill it with hydrogen to make the pressure in the reactor reach 2.5MPa, heat to 170℃, and drop 1370g of purified cyclohexene hydrated light oil (mass content of cyclohexanone + cyclohexanol 50%, molar ratio of total amount of cyclohexanone + cyclohexanol to liquid ammonia 1:3), and the dropwise addition time is 4h; after the dropwise addition is completed, keep the reactor warm for 4h.

[0126] Then, a sample was taken from the reaction solution for analysis. With N,N-diformamide as the internal standard, an HP-5 capillary column and an FID detector were used to perform quantitative analysis on the reaction solution. The analysis results are shown in Table 1.

[0127] The reaction liquid is degassed at normal pressure in a degassing kettle at 60°C; then it is dehydrated in a dehydration tower at normal pressure, and the top temperature of the dehydration tower is less than 110°C; then the bottom liquid of the dehydration tower is distilled in a refining tower at a temperature of 120°C and a negative pressure of 20KPa to obtain cyclohexylamine with a purity greater than 99%.

[0128] Embodiment 15

[0129] Weigh 400g of nickel alloy catalyst with an average particle size of 5mm-8mm (wherein, in terms of mass percentage, the nickel alloy catalyst includes Ni 80%, Cu 5%, and Al 15%), add 400g of potassium hydroxide aqueous solution with a mass fraction of 10%, heat to 85℃ and react for 2h; then filter and wash with deionized water until neutral. Immobilize the activated nickel alloy catalyst in a reactor, introduce nitrogen, replace the air in the reactor until the O2 content in the reactor is ≤0.2%, and stop introducing nitrogen; add 600g of liquid ammonia to the reactor and fill it with hydrogen to make the pressure in the reactor reach 2.5MPa, heat to 180℃, and drop 685g of purified cyclohexene hydrated light oil (mass content of cyclohexanone + cyclohexanol 85%, molar ratio of total amount of cyclohexanone + cyclohexanol to liquid ammonia 1:6), and the dropwise addition time is 5h; after the dropwise addition is completed, keep the reactor warm for 4h.

[0130] The reaction liquid was discharged, and the nickel alloy catalyst was retained in the reactor. According to the above reaction steps, the catalyst was recycled for 4 times, and the selectivity of cyclohexylamine, the conversion rate of cyclohexanol and the conversion rate of cyclohexanone in the reaction liquid obtained when the catalyst was recycled each time were tested.

[0131] The quantitative analysis method for the content of each substance in the reaction solution is:

[0132] Sampling was taken from the reaction solution for analysis. N,N-diformamide was used as the internal standard. HP-5 capillary column and FID detector were used to perform quantitative analysis on the reaction solution. The analysis results are shown in Table 2.

[0133] Comparative Example 1

[0134] 400g of a loaded catalyst with an average particle size of 5mm-8mm (calculated by mass percentage, the loaded catalyst includes 50% Ni, 15% Cu and 35% carrier Al2O3) is added to the reactor, and hydrogen is introduced. The loaded catalyst is reduced under normal pressure, 350°C and hydrogen conditions for 24h; 600g of liquid ammonia is added to the reactor and hydrogen is introduced to make the pressure in the reactor reach 2.5MPa; after heating to 180°C, 685g of cyclohexene hydrated light oil (85% content of cyclohexanone + cyclohexanol) is added dropwise at a molar ratio of 1:6 between the total amount of cyclohexanone + cyclohexanol and liquid ammonia, the addition time is 5h, and the addition is completely kept warm for 4h.

[0135] The reaction liquid was discharged, and the nickel alloy catalyst was retained in the reactor. According to the above reaction steps, the catalyst was recycled for 4 times, and the selectivity of cyclohexylamine, the conversion rate of cyclohexanol and the conversion rate of cyclohexanone in the reaction liquid obtained when the catalyst was recycled each time were tested.

[0136] The quantitative analysis method for the content of each substance in the reaction solution is:

[0137] Sampling was taken from the reaction solution for analysis. N,N-diformamide was used as the internal standard. HP-5 capillary column and FID detector were used to perform quantitative analysis on the reaction solution. The analysis results are shown in Table 2.

[0138] Table 1

[0139]

[0140] Note: In Table 1, cyclohexylamine selectivity = molar mass of cyclohexylamine in the reaction solution / sum of molar mass of cyclohexanone and cyclohexanol participating in the reaction × 100%;

[0141] Cyclohexanol conversion rate = (mass of cyclohexanol input - mass of cyclohexanol remaining in the reaction solution) / mass of cyclohexanol input × 100%;

[0142] Cyclohexanone conversion rate = (mass of cyclohexanone input - mass of cyclohexanone remaining in the reaction solution) / mass of cyclohexanone input × 100%.

[0143] Table 2

[0144]

[0145] As can be seen from Table 1 and Table 2, the selectivity of the cyclohexylamine prepared by the preparation method of the present application in Examples 1 to 15 is higher, and the conversion rates of cyclohexanol and cyclohexanone are also higher. And it can be seen from Example 15 that the catalyst used in the present application still has a higher catalytic effect after being recycled 5 times, and the selectivity of the cyclohexylamine in the obtained reaction solution reaches 96.05%, the conversion rate of cyclohexanol reaches 98.65%, and the conversion rate of cyclohexanone reaches 99.05%. It shows that the nickel alloy catalyst in the present application has higher catalytic activity and good catalytic stability, good reproducibility, can be recycled for many times and maintain higher catalytic activity. Moreover, the preparation method of cyclohexylamine in the present application has mild reaction conditions, high selectivity of cyclohexylamine, good economic efficiency of the synthetic cyclohexylamine process, and green and clean reaction process.

[0146] In Comparative Example 1, a supported catalyst was used to catalyze the amination reaction between cyclohexanol, cyclohexanone, liquid ammonia and hydrogen. The selectivity of the prepared cyclohexylamine was 97.38%. However, after the supported catalyst was recycled, the conversion rates of cyclohexanone and cyclohexanol were significantly reduced, indicating that the catalytic activity of the supported catalyst was significantly reduced, that is, its recycling regeneration effect was poor.

[0147] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0148] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims, and the description can be used to interpret the content of the claims.

Claims

1. A nickel alloy catalyst, characterized in that Calculated by mass percentage, it includes 70% to 85% Ni, 5% to 15% Cu and 5% to 15% Al.

2. A method for preparing cyclohexylamine, characterized in that, The steps include: Cyclohexanone, cyclohexanol, liquid ammonia and hydrogen are subjected to an amination reaction under the action of a catalyst to obtain cyclohexylamine; The catalyst is a nickel alloy catalyst, which comprises 70% to 85% Ni, 5% to 15% Cu and 5% to 15% Al in terms of mass percentage.

3. The preparation method according to claim 2, characterized in that: The cyclohexanone and cyclohexanol are added in the form of cyclohexene hydrated light oil as raw materials.

4. The preparation method according to claim 3, characterized in that: The total mass percentage of cyclohexanone and cyclohexanol in the cyclohexene hydrated light oil is ≥40%, and can be optionally ≥80%.

5. The preparation method according to any one of claims 2 to 4, characterized in that: The molar ratio of the total amount of the cyclohexanone and the cyclohexanol to the liquid ammonia is 1:(1-15).

6. The preparation method according to any one of claims 3 to 4, characterized in that: The mass of the catalyst is 5% to 45% of the mass of the cyclohexene hydrated light oil.

7. The preparation method according to any one of claims 2 to 4, characterized in that: The reaction temperature of the amination reaction is 140°C to 250°C.

8. The preparation method according to any one of claims 3 to 4, characterized in that: The step of subjecting cyclohexene hydrated light oil, liquid ammonia and hydrogen to an amination reaction under the action of a catalyst comprises: The catalyst is loaded into a reactor, the liquid ammonia and the hydrogen are introduced, the temperature is raised to the reaction temperature of the amination reaction, and then the cyclohexene hydrate light oil is added dropwise.

9. The preparation method according to claim 8, characterized in that: The preparation method satisfies at least one of the following conditions: (1) introducing the hydrogen gas so that the initial gas pressure in the reactor reaches 1.0 MPa to 3.0 MPa, and then raising the temperature; (2) The dripping time of the cyclohexene hydration light oil is 1h~8h; (3) After the cyclohexene hydration light oil is added dropwise, the mixture is kept warm for 3 h to 5 h.

10. The preparation method according to claim 8, characterized in that: Before the catalyst is loaded into the reactor, the step of activating the catalyst is also included; The activation treatment step comprises: The catalyst is mixed with a strong alkaline solution to perform an activation reaction, and then washed with desalted water to neutrality.

11. The preparation method according to claim 10, characterized in that: The temperature of the activation reaction is 80° C. to 90° C.; the time of the activation reaction is 1 h to 3 h.

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