A method for preparing N-hexylcyclohexylamine by using light components of cyclohexanone oxime gas phase rearrangement reaction

Abstract

The application provides a method for preparing N-hexylcyclohexylamine by using light components of cyclohexanone oxime gas phase rearrangement reaction, and the method comprises the following steps: reducing amination of the light components of cyclohexanone oxime gas phase rearrangement reaction to prepare N-hexylcyclohexylamine. According to the application, the light components of cyclohexanone oxime gas phase rearrangement reaction are converted into N-hexylcyclohexylamine, the utilization rate of the light components is significantly improved, the prepared N-hexylcyclohexylamine product is high in purity and high in added value, and the economic competitiveness of the gas phase Beckmann rearrangement technical route is improved.

Description

Technical Field

[0001] This invention relates to the field of organic catalytic synthesis technology, and in particular to a method for preparing N-hexylcyclohexylamine from the light component of a cyclohexanone oxime gas-phase rearrangement reaction. Background Technology

[0002] Caprolactam is a widely used organic raw material with significant application prospects, primarily used in the production of nylon, industrial tire cord, and nylon engineering plastics. Currently, the Beckmann rearrangement reaction of cyclohexanone oxime is a mainstream caprolactam production process and plays a crucial role in my country's caprolactam production. The Beckmann rearrangement technology for caprolactam production includes two routes: liquid-phase and gas-phase, both using cyclohexanone oxime as a raw material. The liquid-phase Beckmann rearrangement uses fuming sulfuric acid as a catalyst under liquid conditions; however, the use of highly corrosive fuming sulfuric acid causes corrosion to equipment. Furthermore, this process consumes a large amount of liquid ammonia, and the low-value ammonium sulfate byproduct somewhat hinders the techno-economic efficiency of the process. Therefore, the gas-phase Beckmann rearrangement technology, which does not produce ammonium sulfate, has attracted considerable attention.

[0003] The gas-phase Beckmann rearrangement process requires high-temperature conditions and inevitably produces light components such as hexanonilonitrile, 5-hexenonium, cyclohexanone, cyclohexenone, 3-methoxycyclohexanone, and N-methylcaprolactam. Failure to utilize these substances would result in significant resource waste.

[0004] Therefore, it is crucial to develop and utilize light component resources to enhance the economic competitiveness of the gas-phase Beckmann rearrangement technology route. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for preparing N-hexylcyclohexylamine from light components using a gas-phase rearrangement reaction of cyclohexanone oxime. This method solves the problem of low utilization rate of light components in existing technologies, and utilizes light components to prepare high-value-added N-hexylcyclohexylamine, significantly improving the economic competitiveness of the gas-phase Beckmann rearrangement technology route.

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

[0007] This invention provides a method for preparing N-hexylcyclohexylamine from the light component of the cyclohexanone oxime gas-phase rearrangement reaction. The method includes the following steps: the light component of the cyclohexanone oxime gas-phase rearrangement reaction is reduced and aminationed to prepare N-hexylcyclohexylamine.

[0008] The light components of the cyclohexanone oxime gas-phase rearrangement reaction in this invention include hexanilide, 5-hexenonide, cyclohexanone, cyclohexenone, 3-methoxycyclohexanone, and N-methylcaprolactam, among others. However, the recovery and utilization of these substances are difficult. This invention discovers that hexanilide, 5-hexenonide, and cyclohexenone can be converted into hexylamine and cyclohexanone through hydrogenation reduction. Cyclohexanone can then undergo an amination reaction with hexylamine to convert into N-hexylcyclohexylamine, yielding a high-value-added product. Furthermore, this series of reactions exhibits high conversion and yield rates, significantly improving the utilization rate of the light components in the cyclohexanone oxime gas-phase rearrangement reaction.

[0009] Preferably, the catalyst for reductive amination is a metal-supported solid acid catalyst.

[0010] Preferably, the support for the metal-supported solid acid catalyst includes any one or a combination of at least two of Al2O3, SiO2, ZrO2 or SnO2, wherein typical but non-limiting combinations are combinations of Al2O3 and SiO2, combinations of ZrO2 and SiO2, combinations of Al2O3 and ZrO2, combinations of SnO2 and SiO2, and combinations of Al2O3 and SnO2.

[0011] Preferably, the metal active component of the metal-supported solid acid catalyst includes any one or a combination of at least two of Ru, Pd, Pt, Ni, Co, Fe, Cu, or Mo. Typical but non-limiting combinations include Ru and Pd, Co and Pd, Ru and Co, Mo and Pd, and Cu and Mo. Nickel is preferred, and more preferably, it is a combination of nickel and any one or at least two of iron, copper, cobalt, or molybdenum. When the active component in the catalyst contains nickel and other metal active components, the mass ratio of nickel to other metal active components is preferably 0.8–1.2:1, for example, 0.8:1, 0.9:1, 1.0:1, 1.1:1, or 1.2:1. Preferably, the content of the metal active component in the metal-supported solid acid catalyst is 5–11 wt%, for example, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, or 11 wt%.

[0012] It is worth noting that the core of this invention lies in improving the utilization rate of light components, that is, aiming to convert more substances in the light components into N-hexylcyclohexylamine products. Therefore, the catalyst used in this invention is preferably the aforementioned catalyst, which has better yield and utilization rate, and less by-product. Furthermore, since the raw materials of this application contain impurities such as aniline, it is preferred that the active component contains nickel and other metal active components, which has better reaction selectivity and can better avoid the generation of by-products.

[0013] Preferably, the process of the reductive amination reaction includes a batch reaction process or a continuous reaction process.

[0014] Preferably, when the reductive amination reaction is a batch reaction process, the mass ratio of the catalyst to the light component in the reductive amination is 0.01 to 0.1:1, for example, it can be 0.01:1, 0.02:1, 0.03:1, 0.04:1, 0.05:1, 0.06:1, 0.07:1, 0.08:1, 0.09:1 or 0.1:1, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0015] Preferably, when the reductive amination reaction is a batch reaction process, the reductive amination reaction temperature is 100-200℃, for example, it can be 100℃, 110℃, 125℃, 135℃, 145℃, 155℃, 165℃, 170℃, 180℃ or 200℃, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0016] Preferably, when the reductive amination reaction is a batch reaction process, the hydrogen pressure of the reductive amination is 2 to 10 MPa, for example, it can be 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa or 10 MPa, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0017] Preferably, when the reductive amination process is a batch reaction process, the reductive amination reaction time is 4 to 24 hours, for example, it can be 4 hours, 7 hours, 9 hours, 11 hours, 13 hours, 16 hours, 18 hours, 20 hours, 22 hours or 24 hours, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0018] Preferably, when the reductive amination reaction is a continuous reaction process, the weight hourly space velocity (WHSV) of the reductive amination is 0.01–0.2 h⁻¹. -1 For example, it could be 0.01h -1 0.04h -1 0.06h -1 0.08h -1 0.1h -1 0.12h -1 0.14h -1 0.16h -1 0.18h -1 or 0.2h -1 This includes, but is not limited to, the listed values; other unlisted values ​​within this range also apply.

[0019] Preferably, when the reductive amination reaction is a continuous reaction process, the reductive amination reaction temperature is 100-200℃, for example, it can be 100℃, 110℃, 125℃, 135℃, 145℃, 155℃, 165℃, 170℃, 180℃ or 200℃, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0020] Preferably, when the reductive amination reaction is a continuous reaction process, the reaction pressure of the reductive amination is 2 to 10 MPa, for example, it can be 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa or 10 MPa, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0021] In this invention, the reductive amination reaction is actually a two-step series of reactions consisting of hydrogen reduction and amination. By optimizing and controlling the process conditions within the above-mentioned range, this invention can better improve the reaction effect and increase the utilization rate of light components.

[0022] Preferably, the light component comprises a main reactive component and an auxiliary component, wherein the main reactive component comprises: hexanonitrile, 5-hexenonitrile, cyclohexanone, and cyclohexenone.

[0023] Preferably, the main reactive component accounts for more than 94 wt% of the light component, for example, it can be 94 wt%, 94.5 wt%, 95 wt%, 95.4 wt%, 96.3 wt%, 97.2 wt%, or 98 wt%, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0024] Preferably, the hexanolyte accounts for 25 to 30.5 wt% of the light component, for example, it can be 25 wt%, 25.7 wt%, 26.3 wt%, 26.9 wt%, 27.5 wt%, 28.1 wt%, 28.7 wt%, 29.3 wt%, 29.9 wt%, or 30.5 wt%, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0025] Preferably, the 5-hexenonitrile accounts for 20 to 30 wt% of the light component, for example, it can be 20 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, or 30 wt%, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0026] Preferably, the cyclohexanone accounts for 20 to 35 wt% of the light component, for example, 20 wt%, 22 wt%, 24 wt%, 25 wt%, 27 wt%, 29 wt%, 30 wt%, 32 wt%, 34 wt%, or 35 wt%, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0027] Preferably, the cyclohexenone accounts for 15 to 25 wt% of the light component, for example, it can be 15 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, or 25 wt%, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0028] Preferably, the excipient comprises any one or a combination of at least two of 3-methoxycyclohexanone, 5-cyano-1-pentene, aniline or N-methylcaprolactam or 2-methoxycyclohexanone, wherein typical but non-limiting combinations are the combination of 3-methoxycyclohexanone and 5-cyano-1-pentene, the combination of aniline or N-methylcaprolactam and 5-cyano-1-pentene, and the combination of 3-methoxycyclohexanone and aniline or N-methylcaprolactam.

[0029] It is worth noting that aniline in the excipient component of this invention can easily lead to reaction byproducts. Preferably, aniline in the excipient component accounts for 0.01 to 0.1 wt% of the light component, for example, it can be 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, or 0.1 wt%.

[0030] Preferably, the source of the light component in the method includes: a first distillation of the cyclohexanone oxime vapor-phase rearrangement reaction solution to obtain crude caprolactam, and a second vacuum distillation of the crude caprolactam to obtain the light component.

[0031] Preferably, the top temperature of the first distillation column is 60 to 120°C, for example, it can be 60°C, 67°C, 74°C, 80°C, 87°C, 94°C, 100°C, 107°C, 114°C or 120°C, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0032] Preferably, the temperature of the reboiler of the first distillation column is 130 to 160°C, for example, it can be 130°C, 134°C, 137°C, 140°C, 144°C, 147°C, 150°C, 154°C, 157°C or 160°C, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0033] Preferably, the top temperature of the second vacuum distillation column is 30 to 80°C, for example, it can be 30°C, 36°C, 42°C, 47°C, 53°C, 58°C, 64°C, 69°C, 75°C or 80°C, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0034] Preferably, the reboiler temperature of the second vacuum distillation column is 90 to 150°C, for example, it can be 90°C, 97°C, 104°C, 110°C, 117°C, 124°C, 130°C, 137°C, 144°C or 150°C, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0035] Preferably, the absolute pressure inside the column of the second vacuum distillation is 1 to 100 kPa, for example, it can be 1 kPa, 12 kPa, 23 kPa, 34 kPa, 45 kPa, 56 kPa, 67 kPa, 78 kPa, 89 kPa or 100 kPa, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0036] Preferably, the method further includes: subjecting the crude N-hexylcyclohexylamine obtained by the reductive amination to a third vacuum distillation to obtain the N-hexylcyclohexylamine product.

[0037] Preferably, the top temperature of the third vacuum distillation column is 80-120°C, for example, it can be 80°C, 85°C, 89°C, 94°C, 98°C, 103°C, 107°C, 112°C, 116°C or 120°C, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0038] Preferably, the reboiler temperature of the third vacuum distillation column is 110-180°C, for example, it can be 110°C, 118°C, 126°C, 134°C, 142°C, 149°C, 157°C, 165°C, 173°C or 180°C, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0039] Preferably, the absolute pressure inside the column of the third vacuum distillation is 1 to 20 kPa, for example, it can be 1 kPa, 4 kPa, 6 kPa, 8 kPa, 10 kPa, 12 kPa, 14 kPa, 16 kPa, 18 kPa or 20 kPa, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0040] As a preferred technical solution of the present invention, the method includes the following steps:

[0041] (1) The cyclohexanone oxime vapor-phase rearrangement reaction liquid is subjected to a first distillation, the top temperature of the first distillation column is 60-120℃, the bottom temperature is 130-160℃, to obtain crude caprolactam. The crude caprolactam is subjected to a second vacuum distillation, the top temperature of the second vacuum distillation column is 30-80℃, the bottom temperature is 90-150℃, and the absolute pressure inside the column is 1-100kPa, to obtain a light component.

[0042] (2) The light component was reduced and aminationd to prepare N-hexylcyclohexylamine, yielding crude N-hexylcyclohexylamine;

[0043] When the reductive amination reaction is a batch reaction process, the mass ratio of the catalyst to the light component is 0.01–0.1, the reaction temperature is 100–200°C, the hydrogen pressure is 2–10 MPa, and the reaction time is 4–24 h; or when the reductive amination reaction is a continuous reaction process, the weight hourly space velocity (WHSV) is 0.01–0.2 h⁻¹. -1 The reaction temperature is 100–200℃, and the reaction pressure is 2–10 MPa;

[0044] (3) The crude N-hexylcyclohexylamine is subjected to a third vacuum distillation, wherein the top temperature of the third vacuum distillation column is 80-120℃, the bottom temperature is 110-180℃, and the absolute pressure inside the column is 1-20kPa, to obtain the N-hexylcyclohexylamine product.

[0045] The present invention does not impose any particular limitations on the above-mentioned cyclohexanone oxime gas-phase rearrangement reaction. Any apparatus and process known to those skilled in the art for cyclohexanone oxime gas-phase rearrangement reaction can be used, and adjustments can be made according to the actual process.

[0046] Compared with the prior art, the present invention has at least the following beneficial effects:

[0047] (1) The method for preparing N-hexylcyclohexylamine by gas-phase rearrangement reaction of cyclohexanone oxime provided by the present invention can effectively solve the problem of low utilization rate of light components, and prepare high-value-added fine chemical N-hexylcyclohexylamine by light components. The overall process is simple, fast and efficient, easy to industrial application, and can effectively improve the economic competitiveness of gas-phase Beckmann rearrangement technology route.

[0048] (2) The method for preparing N-hexylcyclohexylamine by gas-phase rearrangement reaction of cyclohexanone oxime provided by the present invention has high purity of N-hexylcyclohexylamine product, with a purity of more than 99.4 wt% and high yield, with a yield of more than 76%; moreover, the utilization rate of light component is more than 41.27%, more than 64.97% in the preferred range, and more than 70% in the preferred range, which has great economic value. Detailed Implementation

[0049] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0050] It should be understood that in the description of this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0051] As a specific embodiment of the present invention, a method for preparing N-hexylcyclohexylamine using the light component of cyclohexanone oxime gas-phase rearrangement reaction is provided, the method comprising the following steps:

[0052] (1) The cyclohexanone oxime vapor-phase rearrangement reaction solution was subjected to a first distillation to obtain crude caprolactam, and the crude caprolactam was subjected to a second vacuum distillation to obtain a light component;

[0053] (2) The light component was reduced and aminationd to prepare N-hexylcyclohexylamine, yielding crude N-hexylcyclohexylamine;

[0054] (3) The crude N-hexylcyclohexylamine is subjected to a third vacuum distillation to obtain the N-hexylcyclohexylamine product.

[0055] In this specific embodiment, the reductive amination reaction is shown in the following formula, where Cat represents the catalyst:

[0056]

[0057] The side reactions that occur are shown below:

[0058]

[0059]

[0060] Obtaining the vapor-phase rearrangement reaction solution of cyclohexanone oxime: Nitrogen gas and cyclohexanone oxime solution are vaporized and introduced into a reactor. The Beckmann rearrangement reaction is carried out under certain reaction pressure and temperature to obtain the rearrangement reaction solution.

[0061] It is worth noting that, for the convenience of experiments, the specific embodiments described below all use the above-mentioned cyclohexanone oxime vapor-phase rearrangement reaction solution. The method for preparing N-hexylcyclohexylamine using the light component of the cyclohexanone oxime vapor-phase rearrangement reaction provided by the present invention is not limited to the above-mentioned cyclohexanone oxime vapor-phase rearrangement reaction solution. Other cyclohexanone oxime vapor-phase rearrangement reaction solutions in the art can also be processed using the method of the present invention.

[0062] Preparation of light component A

[0063] The cyclohexanone oxime vapor-phase rearrangement reaction solution was subjected to a first distillation at a top temperature of 65–70°C and a bottom temperature of 130–135°C to obtain crude caprolactam in the bottom of the column. Then, it was subjected to a second vacuum distillation at a top temperature of 40–45°C, a bottom temperature of 110–120°C, and a pressure of 20 kPa(A) to obtain the light component of the top fraction.

[0064] The main reactive components of the light component are, by mass percentage: hexanolyl: 28.45 wt%, 5-hexenone: 24.37 wt%, cyclohexanone: 25.24 wt%, and cyclohexenone: 18.61 wt%.

[0065] The proportions of excipients are as follows: 3-methoxycyclohexanone: 0.37wt%, 5-cyano-1-pentene: 1.34wt%, aniline: 0.02wt%, N-methylcaprolactam: 0.65wt%, and 2-methoxycyclohexanone: 0.37wt%.

[0066] Light components B to E

[0067] The difference between the light component and the light component A lies in the fact that the light component was obtained under different conditions by first distillation and second vacuum distillation, as shown in Table 1.

[0068] Table 1

[0069]

[0070]

[0071] Example 1

[0072] This embodiment provides a method for preparing N-hexylcyclohexylamine from the light component of a cyclohexanone oxime gas-phase rearrangement reaction, the method comprising the following steps:

[0073] The light component A was reduced and aminationd to prepare N-hexylcyclohexylamine using a batch reactor process. 30.0 g of Ni-Cu / Al2O3 (Ni: 5.0 wt%, Cu: 5.0 wt%) catalyst and 600.0 g of catalyst were added to a 1 L reactor. Nitrogen gas was introduced into the reactor to purge air. After replacement, hydrogen gas was introduced until the reaction pressure was maintained at 6 MPa, and the temperature was simultaneously raised to 150 °C. The reaction time was 12 h, and the reaction was completed to obtain crude N-hexylcyclohexylamine.

[0074] The crude N-hexylcyclohexylamine is subjected to a third vacuum distillation, wherein the top temperature of the third vacuum distillation column is 90-100°C, the bottom temperature is 120-130°C, and the absolute pressure inside the column is 1.5 kPa, to obtain the N-hexylcyclohexylamine product.

[0075] In this embodiment, the utilization rate of light component A was 78.32%, the yield of N-hexylcyclohexylamine product was 79.75%, and the purity of N-hexylcyclohexylamine product was 99.67%.

[0076] Examples 2-8

[0077] The difference from Example 1 is that a different catalyst is used for the reductive amination reaction, and the specific design is shown in Table 2.

[0078] Table 2

[0079]

[0080]

[0081] As can be seen from Examples 1 and 2-8, the present invention significantly improves the utilization rate of light components by preferably using a combination of nickel and other metal active components.

[0082] Examples 9-16

[0083] The difference from Example 1 is that reductive amination was carried out under different reaction conditions, as shown in Table 3.

[0084] Table 3

[0085]

[0086] As can be seen from Examples 1 and 11-14, the selection of reaction pressure and temperature in this invention has a significant impact on the utilization rate of light components. This invention further improves the utilization rate of light components by preferably using a combination of reaction pressure and reaction temperature within a specific range.

[0087] Example 17

[0088] This embodiment provides a method for preparing N-hexylcyclohexylamine from the light component of a cyclohexanone oxime gas-phase rearrangement reaction, the method comprising the following steps:

[0089] The light component B was reduced and aminationd to prepare N-hexylcyclohexylamine using a continuous fixed-bed reaction process. The reactor was packed with 100.0 g of 5wt% Ni-5wt% Cu / Al₂O₃ catalyst, and the weight hourly space velocity (WHSV) was 0.05 h⁻¹. -1 The reaction pressure was 6 MPa, the reaction temperature was 150 °C, and the reaction was completed to obtain crude N-hexylcyclohexylamine.

[0090] The crude N-hexylcyclohexylamine is subjected to a third vacuum distillation, wherein the top temperature of the third vacuum distillation column is 100-110°C, the bottom temperature is 110-120°C, and the absolute pressure inside the column is 1.0 kPa, to obtain the N-hexylcyclohexylamine product.

[0091] In this embodiment, the utilization rate of light component B was 79.41%, the yield of N-hexylcyclohexylamine product was 80.96%, and the purity of N-hexylcyclohexylamine product was 99.78%.

[0092] Examples 18-24

[0093] The difference from Example 17 is that a different catalyst is used for the reductive amination reaction, and the specific design is shown in Table 4.

[0094] Table 4

[0095]

[0096]

[0097] As can be seen from Examples 17 and 18-24, the present invention significantly improves the utilization rate of light components by preferably using a combination of nickel and other metal active components.

[0098] Examples 25-30

[0099] The difference from Example 17 is that the reductive amination reaction was carried out under different reaction conditions.

[0100] Table 5

[0101] Example 25 80 6 0.05 67.46 Example 26 220 6 0.05 65.35 Example 27 100 2 0.02 75.89 Example 28 190 10 0.18 72.73 Example 29 150 6 0.005 69.58 Example 30 150 6 0.3 63.42

[0102] As can be seen from Examples 17, 25-26, and 29-30, when the method for preparing N-hexylcyclohexylamine using the gas-phase rearrangement reaction of cyclohexanone oxime provided by the present invention is carried out in a continuous reaction process, the weight hourly space velocity and reaction temperature have a significant impact on the utilization rate of the light component. Therefore, the present invention further improves the utilization rate of the light component by controlling the process parameters within a specific range.

[0103] Examples 31-32

[0104] The difference from Example 17 is that different light components were used, and N-hexylcyclohexylamine products were obtained by third vacuum distillation under different conditions, as shown in Table 6.

[0105] Table 6

[0106]

[0107] Examples 33-34

[0108] The difference from Example 1 is that different light components were used, and N-hexylcyclohexylamine products were obtained by third vacuum distillation under different conditions, as shown in Table 7.

[0109] Table 7

[0110]

[0111] The above formula for calculating the utilization rate of light components is as follows: Formula for calculating the yield of N-hexylcyclohexylamine:

[0112] Where X is the yield of N-hexylcyclohexylamine, m0 is the total mass of the light component, m1 is the mass of the N-hexylcyclohexylamine product, and m2 is the total mass of the main reactive components in light component A.

[0113] In this invention, when a certain process parameter is limited to a range, it indicates that the temperature is difficult to control within a small range during long-term operation, so the range value is limited.

[0114] The present invention has been illustrated with the above embodiments to illustrate its detailed structural features. However, the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the components used in the present invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing N-hexylcyclohexylamine from the light component of a cyclohexanone oxime gas-phase rearrangement reaction, characterized in that, The method includes the following steps: The light component of the cyclohexanone oxime gas-phase rearrangement reaction is reduced-amination to prepare N-hexylcyclohexylamine; the catalyst for the reduced amination is a metal-supported solid acid catalyst; the metal active component of the metal-supported solid acid catalyst is any one or a combination of at least two of nickel, iron, copper, cobalt or molybdenum. The reductive amination reaction temperature is 100~200℃; the hydrogen pressure during the reductive amination is 2~10MPa. The light component includes a main reactive component and an auxiliary component. The main reactive component includes hexanonitrile, 5-hexenonitrile, cyclohexanone, and cyclohexenone. Aniline accounts for 0.01 to 0.1 wt% of the light component in the auxiliary component.

2. The method according to claim 1, characterized in that, The support for the metal-supported solid acid catalyst includes any one or a combination of at least two of Al2O3, SiO2, ZrO2 or SnO2.

3. The method according to claim 1, characterized in that, The process of the reductive amination reaction includes a batch reaction process or a continuous reaction process.

4. The method according to claim 3, characterized in that, When the reductive amination reaction is a batch reaction process, the mass ratio of the catalyst to the light component is 0.01~0.1:

1.

5. The method according to claim 3, characterized in that, When the reductive amination reaction is a batch reaction process, the reaction time of the reductive amination is 4~24h.

6. The method according to claim 3, characterized in that, When the reductive amination reaction is a continuous process, the weight hourly space velocity (WHSV) of the reductive amination is 0.01~0.2 h⁻¹. -1 .

7. The method according to claim 1, characterized in that, The main reactive component accounts for more than 94 wt% of the light component.

8. The method according to claim 1, characterized in that, The excipients also include any one or a combination of at least two of 3-methoxycyclohexanone, 5-cyano-1-pentene, N-methylcaprolactam, or 2-methoxycyclohexanone.

9. The method according to claim 1, characterized in that, The source of the light component in the method includes: a first distillation of cyclohexanone oxime vapor-phase rearrangement reaction solution to obtain crude caprolactam, and a second vacuum distillation of the crude caprolactam to obtain the light component.

10. The method according to claim 9, characterized in that, The top temperature of the first distillation column is 60~120℃.

11. The method according to claim 9, characterized in that, The temperature of the bottom of the first distillation column is 130~160℃.

12. The method according to claim 9, characterized in that, The top temperature of the second vacuum distillation column is 30~80℃.

13. The method according to claim 9, characterized in that, The temperature of the bottom of the second vacuum distillation column is 90~150℃.

14. The method according to claim 9, characterized in that, The absolute pressure inside the column of the second vacuum distillation is 1~100 kPa.

15. The method according to claim 1, characterized in that, The method further includes: subjecting the crude N-hexylcyclohexylamine obtained by the reductive amination to a third vacuum distillation to obtain the N-hexylcyclohexylamine product.

16. The method according to claim 15, characterized in that, The top temperature of the third vacuum distillation column is 80~120℃.

17. The method according to claim 15, characterized in that, The temperature of the bottom of the third vacuum distillation column is 110~180℃.

18. The method according to claim 15, characterized in that, The absolute pressure inside the column of the third vacuum distillation unit is 1~20 kPa.

19. The method according to claim 1, characterized in that, The method includes the following steps: (1) The cyclohexanone oxime vapor-phase rearrangement reaction liquid is subjected to a first distillation, the top temperature of the first distillation column is 60~120℃, the bottom temperature is 130~160℃, to obtain crude caprolactam. The crude caprolactam is subjected to a second vacuum distillation, the top temperature of the second vacuum distillation column is 30~80℃, the bottom temperature is 90~150℃, and the absolute pressure inside the column is 1~100kPa, to obtain a light component. (2) The light component was reduced and aminationd to prepare N-hexylcyclohexylamine, yielding crude N-hexylcyclohexylamine; When the reductive amination reaction is a batch reaction process, the mass ratio of the catalyst to the light component is 0.01~0.1, the reaction temperature is 100~200℃, the hydrogen pressure is 2~10MPa, and the reaction time is 4~24h; or when the reductive amination reaction is a continuous reaction process, the weight hourly space velocity is 0.01~0.2h. -1 The reaction temperature is 100~200℃, and the reaction pressure is 2~10MPa; (3) The crude N-hexylcyclohexylamine is subjected to a third vacuum distillation, wherein the top temperature of the third vacuum distillation column is 80~120℃, the bottom temperature is 110~180℃, and the absolute pressure inside the column is 1~20kPa, to obtain the N-hexylcyclohexylamine product.

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