Rectification equipment for cyclohexylamine rectification

Abstract

The invention provides rectification equipment for cyclohexylamine rectification. The rectifying equipment comprises a rectifying tower with a cylindrical barrel structure, the rectifying tower is divided into a pre-fractionation section, a rectifying section, a stripping section and a middle discharging section, and a vertical partition plate is arranged in the tower to separate the pre-fractionation section from the middle discharging section. By utilizing the rectification equipment, the quantity of equipment can be reduced, the process flow is simplified, the device investment is reduced, the raw material and energy consumption in production is reduced, the production cost is reduced, and the carbon emission of a production device is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of chemical distillation, and in particular to a distillation device for distilling cyclohexylamine. Background Art

[0002] Cyclohexylamine is miscible in most organic solvents and is mainly used as a solvent. 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; dicyclohexylamine is used in organic synthesis and is also used as a pesticide, acid gas absorbent and steel rust inhibitor.

[0003] The organic mixed liquid used in the production of cyclohexylamine usually contains cyclohexylamine with a mass concentration of ≥80%, aniline with a mass concentration of ≤5%, dicyclohexylamine with a mass concentration of ≤10%, and a small amount of light components. These organic mixed liquids need to be distilled and separated to recover useful components. In the existing production, a two-step distillation process is usually used. Step 1: First, add the organic mixed liquid from the cyclohexylamine production system to the distillation separation and recovery system I to separate the target product 1-cyclohexylamine; Step 2: Then add the remaining bottom liquid to the distillation separation and recovery system II to separate the target product 2-aniline; the bottom liquid of the distillation separation and recovery system II is used as the target product 3-dicyclohexylamine. The above organic mixed liquid containing cyclohexylamine, aniline, and dicyclohexylamine is separated and recovered by two sets of distillation separation and recovery systems, which has low efficiency and high energy consumption. Distillation separation is the most mature and widely used separation technology in chemical production, but the distillation process consumes a lot of energy. More than 50% of the energy consumption in chemical production is used for separation, and distillation separation energy consumption accounts for 95% of it.

[0004] Therefore, it is necessary to improve the existing cyclohexylamine organic mixed liquid distillation separation and recovery equipment, and it is urgent to provide a distillation equipment for cyclohexylamine distillation with short process, small footprint, low investment, stable operation, high efficiency and low energy consumption. Summary of the invention

[0005] The purpose of the present invention is to provide a distillation device for cyclohexylamine distillation, and to distill and separate the organic mixed liquid containing cyclohexylamine, aniline and dicyclohexylamine from the cyclohexylamine production system in a vertical partition plate distillation tower. Unlike the previous distillation tower, the vertical partition plate distillation tower not only has a distillation section and a stripping section, but also has a pre-fractionation section and an intermediate discharge section. The target product 1 - cyclohexylamine recovered in the distillation section of the distillation tower is used as a product delimiting zone; the target product 2 - aniline recovered in the intermediate discharge section of the distillation tower is directly returned to the cyclohexylamine production system as a raw material for use; the target product 3 - dicyclohexylamine recovered at the bottom of the reboiler of the distillation tower is used as a by-product delimiting zone.

[0006] By adopting the above distillation equipment, only one set of distillation equipment is needed to recover the target product for continuous production. It is a distillation equipment for cyclohexylamine distillation with stable operation, high efficiency and low energy consumption. The present invention aims to save energy and reduce consumption, reduce carbon emissions and protect the environment.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] A distillation device for rectifying cyclohexylamine comprises a condenser, a rectifying tower and a reboiler; the condenser has a tube side for light components and a shell side for circulating water, the top of the condenser is connected to a head via a light component outlet B, the top of the head is provided with a light component outlet A, the bottom of the condenser is connected to the top of the rectifying tower via a gas outlet reflux port E, and the bottom of the rectifying tower is connected to the reboiler via a discharge reflux port J; the rectifying tower is provided with a rectifying section at the top, a pre-fractionation section and an intermediate discharge section at the middle, and a stripping section at the bottom, a vertical partition plate is installed between the middle pre-fractionation section and the intermediate discharge section, and the pre-fractionation section and the intermediate discharge section are both provided with a stripping layer and a rectifying layer; wherein the cyclohexylamine liquid at the top of the tower is refluxed via the gas outlet reflux port E, and the steam at the bottom of the tower is refluxed via the discharge reflux port J.

[0009] As a preferred embodiment of the present invention, the condenser and the distillation tower are vertical cylindrical shells, and the reboiler is a horizontal cylindrical shell.

[0010] As a preferred embodiment of the present invention, the upper side shell side of the condenser is provided with a circulating return water outlet C, and the lower side shell side is provided with a circulating supply water inlet D.

[0011] As a preferred embodiment of the present invention, an organic mixed liquid feed inlet G is provided on the side shell side in the middle of the pre-fractionation section of the distillation tower, a raw material feed pipe is horizontally installed at the organic mixed liquid feed inlet G, a first distillation layer is installed above the raw material feed pipe, a first liquid distributor is horizontally installed below the raw material feed pipe, and a first stripping layer is provided below the first liquid distributor.

[0012] As a preferred embodiment of the present invention, a fourth liquid distributor is horizontally installed on the upper part of the stripping section of the distillation tower, and a second stripping layer is provided below the fourth liquid distributor.

[0013] As a preferred embodiment of the present invention, an aniline outlet H is provided on the side shell side of the middle discharge section of the distillation tower, a fifth liquid distributor is horizontally installed below the aniline outlet H, and a third stripping layer is installed below the fifth liquid distributor.

[0014] As a preferred embodiment of the present invention, a cyclohexylamine outlet F is provided on the upper side shell side of the rectifying section of the rectifying tower, a second liquid distributor is horizontally installed below the cyclohexylamine outlet F, and a second rectifying layer is provided below the second liquid distributor.

[0015] As a preferred embodiment of the present invention, a dicyclohexylamine outlet M is provided at the bottom shell side of the reboiler; an opening is provided on the side of the reboiler, a horizontal heater is provided at the opening, a steam inlet K is provided at the top of the horizontal heater on the outer side of the reboiler shell side, and a condensate outlet L is provided at the bottom.

[0016] As a preferred embodiment of the present invention, the top of the first distillation layer is the same height as or lower than the top of the vertical partition plate, and the tops of the first distillation layer and the third distillation layer are the same height; the bottom of the first stripping layer is the same height as or higher than the bottom of the vertical partition plate, and the bottoms of the first stripping layer and the third stripping layer are the same height; the ratio of the horizontal cross-sectional area of ​​the first distillation layer to the third distillation layer and / or the first stripping layer to the third stripping layer is 1:10 to 10:1.

[0017] As a preferred embodiment of the present invention, the first, second and third rectification layers and the first, second and third stripping layers are all packing layers and the heights are all 2 to 12 meters.

[0018] The present invention also provides a method for implementing the distillation of cyclohexylamine using the above distillation equipment, the method comprising the following steps:

[0019] (1) Pre-fractionation section: The raw material from the cyclohexylamine production system, the organic mixed liquid, enters the pre-fractionation section of the distillation tower from the inlet G of the pre-fractionation section of the distillation tower. In the pre-fractionation section, the organic mixed liquid is initially fractionated. The mixed gas of light components, cyclohexylamine and aniline flows upward and is first distilled in the distillation layer of the pre-fractionation section, and then goes to the distillation section; the mixed liquid of aniline and dicyclohexylamine flows downward and is first retained in the stripping layer of the pre-fractionation section, and then goes to the stripping section.

[0020] (2) Distillation section: The mixed gas of light components, cyclohexylamine and aniline is distilled in the distillation layer of the distillation section, and heat and mass transfer is carried out with the cyclohexylamine refluxed from the gas outlet reflux port E at the top of the distillation tower. The aniline solution flows downward into the middle discharge section, and the mixed gas of the light components and cyclohexylamine after distillation flows upward, exits the distillation section of the distillation tower from the gas outlet reflux port E at the top of the distillation tower, and enters the condenser tube side through the bottom of the condenser. In the condenser, cyclohexylamine is condensed into liquid by circulating water, and refluxes from the bottom of the condenser through the gas outlet reflux port E into the distillation section of the distillation tower, wherein a part of the refluxed cyclohexylamine is used as the target product 1 from the liquid discharge distributor through the cyclohexylamine outlet F on the upper side of the distillation tower to the boundary area; the light component gas in the condenser is from the light component outlet B at the top of the condenser through the light component outlet A at the top of the head to the boundary area vacuum system. The circulating water from the boundary zone enters the condenser shell from the circulating water inlet D on the lower side of the condenser shell. The circulating water after heat exchange in the condenser goes to the boundary zone from the circulating return water outlet C on the upper side of the condenser shell as circulating return water.

[0021] (3) Distillation section: The mixed liquid of aniline and dicyclohexylamine is distilled in the stripping layer of the stripping section, and heat and mass transfer is carried out with the gas phase refluxed from the bottom discharge reflux port J of the distillation tower. The aniline gas after distillation flows upward and enters the middle discharge section, and the dicyclohexylamine solution flows downward and exits the distillation section of the distillation tower from the bottom discharge reflux port J of the distillation tower and enters the reboiler. In the reboiler, the dicyclohexylamine solution is heated by the heater, and the aniline in the dicyclohexylamine solution is heated and evaporated into gas as the gas phase and exits the reboiler from the bottom discharge reflux port J of the distillation tower and enters the distillation section of the distillation tower; the dicyclohexylamine solution at the bottom of the reboiler exits the reboiler from the bottom dicyclohexylamine outlet M of the reboiler as the target product 3 to the boundary area. The water vapor from the boundary area enters the horizontal heater tube side from the steam inlet K of the top tube side of the heater, and the condensed water after heat exchange in the reboiler exits the boundary area from the condensed water outlet L of the bottom tube side of the horizontal heater.

[0022] (4) Intermediate discharging section: Aniline solution flowing downward from the rectifying section of the rectifying tower into the intermediate discharging section of the rectifying tower is rectified in the rectifying layer of the intermediate discharging section, and aniline gas flowing upward from the stripping section of the rectifying tower into the intermediate discharging section of the rectifying tower is retained in the stripping layer of the intermediate discharging section. Aniline is purified in the intermediate discharging section and the purified aniline is recycled as the target product 2 to the cyclohexylamine production system from the aniline outlet H of the intermediate discharging section on the side of the middle of the rectifying tower.

[0023] In the above method, the raw materials from the cyclohexylamine production system contain cyclohexylamine at a mass concentration of ≥80%, aniline at a mass concentration of ≤5%, and dicyclohexylamine at a mass concentration of ≤10%.

[0024] Beneficial effects of the present invention:

[0025] In the production of cyclohexylamine, the product organic mixed liquid contains trace light components, target product 1-cyclohexylamine mass concentration ≥80%, target product 2-aniline mass concentration ≤5% and target product 3-dicyclohexylamine mass concentration ≤10%. The above substances need to be effectively separated, otherwise the product quality and the recycling of raw materials will be affected. The present invention provides a distillation device for cyclohexylamine distillation, which uses a vertical partition plate distillation device to replace the original two sets of distillation equipment to continuously distill and separate the components in the organic mixed liquid. Compared with the original two sets of distillation equipment, under the same output and quality requirements, the vertical partition plate distillation equipment has a shorter process, uses less equipment, and can save about 30% of the device investment; the device is more energy-saving and can save about 30% of energy consumption.

[0026] The condenser is arranged vertically on the top of the distillation tower. The equipment is compactly arranged, which is conducive to the operation of the distillation tower under negative pressure, reducing the boiling points of cyclohexylamine and aniline, and is more conducive to the separation of light components. The liquid cyclohexylamine in the condenser directly refluxes into the distillation tower, eliminating the pipeline connecting the condenser and the distillation tower.

[0027] The distillation tower and the reboiler are directly connected, which reduces the equipment footprint and eliminates the need for a pipe connecting the distillation tower and the reboiler. Compared with discharging from the bottom of the distillation tower, discharging from the bottom of the reboiler, under the same energy consumption, the target product 3 has a lower aniline content and a higher dicyclohexylamine content.

[0028] By adopting the above distillation equipment, three target products can be obtained. It is a safe, environmentally friendly, high-yield, low-energy-consuming distillation equipment for cyclohexylamine distillation. The present invention aims to save energy and reduce consumption, reduce carbon emissions from production equipment and protect the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The working section division diagram of the distillation equipment in the present invention is

[0030] Figure 2 The distillation equipment diagram of the present invention

[0031] Figure 3 The schematic diagram of the process flow in the present invention is

[0032] Among them, there are a distillation tower 1, a raw material feed pipe 1-1, a first liquid distributor 1-2, a first distillation layer 1-3, a first stripping layer 1-4, a second distillation layer 1-5, a second stripping layer 1-6, a second liquid distributor 1-7, a third liquid distributor 1-8, a fourth liquid distributor 1-9, a third distillation layer 1-10, a third stripping layer 1-11, a fifth liquid distributor 1-12, a vertical partition plate 2, a condenser 3, a head 4, a reboiler 5, and a horizontal heater 6. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. The components of the embodiment of the present invention described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiment of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but only represents the selected embodiment of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the drawings, where the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present invention, and cannot be understood as limitations on the present invention.

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0035] like Figure 1 A distillation device for rectifying cyclohexylamine comprises a condenser 3, a rectifying tower 1 and a reboiler 5; the condenser 3 has a tube side for light components and a shell side for circulating water, the top of which is connected to a head 4 via a light component outlet B, the top of which is provided with a light component outlet A, the bottom of the condenser 3 is connected to the top of the rectifying tower 1 via a gas outlet reflux port E, and the bottom of the rectifying tower 1 is connected to the reboiler 5 via a discharge reflux port J; the rectifying tower 1 is provided with a rectifying section at the top, a pre-fractionation section and an intermediate discharge section at the middle, a stripping section at the bottom, and a vertical partition plate 2 is installed between the middle pre-fractionation section and the intermediate discharge section; the cyclohexylamine liquid at the top of the tower is refluxed via the gas outlet reflux port E, and the steam at the bottom of the tower is refluxed via the discharge reflux port J.

[0036] The condenser 3 and the distillation tower 1 are vertical cylindrical shells, and the reboiler 5 is a horizontal cylindrical shell.

[0037] The upper side shell side of the condenser 3 is provided with a circulating water return outlet C, and the lower side shell side is provided with a circulating water supply inlet D.

[0038] An organic mixed liquid feed inlet G is provided on the side shell side of the middle part of the pre-fractionation section of the distillation tower 1, a raw material feed pipe 1-1 is horizontally installed at the organic mixed liquid feed inlet G, a first distillation layer 1-3 is installed above the raw material feed pipe 1-1, a first liquid distributor 1-2 is horizontally installed below the raw material feed pipe 1-1, and a first stripping layer 1-4 is provided below the first liquid distributor 1-2.

[0039] A fourth liquid distributor 1-9 is horizontally installed at the upper part of the stripping section of the distillation tower 1, and a second stripping layer 1-6 is arranged below the fourth liquid distributor 1-9.

[0040] The distillation tower 1 is provided with an aniline outlet H on the side shell side in the middle of the middle discharge section, a fifth liquid distributor 1-12 is horizontally installed below the aniline outlet H, and a third stripping layer 1-11 is installed below the fifth liquid distributor 1-12.

[0041] The distillation tower 1 is provided with a cyclohexylamine outlet F on the side shell side of the upper part of the distillation section, a second liquid distributor 1-7 is horizontally installed below the cyclohexylamine outlet F, and a second distillation layer 1-5 is provided below the second liquid distributor 1-7.

[0042] The bottom shell of the reboiler 5 is provided with a dicyclohexylamine outlet M; the side of the reboiler 5 is provided with an opening, and a horizontal heater 6 is provided at the opening. The top of the horizontal heater 6 on the outer side of the shell of the reboiler 5 is provided with a steam inlet K, and the bottom is provided with a condensed water outlet L.

[0043] The top of the first distillation layer 1-3 is not higher than the top of the vertical partition plate 2, and the tops of the first distillation layer 1-3 and the third distillation layer 1-10 are at the same height; the bottom of the first distillation layer 1-4 is not lower than the bottom of the vertical partition plate 2, and the bottoms of the first distillation layer 1-4 and the third distillation layer 1-11 are at the same height; the ratio of the horizontal cross-sectional area of ​​the first distillation layer 1-3 to the third distillation layer 1-10 and the first distillation layer 1-4 to the third distillation layer 1-11 is 26:10.

[0044] The first distillation layer 1-3, the first stripping layer 1-4, the second distillation layer 1-5, the second stripping layer 1-6, the third distillation layer 1-10 and the third stripping layer 1-11 are packing layers and have a height of 3 meters.

[0045] In some more specific embodiments, the content is as follows:

[0046] The organic mixed liquid feed inlet G on the middle side of the distillation tower 1 is connected to the raw material from the cyclohexylamine production system - the organic mixed liquid pipeline, the cyclohexylamine outlet F on the upper side of the distillation tower 1 is connected to the target product 1 in the de-boundary zone - the cyclohexylamine delivery pipeline, the aniline outlet H on the middle side of the distillation tower 1 is connected to the target product 2 recycled in the de-boundary zone - the aniline delivery pipeline, and the dicyclohexylamine outlet M at the bottom of the reboiler 5 is connected to the target product 3 in the de-boundary zone - the dicyclohexylamine solution delivery pipeline.

[0047] The light component outlet A at the top of the top cover 4 of the condenser 3 is connected to the light component vacuum pipeline of the deboundary area.

[0048] The shell-side circulating water return outlet C on the upper side of the condenser 3 is connected to the circulating water return pipe of the delimited area, and the shell-side circulating water supply inlet D on the lower side of the condenser 3 is connected to the circulating water supply pipe from the limit area.

[0049] The steam inlet K at the top of the horizontal heater 6 is connected to the water vapor pipeline from the boundary zone, and the condensate outlet L at the bottom of the horizontal heater 6 is connected to the condensate pipeline to the boundary zone.

[0050] A method for rectifying cyclohexylamine using the above-mentioned rectification equipment, the method comprising the following steps:

[0051] (1) Pre-fractionation section: The raw material from the cyclohexylamine production system, the organic mixed liquid (temperature is room temperature, containing cyclohexylamine mass concentration of 90.23%, aniline mass concentration of 2.17%, and dicyclohexylamine mass concentration of 6.5%), enters the first liquid distributor 1-2 of the distillation tower 1 through the raw material feed pipe 1-1 from the organic mixed liquid feed port G on the middle side of the distillation tower 1 for pre-fractionation. After the pre-fractionation, the organic mixed liquid is preliminarily fractionated. The mixed gas of light components, cyclohexylamine and aniline flows upward and is first distilled in the first distillation layer 1-3, and then goes to the distillation section; the mixed liquid of aniline and dicyclohexylamine flows downward and is first distilled in the first stripping layer 1-4, and then goes to the stripping section.

[0052] (2) Distillation section: The mixed gas of light components, cyclohexylamine and aniline from the pre-fractionation section of the distillation tower 1 is distilled in the distillation section. The mixed gas of light components, cyclohexylamine and aniline flows upward and is first distilled in the second distillation layer 1-5, and performs heat and mass transfer with the cyclohexylamine distributed by the second liquid distributor 1-7 refluxed from the gas outlet reflux port E at the top of the distillation tower 1. The aniline solution flows downward and is distributed by the third liquid distributor 1-8 and then enters the intermediate discharge section. The mixed gas of light components and cyclohexylamine after distillation flows upward and exits the distillation section of the distillation tower 1 from the gas outlet reflux port E at the top of the distillation tower 1 and enters the condenser 3 tube side through the bottom of the condenser 3. Cyclohexylamine is condensed into liquid by circulating water in condenser 3, and refluxes from the bottom of condenser 3 through gas outlet reflux port E into the rectifying section of rectifying tower 1, wherein a part of the refluxed cyclohexylamine (temperature 84°C, cyclohexylamine mass concentration 99.46%) is taken as target product 1 from second liquid distributor 1-7 through cyclohexylamine outlet F on the upper side of rectifying tower 1 to the boundary area; light component gas (temperature 60°C, vacuum degree 0.079MPa) in condenser 3 is taken from light component outlet B on the top of condenser 3 through light component outlet A on top head 4 to the boundary area vacuum system. Circulating upper water (temperature 25°C) from the boundary area enters the shell side of condenser 3 from circulating upper water inlet D on the lower side of condenser 3, and circulating water (temperature 35°C) after heat exchange in condenser 3 is taken as circulating return water from circulating return water outlet C on the upper side of condenser 3 to the boundary area.

[0053] (3) Distillation section: The mixed liquid of aniline and dicyclohexylamine from the pre-fractionation section of the distillation tower 1 is distilled in the distillation section. The mixed liquid of aniline and dicyclohexylamine flows downward and is distributed by the fourth liquid distributor 1-9 and then enters the second stripping layer 1-6. The mixed liquid conducts heat and mass transfer with the reflux gas phase (temperature 155° C.) at the bottom discharge reflux port J of the distillation tower 1. The stripped aniline gas flows upward and enters the middle discharge section. The dicyclohexylamine solution flows downward and exits the distillation tower 1 from the bottom discharge reflux port J of the distillation tower 1. The distillation section enters the reboiler 5, where the dicyclohexylamine solution is heated by the horizontal heater 6, and the aniline in the dicyclohexylamine solution (temperature 155°C) is heated and evaporated into gas (temperature 155°C) as the gas phase from the bottom discharge reflux port J of the distillation tower 1 to the distillation section of the distillation tower 1; the dicyclohexylamine solution at the bottom of the reboiler 5 (temperature 155°C, containing 97.26% of dicyclohexylamine by mass) is discharged from the reboiler 5 from the dicyclohexylamine outlet M at the bottom of the reboiler 5 as the target product 3 to the boundary area. The water vapor from the boundary area (temperature 183°C, pressure 1.1MPa) enters the horizontal heater 6 tube side from the steam inlet K at the top tube side of the horizontal heater 6, and the condensed water (temperature 183°C) after heat exchange in the reboiler 5 is discharged from the condensed water outlet L at the bottom tube side of the horizontal heater 6 to the boundary area.

[0054] (4) Intermediate discharging section: The aniline solution flowing downward from the rectifying section of the rectifying tower 1 into the third rectifying layer 1-10 of the rectifying tower 1 is subjected to heat and mass transfer with the aniline gas flowing upward from the stripping section of the rectifying tower 1 into the intermediate discharging section of the rectifying tower 1. Aniline is rectified in the third rectifying layer 1-10. The aniline after rectification enters the fifth liquid distributor 1-12. A portion of the aniline (containing aniline at a mass concentration of 99.6%) in the fifth liquid distributor 1-12 is taken as the target product 2 and is recycled to the cyclohexylamine production system from the aniline outlet H of the intermediate discharging section of the rectifying tower 1. The remaining portion of the aniline flows downward into the third stripping layer 1-11 and is subjected to heat and mass transfer with the gas phase from the stripping section.

[0055] The results of the operation of the present invention are shown in Table 1.

[0056] Table 1 Performance evaluation results of cyclohexylamine distillation unit in 2,000 tons / year cyclohexylamine production

[0057]

[0058]

Claims

1. A distillation equipment for cyclohexylamine rectification, characterized in that: The distillation equipment comprises a condenser (3), a distillation tower (1) and a reboiler (5); the top of the condenser (3) is connected to the head (4) through a light component outlet B, the top of the head (4) is provided with a light component outlet A, the bottom of the condenser (3) is connected to the top of the distillation tower (1) through a gas outlet reflux port E, and the bottom of the distillation tower (1) is connected to the reboiler (5) through a discharge reflux port J; the distillation tower (1) is provided with a distillation section at the top, a pre-fractionation section and an intermediate discharge section at the middle, and a stripping section at the bottom, a vertical partition plate (2) is installed between the middle pre-fractionation section and the intermediate discharge section, and the pre-fractionation section and the intermediate discharge section are both provided with a stripping layer and a distillation layer.

2. The distillation equipment according to claim 1, characterized in that: The condenser (3) and / or the distillation tower (1) are vertical cylindrical shells, and the reboiler (5) is a horizontal cylindrical shell.

3. The distillation equipment according to claim 1, characterized in that: The upper side shell side of the condenser (3) is provided with a circulating water return outlet C, and the lower side shell side is provided with a circulating water supply inlet D.

4. The distillation equipment according to claim 1, characterized in that: An organic mixed liquid feed inlet G is provided on the side shell side of the middle part of the pre-fractionation section of the distillation tower (1), a raw material feed pipe (1-1) is horizontally installed at the organic mixed liquid feed inlet G, a first distillation layer (1-3) is provided above the raw material feed pipe (1-1), a first liquid distributor (1-2) is horizontally installed below the raw material feed pipe (1-1), and a first stripping layer (1-4) is provided below the first liquid distributor (1-2).

5. The distillation equipment according to claim 1, characterized in that: A fourth liquid distributor (1-9) is horizontally installed at the upper part of the stripping section of the distillation tower (1), and a second stripping layer (1-6) is arranged below the fourth liquid distributor (1-9).

6. The distillation equipment according to claim 1, characterized in that: The distillation tower (1) is provided with an aniline outlet H on the side shell side of the middle discharge section of the distillation tower (1), a fifth liquid distributor (1-12) is horizontally installed below the aniline outlet H, and a third stripping layer (1-11) is installed below the fifth liquid distributor (1-12).

7. The distillation equipment according to claim 1, characterized in that: The distillation tower (1) is provided with a cyclohexylamine outlet F on the upper side shell side of the distillation section, a second liquid distributor (1-7) is horizontally installed below the cyclohexylamine outlet F, and a second distillation layer (1-5) is provided below the second liquid distributor (1-7).

8. The distillation equipment according to claim 1, characterized in that: The bottom shell side of the reboiler (5) is provided with a dicyclohexylamine outlet M; the side of the reboiler (5) is provided with an opening, and a horizontal heater (6) is provided at the opening; the top of the horizontal heater (6) on the outer side of the shell side of the reboiler (5) is provided with a steam inlet K, and the bottom is provided with a condensed water outlet L.

9. The distillation equipment according to claim 1, characterized in that: The top of the rectifying layer is at the same height as or lower than the top of the vertical partition plate (2), and the bottom of the stripping layer is at the same height as or higher than the bottom of the vertical partition plate (2); the ratio of the horizontal cross-sectional area of ​​the rectifying layer of the pre-fractionation section and the intermediate discharge section and / or the ratio of the horizontal cross-sectional area of ​​the stripping layer of the pre-fractionation section and the intermediate discharge section is 1:10 to 10:

1.

10. The distillation equipment according to claim 1, characterized in that: The rectification layer and / or stripping layer is a packing layer and has a height of 2 to 12 meters.

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