System and method for separating 1-hexene from ethylene trimerization product

Abstract

The invention discloses a system and method for separating 1-hexene in an ethylene trimerization product, and the system comprises a light component removal tower which is provided with a tower top outlet and a tower kettle outlet; the dividing wall tower is connected with the tower kettle outlet of the light component removal tower, the tower top of the dividing wall tower is provided with a light component outlet, the tower kettle is provided with a heavy component outlet, and the side line is provided with a solvent outlet; the purification tower is connected with the light component outlet of the dividing wall tower, a butene outlet is formed in the tower top of the purification tower, and a product outlet is formed in the tower kettle of the purification tower; wherein a heat exchange device is also arranged between the solvent outlet and the heavy component outlet of the dividing wall column, so that a solvent component flowing out of the solvent outlet exchanges heat with a heavy component flowing out of the heavy component outlet, the heavy component after heat exchange returns to the bottom of the dividing wall column, and part of the solvent component after heat exchange returns to the dividing wall column. The system is low in energy consumption.

Description

Technical Field

[0001] The invention belongs to the field of chemical distillation, and particularly relates to a system for separating 1-hexene from ethylene trimerization products, and a method for separating 1-hexene from ethylene trimerization products. Background Art

[0002] 1-Hexene is an organic compound mainly used in the manufacture of fragrances, dyes and synthetic resins.

[0003] The conventional process for separating 1-hexene from ethylene trimerization products is as follows: Figure 1 As shown, the ethylene trimerization product S01 is passed into the light-removing tower C2-T, and the obtained bottom liquid phase logistics S02 is directly passed into the decene recovery tower C10-T, and the solvent is completely vaporized by the decene recovery tower C10-T, and then the solvent discharged from the top gas phase of the decene recovery tower is recondensed and enters the solvent recovery tower C6-T, and is discharged and separated from the bottom of the solvent recovery tower C6-T. The gas phase product S04 is separated from the top of the solvent recovery tower C6-T and enters the purification tower C4-T, and the light component by-product is obtained at the top of the tower, and hexene is obtained in the bottom of the tower.

[0004] Therefore, the recovery and utilization of solvents in the traditional method requires at least two distillation towers, and the concentration of the intermediate component, namely the solvent, is prone to peak in the tower, that is, the intermediate component is prone to back-mixing, thereby reducing the separation efficiency and increasing energy consumption.

[0005] CN1609083A uses two series-connected distillation towers to refine 1-hexene. In terms of the process, a side-line discharge tower is used to complete the heavy and light removal tasks in one tower, which reduces production costs and device investment compared to the traditional three-tower series connection. However, the patent does not significantly reduce energy consumption, only about 7%.

[0006] CN113166001A is directed to the product obtained by oligoethylene in the presence of a Ziegler type catalyst. It is usually necessary to separate the linear alpha-olefin product (LAO) with multiple distillation columns until the desired carbon number, but multiple distillation columns can cause energy and capital intensive problems. It is proposed that the use of at least one dividing wall tower to separate the LAO product can reduce these burdens. However, the dividing wall tower of this method requires at least one reboiler and one condenser, and the heat at the top and bottom of the tower cannot be effectively utilized.

[0007] Therefore, there is still a need in the art to further study the method for separating 1-hexene from the ethylene trimerization product. Summary of the invention

[0008] The main purpose of the present invention is to provide a system and method for separating 1-hexene from ethylene trimerization products, so as to overcome the problems in the prior art of separating 1-hexene from ethylene trimerization products, such as the need for multiple distillation towers, low separation efficiency and high energy consumption.

[0009] In order to achieve the above object, the present invention provides a system for separating 1-hexene from ethylene trimerization products, comprising:

[0010] The lightness removal tower is provided with a tower top outlet and a tower bottom outlet;

[0011] A bulkhead tower is connected to the bottom outlet of the light component removal tower, the top of the bulkhead tower is provided with a light component outlet, the bottom of the tower is provided with a heavy component outlet, and the side line is provided with a solvent outlet and a solvent component inlet;

[0012] A purification tower connected to the light component outlet of the next-door tower, wherein the top of the purification tower is provided with a butene outlet, and the bottom of the tower is provided with a 1-hexene product outlet;

[0013] Wherein, a heat exchange device is also provided between the solvent outlet and the heavy component outlet of the bulkhead tower, so that the solvent component flowing out of the solvent outlet can exchange heat with the heavy component flowing out of the heavy component outlet, and the heavy component after heat exchange is returned to the bottom of the bulkhead tower, and part of the solvent component after heat exchange is returned to the bulkhead tower.

[0014] In the system for separating 1-hexene from ethylene trimerization products of the present invention, a pressurizing device is further provided between the solvent outlet of the bulkhead tower and the heat exchange device, so that the solvent component flowing out of the solvent outlet is pressurized and heated before entering the heat exchange device.

[0015] The system for separating 1-hexene from ethylene trimerization products of the present invention is characterized in that a side line of the light-removal tower is provided with an inlet, and the ethylene trimerization product enters the light-removal tower through the inlet.

[0016] The system for separating 1-hexene from ethylene trimerization products of the present invention comprises a partition plate disposed in the dividing wall tower to separate the dividing wall tower into a pre-separation tower and a main tower, and the solvent component after heat exchange is partially returned to the main tower.

[0017] The system for separating 1-hexene from ethylene trimerization products of the present invention comprises the following steps: the theoretical plate number of the pre-separation tower is 20-36, the theoretical plate number of the main tower is 30-66, and the reflux ratio of the dividing wall tower is 10-12.

[0018] The system for separating 1-hexene from ethylene trimerization products of the present invention, wherein the dividing wall tower is further provided with a feed inlet, which is located at the 5th to 14th tower plates of the pre-separation tower, the solvent outlet of the main tower is located at the 30th to 50th tower plates, the solvent component inlet of the main tower is located at the upper tower plate of the solvent outlet, the upper end of the partition is located at the 10th to 20th tower plates, and the lower end of the partition is located at the 40th to 55th tower plates.

[0019] The system for separating 1-hexene from ethylene trimerization products of the present invention, wherein the compression ratio of the pressurizing device is 1.75-3.

[0020] The system for separating 1-hexene from ethylene trimerization products of the present invention comprises the following steps: the number of theoretical plates of the purification tower is 10-20, and the reflux ratio is 10-15.

[0021] In order to achieve the above object, the present invention also provides a method for separating 1-hexene from the ethylene trimerization product, comprising the following steps:

[0022] Step 1, passing the ethylene trimerization product into a lightness removal tower to separate ethylene and a bottom liquid phase;

[0023] Step 2, the liquid phase from the bottom of the tower in step 1 is passed into the next-door tower, a light component flows out from the top of the tower, a heavy component flows out from the bottom of the tower, and a solvent component is obtained by the side line;

[0024] Step 3, the light component in step 2 is passed into a purification tower, a light component by-product is obtained at the top of the tower, and a 1-hexene product is obtained at the bottom of the tower;

[0025] The solvent component exchanges heat with the heavy component, and the heavy component after heat exchange is returned to the bottom of the dividing wall tower, and part of the solvent component after heat exchange is returned to the dividing wall tower.

[0026] The method for separating 1-hexene from ethylene trimerization products of the present invention comprises the following steps: the solvent component is pressurized and heated before heat exchange with the heavy component, and the solvent component after heat exchange is depressurized and cooled before partly returning to the bulkhead tower.

[0027] Beneficial effects of the present invention:

[0028] In the system for separating 1-hexene from ethylene trimerization products of the present invention, the side-line solvent component of the bulkhead tower is pressurized and heated to exchange heat with the heavy component in the bottom of the tower, part of the solvent component after the heat exchange is returned to the bulkhead tower, and part of it can be recycled for ethylene trimerization reaction, so that the heat source can be effectively utilized to improve the thermodynamic efficiency, while at the same time reducing the number of distillation towers and the floor space occupied by the equipment, and overall, the economic cost can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The figure is a process flow chart for separating 1-hexene in ethylene trimerization according to a comparative example of the present invention.

[0030] Figure 2 The present invention is a process flow chart for separating 1-hexene from ethylene trimerization according to one embodiment of the present invention.

[0031] Wherein, the reference numerals are:

[0032] C10-T Decene Recovery Tower

[0033] C6-T Solvent Recovery Tower

[0034] C2-T Lightness Removal Tower

[0035] S04 Gas phase products

[0036] DWC Next Door Tower

[0037] C4-T Purification Tower

[0038] C3 Heat Exchanger

[0039] C5 Pressurization device

[0040] C6 Pressure Reducing Valve

[0041] C7 Cooler

[0042] C8 Separator

[0043] a Pre-separation tower

[0044] b Main Tower

[0045] S01 Ethylene trimerization products

[0046] S02 Liquid Phase Logistics

[0047] S03 Light Component DETAILED DESCRIPTION

[0048] The technical scheme of the present invention is described in detail below. The following implementation modes are implemented on the premise of the technical scheme of the present invention, and a detailed implementation process is given. However, the protection scope of the present invention is not limited to the following implementation modes. The structures or experimental methods of specific conditions are not specified in the following implementation modes, and generally conventional conditions are followed.

[0049] The present invention provides a system for separating 1-hexene from ethylene trimerization products, such as Figure 2 As shown, it includes a light removal tower C2-T, a dividing wall tower DWC, and a purification tower C4-T. In one embodiment, the system of the present invention is applicable to a chromium ethylene trimerization catalytic system, and the product is mainly 1-hexene, and a small amount of by-products such as butene and decene.

[0050] The lightness removal tower C2-T is provided with a tower top outlet and a tower bottom outlet, the tower top outlet is arranged at the tower top of the lightness removal tower C2-T, and the tower bottom outlet is arranged at the tower bottom of the lightness removal tower C2-T. In addition, the side line of the lightness removal tower C2-T is also provided with an inlet, and the ethylene trimerization product S01 enters the lightness removal tower C2-T through the inlet. In one embodiment, after the ethylene trimerization product S01 is treated, the resulting liquid phase enters the lightness removal tower C2-T. The lightness removal tower C2-T is, for example, a distillation tower, and the ethylene trimerization product S01 is distilled in the lightness removal tower C2-T, and the separated ethylene is discharged via the tower top outlet, and the liquid phase logistics S02 is discharged from the tower bottom outlet. The present invention does not particularly limit the light removal tower C2-T. The theoretical number of plates is, for example, 8-20, the feed position is, for example, the 3rd to 6th plates, the reflux ratio is, for example, 0.3-0.4, the mass ratio of the distillate to the feed is, for example, 0.1-0.2, the tower top pressure is, for example, controlled at 1-2 MPa, and the tower bottom pressure is, for example, controlled at 1-2 MPa.

[0051] The next-door tower DWC is connected to the tower bottom outlet of the light-removing tower C2-T, the tower top of the next-door tower DWC is provided with a light component outlet, the tower bottom is provided with a heavy component outlet, and the side line is provided with a solvent outlet and a solvent component inlet. In one embodiment, a partition is provided in the next-door tower DWC, and the partition is vertically arranged to separate the next-door tower DWC into a pre-separation tower a and a main tower b, and the solvent outlet is provided in the main tower b.

[0052] In one embodiment, the number of theoretical plates of the pre-separation tower a is 20-36, the number of theoretical plates of the main tower b is 30-66, and the reflux ratio of the bulkhead tower is 10-12. The bulkhead tower DWC is provided with a feed port, which is located at the 5th to 14th plates of the pre-separation tower a, the position of the solvent outlet of the main tower b is the 30th to 50th plates, the upper end of the partition is located at the 10th to 20th plates, and the lower end of the partition is located at the 40th to 55th plates. The position of the solvent component inlet of the main tower of the present invention is the upper plate of the solvent outlet. If the position of the solvent outlet is the 30th plate, the position of the solvent component inlet should be the 31st plate.

[0053] The DWC distillation tower is a fully thermally coupled distillation technology. The partition cleverly divides the distillation tower into two parts, namely the pre-separation tower and the main tower. The two towers are connected by mutually flowing thermally coupled gas-liquid streams, which can reduce the back-mixing phenomenon of the intermediate components and achieve complete thermal coupling.

[0054] A heat exchange device C3 is also provided between the solvent outlet and the heavy component outlet of the bulkhead tower DWC of the present invention, that is, the heat exchange device C3 is connected to the heavy component outlet and the solvent outlet of the bulkhead tower DWC respectively, and the heavy component and the solvent component enter the heat exchange device C3 respectively for heat exchange, and the heavy component after heat exchange returns to the bottom of the bulkhead tower DWC, and the solvent component after heat exchange is partially extracted through the side line. In one embodiment, a pressurizing device C5 is also provided between the solvent outlet of the bulkhead tower DWC and the heat exchange device C3, such as a compressor, so that the solvent flowing out of the solvent outlet is pressurized and heated before entering the heat exchange device C3. Among them, the compression ratio is, for example, 1.75-3. In another embodiment, a pressure reducing valve C6, a cooler C7, and a separator C8 are also sequentially provided on the pipeline where the solvent after heat exchange returns to the bulkhead tower DWC through the solvent component inlet. Separator C8 separates the solvent component into solvent (such as cyclohexane) and other logistics, including part of 1-hexene, light components and heavy components, etc. The solvent is discharged from the system or recycled to the reaction device, and the other logistics are returned to the isolation tower.

[0055] The present invention adopts a dividing wall tower to separate the ethylene trimerization product, optimizes the parameters of the dividing wall tower, significantly reduces the energy consumption on the basis of meeting the purity of the product 1-hexene, utilizes the side line solvent to exchange heat with the heavy components in the tower bottom, effectively utilizes the heat source, improves the thermodynamic efficiency, and at the same time reduces the number of distillation towers and the floor space occupied by the equipment, and can achieve a significant reduction in economic costs as a whole.

[0056] In this way, the liquid phase logistics S02 of the light removal tower C2-T enters the next-door tower DWC through the feed port, specifically enters the pre-separation tower a of the next-door tower DWC for simple pre-separation, and then enters the main tower b for further component separation, and the obtained light component S03 flows out from the light component outlet at the top of the tower, the obtained heavy component flows out from the heavy component outlet at the bottom of the tower, and the solvent component flows out from the solvent outlet. Among them, the light component is a liquid phase, including by-products and butene, 1-hexene; the solvent includes at least one of cyclohexane, toluene, methylcyclohexane, and heptane; the heavy component is octene and C8 or higher olefin by-products, and C8 or higher olefin by-products include decene, which can be recycled in other processes.

[0057] The solvent component and part of the heavy component are passed into the heat exchange device C3 for heat exchange, for example, non-contact heat exchange. The heavy component after heat exchange is returned to the bottom of the bulkhead tower DWC, and part of the solvent component after heat exchange is returned to the bulkhead tower DWC, and part is recycled back to the ethylene trimerization reactor.

[0058] In one embodiment, the solvent component is pressurized and heated in the pressurizing device C5 and then passed into the heat exchange device C3 to exchange heat with the heavy component to provide heat for the bottom of the tower. The solvent component after heat exchange is decompressed by the pressure reducing valve C6, cooled by the cooler C7, and separated by the separator C8. Part of it returns to the next-door tower DWC, and part of it is recycled to the ethylene trimerization reactor; the heavy component after heat exchange returns to the bottom of the next-door tower DWC.

[0059] The purification tower C4-T is connected to the light component outlet of the next-door tower DWC, the top of the purification tower C4-T is provided with a butene outlet, and the bottom of the tower is provided with a product outlet. In one embodiment, the purification tower is, for example, a distillation tower, the number of theoretical plates is, for example, 10-20, the reflux ratio is, for example, 10-18, and the operating pressure is, for example, 0.05-0.2 MPa.

[0060] The light component S03 obtained from the light removal tower C2-T is passed into the purification tower C4-T to separate the light component by-product (mainly butene) and the product 1-hexene. The light component by-product can be flared.

[0061] The above system of the present invention is used for separating 1-hexene from ethylene trimerization products, and the separation method comprises the following steps:

[0062] Step 1, passing the ethylene trimerization product into a lightness removal tower to separate ethylene and a bottom liquid phase;

[0063] Step 2, the liquid phase from the bottom of the tower in step 1 is passed into the next-door tower, a light component flows out from the top of the tower, a heavy component flows out from the bottom of the tower, and a solvent component is obtained by the side line;

[0064] Step 3, the light component in step 2 is passed into a purification tower, a light component by-product is obtained at the top of the tower, and a 1-hexene product is obtained at the bottom of the tower;

[0065] The solvent component exchanges heat with the heavy component, and the heavy component after heat exchange is returned to the bottom of the dividing wall tower, and part of the solvent component after heat exchange is returned to the dividing wall tower.

[0066] In one embodiment, the solvent component is pressurized and heated before exchanging heat with the heavy component, and the solvent component after heat exchange is depressurized and cooled and then partially returned to the dividing wall tower.

[0067] In a specific embodiment, the method for separating 1-hexene from the ethylene trimerization product of the present invention is as follows: ethylene trimerization reacts in a reactor, and the obtained reaction liquid enters the light removal tower C2-T, and the bottom stream of the light removal tower C2-T first enters the next-door tower DWC, and is separated by the next-door tower DWC. The light components butene and 1-hexene are obtained at the top of the next-door tower DWC, and the top stream enters the purification tower C4-T to complete the purification of 1-hexene and product extraction; the side line of the next-door tower DWC The obtained stream is a solvent component, which is pressurized and heated by a compressor to exchange heat with the heavy component in the bottom of the tower, and the obtained solvent component after heat exchange is separated by decompression and cooling, and returned to the reactor to continue the ethylene trimerization reaction; the bottom of the next-door tower DWC obtains octene and C8 or higher olefin by-products, which can be recycled.

[0068] In the present invention, the C10-T decene recovery tower and the C6-T solvent recovery tower are combined into a bulkhead tower, and the side line extraction stream is used as an intermediary between the heat pump and the bulkhead tower to achieve an effective combination of intermediate heat exchange, heat pump technology and the bulkhead tower. The intermediate heat exchanger is used to replace the high-quality heat source with a relatively cheap heating medium, thereby reducing energy consumption, saving operating costs and reducing the economic cost of 1-hexene.

[0069] The technical solution of the present invention will be described in detail by way of specific examples. The present invention does not limit the specific parameters of the ethylene trimerization process, and the ethylene trimerization product used in the following examples is a product obtained by a chromium ethylene trimerization catalyst system.

[0070] Example 1

[0071] The 1-hexene is separated by a dividing wall tower in ethylene trimerization. The specific method is as described above. The parameters of each device used are as follows:

[0072] Parameters of the light removal tower C2-T: the theoretical number of plates is 10, the feed position is the 3rd plate, the reflux ratio is 0.378, the ratio of the overhead distillate to the feed amount is 0.110, the top pressure is 1.5MPa, and the bottom pressure is 1.5MPa.

[0073] DWC parameters of the dividing wall tower: the operating pressure of the partition tower is 0.1MPa, the number of plates of the pre-separation tower is 24, the number of plates of the main tower is 44, the reflux ratio is 10.90, the feed position of the pre-separation tower is the 7th plate, the side line solvent component extraction position is the 35th plate, the upper end position of the partition is the 20th plate, the lower end position of the partition is the 37th plate, the liquid phase distribution ratio (the distribution ratio of the liquid phase extraction flow) is 0.72, the gas phase distribution ratio (the distribution ratio of the gas phase extraction flow) is 0.53, and the compression ratio is 1.75.

[0074] The operating pressure of purification tower C4-T is 0.1MPa, the theoretical plate number is 12, and the reflux ratio is 16.18.

[0075] The purity of the 1-hexene product obtained by using the above device is 99.5%, and the energy consumption is reduced by 29.5% compared with the traditional process of the comparative example, saving 16.21% of the annual economic cost.

[0076] The feed and product results of Example 1 are shown in Table 1.

[0077] Table 1 Example 1 Feed and product results

[0078]

[0079] The mass ratio refers to the percentage of the substance in the entire logistics.

[0080] Example 2

[0081] The 1-hexene is separated by a dividing wall tower in ethylene trimerization. The specific method is as described above. The parameters of each device used are as follows:

[0082] Parameters of the light removal tower C2-T: the theoretical number of plates is 10, the feed position is the 3rd plate, the reflux ratio is 0.378, the distillate to feed ratio is 0.110, the top pressure is 1.5 MPa, and the bottom pressure is 1.5 MPa.

[0083] Parameters of the dividing wall tower DWC: the operating pressure of the dividing wall tower is 0.1MPa, the number of plates of the pre-separation tower is 32, the number of plates of the main tower is 56, the reflux ratio is 10.85, the feed position of the pre-separation tower is the 12th plate, the side line solvent component extraction position is the 43rd plate, the upper end position of the dividing wall is the 19th plate, the lower end position of the dividing wall is the 47th plate, the liquid phase distribution ratio is 0.71, the gas phase distribution ratio is 0.53, and the compression ratio is 1.80.

[0084] The operating pressure of purification tower C4-T is 0.1MPa, the theoretical plate number is 18, and the reflux ratio is 15.86.

[0085] The purity of the 1-hexene product obtained by using the above device is 99.5%, and the energy consumption is reduced by 22.94% compared with the traditional process of the comparative example, saving 14.90% of the annual economic cost.

[0086] The feed and product results of Example 2 are shown in Table 2.

[0087] Table 2 Example 2 Feed and Product Results

[0088]

[0089] The mass ratio refers to the percentage of the substance in the entire logistics.

[0090] Example 3

[0091] The 1-hexene is separated by a dividing wall tower in ethylene trimerization. The specific method is as described above. The parameters of each device used are as follows:

[0092] Parameters of the light removal tower C2-T: theoretical plate number is 10, feed position is 3, reflux ratio is 0.378, distillate to feed ratio is 0.110, tower top pressure is 1.5MPa, and tower bottom pressure is 1.5MPa.

[0093] Parameters of the dividing wall tower DWC: the operating pressure of the dividing wall tower is 0.1MPa, the number of plates of the pre-separation tower is 36, the number of plates of the main tower is 66, the reflux ratio is 10.5, the feed position of the pre-separation tower is the 14th plate, the side line solvent component extraction position is the 51st plate, the upper end position of the dividing wall is the 19th plate, the lower end position of the dividing wall is the 57th plate, the liquid phase distribution ratio is 0.72, the gas phase distribution ratio is 0.53, and the compression ratio is 1.75.

[0094] The operating pressure of purification tower C4-T is 0.1MPa, the theoretical plate number is 14, and the reflux ratio is 17.62.

[0095] The purity of the 1-hexene product obtained by using the above device is 99.5%, which reduces energy consumption by 22.80% compared with the traditional process and saves 13.60% of annual economic costs.

[0096] The feed and product results of Example 3 are shown in Table 3.

[0097] Table 3 Example 3 Feed and product results

[0098]

[0099]

[0100] The mass ratio refers to the percentage of the substance in the entire logistics.

[0101] Comparative Example

[0102] The process of this comparative example is as follows Figure 1 As shown, the process parameters of each device are:

[0103] Parameters of the light removal tower C2-T: the theoretical number of plates is 10, the feed position is the 3rd plate, the reflux ratio is 0.378, the distillate to feed ratio is 0.110, the top pressure is 1.5 MPa, and the bottom pressure is 1.5 MPa.

[0104] The pressure of the decene recovery tower C10-T is 0.1 MPa, the number of plates is 31, the feed position is the 23rd plate, and the reflux ratio is 0.592.

[0105] The pressure of the solvent purification tower C6-T is 0.1 MPa, the number of plates is 54, the feed position is the 23rd plate, and the reflux ratio is 6.91.

[0106] The operating pressure of purification tower C4-T is 0.1MPa, the theoretical plate number is 12, and the reflux ratio is 16.18.

[0107] The purity of the 1-hexene product obtained by using the above device is 99.5%.

[0108] The feed and product results of the comparative example are shown in Table 4.

[0109] Table 4 Comparative Example Feed and Product Results

[0110]

[0111] The mass ratio refers to the percentage of the substance in the entire logistics.

[0112] As shown in Tables 1-4, compared with the conventional process of the comparative example, the purity of 1-hexene in the technical solution of the present invention is basically 99.5%. Under the condition that the purity of 1-hexene separated is 99.5%, the energy consumption of the dividing wall tower technical solution of the present invention is reduced by 22.80% compared with the conventional process, and the annual economic cost is saved by 13.60%.

[0113] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and deformations based on the present invention, but these corresponding changes and deformations should all fall within the scope of protection of the claims of the present invention.

Claims

1. A system for separating 1-hexene from ethylene trimerization products, characterized in that: include: The lightness removal tower is provided with a tower top outlet and a tower bottom outlet; A bulkhead tower is connected to the bottom outlet of the light component removal tower, the top of the bulkhead tower is provided with a light component outlet, the bottom of the tower is provided with a heavy component outlet, and the side line is provided with a solvent outlet and a solvent component inlet; A purification tower connected to the light component outlet of the next-door tower, wherein the top of the purification tower is provided with a butene outlet, and the bottom of the tower is provided with a 1-hexene outlet; Wherein, a heat exchange device is also provided between the solvent outlet and the heavy component outlet of the bulkhead tower, so that the solvent component flowing out of the solvent outlet can exchange heat with the heavy component flowing out of the heavy component outlet, and the heavy component after heat exchange is returned to the bottom of the bulkhead tower, and part of the solvent component after heat exchange is returned to the bulkhead tower.

2. The system for separating 1-hexene from ethylene trimerization products according to claim 1, characterized in that: A pressurizing device is also provided between the solvent outlet of the dividing wall tower and the heat exchange device, so that the solvent component flowing out of the solvent outlet is pressurized and heated before entering the heat exchange device.

3. The system for separating 1-hexene from ethylene trimerization products according to claim 1, characterized in that: The side line of the light removal tower is provided with an inlet, and the ethylene trimerization product enters the light removal tower through the inlet.

4. The system for separating 1-hexene from ethylene trimerization products according to claim 1, characterized in that: A partition is arranged in the dividing wall tower to divide the dividing wall tower into a pre-separation tower and a main tower, and part of the solvent component after heat exchange is returned to the main tower.

5. The system for separating 1-hexene from ethylene trimerization products according to claim 4, characterized in that: The number of theoretical plates of the pre-separation tower is 20-36, the number of theoretical plates of the main tower is 30-66, and the reflux ratio of the dividing wall tower is 10-12.

6. The system for separating 1-hexene from ethylene trimerization products according to claim 4, characterized in that: The next-wall tower is also provided with a feed inlet, which is located at the 5th to 14th tower plates of the pre-separation tower, the solvent outlet of the main tower is located at the 30th to 50th tower plates, the solvent component inlet of the main tower is located at the upper tower plate of the solvent outlet, the upper end of the partition is located at the 10th to 20th tower plates, and the lower end of the partition is located at the 40th to 55th tower plates.

7. The system for separating 1-hexene from ethylene trimerization products according to claim 2, characterized in that: The compression ratio of the pressurizing device is 1.75-3.

8. The system for separating 1-hexene from ethylene trimerization products according to claim 1, characterized in that: The purification tower has a theoretical plate number of 10-20 and a reflux ratio of 10-15.

9. A method for separating 1-hexene from ethylene trimerization products, characterized in that: The steps include: Step 1, passing the ethylene trimerization product into a lightness removal tower to separate ethylene and a bottom liquid phase; Step 2, the liquid phase from the bottom of the tower in step 1 is passed into the next-door tower, a light component flows out from the top of the tower, a heavy component flows out from the bottom of the tower, and a solvent component is obtained by the side line; Step 3, the light component in step 2 is passed into a purification tower, a light component by-product is obtained at the top of the tower, and a 1-hexene product is obtained at the bottom of the tower; The solvent component exchanges heat with the heavy component, and the heavy component after heat exchange is returned to the bottom of the dividing wall tower, and part of the solvent component after heat exchange is returned to the dividing wall tower.

10. The method for separating 1-hexene from ethylene trimerization products according to claim 9, characterized in that: The solvent component is pressurized and heated, and then heat-exchanged with the heavy component. After the heat-exchanged solvent component is depressurized and cooled, a portion of it is returned to the dividing wall tower.

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