阅读说明：本技术 一种乙烯齐聚合成1-辛烯和1-己烯的生产系统及生产方法 (Production system and production method for synthesizing 1-octene and 1-hexene through ethylene oligomerization ) 是由 欧阳瑞 任鹏 常伟先 贺霞 冯建华 于 2019-10-31 设计创作，主要内容包括：本发明提供了一种乙烯齐聚合成1-辛烯和1-己烯的生产系统及生产方法,所述的生产系统包括依次连接的原料压缩单元、反应聚合单元、终止反应单元和产物分离单元；所述的产物分离单元包括依次连接的1-己烯分离装置和1-辛烯分离装置。本发明提供的生产系统实现了在同一流程下的不同工段生产1-辛烯和1-己烯两种不同产品,不仅实现了反应产物的高效分离,大大节省投资、降低能耗,而且可以通过控制催化剂的加入量及配比,来调节产物的选择性。(The invention provides a production system and a production method for synthesizing 1-octene and 1-hexene by ethylene oligomerization, wherein the production system comprises a raw material compression unit, a reaction polymerization unit, a reaction termination unit and a product separation unit which are sequentially connected; the product separation unit comprises a 1-hexene separation device and a 1-octene separation device which are sequentially connected. The production system provided by the invention realizes the production of two different products, namely 1-octene and 1-hexene, in different working sections under the same flow, not only realizes the high-efficiency separation of reaction products, greatly saves the investment and reduces the energy consumption, but also can adjust the selectivity of the products by controlling the addition amount and the proportion of the catalyst.)

1. A production system for synthesizing 1-octene and 1-hexene by ethylene oligomerization is characterized by comprising a raw material compression unit, a reaction polymerization unit, a reaction termination unit and a product separation unit which are sequentially connected;

the product separation unit comprises a 1-hexene separation device and a 1-octene separation device which are sequentially connected.

2. The production system according to claim 1, wherein the feed compression unit comprises a compression device for compressing an ethylene feed.

3. The production system according to claim 1 or 2, wherein the reactive polymerization unit comprises a reaction device;

preferably, the upper part, the middle part and the lower part of the reaction device are provided with a catalyst injection port and a cocatalyst injection port;

preferably, the reaction device is a stirred tank reactor;

preferably, a solvent feeding pipeline is externally connected to a connecting pipeline between the compression device and the reaction device, and the ethylene raw material is compressed by the compression device and then mixed with the solvent introduced into the solvent feeding pipeline to enter the reaction device.

4. The production system of any one of claims 1 to 3, wherein an inner coil is arranged in the reaction device, the inner coil is of a spiral structure, and a cooling medium is introduced into the inner coil to cool the interior of the reaction device;

preferably, a jacket is arranged on the outer side of the shell of the reaction device, and a cooling medium is introduced into the jacket to cool the interior of the reaction device;

preferably, the reaction polymerization unit further comprises a circulating heat removal device, the circulating heat removal device comprises a circulating pipeline, one end of the circulating pipeline is connected to a bottom circulating outlet of the reaction device, the other end of the circulating pipeline is connected to a top circulating inlet of the reaction device, and a circulating pump and a cooling device are sequentially arranged on the circulating pipeline along the flow direction of the reaction liquid.

5. The production system according to any one of claims 1 to 4, wherein the termination reaction unit comprises a termination reaction device, and the termination reaction device is filled with a terminator to terminate the ethylene oligomerization synthesis reaction;

preferably, the termination reaction device is a stirred tank reactor;

preferably, the length-diameter ratio of the terminating reaction device is 3.0-6.0;

preferably, the upper part and the middle part of the reaction terminating device are both provided with a terminator inlet;

preferably, the upper overflow port of the reaction device is connected with the liquid inlet of the termination reaction device through an overflow pipe, and the reaction product flows through the overflow pipe from the overflow port and enters the termination reaction device;

preferably, the overflow pipe is arranged obliquely downwards along the flow direction of the reaction products;

preferably, the included angle between the overflow pipe and the horizontal direction is 20-45 degrees.

6. The production system according to any one of claims 1 to 5, wherein an ethylene removal unit is further arranged between the reaction terminating unit and the product separation unit, and the ethylene removal unit is used for removing unreacted ethylene raw materials in the reaction products;

preferably, the ethylene removal unit comprises a flash distillation device and a deethylenizer which are connected in sequence;

preferably, a liquid outlet at the bottom of the reaction terminating device is connected with a liquid inlet of the flash evaporation device, a collecting port at the top of the flash evaporation device is externally connected with an ethylene gas collecting device, and a liquid outlet at the bottom of the flash evaporation device is connected with a liquid inlet of the ethylene removing device;

preferably, an outlet at the top of the ethylene removal device is externally connected with an ethylene gas collecting device, and a liquid outlet at the bottom of the ethylene removal device is connected with a liquid inlet of the 1-hexene separation device.

7. The production system according to any one of claims 1 to 6, wherein the product separation unit further comprises a solvent separation device and a by-product separation device, and the solvent separation device is disposed between the 1-hexene separation device and the 1-octene separation device along the product separation route;

preferably, a top outlet of the 1-hexene separating device is connected with a 1-hexene collecting device, and 1-hexene is collected from the top of the 1-hexene separating device and then enters the 1-hexene collecting device; a liquid outlet at the bottom of the 1-hexene separation device is connected with a liquid inlet of the solvent separation device;

preferably, the top extraction port of the solvent separation device is divided into two paths, one path is connected to a solvent feeding pipeline, and the other path is connected to the liquid inlet of the byproduct separation device; a liquid outlet at the bottom of the solvent separation device is connected with a liquid inlet of the 1-octene separation device;

preferably, a liquid outlet at the bottom of the byproduct separation device is connected with a solvent feeding pipeline, the separated solvent is extracted from the bottom of the tower and flows back to the solvent feeding pipeline, the byproduct separated by the byproduct separation device is discharged from the top of the tower, and the byproduct comprises methylcyclopentane;

preferably, the top production outlet of the 1-octene separation device is connected with a 1-octene collection device, and 1-octene enters the 1-octene collection device after being produced from the top of the 1-octene separation device.

8. A production method for synthesizing 1-octene and 1-hexene by ethylene oligomerization is characterized by comprising the following steps:

the raw materials are mixed with a solvent after being compressed by a raw material compression unit and then are introduced into a reaction polymerization unit for oligomerization, reaction products enter a product separation unit after reaction is interrupted by a reaction termination unit, 1-hexene is obtained by separation through a 1-hexene separation device, and 1-octene is obtained by separation through a 1-octene separation device.

9. The production method according to claim 8, characterized in that it comprises in particular the steps of:

introducing a solvent into a solvent feeding pipeline, compressing the raw materials by a raw material compression unit, mixing the raw materials with the solvent, and introducing the mixture into a reaction device; simultaneously injecting a catalyst and a cocatalyst into the upper part, the middle part and the lower part of the reaction device, carrying out oligomerization reaction on the raw materials and the solvent in the reaction device, circularly injecting a cooling medium into the inner coil and/or the jacket, and cooling reaction liquid in the reaction device by the circular heat removal device to remove reaction heat;

(II) overflowing the reaction product into a reaction terminating device through an overflow pipe, injecting a terminating agent into the upper part and the middle part of the reaction terminating device simultaneously, and interrupting the ethylene oligomerization reaction; the reaction product discharged from the reaction terminating device sequentially flows through a flash evaporation device and a deethylenizer to remove unreacted ethylene in the reaction product, and the reaction product discharged from the deethylenizer enters a product separation unit;

(III) feeding the reaction product into a 1-hexene separation device, controlling the temperature and the pressure in the 1-hexene separation device, collecting the separated 1-hexene from the top of the 1-hexene separation device, discharging the material from the bottom of the 1-hexene separation device into a solvent separation device, and controlling the temperature and the pressure in the solvent separation device to separate feed liquid;

(IV) one part of the tower top discharge of the solvent separation device is recycled to the solvent feeding pipeline to participate in ethylene oligomerization reaction, the other part of the tower top discharge enters the byproduct separation device, the temperature and the pressure in the byproduct separation device are controlled to separate the feeding liquid containing the solvent and the byproducts, the byproducts are extracted and collected from the tower bottom of the byproduct separation device, and the solvent is discharged from the tower bottom of the byproduct separation device and recycled to the solvent feeding pipeline to participate in ethylene oligomerization reaction;

(V) feeding the discharged material at the bottom of the solvent separation device into a 1-octene separation device, controlling the temperature and pressure in the 1-octene separation device, and collecting the separated 1-octene from the top of the 1-octene separation device.

10. The production method according to claim 9, wherein the solvent in step (i) is one or a combination of at least two of cyclohexane, methylcyclopentane or methylcyclohexane;

preferably, the raw material is ethylene;

preferably, the raw materials are compressed to 3.0 MPaG-6.0 MPaG and then mixed with the solvent;

preferably, the catalyst comprises a Cr-based selective catalyst;

preferably, the cocatalyst comprises methylaluminoxane;

preferably, the mass flow ratio of the solvent to the raw material is 2-6;

preferably, the reaction temperature in the reaction device is 40-120 ℃;

preferably, the reaction pressure in the reaction device is 3.0 MPaG-6.0 MPaG;

preferably, the reaction time of the raw materials and the solvent in the reaction device is 0.8-1.5 h;

preferably, the oligomerization reaction is carried out under stirring conditions;

preferably, the terminating agent in step (II) comprises one or a combination of at least two of isopropanol, isobutanol or isooctanol;

preferably, the operating temperature of the flash evaporation device is 40-120 ℃;

preferably, the operating pressure of the flash device is 1.6 MPaG-2.5 MPaG;

preferably, the tower top temperature of the ethylene removal device is 90-97 ℃;

preferably, the operation pressure of the top of the deethylenizer is 1.2 MPaG-1.4 MPaG;

preferably, the bottom temperature of the ethylene removal device is 200-210 ℃;

preferably, the operation pressure of the bottom of the ethylene removal device is 1.25 MPaG-1.45 MPaG;

preferably, the tower top temperature of the 1-hexene separation device in the step (III) is 100-105 ℃;

preferably, the operation pressure of the top of the 1-hexene separation device is 0.10 MPaG-0.15 MPaG;

preferably, the bottom temperature of the 1-hexene separation device is 125-135 ℃;

preferably, the operation pressure of the bottom of the 1-hexene separation device is 0.15 MPaG-0.20 MPaG;

preferably, the tower top temperature of the solvent separation device is 105-115 ℃;

preferably, the operation pressure of the top of the solvent separation device is 0.08MPaG to 0.14 MPaG;

preferably, the bottom temperature of the solvent separation device is 192-202 ℃;

preferably, the operation pressure of the bottom of the solvent separation device is 0.11 MPaG-0.17 MPaG;

preferably, the by-product in step (iv) is methylcyclopentane;

preferably, the tower top temperature of the byproduct separation device is 70-78 ℃;

preferably, the overhead operating pressure of the byproduct separation device is 0.05 MPaG-0.10 MPaG;

preferably, the bottom temperature of the byproduct separation device is 80-90 ℃;

preferably, the operation pressure of the bottom of the byproduct separation device is 0.10 MPaG-0.15 MPaG;

preferably, the overhead temperature of the 1-octene separation unit described in step (v) is from 80 ℃ to 85 ℃;

preferably, the overhead operating pressure of the 1-octene separation device is-0.075 MPaG to 0.070 MPaG;

preferably, the bottom temperature of the 1-octene separation device is 145-150 ℃;

preferably, the operation pressure of the bottom of the 1-octene separating device is-0.065 MPaG to 0.060 MPaG.

Technical Field

The invention belongs to the technical field of preparation of 1-octene and 1-hexene, relates to a production system and a production method of 1-octene and 1-hexene, and particularly relates to a production system and a production method for synthesizing 1-octene and 1-hexene by ethylene oligomerization.

Background

With the rapid development of polyethylene industry, 1-octene and 1-hexene are increasingly demanded as important comonomers and important chemical raw materials for synthesizing high-performance polyethylene.

The 1-octene is an important organic chemical raw material and chemical intermediate, is mainly used as a comonomer of Linear Low Density Polyethylene (LLDPE), can also be used for producing plasticizers, detergents, synthetic oil, surfactants and the like, is particularly suitable for producing PE-RT (heat-resistant polyethylene) and POE (polyolefin elastomer), and a copolymerization product has the advantages of high toughness, high tear resistance, high temperature and pressure resistance, convenience and reliability in connection.

1-hexene is a main comonomer for synthesizing Linear Low Density Polyethylene (LLDPE) and High Density Polyethylene (HDPE) with high added value and high performance, and compared with a butene copolymerization product, the 1-hexene copolymerization product has the advantages of high tensile strength, strong impact resistance and tear resistance and the like, and is widely applied to industries of agriculture, packaging, building materials and the like.

At present, the domestic demand of 1-octene and 1-hexene is about 85 ten thousand tons/year, and the product is basically in a complete import state. With the increasing demand for quality, the demand for 1-octene and 1-hexene in particular will increase. Foreign related process technologies are in monopoly and secretly kept from the domestic state, which is in the experimental research stage. The development of a process technology for synthesizing 1-octene and 1-hexene is urgent and very important.

Currently, the main processes for producing higher alpha olefins such as 1-hexene, 1-octene, etc. are ethylene oligomerization processes, such as:

CN106588551A discloses a method for separating 1-hexene from an ethylene oligomerization product, which comprises the following steps: introducing the ethylene oligomerization product I into a flash tank for flash evaporation, and feeding a liquid-phase discharge II flowing out of the flash tank into a light component removal tower; introducing a liquid phase discharge material III flowing out of the light component removal tower into a carbon six separation tower to obtain a 1-hexene product; carrying out gas-liquid separation on a gas-phase discharge IV flowing out of the flash tank through condensation, and introducing the obtained gas phase V into a carbon four-separation tower; gas-liquid separation is carried out on a gas-phase discharge VI flowing out of the light component removal tower through condensation, and an obtained gas phase VII is introduced into a carbon four-separation tower; rectifying in a carbon four separation tower to obtain 1-hexene isomer at the bottom of the tower.

CN102464545A discloses a method for preparing 1 octene by ethylene oligomerization, which comprises the following steps: (1) after premixing part of raw material ethylene gas and a solvent in a premixer, mixing the premixed raw material ethylene gas with a catalytic system a + b component, a component c and a component d, and then entering a reactor through a gas distributor, wherein the other part of raw material ethylene gas directly enters the reactor; (2) the reaction liquid of the reactor flows out to the overflow groove from the middle upper part, the catalyst terminator is added into the overflow groove, and then the reaction product enters the separation device.

CN106588551A discloses a method for preparing 1-hexene in the presence of an ethylene oligomerization catalyst system, which specifically comprises the following steps: (1) after premixing a part of raw material ethylene and a solvent in a premixer, respectively mixing the raw material ethylene and the solvent with a chromide (a) of a catalyst for preparing 1-hexene by ethylene oligomerization, a pyrrole derivative (b), an alkyl aluminum (c) and an improver (d), and then feeding the mixture into a reactor with a stirrer through a gas distributor; (2) the other part of the ethylene gas directly enters the reactor; (3) the reaction liquid of the reactor flows out to the overflow groove from the middle part, the catalyst terminator is added in the overflow groove, and then the reaction product enters the separation device.

However, in summary, the currently known ethylene oligomerization reaction system can only produce one product, and cannot realize the co-production of 1-octene and 1-hexene, so at least two sets of equipment are required for separately producing 1-octene and 1-hexene, and in order to simplify the production flow and reduce the equipment investment cost, it is necessary to design a production system for realizing the co-production of 1-octene and 1-hexene.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a production system and a production method for synthesizing 1-octene and 1-hexene by ethylene oligomerization, the invention synthesizes 1-octene and 1-hexene by ethylene oligomerization, and the complete flow of synthesizing 1-octene and 1-hexene is realized by a raw material compression unit, a reaction polymerization unit, a termination reaction unit and a product separation unit. The complete equipment realizes the production of two different products of 1-octene and 1-hexene in different working sections under the same flow, not only realizes the high-efficiency separation of reaction products, greatly saves the investment and reduces the energy consumption, but also can adjust the selectivity of the products (1-octene and 1-hexene) by controlling the adding amount and the proportion of the catalyst.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides a production system for synthesizing 1-octene and 1-hexene by ethylene oligomerization, which comprises a raw material compression unit, a reaction polymerization unit, a reaction termination unit and a product separation unit which are sequentially connected.

The product separation unit comprises a 1-hexene separation device and a 1-octene separation device which are sequentially connected.

The invention synthesizes 1-octene and 1-hexene through ethylene oligomerization, and realizes a complete flow of synthesizing 1-octene and 1-hexene through a raw material compression unit, a reaction polymerization unit, a reaction termination unit and a product separation unit. The complete equipment realizes the production of two different products of 1-octene and 1-hexene in different working sections under the same flow, not only realizes the high-efficiency separation of reaction products, greatly saves the investment and reduces the energy consumption, but also can adjust the selectivity of the products (1-octene and 1-hexene) by controlling the adding amount and the proportion of the catalyst.

It should be noted that, in the present invention, the 1-hexene separation device and the 1-octene separation device are olefin separation devices known in the art, and mainly include a rectification column device, a vacuum pumping system and other accessories, and the structures and functions thereof are well known to those skilled in the art and will not be described herein again.

As a preferred technical solution of the present invention, the raw material compression unit comprises a compression device, and the compression device is used for compressing the ethylene raw material.

In the invention, a raw material liquid separation device is also arranged in the front-stage process of the compression device and is used for carrying out gas-liquid separation on the raw materials, the separated gas ethylene enters the compression device, and the liquid in the raw materials needs to be separated in advance before entering the compression device due to the small amount of liquid in the raw materials, which is the conventional operation of the raw materials entering the compression device in the field.

In a preferred embodiment of the present invention, the reactive polymerization unit comprises a reaction apparatus.

Preferably, the upper part, the middle part and the lower part of the reaction device are provided with a catalyst injection port and a cocatalyst injection port.

Preferably, the reaction device is a stirred tank reactor.

Preferably, a solvent feeding pipeline is externally connected to a connecting pipeline between the compression device and the reaction device, and the ethylene raw material is compressed by the compression device and then mixed with the solvent introduced into the solvent feeding pipeline to enter the reaction device.

In the invention, the reaction polymerization unit also comprises a catalyst configuration and injection device, wherein the catalyst configuration and injection device is used for configuring the catalyst and then injecting the catalyst into the reaction device through a catalyst injection pump.

As a preferable technical scheme, an inner coil is arranged in the reaction device, the inner coil is of a spiral structure, and a cooling medium is introduced into the inner coil to cool the interior of the reaction device.

Preferably, the jacket is arranged on the outer side of the shell of the reaction device, and a cooling medium is introduced into the jacket to cool the interior of the reaction device.

Preferably, the reaction polymerization unit further comprises a circulating heat removal device, the circulating heat removal device comprises a circulating pipeline, one end of the circulating pipeline is connected to a bottom circulating outlet of the reaction device, the other end of the circulating pipeline is connected to a top circulating inlet of the reaction device, and a circulating pump and a cooling device are sequentially arranged on the circulating pipeline along the flow direction of the reaction liquid.

In fact, the present invention provides three different heat removal schemes, one of which is to cool the interior of the reaction device by introducing a cooling medium into an inner coil pipe arranged inside the reaction device; secondly, cooling the interior of the reaction device by introducing a cooling medium into a jacket coated on the outer side of the reaction device; and thirdly, controlling the reaction temperature by circularly cooling the high-temperature reaction product in the reaction device through a circulating pipeline through a circulating heat removal device. Those skilled in the art need a heat removal scheme in which one or more of them are freely selected depending on the reaction temperature in the reaction apparatus.

The heat of polymerization reaction in the reaction device is timely removed, so that the equilibrium and stability of the reaction temperature are ensured, and the wall sticking phenomenon of polymerization byproducts in subsequent equipment and pipelines is favorably reduced.

In a preferred embodiment of the present invention, the termination reaction unit includes a termination reaction device, and the termination reaction device is filled with a terminator to terminate the progress of the ethylene oligomerization synthesis reaction.

Preferably, the termination reaction device is a stirred tank reactor.

Preferably, the length-to-diameter ratio of the terminating reactor is 3.0 to 6.0, and may be, for example, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9 or 6.0, but is not limited to the recited values, and other values not recited in the range of values are also applicable.

Preferably, the upper part and the middle part of the reaction terminating device are both provided with a terminator inlet.

Preferably, the upper overflow port of the reaction device is connected with the liquid inlet of the termination reaction device through an overflow pipe, and the reaction product flows through the overflow pipe from the overflow port and enters the termination reaction device.

Preferably, the overflow pipe is arranged obliquely downwards along the flow direction of the reaction product.

Preferably, the angle between the overflow tube and the horizontal is 20 ° to 45 °, for example, 20 °, 21 °, 22 °, 23 °, 24 °, 25 °, 26 °, 27 °, 28 °, 29 °, 30 °, 31 °, 32 °, 33 °, 34 °, 35 °, 36 °, 37 °, 38 °, 39 °, 40 °, 41 °, 42 °, 43 °, 44 °, or 45 °, but is not limited to the listed values, and other values not listed in the numerical range are also applicable.

It should be noted that, in the present invention, those skilled in the art can set the length of the overflow pipe as short as possible according to the size of the equipment layout site and the scale of the system.

As a preferable technical scheme of the invention, an ethylene removal unit is also arranged between the reaction termination unit and the product separation unit and is used for removing unreacted ethylene raw materials in reaction products.

Preferably, the ethylene removal unit comprises a flash distillation device and a deethylenizer which are connected in sequence.

Preferably, a liquid outlet at the bottom of the reaction terminating device is connected with a liquid inlet of the flash evaporation device, an ethylene gas collecting device is connected with an outlet at the top of the flash evaporation device, and a liquid outlet at the bottom of the flash evaporation device is connected with a liquid inlet of the ethylene removing device.

Preferably, an outlet at the top of the ethylene removal device is externally connected with an ethylene gas collecting device, and a liquid outlet at the bottom of the ethylene removal device is connected with a liquid inlet of the 1-hexene separation device.

It should be noted that the flash unit and the deethylenizer defined in the present invention are conventional apparatuses in the art, and the structure and function thereof are well known to those skilled in the art, and the flash unit is a flash drum known in the art, and the deethylenizer is a deethylenizer known in the art. The ethylene gas collection device and the various collection devices hereinafter are all types of storage tanks known in the art, the structure and function of which are well known to those skilled in the art and will not be described in detail herein.

As a preferred embodiment of the present invention, the product separation unit further includes a solvent separation device and a byproduct separation device, and the solvent separation device is disposed between the 1-hexene separation device and the 1-octene separation device along the product separation route.

Preferably, a top outlet of the 1-hexene separating device is connected with a 1-hexene collecting device, and 1-hexene is collected from the top of the 1-hexene separating device and then enters the 1-hexene collecting device; a liquid outlet at the bottom of the 1-hexene separation device is connected with a liquid inlet of the solvent separation device.

Preferably, the top extraction port of the solvent separation device is divided into two paths, one path is connected to a solvent feeding pipeline, and the other path is connected to the liquid inlet of the byproduct separation device; and a liquid outlet at the bottom of the solvent separation device is connected with a liquid inlet of the 1-octene separation device.

Preferably, a liquid outlet at the bottom of the byproduct separation device is connected with a solvent feeding pipeline, the separated solvent is extracted from the bottom of the tower and flows back to the solvent feeding pipeline, the byproduct separated by the byproduct separation device is discharged from the top of the tower, and the byproduct comprises methylcyclopentane.

Preferably, the top production outlet of the 1-octene separation device is connected with a 1-octene collection device, and 1-octene enters the 1-octene collection device after being produced from the top of the 1-octene separation device.

It should be noted that, in the present invention, the solvent separation device and the byproduct separation device are distillation column separation devices known in the art, and mainly include column equipment and other complete equipment, whose structures and functions are well known to those skilled in the art, and will not be described herein again.

In a second aspect, the invention provides a production method for synthesizing 1-octene and 1-hexene by ethylene oligomerization, which comprises the following steps:

the raw materials are mixed with a solvent after being compressed by a raw material compression unit and then are introduced into a reaction polymerization unit for oligomerization, reaction products enter a product separation unit after reaction is interrupted by a reaction termination unit, 1-hexene is obtained by separation through a 1-hexene separation device, and 1-octene is obtained by separation through a 1-octene separation device.

As a preferable technical scheme of the invention, the production method specifically comprises the following steps:

introducing a solvent into a solvent feeding pipeline, compressing the raw materials by a raw material compression unit, mixing the raw materials with the solvent, and introducing the mixture into a reaction device; simultaneously injecting a catalyst and a cocatalyst into the upper part, the middle part and the lower part of the reaction device, carrying out oligomerization reaction on the raw materials and the solvent in the reaction device, circularly injecting a cooling medium into the inner coil and/or the jacket, and cooling reaction liquid in the reaction device by the circular heat removal device to remove reaction heat;

(II) overflowing the reaction product into a reaction terminating device through an overflow pipe, injecting a terminating agent into the upper part and the middle part of the reaction terminating device simultaneously, and interrupting the ethylene oligomerization reaction; the reaction product discharged from the reaction terminating device sequentially flows through a flash evaporation device and a deethylenizer to remove unreacted ethylene in the reaction product, and the reaction product discharged from the deethylenizer enters a product separation unit;

(III) feeding the reaction product into a 1-hexene separation device, controlling the temperature and the pressure in the 1-hexene separation device, collecting the separated 1-hexene from the top of the 1-hexene separation device, discharging the material from the bottom of the 1-hexene separation device into a solvent separation device, and controlling the temperature and the pressure in the solvent separation device to separate feed liquid;

(IV) one part of the tower top discharge of the solvent separation device is recycled to the solvent feeding pipeline to participate in ethylene oligomerization reaction, the other part of the tower top discharge enters the byproduct separation device, the temperature and the pressure in the byproduct separation device are controlled to separate the feeding liquid containing the solvent and the byproducts, the byproducts are extracted and collected from the tower bottom of the byproduct separation device, and the solvent is discharged from the tower bottom of the byproduct separation device and recycled to the solvent feeding pipeline to participate in ethylene oligomerization reaction;

(V) feeding the discharged material at the bottom of the solvent separation device into a 1-octene separation device, controlling the temperature and pressure in the 1-octene separation device, and collecting the separated 1-octene from the top of the 1-octene separation device.

In a preferred embodiment of the present invention, the solvent in step (i) is one or a combination of at least two of cyclohexane, methylcyclopentane, and methylcyclohexane, and may be, for example, a combination of cyclohexane and methylcyclopentane, a combination of cyclohexane and methylcyclohexane, or a combination of methylcyclopentane and methylcyclohexane.

Preferably, the feedstock is ethylene.

Preferably, the raw material is compressed to 3.0MPaG to 6.0MPaG and mixed with a solvent, such as 3.0MPaG, 3.2MPaG, 3.4MPaG, 3.6MPaG, 3.8MPaG, 4.0MPaG, 4.2MPaG, 4.4MPaG, 4.6MPaG, 4.8MPaG, 5.0MPaG, 5.2MPaG, 5.4MPaG, 5.6MPaG, 5.8MPaG or 6.0MPaG, but not limited to the values listed, and other values not listed in the range of values are also applicable.

Preferably, the catalyst comprises a Cr-based selective catalyst.

Preferably, the cocatalyst comprises methylaluminoxane.

Preferably, the mass flow ratio of the solvent to the starting material is 2 to 6, for example 2, 3, 4, 5 or 6, but not limited to the recited values, and other values not recited within this range are also applicable.

Preferably, the reaction temperature in the reaction device is 40 ℃ to 120 ℃, for example, 40 ℃, 50 ℃, 60 ℃, 70 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃ or 120 ℃, but not limited to the values listed, and other values not listed in the range of the values are also applicable.

Preferably, the reaction pressure in the reaction apparatus is 3.0MPaG to 6.0MPaG, and may be, for example, 3.0MPaG, 3.2MPaG, 3.4MPaG, 3.6MPaG, 3.8MPaG, 4.0MPaG, 4.2MPaG, 4.4MPaG, 4.6MPaG, 4.8MPaG, 5.0MPaG, 5.2MPaG, 5.4MPaG, 5.6MPaG, 5.8MPaG, or 6.0MPaG, but is not limited to the values listed, and other values not listed in the range of the values are also applicable.

Preferably, the reaction time of the raw materials and the solvent in the reaction device is 0.80h to 1.50h, for example, 0.80h, 0.85h, 0.90h, 0.95h, 1.00h, 1.05h, 1.10h, 1.15h, 1.20h, 1.25h, 1.30h, 1.35h, 1.40h, 1.45h or 1.50h, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the oligomerization is carried out under stirring conditions.

Preferably, the terminating agent in step (II) comprises one or a combination of at least two of isopropanol, isobutanol or isooctanol, and can be, for example, a combination of isopropanol and isobutanol, a combination of isopropanol and isooctanol or a combination of isobutanol and isooctanol.

Preferably, the flash evaporation device operating temperature is 40 ~ 120 ℃, for example can be 40 ℃, 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃ or 120 ℃, but not limited to the number, in the range of other values are also applicable.

Preferably, the flash unit is operated at a pressure of 1.6MPaG to 2.5MPaG, such as 1.6MPaG, 1.7MPaG, 1.8MPaG, 1.9MPaG, 2.0MPaG, 2.1MPaG, 2.2MPaG, 2.3MPaG, 2.4MPaG or 2.5MPaG, but not limited to the values listed, and other values not listed within this range are equally applicable.

Preferably, the top temperature of the deethylenizer is 90 ℃ to 97 ℃, for example, 90 ℃, 91 ℃, 92 ℃, 93 ℃, 94 ℃, 95 ℃, 96 ℃ or 97 ℃, but is not limited to the values listed, and other values not listed in the range of values are equally applicable.

Preferably, the operating pressure at the top of the deethylenizer is 1.20MPaG to 1.40MPaG, and may be, for example, 1.20MPaG, 1.21MPaG, 1.22MPaG, 1.23MPaG, 12.4MPaG, 1.25MPaG, 12.6MPaG, 1.27MPaG, 1.28MPaG, 1.29MPaG, 1.30MPaG, 1.31MPaG, 1.32MPaG, 1.33MPaG, 1.34MPaG, 1.35MPaG, 1.36MPaG, 1.37MPaG, 1.38MPaG, 1.39MPaG or 1.40MPaG, but is not limited to the values listed, and other values not listed in this range are equally applicable.

Preferably, the temperature of the bottom of the deethylenizer is 200 ℃ to 210 ℃, for example, 200 ℃, 201 ℃, 202 ℃, 203 ℃, 204 ℃, 205 ℃, 206 ℃, 207 ℃, 208 ℃, 209 ℃ or 210 ℃, but is not limited to the values listed, and other values not listed in the range of values are also applicable.

Preferably, the operation pressure of the deethylenizer at the bottom of the tower is 1.25MPaG to 1.45MPaG, and may be, for example, 1.25MPaG, 1.26MPaG, 1.27MPaG, 1.28MPaG, 1.29MPaG, 1.30MPaG, 1.31MPaG, 1.32MPaG, 1.33MPaG, 1.34MPaG, 1.35MPaG, 1.36MPaG, 1.37MPaG, 1.38MPaG, 1.39MPaG, 1.40MPaG, 1.41MPaG, 1.42MPaG, 1.43MPaG, 1.44MPaG or 1.45MPaG, but is not limited to the values listed, and other values not listed in the range of values are also applicable.

Preferably, the overhead temperature of the 1-hexene separation unit in step (iii) is from 100 ℃ to 105 ℃, and may be, for example, 100 ℃, 101 ℃, 102 ℃, 103 ℃, 104 ℃ or 105 ℃, but is not limited to the recited values, and other values not recited within the range of values are equally applicable.

Preferably, the 1-hexene separation unit has a top pressure of from 0.10MPaG to 0.15MPaG, which may be, for example, 0.10MPaG, 0.11MPaG, 0.12MPaG, 0.13MPaG, 0.14MPaG or 0.15MPaG, but is not limited to the values listed, and other values not listed in this range are equally applicable.

Preferably, the temperature of the bottom of the 1-hexene separating apparatus is 125 ℃ to 135 ℃, for example 125 ℃, 126 ℃, 127 ℃, 128 ℃, 129 ℃, 130 ℃, 131 ℃, 132 ℃, 133 ℃, 134 ℃ or 135 ℃, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the operating pressure of the 1-hexene separating apparatus at the bottom of the column is 0.15MPaG to 0.20MPaG, for example, 0.15MPaG, 0.16MPaG, 0.17MPaG, 0.18MPaG, 0.19MPaG or 0.20MPaG, but not limited to the values listed, and other values not listed in this range are also applicable.

Preferably, the overhead temperature of the solvent separation apparatus is 105 ℃ to 115 ℃, and may be, for example, 105 ℃, 106 ℃, 107 ℃, 108 ℃, 109 ℃, 110 ℃, 111 ℃, 112 ℃, 113 ℃, 114 ℃ or 115 ℃, but is not limited to the recited values, and other values not recited within the range of values are also applicable.

Preferably, the solvent separation unit has a top pressure of 0.08MPaG to 0.14MPaG, such as 0.08MPaG, 0.09MPaG, 0.10MPaG, 0.11MPaG, 0.12MPaG, 0.13MPaG, or 0.14MPaG, but not limited to the values recited, and other values not recited within this range are equally applicable.

Preferably, the bottom temperature of the solvent separation apparatus is 192 ℃ to 202 ℃, for example 192 ℃, 193 ℃, 194 ℃, 195 ℃, 196 ℃, 197 ℃, 198 ℃, 199 ℃, 200 ℃, 201 ℃ or 202 ℃, but is not limited to the recited values, and other values not recited in the range of values are also applicable.

Preferably, the solvent separation apparatus has a bottom operating pressure of 0.11MPaG to 0.17MPaG, such as 0.11MPaG, 0.12MPaG, 0.13MPaG, 0.14MPaG, 0.15MPaG, 0.16MPaG, or 0.17MPaG, but not limited to the values recited, and other values not recited within the range are equally applicable.

Preferably, the by-product described in step (iv) is methylcyclopentane.

Preferably, the overhead temperature of the by-product separation apparatus is 70 ℃ to 78 ℃, and may be, for example, 70 ℃, 71 ℃, 72 ℃, 73 ℃, 74 ℃, 75 ℃, 76 ℃, 77 ℃ or 78 ℃, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the overhead operating pressure of the byproduct separation apparatus is in the range of 0.05MPaG to 0.10MPaG, and may be, for example, 0.05MPaG, 0.06MPaG, 0.07MPaG, 0.08MPaG, 0.09MPaG, or 0.10MPaG, but is not limited to the recited values, and other values not recited in this range are also applicable.

Preferably, the temperature of the bottom of the by-product separation apparatus is 80 ℃ to 90 ℃, and may be, for example, 80 ℃, 81 ℃, 82 ℃, 83 ℃, 84 ℃, 85 ℃, 86 ℃, 87 ℃, 88 ℃, 89 ℃ or 90 ℃, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the byproduct separation apparatus has a bottom operating pressure of 0.10MPaG to 0.15MPaG, such as 0.10MPaG, 0.11MPaG, 0.12MPaG, 0.13MPaG, 0.14MPaG, or 0.15MPaG, but not limited to the values listed, and other values not listed in this range are also applicable.

Preferably, the overhead temperature of the 1-octene separation unit described in step (V) is from 80 ℃ to 85 ℃, and may be, for example, 80 ℃, 81 ℃, 82 ℃, 83 ℃, 84 ℃ or 85 ℃, but is not limited to the recited values, and other values not recited in this range are equally applicable.

Preferably, the overhead operating pressure of the 1-octene separating device is-0.075 MPaG to 0.070MPaG, and may be, for example, -0.075MPaG, -0.065MPaG, -0.055MPaG, -0.045MPaG, -0.035MPaG, -0.025MPaG, -0.015MPaG, 0MPaG, 0.01MPaG, 0.02MPaG, 0.03MPaG, 0.04MPaG, 0.05MPaG, 0.06MPaG, or 0.07MPaG, but is not limited to the recited values, and other values in the recited values are also applicable.

Preferably, the temperature of the bottom of the 1-octene separation unit is in the range of 145 ℃ to 150 ℃, and may be, for example, 145 ℃, 146 ℃, 147 ℃, 148 ℃, 149 ℃ or 150 ℃, but is not limited to the recited values, and other values not recited in this range are equally applicable.

Preferably, the operating pressure of the bottom of the 1-octene separating device is-0.065 MPaG to 0.060MPaG, and may be, for example, -0.065MPaG, -0.055MPaG, -0.045MPaG, -0.035MPaG, -0.025MPaG, -0.015MPaG, 0MPaG, 0.01MPaG, 0.02MPaG, 0.03MPaG, 0.04MPaG, 0.05MPaG or 0.06MPaG, but is not limited to the enumerated values, and other non-enumerated values within the numerical range are equally applicable.

Illustratively, the production system provided by the invention is used for the reaction of synthesizing 1-octene and 1-hexene by ethylene oligomerization, and specifically comprises the following steps:

(1) the method comprises the steps of boosting the pressure of raw material ethylene to 3.0-6.0 MPaG through a compression device, mixing the raw material ethylene with a solvent (one or a combination of at least two of cyclohexane, methyl cyclopentane or methyl cyclohexane), and then feeding the mixture into a reaction device, wherein the mass flow ratio of the solvent to the raw material is 2-6.

(2) Injecting catalyst and cocatalyst into the upper part, the middle part and the lower part of the reaction device, keeping the reaction temperature at 40-120 ℃, the reaction pressure at 3.0-6.0 MPaG and the reaction time at 0.8-1.5 h, and carrying out ethylene oligomerization while stirring. The reaction heat is rapidly and timely removed through an inner coil pipe, a jacket and a circulating heat removal device arranged outside the reaction device, and stable reaction conditions are ensured.

(3) Reaction products overflowing from the reaction device enter the reaction terminating device through the overflow pipe, the arrangement distance between the reaction device and the reaction terminating device is as short as possible, the inclination angle of the overflow pipe is 20-45 degrees, terminating agents are injected into the upper part and the middle part of the reaction terminating device, and the ethylene oligomerization reaction is rapidly terminated along with the stirring.

(4) The reaction product enters a flash evaporation device, the operation condition is controlled at 40-120 ℃, and the operation pressure is 1.6-2.5 MPaG. The ethylene gas extracted from the top of the flash evaporation device is introduced into an ethylene collecting device, and the discharge from the bottom of the flash evaporation device enters an ethylene removal device.

(5) The temperature of the top of the ethylene removing device is controlled to be 90-97 ℃, the operating pressure is controlled to be 1.2-1.4 MPaG, the temperature of the bottom of the ethylene removing device is controlled to be 200-210 ℃, and the operating pressure is controlled to be 1.25-1.45 MPaG. Leading ethylene gas extracted from the top of the ethylene removal device into an ethylene collecting device, and discharging from the bottom of the ethylene removal device into a 1-hexene separating device.

(6) The temperature of the top of the 1-hexene separation device is controlled between 100 ℃ and 105 ℃, and the operating pressure is controlled between 0.10MPaG and 0.15 MPaG. The temperature of the bottom of the 1-hexene separation device is controlled at 125-135 ℃, and the operating pressure is controlled at 0.15-0.20 MPaG. Introducing a 1-hexene product collected from the top of the 1-hexene separation device into a 1-hexene collecting device, and discharging the material from the bottom of the 1-hexene device to enter a solvent separation device.

(7) The temperature of the top of the solvent separation device is controlled to be 105-115 ℃, the operating pressure is controlled to be 0.08-0.14 MPaG, the temperature of the bottom of the solvent separation device is controlled to be 192-202 ℃, and the operating pressure is controlled to be 0.11-0.17 MPaG. Part of the solvent (containing byproduct methylcyclopentane) extracted from the tower top of the solvent separation device is mixed with the fresh solvent and then flows back to the solvent feeding pipeline for reuse, and part of the solvent enters the byproduct separation device.

(8) The temperature of the top of the byproduct separation device is controlled to be 70-78 ℃, the operating pressure is controlled to be 0.05-0.1 MPaG, the temperature of the bottom of the byproduct separation device is controlled to be 80-90 ℃, and the operating pressure is controlled to be 0.10-0.15 MPaG. The byproduct methylcyclopentane is extracted from the top of the byproduct separation device, the high-purity solvent (one or the combination of at least two of cyclohexane, methylcyclopentane or methylcyclohexane) is extracted from the bottom of the byproduct separation device, and the high-purity solvent flows back to the solvent feeding pipeline for reuse.

(9) The bottom discharge of the solvent separation device enters a 1-octene separation device, the temperature of the top of the 1-octene separation device is controlled at 80-85 ℃, and the operating pressure is controlled at-0.075 MPaG-0.070 MPaG. The temperature of the bottom of the 1-octene separation device is controlled to be 145-150 ℃, and the operation pressure is controlled to be-0.065 MPaG-0.060 MPaG. 1-octene products extracted from the top of the 1-octene separation device are led into the 1-octene collection device, and C is extracted from the bottom of the 1-octene separation device₁₀ ⁺And (4) components.

The system refers to an equipment system, or a production equipment.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention synthesizes 1-octene and 1-hexene through ethylene oligomerization, and realizes a complete flow of synthesizing 1-octene and 1-hexene through a raw material compression unit, a reaction polymerization unit, a reaction termination unit and a product separation unit. The complete equipment realizes the production of two different products of 1-octene and 1-hexene in different working sections under the same flow, efficiently separates the reaction products according to the sequence of the boiling points of the reaction products from low to high, greatly saves the equipment investment, reduces the production energy consumption, and can adjust the proportion of the two products according to the production requirements.

(2) The heat of polymerization reaction in the reaction device is timely removed, so that the equilibrium and stability of the reaction temperature are ensured, and the wall sticking phenomenon of polymerization byproducts in subsequent equipment and pipelines is favorably reduced.

(3) The reaction is quickly terminated in time through the innovative design of the termination reaction device, and the generation of polymerization byproducts is reduced, so that the influence of the polymerization byproducts on the wall sticking of subsequent equipment and pipelines is greatly reduced.

Drawings

Fig. 1 is a schematic structural diagram of a production system according to an embodiment of the present invention.

Wherein, 1-a compression device; 2-a reaction device; 3-a circulating pump; 4-a cooling device; 5-terminating the reaction apparatus; 6-a flash evaporation device; 7-a deethylenizer; an 8-1-hexene separation unit; 9-a solvent separation unit; a 10-1-octene separation unit; 11-byproduct separation unit.

Detailed Description

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

In a specific embodiment, the invention provides a production system for synthesizing 1-octene and 1-hexene by ethylene oligomerization, which is shown in fig. 1 and comprises a raw material compression unit, a reaction polymerization unit, a reaction termination unit and a product separation unit which are connected in sequence.

The feed compression unit comprises a compression device 1, said compression device 1 being adapted to compress an ethylene feed.

The reaction polymerization unit comprises a reaction device 2, and a catalyst injection port and a cocatalyst injection port are arranged at the upper part, the middle part and the lower part of the reaction device 2. In this embodiment, the reaction apparatus 2 may optionally employ a stirred tank reactor. A solvent feeding pipeline is externally connected to a connecting pipeline between the compression device 1 and the reaction device 2, and the ethylene raw material is compressed by the compression device 1 and then mixed with the solvent introduced into the solvent feeding pipeline to enter the reaction device 2. The inner coil is arranged in the reaction device 2, the adopted inner coil is of a spiral structure, and the interior of the reaction device 2 is cooled by introducing a cooling medium into the inner coil. The outer side of the shell of the reaction device 2 is provided with a jacket, and a cooling medium is introduced into the jacket to cool the interior of the reaction device 2. The reaction polymerization unit further comprises a circulating heat removal device, the circulating heat removal device comprises a circulating pipeline, one end of the circulating pipeline is connected into a bottom circulating outlet of the reaction device 2, the other end of the circulating pipeline is connected into a top circulating inlet of the reaction device 2, the circulating pipeline is sequentially provided with a circulating pump 3 and a cooling device 4 along the flow direction of reaction liquid.

The termination reaction unit comprises a termination reaction device 5, the upper part and the middle part of the termination reaction device 5 are both provided with a terminator inlet, and the ethylene oligomerization synthesis reaction is terminated by injecting a terminator into the termination reaction device 5. The upper overflow port of the reaction device 2 is connected with the liquid inlet of the termination reaction device 5 through an overflow pipe, the reaction product flows through the overflow pipe from the overflow port and enters the termination reaction device 5, the overflow pipe is obliquely and downwards arranged along the flow direction of the reaction product, and the included angle between the overflow pipe and the horizontal direction is any one angle of 20-45 degrees. In this embodiment, the termination reaction device 5 may optionally employ a stirred tank reactor.

An ethylene removal unit is also arranged between the reaction termination unit and the product separation unit and is used for removing unreacted ethylene raw materials in reaction products. The ethylene removal unit comprises a flash evaporation device 6 and a deethylenizer 7 which are sequentially connected, a liquid outlet at the bottom of the termination reaction device 5 is connected with a liquid inlet of the flash evaporation device 6, an outlet at the top of the flash evaporation device 6 is externally connected with an ethylene gas collecting device, and a liquid outlet at the bottom of the flash evaporation device 6 is connected with a liquid inlet of the deethylenizer 7. The top collecting port of the ethylene removing device 7 is externally connected with an ethylene gas collecting device, and the bottom liquid outlet of the ethylene removing device 7 is connected with the liquid inlet of the 1-hexene separating device 8.

The product separation unit comprises a 1-hexene separation device 8, a solvent separation device 9, a 1-octene separation device 10 and a byproduct separation device 11 which are connected in sequence, and the specific connection relationship among the four devices is as follows:

the top outlet of the 1-hexene separating device 8 is connected with a 1-hexene collecting device, 1-hexene is collected from the top of the 1-hexene separating device 8 and enters the 1-hexene collecting device, and the bottom liquid outlet of the 1-hexene separating device 8 is connected with the liquid inlet of the solvent separating device 9.

The tower top outlet of the solvent separation device 9 is divided into two paths, one path is connected to a solvent feeding pipeline, the other path is connected to a liquid inlet of the byproduct separation device 11, and a liquid outlet at the bottom of the solvent separation device 9 is connected to a liquid inlet of the 1-octene separation device 10.

A liquid outlet at the bottom of the byproduct separating device 11 is connected with a solvent feeding pipeline, the solvent obtained by separation is extracted from the bottom of the tower and flows back to the solvent feeding pipeline, the byproduct obtained by separation of the byproduct separating device 11 is discharged from the top of the tower, and the byproduct comprises methylcyclopentane.

The outlet of the 1-octene separating device 10 is connected with a 1-octene collecting device, and 1-octene is extracted from the top of the 1-octene separating device 10 and then enters the 1-octene collecting device.

In another embodiment, the invention provides a production method for synthesizing 1-octene and 1-hexene by ethylene oligomerization, which specifically comprises the following steps:

introducing a solvent into a solvent feeding pipeline, compressing the raw materials by a raw material compression unit, mixing the raw materials with the solvent, and introducing the mixture into a reaction device 2; simultaneously injecting a catalyst and a cocatalyst into the upper part, the middle part and the lower part of the reaction device 2, carrying out oligomerization reaction on the raw materials and the solvent in the reaction device 2, circularly injecting a cooling medium into the inner coil and/or the jacket, and cooling and removing reaction heat from reaction liquid in the reaction device 2 through a circular heat removal device;

(II) overflowing the reaction product into a termination reaction device 5 through an overflow pipe, injecting a terminator into the upper part and the middle part of the termination reaction device 5 simultaneously, and interrupting the ethylene oligomerization reaction; the reaction product discharged from the reaction terminating device 5 sequentially flows through a flash evaporation device 6 and a deethylenizer 7 to remove unreacted ethylene in the reaction product, and the reaction product discharged from the deethylenizer 7 enters a product separation unit;

(III) feeding the reaction product into a 1-hexene separation device 8, controlling the temperature and the pressure in the 1-hexene separation device 8, collecting the separated 1-hexene from the top of the 1-hexene separation device 8, discharging the material from the bottom of the 1-hexene separation device 8 into a solvent separation device 9, and controlling the temperature and the pressure in the solvent separation device 9 to separate the feed liquid;

(IV) one part of the tower top discharge of the solvent separation device 9 is recycled to the solvent feeding pipeline to participate in the ethylene oligomerization reaction, the other part of the tower top discharge enters the byproduct separation device 11, the temperature and the pressure in the byproduct separation device 11 are controlled to separate the feeding liquid containing the solvent and the byproducts, the byproducts are collected from the tower bottom of the byproduct separation device 11, and the solvent is discharged from the tower bottom of the byproduct separation device 11 and recycled to the solvent feeding pipeline to participate in the ethylene oligomerization reaction;

(V) the bottom discharge of the solvent separation device 9 enters a 1-octene separation device 10, the temperature and the pressure in the 1-octene separation device 10 are controlled, and the separated 1-octene is extracted and collected from the top of the 1-octene separation device 10.