An apparatus for oligomerization and oligomerization process and applications

Abstract

The application discloses a device and a method for oligomerization reaction and application. The reactor comprises a kettle body, a liquid feeding cavity arranged from top to bottom in the kettle body, a gas-liquid mixing spraying part, a reaction cavity and a vertical stirring shaft; a first solvent feeding port is arranged on the surface of the kettle body and at the position of the liquid feeding cavity; an olefin feeding port is arranged on the surface of the kettle body and at the position of the gas-liquid mixing spraying part; a main catalyst feeding port, a second solvent feeding port and a cocatalyst feeding port are arranged on the surface of the kettle body and at the position of the reaction cavity; the first solvent feeding port feeds the first solvent into the liquid feeding cavity, the first solvent enters the gas-liquid mixing spraying part and mixes with the olefin fed by the olefin feeding port, then the mixture is sprayed into the reaction cavity and reacts with the main catalyst, the second solvent and the cocatalyst. The reactor and the method can effectively prevent the fouling at the olefin inlet, and the reactor can be stably operated for a long time.

Description

Technical Field

[0001] This invention relates to the field of oligomerization, and more specifically to an apparatus, method and application for oligomerization. Background Technology

[0002] Oligopolymerization is the process of converting one or more reactants into one or more products. The reaction typically takes place in an oligopolymerization reactor, into which the reactants are added. The reactants can often react with other components (e.g., other reactants and / or catalysts) upon contact with the reactor, forming undesirable byproducts (such as polymers). In some cases, these byproducts can accumulate as fouling at the reactor inlet, affecting the continuous progress of the reaction. For example, in ethylene tetramerization, a localized high concentration of ethylene may occur at the ethylene inlet. Under certain conditions, the contact between this high concentration of ethylene and the catalyst system can produce high-polymer products. These high-polymer products accumulate at the ethylene inlet end, affecting the reaction process and even clogging the ethylene inlet.

[0003] To address scaling issues, most processes employ the addition of inhibitors. For example, US Patent 10870098B2 involves injecting a scaling inhibitor containing petroleum-based wax or polyolefin wax with a melting point of 30-130°C into the reactor. Chinese Patent Application CN114206814A discloses a method for reducing scaling in an upgrading reactor, which includes upgrading C2 to C4 hydrocarbons in the presence of a scaling inhibitor with a particle size D50 of less than 100 micrometers, forming linear α-olefins and polymers during the upgrading process, wherein the scaling inhibitor alters the morphology of the polymers. While the addition of inhibitors can suppress scaling to some extent, the introduction of new substances increases reaction costs and may affect the reaction process. Therefore, some processes employ timely scaling removal methods. EP3338884B1 discloses a method for olefin oligomerization using a cleaning device, in which at least a portion of the reaction effluent is moved through at least two switchable heat exchangers, which are alternately cleaned by an integrated cleaning device. CN101237924A discloses a method for cleaning reactors prone to scaling due to solid deposits, by applying a hot solvent to the reactor to substantially dissolve the solids, and then discharging the dissolved solids from the reactor. Although timely reactor cleaning can remove scaling, even switching cleaning methods significantly increase the number of operational steps. Summary of the Invention

[0004] To address the aforementioned problems in the existing technology, the purpose of this invention is to provide a reactor and method for oligomerization reactions. The reactor and method of this invention can effectively prevent fouling at the olefin inlet, and the reactor can operate stably for extended periods.

[0005] The first aspect of the present invention provides a reactor for oligomerization reaction, the reactor comprising a vessel body 1, a liquid feed chamber 2 disposed from top to bottom inside the vessel body 1, a gas-liquid mixing jet component 3, a reaction chamber 4, and a vertical stirring shaft 5; a first solvent inlet 11 is disposed on the surface of the vessel body 1 at the position of the liquid feed chamber 2; an olefin feed inlet 12 is disposed on the surface of the vessel body 1 at the position of the gas-liquid mixing jet component 3; and a main catalyst feed inlet 13, a second solvent feed inlet 14, and a co-catalyst feed inlet 15 are disposed on the surface of the vessel body 1 at the position of the reaction chamber 4.

[0006] According to some embodiments of the reactor of the present invention, preferably, the first solvent introduced into the liquid feed chamber 2 through the first solvent inlet 11 enters the gas-liquid mixing spray component 3 and mixes with the olefin introduced into the olefin inlet 12 in the gas-liquid mixing spray component 3, and then sprays it into the reaction chamber 4 to react with the mixture formed by the main catalyst introduced into the main catalyst inlet 13, the second solvent introduced into the second solvent inlet 14, and the co-catalyst introduced into the co-catalyst inlet 15.

[0007] In this invention, "oligomery reaction" refers to the synthesis of α-olefins through an oligomerization reaction using ethylene as the main raw material under the action of a catalyst, yielding olefin oligomers. The obtained olefin oligomers have 4 or more carbon atoms, particularly 4 to 18 carbon atoms. Specific examples of olefin oligomers include ethylene oligomers such as 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octadecene. The olefin oligomers produced by this invention can be in the form of a mixture of any two or more of the above-mentioned oligomers.

[0008] According to some embodiments of the reactor of the present invention, preferably, the gas-liquid mixing injection component 3 includes a liquid distribution plate 31 arranged from top to bottom, at least one set of injectors 32 and a gas distribution plate 33, wherein each set of injectors 32 includes a mixing chamber 321, a liquid branch pipe 322 and a nozzle 323 are arranged at the coaxial center of the mixing chamber 321, a gas inlet 324 is arranged on the side wall of the mixing chamber 321, a static mixer is arranged inside the mixing chamber 321, and a throat pipe 325 and a diffusion chamber 326 are arranged sequentially at the lower end of the mixing chamber 321;

[0009] The first solvent introduced through the first solvent inlet 11 enters the liquid branch pipe 322 and enters the mixing chamber 321 through the nozzle 323; the olefin introduced through the olefin inlet 12 enters the mixing chamber 321 through the gas inlet 324. In the mixing chamber 321, the first solvent mixes with the olefin, and then enters the throat pipe 325 and the diffusion chamber 326 in sequence, and is sprayed into the reaction chamber 4.

[0010] According to some embodiments of the reactor of the present invention, preferably, the central axes of the mixing chamber 321, the liquid branch pipe 32, the nozzle 323, the throat 325 and the diffusion chamber 326 are located on the same straight line.

[0011] According to some embodiments of the reactor of the present invention, preferably, the gas distribution plate 33 and the liquid distribution plate 31 are coaxial plates with a hollow center, and the gas distribution plate 33 is provided with a first hole and the liquid distribution plate 31 is provided with a second hole; the first hole is the mounting hole of the throat pipe 325 and the second hole is the mounting hole of the liquid branch pipe 322.

[0012] According to some embodiments of the reactor of the present invention, preferably, the first hole and the second hole correspond one-to-one, serving as mounting holes for a set of ejectors 32. In the present invention, "one-to-one correspondence" means that one first hole is provided in relation to one second hole.

[0013] According to some embodiments of the reactor of the present invention, preferably, the top diameter of the liquid branch pipe 322 is the same as the diameter of the opening on the liquid distribution plate 31.

[0014] According to some embodiments of the reactor of the present invention, preferably, the lower end of the liquid branch pipe 322 is a conical hole and is located inside the mixing chamber 321.

[0015] According to some embodiments of the reactor of the present invention, preferably, the diameter of the throat 325 is 2-3 times the diameter of the conical hole at the lower end of the liquid branch pipe 322.

[0016] According to some embodiments of the reactor of the present invention, preferably, the diameter of the mixing chamber 321 is 2-3 times the diameter of the liquid branch pipe 322.

[0017] According to some embodiments of the reactor of the present invention, preferably, the height of the diffusion chamber 326 is 0.6-1 times the height between the liquid distribution plate 31 and the gas distribution plate 33.

[0018] According to some specific embodiments of the reactor described in this invention, in order to ensure that the sprayed gas-liquid mixture reaches the catalyst solution inside the reactor, the distance between the lower end of each injector and the part of the gas-liquid mixture to be sprayed is preferably 5 cm or less, and they do not directly contact each other.

[0019] According to some embodiments of the reactor of the present invention, preferably, a blade 42 is further provided inside the reaction chamber 4. In the present invention, there may be one or more blades 42, depending on the need.

[0020] According to some specific embodiments of the reactor of the present invention, the stirring shaft 5 extends vertically downward from the top of the reactor, passes through the central hollow of the liquid distribution plate 31 and the gas distribution plate 33 to the lower part of the reactor, and the stirring shaft 5 has at least two sets of blades 42.

[0021] According to some specific embodiments of the reactor described in this invention, preferably, the reactor further includes a rotating component 6 for providing kinetic energy to the stirring shaft 5 to rotate.

[0022] According to some embodiments of the reactor of the present invention, preferably, an inner coil 41 is also provided in the reaction chamber 4 for heat exchange.

[0023] According to some embodiments of the reactor of the present invention, a circulating olefin outlet 17 is provided on the surface of the vessel body 1 and at the upper position of the reaction chamber 4, and a circulating olefin inlet 18 is provided on the surface of the vessel body 1 and at the position of the gas-liquid mixing injection component 3. A gas condensation circulation pipeline 7 is connected to the circulating olefin outlet 17 and the circulating olefin inlet 18 for circulating unreacted olefins to the vessel body 1.

[0024] According to some embodiments of the reactor described in this invention, a discharge port 16 is also provided at the bottom of the vessel body 1.

[0025] According to some embodiments of the reactor of the present invention, a heat exchange jacket 19 is further provided on the outside of the vessel body 1.

[0026] A second aspect of the present invention provides a method for carrying out an oligomerization reaction using the above-described reactor, comprising the following steps: A first solvent is introduced into a liquid feed chamber 2 through a first solvent inlet 11 and then into a gas-liquid mixing spray component 3, where it is mixed with olefins introduced through an olefin inlet 12 in the gas-liquid mixing spray component 3. The mixture is then sprayed into a reaction chamber 4 to react with a catalyst solution within the reaction chamber 4. The catalyst solution is formed by mixing a main catalyst introduced through a main catalyst inlet 13, a second solvent introduced through a second solvent inlet 14, and a co-catalyst introduced through a co-catalyst inlet 15. In this invention, the first solvent is introduced into the liquid feed chamber 2 through the first solvent inlet 11 and then into the gas-liquid mixing spray component 3, where it is mixed with olefins introduced through an olefin inlet 12 in the gas-liquid mixing spray component 3. During this process, the solvent does not contact the liquid below before spraying; that is, the liquid outlet at the top does not contact the liquid below.

[0027] According to some embodiments of the method of the present invention, preferably, the olefins include fresh olefins and recycled olefins, and more preferably ethylene.

[0028] According to some embodiments of the method described in this invention, the method can be operated batchwise or continuously, using ethylene as the main raw material to synthesize α-olefins through an oligomerization reaction under the action of a catalyst. This polymerization reaction is carried out in a reactor. In this invention, "oligomerization reaction" refers to the synthesis of α-olefins through an oligomerization reaction using ethylene as the main raw material under the action of a catalyst, yielding olefin oligomers. The obtained olefin oligomers have 4 or more carbon atoms, particularly 4 to 18 carbon atoms. Specific examples of olefin oligomers include ethylene oligomers such as 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, etc. The olefin oligomers produced by this invention can be in the form of a mixture of any two or more of the above-mentioned oligomers.

[0029] In some embodiments of the method according to the present invention, preferably, the first solvent and the second solvent are each independently selected from one or more straight-chain alkanes, cycloalkanes, and substituted cycloalkanes. For example, the solvent can be a compound such as heptane, cyclohexane, or methylcyclohexane. In the present invention, the solvent and the reaction system are under anhydrous and oxygen-free conditions.

[0030] According to some embodiments of the method of the present invention, preferably, the weight ratio of the first solvent and the second solvent is 1:0.1-4.

[0031] According to some embodiments of the method described in this application, preferably, the polymerization catalyst used in this application can be a conventional catalyst system for catalyzing the oligomerization of ethylene, and more preferably a chromium-based catalyst system. This chromium-based catalyst system may, for example, include a chromium-containing main catalyst, which is composed of a chromium-containing compound and a phosphine-containing ligand, and a co-catalyst that is an alkylaluminum compound or an alkoxyaluminum compound.

[0032] According to some embodiments of the method of the present invention, preferably, the amount of organic solvent used is such that the concentration of the catalyst composition is 0.1-100 μmol / L, and the catalyst composition is based on the metal element in the main catalyst metal compound. The molar ratio of the main catalyst to the co-catalyst is 1:1-5000.

[0033] According to some embodiments of the method described in this invention, the reaction of this invention can generally be carried out at a temperature of 0 to 200°C and a pressure of 0.1 to 20.0 MPa. The reaction time varies depending on the temperature and pressure. The residence time in the reactor is typically from about 10 to about 60 minutes.

[0034] According to some specific embodiments of the method described in this invention, olefins and a portion of the solvent are sprayed from the top of the reactor into the catalyst solution inside the reactor in a suspended manner, and, if necessary, onto the mechanical seal or the stirring shaft of the agitator to carry out the ethylene oligomerization reaction.

[0035] Specific embodiments of the oligomerization method of the present invention include:

[0036] Based on the requirements of the reaction, determine the operating parameters such as reaction temperature, reaction pressure, reaction time, and material flow rate.

[0037] Open the material inlet valve and add the prepared main catalyst, co-catalyst solution and solvent at a certain flow rate from the main catalyst inlet, the co-catalyst inlet and the second solvent inlet respectively, and start the agitator;

[0038] Open the valves of the first solvent inlet and the ethylene inlet, allowing some solvent to enter the liquid feed chamber through the first solvent inlet, and ethylene to enter the gas feed chamber through the ethylene inlet located on the side wall of the gas feed chamber. The first solvent forms a liquid surface of a certain height in the liquid feed chamber. Then, under the action of its own water pressure and kinetic energy, the solvent is ejected at high speed through the nozzle of the liquid branch pipe of the ejector into the mixing chamber, forming a high-speed jet. Ethylene enters the mixing chamber through the gas inlet on the side wall of the mixing chamber. The ethylene is forcibly carried by the high-speed jet, and then the ethylene and the solvent in the high-speed jet rub, mix and compress each other to form a gas-liquid mixed flow. The gas-liquid mixed flow enters the diffuser after passing through the throat, thereby reducing the pressure in the mixing chamber and forming a vacuum or negative pressure zone, which is more conducive to the intake and mixing of gas and improves the gas-liquid mixing effect. The gas-liquid mixed flow is ejected from the outlet end of the diffuser into the catalyst solvent in the reactor for reaction.

[0039] As the amount of material in the reactor increases, when the liquid in the reactor reaches the set reaction volume, the feed and discharge flow rates are adjusted according to the reaction requirements. When the feed and discharge gradually reach equilibrium, continuous operation is achieved.

[0040] If the reaction is an intermittent operation, the feed valve is closed when the liquid in the reactor reaches the set volume. After the reaction is completed, the ethylene feed valve is closed, the pressure is released, and the material is discharged from the bottom of the reactor.

[0041] The third aspect of the present invention provides the application of the above-described reactor or the above-described oligomerization reaction method in olefin oligomerization processes.

[0042] The beneficial effects of this invention are:

[0043] (1) The reactor and method of the present invention can be used for oligomerization of olefins in contact with a catalyst and an organic solvent in a reactor. The olefins and a portion of the solvent are injected into the catalyst solution in the reactor from the top of the reactor in a suspended manner (the first solvent inlet enters the liquid feed chamber and enters the gas-liquid mixing spray component, and mixes with the olefins inlet in the gas-liquid mixing spray component). The olefins and a portion of the solvent are injected into the catalyst solution in the reactor through the gas-liquid mixing spray component (at least one set of sprayers), and the outlet of the gas-liquid mixing spray component does not directly contact the catalyst solution in the reactor. First, (1) the olefins (ethylene) and the solvent are fully mixed during feeding, which improves the solubility of ethylene; (2) during feeding, the olefins (ethylene) do not directly contact the catalyst solution, which can effectively prevent scale buildup at the ethylene inlet and enable the reactor to operate stably for a long time.

[0044] (2) The reactor and method of the present invention can achieve the purpose of temperature control by one or more combinations of heat exchange jacket 19, inner coil 41, and external circulation (circulating olefin outlet 17, gas condensation circulation pipeline 7 and olefin inlet 12; or circulating olefin outlet 17, the circulating olefin inlet 18 and gas condensation circulation pipeline 7). Attached Figure Description

[0045] Figure 1 This is a schematic diagram of a reactor for oligomerization provided in Embodiment 1 of the present invention.

[0046] Figure 2 This is a partial schematic diagram of the gas-liquid mixing and spraying component of the reactor for oligomerization provided in Embodiment 1 of the present invention.

[0047] Explanation of reference numerals in the attached figures

[0048] 1. Reactor body; 11. First solvent inlet; 12. Olefin inlet

[0049] 13. Main catalyst inlet; 14. Second solvent inlet; 15. Co-catalyst inlet

[0050] 16. Discharge port 17. Circulating olefins outlet 18. Circulating olefins inlet

[0051] 19. Heat exchange jacket; 2. Liquid feed chamber; 3. Gas-liquid mixing jet component

[0052] 31. Liquid distribution plate; 32. Injector; 321. Mixing chamber

[0053] 322. Liquid branch pipe; 323. Nozzle; 324. Gas inlet

[0054] 325, throat tube; 326, diffusion chamber; 33, gas distribution plate

[0055] 4. Reaction chamber 41, inner coil 42, impeller

[0056] 5. Stirring shaft; 6. Transmission components; 7. Gas condensation circulation pipeline. Detailed Implementation

[0057] To make the present invention easier to understand, the present invention will be described in detail below with reference to embodiments. These embodiments are for illustrative purposes only and are not limited to the scope of application of the present invention.

[0058] In the following examples and comparative examples, the reactivity, the total selectivity of 1-hexene and 1-octene were calculated according to the following formula:

[0059]

[0060]

[0061]

Example 1

[0062] Adopting such Figure 1 and Figure 2 The reactor shown is for oligomerization reaction. The reactor has a vessel body 1, a liquid feed chamber 2 arranged from top to bottom inside the vessel body 1, a gas-liquid mixing spray component 3, a reaction chamber 4, and a vertical stirring shaft 5. A first solvent inlet 11 is provided on the surface of the vessel body 1 at the position of the liquid feed chamber 2. An olefin feed inlet 12 is provided on the surface of the vessel body 1 at the position of the gas-liquid mixing spray component 3. A main catalyst feed inlet 13, a second solvent feed inlet 14, and a co-catalyst feed inlet 15 are provided on the surface of the vessel body 1 at the position of the reaction chamber 4. The first solvent introduced into the liquid feed chamber 2 through the first solvent feed inlet 11 enters the gas-liquid mixing spray component 3 and mixes with the olefin introduced into the olefin feed inlet 12 in the gas-liquid mixing spray component 3. Then, it is sprayed into the reaction chamber 4 and reacts with the mixture formed by the main catalyst introduced into the main catalyst feed inlet 13, the second solvent introduced into the second solvent feed inlet 14, and the co-catalyst introduced into the co-catalyst feed inlet 15.

[0063] The gas-liquid mixing injection component 3 has a liquid distribution plate 31, six sets of injectors 32, and a gas distribution plate 33 arranged from top to bottom. Each set of injectors 32 has a mixing chamber 321. A liquid branch pipe 322 and a nozzle 323 are arranged coaxially at the center of the mixing chamber 321. A gas inlet 324 is arranged on the side wall of the mixing chamber 321. A static mixer is arranged inside the mixing chamber 321. A throat pipe 325 and a diffusion chamber 326 are arranged sequentially at the lower end of the mixing chamber 321. The first solvent introduced through the first solvent inlet 11 enters the liquid branch pipe 322 and enters the mixing chamber 321 through the nozzle 323. The olefin introduced through the olefin inlet 12 enters the mixing chamber 321 through the gas inlet 324. In the mixing chamber 321, the first solvent mixes with the olefin and then enters the throat pipe 325 and the diffusion chamber 326 sequentially, and is injected into the reaction chamber 4.

[0064] The central axes of the mixing chamber 321, liquid branch pipe 32, nozzle 323, throat 325, and diffuser chamber 326 are located on the same straight line. The gas distribution plate 33 and liquid distribution plate 31 are coaxial plates with a hollow center, and the gas distribution plate 33 has a first opening, while the liquid distribution plate 31 has a second opening. The first opening serves as the mounting hole for the throat 325, and the second opening serves as the mounting hole for the liquid branch pipe 322. The first and second openings correspond one-to-one, serving as mounting holes for a set of injectors 32. The top diameter of the liquid branch pipe 322 is the same as the diameter of the opening on the liquid distribution plate 31. The lower end of the liquid branch pipe 322 is a conical opening located inside the mixing chamber 321. The diameter of the throat 325 is twice the diameter of the conical opening at the lower end of the liquid branch pipe 322. The diameter of the mixing chamber 321 is twice the diameter of the liquid branch pipe 322. The height of the diffusion chamber 326 is 0.6 times the height between the liquid distribution plate 31 and the gas distribution plate 33. A stirring shaft 5 extends vertically downwards from the top of the reactor, passing through the central hollow area between the liquid distribution plate 31 and the gas distribution plate 33 to the lower part of the reactor. The stirring shaft 5 has at least two sets of blades 42. The reactor also includes a rotating component 6 to provide kinetic energy to the stirring shaft 5 for rotation. An inner coil 41 is also installed inside the reaction chamber 4 for heat exchange. A circulating olefin outlet 17 is located on the surface of the vessel body 1 at the upper part of the reaction chamber 4, and a circulating olefin inlet 18 is located on the surface of the vessel body 1 at the location of the gas-liquid mixing injection component 3. A gas condensation circulation pipeline 7 is connected to the circulating olefin outlet 17 and the circulating olefin inlet 18 to circulate unreacted olefins back to the vessel body 1. A discharge port 16 is also provided at the bottom of the vessel body 1. A heat exchange jacket 19 is also provided on the exterior of the vessel body 1.

[0065]

Example 2

[0066] A reactor for oligomerization reaction includes a vessel body 1, a liquid feed chamber 2 arranged from top to bottom inside the vessel body 1, a gas-liquid mixing spray component 3, a reaction chamber 4, and a vertical stirring shaft 5; a first solvent inlet 11 is provided on the surface of the vessel body 1 at the position of the liquid feed chamber 2; an olefin feed inlet 12 is provided on the surface of the vessel body 1 at the position of the gas-liquid mixing spray component 3; a main catalyst feed inlet 13, a second solvent feed inlet 14, and a co-catalyst feed inlet 15 are provided on the surface of the vessel body 1 at the position of the reaction chamber 4; wherein, the first solvent introduced into the liquid feed chamber 2 through the first solvent feed inlet 11 enters the gas-liquid mixing spray component 3 and mixes with the olefin introduced into the olefin feed inlet 12 in the gas-liquid mixing spray component 3, and then is sprayed into the reaction chamber 4 to react with the mixture formed by the main catalyst introduced into the main catalyst feed inlet 13, the second solvent introduced into the second solvent feed inlet 14, and the co-catalyst introduced into the co-catalyst feed inlet 15.

[0067] The gas-liquid mixing injection component 3 has a liquid distribution plate 31, six sets of injectors 32, and a gas distribution plate 33 arranged from top to bottom. Each set of injectors 32 has a mixing chamber 321. A liquid branch pipe 322 and a nozzle 323 are arranged coaxially at the center of the mixing chamber 321. A gas inlet 324 is arranged on the side wall of the mixing chamber 321. A static mixer is arranged inside the mixing chamber 321. A throat pipe 325 and a diffusion chamber 326 are arranged sequentially at the lower end of the mixing chamber 321. The first solvent introduced through the first solvent inlet 11 enters the liquid branch pipe 322 and enters the mixing chamber 321 through the nozzle 323. The olefin introduced through the olefin inlet 12 enters the mixing chamber 321 through the gas inlet 324. In the mixing chamber 321, the first solvent mixes with the olefin and then enters the throat pipe 325 and the diffusion chamber 326 sequentially, and is injected into the reaction chamber 4.

[0068] The central axes of the mixing chamber 321, liquid branch pipe 32, nozzle 323, throat 325, and diffuser chamber 326 are collinear. The gas distribution plate 33 and liquid distribution plate 31 are coaxial plates with a hollow center, and the gas distribution plate 33 has a first opening, while the liquid distribution plate 31 has a second opening. The first opening serves as the mounting hole for the throat 325, and the second opening serves as the mounting hole for the liquid branch pipe 322. The first and second openings correspond one-to-one, serving as mounting holes for a set of injectors 32. The top diameter of the liquid branch pipe 322 is the same as the diameter of the opening on the liquid distribution plate 31. The lower end of the liquid branch pipe 322 is a conical opening located inside the mixing chamber 321. The diameter of the throat 325 is three times the diameter of the conical opening at the lower end of the liquid branch pipe 322. The diameter of the mixing chamber 321 is three times the diameter of the liquid branch pipe 322. The height of the diffusion chamber 326 is one time the height between the liquid distribution plate 31 and the gas distribution plate 33. A stirring shaft 5 extends vertically downwards from the top of the reactor, passing through the central hollow area between the liquid distribution plate 31 and the gas distribution plate 33 to the lower part of the reactor. The stirring shaft 5 has at least two sets of blades 42. The reactor also includes a rotating component 6 to provide kinetic energy to the stirring shaft 5 for rotation. An inner coil 41 is also installed inside the reaction chamber 4 for heat exchange. A circulating olefin outlet 17 is located on the surface of the vessel body 1 and at the upper part of the reaction chamber 4. A gas condensation circulation pipeline 7 is connected to the circulating olefin outlet 17 and the circulating olefin inlet 18 to circulate unreacted olefins back to the vessel body 1. A discharge port 16 is also provided at the bottom of the vessel body 1. A heat exchange jacket 19 is also provided on the outside of the vessel body 1.

[0069]

Example 3

[0070] The reactor used for the oligomerization reaction in Example 1 was employed. Operating parameters such as reaction temperature, reaction pressure, reaction time, and material flow rate were determined based on the required reaction conditions.

[0071] Open the material inlet valve and add the prepared main catalyst, co-catalyst solution and second solvent into the main catalyst inlet 13, co-catalyst inlet 15 and second solvent inlet 14 at a certain flow rate, and start the agitator.

[0072] Open the inlet valves of the first solvent inlet 11 and the olefin inlet 12 (olefin is ethylene), allowing part of the first solvent to enter the liquid feed chamber 2 through the first solvent inlet 11. Ethylene enters the mixing chamber 321 through the olefin inlet 12 and through the gas inlet 324 on its side wall. The first solvent forms a liquid level of a certain height in the liquid feed chamber 2. Then, under the action of its own water pressure and kinetic energy, the first solvent is ejected at high speed through the nozzle of the liquid branch pipe 322 of the ejector 32 into the mixing chamber 321, forming a high-speed jet. Ethylene enters the mixing chamber 321 through the gas inlet 324 on its side wall. 24 enters the mixing chamber, where ethylene is forcibly carried by the high-speed jet. The ethylene then rubs, mixes, and is compressed with the solvent in the high-speed jet to form a gas-liquid mixture. The gas-liquid mixture flows through the throat 325 and enters the diffusion chamber 326, thereby reducing the pressure in the mixing chamber and forming a vacuum or negative pressure zone, which is more conducive to the intake and mixing of gases and improves the gas-liquid mixing effect. The gas-liquid mixture is ejected from the outlet end of the diffusion chamber 326 to the reaction chamber 4 and reacts with the main catalyst introduced through the main catalyst inlet 13, the first solvent introduced through the first solvent inlet 14, and the co-catalyst introduced through the co-catalyst inlet 15.

[0073] As the amount of material in the reactor increases, when the liquid in the reactor reaches the set reaction volume, the feed and discharge flow rates are adjusted according to the reaction requirements. When the feed and discharge gradually reach equilibrium, continuous operation is achieved.

[0074] The reactor has a volume of 3.0 L. After evacuation, it is purged with nitrogen, followed by purging with ethylene. Methylcyclohexane is then introduced into the reactor at a flow rate of 2 L / h from the solvent tank outlet. 60% by weight of the methylcyclohexane enters the reactor through the second solvent inlet, while the remaining 40% by weight enters the reactor's liquid feed chamber through the first solvent inlet. After mixing with ethylene through a gas-liquid injection pipe, the mixture is injected into the catalyst-containing solution. A methylcyclohexane solution of modified methylaluminoxane (MMAO, purchased from AkzoNobel) is introduced into the reactor at a flow rate of 50 mL / h (20 mmol / h as Al) from the co-catalyst inlet. The main catalysts are chromium acetylacetone (purchased from Beijing Bailingwei Chemical Reagent Co., Ltd.) and bisphosphine ligands (prepared in-house, preparation process referenced from Chinese Patent CN 111434669). Preparation Example 3) The catalyst was mixed at a molar ratio of 1:2 and prepared into a solution using methylcyclohexane. The solution was then introduced into the reaction chamber through the main catalyst inlet at a flow rate of 50 mL / h (10 μmol / h as Cr). High-purity ethylene was continuously supplied to the reactor through the olefin inlet, and after being mixed with the solvent via an injector, it was injected into the catalyst-containing solution. The ethylene oligomerization reaction was carried out at 4 MPa and 40 °C, producing 1-hexene, 1-octene, and other C10+ oligomers. The reaction solution was collected from the bottom outlet of the reactor, quenched, and sent to the separation unit. The discharge rate of the reaction solution was adjusted according to the reaction conditions (maintaining a liquid level of 2 L in the reactor).

[0075] The device operated continuously for 120 hours under the above process without any pipe blockage. The heat removal effect of the reactor was stable. Periodic sampling and analysis of the reaction solution composition were performed to calculate catalyst activity and product composition. Experimental results showed that the reaction activity was 4.0 × 10⁻⁶. 8 g·mol(Cr) -1 ·h -1 The overall selectivity for 1-hexene and 1-octene was 94.7%. The reactor was opened to check for any polymer fouling at the reactor ejector outlet, and it was confirmed that no polymer fouling was deposited.

[0076]

Example 4

[0077] The ethylene polymerization reaction was carried out using the same method as in Example 3, except that the main catalyst, chromium acetylacetone, was replaced with chromium tri(tetrahydrofuran)trichloride. The experimental results showed that the reaction activity was 2.7 × 10⁻⁶. 8 g·mol(Cr) -1 ·h -1 The overall selectivity for 1-hexene and 1-octene was 93.9%. The reactor was opened to check for any polymer fouling at the reactor ejector outlet, and it was confirmed that no polymer fouling was deposited.

[0078]

Example 5

[0079] The ethylene polymerization reaction was carried out using the same method as in Example 3, but the solvent was replaced with heptane. The experimental results showed that the reaction activity was 4.1 × 10⁻⁶. 8 g·mol(Cr) -1 ·h -1 The overall selectivity for 1-hexene and 1-octene was 93.1%. The reactor was opened to check for any polymer fouling at the reactor ejector outlet, and it was confirmed that no polymer fouling was deposited.

[0080]

Example 6

[0081] The ethylene polymerization reaction was carried out using the same method as in Example 3, but the solvent was changed to toluene. The experimental results showed that the reaction activity was 1.6 × 10⁻⁶. 8 g·mol(Cr) -1 ·h -1 The total selectivity for 1-hexene and 1-octene was 92.9%. The reactor was opened to check for any polymer fouling at the reactor ejector outlet, and it was confirmed that no polymer fouling was deposited.

[0082]

Example 7

[0083] The ethylene polymerization reaction was carried out using the same method as in Example 1, wherein 80% by weight of methylcyclohexane entered the reactor through the second solvent inlet, and 20% by weight of methylcyclohexane entered the liquid feed chamber of the reactor through the first solvent inlet. After being mixed with ethylene through a gas-liquid injection pipe, the mixture was injected into the catalyst-containing solution. Experimental results: The reaction activity was 3.2 × 10⁻⁶. 8 g·mol(Cr) -1 ·h -1 The total selectivity for 1-hexene and 1-octene was 94.8%. The reactor was opened to check for any polymer fouling at the reactor ejector outlet, and it was confirmed that no polymer fouling was deposited.

[0084]

Example 8

[0085] The ethylene polymerization reaction was carried out using the same method as in Example 1, except that all the solvent methylcyclohexane was introduced into the liquid feed chamber of the reactor through the first solvent inlet, mixed with ethylene through a gas-liquid injection pipe, and then injected into the catalyst-containing solution. Experimental results showed that the reaction activity was 4.2 × 10⁻⁶. 8 g·mol(Cr) -1 ·h -1 The total selectivity for 1-hexene and 1-octene was 92.1%. The reactor was opened to check for any polymer fouling at the reactor ejector outlet, and it was confirmed that no polymer fouling was deposited.

[0086] Comparative Example 1

[0087] This comparison is based on Figure 1 The reactor shown differs in that the ethylene used for the reaction is fed directly into the reactor via a separate gas-phase pipeline, and the inlet pipe does not contact the catalyst-containing solution. All other conditions are identical to the example. The device operated for 120 hours without pipeline blockage, and the reactor's heat dissipation effect remained stable. Periodic sampling and analysis of the reaction solution composition were conducted to calculate catalyst activity and product composition. Experimental results showed a reaction activity of 1.3 × 10⁻⁶. 8 g·mol(Cr) -1 ·h -1 The total selectivity for 1-hexene and 1-octene was 92.5%. The reactor was opened to check for any polymer fouling at the reactor ejector outlet, and it was confirmed that no polymer fouling was deposited.

[0088] Comparative Example 2

[0089] This comparison is based on Figure 1 The reactor shown differs in that the ethylene used for the reaction is fed directly into the reactor from the bottom via a separate gas-phase line, with the inlet pipe in contact with the catalyst-containing solution. All other conditions are identical to the example. After 24 hours of operation, no gas flow was observed at the ethylene inlet, and the reaction temperature gradually decreased. The reactor was opened to check for any polymer fouling at the reactor ejector outlet, and it was confirmed that the ethylene inlet was blocked by polymer.

[0090] The above description is merely a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, based on the technical teachings provided by the present invention and as common knowledge in the field, other equivalent modifications and improvements can be made, and these should also be considered within the scope of protection of the present invention.

Claims

1. A method for carrying out an oligomerization reaction using a reactor for oligomerization, characterized in that, The reactor includes a vessel body (1), and inside the vessel body (1) arranged from top to bottom: a liquid feed chamber (2), a gas-liquid mixing jet component (3), and a reaction chamber (4). A vertical stirring shaft (5) is also provided inside the vessel body (1). A first solvent inlet (11) is provided on the surface of the vessel body (1) at the position of the liquid feed chamber (2). An olefin inlet (12) is provided on the surface of the vessel body (1) at the position of the gas-liquid mixing jet component (3). A main catalyst inlet (13), a second solvent inlet (14), and a co-catalyst inlet (15) are provided on the surface of the vessel body (1) at the position of the reaction chamber (4). The gas-liquid mixing injection component (3) includes a liquid distribution plate (31), multiple sets of injectors (32), and a gas distribution plate (33) arranged from top to bottom. Each set of injectors (32) includes a mixing chamber (321), a liquid branch pipe (322) and a nozzle (323) are arranged at the coaxial center of the mixing chamber (321), a gas inlet (324) is arranged on the side wall of the mixing chamber (321), a static mixer is arranged inside the mixing chamber (321), and a throat pipe (325) and a diffusion chamber (326) are arranged sequentially at the lower end of the mixing chamber (321). The first solvent introduced through the first solvent inlet (11) enters the liquid branch pipe (322) and enters the mixing chamber (321) through the nozzle (323); the olefin introduced through the olefin inlet (12) enters the mixing chamber (321) through the gas inlet (324). In the mixing chamber (321), the first solvent mixes with the olefin and then enters the throat pipe (325) and the diffusion chamber (326) in sequence, and is sprayed into the reaction chamber (4). The gas distribution plate (33) and the liquid distribution plate (31) are coaxial plates with a central hole, and the gas distribution plate (33) is provided with a first hole and the liquid distribution plate (31) is provided with a second hole; the first hole is the mounting hole for the throat pipe (325) and the second hole is the mounting hole for the liquid branch pipe (322); the first hole and the second hole correspond one-to-one as mounting holes for a set of injectors (32); The method includes the following steps: a first solvent is introduced into a liquid feed chamber (2) through a first solvent inlet (11) and then into a gas-liquid mixing spray component (3), and then mixed with olefins introduced through an olefin inlet (12) in the gas-liquid mixing spray component (3), and then sprayed into a reaction chamber (4) to react with the catalyst solution in the reaction chamber (4). The catalyst solution is formed by mixing the main catalyst introduced through the main catalyst inlet (13), the second solvent introduced through the second solvent inlet (14), and the co-catalyst introduced through the co-catalyst inlet (15).

2. The method according to claim 1, characterized in that, The central axes of the mixing chamber (321), liquid branch pipe (322), nozzle (323), throat pipe (325) and diffusion chamber (326) are located on the same straight line.

3. The method according to claim 1, characterized in that, The top diameter of the liquid branch pipe (322) is the same as the diameter of the opening on the liquid distribution plate (31).

4. The method according to any one of claims 1-3, characterized in that, The lower end of the liquid branch pipe (322) is a conical hole located inside the mixing chamber (321).

5. The method according to claim 4, characterized in that, The diameter of the throat (325) is 2-3 times the diameter of the conical hole at the lower end of the liquid branch (322).

6. The method according to any one of claims 1-3, characterized in that, The diameter of the mixing chamber (321) is 2-3 times the diameter of the liquid branch pipe (322).

7. The method according to any one of claims 1-3, characterized in that, The height of the diffusion chamber (326) is 0.6-1 times the height between the liquid distribution plate (31) and the gas distribution plate (33).

8. The method according to any one of claims 1-3, characterized in that, The reaction chamber (4) is also equipped with a paddle (42).

9. The method according to any one of claims 1-3, characterized in that, An inner coil (41) is also provided inside the reaction chamber (4) for heat exchange.

10. The method according to any one of claims 1-3, characterized in that, A circulating olefin outlet (17) is provided on the surface of the vessel body (1) and at the upper part of the reaction chamber (4). A circulating olefin inlet (18) is provided on the surface of the vessel body (1) and at the position of the gas-liquid mixing injection component (3). A gas condensation circulation pipeline (7) is connected to the circulating olefin outlet (17) and the circulating olefin inlet (18) to circulate unreacted olefins into the vessel body (1).

11. The method according to any one of claims 1-3, characterized in that, The bottom of the vessel body (1) is also provided with a discharge port (16).

12. The method according to any one of claims 1-3, characterized in that, A heat exchange jacket (19) is also provided on the outside of the vessel body (1).

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