Oscillating micro-reaction system and method for preparing alkylaluminoxane by using oscillating micro-reaction system
By using an oscillating microreaction system in the synthesis of alkylaluminoxanes, and utilizing a combination of a helical tube and an oscillating device, the safety risks and clogging problems in the synthesis of alkylaluminoxanes have been solved, and safe, stable, continuous production and efficient preparation have been achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-12
- Publication Date
- 2026-04-14
AI Technical Summary
Existing alkylaluminoxane synthesis processes suffer from high safety risks, low yields, small production capacities, large amounts of hazardous waste, and easy clogging of microreactors. In particular, continuous production and safety control are difficult to achieve in direct hydrolysis processes.
An oscillating microreactor system is adopted, including an aqueous phase storage tank, an alkyl aluminum solution storage tank, a spiral tube microreactor with a smooth inner wall, and an oscillation device. The spiral tube extends the material residence time, and the oscillation device controls the material dispersion and mixing uniformity, avoiding excessively violent local reactions, and the oscillation washes the inner wall to prevent clogging.
It has enabled the safe and stable production of alkylaluminoxanes, avoided microreactor clogging, ensured continuous production, improved production safety and economy, simplified equipment structure and reduced maintenance difficulty.
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Figure CN121847018A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of polyolefin cocatalyst technology, and in particular to an oscillating microreaction system and a method for preparing alkylaluminoxanes using the oscillating microreaction system. Background Technology
[0002] Alkyl aluminum oxanes are among the most important cocatalysts in the field of olefin polymerization, mainly including methylaluminoxane (MAO) and modified methylaluminoxane (MMAO). When combined with metallocene catalysts or post-transition metal catalysts, they exhibit high catalytic activity and can be used to prepare various homopolymers and copolymers with special structures and properties, finding wide application in food, automotive, agriculture, construction, packaging, aerospace, and defense industries.
[0003] Alkyl aluminum oxanes can be generated by partial hydrolysis of alkyl aluminum. However, alkyl aluminum, especially low-carbon alkyl aluminum, has the physical and chemical properties of burning in air and exploding in water. This makes its hydrolysis preparation reaction a violent reaction that is instantaneously exothermic. This not only may cause a violent explosion and poses a great safety risk, but also places extremely high demands on reaction control and synthesis equipment.
[0004] Among existing synthesis processes, indirect hydrolysis, while safe and controllable, suffers from low yield, small production capacity, and large amounts of hazardous waste. Direct water processes, on the other hand, offer advantages such as high reaction yield, less solid waste, and shorter reaction time, making them a suitable choice for large-scale production. However, direct water processes require specific process conditions or special micro-water introduction equipment to introduce gaseous, liquid, or solid water into the reactor to react with alkylaluminum. The core challenge lies in reaction control and safety assurance. With the development of microreactor technology, reaction processes centered on microflow reactors / reactors have been applied. However, insoluble products are inevitably generated during the synthesis of alkylaluminoxanes. For microreactors with extremely small diameters, the preparation of alkylaluminoxanes is prone to clogging, leading not only to frequent forced shutdowns for cleaning and preventing continuous reaction but also posing significant safety risks. In related technologies, continuous stirring is often used to improve solids handling capacity, or mass transfer is enhanced through built-in static mixing structures to reduce solid agglomeration and thus avoid pipeline blockage. However, neither of these methods has clearly demonstrated its effectiveness in solving the blockage problem. Moreover, the device design is complex and requires the addition of plate / block structures inside the device. These structures themselves are also prone to precipitation and solid accumulation, which may lead to blockage problems. Summary of the Invention
[0005] This application is made in view of the above problems. This application provides an oscillating microreaction system, comprising: Aqueous phase storage tanks, alkyl aluminum solution storage tanks, tubular microreactors, shaking devices, and reaction vessels; The tubular microreactor includes at least one set of spiral tubes with smooth inner walls; the outlets of the aqueous phase storage tank and the alkyl aluminum solution storage tank are respectively connected to the inlet of the spiral tubes, and the outlet of the spiral tubes is connected to the inlet of the reaction vessel; the oscillation device is disposed on the tubular microreactor; wherein the aqueous phase storage tank has an emulsification function.
[0006] Compared with existing technologies, the oscillating microreactor system provided in this application includes an aqueous phase storage tank, an alkyl aluminum solution storage tank, a tubular microreactor, an oscillation device, and a reaction vessel. The tubular microreactor includes at least one set of spiral tubes with smooth inner walls. The outlets of the aqueous phase storage tank and the alkyl aluminum solution storage tank are respectively connected to the inlets of the spiral tubes, and the outlet of the spiral tubes is connected to the inlet of the reaction vessel. Therefore, when the reactants enter the tubular microreactor along the aqueous phase storage tank and the alkyl aluminum solution storage tank, the residence time of the materials can be extended through the spiral tubes. Furthermore, under the action of the oscillation device installed on the tubular microreactor, the dispersion of the alkyl aluminum feed stream and the water feed stream can be controlled, ensuring sufficient contact and uniform mixing between the two phases. This achieves stable control of the reaction process, avoids excessively violent local reactions, and improves the safety of the oscillating microreactor system. Furthermore, due to the smooth inner wall of the helical tube and the absence of baffles and stirrers that easily accumulate solids, the continuous flushing of the inner wall by the reactants under the action of the oscillation device can promptly remove any solid precipitates that may form. This solves the problem of clogging in microreactors and avoids safety hazards such as reaction interruptions or sudden pressure increases caused by pipeline blockage, greatly improving process safety and providing a stable guarantee for large-scale, continuous production. In addition, the synergistic effect of the helical tube's flow channel design and the oscillation device can generate strong flow field disturbances and form fluid vortices, achieving rapid and uniform mixing of materials. This eliminates the need for complex structures for mixing materials inside the helical tube, simplifying the internal structure of the tubular microreactor, reducing equipment processing and manufacturing costs and maintenance difficulty, and further enhancing the system's economy and practicality.
[0007] Based on this, the oscillating microreactor system provided in this application, with its simple structure and low operation and maintenance difficulty, can not only achieve stable control of the reaction process, but also solve the problem of microreactor blockage, thus avoiding safety hazards such as reaction interruption or sudden pressure rise caused by pipeline blockage.
[0008] According to another aspect of this application, an application of an oscillating microreaction system in the preparation of alkylaluminoxanes is also provided.
[0009] Compared with the prior art, the beneficial effects of the oscillating microreaction system provided in this application in the preparation of alkylaluminoxanes are the same as those of the oscillating microreaction system described above, and will not be repeated here.
[0010] It should be understood that both the foregoing general description and the following detailed description are exemplary and intended to provide further illustration of the claimed technology. Attached Figure Description
[0011] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments of this application in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof. In the accompanying drawings, the same reference numerals generally represent the same components or steps.
[0012] Figure 1 A schematic diagram of the structure of the oscillating microreaction system according to an embodiment of this application is shown; Figure 2 A schematic diagram of the tubular microreactor and oscillation device according to an embodiment of this application is shown. Detailed Implementation
[0013] To make the objectives, technical solutions, and advantages of this application more apparent, exemplary embodiments according to this application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments of this application. It should be understood that this application is not limited to the exemplary embodiments described herein.
[0014] Alkyl aluminum oxanes are among the most important cocatalysts in the field of olefin polymerization, mainly including methylaluminoxane (MAO) and modified methylaluminoxane (MMAO). When combined with metallocene catalysts or post-transition metal catalysts, they exhibit high catalytic activity and can be used to prepare various homopolymers and copolymers with special structures and properties, finding wide application in food, automotive, agriculture, construction, packaging, aerospace, and defense industries.
[0015] Alkyl aluminum oxanes can be generated by partial hydrolysis of alkyl aluminum. However, alkyl aluminum, especially low-carbon alkyl aluminum, has the physical and chemical properties of burning in air and exploding in water. This makes its hydrolysis preparation reaction a violent reaction that is instantaneously exothermic. This not only may cause a violent explosion and poses a great safety risk, but also places extremely high demands on reaction control and synthesis equipment.
[0016] Among existing synthesis processes, indirect hydrolysis, while safe and controllable, suffers from low yield, small production capacity, and large amounts of hazardous waste. Direct water processes, on the other hand, offer advantages such as high reaction yield, less solid waste, and shorter reaction time, making them a suitable choice for large-scale production. However, direct water processes require specific process conditions or special micro-water introduction equipment to introduce gaseous, liquid, or solid water into the reactor to react with alkylaluminum. The core challenge lies in reaction control and safety assurance. With the development of microreactor technology, reaction processes centered on micro-pipeline reactors have been applied. However, the alkylaluminum oxanes generated during the synthesis of alkylaluminum oxanes further react with water, producing solid precipitates. This side reaction is also a violent, instantaneous reaction, difficult to control, inevitably leading to the formation of insoluble products during synthesis. For microreactors with extremely small diameters, these products easily cause blockages, leading not only to frequent forced shutdowns for cleaning and preventing continuous reaction but also posing significant safety risks. In related technologies, continuous stirring is often used to improve solids handling capacity, or mass transfer is enhanced through built-in static mixing structures to reduce solid agglomeration and thus avoid pipeline blockage. However, neither of these methods has clearly demonstrated its effectiveness in solving the blockage problem. Moreover, the device design is complex and requires the addition of plate / block structures inside the device. These structures themselves are also prone to precipitation and solid accumulation, which may lead to blockage problems.
[0017] To address the aforementioned issues, this application provides an oscillating microreactor system that, while possessing a simple structure and low operational and maintenance difficulty, not only enables stable control of the reaction process but also solves the problem of microreactor blockage, thus avoiding safety hazards such as reaction interruption or sudden pressure surge caused by pipeline blockage. Figure 1 A schematic diagram of the structure of an oscillating microreaction system according to an embodiment of this application is shown. Figure 2 A schematic diagram of the tubular microreactor and oscillation device according to an embodiment of this application is shown. Figure 1 and Figure 2 As shown, the oscillating microreaction system includes: 1. Aqueous phase storage tank; 2. Alkyl aluminum solution storage tank; 3. Tubular microreactor; 4. Shaking device; and 5. Reactor. The tubular microreactor 3 includes at least one set of spiral tubes 301 with smooth inner walls; the outlets of the aqueous phase storage tank 1 and the alkyl aluminum solution storage tank 2 are respectively connected to the inlet of the spiral tube 301, and the outlet of the spiral tube 301 is connected to the inlet of the reaction vessel 5; the oscillation device 4 is installed on the tubular microreactor 3; wherein the aqueous phase storage tank 1 has an emulsification function.
[0018] Understandably, the aqueous phase storage tank 1 is a tank for water or water and an inert solvent, equipped with means such as high-speed stirring or ultrasound to thoroughly mix the two into an emulsion of water. The alkyl aluminum solution storage tank 2 is a tank for a dilute alkyl aluminum solution, which requires a stirring and cooling temperature control system. The tubular microreactor 3 requires a cooling temperature control system. The reaction vessel 5 is a jacketed and stirred reaction vessel used to receive the material flowing out of the tubular microreactor 3 and to carry out subsequent reactions. Furthermore, as long as the volume of the product receiving reaction vessel 5 is large enough or multiple reaction vessels 5 exist, 24-hour continuous production can be achieved without stopping for a long period of time.
[0019] In practice, emulsified water or distilled water stored in aqueous phase storage tank 1 and low-temperature dilute alkyl aluminum solution stored in alkyl aluminum solution storage tank 2 are transported to the inlet of the spiral tube 301 of the tubular microreactor 3. The two materials converge at low temperature, and at the same time, the oscillation device 4 is started to drive the materials in the spiral tube 301 to form an oscillating flow. This not only achieves rapid and uniform mixing of materials, but also avoids the adhesion and accumulation of insoluble solid precipitates generated during the reaction by scouring the smooth inner wall of the spiral tube 301 through oscillation. After the above materials undergo the hydrolysis reaction of alkyl aluminum, the reaction liquid flows into the inlet of the reactor 5 through the outlet of the spiral tube 301. After being fully stirred and reacted for a period of time at room temperature, the alkyl aluminum oxane product is finally obtained.
[0020] In one alternative approach, such as Figure 1 and Figure 2 As shown, the length of the spiral tube 301 in this embodiment is 0.1 to 30 meters, which can meet the reaction time required for the hydrolysis reaction of alkyl aluminum and water and the control of side reactions, ensure that the two materials are fully mixed in the tube, and guarantee the product yield and purity. It can also avoid the problem of insufficient reaction due to insufficient material contact time caused by the tube being too short.
[0021] Furthermore, the inner wall of the spiral tube 301 in this embodiment does not contain any structural design and requires a smoothing process, such as polishing. It should be understood that the number and length of the spiral tubes 301 can be adjusted according to actual conditions, and a range of 0.1 to 30 meters is a preferred range in this embodiment.
[0022] For example, such as Figure 1 and Figure 2As shown, the tubular microreactor 3 in this embodiment further includes a shell 302 with temperature control function. A spiral tube 301 is disposed inside the shell 302. The shell 302 has an inlet and an outlet. The outlets of the aqueous phase storage tank 1 and the alkyl aluminum solution storage tank 2 are respectively connected to the inlet of the spiral tube 301 through the inlet. The outlet of the spiral tube 301 extends out of the outlet and is connected to the inlet of the reactor 5. An oscillation device 4 is disposed on the outer wall of the shell 302. The shell 302 provides stable support and protection for the spiral tube 301, avoiding damage or material leakage risks caused by direct exposure of the spiral tube 301. The oscillation device 4 is disposed on the outer wall of the shell 302, which can uniformly transmit the oscillation force to the internal spiral tube 301 through the shell 302, ensuring that the material inside the tube forms a stable oscillating flow, enhancing the mixing effect and flushing the inner wall to prevent blockage. It also avoids direct contact between the oscillation device 4 and the reactants inside the tube, reducing the risk of equipment corrosion or contamination products.
[0023] For example, such as Figure 1 and Figure 2 As shown, the tubular microreactor 3 in this embodiment further includes a connector 303 for multiple feeds. The connector 303 is disposed inside the feed inlet and has a first branch inlet 3031, a second branch inlet 3032, and a total outlet 3033. The first branch inlet 3031 is connected to the outlet of the aqueous phase storage tank 1, the second branch inlet 3032 is connected to the outlet of the alkyl aluminum solution storage tank 2, and the outlet of the connector 303 is connected to the inlet of the spiral tube 301. In this embodiment, by connecting the first branch inlet 3031 and the second branch inlet 3032 to the aqueous phase storage tank 1 and the alkyl aluminum solution storage tank 2 respectively, and then connecting the total outlet 3033 to the inlet of the spiral tube 301, precise pre-convergence of the two materials before entering the spiral tube 301 can be achieved, avoiding the problem of uneven mixing caused by direct material input.
[0024] Specifically, the connector 303 for various feeds in this application embodiment includes a T-type connector or a Y-type connector. It should be understood that other micro-water injection methods applied to the oscillating flow microreactor should be considered variations of this invention, including but not limited to the use of various nano / micro-scale or even molecular-scale delivery methods such as micro / miniature syringes, micro-sieve arrays, capillaries or capillary arrays, membrane materials, and microchannel reactors in the oscillating microreactor system for the production of alkylaluminoxanes.
[0025] For example, such as Figure 1 and Figure 2 As shown, the oscillating microreaction system in this embodiment of the application further includes a delivery pump P1 and an oscillating pump P2; the delivery pump P1 is located between the outlet of the aqueous phase storage tank 1 and the first branch inlet 3031, and the oscillating pump P2 is located between the outlet of the alkyl aluminum solution storage tank 2 and the second branch inlet 3032.
[0026] In practice, after the transfer pump P1 starts, it stably delivers the emulsified water or distilled water stored in the aqueous phase storage tank 1 to the first branch inlet 3031 of the connector 303. Simultaneously, the oscillating pump P2 starts, precisely pumping the dilute alkyl aluminum solution from the alkyl aluminum solution storage tank 2 to the second branch inlet 3032 of the connector 303. This further enhances the oscillating flow of the material within the spiral tube 301, enabling rapid and uniform mixing of the material and increasing the scouring effect on the inner wall of the tube, reducing the accumulation of insoluble solids. Furthermore, the transfer pump P1 and the oscillating pump P2 can independently control the feed rate of their respective materials to achieve precise control of the reaction process. Subsequent processes are described above and will not be repeated here.
[0027] For example, such as Figure 1 and Figure 2 As shown, in the embodiments of this application, the pipeline between the outlet of the aqueous phase storage tank 1 and the first branch inlet 3031, and the pipeline between the outlet of the alkyl aluminum solution storage tank 2 and the second branch inlet 3032, are all flexible hoses resistant to alkyl aluminum inert solvents.
[0028] The flexible hose possesses excellent flexibility and deformation capabilities, enabling it to adapt to the oscillation characteristics of the oscillating pump P2 and the oscillation effect of the tubular microreactor 3. This avoids the rigidity of hard pipes and connections from hindering the transmission of oscillating force, ensuring the stable formation of the oscillating flow state, and thus ensuring material mixing efficiency and anti-clogging effect. At the same time, the flexible hose can better adapt to equipment installation deviations, reduce stress concentration at connection points, reduce the risk of sealing failure that is prone to occur with hard connections, and avoid safety accidents caused by leakage of flammable and explosive materials such as alkyl aluminum. It not only meets the process requirements for oscillation effect but also enhances the airtightness and safety of the device operation, providing an important guarantee for the stable and continuous operation of the system.
[0029] Preferably, the hose resistant to alkyl aluminum inert solvents in this application embodiment is a stainless steel hose.
[0030] In one alternative approach, such as Figure 1 and Figure 2 As shown, the oscillating micro-reaction system of this application embodiment also includes a one-way valve F, which is disposed at the first branch inlet 3031 and the second branch inlet 3032 to ensure the one-way flow of emulsified water or distilled water.
[0031] Preferably, the oscillation device 4 of this application can be a common device that causes the microreactor to oscillate, such as a rotary oscillator, a vertical oscillator, a vortex oscillator, a vibrating shaker, an ultrasonic oscillator, etc.
[0032] This application also provides a method for preparing alkylaluminoxanes using an oscillating microreactor system, which can safely, stably, and efficiently produce alkylaluminoxanes. The method includes: emulsified water in an aqueous phase storage tank and a low-temperature dilute alkylaluminum solution in an alkylaluminum solution storage tank are introduced into a tubular microreactor and reacted under the action of an oscillating device; the reaction solution leaves the tubular microreactor and enters a reaction vessel; after the reaction is completed under stirring, it is filtered, desolventized, and dried to obtain the alkylaluminoxane product.
[0033] In an alternative embodiment, the alkylaluminum in this application can be any hydrocarbon aluminum compound capable of reacting with water to form aluminum oxanes, preferably trialkylaluminum, such as one or more of triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, and tri-n-octylaluminum.
[0034] In one alternative embodiment, the solvent used for the alkyl aluminum dilute solution in this application is any inert solvent, preferably aliphatic and aromatic hydrocarbons. More preferably, aromatic hydrocarbons, such as toluene, xylene, ethylbenzene, cumene, mesitylene, etc., and most preferably toluene and heptane.
[0035] In one alternative approach, the concentration range of the alkyl aluminum dilute solution in this application embodiment is 1-60 wt%, preferably 5-50 wt%, and more preferably 10-40 wt%.
[0036] In one alternative embodiment, the molar ratio of the total amount of reaction water to the total amount of alkyl aluminum added in this application embodiment is 0.1-2, preferably 0.2-1.5, and more preferably 0.3-1.2.
[0037] In one alternative approach, the reaction temperature of the embodiments of this application is controlled between -80°C and 300°C, preferably between -60°C and 200°C, and more preferably between -40°C and 180°C.
[0038] In one alternative approach, the reaction time of the embodiments of this application can be 0-72 hours, preferably 3-48 hours, and more preferably 6-24 hours.
[0039] To verify the effectiveness of the oscillating microreaction system provided in the embodiments of this application, the following are examples and comparative examples.
[0040] Example 1 This embodiment is used to prepare MAO, and the specific process is as follows: The oscillating microreactor system was thoroughly vacuum dried and purged with nitrogen. Under nitrogen protection, toluene and distilled water were added to the aqueous phase tank at a volume ratio of 30:1, and high-speed stirring was activated to create an emulsion of water and toluene in the aqueous phase tank. Under nitrogen protection, a 2 mol / L toluene solution of trimethylaluminum was added to the alkylaluminum solution tank, and stirring was activated. The cryogenic system was then activated to cool the dilute trimethylaluminum solution in the alkylaluminum solution tank to -40°C. The cryogenic system of the tubular microreactor was activated and set to -40°C. The emulsion water was pumped at a flow rate of 50 ml / min and injected into the inlet of the spiral tube of the tubular microreactor through the first branch inlet. The trimethylaluminum toluene solution was pumped at a flow rate of 60 ml / min and injected into the inlet of the spiral tube of the tubular microreactor through the second branch inlet. The feed rate was approximately 0.75 molar ratio of water to alkylaluminum. Simultaneously, the oscillation device was activated to prevent solid precipitation, accumulation, and blockage inside the tubular microreactor. Then, the stirrer in the reactor was turned on and the temperature was maintained at 20°C. The reaction was continued for 10 hours without any clogging of the microreactor. The discharged reaction solution was filtered and toluene was removed under reduced pressure to obtain approximately 3.2 kg of white methylaluminoxane product, with a yield of 76%.
[0041] Example 2 This embodiment is used to prepare isobutyl-modified MMAO, and the specific process is as follows: The oscillating microreactor system was thoroughly vacuum dried and purged with nitrogen. Under nitrogen protection, heptane and distilled water were added to the aqueous phase tank at a volume ratio of 30:1, and high-speed stirring was activated to create an emulsion of water and toluene in the aqueous phase tank. Under nitrogen protection, a heptane solution with a concentration of 2 mol / L trimethylaluminum and 2 mol / L triisobutylaluminum was added to the alkylaluminum solution tank at a volume ratio of 6:4, and stirring was activated. The cryogenic system was then activated to cool the dilute trimethylaluminum solution in the alkylaluminum solution tank to -40°C. The cryogenic system of the tubular microreactor was activated and the temperature was set to -40°C. The delivery pump pump delivered emulsified water at a flow rate of 50 ml / min, injecting it into the inlet of the spiral tube of the tubular microreactor through the first branch inlet. The oscillating pump delivered a toluene solution of trimethylaluminum at a flow rate of 60 ml / min, injecting it into the inlet of the spiral tube of the tubular microreactor through the second branch inlet. The feed rate was approximately 0.75 (water / alkylaluminum molar ratio). Simultaneously, the oscillator was activated to prevent solid precipitation, accumulation, and clogging inside the tubular microreactor. Then, the agitator in the reactor was turned on, and the temperature was maintained at 20°C. After 10 hours of continuous reaction, no microreactor clogging was observed. The discharged reaction solution was filtered and subjected to reduced pressure to remove volatile components, ultimately yielding approximately 21.7 kg of MMAO solution with a 7% aluminum content, representing a yield of 78%.
[0042] Example 3 In this embodiment, MAO was used as a co-catalyst for ethylene polymerization. The main catalyst used in the polymerization experiment evaluation was rac-ethylene bis(1-indenyl)zirconium dichloride, with the following structural formula:
[0043] The 500ml polymerization reactor, after being heated and dried, was evacuated and purged with nitrogen three times. After evacuation again, ethylene gas was introduced. Then, 5ml of a 10% MAO toluene solution prepared in Example 1, 150ml of anhydrous and oxygen-free n-hexane, and 1ml of a toluene / heptane solution containing 5.0 μmol / ml rac-ethylenebis(1-indenyl)zirconium dichloride were added sequentially. Ethylene was introduced at a pressure of 0.7 MPa under mechanical stirring, and the reaction was carried out at 50°C for 30 min. Ethanol was then added to terminate the reaction. The resulting polymer was weighed and its activity was calculated. The results are shown in Table 1.
[0044] Example 4 This embodiment uses MMAO as a co-catalyst for ethylene polymerization, and the specific process is as follows: The method of Example 3 is the same, except that 5 ml of MMAO heptane aluminum solution with a mass fraction of 7% prepared in Example 2 is used as a co-catalyst.
[0045] Comparative Example 1 This comparative example was used to prepare MAO, and the specific process is as follows: The tubular microreactor in the oscillating microreactor system was replaced with a transparent, visible conventional microreactor, without an oscillating pump, helical tube design, or oscillation device. This conventional reaction system was thoroughly vacuum-dried and purged with nitrogen. Under nitrogen protection, toluene and distilled water were added to the aqueous phase tank at a volume ratio of 30:1, and high-speed stirring was activated to create an emulsion of water and toluene in the aqueous phase tank. Under nitrogen protection, a 2 mol / L toluene solution of trimethylaluminum was added to the alkylaluminum solution tank, and stirring was activated. The cryogenic system was then activated to cool the dilute trimethylaluminum solution in the alkylaluminum solution tank to -40°C. The cryogenic system of the conventional microreactor was activated and set to -40°C. A delivery pump delivered the emulsion water to the inlet of the conventional microreactor at a flow rate of 50 ml / min. A conventional delivery pump delivered the toluene solution of trimethylaluminum to the inlet of the conventional microreactor at a flow rate of 60 ml / min. After preliminary reaction, the solution entered the reaction vessel for further reaction. Then, the stirring in the reaction vessel was activated, and the temperature was maintained at 20°C. After about 10 minutes of reaction, solids began to accumulate on the inner wall of the microreactor. After 0.5 hours, more serious solid accumulation and blockage occurred (the amount of reaction liquid flowing into the reaction vessel through the microreactor was significantly reduced). For safety reasons, the reaction was forced to stop.
[0046] Finally, ethylene polymerization was carried out according to the method of Example 3.
[0047] Comparative Example 2 This comparative example uses imported MAO as a co-catalyst for ethylene polymerization, following the method of Example 3, except that 5 ml of 10% toluene solution of commercial-grade MAO from Grace Company is used as the co-catalyst.
[0048] Comparative Example 3 This comparative example uses imported MMAO-3A as a cocatalyst for ethylene polymerization, following the method of Example 3, except that 5 ml of Nouryon's commercial-grade 7% aluminum MMAO-3A heptane solution is used as the cocatalyst.
[0049] Table 1 shows the test results of Embodiments 3 and 4 of this application and the comparative example.
[0050] Table 1
[0051] As shown in Table 1, comparing the evaluation results of Example 3 and Comparative Examples 1 and 2, it can be seen that the MAO synthesized using the oscillating microreactor system of this application has a high product yield, and the microreactor achieves continuous and stable control of the hydrolysis reaction. The obtained MAO has high catalytic activity, and the reactor is not clogged. Moreover, its activity performance is slightly better than that of imported commercial catalysts.
[0052] As shown in Table 1, the evaluation results of Comparative Example 4 and Comparative Example 2 show that the MMAO synthesized using the oscillating microreactor system of this application has a high product yield, and the microreactor achieves continuous and stable control of the hydrolysis reaction. The obtained MMAO has high catalytic activity, and its activity performance is slightly better than that of imported commercial products.
[0053] The above description is merely a specific embodiment of this application. Obviously, various modifications and combinations can be made without departing from the spirit and scope of this application. Accordingly, this specification and accompanying drawings are merely exemplary descriptions of this application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and modifications of this application fall within the scope of the claims of this application and their equivalents, the intent of this application includes these modifications and modifications. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the stated claims. It should also be noted that in the apparatus and method of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered equivalent solutions of this application. The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be applied within the widest scope consistent with the principles and novel features disclosed herein. The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although several exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.
Claims
1. An oscillating microreaction system, characterized in that, include: Aqueous phase storage tanks, alkyl aluminum solution storage tanks, tubular microreactors, shaking devices, and reaction vessels; The tubular microreactor comprises at least one set of spiral tubes with smooth inner walls; The outlets of the aqueous phase storage tank and the alkyl aluminum solution storage tank are respectively connected to the inlet of the spiral tube, and the outlet of the spiral tube is connected to the inlet of the reactor; the oscillation device is installed on the tubular microreactor; wherein the aqueous phase storage tank has an emulsification function.
2. The oscillating microreaction system according to claim 1, characterized in that, The length of the spiral tube is 0.1 to 30 meters.
3. The oscillating microreaction system according to claim 2, characterized in that, The tubular microreactor also includes a shell with temperature control function. The spiral tube is disposed inside the shell. The shell has an inlet and an outlet. The outlets of the aqueous phase storage tank and the alkyl aluminum solution storage tank are respectively connected to the inlet of the spiral tube through the inlet. The outlet of the spiral tube extends out of the outlet and is connected to the inlet of the reactor. The oscillation device is disposed on the outer wall of the shell.
4. The oscillating microreaction system according to claim 3, characterized in that, The tubular microreactor also includes a connector for multiple feeds, which is disposed inside the feed inlet. The connector has a first branch inlet, a second branch inlet, and a total outlet. The first branch inlet is connected to the outlet of the aqueous phase storage tank, the second branch inlet is connected to the outlet of the alkyl aluminum solution storage tank, and the total outlet of the connector is connected to the inlet of the spiral tube.
5. The oscillating microreaction system according to claim 4, characterized in that, The connectors for various feed types include T-type connectors or Y-type connectors.
6. The oscillating microreaction system according to claim 4, characterized in that, The oscillating microreaction system also includes a delivery pump and an oscillating pump; The delivery pump is located between the outlet of the aqueous phase storage tank and the first branch inlet, and the oscillation pump is located between the outlet of the alkyl aluminum solution storage tank and the second branch inlet.
7. The oscillating microreaction system according to claim 4, characterized in that, The pipeline between the outlet of the aqueous phase storage tank and the first branch inlet, as well as the pipeline between the outlet of the alkyl aluminum solution storage tank and the second branch inlet, are all flexible hoses resistant to alkyl aluminum inert solvents.
8. The oscillating microreaction system according to claim 7, characterized in that, The hose resistant to alkyl aluminum inert solvents is a stainless steel hose.
9. The oscillating microreaction system according to any one of claims 4 to 8, characterized in that, The oscillating microreaction system also includes a one-way valve, which is located at the first branch inlet and the second branch inlet.
10. A method for preparing alkylaluminoxanes using the oscillating microreaction system according to any one of claims 1 to 9, characterized in that: Emulsified water in an aqueous phase storage tank and a low-temperature dilute alkyl aluminum solution in an alkyl aluminum solution storage tank are introduced into a tubular microreactor and reacted under the action of an oscillation device. After the reaction liquid leaves the tubular microreactor, it enters a reaction vessel. After the reaction is completed under stirring, it is filtered, desolventized and dried to obtain the alkyl aluminum oxane product.