Homogeneous metallocene catalyst preparation system and method

Abstract

The invention provides a homogeneous metallocene catalyst preparation system and method. In the system, a ligand synthesis unit and a combination reaction unit are respectively connected with a recrystallization unit; the ligand synthesis unit is used for synthesizing a primary metallocene ligand; the combination reaction unit is used for generating a homogeneous metallocene catalyst; the recrystallization unit is used for dissolving the primary cyclopentadienyl ligand by using a third solvent, cooling and crystallizing, separating the solvent, filtering to obtain a solid product, separating out impurities from the solid product by adopting an evaporative crystallization mode to obtain a crystallized product, dissolving the crystallized product by using a fourth solvent, cooling and crystallizing to obtain a solid cyclopentadienyl ligand; and dissolving the homogeneous metallocene catalyst by using a fifth solvent, then carrying out cooling crystallization, separating the solvent, filtering to obtain a solid catalyst, separating out impurities from the solid catalyst by adopting an evaporative crystallization mode to obtain a crystallized catalyst product, dissolving the crystallized catalyst product by using a sixth solvent, then carrying out cooling crystallization, the high-yield homogeneous-phase metallocene catalyst is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of homogeneous metallocene catalysts, and in particular to a homogeneous metallocene catalyst preparation system and method. Background Art

[0002] Homogeneous metallocene catalyst system is a catalyst system with pentadentate coordination compounds formed by cyclopentadiene and its derivatives (such as indene, fluorene, etc.) and group IVB transition metals (such as titanium, zirconium, etc.) as the main catalyst, and methylaluminoxane (MAO) or organic boron compounds as the co-catalyst. Compared with the traditional Ziegler-Natta catalyst, the metallocene complex as the main catalyst has a more precise control ability, which mainly depends on the structure of the metallocene ligand: on the one hand, the metallocene ligand complexes the metal of the fourth group to form a single active center; on the other hand, the metallocene ligand "regulates" the three-dimensional space geometry around the single active center, thereby "regulating" the coordination insertion chain growth reaction of olefin molecules in the active center, and then can produce polymers with high stereoregularity.

[0003] Although homogeneous metallocene catalysts have many advantages as mentioned above, they also have some shortcomings that need to be overcome: (1) Homogeneous metallocene catalysts (in this case, metallocene complexes used as main catalysts) are extremely sensitive to water and oxygen, and the synthesis conditions are extremely harsh; (2) During the preparation of homogeneous metallocene catalysts, the reaction conversion rate of metal ions and ligands is low, resulting in low catalyst synthesis efficiency; (3) The synthesis of homogeneous metallocene catalysts with complex molecular structures has many steps, a long reaction process, and complex by-products, so the separation of the catalyst and the recovery and regeneration of the solvent are very difficult.

[0004] In the prior art, the preparation of homogeneous metallocene catalysts is in the laboratory stage, and the conventional method is that all synthesis and treatment related to metallocene complexes and sensitive substances adopt standard Schlenk anhydrous oxygen-free technology. The anhydrous oxygen-free technology uses high-purity nitrogen as a protective gas through a double-row tube for standard operation, and special operation requirements need to be operated in a glove box. The glassware used in the experiment must be vacuum-baked under a gas lamp and cooled to room temperature before use. The anhydrous solvents used in the experiment must be used after special treatment. For example, aprotic solvents such as anhydrous tetrahydrofuran, anhydrous toluene, and anhydrous ether need to be added to sodium metal and benzophenone under a high-purity nitrogen atmosphere and refluxed to purple-red, and then evaporated into an ampoule containing 4A molecular sieves for storage and standby. For another example, anhydrous n-pentane, n-hexane, and dichloromethane need to be added with an appropriate amount of calcium hydride and stirred for 2-3 days under a protective gas atmosphere, and then evaporated into an ampoule containing 4A molecular sieves for storage and standby.

[0005] CN210058286U discloses a preparation device for a catalyst system. The preparation device comprises: a preparation kettle, a feed tank, a gas injection pipeline, a liquid injection pipeline, a liquid level control unit and a pressure control unit. The preparation device can improve the controllability of the complex reaction between the gaseous catalyst and the liquid promoter and the quality of the catalyst system. The feed tank is located above the preparation kettle, so that the promoter in the feed tank automatically flows into the preparation kettle, does not require external energy, and saves energy consumption.

[0006] CN204224504U discloses a metallocene catalyst preparation device for producing low crystal point polyethylene. The preparation device includes an alkyl aluminum configuration tank, which is sequentially connected to a flow limiting orifice plate, an alkyl aluminum feed injector, and a catalyst carrier configuration tank. The preparation device can control the feed rate of the alkyl aluminum by adding a flow limiting orifice plate on the pipeline, and by adding an alkyl aluminum feed injector on the pipeline, it is ensured that the alkyl aluminum and the silica gel react uniformly to obtain a uniform carrier, thereby improving the performance of the catalyst.

[0007] CN112745404A discloses a metallocene catalyst composition and a method for preparing a polyolefin elastomer using the same. The metallocene catalyst composition comprises a metallocene compound having a single active center and a cocatalyst. When the metallocene catalyst composition is used for the copolymerization of ethylene and 1-octene, the catalyst activity is greater than 1×10 6 g(mPE) / mol(cat)·h, and the density of the obtained polyolefin elastomer is 0.865-0.935g / cm 3 The number average molecular weight is between 104 and 106 Daltons, and the molecular weight distribution is between 1.2 and 8.5.

[0008] EP0416815A2 discloses a metallocene catalyst and a preparation method thereof. The catalyst replaces one Cp ring in a conventional organometallic compound containing a double Cp ring with a heteroatom N, and connects the other Cp ring to the N atom with a Si bridge group to form a spatial four-membered ring structure with geometric tension. The four-membered ring structure restricts the free rotation of Cp around the metal center, making the catalyst structure rigid, and due to the lack of steric hindrance, the openness of the metal active center is increased, thereby improving the insertion rate of long-chain α-olefin comonomers.

[0009] However, the above-mentioned prior arts have not been able to effectively solve the problems of low synthesis efficiency and yield of homogeneous metallocene catalysts, and low purity of homogeneous metallocene catalysts. Therefore, developing a new homogeneous metallocene catalyst preparation system and method is still one of the problems to be solved in the art. Summary of the invention

[0010] In order to solve the above technical problems, the object of the present invention is to provide a homogeneous metallocene catalyst preparation system and method. The present invention adopts a multi-solvent circulation multi-stage recrystallization unit. Through the system and method for preparing a homogeneous metallocene catalyst provided by the present invention, efficient, green and stable operation of homogeneous metallocene catalyst preparation can be achieved, the synthesis efficiency and yield of the homogeneous metallocene catalyst can be improved, and the purity of the homogeneous metallocene catalyst is improved, which is particularly suitable for preparing non-bridged metallocene catalysts, bridged catalysts and catalysts with limited geometry.

[0011] In order to achieve the above-mentioned object, the first aspect of the present invention provides a homogeneous metallocene catalyst preparation system, comprising: a ligand synthesis unit, a chemical reaction unit and a recrystallization unit;

[0012] Wherein, the ligand synthesis unit and the chemical reaction unit are respectively connected to the recrystallization unit;

[0013] The ligand synthesis unit is used to add ligand synthesis raw materials and a first solvent under protective gas conditions to synthesize a preliminary cyclopentadienyl ligand;

[0014] The chemical reaction unit is used to add a solid metallocene ligand and a second solvent under protective gas conditions, and attach metal ions in the metal ion solution to the solid metallocene ligand for reaction to generate a homogeneous metallocene catalyst;

[0015] The recrystallization unit is used to use a third solvent to dissolve the preliminary cyclopentadienyl ligand, then cool and crystallize it, separate the solvent and filter to obtain a solid product, use evaporation and crystallization to separate impurities from the solid product to obtain a crystalline product, use a fourth solvent to dissolve the crystalline product, then cool and crystallize it to obtain the solid cyclopentadienyl ligand; and,

[0016] The homogeneous metallocene catalyst is dissolved in a fifth solvent and then cooled and crystallized, the solvent is separated and filtered to obtain a solid catalyst, the solid catalyst is evaporated and crystallized to precipitate impurities to obtain a crystalline catalyst product, the crystalline catalyst product is dissolved in a sixth solvent and then cooled and crystallized to obtain a high-yield homogeneous metallocene catalyst.

[0017] In the above homogeneous metallocene catalyst preparation system, preferably, the recrystallization unit includes a ligand recrystallization unit and a compound recrystallization unit;

[0018] The ligand recrystallization unit comprises a first-stage ligand crystallizer, a second-stage ligand crystallizer and a third-stage ligand crystallizer;

[0019] The first stage ligand crystallizer is used to dissolve the preliminary cyclopentadienyl ligand with a third solvent, then cool and crystallize it, separate the solvent and filter to obtain a solid product;

[0020] The second stage ligand crystallizer is used to precipitate impurities from the solid product by evaporation and crystallization to obtain a crystalline product;

[0021] The third stage ligand crystallizer is used to dissolve the crystal product with a fourth solvent and then cool and crystallize it to obtain a solid cyclopentadienyl ligand;

[0022] The compound recrystallization unit comprises a first-stage compound crystallizer, a second-stage compound crystallizer and a third-stage compound crystallizer;

[0023] The first stage compound crystallizer is used to dissolve the homogeneous metallocene catalyst with a fifth solvent, then cool and crystallize it, separate the solvent and filter to obtain a solid catalyst;

[0024] The second stage compound crystallizer is used to precipitate impurities from the solid catalyst by evaporation and crystallization to obtain a crystalline catalyst product;

[0025] The third stage compound crystallizer is used to dissolve the crystallized catalyst product with the sixth solvent and then cool and crystallize it to obtain a high-yield homogeneous metallocene catalyst.

[0026] In the above-mentioned homogeneous metallocene catalyst preparation system, preferably, the first-stage ligand crystallizer, the second-stage ligand crystallizer, the third-stage ligand crystallizer, the first-stage compound crystallizer, the second-stage compound crystallizer and the third-stage compound crystallizer are sieve plate crystallizers.

[0027] In the above homogeneous metallocene catalyst preparation system, preferably, the first-stage ligand crystallizer, the third-stage ligand crystallizer, the first-stage compound crystallizer and the third-stage compound crystallizer adopt a gradient cooling method for cooling crystallization.

[0028] In the above-mentioned homogeneous metallocene catalyst preparation system, preferably, the second-stage ligand crystallizer is used to set the evaporation temperature according to the boiling point of the third solvent for evaporation crystallization;

[0029] The second-stage combined crystallizer is used to set the evaporation temperature according to the boiling point of the fifth solvent to perform evaporation crystallization.

[0030] In the above-mentioned homogeneous metallocene catalyst preparation system, preferably, the first solvent, the second solvent, the third solvent, the fourth solvent, the fifth solvent and the sixth solvent are respectively one of ethanol and ether, ethanol and acetone, ethanol and chloroform, ether and petroleum ether, chloroform and petroleum ether.

[0031] In the above homogeneous metallocene catalyst preparation system, preferably, the homogeneous metallocene catalyst preparation system further comprises: a solvent recovery unit for purifying and recovering the third solvent, the fourth solvent, the fifth solvent and the sixth solvent after recrystallization filtration by distillation.

[0032] In the above-mentioned homogeneous metallocene catalyst preparation system, preferably, the chemical reaction unit includes a fluidized bed reactor and a temperature and pressure detection component; the fluidized bed reactor includes a reactor shell, an air inlet, an air outlet, a metallocene ligand feed port, a metal ion solution feed port, a solvent feed port, a discharge port, and a nozzle; the air inlet and the discharge port are arranged at the lower part of the reactor shell; the metallocene ligand feed port, the metal ion solution feed port and the solvent feed port are arranged on the side wall of the reactor shell; the air outlet is arranged at the top of the reactor shell; the nozzle is arranged on the inner wall of the reactor shell; the nozzle is connected to the metal ion solution feed port; the temperature and pressure detection component is arranged at the top of the reactor shell, for detecting the temperature and pressure inside the reactor shell.

[0033] In the above-mentioned homogeneous metallocene catalyst preparation system, preferably, the homogeneous metallocene catalyst preparation system further comprises a solvent condensation and collection unit;

[0034] The solvent condensation and collection unit includes a condenser; the condenser is at least provided with a condensation medium inlet, a condensation medium outlet, an air inlet, an air outlet, and a solvent outlet; the condensation medium inlet is arranged at the lower part of the condenser, the condensation medium outlet is arranged at the upper part of the condenser, the air inlet is arranged at the upper part of the condenser, the air outlet is arranged at the top of the condenser, and the solvent outlet is arranged at the bottom of the condenser.

[0035] In the above-mentioned homogeneous metallocene catalyst preparation system, preferably, the homogeneous metallocene catalyst preparation system further comprises the atmosphere purification unit;

[0036] The atmosphere purification unit comprises a fluidized bed gas purifier; the fluidized bed gas purifier comprises a purifier housing, an air inlet, and an air outlet; the air inlet is arranged at the lower part of the purifier housing; the air outlet is arranged at the top of the purifier housing; the interior of the purifier housing has adsorbent particles;

[0037] The gas outlet of the fluidized bed reactor is connected to the gas inlet of the condenser through a pipeline;

[0038] The gas outlet of the condenser is connected to the gas inlet of the fluidized bed gas purifier through a pipeline;

[0039] The gas outlet of the fluidized bed gas purifier is connected to the gas inlet of the fluidized bed reactor through a pipeline.

[0040] In the above homogeneous metallocene catalyst preparation system, preferably, the chemical reaction unit and the atmosphere purification unit further include: a material level detection component, and the material level detection component is respectively arranged inside the reactor shell and inside the purifier shell.

[0041] In the above-mentioned homogeneous metallocene catalyst preparation system, preferably, the atmosphere purification unit further comprises a gas impurity detection component, which is arranged at the gas outlet of the fluidized bed gas purifier.

[0042] In the above-mentioned homogeneous metallocene catalyst preparation system, preferably, in the fluidized bed reactor, the number of the nozzles is one or more, all of which are arranged on the inner wall of the reactor shell. It can be understood by those skilled in the art that when multiple nozzles are provided, the number of the metal ion solution feed ports is also multiple, and they are respectively connected to multiple nozzles.

[0043] In the above homogeneous metallocene catalyst preparation system, preferably, a gas distributor is further provided inside the fluidized bed reactor, and the gas distributor is located above the gas inlet of the fluidized bed reactor. The gas distributor used is a conventional device in the art, and the present invention does not specifically limit its specific structure.

[0044] In the above homogeneous metallocene catalyst preparation system, preferably, a compressor is provided on the pipeline connecting the gas outlet of the fluidized bed gas purifier and the gas inlet of the fluidized bed reactor.

[0045] In the above homogeneous metallocene catalyst preparation system, preferably, the condenser comprises a shell-and-tube condenser. More preferably, the condenser comprises a condenser shell, a plurality of heat exchange tubes and a plurality of baffles, the plurality of heat exchange tubes and the plurality of baffles are arranged inside the condenser shell, the condensing medium inlet and the condensing medium outlet are connected to the plurality of heat exchange tubes, and the plurality of baffles are staggered along the vertical direction of the condenser shell.

[0046] In the above homogeneous metallocene catalyst preparation system, preferably, a pressure relief valve is provided on the top of the condenser.

[0047] In the above homogeneous metallocene catalyst preparation system, preferably, a gas supply port is provided on the side wall of the condenser.

[0048] In the present invention, the air inlet and the pressure relief valve of the condenser can control the pressure of the system, and can supplement the pressure or release the pressure of the system, thereby avoiding accidents of abnormal working conditions such as excessive system pressure and incomplete condensation.

[0049] In the above-mentioned homogeneous metallocene catalyst preparation system, preferably, a solution concentration detector is provided at the solvent outlet of the condenser. The solution concentration detector is used to detect the concentration and composition of the liquid discharged from the solvent outlet of the condenser. The solution concentration detector used can be a conventional device in the art, and the present invention does not specifically limit its specific structure.

[0050] In the above homogeneous metallocene catalyst preparation system, preferably, the plurality of baffles in the condenser form a baffle group that is in a zigzag shape in the vertical direction.

[0051] In the above homogeneous metallocene catalyst preparation system, the adsorbent particles inside the purifier housing are particles that can adsorb water and oxygen. Preferably, the adsorbent includes a molecular sieve. Specifically, the molecular sieve includes one or a combination of 5A molecular sieve, 3A molecular sieve, 4A molecular sieve and 13X molecular sieve.

[0052] In the above-mentioned homogeneous metallocene catalyst preparation system, preferably, the atmosphere purification unit further comprises: an initial protective gas delivery pipeline, which is connected to the air inlet of the fluidized bed gas purifier and is used to provide initial protective gas to the system.

[0053] In the above-mentioned homogeneous metallocene catalyst preparation system, preferably, the gas impurity detection component includes a gas chromatograph and an online sampling probe thereof.

[0054] In the above-mentioned homogeneous metallocene catalyst preparation system, preferably, the atmosphere purification unit further comprises: a protective gas return pipeline, one end of which is connected to the gas impurity detection component, and the other end is connected to the air inlet of the fluidized bed gas purifier, so as to allow the protective gas whose water and oxygen content does not meet the requirements after detection by the gas impurity detection component to re-enter the fluidized bed gas purifier for purification.

[0055] In the above homogeneous metallocene catalyst preparation system, preferably, a gas distributor is further provided inside the fluidized bed gas purifier, and the gas distributor is located above the gas inlet of the fluidized bed gas purifier. The gas distributor used is a conventional device in the art, and the present invention does not specifically limit its specific structure.

[0056] In the above homogeneous metallocene catalyst preparation system, preferably, the solvent outlet of the condenser is connected to the solvent feed inlet of the fluidized bed reactor through a pipeline.

[0057] In the above-mentioned homogeneous metallocene catalyst preparation system, the temperature and pressure detection components, the material level detection components in the chemical reaction unit, and the material level detection components in the atmosphere purification unit are all conventional devices in the art, and the present invention does not specifically limit their specific structures.

[0058] According to a specific embodiment of the present invention, preferably, the above system further comprises: a raw material storage unit, the raw material storage unit comprises a storage device for the raw material of the synthetic ligand, a storage device for the metal ion solution, and a storage device for the solvent, etc.; the storage device for the raw material of the synthetic ligand is connected to the ligand synthesis unit; the storage device for the metal ion solution is connected to the metal ion solution feed port of the fluidized bed reactor, and the storage device for the solvent is connected to the solvent feed port of the fluidized bed reactor. These storage devices can all adopt storage devices in the prior art, and the present invention does not specifically limit them.

[0059] According to a specific embodiment of the present invention, preferably, the above system further comprises: a raw material refining unit, the raw material refining unit is connected to the raw material storage unit, and is used to purify the raw material for synthesizing the ligand, the raw material for synthesizing the metal ion solution, and the solvent, etc. The raw material refining unit can adopt the raw material refining device in the prior art, and the present invention does not specifically limit its structure.

[0060] According to a specific embodiment of the present invention, preferably, the above-mentioned system further comprises: the solvent recovery unit is connected to the solvent outlet of the condenser through a pipeline, for recovering the solvent. The recovered solvent can be returned to the above-mentioned raw material refining unit and raw material storage unit, and then returned to the chemical reaction unit to achieve the reuse of the solvent. It can be understood by those skilled in the art that the solvent recovered by the solvent recovery unit includes the solvent in the metal ion solution and the solvent entering the system from the solvent feed port of the fluidized bed reactor. In addition, it can be understood by those skilled in the art that when the system of the present invention does not include a solvent recovery unit, as described above, the solvent outlet of the condenser can be directly connected to the solvent feed port of the fluidized bed reactor through a pipeline.

[0061] According to a specific embodiment of the present invention, preferably, the above system further comprises: a catalyst storage unit, which is connected to the discharge port of the fluidized bed reactor through a pipeline and is used to store the prepared homogeneous metallocene catalyst.

[0062] In the present invention, fluidized bed refers to a large number of solid particles suspended in a moving fluid, so that the particles have certain apparent characteristics of the fluid. Specifically, when the speed of the fluid passing through the bed gradually increases to a certain value, the particles become loose, the gaps between the particles increase, and the volume of the bed expands. If the fluid speed is further increased, the bed will not be able to maintain a fixed state. At this time, all the particles are suspended in the fluid, showing quite irregular movement. As the flow rate increases, the movement of the particles becomes more intense, and the expansion of the bed also increases, but the particles still stay in the bed and are not carried out by the fluid. At this time, the state of the bed is similar to that of a liquid. This fluid-solid contact state is called solid fluidization, i.e., a fluidized bed.

[0063] The fully fluidized bed exhibits properties similar to those of a liquid. The fluidized bed in the present invention has the following characteristics: a fluid with a density less than the average density of the bed can be suspended on the bed surface; the bed surface remains horizontal; the bed obeys the hydrostatic relationship, that is, the pressure difference Δp=ρgL between two sections with a height difference of L; the particles have a fluidity similar to that of a liquid; there is dispersed fluidization; the two connected fluidized beds used in the present invention can adjust the upper surface of the bed to be on the same horizontal plane by themselves.

[0064] The homogeneous metallocene catalyst preparation system provided by the present invention adopts multiple solvents to circulate and recrystallize in multiple stages, with one solvent in each stage. After dissolving, the temperature is lowered and crystallized, and the solvent is separated to filter out the product. In the next step, the temperature is raised, and impurities are precipitated by evaporation and crystallization. The solution is transported to the next stage, and after evaporation and drying, the solvent is changed and dissolved again, and the solvent is separated by crystallization. The purification efficiency is improved through multiple recrystallization processes, and the purity of the prepared homogeneous catalyst is higher. The present invention improves the synthesis efficiency and yield of the homogeneous metallocene catalyst, and improves the purity of the homogeneous metallocene catalyst, thereby reducing the preparation cost of the catalyst.

[0065] The second aspect of the present invention provides a method for preparing a homogeneous metallocene catalyst, using the homogeneous metallocene catalyst preparation system described in the first aspect.

[0066] The method for preparing a homogeneous metallocene catalyst comprises the following steps:

[0067] Under protective gas conditions, adding ligand synthesis raw materials and a first solvent to synthesize a preliminary cyclopentadienyl ligand;

[0068] Using a third solvent to dissolve the preliminary cyclopentadienyl ligand, then cooling and crystallizing, separating the solvent and filtering to obtain a solid product, using the solid product to precipitate impurities by evaporation and crystallization to obtain a crystalline product, using a fourth solvent to dissolve the crystalline product, then cooling and crystallizing to obtain the solid cyclopentadienyl ligand;

[0069] Under protective gas conditions, a solid metallocene ligand and a second solvent are added, and metal ions in the metal ion solution are attached to the solid metallocene ligand for reaction to generate a homogeneous metallocene catalyst;

[0070] The homogeneous metallocene catalyst is dissolved in a fifth solvent and then cooled and crystallized, the solvent is separated and filtered to obtain a solid catalyst, the solid catalyst is evaporated and crystallized to precipitate impurities to obtain a crystalline catalyst product, the crystalline catalyst product is dissolved in a sixth solvent and then cooled and crystallized to obtain a high-yield homogeneous metallocene catalyst.

[0071] In the method for preparing a homogeneous metallocene catalyst, a solid metallocene ligand and a second solvent are added under protective gas conditions, and metal ions in a metal ion solution are attached to the solid metallocene ligand for reaction to generate a homogeneous metallocene catalyst, which specifically includes the following steps:

[0072] Solid metallocene ligand and solvent are added to the fluidized bed reactor, and then protective gas is introduced into the fluidized bed reactor. The protective gas is the protective gas purified by the fluidized bed gas purifier. The solid metallocene ligand is strongly disturbed by the protective gas to form a fluidized bed. The metal ion solution is sprayed into the fluidized bed reactor in the form of droplets through the nozzle. The metal ions react with the metallocene ligand to generate a homogeneous metallocene catalyst. The protective gas entrains the solvent and is discharged from the gas outlet of the fluidized bed reactor.

[0073] The method for preparing a homogeneous metallocene catalyst also includes:

[0074] The protective gas discharged from the gas outlet of the fluidized bed reactor carries the solvent into the condenser, and the protective gas obtained after condensation is discharged from the gas outlet of the condenser, and the obtained solvent is discharged from the solvent outlet of the condenser.

[0075] The method for preparing a homogeneous metallocene catalyst also includes:

[0076] The protective gas discharged from the gas outlet of the condenser enters the fluidized bed gas purifier, and the adsorbent particles in the fluidized bed gas purifier are strongly disturbed to form a fluidized bed. The adsorbent particles adsorb water and oxygen in the protective gas to obtain purified protective gas, which is discharged from the gas outlet of the fluidized bed gas purifier. The discharged protective gas enters the fluidized bed reactor.

[0077] In the above preparation method, preferably, the reaction temperature in the fluidized bed reactor is -40 to 40°C.

[0078] In the above preparation method, preferably, the reaction pressure in the fluidized bed reactor is 0.1-2 MPa.

[0079] In the above preparation method, the temperature and pressure in the fluidized bed reactor can be detected by the temperature and pressure detection assembly at the top of the fluidized bed reactor.

[0080] In the above preparation method, preferably, the fluidization velocity in the fluidized bed reactor is 0.1-5 m / s. Those skilled in the art will understand that the fluidization velocity refers to the superficial velocity of the fluid formed by the solid octylene ligand.

[0081] In the above preparation method, preferably, the crystal size of the solid cyclopentadienyl ligand is 10-100 μm.

[0082] In the above preparation method, preferably, the particle size of the solid octahedral ligand is 500-5000 μm.

[0083] In the above preparation method, preferably, the usage ratio of the solid cyclopentadienyl ligand to the solvent is 50-500 g:1 L.

[0084] In the above preparation method, preferably, the metal ion concentration in the metal ion solution is 0.1-100 g / L.

[0085] In some specific embodiments of the present invention, the solid metallocene ligand, the solvent and the metal ion solution can all be conventional raw materials for preparing homogeneous metallocene catalysts in the art, and the present invention does not impose any particular limitation on the specific compounds that can be selected.

[0086] In the above preparation method, preferably, the temperature in the condenser is -50 to 50°C.

[0087] In the above preparation method, preferably, the pressure in the condenser is 0.1-2 MPa. The pressure in the condenser can be adjusted by a pressure relief valve at the top of the condenser and / or by supplementing protective gas through a gas supplement port.

[0088] In the above preparation method, preferably, the residence time of the protective gas entrained with the solvent discharged from the gas outlet of the fluidized bed reactor in the condenser is 0.1-20 minutes. The residence time in the condenser can ensure that the solvent entrained in the protective gas is fully settled, so the design of the pipeline in the condenser should be long enough to ensure that the solvent can be fully settled.

[0089] In the above preparation method, preferably, the flow rate of the protective gas entrained with the solvent in the condenser is less than 1 m / min. If the flow rate is too fast, it will have an adverse effect on the sedimentation of the entrained solvent in the protective gas.

[0090] According to a specific embodiment of the present invention, the present invention adopts supercondensation to condense and recover the solvent entrained in the protective gas to ensure that all gaseous solvents are completely liquefied, and adopts folded plate condensation to increase the residence time of the protective gas, thereby improving the solvent recovery efficiency.

[0091] In the above preparation method, preferably, the temperature in the fluidized bed gas purifier is -50 to 50°C.

[0092] In the above preparation method, preferably, the pressure in the fluidized bed gas purifier is 0.1-2 MPa.

[0093] In the above preparation method, preferably, the fluidization velocity in the fluidized bed gas purifier is 0.1-5 m / s. It can be understood by those skilled in the art that the fluidization velocity refers to the superficial velocity of the fluid formed by the adsorbent particles.

[0094] In the above preparation method, preferably, it further comprises: after detecting the water and oxygen contents in the protective gas at the gas outlet of the fluidized bed gas purifier by the gas impurity detection component, if the water and oxygen contents do not meet the requirements, the protective gas is re-entered into the fluidized bed gas purifier for purification. More preferably, if the water content in the protective gas is less than 5ppm and the oxygen content is less than 5ppm, the requirements are met.

[0095] According to a specific embodiment of the present invention, the present invention adopts a fluidized bed gas purifier to purify the protective gas. During the purification process, the protective gas strongly disturbs the adsorbent particles (such as molecular sieves, etc.) to form a fluidized bed, thereby efficiently adsorbing water and oxygen in the protective gas, and causing the protective gas that does not meet the water and oxygen content requirements to be re-purified, and the protective gas that meets the water and oxygen content requirements enters the fluidized bed reactor.

[0096] In the above preparation method, preferably, the purified protective gas discharged from the gas outlet of the fluidized bed gas purifier is compressed by a compressor and then enters the fluidized bed reactor. More preferably, the pressure of the purified protective gas after compression by the compressor is 0.1-2MPa and the temperature is -50 to 50°C. The present invention uses a compressor to provide the pressure of the entire reaction system.

[0097] In the above preparation method, preferably, the protective gas includes one or a combination of nitrogen, helium and neon.

[0098] In the above preparation method, preferably, the prepared homogeneous metallocene catalyst (ie, metallocene complex) has a crystal size of 10-100 μm and a particle size of 500-5000 μm.

[0099] The present invention provides a homogeneous metallocene catalyst preparation system and method. The present invention adopts multiple recrystallization processes to improve the purification efficiency, and the prepared homogeneous catalyst has higher purity, which can achieve efficient, green and stable synthesis of homogeneous metallocene catalysts. The homogeneous metallocene catalyst preparation system and method of the present invention are particularly suitable for the production of non-bridged metallocene catalysts, bridged catalysts and catalysts with limited geometry configurations.

[0100] The technical solution of the present invention has at least the following beneficial effects:

[0101] The homogeneous metallocene catalyst preparation system provided by the present invention adopts multiple solvents to circulate and recrystallize in multiple stages, with one solvent in each stage. After dissolving, the temperature is lowered and crystallized, and the solvent is separated to filter out the product. In the next step, the temperature is raised, and impurities are precipitated by evaporation and crystallization, and the solution is transported to the next stage. After evaporation and drying, the solvent is changed and dissolved again, and the solvent is separated by crystallization. The purification efficiency is improved through multiple recrystallization processes, and the purity of the prepared homogeneous catalyst is higher. Therefore, the technical scheme of the present invention improves the synthesis efficiency and yield of the homogeneous metallocene catalyst, and improves the purity of the homogeneous metallocene catalyst, thereby reducing the preparation cost of the catalyst. The purity of the homogeneous metallocene catalyst provided by the present invention is more than 97%, and the yield is more than 85%. In addition, the technical scheme of the present invention makes it easy to separate the prepared catalyst, and makes the recovery of the solvent simple and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0102] Figure 1 A schematic diagram of the structure of a homogeneous metallocene catalyst preparation system provided in an embodiment of the present invention;

[0103] Figure 2 It is a schematic structural diagram of a homogeneous metallocene catalyst preparation system in a specific embodiment of the present invention.

[0104] Description of Figure Numbers:

[0105] 100, raw material storage unit; 200, raw material refining unit; 300, ligand synthesis unit; 400, recrystallization unit; 500, chemical reaction unit; 600, solvent recovery unit; 700, solvent condensation and collection unit; 800, atmosphere purification unit; 900, catalyst storage unit;

[0106] 1. Fluidized bed reactor; 2. Temperature and pressure detection assembly; 3. First material level detection assembly; 11. Nozzle; 12. First gas distributor;

[0107] 4. Condenser; 41. Baffle; 42. Pressure relief valve; 43. Air supply port;

[0108] 5. Fluidized bed gas purifier; 51. Second gas distributor; 6. Gas impurity detection assembly; 7. Second material level detection assembly; 8. Compressor; 9. Initial protective gas delivery pipeline; 10. Protective gas return pipeline; 13. First-stage combined crystallizer; 14. Second-stage combined crystallizer; 15. Third-stage combined crystallizer. DETAILED DESCRIPTION

[0109] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be construed as limiting the applicable scope of the present invention.

[0110] A specific embodiment of the present invention provides a homogeneous metallocene catalyst preparation system, the structure of which is as follows Figure 1 As shown, the system at least includes:

[0111] A ligand synthesis unit 300, a chemical reaction unit 500 and a recrystallization unit 400;

[0112] The ligand synthesis unit 300 and the chemical reaction unit 500 are respectively connected to the recrystallization unit 400;

[0113] The ligand synthesis unit 300 is used to add ligand synthesis raw materials and a first solvent under protective gas conditions to synthesize a preliminary cyclopentadienyl ligand;

[0114] The chemical reaction unit 500 is used to add a solid metallocene ligand and a second solvent under a protective gas condition, and attach metal ions in the metal ion solution to the solid metallocene ligand for reaction to generate a homogeneous metallocene catalyst;

[0115] The recrystallization unit 400 is used to use a third solvent to dissolve the preliminary cyclopentadienyl ligand, then cool and crystallize it, separate the solvent and filter to obtain a solid product, use the solid product to evaporatively crystallize to separate impurities to obtain a crystalline product, use a fourth solvent to dissolve the crystalline product, then cool and crystallize it to obtain a solid cyclopentadienyl ligand; and,

[0116] The homogeneous metallocene catalyst is dissolved in the fifth solvent and then cooled and crystallized, the solvent is separated and filtered to obtain a solid catalyst, the solid catalyst is evaporated and crystallized to precipitate impurities to obtain a crystalline catalyst product, the crystalline catalyst product is dissolved in the sixth solvent and then cooled and crystallized to obtain a high-yield homogeneous metallocene catalyst.

[0117] The inventors have found through experiments that the key step in the preparation of the catalyst is to separate the products synthesized by the chemical reaction unit, and the efficiency of purification directly determines the purity and yield of the metallocene compound, and the commonly used method is recrystallization. The conventional recrystallization operation method is to use the difference in the solubility of the substance at temperature to separate the mixture through the recrystallization operation. Using recrystallization to separate the mixture requires that the solubility of one component in the mixture is greatly affected by temperature, and the solubility of the other component is less affected by temperature. The solubility of solid substances is affected by temperature, solute and solvent properties. The solubility of some substances is greatly affected by temperature, and the solubility of some substances is less affected by temperature. The mixture can be separated by recrystallization operation using the difference in the solubility of the substance at temperature.

[0118] Commonly used mixed solvents can improve product purity and yield, but mixed solvents are difficult to separate during the preparation of catalyst compounds. In the prior art, how to separate mixed solvents during the preparation of metallocene catalysts is an urgent problem to be solved. Based on this, the inventors proposed the above-mentioned homogeneous metallocene catalyst preparation system in combination with the characteristics of the products in the synthesis of metallocene compounds. The system uses multiple solvents to circulate and recrystallize in multiple stages, with multiple solvents, one solvent for each stage, and separates the solvent after cooling and crystallization after dissolving to filter out the product. The next step is to heat up, and evaporation and crystallization are used to precipitate impurities, and the solution is transported to the next stage. After evaporation and drying, the solvent is changed and dissolved again, and the solvent is crystallized and separated. After multiple recrystallization processes, the purification efficiency is improved, and the purity of the prepared homogeneous catalyst is higher. Therefore, the technical solution of the present invention improves the synthesis efficiency and yield of the homogeneous metallocene catalyst, and improves the purity of the homogeneous metallocene catalyst, thereby reducing the preparation cost of the catalyst. The purity of the homogeneous metallocene catalyst provided by the present invention is more than 97%, and the yield is more than 85%. In addition, the technical solution of the present invention makes it easy to separate the prepared catalyst, and makes the recovery of the solvent simple and efficient.

[0119] It should be noted that, in the embodiment of the present invention, in order to avoid the precipitation of the substance that does not wish to be purified in the solution, it should be noted that the water evaporated in the evaporative crystallization operation should not be too much, and the amplitude of the temperature reduction in the cooling crystallization operation should not be too large. Since no other substances are separated in the recrystallization operation, the crystal obtained is pure. Through the steps of filtering, washing, drying, etc., the crystal and solution can be separated and the pure crystal of the substance to be purified is obtained.

[0120] In one embodiment, the recrystallization unit 400 includes a ligand recrystallization unit (not shown in the figure) and a compound recrystallization unit (not shown in the figure);

[0121] The ligand recrystallization unit includes a first-stage ligand crystallizer (not shown in the figure), a second-stage ligand crystallizer (not shown in the figure) and a third-stage ligand crystallizer (not shown in the figure);

[0122] The first stage ligand crystallizer is used to dissolve the preliminary cyclopentadienyl ligand with the third solvent, then cool and crystallize it, separate the solvent and filter to obtain a solid product;

[0123] The second stage ligand crystallizer is used to precipitate impurities from the solid product by evaporation crystallization to obtain a crystalline product;

[0124] The third stage ligand crystallizer is used to dissolve the crystal product with the fourth solvent and then cool and crystallize it to obtain a solid cyclopentadienyl ligand;

[0125] The compound recrystallization unit includes a first-stage compound crystallizer 13, a second-stage compound crystallizer 14 and a third-stage compound crystallizer 15;

[0126] The first stage compound crystallizer 13 is used to dissolve the homogeneous metallocene catalyst with the fifth solvent, then cool and crystallize it, separate the solvent and filter it to obtain a solid catalyst;

[0127] The second stage compound crystallizer 14 is used to precipitate impurities from the solid catalyst by evaporation and crystallization to obtain a crystalline catalyst product;

[0128] The third stage compound crystallizer 15 is used to dissolve the crystallized catalyst product with the sixth solvent and then cool and crystallize it to obtain a high-yield homogeneous metallocene catalyst.

[0129] In one embodiment, the first stage ligand crystallizer, the second stage ligand crystallizer, the third stage ligand crystallizer, the first stage compound crystallizer 13, the second stage compound crystallizer 14 and the third stage compound crystallizer 15 are sieve plate crystallizers.

[0130] In one embodiment, the first-stage ligand crystallizer, the third-stage ligand crystallizer, the first-stage compound crystallizer 13 and the third-stage compound crystallizer 15 use a gradient cooling method to perform cooling crystallization.

[0131] In one embodiment, the second stage ligand crystallizer is used to set the evaporation temperature according to the boiling point of the third solvent for evaporation crystallization;

[0132] The second stage compound crystallizer 14 is used to set the evaporation temperature according to the boiling point of the fifth solvent to perform evaporation crystallization.

[0133] In one embodiment, referring to Figure 1 As shown, the homogeneous metallocene catalyst preparation system further includes: a solvent recovery unit 600, which is used to purify and recover the third solvent, the fourth solvent, the fifth solvent and the sixth solvent after recrystallization filtration by distillation.

[0134] In one embodiment, referring to Figure 2As shown, the chemical reaction unit 500 includes a fluidized bed reactor 1 and a temperature and pressure detection component 2; the fluidized bed reactor 1 includes a reactor shell, an air inlet, an air outlet, a cyclopentadienyl ligand feed port, a metal ion solution feed port, a solvent feed port, a discharge port, and a nozzle 11; the air inlet and the discharge port are arranged at the lower part of the reactor shell; the cyclopentadienyl ligand feed port, the metal ion solution feed port and the solvent feed port are arranged on the side wall of the reactor shell; the air outlet is arranged at the top of the reactor shell; the nozzle 11 is arranged on the inner wall of the reactor shell; the nozzle 11 is connected to the metal ion solution feed port; the temperature and pressure detection component 2 is arranged at the top of the reactor shell, and is used to detect the temperature and pressure inside the reactor shell.

[0135] The connection method of the first stage compound crystallizer 13, the second stage compound crystallizer 14 and the third stage compound crystallizer 15 in the above-mentioned compound recrystallization unit in the embodiment of the present invention can refer to Figure 2 As shown, the first stage compound crystallizer 13 is connected in sequence, wherein the feed port of the first stage compound crystallizer 13 is connected to the discharge port of the fluidized bed reactor 1. Similar to the compound recrystallization unit, the first stage ligand crystallizer, the second stage ligand crystallizer and the third stage ligand crystallizer in the ligand recrystallization unit are also connected in sequence, wherein the feed port of the first stage ligand crystallizer is connected to the product outlet of the preliminary cyclopentadienyl ligand of the ligand synthesis unit 300, and the discharge port of the third stage ligand crystallizer is connected to the cyclopentadienyl ligand feed port of the fluidized bed reactor 1.

[0136] In one embodiment, the first solvent, the second solvent, the third solvent, the fourth solvent, the fifth solvent and the sixth solvent are respectively one of ethanol and ether, ethanol and acetone, ethanol and chloroform, ether and petroleum ether, chloroform and petroleum ether. For example, it can be that the first solvent selects ethanol and ether, the second solvent selects ethanol and acetone, the third solvent selects ethanol and chloroform, the fourth solvent selects ether and petroleum ether, and the fifth solvent and the sixth solvent select chloroform and petroleum ether. Of course, those skilled in the art can also select other mixed solvents according to actual preparation needs.

[0137] In one embodiment, referring to Figure 1 As shown, the homogeneous metallocene catalyst preparation system also includes a solvent condensation and collection unit 700. Figure 2 As shown, the solvent condensation and collection unit 700 includes a condenser 4; the condenser 4 is at least provided with a condensing medium inlet, a condensing medium outlet, an air inlet, an air outlet, and a solvent outlet; the condensing medium inlet is arranged at the lower part of the condenser 4, the condensing medium outlet is arranged at the upper part of the condenser 4, the air inlet is arranged at the upper part of the condenser 4, the air outlet is arranged at the top of the condenser 4, and the solvent outlet is arranged at the bottom of the condenser 4.

[0138] In one embodiment, referring to Figure 1As shown, the homogeneous metallocene catalyst preparation system also includes an atmosphere purification unit 800. Figure 2 As shown, the atmosphere purification unit 800 includes a fluidized bed gas purifier 5; the fluidized bed gas purifier 5 includes a purifier housing, an air inlet, and an air outlet; the air inlet is arranged at the lower part of the purifier housing; the air outlet is arranged at the top of the purifier housing; the interior of the purifier housing has adsorbent particles;

[0139] The gas outlet of the fluidized bed reactor 1 is connected to the gas inlet of the condenser 4 through a pipeline;

[0140] The gas outlet of the condenser 4 is connected to the gas inlet of the fluidized bed gas purifier 5 through a pipeline;

[0141] The gas outlet of the fluidized bed gas purifier 5 is connected to the gas inlet of the fluidized bed reactor 1 through a pipeline.

[0142] In one embodiment, the chemical reaction unit 500 further includes a first material level detection component 3, which is disposed inside the reactor shell.

[0143] In one embodiment, the atmosphere purification unit 800 further includes a second material level detection assembly 7, which is disposed inside the purifier housing.

[0144] In one embodiment, the atmosphere purification unit 800 further includes a gas impurity detection component 6 , which is disposed at the gas outlet of the fluidized bed gas purifier 5 .

[0145] In one embodiment, in the fluidized bed reactor 1, the number of nozzles 11 is one or more, all of which are arranged on the inner wall of the reactor shell. It can be understood by those skilled in the art that when multiple nozzles 11 are provided, the number of metal ion solution feed ports is also multiple, which are respectively connected to the multiple nozzles 11.

[0146] In one embodiment, a first gas distributor 12 is further provided inside the fluidized bed reactor 1, and the first gas distributor 12 is located above the gas inlet of the fluidized bed reactor 1. The gas distributor used is a conventional device in the art, and the present invention does not specifically limit its specific structure.

[0147] In one embodiment, a compressor 8 is provided on the pipeline connecting the gas outlet of the fluidized bed gas purifier 5 and the gas inlet of the fluidized bed reactor 1 .

[0148] In one embodiment, the condenser 4 is a shell-and-tube condenser. Specifically, the condenser 4 includes a condenser shell, a plurality of heat exchange tubes ( Figure 2The heat exchange tubes and the baffles 41 are arranged inside the condenser shell, the condensing medium inlet and the condensing medium outlet are connected with the heat exchange tubes, the baffles 41 are arranged in an interlaced manner along the vertical direction of the condenser shell, and the baffles 41 can be sealed and sleeved with the heat exchange tubes, and the baffles 41 form a baffle group in a zigzag shape in the vertical direction. The condensing medium can be conventional in the art, such as but not limited to water.

[0149] In one embodiment, a pressure relief valve 42 is disposed on the top of the condenser 4 .

[0150] In one embodiment, a gas supply port 43 is disposed on the side wall of the condenser 4 .

[0151] The air inlet 43 and the pressure relief valve 42 of the condenser 4 can control the pressure of the system, and can supplement the pressure or release the pressure of the system, thereby avoiding accidents of abnormal working conditions such as excessive system pressure and incomplete condensation.

[0152] In one embodiment, a solution concentration detector is provided at the solvent outlet of the condenser 4 to detect the concentration and composition of the liquid discharged from the solvent outlet of the condenser. The solution concentration detector used is a conventional device in the art, and the present invention does not specifically limit its specific structure.

[0153] In one embodiment, the adsorbent particles inside the purifier housing are particles that can adsorb water and oxygen. Preferably, the adsorbent includes a molecular sieve. Specifically, the molecular sieve includes one or a combination of 5A molecular sieve, 3A molecular sieve, 4A molecular sieve and 13X molecular sieve.

[0154] In one embodiment, the atmosphere purification unit 800 further comprises: an initial protective gas delivery pipeline 9, which is connected to the gas inlet of the fluidized bed gas purifier 5 and is used to provide initial protective gas to the system.

[0155] In one embodiment, the gas impurity detection assembly 6 includes a gas chromatograph and an online sampling probe thereof.

[0156] In one embodiment, the atmosphere purification unit 800 further includes: a protective gas return pipeline 10, one end of which is connected to the gas impurity detection component 6, and the other end is connected to the air inlet of the fluidized bed gas purifier 5, so as to allow the protective gas whose water and oxygen content does not meet the requirements after detection by the gas impurity detection component 6 to re-enter the fluidized bed gas purifier 5 for purification.

[0157] In one embodiment, a second gas distributor 51 is further provided inside the fluidized bed gas purifier 5, and the second gas distributor 51 is located above the gas inlet of the fluidized bed gas purifier 5. The gas distributor used is a conventional device in the art, and the present invention does not specifically limit its specific structure.

[0158] In one embodiment, the solvent outlet of the condenser 4 is connected to the solvent feed port of the fluidized bed reactor 1 through a pipeline ( Figure 2 not shown).

[0159] In the above-mentioned embodiments, the temperature and pressure detection component 2 and the first material level detection component 3 in the chemical reaction unit 500, and the second material level detection component 7 in the atmosphere purification unit 800 are conventional devices in the art, and the present invention does not specifically limit their specific structures.

[0160] In the above embodiments, necessary valves, such as stop valves, etc., may be provided on each pipeline, and those skilled in the art may perform conventional settings according to actual conditions.

[0161] In one embodiment, the ligand synthesis unit 300 may adopt a ligand synthesis device in the prior art, and the present invention does not specifically limit its structure.

[0162] In one embodiment, referring to Figure 1 As shown, the system further includes: a raw material storage unit 100, the raw material storage unit 100 includes a storage device for the raw material of the synthetic ligand, a storage device for the metal ion solution, and a storage device for the solvent, etc.; the storage device for the raw material of the synthetic ligand is connected to the ligand synthesis unit 300; the storage device for the metal ion solution is connected to the metal ion solution feed port of the fluidized bed reactor, and the storage device for the solvent is connected to the solvent feed port of the fluidized bed reactor. These storage devices can all adopt storage devices in the prior art, and the present invention does not specifically limit them.

[0163] In one embodiment, referring to Figure 1 As shown, the system further includes: a raw material refining unit 200, which is connected to the raw material storage unit 100 and is used to purify the raw materials for synthesizing the ligand, the raw materials for synthesizing the metal ion solution, and the solvent, etc. The raw material refining unit 200 can adopt the raw material refining device in the prior art, and the present invention does not specifically limit its structure.

[0164] In one embodiment, the solvent recovery unit 600 is also used to be connected to the solvent outlet of the condenser through a pipeline for recovering the solvent. The recovered solvent can be returned to the above-mentioned raw material refining unit 200 and the raw material storage unit 100, and then returned to the chemical reaction unit 500 to achieve the reuse of the solvent. It will be appreciated by those skilled in the art that the solvent recovered by the solvent recovery unit 600 includes the solvent in the metal ion solution and the solvent entering the system from the solvent feed port of the fluidized bed reactor. In addition, it will be appreciated by those skilled in the art that when the system of the present invention does not include a solvent recovery unit, as described above, the solvent outlet of the condenser can be directly connected to the solvent feed port of the fluidized bed reactor through a pipeline.

[0165] In one embodiment, referring to Figure 1 As shown, the above system further includes: a catalyst storage unit 900, which is connected to the discharge port of the fluidized bed reactor through a pipeline and is used to store the prepared homogeneous metallocene catalyst.

[0166] Another specific embodiment of the present invention provides a method for preparing a homogeneous metallocene catalyst, which is a method for preparing a homogeneous metallocene catalyst using the above-mentioned homogeneous metallocene catalyst preparation system, and the method comprises the following steps:

[0167] (1) adding a ligand synthesis raw material and a first solvent under protective gas conditions to synthesize a preliminary cyclopentadienyl ligand;

[0168] (2) using a third solvent to dissolve the preliminary cyclopentadienyl ligand and then cooling and crystallizing it, separating the solvent and filtering to obtain a solid product, using the solid product to evaporatively crystallize impurities to obtain a crystalline product, using a fourth solvent to dissolve the crystalline product and then cooling and crystallizing it to obtain a solid cyclopentadienyl ligand;

[0169] (3) under protective gas conditions, adding a solid metallocene ligand and a second solvent, and attaching metal ions in the metal ion solution to the solid metallocene ligand for reaction to generate a homogeneous metallocene catalyst;

[0170] (4) using a fifth solvent to dissolve the homogeneous metallocene catalyst and then cooling and crystallizing it, separating the solvent and filtering to obtain a solid catalyst, using the solid catalyst to precipitate impurities by evaporation and crystallization to obtain a crystalline catalyst product, using a sixth solvent to dissolve the crystalline catalyst product and then cooling and crystallizing it to obtain a high-yield homogeneous metallocene catalyst.

[0171] In one embodiment, the above-mentioned process of adding a solid metallocene ligand and a second solvent under protective gas conditions, and attaching metal ions in the metal ion solution to the solid metallocene ligand for reaction to generate a homogeneous metallocene catalyst specifically comprises the following steps:

[0172] A solid metallocene ligand and a second solvent are added to a fluidized bed reactor 1, and then a protective gas is introduced into the fluidized bed reactor 1. The protective gas is a protective gas purified by a fluidized bed gas purifier 5. The protective gas strongly disturbs the solid metallocene ligand to form a fluidized bed. The metal ion solution is sprayed onto the bed of the fluidized bed reactor 1 in the form of droplets through a nozzle 11, and the bed temperature of the fluidized bed reactor 1 and the pressure in the fluidized bed reactor 1 are adjusted. The bed temperature of the fluidized bed reactor 1 is adjusted by the feed temperature and the reaction exotherm. The metal ions attach to the solid metallocene ligand to react to generate a homogeneous metallocene catalyst, and the protective gas entrains the second solvent and is discharged from the gas outlet of the fluidized bed reactor 1.

[0173] In one embodiment, the method for preparing a homogeneous metallocene catalyst further comprises:

[0174] The protective gas discharged from the gas outlet of the fluidized bed reactor 1 carries the solvent into the condenser 4 , and the protective gas obtained after condensation is discharged from the gas outlet of the condenser 4 , and the obtained solvent is discharged from the solvent outlet of the condenser 4 .

[0175] In one embodiment, the method for preparing a homogeneous metallocene catalyst further comprises:

[0176] In the initial stage of preparation, the protective gas is allowed to enter the fluidized bed gas purifier 5 through the initial protective gas delivery pipeline 9. After the amount of the protective gas meets the reaction requirements in the fluidized bed reactor 1, the protective gas is no longer provided through the initial protective gas delivery pipeline 9, and the protective gas discharged from the gas outlet of the condenser 4 enters the fluidized bed gas purifier 5. The protective gas strongly disturbs the adsorbent particles in the fluidized bed gas purifier 5 to form a fluidized bed. The adsorbent particles adsorb water and oxygen in the protective gas to obtain purified protective gas and discharge it from the gas outlet of the fluidized bed gas purifier 5. The water and oxygen contents in the protective gas at the gas outlet of the fluidized bed gas purifier 5 are detected by the gas impurity detection component 6. If the water and oxygen contents do not meet the requirements, the protective gas is re-entered into the fluidized bed gas purifier 5 for purification. If the water content in the protective gas is less than 5ppm and the oxygen content is less than 5ppm, it meets the requirements. The protective gas that meets the water and oxygen content requirements is compressed by the compressor 8 and enters the fluidized bed reactor 1.

[0177] In this embodiment, the reaction temperature in the fluidized bed reactor 1 is -40 to 40°C, specifically 0°C. The reaction pressure in the fluidized bed reactor 1 is 0.1-2MPa, specifically 0.5MPa. The temperature and pressure in the fluidized bed reactor 1 can be detected by the temperature and pressure detection assembly 2 at the top of the fluidized bed reactor 1. The fluidization velocity in the fluidized bed reactor 1 is 0.1-5m / s, specifically 2m / s. It can be understood by those skilled in the art that the fluidization velocity refers to the superficial velocity of the fluid formed by the solid cyclopentadienyl ligand.

[0178] In this embodiment, the crystal size of the solid octahedral ligand is 10-100 μm, specifically about 50 μm. The particle size of the solid octahedral ligand is 500-5000 μm, specifically 2000-3000 μm. The dosage ratio of the solid octahedral ligand to the solvent is 50-500 g:1 L, specifically 100 g:1 L. The metal ion concentration in the metal ion solution is 0.1-100 g / L, specifically 50 g / L.

[0179] In this embodiment, the solid metallocene ligand, solvent, and metal ion solution can all be conventional raw materials for preparing homogeneous metallocene catalysts in the art, and the present invention does not impose any particular limitation on the specific compounds that can be selected.

[0180] In this embodiment, the temperature in the condenser 4 is -50 to 50°C, specifically 0°C. The pressure in the condenser 4 is 0.1-2MPa, specifically 1MPa. The pressure in the condenser can be adjusted by the pressure relief valve 42 at the top of the condenser 4 and / or by supplementing the protective gas through the gas replenishment port 43. The residence time of the protective gas entrained solvent discharged from the gas outlet of the fluidized bed reactor 1 in the condenser 4 is 0.1-20min, specifically 10min. The flow rate of the protective gas entrained solvent in the condenser 4 is less than 1m / min.

[0181] In this embodiment, the solvent entrained in the protective gas is condensed and recovered by supercondensation to ensure that all gaseous solvents are completely liquefied, and the folded plate condensation method is used to increase the residence time of the protective gas, thereby improving the solvent recovery efficiency.

[0182] In this embodiment, the temperature in the fluidized bed gas purifier 5 is -50 to 50°C, specifically 0°C. The pressure in the fluidized bed gas purifier 5 is 0.1-2MPa, specifically 0.5MPa. The fluidization velocity in the fluidized bed gas purifier 5 is 0.1-5m / s, specifically 2m / s. It can be understood by those skilled in the art that the fluidization velocity refers to the superficial velocity of the fluid formed by the adsorbent particles.

[0183] According to a specific embodiment of the present invention, the present invention adopts a fluidized bed gas purifier to purify the protective gas. During the purification process, the protective gas strongly disturbs the adsorbent particles (such as molecular sieves, etc.) to form a fluidized bed, thereby efficiently adsorbing water and oxygen in the protective gas, and causing the protective gas that does not meet the water and oxygen content requirements to be re-purified, and the protective gas that meets the water and oxygen content requirements enters the fluidized bed reactor.

[0184] In this embodiment, the pressure of the protective gas after being compressed by the compressor 8 is 0.1-2 MPa, specifically 0.5 MPa, and the temperature is -50 to 50° C., specifically 0° C. In this embodiment, the compressor 8 is used to provide the pressure of the entire reaction system.

[0185] In this embodiment, the protective gas is nitrogen.

[0186] In this embodiment, the crystal size of the prepared homogeneous metallocene catalyst is about 50 μm, and the particle size is 2000-3000 μm.

[0187] According to testing, the purity of the homogeneous metallocene catalyst provided in this embodiment is above 97%, and the yield is above 85%.

Claims

1. A homogeneous metallocene catalyst preparation system, characterized in that: include: A ligand synthesis unit (300), a chemical reaction unit (500) and a recrystallization unit (400); The ligand synthesis unit (300) and the chemical reaction unit (500) are respectively connected to the recrystallization unit (400); The ligand synthesis unit (300) is used to add ligand synthesis raw materials and a first solvent under protective gas conditions to synthesize a preliminary cyclopentadienyl ligand; The chemical reaction unit (500) is used to add a solid metallocene ligand and a second solvent under protective gas conditions, and attach metal ions in the metal ion solution to the solid metallocene ligand for reaction to generate a homogeneous metallocene catalyst; The recrystallization unit (400) is used to use a third solvent to dissolve the preliminary cyclopentadienyl ligand, then cool and crystallize it, separate the solvent and filter to obtain a solid product, use evaporation and crystallization to separate impurities from the solid product to obtain a crystalline product, and use a fourth solvent to dissolve the crystalline product and then cool and crystallize it to obtain the solid cyclopentadienyl ligand; as well as, The homogeneous metallocene catalyst is dissolved in a fifth solvent and then cooled and crystallized, the solvent is separated and filtered to obtain a solid catalyst, the solid catalyst is evaporated and crystallized to precipitate impurities to obtain a crystalline catalyst product, the crystalline catalyst product is dissolved in a sixth solvent and then cooled and crystallized to obtain a high-yield homogeneous metallocene catalyst.

2. The homogeneous metallocene catalyst preparation system according to claim 1, characterized in that: The recrystallization unit (400) includes a ligand recrystallization unit (400) and a compound recrystallization unit (400); The ligand recrystallization unit (400) comprises a first-stage ligand crystallizer, a second-stage ligand crystallizer and a third-stage ligand crystallizer; The first stage ligand crystallizer is used to dissolve the preliminary cyclopentadienyl ligand with a third solvent, then cool and crystallize it, separate the solvent and filter to obtain a solid product; The second stage ligand crystallizer is used to precipitate impurities from the solid product by evaporation and crystallization to obtain a crystalline product; The third stage ligand crystallizer is used to dissolve the crystal product with a fourth solvent and then cool and crystallize it to obtain a solid cyclopentadienyl ligand; The compound recrystallization unit (400) comprises a first-stage compound crystallizer (13), a second-stage compound crystallizer (14) and a third-stage compound crystallizer (15); The first stage compound crystallizer (13) is used to use a fifth solvent to dissolve the homogeneous metallocene catalyst, then cool and crystallize it, separate the solvent and filter to obtain a solid catalyst; The second stage compound crystallizer (14) is used to precipitate impurities from the solid catalyst by evaporation crystallization to obtain a crystalline catalyst product; The third stage compound crystallizer (15) is used to dissolve the crystallized catalyst product with the sixth solvent and then cool and crystallize it to obtain a high-yield homogeneous metallocene catalyst.

3. The homogeneous metallocene catalyst preparation system according to claim 2, characterized in that: The first-stage ligand crystallizer, the second-stage ligand crystallizer, the third-stage ligand crystallizer, the first-stage compound crystallizer (13), the second-stage compound crystallizer (14) and the third-stage compound crystallizer (15) are sieve plate crystallizers.

4. The homogeneous metallocene catalyst preparation system according to claim 2, characterized in that: The first-stage ligand crystallizer, the third-stage ligand crystallizer, the first-stage compound crystallizer (13) and the third-stage compound crystallizer (15) adopt a gradient cooling method to perform cooling crystallization.

5. The homogeneous metallocene catalyst preparation system according to claim 2, characterized in that: The second stage ligand crystallizer is used to set the evaporation temperature according to the boiling point of the third solvent to perform evaporation crystallization; The second-stage combined crystallizer (14) is used to set the evaporation temperature according to the boiling point of the fifth solvent to perform evaporation crystallization.

6. The homogeneous metallocene catalyst preparation system according to claim 1, characterized in that: The first solvent, the second solvent, the third solvent, the fourth solvent, the fifth solvent and the sixth solvent are respectively one of ethanol and ether, ethanol and acetone, ethanol and chloroform, ether and petroleum ether, chloroform and petroleum ether.

7. The homogeneous metallocene catalyst preparation system according to claim 1 or 2, characterized in that: Also includes: The solvent recovery unit (600) is used to purify and recover the third solvent, the fourth solvent, the fifth solvent and the sixth solvent after recrystallization filtration by distillation.

8. The homogeneous metallocene catalyst preparation system according to claim 1, characterized in that: The chemical reaction unit (500) comprises a fluidized bed reactor (1) and a temperature and pressure detection component (2); the fluidized bed reactor (1) comprises a reactor shell, an air inlet, an air outlet, a cyclopentadienyl ligand feed port, a metal ion solution feed port, a solvent feed port, a discharge port, and a nozzle (11); the air inlet and the discharge port are arranged at the lower part of the reactor shell; the cyclopentadienyl ligand feed port, the metal ion solution feed port, and the solvent feed port are arranged on the side wall of the reactor shell; the air outlet is arranged at the top of the reactor shell; the nozzle (11) is arranged on the inner wall of the reactor shell; the nozzle (11) is connected to the metal ion solution feed port; the temperature and pressure detection component (2) is arranged at the top of the reactor shell and is used to detect the temperature and pressure inside the reactor shell.

9. The homogeneous metallocene catalyst preparation system according to claim 8, characterized in that: Also included is a solvent condensation and collection unit (700); The solvent condensation and collection unit (700) comprises a condenser (4); the condenser (4) is at least provided with a condensation medium inlet, a condensation medium outlet, an air inlet, an air outlet, and a solvent outlet; the condensation medium inlet is arranged at the lower part of the condenser (4), the condensation medium outlet is arranged at the upper part of the condenser (4), the air inlet is arranged at the upper part of the condenser (4), the air outlet is arranged at the top of the condenser (4), and the solvent outlet is arranged at the bottom of the condenser (4).

10. The homogeneous metallocene catalyst preparation system according to claim 9, characterized in that: Also includes an atmosphere purification unit; The atmosphere purification unit comprises a fluidized bed gas purifier (5); the fluidized bed gas purifier (5) comprises a purifier housing, an air inlet, and an air outlet; the air inlet is arranged at the lower part of the purifier housing; the air outlet is arranged at the top of the purifier housing; the interior of the purifier housing has adsorbent particles; The gas outlet of the fluidized bed reactor (1) is connected to the gas inlet of the condenser (4) through a pipeline; The gas outlet of the condenser (4) is connected to the gas inlet of the fluidized bed gas purifier (5) through a pipeline; The gas outlet of the fluidized bed gas purifier (5) is connected to the gas inlet of the fluidized bed reactor (1) through a pipeline.

11. A method for preparing a homogeneous metallocene catalyst, using the homogeneous metallocene catalyst preparation system according to any one of claims 1 to 10.

12. The method for preparing a homogeneous metallocene catalyst according to claim 11, characterized in that: include: Under protective gas conditions, adding ligand synthesis raw materials and a first solvent to synthesize a preliminary cyclopentadienyl ligand; Using a third solvent to dissolve the preliminary cyclopentadienyl ligand, then cooling and crystallizing, separating the solvent and filtering to obtain a solid product, using the solid product to precipitate impurities by evaporation and crystallization to obtain a crystalline product, using a fourth solvent to dissolve the crystalline product, then cooling and crystallizing to obtain the solid cyclopentadienyl ligand; Under protective gas conditions, a solid metallocene ligand and a second solvent are added, and metal ions in the metal ion solution are attached to the solid metallocene ligand for reaction to generate a homogeneous metallocene catalyst; The homogeneous metallocene catalyst is dissolved in a fifth solvent and then cooled and crystallized, the solvent is separated and filtered to obtain a solid catalyst, the solid catalyst is evaporated and crystallized to precipitate impurities to obtain a crystalline catalyst product, the crystalline catalyst product is dissolved in a sixth solvent and then cooled and crystallized to obtain a high-yield homogeneous metallocene catalyst.

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