Mixing device and method for slurry-shaped catalyst auxiliary agent

Abstract

The invention discloses a mixing device and method for a slurry-shaped catalyst auxiliary agent, and belongs to the technical field of mixing preparation of the slurry-shaped catalyst auxiliary agent. The mixing device comprises a solid raw material pretreatment system and a mixing preparation system, the solid raw material pretreatment system comprises at least one feeding tank, the feeding tank is provided with a first pressure control module and a first temperature control module, and the bottom of the feeding tank is provided with a first discharge port; the mixing preparation system comprises at least one mixing kettle, the mixing kettle is provided with a solid phase injection port, a liquid phase injection port, a second pressure control module and a second temperature control module, a mechanical stirring assembly is arranged in the mixing kettle, and a closed discharging module is arranged at the bottom of the mixing kettle; and a first discharge port of the feeding tank is connected with a solid phase injection port of the mixing kettle. According to the invention, the impurities of the slurry catalyst auxiliary agent from the raw materials and in the production process can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mixing and preparing of slurry catalyst adjuvant, and particularly relates to a mixing and preparing device and method for slurry catalyst adjuvant. BACKGROUND

[0002] Catalyst adjuvant is an important additive for adjusting or optimizing the process of olefin polymerization, and is often used to improve the catalytic activity, stability or selectivity of the catalyst. Compared with solid powder, slurry catalyst adjuvant is easier to realize automation, accurate metering and closed operation, and is widely used in the process of gas phase olefin polymerization. However, the catalyst for gas phase polymerization of olefin is highly sensitive to impurities, especially the metallocene catalyst system, which is easily affected by impurities such as water (H2O), oxygen (O2), carbon monoxide (CO), carbon dioxide (CO2), etc., resulting in reduced activity, and even complete deactivation in severe cases. The impurities in the slurry catalyst adjuvant usually come from the raw materials themselves or the mixing in the preparation process, and the conventional preparation device has many limitations. For example: (1) the raw materials cannot be pre-refined. It is difficult to effectively reduce the moisture content and gas phase impurities in the solid raw materials and liquid raw materials. (2) The risk of pollution during the transfer of raw materials. Since the conventional equipment is not integrated, when the solid raw materials are transferred into the kettle or the final product is transferred to the storage tank, they are often exposed to air and water vapor. (3) Additional front purification system. Such as multi-stage purification bed device containing copper, zinc, aluminum or molecular sieve adsorbent, which increases the process complexity and equipment investment cost.

[0003] It is an important problem in the preparation process of slurry catalyst adjuvant to effectively reduce the impurity content. Since trace level impurities can also poison the active center of the catalyst, seriously affecting the efficiency of the polymerization reaction and the quality of the polyolefin product, it is of great practical significance to develop a mixing and preparing device and method for slurry catalyst adjuvant to significantly reduce the impurities from the raw materials themselves and the production process. SUMMARY

[0004] To solve the above technical problems, the purpose of the present application is to provide a mixing and preparing device and method for slurry catalyst adjuvant. The present application can reduce the impurities in the slurry catalyst adjuvant from the raw materials themselves and the production process.

[0005] To achieve the above purpose, the first aspect of the present application provides a mixing and preparing device for slurry catalyst adjuvant, comprising: a solid raw material pretreatment system and a mixing and preparing system.

[0006] The solid raw material pretreatment system comprises at least one feeding tank, the feeding tank is provided with a first pressure control module and a first temperature control module, and the bottom of the feeding tank is provided with a first discharge port; the solid raw material pretreatment system is used for reducing pressure drying of the solid raw material to obtain pretreated solid raw material;

[0007] The mixing preparation system comprises at least one mixing kettle, the mixing kettle is provided with a solid phase injection inlet, a liquid phase injection inlet, a second pressure control module and a second temperature control module, the mixing kettle is provided with a mechanical stirring assembly, and the bottom of the mixing kettle is provided with a sealed discharge module; the mixing preparation system is used for reducing pressure distillation of the liquid raw material to obtain pretreated liquid raw material, and is used for uniformly mixing the pretreated solid raw material and the pretreated liquid raw material to obtain a slurry-shaped catalyst aid;

[0008] The first discharge port of the feeding tank is connected with the solid phase injection inlet of the mixing kettle.

[0009] The second aspect of the present application provides a mixing method for a slurry-shaped catalyst aid, the mixing method is carried out by using the mixing device for the slurry-shaped catalyst aid, and the mixing method comprises the following steps:

[0010] (1) the solid raw material is added to the feeding tank, the solid raw material pretreatment system is used for reducing pressure drying of the solid raw material to obtain pretreated solid raw material;

[0011] (2) the liquid raw material is added to the mixing kettle, and the mixing preparation system is used for reducing pressure distillation of the liquid raw material to obtain pretreated liquid raw material;

[0012] (3) the pretreated solid raw material is transferred from the feeding tank to the mixing kettle, and the pretreated solid raw material and the pretreated liquid raw material are uniformly mixed to obtain a slurry-shaped catalyst aid.

[0013] The present application has at least the following beneficial effects:

[0014] The present application can reduce the impurities in the slurry-shaped catalyst aid from the raw materials themselves and the production process, eliminate the pollution risk in the transfer process, thereby significantly reducing the impurity content in the slurry-shaped catalyst aid product, and reducing the mixing unevenness and wall hanging phenomenon of the slurry-shaped catalyst aid, so as to obtain a slurry-shaped catalyst aid with low water and low oxygen content, which can meet the requirements of the extremely sensitive polyolefin catalyst. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a structure schematic view of the mixing device for the slurry-shaped catalyst aid in the embodiment of the present application.

[0016] Figure 2 Flow chart of the mixing method for the slurry catalyst aid in the embodiment of the present application.

[0017] Explanation of reference numerals:

[0018] 1 - solid raw material pretreatment system; 2 - mixing preparation system; 101 - feeding tank; 102 - first discharge port; 103 - discharging module; 201 - mixing kettle; 202 - solid phase injection inlet; 203 - liquid phase injection inlet; 204 - mechanical stirring assembly; 205 - closed discharging module. DETAILED DESCRIPTION

[0019] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present application, the present application will be described in detail below, but it should not be understood as limiting the scope of the present application.

[0020] It should be noted that, unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0021] The various raw materials, reagents, instruments and equipment used in the present application, unless otherwise specified, can be purchased from the market or can be prepared by existing methods.

[0022] It should be understood that the terms "comprise", "include" and / or "contain" used herein specify the presence of stated features, integers, steps, components or combinations thereof, but do not exclude the presence or addition of one or more other features, integers, steps, components or combinations thereof.

[0023] The endpoints of the ranges and any values disclosed in the present application are not limited to the precise values stated. The ranges or values should be interpreted as being approximate, and the endpoints of the ranges of values should be considered to be approximate. For numeric values, the endpoints of each range, the endpoints of each range and individual point values, and individual point values can be combined with each other to obtain one or more new numeric ranges, which should be considered to be specifically disclosed in the present application.

[0024] The compounds, compositions, ingredients, mixtures, preparation methods, dispersion forms, apparent properties, reactors, temperatures, pressures, catalysts, etc. disclosed in the present application should be understood as not being limited to specific compounds, compositions, ingredients, mixtures, preparation methods, dispersion forms, apparent properties, reactors, temperatures, pressures, catalysts, etc. unless otherwise specified, as the above conditions can be adjusted according to the situation. The terms used in the present application are only for the purpose of better describing the embodiments, and are not as a limiting condition for the protection of the present application.

[0025] In the description of the present application, it should be noted that the terms "upper", "lower", "top / bottom end" and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0026] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "provided with", "sleeved / connected", "connected" and the like should be broadly understood, for example, "connected" can be fixedly connected, can also be detachably connected, or integrally connected, can be mechanically connected, can also be electrically connected, can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication of two elements, and those skilled in the art can understand the specific meaning of the above terms in the present application according to the specific circumstances.

[0027] According to the specific embodiment of the first aspect of the present application, the present application provides a mixing device for slurry catalyst additives, comprising a solid raw material pretreatment system and a mixing and preparation system;

[0028] The solid raw material pretreatment system comprises at least one feeding tank, the feeding tank is provided with a first pressure control module and a first temperature control module, and the bottom of the feeding tank is provided with a first discharge port; the solid raw material pretreatment system is used for reducing pressure drying of the solid raw material to obtain pretreated solid raw material;

[0029] The mixing and preparation system comprises at least one mixing kettle, the mixing kettle is provided with a solid phase injection port, a liquid phase injection port, a second pressure control module and a second temperature control module, the mixing kettle is provided with a mechanical stirring assembly, and the bottom of the mixing kettle is provided with a sealed discharge module; the mixing and preparation system is used for reducing pressure distillation of the liquid raw material to obtain pretreated liquid raw material, and for uniformly mixing the pretreated solid raw material and the pretreated liquid raw material to obtain a slurry catalyst additive;

[0030] The first discharge port of the feeding tank is connected with the solid phase injection port of the mixing kettle.

[0031] In some embodiments, the number of feeding tanks can be one or more, and the number of feeding tanks can be selected based on the number of types of solid raw materials. In the case that the solid raw materials have good flowability and do not react with each other, one feeding tank can be optimized and simplified. In addition, it can be understood that the feeding tank is a closable container.

[0032] In some embodiments, in the solid raw material pretreatment system, the feeding tank is a metal feeding tank. Preferably, the material of the feeding tank comprises stainless steel, hastelloy, carbon steel with polytetrafluoroethylene (PTFE) lining, or stainless steel with polytetrafluoroethylene lining, etc. Among them, the stainless steel can specifically comprise 304 stainless steel, 316L stainless steel, or duplex steel, etc. More preferably, the material of the feeding tank comprises 304 stainless steel or 316L stainless steel, and further preferably 304 stainless steel.

[0033] In some embodiments, in the solid raw material pretreatment system, the first pressure control module is arranged at the top of the feeding tank, and the first pressure control module comprises a first pressure sensor, a first protective gas pipeline, a first evacuation pipeline, and a first vacuum pipeline. The first pressure control module is used for protective gas pressure maintaining and pressure lifting and replacement operations of the solid raw material pretreatment system, so as to reduce the pressure of the solid raw material. It can be understood that valves are arranged on each pipeline.

[0034] In some embodiments, in the solid raw material pretreatment system, a dust filter is arranged on the first evacuation pipeline and / or the first vacuum pipeline. By arranging the dust filter, the escape of powder in the solid raw material can be prevented. The dust filter can adopt a high-efficiency filter in the prior art, so as to filter small particle size powder below 1 μm.

[0035] In some embodiments, in the solid raw material pretreatment system, the first temperature control module comprises a first temperature sensor, a first heating layer, and a first heat preservation layer, the first temperature sensor is arranged in the feeding tank, and the first heating layer and the first heat preservation layer are arranged in sequence outside the feeding tank. The first temperature control module is used to provide the temperature required for drying the solid raw material.

[0036] In some embodiments, in the solid raw material pretreatment system, a first water content and oxygen content online detection assembly is further arranged in the feeding tank, which is used for real-time monitoring of the water content and oxygen content in the feeding tank.

[0037] In some embodiments, in the solid raw material pretreatment system, the first discharge port is an inverted cone. By designing the discharge port of the inverted cone, it is beneficial for the solid raw material to move downward under the action of gravity, improves the accuracy of subsequent feeding into the mixing and preparation system, and reduces the solid raw material residue.

[0038] In some embodiments, the inner wall of the feeding tank, the valve body of the valve, and the inner wall of the pipeline in the solid raw material pretreatment system are plated with chromium and / or polished. For solid raw materials that are prone to adhesion, the inner wall of the feeding tank, the valve body of the valve, and the inner wall of the pipeline can be plated with chromium and / or polished, so as to further avoid the adhesion and residue of the solid raw materials.

[0039] In some embodiments, in the solid raw material pretreatment system, the first discharge port is provided with a discharging module, and the discharging module comprises vibrators and / or bin dischargers. The vibrators are arranged on the outer wall of the first discharge port (i.e. the outer wall of the cone), and the bin dischargers are arranged at the bottom of the feeding tank. By adding the vibrators or the bin dischargers, the present application can further reduce the adhesion and residue of the solid raw materials. By arranging the vibrators on the outer wall of the discharge port cone of the feeding tank, the powder bridging of the solid raw materials can be prevented, and stable discharge can be ensured. The bin dischargers can adopt a conventional structure in the art, for example, the bin dischargers can be provided with rotating rake arms and / or fluidization assemblies, so as to destroy the bridging and promote the flow of the solid raw materials by arranging the bin dischargers at the bottom of the feeding tank. The bin dischargers can be arranged in the first discharge port or the upper part of the first discharge port. Preferably, the discharging module is the vibrator.

[0040] The solid raw material pretreatment system of the present application can realize the reduced-pressure drying treatment of the solid raw materials, and can effectively remove the adsorbed air and trace moisture in the solid raw materials.

[0041] In some embodiments, the number of the mixing kettles in the mixing and preparation system can be one. In addition, it can be understood that the mixing kettle is a sealable container.

[0042] In some embodiments, in the mixing and preparation system, the mixing kettle is a metal mixing kettle. Preferably, the material of the mixing kettle comprises stainless steel, hastelloy, carbon steel with a polytetrafluoroethylene (PTFE) lining, or stainless steel with a polytetrafluoroethylene lining, etc. The stainless steel can specifically comprise 304 stainless steel, 316L stainless steel, or duplex steel, etc. More preferably, the material of the mixing kettle comprises 304 stainless steel or 316L stainless steel, and further preferably 304 stainless steel.

[0043] In some embodiments, in the mixing and preparation system, the number of the liquid phase injection ports is one or more, and each liquid phase injection port is connected to a liquid phase injection pipeline. Preferably, the number of the liquid phase injection ports is two, which are respectively used for injecting liquid effective components and liquid solvents. More preferably, a flow regulating assembly is arranged on each liquid phase injection pipeline, so as to ensure the accuracy of the liquid raw material delivery amount.

[0044] In some embodiments, in the mixing and preparation system, the second pressure control module is arranged on the top of the mixing kettle, and comprises a second pressure sensor, a second protective gas pipeline, a second evacuation pipeline and a second vacuum pipeline. The second pressure control module is used for protective gas pressure maintaining and pressure increasing and decreasing replacement operation of the mixing and preparation system, so as to reduce the pressure of the liquid raw material. It can be understood that a valve is arranged on each pipeline.

[0045] In some embodiments, in the mixing and preparation system, the second temperature control module comprises a second temperature sensor, a second heating layer and a second heat preservation layer, the second temperature sensor is arranged in the mixing kettle, and the second heating layer and the second heat preservation layer are arranged in sequence outside the mixing kettle. The second temperature control module is used for providing the temperature required for distillation of the liquid raw material.

[0046] In some embodiments, in the mixing and preparation system, a second water content and oxygen content online detection assembly is further arranged in the mixing kettle, which is used for monitoring the water content and oxygen content in the mixing kettle in real time.

[0047] In some embodiments, in the mixing and preparation system, a glass observation window is arranged on the side wall of the mixing kettle. The material of the glass observation window can be pressure-resistant glass, and the shape can be strip-shaped. By designing the glass observation window, the mixing condition in the mixing kettle can be observed. Preferably, the glass observation window is flush with the inner wall and the outer wall of the mixing kettle. In this way, the probability of wall hanging and wear of the material in the mixing kettle can be reduced. Compared with the liquid level meter, the glass observation window can not only observe the condition in the mixing kettle in real time, but also effectively reduce the hanging rod entanglement phenomenon, and is more suitable for slurry catalyst additives.

[0048] In some embodiments, in the mixing and preparation system, the mechanical stirring assembly comprises a driving unit, a transmission and sealing unit and a stirring execution unit; the transmission and sealing unit comprises a stirring shaft and a double-end face container type mechanical sealing structure, the stirring shaft and the kettle body of the mixing kettle are sealed through the double-end face container type mechanical sealing structure; the stirring execution unit comprises a stirring paddle, the stirring paddle is connected to the stirring shaft; the driving unit is used for driving the stirring shaft to rotate the stirring paddle.

[0049] In some embodiments, in the mixing and preparation system, the driving unit comprises an explosion-proof frequency conversion motor and a parallel shaft gear reducer. Through the explosion-proof frequency conversion motor and the parallel shaft gear reducer, the original power can be provided for the mechanical stirring assembly, and the speed regulation and the torque output are realized; and the explosion-proof characteristic ensures the operation safety in the potentially dangerous environment; the frequency conversion speed regulation function allows flexible adjustment of the stirring speed according to the process requirement, realizes the energy consumption optimization and the process adaptation.

[0050] In some embodiments, in the mixing and preparation system, the transmission and sealing unit further comprises a sealing liquid pressurization and monitoring element. By combining the double-end-face canned mechanical sealing structure and the sealing liquid pressurization and monitoring element, high-reliability sealing between the stirring shaft and the kettle body can be achieved, external air can be effectively isolated, and internal volatile medium can be prevented from leaking out, thereby ensuring that the whole process is carried out in an absolutely sealed protective gas environment.

[0051] In some embodiments, in the mixing and preparation system, the transmission and sealing unit further comprises a self-lubricating bottom bearing, and the bottom of the stirring shaft is provided with the self-lubricating bottom bearing. The self-lubricating bottom bearing provides stable support for the bottom of the stirring shaft, can reduce radial swing during operation, and ensures long-term stable operation of the mechanical stirring assembly.

[0052] In some embodiments, in the mixing and preparation system, the stirring paddle comprises one or more than two of a disc turbine paddle, an inclined blade turbine paddle, a propeller, an axial flow paddle, an anchor paddle, a ribbon paddle, and a frame paddle. Preferably, the stirring paddle comprises an anchor paddle and / or a frame paddle. The anchor paddle and / or the frame paddle are more suitable for medium-high viscosity materials, can generate a large range of circulating flow fields at a lower power consumption, and take into account mixing efficiency and operation economy.

[0053] In some embodiments, in the mixing and preparation system, the stirring paddle is a single-layer structure, a double-layer structure, or a multi-layer structure. Preferably, the stirring paddle is a double-layer structure. The double-layer stirring paddle can extend the strong shearing and mixing effect to the entire space in the axial and radial directions of the kettle, is particularly suitable for high-viscosity slurry, ensures that the material reaches extremely high mixing uniformity in the longitudinal and transverse directions, and improves the mixing efficiency.

[0054] In some embodiments, in the mixing and preparation system, the stirring paddle comprises a double-layer anchor paddle, a double-layer frame paddle, or a double-layer anchor-frame composite paddle, which respectively comprises an upper paddle blade and a lower paddle blade, and the lower paddle blade adopts a near-wall flow type. By adopting the near-wall flow type paddle blade, the gap between the paddle blade and the inner wall of the mixing kettle is small, wall attachments can be effectively scraped, fouling can be prevented, and the mass transfer and heat transfer efficiency in the area close to the wall can be greatly enhanced.

[0055] In some embodiments, in the mixing and preparation system, the closed discharge module comprises a second discharge port, a switch valve, a dry quick connector, and a stainless steel wire reinforced hose with a polytetrafluoroethylene lining, the second discharge port is connected to the stainless steel wire reinforced hose with a polytetrafluoroethylene lining through the switch valve and the dry quick connector. The closed discharge module can realize the sealed connection of the mixing kettle and the subsequent product tank, avoiding the contamination of the slurry catalyst additive during discharge. The dry quick connector can be a sanitary dry quick connector. The stainless steel wire reinforced hose with a polytetrafluoroethylene lining can be a conventional component in the art, wherein the PTFE lining is an extremely excellent synthetic polymer material with excellent chemical inertness, excellent non-stickiness, and wide temperature resistance. As the discharge pipeline, it can ensure that the slurry catalyst additive is not contaminated and is easy to clean.

[0056] The mixing and preparation system of the present application can realize the vacuum distillation of the liquid raw material, effectively remove the air and moisture in the liquid raw material, and uniformly mix the pretreated solid raw material and the pretreated liquid raw material to obtain the slurry catalyst additive. As described above, the liquid raw material preferably comprises a liquid effective component and a liquid solvent.

[0057] In some embodiments, a rotary feeding valve or a screw feeder with purging function is arranged on the pipeline connecting the first discharge port of the feeding tank and the solid phase inlet of the mixing kettle. Preferably, a rotary feeding valve with purging function is used. Preferably, the rotary feeding valve or the screw feeder with purging function is equipped with a loss-in-weight control element or a gravimetric control element. By arranging the feeding valve or the feeder, the solid raw material is transferred from the feeding tank to the mixing kettle in a protective gas environment, without contacting the external air, and realizes continuous, stable and accurate delivery of the solid raw material.

[0058] In some embodiments, the mixing kettle is arranged below the feeding tank.

[0059] It can be understood that the mixing device of the present application also comprises a plurality of conventional but necessary auxiliary accessories, which are summarized as an auxiliary accessory system. The auxiliary accessory system comprises but is not limited to the following components:

[0060] Vacuum pump: used for vacuumizing the solid raw material pretreatment system and the mixing and preparation system, which can be connected to the first vacuumizing pipeline and the second vacuumizing pipeline;

[0061] Product tank: used for storing the slurry catalyst additive product, which is connected to the stainless steel wire reinforced hose with a polytetrafluoroethylene lining of the closed discharge module, and the material can be metal;

[0062] Metering equipment: which can include one or more than two of metering scale, metering pump and mass flow meter, etc., which can be routinely set by those skilled in the art;

[0063] Temperature control equipment: which can include one or more than two of temperature remote control equipment, circulating water / oil system, steam heating system and electric heating system, etc., for temperature control of the first temperature control module and the second temperature control module;

[0064] Other auxiliary equipment: which can include flow regulating valve, pneumatic barrel pump, vacuum buffer tank, dry tail gas system, condenser, connecting pipeline between structures of various equipment, component, element, etc., auxiliary pump, heat exchanger, etc.; these components can be routinely set by those skilled in the art.

[0065] According to the specific embodiment of the second aspect of the present application, the present application provides a mixing method for slurry catalyst adjuvant, which is carried out by using the mixing device for slurry catalyst adjuvant described above, and the mixing method comprises the following steps:

[0066] (1) adding solid raw materials into the feeding tank, and using the solid raw material pretreatment system to carry out vacuum drying on the solid raw materials to obtain pretreated solid raw materials;

[0067] (2) adding liquid raw materials into the mixing kettle, and using the mixing preparation system to carry out vacuum distillation on the liquid raw materials to obtain pretreated liquid raw materials;

[0068] (3) transferring the pretreated solid raw materials from the feeding tank to the mixing kettle, and uniformly mixing the pretreated solid raw materials and the pretreated liquid raw materials to obtain slurry catalyst adjuvant.

[0069] In step (1), a predetermined weight of solid raw materials is added into the feeding tank, and the solid raw material pretreatment system is used to carry out vacuum drying on the solid raw materials to obtain pretreated solid raw materials. Since the solid raw materials can absorb air and moisture during production, storage, transportation and conveying, the present application carries out vacuum drying on the solid raw materials to carry out exhaust and water removal treatment, so as to reduce the adverse effects of the slurry catalyst adjuvant on the polymerization activity. The exhaust principle of the solid raw materials is to create a low partial pressure environment to promote the spontaneous escape of gas molecules, which are then removed from the feeding tank. The water removal principle of the solid raw materials is to reduce the boiling point of water by using vacuum or reduced pressure environment, and to provide a strong mass transfer driving force for water escape, so that efficient and deep drying of the solid raw materials can be achieved under lower temperature conditions, effectively avoiding the decomposition and denaturation of heat-sensitive solid raw materials. Preferably, the solid raw materials in step (1) are hygroscopic solid raw materials, which can be specifically in the form of powder.

[0070] In some embodiments, in step (1), the first pressure control module is controlled to reach the vacuum degree of the reduced-pressure drying, and the first temperature control module is controlled to reach the temperature of the reduced-pressure drying, wherein the vacuum degree of the reduced-pressure drying is 0.1-50 kPa, preferably 2-10 kPa, and the temperature of the reduced-pressure drying is 40-100 ℃, preferably 50-80 ℃.

[0071] Preferably, the procedure of the reduced-pressure drying is divided into four steps: the first step is a vacuumizing stage, in which the pressure is steadily reduced to the target vacuum degree; the second step is a preliminary temperature rising stage, in which the temperature is smoothly raised to an initial value which is 5-10 ℃ lower than the target temperature, so as to avoid thermal inertia caused by rapid temperature rising and to prevent temperature overshooting; the third step is a slow temperature rising stage, in which the temperature is slowly raised from the initial value to the target temperature at a lower power, so as to allow sufficient temperature transfer and to balance the temperature inside and outside the material; and the fourth step is a constant temperature maintaining stage, in which the temperature is maintained constant by intermittent heating, so as to ensure that the reduced-pressure drying process is continuously, efficiently and safely carried out at the constant target temperature.

[0072] In the process of the reduced-pressure drying, the vacuum degree is not the higher the better. An extremely high vacuum degree requires extremely high sealing property of the feeding tank and the vacuum pump, and may cause fine powder to be sucked into the vacuum facility. According to the characteristics (such as particle size and temperature resistance) of the solid raw material, the above-mentioned range of the vacuum degree is selected in the present application, which has the advantages of economy and efficiency. In addition, the vacuum degree needs to be monitored and recorded in real time. Sudden change of the vacuum degree may cause equipment leakage or material boiling. In addition, in the process of the reduced-pressure drying, by controlling the above-mentioned procedure, melting and crust formation of the solid raw material near the inner wall surface of the feeding tank can be prevented.

[0073] In some embodiments, in step (1), when the water content in the feeding tank is 5-200 ppm, preferably 120 ppm or less, more preferably 50 ppm or less, and the oxygen content is 0.1-20 ppm, preferably 5 ppm or less, more preferably 2 ppm or less, then step (1) is ended.

[0074] In step (2), a predetermined weight of the liquid raw material is added to the mixing kettle, and the liquid raw material is subjected to reduced-pressure distillation by using a mixing and preparation system, to obtain the pretreated liquid raw material. Since the liquid raw material may absorb air and moisture during production, storage, transportation and delivery, the liquid raw material is subjected to reduced-pressure distillation in the present application, so as to be subjected to air exhausting and moisture removing treatment, so as to reduce the adverse effect of the slurry-like catalyst additive on the polymerization activity. The principle of air exhausting of the liquid raw material is to create a low partial pressure environment, so as to cause gas molecules to spontaneously escape and be sucked away from the mixing kettle. The principle of moisture removing of the liquid raw material is to reduce the boiling point of water by using a vacuum or reduced-pressure environment, and to provide a strong mass transfer driving force for water to escape, so that efficient and deep drying of the liquid raw material can be realized under a lower temperature condition, and the dissolved water content in the liquid raw material can be effectively reduced.

[0075] In some embodiments, in step (2), the second pressure control module is controlled to reach the vacuum degree of the reduced pressure distillation, and the second temperature control module is controlled to reach the temperature of the reduced pressure distillation, wherein the vacuum degree of the reduced pressure distillation is 0.1-50 kPa, preferably 2-15 kPa, and the temperature of the reduced pressure distillation is normal temperature to 400 ℃, preferably normal temperature to 150 ℃, more preferably 50 ℃ to 150 ℃, and further preferably 50 ℃ to 120 ℃.

[0076] Preferably, the procedure control of the reduced pressure distillation is divided into four steps: the first step is a vacuum extraction phase, in which the pressure is stably reduced to the target vacuum degree; the second step is a preliminary temperature rising phase, in which the temperature is smoothly increased to an initial value which is 5-10 ℃ lower than the target temperature, so as to avoid thermal inertia caused by rapid temperature rising, and to eliminate temperature flying and boiling; the third step is a slow temperature rising phase, in which the temperature is slowly increased from the initial value to the target temperature at a lower power, so as to make the heat transfer of the liquid uniform, and to slowly release the internal dissolved gas; and the fourth step is a constant temperature holding phase, in which the temperature is maintained constant by intermittent heating, so as to ensure that the reduced pressure distillation process is continuously, efficiently and safely carried out at the constant target temperature.

[0077] In some embodiments, step (2) is carried out under the stirring action of the mechanical stirring assembly. The rotation speed of the stirring can be routinely adjusted by those skilled in the art.

[0078] In the process of the reduced pressure distillation, by selecting the above-mentioned vacuum degree and temperature range, and carrying out the whole process under stirring, and further selecting the above-mentioned procedure, the phenomena of boiling and material rushing can be prevented, and the operation safety, purification effect and equipment life can be ensured.

[0079] In steps (1) and (2), the operation sequence of “first vacuum extraction, then heating; first cooling, then vacuum breaking” should be followed, so as to ensure safety.

[0080] In some embodiments, step (2) further comprises adding non-hygroscopic waxy solid raw materials into the mixing kettle, and carrying out the reduced pressure distillation together with the liquid raw materials, to obtain the pretreated liquid raw materials. The non-hygroscopic waxy solid raw materials are waxy solid raw materials with lower melting points. If the slurry-like catalyst adjuvant of the present application comprises non-hygroscopic waxy solid raw materials, the non-hygroscopic waxy solid raw materials can be added into the mixing kettle and carried out the reduced pressure distillation together with the liquid raw materials, without reacting with the liquid raw materials. Before being added into the mixing kettle, the non-hygroscopic waxy solid raw materials can be first melted, and for granular waxy solid raw materials, the melting can also be omitted, and the waxy solid raw materials can be directly added into the mixing kettle.

[0081] In some embodiments, in step (2), the water content in the mixing kettle is 5-200 ppm, preferably 30 ppm or less, more preferably 10 ppm or less, and the oxygen content is 0.1-20 ppm, preferably 5 ppm or less, more preferably 2 ppm or less, and then step (2) is ended.

[0082] In some embodiments, in step (3), the feeding tank and the mixing kettle are cooled, and the feeding tank and the mixing kettle are pressurized to normal pressure using a protective gas, and then the pretreated solid raw material is transferred from the feeding tank to the mixing kettle, and the pretreated solid raw material and the pretreated liquid raw material are mixed uniformly under the stirring action of the mechanical stirring assembly to obtain a slurry-shaped catalyst aid. The cooling temperature, stirring speed and mixing time can be routinely adjusted by those skilled in the art according to the product properties. Preferably, during the process of transferring the pretreated solid raw material from the feeding tank to the mixing kettle, the pressure in the mixing kettle is not higher than the pressure in the feeding tank. This is conducive to the transfer of the solid raw material and prevents the back blowing of the gas in the mixing kettle to the feeding tank. In order to make the pressure in the mixing kettle not higher than the pressure in the feeding tank, the mixing kettle can be emptied and the feeding tank can be supplemented with protective gas during the transfer process.

[0083] In some embodiments, in step (3), the water content of the slurry-shaped catalyst aid is 10-600 ppm, preferably 300 ppm or less, more preferably 100 ppm or less.

[0084] In some embodiments, the mixing method further comprises the following steps: discharging the slurry-shaped catalyst aid in the mixing kettle and sealing in a product tank. Before discharging, the gas in the product tank, the bottom valve, the adapter, the hose, the pipeline and the product tank, etc. can be replaced to exhaust the air. The discharging power is provided by the gravity of the slurry-shaped catalyst aid and the slight positive pressure of the protective gas in the mixing kettle. The product is transported to the product tank through a closed pipeline, and the replaced gas is discharged through the exhaust port. After the loading is completed, all the valves are closed to form a protective gas atmosphere in the product tank, and finally the whole process of the slurry-shaped catalyst aid product is sealed.

[0085] In some embodiments, steps (1)-(3) are carried out in an atmosphere of a protective gas. The protective gas can include nitrogen, argon, carbon dioxide, oxygen-free air, water-free air, water-oxygen-free air, helium, neon and component gases thereof, preferably nitrogen and / or argon, to ensure that the introduction of impurities is minimized during the mixing process.

[0086] In the present application, the liquid raw material can include liquid active components and liquid solvents. The solid raw material can be in the form of particles, partially swollen, partially dissolved, or completely dissolved, etc. in the liquid solvent. When the solid raw material is in the form of particles, partially swollen, or partially dissolved in the liquid solvent, it can be in the form of dispersion such as floating, suspending, settling, sinking, stratifying, emulsifying, and combinations thereof. The present application does not make special restrictions on the specific compounds included in the solid raw material and the liquid raw material, and the raw materials of the slurry catalyst aid in the prior art can be used.

[0087] In the present application, the slurry catalyst aid can be used in different olefin polymerization methods, including solution method, gas phase method, slurry method, high pressure method, etc. The present application can significantly reduce the impurity content in the slurry catalyst aid, making it more suitable for the extremely sensitive gas phase polyolefin catalyst. The polyolefin catalyst can be selected from the group consisting of Ziegler-Natta catalyst, chromium-based catalyst, bifunctional catalyst, metallocene catalyst, non-metallocene catalyst, post-transition metal catalyst, and combinations thereof.

[0088] In the present application, the impurities refer to substances that have a greater impact on the activity of the polyolefin catalyst. In the preparation process, impurities generally involve oxygen-containing elements such as water (H2O), oxygen (O2), carbon monoxide (CO), carbon dioxide (CO2), etc. In addition, different raw materials themselves can also contain some impurities, which generally affect the activity center of the catalyst. In the present application, water and oxygen are mainly described as impurities.

[0089] In the prior art, the slurry catalyst aid is usually treated by nitrogen bubbling. This method has the following disadvantages: (1) low mass transfer efficiency, incomplete impurity removal; (2) difficult process control, unstable effect; (3) time-consuming and gas-consuming, poor economy.

[0090] The mixing device and method for slurry catalyst aid of the present application can reduce impurities from raw materials themselves and production processes, solve the problems of the prior art such as the inability to pre-refine the raw materials, the pollution risk in the material transfer process, the investment in additional purification systems or traditional subsequent nitrogen bubbling operations, etc. The present application significantly reduces the impurity content in the product by pretreating the solid raw material and the liquid raw material. Moreover, the present application eliminates the pollution risk in the transfer process by using a protective gas and a sealed connection. At the same time, the present application reduces the uneven mixing and wall hanging of the slurry catalyst aid by using a mechanical stirring assembly and a simplified design of the overall device. Furthermore, the present application eliminates the need for a pre-raw material purification system or traditional subsequent nitrogen bubbling operation, which has excellent economy. The present application can obtain a slurry catalyst aid with low water and low oxygen content, which can meet the requirements of the extremely sensitive polyolefin catalyst.

[0091] The technical solutions of the present application are specifically illustrated below by examples, but the present application is not limited to these examples, and various modifications can of course be made within the scope of the gist of the present application.

[0092] Example 1

[0093] The present example provides a mixing device for slurry catalyst adjuvant, as shown in the figure, which comprises a solid raw material pretreatment system 1 and a mixing preparation system 2. Figure 1

[0094] The solid raw material pretreatment system 1 comprises at least one charging tank 101, the charging tank 101 is provided with a first pressure control module and a first temperature control module, and the bottom of the charging tank 101 is provided with a first discharge port 102; the solid raw material pretreatment system 1 is used for reducing pressure drying of the solid raw material to obtain pretreated solid raw material.

[0095] The mixing preparation system 2 comprises at least one mixing kettle 201, the mixing kettle 201 is provided with a solid phase injection inlet 202, a liquid phase injection inlet 203, a second pressure control module and a second temperature control module, and the mixing kettle 201 is provided with a mechanical stirring assembly 204, and the bottom of the mixing kettle 201 is provided with a sealed discharge module 205; the mixing preparation system 2 is used for reducing pressure distillation of the liquid raw material to obtain pretreated liquid raw material, and for uniformly mixing the pretreated solid raw material and the pretreated liquid raw material to obtain a slurry catalyst adjuvant.

[0096] The first discharge port 102 of the charging tank 101 is connected with the solid phase injection inlet 202 of the mixing kettle 201.

[0097] In the present example, the number of charging tanks 101 is one. The charging tank 101 is a closable container. The material of the charging tank 101 is 304 stainless steel.

[0098] The first pressure control module is arranged at the top of the charging tank 101, and the first pressure control module comprises a first pressure sensor, a first protective gas pipeline, a first evacuation pipeline and a first vacuum pipeline. The first evacuation pipeline and the first vacuum pipeline are provided with dust filters.

[0099] The first temperature control module comprises a first temperature sensor, a first heating layer and a first heat preservation layer, the first temperature sensor is arranged in the charging tank 101, and the first heating layer and the first heat preservation layer are sequentially arranged outside the charging tank 101.

[0100] The charging tank 101 is further provided with a first water content and oxygen content online detection assembly.

[0101] The first discharge port 102 is an inverted cone. ​

[0102] The first discharge port 102 is provided with a discharging module 103, which is a vibrator; the vibrator is arranged on the outer wall of the first discharge port 102 (i.e. the outer wall of the cone).

[0103] The number of the mixing kettle 201 is one. The mixing kettle 201 is a sealable container. The material of the mixing kettle 201 is 304 stainless steel. The volume of the mixing kettle 201 is 300 L.

[0104] The number of the liquid phase injection ports 203 is two, which are respectively used for injecting liquid effective components and liquid solvents, and each liquid phase injection port 203 is connected with a liquid phase injection pipeline. A flow adjusting assembly is arranged on each liquid phase injection pipeline.

[0105] The second pressure control module is arranged on the top of the mixing kettle 201, and the second pressure control module comprises a second pressure sensor, a second protective gas pipeline, a second evacuation pipeline and a second vacuum pumping pipeline.

[0106] The second temperature control module comprises a second temperature sensor, a second heating layer and a second heat preservation layer. The second temperature sensor is arranged in the mixing kettle 201, and the second heating layer and the second heat preservation layer are arranged in sequence on the outside of the mixing kettle 201.

[0107] The second water content and oxygen content online detection assembly is further arranged in the mixing kettle 201.

[0108] A glass observation window is arranged on the sidewall of the mixing kettle 201. The material of the glass observation window can be pressure-resistant glass, and the shape of the glass observation window can be strip-shaped. The glass observation window is flush with the inner wall and the outer wall of the mixing kettle 201.

[0109] The mechanical stirring assembly 204 comprises a driving unit, a transmission and sealing unit and a stirring execution unit. The transmission and sealing unit comprises a stirring shaft, a self-lubricating bottom bearing, a double-end face container type mechanical sealing structure, a sealing liquid pressurizing and monitoring element, the bottom of the stirring shaft is provided with the self-lubricating bottom bearing, and the stirring shaft and the kettle body of the mixing kettle 201 are sealed through the double-end face container type mechanical sealing structure. The stirring execution unit comprises a stirring paddle, and the stirring paddle is connected to the stirring shaft. The driving unit is used for driving the stirring shaft to rotate the stirring paddle, and the driving unit comprises an explosion-proof frequency conversion motor and a parallel shaft gear reducer. The stirring paddle is a double-layer anchor type frame type composite paddle, which comprises upper paddle blades and lower paddle blades. The upper paddle blades are frame type, and the lower paddle blades are near-wall flow type anchors.

[0110] The closed discharge module 205 includes a second discharge port, a switch valve, a dry quick coupling, and a stainless steel wire reinforced hose with a polytetrafluoroethylene lining. The second discharge port is connected to the dry quick coupling and the stainless steel wire reinforced hose with a polytetrafluoroethylene lining through the switch valve. The closed discharge module 205 can achieve a sealed connection between the mixing kettle 201 and the product tank arranged subsequently.

[0111] A rotary feeding valve with purging function is arranged on the pipeline connecting the first discharge port 102 of the feeding tank 101 and the solid phase injection inlet 202 of the mixing kettle 201. The rotary feeding valve with purging function is equipped with a loss-in-weight control element. The mixing kettle 201 is arranged below the feeding tank 101.

[0112] The mixing device of the present embodiment further includes an auxiliary accessory system. The auxiliary accessory system includes, but is not limited to, the following components:

[0113] Vacuum pump: used for vacuumizing the solid raw material pretreatment system 1 and the mixing and preparation system 2, which can be connected to the first vacuumizing pipeline and the second vacuumizing pipeline;

[0114] Product tank: used for storing the slurry catalyst additive product, which is connected to the stainless steel wire reinforced hose with a polytetrafluoroethylene lining of the closed discharge module 205, and can be made of metal;

[0115] Metering device: which can include one or more than two of a metering scale, a metering pump, and a mass flow meter, which can be routinely arranged by those skilled in the art;

[0116] Temperature control device: which can include one or more than two of a temperature remote transmission device, a circulating water / oil system, a steam heating system, and an electric heating system, etc., for temperature control of the first temperature control module and the second temperature control module;

[0117] Other auxiliary devices: which can include a flow regulating valve, a pneumatic barrel pump, a vacuum buffer tank, a dry tail gas system, a condenser, and connecting pipelines between structures of various devices, components, elements, etc., auxiliary pumps, heat exchangers, etc.; these components can be routinely arranged by those skilled in the art.

[0118] Embodiment 2

[0119] The present embodiment provides a mixing method for a slurry catalyst additive, which is carried out using the mixing device of embodiment 1, and the target output of a single batch is 100 kg of slurry catalyst additive product I.

[0120] The raw materials used in the mixing method include:

[0121] Solid raw material (powdered hygroscopic solid raw material): aluminum stearate powder, added in an amount of 17 kg, accounting for 17% of the total mass of the product;

[0122] Non-hygroscopic waxy solid raw material: solid paraffin particles, melting point 60 ℃, added in an amount of 1 kg, accounting for 1% of the total mass of the product;

[0123] Liquid solvent: mineral oil, added in an amount of 80 kg, accounting for 80% of the total mass of the product;

[0124] Liquid active ingredient: castor oil, added in an amount of 2 kg, accounting for 2% of the total mass of the product.

[0125] Considering the loss in the production process, the total loss rate of raw materials is about 1.2%, and the actual yield is slightly lower than the theoretical value.

[0126] As shown in Figure 2 , the compounding method comprises the following steps:

[0127] (1) Add 17 kg of aluminum stearate powder to the charging tank 101, close the charging tank 101, and then open the first pressure control module and the first temperature control module in sequence. The program control is divided into four steps. The first step is the system vacuum stage, which gradually reduces the pressure in the charging tank 101 from atmospheric pressure to 10 kPa. The second step is the preliminary heating stage, which starts the first heating layer to smoothly raise the temperature in the charging tank 101 to 60 ℃. The third step is the slow heating stage, which slowly raises the temperature from 60 ℃ to 65 ℃ at a lower power. The fourth step is the constant temperature holding stage, which maintains the temperature constant by intermittent heating, ensuring that the vacuum drying process is carried out continuously, efficiently and safely at 65 ℃. After 2 days of vacuum drying treatment, through the first water content and oxygen content online detection assembly, it can be seen that the water and oxygen content readings continue to decrease, and the vacuum degree gradually increases to a higher level as the water content is continuously removed. At the end of the treatment, the water content in the charging tank 101 is stable at below 90 ppm, and the oxygen content is stable at below 2 ppm. The pretreated solid raw material obtained is sampled, and the Karl Fischer direct determination method is used to measure the water content, which is 93 ppm. Compared with the initial water content of the raw material, which is 1390 ppm, the dehydration rate is as high as 93.3%.

[0128] (2) 80 kg of mineral oil and 2 kg of castor oil were pumped into the mixing kettle 201 through two liquid phase injection ports 203, respectively, then 1 kg of solid paraffin particles was directly added into the mixing kettle 201, after the mixing kettle 201 was closed, the second pressure control module and the second temperature control module were opened in turn. The program control was divided into four steps. The first step was the system vacuum stage, the pressure of the mixing kettle 201 was gradually reduced from normal pressure to 15 kPa, at the same time the mechanical stirring assembly 204 was started, and the stirring speed was adjusted to 100 rpm. The second step was the preliminary heating stage, the second heating layer was started, and the temperature in the mixing kettle 201 was steadily increased to 90°C. The third step was the slow heating stage, the temperature was slowly increased from 90°C to 100°C at a lower power. The fourth step was the constant temperature holding stage, the temperature was maintained constant by intermittent heating, ensuring that the vacuum distillation process continued, efficiently and safely at 100°C. The stirring was maintained throughout the vacuum distillation process; through the first water content and oxygen content online detection assembly, the water and oxygen content readings continued to decrease, the vacuum degree gradually increased to a higher level as the water content was continuously removed, and at the end of the treatment, the water content in the mixing kettle 201 was stable below 30 ppm, and the oxygen content was stable below 2 ppm. The pretreated liquid raw material was sampled, and the Karl Fischer direct determination method was used to measure the water content, which was 25 ppm, compared with the initial water content of the raw material of 194 ppm, the dehydration rate was as high as 87.1%.

[0129] (3) After steps (1) and (2) were completed, the heating was stopped, the stirring was maintained, the charging tank 101 and the mixing kettle 201 were cooled to about 40°C, high-purity nitrogen was charged into the charging tank 101 and the mixing kettle 201 through the first pressure control module and the second pressure control module to pressurize to normal pressure, then the charging tank 101 and the mixing kettle 201 were further cooled to room temperature, then the rotary feeding valve with purging function was opened, the pretreated solid raw material was accurately and continuously fed from the charging tank 101 to the mixing kettle 201, ensuring smooth feeding of the material and preventing backflow of the gas in the kettle, after the feeding was completed, the rotary feeding valve was closed, the stirring speed of the mechanical stirring assembly 204 was adjusted to 300 rpm, and the stirring was continued for 2 days to obtain a slurry-shaped catalyst additive product I.

[0130] (4) Before discharging, the bottom valve of the mixing kettle 201, the stainless steel wire reinforced hose with polytetrafluoroethylene lining and the product tank were thoroughly purged with high-purity nitrogen to replace the air, and the air was exhausted, a slight positive pressure of nitrogen was maintained in the mixing kettle 201, and the slurry-shaped catalyst additive product I was pressed into the product tank through the closed discharge module 205 by gravity and air pressure. After the discharging and packaging stirring were completed, about 100 kg of slurry-shaped catalyst additive product I was obtained.

[0131] The water content of the obtained slurry catalyst aid product I was tested. The water content of the product was 230 ppm, which was determined by Karl Fischer water titrator.

[0132] The slurry catalyst aid I obtained in this example was used for ethylene slurry process small-scale homopolymerization test. The reaction process was as follows: 350 g of n-hexane, 2 mM of triethylaluminum, 100 mg of the slurry catalyst aid and 100 mg of metallocene catalyst MEG 0001HA were added into a slurry process polymerization reactor, the stirring rate was 400 rpm, the pressure was 1 MPa, the temperature was 80°C, the reaction time was 1 h, and ethylene was automatically fed by using a gas mass flow meter. The slurry small-scale polymerization results were evaluated by catalyst activity and caking grade. The catalyst activity was gPE / gCat•h, which was defined as the mass of the target product obtained by unit mass of catalyst in unit time. The caking grade was determined by the adhesion dirt on the stirring paddle and the inner wall of the reactor, which was characterized by A, B, C, D and E, wherein A represented less caking, and E represented serious caking. The results showed that the catalyst activity was 463 gPE / gCat•h, and the caking grade was A, and the adhesion dirt was less. It can be seen that the slurry catalyst aid I obtained in this example has low water and oxygen content, which can meet the requirements of polyolefin catalysts which are extremely sensitive to impurities.

[0133] Example 3

[0134] The mixing device of Example 1 was used, and the target output of a single batch was 100 kg of slurry catalyst aid product II.

[0135] The raw materials used in this mixing method include:

[0136] Solid raw material (powdered hygroscopic solid raw material): aluminum stearate powder, the amount added was 17 kg, accounting for 17% of the total mass of the product;

[0137] Solid raw material (powdered hygroscopic solid raw material): stearic acid powder, the amount added was 1.5 kg, accounting for 1.5% of the total mass of the product;

[0138] Solid raw material (powdered hygroscopic solid raw material): fumed silica powder, the amount added was 1.5 kg, accounting for 1.5% of the total mass of the product;

[0139] Liquid solvent: mineral oil, the amount added was 80 kg, accounting for 80% of the total mass of the product;

[0140] The order of adding the solid raw materials was aluminum stearate, stearic acid and fumed silica. Except for the different types and weights of raw materials, the mixing method and the remaining steps of the ethylene slurry process small-scale homopolymerization test were basically the same as those of Example 2.

[0141] At the end of the step (1), the water content in the feeding tank 101 was stabilized at below 100 ppm, and the oxygen content was stabilized at below 2 ppm. Since the feeding tank 101 contained three kinds of solid raw materials which were not mixed uniformly, three samples were taken at different pile heights, and the water content was determined by Karl Fischer direct determination method, which was 82, 95, and 110 ppm, respectively.

[0142] At the end of the step (2), the water content in the mixing kettle 201 was stabilized at below 30 ppm, and the oxygen content was stabilized at below 2 ppm. The pretreated liquid solvent obtained was sampled, and the water content was determined by Karl Fischer direct determination method, which was 24 ppm. Compared with the initial water content of the raw material of 194 ppm, the dehydration rate was as high as 87.6%.

[0143] The water content of the finally obtained slurry-shaped catalyst aid product II was tested, and was directly determined by volumetric Karl Fischer moisture meter, which was 245 ppm.

[0144] The slurry-shaped catalyst aid II was used for ethylene slurry process small-scale homopolymerization test. The results showed that the catalyst activity was 442 gPE / gCat•h, the caking level was A, and the adhesion dirt was less.

[0145] Comparative Example 1

[0146] In this comparative example, the slurry-shaped catalyst aid was prepared by conventional open mixing method under the same raw materials and ratio as in Example 2, and the water content of the finally obtained slurry-shaped catalyst aid was as high as 690 ppm. Under the same reaction conditions as in Example 2, the slurry-shaped catalyst aid prepared by conventional open mixing method was used for ethylene slurry process small-scale homopolymerization test. The results showed that the catalyst activity was 269 gPE / gCat•h, and the caking level was C. Compared with Example 2, the slurry-shaped catalyst aid containing more impurities in this comparative example had an adverse effect on the catalyst activity, which caused a significant decrease in the activity of the ethylene slurry process small-scale homopolymerization, and the adhesion dirt on the stirring paddle and the inner wall of the reaction kettle increased, indicating that the polymerization process of the catalyst was unstable.

[0147] Comparative Example 2

[0148] The comparative example was prepared by using conventional open mixing method under the same raw materials and ratio as example 3, and the water content of the final obtained slurry catalyst additive was as high as 920 ppm. Under the same reaction conditions as example 3, the slurry catalyst additive prepared by using conventional open mixing method was used to carry out the ethylene slurry process small test homopolymerization. The results showed that the catalyst activity was 248 gPE / gCat•h, and the caking level was C. Compared with example 3, the slurry catalyst additive containing more impurities in the comparative example had an adverse effect on the catalyst activity, which caused the activity of the ethylene slurry process small test homopolymerization to decrease obviously, and the adhesion of dirt on the stirring paddle in the reactor and the inner wall of the reactor increased, indicating that the polymerization process of the catalyst was unstable.

[0149] From the above examples and comparative examples, it can be seen that the mixing device and method of the present application realizes the whole process of closed operation, avoids the pollution risk caused by material transfer, and ensures the high purity and batch stability of the slurry catalyst additive product. Test data show that the impurity content, especially the oxygen content and water content, in the mixing device, raw materials and products can be effectively removed, which is beneficial to meet the use requirements of the gas phase polyolefin catalyst which is extremely sensitive to impurities.

[0150] The above specific examples further illustrate the purpose, technical solutions and advantages of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A mixing device for a catalyst adjuvant in slurry form, characterized in that, The application relates to a solid raw material pretreatment system and a mixing preparation system. The solid raw material pretreatment system comprises at least one feeding tank which is provided with a first pressure control module and a first temperature control module, and the bottom of the feeding tank is provided with a first discharge port; the solid raw material pretreatment system is used for reducing-pressure drying of solid raw materials to obtain pretreated solid raw materials; The mixing preparation system comprises at least one mixing kettle which is provided with a solid-phase injection inlet, a liquid-phase injection inlet, a second pressure control module and a second temperature control module, and the mixing kettle is provided with a mechanical stirring assembly; the bottom of the mixing kettle is provided with a sealed discharge module; the mixing preparation system is used for reducing-pressure distillation of liquid raw materials to obtain pretreated liquid raw materials, and is used for uniformly mixing the pretreated solid raw materials and the pretreated liquid raw materials to obtain a slurry-shaped catalyst additive; The first discharge port of the feeding tank is connected with the solid-phase injection inlet of the mixing kettle. In the solid raw material pretreatment system, the feeding tank is a metal feeding tank; 2. The compounding device for a catalyst adjuvant in slurry form according to claim 1, characterized in that, And / or, the material of the feeding tank comprises stainless steel, hastelloy, carbon steel with a polytetrafluoroethylene lining or stainless steel with a polytetrafluoroethylene lining. In the solid raw material pretreatment system, the first pressure control module is arranged at the top of the feeding tank, and the first pressure control module comprises a first pressure sensor, a first protective gas pipeline, a first emptying pipeline and a first vacuum pipeline.

3. The compounding device for catalyst adjuvants in slurry form according to claim 1, characterized in that, In the solid raw material pretreatment system, a dust filter is arranged on the first emptying pipeline and / or the first vacuum pipeline.

4. The compounding device for catalyst adjuvants in slurry form according to claim 3, characterized in that, In the solid raw material pretreatment system, the first temperature control module comprises a first temperature sensor, a first heating layer and a first heat preservation layer; the first temperature sensor is arranged in the feeding tank; and the first heating layer and the first heat preservation layer are arranged in sequence outside the feeding tank.

5. The compounding device for catalyst adjuvants in slurry form according to claim 1, characterized in that, And / or, in the solid raw material pretreatment system, a first water content and oxygen content online detection assembly is further arranged in the feeding tank, and is used for monitoring the water content and oxygen content in the feeding tank in real time. And / or, in the solid raw material pretreatment system, the first discharge port is an inverted cone. The inner wall of the feeding tank, the valve body of the valve and the inner wall of the pipeline in the solid raw material pretreatment system are plated with chromium and / or polished.

6. The compounding device for catalyst adjuvants in slurry form according to claim 1, characterized in that, And / or, in the solid raw material pretreatment system, the first discharge port is provided with a discharging module; the discharging module comprises a vibrator and / or an arch breaker; the vibrator is arranged on the outer wall of the first discharge port; and the arch breaker is arranged at the bottom of the feeding tank. In the mixing preparation system, the mixing kettle is a metal mixing kettle; 7. The compounding device for catalyst adjuvants in paste form according to claim 1, characterized in that, And / or, the material of the mixing kettle comprises stainless steel, hastelloy, carbon steel with a polytetrafluoroethylene lining or stainless steel with a polytetrafluoroethylene lining. In the mixing preparation system, the second pressure control module is arranged at the top of the mixing kettle, and the second pressure control module comprises a second pressure sensor, a second protective gas pipeline, a second emptying pipeline and a second vacuum pipeline.

8. The compounding device for catalyst adjuvants in paste form according to claim 1, characterized in that, ​ And / or, in the mixing and preparing system, the second temperature control module comprises a second temperature sensor, a second heating layer and a second heat preservation layer, the second temperature sensor is arranged in the mixing kettle, and the second heating layer and the second heat preservation layer are arranged in the mixing kettle in sequence. And / or, in the mixing and preparing system, a second water content and oxygen content online detection assembly is further arranged in the mixing kettle, for monitoring the water content and oxygen content in the mixing kettle in real time.

9. The compounding device for catalyst adjuvants in paste form according to claim 1, characterized in that, In the mixing and preparing system, a glass observation window is arranged on the side wall of the mixing kettle.

10. The compounding device for catalyst adjuvants in slurry form according to claim 1, characterized in that, In the mixing and preparing system, the mechanical stirring assembly comprises a driving unit, a transmission and sealing unit and a stirring execution unit; the transmission and sealing unit comprises a stirring shaft and a double-end face containerized mechanical sealing structure, the stirring shaft and the kettle body of the mixing kettle are sealed through the double-end face containerized mechanical sealing structure; the stirring execution unit comprises a stirring paddle, the stirring paddle is connected to the stirring shaft; the driving unit is used for driving the stirring shaft to rotate the stirring paddle.

11. The compounding device for a catalyst adjuvant in slurry form according to claim 10, characterized in that, In the mixing and preparing system, the driving unit comprises an explosion-proof variable frequency motor and a parallel shaft gear reducer. And / or, in the mixing and preparing system, the transmission and sealing unit further comprises a sealing liquid pressurization and monitoring element. And / or, in the mixing and preparing system, the transmission and sealing unit further comprises a self-lubricating bottom bearing, and the bottom of the stirring shaft is provided with the self-lubricating bottom bearing. And / or, in the mixing and preparing system, the stirring paddle comprises one or two or more of a disc turbine paddle, an inclined blade turbine paddle, a propeller, an axial flow paddle, an anchor paddle, a spiral ribbon paddle and a frame paddle. And / or, in the mixing and preparing system, the stirring paddle is a single-layer structure, a double-layer structure or a multi-layer structure. And / or, in the mixing and preparing system, the stirring paddle comprises a double-layer anchor paddle, a double-layer frame paddle or a double-layer anchor-frame composite paddle, which respectively comprises an upper paddle blade and a lower paddle blade, and the lower paddle blade adopts a near-wall flow type.

12. The compounding device for catalyst adjuvants in slurry form according to claim 1, characterized in that, In the mixing and preparing system, the closed discharging module comprises a second discharging port, an on-off valve, a dry quick connector and a stainless steel wire reinforced hose with a polytetrafluoroethylene lining, and the second discharging port is connected to the stainless steel wire reinforced hose with the polytetrafluoroethylene lining through the on-off valve and the dry quick connector.

13. The compounding device for catalyst adjuvants in paste form according to claim 1, characterized in that, A rotary feeding valve or a screw feeder with a purging function is arranged on a pipeline connecting the first discharging port of the feeding tank and the solid phase injection inlet of the mixing kettle.

14. A method for compounding a catalyst adjuvant in slurry form, characterized in that, The mixing and preparing method is carried out by using the mixing and preparing device for slurry catalyst additives in any one of claims 1-13, and the mixing and preparing method comprises the following steps: (1) adding solid raw materials into the feeding tank, and drying the solid raw materials under reduced pressure by using a solid raw material pretreatment system to obtain pretreated solid raw materials; (2) adding liquid raw materials into the mixing kettle, and distilling the liquid raw materials under reduced pressure by using a mixing and preparing system to obtain pretreated liquid raw materials; (3) transferring the pretreated solid raw material from the feeding tank to the mixing kettle, and mixing the pretreated solid raw material and the pretreated liquid raw material uniformly to obtain a slurry-shaped catalyst aid.

15. The process for compounding a catalyst adjuvant in slurry form according to claim 14, characterized in that, In step (1), the first pressure control module is controlled to reach the vacuum degree of the reduced-pressure drying, and the first temperature control module is controlled to reach the temperature of the reduced-pressure drying, wherein the vacuum degree of the reduced-pressure drying is 0.1-50 kPa, and the temperature of the reduced-pressure drying is 40-100 ℃.

16. The process for compounding a catalyst adjuvant in slurry form according to claim 15, characterized in that, In step (1), the program control of the reduced-pressure drying is divided into four steps: the first step is a vacuum extraction stage, in which the pressure is stably reduced to the target vacuum degree; the second step is a preliminary temperature rising stage, in which the temperature is stably increased to an initial value which is 5-10 ℃ lower than the target temperature; the third step is a slow temperature rising stage, in which the temperature is slowly increased from the initial value to the target temperature; and the fourth step is a constant temperature maintaining stage, in which the temperature is maintained constant by intermittent heating.

17. The process for compounding a catalyst adjunct in a slurry according to claim 14, characterized in that, In step (1), when the water content in the feeding tank is 5-200 ppm and the oxygen content is 0.1-20 ppm, step (1) is ended.

18. The process for compounding a catalyst adjunct in a slurry according to claim 14, characterized in that, In step (2), the second pressure control module is controlled to reach the vacuum degree of the reduced-pressure distillation, and the second temperature control module is controlled to reach the temperature of the reduced-pressure distillation, wherein the vacuum degree of the reduced-pressure distillation is 0.1-50 kPa, and the temperature of the reduced-pressure distillation is room temperature to 400 ℃.

19. The process for compounding a catalyst adjuvant in slurry form according to claim 18, characterized in that, In step (2), the program control of the reduced-pressure distillation is divided into four steps: the first step is a vacuum extraction stage, in which the pressure is stably reduced to the target vacuum degree; the second step is a preliminary temperature rising stage, in which the temperature is stably increased to an initial value which is 5-10 ℃ lower than the target temperature; the third step is a slow temperature rising stage, in which the temperature is slowly increased from the initial value to the target temperature; and the fourth step is a constant temperature maintaining stage, in which the temperature is maintained constant by intermittent heating.

20. The process for compounding a catalyst adjunct in a slurry according to claim 14, characterized in that, Step (2) is performed under the stirring action of the mechanical stirring assembly. In step (2), the non-hygroscopic waxy solid raw material is added to the mixing kettle to perform the reduced-pressure distillation with the liquid raw material, thereby obtaining the pretreated liquid raw material.

21. The method for compounding a catalyst adjunct in a slurry form according to claim 14, characterized by, In step (2), when the water content in the mixing kettle is 5-200 ppm and the oxygen content is 0.1-20 ppm, step (2) is ended.

22. The process for compounding a catalyst adjunct in a slurry according to claim 14, characterized in that, In step (3), the feeding tank and the mixing kettle are cooled, and the feeding tank and the mixing kettle are pressurized to normal pressure by using a protective gas, then the pretreated solid raw material is transferred from the feeding tank to the mixing kettle, and the pretreated solid raw material and the pretreated liquid raw material are mixed uniformly under the stirring action of the mechanical stirring assembly, thereby obtaining a slurry-shaped catalyst aid.

23. The process for compounding a catalyst adjunct in a slurry according to claim 14, characterized in that, In step (3), the water content of the slurry-shaped catalyst aid is 10-600 ppm.

24. The process for compounding a catalyst adjunct in a slurry according to claim 14, characterized in that, The mixing method further comprises the following step: discharging the slurry-shaped catalyst aid in the mixing kettle and sealing the slurry-shaped catalyst aid in a product tank.

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