Process for modifying supported catalysts during polymerization of olefins

Abstract

Polymer flaking may be reduced by increasing the contact time between the catalyst solution and the catalyst slurry. A polymerization process may include: introducing a catalyst slurry into a first line in fluid communication with a mechanical agitation mixing tank; introducing at least a first portion of the catalyst solution into a second line in fluid communication with the mechanical agitation mixing tank; contacting a catalyst slurry with the catalyst solution in the mechanically agitated mixing tank to obtain a modified catalyst slurry from the mechanically agitated mixing tank, the modified catalyst slurry comprising a modified supported catalyst, the modified supported catalyst incorporating at least a portion of the first catalyst compound or the second catalyst from the catalyst solution; feeding the modified catalyst slurry to a fluidized bed gas phase reactor; and polymerizing an alpha-olefin in the fluidized bed gas phase reactor under polymerization conditions to obtain a polyolefin.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application 63 / 489,951, filed March 13, 2023, entitled “Method of modifying supported catalyst during olefin polymerization,” the entirety of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure relates to methods of polymerizing one or more olefins, and more particularly, to methods of polymerizing one or more olefins with enhanced supported catalyst mixing techniques prior to polymerization. BACKGROUND

[0003] Gas phase polymerization can be used to polymerize ethylene or ethylene and one or more olefin comonomers. Gas phase polymerization processes conducted in a fluidized bed are particularly economical. One or more olefin monomers and catalyst particles containing an activated catalyst compound can be introduced into a polymerization reactor, where the olefin monomer(s) can polymerize in the presence of the catalyst particles to produce a polyolefin product, preferably in the form of fine particles.

[0004] During polymerization, catalyst particles (i.e., supported catalyst) can begin to overheat, especially when the catalyst compound on the catalyst particles has an aggressive kinetic profile. When catalyst particles overheat, polymer particles within the reactor can begin to stick together, which can lead to eventual buildup of polymer within the reactor. In some cases, buildup of polymer within the reactor (often referred to as agglomeration, caking, or sheeting) can lead to process disruptions, or even reactor shutdowns. The term sheeting is used herein.

[0005] One way to mitigate over-heating of the catalyst particles is by changing the ratio of catalyst compound(s) on the catalyst particles. For maximum process flexibility, modification of the catalyst particles can occur in situ prior to delivery to the polymerization reaction without process shutdown. In some examples, a catalyst solution can be contacted with the catalyst particles to introduce additional catalyst compounds onto the catalyst particles and / or to introduce different catalyst compounds onto the catalyst particles. The catalyst solution that introduces additional catalyst compounds and / or different catalyst compounds to the catalyst particles can be referred to as a "trim catalyst" or a "trim catalyst solution" as the catalyst solution adjusts the performance of the original catalyst particles. Unfortunately, in situ modification of the catalyst particles in the foregoing manner can result in suboptimal catalyst activation and ongoing challenges with process control, including sheeting of the resulting polymer. Short and / or variable contact times between the catalyst particles and the trim catalyst solution can be particularly problematic as a variety of supported catalysts with different polymerization properties can result.

[0006] Some references that can be of interest in the art include: U.S. Patent No. 10,927,205; U.S. Patent Publication Nos. US2022 / 0033536 and US2022 / 0033537; and International Patent Publication No. WO2022 / 174202.

[0007] Accordingly, there remains a need for improved methods for polymerizing one or more olefin monomers during gas phase polymerization to reduce or eliminate polymer build-up within the reactor. SUMMARY SUMMARY

[0008] In various aspects, the methods of the present disclosure include: providing a catalyst slurry comprising a supported catalyst, the supported catalyst comprising a support material, at least one catalyst compound, and at least one activator; introducing the catalyst slurry to a first line in fluid communication with a mechanically agitated mix tank; introducing at least a first portion of a catalyst solution to a second line in fluid communication with the mechanically agitated mix tank, the catalyst solution comprising a first catalyst compound already comprised on the supported catalyst or a second catalyst compound different from the first catalyst compound and not comprised on the supported catalyst; contacting the catalyst slurry with the catalyst solution in the mechanically agitated mix tank to obtain a modified catalyst slurry from the mechanically agitated mix tank, the modified catalyst slurry comprising a modified supported catalyst that incorporates at least a portion of the first catalyst compound or the second catalyst from the catalyst solution; feeding the modified catalyst slurry to a fluidized bed gas phase reactor; and polymerizing an alpha-olefin in the fluidized bed gas phase reactor under polymerization conditions to obtain a polyolefin.

[0009] These and other features and attributes of the disclosed methods of the present disclosure, and the computations thereof, as well as the methods of use and / or operations of the same, will be more fully understood in connection with the following detailed description, when considered in light of the aforementioned background. BRIEF DESCRIPTION OF DRAWINGS

[0010] The accompanying drawings are included to provide a further understanding of the subject matter of this document, and are incorporated in and constitute a part of this specification. The drawings illustrate aspects of the present disclosure and, together with the description, serve to explain principles of the disclosed subject matter. Other aspects of the present disclosure will be apparent to those of ordinary skill in the art in view of the following detailed description, which should be considered in conjunction with the accompanying drawings.

[0011] Figure 1 is a block schematic diagram of a gas phase reactor system in which mixing of catalyst slurry and catalyst solution can be performed in a mechanically agitated mixing tank.

[0012] Figure 2 is a block schematic diagram of a gas phase reactor system in which mixing of catalyst slurry and catalyst solution can be performed in-line upstream of a static mixer or mixing block.

[0013] Figure 3 is a block schematic diagram of a gas phase reactor system in which mixing of catalyst slurry and catalyst solution can be performed in-line upstream of a mechanically agitated mixing tank.

[0014] FIG. 4 is a graphical representation of H2 / ethylene flow ratio and extent of polymer sheeting under conventional catalyst slurry / catalyst solution contacting conditions and extended catalyst slurry / catalyst solution contacting conditions according to the present disclosure. DETAILED DESCRIPTION

[0015] The present disclosure relates to methods of polymerizing one or more olefins, and more particularly, to methods of polymerizing one or more olefins utilizing enhanced supported catalyst mixing techniques prior to polymerization.

[0016] As noted above, catalyst particles (i.e., supported catalysts) can be modified in situ prior to conducting a polymerization reaction to mitigate polymer sheeting. However, in situ modification of catalyst particles can result in inefficient catalyst activation and persistent difficulties with the polymerization process. The foregoing difficulties can be addressed by the present disclosure. In particular, the present disclosure provides for increased and / or less variable contact time between catalyst particles and catalyst solution when producing a modified supported catalyst. As a result, more consistent polymerization performance can be achieved. DEFINITIONS

[0017] Various specific embodiments, versions and examples in which the application is described herein are now described in greater detail. While the application is subject to various embodiments, versions and examples, the specific embodiments, versions and examples disclosed are intended to be illustrative only and the application is not intended to be limited to or by the specific embodiments, versions and examples disclosed. The scope of the application is limited only by the claims, as further defined by the terms of the art, and equivalents thereof. Any reference citations herein are for the convenience of the reader only and do not constitute an admission that any of the documents disclosed therein is prior art.

[0018] As used herein, the indefinite article "a" or "an" is intended to mean "at least one" unless otherwise indicated or the context clearly indicates otherwise. Thus, an embodiment in which "alpha-olefins" are used includes embodiments in which one, two, or more alpha-olefins are used, unless otherwise indicated or the context clearly indicates that only one alpha-olefin is used.

[0019] Unless otherwise indicated, all numbers expressing quantities of items, amounts of ingredients, quantities of compositions, reaction conditions, and so forth used in the present disclosure are to be understood as approximations based on the desired properties sought to be obtained by the employ of the principles disclosed herein. It will be further understood that the exact

[0020] The term "and / or" where used herein is intended to include the possibilities of "A and B", "A or B", "A" and "B".

[0021] As used herein, "wt%" means weight percent, "vol%" means volume percent, "mol%" means mole percent, "ppm" means parts per million, and "ppm wt" and "wppm" are used interchangeably and mean parts per million by weight. Unless otherwise indicated, all concentrations are expressed in terms of total amount of the composition in question.

[0022] For the purposes of the present disclosure, the nomenclature for elements follows the new notation version of the Periodic Table of Elements as provided in Hawley's Condensed Chemical Dictionary, 16thEd., John Wiley & Sons, Inc., (2016), Appendix V, unless otherwise indicated.

[0023] As used herein, the term "optional" or "optionally" means that the subsequently described event or circumstance (or element) can or can not occur or is or is not present, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0024] "Reactor" is any type of vessel or containment device in any configuration of one or more reactors and / or one or more reaction zones in which a similar polymer is produced. The term "gas phase polymerization" refers to the production of a polymer in a gas phase reactor (herein simply "reactor"). It should also be noted that when referring to a "gas phase" polymerization or reactor, it is contemplated that the monomer is generally reacted in the gas phase in the reaction zone; however, the monomer need not necessarily be supplied to the reactor in the gas phase. Rather, the monomer can be supplied in the gas phase, liquid phase (condensed phase), or mixed gas-liquid phase. Thus, when a gaseous monomer stream or recycle gas stream is referred to herein as part of a gas phase polymerization reactor system or process, it is understood that such a gas stream can in fact be at least partially condensed (i.e., in a gas-liquid mixed phase) as known in the art. In other words, in the context of a gas phase reaction system as described herein, any stream referred to as a gas stream, recycle gas, etc. can be considered to be optionally at least partially liquefied as known in the art. See discussion of so-called "condensed mode" operation of certain gas phase polymerization reactors, for example in Namkajorn et al., Condensed Mode Cooling for Ethylene Polymerization: Part III. The Impact of Induced Condensing Agents on Particle Morphology and Polymer Properties, J. Macromol. Chem. and Phys. 217, 1521-1528 (Wiley 2016), where it is noted that in some fluid bed gas phase polymerization reactors, the recycle stream or recycle gas can be cooled to a temperature below its dew point such that it is partially liquefied, then fed to the bottom of the fluid bed reactor, where the latent heat of vaporization of the liquid in the feed absorbs the heat of polymerization, providing the potential for increased cooling and increased reaction rate.

[0025] "Alkoxide" includes an oxygen atom bonded to an alkyl group, which alkyl group is a Ci to C 10 hydrocarbon group. The alkyl group can be a linear, branched, or cyclic alkyl group. The alkyl group can be saturated or unsaturated. In at least one embodiment, the alkyl group can comprise at least one aromatic group.

[0026] The terms "antistatic agent," "continuity additive," "continuity aid," and "antifouling agent" are interchangeable and refer to a compound or mixture of compounds, such as a solid and / or liquid, that can be used to reduce reactor fouling during polymerization. Fouling of a reactor can result from polymer buildup within the reactor. Fouling of a reactor can manifest itself in a number of phenomena, including sheeting of the reactor walls, plugging of inlet and outlet lines, formation of large agglomerates, or other forms of polymer buildup within the reactor that can lead to reactor shutdown. The antistatic agent can be used as part of a catalyst composition or introduced directly into the reactor independent of the catalyst composition. In some embodiments, the antistatic agent can be contained on a support that also supports one or more catalysts.

[0027] The term "catalyst" can be used interchangeably with the terms "catalyst compound," "catalyst precursor," "transition metal compound," "transition metal complex," and "procatalyst."

[0028] A "catalyst system" is a combination of one or more catalyst compounds, activators, optional co-activators, and optional support materials. For the purposes of this disclosure, when a catalyst system is described as comprising a neutral stable form of a component, one skilled in the art will understand that the ionic form of the component is the form that is in equilibrium with the monomer(s) to produce the polymer. Catalyst systems, catalysts, and activators of this disclosure are meant to include both the neutral form of the compound / component as well as the ionic form.

[0029] The terms "radical," "group," and "substituent" are used interchangeably herein.

[0030] The term "hydrocarbon" refers to a class of compounds having hydrogen bound to carbon and encompasses saturated hydrocarbon compounds, unsaturated hydrocarbon compounds, and mixtures of hydrocarbon compounds (saturated and / or unsaturated), including mixtures of hydrocarbon compounds having different numbers of carbon atoms. The term "Cn n "refers to a hydrocarbon(s) or hydrocarbyl group(s) having n carbon atom(s) per molecule or group, wherein n is a positive integer. Such hydrocarbon compounds can be one or more of linear, branched, cyclic, acyclic, saturated, unsaturated, aliphatic, or aromatic.

[0031] The terms "hydrocarbyl radical," "hydrocarbyl group," or "hydrocarbyl" can be used interchangeably and are defined as referring to groups consisting of hydrogen and carbon atoms only, and which can also contain heteroatoms, for example, if an oxygen or nitrogen atom is part of the group when removed from the parent compound.

[0032] The term "optionally substituted" means that the hydrocarbon or hydrocarbyl group can be unsubstituted or substituted. Unless otherwise specified as explicitly unsubstituted, any hydrocarbyl group herein can be optionally substituted. The term "substituted" means that at least one hydrogen atom in the parent hydrocarbyl group has been replaced by at least one non-hydrogen group, such as a hydrocarbyl group, a heteroatom, or a heteroatom-containing group.

[0033] An "olefin" is a linear, branched, or cyclic compound of carbon and hydrogen having at least one double bond. When a polymer or copolymer is referred to as including an olefin, such as ethylene and / or at least one C3 to C12 alpha-olefin, the olefin is in the polymerized form present in such polymer or copolymer. For example, when a copolymer is recited as having a content of "ethylene" of from about 35 wt% to about 55 wt%, it is understood that the repeating / mer units or simply units in the copolymer are derived from ethylene in the polymerization reaction and the derived units are present at from about 35 wt% to about 55 wt% based on the weight of the copolymer. For purposes of this disclosure, ethylene is to be considered an alpha-olefin. 20 An "olefin" is a linear, branched, or cyclic compound of carbon and hydrogen having at least one double bond. When a polymer or copolymer is referred to as including an olefin, such as ethylene and / or at least one C3 to C12 alpha-olefin, the olefin is in the polymerized form present in such polymer or copolymer. For example, when a copolymer is recited as having a content of "ethylene" of from about 35 wt% to about 55 wt%, it is understood that the repeating / mer units or simply units in the copolymer are derived from ethylene in the polymerization reaction and the derived units are present at from about 35 wt% to about 55 wt% based on the weight of the copolymer. For purposes of this disclosure, ethylene is to be considered an alpha-olefin.

[0034] A "polymer" has two or more repeating / mer units or simply units that are the same or different. A "homopolymer" is a polymer having the same unit. A "copolymer" is a polymer having two or more units that are different from each other. A "terpolymer" is a polymer having three units that are different from each other. The term "different" used in connection with units indicates that the units are different from each other by at least one atom and / or are isomerically different. The definition of copolymer used herein includes terpolymers and the like. Likewise, the definition of polymer used herein includes homopolymers, copolymers, and the like. Further, the terms "polyethylene copolymer", "ethylene copolymer", and "ethylene-based polymer" are used interchangeably to refer to a copolymer that includes at least 50 mole percent units derived from ethylene.

[0035] The term "characteristic mass transfer time" refers to the time scale over which diffusion occurs. Once a number (e.g., 2, 3, 4, 5, or even more) of characteristic mass transfer times have elapsed, it can be considered that diffusion-based mixing is complete. The methods of the present disclosure can extend the contact time between the catalyst solution and the catalyst slurry beyond the characteristic mass transfer time over which inter-particle diffusion occurs. By extending the contact time beyond the characteristic mass transfer time, additional time is available for the second catalyst to diffuse into the supported catalyst (intra-particle diffusion) and for catalyst activation to occur. The time over which mass transfer occurs can be shortened beyond that achieved with diffusion alone, for example, via the use of mechanically agitated mix tanks. Polymerization processes and activation of catalyst compounds

[0036] When using a supported catalyst containing one or more catalyst compounds, it can be desirable to modify the final supported catalyst by introducing additional catalyst compound(s) onto the supported catalyst in order to change the dynamic profile during polymerization or to change the composition or properties of the polymer being produced. The additional catalyst compound(s) being introduced can increase the loading of the catalyst compounds already present on the supported catalyst and / or introduce a different catalyst compound not already present on the supported catalyst. One way in which the supported catalyst can be modified is via contacting (i) the supported catalyst within the catalyst slurry with (ii) a catalyst solution containing one or more catalyst compounds, thereby producing a modified supported catalyst within the modified catalyst slurry. The modified catalyst slurry can have a different loading of at least one catalyst compound on the support material compared to the original (pre-contact) catalyst slurry. When the modified catalyst slurry is produced in situ in the manner described above, the dynamic profile and / or the contact time of the modified catalyst slurry is desirably controlled with a specified accuracy. Otherwise, insufficient dynamic control can result in, for example, thermal swings and pressure differentials, resulting in changes in the rheology of the catalyst slurry and / or the catalyst solution, which can result in disturbances within the catalyst system and potentially produce polymer lumps. Insufficient activation of the newly introduced catalyst compound(s) can also occur, thus failing to change the catalyst performance to a sufficient degree during the polymerization reaction. For example, an overly aggressive dynamic profile can result in polymer lumps within the reactor if the dynamic profile is not changed to a sufficient degree. Alternatively or additionally, off-specification polymer can be produced during the gas phase polymerization reaction if the supported catalyst is not modified to a sufficient degree. When introducing modified supported catalysts produced from multiple sources and / or formed in situ in different lines, inconsistent modification and activation can prove to be very problematic, as either the wrong polymer product can be produced or lumps can become more prevalent. Inconsistencies between the catalyst particles and the trim catalyst solution and / or short contact times can result in these and other problems.

[0037] Without wishing to be bound by theory or mechanism, it is believed that catalyst compounds introduced from the catalyst solution to the supported catalyst can undergo suboptimal activation due to limited diffusion into the interior of the support material to enable the catalyst compounds to contact co-supported activators within the interior of the support material. Activation of catalyst compounds introduced from the catalyst solution can be enhanced by increasing the contact time between the catalyst slurry and the catalyst solution before the modified catalyst slurry produced from the catalyst slurry containing supported catalyst and the catalyst solution is passed into the polymerization reactor. Highly variable contact times can also be problematic in that the original catalyst particles can undergo more or less modification than desired, which potentially leads to the formation of undesirable polymer products (e.g., by continuously feeding supported catalyst having non-intentionally varying amounts of activated catalyst compounds thereon, varying over time due to such inconsistent contact times). Surprisingly, enhanced catalyst activation resulting from increased contact time between the catalyst solution and the catalyst slurry according to the disclosure herein can provide improved performance during gas phase polymerization reactions employing supported catalyst after modification thereof. At a minimum, enhanced catalyst activation can reduce the formation of lumps within the gas phase polymerization reactor. Various approaches for increasing the contact time between the catalyst slurry and the catalyst solution to provide improved polymerization performance are described in further detail herein. According to more specific examples, the increased contact time between the catalyst slurry can exceed the characteristic mass transfer mixing time by at least.

[0038] While the present disclosure provides enhanced slurry catalyst activation via more effective contact of the supported catalyst with the catalyst solution, it is understood that uniform delivery of the modified supported catalyst to the reactor is also a factor in achieving good polymerization performance. For example, when the modified supported catalyst is introduced through multiple lines, maintaining uniform delivery rates between the lines can preserve improved polymerization performance. Providing uniform delivery rates of the modified supported catalyst through multiple lines can include individually heating or cooling the lines to control viscosity and delivery rates, or using pinch valves to slow the delivery rate in individual lines as needed.

[0039] For a better understanding of embodiments of the present disclosure, reference is now made to the drawings, which show polymerization processes and reactor systems in which modified catalyst slurries can be produced and fed into gas phase polymerization reactors. It will be understood by those of ordinary skill in the art that elements such as pumps, heat exchangers, valves, and similar system components can be present in the depicted processes and reactor systems, but these elements have been omitted for the sake of clarity. Further, elements having similar structure and function in multiple figures will use common reference numerals herein, and these elements will only be described in detail at their first occurrence for the sake of brevity.

[0040] Figure 1is a block diagram of a gas phase reactor system 100 in which mixing of catalyst slurry and catalyst solution can be performed using a mechanically agitated mixing tank. As shown, a first catalyst-containing mixture containing a supported catalyst in a suitable carrier liquid can be introduced into a first vessel 102. The first vessel 102 can optionally be an agitated holding vessel configured to maintain a substantially constant solids concentration of the supported catalyst in the catalyst slurry. As another option, the vessel 102 can be maintained at an elevated temperature, for example, 30°C, 40°C, or 43°C to 45°C, 60°C, or 75°C. The elevated temperature can be obtained by electrically heating the holding vessel with, for example, a heating blanket. Maintaining the holding vessel at an elevated temperature can further reduce or eliminate the formation of solids deposits on the vessel walls that can otherwise slide off the walls and cause downstream transfer line pluggage. In at least one embodiment, the holding vessel can have a volume of 0.75 m 3 , 1.15 m 3 , 1.5 m 3 , 1.9 m 3 , or 2.3 m 3 to 3 m 3 , 3.8 m 3 , 5.7 m 3 , or 7.6 m 3 . It will be appreciated that the volume of the holding vessel can be selected in response to the rate of catalyst consumption. In non-limiting examples, the volume of the holding vessel can be selected to provide a run time of at least about 12 hours, for example, about 12 hours to about 96 hours, or about 12 hours to about 72 hours, or about 12 hours to about 48 hours, or about 12 hours to about 24 hours, or about 24 hours to about 72 hours, or about 48 hours to about 96 hours.

[0041] The supported catalyst can include a support material, at least one activator, and at least one catalyst compound. The at least one catalyst compound can include at least the first catalyst compound and, optionally, a second catalyst compound, wherein the first catalyst compound and the second catalyst compound are different from one another. The first catalyst-containing mixture can include a catalyst slurry.

[0042] A second catalyst-containing mixture containing the first catalyst compound or the second catalyst compound can be introduced into a second vessel 106. The second catalyst- containing mixture can include a catalyst solution. The second vessel 106 can optionally be a kettle having sufficient volume to appropriately modify the supported catalyst according to the descriptions herein. The kettle for the catalyst solution can have a volume of 0.38 m 3 , 0.75 m 3 , 1.15 m 3 , 1.5 m 3 , 1.9 m 3 , or 2.3 m3 to 3 m 3 , 3.8 m 3 , 5.7 m 3 or 7.6 m 3 The volume of the tank can be selected in response to the rate of catalyst consumption. In non-limiting examples, the volume of the tank can be selected to provide a run time of at least about 12 hours, for example, about 12 hours to about 96 hours, or about 12 hours to about 72 hours, or about 12 hours to about 48 hours, or about 12 hours to about 24 hours, or about 24 hours to about 72 hours, or about 48 hours to about 96 hours. The tank for the catalyst solution can be maintained at an elevated temperature, for example, 30 °C, 40 °C, or 43 °C to 45 °C, 60 °C, or 75 °C, which can be obtained by electrically heating the tank with, for example, a heating blanket. Maintaining the tank at an elevated temperature can provide reduced or eliminated foaming when the catalyst slurry is combined with the catalyst solution according to the description herein.

[0043] In a conventional reactor system for producing a modified supported catalyst, the catalyst slurry is delivered through line 104 and the catalyst solution is delivered through line 108 to a static mixer or mixing block which can provide a total contact time between the catalyst solution and the catalyst slurry of about 1-2 minutes when the resulting modified catalyst is delivered through line 112 to reactor 114. The contact time within the static mixer or mixing block itself can be in the range of only a few seconds.

[0044] In Figure 1In one process configuration of the present disclosure shown in FIG. 1, the contact time between the catalyst solution and the catalyst slurry can be increased by supplementing or replacing the static mixers or mixing blocks of the existing system with a mechanically agitated mixing tank, such as mixing tank 110. The mechanically agitated mixing tank can provide more thorough (higher quality) and longer duration mixing than is possible with static mixers or mixing blocks, as discussed subsequently. The catalyst slurry is delivered from first vessel 102 through line 104, and the catalyst solution is delivered directly from second vessel 106 through line 108 to mechanically agitated mixing tank 110, which can include one or more impellers 111 to facilitate agitation therein. For example, one or more impellers 111 can be present in mixing tank 110 defining a pitched blade turbine. In addition to the volume and configuration of mechanically agitated mixing tank 110, the rate of rotation of one or more impellers 111 can affect the residence time of the catalyst slurry in mixing tank 110. The mechanically agitated mixing tank 110 can be characterized by a volume and configuration sufficient to provide a contact time that is at least about 5 minutes greater than the contact time produced by the mixing blocks or static mixers alone. In non-limiting examples, the mechanically agitated mixing tank 110 can provide a contact time between the catalyst slurry and the catalyst solution within mixing tank 110 of about 20, 22, 25, 27, 28, or 30 minutes to about 30, 33, 35, 37, 38, 39, 40, 42, 45, or 50 minutes (encompassing ranges from any of the foregoing lower limits to any of the foregoing upper limits, e.g., 30 to 40 minutes). In addition to the increased contact time, the mechanically agitated mixing tank 110 can improve mixing quality beyond diffusion-limited processes. Without wishing to be bound by theory or mechanism, the mechanical agitation can provide greater uniformization of the catalyst solution throughout the catalyst slurry and reduce the thickness of the mass transfer boundary layer on the catalyst particles, allowing the catalyst to mass transfer from the catalyst solution into the catalyst particles more quickly to become activated.

[0045] The mechanically agitated mixing tank may, for example, have a total volume of about 10 L to about 30 L, or about 10 L to about 20 L, or about 15 L to about 25 L, or about 20 L to about 30 L. The volumes within the foregoing ranges, in combination with the design configuration of the mechanically agitated mixing tank, can be sufficient to provide a contact time of about 30-40 minutes in the mechanically agitated mixing tank. It goes without saying that the volume can be adjusted upward or downward from the above ranges, depending on the catalyst feed rate, to maintain the contact time within the desired specified range. Changes in catalyst productivity (kg catalyst / kg polymer) and / or production rate (kg / hr of polymer production) can further facilitate an increase or decrease in the volume of the mechanically agitated mixing tank to achieve the desired contact time and / or mixing quality.

[0046] In addition to volume, other mechanically agitated mix tanks suitable for use in the presently disclosed subject matter include, but are not limited to, any of the types of agitated mixing vessels described in Handbook of Industrial Mixing (2004, Editors: Paul, Atiemo-Obeng, and Kresta). The vessel defining the mechanically agitated mix tank can include any suitable shape, such as primarily cylindrical, with various types of vessel heads and bottoms (e.g., flat, oval, or conical). Depending on the impeller selection, baffles can optionally be used to prevent solids rotation and enhance axial mixing. In some embodiments, the vessel can be staged with horizontal baffles to provide multiple connected chambers. In any embodiment, the vessel can be vertical, horizontal, or inclined. In any embodiment, the impeller(s) can be mounted from the top, bottom, or side of the vessel, axially or inclined, centered or off-center, or any combination thereof. Each impeller (e.g., one, two, three, four, or even more impellers of the same or different types) can be any of axial flow, radial flow, mixed flow, close-coupled, helical ribbon, or any combination thereof. The impeller(s) can be sized at different vessel diameter ratios, located at different heights from the vessel bottom, and can be of different types to affect different mixing regimes in different parts of the vessel. Inlet and effluent locations can be at different positions in the vessel depending on the mixing performance desired. The liquid level within the vessel can be manipulated from partially full to fully full of liquid (i.e., no vapor space or limited vapor space).

[0047] In one non-limiting example, the vessel can be a cylindrical vessel with a conical bottom with a 15 degree taper and shrouded with an axial impeller shaft equipped with two inclined turbine blade impellers. The catalyst slurry and catalyst solution can be charged to the top of the vessel filled with liquid and the effluent can be withdrawn from the bottom, with a straight line from the inlet to the outlet passing through the space of the impellers.

[0048] As the catalyst slurry and catalyst solution are contacted in the mixing tank 110, a modified catalyst slurry comprising a modified supported catalyst is obtained and then transported via line 112 to reactor 114. Optionally, one or more static mixers 115 can reside within line 112, which can provide additional mixing contact time if desired. While line 112 has been shown as a single line, it is contemplated that line 112 can include multiple lines, as well as other components, such as pumps, valves, and the like, to facilitate the transport of the modified catalyst slurry to the reactor 114. Figure 1The line 112 is depicted as a single line, but it is understood that the line 112 can alternatively comprise multiple lines to deliver the modified catalyst slurry to the reactor 114 at multiple locations and / or at different flow rates (e.g., the line can be configured such that the modified catalyst slurry flows in parallel through the line). For example, the line 112 can include one, two, three, four, five, six, or more lines in parallel, each line operating independently of one another and having independent thermal control relative to one another. In addition, other components can be delivered to the reactor 114 via the line 112 (or lines 112), combined with the modified catalyst slurry in one or more lines, and / or introduced in one or more separate lines that are free of the modified catalyst slurry. These other components are discussed in more detail below.

[0049] It is understood that while a modified catalyst slurry comprising at least two catalyst compounds is described herein, the modified catalyst slurry can comprise a single catalyst compound if appropriate for a particular process (e.g., where a supported catalyst comprises a catalyst compound deposited thereon, and a catalyst solution comprises the same catalyst compound, such that controlling the amount of catalyst solution mixed with the catalyst slurry effectively controls the amount of deposited catalyst compound). Likewise, the modified catalyst slurry can comprise three or more catalyst compounds, depending on the specific process requirements (e.g., one, two, or three compounds can be present on the supported catalyst in the slurry, and one or two catalyst compounds are added through solution to provide immediate control over the ratio of compounds, and so on for different numbers of different catalyst compounds).

[0050] The reactor 114 can include a reaction zone and a velocity reduction zone. The reaction zone can include a bed comprising growing polymer particles, formed polymer particles, and a small amount of catalyst particles fluidized by the continuous flow of gaseous monomer and diluent to remove the heat of polymerization passing through the reaction zone. An olefinic feed gas can be provided to and recirculated through the reactor 114. Optionally, some of the recirculated gas can be cooled and compressed to form a liquid (e.g., where the gas includes an induced condensing agent (ICA), which can increase the heat removal capacity of the recirculated gas stream as it re-enters the reaction zone. Make-up of gaseous monomer to the recirculated gas stream can be at a rate equal to the rate at which particulate polymer product and monomer associated therewith is withdrawn from the reactor and the composition of the gas passing through the reactor can be adjusted to maintain a substantially steady state gaseous composition within the reaction zone. The gas exiting the reaction zone can flow to the velocity reduction zone, where entrained particles can be removed, e.g., by slowing down and falling back to the reaction zone below the velocity reduction zone. If desired, finer entrained particles and dust can be removed in a separation system, e.g., a cyclone and / or a fine filter. The recirculated gas can pass through a heat exchanger, where at least a portion of the heat of polymerization can be removed and / or the recirculated gas can be compressed and returned to the reaction zone.

[0051] In another suitable process configuration of the present disclosure, the contact time between the catalyst solution and the catalyst slurry can be increased by contacting the catalyst slurry with the catalyst solution in a line prior to further mixing in a mixing location, such as a static mixer or mixing block. In this case, the static mixer or mixing block can continue to be suitably used as the mixing location due to the increased mixing time created upstream thereof. Figure 2 is a block diagram of a gas phase reactor system 200 in which mixing of catalyst slurry and catalyst solution can be performed in-line upstream of a mixing unit 210, which advantageously can be or can include equipment that is a static mixer or mixing block, thereby providing the possibility of significantly simpler equipment compared to a mechanically agitated mixing tank.

[0052] As Figure 2As shown, catalyst slurry is again provided from first vessel 102 into line 104, and catalyst solution is again provided from second vessel 106 into line 108. Instead of being supplied directly to mixing unit 210, at least a portion of the catalyst solution in line 108 is transferred to line 104 via line 116 (i.e., a "jumpover line"), wherein pre-mixing of the catalyst slurry and catalyst solution may be performed in a downstream portion 104a of line 104 prior to entering the static mixer or mixing block 210. Optionally, all of the catalyst solution in line 108 need not necessarily be transferred to line 104 via line 116, and a portion of the catalyst solution may instead be directed to mixing unit 210. Downstream portion 104a includes the portion of line 104 located between mixing unit 210 and the junction of line 116 with line 104. Slurry pump ( Figure 2 104a) can be located immediately upstream of the downstream portion 104a to maximize the contact time in the downstream portion 104a. In a non-limiting example, the catalyst slurry and catalyst solution can have a contact time of at least about 5 minutes (or at least about 6 minutes, such as at least about 7 minutes) in the downstream portion 104a, and the contact time can be further adjusted by selecting the location where the line 116 intersects the line 104. The total (combined) contact time of the catalyst slurry and catalyst solution in the downstream portion 104a and the mixing unit 210 can be at least about twice the total (combined) contact time obtained in the absence of the downstream portion 104a of the line 104 (e.g., when the catalyst slurry and catalyst solution are introduced directly into the mixing unit 210), and / or the total contact time can be increased by at least about 4 minutes relative to the total contact time obtained in the absence of the downstream portion 104a of the line 104 (e.g., when the catalyst slurry and catalyst solution are introduced directly into the mixing unit 210). In a more specific, non-limiting example, when downstream portion 104a of line 104 is present, the total contact time within downstream portion 104a and mixing unit 210 can be at least about 6 minutes, or at least about 7 minutes (e.g., in the range of 6, 7, or 8 minutes to 7, 8, 9, or 10 minutes, with the proviso that the upper limit is greater than the lower limit, e.g., 6-7 minutes).

[0053] After the modified catalyst slurry has been obtained from the mixing unit 210, the modified catalyst slurry can be transported to the reactor 114 via line 112, as described above with reference to Figure 1 The pipeline 112 can be replaced by multiple parallel pipelines (one or more) 112, as described above in conjunction with Figure 1 Optionally, one or more static mixers 115 may reside in line 112 to provide additional contact time for mixing, if desired.

[0054] In yet another example, the inline mixing of catalyst slurry and catalyst solution can be used in combination with a mechanically agitated mixing tank to provide even longer contact times (e.g., such that the mixing unit 210 is or includes a mechanically agitated mixing tank, such as the mixing tank 110 of Figure 1 FIG. 1). Figure 3 An example of such a system is shown in Figure 3 is a block schematic diagram of a gas phase reactor system 300 in which mixing of catalyst slurry and catalyst solution can be performed inline upstream of a mechanically agitated mixing tank. The reactor system 300 can be obtained in the case where the mixing unit 210 of the reactor system 200 is specifically a mechanically agitated mixing tank having one or more impellers 111 (such as the mixing tank 110 of the reactor system 100). Optionally, one or more static mixers or mixing blocks 120 can additionally be placed within the line 104a to provide additional mixing contact time upstream of the mechanically agitated mixing tank 110 if desired. In such embodiments, the contact time between the catalyst slurry and the catalyst solution in the downstream portion of the line 104a can be, for example, at least about 5, 6, or 7 minutes as described above in connection with Figure 2 ; and the contact time in the agitated mixing tank 110 can be additionally, for example, 30-40 minutes as described in connection with Figure 1 ; or more generally from a lower limit of any one of 20, 22, 25, 27, 28, or 30 minutes to an upper limit of any one of about 30, 33, 35, 37, 38, 39, 40, 42, 45, or 50 minutes, where the total contact time is the sum of the line 104a contact time and the mixing tank 110 contact time.

[0055] The modified catalyst slurry can be introduced into the polymerization reactor via a single line in fluid contact with the polymerization reactor or via two or more lines, e.g., 2, 3, 4, or more lines, in fluid contact with the polymerization reactor. It is also contemplated that multiple modified catalyst slurries having different compositions can be introduced via two or more lines in fluid contact with the polymerization reactor. Such lines can include specialized equipment for delivering one or more modified catalyst slurries through the line and into the polymerization reactor. Examples of such specialized equipment include, but are not limited to, pinch valves, nozzles (e.g., spray nozzles and solids flow nozzles), temperature controllers, and the like, and any combination thereof. The specialized equipment can be used to control the uniformity of the catalyst entering the reactor. The line(s) into the polymerization reactor can be temperature controlled upstream of the specialized equipment or within the equipment itself. Temperature control can help to adjust the viscosity of the modified catalyst slurry and limit temperature variations within the reactor due to one or more modified catalyst slurries entering the polymerization reactor at different rates. When multiple lines are present, each line can be operated with independent flow control and / or independent temperature control.

[0056] More generally summarized, a modified catalyst slurry and one or more olefins and other potential streams can be introduced into a polymerization reactor, preferably a gas phase reactor, more preferably a fluidized bed gas phase reactor. The modified catalyst slurry can be obtained by combining an initial catalyst slurry containing a supported catalyst comprising at least one catalyst compound with a catalyst solution comprising a first catalyst compound already comprised on the supported catalyst and / or a second catalyst compound not yet comprised on the supported catalyst. In addition to the at least one catalyst compound, the supported catalyst can comprise at least one activator supported on a support material. The catalyst slurry and the catalyst solution can each comprise a carrier liquid suitable for transporting the supported catalyst and the catalyst compound(s) therein, and wherein contact between the supported catalyst of the catalyst slurry and the catalyst compound(s) of the catalyst solution can occur. The carrier liquids in the catalyst slurry and the catalyst solution can be the same or different. By contacting the catalyst slurry with the catalyst solution, different catalyst compounds can be introduced onto the support material and / or the loading of the at least one catalyst compound on the support material can be increased. Upon contacting the activator on the support material, a modified catalyst slurry having a tuned activity for conducting a polymerization reaction can be obtained. In non-limiting examples, the modified catalyst slurry can be less prone to sheeting during polymerization, a direct result of the increased contact time between the catalyst slurry and the catalyst solution provided by the disclosure herein. The contact time can be further selected to reduce the extent of polymer sheeting to a desired extent.

[0057] Accordingly, some methods for increasing the contact time between a catalyst slurry and a catalyst solution according to the present disclosure can comprise: providing a catalyst slurry comprising a supported catalyst, the supported catalyst comprising a support material, at least one catalyst compound, and at least one activator; introducing the catalyst slurry into a first line in fluid communication with a mechanically agitated mix tank; introducing at least a first portion of a catalyst solution into a second line in fluid communication with the mechanically agitated mix tank, the catalyst solution comprising a first catalyst compound already comprised on the supported catalyst or a second catalyst compound different from the first catalyst compound and not comprised on the supported catalyst; contacting the catalyst slurry with the catalyst solution in the mechanically agitated mix tank to obtain a modified catalyst slurry from the mechanically agitated mix tank, the modified catalyst slurry comprising a modified supported catalyst incorporating at least a portion of the first catalyst compound or the second catalyst from the catalyst solution; feeding the modified catalyst slurry to a fluidized bed gas phase reactor; and polymerizing an alpha-olefin in the fluidized bed gas phase reactor under polymerization conditions to obtain a polyolefin.

[0058] In some or other embodiments, a method for increasing contact time between a catalyst slurry and a catalyst solution according to the present disclosure can include: providing a catalyst slurry comprising a supported catalyst, the supported catalyst comprising a support material, at least one catalyst compound, and at least one activator; introducing the catalyst slurry into a line in fluid communication with a mixing unit; introducing at least a first portion of a catalyst solution into the line upstream of the mixing unit, the catalyst solution comprising a first catalyst compound already comprised on the supported catalyst or a second catalyst compound different from the first catalyst compound and not yet comprised on the supported catalyst; contacting the catalyst slurry with the catalyst solution in the line and in the mixing unit to obtain a modified catalyst slurry from the mixing unit, the modified catalyst slurry comprising a modified supported catalyst incorporating at least a portion of the first catalyst compound or the second catalyst compound from the catalyst solution; feeding the modified catalyst slurry to a fluidized bed gas phase reactor; and polymerizing an alpha-olefin in the fluidized bed gas phase reactor under polymerization conditions to obtain a polyolefin.

[0059] As noted above in connection with Figure 2 and 3 To improve mixing efficiency prior to polymerization (i.e., to increase contact time of the catalyst-containing mixture), further in-line contact of the catalyst-containing mixture upstream of the mixing unit can be achieved by utilizing a jumper line. The jumper line can include a pipe or conduit in which at least a portion of the catalyst-containing mixture is diverted for premixing upstream of the mixing unit (e.g., a static mixer or mixing block, or even a mechanically agitated mix tank). For example, the jumper line can facilitate a contact time of about 4, 5, or 6 minutes to about 6, 7, 8, 9, or 10 minutes between the catalyst-containing mixture prior to entering the mixing unit.

[0060] When a jumper line is used, in one or more aspects, the mixing unit can include a static mixer, a mixing block, a mechanically agitated mix tank, or any combination thereof. When a mechanically agitated mix tank is used in place of a static mixer or mixing block, the contact time of the catalyst-containing mixture can be increased to about 30 minutes to about 40 minutes, or about 30 minutes to about 35 minutes, or about 35 minutes to about 40 minutes, plus the increased in-line contact time provided by the jumper line (for a total of, for example, 35, 36, or 37 minutes to 45, 46, 47, 48, 49, or 50 minutes). In one or more aspects, for example according to those aspects as described above in connection with Figure 1 the mechanically agitated mix tank can be utilized without the presence of a jumper line. Similar contact times between the catalyst-containing mixture in the mechanically agitated mix tank can be utilized.

[0061] Implementation of a jump line, a mechanically agitated mix tank, or a combination thereof can significantly reduce the amount of polymer crumb in the polymerization reactor. For example, the polymer crumb rate in the polymerization reactor can be < 0.3%. In various embodiments, the polymer crumb rate can be < 0.3%, < 0.27%, < 0.25%, < 0.23%, < 0.2%, < 0.17%, < 0.15%, < 0.13%, < 0.1%, < 0.09%, < 0.8%, < 0.07%, < 0.06%, < 0.05%, or < 0.04%. The polymer crumb rate refers to the mass percentage of crumb polymer produced relative to the total amount of polymer produced over a given length of time. Reduction in the polymer crumb rate can reduce the frequency of crumb removal downstream of the reactor. Accumulated polymer crumb can not need to be removed from a collection tank in communication with the polymerization reactor, for example, for up to 48 hours, or up to about 36 hours, or up to about 24 hours, or up to about 12 hours, or up to about 6 hours. Catalyst slurry, catalyst solution, and modified catalyst slurry

[0062] The catalyst slurry and the modified catalyst slurry can include at least a carrier liquid and at least one catalyst compound on a supported catalyst. Optionally, the catalyst slurry can further include one or more waxes, mineral oils, an induced condensing agent, or any combination thereof. In some embodiments, the carrier liquid can be or can include, but is not limited to, one or more mineral oils and / or one or more waxes, optionally further combined with an induced condensing agent.

[0063] It should also be noted that some components present within the polymerization reactor can be fed into the reactor via the modified catalyst slurry (e.g., the optional induced condensing agent, carrier fluid such as nitrogen, etc.), or can additionally or alternatively be fed into the reactor via other means. For example, the induced condensing agent in a gas phase polymerization process, particularly a fluidized bed gas phase polymerization process, can be provided to the process in the circulating gas that flows upward through the fluidized bed in the polymerization reactor, or they can also be provided in other streams that are not the modified catalyst slurry or the circulating gas. The circulating gas can refer to a gaseous stream comprising the olefinic feed that is circulated through the reactor and replenished with additional olefin as needed.

[0064] In some embodiments, the catalyst slurry or modified catalyst slurry can include 1 wt%, 5 wt%, 8 wt%, or 10 wt% to 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, or 40 wt% of solids, based on the total weight of the catalyst slurry or modified catalyst slurry. The solids include the catalyst compound(s), the support material, the activator, and any other solid component(s) if present. If present in the carrier fluid, the wax is considered a liquid component rather than a solid component. For example, if the catalyst slurry or modified catalyst slurry includes a first catalyst, a second catalyst, a support, an activator, and a carrier fluid including mineral oil and wax, then the solid components include the first and second catalysts, the support, and the activator; and the liquid components include the mineral oil and the wax.

[0065] The modified catalyst slurry can include a first catalyst compound and a second catalyst compound, where the first catalyst compound is capable of producing high molecular weight polymers and the second catalyst compound is capable of producing low molecular weight polymers. In other words, the first catalyst compound can be a catalyst compound that primarily makes high molecular weight polymer chains and the second catalyst compound primarily makes low molecular weight polymer chains, which can depend on the catalyst structure and the polymerization conditions under which the polymerization is conducted. Thus, in some examples, the polymer product produced by the modified catalyst slurry under the polymerization conditions can include both high molecular weight polymers and low molecular weight polymers. The two catalyst compounds can be present in the modified catalyst slurry in a molar ratio of the first catalyst compound to the second catalyst compound of 99: 1 to 1 :99, 90: 10 to 10:90, 85: 15 to 15:85, 75:25 to 25:75, 60:40 to 40:60, 55:45 to 45:55. In some embodiments, the first catalyst compound and / or the second catalyst compound can also be added to the catalyst slurry as a trim catalyst from a catalyst solution to adjust the molar ratio of the first catalyst compound to the second catalyst compound. In at least one embodiment, the first catalyst compound and the second catalyst compound can each be a metallocene catalyst, as further described below.

[0066] The terms "slurry catalyst" or "catalyst slurry" each refer to a contact product comprising a dispersed supported catalyst comprising at least one catalyst compound supported on a support, a carrier liquid, an activator, and optionally a co-activator. In certain embodiments, the slurry catalyst may comprise two catalyst compounds, such as two metallocene catalyst compounds, particularly after forming a modified catalyst slurry. For example, the modified slurry catalyst may comprise a supported catalyst comprising a first metallocene and a second metallocene that each differ from one another in at least one structural aspect. Additional disclosure regarding suitable catalyst compounds is further provided below.

[0067] As just described, one or more induced condensing agents (ICAs) may be introduced into the reactor; such ICAs may increase the production rate of the polymer product. The ICA may be present in the catalyst slurry, the catalyst solution, or a modified catalyst slurry produced by contacting the catalyst slurry with the catalyst solution. Alternatively, at least a portion of the ICA may be in a line leading from the mixing device to the reactor (e.g., Figures 1-3 The ICA may be introduced into the reactor in combination with the modified catalyst slurry in line(s) 112 as described in the accompanying drawings, or the ICA may be introduced into the reactor independently of the catalyst slurry. The ICA may condense under polymerization conditions within the polymerization reactor. Introducing the ICA into the reactor is generally referred to as operating the reactor in a "condensing mode." The ICA may be non-reactive during the polymerization process, but the presence of the ICA may increase the production rate of the polymer product. In some embodiments, the ICA reagent may be or may include, but is not limited to, one or more alkanes. Exemplary alkanes may be or may include, but are not limited to, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, n-hexane, isohexane, n-heptane, n-octane, or any mixture thereof. Further details regarding ICA may be found in U.S. Patent Nos. 5,352,749; 5,405,922; 5,436,304; and 7,122,607; and International Patent Application Publication No. WO 2005 / 113615 (A2). As indicated, such ICA(s) may be added in-line to the modified catalyst slurry; this may be the primary source of ICA provided to the reactor, or may be in addition to any other ICA introduced separately into the reactor, such as via recycle gas introduced into the reactor. The induced condensing agent may be introduced into the modified catalyst slurry at a rate of from about 0.4 kg / hr, 1 kg / hr, 5 kg / hr, or 8 kg / hr to 11 kg / hr, 23 kg / hr, or 45 kg / hr per line, or at an average rate of from about 0.4 kg / hr, 1 kg / hr, 5 kg / hr, or 8 kg / hr to 11 kg / hr, 23 kg / hr, or 45 kg / hr per line when multiple lines are used.

[0068] When the catalyst slurry or modified catalyst slurry further includes an induced condensing agent, the induced condensing agent can comprise from 30 wt% to 90 wt% of the catalyst slurry or modified catalyst slurry, for example, from 30 wt%, 35 wt%, 40 wt%, 45 wt%, or 50 wt% to 60 wt%, 70 wt%, 80 wt%, or 90 wt% of the catalyst slurry or modified catalyst slurry. In some embodiments, when the catalyst slurry or modified catalyst slurry includes mineral oil and wax in addition to the induced condensing agent, the mineral oil can comprise from a lower limit of 8, 15, 20, or 25 wt% to an upper limit of 40, 50, 60, or 68 wt% of the catalyst slurry or modified catalyst slurry, the wax can comprise from a lower limit of 2, 5, or 7 wt% to an upper limit of 10, 12, or 15 wt% of the catalyst slurry or modified catalyst slurry, and the induced condensing agent can comprise from a lower limit of 30, 40, 45, or 50 wt% to an upper limit of 60, 70, 80, or 90 wt% of the catalyst slurry or modified catalyst slurry, each based on the total mass of the catalyst slurry or modified catalyst slurry.

[0069] The wax, if present, can increase the viscosity of the catalyst-containing mixture. As used herein, the term "wax" includes petrolatum, also known as Vaseline or petroleum wax. Petroleum waxes include paraffin wax and microcrystalline wax, which includes slack wax and scale wax. Commercially available waxes include SONO Paraffin wax, such as SONO 4 and SONO In at least one embodiment, the wax, if present, can have a density (at 100°C) of from 0.7 g / cm 3 , 0.73 g / cm 3 , or 0.75 g / cm 3 to 0.87 g / cm 3 , 0.9 g / cm 3 , or 0.95 g / cm 3 . The wax, if present, can have a 100°C kinematic viscosity of from 5 cSt, 10 cSt, or 15 cSt to 25 cSt, 30 cSt, or 35 cSt. The wax, if present, can have a melting point of from 25°C, 35°C, or 50°C to 80°C, 90°C, or 100°C. The wax, if present, can have a boiling point of 200°C or greater, 225°C or greater, or 250°C or greater.

[0070] It should be understood that the term "wax" also refers to or otherwise includes any wax that is not considered a petroleum wax, including animal waxes, vegetable waxes, mineral fossil or earth waxes, olefinic polymers and polyol ether-esters, chlorinated naphthalenes, and hydrocarbon-type waxes. Animal waxes can include beeswax, lanolin, shellac wax, and Chinese insect wax. Vegetable waxes can include carnauba wax, candelilla wax, bayberry, and sugarcane. Fossil or earth waxes can include ozocerite, ceresin, and montan. Olefinic polymers and polyol ether-esters include polyethylene glycol and methoxypolyethylene glycol. Hydrocarbon-type waxes include waxes produced via Fischer-Tropsch synthesis.

[0071] In some embodiments, the catalyst slurry, catalyst solution, or modified catalyst slurry can be free of any wax having a melting point > 25 °C. In other embodiments, the catalyst slurry, catalyst solution, or modified catalyst slurry can include < 3 wt.%, < 2.5 wt.%, < 2 wt.%, < 1.5 wt.%, < 1 wt.%, < 0.9 wt.%, < 0.8 wt.%, < 0.7 wt.%, < 0.6 wt.%, < 0.5 wt.%, < 0.4 wt.%, < 0.3 wt.%, < 0.2 wt.%, or < 0.1 wt.% of any wax having a melting point > 25 °C, based on the total mass of the catalyst slurry, catalyst solution, or modified catalyst slurry.

[0072] In various embodiments, the aluminum alkyl, ethoxylated aluminum alkyl, aluminoxane, antistatic agent (such antistatic agents are mentioned in WO 2022 / 174202 at paragraphs

[0078] -

[0082] ) or borate ester activator, e.g., C1 to C 15 aluminum alkyl (e.g., triisobutylaluminum, trimethylaluminum, etc.), C1 to C 15Ethoxylated alkylaluminum or methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, modified aluminoxane etc. are added online through modified catalyst slurry.For example, alkylate, antistatic agent, borate ester activator and / or aluminoxane can be directly added online through modified catalyst slurry from container.Extra alkylate, antistatic agent, borate ester activator and / or aluminoxane can be pressed 1ppm, 10ppm, 50ppm, 75ppm or 100ppm to 200ppm, 300ppm, 400ppm or 500ppm amount exist.In some embodiments, optional carrier fluid such as molecular nitrogen, argon, ethane, propane etc. can be added online through modified catalyst slurry. A carrier fluid, such as molecular nitrogen, can be introduced via the lines at a rate of about 0.4, 1, 5, or 8 kg / hr to 11, 23, or 45 kg / hr per line (or an average rate of about 0.4, 1, 5, or 8 kg / hr to 11, 23, or 45 kg / hr per line when multiple lines are used). In other embodiments, the carrier fluid can be introduced via the lines at a rate of about 5, 7, 9, or 10 kg / hr to 11, 13, or 15 kg / hr per line, or an average rate of about 5, 7, 9, or 10 kg / hr to 11, 13, or 15 kg / hr per line when multiple lines are used.

[0073] In some embodiments ( Figure 1 、 2 3 ), a carrier fluid (such as molecular nitrogen, monomer or other material) may be introduced into the modified catalyst slurry after the catalyst solution and catalyst slurry are mixed. The introduction may be carried out along a pipeline leading to a gas phase polymerization reactor or in an injection nozzle, which may include a support tube that may at least partially surround the injection nozzle. The modified catalyst slurry may pass through the injection nozzle into the reactor. In various embodiments, the injection nozzle may atomize the catalyst-containing mixture. Any number of suitable pipe sizes and configurations may be used to atomize and / or inject the slurry / solution mixture.

[0074] In some configurations, the carrier fluid can be separated or otherwise derived directly or indirectly from the recycle gas (e.g., all or a portion of the recycle gas). In such cases, where recycle gas is used as the carrier fluid, those skilled in the art will appreciate that such recycle gas may also include an induced condensing agent. The recycle gas may comprise at least a portion of the polymerization feed recycled through the gas-phase polymerization reactor.

[0075] In some embodiments, the modified catalyst slurry may include from 1 wt%, 5 wt%, 10 wt%, or 15 wt% to 25 wt%, 30 wt%, 35 wt%, or 40 wt% of one or more catalyst compounds, based on the total weight of the modified catalyst slurry. The foregoing weight percentages do not include the support material on which the catalyst is disposed. In such embodiments, the total amount of modified catalyst slurry introduced into the reactor may be at a rate of ≥0.1 kg / hr / cubic meter of polymerization reactor volume, ≥0.11 kg / hr / cubic meter of polymerization reactor volume, ≥0.12 kg / hr / cubic meter of polymerization reactor volume, 0.13 kg / hr / cubic meter of polymerization reactor volume, or ≥0.14 kg / hr / cubic meter of polymerization reactor volume to 0.2 kg / hr / cubic meter of polymerization reactor volume, 0.3 kg / hr / cubic meter of polymerization reactor volume, 0.4 kg / hr / cubic meter of polymerization reactor volume, or 0.5 kg / hr / cubic meter of polymerization reactor volume.

[0076] In some embodiments, to promote the formation of particles in the reactor, a nucleating agent such as silica, alumina, fumed silica or other suitable particulate material may be added directly to the reactor. Alternatively, the nucleating agent may be present in the catalyst solution, catalyst slurry and / or modified catalyst slurry, optionally with further introduction of the nucleating agent into the reactor. Advantageously, in the disclosure herein, the nucleating agent may be optional, but may be included if desired. Preferably, the nucleating agent is excluded from the catalyst solution and catalyst slurry and / or when the catalyst solution and catalyst slurry are mixed (i.e., if present, the nucleating agent is introduced into the modified catalyst slurry in a line(s) downstream of any mixing unit (mechanically agitated mixing tank, static mixer, mixing block, etc.)). For embodiments that do not include a nucleating agent, it has been found that high polymer bulk densities (e.g., 0.4 g / cm 3 or greater), which is greater than the bulk density of the polymer formed by conventional trimming methods. In addition, when a metallocene catalyst or other similar catalyst is used in a gas phase reactor, oxygen or fluorobenzene can be added directly to the reactor or added online to the gas stream (including the carrier fluid) to control the polymerization rate. Therefore, when a metallocene catalyst (which is sensitive to oxygen or fluorobenzene) is used in combination with another catalyst (which is not sensitive to oxygen) in a gas phase reactor, oxygen can be used to change the metallocene polymerization rate relative to the polymerization rate of the other catalyst. For example, for similar purposes, WO 1996 / 009328 discloses the addition of water or carbon dioxide to a gas phase polymerization reactor. Catalyst compounds

[0077] Once the modified supported catalyst is formed, the methods of the present disclosure can generally be used with any catalyst system comprising at least one catalyst compound on a support, preferably two or more catalyst compounds on a support. In particular examples, the supported catalyst in the catalyst slurry can contain a first catalyst compound on a support, and a second catalyst compound different from the first catalyst compound can be delivered to the catalyst slurry from a catalyst solution to form a modified catalyst slurry according to the present disclosure.

[0078] As particular examples, the catalyst compounds can include one or more metallocenes. In some embodiments, the catalyst can include first and second catalyst compounds that are at least a first metallocene and a second metallocene, where the first and second metallocenes have different chemical structures from each other. Metallocenes can include structures having one or more Cp ligands (cyclopentadienyl and ligands isolobal to cyclopentadienyl) bonded to at least one Group 3 to Group 12 metal atom and one or more leaving group(s) bonded to the at least one metal atom.

[0079] Suitable metallocene catalysts can include those described in U.S. Patent Application Publication Nos. 2019 / 0119413 and 2019 / 0119417, which are incorporated by reference herein. Also suitable are catalyst systems that use a mixture of two metallocene catalysts, such as those described in U.S. Patent Application Publication No. 2020 / 0071437, for example, a mixture of (1) a biscyclopentadienyl hafnium and (2) a zirconocene, such as an indenyl-cyclopentadienyl zirconocene. Additional details are provided below.

[0080] More particularly, the biscyclopentadienyl hafnium can be one or more of the metallocenes according to formula (Al) and / or (A2) described in US 2020 / 0071437; for example, those according to formula (Al) described in paragraphs

[0069] -

[0086] of US 2020 / 0071437; or those according to formula (A2) described in paragraphs

[0086] -

[0101] of US 2020 / 0071437, the descriptions of which are incorporated by reference herein.

[0081] Specific examples of bis(cyclopentadienyl)hafnium compounds according to formula (A1) include bis(n-propylcyclopentadienyl)hafnium dichloride, bis(n- propylcyclopentadienyl)hafnium dimethyl, (n-propylcyclopentadienyl, pentamethylcyclopentadienyl)hafnium dichloride, (n-propylcyclopentadienyl, pentamethylcyclopentadienyl)hafnium dimethyl, (n-propylcyclopentadienyl, tetramethylcyclopentadienyl)hafnium dichloride, (n-propylcyclopentadienyl, tetramethylcyclopentadienyl)hafnium dimethyl, bis(cyclopentadienyl)hafnium dimethyl, bis(n-butylcyclopentadienyl)hafnium dichloride, bis(n-butylcyclopentadienyl)hafnium dimethyl, and bis(l-methyl-3-n-butylcyclopentadienyl)hafnium dimethyl.

[0082] Particularly useful bis(cyclopentadienyl)hafnium compounds according to (A2) include one or more of the compounds listed in

[0101] section of US 2020 / 0071437, which is also incorporated herein by reference, such as (for simpler examples): rac / mes Me2Si(Me3SiCH2Cp)2HfMe2; rac Me2Si(Me3SiCH2Cp)2HfMe2; rac / mes Ph2Si(Me3SiCH2Cp)2HfMe2; rac / mes (CH2)3Si(Me3SiCH2Cp)2HfMe2; rac / mes (CH2)4Si(Me3SiCH2Cp)2HfMe2; rac / mes (C6F5)2Si(Me3SiCH2Cp)2HfMe2; rac / mes (CH2)3Si(Me3SiCH2Cp)2ZrMe2; rac / mes Me2Ge(Me3SiCH2Cp)2HfMe2; rac / mes Me2Si(Me2PhSiCH2Cp)2HfMe2; rac / mes Ph2Si(Me2PhSiCH2Cp)2HfMe2; Me2Si(Me4Cp)(Me2PhSiCH2Cp)HfMe2, and the like.

[0083] Thus, in one particular example, the first catalyst compound on the support material can comprise a first metallocene that is a bis(cyclopentadienyl)hafnium, such as rac / mes dimethylsilylbis[((trimethylsilyl)methyl)cyclopentadienyl]hafnium dimethyl. The second catalyst compound in the catalyst solution can comprise a second metallocene that is different from the first metallocene. The second metallocene can comprise a bis(cyclopentadienyl)zirconium, as described below.

[0084] Suitable catalyst compounds can include zirconocenes, such as those according to formula (B) described in paragraphs

[0103] -

[0113] of US2020 / 0071437, which description is also incorporated herein by reference. Particular examples of suitable zirconocenes can be any one or more of those listed in paragraph

[0112] of US2020 / 0071437, for example: bis(indenyl)zirconium dichloride, bis(indenyl)zirconium dimethyl, bis(tetrahydro-1-indenyl)zirconium dichloride, bis(tetrahydro-1-indenyl)zirconium dimethyl, rac / syn-bis(1- ethylindenyl)zirconium dichloride, rac / syn-bis(1-ethylindenyl)zirconium dimethyl, rac / syn-bis(1-methylindenyl)zirconium dichloride, rac / syn-bis(1-methylindenyl)zirconium dimethyl, rac / syn-bis(1-propylindenyl)zirconium dichloride, rac / syn-bis(1-propylindenyl)zirconium dimethyl, rac / syn-bis(1-butylindenyl)zirconium dichloride, rac / syn-bis(1-butylindenyl)zirconium dimethyl, rac / syn-bis(1- ethylindenyl)zirconium dichloride, rac / syn-bis(1-ethylindenyl)zirconium dimethyl, (1- methylindenyl)(pentamethylcyclopentadienyl)zirconium dichloride, (1-methylindenyl)(pentamethylcyclopentadienyl)zirconium dimethyl, or combinations thereof.

[0085] Thus, in particular examples, the second catalyst compound can comprise a second metallocene, which is a zirconocene, such as rac / syn bis(1-methylindenyl)zirconium dimethyl.

[0086] As described above, in addition to one or more catalyst compounds, supported catalysts and / or modified supported catalysts can include one or more activators and / or carriers. The term “activator” refers to any compound or combination of compounds, either supported or unsupported, that can activate a single-site catalyst compound or component (e.g., by creating a cationic species of the catalyst component). For example, this can include abstracting at least one leaving group from the metal center of a single-site catalyst compound / component. The activator can also be referred to as a “cocatalyst.” For example, a supported catalyst or modified supported catalyst within a slurry catalyst or modified slurry catalyst mixture can include two or more activators (such as aluminoxane and modified aluminoxane) and at least one catalyst compound, such as a first catalyst compound and a second catalyst compound. In particular embodiments, a slurry catalyst or modified slurry catalyst can include at least one carrier, at least one activator, and at least two catalyst compounds. By way of example, a slurry can include at least one carrier, at least one activator, and two different catalyst compounds, which can be added individually or in combination to create a slurry catalyst or modified slurry catalyst. In some embodiments, a mixture of a carrier (e.g., silica) and an activator (e.g., aluminoxane) can be contacted with a catalyst compound, allowed to react, and thereafter the mixture can be contacted with another catalyst compound from a catalyst solution to form a modified supported catalyst within a modified catalyst slurry according to the disclosure herein.

[0087] The molar ratio of the metal or non-coordinating anion in the activator to the metal in the catalyst compound(s) in the slurry catalyst can be 1000:1 to 0.5:1, 300:1 to 1:1, 100:1 to 1:1, or 150:1 to 1:1. The carrier material for the supported catalyst can be any inert particulate carrier material known in the art, including but not limited to silica, fumed silica, alumina, clay, talc, or other carrier materials, such as those disclosed above. In one embodiment, the supported catalyst can include silica and an activator, such as methylaluminoxane (“MAO”), modified methylaluminoxane (“MMAO”), and the like. Preferred activators generally include aluminoxane compounds, modified aluminoxane compounds, and ionizing anion precursor compounds that abstract a reactive sigma-bonded metal ligand, cationize the metal compound, and provide a charge-balancing non-coordinating or weakly coordinating anion. For example, suitable activators can include any aluminoxane activators and / or ionizing / non-coordinating anion activators described in

[0118] -

[0128] of US2020 / 0071437, also incorporated by reference herein.

[0088] Suitable supports include, but are not limited to, active and inactive materials, synthetic or naturally occurring zeolites, and inorganic materials such as clays and / or oxides such as silica, alumina, zirconia, titania, silica-alumina, ceria, magnesia, or combinations thereof. In particular, the support can be silica-alumina, alumina, and / or a zeolite, in particular alumina. The silica-alumina can be naturally occurring, or in the form of a gelatinous precipitate or gel including a mixture of silica and metal oxide. Suitable supports can include any of the support materials described in paragraphs

[0129] -

[0131] of US2020 / 0071437, which description is also incorporated herein by reference; with particular reference to AI2O3, ZrO2, SiO2, and combinations thereof. Catalyst solution

[0089] The catalyst solution can include a solvent or diluent and only the catalyst compound(s), such as a metallocene, or can also include an activator. In particular examples, at least one catalyst compound in the catalyst solution can be unsupported. Preferably, the catalyst solution can be prepared by dissolving at least one catalyst compound and optionally an activator in a solvent or diluent. In some embodiments, the diluent or solvent can be an alkane, for example, a C5to C 30 alkane or C5to C 10 alkane. Cycloalkanes such as cyclohexane and aromatic compounds such as toluene can also be used. Mineral oil can also be used as a diluent, as an alternative or in addition to other alkanes such as one or more C5to C 30 alkanes. The mineral oil, if used, in the catalyst solution can have the same properties as the mineral oil that can be used to prepare the catalyst slurry.

[0090] The diluent or solvent used can be liquid and relatively inert under polymerization conditions. In one embodiment, the diluent used in the catalyst solution can be different than the diluent used in the catalyst slurry. In another embodiment, the solvent used in the catalyst solution can be the same as the diluent, i.e., mineral oil(s), and any additional diluents used in the catalyst slurry. In some cases, a hydrocarbon solvent can also be used as an induced condensing agent during the polymerization reaction.

[0091] If the catalyst solution includes both a catalyst and an activator, the ratio of metal or non-coordinating anion in the activator to metal in the catalyst in the catalyst solution can be 1000: 1 to 0.5: 1, 300: 1 to 1: 1, or 150: 1 to 1: 1. In various embodiments, the activator and catalyst can be present in the catalyst solution in up to about 90 wt%, up to about 50 wt%, up to about 20 wt%, for example up to about 10 wt%, up to about 5 wt%, less than 1 wt%, or 100 ppm to 1 wt%, based on the weight of the diluent, activator, and catalyst. The one or more activators in the catalyst solution, if used, can be the same as or different from the one or more activators present in the catalyst slurry on the supported catalyst. Polymerization conditions and polyolefin products

[0092] Once the modified catalyst slurry is produced according to the disclosure above, the modified catalyst slurry can be fed to a polymerization reaction under suitable polymerization conditions in combination with an olefin feed to obtain a polyolefin. In non-limiting examples, the olefin feed can include at least one a-olefin to provide a polyolefin homopolymer or copolymer.

[0093] Monomers useful herein include substituted or unsubstituted C2 to C 40 a-olefins, such as C2 to C 20 a-olefins, such as C2 to C 12 a-olefins, such as ethylene, propylene, butylene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, and isomers thereof. In at least one embodiment, the monomers can include ethylene and one or more optional comonomers selected from C3 to C 40 olefins, such as C4 to C 20 olefins, such as C6 to C 12 olefins. Suitable C4 to C 40 Olefin monomers can be linear, branched, or cyclic. C4 to C 40 Cyclic olefins can be strained or unstrained, monocyclic or polycyclic, and can optionally include heteroatoms and / or one or more functional groups. In at least one embodiment, the monomers can include ethylene and optional comonomers, which can include one or more C3 to C 40 olefins, such as C4 to C 20 olefins, such as C6 to C 12 olefins.

[0094] In some embodiments, C2 to C 40The alpha-olefin monomer and optional comonomer(s) include ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, norbornene, norbornadiene, dicyclopentadiene, cyclopentene, cycloheptene, cyclooctene, cyclooctadiene, cyclododecene, 7-oxanorbornene, 7-oxanorbornadiene, substituted derivatives thereof, and isomers thereof, such as hexene, heptene, octene, nonene, decene, dodecene, cyclooctene, 1,5-cyclooctadiene, 1-hydroxy-4-cyclooctene, 1-acetoxy-4-cyclooctene, 5-methylcyclopentene, cyclopentene, dicyclopentadiene, norbornene, norbornadiene, and their corresponding homologues and derivatives, such as norbornene, norbornadiene, and dicyclopentadiene.

[0095] In at least one embodiment, the one or more dienes can be present in the polymer product up to 10 wt%, such as from 0.00001 wt% to 1.0 wt%, such as from 0.002 wt% to 0.5 wt%, such as from 0.003 wt% to 0.2 wt%, based on the total weight of the composition. In at least one embodiment, 500 ppm or less of diene is added to the polymerization, such as 400 ppm or less, such as 300 ppm or less. In other embodiments, at least 50 ppm of diene, or 100 ppm or more, or 150 ppm or more is added to the polymerization.

[0096] Dienic monomers include any hydrocarbon structure having at least two unsaturated bonds, such as C4to C 30 wherein at least two of the unsaturated bonds are susceptible to incorporation into a polymer by a stereospecific or non-stereospecific catalyst(s). The diene monomer can be selected from alpha, omega-diene monomers (i.e., di-vinyl monomers). The diene monomers are linear di-vinyl monomers, such as those containing 4 to 30 carbon atoms. Examples of dienes include butadiene, pentadiene, hexadiene, heptadiene, octadiene, nonadiene, decadiene, undecadiene, dodecadiene, tridecadiene, tetradecadiene, pentadecadiene, hexadecadiene, heptadecadiene, octadecadiene, nonadecadiene, eicosadiene, heneicosadiene, docosadiene, tricosadiene, tetracosadiene, pentacosadiene, hexacosadiene, heptacosadiene, octacosadiene, nonacosadiene, triacontadiene, especially preferred dienes include 1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,10-undecadiene, 1,11-dodecadiene, 1,12-tridecadiene, 1,13-tetradecadiene, and low molecular weight polybutadienes (Mw less than 1000 g / mol). Cyclic dienes include cyclopentadiene, vinyl norbornene, norbornadiene, ethylidene norbornene, divinyl benzene, dicyclopentadiene, or dienes containing higher rings with or without substituents at various ring positions.

[0097] The temperature within the reactor can be greater than 30°C, greater than 40°C, greater than 50°C, greater than 90°C, greater than 100°C, greater than 110°C, greater than 120°C, greater than 150°C, or higher. Generally, the reactor can be operated at a suitable temperature taking into account the sintering temperature of the polymer product being produced within the reactor. Thus, in one embodiment, the upper limit of the temperature can be the melting temperature of the polymer product produced within the reactor. However, higher temperatures can result in a narrower molecular weight distribution, which can be further improved by the addition of catalyst or other cocatalysts.

[0098] In some embodiments, hydrogen can be used in the polymerization process to help control or otherwise adjust the final properties of the polyolefin, as described in "Polypropylene Handbook", pages 76-78 (Hanser Publishers, 1996). Increasing the concentration (partial pressure) of hydrogen using certain catalyst systems can increase the flow index, for example, the melt index, of the polyethylene polymer. The melt index can thus be affected by the hydrogen concentration. The amount of hydrogen in the polymerization can be expressed as a molar ratio relative to the total polymerizable monomer, for example, ethylene, or a blend of ethylene and hexene or propylene.

[0099] The amount of hydrogen used in the polymerization process can be the amount necessary to achieve the desired melt index of the final polyolefin polymer. For example, the molar ratio of hydrogen to total monomer (H2:monomer) can be 0.0001 or greater, 0.0005 or greater, or 0.001 or greater. Additionally, the molar ratio of hydrogen to total monomer (H2:monomer) can be 10 or lower, 5 or lower, 3 or lower, or 0.10 or lower. The range of molar ratio of hydrogen to monomer can include any combination of any upper molar ratio limit with any lower molar ratio limit described herein. The amount of hydrogen in the reactor can be at most 5,000 ppm, in another embodiment, at most 4,000 ppm, in another embodiment, at most 3,000 ppm, or from 50 ppm to 5,000 ppm, or from 50 ppm to 2,000 ppm, at any time. The amount of hydrogen in the reactor can be from 1 ppm, 50 ppm, or 100 ppm to 400 ppm, 800 ppm, 1,000 ppm, 1,500 ppm, or 2,000 ppm, based on weight. Additionally, the ratio of hydrogen to total monomer (H2:monomer) can be from 0.00001:1 to 2:1, from 0.005:1 to 1.5:1, or from 0.0001:1 to 1:1. The pressure of one or more reactors in a gas phase process (single stage or two or more stages) can vary from 690 kPa, 1,379 kPa, or 1,724 kPa to 2,414 kPa, 2,759 kPa, or 3,448 kPa.

[0100] The reactor can produce greater than 10 kg / hour (kg / hr), greater than 455 kg / hr, greater than 4,540 kg / hr, greater than 11,300 kg / hr, greater than 15,900 kg / hr, greater than 22,700 kg / hr, or greater than 29,000 kg / hr to 45,500 kg / hr, 70,000 kg / hr, 100,000 kg / hr, or 150,000 kg / hr of polymer.

[0101] In some embodiments, the polymer product can have a melt index ratio (I 21.6 / I 2.16 ) of 10 to less than 300, or in many embodiments, 20 to 66. The melt index (I 2.16 ) can be measured according to ASTM D-1238-13, Condition E (190 °C, 2.16 kg), and is also referred to as "I2(190 °C / 2.16 kg)". The melt index (I 21.6 ) can be measured according to ASTM D-1238-13, Condition F (190 °C, 21.6 kg), and is also referred to as "I 21.6 (190 °C / 21.6 kg)".

[0102] In some embodiments, the polymer product can have a density of 0.89 g / cm 3 , 0.90 g / cm 3 , or 0.91 g / cm 3 to 0.95 g / cm 3 , 0.96 g / cm 3 , or 0.97 g / cm 3 . The density can be determined according to ASTM D-792-20. In some embodiments, the polymer product can have a bulk density of 0.25 g / cm 3 to 0.5 g / cm 3 . For example, the polymer can have a bulk density of 0.30 g / cm 3 , 0.32 g / cm 3 , or 0.33 g / cm 3 to 0.40 g / cm 3 , 0.44 g / cm 3 , or 0.48 g / cm 3 . The bulk density can be measured according to ASTM D-1895-17 Method B.

[0103] In some embodiments, the polymerization process can include contacting one or more olefin monomers with a modified catalyst slurry that can include mineral oil and a supported catalyst. The one or more olefin monomers can be ethylene and / or propylene, and the polymerization process can include heating the one or more olefin monomers and the catalyst system to 70 °C or higher to form an ethylene polymer, a propylene polymer, or an ethylene-propylene copolymer.

[0104] In at least one embodiment, the catalysts and processes disclosed herein are capable of producing ethylene polymers having a weight average molecular weight (Mw) of 40,000 g / mol, 70,000 g / mol, 90,000 g / mol, or 100,000 g / mol to 200,000 g / mol, 300,000 g / mol, 600,000 g / mol, 1,000,000 g / mol, or 1,500,000 g / mol. The Mw can be determined using gel permeation chromatography (GPC). For GPC data, the differential refractive index (DRI) method is preferred for Mn, while light scattering (LS) is preferred for Mw and Mz. GPC can be performed on a Waters 150C GPC instrument with a DRI detector. GPC columns can be calibrated by running a series of narrow polystyrene standards. Molecular weights of polymers other than polystyrene are typically calculated by using the Mark Houwink coefficients for the polymer in question.

[0105] The ethylene polymers can have a melt index (MI) of 0.2 g / 10 min or greater, for example, 0.4 g / 10 min or greater, 0.6 g / 10 min or greater, 0.7 g / 10 min or greater, 0.8 g / 10 min or greater, 0.9 g / 10 min or greater, 1.0 g / 10 min or greater, 1.1 g / 10 min or greater, or 1.2 g / 10 min or greater. In some embodiments, the upper limit of the MI of the ethylene polymers can be any of 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, or 5.5 g / 10 min. In some or other embodiments, the ethylene polymers can have a melt index of up to about 25 g / 10 min, or up to about 50 g / 10 min, or up to about 100 g / 10 min.

[0106] “Catalyst productivity” is a measure of how many grams of polymer (P) are produced using a polymerization catalyst comprising W g of catalyst (cat) in a period of T hours; and can be expressed by the following equation: P / (T x W) is expressed in units of g Pgcat -1 hr -1 In at least one embodiment, the productivity of the catalysts disclosed herein can be at least 50 g Pgcat -1 hr -1or higher, for example 500 g Pgcat -1 hr -1 or higher, for example 800 g Pgcat -1 hr -1 or higher, for example 5,000 g Pgcat -1 hr -1 or higher, for example 6,000 g Pgcat -1 hr -1 or higher.

[0107] While the above describes gas phase polymerization processes, it is to be understood that other polymerization processes well known in the art can also be used to make the polymer product. In some embodiments, any suspension, homogeneous, bulk, solution, slurry, and / or other gas phase polymerization processes known in the art can be used. Such processes can be operated in batch, semi-batch, or continuous mode. A homogeneous polymerization process is defined as one in which at least about 90 wt% of the product is soluble in the reaction medium. A bulk process is defined as one in which the monomer concentration in all of the feed to the reactor is 70 vol% or more. Alternatively, no solvent or diluent is present in or added to the reaction medium (except for small amounts used as a carrier for the catalyst system or other additives, or amounts typically found with the monomers, e.g., propane in propylene).

[0108] In some embodiments, the polymerization process can be a slurry polymerization process, preferably a continuous slurry loop polymerization reaction process. A single slurry loop reactor can be used, or multiple reactors in parallel or series (however, to achieve a monomodal molecular weight distribution, it can be preferred to use a single reactor, or to use the same catalyst, feed, and reaction conditions in multiple reactors, e.g., in parallel, such that the polymer product is considered to be made in a single reaction step). As used herein, the term "slurry polymerization process" refers to a polymerization process in which a supported catalyst is used and monomers are polymerized on the particles of the supported catalyst within a liquid medium (comprising, e.g., an inert diluent and unreacted polymerizable monomers) such that a two-phase composition comprising polymer solids and liquid is circulated within the polymerization reactor. Typically, a slurry tank or slurry loop reactor can be used; in particular embodiments herein, a slurry loop reactor is preferred. In such a process, the reaction diluent, dissolved monomer(s), and catalyst can be circulated in a loop reactor, where the polymerization reaction is at a relatively high pressure. The resulting solid polymer is also circulated in the reactor. The slurry of polymer and liquid medium can collect in one or more settling legs of the slurry loop reactor, from which the slurry is periodically withdrawn to a flash chamber, where the mixture can be flashed to a relatively low pressure; alternatively to settling legs, in other examples, a single point discharge method can be used to move the slurry to a flash chamber. Flashing results in the substantial complete removal of the liquid medium from the polymer, which can then be recompressed to condense the evaporated polymerization diluent (e.g., isobutane) into a liquid form suitable for recirculation to the reactor as liquid diluent.

[0109] Slurry polymerization processes can include those described in U.S. Patent No. 6,204,344. Other non-limiting examples of slurry processes include continuous loop or stirred tank processes. Further, other examples of slurry processes include those described in U.S. Patent No. 4,613,484. In still other embodiments, the polymerization process can be a multi-stage polymerization process in which one reactor is operated in a slurry phase, which is fed to a reactor operated in a gas phase, as described in U.S. Patent No. 5,684,097.

[0110] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used herein are to be understood as approximations based on the desired properties sought to be obtained by applicants and embodiments described herein. It is further understood that the individual values stated are to be taken as preferred minimally and are intended to cover equivalents throughout the range thereof, and that the approximations are provided for for convenience and for a better understanding of the application. Additionally, unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions and so forth used herein are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the present application. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0111] This paper presents one or more illustrative examples that are incorporated into one or more inventive elements. For the sake of clarity, all features of physical implementation are not described or shown in this application. It should be understood that in the development of the physical embodiment incorporating one or more elements of the present invention, many execution-specific decisions must be made to realize the developer's goal, such as complying with system-related, business-related, government-related and other constraints, which depend on implementation and change from time to time. Although the developer's efforts may be time-consuming, for those of ordinary skill in the art, this effort remains a routine task and benefits from this disclosure.

[0112] Although compositions and methods are described herein in terms of "comprising" various components or steps, the compositions and methods may also "consist essentially of" or "consist of" the various components and steps. Additional implementations

[0113] The present disclosure is further directed to the following non-limiting embodiments.

[0114] Embodiment 1. A method comprising: providing a catalyst slurry comprising a supported catalyst comprising a support material, at least one catalyst compound, and at least one activator; introducing the catalyst slurry into a first pipeline in fluid communication with a mechanically agitated mixing tank; introducing at least a first portion of a catalyst solution into a second line in fluid communication with the mechanically agitated mix tank, the catalyst solution comprising a first catalyst compound already contained on the supported catalyst or a second catalyst compound different from the first catalyst compound and not contained on the supported catalyst; contacting the catalyst slurry with the catalyst solution in the mechanically agitated mix tank to obtain a modified catalyst slurry from the mechanically agitated mix tank, the modified catalyst slurry comprising a modified supported catalyst incorporating at least a portion of the first catalyst compound or the second catalyst from the catalyst solution; feeding the modified catalyst slurry to a fluidized bed gas phase reactor; and α-olefins are polymerized in the fluidized bed gas phase reactor under polymerization conditions to obtain polyolefins.

[0115] Embodiment 2. The method of Embodiment 1, wherein the catalyst solution and the catalyst slurry have a contact time within the mechanically agitated mix tank of about 30 minutes to about 40 minutes.

[0116] Embodiment 3. The method of embodiment 1 or embodiment 2 further comprises: introducing a second portion of the catalyst solution into the first line upstream of the mechanically agitated mix tank.

[0117] Embodiment 4. The process of embodiment 3, wherein the catalyst solution and the catalyst slurry have a contact time of at least about 5 minutes within the first line.

[0118] Embodiment 5. The process of any one of embodiments 1-4, wherein the mechanically agitated mix tank has a volume of about 10 L to about 30 L.

[0119] Embodiment 6. The process of any one of embodiments 1-5, wherein the catalyst solution comprises the second catalyst compound.

[0120] Embodiment 7. The process of any one of embodiments 1-6, wherein the first catalyst compound comprises a first metallocene, and the second catalyst compound comprises a second metallocene different from the first metallocene.

[0121] Embodiment 8. The process of any one of embodiments 1-7, wherein the at least one catalyst compound on the supported catalyst comprises at least the first catalyst compound, and the catalyst solution comprises the second catalyst compound.

[0122] Embodiment 9. The process of embodiment 8, wherein the at least one catalyst compound on the supported catalyst further comprises the second catalyst compound.

[0123] Embodiment 10. The process of any one of embodiments 1-9, wherein the first catalyst compound comprises rac / meso-dimethyl·dimethylsilylbis[((trimethylsilyl)methyl)cyclopentadienyl]hafnium.

[0124] Embodiment 11. The process of any one of embodiments 1-10, wherein the second catalyst compound comprises rac / meso-dimethyl·bis(1-methylindenyl)zirconium.

[0125] Embodiment 12. The process of any one of embodiments 1-11, wherein the at least one activator comprises aluminoxane.

[0126] Embodiment 13. The process of any one of embodiments 1-12, wherein the modified catalyst slurry is fed into the fluidized bed gas phase reactor at a flow rate of about 0.1 kg / hr·cm 3 to about 0.5 kg / hr·cm 3 based on the volume of the fluidized bed gas phase reactor.

[0127] Embodiment 14. The process of any one of embodiments 1-13, wherein the a-olefins comprise ethylene and, optionally, one or more a-olefin comonomers.

[0128] Embodiment 15. The process of any one of embodiments 1-14, wherein the catalyst slurry further comprises a mineral oil, a wax, an induced condensing agent, or any combination thereof.

[0129] Embodiment 16. The process of embodiment 15, wherein the mineral oil is present at a concentration of about 8 wt% to about 68 wt%, the wax is present at a concentration of about 2 wt% to about 15 wt%, and the induced condensing agent is present at a concentration of about 30 wt% to about 90 wt%, based on the total mass of the mineral oil, the wax, and the induced condensing agent in the catalyst slurry.

[0130] Embodiment 17. The process of embodiment 15 or embodiment 16, wherein the induced condensing agent is present, and the induced condensing agent comprises propane, isobutane, isopentane, isohexane, or any combination thereof.

[0131] Embodiment 18. The process of any one of embodiments 1-17, wherein the catalyst slurry comprises about 1 wt% to about 40 wt% solids, based on the total mass of the catalyst slurry.

[0132] Embodiment 19. The process of any one of embodiments 1-18, wherein a polymer sheet is formed at a rate of about 0.3% or less, based on a total polyolefin production rate (atotal polyolefin production rate).

[0133] To aid better understanding of the various embodiments of the present disclosure, the following examples of preferred or representative embodiments are presented. The following examples should in no way be interpreted as limiting, or as limiting the full scope of the present invention. Example

[0134] 1-hexene / ethylene copolymerization reactions were conducted using a conventional multi-catalyst reaction system in which a static mixer was used to mix the catalyst slurry and catalyst solution to produce a modified catalyst slurry (e.g., similar to the system 100 in Figure 1 with the exception that the mechanically stirred mixing tank was replaced with a static mixer), and using a modified system (e.g., similar to the system 100 in Figure 2The modified system utilizes a jump line to produce a modified catalyst slurry with further in-line mixing upstream of the static mixer. The supported catalyst in the catalyst slurry comprises rac / meso dimethyl dimethylsilyl bis[(trimethylsilyl)methyl)cyclopentadienyl]hafnium, and the catalyst solution comprises a solvent solution of rac / meso dimethyl bis(1-methylindenyl)zirconium. By utilizing the jump line, an additional 6.8 minutes of contact time between the catalyst slurry and the catalyst solution is achieved before the modified catalyst slurry enters the gas phase fluidized bed polymerization reactor. The polymerization reactions are conducted in the same reactor, first under conventional conditions without the jump line (Trial 1), second under modified conditions using the jump line (Trial 2), and finally (Trial 3) after extended run times the reactor is returned to conventional conditions to flush the modified catalyst slurry from the reactor. Further polymerization details and characterization of the ethylene polymers produced by the polymerization reactions are given in Table 1. Table 1 In Table 1, the polymer melt flow ratio is the ratio of the high load polymer melt index (I21, ASTM D-1238, 21.6 kg, 190 °C) to the polymer melt index (I2, ASTM D-1238, 2.16 kg, 190 °C). 21

[0135] Comparing Trial 1 to Trial 2, the polyethylene copolymer produced by increasing the contact time between the catalyst slurry and the catalyst solution has a higher melt flow ratio. In addition, in Trial 2, the fluidized bed has a higher bed density and bed weight. Upon return to conventional conditions in Trial 3, the performance decreases but does not fully reach the performance level in Trial 1, which is likely due to residual modified supported catalyst from Trial 2 remaining in the reactor.

[0136] The foregoing improvement in increasing the contact time between the catalyst slurry and the catalyst solution is further illustrated in FIG. 4. FIG. 4 is a graphical illustration of the H2 / ethylene flow ratio and the extent of polymer sheeting under conventional catalyst slurry / catalyst solution contact conditions and extended catalyst slurry / catalyst solution contact conditions according to the disclosure herein. The baseline conditions are initially established in FIG. 4, where the contact between the catalyst solution and the catalyst slurry is conducted in an in-line mixer. Subsequently, at least a portion of the catalyst solution is diverted and in-line mixed with the catalyst slurry for 5-6 minutes. The conditions are then returned to the baseline conditions.

[0137] ​As shown in Table 1 and Figure 4, the polyethylene copolymer produced by increasing the contact time between the catalyst slurry and the catalyst solution (Test 2 vs. Test 1) had a higher H2 / ethylene gas ratio at a similar H2 / ethylene gas ratio and a higher polymer melt flow ratio. The increase in H2 / ethylene flow ratio and the increase in melt flow ratio at a steady H2 / ethylene gas ratio under the test conditions is consistent with more catalyst in the catalyst solution catalyst becoming activated on the catalyst support with the increase in contact time. The H2 / ethylene flow ratio dropped once the extended contact time was returned to normal conditions.

[0138] As also shown in Figure 4, the increased contact time between the catalyst solution and the catalyst slurry resulted in a decrease in the rate of sheeting, as indicated by the longer time between the removal of sheeted polymer from the waste bin. The fill level was recorded each time the waste bin was emptied in order to estimate the number of hours required for the waste bin to become completely full prior to emptying. The bin chambers emptied during Test 2 and the first bin chamber emptied after Test 2 (Figure 4) show that the increased contact time resulted in a significant improvement from about 13 hours to 60 hours between bin discharges. The increase in bed density and bed weight is also consistent with the expected decrease in sheeting. The sheeting performance decreased when returned to normal conditions.

[0139] Accordingly, the present application is amply adapted to attain the objectives and advantages mentioned as well as those inherent therein. The particular examples and configurations disclosed above are illustrative only as the application can be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative examples disclosed above can be altered, combined, or modified and that all such variations are considered within the scope and spirit of the present application. The application illustratively disclosed herein can suitably be practiced in the absence of any element or step not specifically disclosed herein or any optional element or step disclosed herein. While compositions and methods are described in terms of "comprising," "containing," or "including" various components or steps, the compositions and methods can also "consist essentially of" or "consist of" the various components and steps. All numbers and ranges disclosed above can vary several amounts. Whenever a numerical range is disclosed, any conclusion that a range implies any integer within the scope of the range is explicitly addressed, in particular, each range of values (of the form "from about a to about b", or equivalently "from approximately a to b", or equivalently "from approximately a-b") disclosed herein is to be understood to encompass each and every number and range of values subsumed therein. In addition, the use of the indefinite article "a" or "an" herein is defined as meaning one or more than one, unless explicitly stated otherwise.

Claims

1. Methods, including: providing a catalyst slurry comprising a supported catalyst comprising a support material, at least one catalyst compound, and at least one activator; introducing the catalyst slurry into a first pipeline in fluid communication with a mechanically agitated mixing tank; introducing at least a first portion of a catalyst solution into a second line in fluid communication with the mechanically agitated mix tank, the catalyst solution comprising a first catalyst compound already contained on the supported catalyst or a second catalyst compound different from the first catalyst compound and not contained on the supported catalyst; contacting the catalyst slurry with the catalyst solution in the mechanically agitated mix tank to obtain a modified catalyst slurry from the mechanically agitated mix tank, the modified catalyst slurry comprising a modified supported catalyst incorporating at least a portion of the first catalyst compound or the second catalyst from the catalyst solution; feeding the modified catalyst slurry into a fluidized bed gas phase reactor; and α-olefins are polymerized in the fluidized bed gas phase reactor under polymerization conditions to obtain polyolefins.

2. The process of claim 1 wherein said catalyst solution and said catalyst slurry have a contact time within said mechanically agitated mix tank of from about 30 minutes to about 40 minutes.

3. The method of claim 1 or claim 2, further comprising: A second portion of the catalyst solution is introduced into the first line upstream of the mechanically agitated mix tank.

4. The process of claim 3, wherein the catalyst solution and the catalyst slurry have a contact time in the first line of at least about 5 minutes.

5. The method of claim 1 or any one of claims 2-4, wherein the mechanically agitated mix tank has a volume of about 10 L to about 30 L.

6. The method of claim 1 or any one of claims 2-5, wherein the catalyst solution comprises the second catalyst compound.

7. The process of claim 1 or any one of claims 2-6, wherein the first catalyst compound comprises a first metallocene, and the second catalyst compound comprises a second metallocene different from the first metallocene.

8. The process of claim 1 or any one of claims 2-7, wherein the at least one catalyst compound on the supported catalyst comprises at least the first catalyst compound, and the catalyst solution comprises the second catalyst compound.

9. The process of claim 8, wherein the at least one catalyst compound on the supported catalyst further comprises the second catalyst compound.

10. The process of claim 1 or any one of claims 2-9, wherein the first catalyst compound comprises rac / meso dimethyldimethylsilylbis[((trimethylsilyl)methyl)cyclopentadienyl]hafnium.

11. The process of claim 1 or any one of claims 2-10, wherein the second catalyst compound comprises rac / meso dimethyl bis(1-methylindenyl)zirconium.

12. The method of claim 1 or any one of claims 2-11, wherein the at least one activator comprises an alumoxane.

13. The process of claim 1 or any one of claims 2 to 12, wherein the modified catalyst slurry is fed at a rate of about 0.1 kg / hr·cm 3 based on the volume of the fluidized bed gas phase reactor. 3 to about 0.5 kg / hr·cm 3 The flow rate is fed into the fluidized bed gas phase reactor.

14. The process of claim 1 or any one of claims 2 to 13, wherein the α-olefin comprises ethylene, and optionally, one or more α-olefin comonomers.

15. The process of claim 1 or any one of claims 2-14, wherein the catalyst slurry further comprises mineral oil, wax, an induced condensing agent, or any combination thereof.

16. The process of claim 15, wherein the mineral oil is present at a concentration of about 8 weight percent to about 68 weight percent, the wax is present at a concentration of about 2 weight percent to about 15 weight percent, and the induced condensing agent is present at a concentration of about 30 weight percent to about 90 weight percent, based on the total mass of the mineral oil, wax, and induced condensing agent in the catalyst slurry.

17. The method of claim 15 or claim 16, wherein the induced condensing agent is present, and the induced condensing agent comprises propane, isobutane, isopentane, isohexane, or any combination thereof.

18. The process of claim 1 or any one of claims 2-17, wherein the catalyst slurry comprises from about 1 wt% to about 40 wt% solids, based on the total mass of the catalyst slurry.

19. The method of claim 1 or any one of claims 2 to 18, wherein polymer sheets are formed at a rate of about 0.3% or less based on the total polyolefin production rate.

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