WO2025090149A1

WO2025090149A1 - Methods for modifying a supported catalyst during olefin polymerization through pressurized delivery of a catalyst solution

Info

Publication number: WO2025090149A1
Application number: PCT/US2024/039767
Authority: WO
Inventors: Jason R. FISCHER; Xuan YE; Adriana S. Silva; Ryan W. Impelman; Kevin A. STEVENS; Michael D. Lucas
Original assignee: ExxonMobil Technology and Engineering Co
Current assignee: ExxonMobil Technology and Engineering Co
Priority date: 2023-10-23
Filing date: 2024-07-26
Publication date: 2025-05-01
Anticipated expiration: 2026-04-23

Abstract

Polymerization methods may comprise introducing a catalyst slurry comprising a supported catalyst to a line in fluid communication with a mixing unit; introducing a catalyst solution to the mixing unit via a pressurizable fluid distribution system comprising a first pressure vessel and a second pressure vessel in parallel to each other and in fluid communication with the mixing unit, the first pressure vessel operating in an online mode while the second pressure vessel is in an offline mode; at least partially filling the first pressure vessel with a first portion of the catalyst solution; pressurizing the first pressure vessel to deliver the first portion of the catalyst solution to the mixing unit; contacting the catalyst slurry with the catalyst solution in the line or in the mixing unit to obtain a modified catalyst slurry; feeding the modified catalyst slurry to a polymerization reactor; and polymerizing to obtain a polyolefin.

Description

METHODS FOR MODIFYING A SUPPORTED CATALYST DURING OLEFIN POLYMERIZATION THROUGH PRESSURIZED DELIVERY OF A CATALYST SOLUTION

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application number 63/592450, filed October 23, 2023, entitled “METHODS FOR MODIFYING A SUPPORTED CATALYST DURING OLEFIN POLYMERIZATION THROUGH PRESSURIZED DELIVERY OF A CATALYST SOLUTION”, the entirety of which is incorporated by reference herein.

FIELD

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

BACKGROUND

[0003] Gas-phase polymerization is useful for polymerizing ethylene or ethylene and one or more olefin co-monomers. Gas-phase polymerization processes conducted in fluidized beds are particularly economical. One or more olefin monomers and catalyst particles containing an activated catalyst compound can be introduced into a polymerization reactor, in which the olefin monomer(s) can polymerize in the presence of the catalyst particles to produce a polyolefin product, preferably in fine particle form.

[0004] During polymerization, the catalyst particles (i.e., a supported catalyst) can begin to overheat, especially when a catalyst compound upon the catalyst particles produces an aggressive kinetic profile. When the catalyst particles overheat, the polymer particles within the reactor can begin to stick together, which can lead to the eventual buildup of polymer within the reactor. As used herein, the term “sheeting” is used to refer to the buildup of polymer within the reactor (sometimes alternately referred to as agglomeration or chunking), which can lead to process upsets and even reactor shutdown in some cases.

[0005] One way in which overheating of the catalyst particles can be tempered is by changing the ratio of catalyst compound(s) upon the catalyst particles. For maximum process flexibility, modification of the catalyst particles may take place in situ prior to delivery to the polymerization reaction without process shutdown taking place. In some examples, a catalyst solution may be contacted with the catalyst particles to introduce additional catalyst compound onto the catalyst particles and/or to introduce a different catalyst compound onto the catalyst particles. The catalyst solution introducing the additional catalyst compound and/or the different catalyst compound to the catalyst particles may be referred to as a “trim catalyst” or “trim catalyst solution,” since the catalyst solution modulates the performance of the original catalyst particles. Unfortunately, modification of catalyst particles in situ in the foregoing manner may lead to sub-optimal catalyst activation and continued challenges with process control, including sheeting of the resulting polymer. Short and/or variable contact times between the catalyst particles and the catalyst solution may be especially problematic, since multiple supported catalysts having varied polymerization properties may be produced.

[0006] Some references of potential interest in this area include: US Patent Numbers 10,927,205 and 6,956,089; US Patent Publication Numbers 2022/0033536 and 2022/0033537; and International Patent Publication Number WO2022/174202.

SUMMARY

[0007] In various aspects, methods of the present disclosure comprise: providing a catalyst slurry comprising a supported catalyst, in which the supported catalyst comprises a support material, at least one catalyst compound, and at least one activator; introducing the catalyst slurry to a line in fluid communication with a mixing unit; providing a catalyst solution comprising a first catalyst compound already contained on the supported catalyst or a second catalyst compound different from the first catalyst compound; introducing the catalyst solution to a pressurizable fluid distribution system in fluid communication with the mixing unit, in which the pressurizable fluid distribution system comprises at least one first pressure vessel and at least one second pressure vessel in parallel with one another, and in which the at least one first pressure vessel operates in an online mode while the at least one second pressure vessel is in an offline mode, and the at least one first pressure vessel and the at least one second pressure vessel are switchable between the online mode and the offline mode; at least partially filling the at least one first pressure vessel with a first portion of the catalyst solution; pressurizing the at least one first pressure vessel, such that the pressurizable fluid distribution system supplies the first portion of the catalyst solution from the at least one first pressure vessel to the mixing unit; contacting the catalyst solution with the catalyst slurry in the line, in an inline mixer in the line, in the mixing unit, or any combination thereof to obtain a modified catalyst slurry, in which the modified catalyst slurry incorporates at least a portion of the first catalyst compound or the second catalyst compound from the catalyst solution onto the supported catalyst; feeding the modified catalyst slurry to a polymerization reactor; and polymerizing an a-olefm in the polymerization reactor under polymerization reaction conditions to obtain a polyolefin.

[0008] In some or other aspects, methods of the present disclosure comprise: providing a catalyst slurry comprising a supported catalyst, in which the supported catalyst comprises a support material, at least one catalyst compound, and at least one activator; providing a catalyst solution comprising a first catalyst compound already contained on the supported catalyst or a second catalyst compound different from the first catalyst compound; introducing the catalyst solution to a pressurizable fluid distribution system, in which the pressurizable fluid distribution system comprises at least one first pressure vessel and at least one second pressure vessel in parallel with one another, and in which the at least one first pressure vessel operates in an online mode while the at least one second pressure vessel is in an offline mode, and the at least one first pressure vessel and the at least one second pressure vessel are switchable between the online mode and the offline mode; at least partially filling the at least one first pressure vessel with a first portion of the catalyst solution; pressurizing the at least one first pressure vessel, such that the pressurizable fluid distribution system supplies the first portion of the catalyst solution to a line downstream from the at least one first pressure vessel; introducing the catalyst slurry to the line; contacting the catalyst solution with the catalyst slurry in the line to obtain a modified catalyst slurry, in which the modified catalyst slurry incorporates at least a portion of the first catalyst compound or the second catalyst compound from the catalyst solution onto the supported catalyst; feeding the modified catalyst slurry to a polymerization reactor; and polymerizing an a-olefin in the polymerization reactor under polymerization reaction conditions to obtain a polyolefin.

[0009] These and other features and attributes of the disclosed methods of the present disclosure and their advantageous applications and/or uses will be apparent from the detailed description which follows.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] To assist those of ordinary skill in the relevant art in making and using the subject matter hereof, reference is made to the appended drawings. The following figures are included to illustrate certain aspects of the disclosure, and should not be viewed as exclusive configurations. The subject matter disclosed is capable of considerable modifications, alterations, combinations, and equivalents in form and function, as will occur to those skilled in the art and having the benefit of this disclosure. [0011] FIG. 1 is a block diagram schematic of a gas-phase reactor system, in which mixing of a catalyst slurry and a catalyst solution may take place in a mixing unit.

[0012] FIG. 2 is a block diagram schematic of a gas-phase reactor system, in which mixing of a catalyst slurry and a catalyst solution may take place in a line upstream from a mixing unit.

[0013] FIG. 3 is a block diagram schematic of a gas-phase reactor system, in which mixing of a catalyst slurry and a catalyst solution may take place in an inline mixer upstream from a mixing unit.

DETAILED DESCRIPTION

[0014] The present disclosure relates to methods for polymerizing one or more olefins, and more particularly, methods for polymerizing one or more olefins utilizing enhanced supported catalyst mixing techniques prior to polymerization.

[0015] As discussed above, catalyst particles (i.e., a supported catalyst) may be modified in situ prior to conducting a polymerization reaction, such as to mitigate polymer sheeting. However, in situ modification of catalyst particles may lead to ineffective catalyst activation and continued difficulties with a polymerization process. Ineffective mixing between a catalyst slurry and a catalyst solution, including short mixing contact times, and inconsistent delivery rates for the catalyst solution may lead to these difficulties.

[0016] The foregoing issues may be addressed through various features of the disclosure herein. In particular, the present disclosure provides increased and/or less variable contact times between catalyst particles in a catalyst slurry and a catalyst solution when producing a modified supported catalyst. As part of accomplishing the foregoing, the present disclosure utilizes a pressurizable fluid distribution system, described further hereinbelow, that may afford more stable flow of the catalyst solution and customizable flow rates to provide further process advantages. More consistent polymerization performance may be realized as a result of the robust techniques for modifying a supported catalyst according to the disclosure herein.

Definitions

[0017] Various specific embodiments, versions and examples of the invention will now be described, including preferred embodiments and definitions that are adopted herein for purposes of understanding the claimed invention. While the following detailed description gives specific preferred embodiments, those skilled in the art will appreciate that these embodiments are exemplary only, and that the invention may be practiced in other ways. For purposes of determining infringement, the scope of the invention will refer to any one or more of the appended claims, including their equivalents, and elements or limitations that are equivalent to those that are recited. Any reference to the “invention” may refer to one or more, but not necessarily all, of the inventions defined by the claims.

[0018] As used herein, the indefinite article “a” or “an” shall mean “at least one” unless specified to the contrary or the context clearly indicates otherwise. Thus, embodiments using “an alphaolefin” include embodiments where one, two, or more alpha-olefins are used, unless specified to the contrary or the context clearly indicates that only one alpha-olefin is used.

[0019] Unless otherwise indicated, all numbers indicating quantities in this disclosure are to be understood as being modified by the term “about” in all instances. It should also be understood that the precise numerical values used in the specification and claims constitute specific embodiments.

[0020] The term “and/or” as used in a phrase such as “A and/or B” herein is intended to include “A and B,” “A or B,” “A,” and “B.”

[0021] As used herein, “wt%” means percentage by weight, “vol%” means percentage by volume, “mol%” means percentage by mole, “ppm” means parts per million, and “ppm wt” and “wppm” are used interchangeably and mean parts per million on a weight basis. All concentrations herein, unless otherwise stated, are expressed on the basis of the total amount of the composition in question.

[0022] For the purposes of this disclosure, the nomenclature of elements is pursuant to the NEW NOTATION version of the Periodic Table of Elements as provided in Hawley's Condensed Chemical Dictionary, 16^th Ed., John Wiley & Sons, Inc., (2016), Appendix V unless otherwise noted.

[0023] As used herein, the terms “optional” or “optionally” mean that the subsequently described event or circumstance does or does not occur (or an element is or is not present) and that the description includes instances where said event or circumstance occurs and instances where said event or circumstance does not occur.

[0024] A “reactor” is any type of vessel or containment device in any configuration of one or more reactors, and/or one or more reaction zones, wherein a similar polymer is produced. The term “gas-phase polymerization” refers to the production of polymer in a gas-phase reactor, wherein monomers are reacted in a gas phase in a reaction zone of the reactor. In a gas-phase polymerization, the monomers need not necessarily be supplied to the reactor in a gas phase. Rather, the monomers may be supplied in a gas phase, liquid phase (condensed phase), or a hybrid gas-liquid phase.

[0025] “Alkoxides” include an oxygen atom bonded to an alkyl group that is a Ci to Cio hydrocarbyl. The alkyl group may be straight chain, branched, or cyclic. The alkyl group may be saturated or unsaturated. In at least one embodiment, the alkyl group may comprise at least one aromatic group.

[0026] The terms “anti-static agent,” “continuity additive,” “continuity aid,” and “antifoulant agent” are interchangeable and refer to compounds or mixtures of compounds, such as solids and/or liquids that are useful during polymerization to reduce fouling of a reactor. Fouling of the reactor may be caused by polymer buildup within the reactor. Fouling of the reactor can be manifested by any 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 a shutdown of the reactor. The anti-static agent can be used as a part of a catalyst composition or introduced directly into the reactor independent of the catalyst composition. In some embodiments, the anti-static agent can be included 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 “pre-catalyst.” [0028] A “catalyst system” is a combination of one or more catalyst compounds, an activator, an optional co-activator, and an optional support material. For the purposes of the present disclosure, when catalyst systems are described as comprising neutral stable forms of the components, it is well understood by one of ordinary skill in the art, that the ionic form of the component is the form that reacts with the monomers to produce polymers. Catalyst systems, catalysts, and activators of the present disclosure are intended to embrace ionic forms in addition to the neutral forms of the compounds/components .

[0029] The terms “group,” “radical,” and “substituent” may be 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 “C_n” refers to hydrocarbon(s) or a hydrocarbyl group having n carbon atom(s) per molecule or group, wherein n is a positive integer. Such hydrocarbon compounds may be one or more of linear, branched, cyclic, acyclic, saturated, unsaturated, aliphatic, or aromatic.

[0031] The terms “hydrocarbyl radical,” “hydrocarbyl group,” or “hydrocarbyl” may be used interchangeably and are defined to mean a group consisting of hydrogen and carbon atoms only and bearing at least one unfilled valence position when removed from a parent compound.

[0032] The term “optionally substituted” means that a hydrocarbon or hydrocarbyl group can be unsubstituted or substituted. Unless otherwise specified as being expressly unsubstituted, any of the hydrocarbyl groups herein may be optionally substituted. The term “substituted” means that at least one hydrogen atom in a parent hydrocarbyl group has been replaced with at least a nonhydrogen 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, e.g., ethylene and/or at least one C3 to C20 a-olefin, the olefin present in such polymer or copolymer is the polymerized form of the olefin. For example, when a copolymer is said to have an "ethylene" content of about 35 wt% to about 55 wt%, it is understood that the repeating unit/mer unit or simply unit in the copolymer is derived from ethylene in the polymerization reaction and the derived units are present at about 35 wt% to about 55 wt%, based on a weight of the copolymer. F or the purposes of the present disclosure, ethylene shall be considered an a-olefin.

[0034] A "polymer" has two or more of the same or different repeating units/mer units or simply units (monomer units). A "homopolymer" is a polymer having units that are the same. 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" as used to refer to units indicates that the units differ from each other by at least one atom or are different isomerically. The definition of copolymer, as used herein, includes terpolymers and the like. Likewise, the definition of polymer, as used herein, includes homopolymers, copolymers, and the like. Furthermore, the terms “polyethylene copolymer,” "ethylene copolymer," and "ethylene-based polymer" are used interchangeably to refer to a copolymer that includes at least 50 mol% of units derived from ethylene. A polyolefin polymer includes a polymerized form of one or more olefin monomers.

[0035] The term “characteristic mass transfer time” refers to the time scale over which diffusion occurs. Once multiple (e.g, 2, 3, 4, 5, or even greater) characteristic mass transfer times have passed, diffusion-based mixing may be considered complete. Mixing units in the methods of the present disclosure may extend the contact time between a catalyst solution and a catalyst slurry beyond the characteristic mass transfer time over which interparticle diffusion occurs. By extending the contact time beyond the characteristic mass transfer time, additional time becomes available for a catalyst compound to diffuse from a catalyst solution onto a supported catalyst (intraparticle diffusion) and for catalyst activation to occur. The time over which mass transfer occurs may be shortened beyond that realized with diffusion only, such as through use of a mechanically agitated mixing pot.

Polymerization Processes and Systems and Activation of Catalyst Compounds

[0036] When utilizing a supported catalyst containing one or more catalyst compounds, it may become necessary to modify the final supported catalyst, such as to alter the kinetic profile during polymerization or change the composition or characteristics of the polymer being produced, by introducing additional catalyst compound(s) onto the supported catalyst. The additional catalyst compound(s) being introduced may increase the loading of a catalyst compound already present upon the supported catalyst and/or introduce a different catalyst compound not already present upon the supported catalyst. One way in which modification of the supported catalyst may be performed is through contacting (i) the supported catalyst within a catalyst slurry with (ii) a catalyst solution containing one or more of the catalyst compounds, thereby producing a modified supported catalyst within a modified catalyst slurry. The modified catalyst slurry may have a different loading of at least one catalyst compound upon the support material, as compared to the original (pre-contact) catalyst slurry. When producing a modified catalyst slurry in situ in the foregoing manner, the kinetic profile and/or contact time of the modified catalyst slurry are desirably controlled with a specified degree of precision. Otherwise, inadequate kinetic control may, for example, lead to thermal swing and pressure differentials to result in rheological changes in the catalyst slurry and/or the catalyst solution that may lead to interference within the catalyst system and potentially produce polymer sheeting, among other issues. Inadequate activation may also occur for the catalyst compound(s) being newly introduced, thus failing to alter the catalyst performance to a sufficient degree during a polymerization reaction. An overly aggressive kinetic profile, for example, may lead to polymer sheeting within the reactor if the kinetic profile is not altered to a sufficient degree. Alternately or additionally, if the supported catalyst is not modified to a sufficient degree and/or activated sufficiently, an off-specification polymer may be produced during a polymerization reaction. Inconsistent and/or short contact times between catalyst particles and a catalyst solution may lead to these issues and others. [0037] Without being bound by theory or mechanism, it is believed that a catalyst compound being introduced to a supported catalyst from a catalyst solution may experience sub-optimal activation as a consequence of limited diffusion into the interior of the support material to enable the catalyst compound to contact a co-supported activator in the interior of the support material. By increasing the contact time between a catalyst slurry containing the supported catalyst and the catalyst solution prior to the modified catalyst slurry resulting therefrom entering a polymerization reactor, activation of the catalyst compound introduced from the catalyst solution may be enhanced. Highly variable contact times may also be problematic, as the original catalyst particles may undergo more or less modification or activation than desired, potentially leading to formation of an undesired polymer product (e.g., by continuously feeding supported catalyst having unintentionally differing amounts of activated catalyst compound thereon, and possibly also varying with time due to inconsistent contact times). Enhanced catalyst activation resulting from an increased and less variable contact time between the catalyst solution and the catalyst slurry according to the disclosure herein may afford improved performance during gas-phase polymerization reactions employing the supported catalysts following modification thereof. In addition, regulated delivery of the catalyst solution using the pressurizable fluid distribution system described herein may further aid in enhancing activation of the catalyst compound(s) and improving reliability of the activation process. At the very least, the enhanced catalyst activation may decrease sheeting within the gas-phase polymerization reactor and improve reliability and/or repeatability of the polymerization process. Various approaches for increasing the contact time between the catalyst slurry and the catalyst solution, any of which may be utilized in combination with the pressurizable fluid distribution system described herein, may afford improved polymerization performance, and are described in further detail herein. The increased contact time between the catalyst slurry and the catalyst solution may be at least beyond the characteristic mass transfer mixing time, according to more specific examples.

[0038] The pressurizable fluid distribution system described herein may afford further benefits associated with increasing the contact time between a catalyst solution and a catalyst slurry. Namely, the pressurizable fluid distribution may replace one or more pumps that may be conventionally used in systems for producing a modified catalyst slurry. For example, diaphragm pumps may be among the types of conventional pumps that may be replaced with the pressurizable fluid distribution system disclosed herein. Systems containing conventional pumps may be prone to plugging with solids buildup during operation thereof, and degassing of the catalyst solution may sometimes occur, especially in the pump head, which may lead to operability issues. In addition, flow rates of conventional pumps are not easily regulated, and some types of pumps may produce a pulsating flow at the location where contact occurs between the catalyst solution and the catalyst slurry. Pulsating flow may be particularly prevalent in diaphragm pumps and peristaltic pumping systems. Although systems containing conventional pumps are oftentimes satisfactory, any of the foregoing occurrences may unfavorably impact successful formation of a modified catalyst slurry in some cases. The pressurizable fluid distribution system described herein may overcome one or more of these difficulties to facilitate formation of a modified catalyst slurry with improved reliability, thereby affording improved and more consistent performance during a polymerization process.

[0039] Although the present disclosure provides for enhanced slurry catalyst activation through more effective contacting of a supported catalyst and a catalyst solution, it is to be appreciated that consistent delivery of the modified supported catalyst to a reactor is also a factor in achieving good polymerization performance. For example, when introducing a modified supported catalyst through multiple lines, keeping the delivery rate consistent between lines can maintain improved polymerization performance. Providing a consistent delivery rate of modified supported catalyst through multiple lines may involve heating or cooling the lines individually to control the viscosity and delivery rate, or using pinch valve or other flow-control device to slow the delivery rate in individual lines on an as-needed basis.

[0040] In order for the embodiments of the present disclosure to be better understood, reference is now made to the drawings showing polymerization processes and reactor systems in which a modified catalyst slurry may be produced and fed to a polymerization reactor, preferably a gasphase polymerization reactor. It is to be appreciated by one having ordinary skill in the art that elements such as pumps, heat exchangers, valves, vents, and similar system components may be present in the depicted processes and reactor systems, but such elements have sometimes been omitted in the interest of clarity. Moreover, elements having a similar structure and function in multiple figures will utilize in-common reference characters herein, and such elements will only be described in detail at their first occurrence in the interest of brevity.

[0041] FIG. l is a block diagram schematic of gas-phase reactor system 100, in which mixing of a catalyst slurry and a catalyst solution may take place using a mixing unit. As shown, first catalyst-containing mixture containing a supported catalyst in a suitable carrier liquid can be introduced as a catalyst slurry into first vessel 102. First vessel 102 optionally can be an agitated holding vessel configured to keep the solids concentration of the supported catalyst substantially constant in the catalyst slurry. As a further option, first vessel 102 can be maintained at an elevated temperature, such as from about 30°C, 40°C, or 43°C to about 45°C, 60°C, or 75°C. Elevated temperature can be obtained by electrically heating first vessel 102 with, for example, a heating blanket. Maintaining first vessel 102 at an elevated temperature can further reduce or eliminate solid residue formation on the walls of first vessel 102, which could otherwise slide off the walls and cause plugging in downstream delivery lines, among other issues. First vessel 102 can have a volume sufficient to support a desired run time, such as a volume of about 0.5 m³ to about 15 m³, or about 3 m³ to about 12 m³, or about 6 m³ to about 10 m³. In at least one embodiment, first vessel 102 can have a volume of about 0.75 m³, 1.15 m³, 1.5 m³, 1.9 m³, or 2.3 m³ to 3 m³, 3.8 m³, 5.7 m³, 6.8 m³, 7.6 m³, 12.8 m³, or 14.0 m³, such as about 1.9 m³ to about 12.8 m³, or about 2.3 m³ to about 6.8 m³, or about 5.7 m³ to 7.6 m³. It is to be appreciated that the volume of first vessel 102 may be selected in response to the rate of catalyst consumption. In non-limiting examples, the volume of first vessel 102 may be selected to afford a run time of at least about 12 hours, such as 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.

[0042] The supported catalyst may comprise a support material, at least one activator, and at least one catalyst compound (for instance, it could include two, three, or more catalyst compounds, wherein each of the catalyst compounds are different from one another; or the supported catalyst may include a single catalyst compound). The first catalyst-containing mixture may comprise a catalyst slurry.

[0043] A second catalyst-containing mixture (comprising either or both of (i) a first catalyst compound already contained on the supported catalyst and (ii) a second catalyst compound different from the first catalyst compound) may be introduced to second vessel 106. The second catalyst-containing mixture may comprise a catalyst solution (e.g., a trim catalyst solution) containing either or both of the just-noted first and second catalyst compounds dissolved in a suitable solvent. Second vessel 106 can have a volume sufficient to support a desired run time, such as a volume of about 0.3 m³ to about 10 m³, or about 1 m³ to about 7 m³, or about 2 m³ to about 5 m³. In at least one embodiment, second vessel 106 for the catalyst solution can have a volume within a range from a low of any one of about 0.38 m³, 0.75 m³, 1.15 m³, 1.5 m³, 1.9 m³, or 2.3 m³ to a high of any one of about 3 m³, 3.8 m³, 5.7 m³, or 7.6 m³, such as about 1.5 m³ to about 3.8 m³, or about 2.3 m³ to about 3.8 m³, or about 2.3 m³ to about 3 m³. It is to be appreciated that the volume of second vessel 106 may be selected in response to the rate of catalyst consumption and how long contact needs to be maintained between the catalyst solution and the catalyst slurry. In non-limiting examples, the volume of second vessel 106 may be selected to afford a run time of at least about 12 hours, such as 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. Second vessel 106 for the catalyst solution can be maintained at an elevated temperature, such as from about 30°C, 40°C, or 43°C to about 45°C, 60°C, or 75°C, which may be obtained by electrically heating second vessel 106 with, for example, a heating blanket. Maintaining second vessel 106 at an elevated temperature may aid in decreasing or eliminating foaming when combining the catalyst slurry with the catalyst solution according to the description herein.

[0044] The catalyst slurry is conveyed from first vessel 102 through line 104 to mixing unit 101, and the catalyst solution is conveyed through line 108 to mixing unit 101 after passing through pressurizable fluid distribution system 118, discussed hereinafter. Passage of the catalyst solution to mixing unit 101 may occur directly, as shown in in FIG. 1, or indirectly, as shown in FIGS. 2 and 3 and discussed subsequently.

[0045] Referring still to FIG. 1, the catalyst solution is supplied from second vessel 106 via pressurizable fluid distribution system 118 that includes a plurality of pressure vessels 120a and 120b that are in fluid communication with line 108. Pressure vessels 120a and 120b may each have a volume that is less than that of second vessel 106. In at least one example, pressure vessels 120a and 120b may each have a volume of about 1 m³ to about 2 m³, or about 0.75 m³ to about 1.5 m³. As used herein, the term “pressure vessel” refers to a container that is maintained above atmospheric pressure in its normal operating state. In the case of pressure vessels 120a and 120b, catalyst solution housed therein may be dispensed to mixing unit 101 under pressure, as described subsequently. Pressure vessels 120a and 120b are arranged in parallel with one another, such that pressure vessel 120a may operate in an online mode while pressure vessel 120b is in an offline mode, and the online mode and offline mode are switchable between pressure vessels 120a and 120b. That is, pressure vessel 120a may be in an offline mode while pressure vessel 120b is operating in an online mode and vice versa. The term “online mode” refers to the operating state under which a given pressure vessel is in a pressurized state and providing catalyst solution to line 108. The term “offline mode” refers to the operating state under which a given pressure vessel is not providing catalyst solution to line 108. A pressure vessel may or may not be pressurized when in the offline mode. Although FIG. 1 has depicted a single example of pressure vessel 120a and pressure vessel 120b, it is to be recognized that pressure vessel 120a may represent a group of two or more first pressure vessels 120a in parallel with one another and pressure vessel 120b may similarly represent a group of two or more second pressure vessels 120b in parallel with one another, wherein the two groups operate with one group in the online mode and the other group in the offline mode.

[0046] Additionally, the pressurizable fluid distribution system 118 may optionally include one or more feed vessels 122 that are positioned in-line between second vessel 106 and pressure vessels 120a and 120b, such that one or more feed vessels 122 can provide a steady supply of catalyst solution to pressure vessels 120a and 120b during operation of system 100. Advantageously, one or more feed vessels 122 can facilitate refilling of or replacing second vessel 106 without disrupting the supply of catalyst solution to pressure vessels 120a and 120b. For instance, the catalyst solution can be supplied to one or more of pressure vessels 120a and 120b from one or more feed vessels 122 while second vessel 106 is offline, such as while refilling or conducting maintenance. In another example, one or more feed vessels 122 can continue to supply catalyst solution to one or more of pressure vessels 120a and 120b while second vessel 106 is being replaced with another second vessel 106 containing additional catalyst solution, or if second vessel 106 is otherwise disconnected from feed vessel 122.

[0047] The fluid capacity of pressure vessels 120a and 120b and/or one or more feed vessels 122 can vary depending on, for example, the size of second vessel 106, the flow rate of the catalyst solution in line 108 for mixing with the catalyst slurry, the frequency at which pressure vessels 120a and 120b are cycled between their corresponding online modes and offline modes, and the like.

[0048] The introduction of catalyst solution to pressure vessels 120a and 120b can be managed by corresponding inlet valves 124a and 124b. As shown, inlet valve 124a regulates the supply of catalyst solution to pressure vessel 120a, and inlet valve 124b regulates the supply of catalyst solution to pressure vessel 120b. Similarly, outlet valve 125a regulates the discharge of catalyst solution from first pressure vessel 120a, and outlet valve 125b regulates the discharge of catalyst solution from second pressure vessel 120b. Inlet valves 124a/124b and outlet valves 125a/125b may be any type of valve that provides on/off performance, although valves affording metered flow may also be used. [0049] Generally, the catalyst solution is supplied to pressure vessels 120a and 120b one at a time from second vessel 106 or one or more feed vessels 122. An exception is during the initial startup/loading of system 100, during which both of pressure vessels 120a and 120b may be optionally loaded at the same time, with one of pressure vessels 120a or 120b subsequently being pressurized and entering its corresponding online mode. Any type of conventional pump (not shown) may supply the catalyst solution to pressure vessel(s) 120a and/or 120b from second vessel 106 or one or more feed vessels 122, since pump pulsation does not progress downstream from pressure vessel(s) 120a and/or 120b. Alternately, second vessel 106 or one or more feed vessels 122 may be pressurized with a gas to push the catalyst solution to pressure vessels 120a and/or 120b. Pressure vessels 120a and/or 120b may be at least partially depressurized when loading the catalyst solution and then may be subsequently pressurized in accordance with the further description herein. Outlet valves 125a and 125b are usually closed throughout loading of the catalyst solution to corresponding pressure vessels 120a or 120b. A vent (not shown) upon each of pressure vessels 120a and 120b may be open to discourage pressure buildup during loading of the catalyst solution. The vent may be closed following loading of the catalyst solution to pressure vessel 120a and/or 120b. Once at least partially filled with catalyst solution, preferably fully filled with catalyst solution, one of pressure vessels 120a or 120b is selected to initially supply the catalyst solution to line 108 (i.e., be in the online mode) and the other of pressure vessels 120a or 120b is selected to be in the offline mode. For example, in the event pressure vessel 120a is selected to supply the catalyst solution to mixing unit 101, pressure vessel 120a is pressurized with a gas, preferably an inert gas such as nitrogen, from gas supply 130a via line 131a. Once suitably pressurized, outlet valve 125a is opened to discharge the catalyst solution. The head pressure supplied by the gas may remain constant during discharge of the catalyst solution from pressure vessel 120a (e.g., by keeping a valve in line 131a open to allow gas to continue to enter pressure vessel 120a), or the gas pressure in pressure vessel 120a may be allowed to decrease during discharge of the catalyst solution therefrom. If the gas pressure is allowed to decrease during discharge of the catalyst solution from pressure vessel 120a, the variance in flow rate may be accounted for using one or more control valves 126 downstream from pressure vessels 120a, as discussed further below. Namely, one or more control valves 126 may be adjusted to maintain the flow rate at a substantially constant level. Such adjustment may occur in an automated or manual manner. [0050] When it is desired to switch pressure vessel 120a to an offline mode and pressure vessel 120b to an online mode, pressure vessel 120b may similarly be pressurized with a gas provided from gas supply 130b via line 131b. Further details regarding the switching of pressure vessels 120a and 120b between the corresponding online and offline modes is discussed subsequently. Although separate gas supplies 130a and 130b and corresponding lines 131a and 131b are shown in FIG. 1, it is to be appreciated that a single gas supply may also suitably provide gas to lines 131a and 131b for pressurizing one of pressure vessels 120a and 120b at a given time.

[0051] While pressure vessel 120a is operating in the online mode, outlet valve 125a is open, and the catalyst solution enters line 108 and subsequently mixing unit 101. As the volume of catalyst solution in pressure vessel 120a decreases, a second portion of the catalyst solution may be introduced to pressure vessel 120b while in the offline mode (if not previously loaded with catalyst solution during startup of system 100). To do so, inlet valve 124b and a vent (not shown) may be opened to allow catalyst solution to flow from second vessel 106 or one or more feed vessels 122 to pressure vessel 120b. Once pressure vessel 120b is fully or partially loaded with catalyst solution, preferably fully loaded, inlet valve 124b and the vent (not shown) are closed, and pressure vessel 120b is pressurized with a gas provided from gas supply 130b via line 131b. At this point, pressure vessel 120b is ready to transition to the corresponding online mode as pressure vessel 120a is transitioned to the corresponding offline mode. The timing for loading of catalyst solution into pressure vessel 120b is not particularly limited, other than loading being complete before pressure vessel 120a needs to switch to the corresponding offline mode.

[0052] Once the catalyst solution in pressure vessel 120a is depleted or nearly depleted (e.g. , less than 10% of the remaining catalyst solution, or less than 5% of the remaining catalyst solution), outlet valve 125a can be closed and outlet valve 125b can be opened (e.g., before closing outlet valve 125a, or at the same time or nearly the same time as closing outlet valve 125a), thereby switching pressure vessel 120a to the offline mode and pressure vessel 120b to the online mode. A check valve (not shown) may be used to prevent backflow. Once in the online mode, pressure vessel 120b now supplies the catalyst solution to line 108 without interrupting the flow of the catalyst solution. Once pressure vessel 120a is no longer supplying the catalyst solution to line 108, pressure vessel 120a may be depressurized and subsequently reloaded with catalyst solution in a manner similar to that described above for pressure vessel 120b. For example, pressure vessel 120a may be at least partially refilled in the offline mode with a third portion of the catalyst solution while pressure vessel 120b is operating in the online mode and supplying the second portion of the catalyst solution to the mixing unit. The switching of pressure vessels 120a and 120b between the corresponding online and offline modes may then continue for as many cycles as desired.

[0053] In one or more embodiments, a decision to switch pressure vessel 120a or pressure vessel 120b to the corresponding offline mode may be made based upon the volume of the catalyst solution remaining therein, such as the volume reaching a pre-determined depletion threshold (e.g. , about 10% of the vessel volume or less or about 5% of the vessel volume or less). For instance, the volume of the catalyst solution may be monitored visually or via one or more sensors (not shown), such as, for example, volumetric sensors, level sensors, or the like. Alternately, the flow rate of catalyst solution from pressure vessel 120a or pressure vessel 120b may be monitored, and a decision to switch to the corresponding offline mode may be made based upon the vessel volume and the amount of residual volume anticipated to remain present based upon the flow rate of the catalyst solution, again keeping the residual volume above a pre-determined depletion threshold.

[0054] The pressure within pressure vessels 120a and 120b may be suitably high to promote dispensation of the catalyst solution to line 108. In non-limiting examples, the pressure can be about 300 psi or above, or about 400 psi or above, or about 500 psi or above, such as within a range of about 300 psi to about 500 psi, or about 500 psi to about 600 psi. The pressure may also be at least that of the operating pressure in polymerization reaction 114. Preferably, the pressure may be supplied with an inert gas, such as nitrogen, helium, argon, or any combination thereof. Other inert gases may be alternately supplied depending upon particular process requirements. Optionally, the inert gas may be purified to reduce or remove contaminants, such as oxygen, water, sulfur compounds, or the like that may result in poisoning of one or more components of the catalyst slurry or the catalyst solution.

[0055] Additionally, pressurizable fluid distribution system 118 may include one or more control valves 126 downstream from pressure vessels 120a and 120b and configured to manage or regulate the flow rate of catalyst solution to line 108. For instance, it may be desirable to overpressurize an online pressure vessel (e.g., pressure vessel 120a) to facilitate transport therefrom, but the chosen pressure may produce an excessive flow rate and/or a decreasing flow rate as the overpressure decreases. One or more control valves 126 may facilitate a desired flow rate to accommodate the overpressure, or one or more control valves 126 may be used to maintain the flow rate at a desired level if the flow rate from the online pressure vessel (e.g., pressure vessel 120a) should change. By limiting the flow rate, one or more control valves 126 may also aid in mitigating foaming of the catalyst solution upon delivery to the catalyst slurry. In various embodiments, one or more control valves 126 can be remotely controlled via, for example, a wireless connection to one or more computer devices. Suitable examples of one or more control valves 126 may include metering valves such as, for example, needle valves or globe valves.

[0056] The catalyst solution, which is delivered under gas pressure according to the embodiments of the present disclosure, can adsorb the amount of gas required to reach equilibrium in the headspace of the online pressure vessel to promote dispensation therefrom. The catalyst slurry and the catalyst solution can potentially suffer from foaming if the pressure of the resulting combined liquid stream drops below a defined threshold and the equilibrium solubility of the dissolved gas (e.g., dissolved nitrogen gas) is exceeded at the lower pressure. Formation of gas bubbles and foaming may compromise various components of system 100 and may result in ineffective modification of the supported catalyst. By utilizing one or more control valves 126 to maintain a low ratio of catalyst solution to catalyst slurry, the released gas can be adequately absorbed by the catalyst slurry, which is not at an equilibrium gas solubility condition. That is, by promoting a relatively low flow rate, one or more control valves 126 may limit the amount of releasable gas to a quantity that may be absorbed by the catalyst slurry. Further, the distance between one or more control valves 126 and the location where the catalyst solution contacts the catalyst slurry may be minimized to limit the location over which non-equilibrium gas release may occur.

[0057] The catalyst solution is provided directly or indirectly to mixing unit 101 (direct provision shown in FIG. 1). Mixing unit 101 may be a mechanically agitated mixing pot, a static mixer, or a mixing block. Preferably, the mixing unit is a mechanically agitated mixing pot to afford longer contact times. Static mixers or mixing blocks may afford a total contact time of about 1 -2 minutes between the catalyst solution and the catalyst slurry as the resulting modified catalyst is being conveyed through line 112 to polymerization reactor 114. Contact times within the static mixer or mixing block itself may be in the range of only a few seconds.

[0058] By utilizing a mechanically agitated mixing pot as mixing unit 101 (or as a part of mixing unit 101), more thorough (higher quality) and longer mixing may be realized than is feasible with a static mixer or mixing block alone. Mixing unit 101 containing a mechanically agitated mixing pot may include one or more impellers or other internal components to promote agitation and mixing therein. For example, the one or more impellers may be present in a mechanically agitated mixing pot defining a pitched blade turbine. In addition to the volume and configuration of the mechanically agitated mixing pot, the rotation rate of the one or more impellers may impact the residence time of the catalyst slurry and catalyst solution in mixing unit 101. Suitable mechanically agitated mixing pots may feature a volume and configuration sufficient to afford a contact time that is at least about 5 minutes greater than that produced by a mixing block or static mixer alone. In non-limiting examples, mixing unit 101 incorporating a mechanically agitated mixing pot may afford a contact time therein between the catalyst slurry and the catalyst solution of about 20, 22, 25, 27, 28, or 30 minutes to about 30, 33, 35, 37, 38, 39, 40, 42, 45, or 50 minutes (with ranges from any foregoing low end to any foregoing high end contemplated, such as 30 to 40 minutes). In addition to the increased contact time, mixing unit 101 incorporating a mechanically agitated mixing pot may improve the quality of mixing beyond just diffusion-limited processes. Without being bound by theory or mechanism, the mechanical agitation may provide greater homogenization of the catalyst solution throughout the catalyst slurry and reduce the thickness of a mass transfer boundary layer upon the catalyst particles, thereby allowing faster mass transfer of the catalyst from the catalyst solution into the catalyst particles for activation to occur.

[0059] Mixing unit 101 may feature a mechanically agitated mixing pot having, for example, 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. Volumes in the foregoing ranges, coupled with the design configuration of the mechanically agitated mixing pot, may be sufficient to afford contact times of about 30-40 minutes in the mechanically agitated mixing pot. It is to be appreciated that the volume may be adjusted up or down from the foregoing ranges, depending on catalyst feed rates, to maintain contact times within a desired specified range. Variance in the catalyst productivity (kg of catalyst per kg of polymer) and/or variance in production rates (kg/hr of polymer production) may further prompt an increase or decrease in volume of the mechanically agitated mixing pot to accomplish a desired contact time and/or quality of mixing.

[0060] In addition to the volume, other mechanically agitated mixing pots suitable for use in the disclosure herein within mixing unit 101 include, but are not limited to, any of the types of agitated mixing vessels described in the Handbook of Industrial Mixing (2004, Editors: Paul, Atiemo- Obeng, and Kresta). The vessel defining the mechanically agitated mixing pot may comprise any suitable shape such as, primarily cylindrical with multiple types of vessel heads and bottoms (such as flat, ellipsoidal, or conical). Baffles may be optionally used depending on impeller selection to prevent solid body rotation and to enhance axial mixing. In some embodiments, the vessel of the mechanically agitated mixing pot may be staged with a horizontal baffle to provide multiple connected chambers. In any embodiment, the vessel of the mechanically agitated mixing pot may be vertical, horizontal, or inclined. In any embodiment, impeller(s) may be installed from the top, bottom, or side of the vessel, axial or tilted, centered or off centered, or any combination thereof. Each impeller (e.g., one, two, three, four, or even more impellers of the same or different types) may be any of axial flow, radial flow, mixed flow, close contact, helical ribbon, or any combination thereof. The impeller(s) may be sized to different ratios of vessel diameter, located at varying heights from vessel bottom, and can be of different types to affect different mixing regimes in different sections of the mechanically agitated mixing pot. The inlet and effluent locations can be located in different locations of the mechanically agitated mixing pot according to desired mixing performance. A liquid level within the mechanically agitated mixing pot may be manipulated to be partially full to completely liquid full (e.g., no or limited vapor space).

[0061] In one non-limiting example, the mechanically agitated mixing pot may be a cylindrical vessel with a conical bottom with about a 15 degree taper, and baffled with an axial impeller shaft equipped with two pitched turbine blade impellers. The catalyst slurry and the catalyst solution may be charged into the top of the mechanically agitated mixing pot fdled with liquid, and effluent may be drawn from the bottom, where a direct line from the inlet to the exit passes through the space of the impellers.

[0062] It is also to be appreciated that mixing unit 101 may be eliminated in some process configurations (not shown), in which case contact between the catalyst solution and the catalyst slurry may take place in line 104 or 112.

[0063] As the catalyst slurry and catalyst solution are contacted in mixing unit 101, a modified catalyst slurry comprising a modified supported catalyst is obtained and then conveyed to polymerization reactor 114 via line 112. Optionally, one or more static mixers 115 may reside within line 112, which may provide additional contact time for mixing, if needed. Although line 112 has been depicted as a single line in FIG. 1, it is to be appreciated that line 112 may alternately comprise a plurality of lines in parallel to deliver the modified catalyst slurry to polymerization reactor 114 at multiple locations and/or at different flow rates. For example, line 112 may comprise one, two, three, four, five, six or more lines in parallel, each operating independently of one another and having independent thermal control with respect to each other. Moreover, other components may be delivered to polymerization reactor 114 via line 112 (or multiple lines 112), either being combined with the modified catalyst slurry in one or more lines and/or introduced in one or more separate lines not containing the modified catalyst slurry. Such other components are discussed in more detail below.

[0064] It should be understood that while a modified catalyst slurry that includes at least two catalyst compounds is described herein, the modified catalyst slurry may comprise a single catalyst compound (a first catalyst compound) if suitable for a particular process (e.g., where the supported catalyst comprises the catalyst compound deposited thereon, and the catalyst solution comprises the same catalyst compound, such that control of the amount of catalyst solution mixed with catalyst slurry de facto controls the amount of deposited catalyst compound). Likewise, the modified catalyst slurry may alternately comprise three or more catalyst compounds, depending on particular process requirements (e.g., one, two or three compounds could be present on the supported catalyst of the catalyst slurry, with one or two catalyst compounds or even all three catalyst compounds being added by the catalyst solution to provide on-the-fly control of the ratio of the compounds).

[0065] Polymerization reactor 114 can include a reaction zone and a velocity reduction zone. The reaction zone can include a bed that can include growing polymer particles, formed polymer particles and a minor amount of catalyst particles fluidized by the continuous flow of the gaseous monomer and diluent to remove the heat of polymerization through the reaction zone. An olefinic feed (either gas, liquid, or liquid-gas) may be provided to polymerization reactor 114 and recirculated therethrough. Optionally, some of the re-circulated feed can be cooled and compressed to form liquids (e.g., where the gases include induced condensing agents (ICAs)), that can increase the heat removal capacity of the circulating stream when readmitted to the reaction zone. Make-up of olefinic monomer to the circulating 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 stream passing through the reactor can be adjusted to maintain an essentially steady state gaseous composition within the reaction zone. The gas leaving the reaction zone can be passed to the velocity reduction zone where entrained particles can be removed, for example, by slowing 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, such as a cyclone and/or fines filter. The recirculating stream can be passed through a heat exchanger where at least a portion of the heat of polymerization can be removed and/or the recirculating stream can be compressed and returned to the reaction zone. [0066] Tn another suitable process configuration of the present disclosure, the contact time between the catalyst solution and the catalyst slurry may be increased by contacting the catalyst slurry and the catalyst solution in a line upstream from mixing unit 101. In this case, the increased contact times within the line may facilitate the typically shorter contact times within a static mixer or mixing block, although a mechanically agitated mixing pot may also be used in this configuration. FIG. 2 is a block diagram schematic of gas-phase reactor system 200, in which mixing of a catalyst slurry and a catalyst solution may take place inline upstream from mixing unit 101, which advantageously could be or could comprise a static mixer or mixing block, thereby offering a simpler mixing solution at lower cost in comparison to a mechanically agitated mixing pot.

[0067] As shown in FIG. 2, a catalyst slurry is again provided from first vessel 102 into line 104, and a catalyst solution is again provided from second vessel 106 into line 108 after passing through pressurizable fluid distribution system 118. Instead of being directly supplied to a mixing unit 101, as in FIG. 1, at least a portion of the catalyst solution in line 108 is diverted to line 104 via line 212 (i.e., a “jumpover line”), wherein pre-mixing of the catalyst slurry and the catalyst solution may take place in downstream portion 104a of line 104, prior to entering mixing unit 101. All of the catalyst solution in line 108 need not necessarily be diverted to line 104 through line 212, and a portion of the catalyst solution may instead be optionally directed to mixing unit 101. Preferably, the entirety of the catalyst solution in line 108 is directed to line 104 for mixing with the catalyst slurry in-line prior to entering mixing unit 101. Optionally, one or more static mixers or mixing blocks 302 may additionally be placed within line 104a to provide additional contact time for mixing, if needed, upstream from mixing unit 101, as shown for system 300 in FIG. 3.

[0068] Thus, pressurizable fluid distribution system 118 can supply the catalyst solution to line 104 at a position upstream from mixing unit 101, directly to mixing unit 101, or any combination thereof. Downstream portion 104a includes the portion of line 104 located between mixing unit 101 and the union of line 212 with line 104. A slurry pump (not shown in FIG. 2 or FIG. 3) may be located immediately upstream from downstream portion 104a to maximize the contact time in downstream portion 104a and to facilitate transport of the catalyst slurry and the catalyst solution to mixing unit 101. In non-limiting examples, the catalyst slurry and the catalyst solution may have a contact time of at least about 5 minutes (or at least about 6 minutes, such as at least about 7 minutes) within downstream portion 104a, and the contact time may be further adjusted through choice of the location at which line 212 intersects with line 104. A total (combined) contact time of the catalyst slurry and the catalyst solution in downstream portion 104a and mixing unit 101 may be at least about double that obtained without downstream portion 104a of line 104 being present (e. ., when the catalyst slurry and the catalyst solution are introduced directly to a mixing unit 101) and/or the total contact time may increase by at least about 4 minutes relative to that obtained without downstream portion 104a of line 104 being present (e.g., when the catalyst slurry and the catalyst solution are introduced directly to mixing unit 101). In more specific non-limiting examples, the total contact time within downstream portion 104a and mixing unit 101 may be at least about 6 minutes, or at least about 7 minutes when downstream portion 104a of line 104 is present (such as within a range from 6, 7, or 8 minutes to 7, 8, 9, or 10 minutes; with ranges from any foregoing low to any foregoing high contemplated, provided the high end is greater than the low end; such as 6-7 minutes). A further increase in contact time may be realized by introducing static mixer or mixing block 302 into line 104, as described above for system 300 (FIG. 3).

[0069] 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 in fluid contact with the polymerization reactor, such as 2, 3, 4, or more lines. It is also contemplated that multiple modified catalyst slurries having different compositions may be introduced via two or more lines in fluid contact with the polymerization reactor. Such lines may include specialized equipment used for conveying the modified catalyst slurry/slurries through the line and into the polymerization reactor. Examples of such specialized equipment include, but are not limited to, pinch valves, nozzles such as spray nozzles and solid stream nozzles, temperature controllers, the like, and any combination thereof. The specialized equipment may be used to control the uniformity of the catalyst entering the polymerization reactor. The line(s) entering the polymerization reactor may be temperature controlled either upstream of the specialized equipment or within the equipment itself. The temperature controls may aid in regulating the viscosity of the modified catalyst slurry and limit temperature variability within the polymerization reactor as a consequence of the modified catalyst slurry/slurries entering the polymerization reactor at different rates. When multiple lines are present, each line may be operated with independent flow control and/or independent temperature control.

[0070] Summarizing more generally, a modified catalyst slurry and one or more olefins, among other potential streams, may be introduced into a polymerization reactor, preferably a gas-phase reactor, more preferably a fluidized bed gas-phase polymerization reactor. The modified catalyst slurry may 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 contained upon the supported catalyst and/or a second catalyst compound not already contained upon the supported catalyst. More generally, the supported catalyst could comprise one, two, or three (or even more) distinct catalyst compounds; and the catalyst solution could comprise one or more catalyst compounds, any one of which may either be (i) the same as one of the catalyst compounds of the supported catalyst; or (ii) different from any of the catalyst compounds of the supported catalyst. The supported catalyst may further comprise at least one activator upon a support material, in addition to the at least one catalyst compound. The catalyst slurry and the catalyst solution may each comprise a carrier liquid suitable for conveying the supported catalyst and catalyst compound(s) therein, and in which contact between the supported catalyst of the catalyst slurry and the catalyst compound(s) of the catalyst solution may take place. The carrier liquid in the catalyst slurry and the catalyst solution may be the same or different. By contacting the catalyst slurry with the catalyst solution, a different catalyst compound may be introduced onto the support material and/or the loading of at least one catalyst compound upon the support material may be increased. Upon contacting the activator upon the support material, a modified catalyst slurry having modulated activity for conducting a polymerization reaction may be obtained. In non-limiting examples, the modified catalyst slurry may be less prone to sheeting during the polymerization as a direct consequence of the increased contact time between the catalyst slurry and the catalyst solution afforded by the disclosure herein. The contact time may be further selected to decrease the degree of polymer sheeting to a desired degree.

[0071] Accordingly, methods of the present disclosure may 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 to a line in fluid communication with a mixing unit; providing a catalyst solution comprising a first catalyst compound already contained on the supported catalyst or a second catalyst compound different from the first catalyst compound; introducing the catalyst solution to a pressurizable fluid distribution system in fluid communication with the mixing unit, the pressurizable fluid distribution system comprising at least one first pressure vessel and at least one second pressure vessel in parallel with one another, in which the at least one first pressure vessel operates in an online mode while the at least one second pressure vessel is in an offline mode, and the at least at least one first pressure vessel and the at least one second pressure vessel are switchable between the online mode and the offline mode; at least partially filling the at least one first pressure vessel with a first portion of the catalyst solution; pressurizing the at least one first pressure vessel, such that the pressurizable fluid distribution system supplies the first portion of the catalyst solution from the at least one first pressure vessel to the mixing unit; contacting the catalyst solution with the catalyst slurry in the line, in an inline mixer in the line, in the mixing unit, or any combination thereof to obtain a modified catalyst slurry, the modified catalyst slurry incorporating at least a portion of the first catalyst compound or the second catalyst compound from the catalyst solution onto the supported catalyst; feeding the modified catalyst slurry to a polymerization reactor; and polymerizing an a-olefin in the polymerization reactor under polymerization reaction conditions to obtain a polyolefin. The polymerization reactor may be a fluidized bed gas-phase polymerization reactor in particular examples.

[0072] Implementation of a jumpover line, a mechanically agitated mixing pot, an inline mixer or mixing block, or any combination thereof may increase contact times and substantially reduce the amount of polymer sheeting in the polymerization reactor. For instance, the rate of polymer sheeting in the polymerization reactor may be < 0.3%. In various embodiments, the polymer sheeting rate may 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 sheeting rate refers to the percentage mass of sheeted polymer produced relative to the total amount of polymer produced over a given length of time. The reduction in the rate of polymer sheeting may decrease the frequency of sheeting removal downstream from the reactor. Accumulated polymer sheeting may not need to be removed from a collection bin in communication with the polymerization reactor 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, for example.

Catalyst Slurry, Catalyst Solution, and Modified Catalyst Slurry

[0073] The catalyst slurry and the modified catalyst slurry can include at least a carrier liquid and at least one catalyst compound upon a supported catalyst. Optionally, the catalyst slurry may further include one or more waxes, mineral oil, induced condensing agents, or any combination thereof. In some embodiments, the carrier liquid may be or can include, but is not limited to, one or more mineral oils and/or one or more waxes, optionally in further combination with an induced condensing agent.

[0074] It is also noted that some components present within the polymerization reactor may be fed to the polymerization reactor via the modified catalyst slurry (e.g, the optional induced condensing agent, a carrier fluid, such as nitrogen, or the like) or may additionally or alternately be fed to the polymerization reactor via other means. For example, induced condensing agents in gas-phase polymerization processes, and in particular fluidized bed gas phase polymerization processes, may be provided to the process in a cycle gas flowing up through the fluidized bed in the polymerization reactor, or they may also be provided in other streams that are not the modified catalyst slurry or the cycle gas. Cycle gas may refer to a gas stream comprising an olefinic feed that is circulated through the reactor and replenished with additional olefins when needed.

[0075] In some embodiments, the catalyst slurry or the 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 a total weight of the catalyst slurry or modified catalyst slurry. The solids include the catalyst compound(s), a support material, an activator, and, if present, any other solid component(s). The wax, if present in the carrier liquid, is considered a liquid component and not 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 the carrier liquid that includes a mineral oil and a wax, 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.

[0076] The modified catalyst slurry can include a first catalyst compound and a second catalyst compound, wherein the first catalyst compound is capable of producing a high molecular weight polymer and a second catalyst compound is capable of producing a low molecular weight polymer. In other words, the first catalyst compound can be one that makes primarily high molecular-weight polymer chains, and the second catalyst compound makes primarily low molecular-weight polymer chains, which may be dependent upon the catalyst structure and conducting the polymerization reaction under specified polymerization conditions. Thus, in some examples, the polymer product produced under the polymerization conditions by the modified catalyst slurry may comprise both the high- 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 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 that differ from one another, as described further below. [0077] The terms “slurry catalyst” or “catalyst slurry” each refer to a contact product comprising a dispersed supported catalyst that includes at least one catalyst compound upon a support material, a carrier liquid, an activator, and an optional co-activator. In particular embodiments, the slurry catalyst may include two catalyst compounds, such as two metallocene catalyst compounds that differ from one another, particularly after formation of a modified catalyst slurry. For instance, the modified slurry catalyst may include a supported catalyst comprising a first metallocene and a second metallocene that are each different from the other in at least one structural aspect. Additional disclosure on suitable catalyst compounds is provided further below.

[0078] One or more induced condensing agents (ICAs) can be introduced into the polymerization reactor; such ICAs can increase the production rate of polymer product. The ICA may be present in the catalyst slurry, the catalyst solution, or the modified catalyst slurry resulting from contacting the catalyst slurry with the catalyst solution. Alternately, at least a portion of the ICA may be combined with the modified catalyst slurry in the line leading from the mixing unit, or the ICA can be introduced to the polymerization reactor independently of the catalyst slurry. The ICA can be condensable under the polymerization conditions within the polymerization reactor. The introduction of an ICA into the polymerization reactor is often referred to as operating the reactor in "condensed mode." The ICA can be non-reactive in the polymerization process, but the presence of the ICA can increase the production rate of the polymer product. In some embodiments, the ICA agent can be or can include, but is not limited to, one or more alkanes. Illustrative alkanes can be or can 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 on ICAs can 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 Number WO 2005/113615(A2). As noted, such ICA(s) can be added to the modified catalyst slurry in-line; this may be the main source of ICA provided to the reactor, or may be in addition to any other ICA separately introduced to the reactor, e.g., through recycle gas introduced to the polymerization reactor. The induced condensing agent can be introduced to the modified catalyst slurry at a rate of or, when multiple lines are used, at an average rate of 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.

[0079] When the catalyst slurry or modified catalyst slurry also includes an induced condensing agent, the induced condensing agent may constitute 30 to 90 wt% of the catalyst slurry or modified catalyst slurry by weight, such as 30, 35, 40, 45, or 50 wt% to 60, 70, 80, or 90 wt% of the catalyst slurry or modified catalyst slurry by weight. In some embodiments, when the catalyst slurry or modified catalyst slurry also includes a mineral oil and a wax in addition to the induced condensing agent, the mineral oil may constitute from a low of 8, 15, 20, or 25 wt% to a high of 40, 50, 60, or 68 wt% of the catalyst slurry or modified catalyst slurry, the wax may constitute from a low of 2, 5, or 7 wt% to a high of 10, 12, or 15 wt% of the catalyst slurry or modified catalyst slurry, and the induced condensing agent may constitute from a low of 30, 40, 45, or 50 wt% to a high 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.

[0080] The wax, if present, can increase the viscosity of a catalyst-containing mixture, such as the catalyst slurry or the modified catalyst slurry. As used herein, the term “wax” includes a petrolatum also known as petroleum jelly or petroleum wax. Petroleum waxes include paraffin waxes and microcrystalline waxes, which include slack wax and scale wax. Commercially available waxes include SONO JELL® paraffin waxes, such as SONO JELL® 4 and SONO JELL® 9, available from Sonnebom, LLC. In at least one embodiment, the wax, if present, can have a density (at 100°C) of 0.7 g/cm³, 0.73 g/cm³, or 0.75 g/cm³ to 0.87 g/cm³, 0.9 g/cm³, or 0.95 g/cm³. The wax, if present, can have a kinematic viscosity at 100°C of 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 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.

[0081] It should be understood that the term “wax” also refers to or otherwise includes any wax not considered a petroleum wax, which include animal waxes, vegetable waxes, mineral fossil or earth waxes, ethylenic 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, candelilla, bayberry, and sugarcane. Fossil or earth waxes can include ozocerite, ceresin, and montan. Ethylenic polymers and polyol etheresters include polyethylene glycols and methoxypolyethylene glycols. The hydrocarbon type waxes include waxes produced via Fischer-Tropsch synthesis.

[0082] In some embodiments, the catalyst slurry, the catalyst solution, or the modified catalyst slurry can be free of any wax having a melting point of > 25°C. In other embodiments, the catalyst slurry, the catalyst solution, or the 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 of > 25°C, based on a total mass of the catalyst slurry, the catalyst solution, or the modified catalyst slurry.

[0083] In various embodiments, an aluminum alkyl, an ethoxylated aluminum alkyl, an alumoxane, an anti-static agent (such anti-static agents are referenced in Paragraphs [0078] - [0082] of WO2022/174202) or a borate activator, such as a Ci to C15 alkyl aluminum (for example tri-isobutyl aluminum, imethyl aluminum or the like), a Ci to C15 ethoxylated alkyl aluminum or methyl aluminoxane, ethyl aluminoxane, isobutylaluminoxane, modified aluminoxane or the like can be added in-line to the modified catalyst slurry. For example, the alkyls, antistatic agents, borate activators and/or alumoxanes can be added from a vessel directly to the modified catalyst slurry in-line. The additional alkyls, antistatic agents, borate activators and/or alumoxanes can be present in an amount of 1 ppm, 10 ppm, 50 ppm, 75 ppm, or 100 ppm to 200 ppm, 300 ppm, 400 ppm, or 500 ppm. In some embodiments, an optional carrier fluid such as molecular nitrogen, argon, ethane, propane, and the like, can be added in-line to the modified catalyst slurry. The carrier fluid, e.g., molecular nitrogen, can be introduced through a line at a rate of (or, when multiple lines are used, at an average rate of) 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. In other embodiments, the carrier fluid can be introduced through the line at a rate of or, when multiple lines are used, at an average rate of about 5 kg/hr, 7 kg/hr, 9 kg/hr, or 10 kg/hr to 11 kg/hr, 13 kg/hr, or 15 kg/hr per line.

[0084] In some embodiments (not directly shown in FIGS. 1, 2, or 3), a carrier fluid, such as molecular nitrogen, monomer, or other materials can be introduced to the modified catalyst slurry after mixing the catalyst solution and the catalyst slurry. The introduction can take place along the line leading to the gas-phase polymerization reactor or in an injection nozzle thereof, which can include a support tube that can at least partially surround an injection nozzle. The modified catalyst slurry can be passed through the injection nozzle into the polymerization reactor. In various embodiments, the injection nozzle can aerosolize the resulting catalyst-containing mixture. Any number of suitable tubing sizes and configurations can be used to aerosolize and/or inject the slurry/solution mixture.

[0085] In some configurations, a carrier fluid may be split off or otherwise sourced, directly or indirectly, from cycle gas (e.g., all or a portion of the cycle gas). In this case, where cycle gas is used as a carrier fluid, the skilled artisan might appreciate that such cycle gas could also include induced condensing agent. The cycle gas may comprise at least a portion of a polymerization feed being recycled through the gas-phase polymerization reactor. [0086] Tn some embodiments, the modified catalyst slurry can include 1 wt%, 5 wt%, 10 wt%, or 15 wt% to 25 wt%, 30 wt%, 35 wt%, or 40 wt% of the one or more catalyst compounds, based on a total weight of the modified catalyst slurry. The foregoing weight percentages do not include the support material upon which the catalyst is disposed. In such embodiments, a total amount of the modified catalyst slurry introduced into the polymerization reactor can be at a flow rate of > 0.1 kg/hr per cubic meter of polymerization reactor volume > 0.11 kg/hr per cubic meter of polymerization reactor volume, > 0.12 kg/hr per cubic meter of polymerization reactor volume, 0.13 kg/hr per cubic meter of polymerization reactor volume or > 0.14 kg/hr per cubic meter of polymerization reactor volume to 0.2 kg/hr per cubic meter of polymerization reactor volume, 0.3 kg/hr per cubic meter of polymerization reactor volume, 0.4 kg/hr per cubic meter of polymerization reactor volume, or 0.5 kg/hr per cubic meter of polymerization reactor volume.

[0087] In some embodiments, to promote formation of particles in the polymerization reactor, a nucleating agent, such as silica, alumina, fumed silica or other suitable particulate matter can be added directly into the reactor. Alternatively, a nucleating agent may be present in the catalyst solution, the catalyst slurry, and/or the modified catalyst slurry, optionally with further introduction of nucleating agent to the reactor also taking place. Advantageously, a nucleating agent may be optional in the disclosure herein, but may be included, if desired. Preferably, a nucleating agent is excluded from the catalyst solution and the catalyst slurry and/or when mixing the catalyst solution and the catalyst slurry (that is, a nucleating agent, if any, is introduced into the modified catalyst slurry in line(s) downstream from any mixing unit (mechanically agitated mixing pot, static mixer, mixing block, etc.). For embodiments that do not include a nucleating agent, it has been discovered that a high polymer bulk density (e.g., 0.4 g/cm³ or greater) can be obtained, which is greater than the bulk density of polymers formed by conventional processes. Furthermore, when a metallocene catalyst or other similar catalyst is used in the gas phase reactor, oxygen or fluorobenzene can be added to the polymerization reactor directly or to the gas stream (including carrier fluid) in-line to control the polymerization rate. Thus, when a metallocene catalyst (which is sensitive to oxygen or fluorobenzene) is used in combination with another catalyst (that is not sensitive to oxygen) in a gas phase polymerization reactor, oxygen can be used to modify the metallocene polymerization rate relative to the polymerization rate of the other catalyst. WO 1996/009328 discloses the addition of water or carbon dioxide to gas phase polymerization reactors, for example, for similar purposes.

Catalyst Compounds [0088] The methods of the present disclosure can be employed generally with any catalyst system including at least one catalyst compound localized on a support, preferably two or more catalyst compounds localized on a support once a modified supported catalyst has been formed. In particular examples, the supported catalyst in a catalyst slurry may contain a first catalyst compound on a support, and a second catalyst compound different from the first catalyst compound may be delivered from a catalyst solution to the catalyst slurry to form a modified catalyst slurry according to the disclosure herein.

[0089] As a particular example, 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 one another. Metallocenes can include structures having one or more Cp ligands (cyclopentadienyl and ligands isolobal to cyclopentadienyl) bound to at least one Group 3 to Group 12 metal atom, and one or more leaving group(s) bound to the at least one metal atom.

[0090] Suitable metallocene catalysts may include those described in US Patent Application Publications 2019/0119413 and 2019/0119417, which are incorporated herein by reference. Also suitable are catalyst systems employing a mix of two metallocene catalysts such as those described in US Patent Application Publication 2020/0071437, such as a mix of (1) a bis-cyclopentadienyl hafnocene and (2) a zirconocene, such as an indenyl-cyclopentadienyl zirconocene. Additional details are provided hereinafter.

[0091] More particularly, the bis-cyclopentadienyl hafnocene may be in accordance with one or more of the metallocenes according to formulas (Al) and/or (A2) as described in US2020/0071437; for instance, those per formula (Al) as described in Paragraphs [0069]-[0086] of US2020/0071437; or those per formula (A2) as described in Paragraphs [0086]-[0101 ] of

US2020/0071437, which descriptions are incorporated herein by reference.

[0092] Particular examples of hafnocenes according to formula (Al) include bis(n- propylcyclopentadienyl)hafnium dichloride, bis(n-propylcyclopentadienyl)hafnium dimethyl, (n- propy 1 cy cl opentadi eny 1 , pentamethylcyclopentadienyl)hafnium di chloride, (n- propylcyclopentadienyl, pentamethylcyclopentadi enyl)hafnium dimethyl, (n- propylcyclopentadienyl, tetramethylcyclopentadienyl)hafnium dichloride, (n- propyl cy cl opentadi eny 1 , 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.

[0093] Hafnocene compounds according to (A2) that are particularly useful include one or more of the compounds listed in Paragraph [0101] of US2020/0071437, also incorporated by reference herein, such as (for a relatively brief example): rac/meso Me2Si(Me3SiCH2Cp)2HfMe2; racMe2Si(Me3SiCH2Cp)2HfMe2; rac/meso Ph2Si(Me3SiCH2Cp)2HfMe2; rac/meso (CH2)3Si(Me3SiCH2Cp)2HfMe2; rac/meso (CH2)4Si(Me SiCH2Cp)2HfMe2; rac/meso

(C6Fj)2Si(Me3SiCH2Cp)2HfMe2; rac/meso (CH2)3Si(Me3SiCH2Cp)2ZrMe2; rac/meso

Me2Ge(Me3SiCH2Cp)2HfMe2; rac/meso Me2Si(Me2PhSiCH2Cp)2HfMe2; rac/meso Ph2Si(Me2PhSiCH₂Cp)2HfMe2; Me2Si(Me₄Cp)(Me2PhSiCH₂Cp)HfMe2; etc.

[0094] Accordingly, in a particular example, the first catalyst compound upon the support material may comprise a first metallocene that is a hafnocene, such as a rac/meso dimethylsilylbis[((trimethylsilyl)methyl)cyclopentadienyl] hafnium dimethyl. The second catalyst compound in the catalyst solution may comprise a second metallocene that is different than the first metallocene. The second metallocene may comprise a zirconocene, as described hereinafter.

[0095] Suitable catalyst compounds may include a zirconocene, such as a zirconocene according to formula (B) as described in Paragraphs [0103]-[0113] of US2020/0071437, which description is also incorporated herein by reference. Particular examples of suitable zirconocenes may be any one or more of those listed in Paragraph [0112] of US2020/0071437, e.g. bis(indenyl)zirconium di chloride, bis(indenyl)zirconium dimethyl, bis(tetrahydro-l-indenyl)zirconium dichloride, bis(tetrahydro-l-indenyl)zirconium dimethyl, rac/meso-bis(l-ethylindenyl)zirconium dichloride, rac/meso-bis(l-ethylindenyl)zirconium dimethyl, rac/meso-bis(l-methylindenyl)zirconium dichloride, rac/meso-bis(l-methylindenyl)zirconium dimethyl, rac/meso-bis(l- propylindenyl)zirconium dichloride, rac/meso-bis(l-propylindenyl)zirconium dimethyl, rac/meso-bis(l -butylindenyl)zirconium dichloride, rac/meso-bis(l -butylindenyl)zirconium dimethyl, meso-bis(lethylindenyl) zirconium dichloride, meso-bis(l-ethylindenyl) zirconium dimethyl, (l-methylindenyl)(pentamethyl cyclopentadienyl) zirconium di chloride, (1- methylindenyl)(pentamethyl cyclopentadienyl) zirconium dimethyl, or combinations thereof.

[0096] Accordingly, in particular examples, the second catalyst compound may comprise a second metallocene that is a zirconocene, such as a rac/meso bis(l-methylindenyl) zirconium dimethyl. [0097] As noted above, the supported catalyst and/or the modified supported catalyst can include one or more activators and/or supports in addition to one or more catalyst compounds. The term “activator” refers to any compound or combination of compounds, supported or unsupported, which can activate a single-site catalyst compound or component, such as by creating a cationic species of the catalyst component. For example, this can include the abstraction of at least one leaving group from the metal center of the single-site catalyst compound/component. The activator may also be referred to as a “co-catalyst.” For example, the supported catalyst or modified supported catalyst within the slurry catalyst or modified slurry catalyst mixture can include two or more activators (such as alumoxane and a modified alumoxane) and at least one catalyst compound, such as a first catalyst compound and a second catalyst compound. In particular embodiments, the slurry catalyst or modified slurry catalyst can include at least one support, at least one activator, and at least two catalyst compounds. For example, the slurry can include at least one support, at least one activator, and two different catalyst compounds that can be added separately or in combination to produce the slurry catalyst or modified slurry catalyst. In some embodiments, a mixture of a support, e.g., silica, and an activator, e.g., alumoxane, 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.

[0098] The molar ratio of metal or non-coordinating anion in the activator to 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 support 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 support materials such as disclosed above. In one embodiment, the supported catalyst can include silica and an activator, such as methyl alumoxane ("MAO"), modified methyl alumoxane (“MMAO”), or the like. Preferred activators typically include alumoxane compounds, modified alumoxane compounds, and ionizing anion precursor compounds that abstract a reactive, o-bound, metal ligand making the metal compound cationic and providing a charge-balancing noncoordinating or weakly coordinating anion. For instance, suitable activators may include any of the alumoxane activators and/or ionizing/non-coordinating anion activators described in Paragraphs [0118] - [0128] of US2020/0071437, also incorporated herein by reference.

[0099] Suitable supports include, but are not limited to, active and inactive materials, synthetic or naturally occurring zeolites, as well as inorganic materials such as clays and/or oxides such as silica, alumina, zirconia, titania, silica-alumina, cerium oxide, magnesium oxide, or combinations thereof. In particular, the support may be silica-alumina, alumina and/or a zeolite, particularly alumina. Silica-alumina may be either naturally occurring or in the form of gelatinous precipitates or gels including mixtures of silica and metal oxides. Suitable supports may include any of the support materials described in Paragraphs [0129]-[0131] of US2020/0071437, which description is also incorporated by reference herein; wherein AI2O3, ZrC>2, SiCh and combinations thereof are particularly noted.

Catalyst Solution

[0100] The catalyst solution can include a solvent or diluent and only catalyst compound(s), such as a metallocene, or can also include an activator. The at least one catalyst compound in the catalyst solution may be unsupported in a particular example. Preferably, the catalyst solution can be prepared by dissolving the at least one catalyst compound and an optional activator in the solvent or diluent. In some embodiments, the diluent or solvent can be an alkane, such as a C5 to C30 alkane, or a C5 to C10 alkane. Cyclic alkanes such as cyclohexane and aromatic compounds such as toluene can also be used. Mineral oil can be also used as the diluent alternatively or in addition to other alkanes such as one or more C5 to C30 alkanes. The mineral oil in the catalyst solution, if used, can have the same properties as the mineral oil that can be used to make the catalyst slurry.

[0101] The diluent or solvent employed can be liquid under the conditions of polymerization and relatively inert. In one embodiment, the diluent utilized in the catalyst solution can be different from the diluent used in the catalyst slurry. In another embodiment, the solvent utilized in the catalyst solution can be the same as the diluent, z.e., the mineral oil(s) and any additional diluents used in the catalyst slurry. Hydrocarbon solvents may also function as induced condensing agents during the polymerization reaction in some cases.

[0102] If the catalyst solution includes both the 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 at up to about 90 wt%, at up to about 50 wt%, at up to about 20 wt%, such as at up to about 10 wt%, at up to about 5 wt%, at less than 1 wt%, or between 100 ppm and 1 wt%, based on the weight of the diluent, the activator, and the catalyst. The one or more activators in the catalyst solution, if used, can be the same or different as the one or more activators present in the catalyst slurry upon the supported catalyst. Polymerization Conditions and Polyolefin Product

[0103] Once a modified catalyst slurry has been produced according to the disclosure above, the modified catalyst slurry may be fed to a polymerization reaction in combination with an olefinic feed under suitable polymerization conditions to obtain a polyolefin. In non-limiting examples, the olefinic feed may comprise at least one a-olefin to afford a polyolefin homopolymer or copolymer.

[0104] Preferably, the polymerization reaction may be conducted under gas-phase polymerization conditions. Monomer(s) introduced to a polymerization reaction under gas-phase polymerization conditions may be introduced in a gas phase, a liquid phase, or a combination thereof. Reaction of the monomer(s) may take place in a gas phase in a reaction zone of the reactor. Unreacted monomer(s) may be recirculated through the reactor, if desired.

[0105] Monomers useful herein include substituted or unsubstituted C2 to C40 alpha olefins, such as C2 to C20 alpha olefins, such as C2 to C12 alpha olefins, such as ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene and isomers thereof. In at least one embodiment, the monomer can include ethylene and one or more optional comonomers selected from C3 to C40 olefins, such as C4 to C20 olefins, such as Ce to C12 olefins. Suitable C4 to C40 olefin monomers can be linear, branched, or cyclic. The C4 to C40 cyclic olefins may be strained or unstrained, monocyclic or polycyclic, and may optionally include heteroatoms and/or one or more functional groups. In at least one embodiment, the monomer can include ethylene and an optional comonomer that can include one or more C3 to C40 olefins, such as C4 to C20 olefins, such as Ce to C12 olefins.

[0106] In some embodiments, the C2 to C40 alpha olefin monomer and optional comonomer(s) include ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, norbornene, norbomadiene, dicyclopentadiene, cyclopentene, cycloheptene, cyclooctene, cyclooctadiene, cyclododecene, 7-oxanorbomene, 7-oxanorbornadiene, substituted derivatives thereof, and isomers thereof, such as hexene, heptene, octene, nonene, decene, dodecene, cyclooctene, 1,5-cyclooctadiene, l-hydroxy-4-cyclooctene, l-acetoxy-4-cyclooctene, 5-methylcyclopentene, cyclopentene, dicyclopentadiene, norbornene, norbomadiene, and their respective homologs and derivatives, such as norbornene, norbomadiene, and dicyclopentadiene. [0107] In at least one embodiment, one or more dienes can be present in the polymer product at up to 10 wt%, such as at 0.00001 wt% to 1.0 wt%, such as 0.002 wt% to 0.5 wt%, such as 0.003 wt% to 0.2 wt%, based upon 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 is added to the polymerization, or 100 ppm or more, or 150 ppm or more.

[0108] Diene monomers include any hydrocarbon structure, such as C4 to C30, having at least two unsaturated bonds, where at least two of the unsaturated bonds are readily incorporated into a polymer by either a stereospecific or a non-stereospecific catalyst(s). The diene monomers can be selected from alpha, omega-diene monomers (/.<?., di-vinyl monomers). The diolefin monomers are linear di-vinyl monomers, such as those containing from 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, icosadiene, heneicosadiene, docosadiene, tricosadiene, tetracosadiene, pentacosadiene, hexacosadiene, heptacosadiene, octacosadiene, nonacosadiene, triacontadiene, 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, vinylnorbornene, norbornadiene, ethylidene norbornene, divinylbenzene, dicyclopentadiene or higher ring containing diolefins with or without substituents at various ring positions.

[0109] The temperature within the polymerization 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. In general, the reactor can be operated at a suitable temperature taking into account the sintering temperature of the polymer product being produced within the polymerization reactor. Thus, the upper temperature limit in one embodiment can be the melting temperature of the polymer product produced within in the reactor. However, higher temperatures can result in narrower molecular weight distributions that may be further improved by the addition of a catalyst or other co-catalysts.

[0110] In some embodiments, hydrogen gas can be used in the polymerization process to help control or otherwise adjust the final properties of the polyolefin, such as described in the “Polypropylene Handbook,” at pages 76-78 (Hanser Publishers, 1996). Using certain catalyst systems, increasing concentrations (partial pressures) of hydrogen can increase a flow index such as the melt index of the polyethylene polymer. The melt index can thus be influenced by the hydrogen concentration. The amount of hydrogen in the polymerization can be expressed as a mole ratio relative to the total polymerizable monomer, for example, ethylene, or a blend of ethylene and hexene or propylene.

[01111 The amount of hydrogen used in the polymerization process can be an amount necessary to achieve the desired melt index of the final polyolefin polymer. For example, the mole ratio of hydrogen to total monomer (H2:monomer) can be 0.0001 or greater, 0.0005 or greater, or 0.001 or greater. Further, the mole ratio of hydrogen to total monomer (H2:monomer) can be 10 or less, 5 or less, 3 or less, or 0.10 or less. A range for the mole ratio of hydrogen to monomer can include any combination of any upper mole ratio limit with any lower mole ratio limit described herein. The amount of hydrogen in the reactor at any time can range to up to 5,000 ppm, up to 4,000 ppm in another embodiment, up to 3,000 ppm, or from 50 ppm to 5,000 ppm, or from 50 ppm to 2,000 ppm in another embodiment. 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. Further, the ratio of hydrogen to total monomer (E^monomer) can be 0.00001 : 1 to 2: 1, 0.005: 1 to 1.5: 1, or 0.0001 : 1 to 1 : 1. The one or more reactor pressures in a gas-phase process (either 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.

[0112] The polymerization reactor can be capable of producing greater than 10 kg per 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 of polymer, 70,000 kg/hr, 100,000 kg/hr, or 150,000 kg/hr.

[0113] In some embodiments, the polymer product can have a melt index ratio (I21.6/I2.16) ranging from 10 to less than 300, or, in many embodiments, from 20 to 66. The melt index (I2.16) can be measured according to ASTM D-1238-13, condition E (190°C, 2.16 kg), and also referred to as “I2 (190°C/2.16 kg)”. The melt index (I21.6) can be measured according to ASTM D-1238-13, condition F (190°C, 21.6 kg), and also referred to as “I21.6 (190°C/21.6 kg)”.

[0114] In some embodiments, the polymer product can have a density ranging from 0.89 g/cm³, 0.90 g/cm³, or 0.91 g/cm³ to 0.95 g/cm³, 0.96 g/cm³, or 0.97 g/cm³. Density can be determined in accordance with ASTM D-792-20. In some embodiments, the polymer product can have a bulk density of from 0.25 g/cm³ to 0.5 g/cm³. For example, the bulk density of the polymer can be from 0.30 g/cm³, 0.32 g/cm³, or 0.33 g/cm³ to 0.40 g/cm³, 0.44 g/cm³, or 0.48 g/cm³. The bulk density can be measured in accordance with ASTM D-1895-17 method B. [0115] 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 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 more to form ethylene polymers, propylene polymers, or ethylene-propylene copolymers.

[0116] In at least one embodiment, the catalysts and processes disclosed herein can be capable of producing ethylene polymers having a weight average molecular weight (Mw) from 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 the GPC data, the differential refractive index (DRI) method is preferred for Mn, while light scattering (LS) is preferred for Mw and Mz. The GPC can be performed on a Waters 150C GPC instrument with DRI detectors. GPC Columns can be calibrated by running a series of narrow polystyrene standards. Molecular weights of polymers other than polystyrenes are conventionally calculated by using Mark Houwink coefficients for the polymer in question.

[0117] The ethylene polymers may have a melt index (MI) of 0.2 g/10 min or greater, such as 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, upper limit of MI of the ethylene polymers may be any one 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 may have a melt index up to about 25 g/10 min, or up to about 50 g/10 min, or up to about 100 g/10 min.

[0118] “Catalyst productivity” is a measure of how many grams of polymer (P) are produced using a polymerization catalyst comprising W g of catalyst (cat), over a period of time of T hours; and can be expressed by the following formula: P/(T x W) and expressed in units of gPgcat^hr'¹. In at least one embodiment, the productivity of the catalysts disclosed herein can be at least 50 gPgcaf'hr'¹ or more, such as 500 gPgcaf’hr'¹ or more, such as 800 gPgcat^hr’¹ or more, such as 5,000 gPgcat^hr ¹ or more, such as 6,000 gPgcat^hr’¹ or more.

[0119] While gas-phase polymerization processes are described above, it should be understood that other polymerization processes, which are well-known in the art, can also be used to produce the polymer product. In some embodiments, any suspension, homogeneous, bulk, solution, slurry, and/or other gas-phase polymerization process known in the art can be used. Such processes can be run in a batch, semi-batch, or continuous mode. A homogeneous polymerization process is defined to be a process where at least about 90 wt% of the product is soluble in the reaction medium. A bulk process is defined to be a process where monomer concentration in all feeds to the reactor is 70 volume % or more. Alternately, no solvent or diluent is present or added in the reaction medium, (except for the small amounts used as the carrier for the catalyst or other additives, or amounts typically found with the monomer; e.g., propane in propylene).

[0120] 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 (although, to achieve a unimodal molecular weight distribution it can be preferable that either a single reactor is used, or that the same catalyst, feed, and reaction conditions are used in multiple reactors, e.g., in parallel, such that the polymer product is considered made in a single reactive step). As used herein, the term “slurry polymerization process” means a polymerization process in which a supported catalyst is used and monomers are polymerized on the supported catalyst particles within a liquid medium (comprising, e.g., inert diluent and unreacted polymerizable monomers), such that a two-phase composition including polymer solids and the liquid circulate within the polymerization reactor. Typically, a slurried tank or slurry loop reactor can be used; in particular embodiments herein, a slurry loop reactor is preferred. In such processes the reaction diluent, dissolved monomer(s), and catalyst can be circulated in a loop reactor in which the pressure of the polymerization reaction is relatively high. The produced solid polymer is also circulated in the reactor. A slurry of polymer and the liquid medium may be collected in one or more settling legs of the slurry loop reactor from which the slurry is periodically discharged to a flash chamber where the mixture can be flashed to a comparatively low pressure; as an alternative to settling legs, in other examples, a single point discharge process can be used to move the slurry to the flash chamber. The flashing results in substantially complete removal of the liquid medium from the polymer, and the vaporized polymerization diluent (e.g., isobutane) can then be recompressed in order to condense the recovered diluent to a liquid form suitable for recycling as liquid diluent to the reactor.

[0121] 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. Also, 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 multistage polymerization process where one reactor is operating in slurry phase that feeds into a reactor operating in a gas phase as described in U.S. Patent No. 5,684,097.

[0122] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the present specification and associated claims 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 may vary depending upon the desired properties sought to be obtained by the incarnations of the present inventions. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claim, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0123] One or more illustrative incarnations incorporating one or more invention elements are presented herein. Not all features of a physical implementation are described or shown in this application for the sake of clarity. It is understood that in the development of a physical embodiment incorporating one or more elements of the present invention, numerous implementation-specific decisions must be made to achieve the developer's goals, such as compliance with system-related, business-related, government-related and other constraints, which vary by implementation and from time to time. While a developer's efforts might be timeconsuming, such efforts would be, nevertheless, a routine undertaking for those of ordinary skill in the art and having benefit of this disclosure.

[0124] While compositions and methods are described herein in terms of “comprising” various components or steps, the compositions and methods can also “consist essentially of’ or “consist of’ the various components and steps.

Additional Embodiments

[0125] The present disclosure is further directed to the following non-limiting embodiments.

[0126] Embodiment 1. A method comprising: 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 line in fluid communication with a mixing unit; providing a catalyst solution comprising a first catalyst compound already contained on the supported catalyst or a second catalyst compound different from the first catalyst compound; introducing the catalyst solution to a pressurizable fluid distribution system in fluid communication with the mixing unit, the pressurizable fluid distribution system comprising at least one first pressure vessel and at least one second pressure vessel in parallel with one another; wherein the at least one first pressure vessel operates in an online mode while the at least one second pressure vessel is in an offline mode, and the at least one first pressure vessel and the at least one second pressure vessel are switchable between the online mode and the offline mode; at least partially filling the at least one first pressure vessel with a first portion of the catalyst solution; pressurizing the at least one first pressure vessel, such that the pressurizable fluid distribution system supplies the first portion of the catalyst solution from the at least one first pressure vessel to the mixing unit; contacting the catalyst solution with the catalyst slurry in the line, in an inline mixer in the line, in the mixing unit, or any combination thereof to obtain a modified catalyst slurry, the modified catalyst slurry incorporating at least a portion of the first catalyst compound or the second catalyst compound from the catalyst solution onto the supported catalyst; feeding the modified catalyst slurry to a polymerization reactor; and polymerizing an a-olefin in the polymerization reactor under polymerization reaction conditions to obtain a polyolefin.

[0127] Embodiment 2. The method of Embodiment 1, wherein the polymerization reactor is a fluidized bed gas-phase polymerization reactor.

[0128] Embodiment s. The method of Embodiment 1 or Embodiment 2, wherein the catalyst solution comprises at least the second catalyst compound.

[0129] Embodiment 4. The method of any one of Embodiments 1-3, wherein the second catalyst compound is also present upon the supported catalyst.

[0130] Embodiment 5. The method of any one of Embodiments 1-3, wherein the second catalyst compound is not present upon the supported catalyst.

[0131] Embodiment 6. The method of any one of Embodiments 1-5, wherein the first catalyst compound comprises a first metallocene and the second catalyst compound comprises a second metallocene different from the first metallocene.

[0132] Embodiment 7. The method of any one of Embodiments 1-6, wherein the pressurizable fluid distribution system supplies the first portion of the catalyst solution to the line at a position upstream from the mixing unit or the inline mixer, directly to the mixing unit, or any combination thereof.

[01331 Embodiment 8. The method of any one of Embodiments 1-7, further comprising: at least partially fdling the at least one second pressure vessel in the offline mode with a second portion of the catalyst solution while the at least one first pressure vessel in the online mode is supplying the first portion of the catalyst solution to the line, the mixing unit, or any combination thereof.

[0134] Embodiment 9. The method of any one of Embodiments 1-7, wherein, before initially supplying the first portion of the catalyst solution from the at least one first pressure vessel to the mixing unit, the at least one second pressure vessel is at least partially filled with a second portion of the catalyst solution.

[0135] Embodiment 10. The method of Embodiment 8 or Embodiment 9, further comprising: pressurizing the at least one second pressure vessel containing the second portion of the catalyst solution while maintaining the at least one second pressure vessel in the offline mode; switching the at least one second pressure vessel to the online mode while switching the at least one first pressure vessel to the offline mode, thereby supplying the second portion of the catalyst solution to the line, the mixing unit, or any combination thereof; and depressurizing the at least one first pressure vessel.

[0136] Embodiment 11. The method of Embodiment 10, further comprising: at least partially refilling the at least one first pressure vessel in the offline mode with a third portion of the catalyst solution while the at least one second pressure vessel in the online mode is supplying the second portion of the catalyst solution to the line, the mixing unit, or any combination thereof.

[0137] Embodiment 12. The method of any one of Embodiments 1-11, further comprising: controlling a flow rate of the catalyst solution from the pressurizable fluid distribution system to the line, the mixing unit, or any combination thereof via a control valve downstream from the at least one first pressure vessel and the at least one second pressure vessel.

[0138] Embodiment 13. The method of any one of Embodiments 1-12, wherein pressurizing takes place with a gas.

[0139] Embodiment 14. The method of Embodiment 13, wherein the gas comprises an inert gas. [0140] Embodiment 15. The method of Embodiment 13 or Embodiment 14, wherein the gas has a pressure of at least about 300 psi.

[0141] Embodiment 16. The method of any one of Embodiments 1-15, wherein the mixing unit comprises a mechanically agitated mixing pot, a static mixer, a mixing block, or any combination thereof.

[0142] Embodiment 17. The method of any one of Embodiments 1-16, wherein the a-olefin comprises ethylene and, optionally, one or more a-olefin co-monomers.

[0143] Embodiment 18. The method of any one of Embodiments 1-17, wherein the catalyst slurry further comprises a mineral oil, a wax, an induced condensing agent, or any combination thereof.

[0144] Embodiment 19. The method of Embodiment 18, wherein the induced condensing agent is present and comprises propane, isobutane, isopentane, isohexane, or any combination thereof.

[0145] Embodiment 20. The method of any one of Embodiments 1-19, wherein the at least one activator comprises an alumoxane.

[0146] Embodiment 21. A method comprising: 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; providing a catalyst solution comprising a first catalyst compound already contained on the supported catalyst or a second catalyst compound different from the first catalyst compound; introducing the catalyst solution to a pressurizable fluid distribution system, the pressurizable fluid distribution system comprising at least one first pressure vessel and at least one second pressure vessel in parallel with one another; wherein the at least one first pressure vessel operates in an online mode while the at least one second pressure vessel is in an offline mode, and the at least one first pressure vessel and the at least one second pressure vessel are switchable between the online mode and the offline mode; at least partially filling the at least one first pressure vessel with a first portion of the catalyst solution; pressurizing the at least one first pressure vessel, such that pressurizable fluid distribution system supplies the first portion of the catalyst solution to a line downstream from the at least one first pressure vessel; introducing the catalyst slurry to the line; contacting the catalyst solution with the catalyst slurry in the line to obtain a modified catalyst slurry, the modified catalyst slurry incorporating at least a portion of the first catalyst compound or the second catalyst compound from the catalyst solution onto the supported catalyst; feeding the modified catalyst slurry to a polymerization reactor; and polymerizing an a-olefin in the polymerization reactor under polymerization reaction conditions to obtain a polyolefin.

[0147] Therefore, the present invention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular examples and configurations disclosed above are illustrative only, as the present invention may 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 may be altered, combined, or modified and all such variations are considered within the scope and spirit of the present invention. The invention illustratively disclosed herein suitably may be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element 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 may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every 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 set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the element that it introduces.

Claims

CLAIMS The invention claimed is:

1. A method comprising: providing a catalyst solution comprising a first catalyst compound already contained on the supported catalyst or a second catalyst compound different from the first catalyst compound; introducing the catalyst solution to a pressurizable fluid distribution system in fluid communication with a mixing unit, the pressurizable fluid distribution system comprising at least one first pressure vessel and at least one second pressure vessel in parallel with one another; wherein the at least one first pressure vessel operates in an online mode while the at least one second pressure vessel is in an offline mode, and the at least one first pressure vessel and the at least one second pressure vessel are switchable between the online mode and the offline mode; at least partially filling the at least one first pressure vessel with a first portion of the catalyst solution; pressurizing the at least one first pressure vessel, such that the pressurizable fluid distribution system supplies the first portion of the catalyst solution from the at least one first pressure vessel to the mixing unit; 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 line in fluid communication with the mixing unit; contacting the catalyst solution with the catalyst slurry in the line, in an inline mixer in the line, in the mixing unit, or any combination thereof to obtain a modified catalyst slurry, the modified catalyst slurry incorporating at least a portion of the first catalyst compound or the second catalyst compound from the catalyst solution onto the supported catalyst; feeding the modified catalyst slurry to a polymerization reactor; and polymerizing one or more u-olefin monomers in the polymerization reactor under polymerization reaction conditions to obtain a polyolefin.

2. The method of claim 1, wherein the polymerization reactor is a fluidized bed gas-phase polymerization reactor.

3. The method of claim 1 or claim 2, wherein the catalyst solution comprises at least the second catalyst compound.

4. The method of claim 3, wherein the second catalyst compound is also present upon the supported catalyst.

5. The method of claim 3, wherein the second catalyst compound is not present upon the supported catalyst.

6. The method of claim 1 or any one of claims 2-5, wherein the first catalyst compound comprises a first metallocene and the second catalyst compound comprises a second metallocene different from the first metallocene.

7. The method of claim 1 or any one of claims 2-6, wherein the pressurizable fluid distribution system supplies the first portion of the catalyst solution to the line at a position upstream from the mixing unit or the inline mixer, directly to the mixing unit, or any combination thereof.

8. The method of claim 1 or any one of claims 2-7, further comprising: at least partially filling the at least one second pressure vessel in the offline mode with a second portion of the catalyst solution while the at least one first pressure vessel in the online mode is supplying the first portion of the catalyst solution to the line, the mixing unit, or any combination thereof.

9. The method of claim 1 or any one of claims 2-8, wherein, before initially supplying the first portion of the catalyst solution from the at least one first pressure vessel to the line, the mixing unit, or any combination thereof, the at least one second pressure vessel is at least partially filled with a second portion of the catalyst solution.

10. The method of claim 8, further comprising: pressurizing the at least one second pressure vessel containing the second portion of the catalyst solution while maintaining the at least one second pressure vessel in the offline mode; switching the at least one second pressure vessel to the online mode while switching the at least one first pressure vessel to the offline mode, thereby supplying the second portion of the catalyst solution to the line, the mixing unit, or any combination thereof; and depressurizing the at least one first pressure vessel.

11. The method of claim 10, further comprising: at least partially refilling the at least one first pressure vessel in the offline mode with a third portion of the catalyst solution while the at least one second pressure vessel in the online mode is supplying the second portion of the catalyst solution to the line, the mixing unit, or any combination thereof.

12. The method of claim 1, further comprising: controlling a flow rate of the catalyst solution from the pressurizable fluid distribution system to the line, the mixing unit, or any combination thereof via a control valve downstream from the at least one first pressure vessel and the at least one second pressure vessel.

13. The method of claim 1, wherein pressurizing takes place with a gas, optionally wherein the gas is an inert gas.

14. The method of claim 13, wherein the gas has a pressure of at least about 300 psi.

15. The method of claim 1 or any one of claims 2-14, wherein the mixing unit comprises a mechanically agitated mixing pot, a static mixer, a mixing block, or any combination thereof.

16. The method of claim 1 or any one of claims 2-15, wherein the one or more a-olefm monomers comprise ethylene and, optionally, one or more a-olefm co-monomers.

17. The method of claim 1 or any one of claims 2-16, wherein the catalyst slurry further comprises a mineral oil, a wax, an induced condensing agent, or any combination thereof.

18. The method of claim 17, wherein the induced condensing agent is present and comprises propane, isobutane, n-butane, isopentane, n-pentane, isohexane, n-hexane, or any combination thereof.

19. The method of claim 1 or any one of claims 2-18, wherein the at least one activator comprises an alumoxane.

20. A method comprising: providing a catalyst solution comprising a first catalyst compound already contained on the supported catalyst or a second catalyst compound different from the first catalyst compound; introducing the catalyst solution to a pressurizable fluid distribution system, the pressurizable fluid distribution system comprising at least one first pressure vessel and at least one second pressure vessel in parallel with one another; wherein the at least one first pressure vessel operates in an online mode while the at least one second pressure vessel is in an offline mode, and the at least one first pressure vessel and the at least one second pressure vessel are switchable between the online mode and the offline mode; at least partially filling the at least one first pressure vessel with a first portion of the catalyst solution; pressurizing the at least one first pressure vessel, such that pressurizable fluid distribution system supplies the first portion of the catalyst solution to a line downstream from the at least one first pressure vessel; 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 the line; contacting the catalyst solution with the catalyst slurry in the line to obtain a modified catalyst slurry, the modified catalyst slurry incorporating at least a portion of the first catalyst compound or the second catalyst compound from the catalyst solution onto the supported catalyst; feeding the modified catalyst slurry to a polymerization reactor; and polymerizing an a-olefin in the polymerization reactor under polymerization reaction conditions to obtain a polyolefin.