Method for determining concentration of transition metal compound in multi-component liquid system

Abstract

The invention relates to a method for determining the concentration of a transition metal compound in a multi-component liquid system. A method for determining the concentration of a transition metal compound in a solution containing more than one transition metal compound is described. Polymerization reactor systems that provide real-time monitoring and control of the concentration of transition metal components of multi-component catalyst systems are disclosed, as well as methods for operating such polymerization reactor systems and for improving methods of making the multi-component catalyst systems.

Description

[0001] This application is a divisional application. The original application was filed on July 10, 2018, with application number 201880041493.X, and the invention title was "Method for determining the concentration of transition metal compounds in a multi-component liquid system," the entire contents of which are incorporated herein by reference.

[0002] Cross-references to related applications

[0003] This application was filed on July 10, 2018 as a PCT international patent application and claims priority to U.S. Patent Application No. 16 / 006,976, filed June 13, 2018, and U.S. Patent Application No. 15 / 655,929, filed July 21, 2017, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0004] This disclosure relates to a method for determining the concentration of a transition metal compound in a solution containing more than one transition metal compound, and more specifically, to using ultraviolet-visible (UV-Vis) spectroscopy to determine the concentration of a single transition metal compound. Background Technology

[0005] Polyolefins, such as high-density polyethylene (HDPE) homopolymers and linear low-density polyethylene (LLDPE) copolymers, can be produced using various combinations of catalyst systems and polymerization processes. In many olefin polymerization processes, catalyst systems containing more than one transition metal compound are used. Precise determination of the relative and absolute concentrations of each transition metal compound allows for better control of the polymerization process and the resulting polymer product. It will be advantageous to be able to monitor or measure the corresponding amounts of each transition metal compound present in the catalyst feed stream, catalyst system, and polymerization reactor system in real time to improve control of the polymerization process. Additionally, it will be advantageous to determine the concentration of a first transition metal compound in solution where the UV-Vi spectrum overlaps with that of a second transition metal compound, and / or where the second transition metal compound is in significant excess relative to the first transition metal compound. Therefore, the present invention generally relates to these objectives. Summary of the Invention

[0006] This summary is provided to introduce, in a simplified form, the concept choices further described below in the detailed description. This summary is not intended to identify the desired or essential features of the claimed subject matter. Nor is it intended to limit the scope of the claimed subject matter.

[0007] This document discloses a method for determining the concentration of a first transition metal compound in a solution containing a first transition metal compound and a second transition metal compound. According to an aspect of the invention, such a method may include (i) submitting a sample of the solution to a sample chamber, (ii) irradiating the sample in the chamber with a light beam of a certain wavelength in the UV-Vis spectrum, and (iii) generating a sample absorbance distribution of the sample, subtracting a reference absorbance distribution of the second transition metal compound in a reference solution from the sample absorbance distribution to obtain an absorbance distribution of the first transition metal compound, and correlating the first transition metal compound absorbance distribution with a standard to determine the concentration of the first transition metal compound in the solution.

[0008] In another aspect, a process for operating a polymerization reactor system is disclosed, and in this aspect, the process may include (I) contacting a catalyst system comprising a first transition metal compound, a second transition metal compound, an activator, and optionally a cocatalyst with an olefin monomer and optionally an olefin comonomer in a reactor within the polymerization reactor system under polymerization reaction conditions to produce an olefin polymer; (II) determining the concentration of the first transition metal compound in a solution comprising the first transition metal compound and the second transition metal compound; and (III) adjusting the flow rate of the first transition metal compound into the reactor when the concentration of the first transition metal compound in the solution has reached a predetermined level. In another aspect, a process for preparing a catalyst composition is disclosed, and in this aspect, the process may include (I) contacting a first transition metal compound, a second transition metal compound, a solid activator, and an optional co-catalyst (e.g., in a catalyst preparation vessel) to form the catalyst composition, (II) determining the concentration of the first transition metal compound in a solution containing the first and second transition metal compounds, separating the solution from (or obtaining from) the catalyst composition, and (III) adjusting the relative amounts of at least one component of the catalyst composition based on the concentration of the first transition metal compound in the solution (or based on the determined concentration). In these and other respects, the concentration of the first transition metal compound in the solution comprising the first transition metal compound and the second transition metal compound can be determined by a method comprising the following steps: (i) submitting a sample of the solution to a sample chamber, (ii) irradiating the sample in the chamber with a beam of light of a certain wavelength in the UV-Vis spectrum, and (iii) generating a sample absorbance distribution of the sample, subtracting a reference absorbance distribution of the second transition metal compound in a reference solution from the sample absorbance distribution to obtain an absorbance distribution of the first transition metal compound, and relating the absorbance distribution of the first transition metal compound to a standard to determine the concentration of the first transition metal compound in the solution.

[0009] In addition, various polymerization reactor systems are disclosed herein. One such polymerization reactor system may include (A) a reactor configured to contact a catalyst system with an olefin monomer and optionally an olefin comonomer under polymerization conditions to produce an olefin polymer; (B) a catalyst preparation vessel configured to contact a first transition metal compound, a second transition metal compound, an activator, and optionally a cocatalyst to form the catalyst system; and (C) an analytical system configured to determine the concentration of the first transition metal compound in a solution comprising the first and second transition metal compounds present within the polymerization reactor system. Consistent with a particular aspect of the invention, the analytical system may include a UV-Vis spectrometer.

[0010] This document also discloses a catalyst preparation system. Such a catalyst preparation system may include (a) a catalyst preparation vessel configured to contact a first transition metal compound, a second transition metal compound, and a solid activator (and a co-catalyst, if used) to form a catalyst composition; (b) an activator feed stream configured to introduce the solid activator into the catalyst preparation vessel; (c) a first transition metal compound feed stream configured to introduce the first transition metal compound into the catalyst preparation vessel; (d) a second transition metal compound feed stream configured to introduce the second transition metal compound into the catalyst preparation vessel; (e) a catalyst system feed stream configured to remove the catalyst composition from the catalyst preparation vessel (e.g., and introduce the catalyst composition into a reactor); and (f) an analytical system configured to determine the concentration of the first transition metal compound in a solution comprising the first and second transition metal compounds, and to separate (or obtain) the solution from the catalyst composition. If the cocatalyst is a component of the catalyst composition, the catalyst preparation system may further include a cocatalyst feed stream configured to introduce the cocatalyst into the catalyst preparation vessel. Furthermore, the catalyst preparation system may further include (g) a controller configured to control the flow rate of the activator feed stream, the cocatalyst feed stream, the first transition metal compound feed stream, and / or the second transition metal compound feed stream entering the catalyst preparation vessel based on or according to a concentration determined by the analysis system.

[0011] Both the foregoing summary and the following detailed description are illustrative and exemplary. Therefore, the foregoing summary and the following detailed description should not be considered limiting. Furthermore, features or variations may be provided in addition to those set forth herein. For example, certain aspects may relate to various combinations and sub-combinations of features described in the detailed description. Attached Figure Description

[0012] The following figures form part of this specification and are included to further illustrate certain aspects of the invention. A better understanding of the invention can be achieved by referring to one or more of these figures in conjunction with the specific embodiments presented herein.

[0013] Figure 1 A schematic block diagram of a polymerization reactor system consistent with aspects of the present invention is shown.

[0014] Figure 2 The UV-Vis absorbance distribution of the transition metal compound MET-2 at various concentrations in toluene as a function of wavelength is presented in a graph.

[0015] Figure 3 A linear calibration curve was presented, which correlated absorbance with the concentration of the transition metal compound MET-2 in toluene at various wavelengths.

[0016] Figure 4 The UV-Vis absorbance distribution of the transition metal compound MET-2 at various concentrations in 1-hexene as a function of wavelength is presented.

[0017] Figure 5 A linear calibration curve was presented, which correlated absorbance with the concentration of the transition metal compound MET-2 in 1-hexene at various wavelengths.

[0018] Figure 6 The UV-Vis absorbance distribution of the transition metal compound MET-1 at various concentrations in toluene as a function of wavelength is presented in a graph.

[0019] Figure 7 A linear calibration curve was presented, which correlated absorbance with the concentration of the transition metal compound MET-1 in toluene at various wavelengths.

[0020] Figure 8 The UV-Vis absorbance distribution of the transition metal compound MET-1 at various concentrations in 1-hexene as a function of wavelength is presented in a graph.

[0021] Figure 9 A linear calibration curve was presented, which correlated absorbance with the concentration of the transition metal compound MET-1 in 1-hexene at various wavelengths.

[0022] Figure 10 The UV-Vis absorbance distribution of samples 1-5 with solvent reference is presented as a function of wavelength.

[0023] Figure 11 The graph presents the UV-Vis absorbance distribution of samples 1-5 as a function of wavelength, with sample 5 as the reference absorbance distribution.

[0024] Figure 12 A linear calibration curve is presented, which is used from Figure 11 The collected data correlated the absorbance at 380 nm with the concentration of the transition metal compound MET-1.

[0025] Figure 13 The graph presents the concentrations of MET-1 and MET-3 solutions as a function of the total amount of metallocene absorbed as an activator-carrier.

[0026] Figure 14 The graph shows the amount of absorbed MET-1 and MET-3 relative to the total amount of MET-1 and MET-3 under different amounts of activator-carrier.

[0027] Figure 15 A schematic block diagram of a catalyst preparation system consistent with aspects of the present invention is shown.

[0028] definition

[0029] To more clearly define the terms used herein, the following definitions are provided. Unless otherwise stated, the following definitions apply to this disclosure. If a term is used in this disclosure but is not specifically defined herein, the definition from the IUPAC Chemical Terminology Compendium, 2nd Edition (1997) may apply, provided that the definition does not conflict with any other disclosure or definition applied herein, or render any claim to which the definition applies ambiguous or unenforceable. If any definition or usage provided by reference in any document incorporated herein conflicts with the definition or usage provided herein, the definition or usage provided herein shall prevail.

[0030] The features of the subject matter are described herein, allowing for the contemplation of different combinations of features within a particular aspect. For each aspect and / or feature disclosed herein, all combinations are contemplated, with or without explicit description of a particular combination, without adversely affecting the systems, compositions, processes, and / or methods described herein. Furthermore, unless explicitly stated otherwise, any aspect and / or feature disclosed herein may be combined to describe features of the invention consistent with this disclosure.

[0031] Unless otherwise expressly stated in specific circumstances, all percentages, parts, proportions, etc. used in this document are by weight.

[0032] In this disclosure, although systems, processes and methods are often described in terms of “comprising” various components, devices or steps, systems, processes and methods may also “consist substantially of various components, devices or steps” or “comprise various components, devices or steps”, unless otherwise stated.

[0033] The terms “a / an” and “the” are intended to include plural alternatives, such as at least one. For example, the disclosure of “polymerization reactor,” “transition metal compound,” or “a wavelength” is intended to cover a mixture or combination of one or more polymerization reactors, transition metal compounds, or wavelengths, unless otherwise specified.

[0034] For any particular compound or group disclosed herein, unless otherwise specified, any name or structure presented (general or specific) is intended to cover all conformational isomers, regio isomers, stereoisomers, and mixtures thereof that may derive from a particular set of substituents. Unless otherwise specified, as those skilled in the art will recognize, the name or structure (general or specific) also covers all enantiomers, diastereomers, and other optical isomers (if present) in enantiomeric or racemic forms, as well as mixtures of stereoisomers. For example, general references to pentane generally include n-pentane, 2-methyl-butane, and 2,2-dimethylpropane, and general references to butyl generally include n-butyl, sec-butyl, isobutyl, and tert-butyl.

[0035] The term "about" means that a quantity, dimension, formulation, parameter, or other quantity and characteristic is not, and need not be, precise, but may be approximate, and / or larger or smaller as required, reflecting tolerances, conversion factors, rounding, measurement errors, and other factors known to those skilled in the art. Generally, quantities, dimensions, formulations, parameters, or other quantities or characteristics are "about" or "approximate," whether or not explicitly stated so. The term "about" also covers amounts that vary due to different equilibrium conditions of the composition resulting from a particular initial mixture. Claims, regardless of whether modified by the term "about," include equivalents of the quantities. The term "about" may mean within 10% of the reported value, preferably within 5% of the reported value.

[0036] Other numerical ranges are disclosed herein. When any type of range is disclosed or claimed, it is intended to individually disclose or claim every possible number that such range can reasonably cover, including the endpoints of the range and any sub-ranges and combinations of sub-ranges covered therein, unless otherwise stated. As a representative example, this disclosure cites, in some aspects, polymerization reaction conditions that may include polymerization reaction temperatures in the range of about 60°C to about 115°C. By disclosing that temperatures may be in the range of about 60°C to about 115°C, it is intended to enumerate any temperature that can be within that range, and for example, may be equal to about 60°C, about 65°C, about 70°C, about 75°C, about 80°C, about 85°C, about 90°C, about 95°C, about 100°C, about 105°C, about 110°C, or about 115°C. Additionally, temperatures may be in any range of about 60°C to about 115°C (e.g., temperatures may be in the range of about 70°C to about 110°C), and this also includes any combination of ranges between about 60°C and about 115°C. Similarly, all other scopes disclosed herein should be interpreted in a similar manner to this example.

[0037] In this document, the term "polymer" is generally used to encompass olefin homopolymers, copolymers, terpolymers, etc., as well as alloys and blends thereof. The term "polymer" also includes impact-resistant, block, graft, random, and alternating copolymers. Copolymers can be derived from one olefin monomer and one olefin comonomer, while terpolymers can be derived from one olefin monomer and two olefin comonomers. Therefore, "polymer" covers copolymers and terpolymers. Similarly, the scope of the term "polymerization" includes homopolymers, copolymers, and terpolymers. Therefore, ethylene polymers will include ethylene homopolymers, ethylene copolymers (e.g., ethylene / α-olefin copolymers), ethylene terpolymers, etc., as well as blends or mixtures thereof. Thus, ethylene polymers encompass polymers commonly referred to in the art as LLDPE (linear low-density polyethylene) and HDPE (high-density polyethylene). As an example, ethylene copolymers can be derived from ethylene and comonomers such as 1-butene, 1-hexene, or 1-octene. If the monomer and comonomer are ethylene and 1-hexene, respectively, the resulting polymer can be classified as an ethylene / 1-hexene copolymer. The term "polymer" also includes all possible geometries, including isotactic, syndiotactic, and random symmetries, if present and unless otherwise stated. The term "polymer" also means polymers of all molecular weights, and includes polymers or oligomers of lower molecular weights. It is intended that the term "polymer" cover oligomers (including dimers and trimers) derived from any olefin monomer disclosed herein (and from olefin monomers and one olefin comonomer, olefin monomers and two olefin comonomers, etc.).

[0038] Unless otherwise specified, the term "contact" is used herein to describe systems, compositions, processes, and methods in which components are contacted or combined together in any order, in any manner, and for any duration. For example, components may be combined using any suitable technique by blending or mixing.

[0039] The term "spectrometer" is generally used herein to refer to devices that may be referred to in the art as spectrometers or spectrophotometers, etc.

[0040] As used herein, the term "near real-time" refers to the delay introduced by automated data processing between the occurrence of an event and the use of the processed data. For example, classifying an event as a near real-time event means that the occurrence of a real-time event minus the processing time is almost equal to the time of the real-time event. That is, the time interval between receiving data for analysis and performing and displaying the analysis (e.g., on a computer screen or alternative device), or the time interval between performing an activity (e.g., adjusting the flow rate of a first transition metal compound and / or a second transition metal compound), is within 1 minute to 10 minutes, for example, as short as 3 seconds to 3 minutes.

[0041] As used herein, the term "real-time" or "practically real-time" can refer to the instantaneous capture of a measured item at the moment the capture occurs, such as the instantaneous or near-instantaneous streaming or transmission of data or information. Real-time data can be UV-Vis analysis data or sensor readout data, which, once a UV-Vis reading is obtained, can be immediately provided to a computer system, computer-readable medium, or controller, etc.

[0042] While any methods, apparatus, and materials similar to or equivalent to those described herein may be used in the practice or testing of this invention, typical methods, apparatus, and materials are described herein.

[0043] All publications and patents mentioned herein are incorporated herein by reference for the purpose of describing and disclosing, for example, the structures and methods described in the publications that can be used with the invention described herein. Detailed Implementation

[0044] This document discloses a method for determining the concentration of a first transition metal compound in a solution containing a first transition metal compound and a second transition metal compound, and a related process for operating a polymerization reactor system. This document also discloses a polymerization reactor system including an analytical system for determining the concentration of the first transition metal compound in a solution containing the first and second transition metal compounds, and a process for operating such a reactor system. While not wishing to be bound by theory, it is believed that such reactor systems (and related methods) can provide improved control and / or real-time monitoring or measurement of the amount of transition metal compounds present in the catalyst component feed stream, the catalyst system, and the polymerization reactor system, ultimately leading to improved quality control and consistency of the polymerization process. Advantageously, the reactor systems (and related methods) disclosed herein allow for the determination of the concentration of the first transition metal compound with extremely high accuracy, even when the absorbance distributions of the first and second transition metal compounds significantly overlap, and / or when one of the first and second transition metal compounds is in excess relative to the other. Advantageously, the reactor systems (and related methods) disclosed herein can be applied when the corresponding absorbance distributions of the transition metal compounds cannot be deconvoluted or independently determined. Therefore, since precise information about the concentration of the first transition metal compound can be determined, the polymerization reactor system (and related methods) disclosed herein can allow for real-time monitoring, control, regulation, and / or fine-tuning of the first transition metal concentration within a single grade of polymer resin production operation.

[0045] Methods for determining the concentration of transition metal compounds

[0046] Aspects of the present invention relate to a method for determining the concentration of a first transition metal compound in a solution comprising a first transition metal compound and a second transition metal compound. Such a method may include (or substantially comprise, or comprise): (i) submitting a sample of the solution to a sample chamber; (ii) irradiating the sample in the chamber with a beam of light of a certain wavelength (one or more) in the UV-Vis spectrum; and (iii) generating (e.g., collecting or outputting) a sample absorbance distribution of the sample, subtracting a reference absorbance distribution of the second transition metal compound in a reference solution from the sample absorbance distribution to obtain an absorbance distribution of the first transition metal compound, and relating the first absorbance distribution of the first transition metal compound to a standard to determine the concentration of the first transition metal compound in the solution. Generally, features of the methods disclosed herein (e.g., transition metal compound, solution, wavelength of the beam, absorbance distribution, and standard, etc.) are described independently herein, and these features may be combined in any combination to further describe the disclosed methods. Furthermore, unless otherwise stated, additional process steps may be performed before, during, and / or after any steps listed in the disclosed methods.

[0047] In step (i), a sample containing a solution of a first transition metal compound and a second transition metal compound (at least two transition metal compounds) is submitted to a sample chamber. The sample chamber may be a flow cell, although any suitable design and construction of the sample chamber may be used. The second transition metal compound may include one second transition metal compound, two different second transition metal compounds, etc. Therefore, the solution containing transition metal compounds may contain two or more different transition metal compounds. As a non-limiting example, the solution may contain two metallocene compounds: a bridged metallocene compound and a non-bridged metallocene compound, two different bridged metallocene compounds, or two different non-bridged metallocene compounds.

[0048] Typically, the solution comprises a first transition metal compound, a second transition metal compound, and a hydrocarbon solvent, although the methods disclosed herein can be used with other solvent types, such as chlorinated hydrocarbons, ethers, alcohols, etc. Typical hydrocarbon solvents may include, but are not limited to, propane, cyclohexane, cyclohexene, isobutane, n-butane, n-pentane, isopentane, neopentane, n-hexane, 1-hexene, toluene, etc., and combinations thereof. Other suitable hydrocarbon solvents may comprise mixtures of aliphatic hydrocarbon solvents. Family, for example, C E, G, H, L, M, etc., and mixtures thereof. While not wishing to be bound by theory, it is believed that the type of transition metal compound present in solution and the type of solvent can influence one or more wavelengths to be utilized in the systems and methods / processes disclosed herein. In a particular aspect of the invention, the systems and methods / processes disclosed herein are well-suited for determining the concentration of a first transition metal compound in a solution containing a first transition metal compound, a second transition metal compound, and a hydrocarbon solvent. The hydrocarbon solvent may include, for example, 1-hexene, isobutane, toluene, or cyclohexene, and mixtures or combinations thereof.

[0049] The choice of solvent can affect the absorbance distribution of certain transition metal compounds. Therefore, aspects of the present invention can utilize a reference solution comprising a second transition metal compound and a hydrocarbon solvent, wherein the hydrocarbon solvent is the same as that present in the sample containing the first and second transition metal compounds. In such aspects, the influence of any solvent can be minimized, thereby leading to improved accuracy in determining the concentration of the first transition metal compound.

[0050] In step (ii), the sample in the sample chamber can be irradiated with a beam of light of a certain wavelength in the UV-Vis spectrum. For example, this can be achieved using a UV-Vis spectrometer discussed below. The wavelength of the beam can be a single wavelength or more than one wavelength, such as a series of wavelengths. On one hand, the wavelength of the beam can include wavelengths in the visible spectrum (380 nm to 780 nm). On the other hand, the wavelength of the beam can include wavelengths in the range of 200 nm to 750 nm. However, on yet another hand, the wavelength of the beam can include wavelengths in the range of 300 nm to 600 nm. Therefore, depending on, for example, a specific transition metal compound or a specific hydrocarbon solvent, any suitable wavelength range can be used. Typically, step (ii) can be performed in the wavelength range of 300–600 nm. Furthermore, if desired, in some aspects of the invention, the UV-Vis light / radiation can be filtered.

[0051] In step (iii), a sample absorbance distribution of the sample containing a solution of the first transition metal compound and the second transition metal compound is generated. Optionally, a reference absorbance distribution of a reference solution, which may contain the second transition metal compound, may be generated. The absorbance distribution of the first transition metal compound can be obtained by subtracting the reference absorbance distribution, either previously generated or generated simultaneously with the sample absorbance distribution, from the sample absorbance distribution. Typically, the reference absorbance distribution and the sample absorbance distribution are not generated simultaneously; in these cases, the reference is usually analyzed before the sample is tested. However, if the UV-Vis instrument is equipped with both a sample chamber and a reference chamber, both sample absorbance distributions and reference absorbance distributions can be generated simultaneously.

[0052] In some cases, an actual absorbance distribution can be generated, which can be collected or output, such as in the form of a curve of absorbance as a function of wavelength, and can be viewed on a monitor or computer screen or printed as a hard copy. In other cases, an absorbance distribution is generated, but it is not collected or output in a visible form. For example, by subtracting a reference absorbance distribution from the sample absorbance distribution and subsequently correlating the absorbance distribution of the first transition metal compound with a standard to determine the concentration, data from the sample absorbance distribution (e.g., absorbance as a function of wavelength) can be directly converted into first transition metal compound concentration data.

[0053] In some aspects of the invention, any absorbance distribution described herein (e.g., sample, reference, first transition metal compound) may include an absorbance peak at a single wavelength. For example, the absorbance distribution of the first transition metal compound may include an absorbance peak at the point of maximum absorbance. Therefore, data from the absorbance peak of the first transition metal compound in solution at a single wavelength can be used to determine the concentration of the first transition metal compound in solution. Alternatively, any absorbance distribution described herein may include absorbance curves (peaks and / or areas under the curve as a function of wavelength) within wavelength ranges such as 200 nm to 750 nm or 300 nm to 600 nm. Therefore, data from absorbance curves within a certain wavelength range can be used to determine the concentration of the first transition metal compound in solution. In another aspect, any absorbance distribution described herein may include absorbance curves (peaks and / or areas under the curve as a function of wavelength) spanning subsets of wavelengths less than 200 nm, less than 150 nm, less than 100 nm, or less than 50 nm. Therefore, data from absorbance profiles within a subset of a specific wavelength range can be used to determine the concentration of the first transition metal compound in the solution. Other suitable absorbance distribution options are apparent from this disclosure.

[0054] Typically, the corresponding concentrations of the first and second transition metal compounds in the sample are not limited to any particular range. However, in some aspects, the concentration of the first transition metal compound in the sample can be such that the absorbance peak at a single wavelength in the absorbance distribution of the first transition metal compound (e.g., the absorbance peak at 380 nm) is less than 2, less than 1, or less than 0.5. In specific aspects, the concentration of the first transition metal compound in the sample can be such that the absorbance peak at a single wavelength in the absorbance distribution of the first transition metal compound is in the range of about 0.1 to about 2, about 0.1 to about 1, about 0.3 to about 1, or about 0.5 to about 1.

[0055] Similarly, the corresponding concentrations of the first and second transition metal compounds in the solution are not limited to any particular range. For example, the concentrations of the first and second transition metal compounds in the solution may independently be less than about 5 wt.%, less than about 2 wt.%, less than about 1 wt.%, less than about 0.8 wt.%, less than about 0.5 wt.%, less than about 0.2 wt.%, less than about 0.1 wt.%, less than about 0.05 wt.%, or less than about 0.01 wt.%. Illustrative and non-limiting ranges for the concentrations of the first and second transition metal compounds in the solution may independently include from about 0.01 wt.% to about 5 wt.%, from about 0.01 wt.% to about 1 wt.%, from about 0.01 wt.% to about 0.5 wt.%, from about 0.05 wt.% to about 0.2 wt.%, from about 0.01 wt.% to about 0.1 wt.%, or from about 0.1 wt.% to about 0.3 wt.%.

[0056] Alternatively, or in addition to determining the absolute concentration of the first transition metal compound, the methods described herein can be used to determine the relative concentrations (or relative amounts) of the first and second transition metal compounds. In some aspects, the weight ratio (first:second) of the first to second transition metal compound in solution can be less than about 1:1, less than about 1:4, less than about 1:10, or less than about 1:20. In other aspects, the weight ratio of the first to second transition metal compound in solution can be in the range of about 50:1 to about 1:50, about 10:1 to about 1:10, about 2:1 to about 1:2, about 1:20 to about 1:1, about 1:100 to about 1:2, about 1:50 to about 1:5, about 1:50 to about 1:10, or about 1:20 to about 1:10.

[0057] The absorbance distribution of a first transition metal compound, whether from a single wavelength, a narrow subset of the wavelength range (e.g., spanning less than 50 nm or 100 nm), or from a broad spectrum of wavelengths (e.g., 300 nm to 600 nm), can be correlated with a standard to determine the concentration of the first transition metal compound in solution. For example, data from the absorbance distribution of the first transition metal compound can be correlated with a standard, and the standard may include calibration curves. The correlation step can be performed manually or automatically. If calibration curves are used, these calibration curves can be generated by any procedure known to those skilled in the art. Therefore, the step of correlating the absorbance distribution of the first transition metal compound with a standard may include any suitable method of converting the absorbance distribution (or peaks) of the first transition metal compound into the concentration of the first transition metal compound in solution. As an example, absorbance data can be generated for a sample having a known concentration (wt.%) of the first transition metal compound in a reference solution (e.g., using a specific hydrocarbon solvent) at a single wavelength or over a wide wavelength range. This step can then be repeated while keeping the concentration of a second transition metal compound constant to cover the concentration range of the first transition metal compound.

[0058] Typically, the relevant steps may include any suitable method or technique for converting the absorbance distribution of the first transition metal compound—whether from a single wavelength, a subset of a narrow wavelength range, or a broad spectrum of wavelengths—to the concentration of the first transition metal compound in solution. These steps may be performed manually or configured to automatically convert data from the absorbance distribution of the first transition metal compound into the concentration of the first transition metal compound in solution.

[0059] While not limited thereto, in some aspects of the invention, the generation and subtraction operations in step (iii) can be performed within a broad spectral wavelength range, such as 300-600 nm, while related operations can typically be performed at a single wavelength. Additionally, although not mandatory, the path lengths used in generating the sample absorbance distribution and the reference absorbance distribution can generally be the same. Furthermore, step (iii) can be performed sequentially or simultaneously, and can be performed manually or computerized (e.g., for automatically determining the concentration of the first transition metal compound in the solution).

[0060] The methods disclosed herein are applicable to a variety of situations where the concentration of the transition metal compound in the solution (or a mixture from which a solution may be derived) may be of concern. On one hand, the solution comprising the first and second transition metal compounds can be a feed stream entering a catalyst preparation vessel. The catalyst preparation vessel can be any vessel or device capable of contacting (e.g., mixing or blending) two or more components of a catalyst system to form the catalyst system. Any two or more components can be pre-contacted for a suitable period of time before being contacted with the remaining components to form the final catalyst system, and can then be transferred from the catalyst preparation vessel to the reactor as needed. Typically, in a catalyst preparation vessel, transition metal compounds (two or more) and activators (one or more) are contacted, or alternatively, transition metal compounds (two or more), activators (one or more), and co-catalysts are contacted to form the catalyst system.

[0061] In another aspect, the solution comprising the first transition metal compound and the second transition metal compound can be a liquid (or homogeneous) catalyst system comprising the transition metal compound. In addition to the transition metal compound, the catalyst system may contain components, if desired, a liquid activator (or a solution of a liquid activator), such as MAO, and a liquid co-catalyst (or a solution of a co-catalyst).

[0062] In another aspect, the solution comprising the first transition metal compound and the second transition metal compound may be a solution from a polymerization reactor (e.g., a solution reactor or a slurry reactor), wherein solids or particles from the sample stream (the mixture from the reactor) have been removed, such as by sieving, filtration, centrifugation, etc., and may include a combination or two or more of these techniques, as well as any other suitable techniques for removing solids or particles from the mixture to form a solution.

[0063] In another aspect, the solution comprising the first transition metal compound and the second transition metal compound may be a solution from a heterogeneous or supported catalyst system stream, wherein solids or particles from the sample stream (of the catalyst system mixture) have been removed by any suitable technique or any technique disclosed herein.

[0064] Polymerization reactor system

[0065] This document discloses and describes various polymerization reactor systems and processes for operating or controlling such systems. For example, one aspect of the process for operating a polymerization reactor system may include (I) contacting a catalyst system comprising a first transition metal compound, a second transition metal compound, an activator, and optionally a cocatalyst with an olefin monomer and optionally an olefin comonomer in a reactor within the polymerization reactor system under polymerization reaction conditions to produce an olefin polymer; (II) determining the concentration of the first transition metal compound in a solution comprising the first and second transition metal compounds, determined by the methods described above; and (III) adjusting the flow rate of the first transition metal compound into the reactor when the concentration of the first transition metal compound in the solution has reached a predetermined level. Thus, the flow rate (or feed rate) of the first transition metal compound can be adjusted manually and / or automatically based on the determined concentration. Generally, the characteristics of the processes disclosed herein for operating polymerization reactor systems (e.g., transition metal compounds, catalyst systems, olefin monomers, olefin comonomers, reactors, methods for determining the concentration of the first transition metal compound, and flow rate control of the first transition metal compound, etc.) are described independently herein and can be combined in any combination to further describe the disclosed processes. In addition, unless otherwise stated, other steps may be performed before, during and / or after any of the steps listed in the disclosed process.

[0066] Step (II) involves determining the concentration of the first transition metal compound in a solution comprising the first and second transition metal compounds. Step (II) may include the following steps: (i) submitting a sample of the solution to a sample chamber, (ii) irradiating the sample in the chamber with a beam of light of a certain wavelength in the UV-Vis spectrum, and (iii) generating a sample absorbance distribution of the sample, subtracting a reference absorbance distribution of the second transition metal compound in a reference solution from the sample absorbance distribution to obtain an absorbance distribution of the first transition metal compound, and correlating the absorbance distribution of the first transition metal compound with a standard to determine the concentration of the first transition metal compound in the solution. Therefore, the specific features associated with step (II) may be the same as those disclosed and described herein, as it relates to a method for determining the concentration of the first transition metal compound in a solution containing the first and second transition metal compounds.

[0067] The process disclosed herein is applicable to a variety of situations where the concentration of the transition metal compound in the solution (or a mixture from which a solution may be obtained) may be of concern. On one hand, the solution comprising the first and second transition metal compounds can be a feed stream entering the catalyst preparation vessel. In this regard, the flow rate of the first transition metal compound entering the reactor can be controlled by adjusting the flow rate of the feed stream entering the catalyst preparation vessel and / or by adjusting the relative flow rates entering the catalyst preparation vessel (the ratio of the flow rate of the first transition metal compound to the flow rate of the second transition metal compound), and / or by adjusting the flow rate of the catalyst system leaving the catalyst preparation vessel and entering the reactor.

[0068] As an example, if the concentration of the first transition metal compound is lower than the target concentration, the flow rate of the first transition metal compound entering the reactor can be increased by increasing the relative flow rate entering the catalyst preparation vessel (the ratio of the flow rate of the first transition metal compound to the flow rate of the second transition metal compound). For example, this can be achieved by increasing the feed rate of the first transition metal compound into the catalyst preparation vessel while keeping the feed rate of the second transition metal compound into the catalyst preparation vessel constant.

[0069] As another example, if the concentration of the first transition metal compound is below the target concentration, the flow rate of the first transition metal compound into the reactor can be increased by increasing the relative flow rate to the reactor (the ratio of the flow rate of the first transition metal compound to the flow rate of the second transition metal compound). For example, this can be achieved by increasing the feed rate of the first transition metal compound to the reactor while keeping the feed rate of the second transition metal compound to the reactor constant.

[0070] In another aspect, the catalyst system can be a liquid (or homogeneous) catalyst system, and the solution comprising the first transition metal compound and the second transition metal compound can be a sample of the liquid catalyst system. In this respect, the flow rate of the first transition metal compound into the reactor can be controlled by adjusting the relative flow rate to the reactor (the ratio of the flow rate of the first transition metal compound to the flow rate of the second transition metal compound), and / or by adjusting the flow rate of the liquid catalyst system into the reactor.

[0071] In another aspect, the polymerization reactor system includes a polymerization reactor (e.g., a solution polymerization reactor or a slurry polymerization reactor), and the solution comprising the first transition metal compound and the second transition metal compound can be a solution prepared from a sample of the mixture from the polymerization reactor. In this respect, the flow rate of the first transition metal compound into the polymerization reactor can be controlled by adjusting the relative flow rate to the reactor (the ratio of the flow rate of the first transition metal compound to the flow rate of the second transition metal compound), and / or by adjusting the flow rate of the catalyst system into the polymerization reactor. Solids or particles from the sample of the mixture from the polymerization reactor can be removed by any suitable technique. Optionally, cooling the sample of the mixture may be beneficial. This process can be used to determine the amount of the first transition metal compound not impregnated in, on, or associated with any solid catalyst component and / or polymer particles, for example, to determine the amount (or percentage) of the first transition metal compound present in the solution.

[0072] In another aspect, the catalyst system can be a heterogeneous or supported catalyst system, and the solution comprising the first transition metal compound and the second transition metal compound can be a solution obtained from a sample stream of the heterogeneous or supported catalyst system. In this respect, the flow rate of the first transition metal compound into the polymerization reactor can be controlled by adjusting the relative flow rate to the reactor (the ratio of the flow rate of the first transition metal compound to the flow rate of the second transition metal compound), and / or by adjusting the flow rate of the catalyst system into the polymerization reactor. As described above, this process can be used to determine the amount of the first transition metal compound not impregnated in, on, or associated with the solid catalyst component of the catalyst system, for example, to determine the amount (or percentage) of the first transition metal compound present in the solution.

[0073] Consistent with the aspects disclosed herein, in step (III), when the concentration of the first transition metal compound in the solution has reached a predetermined level, the flow rate of the first transition metal compound into the reactor can be adjusted. Depending on, for example, the history and key conditions of the polymerization reactor system, those skilled in the art can readily determine the predetermined level. As a non-limiting example, the predetermined level may be a decrease in the concentration of the first transition metal compound by a certain percentage (e.g., exceeding a concentration considered permissible during normal primary coating production), or an increase in the concentration of the first transition metal compound in the solution by a certain percentage (e.g., exceeding a concentration considered permissible during normal primary coating production). For example, the target concentration of the first transition metal compound in the solution may be 0.1 wt.%, and the predetermined lower and upper control limits for normal primary coating production may be 0.09 wt.% and 0.11 wt.%, respectively. If the measured concentration of the first transition metal compound in the solution is 0.08 wt.%, the feed rate of the first transition metal compound into the catalyst preparation vessel (and subsequently to the polymerization reactor) can then be increased to bring the concentration of the first transition metal compound to an acceptable level within the predetermined limits of 0.09-0.11 wt.%. Conversely, if the concentration of the first transition metal in the solution is too high (e.g., 0.12+wt.%), the feed rate of the first transition metal compound can be reduced to bring the concentration to an acceptable level within a predetermined limit.

[0074] In another aspect of the invention, a polymerization reactor system is provided, and in this aspect, the polymerization reactor system may include (A) a reactor configured to contact a catalyst system with an olefin monomer and optionally an olefin comonomer under polymerization reaction conditions to produce an olefin polymer, (B) a catalyst preparation vessel configured to contact a first transition metal compound, a second transition metal compound, an activator, and optionally a cocatalyst to form a catalyst system, and (C) an analytical system configured to determine the concentration of the first transition metal compound in a solution comprising the first and second transition metal compounds present within the polymerization reactor system. Generally, features of any polymerization reactor system disclosed herein (e.g., polymerization reactor, catalyst system, olefin monomer (and olefin comonomer, if any), polymerization conditions, olefin polymer, catalyst preparation vessel, analytical system, etc.) are described independently, and these features may be combined in any combination to further describe the disclosed polymerization reactor system. Furthermore, unless otherwise stated, other apparatus or reactor system components other than the reactor, catalyst preparation vessel, and analytical system may be present in the disclosed polymerization reactor system. In addition, in some aspects envisioned herein, the catalyst system can be contacted with olefin monomers and olefin comonomers in the polymerization reactor (e.g., with ethylene and α-olefin comonomers, such as 1-hexene).

[0075] The analytical system can comprise any analytical system or apparatus capable of determining the concentration of a first transition metal compound in a solution containing a first transition metal compound and a second transition metal compound. For example, the analytical system can comprise a UV-Vis spectrometer (e.g., alone or in combination with another analytical apparatus / method, such as fluorescence spectroscopy, a UV-Vis-NIR system, etc.). In one aspect of the invention, the analytical system can comprise a UV-Vis spectrometer having an integrated computer system, such that the spectrometer and the integrated computer system are capable of measuring (or configured to measure) a sample absorbance distribution of the first transition metal compound in the solution, subtracting (or configured to subtract) a reference absorbance distribution of the second transition metal compound from the sample absorbance distribution to obtain the absorbance distribution of the first transition metal compound, and correlating (or configuring to correlate) the absorbance distribution of the first transition metal compound with a standard to determine the concentration of the first transition metal compound in the solution. In this aspect, the UV-Vis spectrometer has a “built-in” computer system that performs absorbance measurements and converts the absorbance data into the concentration of the first transition metal compound. In another respect, the UV-Vis spectrometer can simultaneously or sequentially measure the reference absorbance distribution of a reference solution (including a second transition metal compound and a hydrocarbon solvent).

[0076] In another aspect of the invention, the analytical system may include a UV-Vis spectrometer and an external computer system, such that the UV-Vis spectrometer is capable of measuring (or configured to measure) the sample absorbance distribution of a first transition metal compound in solution, and the external computer system is capable of subtracting (or configured to subtract) a reference absorbance distribution of a second transition metal compound in a reference solution from the sample absorbance distribution to obtain the absorbance distribution of the first transition metal compound, and is capable of correlating (or configuring to correlate) the absorbance distribution of the first transition metal compound with a standard to determine the concentration of the first transition metal compound in solution. In this aspect, the UV-Vis spectrometer can perform absorbance measurements and generate absorbance data and distributions, but the external computer system can take the output from the UV-Vis spectrometer and determine the concentration of the first transition metal compound.

[0077] If desired, the analytical system may further include a filter assembly designed to filter samples containing a first transition metal compound and a second transition metal compound prior to analysis by a UV-Vis spectrometer.

[0078] As described herein, in some aspects of the invention, the absorbance distribution (e.g., sample absorbance distribution, reference absorbance distribution, and first transition metal compound absorbance distribution) can independently comprise absorbance peaks at a single wavelength. Therefore, data from the absorbance peaks of the first transition metal compound in the sample solution at a single wavelength can be used to determine the concentration of the first transition metal compound in the sample solution. Alternatively or additionally, the absorbance distribution can independently comprise absorbance curves (peaks and / or areas under the curves as a function of wavelength) within wavelength ranges such as 200 nm to 750 nm or 300 nm to 600 nm. Therefore, data from absorbance curves within a certain wavelength range can be used to determine the concentration of the first transition metal compound in the sample solution. In another aspect, the absorbance distribution can independently comprise absorbance curves (peaks and / or areas under the curves as a function of wavelength) spanning subsets of wavelengths less than 200 nm, less than 150 nm, less than 100 nm, or less than 50 nm. Therefore, data from absorbance profiles within a subset of a specific wavelength range can be used to determine the concentration of the first transition metal compound in the solution. Other suitable absorbance distribution options and combinations are apparent from this disclosure.

[0079] Each absorbance distribution can be generated independently and therefore can independently include absorbance peaks or absorbance profiles within any wavelength range disclosed herein. Thus, in some aspects, the sample absorbance distribution and the reference absorbance distribution can independently include absorbance profiles, while the first transition metal compound absorbance distribution can include absorbance peaks. Similarly, the sample absorbance distribution can include absorbance profiles within a wavelength range different from the reference absorbance distribution. Therefore, after subtracting the reference absorbance distribution from the sample absorbance distribution, the resulting first transition metal compound absorbance distribution can include absorbance profiles at the same or different wavelengths or at a single wavelength.

[0080] Furthermore, converting the absorbance distribution of the first transition metal compound to a first transition metal concentration may include correlating the absorbance at a single peak of the absorbance distribution of the first transition metal compound with a standard. If a calibration curve is used as the standard, these calibration curves can be generated using any procedure known to those skilled in the art. As an example, absorbance data can be generated for a sample having known concentrations (wt.%) of a first and second transition metal compound in a reference solution (e.g., using a specific hydrocarbon solvent) at a single wavelength or over a wide wavelength range. Absorbance data can then be generated for a range of first transition metal compound concentrations while keeping the concentration of the second transition metal compound constant. Alternatively, the associated steps may include any suitable technique for converting the absorbance distribution (or peak) of the first transition metal compound to the concentration of the first transition metal compound in solution.

[0081] A catalyst preparation vessel can contain any container or apparatus capable of contacting (e.g., mixing or blending) two or more components of a catalyst system to form the catalyst system. The catalyst preparation vessel can be a mixing tank or other suitable stirred tank or container. The catalyst system can be delivered from the catalyst preparation vessel to a reactor as needed. Typically, in a catalyst preparation vessel, transition metal compounds (two or more) and activators (one or more) are contacted, or alternatively, transition metal compounds (two or more), activators (one or more), and co-catalysts are contacted to form the catalyst system. Multi-component catalyst preparation vessels and methods are disclosed, for example, in U.S. Patent No. 7,615,596 (e.g., a pre-contaminant), which is incorporated herein by reference in its entirety.

[0082] Optionally, the polymerization reactor system may further include a controller capable of controlling the flow rate of the first transition metal compound into the reactor system based on or according to a concentration determined by an analytical system. Thus, the polymerization reactor system may include a reactor, a catalyst preparation vessel, an analytical system, and a controller. The controller, which may include any suitable processing unit or computer system, can be used to analyze data regarding the concentration of the first transition metal compound in the solution and, based on the determined concentration, adjust the flow rate of the first transition metal compound into the reactor system. In another aspect, the controller may be programmed using an algorithm to control the flow rate of the first transition metal compound into the reactor system based on a concentration determined by the analytical system. For example, if the concentration determined by the analytical system is too low, the controller may increase the flow rate. In yet another aspect, the controller operable to control the flow rate of the first transition metal compound may include a controller operable to receive information about the concentration of the first transition metal compound to identify new target concentrations of the first transition metal compound (e.g., to increase or decrease the flow rate to achieve a desired effect on the concentration of the first transition metal compound) and provide control signals to adjust the flow rate of the first transition metal compound into the reactor system accordingly.

[0083] Depending on the requirements of the reactor system, the controller can operate as needed, either at set time intervals or continuously. Therefore, it is envisioned that the concentration of the first transition metal compound can be continuously monitored and / or adjusted and / or controlled. Thus, in a particular aspect consistent with the present invention, the polymerization reactor system and controller can operate in real-time or near real-time, allowing the concentration of the first transition metal compound to be determined, and the flow rate or feed rate of the first transition metal compound to be adjusted instantaneously or almost instantaneously using the determined concentration.

[0084] The controller or computing device can be implemented using a personal computer, network computer, server, mainframe, or other similar microcomputer-based workstation. The controller or computing device can include any computer operating environment, such as a handheld device, multiprocessor system, microprocessor-based or programmable transmitter electronics, minicomputer, mainframe, etc. The controller or computing device can also be implemented in a distributed computing environment where tasks are performed by a remote processing device. Furthermore, the controller or computing device can include mobile terminals such as smartphones, cellular phones, cellular phones utilizing Wireless Application Protocol (WAP), personal digital assistants (PDAs), smart pagers, portable computers, handheld computers, traditional telephones, Wi-Fi access points, or fax machines. The foregoing systems and devices are examples, and the controller or computing device can include other systems or devices. The controller or computing device can also be implemented using a system-on-a-chip (SoC), where each and / or many of the components shown above can be integrated onto a single integrated circuit. Such a SoC device may include one or more processing units, graphics units, communication units, system virtualization units, and various application functions, all of which can be integrated (or "burned in") as a single integrated circuit onto a chip substrate. Other controller methods and apparatus will be apparent to those skilled in the art in light of this disclosure.

[0085] The controller of the system disclosed herein can control the flow rate of the first transition metal compound entering or within the polymerization reactor system by any method that provides precise and near-instantaneous control of the concentration of the first transition metal compound.

[0086] The system disclosed herein is applicable to various situations where the concentration of the first transition metal compound in a solution (or mixture of solutions) containing both a first and a second transition metal compound may be of interest. On one hand, the solution comprising the first and second transition metal compounds can be a feed stream entering the catalyst preparation vessel. In this regard, the controller can control the flow rate of the first transition metal compound entering the reactor by adjusting the flow rate of the feed stream into the catalyst preparation vessel and / or by adjusting the relative flow rates of the first and second transition metal compounds entering the catalyst preparation vessel, and / or by adjusting the flow rate of the catalyst system leaving the catalyst preparation vessel and entering the reactor.

[0087] In another aspect, the catalyst system can be a liquid (or homogeneous) catalyst system, and the solution comprising the first transition metal compound and the second transition metal compound can be a sample of the liquid catalyst system. In this respect, the controller can control the flow rate of the first transition metal compound into the reactor by adjusting the relative flow rates of the first and second transition metal compounds to the reactor, and / or by adjusting the flow rate of the liquid catalyst system into the reactor.

[0088] In another aspect, the polymerization reactor system may include a polymerization reactor (e.g., a solution reactor or a slurry reactor) containing a reaction mixture, and the solution comprising the first transition metal compound and the second transition metal compound may be a solution prepared from or separated from a sample stream from the polymerization reactor. In this aspect, the controller controls the flow rate of the first transition metal compound into the reactor by adjusting the relative flow rates of the first and second transition metal compounds to the reactor, and / or by adjusting the flow rate of the catalyst system into the reactor. As described herein, solids or particles in the sample stream (reaction mixture) can be removed by any suitable technique. Optionally, cooling the sample stream may be advantageous. This process can be used to determine the amount of the first transition metal compound not impregnated in, on, or associated with the solid catalyst component and / or polymer particles, for example, to determine the amount (or fraction thereof) of the first transition metal compound present in solution.

[0089] In another aspect, the solution comprising the first transition metal compound and the second transition metal compound can be a solution obtained from or separated from a sample stream of the feed stream of a heterogeneous or supported catalyst system. In this respect, the flow rate of the first transition metal compound into the reactor can be controlled by adjusting the relative flow rate to the reactor and / or by adjusting the flow rate of the catalyst system into the reactor. As described above, this process can be used to determine the amount of the first transition metal compound not impregnated in, on, or associated with the solid catalyst component of the catalyst system, for example, to determine the amount (or fraction thereof) of the first transition metal compound present in the solution.

[0090] A representative polymerization reactor system 100 consistent with aspects of the present invention is shown in Figure 1 The polymerization reactor system 100 includes a catalyst preparation vessel 110, a reactor 120, an analytical system 140, and a controller 150. The analytical system 140 may include a UV-Vis spectrometer as described herein. Figure 1The polymerization reactor system 100 includes a first transition metal compound solution feed stream 102 and a second transition metal compound solution feed stream 104, which form a combined transition metal compound solution feed stream 105 entering the catalyst preparation vessel (separate feed streams for other catalyst components are not shown). Figure 1 In other aspects not shown, feed streams 102 and 104 can be independently and directly fed into catalyst preparation vessel 110 and / or reactor 120. For example... Figure 1 As shown, the sample stream 132 from the combined feed stream 105 can be submitted to the analysis system 140 before entering the catalyst preparation vessel 110 to determine the concentration of the first transition metal compound in the combined feed stream 105.

[0091] The polymerization reactor system 100 includes a catalyst system feed stream 115 from the catalyst preparation vessel 110 to the reactor 120. The catalyst system feed stream 115 can be a liquid (or homogeneous) or supported (or heterogeneous) catalyst system containing a first transition metal compound. A sample stream 134 from the catalyst system feed stream 115 can be submitted to an analytical system 140 to determine the concentration of the first transition metal compound in the solution portion of the feed stream (e.g., solids or particles in the catalyst system feed stream 115 can be removed prior to analysis).

[0092] The polymerization reactor system 100 includes a sample stream 136 from reactor 120. The sample stream 136 from reactor 120 can be submitted to an analysis system 140 to determine the concentration of a first transition metal compound in the solution portion of the reactor contents (e.g., solids or particles in reactor sample stream 136 can be removed prior to analysis).

[0093] Information or data 145 from the analysis system 140 regarding the concentration of the first transition metal compound can be provided to the controller 150, which can then control or regulate the flow rate of the combined feed stream 105 and / or the catalyst system feed stream 115. Alternatively or additionally, the controller 150 can independently control or regulate the flow rates of the first transition metal compound solution feed stream 102 and / or the second transition metal compound solution feed stream 104 to control or regulate the relative flow rates of feed streams 102 and 104. Thus, the controller 150 controls or regulates the flow rate of the first transition metal compound entering the reactor 120 based on or according to the concentration determined by the analysis system 140. For example, if the concentration determined by the analysis system 140 is too low, the controller 150 can increase the flow rate of one or more feed streams.

[0094] The disclosed polymerization reactor systems and their operating methods are intended to cover any olefin polymerization process using any / all types of polymerization reactors and polymerization reaction conditions. As used herein, "polymerization reactor" includes any polymerization reactor capable of polymerizing olefin monomers and comonomers (one or more comonomers, if used) (including oligomers) to produce homopolymers, copolymers, terpolymers, etc. Various types of polymerization reactors include those reactors that may be referred to as slurry reactors, gas-phase reactors, solution reactors, high-pressure reactors, tubular reactors, autoclave reactors, etc., including combinations thereof. The polymerization conditions used for various reactor types are well known to those skilled in the art. Gas-phase reactors may include fluidized bed reactors or staged horizontal reactors. Slurry reactors may include vertical or horizontal loop reactors. High-pressure reactors may include autoclave reactors or tubular reactors. These reactor types are generally designed for continuous operation. Continuous processes may use batch or continuous polymer product discharge. Polymerization reactor systems and processes may also include partial or complete direct recycling of unreacted monomers, unreacted comonomers, and / or diluents.

[0095] The polymerization reactor systems disclosed herein may include one type of polymerization reactor or multiple reactors of the same or different types. For example, a polymerization reactor system may include a solution reactor, a gas-phase reactor, a slurry reactor, or a combination of two or more of these reactors. Polymer production in multiple reactors may be comprised in several stages within at least two separate polymerization reactors interconnected by transfer devices that make it possible to transfer polymer produced by a first polymerization reactor to a second reactor. The polymerization conditions in one of the reactors may differ from the operating conditions of one or more of the other reactors. Alternatively, polymerization in multiple reactors may involve manually transferring polymer from one reactor to a subsequent reactor for continued polymerization. Multiple reactor systems may include any combination, including but not limited to multiple loop reactors, multiple gas-phase reactors, a combination of loop and gas-phase reactors, multiple high-pressure reactors, or a combination of a high-pressure reactor with a loop reactor and / or a gas-phase reactor. Multiple reactors may operate in series, in parallel, or in both ways.

[0096] According to one aspect, the polymerization reactor system may include, for example, at least one loop slurry reactor comprising a vertical or horizontal loop. Monomers, diluents, catalysts, and optionally comonomers may be continuously fed into the loop reactor in which polymerization occurs. Generally, the continuous process may include the continuous introduction of monomers / comonomers, catalysts, and diluents into the polymerization reactor, and the continuous removal of a suspension comprising polymer particles and diluents from the reactor. The reactor effluent may be flashed to remove solid polymers from the liquid comprising diluents, monomers, and / or comonomers. Various techniques may be used for this separation step, including, but not limited to: flashing that may include any combination of heating and depressurization, separation by swirling action in a hydrocyclone or hydrocyclone, or separation by centrifugation.

[0097] Typical slurry polymerization processes (also known as particle formation processes) are disclosed in, for example, U.S. Patents 3,248,179, 4,501,885, 5,565,175, 5,575,979, 6,239,235, 6,262,191, 6,833,415, and 8,822,608, each of which is incorporated herein by reference in its entirety.

[0098] Suitable diluents used in slurry polymerization include, but are not limited to, the monomers to be polymerized and hydrocarbons that are liquid under reaction conditions. Examples of suitable diluents include, but are not limited to, hydrocarbons such as propane, cyclohexane, isobutane, n-butane, n-pentane, isopentane, neopentane, and n-hexane. Some ring polymerization reactions can occur under bulk conditions without the use of diluents, such as in the bulk polymerization of propylene to form polypropylene homopolymers.

[0099] According to another aspect, the polymerization reactor system may include at least one gas-phase reactor (e.g., a fluidized bed reactor). Such reactor systems may employ a continuous recirculation stream containing one or more monomers, continuously circulated through a fluidized bed under polymerization conditions in the presence of a catalyst. The recirculation stream can be extracted from the fluidized bed and recycled back to the reactor. Simultaneously, polymer products can be extracted from the reactor, and new or fresh monomers can be added to replace the monomers polymerized. Such gas-phase reactors may include processes for multi-step gas-phase polymerization of olefins, wherein olefins are polymerized in the gas phase in at least two independent gas-phase polymerization zones, while a catalyst-containing polymer formed in a first polymerization zone is fed into a second polymerization zone. One type of gas-phase reactor is disclosed in U.S. Patents 5,352,749, 4,588,790, 5,436,304, 7,531,606, and 7,598,327, each of which is incorporated herein by reference in its entirety.

[0100] According to another aspect, the polymerization reactor system may include a high-pressure polymerization reactor, for example, a tubular reactor or an autoclave reactor. A tubular reactor may have several zones for adding fresh monomers, initiators, or catalysts. The monomers may be entrained in an inert gas stream and introduced in one zone of the reactor. The initiator, catalyst, and / or catalyst components may be entrained in the gas stream and introduced in another zone of the reactor. The gas streams may be mixed for polymerization. Heat and pressure may be appropriately applied in such high-pressure polymerization reactors to obtain ideal polymerization reaction conditions.

[0101] According to another aspect, the polymerization reactor system may include a solution polymerization reactor, wherein the monomer / comonomer can be contacted with the catalyst composition by appropriate stirring or other means. A carrier comprising an inert organic diluent or excess monomer may be used. Where necessary, the monomer / comonomer can be contacted with the catalytic reaction products in the gas phase, with or without liquid material. The polymerization zone can be maintained at the temperature (e.g., up to between 150°C and 180°C) and pressure at which the polymer will form a solution in the reaction medium. Agitation can be employed to obtain better temperature control and maintain a homogeneous polymerization mixture throughout the polymerization zone. Appropriate means are used to dissipate the exothermic heat of polymerization.

[0102] In some respects, a polymerization reactor system may include any combination of a feed system, a feed system for catalysts and / or catalyst components, and / or a polymer recovery system comprising a continuous system. In other respects, a suitable reactor system may include systems for feedstock purification, catalyst storage and preparation, extrusion, reactor cooling, polymer recovery, classification, recycling, storage, unloading, laboratory analysis, and process control.

[0103] Polymerization conditions that can be monitored, adjusted, and / or controlled to improve efficiency and provide desired polymer properties include, but are not limited to, reactor temperature, reactor pressure, catalyst system flow rate into the reactor, monomer flow rate into the reactor (and comonomer, if used), monomer concentration in the reactor, olefin polymer output rate, recycling rate, hydrogen flow rate (if used), reactor cooling state, etc. Polymerization temperature can affect catalyst productivity, polymer molecular weight, and molecular weight distribution. Suitable polymerization temperatures can be any temperature below the depolymerization temperature according to the Gibbs free energy equation. Typically, this includes about 60°C to about 280°C, for example, about 60°C to about 185°C, about 60°C to about 115°C, or about 130°C to about 180°C, depending on the type of polymerization reactor, polymer grade, etc. In some reactor systems, polymerization reactor temperatures can typically be in the range of about 70°C to about 110°C, or about 125°C to about 175°C.

[0104] The appropriate pressure will also vary depending on the reactor and polymerization type. Pressures for liquid-phase polymerization in loop reactors can typically be less than 1000 psig (6.9 MPa). Pressures for gas-phase polymerization are generally in the range of 200 psig to 500 psig (1.4 MPa to 3.4 MPa). High-pressure polymerization in tubular or autoclave reactors can generally be operated at approximately 20,000 psig to 75,000 psig (138 MPa to 517 MPa). Polymerization reactors can also be operated in the supercritical region, which typically occurs at higher temperatures and pressures (e.g., above 92°C and 700 psig (4.83 MPa)). Operation above the critical point (supercritical phase) of the pressure / temperature diagram can provide advantages to the polymerization process.

[0105] The concentration of reactants entering the polymerization reactor can be controlled to produce a resin with certain physical and mechanical properties. The proposed end-use product formed from the polymerized resin and the method for ultimately forming said product can determine the desired polymer properties and attributes. Mechanical properties include tensile, flexural, impact resistance, creep, stress relaxation, and hardness tests. Physical properties include density, molecular weight, molecular weight distribution, melting temperature, glass transition temperature, crystallization melting temperature, stereoregularity, crack propagation, long-chain branching, and rheological measurements.

[0106] The aspects contemplated herein also relate to and cover polymers (or oligomers) produced by any polymerization reactor system and method disclosed herein. Articles may be formed from and / or may include said polymers (or oligomers) produced according to the systems and methods described herein.

[0107] Catalyst system

[0108] The methods, processes, and reactor systems disclosed herein are applicable to, but not limited to, any catalyst system suitable for the polymerization of olefin monomers. In this document, “catalyst system” may also be referred to as “catalyst composition” or “catalyst mixture.” The first and second transition metal compounds may independently comprise, for example, transition metals from Groups 3–12 of the periodic table (Chemical and Engineering News, 63(5), 27, 1985). In one aspect, the first and / or second transition metal compounds may comprise transition metals from Groups 3, 4, 5, or 6, or combinations of two or more transition metals. In some aspects, one or more first and / or second transition metal compounds may independently comprise chromium, vanadium, titanium, zirconium, hafnium, or combinations thereof, or in other aspects, may comprise chromium, titanium, zirconium, hafnium, or combinations thereof. Thus, one or more first and / or second transition metal compounds may independently comprise chromium, or titanium, or zirconium, or hafnium, in their individual or combined forms. Furthermore, this paper envisions catalyst systems containing two or more transition metal compounds, and these additional transition metal compounds (e.g., a third transition metal compound) may independently include any suitable transition metal, such as chromium, titanium, zirconium, hafnium, vanadium, or combinations thereof.

[0109] In certain aspects of the invention, one or more first transition metal compounds and / or second transition metal compounds may independently comprise any suitable nonmetallocene compound. Generally, the methods, processes, and reactor systems disclosed herein are best suited for transition metal compounds, such as nonmetallocene compounds, wherein the absorbance characteristics of the first and second transition metal compounds overlap and cannot be deconvoluted.

[0110] Illustrative and non-limiting examples of suitable transition metal compounds covered herein may include compounds with the following compounds (R and R' = halides or C1-C). 18 Hydrocarbon groups, n = integers from 0 to 4, Ph = phenyl, tBu = tert-butyl, py = pyridine:

[0111]

[0112]

[0113] Alternatively or additionally, in some aspects, one or more first transition metal compounds and / or second transition metal compounds may independently include metallocene compounds, and the metallocene compounds may include unbridged metallocene compounds. On one hand, the metallocene compounds may include unbridged zirconium or hafnium-based metallocene compounds and / or unbridged zirconium and / or hafnium-based binuclear metallocene compounds. On another aspect, the metallocene compounds may include unbridged zirconium or hafnium-based metallocene compounds containing two indenyl or cyclopentadienyl and indenyl groups. On yet another aspect, the metallocene compounds may include unbridged zirconium or hafnium-based metallocene compounds containing two indenyl groups. On still another aspect, the metallocene compounds may include unbridged zirconium or hafnium-based metallocene compounds containing cyclopentadienyl and indenyl groups.

[0114] On the one hand, metallocene compounds may include unbridged zirconium-based metallocene compounds containing two indenyl groups, or cyclopentadienyl and indenyl groups, while on the other hand, metallocene compounds may include binuclear unbridged metallocene compounds having alkenyl linkage groups.

[0115] Illustrative and non-limiting examples of unbridged metallocene compounds suitable for use as transition metal compounds described herein may include the following compounds (Ph = phenyl, stereochemistry not shown):

[0116]

[0117] And so on, as well as their combinations.

[0118] One or more first transition metal compounds and / or second transition metal compounds are not limited to unbridged metallocene compounds as described above, or suitable unbridged metallocene compounds disclosed in U.S. Patent Nos. 7,199,073, 7,226,886, 7,312,283, and 7,619,047, which are incorporated herein by reference in their entirety. For example, one or more first transition metal compounds and / or second transition metal compounds may include unbridged binuclear metallocene compounds, such as those described in U.S. Patent Nos. 7,919,639 and 8,080,681, the disclosures of which are incorporated herein by reference in their entirety. Illustrative and non-limiting examples of binuclear metallocene compounds suitable for use in this invention may include the following compounds (stereochemistry not shown):

[0119]

[0120] And so on, as well as their combinations.

[0121] Alternatively, one or more first transition metal compounds and / or second transition metal compounds may independently include bridged metallocene compounds. In one aspect, the bridged metallocene compound may include bridged zirconium or a hafnium-based metallocene compound. In another aspect, the bridged metallocene compound may include bridged zirconium or a hafnium-based metallocene compound having an alkenyl substituent. In yet another aspect, the bridged metallocene compound may include bridged zirconium or a hafnium-based metallocene compound having an alkenyl substituent and a fluorenyl group. In still another aspect, the bridged metallocene compound may include bridged zirconium or a hafnium-based metallocene compound having a cyclopentadienyl and a fluorenyl group, and having an alkenyl substituent on the bridging group and / or the cyclopentadienyl group.

[0122] On one hand, the bridged metallocene compound may include a single-atom bridged metallocene compound having a fluorenyl group. On another hand, the bridged metallocene compound may include a single-atom bridged metallocene compound having a fluorenyl group and a cyclopentadienyl group or an indole group. On yet another hand, the bridged metallocene compound may include a single-atom bridged metallocene compound having a fluorenyl group and a cyclopentadienyl group. On still another hand, the bridged metallocene compound may include a single-atom bridged metallocene compound having a fluorenyl group and an indole group.

[0123] In these and other respects, bridged metallocene compounds may contain aryl substituents (e.g., phenyl) on the bridging atom. Additionally or alternatively, bridged metallocene compounds may contain alkenyl substituents, for example, on the bridging atom and / or on the fluorenyl group and / or on the cyclopentadienyl or indenyl group.

[0124] Illustrative and non-limiting examples of suitable bridged metallocene compounds covered herein may include the following compounds (Me = methyl, Ph = phenyl, t-Bu = tert-butyl, stereochemistry not shown):

[0125]

[0126]

[0127] And so on, as well as their combinations.

[0128] Further examples of bridged metallocene compounds suitable for use as described herein may include, but are not limited to, the following compounds (stereochemistry not shown):

[0129]

[0130] And so on, as well as their combinations.

[0131] One or more first transition metal compounds and / or second transition metal compounds are not limited to the bridged metallocene compounds described above. Other suitable bridged metallocene compounds are disclosed in U.S. Patents Nos. 7,026,494, 7,041,617, 7,226,886, 7,312,283, 7,517,939, 7,619,047, 8,288,487, 8,329,834, 8,629,292, and 9,040,642, all of which are incorporated herein by reference in their entirety.

[0132] In addition to the first and second transition metal compounds, the catalyst system may include an activator (one or more) and an optional co-catalyst. Illustrative activators may include, but are not limited to, aluminoxane compounds, organoboron or organoboroester compounds, ionized ionic compounds, activator-support (e.g., solid oxides treated with electron-withdrawing anions), or combinations thereof. Commonly used polymerization co-catalysts may include, but are not limited to, metal alkyl or organometallic co-catalysts, wherein the metal includes boron, aluminum, etc. For example, alkylboron and / or organoaluminum (e.g., alkylaluminum) compounds are commonly used as co-catalysts in catalyst systems. Representative compounds may include, but are not limited to, tri-n-butylborane, tripropylborane, triethylborane, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diisobutylaluminum hydride, diethylethoxyaluminum, diethylaluminum chloride, etc., including combinations thereof.

[0133] The cocatalysts that can be used in the catalyst system of the present invention are not limited to those described above. Other suitable cocatalysts are well known to those skilled in the art, including, for example, those disclosed in U.S. Patent Nos. 3,242,099, 4,794,096, 4,808,561, 5,576,259, 5,807,938, 5,919,983, 7,294,599, 7,601,665, 7,884,163, 8,114,946, and 8,309,485, which are incorporated herein by reference in their entirety.

[0134] solid oxides

[0135] In some respects, the catalyst system may contain a solid oxide. Typically, the solid oxide may include oxygen and one or more elements selected from Groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 of the periodic table, or may include oxygen and one or more elements selected from the lanthanides or actinides (see: Hawley's Condensed Chemical Dictionary, 11th edition, John Wiley & Sons, 1995; Cotton, FA; Wilkinson, G.; Murillo, CA; and Bochmann, M., Advanced Inorganic Chemistry, 6th edition, Wiley-Interscience, 1999). For example, solid inorganic oxides may include oxygen and one or more elements selected from Al, B, Be, Bi, Cd, Co, Cr, Cu, Fe, Ga, La, Mn, Mo, Ni, Sb, Si, Sn, Sr, Th, Ti, V, W, P, Y, Zn, and Zr.

[0136] Suitable examples of solid oxide materials or compounds that can be used as components of a catalyst system may include, but are not limited to, Al2O3, B2O3, BeO, Bi2O3, CdO, Co3O4, Cr2O3, CuO, Fe2O3, Ga2O3, La2O3, Mn2O3, MoO3, NiO, P2O5, Sb2O5, SiO2, SnO2, SrO, ThO2, TiO2, V2O5, WO3, Y2O3, ZnO, ZrO2, etc., including mixed oxides and combinations thereof.

[0137] Solid oxides can encompass oxide materials such as alumina, its “mixed oxide” compounds such as silica-alumina, and combinations or mixtures of more than one solid oxide material. Mixed oxides, such as silica-alumina, can be single-phase or multi-phase, wherein more than one metal is combined with oxygen to form a solid oxide. Examples of mixed oxides that may be used herein include, but are not limited to, silica-alumina, silica-coated alumina, silica-titanium dioxide, silica-zirconia, alumina-titanium dioxide, alumina-zirconia, zinc aluminate, alumina-boron oxide, silica-boron oxide, aluminum phosphate, aluminophosphate, aluminophosphate-silica, titanium dioxide-zirconia, etc., or combinations thereof. Silica-coated alumina is covered herein; such oxide materials are described, for example, in U.S. Patent No. 7,884,163, the disclosure of which is incorporated herein by reference in its entirety.

[0138] The percentage of each oxide in a mixed oxide can vary depending on the specific oxide material. For example, the alumina content in a silica-alumina mixture is typically from 5 wt% to 95 wt%. On one hand, the alumina content in a silica-alumina mixture can be from 5 wt% to 50 wt% alumina, or from 8 wt% to 30 wt% alumina. On the other hand, silica-alumina compounds with high alumina content can be used, wherein the alumina content of these silica-alumina materials is typically from 60 wt% to 90 wt% alumina, or from 65 wt% to 80 wt% alumina.

[0139] On the one hand, the solid oxide may include silica-alumina, silica-coated alumina, silica-titanium dioxide, silica-zirconia, alumina-titanium dioxide, alumina-zirconia, zinc aluminate, alumina-boron oxide, silica-boron oxide, aluminum phosphate, aluminophosphate, aluminophosphate-silica, titanium dioxide-zirconia, or combinations thereof; alternatively, silica-alumina; alternatively, silica-coated alumina; alternatively, silica-titanium dioxide; alternatively, silica-zirconia; alternatively, alumina-titanium dioxide; alternatively, alumina-zirconia; alternatively, zinc aluminate; alternatively, alumina-boron oxide; alternatively, silica-boron oxide; alternatively, aluminum phosphate; alternatively, aluminophosphate; alternatively, aluminophosphate-silica; or alternatively, titanium dioxide-zirconia.

[0140] In another aspect, solid oxides may include silicon dioxide, aluminum oxide, titanium dioxide, zirconium oxide, magnesium oxide, boron oxide, zinc oxide, mixed oxides thereof, or any mixture thereof. For example, solid oxides may include silicon dioxide, aluminum oxide, titanium dioxide, or combinations thereof; alternatively, silicon dioxide; alternatively, aluminum oxide; alternatively, titanium dioxide; alternatively, zirconium oxide; alternatively, magnesium oxide; alternatively, boron oxide; or alternatively, zinc oxide.

[0141] In some respects, the pore volume of solid oxides can be greater than 0.1 cc / g, or alternatively greater than 0.5 cc / g. Typically, the pore volume of solid oxides can be greater than 1.0 cc / g. Additionally or alternatively, the surface area of ​​solid oxides can be greater than 100 m². 2 / g; alternatively, greater than 250m 2 / g; or alternatively, greater than 350m 2 / g. For example, the surface area of ​​a solid oxide can be 100m². 2 / g to 1000m 2 / g、200m 2 / g to 800m2 / g, or 250m 2 / g to 600m 2 / g.

[0142] Activator-Carrier

[0143] This invention covers a variety of catalyst systems that may contain an activator-support. In one aspect, the activator-support may comprise a solid oxide treated with an electron-withdrawing anion. Alternatively, in another aspect, the activator-support may comprise a solid oxide treated with an electron-withdrawing anion, said solid oxide containing a Lewis acid metal ion. Non-limiting examples of suitable activator-supports are disclosed, for example, in U.S. Patents 7,294,599, 7,601,665, 7,884,163, 8,309,485, 8,623,973, and 8,703,886, which are incorporated herein by reference in their entirety.

[0144] Solid oxides can encompass oxide materials such as alumina, their “mixed oxides” such as silica-alumina, coatings of one oxide on another, and combinations and mixtures thereof. Mixed oxides such as silica-alumina can be single- or multi-phase chemical, wherein more than one metal is combined with oxygen to form a solid oxide. Examples of mixed oxides that can be used alone or in combination to form an activator-carrier include, but are not limited to, silica-alumina, silica-titanium dioxide, silica-zirconia, alumina-titanium dioxide, alumina-zirconia, zinc aluminate, alumina-boron oxide, silica-boron oxide, aluminophosphate-silica, titanium dioxide-zirconia, etc. Solid oxides as used herein can also encompass oxide materials such as silica-coated alumina as described in U.S. Patent No. 7,884,163.

[0145] Therefore, on one hand, solid oxides may include silica, alumina, silica-alumina, silica-coated alumina, aluminum phosphate, aluminophosphate, heteropolytungstate, titanium dioxide, silica-titanium dioxide, zirconium oxide, silica-zirconium oxide, magnesium oxide, boron oxide, zinc oxide, any mixed oxides thereof, or any combination thereof. On the other hand, solid oxides may include alumina, silica-alumina, silica-coated alumina, aluminum phosphate, aluminophosphate, heteropolytungstate, titanium dioxide, silica-titanium dioxide, zirconium oxide, silica-zirconium oxide, magnesium oxide, boron oxide, or zinc oxide, and any mixed oxides thereof, or any mixture thereof. On yet another hand, solid oxides may include silica, alumina, titanium dioxide, zirconium oxide, magnesium oxide, boron oxide, zinc oxide, any mixed oxides thereof, or any combination thereof. In another aspect, the solid oxide may include silica-alumina, silica-coated alumina, silica-titanium dioxide, silica-zirconium oxide, alumina-boron oxide, or any combination thereof. Still in another aspect, the solid oxide may include alumina, silica-alumina, silica-coated alumina, or any mixture thereof; alternatively, alumina; alternatively, silica-alumina; or alternatively, silica-coated alumina.

[0146] The silica-alumina or silica-coated alumina solid oxide materials that can be used can have a silica content of about 5% by weight to about 95% by weight. On one hand, the silica content of these solid oxides can be from about 10% by weight to about 80% by weight, or from about 20% by weight to about 70% by weight. On the other hand, the silica content of such materials can be in the range of about 15% by weight to about 60% by weight, or from about 25% by weight to about 50% by weight. As those skilled in the art will recognize, the solid oxides contemplated herein can have any suitable surface area, pore volume, and particle size.

[0147] Electron-withdrawing components used to treat solid oxides can be Lewis or Brønsted components that increase the solid oxide's viscosity after treatment. Any component of acidity (e.g., compared to a solid oxide not treated with at least one electron-withdrawing anion). According to one aspect, the electron-withdrawing component can be an electron-withdrawing anion derived from a salt, acid, or other compound, such as an electron-withdrawing anion from a volatile organic compound used as a source or precursor of said anion. Examples of electron-withdrawing anions may include, but are not limited to, sulfates, bisulfates, fluorides, chlorides, bromides, iodides, fluorosulfates, fluoroborates, phosphates, fluorophosphates, trifluoroacetates, trifluoromethanesulfonates, fluorozirconates, fluorotitanates, phosphotungstates, tungstates, molybdates, etc., including mixtures and combinations thereof. Additionally, other ionic or nonionic compounds that serve as sources of these electron-withdrawing anions may also be used. In some aspects provided herein, it is contemplated that the electron-withdrawing anion can be or may include fluoride ions, chloride ions, bromide ions, phosphate ions, trifluoromethanesulfonate ions, bisulfate ions, or sulfate ions, etc., or any combination thereof. In other respects, electron-withdrawing anions may include sulfate, hydrogen sulfate, fluoride, chloride, bromide, iodide, fluorosulfate, fluoroborate, phosphate, fluorophosphate, trifluoroacetate, trifluoromethanesulfonate, fluorozirconate, fluorotitanate, etc., or combinations thereof. However, in other respects, electron-withdrawing anions may include fluoride and / or sulfate.

[0148] The activator-carrier typically contains from about 1 wt.% to about 25 wt.% of electron-withdrawing anions by weight. In the specific aspects provided herein, the activator-carrier may contain from about 1 to about 20 wt.%, from about 2 wt.% to about 20 wt.%, from about 3 wt.% to about 20 wt.%, from about 2 wt.% to about 15 wt.%, from about 3 wt.% to about 15 wt.%, from about 3 wt.% to about 12 wt.%, or from about 4 wt.% to about 10 wt.% of electron-withdrawing anions by weight.

[0149] On the one hand, the activator-carrier may include fluorinated alumina, chlorinated alumina, brominated alumina, sulfated alumina, fluorinated silica-alumina, chlorinated silica-alumina, brominated silica-alumina, sulfated silica-alumina, fluorinated silica-zirconia, chlorinated silica-zirconia, brominated silica-zirconia, sulfated silica-zirconia, fluorinated silica-titanium dioxide, fluorinated silica-coated alumina, fluorinated-chlorinated silica-coated alumina, sulfated silica-coated alumina, phosphoric silica-coated alumina, etc., as well as any mixture or combination thereof. In another aspect, the activator-support used in the catalyst system described herein may be or may include fluorinated solid oxides and / or sulfated solid oxides, and non-limiting examples may include fluorinated alumina, sulfated alumina, fluorinated silica-alumina, sulfated silica-alumina, fluorinated silica-zirconia, fluorinated silica-coated alumina, sulfated silica-coated alumina, and combinations thereof. In yet another aspect, the activator-support may include fluorinated alumina; alternatively, aluminum chloride; alternatively, aluminum sulfate; alternatively, fluorinated silica-alumina; alternatively, silica sulfate-alumina; alternatively, silica chloride-zirconia; alternatively, silica sulfate-coated alumina; alternatively, fluorinated-chlorinated silica-coated alumina; or alternatively, silica sulfate-coated alumina. In some respects, the activator-carrier may include fluorinated solid oxides, while in others, the activator-carrier may include sulfated solid oxides.

[0150] Various processes can be used to form the activator-carrier that can be used in this invention. Methods for contacting solid oxides with electron-withdrawing components, suitable electron-withdrawing components and amounts, impregnation with metals or metal ions (e.g., zinc, nickel, vanadium, titanium, silver, copper, gallium, tin, tungsten, molybdenum, zirconium, etc., or combinations thereof), and various calcination procedures and conditions are disclosed, for example, in U.S. Patent Nos. 6,107,230, 6,165,929, 6,294,494, 6,300,271, 6,316,553, 6,355,594, 6,376,415, and 6,388,017. The patents mentioned in Nos. 6,391,816, 6,395,666, 6,524,987, 6,548,441, 6,548,442, 6,576,583, 6,613,712, 6,632,894, 6,667,274, 6,750,302, 7,294,599, 7,601,665, 7,884,163, and 8,309,485 are incorporated herein by reference in their entirety. Other suitable processes and procedures for preparing activator-carriers (e.g., fluorinated solid oxides and sulfated solid oxides) are well known to those skilled in the art.

[0151] olefin monomers and olefin polymers

[0152] The olefin monomers envisioned herein typically comprise olefin compounds having 2 to 30 carbon atoms per molecule and at least one olefin double bond. This encompasses homopolymerization processes using a single olefin, such as ethylene, propylene, butene, hexene, octene, etc., as well as copolymerization, homopolymerization, terpolymerization, and similar polymerization reactions using olefin monomers having at least one different olefin compound. As previously disclosed, polymerization processes also refer to oligomerization processes.

[0153] As an example, any resulting ethylene copolymer or terpolymer may typically contain a large amount of ethylene (>50 mol%) and a small amount of comonomer (<50 mol%). Comonomers that can be copolymerized with ethylene often have 3 to 20 carbon atoms in their molecular chains.

[0154] Acyclic, cyclic, polycyclic, terminal (α), internal, straight-chain, branched, substituted, unsubstituted, functionalized, and unfunctionalized olefins can be used. For example, typical unsaturated compounds that can be polymerized to produce olefin polymers may include, but are not limited to, ethylene, propylene, 1-butene, 2-butene, 3-methyl-1-butene, isobutene, 1-pentene, 2-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, 2-hexene, 3-hexene, 3-ethyl-1-hexene, 1-heptene, 2-heptene, 3-heptene, four types of n-octene (e.g., 1-octene), four types of n-nonene, five types of n-decene, etc., or mixtures of two or more of these compounds. As described herein, cyclic and bicyclic olefins can also be polymerized, including, but not limited to, cyclopentene, cyclohexene, norbornene, norbornadiene, etc. Styrene can also be used as a monomer or as a comonomer. On the one hand, olefin monomers can include C2-C 24 Olefins; alternatively, C2-C 12 Olefins; alternatively, C6-C 24 Olefins; alternatively, C2-C 10 α-olefin; alternatively, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene or styrene; alternatively, ethylene, propylene, 1-butene, 1-hexene or 1-octene; alternatively, ethylene or propylene; alternatively, ethylene; or alternatively, propylene.

[0155] When copolymers (or alternatively, terpolymers) are required, the olefin monomer may include, for example, ethylene or propylene, copolymerized with at least one comonomer. According to one aspect, the olefin monomer in the polymerization process may include ethylene. In this aspect, examples of suitable olefin comonomers may include, but are not limited to, propylene, 1-butene, 2-butene, 3-methyl-1-butene, isobutene, 1-pentene, 2-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, 2-hexene, 3-ethyl-1-hexene, 1-heptene, 2-heptene, 3-heptene, 1-octene, 1-decene, styrene, etc., or combinations thereof. According to another aspect, the olefin monomer may include ethylene, and the olefin comonomer may include α-olefin; and in yet another aspect, the comonomer may include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, styrene, or any combination thereof; or alternatively, the olefin comonomer may include 1-butene, 1-hexene, 1-octene, or any combination thereof.

[0156] Typically, the amount of comonomer introduced into the polymerization reactor to produce the copolymer, based on the total weight of the monomers and comonomers, can be from about 0.01 wt.% to about 50 wt%. According to another aspect, the amount of comonomer introduced into the polymerization reactor, based on the total weight of the monomers and comonomers, can be from about 0.01 wt% to about 40 wt%. Still in another aspect, the amount of comonomer introduced into the polymerization reactor, based on the total weight of the monomers and comonomers, can be from about 0.1 wt% to about 35 wt%. However, in yet another aspect, the amount of comonomer introduced into the polymerization reactor, based on the total weight of the monomers and comonomers, can be from about 0.5 wt% to about 20 wt%.

[0157] According to one aspect, at least one monomer / reactant can be ethylene, and thus the polymerization reaction can be a homopolymerization involving only ethylene, or a copolymerization with various acyclic, cyclic, terminal, internal, linear, branched, substituted, or unsubstituted olefins. Additionally, the methods disclosed herein are intended to include diene compounds, including but not limited to 1,3-butadiene, isoprene, 1,4-pentadiene, 1,5-hexadiene, etc.

[0158] The olefin polymers covered herein can comprise any polymer (or oligomer) derived from any olefin monomer (and optionally one or more comonomers) described herein. For example, olefin polymers can include ethylene homopolymers, propylene homopolymers, ethylene copolymers (e.g., ethylene / 1-butene, ethylene / 1-hexene, or ethylene / 1-octene), propylene random copolymers, propylene block copolymers, and combinations thereof. Furthermore, in some aspects, olefin polymers (or oligomers) can include olefin dimers, olefin trimers, or olefin tetramers, and mixtures or combinations thereof. Therefore, olefin polymers cover C6-C... 24 Olefins (or C6-C) 24 Oligomers of α-olefins, or 1-hexene, or 1-octene, or 1-decene, or 1-dodecene, or 1-tetradecene, or 1-hexadecene.

[0159] Catalyst preparation

[0160] The disclosed method for determining the concentration of the first transition metal compound in a solution containing the first and second transition metal compounds can also be used in a process for preparing a catalyst composition. Such a process for preparing a catalyst composition may include (I) contacting the first transition metal compound, the second transition metal compound, a solid activator, and optionally a co-catalyst (e.g., in a catalyst preparation vessel) to form a catalyst composition, (II) determining the concentration of the first transition metal compound in the solution containing the first and second transition metal compounds, separating the solution from (or obtaining from) the catalyst composition, and (III) adjusting the relative amounts of at least one component of the catalyst composition based on the concentration of the first transition metal compound in the solution (or based on the determined concentration). Therefore, the amount of at least one component of the catalyst composition added (e.g., the flow rate or feed rate into the catalyst preparation vessel) can be manually and / or automatically adjusted based on the determined concentration. Typically, this document independently describes the features of the processes disclosed herein for preparing catalyst compositions (e.g., transition metal compounds, solid activators, co-catalysts (if present), methods for determining the concentration of the first transition metal compound, and adjustments to the relative amounts of at least one component, etc.), and these features can be combined in any combination to further describe the disclosed processes. Furthermore, unless otherwise stated, additional steps may be performed before, during, and / or after any steps listed in the disclosed processes.

[0161] Referring first to step (I), a first transition metal compound, a second transition metal compound, a solid activator, and optionally a co-catalyst may be contacted to form a catalyst composition. Thus, in one aspect, step (I) may include contacting the first transition metal compound, the second transition metal compound, and the solid activator, while in another aspect, step (I) may include contacting the first transition metal compound, the second transition metal compound, the solid activator, and the co-catalyst. The respective catalyst components may be contacted in any order or sequence. For example, the solid activator and the co-catalyst may be contacted first (pre-contacted) before being contacted with the transition metal compound. Similarly, a mixture of the first and second transition metal compounds (e.g., in a solvent) may be contacted with the solid activator and the co-catalyst, or the transition metal compounds may be contacted sequentially. The solid activator may be present as a slurry of activator in a suitable diluent, and the co-catalyst may be in solution in a suitable solvent. The solvent or diluent used for the transition metal compound, the solid activator, and the co-catalyst may be any hydrocarbon solvent disclosed herein, alone or in any combination. Therefore, a solution containing a transition metal compound may contain any of the aforementioned hydrocarbon solvents.

[0162] Now for reference Figure 1The first transition metal compound solution feed stream 102 and the second transition metal compound solution feed stream 104 can form a combined transition metal compound solution feed stream 105 entering the catalyst preparation vessel 110. Alternatively, feed streams 102 and 104 can be fed directly into the catalyst preparation vessel 110 independently. Separate feed streams for activator and co-catalyst entering the catalyst preparation vessel are not shown.

[0163] Typically, the amount (and therefore the relative amount) of each component used to form the catalyst composition is known. However, when using a feed stream 105 of combined transition metal compound solutions, the corresponding relative amounts of the transition metal compounds may be unknown or imprecise. In such cases, as... Figure 1 As shown, the sample stream 132 from the combined feed stream 105 can be submitted to the analysis system 140 before entering the catalyst preparation container 110 to determine the concentration of the first transition metal compound in the combined feed stream 105.

[0164] As disclosed herein, the first and second transition metal compounds may independently comprise any suitable transition metal compound or any transition metal compound, whether non-metallocene, bridged metallocene, or non-bridged metallocene, etc. Similarly, the co-catalyst (if present) may comprise any suitable co-catalyst or any co-catalyst disclosed herein. In a particular aspect of the invention, the co-catalyst may comprise an organoaluminum compound, such as trimethylaluminum, triethylaluminum, triisobutylaluminum, etc.

[0165] In the aspects of the invention disclosed above concerning the process of operating a polymerization reactor system, the catalyst composition can be a liquid (or homogeneous) catalyst system. Regarding the processes for preparing the catalyst composition, these processes are most suitable for heterogeneous or supported catalyst systems. Therefore, the activator can be any suitable solid activator, or any solid activator disclosed herein. In one aspect, the solid activator can include solid aluminoxanes, while in another aspect, the solid activator can include activators supported on any suitable support, such as solid oxides (e.g., supported MAO), and in yet another aspect, the solid activator can include an activator-support (e.g., a solid oxide treated with an electron-withdrawing anion). If desired, a combination of more than one solid activator can be used.

[0166] Step (II) involves determining the concentration of the first transition metal compound in a solution comprising the first and second transition metal compounds. The solution containing the first and second transition metal compounds can be separated from (or obtained from) the catalyst composition. Step (II) may include the following steps: (i) submitting a sample of the solution to a sample chamber, (ii) irradiating the sample in the chamber with a beam of light of a specific wavelength in the UV-Vis spectrum, and (iii) generating a sample absorbance distribution of the sample, subtracting a reference absorbance distribution of the second transition metal compound in a reference solution from the sample absorbance distribution to obtain an absorbance distribution of the first transition metal compound, and correlating the absorbance distribution of the first transition metal compound with a standard to determine the concentration of the first transition metal compound in the solution. Therefore, the specific features associated with step (II) may be the same as those disclosed and described herein, as it relates to a method for determining the concentration of the first transition metal compound in a solution containing the first and second transition metal compounds.

[0167] In step (II), any suitable technique for separating liquids from solids can be used to separate the solution containing the first and second transition metal compounds from the catalyst composition. On one hand, for example, the catalyst composition can be sieved, filtered, and / or centrifuged to separate the solution (or liquid portion) containing the first and second transition metal compounds from the solid portion of the catalyst composition. On another hand, a settling tube as described in U.S. Patent No. 9,708,426 (incorporated herein by reference in its entirety) can be used to separate the liquid and solid portions of the catalyst composition. In yet another hand, an improved flow cell can be used. For the improved flow cell, a standard flow cell for UV-Vis analysis can be fitted with an extended lower section, the diameter of which can be the same or different, and can be made of the same or different material as the standard flow cell. The extended lower section can be configured to function like a settling tube, such that the higher density solid component settles to the bottom of the improved flow cell, and the liquid (i.e., the solution containing the transition metal compounds) occupies the upper part of the improved flow cell. Then, the liquid (solution) portion of the improved flow cell can be irradiated with a beam of light of wavelength in the UV visible spectrum (in step (ii)).

[0168] Referring now to step (III), the relative amounts of at least one component of the catalyst composition can be adjusted based on the concentration of the first transition metal compound in the solution (or based on a determined concentration). Therefore, based on the determined concentration, the amount of at least one component of the catalyst composition added—the first transition metal compound, the second transition metal compound, the solid activator, and / or the co-catalyst, if present—can be adjusted. Therefore, based on the concentration of the first transition metal compound in the solution, the amount of the first transition metal compound in the catalyst composition can be increased or decreased (e.g., the amount added into the catalyst preparation vessel or the feed rate can be increased or decreased). Alternatively or additionally, the amount of the second transition metal compound in the catalyst composition can be increased or decreased (e.g., the amount added into the catalyst preparation vessel or the feed rate can be increased or decreased). Alternatively or additionally, the amount of the solid activator in the catalyst composition can be increased or decreased (e.g., the amount added into the catalyst preparation vessel or the feed rate can be increased or decreased). Alternatively or additionally, the amount of the co-catalyst in the catalyst composition can be increased or decreased (e.g., the amount added into the catalyst preparation vessel or the feed rate can be increased or decreased).

[0169] Consistent with the aspects disclosed herein, in step (III), the relative amount of at least one component of the catalyst composition can be adjusted based on the concentration of the first transition metal compound in the solution. The adjustment of the relative amount of a particular catalyst component can be readily determined by those skilled in the art, depending, for example, on the history and primary conditions in the catalyst preparation vessel and on the overall composition of the catalyst composition (e.g., the desired composition). Illustrative techniques are provided in the following examples.

[0170] In another aspect of the invention, a catalyst preparation system is provided, and in this aspect, the catalyst preparation system may include (a) a catalyst preparation vessel configured to contact a first transition metal compound, a second transition metal compound, and a solid activator (and a co-catalyst, if used) to form a catalyst composition; (b) an activator feed stream configured to introduce a solid activator into the catalyst preparation vessel; (c) a first transition metal compound feed stream configured to introduce a first transition metal compound into the catalyst preparation vessel; (d) a second transition metal compound feed stream configured to introduce a second transition metal compound into the catalyst preparation vessel; (e) a catalyst system feed stream configured to remove the catalyst composition from the catalyst preparation vessel (e.g., and introduce the catalyst composition into a reactor); and (f) an analytical system configured to determine the concentration of the first transition metal compound in a solution comprising the first and second transition metal compounds, and to separate (or obtain) the solution from the catalyst composition (e.g., the catalyst system feed stream).

[0171] Typically, the features of any catalyst preparation system disclosed herein are described independently (e.g., catalyst preparation vessel, activator feed stream, first transition metal compound feed stream, second transition metal compound feed stream, catalyst system feed stream, analytical system, etc.), and these features can be combined in any combination to further describe the disclosed catalyst preparation system. Furthermore, unless otherwise stated, other apparatus or catalyst preparation system components may be present in the disclosed catalyst preparation system. For example, the catalyst preparation system may further include a co-catalyst feed stream configured to introduce the co-catalyst into the catalyst preparation vessel.

[0172] The analytical system may comprise any analytical system or apparatus capable of determining the concentration of a first transition metal compound in a solution containing both a first and a second transition metal compound. For example, the analytical system may comprise a UV-Vis spectrometer (e.g., alone or in combination with another analytical apparatus / method, such as fluorescence spectroscopy, a UV-Vis-NIR system, etc.).

[0173] In one aspect of the invention, the analytical system may include a UV-Vis spectrometer with an integrated computer system, as described herein, where the UV-Vis spectrometer has a "built-in" computer system. In another aspect of the invention, the analytical system may include a UV-Vis spectrometer and an external computer system, as described herein; the UV-Vis spectrometer may perform absorbance measurements and generate absorbance data and distributions, but the external computer system may take the output from the UV-Vis spectrometer and determine the concentration of a first transition metal compound.

[0174] Typically, the analytical system may further include a liquid-solid separation device configured to separate the solution (containing the first and second transition metal compounds) from the solid portion of the catalyst composition or catalyst system feed stream prior to analysis by an analytical instrument, such as a UV-Vis spectrometer. While not limited thereto, the liquid-solid separation device may include sieving devices (e.g., filters), filter assemblies, centrifuges, settling tubes, or combinations thereof, to separate or isolate the solution (or liquid portion) containing the first and second transition metal compounds from the solid portion of the catalyst composition. Alternatively or additionally, the liquid-solid separation device may include an improved flow cell as described herein; a standard flow cell for UV-Vis analysis may be fitted with an extended lower section configured to function like a settling tube, such that the higher density solid component settles to the bottom of the improved flow cell, and the liquid (i.e., the solution containing the transition metal compounds) occupies the upper portion of the improved flow cell.

[0175] For catalyst preparation systems, any features or options of the catalyst preparation vessel, absorbance distribution (e.g., sample absorbance distribution, reference absorbance distribution, and first transition metal compound absorbance distribution), and related techniques (e.g., calibration curves) may be the same as those features or options disclosed herein for polymerization reactor systems or processes for operating polymerization reactor systems.

[0176] In one aspect of the catalyst preparation system, the first transition metal compound feed stream and the second transition metal compound feed stream can be fed directly into the catalyst preparation vessel, while in another aspect, the first transition metal compound and the second transition metal compound can be combined and fed into the catalyst preparation vessel. Optionally, the activator and co-catalyst feed streams can be combined (pre-contacted), and the pre-contacted mixture can then be fed into the catalyst preparation vessel.

[0177] The catalyst preparation system may further include (g) a controller configured to control the flow rate of the activator feed stream, the flow rate of the first transition metal compound feed stream, and / or the flow rate of the second transition metal compound feed stream entering the catalyst preparation vessel based on or according to a concentration determined by an analysis system. If a co-catalyst is fed into the catalyst preparation vessel, the controller may be further configured to control the flow rate of the co-catalyst feed stream.

[0178] For catalyst preparation systems, any features or options of the controller may be the same as those disclosed herein for polymerization reactor systems or processes operating polymerization reactor systems. As an example, if it is determined that “free” transition metal compounds are present in the solution analyzed by the analytical system, the flow rate of the activator feed into the catalyst preparation vessel can be increased such that, after increasing the addition rate of the solid activator, all transition metal compounds can be absorbed by or impregnated onto the solid activator.

[0179] In the disclosed catalyst preparation system, the controller can adjust the relative amount of at least one component of the catalyst composition based on the concentration (or a determined concentration) of the first transition metal compound in the solution. Therefore, based on the concentration of the first transition metal compound in the solution, the flow rate of the activator feed stream entering the catalyst preparation vessel can be increased or decreased; additionally or alternatively, the flow rate of the first transition metal compound feed stream can be increased or decreased; additionally or alternatively, the flow rate of the second transition metal compound feed stream can be increased or decreased; and additionally or alternatively, the flow rate of the co-catalyst feed stream can be increased or decreased.

[0180] A representative catalyst preparation system 200 consistent with aspects of the present invention is shown in Figure 15 The catalyst preparation system 200 includes a catalyst preparation vessel 210, an analysis system 240, and a controller 250. The reactor 220 is also shown in... Figure 15 The catalyst preparation system 200 includes a first transition metal compound solution feed stream 202 and a second transition metal compound solution feed stream 204 (which forms a combined transition metal compound solution feed stream 205 entering the catalyst preparation vessel 210), an activator feed stream 206, and a co-catalyst feed stream 208. Although not shown, feed streams 202 and 204 can be independently and directly fed into the catalyst preparation vessel 210. Figure 15 As shown, the sample stream 232 from the combined feed stream 205 can be submitted to the analysis system 240 and UV-Vis spectrometer 260 before entering the catalyst preparation container 210 to determine the concentration of the first transition metal compound in the combined feed stream 205.

[0181] Catalyst system feed stream 215 can flow from catalyst preparation vessel 210 through valve 292 and into reactor 220. Catalyst system feed stream 215 can be a supported (or heterogeneous) catalyst system containing a first transition metal compound and a second transition metal compound. Sample stream 234 from catalyst system feed stream 215 can flow through valve 294 and into analysis system 240 to determine the concentration of the first transition metal compound in the solution portion of stream 234. Sample stream can enter flow cell 270 through settling tube 280 (shown with a tube diameter smaller than the flow cell diameter, but its diameter may be equal to or greater than the flow cell diameter). Flow cell 270 and settling tube 280 (e.g., modified flow cell) can be configured to separate or isolate the solid components of catalyst system sample stream 234 from the liquid components, allowing UV-Vis spectrometer 260 to analyze the liquid portion in flow cell 270. After analysis, the analyzed catalyst sample stream 285 can flow through valve 296 and be recycled together with catalyst system feed stream 215.

[0182] Information or data 245 regarding the concentration of the first transition metal compound from the analysis system 240 can be provided to the controller 250. The controller can then control or regulate the flow rate 255 of the activator feed stream 206 and / or the co-catalyst feed stream 208 and / or the combined feed stream 205 entering the catalyst preparation vessel 210. Alternatively or additionally, the flow rates of the first transition metal compound solution feed stream 202 and / or the second transition metal compound solution feed stream 204 can be controlled or regulated 255. Thus, the controller 250 controls or regulates the flow rates 255 of the activator feed stream 206, the co-catalyst feed stream 208, the first transition metal compound feed stream 202, and / or the second transition metal compound feed stream 204 entering the catalyst preparation vessel 210 based on or according to the concentration determined by the analysis system 240.

[0183] The following is Figure 15 Illustrative and non-limiting examples of the operation of the catalyst preparation system are provided. A first metallocene compound, a second metallocene compound, an activator-support, and an organoaluminum co-catalyst can be continuously fed into the catalyst preparation vessel. Before entering the catalyst preparation vessel, the first and second metallocene compound feed streams are combined, and the corresponding concentrations of the first and second metallocene compounds can be known or can be measured continuously or as needed using an analytical system incorporating a UV-Vis spectrometer, employing the techniques disclosed herein.

[0184] The active catalyst composition formed in the catalyst preparation vessel can be continuously fed into the polymerization reactor. The path taken by the catalyst composition from the catalyst preparation vessel to the reactor can be switched between two possible paths. In path 1, the catalyst composition flows directly to the reactor without interruption or measurement, and this is the path followed most of the time. However, when it is necessary to analyze the catalyst composition, path 2 is used: the catalyst composition flows to the analytical system before finally entering the reactor.

[0185] For path 2, valve 292 is closed, and valves 294 and 296 are opened for a desired time period, which can be as short as 1-5 seconds or as long as 1-5 minutes, but is not limited thereto. This allows the catalyst composition to follow the sample flow 234 and allows the flow cell 270 and settling tube 280 to be purged with a sample of fresh catalyst composition from the catalyst preparation vessel 210. Once the desired time period has ended, valves 294 and 296 are closed, valve 292 is opened, and the catalyst composition flows again through valve 292 to the reactor.

[0186] When valves 294 and 296 are closed, the catalyst composition slurry between these two valves has the opportunity to settle, and the supernatant containing the "free" first and second metallocene compounds can be analyzed by a UV-Vis spectrometer 260 through a flow cell 270. By measuring the corresponding amount of the "free" metallocene, the amount of the corresponding metallocene compound absorbed / impregnated on the activator-support can be determined (by comparing it with the combined first and second metallocene compound feed streams entering the catalyst preparation vessel).

[0187] Advantageously, these measurements can be performed in real time with minimal intervention and waste. The controller 250 can be further configured to control the opening / closing function of the valve and its periodicity and duration. Additionally, the catalyst preparation system can include more than one analytical device; for example, one UV-Vis instrument can be used to measure the concentration of the transition metal entering the catalyst preparation vessel, and another UV-Vis instrument can be used to measure the concentration of the "free" transition metal in the solution portion of the supported catalyst composition.

[0188] Flow cell equipment and related methods

[0189] Because this may involve methods for determining the corresponding concentration of transition metal compounds in a solution separated (or prepared) from a sample mixture from a reactor or from a heterogeneous or supported catalyst system, a method for measuring the properties of a liquid in a container containing a liquid-solid mixture is disclosed. The method for measuring the properties (e.g., transition metal concentration) of a liquid (solution) in a container (e.g., a reactor or catalyst preparation container) containing a liquid-solid mixture may include (i) removing a sample of the liquid-solid mixture from the container, (ii) allowing the sample of the liquid-solid mixture to flow through a flow cell apparatus, (iii) periodically stopping the flow of the sample of the liquid-solid mixture in the flow cell apparatus for a period sufficient to allow the solids to settle to the bottom of the flow cell apparatus (first part) and the liquid to occupy the upper part of the flow cell apparatus (second part), (iv) irradiating the liquid in the upper part of the flow cell apparatus with a beam of light of a specific wavelength in the UV-Vis spectrum to measure the properties of the liquid, and (v) resuming the flow through the flow cell apparatus. Optionally, the sample may be returned to the container. Therefore, in the process for preparing the catalyst composition, the solution and the catalyst composition can be separated, and the corresponding concentration can be determined by a method comprising the following steps: submitting the flow rate of the catalyst composition to a sample chamber including a flow cell device; periodically stopping the flow of the catalyst composition in the flow cell device for a period sufficient to allow the solid portion to settle to the bottom of the flow cell device (first part) and for a period of time allowing the solution (liquid) sample to occupy the upper part of the flow cell device (second part); and irradiating the sample in the upper part of the flow cell device with a beam of light of a specific wavelength in the UV visible spectrum. Subsequently, the flow through the flow cell device can be resumed, and optionally, the flow of the catalyst composition can be returned to the catalyst preparation vessel or introduced into the reactor.

[0190] Referring now to liquid-solid mixtures, a flow cell apparatus consistent with aspects of the present invention can be configured to isolate the solids to the bottom of the flow cell apparatus and allow the liquid to occupy the upper part of the flow cell apparatus, and the upper part of the flow cell apparatus can be configured to irradiate the liquid with a beam of light of a certain wavelength in the UV-Vis spectrum (e.g., the upper part of the flow cell apparatus can be configured to analyze the liquid by a UV-Vis spectrometer). Thus, in a catalyst preparation system, the analytical system may include a flow cell apparatus configured to isolate (or separate) the solid portion of the catalyst composition to the bottom of the flow cell apparatus, and the solution (liquid portion) to occupy the upper part of the flow cell apparatus, and the upper part of the flow cell apparatus can be configured to irradiate the solution with a beam of light of a certain wavelength in the UV-Vis spectrum (e.g., the upper part of the flow cell apparatus can be configured to analyze the solution by a UV-Vis spectrometer). The sedimentation aspect in liquid-solid systems applicable to the methods and systems provided herein is disclosed in U.S. Patent No. 9,708,426, which is incorporated herein by reference in its entirety.

[0191] Example

[0192] The invention is further illustrated by the following examples, which should not be construed as limiting the scope of the invention in any way. Various other aspects, modifications, and equivalents will arise in the minds of those skilled in the art upon reading this description without departing from the spirit of the invention or the scope of the appended claims.

[0193] The chemical structures of the first, second, and third transition metal compounds used in the examples are provided below as MET-1, MET-2, and MET-3, respectively.

[0194]

[0195] Solution containing a transition metal compound

[0196] Separate stock solutions of MET-1 and MET-2 were prepared and used to further prepare solutions of transition metal compounds of different concentrations used in the examples. To prepare the stock solutions, the corresponding transition metal compounds were weighed into a metal weighing pan using an analytical balance contained in a glove box. The glove box atmosphere was maintained at less than 0.1 ppm of oxygen and less than 0.1 ppm of water. Using a volumetric flask, a previously sieved and dried solvent (1-hexene or toluene) was measured to a known volume. All the measured solvent was used to quantitatively rinse the corresponding transition metal compound from the metal weighing pan into a glass vial (approximately 20–30 mL). A small stir bar was added to the vial, and the vial was capped with a diaphragm and metal seal. The contents of the vial were magnetically stirred in the glove box at approximately 1000 rpm, and dissolution was monitored. Depending on the transition metal compound, solvent, and concentration, dissolution was complete within approximately 30 minutes. In this manner, four stock solutions (MET-1 in 1-hexene, MET-1 in toluene, MET-2 in 1-hexene, and MET-2 in toluene) were prepared. The concentration of the transition metal compound in each stock solution was 0.1 wt.%.

[0197] Then, for each stock solution, a sample of the stock solution is dispensed using a syringe and added to a separate vial. An equal volume of the same solvent is added to the sample, and the vial is filled with a stir bar and capped as before. The mixture is allowed to be stirred to obtain a solution with half the original concentration of the stock solution. This procedure is repeated continuously to produce a series of solutions in which the transition metal concentration is halved with each repetition.

[0198] Homogeneity of each sample was verified by visual inspection in a glove box. Quartz cuvettes, previously dried in an oven at 110°C for several hours, and their corresponding caps were placed in the glove box. One cuvette was filled with approximately 3–3.5 mL of pure solvent (1-hexene or toluene, and the same solvent used in the corresponding stock solutions and diluents) and capped as a reference unit. The remaining cuvettes were each filled with approximately 3–3.5 mL of metallocene solution and tightly capped to prevent accidental exposure to the atmosphere. The cuvettes were removed from the glove box and analyzed using a Shimadzu UV-2550UV-Vis spectrometer. Samples were typically analyzed in 0.5 nm increments within the wavelength range of 300–800 nm.

[0199] The raw data from each analysis consisted of a file containing bar charts of wavelength (nm) and absorbance (in arbitrary units). Data from all analyzed samples were copied from the raw data file to a single spreadsheet. The absorbance versus wavelength distribution for each combination of (1) transition metal compounds and (2) solvents was plotted in a single graph. Representative graphs are shown for... Figure 2 (MET-2 in toluene) Figure 4 (MET-2 in 1-hexene) Figure 6 (MET-1 in toluene) and Figure 8 In (MET-1 in 1-hexene). Each transition metal compound in each solvent exhibits a characteristic peak, with its maximum absorbance varying with concentration. Representative wavelengths are selected within this absorbance peak (e.g., one and two additional wavelengths at the maximum wavelength, or one on either side of the maximum wavelength). For each representative wavelength, absorbance is plotted against transition metal concentration. Least-squares regression of the absorbance versus concentration data yields a calibration curve for a given combination of transition metal compound and solvent at the stated representative wavelength. Illustrative calibration curves are shown in... Figure 3 (MET-2 in toluene) Figure 5 (MET-2 in 1-hexene) Figure 7 (MET-1 in toluene) and Figure 9 In (MET-1 in 1-hexene).

[0200] As from Figure 2-9 It can be seen that the absorbance distribution of each UV-Vis depends on the transition metal compound, the solvent, and the concentration of the transition metal compound in the solvent. Furthermore, the linear calibration curve is highly accurate when correlating the measured absorbance with the corresponding concentration of the transition metal compound in the solvent at the selected wavelength: the statistical RV is high in all cases. 2 All values ​​are greater than 0.99.

[0201] Solution containing two transition metal compounds

[0202] In a subsequent set of experiments, stock solutions of MET-1 and MET-2 in toluene were prepared and then combined to produce solutions containing the two transition metal compounds, MET-1 and MET-2. The corresponding compositions of samples 1–5 are shown in Table I.

[0203] Table I. Concentration of transition metal compounds (wt.%).

[0204] sample [MET-2] [MET-1] 1 0.200 0.208 2 0.200 0.139 3 0.200 0.069 4 0.200 0.017 5 0.200 0.000

[0205] Absorption spectra (1 mm path) for each of samples 1-5 were obtained in a similar manner to that described above, using solvent only in the reference cell. The resulting spectra were compiled into a single graph, as shown below. Figure 10 As shown. Figure 10 As can be seen, the characteristic peak of MET-1 at 380 nm is difficult to distinguish due to the overlap of absorbance with MET-2 within the specified range. Indeed, when the concentration of MET-1 is much lower than that of MET-2 (samples 3-4, MET-1:MET-2 weight ratio of ~1:3 to 1:12), the resulting absorbance distribution shows little difference from the solution containing only MET-2 (sample 5). In fact, even when the concentrations of MET-1 and MET-2 are more similar (e.g., samples 1-2, MET-1:MET-2 weight ratio of ~1:1 to 1:1.4), the absorbance of MET-2 near 380 nm overwhelms the characteristic peak of the MET-1 / toluene absorbance distribution (see [reference]). Figure 6 Therefore, only Figure 10 Sufficient data are not available to determine the concentration of MET-1 in a solution containing both MET-1 and MET-2.

[0206] However, unexpectedly, when from Figure 10 When the absorbance distribution of sample 5 is subtracted from the "reference" absorbance distribution (0.2 wt.% MET-2 in toluene) in the absorbance distribution, the result is... Figure 11 Now, sample 5 is the baseline, and for samples 1-4, the characteristic peak of MET-1 at 380 nm and its dependence on MET-1 concentration can be easily identified and quantified. Figure 12 The linear calibration curve is presented, which uses data from... Figure 11 The data correlated the absorbance at 380 nm with the concentration of the transition metal compound MET-1. Statistical R 2The value is greater than 0.99. Therefore, even in samples containing a large amount of the second transition metal compound (MET-2) and / or in cases where the second transition metal compound (MET-2) has overlapping absorbance bands, the concentration of the first transition metal compound (MET-1) in a solution containing the first transition metal compound (MET-1) and the second transition metal compound (MET-2) can be accurately determined.

[0207] The methods, processes, and reactor systems disclosed herein can also be applied to solutions containing three or more transition metal compounds. For example, in a solution containing transition metal compounds MET-A, MET-B, and MET-C, the concentration of transition metal compound MET-A can be determined using a similar procedure, wherein the absorbance distributions of compounds MET-B and MET-C (in a hydrocarbon solvent) are subtracted together from the absorbance distribution of the sample to obtain the absorbance distribution of MET-A, which can then be correlated with a standard to determine the concentration of MET-A in the solution.

[0208] Preparation using catalysts of two transition metal compounds

[0209] Stock solutions of MET-1 and MET-3 in toluene were prepared and then mixed with different amounts of alumina sulfate activator-support (AS) at room temperature for 1 hour to produce a supported catalyst system containing approximately 0.22 wt.% MET-1 and 0.37 wt.% MET-3. Since no co-catalyst was added, the interaction between the transition metal compound and the activator-support could be investigated. Figure 13 The concentrations of the corresponding transition metal compounds present in the absence of an activator-support (zero mg) are shown. As the amount of added activator-support increases (50 mg to 500 mg), the corresponding amounts of “free” MET-1 and MET-3 present in solution (e.g., not impregnated in, on, or associated with the activator-support) decrease. The corresponding concentrations of MET-1 and MET-3 can be determined by separating the solution (and the “free” MET-1 and MET-3) from the solid catalyst components by filtration, and can then be determined as described herein. Figure 10-12 The demonstration shows how to determine the concentration of a solution.

[0210] like Figure 13 As shown, when 300 mg (or more) of activator-carrier (AS) is present, there are no "free" MET-1 and MET-3 in the solution—all MET-1 and MET-3 are absorbed or impregnated on the solid activator-carrier. Also noteworthy is that... Figure 13 This demonstrates that MET-1 is absorbed more rapidly (preferably) by the activator-carrier. When the amount of activator-carrier is 150 mg or higher, there is almost no “free” MET-1 in the solution.

[0211] Figure 14 It was shown in another way Figure 13 The data is presented as follows. The dashed line (100% absorption) starting from the origin reflects the following: the amount of activator-carrier (AS) present is sufficient for all present MET-1 and MET-3 to be absorbed or impregnated on the activator-carrier—without “free” MET-1 and MET-3. This occurs at activator-carrier loadings in the range of 300–500 mg. The faster relative absorption of MET-1 (compared to MET-3) is shown by the MET-1 line (as a function of activator-carrier) approaching the dashed line at much lower activator-carrier loadings. For example, when 100 mg of activator-carrier is present, the MET-1 line is very close to the dashed line (the added ~0.13 MET-1 absorbs ~0.12 MET-1), while the MET-3 line is not close to the dashed line. At 100 mg of activator-carrier, the added ~0.12 MET-3 absorbs only ~0.035 MET-3. Therefore, in order to produce a catalyst composition with equal absorption of MET-1 and MET-3 with a fixed amount of 100 mg activator-carrier, the amount of MET-1 added can be reduced, the amount of MET-3 added can be increased, or both.

[0212] The amount of "free" transition metal compounds in solution is crucial for catalyst preparation compared to absorption or impregnation onto solid activators. Figure 13-14 Data, for example, suggests that approximately 300 mg of solid activator is sufficient to eliminate any “free” transition metal compounds – all of which are absorbed or impregnated. Therefore, if the typical loading of solid activator during the catalyst preparation step is 500 mg or 600 mg or more, this data indicates that the amount of solid activator can be significantly reduced, thereby reducing waste and improving cost and efficiency.

[0213] As another example, if a MET-1 and MET-3 catalyst system is used to produce polymers for which improved properties are desired, and these properties are positively affected by the addition of more MET-1, then... Figure 13-14 The data indicate that this can be easily accomplished without adding more catalyst composition. Conversely, due to the rapid and preferential absorption of MET-1, the amount of MET-1 fed into the catalyst preparation vessel can be increased, resulting in a relative increase in the amount of MET-3 present in the entire catalyst composition.

[0214] As will be readily apparent to those skilled in the art, it is possible to obtain from similar Figure 13-14The UV-Vis data, representatively illustrated herein, identify a variety of other possibilities for modifying and optimizing the catalyst system, and adjust the relative amounts of at least one component of the catalyst composition based on the concentration of the first transition metal compound (and / or the second transition metal compound) in solution determined by the UV-Vis method disclosed herein. Therefore, depending on the determined concentrations of one or more, the amount of the first transition metal compound in the catalyst composition can be increased or decreased, and / or the amount of the second transition metal compound in the catalyst composition can be increased or decreased, and / or the amount of the solid activator in the catalyst composition can be increased or decreased, and / or the amount of the co-catalyst in the catalyst composition can be increased or decreased to optimize the catalyst composition for better determinism and predictability of results.

[0215] The invention has been described above, with reference to numerous aspects and specific examples. Based on the specific embodiments described above, it will be apparent to those skilled in the art that many variations exist. All such apparent variations are within the full scope of the appended claims. Other aspects of the invention may include, but are not limited to, the following (aspects are described as “comprising,” but alternatively, may “consist mainly of” or “comprise” unless otherwise specified):

[0216] Aspect 1. A method for determining the concentration of a first transition metal compound in a solution comprising a first transition metal compound and a second transition metal compound, the method comprising:

[0217] (i) Submit a sample of the solution to the sample chamber;

[0218] (ii) Irradiating the sample in the room with a beam of light of a specific wavelength in the UV-visible spectrum; and

[0219] (iii) Generate a sample absorbance distribution of the sample, subtract a reference absorbance distribution of the second transition metal compound in a reference solution from the sample absorbance distribution to obtain a first transition metal compound absorbance distribution, and correlate the first transition metal compound absorbance distribution with a standard to determine the concentration of the first transition metal compound in the solution.

[0220] Aspect 2. The method according to aspect 1, wherein the solution of the first transition metal compound and the second transition metal compound is a feed stream entering a catalyst preparation vessel.

[0221] Aspect 3. The method according to aspect 1, wherein the solution of the first transition metal compound and the second transition metal compound is a liquid (or homogeneous) catalyst system comprising the first transition metal compound, the second transition metal compound and other catalyst components.

[0222] Aspect 4. The method according to aspect 1, wherein the solution of the first transition metal compound and the second transition metal compound is a solution of a heterogeneous catalyst system (e.g., a solution prepared from a sample mixture of catalyst systems, such as a catalyst preparation vessel), or a solution from a polymerization reactor (e.g., a solution prepared from a sample mixture from a polymerization reactor).

[0223] Aspect 5. A process for preparing a catalyst composition, the process comprising:

[0224] (I) Contacting a first transition metal compound, a second transition metal compound, a solid activator, and an optional co-catalyst (e.g., in a catalyst preparation vessel) to form the catalyst composition;

[0225] (II) Determining the concentration of the first transition metal compound in a solution containing the first transition metal compound and the second transition metal compound, wherein the solution is separated from (or obtained from) the catalyst composition, and the concentration is determined by the following steps:

[0226] (i) Submit a sample of the solution to the sample chamber;

[0227] (ii) Irradiating the sample in the room with a beam of light of a specific wavelength in the UV-visible spectrum; and

[0228] (iii) Generating a sample absorbance distribution of the sample, subtracting a reference absorbance distribution of the second transition metal compound in a reference solution from the sample absorbance distribution to obtain a first transition metal compound absorbance distribution, and correlating the first transition metal compound absorbance distribution with a standard to determine the concentration of the first transition metal compound in the solution; and

[0229] (III) Adjust the relative amount of at least one component of the catalyst composition based on the concentration of the first transition metal compound in the solution (or based on the determined concentration).

[0230] Aspect 6. The process according to aspect 5, wherein in step (I), the first transition metal compound, the second transition metal compound, the solid activator and the co-catalyst are in contact.

[0231] Aspect 7. The process according to aspect 6, wherein in step (I), a solution containing both the first transition metal compound and the second transition metal compound is contacted with a slurry of the co-catalyst and the solid activator.

[0232] Aspect 8. The process according to any one of Aspects 5 to 7, wherein the solution is separated from (or obtained from) the catalyst composition using any suitable technique or any technique disclosed herein, such as sieving (e.g., tightening), filtration, centrifugation, sedimentation, etc., or any combination thereof.

[0233] Aspect 9. The process according to any one of Aspects 5 to 8, wherein in step (III), the relative amounts of the first transition metal compound, the second transition metal compound, the solid activator, the co-catalyst (if used), or any combination thereof are adjusted.

[0234] Aspect 10. A process for operating a polymerization reactor system, the process comprising:

[0235] (I) Under polymerization reaction conditions, a catalyst system comprising a first transition metal compound, a second transition metal compound, an activator and an optional cocatalyst is contacted with an olefin monomer and an optional olefin comonomer in a reactor within the polymerization reactor system to produce an olefin polymer.

[0236] (II) Determine the concentration of the first transition metal compound in a solution comprising the first transition metal compound and the second transition metal compound, wherein the concentration is determined by the following steps:

[0237] (i) Submit a sample of the solution to the sample chamber;

[0238] (ii) Irradiating the sample in the room with a beam of light of a specific wavelength in the UV-visible spectrum; and

[0239] (iii) Generating a sample absorbance distribution of the sample, subtracting a reference absorbance distribution of the second transition metal compound in a reference solution from the sample absorbance distribution to obtain a first transition metal compound absorbance distribution, and correlating the first transition metal compound absorbance distribution with a standard to determine the concentration of the first transition metal compound in the solution; and

[0240] (III) When the concentration of the first transition metal compound in the solution has reached a predetermined level, the flow rate of the first transition metal compound entering the reactor is adjusted (or the flow rate of the first transition metal compound is adjusted based on a determined concentration).

[0241] Aspect 11. The process according to aspect 10, wherein the solution of the first transition metal compound and the second transition metal compound is a feed stream into a catalyst preparation vessel, and the flow rate of the first transition metal compound into the reactor is controlled by adjusting the flow rate of the feed stream into the catalyst preparation vessel, and / or by adjusting the relative flow rate (ratio of the first transition metal compound to the second transition metal compound) into the catalyst preparation vessel, and / or by adjusting the flow rate of the catalyst system leaving the catalyst preparation vessel and entering the reactor.

[0242] Aspect 12. The process according to aspect 10, wherein the catalyst system is a liquid (or homogeneous) catalyst system, and the solution comprising the first transition metal compound and the second transition metal compound is a sample of the liquid catalyst system, and wherein the flow rate of the first transition metal compound into the reactor is controlled by adjusting the relative flow rate to the reactor (the ratio of the first transition metal compound to the second transition metal compound), and / or by adjusting the flow rate of the liquid catalyst system into the reactor.

[0243] Aspect 13. The process according to aspect 10, wherein the polymerization reactor system comprises a polymerization reactor containing a mixture, and the solution comprising the first transition metal compound and the second transition metal compound is a solution prepared from a sample of the mixture from the polymerization reactor (e.g., a solution polymerization reactor, a slurry polymerization reactor), and wherein the flow rate of the first transition metal compound into the polymerization reactor is controlled by adjusting the relative flow rate to the reactor (the ratio of the first transition metal compound to the second transition metal compound), and / or by adjusting the flow rate of the catalyst system into the polymerization reactor.

[0244] Aspect 14. The method or process according to any one of the preceding aspects, wherein the sample chamber includes a flow cell.

[0245] Aspect 15. The method or process according to any one of Aspects 1 to 14, wherein the wavelength is a single wavelength.

[0246] Aspect 16. The method or process according to any one of Aspects 1 to 14, wherein the wavelength is a range of wavelengths.

[0247] Aspect 17. The method or process according to any one of Aspects 1 to 14, wherein the wavelength includes wavelengths within the visible spectrum (380 nm to 780 nm).

[0248] Aspect 18. The method or process according to any one of Aspects 1 to 14, wherein the wavelength includes wavelengths in the range of 200 nm to 750 nm.

[0249] Aspect 19. The method or process according to any one of Aspects 1 to 14, wherein the wavelength includes wavelengths in the range of 300 nm to 600 nm.

[0250] Aspect 20. The method or process according to any one of Aspects 1 to 19, wherein the absorbance distribution of the sample (or reference or first transition metal compound) includes an absorbance peak at a single wavelength.

[0251] Aspect 21. The method or process according to any one of Aspects 1 to 19, wherein the absorbance distribution of the sample (or reference or first transition metal compound) comprises an absorbance profile (e.g., peaks and / or areas under the profile) in the wavelength range of 200 nm to 750 nm or 300 nm to 600 nm.

[0252] Aspect 22. The method or process according to any one of Aspects 1 to 19, wherein the absorbance distribution of the sample (or reference or first transition metal compound) comprises an absorbance profile within a subset of wavelengths less than 200 nm, less than 150 nm, less than 100 nm, or less than 50 nm.

[0253] Aspect 23. The method or process according to any one of the preceding aspects, wherein the relevant steps are performed at a single wavelength, and wherein the absorbance peak at the single wavelength (in the absorbance distribution of the first transition metal compound) is less than 2 or less than 1.

[0254] Aspect 24. The method or process according to any one of the preceding aspects, wherein the reference solution comprises the second transition metal compound and a hydrocarbon solvent.

[0255] Aspect 25. The method or process according to any one of the preceding aspects, wherein the standard includes a calibration curve.

[0256] Aspect 26. The method or process according to any one of the preceding aspects, wherein the associated steps include any suitable method for converting the absorbance distribution (or peak) of the first transition metal compound into the concentration of the first transition metal compound in the solution.

[0257] Aspect 27. A catalyst preparation system comprising:

[0258] (a) A catalyst preparation container configured to contact a first transition metal compound, a second transition metal compound, a solid activator, and an optional co-catalyst to form a catalyst composition;

[0259] (b) An activator feed stream configured to introduce the solid activator into the catalyst preparation vessel;

[0260] (c) A first transition metal compound feed stream, the first transition metal compound feed stream being configured to introduce the first transition metal compound into the catalyst preparation vessel;

[0261] (d) A second transition metal compound feed stream, the second transition metal compound feed stream being configured to introduce the second transition metal compound into the catalyst preparation vessel;

[0262] (e) a catalyst system feed stream configured to remove the catalyst composition from the catalyst preparation vessel (e.g., and configured to introduce the catalyst composition into the reactor, if desired); and

[0263] (f) An analytical system configured to determine the concentration of the first transition metal compound in a solution comprising the first transition metal compound and the second transition metal compound, wherein the solution is separated from (or obtained from) the catalyst composition (e.g., from the catalyst system feed stream).

[0264] Aspect 28. The system according to aspect 27, wherein the catalyst preparation system further includes a co-catalyst feed stream configured to introduce the co-catalyst into the catalyst preparation vessel.

[0265] Aspect 29. The system according to aspect 27 or 28, wherein the catalyst preparation system further comprises (g) a controller configured to control the flow rate of the activator feed stream, the flow rate of the first transition metal compound feed stream, and / or the flow rate of the second transition metal compound feed stream (and / or the flow rate of the co-catalyst, if used) entering the catalyst preparation vessel based on or according to a concentration determined by the analysis system.

[0266] Aspect 30. The system according to any one of Aspects 27 to 29, wherein the first transition metal compound feed stream and the second transition metal compound feed stream are directly fed into the catalyst preparation vessel.

[0267] Aspect 31. The system according to any one of Aspects 27 to 29, wherein the first transition metal compound feed stream and the second transition metal compound feed stream are combined before the catalyst preparation container.

[0268] Aspect 32. The system according to any one of Aspects 27-31, wherein the analytical system further comprises a liquid-solid separation device configured to separate the solution (comprising the first transition metal compound and the second transition metal compound) from the catalyst composition (e.g., from the catalyst system feed stream).

[0269] Aspect 33. A polymerization reactor system comprising:

[0270] (A) A reactor configured to contact a catalyst system with olefin monomers and optional olefin comonomers under polymerization reaction conditions to produce an olefin polymer.

[0271] (B) A catalyst preparation container configured to contact a first transition metal compound, a second transition metal compound, an activator, and an optional co-catalyst to form the catalyst system; and

[0272] (C) An analytical system configured to determine the concentration of the first transition metal compound in a solution containing the first transition metal compound and the second transition metal compound present within the polymerization reactor system.

[0273] Aspect 34. The system according to any one of Aspects 27 to 33, wherein the analytical system comprises a UV-Vis spectrometer having an integrated computer system, the UV-Vis spectrometer being used to measure a sample absorbance distribution of the solution, to subtract a reference absorbance distribution of the second transition metal compound in a reference solution from the sample absorbance distribution to obtain a first transition metal compound absorbance distribution, and to correlate the first transition metal compound absorbance distribution with a standard to determine the concentration of the first transition metal compound in the solution.

[0274] Aspect 35. The system according to any one of Aspects 27 to 33, wherein the analytical system comprises a UV-Vis spectrometer and an external computer system, the UV-Vis spectrometer being configured to measure a sample absorbance distribution of the solution, and the external computer system being configured to subtract a reference absorbance distribution of the second transition metal compound in a reference solution from the sample absorbance distribution to obtain a first transition metal compound absorbance distribution, and to correlate the first transition metal compound absorbance distribution with a standard to determine the concentration of the first transition metal compound in the solution.

[0275] Aspect 36. The system according to any one of Aspects 34 to 35, wherein the analytical system further comprises a filter assembly configured to filter a sample of the solution prior to analysis by the UV-Vis spectrometer.

[0276] Aspect 37. The system according to any one of Aspects 34 to 36, wherein the absorbance distribution of the sample (or reference or first transition metal compound) includes an absorbance peak at a single wavelength.

[0277] Aspect 38. The system according to any one of Aspects 34 to 36, wherein the absorbance distribution of the sample (or reference or first transition metal compound) comprises an absorbance profile (e.g., peaks and / or areas under the profile) in the wavelength range of 200 nm to 750 nm or 300 nm to 600 nm.

[0278] Aspect 39. The system according to any one of Aspects 34 to 25, wherein the absorbance distribution of the sample (or reference or first transition metal compound) comprises an absorbance profile within a subset of wavelengths less than 200 nm, less than 150 nm, less than 100 nm, or less than 50 nm.

[0279] Aspect 40. The system according to any one of Aspects 34 to 39, wherein the reference solution comprises the second transition metal compound and a hydrocarbon solvent.

[0280] Aspect 41. The system according to any one of Aspects 34 to 40, wherein the standard includes a calibration curve.

[0281] Aspect 42. The system according to any one of Aspects 34 to 41, wherein the associated steps include any suitable technique for converting the absorbance distribution (or peak) of the first transition metal compound into the concentration of the first transition metal compound in the solution.

[0282] Aspect 43. The system according to any one of Aspects 33 to 42, wherein the reactor system further comprises (D) a controller configured to control the flow rate of the first transition metal compound entering the reactor based on (or according to) the concentration determined by the analysis system.

[0283] Aspect 44. The system according to aspect 43, wherein the controller includes a processing unit.

[0284] Aspect 45. The system according to any one of Aspects 43 to 44, wherein the solution of the first transition metal compound and the second transition metal compound is a feed stream into a catalyst preparation vessel, and the controller controls the flow rate of the first transition metal compound into the reactor by adjusting the flow rate of the feed stream into the catalyst preparation vessel, and / or by adjusting the relative flow rate (ratio of the first transition metal compound to the second transition metal compound) into the catalyst preparation vessel, and / or by adjusting the flow rate of the catalyst system leaving the catalyst preparation vessel and entering the reactor.

[0285] Aspect 46. The system according to any one of Aspects 43 to 44, wherein the catalyst system is a liquid (or homogeneous) catalyst system, and the solution comprising the first transition metal compound and the second transition metal compound is a sample of the liquid catalyst system, and wherein the controller controls the flow rate of the first transition metal compound into the reactor by adjusting the relative flow rate to the reactor (the ratio of the first transition metal compound to the second transition metal compound), and / or by adjusting the flow rate of the liquid catalyst system into the reactor.

[0286] Aspect 47. The system according to any one of Aspects 43 to 44, wherein the polymerization reactor system comprises a polymerization reactor containing a mixture, and the solution comprising the first transition metal compound and the second transition metal compound is a solution prepared from a sample of the mixture from the polymerization reactor (e.g., a solution polymerization reactor, a slurry polymerization reactor), and wherein the controller controls the flow rate of the first transition metal compound into the polymerization reactor by adjusting the relative flow rate to the reactor (the ratio of the first transition metal compound to the second transition metal compound), and / or by adjusting the flow rate of the catalyst system into the polymerization reactor.

[0287] Aspect 48. The process or system according to any one of Aspects 10 to 26 or 33 to 47, wherein the reactor system comprises a reactor.

[0288] Aspect 49. The process or system according to any one of Aspects 10 to 26 or 33 to 47, wherein the reactor system comprises two or more reactors.

[0289] Aspect 50. The process or system according to any one of Aspects 10 to 26 or 33 to 49, wherein the reactor system comprises a solution reactor, a gas phase reactor, a slurry reactor, or a combination thereof.

[0290] Aspect 51. The process or system according to any one of Aspects 10 to 26 or 33 to 50, wherein the reactor system comprises a circulating slurry reactor.

[0291] Aspect 52. The process or system according to any one of Aspects 10 to 26 or 33 to 51, wherein the polymerization reaction conditions include a polymerization reaction temperature in the range of about 60°C to about 185°C, about 60°C to about 115°C, or about 130°C to about 180°C, and any suitable reaction pressure, such as about 200 psig to about 1000 psig.

[0292] Aspect 53. The process or system according to any one of Aspects 5 to 52, wherein the catalyst system (or catalyst composition) comprises a solid oxide.

[0293] Aspect 54. The process or system according to any one of Aspects 5 to 53, wherein the activator comprises an activator-carrier (e.g., fluorinated silica-coated alumina or sulfated alumina).

[0294] Aspect 55. The process or system according to any one of Aspects 5 to 53, wherein the activator comprises aluminoxane.

[0295] Aspect 56. The process or system according to any one of Aspects 5 to 55, wherein the catalyst system includes a co-catalyst.

[0296] Aspect 57. The process or system according to any one of Aspects 5 to 55, wherein the catalyst system comprises an organoaluminum co-catalyst.

[0297] Aspect 58. The process or system according to any one of Aspects 10 to 26 or 33 to 57, wherein the olefin monomer comprises C2-C 24 Olefins.

[0298] Aspect 59. The process or system according to any one of Aspects 10 to 26 or 33 to 57, wherein the olefin monomer comprises propylene.

[0299] Aspect 60. The process or system according to any one of Aspects 10 to 26 or 33 to 57, wherein the olefin monomer comprises ethylene.

[0300] Aspect 61. The process or system according to any one of Aspects 10 to 26 or 33 to 57, wherein the catalyst system is in contact with ethylene and an olefin comonomer comprising 1-butene, 1-hexene, 1-octene, or mixtures thereof.

[0301] Aspect 62. The process or system according to any one of Aspects 10 to 26 or 33 to 57, wherein the olefin polymer comprises ethylene homopolymer, ethylene copolymer, propylene homopolymer or propylene-based copolymer.

[0302] Aspect 63. The process or system according to any one of Aspects 10 to 26 or 33 to 57, wherein the olefin polymer comprises ethylene / 1-butene copolymer, ethylene / 1-hexene copolymer, or ethylene / 1-octene copolymer.

[0303] Aspect 64. The method, process, or system according to any one of Aspects 1-63, wherein the first transition metal compound and the second transition metal compound independently comprise any suitable nonmetallocene compound.

[0304] Aspect 65. The method, process, or system according to any one of Aspects 1-63, wherein the first transition metal compound and the second transition metal compound independently comprise any suitable metallocene compound.

[0305] Aspect 66. The method, process, or system according to any one of Aspects 1-63, wherein the first transition metal compound and the second transition metal compound independently comprise chromium, vanadium, titanium, zirconium, hafnium, or combinations thereof.

[0306] Aspect 67. The method, process, or system according to any one of Aspects 1-63, wherein at least one of the first transition metal compound and the second transition metal compound is a bridged metallocene compound.

[0307] Aspect 68. The method, process, or system according to any one of Aspects 1-63, wherein at least one of the first transition metal compound and the second transition metal compound is a non-bridging metallocene compound.

[0308] Aspect 69. The method, process, or system according to any one of Aspects 1-68, wherein the solution comprises the first transition metal compound, the second transition metal compound, and a hydrocarbon solvent.

[0309] Aspect 70. The method, process, or system according to any one of Aspects 1-68, wherein the solution comprises the first transition metal compound, the second transition metal compound, and a hydrocarbon solvent, said hydrocarbon solvent comprising 1-hexene, isobutane, toluene, or cyclohexene, and mixtures or combinations thereof.

[0310] Aspect 71. The method, process, or system according to any one of Aspects 1-70, wherein the weight ratio of the first transition metal compound to the second transition metal compound in the solution is in the range of about 50:1 to about 1:50, about 10:1 to about 1:10, about 2:1 to about 1:2, about 1:20 to about 1:1, etc.

[0311] Aspect 72. The method, process, or system according to any one of Aspects 1-71, wherein the second transition metal compound comprises one second transition metal compound, two different second transition metal compounds, or three or more different second transition metal compounds.

[0312] Aspect 73. A method for measuring the properties of a liquid in a container containing a liquid-solid mixture, the method comprising:

[0313] (i) Remove a sample of the liquid-solid mixture from the container;

[0314] (ii) passing the sample of the liquid-solid mixture through a flow cell device;

[0315] (iii) Periodically stopping the flow of the sample of the liquid-solid mixture in the flow cell device for a period of time sufficient to allow the solid to settle to the bottom of the flow cell device and the liquid to occupy the upper part of the flow cell device;

[0316] (iv) Irradiating the liquid in the upper part of the flow cell apparatus with a light beam of a specific wavelength in the UV-visible spectrum to measure the properties of the liquid; and

[0317] (v) Restore the flow through the flow pool device.

[0318] Aspect 74. A flow tank apparatus for a mixture of liquid and solid, wherein:

[0319] The flow cell device is configured to isolate the solid to the bottom of the flow cell device and to allow the liquid to occupy the upper part of the flow cell device; and the upper part of the flow cell device is configured to irradiate the liquid with a light beam of a certain wavelength in the UV visible spectrum.

[0320] Aspect 75. An analytical system for measuring the properties of a liquid in a mixture of said liquid and solid, said system comprising: a flow cell apparatus according to aspect 74; and a UV-Vis spectrometer configured to irradiate the liquid in the upper part of said flow cell apparatus to measure the properties of said liquid.

Claims

1. A process for operating a polymerization reactor system, the process comprising: (I) Under polymerization reaction conditions, a catalyst system comprising a first transition metal compound, a second transition metal compound, an activator and an optional cocatalyst is contacted with an olefin monomer and an optional olefin comonomer in a reactor within the polymerization reactor system to produce an olefin polymer. (II) Determine the concentration of the first transition metal compound in a solution comprising the first transition metal compound and the second transition metal compound, the concentration being determined by the following steps: (i) Submit a sample of the solution to the sample chamber; (ii) Irradiate the sample in the room with a beam of light of a certain wavelength in the UV-visible spectrum; as well as (iii) Generate the sample absorbance distribution of the sample, and subtract the reference absorbance distribution of the second transition metal compound in the reference solution from the sample absorbance distribution to obtain the absorbance distribution of the first transition metal compound, and The absorbance distribution of the first transition metal compound is correlated with a standard to determine the concentration of the first transition metal compound in the solution; as well as (III) When the concentration of the first transition metal compound in the solution has reached a predetermined level, the flow rate of the first transition metal compound entering the reactor is adjusted.

2. The process according to claim 1, wherein the solution comprising the first transition metal compound and the second transition metal compound is: The feed stream enters the catalyst preparation vessel; Liquid or homogeneous catalyst systems; Solutions prepared from heterogeneous or supported catalyst systems; or A solution prepared from a sample mixture from the reactor.

3. The process according to claim 1 or 2, wherein: The wavelengths mentioned in step (ii) include wavelengths in the range of 300 nm to 600 nm; The sample absorbance distribution in step (iii) includes absorbance curves within a certain wavelength range; and The relevant steps are performed at a single wavelength.

4. The process according to any one of claims 1 to 3, wherein: The first transition metal compound and the second transition metal compound independently comprise chromium, vanadium, titanium, zirconium, hafnium, or combinations thereof; The olefin monomer includes C2-C 24 olefins; and The polymerization reactor system includes a solution reactor, a gas phase reactor, a slurry reactor, or a combination thereof.

5. The process according to any one of claims 1 to 4, wherein: The first transition metal compound is an unbridged metallocene compound; and The second transition metal compound is a bridged metallocene compound.

6. The process according to any one of claims 1 to 4, wherein the second transition metal compound comprises two or more different second transition metal compounds.

7. The process according to any one of claims 1 to 6, wherein: The catalyst system comprises a first metallocene compound, a second metallocene compound, an activator, and a co-catalyst; and The catalyst system is contacted with ethylene and olefin comonomers including 1-butene, 1-hexene, 1-octene, or mixtures thereof.

8. The process according to any one of claims 1 to 7, wherein the reference solution comprises the second transition metal compound and a hydrocarbon solvent.

9. The process according to claim 8, wherein: The hydrocarbon solvent includes 1-hexene, isobutane, toluene, cyclohexene, or any combination thereof; and The weight ratio of the first transition metal compound to the second transition metal compound in the solution is in the range of about 1:50 to about 1:

5.

10. The process according to any one of claims 1 to 9, wherein: The sample absorbance distribution, the reference absorbance distribution, and the absorbance distribution of the first transition metal compound independently include absorbance curves within a certain wavelength range; and The standard includes calibration curves.

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