# US 10,870,094 B2 · Methods for determining transition metal compound concentrations in multicomponent liquid systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,870,094 B2 - Document ID: US10870094B2 - Status: Granted - Kind: B2 - Application number: 16/587,149 - Filed: 2019-09-30 - Published: 2020-01-23 - Granted: 2020-12-22 - Earliest claimed: 2018-03-29 - Assignees: Chevron Phillips Chemical Company LP - Applicants: Chevron Phillips Chemical Company LP - Inventors: Richard M. Buck; Qing Yang - Web page: https://patentgrep.com/patent/US10870094B2 ## CPC - B01J 8/085: {Feeding reactive fluids (for solid material, see B01J8/0015)} - G05D 11/132: {by controlling the flow of the individual components (G05D11/133 takes precedence)} - B01J 12/007: {in the presence of catalytically active bodies, e.g. porous plates} - C08F 4/6192: containing at least one cyclopentadienyl ring, condensed or not, e.g. an indenyl or a fluorenyl ring - C08F 10/02: Ethene - C08F 10/04: Monomers containing three or four carbon atoms - C08F 10/14: Monomers containing five or more carbon atoms - C08F 210/16: Copolymers of ethene with alpha-alkenes, e.g. EP rubbers - G01N 21/314: {with comparison of measurements at specific and non-specific wavelengths (dual wavelength spectrometry G01J3/427)} - G05D 7/0623: {characterised by the set value given to the control element} - G05D 7/0682: {using a plurality of flow sources} - C08F 4/65925: {two cyclopentadienyl rings being mutually non-bridged} - C08F 4/65927: {two cyclopentadienyl rings being mutually bridged} - C08F 2400/02: Control or adjustment of polymerization parameters - C08F 2420/00: Metallocene catalysts - C08F 2500/07: High density, i.e. > 0.95 g/cm3 - C08F 2500/08: Low density, i.e. < 0.91 g/cm3 - G01N 2021/3155: {Measuring in two spectral ranges, e.g. UV and visible} - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract Methods for simultaneously determining the concentrations of transition metal compounds in solutions containing two or more transition metal compounds are described. Polymerization reactor systems providing real-time monitoring and control of the concentrations of the transition metal components of a multicomponent catalyst system are disclosed, as well as methods for operating such polymerization reactor systems. ## Claims ### Claim 1 A polymerization reactor system comprising: (A) a reactor configured to contact a catalyst system with an olefin monomer and an optional 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 an optional co-catalyst to form the catalyst system; and (C) an analytical system configured to determine a first concentration of the first transition metal compound and a second concentration of the second transition metal compound in a solution comprising the first transition metal compound and the second transition metal compound present within the polymerization reactor system; wherein: the polymerization reactor system comprises a slurry reactor, a gas-phase reactor, a solution reactor, or a combination thereof. ### Claim 2 (depends on 1) The reactor system of claim 1, wherein the analytical system comprises an ultraviolet-visible spectrometer. ### Claim 3 (depends on 2) The reactor system of claim 2, wherein the analytical system further comprises a filter assembly configured to filter a sample of the solution comprising the first transition metal compound and the second transition metal compound before analysis by the ultraviolet-visible spectrometer. ### Claim 4 (depends on 1) The reactor system of claim 1, wherein the reactor system further comprises (D) a controller configured to control a first flow rate of the first transition metal compound and/or a second flow rate of the second transition metal compound into the reactor based on the first concentration and/or the second concentration determined by the analytical system. ### Claim 5 (depends on 4) The reactor system of claim 4, wherein: the analytical system comprises an ultraviolet-visible spectrometer with an integrated computer system: (a) for measuring a sample absorbance profile of the solution; (b) for calculating a curve having the formula β1F1+β2F2 to fit the sample absorbance profile to a least-squares regression fit value (R2) of at least 0.9, wherein: β1 is a first weighting coefficient; F1 is a first reference absorbance profile of the first transition metal compound in a first reference solution at a first known concentration; β2 is a second weighting coefficient; and F2 is a second reference absorbance profile of the second transition metal compound in a second reference solution at a second known concentration; and (c) for multiplying the first known concentration with β1 to determine the first concentration of the first transition metal compound in the solution, and multiplying the second known concentration with β2 to determine the second concentration of the second transition metal compound in the solution. ### Claim 6 (depends on 4) The reactor system of claim 4, wherein: the solution comprises the first transition metal compound, the second transition metal compound, and a hydrocarbon solvent; and the solution is a feed stream to the catalyst preparation vessel, and the controller controls the first flow rate and/or the second flow rate into the reactor by adjusting a flow rate ratio of the first:second transition metal compound to the catalyst preparation vessel, and/or by adjusting a flow rate of the catalyst system exiting the catalyst preparation vessel and entering the reactor. ### Claim 7 (depends on 4) The reactor system of claim 4, wherein the controller is configured to control the first flow rate and/or the second flow rate based on the first concentration and/or the second concentration determined by the analytical system in real-time. ### Claim 8 (depends on 4) The reactor system of claim 4, wherein: the reactor system comprises two or more reactors, at least one of which is a loop slurry reactor; the polymerization reaction conditions comprise a reaction temperature in a range from about 60° C. to about 185° C., and a reaction pressure of less than about 1000 psig; the olefin polymer comprises an ethylene homopolymer, an ethylene/1-butene copolymer, an ethylene/1-hexene copolymer, or an ethylene/1-octene copolymer; and the first transition metal compound and the second transition metal compound independently comprise a bridged or unbridged metallocene compound. ### Claim 9 A polymerization reactor system comprising: (A) a loop slurry reactor configured to contact a catalyst system with ethylene and an optional olefin comonomer under polymerization reaction conditions to produce an ethylene polymer; (B) a catalyst preparation vessel 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 (C) an analytical system configured to determine a first concentration of the first transition metal compound and a second concentration of the second transition metal compound in a solution comprising the first transition metal compound and the second transition metal compound present within the polymerization reactor system. ### Claim 10 (depends on 9) The reactor system of claim 9, wherein the reactor system further comprises (D) a controller configured to control a first flow rate of the first transition metal compound and/or a second flow rate of the second transition metal compound into the loop slurry reactor based on the first concentration and/or the second concentration determined by the analytical system. ### Claim 11 (depends on 9) The reactor system of claim 9, wherein the analytical system comprises an ultraviolet-visible spectrometer. ### Claim 12 (depends on 11) The reactor system of claim 11, wherein the analytical system further comprises a filter assembly configured to filter a sample of the solution comprising the first transition metal compound and the second transition metal compound before analysis by the ultraviolet-visible spectrometer. ### Claim 13 (depends on 9) The reactor system of claim 9, wherein the analytical system comprises an ultraviolet-visible spectrometer with an integrated computer system (a) for measuring a sample absorbance profile of the solution; (b) for calculating a curve having the formula β1F1+β2F2 to fit the sample absorbance profile to a least-squares regression fit value (R2) of at least 0.9, wherein: β1 is a first weighting coefficient; F1 is a first reference absorbance profile of the first transition metal compound in a first reference solution at a first known concentration; β2 is a second weighting coefficient; and F2 is a second reference absorbance profile of the second transition metal compound in a second reference solution at a second known concentration; and (c) for multiplying the first known concentration with β1 to determine the first concentration of the first transition metal compound in the solution, and multiplying the second known concentration with β2 to determine the second concentration of the second transition metal compound in the solution. ### Claim 14 (depends on 9) The reactor system of claim 9, wherein the analytical system comprises an ultraviolet-visible spectrometer and an external computer system, the ultraviolet-visible spectrometer configured to (a) measure a sample absorbance profile of the solution, and the external computer system configured to (b) calculate a curve having the formula β1F1+β2F2 to fit the sample absorbance profile to a least-squares regression fit value (R2) of at least 0.9, wherein: β1 is a first weighting coefficient; F1 is a first reference absorbance profile of the first transition metal compound in a first reference solution at a first known concentration; β2 is a second weighting coefficient; and F2 is a second reference absorbance profile of the second transition metal compound in a second reference solution at a second known concentration; and (c) multiply the first known concentration with β1 to determine the first concentration of the first transition metal compound in the solution, and multiplying the second known concentration with β2 to determine the second concentration of the second transition metal compound in the solution. ### Claim 15 (depends on 9) The reactor system of claim 9, wherein: the analytical system comprises an ultraviolet-visible spectrometer; and the reactor system further comprises (D) a controller configured to control a first flow rate of the first transition metal compound and/or a second flow rate of the second transition metal compound into the loop slurry reactor based on the first concentration and/or the second concentration determined by the analytical system. ### Claim 16 (depends on 15) The reactor system of claim 15, wherein the solution comprises the first transition metal compound, the second transition metal compound, and a hydrocarbon solvent. ### Claim 17 (depends on 15) The reactor system of claim 15, wherein: the ethylene polymer comprises an ethylene homopolymer, an ethylene/1-butene copolymer, an ethylene/1-hexene copolymer, or an ethylene/1-octene copolymer; and the first transition metal compound and the second transition metal compound independently comprise a bridged or unbridged metallocene compound. ### Claim 18 (depends on 15) The reactor system of claim 15, wherein the polymerization reaction conditions comprise a reaction temperature in a range from about 60° C. to about 185° C., and a reaction pressure of less than about 1000 psig. ### Claim 19 (depends on 15) The reactor system of claim 15, wherein: the solution is a feed stream to the catalyst preparation vessel; and the controller controls the first flow rate and/or the second flow rate into the loop slurry reactor by adjusting a flow rate ratio of the first:second transition metal compound to the catalyst preparation vessel, and/or by adjusting a flow rate of the catalyst system exiting the catalyst preparation vessel and entering the loop slurry reactor. ### Claim 20 (depends on 15) The reactor system of claim 15, wherein: the loop slurry reactor contains a mixture; 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 loop slurry reactor; and the controller controls the first flow rate and/or the second flow rate by adjusting a relative flow rate of the first and second transition metal compounds to the loop slurry reactor, and/or by adjusting a flow rate of the catalyst system entering the loop slurry reactor.