# US 9,433,914 B2 · Polyolefin reactor system having a gas phase reactor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,433,914 B2 - Document ID: US9433914B2 - Status: Granted - Kind: B2 - Application number: 14/136,868 - Filed: 2013-12-20 - Published: 2015-06-25 - Granted: 2016-09-06 - Earliest claimed: 2013-12-20 - Assignees: Chevron Phillips Chemical Company LP - Applicants: Chevron Phillips Chemical Company, LP - Inventors: Gregory G. Hendrickson; Leonard E. Powell; Michael A. Rhodes; Joel Mutchler; Bruce E. Kreischer; Maruti Bhandarker; Rebecca A. Gonzales; Bruce H. Marantis - Web page: https://patentgrep.com/patent/US9433914B2 ## CPC - B01J 19/0033: {Optimalisation processes, i.e. processes with adaptive control systems (adaptive control systems per se G05B13/00)} - B01J 8/0055: {using cyclones} - B01J 8/1809: {Controlling processes} - B01J 8/1863: {followed by a downward movement outside the reactor and subsequently re-entering it} - C08F 10/02: Ethene - B01J 2208/00734: Controlling static charge - B01J 2208/00991: Disengagement zone in fluidised-bed reactors - B01J 2219/00103: in a heat exchanger separate from the reactor - B01J 2219/00108: involving reactant vapours - B01J 2219/00186: controlling the composition of the reactive mixture - B01J 2219/002: inside the reactor - B01J 2219/00202: at the reactor outlet - B01J 2219/00213: Fixed parameter value - B01J 2219/00231: at the reactor inlet - B01J 2219/00236: at the reactor outlet - B01J 2219/00238: of the heat exchange system - B01J 2219/00268: Detecting faulty operations - B01J 2219/00272: Addition of reaction inhibitor - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS ## Abstract A system and method for polymerizing olefin in a gas phase reactor into a polyolefin in presence of catalyst, measuring static charge in the reactor system; determining an indication of polyolefin fines in the reactor system, and adjusting operation of the reactor system in response to the indication. ## Claims ### Claim 1 A polyolefin reactor system comprising: a gas phase reactor configured to polymerize olefin into a polyolefin in presence of a catalyst; a static charge probe configured to measure static electricity in the gas phase reactor; and a control system configured to determine polyolefin fines accumulation in the gas phase reactor based on the measured static electricity and anticipated polyolefin fines accumulation in the gas phase reactor based on a transition to a different catalyst, and the control system configured to adjust an addition rate of antistat to the gas phase reactor in response to the determination. ### Claim 2 (depends on 1) The polyolefin reactor system of claim 1, wherein the static charge probe is disposed at a disengagement section of the gas phase reactor. ### Claim 3 (depends on 1) The polyolefin reactor system of claim 1, wherein the static charge probe is disposed at a reaction zone of the gas phase reactor. ### Claim 4 (depends on 1) The polyolefin reactor system of claim 1, wherein the static charge probe is configured to measure static electricity at a point in a top twelve inches of a fluidized bed in the gas phase reactor. ### Claim 5 (depends on 1) The polyolefin reactor system of claim 1, wherein the static charge probe is disposed on overhead piping from the gas phase reactor. ### Claim 6 (depends on 1) The polyolefin reactor system of claim 1, wherein the determination of polyolefin fines accumulation comprises a disturbance of the static electricity indicated by the static charge probe. ### Claim 7 (depends on 1) The polyolefin reactor system of claim 1, wherein the determination of polyolefin fines accumulation comprises a change in amount of polyolefin fines. ### Claim 8 (depends on 1) The polyolefin reactor system of claim 1, wherein the determination of polyolefin fines accumulation comprises an anticipated onset of an operating problem related to polyolefin fines. ### Claim 9 (depends on 1) The polyolefin reactor system of claim 1, wherein the control system is configured to adjust fluidization velocity through a fluidized bed in the gas phase reactor, and wherein the fluidized bed comprises the polyolefin and the catalyst. ### Claim 10 (depends on 1) The polyolefin reactor system of claim 1, comprising: a first lock hopper disposed at a first location along a reaction zone of the gas phase reactor for a first product withdrawal of the polyolefin from the gas phase reactor; and a second lock hopper disposed at a second location along a reaction zone for a second product withdrawal of the polyolefin from the gas phase reactor, wherein the control system is configured to adjust a ratio of a first rate of the first product withdrawal to a second rate of the second product withdrawal in response to the indication of polyolefin fines accumulation. ### Claim 11 (depends on 1) The polyolefin reactor system of claim 1, comprising a catalyst feed system configured to feed the catalyst to the gas phase reactor and to transition to feeding a different catalyst to the gas phase reactor without interrupting the polymerizing of the olefin to a polyolefin in the gas phase reactor. ### Claim 12 (depends on 1) The polyolefin reactor system of claim 1, comprising: a primary feed vessel configured to feed the catalyst to the gas phase reactor; and an intermediate feed vessel configured to feed a different catalyst to the gas phase reactor while the primary feed vessel is being prepared to feed the different catalyst to the gas phase reactor. ### Claim 13 A reactor system comprising: a gas phase reactor configured to polymerize olefin into a polyolefin in presence of a catalyst; an overhead system configured to receive overhead gas from the gas phase reactor, the overhead gas having entrained polyolefin fines from the gas phase reactor; a plurality of static charge probes configured to measure static charge at different locations in the reactor system; and a control system configured to detect polyolefin fines accumulation in the reactor system based on the measured static charge and anticipated polyolefin fines accumulation in the reactor system based on a transition to a different catalyst, and the control system configured to adjust an addition rate of antistat to the reactor system in response to the detecting polyolefin fines accumulation. ### Claim 14 (depends on 13) The reactor system of claim 13, wherein detecting polyolefin fines accumulation comprises receiving an indication of a static electricity disturbance in the reactor system from one or more of the static charge probes. ### Claim 15 A polyolefin reactor system comprising: a gas phase reactor configured to polymerize olefin into a polyolefin in presence of a catalyst; a catalyst feed system configured to feed the catalyst to the gas phase reactor and to transition to feeding a different catalyst to the gas phase reactor without interrupting the polymerizing of the olefin to a polyolefin in the gas phase reactor; a static charge probe configured to measure static electricity in the gas phase reactor; and a control system configured to determine polyolefin fines accumulation in the gas phase reactor based on the measured static electricity and to adjust an addition rate of antistat to the gas phase reactor in response to the determination. ### Claim 16 (depends on 15) The polyolefin reactor system of claim 15, wherein the determination of polyolefin fines accumulation comprises a disturbance of the static electricity indicated by the static charge probe. ### Claim 17 (depends on 15) The polyolefin reactor system of claim 15, wherein the determination of polyolefin fines accumulation comprises a change in amount of polyolefin fines. ### Claim 18 (depends on 15) The polyolefin reactor system of claim 15, wherein the determination of polyolefin fines accumulation comprises an anticipated onset of an operating problem related to polyolefin fines. ### Claim 19 (depends on 15) The polyolefin reactor system of claim 15, wherein the control system is configured to adjust fluidization velocity through a fluidized bed in the gas phase reactor, and wherein the fluidized bed comprises the polyolefin and the catalyst.