Univation Technologies, LLC

Exxonmobil Chemical Patents Inc.

Robert Olds Hagerty

Michael E Muhle

Richard B Pannell

Randall B Laird

Eric John Markel

Kevin Bruce Stavens

Pradeep P Shirodkar

Peijun Jiang

Larry Lee Iaccino

F David Hussein

Michael A Risch

Zerong Lin

Agapios Kyriacos Agapiou

John Richard Shutt

Charles Stanley Speed

James McLeod Farley

Marc L DeChellis

D Brett Fischbuch

Mark Gregory Goode

Bruce Jon Savatsky

Fathi David Hussein

Chia Shian Chee

Per K Husby

Michael E Sieloff

Gary David Mohr

John Francis Szul

David Michael Glowczwski

Edward F Smith

Keith Wesley Trapp

Robert Lynn Santana

Kathryn Ann Russell

Daniel P Zilker

Brian Egan

Ted A Powell

X Simon Zhang

Mark Peter Bartilucci

Ernest Raymond Davis, Jr

Kevin Joseph Cann

Chi-I Kuo

Mark Bradley Davis

Michael D Awe

Michael F McDonald, Jr

R Eric Pequeno

Haiqing Peng

Maria A Apecetche

Ryan Winston Impelman

Jose Fernando Cevallos-Candau

Jaimes Sher

Mark Williams Blood

Brandon C Locklear

Randall L Force

Maria Pollard

Richard E Pequeno

Laurence G Britton

Ian D Burdett

Diwaker Singh

William J Blickley

Chia S Chee

Edward Allen Leach

Sandy Clay Hinds

Douglas R Holroyd

Ai Vey Ng

Frederick Yip-Kwai Lo

Jerome Holveck

John James Weick

Cecile F Saladino

David A Yahn

David F Hussein

Edward A Leach

Brett D Fischbuch

Methods for reducing gels and/or dome sheeting in gas phase polymerization processes and their resulting products are provided. The polymerization processes include polymerizing ethylene and one or more optional comonomers in a fluidized bed reactor in the presence of a metallocene catalyst, hydrogen, and at least one condensing agent.

Methods for making polyethylene polymers

A method for controlling the start up conditions in a gas phase polymerization process is provided. An inventory can be calculated for each monomer, comonomer, and hydrogen sufficient to produce a polyethylene polymer having desired properties, such as, a certain melt index and/or density.

Methods for controlling start up conditions in polymerization processes

Various methods and systems for removing particulates from a cycle gas stream, e.g., in a reactor system, are provided. In certain embodiments, the methods are performed in conjunction with a polymerization reactor system such as a gas-phase reactor system.

Systems and methods for removing entrained particulates from gas streams, and reactor systems

Catalysts and methods for making and using the same are provided. The method for fabricating a catalyst may includes contacting a supported catalyst with a monomer under conditions that reduce an overall charge of the catalyst to less than about 75% of an initial charge of the catalyst. A method for polymerization may include introducing a pre-polymerized catalyst and one or more olefins into a gas phase fluidized bed reactor, operating the reactor at conditions sufficient to produce a polyolefin, wherein the polymerization is carried out in the substantial absence of any continuity additives.

Methods for reducing static charge of a catalyst and methods for using the catalyst to produce polyolefins

Methods for shutting down and restarting polymerization in a gas phase polymerization reactor are provided. The method can include introducing a polymerization neutralizer to the reactor in an amount sufficient to stop polymerization therein. The method can also include stopping recovery of a polymer product from the reactor and stopping introduction of a catalyst feed and a reactor feed to the reactor. The method can also include adjusting a pressure within the reactor from an operating pressure to an idling pressure. The method can also include adjusting a superficial velocity of a cycle fluid through the reactor from an operating superficial velocity to an idling superficial velocity. The method can also include maintaining the reactor in an idled state for a period of time.

Methods for operating a polymerization reactor

Generally, a method of monitoring a polymerization reaction in a fluid bed reactor to generate, in on-line fashion, data indicative of the imminent occurrence of a discontinuity event (for example, sheeting) and optionally also control the reaction to prevent the occurrence of the discontinuity event is provided. Typical embodiments include the steps of generating in on-line fashion at least one of bed static data indicative of static charge in the fluidized bed and carryover static data indicative of carryover static; and generating at least one of temperature data (in on-line fashion using at least one monitored reaction parameter) indicative of a first temperature and acoustic emission data indicative of resin stickiness in the reactor, where the first temperature is indicative of at least one of degree of resin stickiness in the reactor and a characteristic of melting behavior of polymer resin in the reactor in the presence of at least one diluent.

Method for on-line monitoring and control of polymerization processes and reactors to prevent discontinuity events

Systems and methods for monitoring a polymerization reactor are provided. The method can include estimating an acoustic condition of a polymer produced in a reactor. The method can also include estimating a stickiness control parameter of the polymer produced in the reactor. The method can further include pairing the acoustic condition with the stickiness control parameter to provide a paired acoustic condition and stickiness control parameter.

Systems and methods for monitoring a polymerization reaction

A method for cleaning a distributor plate in a fluidized bed polymerization reactor system according to one embodiment includes, in a first mode, operating with about a normal, baseline value of superficial gas velocity in a fluidized bed polymerization reactor system having a reactor vessel, a recycle line, and a distributor plate in the reactor vessel near an inlet of the reactor vessel. In a second mode, the superficial gas velocity is increased above the baseline value of the first mode to a level sufficient to raise the temperature of the cycle gas at the inlet above an average temperature of the cycle gas at the inlet in the first mode, and to a level sufficient to dislodge foulant from holes in the distributor plate.

Methods for cleaning the distributor plate in a fluidized bed reactor system

In some embodiments, a method including the steps of monitoring a polymerization reaction which produces a polymer resin in a fluid bed reactor, where a dry melt reference temperature is characteristic of melting behavior of a dry version of the resin, and in response to data indicative of at least one monitored parameter of the reaction, determining in on-line fashion a reduced melt reference temperature that is at least substantially equal to the difference between the dry melt reference temperature and a temperature by which the dry melt reference temperature is depressed by the presence of condensable diluent gas with the resin in the reactor. Optionally, the method also includes the step of controlling the reaction in response to the reduced melt reference temperature or a stickiness parameter determined from the reduced melt reference temperature.

Methods for determining temperature value indicative of resin stickiness from data generated by polymerization reaction monitoring

A method for preparing a reactor for performance of a polymerization reaction, the method including providing at least one seed bed into the reactor; wherein the at least one seed bed includes at least one organometallic compound and polymer particles.

Method for seed bed treatment for a polymerization reaction

A method for treating at least one interior surface (for example, a bed wall) of a fluidized bed polymerization reactor system, including by applying a solution catalyst (preferably at least substantially uniformly and in liquid form) to each surface, and optionally (where a catalyst component of the solution catalyst comprises at least one chromium containing compound) oxidizing at least some of the applied chromium containing compound in a controlled manner.

Methods for applying solution catalysts to reactor surfaces

Embodiments of the present invention relate to measuring and controlling static in a gas phase reactor polymerization. In particular, embodiments relate to monitoring carryover static in an entrainment zone during gas phase polymerization to determine the onset of reactor discontinuity events such as chunking and sheeting. Embodiments also relate to monitoring carryover static to determine the need for effective additions of continuity additives that minimize reactor static activity and thereby preventing discontinuity events.

Method for controlling sheeting in gas phase reactors

This invention relates to a process to polymerize olefins comprising contacting a catalyst or catalyst system with olefin(s) in the presence of a fluorocarbon at a temperature above the onset melting point of the polymer. This invention also relates to a solution process to polymerize olefins comprising contacting a catalyst or catalyst system with olefin(s) in the presence of a fluorocarbon at a temperature above the onset melting point of the polymer.

Polymerization process

Embodiments of the present invention relate to operating a gas-phase reactor at or near maximum production rates and to measuring and controlling polymer stickiness in a gas phase reactor polymerization. In particular, embodiments relate to monitoring acoustic emissions in a reactor during gas phase polymerization to determine the onset of reactor stickiness and possibly discontinuity events such as chunking and sheeting resulting from that stickiness. Embodiments also relate to monitoring acoustic emissions to determine the need for effective control of parameters that minimize reactor stickiness and thereby preventing discontinuity events. The emissions are processed by arithmetic averaging.

Method for operating a gas-phase reactor at or near maximum production rates while controlling polymer stickiness

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LaPorte, TX, United States of America

Robert Olds Hagerty