Univation Technologies, LLC

Exxon Chemical Patents, Inc.

Exxonmobil Chemical Patents Inc.

Exxon Chemical Company

Unication Technolofies, LLC

Michael E Muhle

Agapios Kyriacos Agapiou

Robert Olds Hagerty

F David Hussein

Richard B Pannell

Gary Thomas Renola

Eric John Markel

Keith Wesley Trapp

Mark Gregory Goode

Gary David Mohr

Zerong Lin

David Michael Glowczwski

Kevin Bruce Stavens

Edward F Smith

John R Griffin

Michael E Sieloff

Ted A Powell

Chi-I Kuo

Fathi David Hussein

George Alan Vaughan

Marc L DeChellis

Dwayne Lee Litteer

John Francis Szul

Anthony Nicholas Speca

Ching-Tai Lue

Bruce Jon Savatsky

Fred David Ehrman

Ping P Cai

Natalie Ann Merrill

Randall B Laird

Mark Williams Blood

Robert Lynn Santana

Daniel P Zilker

Kathryn Ann Russell

Ian D Burdett

Myron Bernard Kurtzman

Ke Nguyen

Brant Patrick

Matt Kuchta

X Simon Zhang

Patrick Brant

Pradeep P Shirodkar

James McLeod Farley

Porter Clarke Shannon

Mark Bradley Davis

Ronald Steven Eisinger

Haiqing Peng

Michael A Kinnan

Brandon C Locklear

James Leland Swecker, Ii

Richard E Pequeno

Laurence G Britton

Charles E A Finney

C Stuart Daw

David A Yahn

Charles Ea Finney

Stuart C Daw

David F Hussein

Mark W Blood

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

A process for the polymerization of olefins is disclosed. The process may include: feeding a catalyst, a liquid diluent, and an olefin to a polymerization vessel having, from a polymerization vessel bottom to a polymerization vessel top, a vapor introduction zone, a three-phase reaction zone and a vapor disengagement zone; contacting the catalyst and olefin under conditions of temperature and pressure in the presence of the liquid diluent as a continuous phase in the three-phase reaction zone to form a solid phase polyolefin; withdrawing a gas phase composition from an outlet in fluid communication with the vapor disengagement zone; circulating the gas phase composition through a gas circulation loop to an inlet in fluid communication with the vapor distribution zone at a rate sufficient to agitate the solid and liquid phases within the three-phase reaction zone; and withdrawing a reaction mixture comprising polyolefin and diluents from the three-phase reaction zone.

Polymerization reaction system

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 of treating a gas phase fluidized bed reactor and a method of polymerizing olefins in a gas phase fluidized bed reactor in the presence of a catalyst prone to cause sheeting by introducing a chromium-containing compound into the reactor and forming a high molecular weight polymer coating on the walls of the reactor. Furthermore, a device for and method of introducing the chromium-containing compound into the fluidized bed reactor at a plurality of locations in proximity to a lower section of a bed section wall of the fluidized bed reactor, and forming a high molecular weight polymer coating on the bed section wall.

Methods and devices for polymerization

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

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

Provided is a method for monitoring a polymerization reaction in a fluid bed reactor to determine in on-line fashion a current value, and preferably also a limiting value, of a stickiness control temperature, and optionally controlling the reaction in response thereto in an effort to prevent occurrence of a discontinuity event. The stickiness control temperature is a temperature indicative of a characteristic of melting behavior of polymer resin in the reactor, and may be indicative of occurrence of resin sheeting or another discontinuity event. Optionally , a predetermined relation between values of acoustic energy in the reactor and values of a stickiness control temperature in used to provide error checking for determination of the stickiness control temperature, or a current value of the stickiness control temperature is determined from acoustic data and a predetermined relation between values of an acoustic condition in the reactor and values of the stickiness control temperature.

Method for on-line determination of degree or onset of resin stickiness using acoustic data

In some embodiments, a method of monitoring a resin-producing polymerization reaction in a fluid bed reactor system to generate reaction parameter data in on-line fashion, determining an indicator of at least one of entropy and complexity (for example, Kolmogorov or Shannon entropy) of each of at least two subsets of the reaction parameter data, and optionally also determining from at least one value of the indicator (for example, from a time series of Kolmogorov or Shannon entropy values) an indication of at least one of degree of resin stickiness, an approach to or imminence of resin stickiness, and an approach to or imminence of an unsafe or undesired reactor operating condition (e.g., that can result in sheeting or chunking). Optionally also, the reaction is controlled in response to at least one value of the indicator, for example, in an effort to prevent the occurrence of sheeting or another discontinuity event or to maintain the reactor in a stable, non-sticking condition.

Method for polymerization reaction monitoring with determination of entropy of monitored data

The present invention is directed to various methods and systems for detecting at least one impurity in a bulk fluid. 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 detecting impurities in reactor systems

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Kingwood, TX, United States of America

Michael E Muhle