Univation Technologies, LLC

Union Carbide Chemicals & Plastics Technology Corporation

Exxonmobil Chemical Patents Inc.

W.r. Grace & Co. -conn.

Mark Williams Blood

Bruce Jon Savatsky

Mark Bradley Davis

Randall L Force

Mark Gregory Goode

Timothy R Lynn

Michael E Muhle

F David Hussein

John Henry Oskam

Ping P Cai

Robert Darrell Olson

James Leland Swecker, Ii

Thomas Arthur Maliszewski

Gerardo Corona

Dung P Le

W Scott Hamilton

Robert Aronson

William K Lutz

Theodore Duncan

Robert Olds Hagerty

Richard B Pannell

Eric John Markel

Daniel Paul Zilker, Jr

John Roberts Parrish

Kersten Anne Terry

Laura J Dietsche

William George Sheard

Richard E Pequeno

George W Schwarz, Jr

Cloid Russell Smith, Iii

William J Blickley

Timothy Joseph Howley

Billy Jack Garner

Donald A Fischer

Glenn W Baldwin

Sharon E Peterson

Douglas H Jackson

Thomas Walter Pilgrim

Daniel W Mosser

Ralph Niels Hesson

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

The present disclosure provides a process. In an embodiment, the process includes producing a propylene-based polymer in a gas-phase polymerization reactor () under polymerization conditions. The polymerization conditions include a combined propylene-plus-propane partial pressure from 290 psia to 450 psia. The process further includes maintaining the combined propylene-plus-propane partial pressure in the range from 290 psia to 450 psia while simultaneously: (i) reducing propylene partial pressure in the gas-phase polymerization reactor; (ii) adding propane to the gas-phase polymerization reactor; (iii) introducing at least one C4-C10 comonomer into the gas-phase polymerization reactor (); and forming a propylene/C4-C10 interpolymer in the gas-phase polymerization reactor ().

Propylene/butene interpolymer production system and method

Disclosed herein are improvements in recycle gas cooler systems in gas-phase polymerization processes that reduce the tendency for cooler fouling, including a recycle gas cooler system comprising a shell-and-tube heat exchanger. One or more of the tubes of the shell-and-tube heat exchanger may have a flared tube inlet at the tube sheet. The shell-and-tube heat exchanger may also be coupled to a straight inlet pipe having a length that is either at least about 5 times the inner diameter of the straight inlet pipe or at least about 15 feet, whichever is greater.

Recycle gas cooler systems for gas-phase polymerization processes

Provided are systems and methods for separating a purge gas recovered from a polyethylene product. The method includes recovering a polyethylene product containing one or more volatile hydrocarbons from a polymerization reactor and contacting the polyethylene product with a purge gas to remove at least a portion of the volatile hydrocarbons to produce a polymer product having a reduced concentration of volatile hydrocarbons and a purge gas product enriched in volatile hydrocarbons. The purge gas product is compressed to a pressure of 2,500 kPaa to 10,000 kPaa, and is then cooled and separated into at least a first product, a second product, and a third product. A portion of one or more of the first, second, or third products is then recycled as a purge gas, to the polymerization reactor, or to the purge gas product enriched in volatile hydrocarbons prior to compression, respectively.

Systems and methods for recovering hydrocarbons from a polyolefin purge gas product

A discharge system for removing a solid/gas mixture from a fluidized bed pressure vessel is provided. The system includes a fluidized bed pressure vessel, settling vessels, discharge lines, primary discharge valves, vent lines, primary vent valves, crosstie lines, crosstie valves, and primary exit valves wherein the system is absent a transfer tank, and absent a filter element. The method provides for transferring a solid/gas mixture via a discharge line from the pressure vessel to a settling vessel, wherein gas is separated from the mixture, and the gas is transferred to at least one other settling vessel via a crosstie line. After the solids are transferred out of the settling vessel, the empty vessel then receives gas from other settling vessels in the system.

Discharge system to remove solids from a vessel

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

A system in one embodiment includes a barrier; an inverted cone in the barrier; and a member under the inverted cone and having dimensions that cause solids passing therealong between the member and the barrier to have about a constant velocity profile thereacross. A method for purging a gas from a solid/gas mixture according to one embodiment includes adding solids to a barrier having an inverted cone therein and a member under the inverted cone, wherein the solids passing along the member have about a constant vertical velocity profile thereacross; and injecting a purge gas into the solids from at least one point adjacent the member.

Systems using mass flow promoting insert with gas purging and methods thereof

A method of performing a polymerization reaction in a gas phase polymerization reactor to produce a bimodal polymer while controlling activity of a bimodal polymerization catalyst composition in the reactor by controlling concentration of at least one induced condensing agent ('ICA') in the reactor is provided. In some embodiments, the ICA is isopentane (or another hydrocarbon compound) and the bimodal catalyst composition includes a Group 15 and metal containing catalyst compound (or other HMW catalyst for catalyzing polymerization of a high molecular weight fraction of the product), and a metallocene catalyst compound (or other LMW catalyst for catalyzing polymerization of a low molecular weight fraction of the product).

Method for controlling bimodal catalyst activity during polymerization

A discharge system for removing a solid/gas mixture from a fluidized bed pressure vessel is provided. The discharge system includes a fluidized bed pressure vessel, a settling vessel, a transfer vessel, discharge line, primary discharge valve, and primary exit valve. Also in included is a method to operate the discharge system. The method includes transferring a solid/gas mixture from a fluidized bed pressure vessel to a settling vessel, transferring the solids to a transfer vessel, and then emptying the transfer vessel.

Discharge systems and methods of using the same

A system and method for olefin polymerization is provided. The method includes polymerizing one or more olefins within a reactor having one or more injection tubes in fluid communication therewith, at least one of the one or more injection tubes having two or more concentric flow paths; flowing a catalyst through a first flow concentric path of the injection tube into the reactor; flowing one or more monomers through a second concentric flow path of the injection tube into the reactor; measuring rate of heat removal within the reactor; and adjusting the one or more monomers flow through the injection tube in response to the rate of heat removal in the reactor.

Method for preventing catalyst agglomeration based on production rate changes

The liquid content of granular product removed from a fluidized bed polymerization reactor operating in the condensing mode is reduced or minimized by removing the product from a level in the fluidized bed which is about 0.21 to about 0.59 of its height while venting the product discharge tank to a point higher in the fluidized bed.

Dry product discharge from a gas phase polymerization reactor operating in the condensing mode

A fluidized bed olefin polymerization process is operated in the turbulent regime while utilizing greater than 17.5% liquid in the recycle fluid to remove the heat of reaction. The ratio of fluidized bed density to settled bed density may, contrary to prior art predelictions, be maintained at lower than 0.59.

High condensing mode polyolefin production under turbulent conditions in a fluidized bed

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Hurricane, WV, United States of America

Mark Williams Blood