Univation Technologies, LLC

James Leland Swecker, Ii

Mark Gregory Goode

F David Hussein

John Roberts Parrish

Ronald Steven Eisinger

Ping P Cai

Mark Williams Blood

Michael E Muhle

Daniel Paul Zilker, Jr

Michael A Kinnan

Laura J Dietsche

Robert Darrell Olson

Randall L Force

Ian D Burdett

Jeffrey Brian Drabish

George W Schwarz, Jr

Dale A Wright

Cloid Russell Smith, Iii

Donald A Fischer

Theodore Duncan

Oscar M Longoria, Jr

Daniel W Mosser

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 method for the delivery of a catalyst to a polymerization reactor is disclosed, comprising: contacting a catalyst with a carrier fluid comprising an inert hydrocarbon in gaseous form, the inert hydrocarbon having a normal boiling point of about &#x2212;1&#xb0; C. to about 81&#xb0; C.; and flowing the carrier fluid to the polymerization reactor such that the carrier fluid transports the catalyst to the polymerization reactor. A catalyst delivery system is disclosed, comprising: a catalyst vessel for containing a catalyst; a catalyst injection line for delivering the catalyst to a polymerization reactor, the catalyst injection line being in fluid communication with the catalyst vessel and the polymerization reactor; and a carrier fluid line in fluid communication with the catalyst injection line for delivering a carrier fluid comprising an inert hydrocarbon to the catalyst injection line, the inert hydrocarbon having a normal boiling point of about &#x2212;1&#xb0; C. to about 81&#xb0; C.

Methods and systems for catalyst delivery

A method and apparatus are disclosed for controlling product discharge from a fluidized bed reactor and for minimizing the loss of the unreacted monomer in the fluidizing gas upon removing the solid polymer product from the reactor. The method and apparatus utilize at least one detector in the product tank or its vent line and a control system in communication with the detector and the product tank fill valve, along with certain algorithms, to adjust by an iterative process, the product discharge time, thereby maximizing resin fill in the product tank and minimizing the lost reactor gas volume.

Raw material efficiency method and process

A method for olefin polymerization is provided. A feed stream comprising more than 0.1 ppm by volume of oxygen and 0.3 ppm by volume of water is passed through a first packed bed to selectively remove at least a portion of the oxygen. The feed stream is then passed through a second packed bed to selectively remove at least a portion of the water, providing a purified feed stream comprising less than 0.1 ppm by volume of oxygen and 0.3 ppm by volume of water. Both the first and second packed beds operate at a temperature of from about 0&#xb0; C. to about 50&#xb0; C. The purified feed stream is then passed to a polymerization reactor.

Feed purification at ambient temperature

This invention relates to processes for transitioning among polymerization catalyst systems, preferably catalyst systems, which are incompatible with each other. Particularly, the invention relates to processes for transitioning among olefin polymerization reactions utilizing Ziegler-Natta catalyst systems, metallocene catalyst systems and chromium-based catalyst systems.

Processes for transitioning between various polymerization catalysts

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Clendenin, WV, United States of America

James Leland Swecker, Ii