Exxonmobil Chemical Patents Inc.

Brian R Greenhalgh

Joseph Moebus

Jay L Reimers

Bruce Jon Savatsky

Ryan Winston Impelman

Aaron C McGinnis

Anne A Bernard-brunel

Philip M Duvall

Ronnie D Bryant

Allison C Buenemann

Benjamin C Duff

Joseph A Moebus

This disclosure relates to processes for producing polyolefins in a gas phase reactor using condensing agent(s) (CAs), and real-time calculation of the ratio of one type of CA to another CA within a CA composition. This disclosure provides methods for controlling condensed phase cooling in a gas phase reactor used to polymerize olefins. The polymerization may employ one or more polymerization catalysts to polymerize one or more olefin monomers, and may include introducing a first condensing agent and a second condensing agent in a ratio of first condensing agent to second condensing agent, which ratio is calculated by ascertaining a stick limit for a first condensing agent, calculating an equivalence factor relating the first condensing agent and a second condensing agent, ascertaining a total allowable condensing agent, and calculating a first amount of the first condensing agent removed and replaced by a second amount of the second condensing agent.

Methods for improving gas phase polymerization

The present disclosure relates to processes for production of polyolefins from olefin monomer(s) in a gas phase reactor using condensing agent(s) (CAs), and in particular relates to controlling condensed phase cooling in a gas phase reactor used to polymerize olefin monomer(s). The method may include introducing first and second condensing agent(s) into the reactor at ratio(s) determined by ascertaining a stick limit for the first condensing agent, calculating an equivalence factor relating the first and second condensing agents, ascertaining total allowable condensing agent, and calculating amount of the first condensing agent removed and replaced by the second condensing agent. The method may further include calculating the dew point limit of a gas phase composition including olefin monomer(s) as well as the first and second condensing agents; and determining if introducing a mixture comprising the olefin monomer(s) and the condensing agent composition would exceed the calculated dew point limit.

Methods for improving production in gas phase polymerization

Methods of online cleaning of heat exchangers at elevated temperatures are provided. Cleaning of the heat exchanger is achieved through an increasing heat exchanger effluent temperature of a polymer solution together with operating under optimized process conditions provided by a phase diagram constructed for the polymer solution. The separation of polymer from unreacted monomers and solvent in the polymer solution is carried out by raising the temperature of the polymer solution as reactor effluent flowing through the heat exchanger. Then, subsequently and by reducing pressure of the heat exchanger effluent, the polymer solution separates into two liquid phases.

Method of online cleaning of heater exchangers

This disclosure describes polymerization processes and processes for quenching polymerization reactions using high molecular weight polyhydric quenching agents.

Polymerization processes using high molecular weight polyhydric quenching agents

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Houston, TX, United States of America

Brian R Greenhalgh