Exxonmobil Chemical Patents Inc.

Lawrence Carl Smith

Terry John Burkhardt

Kevin Wayne Lawson

Patrick Brant

Anthony Nicholas Speca

Cor F Van Egmond

John Richard Shutt

James Charles Vizzini

Gerhard Luft

Randell Wayne Dickey

Shiaw Tzuu Ju

Ted Alexander Powell

Douglas J McLain

James Harding Beech, Jr

Robert Tan Li

Prasadarao Meka

Michael Peter Nicoletti

Ronald G Searle

Eric D Nelson

Jennifer L Bancroft

Gerald G McGlamery, Jr

Robin Lynne Rubish

John D Hedengren

Gerhard Franz Luft

Disclosed herein are methods for controlling bubble formation in a polymerization reactor. The method includes: (a) determining a concentration of at least one component at a location in the reactor using a mathematical model; (b) determining a vapor pressure of the composition based at least in part upon the concentration of the component; (c) determining an operating pressure of the reactor at the location; (d) determining a pressure difference as &#x394;P=P&#x2212;P, wherein Pis the operating pressure and Pis the vapor pressure; (e) comparing the &#x394;P to a threshold value; and (f) implementing an effect when the &#x394;P is less than the threshold value.

Method for controlling bubble formation in polymerization reactors

Bubble formation is monitored in a reactor such as a loop polymerization reactor which effectively operates at pressures above or near the vapor pressure of a circulating slurry liquid. The method measures a property of the reactor composition at a first location within the reactor, and then at a second location within the reactor. The process is repeated, followed by determining if the difference in measured property varies from a reference difference, derived under bubble-free conditions. When the difference in measured physical property has changed relative to the reference difference, an effect may be implemented, e.g., increase of reactor pressure, decrease of composition vapor pressure, and decrease of reactor temperature, to an extent sufficient to reduce or eliminate bubbling.

System and method for monitoring bubble formation within a reactor

Provided is a method of producing polypropylene comprising contacting an oxygenate stream with a molecular sieve to form an olefin stream comprising propane, propylene and dimethylether; introducing the olefin stream into a propylene rectification tower possessing from less than 200 theoretical stages; withdrawing from the propylene rectification tower a bottom stream comprising dimethylether, a sidestream comprising propane, and an overhead stream comprising propane and propylene; introducing the overhead to a condenser to accumulate a propylene-rich stream; passing the propylene-rich stream to a splitter to produce (i) a first propylene stream that is introduced into a polypropylene reactor to contact a polyolefin catalyst, and (ii) a second propylene stream that is re-introduced into the rectification tower, the first and second propylene streams introduced at a desirable ratio; and recirculating the dimethylether stream to contact the molecular sieve.

Integrated dimethyl ether recovery from an oxygenate-to-olefins process and production of polypropylene

Provided for separating polymer from a slurry comprising polymer and unreacted carrier fluid is (a) a method comprising supplying slurry to a first heating means to increase the temperature of the slurry, using a first separator means to extract a portion of unreacted carrier fluid from the slurry to obtain a slurry enriched in polymer, supplying the enriched slurry to a second heating means to increase the temperature of the enriched slurry, and using a second separator means to extract an additional portion of unreacted carrier fluid from the enriched slurry to obtain a further enriched slurry, and (b) an apparatus comprising a first heating means, a first separator means, a second heating means and a second separator means.

Method and apparatus for separation of polymer from a slurry

The invention relates to the production of polymers using polymerization processes and reactor systems including a plurality of multi-zone circulating reactors. In particular, the invention relates to the production of impact copolymers using reactor systems including a plurality of multi-zone circulating reactors.

Reactor systems and polymerization processes using multi-zone circulating reactors

Aspects of the invention are directed to a process for producing polypropylene comprising: providing series reactors comprising a first and a second loop allowing flow of polypropylene, catalyst, hydrogen and propylene there between, wherein each loop comprises from six to eight legs, each leg having fluid connections there between; injecting into the first loop an amount of a catalyst, propylene and optionally hydrogen; withdrawing polypropylene, and unreacted propylene and optionally unreacted hydrogen from the first loop and injecting the polypropylene, and unreacted propylene and optionally unreacted hydrogen into the second loop; and providing a propylene/polypropylene separator fluidly connected to the second loop and isolating polypropylene therefrom. In one embodiment a recycle conduit is provided between the propylene/polypropylene separator and the second loop allowing the recycling of unreacted propylene and optionally hydrogen into the second loop.

Polypropylene series reactor

The present invention provides a process for cooling a polymerization reactor having at least four leg jackets. In the four leg jacket embodiment, the process comprises pumping a first coolant through a first pair of leg jackets, and pumping a second coolant through a different pair of leg jackets. In this process, the first coolant does not contact the second coolant while inside the leg jackets.

Loop reactor heat removal

A polymerization process is provided. For example, a polymerization process is described, including providing a catalyst slurry having a metallocene catalyst and a first oil, providing a transport medium including a second oil and combining the transport medium and the catalyst slurry to form a catalyst mixture. The process may further include introducing the catalyst mixture to a polymerization reactor and contacting olefin monomers with the catalyst mixture to polymerize the olefin monomers and form polyolefins.

Methods of delivering catalyst systems for propylene polymerization

This invention provides an integrated system and process for forming light olefins and polymers from oxygenates, and optionally from natural gas. The integrated system includes an air separation unit, which separates air components into an oxygen stream and a nitrogen stream, and which also forms a compressed air stream. According to the present invention, the oxygen stream, the nitrogen stream and/or the compressed air stream from the air separation unit may serve as a reactant in syngas generation, as a regeneration medium in the methanol-to-olefins reaction system, as a fluidizing stream, as a blanketing medium, as a stripping medium, as instrument air, and/or as a reactant in a sulfur removal unit.

Integrating an air separation unit into an oxygenate-to-olefins reaction system

This invention relates to a process to polymerize olefins comprising contacting, in a polymerization system, olefins having three or more carbon atoms with a catalyst compound, activator, optionally comonomer, and optionally diluent or solvent, at a temperature above the cloud point temperature of the polymerization system and a pressure no lower than 10 MPa below the cloud point pressure of the polymerization system, where the polymerization system comprises any comonomer present, any diluent or solvent present, the polymer product, where the olefins having three or more carbon atoms are present at 40 weight % or more.

Polymer production at supercritical conditions

A polymerization process and a catalyst delivery system are provided. For example, a polymerization process is described, including providing a conduit having a catalyst inlet, a first propylene stream inlet located downstream of the catalyst inlet, and a second propylene stream inlet located downstream of the first propylene stream inlet, the conduit being operably connected to a polymerization vessel, introducing a catalyst to the conduit through the catalyst inlet, and passing the catalyst through the conduit to the polymerization vessel. The process may further include introducing a first propylene stream to the conduit to provide a mixed catalyst stream downstream of the catalyst inlet. The process may additionally include stopping the flow of the catalyst passing through the conduit, introducing a second propylene stream to the conduit through the second propylene stream inlet, removing a section of the conduit, and replacing the removed section of the conduit with a different conduit section. The catalyst delivery system may include a conduit having a catalyst inlet, a first propylene stream inlet and a second propylene stream inlet located downstream of the first propylene stream inlet, the conduit being operably connected to a polymerization vessel and having a removable portion, the second propylene stream inlet being configured to prevent polymer from passing from the polymerization vessel into the conduit during conduit maintenance.

Methods for injecting catalyst into a polymerization reactor

The present invention provides a method of separating unreacted monomer from a polymerization process effluent stream. The polymerization process effluent stream has at least the following components: unreacted monomer, polymer, and solid fines. The method comprises passing the effluent stream through one or more filters disposed within a vessel at a pressure of from about 150 psig to about 400 psig and thereby obtaining a stream of vapor containing less than about 0.5 weight percent solid fines.

High pressure filter method of separating polymer solids and unreacted monomer

This invention concerns using an intermediate grade propylene stream as feed to a polypropylene forming reaction system. The intermediate grade propylene stream is preferably recovered form the olefin product of an oxygenate to olefins reaction process, and low in dimethyl ether content.

Growing community of inventors

Houston, TX, United States of America

Lawrence Carl Smith