System and process for production of polyethylene and polypropylene

Abstract

A system for production of a polymer that may include a first high shear mixing device configured for producing a nanodispersion comprising particles or bubbles having a mean diameter less than 1 micron dispersed in a monomer-containing liquid or gaseous phase; a pump configured for delivering a pressurized liquid stream comprising the monomer to the first high shear mixing device; and a vessel configured for receiving the nanodispersion and for maintaining a predetermined pressure and temperature.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a divisional application of U.S. Ser. No. 12 / 141,191 filed on Jun. 18, 2008, which application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 60 / 946,450 filed Jun. 27, 2007, and U.S. Provisional Patent Application No. 60 / 946,456 filed Jun. 27, 2007, the disclosures of which are hereby incorporated herein by reference.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not Applicable.TECHNICAL FIELD[0003]The present invention generally relates to the liquid phase polymerization of ethylene or propylene monomer, in the presence of a highly dispersed catalyst, to form polyethylene or polypropylene, respectively. More particularly, the invention relates to apparatus, systems, and methods for producing polyethylene or polypropylene which employ high shear mixing of the reactants.BACKGROUND[0004]Polyethylene is a thermoplastic material that is created through polymeriza...

AI Technical Summary

Benefits of technology

[0010]In accordance with certain embodiments of the invention, a system for production of a polymer is provided that may include a first high shear mixing device configured for producing a nanodispersion having particles or bubbles having a mean diameter less than 1 micron dispersed in a monomer-containing liquid or gaseous phase; a pump configured for delivering a pressurized liquid stream having the monomer to the first high shear mixing device; and a vessel configured for receiving the nanodispersion and for maintaining a predetermined pressure and temperature.

[0011]In accordance with certain embodiments of the invention, a system for production of a polymer is provided that may include at least one high shear mixing device configured for producing a nanodispersion comprising particles or bubbles having a mean diameter less than 1 micron, the at least one high shear mixing device having at least one rotor and at least one stator separated by a shear gap, and wherein the high shear mixing device is configured to produce a tip speed at a tip of the at least one rotor of greater than 22.9 m/s (4,500 ft/min); a pump configured for delivering a pressurized liquid stream to the at least one high shear mixing device; and a vessel configured for receiving the nanodispers

Problems solved by technology

Although polymerization rates increase with temperature, reaction temperatures above 70-100° C. seldom are employed because high temperatures result in loss of stereospecificity as well as lowered polymerization rates as a result of the decreased stability of the initiator.

Although polymerization rates increase with temperature, reaction temperatures above 70-100° C. seldom are employed because high temperatures result in loss of stereospecificity as well as lowered polymerization rates as a result of the decreased stability of the catalyst.

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