Dow Global Technolgoies LLC

Dow Brasil Sudeste Industrial Ltda

Sergio E Goncalves

Otto J Berbee

Cornelis J F Hosman

Sarat Munjal

Stefan Hinrichs

Joaquin Flores

Nhi Dang

Luiz Rodriguez

Michael E Bishop

Cornelis Jf Hosman

Ethylene-based polymer, LDPE, is made in a high pressure polymerization process to comprising at least the step of polymerizing a reaction mixture comprising ethylene, using a reactor configuration comprising (A) at least two reaction zones, a first reaction zone (reaction zone 1) and an i reaction zone (reaction zone i where i&#x3e;2), (B) at least two ethylene feed streams, each feed stream comprising a percentage of the total make-up ethylene fed to the polymerization process, in which a first ethylene feed stream is sent to reaction zone 1 and a second ethylene feed stream is sent to reaction zone i, and (C) a control system to control the percentage of the total make-up ethylene in the ethylene feed stream sent to reaction zone 1 and the percentage of the total make-up ethylene in the ethylene feed stream sent to reaction zone i.

High pressure free radical polymerization process with flexible control of molecular weight distribution

A process to form an ethylene-based polymer, said process comprising at least the following: polymerizing a mixture comprising ethylene, in the presence of at least one free-radical initiator, and in a reactor configuration comprising at least three reaction zones and at least two ethylene feed streams; and wherein the inlet pressure of the first reaction zone is less than, or equal to, 3200 Bar; and wherein the amount of ethylene, and optionally one or more comonomers, and optionally one or more CTAs, fed to the first reaction zone is from 40 mole % to 80 mole %, based on the total moles of ethylene, and optionally one or more comonomers, and optionally one or more CTAs, fed to the polymerization; and wherein the average polymerization temperature of the first 40 wt % polymer formed (APT) (based on the total amount of polymer formed) is less than, or equal to, 200&#xb0; C.

High pressure, free radical polymerizations to produce ethylene-based polymers

The invention provides a process to prepare an ethylene-based polymer, said process comprising polymerizing ethylene in the presence of at least one initiator system selected from the following: a) class 1 initiator system, b) class 2 initiator system, c) class 3 initiator system, or d) a combination thereof; and at a inlet pressure (P) greater than, or equal to, 1000 Bar (100 MPa); and in a reactor system comprising at least one hyper compressor and a reactor configuration comprising at least one reactor, which comprises at least one reaction zone; and wherein the inlet pressure (P) is reduced by at least 200 Bar, as compared to a similar polymerization, in the same reactor system, except it is operated at a higher inlet pressure (P), and at a different hyper compressor throughput, and at a different maximum temperature for at least one reaction zone, and optionally, at a different amount of CTA system fed to the reactor configuration; and wherein, for the process, the 'Ratio of total reactor consumption of the highest temperature class initiator system(s) (Y)' meets the following Equation D: 0.95*x^((P&#x2212;P)/10 MPa)&#x3c;Y&#x3c;1.04*z^((P&#x2212;P)/10 MPa) (Eqn. D), wherein x is greater than, or equal to, 0.97; and wherein z is less than, or equal to, 1.03. The invention also provides a process to prepare an ethylene-based polymer, said process comprising polymerizing ethylene in the presence of at least one initiator system selected from the following: a) a class 1 initiator system, b) a class 2 initiator system, c) a class 3 initiator system, or d) a combination thereof; and at an inlet pressure (P) greater than, or equal to, 1000 Bar (100 MPa); and in a reactor system comprising a reactor configuration comprising at least one reactor, which comprises at least one reaction zone; and wherein the inlet pressure (P) is reduced by at least 200 Bar, as compared to a similar polymerization, in the same reactor configuration, except it is operated at a higher inlet pressure (P), and at a different maximum temperature for at least one reaction zone, and optionally, at a different amount of CTA system fed to the reactor configuration; and wherein, for the process, the 'Ratio of total reactor consumption of the highest temperature class initiator system(s) (Y)' meets the following Equation D: 0.95*x^((P&#x2212;P)/10 MPa)&#x3c;Y&#x3c;1.04*z^((P&#x2212;P)/10 MPa) (Eqn. D), wherein x is greater than, or equal to, 0.97; and wherein z is less than, or equal to, 1.03.

Process to control output and quality of ethylene-based polymer formed by high pressure free radical polymerization

Growing community of inventors

Guaruja, Brazil

Sergio E Goncalves