| abstract |
A high pressure polymerization, as described herein, to form an ethylene-based polymer, comprising the following steps: polymerizing a reaction mixture comprising ethylene, using a reactor system comprising at least three ethylene-based feed streams and a reactor configuration that comprises at least four reaction zones, and at least one of the following a) through c), is met: (a) up to 100 wt% of the ethylene stream to the first zone comes from a high pressure recycle, and/or up to 100 wt% of the last ethylene stream to a zone comes from the output from a Primary compressor system; and/or (b) up to 100 wt% of the ethylene stream to first zone comes from the output from a Primary compressor system, and/or up to 100 wt% of the last ethylene stream to a zone comes from a high pressure recycle; and/or (c) the ethylene stream to the first zone, and/or the last ethylene stream to a zone, each comprises a controlled composition; and wherein each ethylene stream to a zone receives an output from two or more cylinders of the last compressor stage of a Hyper compressor system. |