Patent ID: 11473016

Abstract:
Provided is a continuous process for converting waste plastic into recycle for polyethylene polymerization. In one embodiment, the process comprises selecting waste plastics containing polyethylene and/or polypropylene and passing the waste plastics through a pyrolysis reactor to thermally crack at least a portion of the polyolefin waste and produce a pyrolyzed effluent. The pyrolyzed effluent is separated into offgas, a naphtha/diesel fraction, a heavy fraction, and char. The naphtha/diesel fraction is passed to a crude unit distillation column in a refinery where a straight run naphtha (C5-C8) fraction or a propane/butane (C3-C4) fraction is recovered. The straight run naphtha fraction (C5-C8) or the propane/butane (C3-C4) fraction is passed to a steam cracker for ethylene production. The heavy fraction from the pyrolysis unit can also be passed to an isomerization dewaxing unit to produce a base oil.