Invention Grant
- Patent Title: Circular economy for plastic waste to polyethylene and chemicals via refinery crude unit
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Application No.: US17131839Application Date: 2020-12-23
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Publication No.: US11518943B2Publication Date: 2022-12-06
- Inventor: Hye-Kyung Timken
- Applicant: Chevron U.S.A. Inc.
- Applicant Address: US CA San Ramon
- Assignee: Chevron U.S.A. Inc.
- Current Assignee: Chevron U.S.A. Inc.
- Current Assignee Address: US CA San Ramon
- Agent E. Joseph Gess; Melissa M. Hayworth; Terrence M. Flaherty
- Main IPC: C10G1/10
- IPC: C10G1/10 ; C07C4/04 ; C07C2/30 ; C10G73/02 ; C08F10/02 ; C10B53/07 ; C10G1/00

Abstract:
Provided is a continuous process for converting waste plastic into recycle for polyethylene polymerization or for normal alpha olefins. The process comprises selecting waste plastics containing polyethylene and/or polypropylene and then 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 in a refinery from which is recovered a straight run naphtha fraction (C5-C8) or a propane/butane (C3-C4) fraction. The straight run naphtha fraction, or propane and butane (C3-C4) fraction, is passed to a steam cracker for ethylene production. The ethylene is converted to normal alpha olefin and/or polyethylene. Also, a heavy fraction from the pyrolysis reactor can be combined with a heavy fraction of normal alpha olefin stream recovered from the steam cracker. The combined heavy fraction and heavy fraction of normal alpha olefin stream can be passed to a wax hydrogenation zone to produce wax.
Public/Granted literature
- US20210189250A1 CIRCULAR ECONOMY FOR PLASTIC WASTE TO POLYETHYLENE AND CHEMICALS VIA REFINERY CRUDE UNIT Public/Granted day:2021-06-24
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