Circular economy for plastic waste to polyethylene and base oil via refinery hydrocracking unit
AssigneeChevron U.S.A. Inc.
InventorHye-Kyung C. Timken
Life of this patent
Estimating the term…
Abstract
Provided is a continuous process for converting waste plastic into recycle for polyethylene polymerization. The process comprises selecting waste plastics containing polyethylene and/or polypropylene and preparing a blend of petroleum and the selected plastic. The amount of plastic in the blend comprises no more than 20 wt. % of the blend. The blend is passed to a refinery hydrocracking unit. A liquid petroleum gas C3-C4 olefin/paraffin mixture, and optionally naphtha, is recovered from the hydrocracking unit and passed to a steam cracker to make ethylene. A heavy fraction can also be recovered from the hydrocracking unit and passed to an isomerization dewaxing unit to prepare base oil.
Claims25
A continuous process for converting waste plastic into recycle for polyethylene polymerization comprising:
- (a) selecting waste plastics comprising polyethylene and/or polypropylene;
- (b) preparing a homogeneous liquid blend of petroleum and the selected waste plastic with the blend comprising less than 20 wt. % of the selected waste plastic by mixing the petroleum and waste plastic in a preparation unit;
- (c) passing the blend at a temperature above the melting point of the waste plastic in the blend directly to a refinery hydrocracking unit for cracking over a cracking catalyst;
- (d) recovering a liquid petroleum gas C3-C4 olefin/paraffin mixture from the hydrocracking unit;
- and
- (e) passing the C3-C4 mixture to a steam cracker to make ethylene.
A process for converting waste plastic into chemicals useful in preparing polyethylene, comprising:
- (a) selecting waste plastics containing polyethylene and/or polypropylene;
- (b) preparing a homogeneous liquid blend of petroleum and the selected waste plastic, with the blend comprising less than 20 wt. % of the selected plastic by mixing the petroleum and waste plastic in a preparation unit;
- and
- (c) passing the blend prepared in (b) at a temperature above the melting point of the waste plastic directly to a refinery hydrocracking unit for cracking over a cracking catalyst.
A continuous process for converting waste plastic into recycle for preparation of base oil comprising:
- (a) selecting waste plastics comprising polyethylene and/or polypropylene;
- (b) preparing a homogeneous liquid blend of petroleum and the selected waste plastic with the blend comprising less than 20 wt. % of the selected waste plastic by mixing the petroleum and waste plastic in a preparation unit;
- (c) passing the blend prepared in (b) at a temperature above the melting point of the plastic in the blend directly to a refinery hydrocracking unit for cracking over a cracking catalyst;
- (d) recovering a heavy fraction from the hydrocracking unit and passing the heavy fraction to a refinery isomerization/dewaxing unit;
- and
- (e) recovering base oil from the isomerization dewaxing unit.
A continuous process for converting waste plastic into recycle for preparation of lower carbon footprint fuels and base oil comprising:
- (a) selecting waste plastics comprising polyethylene and/or polypropylene;
- (b) preparing a homogeneous liquid blend of petroleum and the selected waste plastic with the blend comprising less than 20 wt. % of the selected waste plastic by mixing the petroleum and waste plastic in a preparation unit;
- (c) passing the blend prepared in (b) at a temperature above the melting point of the plastic in the blend directly to a refinery hydrocracking unit for cracking over a cracking catalyst;
- (d) recovering a heavy fraction from the hydrocracking unit and passing the heavy fraction to a refinery isomerization/dewaxing unit;
- and
- (e) recovering base oil from the isomerization dewaxing unit, and
- recovering fractions from the hydrocracking unit to prepare lower carbon footprint fuels which include gasoline, jet fuel, diesel, and/or marine off.
A continuous process for converting waste plastic into recycle for polyethylene polymerization comprising:
- (a) selecting waste plastics comprising polyethylene and/or polypropylene;
- (b) preparing a blend of petroleum and the selected waste plastic in a preparation unit with the blend comprising less than 20 wt. % of the selected waste plastic by heating the waste plastic above the melting point of the plastic and mixing with petroleum, and then cooling the blend to a temperature below the melting point of the waste plastic;
- (c) heating the blend prepared in (b) to a temperature above the melting point of the plastic to create a homogeneous liquid blend and then passing the blend from the preparation unit at a temperature above the melting point of the plastic directly to a refinery hydrocracking unit;
- (d) recovering a liquid petroleum gas C3-C4 olefin/paraffin mixture from the hydrocracking unit;
- and
- (e) passing the C3-C4 mixture to a steam cracker to make ethylene.
Dependencies are inferred from the claim text.