Back to results
US 12,612,561 B2Granted
Direct steam cracking methods for liquids produced from plastic waste
AssigneeExxonMobil Chemical Patents Inc.
InventorsPhilippe Laurent, Jennifer L Rougeau, Beshoy G. Abdelmalek
Life of this patent
Estimating the term…
Abstract
A method for steam cracking a plastic-derived liquid feedstock can comprise: steam cracking a plastic-derived liquid feedstock in a steam cracker to produce a cracked product, wherein the plastic-derived liquid feedstock has a final boiling point of about 550° C. or less and an olefin content of about 40 wt % or less; quenching the cracked product from a temperature of about 750° C. or greater to a temperature of about 350° C. or less with a quench oil; and wherein the method does not comprise hydrotreating and/or fractionating the plastic-derived liquid feedstock before steam cracking.
Claims20
A method comprising:
- heating a plastic material to 300° C. to 320° C. to form molten plastics;
- heating the molten plastics in a pyrolysis chamber to 390° C. to 410° C. in a nitrogen purged system while agitating the molten plastics to form a plastic derived liquid feedstock;
- flash separating C1 to C4 hydrocarbons from the plastic-derived liquid feedstock;
- directly supplying the plastic-derived liquid feedstock from the flash separating to a cracking furnace without any other intermediate processing including hydrotreating and fractionation;
- heating the plastic-derived liquid feedstock by a flue gas in a first convection section of the cracking furnace to a temperature from 160° C. to 230° C., wherein the first convection section comprises an uppermost convection section of the cracking furnace;
- diluting the plastic-derived liquid feedstock with steam between the first convection section and a second convection of the cracking furnace to give a diluted plastic-derived liquid feedstock;
- passing the diluted plastic-derived feedstock sequentially through the second convection, a third convection section of the cracking furnace, and a fourth convection section of the cracking furnace, thereby heating by the flue gas the diluted plastic-derived liquid feedstock in the second convection section, the third convection section, and the fourth convection section;
- steam cracking the diluted plastic-derived liquid feedstock in a steam cracker comprising the cracking furnace to produce a cracked product, wherein the plastic-derived liquid feedstock supplied to the first convection section has a final boiling point of about 500° C. to about 550° C. and an olefin content of about 40 wt % or less;
- quenching the cracked product from a temperature of about 750° C. or greater to a temperature of about 350° C. or less by tangential injection or swirl-type injection of a quench oil comprising C10 to C15 hydrocarbon around and along an inside surface of a quenching unit, wherein a weight ratio of flow rate of quench oil to flow rate of cracked product is in a range of about 2 to about 15;
- and
- wherein the method does not comprise hydrotreating the plastic-derived liquid feedstock before the steam cracking.
8 more elements
A method comprising:
- producing a plastic-derived liquid feedstock from plastic material by heating the plastic material to 300° C. to 320° C. to form molten plastics without any feedstock pretreatment;
- heating the molten plastics in a pyrolysis chamber to 390° C. to 410° C. in a nitrogen purged system while agitating the molten plastics to form the plastic derived liquid feedstock;
- flash separating C1 to C4 hydrocarbons from the plastic-derived liquid feedstock;
- directly supplying the plastic-derived liquid feedstock from the flash separating to a cracking furnace without any other intermediate processing including hydrotreating and fractionation;
- heating the plastic-derived liquid feedstock by a flue gas in a first convection section of the cracking furnace to a temperature from 160° C. to 230° C., wherein the first convection section comprises an uppermost convection section of the cracking furnace;
- diluting the plastic-derived liquid feedstock with steam between the first convection section and a second convection of the cracking furnace to give a diluted plastic-derived liquid feedstock;
- passing the diluted plastic-derived feedstock sequentially through the second convection, a third convection section of the cracking furnace, and a fourth convection section of the cracking furnace, thereby heating by the flue gas the diluted plastic-derived liquid feedstock in the second convection section, the third convection section, and the fourth convection section;
- steam cracking the diluted plastic-derived liquid feedstock in a steam cracker comprising the cracking furnace to produce a cracked product, wherein the plastic-derived liquid feedstock supplied to the first convection section has a final boiling point of about 500° C. to about 550° C. and an olefin content of about 40 wt % or less;
- quenching the cracked product from a temperature of about 750° C. or greater to a temperature of about 350° C. or less with a quench oil;
- and
- wherein the method does not comprise fractionating the plastic-derived liquid feedstock from the flash separating before the steam cracking.
8 more elements
A method comprising:
- producing a plastic-derived liquid feedstock from plastic material by heating the plastic material to 300° C. to 320° C. to form molten plastics;
- heating the molten plastics in a pyrolysis chamber to 390° C. to 410° C. in a nitrogen purged system while agitating the molten plastics to form a plastic derived liquid feedstock;
- flash separating C1 to C4 hydrocarbons from the plastic-derived liquid feedstock;
- directly supplying a plastic-derived liquid molten plastic feedstock from the flash separating to a cracking furnace without any other intermediate processing including hydrotreating and fractionation;
- heating the plastic-derived liquid feedstock by a flue gas in a first convection section of the cracking furnace to a temperature from 160° C. to 230° C., wherein the first convection section comprises an uppermost convection section of the cracking furnace;
- diluting the plastic-derived liquid feedstock with steam between the first convection section and a second convection of the cracking furnace to give a diluted plastic-derived liquid feedstock;
- passing the diluted plastic-derived feedstock sequentially through the second convection, a third convection section of the cracking furnace, and a fourth convection section of the cracking furnace, thereby heating by the flue gas the diluted plastic-derived liquid feedstock in the second convection section, the third convection section, and the fourth convection section;
- steam cracking the diluted plastic-derived liquid feedstock in a steam cracker comprising the cracking furnace to produce a cracked product, wherein the steam cracking has a weight ratio of steam to the diluted plastic-derived liquid feedstock is from 0.25:1 to about 0.75:1;
- wherein the plastic-derived liquid feedstock supplied to the first convection section has a final boiling point of about 500° C. to about 550° C. and an olefin content of about 40 wt % or less;
- quenching the cracked product from a temperature of about 750° C. or greater to a temperature of about 350° C. or less by tangential injection or swirl-type injection of a quench oil comprising C10 to C15 hydrocarbon around and along an inside surface of a quenching unit, wherein a weight ratio of flow rate of quench oil to flow rate of cracked product is in a range of about 2 to about 15;
- and
- wherein the method does not comprise hydrotreating the plastic-derived liquid feedstock before the steam cracking.
9 more elements
Dependencies are inferred from the claim text.