Systems and methods for redox thermal degradation of plastic materials

Patent metadata

Field	Value
Publication number	US-2025270459-A1
Application number	US-202318856529-A
Country	US
Kind code	A1
Filing date	Apr 14, 2023
Priority date	Apr 14, 2022
Publication date	Aug 28, 2025
Grant date	—

Abstract

Exemplary systems and methods relate to processing plastic material. A feedstock comprising plastic material and oxygen carriers comprising active material may be provided to a first reactor. A weight ratio of active material to feedstock may be no less than 4:1 and no greater than 10:1. Oxidation products may be obtained from the first reactor. Reduced oxygen carriers may be provided from the first reactor to a second reactor. Oxidizing material may be provided to the second reactor, which may oxidize the reduced oxygen carriers. Energy and/or a product stream may be obtained from the second reactor.

First claim

What is claimed is:

1 . A method for processing plastic material, the method comprising:
providing a feedstock to a first inlet of a first reactor, the feedstock comprising plastic material; providing oxidized oxygen carriers to a second inlet of the first reactor, the oxidized oxygen carriers comprising active material and being provided such that a weight ratio of active material to feedstock is no less than 4:1 and no greater than 10:1; obtaining oxidation products from a first outlet of the first reactor; providing reduced oxygen carriers from a second outlet of the first reactor to a first inlet of the second reactor; providing an oxidizing material to a second inlet of the second reactor; and obtaining energy and/or a second reactor product stream from the second reactor.

2 . The method according to claim 1 , the method further comprising:
transporting, using a riser, the oxidized oxygen carriers to the second inlet of the first reactor from a first outlet of the second reactor.

3 . The method according to claim 1 , further comprising providing the feedstock to an inlet of a pyrolysis reactor in fluid communication with the first inlet of the first reactor;
generating char or heavy volatiles using the pyrolysis reactor; and providing the char or heavy volatiles from an outlet of the pyrolysis reactor to the first inlet of the first reactor.

4 . The method according to claim 1 , wherein the oxidized oxygen carriers comprise 50% by weight active material; and
wherein the weight ratio of active material to the feedstock is no less than 5:1 and no greater than 9:1.

5 . The method according to claim 1 , the feedstock and the oxidized oxygen carriers being provided to the first reactor as co-current streams.

6 . The method according to claim 1 , further comprising an oxidizer reactor in fluid communication with the first reactor and the second reactor;
providing the reduced oxygen carriers to a first inlet of the oxidizer reactor from the second outlet of the first reactor; providing steam (H 2 O) to a second inlet of the oxidizer reactor; generating hydrogen gas (H 2 ) in the oxidizer reactor; and providing partially reduced oxygen carriers to the first inlet of the second reactor.

7 . The method according to claim 6 , further comprising a bypass stream, the bypass stream directing at least 10% of the reduced oxygen carriers from the first reactor to the second reactor.

8 . The method according to claim 1 , the first reactor operating at a temperature between 300° C. to 1500° C.; and
the first reactor operating at a pressure between 0.1 MPa to 15 MPa.

9 . The method according to claim 1 , the second reactor operating at a temperature between 300° C. to 1500° C.; and
the second reactor operating at a pressure between 0.1 MPa to 15 MPa.

10 . The method according to claim 1 , the feedstock further comprising char or heavy volatiles.

11 . The method according to claim 1 , the oxidizing material comprising carbon dioxide (CO 2 ), steam (H 2 O), air, oxygen (O 2 ), or combinations thereof; and
the second reactor product stream comprising carbon monoxide (CO), hydrogen gas (H 2 ) and/or syngas.

12 . The method according to claim 1 , further comprising:
removing, using a third reactor, at least one of chlorine (Cl − ) ions, bromine (Br − ) ions, or fluorine (F − ) ions from the feedstock, thereby generating a dehalogenated stream, the first reactor being in fluid communication with the third reactor; and providing the dehalogenated stream to the first inlet of the first reactor.

13 . The method according to claim 1 , wherein the second reactor product stream has a maximum tar content of no greater than 50 g/Nm 3 .

14 . The method according to claim 1 , the method further comprising:
providing one or more oxygen-source materials to a third inlet of the first reactor,
the one or more oxygen source materials comprising steam (H 2 O) and/or carbon dioxide (CO 2 ).

15 . The method according to claim 1 , the method further comprising:
collecting an output stream comprising the oxidized oxygen carriers from a third outlet of the second reactor; and providing the collected oxidized oxygen carriers to the second inlet of the first reactor.

16 . A method for processing plastic material, the method comprising:
providing a feedstock to a first inlet positioned near a top portion of a cross-current reactor, the feedstock comprising plastic material; providing oxidized oxygen carriers to a second inlet of the cross-current reactor, the oxidized oxygen carriers comprising active material and being provided such that a weight ratio of active material to feedstock is no less than 4:1 and no greater than 10:1; providing one or more oxygen-source materials to a third inlet positioned near a bottom portion of the cross-current reactor, the one or more oxygen-source materials comprising steam (H 2 O), carbon dioxide (CO 2 ), and/or oxygen (O 2 ); obtaining syngas from a first outlet positioned near a middle portion of the cross-current reactor, obtaining oxidized oxygen carriers from a second outlet positioned near the bottom portion of the cross-current reactor; and recycling the oxidized oxygen carriers to the second inlet positioned near the top portion of the cross-current reactor.

17 . The method according to claim 16 , the method further comprising:
recycling, using a riser, the oxidized oxygen carriers from the second outlet to the second inlet of the cross-current reactor.

18 . The method according to claim 16 , further comprising a second reactor in fluid communication with the cross-current reactor, and the method further comprising:
providing the oxidized oxygen carriers and/or partially oxidized oxygen carriers to a bottom inlet of the second reactor; oxidizing the partially oxidized oxygen carriers in the second reactor; and providing the oxidized oxygen carriers to the second inlet of the cross-current reactor,
wherein the oxidized oxygen carriers are transported using a riser to the second inlet of the cross-current reactor.

19 . A reactor system configured to process plastic material, the reactor system comprising:
a first reactor comprising metal oxide-based redox materials, the metal oxide-based redox materials comprising active material:
a first inlet of the first reactor configured to receive a feedstock;
a second inlet of the first reactor configured to receive oxidized metal oxide-based redox materials,
wherein the active material and the feedstock have a weight ratio no less than 4:1 and no greater than 10:1 in the first reactor;

a first outlet of the first reactor configured to provide oxidization products from the first reactor; and
a second outlet of the first reactor configured to provide reduced metal oxide-based redox materials to the second reactor; and
the second reactor in fluid communication with the first reactor, the second reactor comprising:
a first inlet of the second reactor configured to the receive reduced metal oxide-based redox materials from the first reactor;
a second inlet of the second reactor configured to receive an oxidizing material;
a first outlet of the second reactor configured to provide reduced products from the second reactor; and
a second outlet of the second reactor configured to provide oxidized metal oxide-based redox materials.

20 . The reactor system according to claim 19 , wherein the second reactor is a fluidized bed reactor or a moving bed reactor.

Assignees

• Ohio State Innovation Foundation

Inventors

• Fan Liang-Shih
• Tong Andrew
• Falascino Eric
• Joshi Rushikesh

Classifications

• B29B2017/0496

  Pyrolysing the materials · CPC title

• B29B17/04 Primary

  Disintegrating plastics, {e.g. by milling}(B29B9/02, B29B11/02, B29B13/10, {B29B17/02} take precedence) · CPC title

• C10G2300/1003

  Waste materials · CPC title

• B01J2208/00769

  Details of feeding or discharging · CPC title

• C10J3/721

  Multistage gasification, e.g. plural parallel or serial gasification stages · CPC title