Method of carrying out thermolysis and thermolysis apparatus

Patent metadata

Field	Value
Publication number	US-12030232-B2
Application number	US-201916975558-A
Country	US
Kind code	B2
Filing date	Feb 25, 2019
Priority date	Feb 26, 2018
Publication date	Jul 9, 2024
Grant date	Jul 9, 2024

Abstract

A method and apparatus for thermolysing organic material. The method comprises steps of: A) feeding the material in a single-screw extruder (100), the extruder comprising —a cylindrical rotor member (1) having diameter (D) and length (L) and comprising a feeding zone (14), —the rotor member (1) arranged in a barrel (2), —the cylindrical surface of the rotor member (1) carrying cavity/cavities and/or projection(s) (5) arranged in helically extending rows, —the helically extending row(s) of the rotor member (1) having a pitch (P) and depth (d) in the feeding zone (14) of the rotor member, wherein —the relation of the depth (d) to the diameter (D) of the rotor member, i.e. d:D, is not more than 1:20, and —the relation of the pitch (P) of the rotor member to the diameter (D) of the rotor member, i.e. P:D, is not more than 1:4, B) heating the material in the single-screw extruder (100) to a flowable state, and C) thermolysing the material.

First claim

The invention claimed is:

1. A method for thermolysing organic material, the method comprising:
A) feeding the material in a single-screw extruder, the extruder comprising
a cylindrical rotor member having diameter D and length L and comprising a feeding zone,
a feed opening, and
a drying zone and a pyrolysis zone,
the rotor member arranged in a barrel,
a cylindrical surface of the rotor member carrying cavity/cavities and/or projection(s) arranged in helically extending rows,
the helically extending row(s) of the rotor member having a pitch P and depth d in the feeding zone of the rotor member, wherein
the pitch of the helically extending rows is a distance between two consecutive helically extending rows,
the feeding zone comprises a part of the rotor member directly under the feed opening and five laps of the helically extending rows following the feed opening,
a relation of the depth d to the diameter D of the rotor member, i.e. d:D, is not more than 1:20, and
a relation of the pitch P of the rotor member to the diameter D of the rotor member, i.e. P:D, is not more than 1:4,

B) heating the material in the single-screw extruder to a flowable state, and
C) thermolysing the material, wherein the extruder is configured as a thermolysis reactor such that the thermolysis occurs in the single-screw extruder.

2. The method as claimed in claim 1 , wherein said thermolysing comprises pyrolysis.

3. The method as claimed in claim 1 , wherein the organic material comprises plastic waste.

4. The method as claimed in claim 1 , comprising feeding the material in flowable state from the single-screw extruder.

5. The method as claimed in claim 4 , further comprising using secondary gas generated in the thermolysis process for heating the single-screw extruder.

6. The method as claimed in claim 1 , further comprising removing halogen-containing gas(es) from the extruder in the thermolysis.

7. The method as claimed in claim 6 , wherein the removing halogen-containing gas(es) comprises adding an additive, for assisting in the removing of the removing halogen-containing gas(es).

8. The method as claimed in claim 1 , further comprising adding a catalyst in the thermolysis for removing bromine-containing gas(es).

9. The method as claimed in claim 1 , further comprising heating the organic material to a temperature of 200° C. to 700° ° C.

10. A thermolysing apparatus, comprising a single-screw extruder, comprising:
a cylindrical rotor member having diameter D and length L and comprising a feeding zone,
a feed opening;
the rotor member arranged in a barrel,
a cylindrical surface of the rotor member carrying cavity/cavities and/or projection(s) arranged in helically extending rows,
the helically extending rows of the rotor member having a pitch P and depth d in the feeding zone of the rotor member, wherein the pitch of the helically extending rows is a distance between two consecutive helically extending rows, and wherein the feeding zone comprises a part of the rotor member directly under the feed opening and five laps of the helically extending rows following the feed opening, and the extruder further comprising
a drive system for the rotation of the rotor member in the barrel,
wherein
a relation of the depth d to the diameter D of the rotor member, i.e. d:D, is not more than 1:20,
a relation of the pitch P of the rotor member to the diameter D of the rotor member, i.e. P:D, is not more than 1:4, and
the extruder is configured as a thermolysis reactor such that thermolysis occurs in the extruder; and
the extruder comprises a drying zone and a pyrolysis zone.

11. The apparatus as claimed in claim 10 , wherein the cylindrical surface of the rotor member caries the projection(s),
the projection(s) of the rotor member comprise(s) a screw thread comprising at least one screw flight, and
at least one screw channel between the at least one screw flight, the screw flight having the pitch P and the screw channel having the depth d.

12. The apparatus as claimed in claim 10 , wherein the cylindrical surface of the rotor member carries the cavity/cavities, and the cavity/cavities comprise(s) helically extending rows of a plurality of separate cavities.

13. The apparatus as claimed in claim 10 , wherein the cylindrical surface of the rotor member caries the projection(s), and the projection(s) comprise(s) helically extending rows of a plurality of discrete projections.

14. The apparatus as claimed in claim 10 , wherein the rotor member comprises a cylindrical channel, a diameter of which is at least 75% of the diameter D of the rotor member.

15. The apparatus as claim 10 , wherein d:D is 1:300 to 1:20.

16. The apparatus as claimed in claim 10 , wherein P:D is 1:60 to 1:4.

17. The apparatus as claimed in claim 10 , wherein
CL·d≤RD·0.01, wherein
CL=channel length measured in a direction of the length L of the rotor member,
d=the depth of the helically extending rows, and
RD=cross-sectional area of the rotor member.

18. The apparatus as claimed in claim 10 , wherein the barrel comprises barrel cavity/cavities and/or projection(s) arranged in helically extending rows.

19. The apparatus as claimed in claim 18 , wherein the barrel cavity/cavities and/or projection(s) realize a screw thread comprising at least one barrel flight and
at least one barrel channel between the at least one flight, the barrel flight having a barrel pitch BP and the barrel channel having a barrel depth BD.

20. The apparatus as claimed in claim 18 , wherein the barrel cavities realize helically extending rows of a plurality of separate cavities.

21. The apparatus as claimed in claim 10 , wherein L:D is 2:1 to 4:1.

22. The apparatus as claimed in claim 10 , wherein the depth d of the helically extending rows in the feeding zone of the cavity/cavities and/or projection(s) arranged in the helically extending rows is arranged to decrease after the feeding zone.

23. The apparatus as claimed in claim 10 , wherein a cross-sectional area of the feed opening is 15 cm 2 -150 cm 2 per kilowatt (kW) of rotor motor power.

24. The apparatus as claimed in claim 10 , wherein the barrel comprises at least one gas-removing channel for removing gas in the extruder.

25. The apparatus as claimed in claim 24 , wherein the gas-removing channel is connected to a gas-removing zone arranged in the extruder, and wherein the gas-removing zone comprises a barrel cavity/cavities having a larger volume than zones before and after said gas-removing zone.

26. The apparatus as claimed in claim 10 , wherein the extruder comprises a connection for receiving gaseous heating medium for heating the barrel and/or the rotor member.

27. The apparatus as claimed in claim 10 , wherein the barrel comprises a support structure being arranged outside of the barrel, the support structure comprising
a first support attached to the barrel between the feed opening and an extruder outlet end of the extruder,
a second support attached to a drive system side of the extruder, and
a load transmit structure connecting the first support to the second support.

28. The apparatus as claimed in claim 10 , further comprising an axial slot arranged between the feeding zone of the barrel and a bearing housing of the extruder for receiving material flowing from the feeding zone backwards.

Assignees

• Teknologian Tutkimuskeskus Vtt Oy

Inventors

• Oasmaa Anja
• Minkkinen Hannu
• Lindfors Christian
• Lehto Jani
• Mannila Juha

Classifications

• C10B1/06

  Horizontal retorts · CPC title

• C10B53/07

  {of solid raw materials consisting} of synthetic polymeric materials, e.g. tyres (recovery or working-up of waste materials of organic macromolecular compounds or compositions based thereon by dry-heat treatment for obtaining partially depolymerised materials C08J11/10; production of liquid hydrocarbon mixtures from rubber or rubber waste C10G1/10) · CPC title

• C10B47/44

  with conveyor-screws · CPC title

• C10B7/10 Primary

  with conveyor-screws · CPC title

• B29B7/92

  Wood chips or wood fibres · CPC title