METHOD AND APPARATUS FOR CONVEYING A CELLULOSIC FEEDSTOCK

• US 20100028089A1
• Filed: 07/29/2008
• Published: 02/04/2010
• Est. Priority Date: 07/24/2008
• Status: Active Grant

• Current Assignee: Abengoa Bioenergy New Technologies, LLC (Abengoa SA)
• Original Assignee: Sunopta Bioprocess Inc. (Lallemand Inc.)
• Inventors: Burke, Murray J., Hillier, Sunalie N.
• Granted Patent: US 9,010,522 B2
• Time in Patent Office: Days
• US Class Current: 406/53
• CPC Class Codes: B65G 33/18 with multiple screws in parallel arrangements , e.g. concentric
• CPC Class Codes: C12M 45/02 by mechanical forces; Stirring; Trituration; Comminuting crushing, pulverizing, disintegrating in general B02C
• CPC Class Codes: C12M 45/20 Heating; Cooling heating or cooling apparatus for laboratory uses B01L7/00
• CPC Class Codes: C12P 2201/00 Pretreatment of cellulosic or lignocellulosic material for subsequent enzymatic treatment or hydrolysis
• CPC Class Codes: C12P 7/10 substrate containing cellulosic material
• CPC Class Codes: D21B 1/16 in the presence of chemical agents
• CPC Class Codes: D21B 1/22 with screw feed
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

An apparatus for conveying a cellulosic feedstock is disclosed. The apparatus comprises an enclosed volume having a lower surface comprising a plurality of longitudinally extending portions. Each longitudinally extending portion has an inner surface that is arcuate in transverse section. A plurality of conveyance members are provided within the enclosed volume. Each conveyance member is associated with one of the inner surfaces and configured to sweep the one of the inner surfaces. Additionally, a method for treating a cellulosic feedstock is disclosed. The method comprises providing a cellulosic feedstock being less than 100% saturated moisture. The cellulosic feedstock is introduced into a longitudinally extending enclosed volume, and conveyed longitudinally through the enclosed volume while being mixed.

Claims

1. An apparatus for conveying a cellulosic feedstock, comprising:

an enclosed volume having a length along which the cellulosic feedstock is conveyed, the enclosed volume having a lower surface comprising a plurality of longitudinally extending portions, each portion having an inner surface that is arcuate in transverse section; and

,

a plurality of conveyance members provided within the enclosed volume, each conveyance member being associated with one of the inner surfaces and configured to sweep the one of the inner surfaces.

2. The apparatus of claim 1, wherein each conveyance member comprises a longitudinally extending rotary shaft, and a conveying member extending outwardly from the shaft.

3. The apparatus of claim 2, wherein the conveying member and the lower surface are configured to maintain a space between the conveying member and the lower surface of less than 6.5 mm.

4. The apparatus of claim 2, wherein the conveying member comprises a plurality of paddles each comprising a generally planar blade having a radial inner edge attached to stem, a radial outer edge opposite the radial inner edge, and opposing first and second side edges extending between the radial inner and outer edges and the radial outer edge is curved to match an arc swept by the outer edge when the shaft rotates.

5. The apparatus of claim 4, wherein each blade is canted, wherein the first side edge is axially nearer the outlet and rotationally trailing relative to a second side edge.

6. The apparatus of claim 5, wherein the first side edge of one paddle axially overlaps the second side edge of a next adjacent paddle.

7. The apparatus of claim 2, wherein adjacent shafts are spaced transversely apart from each other and are generally parallel and rotate in opposite directions.

8. The apparatus of claim 2, wherein at least some of the paddles have an arcuate radial outer edge that is shaped to mate with at least one of the inner surfaces.

9. The apparatus of claim 2, wherein each inner surface defines a first sector of a circle having a first radius and a radial outer edge of the each paddle describes a second sector of a circle having a second radius as it rotates, and the second radius is essentially the same as the first radius of at least one of the inner surfaces.

10. The apparatus of claim 2, wherein the paddles are staggered circumferentially along the shaft.

11. The apparatus of claim 1, wherein the enclosed volume comprises an upper inner arcuate surface having first and second transversely opposed lower longitudinally extending sides, wherein one of the longitudinally extending portions has an upper outer side configured to merge with the first lower longitudinally extending side, and another of the longitudinally extending portions has an upper outer side configured to merge with the second lower longitudinally extending side.

12. The apparatus of claim 1, wherein the conveyance members have fluid injection ports.

13. The apparatus of claim 12, wherein each conveyance member comprises a longitudinally extending rotary shaft and the shaft comprises a fluid conduit extending longitudinally therethrough.

14. The apparatus of claim 2, wherein the shaft comprises a fluid conduit extending longitudinally therethrough and at least one of the stem and the paddles comprise injection ports.

15. The apparatus of claim 1, wherein the longitudinally extending portions are positioned side-by-side.

17. The method of claim 15, further comprising operating the enclosed volume at less then 100% fill volume whereby an upper portion of the enclosed volume is open.

19. The method of claim 17, wherein the enclosed volume has a plurality of longitudinally extending portions, each portion having an inner surface that is arcuate in transverse section, and the method further comprises conveying the cellulosic feedstock longitudinally along each inner surface.

21. The method of claim 19, wherein the lower surface comprises a plurality of longitudinally extending portions and the method further comprises rotating a plurality of conveyance members to pass conveying members of each conveyance member proximate one of the inner surfaces such that conveying members of each conveyance member contact the cellulosic feedstock and urge the cellulosic feedstock along the length of each inner surface.

22. The method of claim 15, further comprising maintaining a residence time of less than 10 minutes.

23. The method of claim 15, wherein the feedstock is mixed such that the feedstock has a generally uniform moisture content of 30% to 60% by weight upon exiting the enclosed volume.

24. The method of claim 15, wherein the feedstock is mixed such that the feedstock has a generally uniform moisture content of 45% to 55% by weight upon exiting the enclosed volume.

25. The method of claim 15, further comprising conveying the cellulosic feedstock downwardly to a holding tank upon exiting the enclosed volume.

26. The method of claim 15, further comprising subsequently subjecting the cellulosic feedstock to a downstream hydrolysis process.

16. A method for conveying a cellulosic feedstock comprising:

providing a cellulosic feedstock being less than 100% saturated with moisture;

introducing the cellulosic feedstock into a longitudinally extending enclosed volume and conveying the cellulosic feedstock longitudinally through the enclosed volume while heating the cellulosic feedstock; and

,

mixing the cellulosic feedstock as it is conveyed through the enclosed volume.

18. The method of claim 16, wherein step c) comprises projecting a portion of the cellulosic feedstock into the upper open portion of the enclosed volume while conveying the cellulosic feedstock longitudinally through the enclosed volume.

20. The method of claim 16, wherein the enclosed volume has a lower surface, and the method further comprises sweeping a lower surface to convey the cellulosic feedstock through the enclosed volume.