METHOD AND APPARATUS FOR CONVEYING A CELLULOSIC FEEDSTOCK

• US 20100024809A1
• 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 8,911,557 B2
• Time in Patent Office: Days
• US Class Current: 127/1
• CPC Class Codes: C12M 33/16 Screw conveyor
• CPC Class Codes: C12M 45/06 by chemical means or hydrolysis
• CPC Class Codes: C12M 45/09 by enzymatic treatment
• CPC Class Codes: C12M 45/20 Heating; Cooling heating or cooling apparatus for laboratory uses B01L7/00
• CPC Class Codes: C13K 1/02 obtained by saccharification of cellulosic materials manufacture of fodder A23K10/32
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

A method and apparatus for preparing a cellulosic feedstock are disclosed. Embodiments of the method comprise passing the cellulosic feedstock through an optional impregnation chamber to an outlet of the impregnation chamber, passing the cellulosic feedstock from the outlet of the impregnation chamber to a holding tank having an inlet and an outlet, and conveying the cellulosic feedstock downwardly and laterally as it travels through the holding tank. Embodiments of the apparatus comprise at least one sidewall defining a passage. The passage has an upper portion and a lower portion, and the lower portion has a greater cross-sectional area than the upper portion. At least one inlet is provided adjacent the upper portion, and at least one outlet is provided adjacent the lower portion, at an elevation below the inlet.

Claims

1. A method of preparing a cellulosic feedstock for ethanol production, comprising:

passing the cellulosic feedstock through an impregnation chamber to an outlet of the impregnation chamber;

passing the cellulosic feedstock from the outlet of the impregnation chamber to a holding tank, the holding tank having an inlet and an outlet; and

,

conveying the cellulosic feedstock downwardly and laterally as it travels through the holding tank.

2. The method of claim 1, further comprising maintaining a temperature in the holding tank between about 50°

Celsius and about 75°

Celsius.

3. The method of claim 2, wherein the cellulosic feedstock moves from the inlet to the outlet of the holding tank in about 10 to about 30 minutes.

4. The method of claim 1, wherein the inlet of the holding tank is disposed at an elevation above the outlet of the holding tank, and the cellulosic feedstock migrates from the inlet towards the outlet of the holding tank under the force of gravity.

5. The method of claim 1, further comprising conveying the cellulosic feedstock laterally across the outlet.

6. The method of claim 5, wherein the step of conveying the cellulosic feedstock laterally across the outlet comprises actively withdrawing the cellulosic feedstock from essentially an entirety of the outlet.

7. The method of claim 5, wherein the step of conveying the cellulosic feedstock laterally across the outlet comprises withdrawing a generally equal amount of cellulosic feedstock from each portion of the outlet

8. The method of claim 5, wherein the step of conveying the cellulosic feedstock laterally across the outlet comprises withdrawing a first portion of the cellulosic feedstock in a first lateral direction and withdrawing a second portion of the cellulosic feedstock in a second lateral direction.

9. A holding tank for a cellulosic feedstock comprising:

at least one sidewall defining a passage having an upper portion and a lower portion, the lower portion having a greater cross sectional area then the upper portion;

at least one inlet adjacent the upper portion; and

,

at least one outlet adjacent the lower portion, at an elevation below the inlet.

13. The holding tank of claim 9, wherein the at least one discharge member comprises a base, an open top that is at least as large as, and is in vertical registration with, the at least one outlet, and at least a first discharge member outlet that is laterally positioned.

29. The holding tank of claim 9, further comprising a heating jacket provided on at least a portion of the sidewalls.

30. The holding tank of claim 9, further comprising a heating jacket provided on the sidewalls.

10. The holding tank of claim 10, wherein the sidewalls comprise a first sidewall and a second sidewall opposed to the first sidewall, the first and second sidewalls diverging relative to each other from the upper portion to the lower portion.

12. The holding tank of claim 10, further comprising at least one discharge member adjacent the at least one outlet.

11. The holding tank of claim 11, wherein the sidewalls comprise a third sidewall and a fourth sidewall opposed to the third sidewall, the third and fourth sidewalls extending between the first and second sidewalls, the third and fourth sidewalls diverging relative to each other from the upper portion to the lower portion.

14. The holding tank of claim 14, wherein the at least one discharge member comprises at least one screw conveyor mounted above the base.

15. The holding tank of claim 14, wherein the at least one discharge member comprises a first pair of screw conveyors, each conveyor in the first pair rotating about respective first and second generally parallel axes.

16. The holding tank of claim 16, wherein the screw conveyors are rotated in the same direction and feed material from above towards the first discharge member outlet.

17. The holding tank of claim 16, wherein the screw conveyors have a first pitch adjacent the first discharge member outlet, and a second pitch narrower than the first pitch distal to the first discharge member outlet.

18. The holding tank of claim 16 wherein the screw conveyors each have a first flight and a second flight, the first flight having a first pitch and disposed adjacent the first discharge member outlet, the second flight having a narrower pitch and disposed along the shaft upstream from the first flight.

20. The holding tank of claim 16, wherein the axes extend at an angle of less than 45°

relative to horizontal.

22. The holding tank of claim 16, wherein the discharge member further comprises a second pair of screw conveyors.

19. The holding tank of claim 19, wherein each screw conveyor comprises a third flight intermediate the first and second flights, the third flight having an intermediate pitch that is wider than the first pitch and narrower than the wider pitch.

21. The holding tank of claim 21, wherein the axes are generally horizontal.

23. The holding tank of claim 23, wherein the second pair of screw conveyors urges material from above towards a second discharge member outlet that is laterally positioned and spaced away from the first discharge member outlet.

24. The holding tank of claim 23, wherein the second discharge member outlet is in a different direction to the first discharge member outlet.

25. The holding tank of claim 23, wherein second pair of screw conveyors are rotatable about parallel axes.

26. The holding tank of claim 25, wherein each screw conveyor in the second pair rotates in the same direction.

28. The holding tank of claim 26, wherein the axes are generally horizontal.

27. The holding tank of claim 27, wherein the screw conveyors of first pair rotate opposite to the screw conveyors of second pair.