METHOD AND APPARATUS FOR CONVEYING A CELLULOSIC FEEDSTOCK

• US 20100024806A1
• 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 8,900,370 B2
• Time in Patent Office: Days
• US Class Current: 127/1
• CPC Class Codes: B01F 23/70 Pre-treatment of the materials to be mixed
• CPC Class Codes: B01F 25/00 Flow mixers; Mixers for falling materials, e.g. solid particles centrifugal mixers B04
• CPC Class Codes: C12M 33/16 Screw conveyor
• 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: C12P 7/10 substrate containing cellulosic material
• CPC Class Codes: C13K 1/02 obtained by saccharification of cellulosic materials manufacture of fodder A23K10/32
• CPC Class Codes: C13K 13/00 Sugars not otherwise provided for in this class
• CPC Class Codes: D21C 7/00 Digesters
• CPC Class Codes: D21C 7/06 Feeding devices
• 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 obtaining a cellulosic feedstock having a moisture content of 30 wt % to 60 wt %; passing the cellulosic feedstock through a heated holding tank; withdrawing the cellulosic feedstock from the holding tank; and, subsequently subjecting the cellulosic feedstock to hydrolysis. Embodiments of the apparatus comprise at least one sidewall defining a volume having an upper portion and a lower portion. At least one inlet is provided adjacent the upper portion, and the inlet is in fluid communication with an impregnation chamber provided upstream from the holding tank. At least one outlet is provided adjacent the lower portion, and the outlet is in fluid communication with hydrolysis reactor positioned downstream from the holding tank. At least one conveyor is positioned adjacent the at least one outlet. A heating jacket provided on at least a portion of the apparatus.

Claims

1. A method for preparing a cellulosic feedstock comprising:

(a) obtaining a cellulosic feedstock having a moisture content of 30 wt % to 60 wt %;

(b) passing the cellulosic feedstock through a heated holding tank;

(c) withdrawing the cellulosic feedstock from the holding tank; and

,

(d) subsequently subjecting the cellulosic feedstock to hydrolysis.

2. The method of claim 1, wherein the moisture content is between 45 wt % and 55 wt %.

3. The method of claim 1, wherein step (b) comprises passing the cellulosic feedstock downwardly through the heated holding tank.

4. The method of claim 3, wherein the cellulosic feedstock is passed downwardly through the heated holding tank under the force of gravity.

5. The method of claim 1, wherein the cellulosic feedstock has a residence time of up to 60 minutes in the heated holding tank.

6. The method of claim 1, wherein the cellulosic feedstock has a residence time of between 5 minutes and 45 minutes in the heated holding tank.

7. The method of claim 1, wherein cellulosic feedstock has a residence time of between 10 minutes and 30 minutes in the heated holding tank.

8. The method of claim 1, wherein the heated holding tank is heated by passing a heated fluid through a heating jacket provided on at least a portion of the heated holding tank.

9. The method of claim 1, wherein the cellulosic feedstock enters the heated holding tank at a temperature of between 50°

C. and 70°

C.

10. The method of claim 9, wherein the cellulosic feedstock enters the heated holding tank at a temperature between 50°

C. and 65°

C.

11. The method of claim 1, further comprising maintaining the cellulosic feedstock at a temperature of between 50°

C. and 70°

C. while in the heated holding tank.

12. The method of claim 1, wherein the cellulosic feedstock enters the heated holding tank at a first temperature, and exits the heated holding tank at a second temperature higher than the first temperature.

13. The method of claim 12, wherein the first temperature is below 50°

C., and the second temperature is between 50°

C. and 70°

C.

14. The method of claim 1, wherein the heated holding tank has a lower open end and step c) comprises withdrawing cellulosic feedstock from essentially the entirety of the lower open end.

15. The method of claim 1, further comprising monitoring a temperature of the cellulosic material in the heated holding tank.

16. The method of claim 15, further comprising adjusting an amount of heat applied to the heated holding tank based on the temperature of the cellulosic material in the holding tank.

17. The method of claim 1, further comprising obtaining the cellulosic feedstock from a water impregnator.

18. A holding tank for preparing a cellulosic feedstock comprising:

(a) at least one sidewall defining a passage having an upper portion and a lower portion;

(b) at least one inlet adjacent the upper portion wherein, in use, the inlet is in fluid communication with a water impregnator provided upstream from the holding tank;

(c) at least one outlet adjacent the lower portion wherein, in use, the outlet is in fluid communication with hydrolysis reactor positioned downstream from the holding tank;

(d) at least one conveyor adjacent the at least one outlet; and

,

(e) a heating jacket provided on at least a portion of the apparatus.

19. The holding tank of claim 18 wherein the heating jacket is provided on the sidewalls of the holding tank.

20. The holding tank of claim 18 wherein at least one conveyor conveys the cellulosic feedstock laterally across the outlet.

21. The holding tank of claim 20 wherein the outlet extends across the lower portion of the passage.

22. The holding tank of claim 20 wherein the holding tank has a longitudinal axis and each of the at least one conveyors comprises a screw conveyor extending transversely to the longitudinal axis and provided in a housing positioned adjacent the outlet, and wherein the housing comprises a second heating jacket.

23. The holding tank of claim 18, wherein the holding tank is operable to provide a residence time of up to 60 minutes.

24. The holding tank of claim 18, wherein the holding tank is operable to provide a residence time of between 5 minutes and 45 minutes.

25. The holding tank of claim 18 wherein the holding tank has a longitudinal axis and at least one of the at least one sidewalls diverges from the longitudinal axis from the upper portion to the lower portion.