HIGHLY DISORDERED CELLULOSE

• US 20110091940A1
• Filed: 04/03/2009
• Published: 04/21/2011
• Est. Priority Date: 04/03/2008
• Status: Active Grant

• Current Assignee: Cellulose Sciences International, Inc.
• Original Assignee: Cellulose Sciences International, Inc.
• Inventors: Atalla, Rajai H.
• Granted Patent: US 8,617,851 B2
• Time in Patent Office: Days
• US Class Current: 435/105
• CPC Class Codes: C08B 1/08 Alkali cellulose
• CPC Class Codes: C12P 7/06 Ethanol, i.e. non-beverage
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02E 50/30 Fuel from waste, e.g. synthetic alcohol or diesel

Abstract

Disclosed are methods and systems for treating cellulose to make it more accessible for enzymatic or chemical modification. The invention includes treating cellulose with an alkali in an alcohol/water co-solvent system. The treatment decrystallizes or deaggregates the cellulosic material. The methods and systems increase the efficiency of enzymatic or chemical modifications of cellulose for use as biofuels or cellulose derivatives.

Claims

1. A method of decrystallizing cellulose, comprising:

treating a cellulosic material with an alkali in a co-solvent system to form a decrystallized cellulose, the co-solvent system comprising water and a second water-miscible solvent,

and stabilizing the decrystallized cellulose by washing out the alkali to yield a decrystallized cellulose stable in aqueous medium.

2. The method of claim 1, wherein the water-miscible solvent is a primary, secondary or tertiary alcohol or a polyol.

3. The method of claim 1, wherein the water-miscible solvent is an organic polar solvent.

4. A method of producing glucose as a feedstock for production of biofuels, comprising hydrolyzing the decrystallized cellulose stable in aqueous media of claim 1 to sugars.

8. A decrystallized cellulose, produced by the method of claim 1.

5. A method of producing cellulosic ethanol, comprising treating a cellulosic material with an alkali in an alcohol/water co-solvent system to yield a decrystallized cellulosic material;

washing the cellulosic material to remove the alkali;

hydrolyzing the cellulosic material to yield sugars;

fermenting the sugars to produce ethanol; and

separating the ethanol from the fermentation mix.

6. The method of claim 5, further comprising recycling a portion of the produced ethanol to the treating step.

7. The method of claim 5, wherein a portion of the ethanol is used to produce the alcohol/water co-solvent system.

9. A method of pretreating cellulose to decrystallize the cellulose, comprising contacting the cellulose with a treatment solution of an alkali in an alcohol/water co-solvent system.

10. A method of producing sugars, comprising treating a cellulosic material with an alkali in an alcohol/water co-solvent system to yield a decrystallized cellulosic material;

washing the cellulosic material to remove the alkali, and hydrolyzing the cellulosic material to yield sugars.

11. The method of claim 10, further comprising fermenting the sugars to yield ethanol and recycling a portion of the ethanol to decrystallize the cellulosic material.

12. A kit comprising an alkali in an alcohol/water co-solvent, cellulase enzymes, one or more flocculants, and instructions for decrystallizing the cellulose to produce a decrystallized cellulose and instructions for hydrolyzing the decrystallized cellulose to produce a hydrolysis product.

13. A method of producing cellulosic biofuels, the method comprising:

treating a cellulosic material with an alkali in an alcohol/water co-solvent system to yield a decrystallized cellulose;

washing the decrystallized cellulose to remove the alkali; and

catalytically reforming the decrystallized cellulose into hydrocarbons or biofuels.

14. A method of producing cellulosic biofuels, the method comprising:

treating a cellulosic material with an alkali in an alcohol/water co-solvent system to yield a decrystallized cellulose;

washing the decrystallized cellulose to remove the alkali;

hydrolyzing the cellulose to glucose and cello-oligodextrins; and

catalytically reforming the glucose and cello-oligodextrins into hydrocarbons

15. A method of producing biofuels, comprising:

a) hydrolyzing a cellulosic material to form glucose and a residual cellulose to the beginning of a second kinetic hydrolysis step;

b) treating the residual cellulose with an alkali in an alcohol/water co-solvent system to yield a decrystallized cellulose;

c) washing the decrystallized cellulose to remove the alkali; and

d) hydrolyzing the cellulose to glucose and cello-oligodextrins.

16. The method of claim 15, wherein the hydrolysis of step (d) is accomplished with the enzymes.

17. The method of claim 16, wherein the hydrolysis of step (d) is accomplished with the enzymes of step (a).

18. The method of claim 15, further comprising fermenting the glucose and cello-oligodextrins to alcohols.

19. The method of claim 15, further comprising catalytically reforming the glucose and cello-dextrins to hydrocarbons.