TREATMENT OF LIGNOCELLULOSIC MATERIALS UTILIZING DISC REFINING AND ENZYMATIC HYDROLYSIS

• US 20090098618A1
• Filed: 10/10/2008
• Published: 04/16/2009
• Est. Priority Date: 10/10/2007
• Status: Abandoned Application

• Current Assignee: Mascoma Canada Inc.
• Original Assignee: Mascoma Canada Inc.
• Inventors: Burke, Murray, Ishizawa, Claudia, Saville, Bradley
• Application Number:
  US12/249,336
• Publication Number:
  US 20090098618A1
• Time in Patent Office: Days
• US Class Current: 435/99
• CPC Class Codes: C12P 19/02 Monosaccharides 2-ketogulonic acid C12P7/60
• CPC Class Codes: C12P 19/14 produced by the action of a carbohydrase (EC 3.2.x), e.g. by alpha-amylase , e.g. by cellulase, hemicellulase

Abstract

A method for treating plant materials to release fermentable sugars is disclosed. More specifically, lignocellulosic materials are subjected to disc refining together with enzymatic hydrolysis to produce a sugar rich process stream that may subsequently be subjected to fermentation to produce biofuels and chemicals is disclosed.

Claims

1. A method for treating a lignocellulosic feedstock comprising cellulose, hemicellulose and lignin to produce a sugar rich process stream, the method comprising:

(a) passing the feedstock through a disc refiner; and

(b) subjecting the feedstock under a vacuum to enzymatic hydrolysis and obtaining a volatile component stream and a sugar rich process stream.

2. The method of claim 1 wherein the feedstock comprises from about 1% to about 60% wt total solids.

3. The method of claim 1 wherein the enzymatic hydrolysis comprises first and second enzymatic hydrolysis processes.

4. The method of claim 3 wherein the first enzymatic hydrolysis process uses a first enzyme preparation and produces a volatile component stream and a low viscosity effluent stream and the low viscosity effluent stream is subjected to the second enzymatic hydrolysis using a second enzyme preparation and produces the sugar rich process stream.

5. The method of claim 4 wherein the first enzyme preparation preferentially acts upon the hemicellulose relative to cellobiose in the feedstock.

6. The method of claim 5 wherein the first enzyme preparation has hemicellulase activity and cellulase activity.

7. The method of claim 6 wherein the first enzyme preparation has a hemicellulase activity of about 10% to about 90% and a cellulase activity of between 90% to 10%.

8. The method of claim 7, wherein the first enzyme preparation has a hemicellulase activity of about 30% to about 90% and a cellulase activity of about 70% to about 10%.

9. The method of claim 8, wherein the first enzyme preparation has a hemicellulase activity of about 50% to about 90% and a cellulase activity of about 50% to 10%

10. The method of claim 9 wherein the hemicellulase enzymes preferentially act upon the β

-1,4 linkage of the xylose residues of xylan and the β

-1,4 linkage of the mannose residues of mannan.

11. The method of claim 4 wherein the second enzyme preparation preferentially acts on the cellulose and cellobiose relative to xylan in the feedstock.

12. The method of claim 4 wherein the second enzyme preparation comprises β

-glucosidase and cellulase enzymes, wherein the β

-glucosidase and cellulase enzymes preferentially act upon the β

-1,4 linkage of cellobiose and cellulose.

13. The method of claim 12 wherein the β

-glucosidase and cellulase enzymes completely convert cellulose and oligosaccharides produced from the first enzymatic hydrolysis to monomeric sugars.

14. The method of claim 4 further comprising obtaining a recycle stream from the first enzymatic hydrolysis process and reintroducing the recycle stream into the first enzymatic hydrolysis process.

15. The method of claim 14 comprising passing at least a portion of the recycle stream through the disc refiner prior to reintroducing the recycle stream to the first enzymatic hydrolysis process.

16. The method of claim 15 wherein the portion of the recycle stream that is passed through the disc refiner is from about 10 to about 90%.

17. A method for treating a lignocellulosic feedstock comprising cellulose, hemicellulose and lignin to produce a sugar rich process stream, the method comprising:

(a) subjecting the feedstock to enzymatic hydrolysis under a vacuum and obtaining a volatile components stream and a sugar rich process stream,

(b) obtaining a recycle stream from the enzymatic hydrolysis and passing at least a portion of the recycle stream through a disc refiner prior to reintroducing the recycle stream to the enzymatic hydrolysis.

18. The method of claim 17 wherein the feedstock comprises from about 1% to about 60% wt total solid.

19. The method of claim 17 wherein the enzymatic hydrolysis comprises first and second enzymatic hydrolysis processes.

20. The method of claim 19 wherein the first enzymatic hydrolysis process uses a first enzyme preparation and produces a volatile component stream and a low viscosity effluent stream and the low viscosity effluent stream is subjected to the second enzymatic hydrolysis using a second enzyme preparation and produces the sugar rich process stream.

21. The method of claim 20 wherein the first enzyme preparation preferentially acts upon the hemicellulose relative to cellobiose in the feedstock.

22. The method of claim 21 wherein the first enzyme preparation has hemicellulase activity and cellulase activity.

23. The method of claim 22 wherein the first enzyme preparation has a hemicellulase activity of about 10% to about 90% and a cellulase activity of about 90% to about 10%.

24. The method of claim 22, wherein the first enzyme preparation has a hemicellulase activity of about 30% to about 90% and a cellulase activity of about 70% to about 10%.

25. The method of claim 24, wherein the first enzyme preparation has a hemicellulase activity of about 50% to about 90% and a cellulase activity of about 50% to 10%

26. The method of claim 25 wherein the hemicellulase enzymes preferentially act upon the β

-1,4 linkage of the xylose residues of xylan and the β

-1,4 linkage of the mannose residues of mannan.

27. The method of claim 20 wherein the second enzyme preparation preferentially acts on the cellulose and cellobiose relative to xylan in the feedstock.

28. The method of claim 27 wherein the second enzyme preparation comprises β

-glucosidase and cellulase enzymes, wherein the β

-glucosidase and cellulase enzymes preferentially act upon the β

-1,4 linkage of cellobiose and cellulose.

29. The method of claim 28 wherein the β

-glucosidase and cellulase enzymes completely convert cellulose and oligosaccharides produced from the first enzymatic hydrolysis to monomeric sugars.

30. The method according to claim 17, wherein the portion of the recycle stream that is passed through the disc refiner is from about 10 to about 90%.