Integration of alternative feedstreams for biomass treatment and utilization

• US 20070037259A1
• Filed: 04/12/2006
• Published: 02/15/2007
• Est. Priority Date: 04/12/2005
• Status: Active Grant

• Current Assignee: Alliance For Sustainable Energy LLC, Sustainable Technology Corporation
• Original Assignee: Alliance For Sustainable Energy LLC
• Inventors: Friend, Julie, Hames, Bonnie, Tucker, Melvin, Elander, Richard, Hennessey, Susan, Dunson, James
• Granted Patent: US 7,910,338 B2
• Time in Patent Office: Days
• US Class Current: 435/105
• CPC Class Codes: C12M 27/02 Stirrer or mobile mixing elements
• CPC Class Codes: C12M 27/20 Baffles; Ribs; Ribbons; Auger vanes
• CPC Class Codes: C12M 45/02 by mechanical forces; Stirring; Trituration; Comminuting crushing, pulverizing, disintegrating in general B02C
• CPC Class Codes: C12M 45/09 by enzymatic treatment
• CPC Class Codes: C12P 19/02 Monosaccharides 2-ketogulonic acid C12P7/60
• CPC Class Codes: C12P 2201/00 Pretreatment of cellulosic or lignocellulosic material for subsequent enzymatic treatment or hydrolysis
• CPC Class Codes: C12P 7/08 produced as by-product or from waste or cellulosic material substrate
• 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
• CPC Class Codes: Y02W 10/40 Valorisation of by-products of wastewater, sewage or sludge processing

Abstract

The present invention provides a method for treating biomass composed of integrated feedstocks to produce fermentable sugars. One aspect of the methods described herein includes a pretreatment step wherein biomass is integrated with an alternative feedstream and the resulting integrated feedstock, at relatively high concentrations, is treated with a low concentration of ammonia relative to the dry weight of biomass. In another aspect, a high solids concentration of pretreated biomass is integrated with an alternative feedstream for saccharifiaction.

Claims

1. A method for treating biomass composed of integrated feedstocks, said method comprising:

a) providing biomass;

b) adding to the biomass of a) at least one alternative feedstream to produce an integrated feedstock;

c) contacting the integrated feedstock of b) with an aqueous solution comprising ammonia to form an integrated feedstock-aqueous ammonia mixture, wherein the ammonia is present at a concentration at least sufficient to maintain alkaline pH of the integrated feedstock-aqueous ammonia mixture but wherein said ammonia is present at less than about 12 weight percent relative to dry weight of integrated feedstock, and further wherein the dry weight of integrated feedstock is at a high solids concentration of at least about 15 weight percent relative to the weight of the integrated feedstock-aqueous ammonia mixture, to produce a pretreated integrated feedstock product; and

d) contacting the product of c) with a saccharification enzyme consortium under suitable conditions to produce a fermentable sugar product.

2. The method of claim 1 wherein the pH of the integrated feedstock-aqueous ammonia mixture is greater than 8.

3. The method of claim 1 wherein said dry weight of integrated feedstock is at an initial concentration of from at least about 15% to about 80%.

4. The method of claim 3 wherein said dry weight of integrated feedstock is at an initial concentration of from at least about 15% to about 60%.

5. The method of claim 1 wherein said ammonia is present at less than about 10 weight percent relative to dry weight of integrated feedstock

6. The method of claim 1 wherein said ammonia is present at about 6% or less weight percent relative to dry weight of integrated feedstock.

7. The method of claim 1 wherein step (c) is carried out at a temperature of from about 4°

C. to about 200°

C.

8. The method of claim 7 wherein the step (c) is carried out at a temperature of from about 75°

C. to about 150°

C.

9. The method of claim 8 wherein the step (c) is carried out at a temperature of from greater than 90°

C. to about 150°

C.

10. The method of claim 1 wherein step (c) is carried out for a period of time of up to about 8 hours.

24. The method of claims 1 or 11 wherein biomass is selected from the group consisting of bioenergy crops, agricultural residues, municipal solid waste, industrial solid waste, yard waste, wood and forestry waste.

25. The method of claims 1 or 11 wherein biomass is selected from the group consisting of switchgrass, waste paper, sludge from paper manufacture, corn grain, corn cobs, corn husks, corn stover, grasses, wheat, wheat straw, hay, rice straw, sugar cane bagasse, sorghum, soy, trees, branches, roots, leaves, wood chips, sawdust, shrubs and bushes, vegetables, fruits, flowers and animal manure.

26. The method of claims 1 or 11 wherein biomass is selected from the group consisting of corn cobs, corn stover, corn husks, sugar cane bagasse, switchgrass, wheat straw, hay, barley, barley straw, rice straw, and grasses.

27. The method of claim 26 wherein biomass is selected from the group consisting of corn cobs, corn stover and sugar cane bagasse.

28. The method of claims 1 or 12 wherein ammonia selected from the group consisting of ammonia gas, ammonium hydroxide, urea, and combinations thereof.

29. The method of claims 1 or 12 wherein said aqueous solution comprising ammonia further comprises at least one additional base.

30. The method of claims 1 or 12 wherein ammonia is recycled.

31. The method of claims 1 or 11 wherein the alternative feedstream is selected from the group consisting of a co-product, an in-process stream, and a waste stream.

32. The method of claim 31 wherein alternative feedstream is a seed process stream from corn, oats, wheat, barley, rice, canola, sunflower, cotton, pea, or soybean, and other legumes.

33. The method of claims 1 or 11 wherein said saccharification enzyme consortium comprises at least one glycosidase.

34. The method of claims 1 or 11 wherein said saccharification enzyme consortium comprises an at least one enzyme selected from the group consisting of cellulose-hydrolyzing glycosidases, hemicellulose-hydrolyzing glycosidases, starch-hydrolyzing glycosidases, peptidases, lipases, ligninases and feruloyl esterases.

35. The method of claims 1 or 11 wherein said saccharification enzyme consortium comprises at least one enzyme selected from the group consisting of cellulases, endoglucanases, exoglucanases, cellobiohydrolases, β

-glucosidases, xylanases, endoxylanases, exoxylanases, β

-xylosidases, arabinoxylanases, mannases, galactases, pectinases, glucuronidases, amylases, α

-amylases, β

-amylases, glucoamylases, α

-glucosidases, isoamylases.

36. The method of claims 1 or 11 wherein step (d) is performed at a temperature of from about 15°

C. to about 100°

C. and at a pH of from about 2 to about 11.

39. The method of claims 1 or 11, where said fermentables sugars are used to produce value-added chemicals, fuels or other high-value products

11. A method of treating biomass composed of integrated feedstocks, said method comprising:

a) providing biomass;

b) subjecting the biomass of a),to a pretreatment process to produce a pretreated biomass product;

c) adding to the pretreated biomass product of b) at least one alternative feedstream to produce a first or second integrated feedstock; and

d) contacting the first or second integrated feedstock of c) with a saccharification enzyme consortium under suitable conditions, to produce a fermentable sugar product.

12. The method of claim 11 wherein the pretreatment process in (b) includes contacting the biomass with an aqueous solution comprising ammonia to form a biomass-aqueous ammonia mixture, wherein the ammonia is present at a concentration at least sufficient to maintain alkaline pH of the biomass-aqueous ammonia mixture but wherein said ammonia is present at less than about 12 weight percent relative to dry weight of biomass, and further wherein the dry weight of biomass is at a high solids concentration of at least about 15 weight percent relative to the weight of the biomass-aqueous ammonia mixture.

13. The method of claim 12 wherein the pH of the biomass-aqueous ammonia mixture is greater than 8.

14. The method of claim 12 wherein said dry weight of biomass is at an initial concentration of from at least about 15% to about 80%.

15. The method of claim 12 wherein said dry weight of biomass is at an initial concentration of from at least about 15% to about 60%.

16. The method of claim 12 wherein said ammonia is present at less than about 10 weight percent relative to dry weight of biomass.

17. The method of claim 16 wherein said ammonia is present at about 6% or less weight percent relative to dry weight of biomass.

18. The method of claim 12 wherein step (b) is carried out at a temperature of from about 4°

C. to about 200°

C.

19. The method of claim 18 wherein the step (b) is carried out at a temperature of from about 75°

C. to about 150°

C.

20. The method of claim 19.wherein the step (b) is carried out at a temperature of from greater than 90°

C. to about 150°

C.

21. The method of claim 12 wherein step (b) is carried out for a period of time of up to about 8 hours.

22. The method of claim 11 wherein the biomass of step a) is an integrated feedstock.

23. The method of claim 11 wherein the alternative feedstream is composed of stillage.

37. The method of claim 11, wherein the biomass of a) is composed of at least one alternative feedstream.

38. The method of claim 23, wherein said stillage is employed to reduce the pH of the pretreated material making it more amenable to saccharification.