PROCESS FOR TREATING BIOMASS TO DERIVATIZE POLYSACCHARIDES CONTAINED THEREIN TO INCREASE THEIR ACCESSIBILITY TO HYDROLYSIS AND SUBSEQUENT FERMENTATION

• US 20110039309A1
• Filed: 02/03/2010
• Published: 02/17/2011
• Est. Priority Date: 02/03/2009
• Status: Active Grant

• Current Assignee: Hercules, LLC (Ashland Global Holdings, Inc.)
• Original Assignee: Hercules Incorporated (Ashland Global Holdings, Inc.)
• Inventors: COWAN, Patrick J., GAST, John C., CONNER, Herbert T.
• Granted Patent: US 8,795,993 B2
• Time in Patent Office: Days
• US Class Current: 435/105
• CPC Class Codes: C08B 11/12 substituted with carboxylic radicals , e.g. carboxymethylcellulose [CMC]
• 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
• CPC Class Codes: C12P 2201/00 Pretreatment of cellulosic or lignocellulosic material for subsequent enzymatic treatment or hydrolysis
• CPC Class Codes: C12P 7/10 substrate containing cellulosic material
• CPC Class Codes: C12P 7/16 Butanols
• CPC Class Codes: D21C 1/00 Pretreatment of the finely-divided materials before digesting of waste paper D21C5/02
• CPC Class Codes: D21C 5/00 Other processes for obtaining cellulose, e.g. cooking cotton linters obtaining fibres for spinning D01C; Processes characterised by the choice of cellulose-containing starting materials
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

A process is described for producing fermentable sugars derivable from biomass that contains polysaccharide, such as cellulose, made increasingly accessible as a substrate for enzymatic degradation or other methods of depolymerization. These fermentable sugars are subsequently able to be fermented to produce various target chemicals, such as alcohols, aldehydes, ketones or acids.

Claims

1. A process for producing fermentable sugars derivable from a biomass that contains polysaccharide comprising the steps of:

obtaining the biomass;

treating the biomass with a swelling agent;

contacting the biomass with a derivatization agent producing a derivatized polysaccharide with increased accessibility; and

converting the polysaccharide with increased accessibility to fermentable sugars by hydrolysis, wherein the derivatized polysaccharide with increased accessibility exhibits an increase in the soluble portion as determined by the enzyme accessibility test and wherein the derivatized polysaccharide with increased accessibility is substantially insoluble as measured by the solubility test.

2. The process of claim 1, further comprising the step of removal or neutralization of the swelling agent after the biomass is contacted with the derivatization agent.

3. The process of claim 1, wherein the derivatization agent is incorporated and retained within the polysaccharide using a chemical reaction with the hydroxyl, carboxyl, or other functional groups of the polysaccharide.

4. The process of claim 3, wherein the derivatization agent is selected from the group consisting of chloroacetic acid, sodium chloroacetate, ethylene oxide, propylene oxide, and other epoxides, methyl chloride and other alkyl halides, anhydrides, aldehydes, compounds containing quaternary cation functionality, epichlorhydrin and mixtures thereof.

5. The process of claim 4, wherein the derivatization agent comprises chloroacetic acid or sodium chloroacetate.

6. The process of claim 4, wherein the derivatization agent comprises ethylene oxide.

7. The process of claim 3, wherein the polysaccharide with increased accessibility has a degree of substitution (D.S.) of between about of 0.01 to 1.2.

8. The process of claim 7, wherein the polysaccharide with increased accessibility has a degree of substitution (D.S.) of between about of 0.01 to 0.4.

9. The process of claim 3, wherein the polysaccharide with increased accessibility has a molar substitution (M.S.) in a range of from about 0.05 to about 3.0.

10. The process of claim 9, wherein the polysaccharide with increased accessibility has a molar substitution (M.S.) of less than about 1.5.

11. The process of claim 10, wherein the polysaccharide with increased accessibility has a molar substitution (M.S.) of less than about 1.0.

12. The process of claim 1, wherein the polysaccharide comprises cellulose and the fermentable sugar comprises glucose.

13. The process of claim 1, wherein the hydrolysis of the polysaccharide with increased accessibility further comprises the step of contacting the polysaccharide with increased accessibility with a saccharification enzyme or enzymes under suitable conditions to produce fermentable sugars.

14. The process of claim 1, wherein the hydrolysis of the polysaccharide with increased accessibility further comprises the step of acid hydrolysis of the polysaccharide with increased accessibility to produce fermentable sugars.

15. The process of claim 1, wherein the polysaccharide is selected from the group consisting of cellulose, hemicellulose, chitin, chitosan, guar gum, pectin, alginate, agar, xanthan, starch, amylose, amylopectin, alternan, gellan, mutan, dextran, pullulan, fructan, locust bean gum, carrageenan, glycogen, glycosaminoglycans, murein, and bacterial capsular polysaccharides.

16. The process of claim 15, wherein the polysaccharide comprises cellulose.

17. The process of claim 1, wherein the biomass is selected from the group consisting of corn grain, corn cobs, crop residues such as corn husks, corn stover, grasses, wheat, wheat straw, barley, barley straw, hay, rice straw, cotton, cotton linters switchgrass, waste or post consumer paper, waste or post consumer paperboard, sugar cane bagasse, sorghum, soy, components obtained from milling of grains, trees, branches, roots, leaves, wood chips, sawdust, wood pulp, shrubs and bushes, vegetables, fruits, flowers, animal manure, bacteria, algae and fungi.

18. The process of claim 4, wherein the polysaccharide with increased accessibility is selected from the group consisting of hydroxyethyl cellulose, ethylhydroxyethyl cellulose, carboxymethylcellulose, carboxymethylhydroxyethyl cellulose, hydroxypropylhydroxyethyl cellulose, methyl cellulose, methylhydroxypropyl cellulose, methylhydroxyethyl cellulose, carboxymethylmethyl cellulose, hydrophobically modified carboxymethyl cellulose, hydrophobically modified hydroxyethyl cellulose, hydrophobically modified hydroxypropyl cellulose, hydrophobically modified ethylhydroxyethyl cellulose, hydrophobically modified carboxymethylhydroxyethyl cellulose, hydrophobically modified hydroxypropylhydroxyethyl cellulose, hydrophobically modified methyl cellulose, hydrophobically modified methylhydroxypropyl cellulose, hydrophobically modified methylhydroxyethyl cellulose, hydrophobically modified carboxymethylmethyl cellulose, nitrocellulose, cellulose acetate, cellulose sulfate, cellulose vinyl sulfate, cellulose phosphate, methylol cellulose, and cellulose phosphonate.

19. The process of claim 18, wherein the polysaccharide with increased accessibility is carboxymethylcellulose.

20. The process of claim 19, wherein the carboxymethylcellulose has a degree of substitution (D.S.) of between about of 0.01 to 0.6.

21. The process of claim 18, wherein the polysaccharide with increased accessibility is hydroxyethylcellulose.

22. The process of claim 21, wherein the hydroxyethylcellulose has a molar substitution (M.S.) in a range of from about 0.05 to about 2.0.

23. The process of claim 1, wherein the swelling agent is selected from the group consisting of alkali metal oxides, alkali metal hydroxides, alkaline earth metal oxides, alkaline earth metal hydroxides, alkali silicates, alkali aluminates, alkali carbonates, amines, ammonia, ammonium hydroxide;

tetramethyl ammonium hydroxide;

lithium chloride;

N-methyl morpholine N-oxide, urea and mixtures thereof.

24. The process of claim 23, wherein the swelling agent comprises sodium hydroxide.

25. The process of claim 23, wherein the swelling agent comprises ammonium hydroxide.

26. A process for producing a target chemical derivable from biomass containing polysaccharide comprising the steps of:

obtaining the biomass;

treating the biomass with a swelling agent;

contacting the biomass with a derivatization agent producing a derivatized polysaccharide with increased accessibility; and

converting the derivatized polysaccharide with increased accessibility to fermentable sugars by hydrolysis under suitable conditions to produce fermentable sugars; and

contacting the fermentable sugars with at least one biocatalyst able to ferment the fermentable sugars to produce a target chemical under suitable fermentation conditions, wherein the derivatized polysaccharide with increased accessibility exhibits an increase in the soluble portion as determined by the enzyme accessibility test and wherein the derivatized polysaccharide with increased accessibility is substantially insoluble as measured by the solubility test.

27. The process of claim 26, wherein the target chemical is selected from the group consisting of alcohols, aldehydes, ketones and acids.

28. The process of claim 27 wherein the target chemical comprises alcohol.

29. The process of claim 27, wherein the alcohol comprises ethanol.

30. The process of claim 27, wherein the alcohol comprises butanol.

31. The process of claim 26, further comprising the step of removal or neutralization of the swelling agent after the biomass is contacted with the derivatization agent.

32. The process of claim 28, wherein the derivatization agent is incorporated and retained within the polysaccharide using a chemical reaction with the hydroxyl, carboxyl, or other functional groups of the polysaccharide.

33. The process of claim 32, wherein the derivatization agent is selected from the group consisting of chloroacetic acid, sodium chloroacetate, ethylene oxide, propylene oxide, and other epoxides, methyl chloride and other alkyl halides, anhydrides, aldehydes, compounds containing quaternary cation functionality, epichlorhydrin and mixtures thereof.

34. The process of claim 33, wherein the derivatization agent comprises chloroacetic acid, sodium chloroacetate, or ethylene oxide.

35. The process of claim 34, wherein the polysaccharide with increased accessibility has a degree of substitution (D.S.) of between about of 0.01 to 1.2 D.S.

36. The process of claim 35, wherein the polysaccharide with increased accessibility has a degree of substitution (D.S.) of between about of 0.01 to 0.4 D.S.

37. The process of claim 34, wherein the polysaccharide with increased accessibility has a molar substitution (M.S.) in a range of from about 0.05 to about 3.0.

38. The process of claim 37, wherein the polysaccharide with increased accessibility has a molar substitution (M.S.) of less than about 1.5.

39. The process of claim 38, wherein the polysaccharide with increased accessibility has a molar substitution (M.S.) of less than about 1.0.

40. The process of claim 26, wherein the polysaccharide comprises cellulose and the fermentable sugar comprises glucose.

41. The process of claim 26, wherein the polysaccharide is selected from the group consisting of cellulose, hemicellulose, chitin, chitosan, guar gum, pectin, alginate, agar, xanthan, starch, amylose, amylopectin, alternan, gellan, mutan, dextran, pullulan, fructan, locust bean gum, carrageenan, glycogen, glycosaminoglycans, murein, and bacterial capsular polysaccharides.

42. The process of claim 26, wherein the biomass is selected from the group consisting of corn grain, corn cobs, crop residues such as corn husks, corn stover, grasses, wheat, wheat straw, barley, barley straw, hay, rice straw, cotton, cotton linters switchgrass, waste or post consumer paper, waste or post consumer paperboard, sugar cane bagasse, sorghum, soy, components obtained from milling of grains, trees, branches, roots, leaves, wood chips, sawdust, wood pulp, shrubs and bushes, vegetables, fruits, flowers, animal manure, bacteria, algae and fungi.

43. The process of claim 41, wherein the polysaccharide comprises cellulose.

44. The process of claim 34, wherein the polysaccharide with increased accessibility is selected from the group consisting of hydroxyethyl cellulose, ethylhydroxyethyl cellulose, carboxymethylcellulose, carboxymethylhydroxyethyl cellulose, hydroxypropylhydroxyethyl cellulose, methyl cellulose, methylhydroxypropyl cellulose, methylhydroxyethyl cellulose, carboxymethylmethyl cellulose, hydrophobically modified carboxymethyl cellulose, hydrophobically modified hydroxyethyl cellulose, hydrophobically modified hydroxypropyl cellulose, hydrophobically modified ethylhydroxyethyl cellulose, hydrophobically modified carboxymethylhydroxyethyl cellulose, hydrophobically modified hydroxypropylhydroxyethyl cellulose, hydrophobically modified methyl cellulose, hydrophobically modified methylhydroxypropyl cellulose, hydrophobically modified methylhydroxyethyl cellulose, hydrophobically modified carboxymethylmethyl cellulose, nitrocellulose, cellulose acetate, cellulose sulfate, cellulose vinyl sulfate, cellulose phosphate, methylol cellulose, and cellulose phosphonate.

45. The process of claim 44, wherein the polysaccharide with increased accessibility is carboxymethylcellulose.

46. The process of claim 45, wherein the carboxymethylcellulose has a degree of substitution (D.S.) of between about of 0.01 to 0.6.

47. The process of claim 44, wherein the polysaccharide with increased accessibility is hydroxyethylcellulose.

48. The process of claim 47, wherein the hydroxyethylcellulose has a molar substitution (M.S.) in a range of from about 0.05 to about 2.0.

49. The process of claim 26, wherein the swelling agent is selected from the group consisting of alkali metal oxides, alkali metal hydroxides, alkaline earth metal oxides, alkaline earth metal hydroxides, alkali silicates, alkali aluminates, alkali carbonates, amines, ammonia, ammonium hydroxide;

tetramethyl ammonium hydroxide;

lithium chloride;

N-methyl morpholine N-oxide, urea and mixtures thereof.

50. The process of claim 49, wherein the swelling agent comprises sodium hydroxide.

51. The process of claim 49, wherein the swelling agent comprises ammonium hydroxide.

52. The process of claim 26, wherein the hydrolysis of the polysaccharide with increased accessibility further comprises the step of contacting the polysaccharide with increased accessibility with a saccharification enzyme or enzymes under suitable conditions to produce fermentable sugars.

53. The process of claim 28, wherein the hydrolysis of the polysaccharide with increased accessibility further comprises the step of acid hydrolysis of the polysaccharide with increased accessibility to produce fermentable sugars.

54. A process for producing a target chemical derivable from biomass containing polysaccharide comprising the steps of:

obtaining the biomass;

treating the biomass with a swelling agent;

contacting the biomass with a derivatization agent producing a derivatized polysaccharide with increased accessibility; and

converting the derivatized polysaccharide with increased accessibility to fermentable sugars by hydrolysis under suitable conditions to produce fermentable sugars;

contacting the fermentable sugars with at least one biocatalyst able to ferment the fermentable sugars to produce a target chemical under suitable fermentation conditions,

converting a portion of the target chemical into a derivatization agent; and

feeding back the portion of the derivatization agent converted from the target chemical back in the process to contact the biomass with the derivatization agent to produce the derivatized polysaccharide with increased accessibility, wherein the derivatized polysaccharide with increased accessibility exhibits an increase in the soluble portion as determined by the enzyme accessibility test and wherein the derivatized polysaccharide with increased accessibility is substantially insoluble as measured by the solubility test.

55. The process of claim 54 wherein the target chemical comprises ethanol and wherein the derivatization agent comprises ethylene oxide.