METHOD FOR PRODUCING ETHANOL USING RAW STARCH

• US 20100041116A1
• Filed: 03/16/2009
• Published: 02/18/2010
• Est. Priority Date: 03/10/2003
• Status: Active Grant

• Current Assignee: Poet Research Inc.
• Original Assignee: Broin & Associates, Inc.
• Inventors: Roth, Debbie Lynn, Finck, John Michael, Lewis, Stephen M., Van Hulzen, Shon Erron
• Granted Patent: US 7,919,291 B2
• Time in Patent Office: Days
• US Class Current: 435/161
• CPC Class Codes: A23L 7/104 Fermentation of farinaceous cereal or cereal material; Addition of enzymes or microorganisms
• CPC Class Codes: A23L 7/20 Malt products preparation of malt for brewing C12C
• CPC Class Codes: C12P 7/06 Ethanol, i.e. non-beverage
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

The present invention relates to methods for producing high levels of alcohol during fermentation of plant material, and to the high alcohol beer produced. The present invention also relates to methods for producing high protein distiller'"'"'s dried grain from fermentation of plant material, and to the high protein distiller'"'"'s dried grain produced. The present invention further relates to reduced stack emissions from drying distillation products from the production of ethanol.

Claims

1. A process for producing ethanol from plant material comprising:

providing plant material comprising raw starch that has been made available for saccharification and fermentation;

saccharifying the raw starch without cooking with glucoamylase activity (AGU) and acid fungal amylase activity (AFAU) in a ratio (AGU/AFAU) of about 5 to about 60;

fermenting the saccharified starch to yield after up to about 150 hours 18 vol-% to about 23 vol-% ethanol and up to 30% residual starch; and

recovering ethanol produced by fermenting.

2. The process of claim 1 comprising saccharifying with an enzyme composition comprising about 0.1 to about 10 acid fungal amylase units (AFAU) per gram of dry solids plant material and about 0.5 to about 6 glucoamylase units (AGU) per gram dry solids plant material;

3. The process of claim 1 wherein fermenting is conducted for more than about 25 hours.

4. The process of claim 3 wherein fermenting is conducted for about 48 to about 96 hours.

5. The process of claim 1 wherein fermenting yields 15 to 30% residual starch.

6. The process of claim 1 wherein fermenting yields about 6 to about 26% residual starch.

7. The process of claim 1 wherein the saccharification without cooking provides increased levels of free amino nitrogen from the plant material and saccharifying and fermenting are carried out with quantities of enzyme and yeast selected for effective fermentation without added exogenous nitrogen, without added protease, without added backset, or without a combination thereof.

8. The process of claim 7 wherein saccharifying is carried out without added protease.

9. The process of claim 7 wherein fermenting is carried out without added protease.

10. The process of claim 1 wherein fermenting is carried out with added protease, added phytase, or added protease and phytase.

11. The process of claim 7 wherein saccharifying is carried out without added backset.

12. The process of claim 7 wherein fermenting is carried out without added backset.

13. The process of claim 1 wherein fermenting is carried out with added stillage.

14. The process of claim 1 wherein saccharifying is conducted at temperatures below starch gelatinization temperatures.

15. The process of claim 1 wherein saccharifying is conducted below a temperature of 57°

C. to 93°

C.

16. The process of claim 15 wherein saccharifying is conducted at a temperature of about 30 to about 35°

C.

17. The process of claim 15 further comprising reducing temperature during saccharifying by about 5 to about 10°

C.

18. The process of claim 1 wherein fermenting is conducted at a temperature of about 30 to about 35°

C.

19. The process of claim 1 further comprising reducing temperature during fermenting by about 5 to about 10°

C.

20. The process of claim 1 comprising fermenting during saccharification.

21. The process of claim 20 comprising saccharifying in the presence of yeast.

22. The process of claim 20 comprising simultaneous saccharification and fermentation.

23. The process of claim 21, wherein concentration of enzymes and yeast are selected to maintain glucose at a concentration less than about 3 wt-%.

24. The process of claim 1 comprising simultaneous saccharification and fermentation.

25. The process of claim 24 comprising simultaneously converting raw starch to sugars and fermenting those sugars with a microorganism.

26. The process of claim 1 further comprising recovering coproducts derived from plant material.

27. The process of claim 26 wherein the coproducts derived from plant material comprise distillers dried grain;

and

the distillers dried grain comprises about 30 to about 45 wt-% protein, about 13 to about 17 wt-% fat, about 23 to about 37 wt-% fiber, and about 1 to about 23 wt-% starch.

28. The process of claim 1 further comprising preparing the plant material for saccharifying.

29. The process of claim 28 comprising reducing the plant material to a size such that at least about 35% of the reduced plant material fits through a 0.5 mm screen.

30. The process of claim 28 comprising grinding the plant material.

31. The process of claim 30 comprising grinding with hammer mill, roller mill, or both hammer mill and roller mill.

32. The process of claim 1 comprising providing water containing about 25 to about 45 wt-% plant material comprising raw starch that has been made available for saccharification and fermentation.

33. The process of claim 1 comprising saccharifying at pH of about 4 to about 5.

34. The process of claim 1 comprising fermenting at pH of about 4 to about 5.

35. The process of claim 1 wherein fermenting yields less than or equal to about 0.2 wt-% glucose, less than or equal to about 0.1 wt-% DP3, undetectable DP4+, less than or equal to 0.45 wt-% glycerol, less than or equal to about 0.01 wt-% lactic acid, less than or equal to about 0.4 wt-% fusel oils, or mixture thereof.

36. The process of claim 1 wherein the ratio (AGU/AFAU) of glucoamylase activity and acid fungal amylase activity is about 10.

37. A process for producing ethanol from plant material comprising:

providing plant material comprising raw starch that has been made available for saccharification and fermentation;

saccharifying the raw starch at a temperature below 57°

C. to 93°

C. with glucoamylase activity (AGU) and acid fungal amylase activity (AFAU) in a ratio (AGU/AFAU) of about 3 to about 10;

fermenting the saccharified starch to yield after up to about 150 hours 18 vol-% to about 23 vol-% ethanol and up to 30% residual starch; and

recovering ethanol produced by fermenting.

38. The process of claim 37 comprising saccharifying with an enzyme composition comprising about 0.1 to about 10 acid fungal amylase units (AFAU) per gram of dry solids plant material and about 0.5 to about 6 glucoamylase units (AGU) per gram dry solids plant material.

39. The process of claim 37 wherein fermenting is conducted for about 48 to about 96 hours.

40. The process of claim 37 wherein fermenting yields about 6 to about 26% residual starch.

41. The process of claim 37 wherein saccharifying is conducted at a temperature of about 30 to about 35°

C.

42. The process of claim 37 wherein saccharifying is conducted at a temperature that decreases about 5 to about 10°

C.

43. The process of claim 37 comprising saccharifying in the presence of yeast.

44. The process of claim 43, wherein concentrations of enzyme and yeast are selected to maintain glucose at a concentration less than about 3 wt-%.

45. The process of claim 43 comprising simultaneously converting raw starch to sugars and fermenting those sugars with a microorganism.

46. The process of claim 37 comprising simultaneous saccharification and fermentation.

47. A process for producing ethanol from plant material comprising:

providing plant material comprising raw starch that has been made available for saccharification and fermentation;

saccharifying the raw starch without cooking with an enzyme composition comprising glucoamylase activity (AGU) and acid fungal amylase activity (AFAU) in a ratio (AGU/AFAU) of about 5 to about 60;

fermenting the saccharified starch in the presence of phytase to yield after up to about 150 hours a composition comprising 18 vol-% to about 23 vol-% ethanol and up to 30% residual starch; and

recovering ethanol produced by fermenting.

48. The process of claim 47 comprising saccharifying with an enzyme composition comprising about 0.1 to about 10 acid fungal amylase units (AFAU) per gram of dry solids plant material and about 0.5 to about 6 glucoamylase units (AGU) per gram dry solids plant material.

49. The process of claim 47 wherein fermenting is conducted for about 48 to about 96 hours.

50. The process of claim 47 wherein fermenting yields about 6 to about 26% residual starch.

51. The process of claim 47 wherein the fermenting composition further comprises protease.

52. The process of claim 47 wherein saccharifying is conducted at a temperature of about 30 to about 35°

C.

53. The process of claim 47 further comprising reducing temperature during saccharifying by about 5 to about 10°

C.

54. The process of claim 47 comprising saccharifying in the presence of yeast.

55. The process of claim 54 comprising simultaneous saccharification and fermentation.

56. A process for producing ethanol from plant material comprising:

providing plant material comprising raw starch that has been made available for saccharification and fermentation;

saccharifying the raw starch without cooking with an enzyme composition comprising acid fungal amylase;

fermenting the saccharified starch to yield after about 48 to about 96 hours at least about 18 vol-% to about 23 vol-% ethanol and up to 30% residual starch; and

recovering ethanol.

57. The process of claim 56 wherein saccharifying comprises saccharifying the raw starch at a temperature below 57°

C. to 93°

C. with glucoamylase activity (AGU) and acid fungal amylase activity (AFAU) in a ratio (AGU/AFAU) of about 3 to about 10.

58. The process of claim 56 comprising saccharifying with an enzyme composition comprising about 0.1 to about 10 acid fungal amylase units (AFAU) per gram of dry solids plant material and about 0.5 to about 6 glucoamylase units (AGU) per gram dry solids plant material.

59. The process of claim 56 further comprising recovering coproducts derived from plant material;

wherein the coproducts derived from plant material have been maintained at a temperature below 57°

C. to 93°

C. during the process.

60. A process for producing ethanol from starch comprising:

providing a mixture of raw starch and gelatinized starch;

saccharifying the raw starch at a temperature below 57°

C. to 93°

C. with glucoamylase activity (AGU) and acid fungal amylase activity (AFAU) in a ratio (AGU/AFAU) of about 5 to about 60;

fermenting the saccharified starch to yield after up to about 150 hours 18 vol-% to about 23 vol-% ethanol and up to 30% residual starch; and

recovering ethanol produced by fermenting.

61. The process of claim 60 comprising saccharifying with an enzyme composition comprising about 0.1 to about 10 acid fungal amylase units (AFAU) per gram of dry solids plant material and about 0.5 to about 6 glucoamylase units (AGU) per gram dry solids plant material.