Grain milling process

• US 9,096,911 B2
• Filed: 01/19/2011
• Issued: 08/04/2015
• Est. Priority Date: 02/03/2010
• Status: Active Grant

• Current Assignee: Vantage Corn Processors LLC
• Original Assignee: Archer Daniels Midland Company
• Inventors: Binder, Thomas P.
• Primary Examiner(s): DESAI, ANAND U
• Application Number:
  US13/521,365
• Publication Number:
  US 20130102045A1
• Time in Patent Office: 1,658 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: A23V 2002/00 Food compositions, function of food ingredients or processes for food or foodstuffs
• CPC Class Codes: A23V 2250/02 Acid
• CPC Class Codes: C08B 30/12 Degraded, destructured or non-chemically modified starch , e.g. mechanically, enzymatically or by irradiation; Bleaching of starch preparation of chemical derivatives of starch C08B31/00
• CPC Class Codes: C08L 1/02 Cellulose; Modified cellulose
• CPC Class Codes: C08L 97/00 Compositions of lignin-containing materials of polysaccharides C08L1/00 - C08L5/00
• CPC Class Codes: C12P 2203/00 Fermentation products obtained from optionally pretreated or hydrolyzed cellulosic or lignocellulosic material as the carbon source ethanol C12P7/10
• CPC Class Codes: C12P 7/10 substrate containing cellulosic material
• CPC Class Codes: C13B 10/003 using chemicals other than extracting agents
• CPC Class Codes: C13K 13/00 Sugars not otherwise provided for in this class
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

A modification is described of a dry grind process for producing ethanol and other co-products from whole grain, whereby the mash is thermochemically treated by cooking the mash in the presence of an organic acid. The organic acid effectively hydrolyzes both the starch and hemicellulosic components in the milled corn to provide fermentable sugars from both the endosperm and other parts of the kernel, without, however, also producing fermentation-inhibiting levels of other known products of the acid hydrolysis of hemicellulosic materials, such as hydroxymethylfurfural (HMF) and furfural. Further, the organic acid is able to solubilize both the starch and the more recalcitrant hemicelluloses while only partially hydrolyzing the same, so that most of the starch and hemicelluloses are hydrolyzed to oligomers and the amount of chemically labile and reducing sugars is kept sufficiently low as to also not appreciably interfere with the fermentation to ethanol.

Claims

1. An improved grain milling process including the production of ethanol by fermentation, comprising:

grinding a whole grain;

forming a slurry with water of the ground whole grain;

adding one or more enzymes and one or more organic acids to the slurry with heating to liquefy fermentable components of the ground whole grain and produce a mash;

recovering and recycling at least a portion of the one or more organic acids used to produce the mash;

adding an enzyme to the mash to form a fermentation medium for producing ethanol; and

fermenting the fermentation medium in the presence of yeast and one or more added enzymes.

2. A process as described in claim 1, wherein the one or more organic acids are added in the form of a solution of acetic acid, formic acid or a combination of acetic and formic acids in water.

3. A process as described in claim 2, wherein the aqueous organic acid solution is 50 percent or more by weight of acid.

4. A process as described in claim 3, wherein the aqueous acid solution is from 50 to 70 percent by weight acid in water.

5. A modified dry grind process for milling a whole grain in order to produce ethanol by fermentation, comprising:

grinding a whole grain;

forming a slurry of the ground whole grain in from two to three times the weight of the ground whole grain of water;

adding an aqueous solution of 50 percent by weight and greater of acetic acid or formic acid or both to the slurry, while maintaining the temperature of the slurry at from 70 degrees Celsius to 90 degrees Celsius;

adding α

-amylase enzyme and increasing the slurry'"'"'s temperature to from 105 to 110 degrees Celsius for from 5 to 15 minutes;

reducing or allowing the temperature of the resulting mash to cool to between 60 and 75 degrees Celsius;

adding glucoamylase enzyme to the mash, with maintaining a temperature of between 60 and 75 degrees Celsius for from 1 to 48 hours;

fermenting the resultant fermentation medium with the addition of one or more of glucoamylase, hemicellulases, proteases, cellulases and feruloyl esterases and yeast to produce ethanol; and

recovering the ethanol.

6. A process as described in claim 5, further comprising recovering at least a portion of the added acetic acid or formic acid or both before the addition of the glucoamylase enzyme to the mash, and recycling recovered acetic acid or formic acid or both for combining with the slurry of the ground whole grain.