Method for increasing backset recycle in dry grind alcohol production
AssigneeDanisco US Inc.
InventorsGopal K. Chotani, Jaclyn Diana Demartini, Jacob Andrew Latone, Vivek Sharma, Jayarama K. Shetty
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Abstract
The present invention relates to a dry grind ethanol process in which post-distillation backset is subjected to aerobic fermentation to remove components that are inhibitory to an ethanolagen, such as yeast, allowing the utilization of an increased amount of post-distillation backset during the initial preparation of starch-containing substrates for the dry grind ethanol process. Aerobic fermentation of the post-distillation backset allows substantially higher backset recycle, resulting in fresh water savings and increased sustainability.
Claims11
A method for increasing utilization of recycled liquid backset in a dry grind ethanol process, comprising:
- (a) hydrolyzing a starch-containing feedstock with an α-amylase in the presence of recycled liquid backset to produce a starch liquefact;
- (b) saccharifying the starch liquefact with a glucoamylase to produce glucose;
- (c) fermenting the glucose with an organism under anaerobic conditions to produce an ethanol-containing fermented mash;
- (d) distilling the fermented mash to recover an ethanol product resulting in an ethanol-depleted, post-distillation slurry;
- (e) separating the solid and liquid portions of the post-distillation slurry;
- (f) subjecting the liquid portion of the post-distillation slurry to aerobic fermentation using a non-pathogenic bacteria capable of consuming lactic acid and/or glycerol to produce a post-aerobic-fermentation backset;
- and
- (g) recycling the post-aerobic-fermentation backset for use as recycled liquid backset in step (a);
- wherein the amount of recycled liquid backset used in step (a) is greater than the amount of backset in an otherwise identical method lacking step (f).
Dependencies are inferred from the claim text.