US 12,338,478 B2
Method for increasing backset recycle in dry grind alcohol production
Gopal K. Chotani, Cupertino, CA (US); Jaclyn Diana Demartini, Palo Alto, CA (US); Jacob Andrew Latone, San Jose, CA (US); Vivek Sharma, Palo Alto, CA (US); and Jayarama K. Shetty, Palo Alto, CA (US)
Assigned to DANISCO US INC., Palo Alto, CA (US)
Appl. No. 17/641,507
Filed by DANISCO US INC, Palo Alto, CA (US)
PCT Filed Sep. 9, 2020, PCT No. PCT/US2020/049799
§ 371(c)(1), (2) Date Mar. 9, 2022,
PCT Pub. No. WO2021/050451, PCT Pub. Date Mar. 18, 2021.
Claims priority of provisional application 62/900,325, filed on Sep. 13, 2019.
Prior Publication US 2022/0333141 A1, Oct. 20, 2022
Int. Cl. C12P 7/14 (2006.01); C12P 19/14 (2006.01)
CPC C12P 7/14 (2013.01) [C12P 19/14 (2013.01); C12Y 302/01001 (2013.01); C12Y 302/01003 (2013.01)] 11 Claims
 
1. 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).