title: Vacuum stripping of ethanol during high solids fermentation of corn.
abstract: In corn-ethanol industry, yeast stress inducing glucose concentrations produced during liquefaction and subsequent high ethanol concentrations produced during fermentation restrict slurry solids to 32 % w/w. These limits were circumvented by combining two novel technologies: (1) granular starch hydrolyzing enzyme (GSHE) to break down starch simultaneously with fermentation and (2) vacuum stripping to remove ethanol. A vacuum stripping system was constructed and applied to fermentations at 30, 40, and 45 % solids. As solids increased from 30 to 40 %, ethanol yield decreased from 0.35 to 0.29 L/kg. Ethanol yield from 45 % solids was only 0.18 L/kg. An improvement was conducted by increasing enzyme dose from 0.25 to 0.75 g/g corn and reducing yeast inoculum by half. After improvement, ethanol yield from 40 % solids vacuum treatment increased to 0.36 L/kg, comparable to ethanol yield from 30 % solids (control).
authors.forename: Jameel K
authors.initials: JK
authors.lastname: Shihadeh
authors.forename: Haibo
authors.initials: H
authors.lastname: Huang
authors.forename: Kent D
authors.initials: KD
authors.lastname: Rausch
authors.forename: Mike E
authors.initials: ME
authors.lastname: Tumbleson
authors.forename: Vijay
authors.initials: V
authors.lastname: Singh
mesh_terms: D019342:Acetic Acid / Q000378:metabolism; D001709:Biotechnology / Q000379:methods*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism; D050296:Microbial Viability; D012441:Saccharomyces cerevisiae / Q000378:metabolism / Q000502:physiology; D014618:Vacuum; D003313:Zea mays / Q000378:metabolism*
chemical_list: D019344:Lactic Acid; D000431:Ethanol; D005947:Glucose; D019342:Acetic Acid