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).
Original language | English (US) |
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Pages (from-to) | 486-500 |
Number of pages | 15 |
Journal | Applied Biochemistry and Biotechnology |
Volume | 173 |
Issue number | 2 |
DOIs | |
State | Published - May 2014 |
Keywords
- Dry grind ethanol
- Granular starch hydrolyzing enzyme
- High solids fermentation
- Vacuum stripping
ASJC Scopus subject areas
- Biotechnology
- Bioengineering
- Biochemistry
- Applied Microbiology and Biotechnology
- Molecular Biology