Fuel ethanol production from steam-pretreated corn stover using SSF at higher dry matter content

• Published in: Biomass & bioenergy Vol. 30; no. 10; pp. 863 - 869
• Main Authors: Öhgren, Karin, Rudolf, Andreas, Galbe, Mats, Zacchi, Guido
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-10-2006; Elsevier
• Subjects: Alcohols: methanol, ethanol, etc; Alternative fuels. Production and utilization; Applied sciences; Biomass; Chemical Engineering; concentration; Corn stover; Energy; Engineering and Technology; ethanol; Ethanol concentration; Ethanol production; Exact sciences and technology; Fuels; Kemiteknik; Natural energy; Saccharomyces cerevisiae; SO 2; SO2; SSF; Steam pretreatment; Teknik; SO 2; Steam pretreatment; Ethanol concentration; Corn stover; SSF; Ethanol production; Alternative fuel; Air pollution control; Ethanol; Corn; Saccharification; Fermentation; Fungi; Renewable energy; Production; SO2; Ascomycetes; Pretreatment; Saccharomyces cerevisiae; Thallophyta
• ISSN: 0961-9534; 1873-2909; 1873-2909
• DOI: 10.1016/j.biombioe.2006.02.002

Replacing fossil fuels by bio-fuels has many advantages, such as the reduction of CO
2-emission to the atmosphere, the possibility for non-oil-producing countries to be self-sufficient in fuel, and increased local job opportunities. Bio-ethanol is such a promising renewable fuel. However, today it is produced from sugar or starch—raw materials that are relatively expensive. To lower the production cost of bio-ethanol the cost of the raw material must be reduced and the production process made more efficient. The production of bio-ethanol from corn stover using simultaneous saccharification and fermentation (SSF) at high dry matter content addresses both issues. Corn stover is an agricultural by-product and thus has a low economic value. SSF at high dry matter content results in a high ethanol concentration in the fermented slurry, thereby decreasing the energy demand in the subsequent distillation step.
In this study, SSF was performed on steam-pretreated corn stover at 5, 7.5 and 10% water-insoluble solids (WIS) with 2
g/L hexose-fermenting
Saccharomyces cerevisiae (ordinary compressed baker's yeast). SSF at 10% WIS resulted in an ethanol yield of 74% based on the glucose content in the raw material and an ethanol concentration of 25
g/L. Neither higher yeast concentration (5
g/L) nor yeast cultivated on the liquid after the pretreatment resulted, under these conditions, in a higher overall ethanol yield.