Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/21/2013
Publication Date: 10/1/2013
Citation: Avci, A., Saha, B.C., Kennedy, G.J., Cotta, M.A. 2013. High temperature dilute phosphoric acid pretreatment of corn stover for furfural and ethanol production. Industrial Crops and Products. 50:478-484.
Interpretive Summary: Corn stover contains 68% carbohydrates that could potentially be used for production of fuel ethanol and other value-added chemicals. Generally, three steps are involved for its conversion to ethanol or chemicals: pretreatment, enzymatic hydrolysis and fermentation. Pretreatment is crucial because corn stover in its native state is resistant to enzymatic hydrolysis. In this research, we have demonstrated that dilute phosphoric acid pretreatment of corn stover at high temperature generates furfural with a very good yield and the solid residues after enzymatic hydrolysis can be efficiently fermented to ethanol by using baker's yeast. Furfural is a useful chemical solvent with multiple industrial uses. These findings are important for development of a commercially viable biomass to furfural and ethanol conversion process technology.
Technical Abstract: Furfural was produced from corn stover by one stage pretreatment process using dilute H3PO4 and solid residues following furfural production were used for ethanol production by Saccharomyces cerevisiae NRRL- Y2034. A series of experiments were conducted at varied temperatures (140-200 oC) and acid doses (0.0-2.0%, v/v) in order to determine optimal conditions. The effects of time (5-25 min) and substrate concentration (5-15 %, w/w) on furfural production were determined at optimal temperature (200 oC) and acid dose (0.75%, v/v). Maximum furfural yield (10.8±0.3 g/100 g stover) was achieved at 20-25 min duration with 5% (w/w) corn stover which corresponds to 61.6% of the potential yield. About 74% of the glucan content of corn stover was converted to glucose after enzymatic digestion of solid residues. S. cerevisiae NRRL- Y2034 fermented glucose from the solid residues efficiently to ethanol. It produced 0.47-0.50 g ethanol per g glucose which corresponds to 92-99% of the theoretical yield.