Due to concerns with stover collection systems, soil sustainability, and processing costs to produce ethanol, there are opportunities to investigate the optimal plant fractions to collect. Wheat stover fractions were separated by hand and analyzed for glucan, xylan, acid-soluble lignin, acid-insoluble lignin, and ash composition. Internodes had the highest glucan content (38.2% zero percent moisture basis) and the other fractions varied between 29.9% and 33.4%. The stover fractions were pretreated with either 0%, 0.4%, or 0.8% NaOH for 2 h at room temperature, washed, autoclaved, and saccharified. In addition, acid pretreated samples underwent simultaneous saccharification and fermentation (SSF) to ethanol. In general, the acid and alkaline pretreatments produced similar trends with leaves requiring very little pretreatment to achieve high conversion rates (greater than 80%). Chaff responded very well to pretreatment and high conversion efficiencies resulted when pretreated under alkaline or acidic conditions. Nodes and internodes were more recalcitrant than the other anatomical fractions. Pretreatment with 0.8% sulfuric acid (0.24 g sulfuric acid/g biomass) did not result in a significantly higher conversion of glucan to ethanol as the native material. Pretreatment with 0.8% NaOH (0.06 g NaOH/g biomass) at room temperature for 2 h resulted in high conversion efficiencies for all plant fractions, greater than 73% of the available glucan. These differences in pretreatment susceptibilities suggest that a biomass collection system that removes specific portions of wheat stover could result in significant differences in ethanol production costs.
|Number of pages||8|
|Journal||Biomass and Bioenergy|
|State||Published - Aug 2007|
Bibliographical noteFunding Information:
The authors thank Alltech, Inc., for generously providing the cellulase and xylanase enzymes for the alkaline hydrolysis work, and Genencor International for providing the Spezyme-CP for use in ethanol SSF. The authors would also like to thank Wei Chen at UK, Brad Blackwelder, Heather Silverman, Cindy Breckenridge, and Debby Bruhn for assisting with laboratory work at INL and Dan Schell of the National Renewable Energy Laboratory (NREL) for generously supplying the dilute acid pretreated corn stover control material. This article is published with the approval of the Director of the Kentucky Agricultural Experiment Station and designated paper number 06-05-078. The INL work was supported by the US Department of Energy, Office of Energy Efficiency and Renewable Energy, under DOE Idaho Operations Office Contract DE-AC07-05ID14517.
- Triticum aestivum
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Agronomy and Crop Science
- Waste Management and Disposal