|
Poster Presentation 1-29
Spectroscopic Characterization of Pretreated Corn Stover
B. E. Dale and L. Laureano-Perez
Department of Chemical Engineering and Materials Science Michigan State University East Lansing, MI, 48823
Telephone: (517) 353-6777; Fax: (517) 432-1105; E-mail: bdale@egr.msu.edu
Leading biomass pretreatment techniques are being studied in an integrated multi-university research project funded by the U. S. Department of Agriculture’s Initiative for Future Agriculture and Food Systems (IFAFS). Pretreatment alters the complex physical-chemical characteristics of biomass and enhances enzymatic conversion of structural polysaccharides (cellulose and hemicellulose) to fermentable sugars. A better fundamental understanding of the factors limiting enzymatic hydrolysis will assist efforts to commercialize biomass conversion technologies. Michigan State University is using spectroscopy to characterize corn stover pretreated by a variety of pretreatment approaches including aqueous ammonia recycle percolation (ARP), uncatalyzed hydrolysis, dilute acid hydrolysis, controlled pH, lime and ammonia fiber explosion (AFEX). The spectroscopic techniques used are X-ray diffraction to determine cellulose crystallinity; diffusive reflectance infrared spectroscopy (DRIFT) for changes in C-C and C-O bonds; and fluorescence to characterize lignin and lower molecular weight aromatics. Preliminary results show that increased reaction time decreases both lignin content and cellulose crystallinity during ARP. Under AFEX conditions, the cellulose crystallinity and lignin content decrease as the ammonia/biomass ratio increases. Decreased crystallinity is corroborated by IR analysis, which shows an increase in C-H and O-H peak intensities as reaction time increases for ammonia ARP and as the ammonia/biomass ration increases for AFEX.
|