Lizbeth Laureano-Perez, Farzaneh Teymouri, Hasan Alizadeh and Bruce E. Dale*

Department of Chemical Engineering and Materials Science

2527 Engineering Building

Michigan State University

East Lansing, MI, 48824

Phone: (517)353-6777

Fax: (517)432-1105

E-mail: bdale@egr.msu.edu

Pretreatment of lignocellulosic biomass is necessary to obtain high sugar yields by enzyme catalysis. However, the fundamental characteristics of biomass that limit its enzymatic conversion are not clearly understood. A better fundamental understanding of these factors would help improve pretreatment/hydrolysis systems. Toward this end of improved fundamental understanding, 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). As part of this joint research effort, Michigan State University is using spectroscopy and other methods 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).

Spectroscopic characterization of both untreated and treated material is being performed in order to determine changes in the biomass and the effects of pretreatment on crystallinity, lignin content, selected chemical bonds and depolymerization of hemicellulose and lignin. The methods used are X-Ray diffraction for determination of cellulose crystallinity (CrI); diffusive reflectance infrared (DRIFT) for changes in C-C and C-O bonds; and fluorescence to determine lignin content. Changes in spectral characteristics and crystallinity are statistically correlated with enzymatic hydrolysis results to identify and better understand the fundamental features of biomass that govern its enzymatic conversion to monomeric sugars.