Monday, April 19, 2010
LL Conference Facility (Hilton Clearwater Beach)
The concept of severity combining residence time and temperature is often used in the pulp and paper industry. The influence of the severity of dilute acid hydrolysis of corn stover on sugar yield and on the subsequent enzymatic hydrolysis of both the hydrolyzate and the treated corn stover by commercial enzyme preparation (from Novozymes) was investigated. A dilute acid pretreatment was performed at 8 % (w/v) solid concentration with 100 mL Accelerated Solvent Extraction (ASE Dionex Corp.). The pretreatment conditions (residence time, temperature) were treated as a single parameter, severity factor (log Ro), with constant acid concentration. The decrease in the yield of oligosaccharides coincided with the maximum concentrations of furfural and 5-hydroxymethylfurfural (5-HMF). With the further increase in severity factor, the concentrations of furfural and 5-HMF decreased while the formation of formic acid and levulinic acid increased. The effect of acetic acid, formic acid, levulinic acid, furfural, and 5-HMF on enzymatic hydrolysis was investigated with a rapid microassay method. The method shows considerable time and cost benefits over the traditional assay protocol and is applicable to a broad range of lignocellulosic substrates.