(274f) The Evaluation of Inhibition of Enzymatic Hydrolysis Following Dilute Acid Pretreatment of Herbaceous, Softwood and Hardwood

The Evaluation of Inhibition of Enzymatic Hydrolysis following Dilute Acid Pretreatment of herbaceous, softwood and hardwood

Peter Van Walsum* and Mahdieh Aghazadeh 
 
Department of Chemical and Biological Engineering

University of Maine, Orono, Maine 04496

Phone:             207-581-2226

Fax:                 207-581-2323

Email:              pvanwalsum@umche.maine.edu

ABSTRACT

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 lignocellulosic biomass on sugar yield and on the subsequent enzymatic hydrolysis of the hydrolysate by commercial enzyme preparation (from Novozymes) was investigated. A dilute acid pretreatment was performed at 0.7 % (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 R_o), 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. In former studies the effect of the sugar produced from the hydrolysate itself had not been studied -  in this study the different enzyme inhibition effect on three major types of biomass, herbaceous (corn stover), soft wood (pine) and hardwood (maple/oak) were observed.