Tuesday, May 3, 2011
The challenges of organosolv pretreatment are to develop the cost-effective conditions and meet the cost balance. Previous studies on organosolv pretreatment have conducted with the fixed and high solvent ratio, varying kinds of solvents, catalysts or pretreatment conditions. It has been reported that efficiency of enzymatic hydrolysis of solid fraction was improved remarkably after pretreatment with high yield of lignin. However, using organic solvent itself can be defects because it raises the process cost. Therefore, to enhance the overall process cost, following two subjects should be achieved; less usage of solvent and high product yields including sugars and ethanol from the feedstock. Therefore, this study aims to seek the optimal solvent condition for organosolv pretreatment with variation of ethanol/water ratio. In addition, by analyzing the characteristics of both of pretreated liquid and solid fractions, effect of organic solvents to biomass can be found related to the product yield by simultaneous saccharification and fermentation.
Powders of yellow poplar (Liriodendron tulipifera) were used as fast growing woody biomass. Ethanol / water solvent ratio were adjusted from 0 to 60% (v/v) with addition of 1% H2SO4 (w/v). After pretreatment, the components in separated solid and liquid fractions were analyzed and pretreated biomass was used for fermentation to produce bio-ethanol. Related to the final products yield, the solvent ratio condition with highest ethanol yield can be determined as the optimal condition. Afterwards, the changed characteristics thereof were analyzed by topochemical methods and the effect of ethanol solvent in pretreatment was studied.