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Poster Presentation 3-09
Effect of Agitation on Removal of Acetic Acid From Pretreated Hydrolysate by Activated Carbon
Sarah A. Priddy and Thomas R. Hanley Department of Chemical Engineering University of Louisville Louisville, Kentucky 40292
Telephone: (502) 852-6281; Fax: (502) 852-7033; E-mail: trhanl01@gwise.louisville.edu
Pretreatment of lignocellulosic biomass often results in the formation of undesirable chemicals. While not produced in great quantity, pretreatment degradation byproducts such as furfural, hydroxy methyl furfural, and acetic acid have proved detrimental to the fermenting organisms. Most often, the presence of these chemicals in the fermentation media results in a loss of ethanol productivity. Modifications of pretreatment and fermentation regimes have proven moderately successful, but a secondary hydrolysate detoxification step could increase byproduct removal. Previous studies suggest activated carbon as a potential means for removal of these contaminants.
In this study, the effect of temperature and agitation on a combined external mass transfer-surface diffusion model is tested. Simulated pretreated biomass is contacted with activated carbon under prescribed conditions of temperature and agitation. Testing focuses on the effect of acetic acid on hydrolysate detoxification. Adsorption isotherm studies are presented as well as batch kinetic rate studies and a computational fluid dynamic dispersion correlation. Use of these data enables the determination of isotherm constants, an external film transfer coefficient, and a surface diffusion coefficient for each study. A developed mathematical model then incorporates these parameters. The results of these models and the experimental parameters suggest an efficacious method and conditions for the removal of undesirable chemicals.
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