Rajiv Ranjan1, Maybelle Woo2, Stefan Thust3, Marc von Keitz4, Kenneth Valentas4, and Michael Tsapatsis1. (1) Department of Chemical Engg. & Material Science, Univ. of Minnesota, Minneapolis (USA), 421 Washington Ave SE, Minneapolis, MN 55455, (2) (With Millipore at present) Department of Chemical Engg. & Material Science, Univ. of Minnesota, Minneapolis (USA), Minneapolis, MN 55455, (3) Biotechnology Institute, University of Minnesota, 140 Gortner Lab, 1479 Gortner Avenue, St. Paul, MN 55108, (4) BioTechnology Institute, University of Minnesota, 1479 Gortner Avenue, Suite 240, St. Paul, MN 55108
Ethanol produced from lignocellulosic biomass is an alternate energy source to conventional fossil fuel. However, toxic inhibitors produced from hydrolysis of biomass decrease ethanol yield during fermentation. Several methods have been used to pretreat these inhibitors and enhance ethanol productivity. In this work, the use of zeolites for the pretreatment of hydrolyzate in order to remove inhibitors like 5-Hydroxymethylfurfuraldehyde (HMF) and furfural by preferential adsorption from aqueous solution is demonstrated. Ideal Adsorbed Solution Theory (IAST) is used to calculate adsorption isotherm for mixtures using single component adsorption data. The predictions are compared with the experimental adsorption isotherms for aqueous mixtures of HMF, furfural and xylose. Finally, desorption of the industrially valuable HMF from the zeolites after the adsorption process is demonstrated.