Dehydration of an Ethanol/Water Mixture Using Lignocellulosic Based Adsorbents

This study evaluated the effectiveness of using cellulosic adsorbents to dehydrate 95 wt% ethanol/5 wt% water mixture. Hardwood sawdust, kenaf core, and bleached wood pulp were used as adsorbents in both liquid phase and gas phase experiments. All three adsorbents preferentially adsorbed water compared to ethanol. Bleached wood pulp exhibited the best performance of adsorbents examined. Data from the liquid ? phase experiments were fitted to the Chakravarti ? Dhar isotherm equation. From the vapor ? phase experiments, the average water loading of hardwood sawdust, kenaf core, and bleached wood pulp was 0.0037, 0.0076, and 0.0121 g H2O/g adsorbent, respectively. Two methods, the Colburn J Factor and the Thoenes ? Kramers correlation, were used to evaluate the mass transfer coefficient of water. Furthermore, the surface area of the adsorbents was measured using the B.E.T. method. Surface areas were 4.91, 9.99, and 8.84 m2/g for the hardwood sawdust, kenaf core, and the bleached wood pulp, respectively