The adsorption isotherms of water vapor on cornmeal and the breakthrough curves at 82-100 degrees C were measured in a fixed-bed apparatus for ethanol dehydration. Using the water isotherms measured and fitting the experimental data to fixed-bed model for breakthrough curve, the effective diffusivity of water was obtained. The effective diffusivity was estimated and used to predict breakthrough curves at other adsorption conditions. The controlling factor for mass-transfer resistance was discussed. (c) 2006 Elsevier B.V. All rights reserved.