Pervaporative dehydration of tetrahydrofuran (THF) over the concentration range of 0-27 wt% water in feed has been studied using poly(acrylonitrile-co-methyl acrylate) copolymer membrane. The permeate water flux and selectivity for water was measured over the same concentration range at 30, 40 and 50 degrees C. The membrane was found to exhibit reasonable water flux (76 g/m(2) h) with high water selectivity (107.25) for dehydration of highly concentrated THF (1.13 wt% water in feed) at 30 degrees C. The activation energy for permeation was found to decrease linearly with increase in water concentration in feed after a certain feed concentration (above around 5 wt% water in feed). The permeation factor of water was found to be greater than unity signifying positive coupling effect of THF on water permeation. (C) 2005 Elsevier B.V. All rights reserved.