Pervaporation and Vapor Permeation Characteristics of a Porous SiO_2-ZrO_2 Membrane for Separation of Organic Solvents/Water Mixtures

摘要

The sol-gel techniques were applied to fabricate some improved porous SiO_2-ZrO_2(50%) membranes for separation of organic solvents/water mixtures by pervaporation and vapor permeation methods at the normal boiling points of mixtures such as iso-propanol(IPA)/water and 1-propanol / water mixtures. The porous SiO_2-ZrO_2 membranes were found quite stable even at a high water content in the feed mixtures. They showed quite large pervaporation fluxes more than 450moles/(m~2 h) at 73mol% of IPA in the feed, for example, while the water flux for vapor phase separation at the same conditions was around 250mol/(m~2 h). The separation characteristics of organic chemicals/water mixtures by pervaporation and the vapor permeation methods are largely different in many points. Especially in this work separation by vapor permeation has been studied to compare with that of pervaporation taking into account the vapor-liquid equilibrium characteristics of the mixtures.