Conventional distillation separation faces technical, economic, and environmental challenges for the separation of azeotrope-forming solvent−water mixtures. Membrane assisted technologies such as pervaporation and vapor permeation using perm-selective membranes provide an efficient alternative for water separation from solvents. Development of stable water selective membrane for the dehydration of a wide range of ethanol- water concentration ratios (0-98wt%) is a challenge. In this study, we developed a bilayer membrane system coated onto a poly vinylidene fluoride ultrafiltration membrane as a support and heated at 140 °C for 48 hours in air. The bottom layer consists of a water-selective blend of polyvinyl alcohol and poly allylamine-hydrochloride and the top layer was made of 1,2-polybutadiene or polyvinyl alcohol. During thermal treatment the polybutadiene layer becomes crosslinked through carbon-carbon bond formation and becomes hydrophilic due to oxidation. These polymeric membranes possess good water permeability, selectivity, and stability even at high water content (95wt%) or industrially useful conditions. In this study, membrane assisted pervaporation technology is used to evaluate the dehydration of ethanol-water feed solutions of varying concentrations. The membrane properties such as selectivity, permeance, and flux will be presented.
KEYWORDS: Pervaporation, Azeotrope separation, dehydration, Water-selective membranes, bilayer
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See more of this Group/Topical: 2018 North American Membrane Society Meeting: Poster Submissions