The separation of ethanol-hexane mixtures by pervaporation

[摘要] ENGLISH ABSTRACT: Pervaporation experiments, using polyvinyl alcohol (PVA) and modified PVAmembranes cast on permeable polyether sulfone substrates, were performed withethanol-hexane mixtures. The modified PVA membranes comprised a speciallysynthesized and well defined series of poly(acrylic acid-co-vinyl alcohol-cohydroxyethyl-acrylate) terpolymers.Experimental variables were investigated. Variation of membrane thicknessshowed that at least two polymer layers were necessary. The effect of changingthe binary feed ratio was that selectivity increased with increasing ethanol content.Pretreatment proved to be effective in terms of both flux and selectivity.Increasing hydrophilicity in the chemical structure of the membrane caused adecrease in the selectivity for ethanol, i.e. GFT-standard (3 300); GFT-wasserreich(270); Gantrez AN 119 (15); best synthesized terpolymer (2 200). These valueswere measured with a 5% ethanol mixture.

[发布机构] Stellenbosch University