Separation of Alcohol-Water Solutions by Distillation through Hollow Fibers

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• 作者：Guoliang Zhang ; Lan Lin ; Qin Meng ; Youyi Xu
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2007
• 出版时间：November 7, 2007
• 年：2007
• 卷：46
• 期：23
• 页码：7820 - 7825
• 全文大小：77K
• 年卷期：v.46,no.23(November 7, 2007)
• ISSN：1520-5045

文摘

New results of an investigation on distillation in hollow fiber structured packing are discussed. The membranesused here for separation of methanol-, ethanol-, and 2-propanol-water solutions are nonselective coatedhollow fibers, unlike those of membrane distillation. The fibers are nonselective with coating and have littleresistance to mass transfer. Because liquid flows inside the lumens of the fibers and vapors flow countercurrentlyoutside the fibers, this distillation process can avoid flooding effectively even at very high flows. As a result,when a mole fraction of alcohol equal to 0.04 was prepared as feed in all distillations, an attractive low valueof the height of mass transfer unit (HTU) less than 0.1 m could be obtained at total reflux. Both the distillateconcentration and the height of mass transfer unit more significantly decreased with heat rate in alcohols atlow molecular weight than in those at high molecular weight. Compared with conventional structured packing,the ordinate data of the common capacity factor of hollow fiber column calculated with the Eckert versionof the generalized pressure drop correlation (GPDC) were 3-5 times higher above flooding. The presentedtechnology offered the possibility of distillation with better, more productive separations.