Conditions and process of pervaporation benzene/cyclohexane mixture by waterborne polyurethane membranes

doi:10.11949/j.issn.0438-1157.20151807

Abstract

Abstract:

The waterborne polyurethane membrane was synthesized with poly-1,4-butylene adipate glycol (PBA-2000) and toluene diisocyanate (TDI) and the properties of pervaporation benzene/cyclohexane mixture were tested to study the mass transfer characteristics during pervaporation process. From experimental data it can be concluded that the separation factor and flux should get bigger and smaller obviously as the membrane is very thin. And the variation of separation factor and flux was slight as the membrane thickness was certain thick. The improvement of downstream vacuum of the membrane should improve both the separation factor and flux. The bigger feed concentration and temperature should increase the flux and decrease the separation factor. The components in the pervaporation membrane should undergo the course of adsorbing swelling-evaporation in membrane-gaseous diffusion. The dry region of the membrane plays more effect during the pervaporation process.

Key words: waterborne polyurethane, membrane, pervaporation, benzene/cyclohexane, transport processes

摘要：

以聚己二酸1，4-丁二醇酯二醇（PBA-2000）和甲苯二异氰酸酯（TDI）为主要原料合成水性聚氨酯膜，并对苯/环己烷混合液渗透蒸发性能进行测试，讨论了苯/环己烷混合体系的渗透蒸发分离过程特点。结果表明，当膜厚度增大时，分离因子提高而渗透通量随之下降，这个变化趋势在膜较薄时很明显，达到一定厚度后则变化比较平缓；膜下游侧真空度提高会同时提高膜的分离因子和通量；增大料液中苯的浓度，提高料液温度会提高通量并降低分离因子。液体被分离组分在渗透蒸发膜中经历了吸附溶胀-膜内汽化-气体扩散的质量传递过程，“干区”对分离的影响作用更加显著。

关键词: 水性聚氨酯, 膜, 渗透蒸发, 苯/环己烷, 传递过程

CLC Number:

TQ028.8

YAO Lulu, YE Hui, SONG Ying, CUI Peng. Conditions and process of pervaporation benzene/cyclohexane mixture by waterborne polyurethane membranes[J]. CIESC Journal, 2016, 67(S1): 289-295.

姚路路, 叶辉, 宋影, 崔鹏. 水性聚氨酯膜渗透蒸发分离苯/环己烷的条件及过程[J]. 化工学报, 2016, 67(S1): 289-295.

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