离子液体复合膜用于渗透汽化分离乙醇水溶液

Pervaporation of ethanol aqueous solution by using ionic liquid composite membrane

将离子液体[bmim]PF6引入制膜过程,制备了PDMS膜以及离子液体支撑液膜和PDMS-IL共混膜.用所制的膜进行渗透汽化实验分离乙醇水溶液,研究料液温度、浓度和真空度等对膜渗透通量和分离因子的影响,并比较了3种膜的分离效果.实验结果表明,在分离乙醇水溶液时,PDMS-IL共混膜的综合分离效果优于普通的PDMS膜,而离子液体支撑液膜分离性能不理想.此外膜渗透通量都随料液温度、浓度的增大而增大,随透过侧压力的增大而减小;分离因子随料液温度、浓度和透过侧压力的增大而减小.

Ionic liquid（IL）[bmim]PF6 was introduced into membrane preparation process to form supported ionic liquid membrane （SILM） and PDMS-IL composite membrane. Pervaporation performance of the prepared membranes were measured and compared thorougMy in the process of ethanol removal from water. The effects of feed temperature, feed concentration and permeation pressure on pervaporation performance were investigated systematically. The experimental results showed that PDMS-IL composite membranes exhibited superior separation performance to common PDMS membrane, while unfortunately that of SILM was not satisfactory. Besides, permeation fluxes of the membranes all increased with increasing temperature and concentration, whereas they decreased with ascending permeation pressure. Furthermore, separation factors descended with climbing temperature, concentration and permeation pressure.