聚二甲基硅氧烷/聚醚砜复合膜渗透汽化分离水中乙酸的性能研究

Separation of acetic acid from water by pervaporation with polydimethylsiloxane/polyether sulfone composite membrane

制备了聚二甲基硅氧烷/聚醚砜(PDMS/PES)复合膜,用于乙酸/水体系的渗透汽化分离。研究了料液质量浓度、温度、流速及下游侧压力对渗透汽化分离性能的影响。实验结果表明,随着料液中乙酸质量浓度的增大,渗透通量增加,而分离因子呈先增大后减小的趋势;随着料液温度的升高,渗透通量增大而分离因子减小;随着料液流速的增大,渗透通量增大而分离因子减小,当达到湍流状态后,两者的变化趋势不明显;随着下游侧压力的增大,渗透通量和分离因子均减小,为获得较好的分离效果应使透过侧保持尽可能高的真空度。

Polydimethylsiloxane/polyether sulfone （PDMS/PES） composite membrane is prepared for the separation of acetic acid from water. The effects of feed concentration, temperature, flow rate, and down stream pressure on the performance of composite membrane are studied. The results show that with feed concentration increasing, the flux increases,while the separation factor firstly increases and then decreases, With temperature increasing, the flux increases quickly while the selectivity decreases. With flow rate increasing, the flux increases and is then stable while the selectivity decreases and is then stable. With down stream pressure increasing, the flux increases and the selectivity decreases. The higher vacuum should be maintained in down stream for better selectivity.