PVA膜渗透汽化分离低浓度乙醇/水溶液的实验研究

Experimental study on pervaporation separating solution of ethanol/water at low concentration with PVA membrane

将聚乙烯醇(PVA)复合膜用于乙醇/水溶液的渗透汽化过程,考察了料液浓度、操作温度、膜后真空度等操作条件对复合膜渗透通量和分离因子的影响。实验结果表明,复合膜的渗透通量随着操作温度和膜后真空度的升高而增加,分离因子随着料液浓度、操作温度和膜后真空度的升高而减小,在料液浓度低于70%时显优先透醇性,在料液浓度高于70%时显优先透水性。温度对PVA膜渗透通量的影响符合Arrhenius方程。由Arrhenius公式计算得到乙醇组分的渗透活化能Ep=42.88kJ/mol。

The Poly（vinyl alcohol） （PVA） composite membrane was applied in the pervaporation separation of eth- anol/water feed mixtures,and the influence of operating conditions such as the feed concentration, operating temperature and downstream pressure on the permeation ;flux and separation factors were analysed. The result showed that with the in- crease of the operating temperature and the downstream pressure, the permeation flux was increased. With regard to the separation factor, it wasdecreased with the increase of feed concentration, the temperature and the downstream pressure. The membrane showed priority of alcohol through it when the ~eed concentration was below 70 percent, and it showed pri- ority of water through when the feed concentration was above 70 percent. Temperature and permeation flux conformed to Arrhenius equation. The activation energy of ethanol penetration Calculated by Arrhenius equation was EP=42. 88kJ/mol