PVA膜在低浓度正丁醇/水溶液中渗透汽化行为研究

Study on pervaporation behavior of PVA membrane in low concentration of n-butanol/water solution

在传统的正丁醇发酵过程中,通常正丁醇的浓度不仅很低,而且对发酵过程有一定的产物抑制,影响发酵过程的连续正常进行。因此考虑使用聚乙烯醇(PVA)膜在渗透蒸发的作用下浓缩低浓度正丁醇/水溶液,考察了正丁醇原料液浓度、实验温度、真空度等操作条件对膜渗透通量和分离因子的影响。结果表明,渗透通量和分离因子均随温度的增加而增加,在60℃时,分离因子达到最大值;渗透通量随正丁醇进料浓度的增加而降低,分离因子则呈先升高后减小的趋势,并出现最大值;渗透通量和分离因子均随真空度的增加而增加。

In the conventional n-butanol fermentation process ,the concentration of n-butanol product is not only very low ,but also to certain product inhibition ,affect normal continuous fermentation process .So con-sider using polyvinyl alcohol （ PVA ） membrane to concentrate and pevaporation low concentration of n-butanol/water solution , investigate butanol feedstock concentration , experimental temperature , vacuum and other operating conditions on membrane flux and separation factor .And PVA membrane is usually used in highly concentrated organic solution ,and less involved in low concentration of organic solution . Conclusions show that permeation flux and separation factor increased with temperature increasing ,which at 60 ℃,separation factor reached the highest value;with concentration of n-butanol increasing ,perme-ation flux decreases ,separation factor increased first then decreased;with the degree of vacuum increas-ing,permeate flux and separation factor increased .