聚偏氟乙烯/聚二甲基硅氧烷渗透气化膜在丁醇分离中的应用

通过相转化法制备PVDF多孔支撑膜，在其上涂覆致密的PDMS分离层制备得到PVDF/PDMS复合膜，用于丁醇的分离纯化。以丁醇水溶液为原料液，流速为1.6 L·min^-1，丁醇浓度为15 g·L^-1，温度为37℃时， PVDF/PDMS复合膜的总通量为158.2 g·m^-2·h^-1，分离因子为17.3。向丁醇水溶液中按丁醇：丙酮：乙醇比例为6：3：1添加丙酮和乙醇模拟发酵液，PVDF/PDMS复合膜的总通量升高到189.5 g·m^-2·h^-1，分离因子降低到14.8。进一步考察了以丙酮-丁醇-乙醇（ABE）发酵液为原料液的渗透气化膜分离性能，发酵液中不存在菌体时，PVDF/PDMS复合膜的总通量和分离因子分别为120.2 g·m^-2·h^-1和19.7，而菌体存在时，复合膜的总通量和分离因子分别为122.1 g·m^-2·h^-1和16.7。与PDMS均质膜相比，PVDF/PDMS复合膜在丁醇分离过程中的分离性能有了显著的提升， 具有潜在的应用价值。

Application of polyvinylidene fluoride/polydimethylsiloxane composite membrane in butanol recovery

A polyvinylidene fluoride (PVDF)/polydimethylsiloxane (PDMS) composite membrane for butanol recovery was fabricated by coating a dense PDMS separation layer on a PVDF porous support layer prepared by phase inversion. The total flux and separation factor of the PVDF/PDMS composite membrane could be 158.2 g·m^-2·h^-1 and 17.3, respectively, when feed solution was 15 g·L^-1 butanol at 37℃ with a flow rate 1.6 L·min^-1. To simulate the fermentation liquor, acetone and ethanol were added into the feed solution in a ratio 6(butanol):3:1, the total flux of PVDF/PDMS composite membrane increased to 189.5 g·m^-2·h^-1, but separation factor decreased to 14.8. Furthermore, fermentation broths with/without biomass as feed solution were investigated to evaluate pervaporation performance of the PVDF/PDMS composite membrane. The total flux and separation factor were 120.2 g·m^-2·h^-1 and 19.7 for without biomass case, 122.1 g·m^-2·h^-1 and 16.7 for with biomass case, respectively. Compared with PDMS membrane, the performance of PVDF/PDMS composite membrane had significant improvement for butanol recovery, indicating that it is of potential for industrial application of butanol recovery.