CHA分子筛膜用于DMF渗透汽化脱水研究

Study on pervaporation dehydration of DMF by CHA zeolite membrane

将氧化钇稳定型氧化锆(YSZ)中空纤维载体上制备的CHA分子筛膜用于二甲基甲酰胺(DMF)渗透汽化脱水,系统考察了进料水含量和操作温度对膜分离性能的影响,并研究了CHA分子筛膜渗透汽化的长期稳定性。结果表明:膜的渗透水通量随进料水含量和操作温度的升高而增加;对于质量分数为10.0%水/DMF溶液,当操作温度为75℃时,CHA分子筛膜的初始渗透水通量和分离因子分别为5.7 kg/(m^2·h)和1 180;DMF分子在CHA分子筛膜表面和孔道内的吸附阻碍了水的渗透,膜的渗透水通量逐渐下降并在24 h后稳定在1.0 kg/(m^2·h)左右,渗透侧水质量分数稳定在99.0%以上。

A CHA zeolite membrane supported on external surface of yttria-stabilized zirconia（ YSZ）hollow fiber was used for pervaporation（ PV） dehydration of dimethylformamide（ DMF）. Effects of feed water content and operating temperature on separation performance of the membrane were investigated.The long-term PV stability of CHA zeolite membrane was also studied. Results showed that water fluxes increased with the increasing water content and operation temperature in the water/DMF mixture. The membrane exhibited a high water permeation flux of 5. 7 kg/（m2·h） together with a separation factor of 1 180 at 75 ℃ in dehydration of 10. 0% water/DMF mixture.Due to the adsorption of DMF on membrane surface and in pores,the water permeation flux initially decreased and then stabilized at about 1. 0 kg/（m2·h） after 24 h stabilization period and the water content in permeate stabilized at above 99. 0%.