改性ZSM-5分子筛膜错流过滤分离苯并噻吩/3-甲基噻吩

ZSM-5 zeolite membrane separation performance of BT/3-MT by cross-flow filtration

二次水热合成法制得ZSM-5分子筛膜,经X线衍射光谱仪(XRD)和扫描电子显微镜(SEM)表征后,确定所合成为ZSM-5分子筛膜,对其进行Ag+、Cu2+、Zn2+金属离子改性,错流过滤下分离含苯并噻吩/3-甲基噻吩的正己烷模拟汽油,并考察了离子浓度、活化温度、再生时间、再生次数对脱硫效果的影响。结果表明:负载浓度为0.2mol/L的Ag+对苯并噻吩/3-甲基噻吩的脱除率可达75%,分离因子最大接近1.6;活化温度在550℃时脱硫效果最佳;使用后的膜经再生4 h、再生2次以内可恢复一定的性能。

ZSM-5 zeolite membranes were prepared by a second-step hydrothermal synthesis method and characterized by X-ray diffraction （XRD） and scanning electron microscope （SEM）. The membranes were modified by Ag ＋ , Cu2＋ , Zn2＋ metal ions and used to remove benzothiophene/3-methylthiophene （BT/3-MT） from n-hexane by cross-flow filtration. Effects of ion concentration, activation temperature, re- generation time and regeneration frequencies on desulfurization were studied. The results showed that the best separation factor amounted to 1.6 and the desulfurization ratio amounted to 75% when ZSM-5 zeolite loaded with 0. 2 mol/L Ag ＋ solution. The most suitable activation temperature was 550℃. The used membranes could restore certain performance when regeneration time was 4 h and regenerated twice.