硅铝比对ZSM 5分子筛膜晶体形貌及其脱硫性能的影响

摘要

采用二次水热合成法合成ZSM 5分子筛膜，并用Co2＋进行改性。考察合成液中SiO2与Al2 O3摩尔比（硅铝比，25～250）对ZSM 5分子筛膜晶体形貌的影响。分别采用X线衍射仪（ XRD）和扫描电子显微镜（ SEM）对不同硅铝比的ZSM 5分子筛膜进行表征，以噻吩（TP）、苯并噻吩（BT）的模拟汽油测试分子筛膜的脱硫效果。结果表明：随着硅铝比的增大，ZSM 5分子筛膜的颗粒形貌逐渐规整，致密度及完整性越好；但硅铝比较大时，膜颗粒形貌不固定，较致密的分子筛膜无法进行脱硫实验。在硅铝比为100时，ZSM 5分子筛膜颗粒形状趋于规整，晶粒比较均匀，晶粒间互锁生长良好且对噻吩的脱硫率达到45％；TP BT双组分硫化物脱硫率高于单组分；Co2＋改性后的ZSM 5分子筛膜脱除噻吩的效果优于未改性的分子筛膜，脱硫率达到62％。%Supported ZSM⁃5 zeolite membranes were obtained by twice hydrothermal synthesis. ZSM⁃5 zeolite membranes were characterized by X⁃ray diffraction ( XRD ) and scanning electron microscope ( SEM) to uncover the crystal morphology with silica⁃alumina mole ratios from 25 to 250. Desulfurization experiments were carried out with model gasoline of thiophene ( TP ) and bicomponent ( BT) components. With the increase of silica⁃alumina male ratio of the membrane, membrane particle shape gradually became regular, but an overly high silica⁃alumina male ratio could make membrane particle shape irregular.When the silica⁃alumina male ratio was about 100,it appeared to be unique. SEM results proved the membrane was continuous and complete without observable defects. TP removal was 45%.The removal of TP⁃BT bicomponent sulfides was better than the the removal of TP in single component model gasoline. Co2+ modified membrane increased the removal of TP for the desulfurization rate of 62%.