蒸汽相转化涂晶法SAPO-34分子筛膜的制备及表征

摘要

采用一种新型涂晶方法即蒸汽相转化涂晶法，在廉价大孔α-Al2O3载体上水热合成制备高质量的 SAPO-34分子筛膜。该方法能够有效修复α-Al2O3载体的大孔缺陷，通过制备平整均匀的晶种层，最终得到了连续并且无明显“针孔”缺陷的SAPO-34膜。实验考察了浆料中添加尺寸分别为2μm、1μm、500 nm及100 nm的晶种对形成晶种层及分子筛膜的影响，并将制备的分子筛膜用于渗透汽化异丙醇脱水实验。在75℃下对90wt%的异丙醇/水混合物具有优良的分离性能，其通量和分离系数分别为1.396 kg/(m2·h)和973。%A new seeding method, the steam-assisted conversion seeding, was used to prepare the high-quality SAPO-34 molecular sieve membranes by secondary growth method on the low cost macroporousα-Al2O3 sup-ports. The seeds with different sizes of 2μm, 1μm, 500 nm, and 100 nm were mixed in the synthesis solution to prepare the seeds-containing pastes which was coated on the surface of the support. The effects of the particle size on the paste layers, seed layers and membranes were investigated. A perfect seed layer was formed and ef-fectively modified the defects of the macroporousα-Al2O3 support and then, induced a continuous, compact and unconspicuousl pinholes SAPO-34 membrane. The SAPO-34 membrane displayed high performance in the per-vaporation dehydration of 90wt% IPA/water mixtures at 348 K, showing waterflux up to 1.396 kg/(m2·h) and separation factor at 973.