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论文类型：期刊论文

发表时间：2020-03-15

发表刊物：JOURNAL OF MEMBRANE SCIENCE

收录刊物：EI、SCIE

卷号：598

ISSN号：0376-7388

关键字：MFI zeolites membranes; Binary structure directing agents; Ethanol/water mixture; Compactness

摘要：Good quality MFI zeolite membranes were prepared by altering a small amount of tetrapropylammonium (TPA(+)) with tetrabutylammonium (TBA(+)) in the synthesis solution. The effects of TBA(+)/Si ((TBA(+)+TPA(+))/Si ratio invariant) on the separation performance, hydrophobicity and compactness of MFI zeolite membranes were explored by pervaporation, water contact angle, scanning electron microscopy (SEM), X-ray diffraction (XRD), single-component gas permeation and permporosimetry. It was found that replacement of a small amount TPA(+) with TBA(+) could impair the hydrophobicity of membrane surface, but improve the membrane compactness verified by the ideal selectivity of N-2/SF6 and permporosimetry. When TBA(+)/Si ratio increased to 0.02 from 0, the membrane separation factor was increased to 56 from 37 under crystallization time of 24 h, and 71 from 43 under crystallization time of 48 h. With increase of ethanol concentration in the feed from 1 to 50 wt%, the observed ethanol flux increased first and then decreased to that of single component pervaporation of ethanol, resulting in a peak value of the separation factor. The membrane M3 exhibited the highest separation factor of 79 with the flux of 1.40 kg m(-2) h(-1) for 3 wt% ethanol/water mixture while the highest separation factor of membrane M3-48 was 86 with the flux of 1.52 kg m(-2) h(-1) for 8 wt% ethanol/water mixture.