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Indexed by:Journal Papers

Date of Publication:2015-10-01

Journal:JOURNAL OF MEMBRANE SCIENCE

Included Journals:SCIE、EI、Scopus

Volume:491

Page Number:168-175

ISSN No.:0376-7388

Key Words:Boron-substituted; B-ZSM-11 zeolite membrane; Pervaporation; Ethanol/water mixture

Abstract:Boron-substituted silicalite-2 (B-ZSM-11) membranes were prepared on seeded cheap macroporous alpha-Al2O3 tubes to separate ethanol from water by pervaporation. The incorporation of boron atom into MEL framework was confirmed by XRD and FTIR. The effects of B/Si ratio in the synthesis solution together with PV operation temperature and feed concentration on separation properties of the membranes were investigated. The B-ZSM-11 membrane prepared with B/Si ratio of 0.06 exhibited the highest separation factor of 35.0 with a total flux of 1.51 kg m(-2) h(-1) for 5 wt% ethanol/water mixtures at 60 degrees C. The total flux increased with increasing PV temperature from 30 to 75 degrees C and the separation factor showed the highest value at 60 degrees C. The separation factor decreased with feed concentration from 1 to 7 wt% and the total flux also showed the highest value for a 5 wt% mixture. It is demonstrated that the incorporation of boron atom into MEL structure improved separation performance of B-ZSM-11 membrane for ethanol/water solutions. On the other hand, the better hydrophobicity of B-ZSM-11 membranes, evidenced by contact angle measurements, is responsible for pervaporation performance for ethanol/water mixtures. (C) 2015 Elsevier B.V. All rights reserved.