Effects of adsorption-induced microstructural changes on separation of xylene isomers through MFI-type zeolite membranes

Jessica O'Brien-Abraham, Masakoto Kanezashi, Jerry Lin

Research output: Contribution to journalArticle

37 Scopus citations

Abstract

Various factors were found to affect the performance of MFI-type zeolite membranes in separating xylene isomers (p-xylene, PX; o-xylene, OX) by pervaporation. In this work the effect of membrane microstructure, membrane quality, and pervaporation operating conditions were investigated using three membrane microstructures: random, c-oriented, and h,0,h-oriented. Operation under pervaporation conditions means that high loadings of PX will be present in the framework; therefore, the role of PX-framework and PX-OX interactions needs to be taken into consideration. Single component experiments demonstrated that the order of experimentation with OX and PX will affect the ideal selectivity. Multi-component studies showed that membrane performance is highly dependent on the relative concentration of the isomers in the feed; the higher the PX concentration the lower the selectivity observed. However, although high selectivity (∼18) was observed at low PX concentrations in the feed, it was not stable over time. Similar trends were observed for all membrane microstructures but differences in the selectivity values occurred. The structural deformation caused by high loadings of PX into the silicalite crystal affects each microstructure differently, ultimately leading to differences in performance.

Original languageEnglish (US)
Pages (from-to)505-513
Number of pages9
JournalJournal of Membrane Science
Volume320
Issue number1-2
DOIs
StatePublished - Jul 15 2008

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Keywords

  • MFI-type zeolite membranes
  • Microstructure
  • Pervaporation
  • Xylene separation
  • p-Xylene loading

ASJC Scopus subject areas

  • Biochemistry
  • Materials Science(all)
  • Physical and Theoretical Chemistry
  • Filtration and Separation

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