Time-lag measurements for diffusion of aromatics through a silicalite membrane

Permeation of Aromatic Isomer Vapors through Oriented MFI-Type Membranes Made by Secondary Growth

“…As shown in Table 3, o-xylene alone permeates much slower as compared to the case where The mixture permeation behavior in the case of our membranes (slow-permeating isomer accelerated in the presence of the fast-permeating isomer) is entirely different from that observed by Baertsch et al 16 (fastpermeating isomer retarded in the presence of the slowpermeating isomer) or Keizer et al 17 (no effect of the presence of either isomer on the flux of the fast-or slowpermeating one). An entirely different single-component permeation behavior was also observed by Shah and Liou, 18 who found that all three xylene isomers permeate at equivalent rates through a c-oriented MFI singlecrystal membrane. In contrast, single-component permeation measurements with the membranes reported here indicate that p-xylene permeates at a rate more than 1 order of magnitude higher than the other two isomers.…”

Diffusion measurements through embedded zeolite crystals

“…The technique of measuring diffusivity with a single zeolite crystal membrane was first developed by Paravar and Hayhurst (1984) and Wernick andOsterhuber (1984, 1985). Later, the technique was applied to measure the intracrystalline diffusivities of C, hydrocarbons (Shah et al, 1993) and aromatics (Shah and Liou, 1994) in silicalite. In the preceding studies, a membrane was fabricated from a large zeolite crystal.…”

Mathematical modeling and parameter estimation of MFI membranes for para/ortho‐xylene separation

“…In the model formulated above, the diffusivities of the xylenes in the MFI membrane are required. Although several studies have measured the diffusivity of xylenes in MFI zeolites, 51,[74][75][76][77][78] the reported values vary significantly. Therefore, instead of using reported values, we fitted the model to the experimental data to extract diffusivity values that could reproduce the separation performance.…”