Nanocomposite MFI–ceramic hollow fibre membranes via pore-plugging synthesis: Prospects for xylene isomer separation

Abstract

Nanocomposite MFI–alumina hollow fibres and membrane tubes have been prepared by pore-plugging hydrothermal synthesis and tested in the separation of xylene vapour mixtures. Single component and ternary xylene isomer mixtures diluted in N 2 gas have been fed into the membrane lumen, while N 2 gas swept over the outer membrane surface. The fibres showed a maximum p-xylene flux of 4.5 μmol m 2 s −1 at 573 K for p/m/o-xylene partial pressures 0.62 kPa/0.27 kPa/0.32 kPa, the pxylene to o-xylene (p/o) separation factor showing a value of 107. As expected for a nanocomposite material, xylene fluxes show no indication of flux increase beyond 573 K due to pore opening. When comparing MFI–alumina hollow fibres to membrane tubes, the surface-to-volume ratios can be increased by one order of magnitude, allowing for more compact and cost-effective units.