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

Oriented MFI-type membranes made by secondary (seeded) growth exhibit potential for size-selective separation of p-xylene from its bulkier o- and m-xylene isomers, as judged by substantial single-component (up to 40) or mixture (up to 18) permeation flux ratios at 100 °C. However, increased permeation of the bulkier isomers, attributed to the flexibility of the MFI framework and resulting in lower selectivities, is observed under conditions of high temperature or high p-xylene loading in the MFI membranes.