This thesis describes a novel synthesis method to prepare engineered supported MFI-type zeolite membranes with tailored microstructures by ex-situ crystallization involving preseeding of the porous support with zeolite nanocrystals, followed by hydrothermal treatment. The microstructures are defined by membrane thickness and orientation, surface porosity, crystal shape, size and intergrowth. These microstructural properties were studied under different synthesis parameters such as the concentration of silica precursor, organic template, and hydroxyl ions, as well as synthesis temperature and time. Instead of complex mechanistic growth model for zeolite, two empirical mathematical models have been developed for two key microstructures, membrane thickness and crystal size. Based on these...[ Read more ]

This thesis describes a novel synthesis method to prepare engineered supported MFI-type zeolite membranes with tailored microstructures by ex-situ crystallization involving preseeding of the porous support with zeolite nanocrystals, followed by hydrothermal treatment. The microstructures are defined by membrane thickness and orientation, surface porosity, crystal shape, size and intergrowth. These microstructural properties were studied under different synthesis parameters such as the concentration of silica precursor, organic template, and hydroxyl ions, as well as synthesis temperature and time. Instead of complex mechanistic growth model for zeolite, two empirical mathematical models have been developed for two key microstructures, membrane thickness and crystal size. Based on these models, three-dimensional growth behaviour of zeolite membrane can be predicted given the initial synthesis parameters. To further tailor-make the membrane properties, inorganic and organic additives with selective growth inhibition effect were also studied. Single gas permeation was conducted to study the influence of microstructures on membrane performance. Permeation behaviour of permanent gases and hydrocarbons including butane isomers was investigated. Preliminary study of the xylene separation and isomerization in catalytic zeolite membrane was also conducted.