Proposal Title: High-flux, High-selectivity MFI Molecular Sieve Membranes: Microstructure Control and High-temperature, High-pressure Use Proposal Number: CTS-0522518 Principal Investigator: Michael Tsapatsis Institution: University of Minnesota
The objective of this project is to synthesize highly oriented micrometer-thick MFI films on tubular porous stainless steel supports, and to test their performance under high temperature membrane reactor conditions. It is also proposed to extend the current methodology and prepare for the first time three types of membranes with the three main pore orientations (straight, zig-zag, tortuous) of the MFI structure perpendicular to the film surface and examine their microstructure and separation performance. The level of microstructural control that will be demonstrated will bring practical zeolite polycrystalline thin films as close they can be to single crystals. The microstructure will be characterized and separation performance will be measured. In addition to their practical significance (identifying high performance microstructures), the proposed experiments are of fundamental significance because they will provide the first set of gas and vapor permeation data through zeolite membranes of a given structure type with drastically different preferred orientations. Such a data set is expected to be valuable in providing a connection between microstructure and membrane performance and to guide further developments in the field of inorganic membranes. The proposed research will have broader impacts on the worldwide effort for developing energy efficient separation technologies. High quality film growth on commercial, high-flux, stainless steel supports is a necessary step towards scale up and to make our membranes available to the separations and reaction engineering communities. Moreover, the engineering issues that will be addressed with respect to oriented assembly of inorganic nanoparticles on surfaces and control of templated crystal growth are central for the fabrication of functional nanostructures. Consequently, an entire range of new technologies at the nanoscale, ranging from sensors to catalysts with controlled porosity and nanostructure may be affected by the findings of the current effort. The research program has an educational component including involvement of undergraduate students in the research and a well-defined outreach effort. This project may stimulate the development of new separation processes and catalytic membrane reactors.
