Multilayer ceramic membranes for gas separation

At VITO, multilayer ceramic membranes for gas separation are being developed. Conventionally these membranes consist of a macroporous support material, a mesoporous interlayer and a gas separative top layer. A porous Reaction Bonded Al2O3 (RBAO), a VITO development, was used as the membrane support. This material is much stronger than conventional porous Al2O3; a property which allows the use of thinner substrates with a higher porosity. As an intermediate layer we used gamma-Al2O3 with a pore size of 6nm produced by dip coating. Different top layers can be considered depending of the application: silica, zeolites and pillared clays are under study. To optimize the synthesis of the supports as well as the different layers several characterization techniques are being used. Accurate measurements of the gas permeation through the membranes are the ultimate test to evaluate the membrane performance. Permeation of different gases, the permselectivity and the real separation factor can be determined in our ''Velterop turn key'' membrane test apparatus.