A new microporous titanosilicate AM-3 has been synthesized on alumina tubular support by seeded hydrothermal synthesis. The dynamic characterization has been carried out by permeation assays of single gases at fixed and programmed temperature, and for several transmembrane pressure drops. The mechanisms involved in the gas transport have been investigated, namely viscous. Knudsen, activated gaseous and surface diffusions. Results published for the first AM-3 membrane have been modelled as well in order to comprise all transport contributions occurring in porous media. The obtained results pointed out the existence of macro-, meso- and micro-defects. The representation of the experimental data was achieved successfully with absolute average relative deviations between 1.5% and 2.5%. (C) 2010 Elsevier B.V. All rights reserved.