关键词: porous membrane;gas permeability;mathematical model

Abstract: Membrane-based separation processes are new technology combined membrane separation with
conven-tional separation. Hydrophobic porous membranes are often used in these processes.
The structure of hydrophobicporous membrane has significant effect on mass transfer
process. The permeabilities of five kinds of gas, He, N2,O2, CO2 and water vapor, across
six polytetrafiuoroethylene(PTFE) flat membranes were tested experimentally.Results
indicated that the greater the membrane mean pore size and the wider the pore size
distribution are, thehigher the gas permeability. A gas permeation model, including the
effects of membrane structure parameter and gasproperties, was established. A comprehensive
characteristic parameter (including porosity, thickness and tortuosity)was found more
effective to express the influence of membrane structure in gas permeation process. The
predictedpermeation coefficients were in good agreement with experimental data.

Key words: porous membrane, gas permeability, mathematical model