MOLECULAR-DYNAMICS SIMULATION OF ISO-BUTANE AND N-BUTANE PERMEATIONS THROUGH A ZSM-5 TYPE SILICALITE MEMBRANE

Molecular dynamics simulation of the permeation processes of single an d mixed gases of iso-and ii-butane through a ZSM-5 type silicalite mem brane are presented. After 200 ps of simulation time the permeation of n-butane is observed whereas the permeation of iso-butane is not obse rved. The permeation of n-butane at 373 K takes place after the satura tion of the zeolite pores, whereas at higher temperature, 773 K, it oc curs without significant pores saturation. The calculated permeability of it-butane is close to experimental data. The permeation of the gas mixture shows that the membrane can separate the two isomers, n-butan e permeates whereas iso-butane does not.