Separation of gaseous olefin isomers using facilitated transport membranes

Abstract The sorption and transport of c-2-butene and t-2-butene in hydrated Nafion cation exchange membranes containing Ag + ions and Na + ions has been studied. The results of the flux measurements at 298.2 K and at feed pressures of up to 3 bars indicate that for c-2-butene/t-2-butene mixtures, a competitive effect in the Ag + membranes occurs which increases the selectivity from the ideal value of 1.4 calculated from pure gas fluxes at about 1.9–2.7 depending on the feed composition. Even at the highest feed gas concentrations the mixed gas selectivities do not drop below 1.9. The mixed gas solubility data of the Ag + membranes show the same enhancement in selectivity compared to the ideal sorption selectivity calculated from pure gas solubilities. All experimental results can be described consistently with a reaction equilibrium model which does not require any adjustable parameters.