Propylene and propane single-adsorption equilibrium isotherms and mass-transfer kinetics over 13X and 4A zeolite pellets have been investigated using gravimetry and zero length column techniques, respectively. The 13X zeolite shows a higher loading capacity and lower mass-transfer resistance while 4A zeolite shows the highest selectivity for propylene. The experimental adsorption equilibrium isotherms were adjusted with the Toth isotherm. Kinetic studies indicate that macropore diffusion controls the mass transfer inside 13X zeolite pellets while micropore diffusion controls the propylene adsorption on 4A zeolite pellets.