Adsorption of propane and propylene in pellets and crystals of 5A zeolite

Equilibrium and kinetic data for propane and propylene adsorption in pellets (Grace Davison) and crystals (PQ Corp.) of 5A zeolite are presented in the temperature range 323-423 K. The pellet adsorption loading measured by gravimetry is 1.7 mmol/g for propylene and 1.3 mmol/g for propane at 100 kPa and 423 K. The selectivity for propylene increases with temperature and is in the range 1.08-1.35 at 100 kPa, being higher at lower pressures. The kinetic data measured by zero-length-column (ZLC) chromatography indicate that the transport of sorbate in the pellets is controlled by macropore diffusion; pore diffusivities are in the range 0.018-0.027 cm(2)/s for both gases. Crystal diffusivities are in the range (1.1-7.2) x 10(-11) cm(2)/s for propane and (0.2-6.2) x 10(-11) cm(2)/s for propylene.