Sorption kinetics of linear paraffins in zeolite BEA nanocrystals

The objective of this study was to evaluate the sorption kinetics of linear paraffins in zeolite beta crystals using the ZLC technique to better understand its catalytic properties. The experiments were made under the influence of desorption flow rate and temperature. The diffusivity values, estimated using a transient Fickian diffusion model, were very low compared to others reported in the literature for zeolites with similar pores aperture. This indicates the probable influence of extracrystalline diffusion due to the very small size of zeolite beta crystals and also very pronounced heat effects in the experiments. The n-paraffins desorption rates in zeolite beta were much faster when compared to those under similar conditions obtained for zeolite HUSY. The very short diffusional length and probable intercrystalline mesoporosity in zeolite beta may facilitate the molecules kinetics through the pores and thus the catalytic performance in the isomerization reaction of n-alkanes.