The sorption mass transport of C3-C5 alkanes in zeolites was studied using the frequency response (FR) rate spectroscopic method. Rate spectra were recorded in the 0 to 160°C temperature and 60 to 600 kPa pressure ranges. The studied alkanes had a fixed backbone of three carbons and different kinetic diameters depending on the number of methyl groups on the central carbon atom. The studied zeolites had 12-, 10-, or 8-member ring (MR) entrances to the intracrystalline cavities. Only propane was found to pass through the 8-MR apertures of zeolite Ca,Na-A. The diffusion resistance of 10-MR channels governed the rate of i-butane and neopentane transport in zeolite H-ZSM-5. in large pore H-zeolites, having 12-MR windows, such as, faujasite, mordenite and beta, sorption was the rate-controlling slowest step of alkane mass transport for all three sorbates studied.
ASJC Scopus subject areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry