EFFECT OF PROPANE ON THE KINETICS OF CARBON-DIOXIDE ADSORPTION IN NAAZEOLITES

Results obtained in a batch adsorption system with constant volume sho wed that preadsorption of small amounts of propane on NaA zeolite can significantly slow down the rate of carbon dioxide uptake. The observe d decrease in the carbon dioxide uptake rate was related to a decrease in accessibility of the external surface of the microcrystallites due to the effect of an external film resistance created by the preadsorb ed propane molecules. Small amounts of preadsorbed propane localized i nside the zeolite microcrystallites were found to have no affect on th e COP adsorption rate. Experiments carried out using the frequency res ponse technique confirmed the significant influence of the external fi lm resistance on the kinetics of adsorption of carbon dioxide/propane mixtures on 4A zeolite even at low propane concentrations (2-3%).