(751d) Adsorption Kinetics Measurement Using a Volumetric System

Examples of adsorption kinetics with powders and pellets are presented in order to investigate in detail the use of the Quantachrome Autosorb iQ for the determination of mass transfer kinetics in nano-, meso- and macro-porous adsorbents.

The interpretation of volumetric dynamic experiments is extended to the uptake of argon at liquid argon temperatures in Y-type zeolites and the isothermal solution to the dynamic response is adapted for the case where the dosing volume is at a higher temperature. Differential pressure increments as well as large pressure steps are considered.

Carbon dioxide and nitrogen adsorption in pellets of 5A and 13X zeolites is used to discuss the interpretation of experiments where mild and significant heat effects are present. A description of how to plot the measured dosing cell pressure vs time is used to identify the controlling regimes at various stages of the adsorption dynamics - valve effect; near-isothermal uptake; and heat limited approach to final equilibrium.