Collect. Czech. Chem. Commun. 1999, 64, 726-734

Transient Kinetic and Thermodynamic Behaviour of Langmuir Adsorption in a Flow System

Miloslav Pekař* and Josef Koubek

Department of Organic Technology, Prague Institute of Chemical Technology, Technická 5, 166 28 Prague 6, Czech Republic


Various kinetic pathways to the adsorption equilibrium in an isothermal differential bed of adsorbent are illustrated on several examples. Discussion is based on the computed transient responses of adsorption rate and distance from adsorption equilibrium to the start of adsorptive feed. It is shown that adsorption behaviour in flow system may not be smooth and very steep changes on the rate responses may appear. Even the simple reaction need not approach equilibrium smoothly but at a jump. The approach assuming "closeness to the equilibrium" should be used very carefully, in this case.

Keywords: Adsorption equilibrium; Kinetics of adsorption; Nonstationary kinetics; Transient response method; Heterogeneous catalysis.