Dynamics of non-isothermal adsorption in packed bed of biporous zeolites

Adsorption dynamics were investigated in a laboratory scale fixed bed column, functioning under three different non-isothermal conditions: adiabatic, near adiabatic and non-adiabatic. Axial and radial temperature profiles were registered, as well as a corresponding breakthrough curves at the column exit. Experimentally it has been demonstrated that the thermal effect of adsorption leads to deformation of the temperature profiles along the column. This directly affects the total amount adsorbed in the bed and breakthrough at the exit, an effect which is different for the different non-isothermal conditions. A two-dimensional mathematical model for description of non-isothermal adsorption was developed, including the effects of the radial temperature gradients. A biporous structure of the adsorbent particles is assumed and the heat effect on the equilibrium is taken into account. Good agreement is shown between experimental and theoretical results, when the mathematical model accounts for the radial thermal conduction and thermal flow through the wall. (C) 2002 Elsevier Science B.V. All rights reserved.