FIXED-BED ADSORPTION OF 2 LINEARLY ADSORBED COMPONENTS IN PRESENCE OFAN INERT

The effect of velocity changes in fixed-bed adsorption of ternary mixt ures (two absorbable components and one inert) is analyzed. In a dilut ed system governed by linear isotherms transition types are contact di scontinuities. It is shown that the velocity variations (nontrace syst ems) resulting from changes in gas composition influence the transitio n types producing simple waves or shocks. Roll-up phenomena can appear in the adsorption step. Two models of fixed-bed adsorption are analyz ed: a dispersed plug flour model and a plug flow model both with therm odynamic equilibrium between bulk gas phase and solid phase. The mathe matical approach for the solution of the equilibrium model is based on the theory of characteristics. The axial dispersion model is solved b y orthogonal collocation. Examples of fixed-bed adsorption in a clean bed and desorption of a saturated bed are shown. (C) 1998 Elsevier Sci ence Ltd. All rights reserved.