Adsorption/Desorption Characteristics of Solid Particles in Desiccant Bed for Different Design Configurations

Abstract

Unsteady-state (batch) adsorption is very widely used in recovery of valuable solvent vapors from gases as well as dehumidification of air for air-conditioning and industrial applications. In such systems, the desiccant is subjected to cyclic operation of adsorption and subsequent desorption. The design of a solid bed adsorber and prediction of the adsorption cycle require knowledge of the percentage approach to saturation. The unsteady-state circumstances of solid-bed adsorption and many factors which influence the adsorption make such computation for the general case very difficult. Moreover, the inconvenience and relatively high cost of continuously transporting solid particles as required in steady-state operations frequently make it more economical to pass the fluid mixture to be treated through a stationary bed of adsorbent. As increasing amounts of fluid are passed through such a bed, the solid adsorbs increasing amounts of solute, and an unsteady prevails.