ABSTRACT
Adsorption is typified by drying of gases, recovery of higher hydrocarbons from natural gas, decolorizing of sugar syrups, or removal of phenols from waste water. Ion exchange as a treating method for aqueous solutions is similar in many respects to adsorption. Desorption is a necessary accompaniment to adsorption. The design of an adsorber is a matter of equilibrium between fluid and solid, stoichiometry between the fluid and the solid, and rate. For adsorption of a single “solute” in a fixed bed, design focuses upon the breakthrough curve and the tolerable quantity of impurity that can be allowed to emerge before the “run” or “cycle” is terminated. Numerical or graphical differentiation of the experimental isotherm data can be used to generate the local-equilibrium limit curve, without recourse to empirical equations for the equilibrium. The literature is replete with theories and equations describing the equilibrium between adsorbates and adsorbents. The bulk of published experimental data pertaining to adsorption represents equilibrium measurements.
