EXPERIMENTAL-STUDY OF A SIMULATED COUNTERCURRENT ADSORPTION SYSTEM .7. EFFECTS OF NONLINEAR AND INTERACTING ISOTHERMS

Continuous operation of a simulated counter-current adsorption process for separating a binary mixture with non-linear, interacting equilibrium relationships has been demonstrated experimentally. Emphasis is placed on the derivation of operating conditions for attaining high product purity and recovery when the isotherm is non-linear. With properly chosen flow conditions efficient separation is possible but the extract and raffinate products are generally recovered at concentrations lower than the feed. It is shown that this limitation can be avoided, and for our model system the extract product can be produced in high concentration and in relatively pure form by taking advantage of the effect of isotherm interaction. The suggested mode of operation may be applied, in principle, to increase the concentration of the extract product in any separation in which the adsorption equilibrium for the extract product component increases with increasing concentration of the raffinate product component. The practical feasibility of this mode of operation depends on the extent of the isotherm interaction.