FRACTIONATION OF MULTICOMPONENT MIXTURES BY STAGED SEQUENCE CYCLIC PROCESS AND PARAMETRIC PUMPING.

摘要

The continuous fractionation of multicomponent fluid mixtures has been experimentally and theoretically investigated by staged sequence cyclic process and parametric pumping operating in the direct thermal mode.; A multicolumn staged sequence cyclic process for the separation of solute mixtures was developed. The criteria necessary for the continuous fractionation of a system of n solutes with n + 1 columns arranged in a series operated with n + 1 cyclic variables is presented. The feasibility for practical application of this process was demonstrated by fractionating the model system, O-xylene-Anisole-n-heptane on silica gel. The separation was modeled by one column staged sequence experimental data and by the equations of continuity under nonequilibrium conditions with nonlinear equilibria of the individual solutes. Diverse operating variables necessary for maximum separation were optimized. The results showed that this process could be a viable alternative to parametric pumping, cycling zone adsorption, or simulated moving bed.; Two column parametric pumping arranged back-to-back with alternating top and bottom feed (to minimize reservoir mixing) was also used in the continuous fractionation of a model system consisting of toluene-acetophenone-n-heptane in silica gel. A simple method for predicting the purification of a given solute(s) was derived based on the method of characteristics, by assuming the existence of pseudo binary systems, each system consisting of one solute and the common solvent. Comparatively, two column parametric pumping provides better separation capability than a one column parapump.