Mass transfer performance of centrifugal adsorption technology

Centrifugal adsorption technology (CAT) provides a new way of countercurrently contacting micrometer range adsorbent particles and liquid feed. As a result of the fast mass transfer kinetics and countercurrent contact, CAT can lead to very compact adsorption equipment with high throughputs and very good separation efficiencies. A model for predicting the performance of CAT is described. The model calculations are based on the safety-state continuity equations and include mass transfer resistance in both phases as well as longitudinal dispersion effects in both phases. Data for the degree of backmixing have been taken from earlier work on CAT. The model predictions are compared with experimental data for Ca²⁺/Na⁺ ion exchange on Dowex 50 WX8 cation-exchange resin in a pilot scale CAT rotor. The experimentally observed separation efficiencies range from 90% for a separation factor equal to one, to 99% and beyond for higher separation factors. The model is shown to give accurate predictions of the performance of CAT. Model calculations demonstrate that the performance of CAT is limited by the degree of backmixing in the adsorbent phase mainly.