Application of Displacement Chromatography to Isotope Separation

Publisher Website
Google Scholar
Abstract
It is shown that a chromatographic column, operating according to the band-displacement principle, with internal reflux at each end, may be compared to a countercurrent separation column. Simple formulas relate the three parameters which determine the separative performances of the column to the physicochemical characteristics of the process. The parameters are the separation coefficient, the height equivalent to a theoretical plate (HETP), and the theoretical flow. The determination of the HETP can be accomplished by either the method of frontal analysis or the method of isotope remixing, by comparing the evolution of the isotope concentration predicted by an appropriate mathematical model and that observed experimentally. The first method concerns a semi-infinite band, limited by a front situated either at the leading or trailing edge of the band and the enrichment directed toward either the solid or liquid phase. Therefore, there are four possible cases. In the second method, the isotope concentration at the top of the column is changed suddenly and the response at the exit-end is observed. For each above-mentioned case, the theoretical formulation of the model, the necessary calculations in a form suitable for solution with a desk computer, the operating mode for treating the experimental results, and some examples are presented.