Analysis of Isotope Separation Factor for Adsorption of Tracer-HTO/Bulk-H₂O on Cobalt Complex [Co (en) ₃] Cl₃ Based on Ideal Adsorbed Solution Theory

Abstract

The isotope separation factor for adsorption of tracer-HTO/bulk-H₂Oon tris (ethylenediamine) cobalt complex [Co (en) ₃] Cl₃is analyzed in accordance with the ideal adsorbed solution theory by using the isotherms for pure-component adsorption ofH₂OandD₂O.It has been studied that the isotherms are composite which result from two types of adsorption of water molecules on primary and secondary coordination sites in the complex crystal. The separation factorβshows two of high and low plateaus which respectively correspond to the primary adsorption where the equilibrium pressure exhibits a plateau and the secondary adsorption where the pressure rises up to the saturated vapor pressure. The high plateauβis larger thanα, the relative volatility ofH₂OtoHTO.On the other hand, the low plateauβis smaller thanα.In this paper, approximate equations are presented for estimating the plateausβwith respect to temperature.