Continuous Isotope Separation by Simulated Countercurrent Moving Bed Chromatography and Ion Exchange

Abstract

The Simulated Moving Bed technology has been applied to separate isotopes of light elements. For nitrogen isotope separation a chemical exchange between ammonia in aqueous solution and the appropriate form of cation exchange resin was used. To separate hydrogen isotopes in the gas phase, a hydride-forming palladium adsorbent and a zeolite 13A were used as solid phase. This molecular sieve was also used to separate oxygen, nitrogen and argon isotopes.

It was shown experimentally that both liquid and gas phase operations possess very high separation efficiency. The liquid phase SMB separation by ion exchange displacement band chromatography appears to provide the opportunity of flexible production of a whole number of isotopes, whenever the system with non-dispersive ends of the band is found. The gas phase separation process, developed in this study, is ideally suited for processing tritium-containing streams to produce commodity-grade tritium and also may be effectively used to separate isotopes of other light elements.