CONTINUOUS ISOTOPE-SEPARATION IN SYSTEMS WITH SOLID-PHASE .1. GAS-PHASE SEPARATION OF ISOTOPES OF THE LIGHT-ELEMENTS

A continuous countercurrent process for separation of isotopes of the light elements in gas-solid systems is reported. To separate hydrogen isotopes a hydride-forming palladium adsorbent and a zeolite 13A were used as a solid phase. The molecular sieve was also used to separate o xygen, nitrogen, and argon isotopes. The simulated moving-bed techniqu e (SMB) was employed to organize a counter-currency between gas and so lid phases without actual movement of the latter phase. Details of the experimental SMB unit operating in the gas phase are presented, and t he results of the separation tests are discussed. A multichannel disk rotary valve was used to switch the flows. It is shown that the proces s takes advantage of a continuous operation and possesses very high se paration efficiency with HETP values comparable to those for the equiv alent conventional chromatographic process. It appears that the proces s proposed is ideally suited for processing tritium-containing streams to produce commodity-grade tritium and may be effectively used to sep arate isotopes of other light elements.