Hydrogen isotope separation by displacement chromatography with palladium

In order to establish a lab-scale hydrogen isotope separation system, experimental and numerical studies were performed by means of displacement chromatography of protium and deuterium using a bed of spongy palladium particles. The inlet deuterium concentration of 5.0% D or 54.9% D was prepared for the experiment. The equations of the material balance of deuterium in the bed and the isotopic exchange rate between protium and deuterium were simultaneously solved. The contributions of isotopic exchange reaction on Pd surfaces, diffusion in the solid and axial dispersion in the interstitial of the Pd bed to overall mass transfer were taken into consideration in the equations. The numerical calculation results fitted to the experimental data. They predicted well the maximum deuterium concentration in the effluent and the shape of the displacement band. In the calculations, we used the values of the concentration-dependent isotope separation factor and the isotopic exchange rate constant determined in our previous exchange experiment. We formulated an equation to evaluate the Pd bed height necessary for the complete separation of any mixtures of hydrogen isotopes including H, D and T.