Ortho-para-hydrogen and para-ortho-deuterium separation factors on LiX zeolite at 50-112 K

Abstract

The paper reports on a comprehensive set of experimentally measured orthopara- H2 and para-ortho-D2 separation factors at low temperature adsorption on an especially prepared sample of X type zeolite. The zeolite was investigated in its lithium cationic form by a new version of the gas solid chromatographic technique ECMA (Elution Chromatography with Modifying Adsorbates). Six types of eluents were used: four pure gases He, Ne, H2, D2, and two mixed eluents – He-H2 and He- D2 various compositions. The new ECMA version gives results of high precision. At easily attainable temperatures 77-50 K and practically suitable fractional coverages 0.6-0.8, the selectivity of adsorbent LiX ranges from 1.45 to 2.0 for ortho-para-H2, and 1.108 - 1.254 for para-ortho-D2. A low ortho-para-conversion catalytic activity and high selectivity of new sorbent LiX allow separation of orthopara- isomers of dihydrogens by Moving Temperature Gradient Adsorption technique