Hydrogen Purification Characteristics Comparison Between Zeolite Adsorbents 13X and LiX

Zeolite is a commonly used material for hydrogen purification by pressure swing adsorption (PSA) technology to remove weak components such as N2 and CO, so the selection of zeolite material is critical to the influence of hydrogen purification performance. In this study, the adsorption capacity of CO2/CO/N2/H2/Ar in zeolite 13X and zeolite LiX was fitted by temperature-dependent Dual-site Langmuir (TD DSL) isotherm model, and the adsorption selectivity, working capacity and isosteric heat adsorption of the two adsorbents were compared and analyzed. The findings demonstrated that zeolite 13X had a higher CO2 adsorption capacity than zeolite LiX. However, zeolite 13X had a lower CO and N2 adsorption capacity than zeolite LiX. The selectivity of \(\alpha\) -CO/H2 and \(\alpha\) -N2/H2 in zeolite LiX is higher than that of zeolite 13X. The working capacity of CO at 13X is slightly higher than that of LiX, while the working capacity of N2 at LiX is slightly higher than that of 13X. Therefore, zeolite LiX is more suitable for removing N2 and CO gas than 13X. The selectivity of Ar/H2 in zeolite LiX is lower than that in zeolite 13X, and the working capacity of Ar in the two adsorbents is almost the same. Therefore, zeolite 13X is more suitable for removing Ar than LiX. The TD DSL model can accurately predict the static single adsorption behavior and dynamic breakthrough behavior of multi-component on the two adsorbents. The breakthrough behavior of multi-component shows that the weakest component gas (N2 or Ar) as the major impurity is the first component to breakthrough.