NITROGEN ADSORBENT AND USE THEREOF

摘要

A nitrogen adsorbent comprising a crystalline type X zeolite which has a faujasite structure having an SiO2 to Al2O3 ratio of less than 3.0 and, within the crystal, has at least one trivalent element selected from among iron, boron, and gallium and wherein cations are associated with tetrahedral (AlO4)<5->units. Despite the fact that a predetermined trivalent element is contained in zeolite, the number of cation sites contributing to the adsorption are ensured, so that the nitrogen adsorbent can offer a high level of nitrogen/oxygen separation and possesses excellent heat resistance. The nitrogen adsorbent has an improved adsorption performance when it is used according to such a special method that vacuum heat treatment is carried out before nitrogen adsorption.