ADSORBENT FOR OXYGEN PSA(PRESSURE SWING ADSORPTION), ITS PREPARATION AND PREPARATION OF OXYGEN USING IT

摘要

PROBLEM TO BE SOLVED: To improve selective adsorptivity of nitrogen by a method wherein a crystalline zeolite X with a specified molar ratio is used and lithium cation and cesium cation each with a specified amt. are incorporated in a crystalline zeolite X adsorbent being ion-exchanged with lithium cation. SOLUTION: In preparing a zeolite adsorbent used for preparing oxygen gas, a crystalline zeolite X with a molar ratio of SiO2 /Al2 O3 of not larger than 3.0 is used and at least 90% cations associated with its Al2 O3 tetrahedron unit are ion-exchanged. Thereafter, ion exchange is performed again with a mixed salt aqueous soln. wherein sodium cation is an essential cation and either monovalent cation of cesium cation or rubidium cation and/or a mixed cation thereof are incorporated with at least 1% and less than 5%. In addition, after lithium cation associated with Al2 O3 tetrahedron unit is made to be at least 80% and less than 88%, it is washed, dried and activated.