The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 09, 1999
Filed:
May. 29, 1997
Tosoh Corporation, Yamaguchi, JP;
Abstract
A crystalline zeolite X adsorbent comprising a crystalline zeolite X having an SiO.sub.2 /A.sub.2 O.sub.3 molar ratio of not larger than 3.0, where lithium cations associated with an AlO.sub.2 tetrahedron unit are 80 to less than 88 mol % of the total cations and the content of alkaline earth metal cations is from 0.5 to less than 4.6 mo % is produced by ion-exchanging with lithium cations at least 90 mol % of the cations associated with an Al.sub.2 O.sub.3 tetrahedron unit of a crystalline zeolite X having an SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio of not larger than 3.0, ion-exchanging the crystalline zeolite X again with an aqueous solution of mixed salts of an alkali metal salt and an alkaline earth metal salt to decrease the lithium cations associated with the AlO.sub.2 tetrahedron unit to 80 to less than 88 mol %, followed by washing and drying, and activating the crystalline zeolite X. The crystalline zeolite X adsorbent is used for the recovery of oxygen from air by a pressure swing adsorption method by using the crystalline zeolite adsorbent.