Adsorbent for air separation, production method thereof, and air-separation method using it
US5868818A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 1997 |
| Grant date | Feb 9, 1999 |
| Priority date | — |
| Expiry date | May 29, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S423/21
- WIPO fieldChemical engineering
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.