Lithium-based zeolites containing silver and copper and use thereof for selective absorption
US6780806B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 2001 |
| Grant date | Aug 24, 2004 |
| Priority date | — |
| Expiry date | Jun 28, 2021 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2259/40064
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The invention provides new methods for separating nitrogen from a mixture. The invention provides adsorbents specifically for accomplishing nitrogen separation. The adsorbents and separation methods are particularly useful for the selective adsorption of nitrogen from air. In one aspect, the adsorbent comprises an ion exchange zeolite X and preferably zeolite LSX (low silica zeolite X). The zeolite is most preferably a lithium-based zeolite. Further, the zeolite has exchangeable cationic sites, with silver cation or copper cation occupying at least some of the exchangeable cationic sites. The Ag/Cu exchanged zeolite is heat-treated under specific conditions as per the invention. The presence of the silver cation or copper cation at any of the sites will provide an improvement over the non-exchanged zeolite.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.