Method of increasing the thermal stability of crystalline zeolites
US3933983A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 12, 1973 |
| Grant date | Jan 20, 1976 |
| Priority date | — |
| Expiry date | Nov 12, 1993 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S423/38
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Methods of increasing the thermal stability of crystalline zeolites are disclosed. The methods are characterized by the steps of either (i), treating the crystalline zeolite first in at least one step with a dilute solution of a fluorine compound whereby a very small amount of fluoride is incorporated in the zeolite with a subsequent exchange with an ammonium ion, rare earth ion, or other metal ion solution, (ii), first exchanging the zeolite with an ammonium ion, rare earth ion or other metal ion solution followed by a treating with a dilute fluoride solution, or (iii), concurrently treating the zeolite with the fluoride ion and exchanging the zeolite in a simultaneous operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.