Process for optimizing the removal of NO.sub.X and SO.sub.X from gases utilizing lanthanide compounds
US5213779A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 1, 1991 |
| Grant date | May 25, 1993 |
| Priority date | — |
| Expiry date | Aug 1, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21C1/02
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for optimizing the removal of nitrogen oxide (NO.sub.x) and sulfur oxide (SO.sub.X) from flue gases is provided in which the flue gases pass over a lanthanide-oxygen-sulfur catalyst. The catalyst has active sites provided on its surface which promote the dissociation of NO.sub.X and receive and entrap oxygen released during the dissociation of the NO.sub.X. While the flue gases pass over the catalyst, a reducing gas contacts the catalyst to reduce the oxygen on the active sites of the catalyst and permit the catalyst to continue to promote the dissociation of the NO.sub.x in the flue gas. If the flue gases contain SO.sub.X, they are then passed over a solid solution having a solvent of a first lanthanide oxide compound which crystallizes in the fluorite habit and a solute of at least one altervalent oxide of a second lanthanide. The SO.sub.X in the flue gases reacts with the solid solution to form a sulfated lanthanide oxide which is removed from the flue gases. The sulfated lanthanide oxide may then be dissociated by raising its temperature to regenerate the lanthanide oxide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.