Removal of nitric oxide from gas streams
US6231824A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 1999 |
| Grant date | May 15, 2001 |
| Priority date | — |
| Expiry date | Aug 10, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J29/061
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Nitric oxide is removed from a gas stream by contacting the gas stream with oxygen in the presence of a metal-cation exchanged zeolite, thereby oxidizing the nitric oxide to nitrogen dioxide, then contacting the resulting nitrogen dioxide-containing gas stream with ozone, thereby converting the nitrogen dioxide to nitric acid, nitric acid precursors or mixtures thereof, then contacting the gas stream with an aqueous liquid, thereby scrubbing the nitric acid, nitric acid precursors or mixtures thereof from the gas stream. Contact of the gas stream with oxygen in the presence of a zeolite is carried out at a temperature above the temperature at which significant adsorption of nitrogen dioxide occurs, and the aqueous liquid used as scrubbing agent preferably has a pH greater than 7.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.