Conversion of oxides of nitrogen to nitrogen for pollution abatement
US4663135A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 23, 1985 |
| Grant date | May 5, 1987 |
| Priority date | — |
| Expiry date | Dec 23, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02A50/20
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process for removing oxides of nitrogen from a gas in which the molar ratio of NO to NO.sub.2 is greater than 1. Sufficient NO is oxidized by the reaction NO+2HNO.sub.3 =H.sub.2 O+3NO.sub.2 by a solution whose HNO.sub.3 concentration is maintained above about 20% to form a gas whose molar ratio of NO to NO.sub.2 is close to 1. Substantially equivalent amounts of NO and NO.sub.2 are absorbed by a solution whose pH is maintained below about 2 containing HNO.sub.3 and dissolved NH.sub.3. The absorbed oxides of nitrogen react with the dissolved NH.sub.3 at a temperature above about 50.degree. C. to form elemental nitrogen and water. The process can be carried out in several steps or in substantially one step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.