NOx reduction in lean burn engine exhaust
US7272925B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 25, 2005 |
| Grant date | Sep 25, 2007 |
| Priority date | — |
| Expiry date | Oct 25, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
The nitric oxide (NO) and nitrogen dioxide (NO2) content of lean-burn engine exhaust is beneficially prepared for selective catalytic reduction (SCR) of these oxides to nitrogen by two sidestream additions to the exhaust. An ozone-containing air stream is added to the exhaust to affect oxidation of NO to NO2. And a hydrocarbon(s) fuel constituent is added to a second humidified ozone-containing air stream and that mixture subjected to UV radiation. Strongly oxidizing hydroxyl radicals are formed by interaction of ozone, water, and UV radiation for reaction with the hydrocarbon. The resulting partially oxidized hydrocarbons (Pox) are added to the exhaust, providing effective reduction materials for the SCR of NO2 to nitrogen and water.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.