Method for purifying exhaust gas and system therefor
US8263031B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 23, 2011 |
| Grant date | Sep 11, 2012 |
| Priority date | — |
| Expiry date | Mar 16, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method is provided for purifying exhaust gas from an engine having an exhaust passage with a selective reducing catalyst and an oxidation catalyst upstream of the selective reducing catalyst. The method calculates an amount of NOx that flows into the selective reducing catalyst; sets an amount of an additive agent to be supplied to the selective reducing catalyst based on the calculated amount of NOx; determines a degradation degree of the oxidation catalyst; determines whether a correction to the amount of the additive agent is necessary based on the determined degradation degree of the oxidation catalyst; corrects the amount of the additive agent to be supplied when the correction is necessary; and supplies the additive agent to the selective reducing catalyst in the corrected amount if the amount is determined to be corrected and in the uncorrected amount if the amount is determined not to be corrected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.