Exhaust gas purification method and exhaust gas purification system
US8671661B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 2009 |
| Grant date | Mar 18, 2014 |
| Priority date | — |
| Expiry date | Apr 26, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An exhaust gas purification method, and system. In order from an upstream side of an engine exhaust passage there are provided, a NOx occlusion-reduction catalyst, a hydrocarbon (“HC”) adsorbing member, and a catalyzed diesel particulate filter or oxidation catalyst. During NOx regeneration control, an air-fuel ratio of exhaust gas in terms of excess air factor is taken to be 0.8 to 1.1 when an index temperature representative of the HC-adsorbing member is a first judgment temperature or less, is taken to be 1.0 to 1.1 when the index temperature is between a first judgment temperature and a second judgment temperature, and is taken to be 0.8 to 1.1 when the index temperature is the second judgment temperature or above, causing an outflow of HC to the atmosphere to be reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.