Exhaust emission control system and method for internal combustion engines
US6911184B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 2000 |
| Grant date | Jun 28, 2005 |
| Priority date | — |
| Expiry date | Dec 6, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An NOx storage-and-reduction type catalyst is used which exhibits a saturated NOx storage amount of 5 g or more as NO2 with respect to 1 liter of a catalyst volume at 500° C., and rich spiking is controlled so that an actual NOx storage amount of the NOx storage-and-reduction type catalyst becomes 50% or less of the saturated NOx storage amount.Since the saturated NOx storage amount is large, the NOx storage amount is large even when it is 50% or less, it is possible to prolong intervals of the rich spiking. Then, since NOx storage component stores NOx preferentially into the sites which are likely to store and release NOx, a reduction efficiency is high. Therefore, while prolonging the intervals of the rich spiking and sustaining an effect of mileage improvement, it is possible to improve the reduction efficiency of NOx.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.