Diesel engine exhaust gas purification method
US5943857A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 19, 1997 |
| Grant date | Aug 31, 1999 |
| Priority date | — |
| Expiry date | Nov 19, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process for the improved conversion of NO.sub.x in the exhaust gases from a light diesel engine using lean NO.sub.x catalyst converter in the exhaust system. The process is characterized in that unburned hydrocarbons are adsorbed into an adsorbent in the catalytic converter at temperatures below 190.degree. C. during cooler parts of the operating cycle, and are desorbed in the temperature range of 198.degree. to 200.degree. C. during hotter parts of the operating cycle. The desorbed hydrocarbons are combined with unburned hydrocarbons in the exhaust to form a composition stream having a higher amount of hydrocarbons than either constituent stream which are then oxidized at the same time as at least a portion of the NO.sub.x is catalytically reduced to form N.sub.2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.