Method for reducing emissions of NO.sub.x and particulates from a diesel engine
US6051040A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 26, 1997 |
| Grant date | Apr 18, 2000 |
| Priority date | — |
| Expiry date | Nov 26, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method improves the operation of a diesel engine through the use of a fuel additive, a diesel particulate trap and a NO.sub.x -reducing catalyst. The operation of the NO.sub.x -reducing catalyst is enhanced by the introduction of urea or like compound upstream of the catalyst at temperatures effective for non-catalytic NO.sub.x reduction and the generation of ammonia. The additive comprises fuel-soluble compositions of platinum group metal in effective amounts to lower the emissions of unburned hydrocarbons and carbon monoxide from the trap. The catalytic activity provided to the exhaust system by the fuel additive is selective and preferably reduces the oxidation of SO.sub.2 to SO.sub.3. The platinum group metal compositions are preferably added in amounts effective to provide concentrations of the metal in the fuel of less than 1 part per million (ppm). Lithium and/or sodium compositions can be used in amounts effective to reduce the trap regeneration temperature, e.g. concentrations to provide about 1 to 100 ppm lithium metal, and/or 1 to 30 ppm sodium metal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.