Vehicle sulfur oxide trap and related method
US7021049B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 2002 |
| Grant date | Apr 4, 2006 |
| Priority date | — |
| Expiry date | Mar 31, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S502/517
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An automobile exhaust system includes a catalytic converter, a NOx trap, and a sulfur oxide trap. The sulfur oxide trap improves the efficiency of the NOx trap. Sulfur oxide has a deleterious effect on the performance of nitrogen oxide traps. The sulfur oxide trap comprises a monolithic substrate which is over-coated with an aluminum oxide layer and a mixed oxide layer of calcium oxide and magnesium oxide. In a variation, a sulfur oxide trap is integrated with a nitrogen oxide trap by coating the catalyst contained within a nitrogen oxide trap with a mixed oxide layer of calcium oxide and magnesium oxide. In each embodiment, the sulfur oxide trap can be regenerated by heating at elevated temperature for a short time period.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.