Method and arrangement for improving the hydrolysis of a reduction agent in an exhaust gas post treatment system
US8220254B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 16, 2008 |
| Grant date | Jul 17, 2012 |
| Priority date | — |
| Expiry date | Feb 11, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method and arrangement for improving hydrolysis of a reduction agent in an exhaust gas post treatment system for selective catalytic reduction of NOx in the exhaust gas of an internal combustion engine operated with excess air. A partial exhaust gas stream is branched off from an exhaust gas stream upstream of an SCR catalytic converter. A hydrolysis catalytic converter is disposed in the partial exhaust gas stream downstream of a metering arrangement for supplying reduction agent thereto. The partial stream is conveyed back to the main stream downstream of the hydrolysis catalytic converter and upstream of the SCR catalytic converter. The temperature at the hydrolysis catalytic converter is maintained within prescribed limits by actively controlling exhaust gas quantity conveyed in the partial stream by entirely or partially blocking the partial stream, via a flow control device, if temperature values at the hydrolysis catalytic converter and the main or partial stream exceed or do not reach specified or threshold values, and/or if certain operating conditions or condition changes of the engine occur.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.