Selective catalytic reduction of NOx enabled by urea decomposition in heat-exchanger bypass
US7615200B2 · kind B2 · utility
13Cited by
2References
20Claims
0Family size
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Key dates
| Filing date | Apr 3, 2007 |
| Grant date | Nov 10, 2009 |
| Priority date | — |
| Expiry date | Aug 30, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S423/05
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Disclosed are a process and apparatus for selective catalytic reduction of NOx. The process is enabled by passing a heat exchanger section, such as an economizer, of the boiler in advance of an SCR unit at low load conditions to enable NOx reduction even at low loads using urea instead of ammonia. In a preferred form, under high load conditions, the bypass can be almost fully closed and the economizer can be operated normally without excessively cooling the combustion gases, using only a portion of bypassed gases which are hot enough to decompose the urea into its active components including ammonia.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.