Method for reducing NOX in combustion flue gas using metal-containing additives
US6206685A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 1999 |
| Grant date | Mar 27, 2001 |
| Priority date | — |
| Expiry date | Aug 31, 2019 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF23J2219/20
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Various methods for decreasing the amount of nitrogen oxides released to the atmosphere as a component of combustion gas mixtures are provided. The methods specifically provide for the removal of nitric oxide and nitrogen dioxide (NO.sub.x) from gas mixtures emitted from stationary combustion systems. In particular, methods for improving efficiency of nitrogen oxide reduction from combustion systems include injecting metal-containing compounds into the main combustion zone and/or the reburning zone of a combustion system. The metal containing compounds react with active combustion species, and these reactions change radical concentrations and significantly improve NO.sub.x conversion to molecular nitrogen. The metal-containing additives can be injected with the main fuel, in the main combustion zone, with secondary or reburning fuel addition, or at several locations in the main combustion zone and reburning zone. Optionally, nitrogenous reducing agents and/or overfire air can be injected downstream to further increase NO.sub.x reduction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.