Method of treating nitrogen oxide-containing gas
US7972581B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 2007 |
| Grant date | Jul 5, 2011 |
| Priority date | — |
| Expiry date | Apr 13, 2027 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF23N2241/04
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
First, the emission amount of nitrogen oxides can be decreased close to zero as much as possible, and the emission amount of carbon monoxide is decreased to a permissible range. Second, energy saving by combustion at a low air ratio close to 1.0 is realized. Third, air ratio control is performed stably in a combustion region at a low air ratio.The present invention includes: a combustion step of burning hydrocarbon-containing fuel in the burner, thereby generating gas free of hydrocarbons but containing oxygen, nitrogen oxides, and carbon monoxide; a hazardous-substance decreasing step of bringing the gas into contact with an oxidation catalyst, thereby oxidizing carbon monoxide contained in the gas by oxygen and reducing nitrogen oxides by carbon monoxide; and a concentration ratio adjusting step of adjusting a concentration ratio of oxygen, nitrogen oxides, and carbon monoxide in gas on a primary side of the oxidation catalyst to a predetermined concentration ratio in which a concentration of nitrogen oxides on a secondary side of the oxidation catalyst is decreased to substantially zero or a value equal to or lower than a predetermined value and a concentration of carbon monoxid…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.