Method for reducing the emission of NO.sub.x in a combustion process

US5407649A · kind A · utility

Assignee

• ABB Carbon AB · SE

Inventors

• Mats Andersson · Mullsjö, SE
• Hans-Jorgen Damsgaard · Västerås, SE
• Ingemar Greis
• Lotta Lindgren · Västerås, SE
• Olle Nystrom · Finspång, SE
• Sven-Erik Ohlsson · Kil, SE
• Henrik Wallman · Göteborg, SE

Key dates

• Filing date: Jul 15, 1992
• Grant date: Apr 18, 1995
• Expiry date: Jul 15, 2012

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01D53/56
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

The invention provides a method for reducing the emission of NO.sub.x in a pressurized fluidized bed combustion process comprising (a) combusting reaction products in the presence of a sulfur absorbent in a pressurized fluidized bed at a pressure of at least 5 bar to form a flue gas comprising dust particles and an initial concentration of NO.sub.x, (b) reacting the NO.sub.x in the flue gas with a substance which reduces NO.sub.x in a first reaction zone to form a flue gas which has a lower NO.sub.x concentration as compared to its initial NO.sub.x concentration, wherein the absolute pressure of the flue gas is at least 5 bar and the temperature of the flue gas is at least 450.degree. C. in the first reaction zone, and (c) reducing the NO.sub.x concentration in the flue gas provided by step (b) in a second reaction zone by contacting the gas with a solid surface comprised of flue gas dust particles.