Use of aqueous guanidinium formate solutions for the selective catalytic reduction of nitrogen oxides in exhaust gases of vehicles

US8652426B2 · kind B2 · utility

Assignee

• Alzchem Trostberg GmbH · DE

Inventors

• Benedikt Hammer · Trostberg, DE
• Hans-Peter Krimmer · Burgkirchen an der Alz, DE
• Bernd Schulz · Radebeul, DE
• Eberhard Jacob · Krailling, DE

Key dates

• Filing date: Dec 20, 2007
• Grant date: Feb 18, 2014
• Expiry date: Dec 20, 2027

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/12
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

The invention relates to the use of aqueous guanidinium formiate solutions, optionally combined with urea and/or ammonia and/or ammonium salts, for the selective catalytic reduction of nitrogen oxides using ammonia in exhaust gases of vehicles. The inventive guanidinium formiate solutions enable a reduction of the nitrogen oxides by approximately 90%. Furthermore, said guanidinium formiate solutions can enable an increase in the ammonia forming potential from 0.2 kg, corresponding to prior art, up to 0.4 kg ammonia per liter of guanidinium formiate, along with freezing resistance (freezing point below −25° C.). The risk of corrosion of the inventive guanidinium formiate solutions is also significantly reduced compared to that of solutions containing ammonium formiate.