Process for reducing nitrogen oxides

Details Process for reducing nitrogen oxides Process for reducing nitrogen oxides

2006-02-28

2006-02-28

Johnson, Edward M. (Department: 1754)

Chemistry of inorganic compounds

Modifying or removing component of normally gaseous mixture

Nitrogen or nitrogenous component

C423S239100

Reexamination Certificate

active

07005116

ABSTRACT:
A process for reducing the nitrogen oxides present in a lean exhaust gas from an internal combustion engine by selective catalytic reduction on a reduction catalyst using ammonia, wherein a fraction of the nitrogen monoxide present in the exhaust gas is oxidized to nitrogen dioxide before the exhaust gas, together with ammonia, is passed over the reduction catalyst. The reduction catalyst contains a zeolite exchanged with transition metals and oxidation of the nitrogen monoxide is performed in such a way that the exhaust gas contains 30 to 70 vol. % of nitrogen dioxide before contact with the reduction catalyst.

REFERENCES:
patent: 4778665 (1988-10-01), Krishnamurthy et al.
patent: 4961917 (1990-10-01), Byrne
patent: 5116586 (1992-05-01), Baacke et al.
patent: 5451387 (1995-09-01), Farnos et al.
patent: 5482692 (1996-01-01), Audeh et al.
patent: 5711147 (1998-01-01), Vogtlin et al.
patent: 6843971 (2005-01-01), Schafer-Sindlinger et al.
patent: 0 283 913 (1988-09-01), None
patent: 198 20 682 (1998-11-01), None
patent: 0 955 080 (1999-11-01), None
patent: WO 90/13362 (1990-11-01), None
patent: WO 96/01689 (1996-01-01), None
patent: WO 99/39809 (1999-08-01), None
H. Mishima et al: “Selective catalytic reduction on NO with NH3 over natural zeolites and its application to stationary diesel engine exhaust”; Appl. Cat. B. Environmental 19 (1998) pp. 119-125, no month.
S. Kasaoka et al: “Effect of Inlet NO/NO2 Molar Ratio and Contribution of Oxygen in the Catalytic Reduction of Nitrogen Oxides with Ammonia”; Nippon Kagaku Kaishi, (1978) No. 6, pp. 874-881, no month.
J.G.M. Brandin et al: “Catalytic Reduction of Nitrogen Oxides on Moredenite—Some Aspect on the Mechanism”; Catalysis Today, (1989) No. 4; pp. 187-203, no month.
A. Kato et al: “Reaction between Nox and NH3 on Iron Oxide-Titanium Oxide Catalyst”, J. Phys. Chem. (1981) No. 85, pp. 4099-4102, no month.
T. Seiyama et al: “Catalystic Activity of Transition Metal Ion exchanged Y Zeolites in the Reduction of Nitric Oxide with Ammonia”; Journal of Catalysis, (1977) No. 48, pp. 1-7, no month.
G. Centi et al: “Role of the Nature of Copper Sites in the Activity of Copper-based Catalysts for NO Conversion”, Res. Chem. Intermed. No. 17 (1992), pp. 125-135, no month.
J. Gieshoff et al., SAE 2000-01-0189: Improved SCR Systems for Heavy Duty Applications, presented at SAE 2000 World Congress, Detroit, Michigan Mar. 6-9, 2000.
*European Search Report for counterpart application No. EP 01 10 8785, dated Jul. 5, 2001.

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