Chemistry of inorganic compounds – Modifying or removing component of normally gaseous mixture – Nitrogen or nitrogenous component
Reexamination Certificate
2005-01-18
2005-01-18
Silverman, Stanley S. (Department: 1754)
Chemistry of inorganic compounds
Modifying or removing component of normally gaseous mixture
Nitrogen or nitrogenous component
C423S213200, C423S213500, C423S213700, C423S237000, C423S239100, C502S074000, C502S077000, C502S079000
Reexamination Certificate
active
06843971
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: 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 9601689 (1996-01-01), None
patent: WO 9939809 (1999-08-01), None
European Search Report for counterpart application No. EP 01 10 8785, dated Jul. 5, 2001.
Demel Yvonne
Kreuzer Thomas
Lox Egbert
Pfeifer Marcus
Schäfer-Sindlinger Adolf
Kalow & Springut LLP
Silverman Stanley S.
Strickland Jonas N.
UMICORE AG & Co. KG
LandOfFree
Process and catalyst for reducing nitrogen oxides does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process and catalyst for reducing nitrogen oxides, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process and catalyst for reducing nitrogen oxides will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3428788