The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 15, 2014
Filed:
Dec. 12, 2008
Lothar Mussmann, Offenbach, DE;
Ingo Lappas, Glashuetten, DE;
Andreas Geisselmann, Offenbach, DE;
Wilfried Mueller, Karben, DE;
Lothar Mussmann, Offenbach, DE;
Ingo Lappas, Glashuetten, DE;
Andreas Geisselmann, Offenbach, DE;
Wilfried Mueller, Karben, DE;
UMICORE AG & Co. KG, Hanau-Wolfgang, DE;
Abstract
The adherence to future legally obligatory exhaust gas limit values for diesel vehicles in Europe, North America and Japan requires not only the removal of particles but also effective removal of nitrogen oxides from the exhaust gas ('deNOx'). The 'active SCR process' is the preferred method for this. The nitrogen oxide conversions achieved by means of this process are particularly high when an optimal NO/NOratio, preferably 0.5, is set upstream of the SCR catalyst. The invention proposes a process which solves the problem of supplying NOin accordance with requirements by means of temperature control of the precatalyst which is decoupled from the operating state of the engine. In an associated apparatus, a precatalyst () which contains at least one oxidation component and whose temperature can be controlled independently of the operating state of the engine and an active SCR stage comprising an SCR catalyst () with upstream metering facility () for a reducing agent from an external source () are arranged in series. A particle filter () can be arranged between precatalyst and metering facility. The precatalyst preferably additionally contains a nitrogen oxide storage material.