Method for estimating slippage of a selective catalyst reduction system

In this study, the authors describe NH3 and NOx slippage through a SCR. In one example, signals from NOx sensors positioned upstream and downstream of a SCR are processed and provide indication of NH3 and NOx slippage. Engine emissions may be reduced with information provided via the NOx sensors, at least during some conditions.

Authors: Upadhyay, Devesh; Van Nieuwstadt, Michiel J. ;Full Source: U.S. Pat. Appl. Publ. US 2011 185,707 (Cl. 60-274; F01N3/18), 4 Aug 2011, Appl. 2011/71,321, 24 Mar 2011; 16pp. (USA). ;