Patent ID: 6993900
Filing Date: 2006-02-07
Classification: B01D,F01N,Y02T

Abstract:
1. A method for controlling injection of a reductant into a substance to be reduced by such reductant, such reduction being facilitated by a catalyst, such method comprising: estimating an amount of reductant stored in the catalyst based on an amount of an unreduced substance downstream of the catalyst; estimating an amount of reductant in said engine exhaust gas mixture downstream of the device based on said estimated amount of reductant stored in the device; and adjusting an amount of reductant injected into the substance based on said estimate and a desired amount of stored reductant and further based on said amount of reductant in said exhaust gas mixture downstream of the device, to control said amount of reductant stored in the catalyst at said desired amount and thereby reduce reductant desorption during high catalyst temperature.