Patent ID: 8220254
Filing Date: 2012-07-17
Classification: B01D,F01N,F02B,Y02T

Abstract:
1. A method of improving the hydrolysis of a reduction agent in an exhaust gas post treatment system for the selective catalytic reduction of NOx in the exhaust gas of an internal combustion engine ( 1 ) that is operated with excess air, including the steps of: providing an SCR catalytic converter ( upstream of said SCR catalytic converter ( disposing in said partial exhaust gas stream ( disposing a hydrolysis catalytic converter ( conveying said partial exhaust gas stream ( disposing a flow control device ( maintaining the temperature at said hydrolysis catalytic converter ( measured or indirectly determined temperature values at said hydrolysis catalytic converter ( 16 ) and in said exhaust gas stream ( 2 ) and/or in said partial exhaust gas stream exceed or do not reach specified threshold values, and/or if certain operating conditions and/or operating condition changes of the internal combustion engine ( 1 ) occur; increasing the quantity of exhaust gas conveyed via said partial exhaust gas stream ( at a low temperature at said hydrolysis catalytic converter (