Patent ID: 6820415
Filing Date: 2004-11-23
Classification: B01D,F01N,F02B,F02D,Y02A,Y02T

Abstract:
A method for operating an internal combustion engine including an exhaust gas purification system, comprising:alternately setting a rich mode of the internal combustion engine with a rich exhaust gas composition and a lean mode of the internal combustion engine with a lean exhaust gas composition; synthesizing and storing ammonia by the exhaust gas purification system with the rich exhaust gas composition; reducing nitrogen oxides to form nitrogen by the stored ammonia by the exhaust gas purification system with the lean exhaust gas composition; introducing a quantity of fuel during a combustion cycle of the internal combustion engine by at least one preinjection, at least one main injection and at least one afterinjection; and burning the at least one preinjection and the at least one main injection under excess oxygen to generate a quantity of nitrogen oxides sufficient for ammonia synthesis; wherein the rich exhaust gas composition and the lean exhaust gas composition are set in the setting step in accordance with the at least one afterinjection.