Patent ID: 6055807
Filing Date: 2000-05-02
Classification: B01D,F01N,Y02A

Abstract:
A method of reducing harmful emissions in the exhaust gases of an internal combustion engine of the type operated by a lean fuel air mixture, wherein the exhaust gases of the internal combustion engine are subjected to a catalytic treatment for oxidizing carbon monoxide and hydrocarbons and wherein the exhaust gases are throttled in order to increase their temperature under operative conditions of heat deficiency, the improvement of which comprises subjecting the exhaust gases to an additional catalytic treatment in a deoxidation means for deoxidizing nitrogen oxides, said deoxidation means being operative only within a predetermined temperature range, with the amount of throttling of the exhaust gases being continuously varied such that the temperature of the exhaust gases at least in said deoxidation means will be within said predetermined temperature range.