Patent ID: 6327851
Filing Date: 2001-12-11
Classification: B01D,F01N,Y02A,Y02T

Abstract:
A process for controlled injection of hydrocarbons into an exhaust line of a lean-burn internal-combustion engine, comprising catalytic elimination of nitrogen oxides from exhaust gases, characterized in that the process comprises monitoring the temperature of the exhaust gases, injecting a certain amount of hydrocarbons upstream from the catalytic elimination, periodically and for a short time interval, by means of pulsed hydrocarbon injections, according to the temperature of the exhaust gases when the temperature of the exhaust gases is at least 200.degree. C., and carrying out catalytic conversion of the nitrogen oxides with a catalyst having a Platinum/Alumina type formulation, and characterized in that the pulsed hydrocarbon injections are combined with a continuous hydrocarbon injection.