Apparatus and method for clarifying exhaust gas of diesel engine

摘要

An apparatus for purifying an exhaust gas of a diesel engine, characterized in that it has an NOx adsorption and reduction type catalyst and a diesel particulate filter for oxidizing and removing particulate matters in the exhaust gas, which are provided in the flow route for the exhaust gas and are arranged in the above described order from the upstream of the flow of the exhaust gas. The above arrangement allows the elevation of the temperature of the catalyst with ease and the precise control of the temperature and atmosphere therein, resulting in the achievement of satisfactory NOx purification performance, and the employment of the NOx adsorption and reduction type catalyst allows the enhancement of the rate of reduction of the NO₂ captured, which shortens the time to keep a stoichiometric-rich atmosphere to a time of several seconds to several minutes.