| 摘要 |
Exhaust gas purification method and system of an internal combustion engine. The internal combustion engine comprises a generator driven by said internal combustion engine, a battery charged with an electricity generation output from the generator, and a NOx adsorption catalyst placed in an exhaust gas passage. The catalyst chemisorbs NOx in a state where the amount of an oxidizer is larger than that of a reducer in the stoichiometry relation of oxidoreduction between components contained in exhaust gas exhausted from said internal combustion engine and catalytically reduces the adsorbed or absorbed NOx in a state where the amount of the reducer is at least equivalent to that of the oxidizer. When the time-elapsing deterioration of the NOx adsorption catalyst reaches to a predetermined degree, the combustion condition of said internal combustion engine is controlled at the stoichiometric air-fuel ratio or an excess fuel air-fuel ratio in a predetermined time period to reactivate the NOx adsorption catalyst from the time-elapsing deterioration, and the increased proportion of the internal combustion engine output generated during the above time period is absorbed with said generator. |
