| 摘要 |
PROBLEM TO BE SOLVED: To simplify an exhaust emission control system while efficiently treating NOx and particulate contained in an exhaust gas of a lean-burn engine.SOLUTION: In the exhaust emission control system, a first catalyst 2 and a second catalyst 5 are arranged upstream of an exhaust gas flow direction in this order in an exhaust gas passage 1 of the engine, where the first catalyst 2 is a composite catalyst of an oxidation catalyst and an LNT catalyst, while the second catalyst 5 is a composite catalyst where a PM combustion catalyst and an SCR catalyst are supported to a PM collection filter.SELECTED DRAWING: Figure 1 |
