EXHAUST GAS PURIFICATION SYSTEM AND METHOD FOR PURIFYING EXHAUST GAS

文件类型：PDF文档
文件大小：137K
PROBLEM TO BE SOLVED : To provide an exhaust gas purification system and an exhaust gas purification method which, by properly disposing exhaust gas purification units, can improve the percentage of NOx removal in wide ranges from low to high temperatures and to high flow rate areas, can keep the temperature of a DPF device high to increase the period and frequency of continuous regeneration, and thereby can reduce the frequency of forced regeneration of a DPF device and the discharge amount of CO2 generated during the forced regeneration. SOLUTION : A preceding oxidation catalyst device 21, a DPF device 22, a turbine 14 of a turbocharger, a preceding selective reduction NOx catalyst device 23, and a subsequent selective reduction NOx catalyst device 24 are disposed in an exhaust system of an internal combustion engine 10 in this order from an exhaust port side, and an ammonia-based solution feeder 25 is disposed on the inlet side or outlet side of the DPF device 22. The NOx selective reduction catalyst of the preceding selective reduction NOx catalyst device 23 is constituted of a catalyst comprising a rare-earth composite oxide, and the NOx selective reduction catalyst of the subsequent selective reduction NOx catalyst device 24 is constituted of a zeolite catalyst. COPYRIGHT : (C)2014, JPO&INPIT