| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress the flow-in of SOx into an NOx storage catalyst at the time of SOx emission. <P>SOLUTION: The upstream of the NOx storage catalyst 13 is branched into a plurality of exhaust branch passages 11a, 11b and 11c, and SOx trap catalysts 12b, 12c capable of capturing SOx inside exhaust gas are disposed in a part of the exhaust branch passages 11b, 11c. Normally, the exhaust gas is circulated only through the exhaust branch passages 11b, 11c disposed with the SOx trap catalysts 12b, 12c. When the SOx should be discharged from the NOx storage catalyst 13, a reducer is supplied from a reducer supply valve 22, and the exhaust gas is circulated only through the exhaust branch passage 11a not disposed with the SOx trap catalyst. <P>COPYRIGHT: (C)2008,JPO&INPIT |
