| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device capable of satisfactorily performing oxidation treatment of an unburned component of gas fuel such as natural gas from exhaust temperature lower than conventional one. <P>SOLUTION: In regard to the exhaust emission control device for a CNG engine 1 (gas engine) using natural gas (gas fuel mainly comprising methane), a plasma generator 9 for generating plasma by discharging in exhaust gas 8 is provided in an outlet part of an exhaust manifold 7 (upstream side of an exhaust flow passage). A pre-oxidation catalyst 15 is provided in the downstream side of the plasma generator 9, and a main oxidation catalyst 16 is provided in the downstream side of the pre-oxidation catalyst 15. Due to discharging of plasma generator 9, methane constituting the unburned component of the natural gas becomes methyl free radial (-CH<SB>3</SB>), which causes oxidation reaction to easily occur, and oxidation treatment of this substance is effectively performed by using the pre-oxidation catalyst 15 and the main oxidation catalyst 16. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
