Patent ID: 10161281

Abstract:
The present disclosure provides an exhaust purification system including: an engine; a lean NOx trap (LNT) mounted on an exhaust pipe and enable to absorb nitrogen oxide (NOx) contained in an exhaust gas at a lean air/fuel ratio, or to release the absorbed NOx at a rich air/fuel ratio; a selective catalytic reduction (SCR) catalyst provided downstream of the LNT so as to reduce the NOx contained in the exhaust gas; a controller to perform denitrification (DeNOx) by using the LNT and/or the SCR catalyst based on a driving condition of the engine; a first oxygen sensor disposed between the engine and the LNT to detect an oxygen amount in the exhaust gas; a second oxygen sensor disposed between the LNT and the SCR catalyst to detect an oxygen amount in the exhaust gas exhausted from the LNT; and an air injection device selectively injecting air into the exhaust pipe.