Exhaust gas purifier

Abstract

The present invention provides an exhaust gas purifier capable of appropriately purifying harmful components discharged even from an internal combustion engine or a combustion instrument operated mainly in excess-air conditions. Particularly, the exhaust gas purifier is capable of appropriately removing nitrogen oxides, particulate matters including soot, etc. and in addition, capable of maintaining its purification capability without reduction. the exhaust gas purifier has, in the exhaust passage () of an internal combustion engine (), a nitrogen oxide adsorbent () for temporarily adsorbing nitrogen oxides and desorbing the adsorbed nitrogen oxides in a temperature-increased environment or a reducing environment, an adsorbed substance desorbing means () being disposed on an exhaust gas upstream side of the nitrogen oxide adsorbent (), the adsorbed substance desorbing means () heating the exhaust gas or air or converting the exhaust gas or air into a reducing atmosphere, a combustion apparatus () being disposed on an exhaust gas downstream side of the nitrogen oxide adsorbent (), the combustion apparatus () including air supply means (), fuel supply means (), and ignition means (); and a filter apparatus () being disposed on an exhaust gas downstream side of the combustion apparatus () to be able to capture a particulate substance contained in the exhaust gas.