Exhaust gas purifying filter, system and regenerating gasoline particulate filter, and method thereof

Abstract

An exhaust gas purifying filter, a system for regenerating a particulate filter, and a method therefore are disclosed. An exhaust gas purifying filter may include: an ammonia storage catalyst unit adapted to absorb ammonia contained in the exhaust gas when a temperature of the ammonia storage catalyst unit is lower than a predetermined temperature, release the absorbed ammonia when the temperature of the ammonia storage catalyst unit is higher than or equal to the predetermined temperature, and generate nitrogen oxide from the released ammonia; and a particulate filter adapted to trap particulate matter contained in the exhaust gas and regenerate the trapped particulate matter by using the nitrogen oxide generated from the ammonia storage catalyst unit.

1 .- 8 . (canceled) 
     
     
         9 . A method for regenerating a particulate filter that comprises an ammonia storage catalyst unit adapted to absorb or release ammonia contained in exhaust gas depending on a temperature of the ammonia storage catalyst unit, and a particulate filter adapted to trap particulate matter contained in the exhaust gas, the method comprising:
 absorbing ammonia contained in the exhaust gas;   comparing a pressure difference of the particulate filter to a predetermined pressure difference;   creating a lean atmosphere when the pressure difference of the particulate filter is larger than or equal to the predetermined pressure difference;   releasing the ammonia from the ammonia storage catalyst unit;   generating nitrogen oxide from the released ammonia; and   regenerating the particulate filter using the generated nitrogen oxide.   
     
     
         10 . The method of  claim 9 , wherein the step of generating the nitrogen oxide is performed by creating a lean atmosphere depending on the temperature of the ammonia storage catalyst unit. 
     
     
         11 . The method of  claim 9 , wherein a ratio of the ammonia in the exhaust gas is raised by creating a rich atmosphere when the ammonia is absorbed.