Patent ID: 6863874

Claim:
A system for treating combustion exhaust gas, which system comprises a catalyst effective to promote oxidation of at least NO to NO 2 ; a filter downstream of the oxidation catalyst, which filter being effective to collect soot and hold it for combustion reaction with the NO 2 in the gas; a NOx absorber downstream of the filter, which NOx absorber is charged with solid adsorbent; means for introducing intermittently a regenerant of the absorber between the filter and the absorber, which means being effective to inject a NOx-specific reactant upstream of the absorber; and a catalyst system effective to promote reactions of hydrocarbons (HC) and CO with O 2 to H 2 O and CO 2 and to convert NOx to N 2 , wherein said catalyst system is at least one of: (1) associated with the absorber; or (2) located downstream of the absorber.