Patent ID: 8713919

Claim:
An exhaust gas after treatment system for an internal combustion engine comprising: an exhaust gas conduit configured to transport exhaust gas from the internal combustion engine to exhaust treatment devices of the exhaust gas treatment system; an oxidation catalyst device configured to oxidize unburned gaseous and non-volatile HC and CO in the exhaust gas; a selective catalytic reduction device disposed downstream of the oxidation catalyst device configured to convert NOx constituents in the exhaust gas, in the presence of a reductant, within an active temperature range; a NOx adsorber assembly disposed upstream of the selective catalytic reduction device, between the selective catalytic reduction device and the oxidation catalyst device, comprising: a cylindrical substrate defining flow passages having an adsorbent compound applied thereto to entrain NOx constituents from the exhaust gas, the cylindrical substrate having a tubular shape defining an exhaust bypass extending therethrough; and a valve assembly disposed in fluid communication with the exhaust bypass and operable to move from an open position in which exhaust gas flows through the exhaust bypass and to the selective catalytic reduction device to a closed position in which exhaust gas is prevented from flowing through the bypass and is forced to flow through the exhaust passages and to the selective catalytic reduction device; and a controller in signal communication with the exhaust gas aftertreatment system and configured to monitor the temperature of the selective catalytic reduction device, wherein the controller is operable to move the valve assembly to the open position when the selective catalytic reduction device is at or above an operating temperature and to move the valve assembly to a closed position when the selective catalytic reduction device is below the operating temperature for entrainment of NOx constituents from the exhaust gas.