Patent ID: 8505282

Claim:
An exhaust gas treatment system for an internal combustion engine, comprising: an exhaust gas conduit in fluid communication with, and configured to receive an exhaust gas from the internal combustion engine, the exhaust gas containing oxides of nitrogen (“NO x ”), carbon monoxide and hydrocarbons; an oxidation catalyst (“OC”) device in fluid communication with the exhaust gas conduit, the OC device having a front face, the OC device adsorbing hydrocarbons and selectively activated to induce oxidation of the hydrocarbons in the exhaust gas; an electrically heated catalyst (“EHC”) device in fluid communication with the exhaust gas conduit and configured to receive the exhaust gas, wherein the EHC device is located within the OC device and is selectively activated to produce heat and induce further oxidation of the exhaust gas, the EHC device having an oxidation catalyst compound disposed thereon for converting nitrogen oxide (“NO”) to nitrogen dioxide (“NO 2 ”), the EHC device being positioned downstream of the front face of the OC device such that hydrocarbons in the exhaust gas do not substantially interfere with the generation of NO 2 by the EHC device; a selective catalytic reduction (“SCR”) device in fluid communication with the exhaust gas conduit and configured to receive the exhaust gas, the SCR device located downstream of the EHC device and the OC device, and wherein the SCR device is in communication with and receives and stores reductant from a reductant source; a control module in communication with the EHC device and the internal combustion engine, comprising: a control logic for determining if the SCR device has a threshold value of reductant stored therein, wherein the threshold value of reductant is the amount of reductant needed to create a chemical reaction to convert the reductant and the oxides of nitrogen NO x in the exhaust gas into intermediates; and a control logic for activating the reductant source if the SCR device has not stored the threshold value of reductant.