Patent ID: 8635862

Claim:
An exhaust gas treatment system for an internal combustion engine, the internal combustion engine having at least one operating parameter, 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 ”) and hydrocarbons, the exhaust gas having an exhaust gas temperature; an oxidation catalyst (“OC”) device in fluid communication with the exhaust gas conduit, the OC device activated to induce oxidation of hydrocarbons in the exhaust gas, the OC device having an oxidation catalyst compound disposed thereon that is selectively activated at a specified temperature range for converting nitrogen oxide (“NO”) to nitrogen dioxide (“NO 2 ”) at a specified percentage; 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 OC device, wherein the SCR device is selectively heated to a SCR light-off temperature, and wherein the overall temperature of the SCR device is represented by a SCR temperature profile; and a control module in communication with the internal combustion engine and the exhaust gas treatment system, comprising: a control logic for monitoring the SCR temperature profile; a control logic for determining if the SCR device is above the SCR light-off temperature based on the SCR temperature profile; a control logic for monitoring an OC device temperature of the OC device; a control logic for determining if the OC device is operating at the specified temperature range based on the OC device temperature; and a control logic for adjusting at least one operating parameter of the internal combustion engine for controlling the exhaust gas temperature such that the OC device is not operating within the specified temperature range, wherein the at least one parameter of the internal combustion engine is adjusted if the SCR device is above the light-off temperature and if the OC device is operating at the specified temperature range.