Exhaust gas processing apparatus and method
AssigneeHyundai Motor Company
InventorSung Mu Choi
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Abstract
An apparatus and a method for processing exhaust gas are provided. The apparatus includes a lean NOx trap (LNT), a selective catalytic reduction (SCR) catalyst, and an oxygen storage catalyst containing an oxygen storage material and a precious metal sequentially disposed along an exhaust gas flow direction. The apparatus also includes a front lambda sensor disposed upstream of the LNT, a rear lambda sensor disposed downstream of the oxygen storage catalyst, and a temperature sensor configured to measure a temperature of exhaust gas.
Claims20
An exhaust gas processing apparatus, comprising:
- a lean NOx trap (LNT);
- a temperature sensor configured to measure a temperature of an exhaust gas;
- a selective catalytic reduction (SCR) catalyst;
- and
- an oxygen storage catalyst containing an oxygen storage material and a precious metal, wherein the LNT, the SCR and the oxygen storage catalyst are sequentially disposed along an exhaust gas flow direction, and wherein a front lambda sensor is disposed upstream of the LNT, a rear lambda sensor is disposed downstream of the oxygen storage catalyst.
A method of controlling an exhaust gas processing apparatus, wherein a lean NOx trap (LNT), a selective catalytic reduction (SCR) catalyst, and an oxygen storage catalyst containing an oxygen storage material and a precious metal are sequentially disposed along an exhaust gas flow direction, and wherein a front lambda sensor is disposed upstream of the LNT, and a rear lambda sensor is disposed downstream of the oxygen storage catalyst, the method comprising:
- measuring a temperature, by a temperature sensor, of exhaust gas disposed within the exhaust path, and
- eliminating NOx, by the SCR catalyst during a rich operation when NH3 generated by the LNT and NOx in the exhaust gas react with each other in the SCR catalyst.
Dependencies are inferred from the claim text.