Method for exhaust gas after treatment
AssigneeCaterpillar Inc.
InventorPraveen S. Chavannavar
Life of this patent
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Abstract
A hydrocarbon selective catalytic reduction (HC-SCR) catalyst is regenerated using a nitrogen-based reductant agent. The HC-SCR catalyst is in communication with a power system such as an internal combustion engine and receives exhaust gasses from the internal combustion engine. Sulfur in the exhaust gasses may deactivate the HC-SCR catalyst by sulfur oxides forming thereon. To remove the sulfur oxides, a nitrogen-based reductant agent is introduced to the exhaust gasses. The nitrogen-based reductant agent decomposes to nitrogen oxides and hydrogen. The hydrogen reacts with the sulfur oxides to form hydrogen sulfides thereby removing the sulfur oxides from the HC-SCR catalyst.
Claims7
A method of regenerating a hydrocarbon selective catalytic reduction (HC-SCR) catalyst for a hydrocarbon selective catalytic reduction system comprising:
- providing an HC-SCR catalyst in communication with an internal combustion engine;
- directing exhaust gasses from the internal combustion engine to the HC-SCR catalyst, the exhaust gasses including sulfurs;
- deactivating at least in part the HC-SCR catalyst by depositing the sulfurs thereon to form sulfur oxides;
- introducing a nitrogen-based reductant agent to the exhaust gasses;
- decomposing the nitrogen-based reductant agent to nitrogen oxides and hydrogen;
- and
- removing the sulfur oxides from the HC-SCR catalyst by converting at least a portion of the sulfur oxides and the hydrogen to hydrogen sulfides.
Dependencies are inferred from the claim text.