Exhaust gas treatment system and method having improved low temperature performance
AssigneeDeere & Company
InventorsDanan Dou, Shyan-Cherng Huang, Ayyappan Ponnaiyan
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Abstract
A method of treating exhaust gas from an internal combustion engine includes sensing a temperature of the exhaust gas with a temperature sensor, comparing the sensed temperature with a threshold temperature, injecting a first reductant into the exhaust gas at a first location if the sensed temperature is less than the threshold temperature, and injecting a second reductant having a different composition than the first reductant into the exhaust gas at a second location if the sensed temperature is greater than the threshold temperature.
Claims19
A method of treating exhaust gas from an internal combustion engine, the method comprising:
- sensing a temperature of the exhaust gas with a temperature sensor;
- comparing the sensed temperature with a threshold temperature;
- injecting a first reductant into the exhaust gas at a first location if the sensed temperature is less than the threshold temperature;
- injecting a second reductant having a different composition than the first reductant into the exhaust gas at a second location if the sensed temperature is greater than the threshold temperature;
- and
- converting a quantity of the second reductant into the first reductant when the sensed temperature is greater than the threshold temperature.
A method of treating exhaust gas from an internal combustion engine, the method comprising:
- injecting an ammonium carbamate solution into the exhaust gas at a first location upstream of a first treatment element during a cold temperature operating state;
- injecting diesel exhaust fluid (DEF) into the exhaust gas at a second location between the first treatment element and a second treatment element located downstream of the first treatment element during a warm temperature operating state;
- converting DEF into additional ammonium carbamate solution in a reaction chamber during the warm temperature operating state;
- and
- storing the converted ammonium carbamate solution for use during the cold temperature operating state.
A method of treating exhaust gas from an internal combustion engine, the method comprising:
- storing diesel exhaust fluid (DEF) in a reservoir;
- transferring a quantity of the stored DEF to a reaction chamber;
- heating the reaction chamber to an elevated temperature to convert at least a portion of the DEF to ammonium carbamate;
- storing the ammonium carbamate in the reaction chamber;
- and
- actuating a valve to select one of the stored ammonium carbamate and the stored DEF for injection into the exhaust gas.
Dependencies are inferred from the claim text.