Abstract: An exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway configured to receive exhaust gas from the internal combustion engine, a first treatment element positioned within the exhaust gas pathway, a first injector configured to introduce a first reductant into the exhaust gas pathway upstream of the first treatment element, a second injector configured to introduce a second reductant into the exhaust gas pathway downstream of the first treatment element, a second treatment element positioned within the exhaust gas pathway downstream of the second injector, the second treatment element including a SCR element, and a controller configured to periodically initiate a desulfuring regeneration cycle by increasing a concentration of hydrocarbons in the exhaust gas and increasing the flow of the first reductant through the first injector to oxidize sulfur contamination in the first treatment element at temperatures between 400 and 500 degrees Celsius.

Abstract: An exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway configured to receive exhaust gas from the internal combustion engine, a first treatment element positioned within the exhaust gas pathway, a first injector configured to introduce a first reductant into the exhaust gas pathway upstream of the first treatment element, a second injector configured to introduce a second reductant into the exhaust gas pathway downstream of the first treatment element, a second treatment element positioned within the exhaust gas pathway downstream of the second injector, the second treatment element including a SCR element, and a controller configured to periodically initiate a desulfuring regeneration cycle by increasing a concentration of hydrocarbons in the exhaust gas and increasing the flow of the first reductant through the first injector to oxidize sulfur contamination in the first treatment element at temperatures between 400 and 500 degrees Celsius.

Abstract: An exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway configured to receive exhaust gas from the internal combustion engine, a first injector configured to selectively introduce a first reductant into the exhaust gas pathway in response to a sensed temperature of the exhaust gas being within a predetermined temperature range, and a first treatment element positioned within the exhaust gas pathway downstream of the first injector. The first treatment element includes a selective catalytic reduction (SCR) layer, a porous filter substrate, and a precious metal catalyst layer. The system also includes a second injector configured to introduce a second reductant into the exhaust gas pathway downstream of the first treatment element and a second treatment element positioned within the exhaust gas pathway downstream of the second injector. The second treatment element includes a SCR element.

Abstract: An exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway configured to receive exhaust gas from the internal combustion engine, a first injector configured to selectively introduce a first reductant into the exhaust gas pathway in response to a sensed temperature of the exhaust gas being within a predetermined temperature range, and a first treatment element positioned within the exhaust gas pathway downstream of the first injector. The first treatment element includes a selective catalytic reduction (SCR) layer, a porous filter substrate, and a precious metal catalyst layer. The system also includes a second injector configured to introduce a second reductant into the exhaust gas pathway downstream of the first treatment element and a second treatment element positioned within the exhaust gas pathway downstream of the second injector. The second treatment element includes a SCR element.

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.

Abstract: An exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway configured to receive exhaust gas from the internal combustion engine, a temperature sensor configured to sense a temperature of the exhaust gas, a first injector configured to inject a first reductant into the exhaust gas pathway at a first location when the sensed temperature is below a threshold temperature, and a first treatment element positioned downstream of the first location. A second injector is configured to inject a second reductant of a different composition than the first reductant into the exhaust gas pathway at a second location downstream of the first treatment element when the sensed temperature is above the threshold temperature. The system further includes a second treatment element positioned downstream of the second location.

Abstract: An exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway configured to receive exhaust gas from the internal combustion engine, a temperature sensor configured to sense a temperature of the exhaust gas, a first injector configured to inject a first reductant into the exhaust gas pathway at a first location when the sensed temperature is below a threshold temperature, and a first treatment element positioned downstream of the first location. A second injector is configured to inject a second reductant of a different composition than the first reductant into the exhaust gas pathway at a second location downstream of the first treatment element when the sensed temperature is above the threshold temperature. The system further includes a second treatment element positioned downstream of the second location.

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.