A system and method for managing the temperature of a urea solution are thereby provided, in which air bubble formation in the urea solution caused by increases in the urea solution temperature is suppressed while thawing of the urea solution stored in the urea solution tank and used for NOx purification treatment is ensured, the concentration of the urea contained in the urea solution is accurately determined, and NOx is precisely reduced.

In a method for the diagnosis of an exhaust gas aftertreatment system for an internal combustion engine, the exhaust gas aftertreatment system comprises at least one NOx storage catalytic converter (10) and at least one SCR catalytic converter (30) which is arranged downstream of the NOx storage catalytic converter (10). According to the invention, a regeneration of the NOx storage catalytic converter (10) is blocked and/or interrupted in order to improve the frequency and/or quality of the diagnosis of the SCR catalytic converter (30).

In the case of a method for operating an exhaust gas aftertreatment system of a motor vehicle, the exhaust gas aftertreatment system comprises at least one NOx storage catalyst (10) and at least one SCR catalyst (30). According to the invention, when an inadequate function of the NOx storage catalyst (10) or of the SCR catalyst (30) is identified, at least one auxiliary measure is initiated which leads to a reduction of the NOx emissions of the motor vehicle.

A boiler or other fired vessel includes a housing with a burner at one end, a furnace downstream of the burner, a convection section downstream of the furnace and a flue gas outlet downstream of the convection section. A first means for loading a reducing agent comprising at least two injectors is located downstream of the furnace. A second means for loading a reducing agent is located downstream of the first means for loading a reducing agent. A selective catalytic reduction catalyst is located either downstream of the second means for loading a reducing agent or adjacent the second means for loading a reducing agent such that the catalyst is provided to the boiler or other fired vessel approximately simultaneously with the reducing agent from the second means for loading the reducing agent.

An exhaust after-treatment system for treating an exhaust produced by an engine. The exhaust after-treatment system includes an exhaust passage, at least one catalytic exhaust after-treatment component in communication with the exhaust passage for treating the exhaust, and a water-removal device in communication with the exhaust passage that receives a portion of the exhaust therein at a location positioned upstream from the catalytic exhaust after-treatment component. The water-removal device is defined by a housing that includes a water-removal membrane that separates water from the portion of the exhaust to provide a permeate that is enriched with water, and to produce a retentate that is water depleted that facilitates the treating of the exhaust by the catalytic exhaust after-treatment component.

Methods and systems are provided for detecting NOx sensor degradation based on results from a NOx sensor self-diagnostic (SD) test performed after a key-off event. In one example, a method may comprise waiting a duration to perform a SD test of a NOx sensor after a key-off event until engine operating conditions stabilize and reach a set of qualifying conditions. One or more SD tests may be performed after waiting the duration, but outputs generated under conditions where one or more of a temperature at the sensor is greater than a threshold, and an oxygen concentration is outside a threshold range, may be excluded when determining whether or not the NOx sensor is degraded.

According to various embodiments, an exhaust treatment system includes a catalyst that is in direct contact with an exhaust stream, at least one sensor that senses a system parameter and produces one or more signals corresponding to the system parameter, and a controller that is configured to receive the one or more signals and control catalyst performance based on the one or more signals by regenerating the catalyst. Regenerating the catalyst includes increasing a temperature of the exhaust stream flowing to the catalyst and directing a reductant injector to adjust a flow rate of reductant being injected into the exhaust stream flowing to the catalyst.

A catalyst includes LTA zeolite including copper ions, wherein a Si/Al ratio of the LTA zeolite is 2 to 50. The catalyst is coated on a honeycomb carrier or a filter. The catalyst removes NOx from a reaction gas at 100° C. or above. The catalyst has an NOx conversion rate of 80% at 450° C. or above.

A high-end processing device for purification of exhaust of a diesel engine includes a connection channel, a plurality of catalytic converters, a plurality of direct-passage ceramic filters, and at least one wall-flow filter. The catalytic converters are arranged, in a manner of being spaced from each other, at a front portion of an exhaust gas flow path defined by the connection channel. The direct-passage ceramic filters and the wall-flow filter are arranged, in a manner of being spaced from each other, at a rear portion of the exhaust gas flow path of the connection channel. The direct-passage ceramic filters and the wall-flow filter are impregnated with urea or ammonia and dried so as to reduce nitrogen oxides (NOx) into nitrogen and water to reduce impact to the environment.

Disclosed are a NOx reducing catalyst including a carrier including a cerium-zirconium composite oxide, and the palladium supported on the carrier. The catalyst includes palladium in an amount of about 1 wt% to about 5 wt% based on the total weight of the catalyst.