An apparatus includes an exhaust analysis circuit and a sensor diagnostics circuit. The exhaust analysis circuit is structured to interpret first oxygen data acquired by a first sensor indicative of a first amount of oxygen in an exhaust flow at a first location along an exhaust aftertreatment system, and interpret second oxygen data acquired by a second sensor indicative of a second amount of oxygen in the exhaust flow at a second location along the exhaust aftertreatment system. The sensor diagnostic circuit is structured to determine at least one of the first sensor and the second sensor are faulty based on the first amount of oxygen and the second amount of oxygen differing more than a threshold value.

The present invention relates to a catalyst comprising a carrier substrate of the length L, a passive nitrogen oxide adsorber and means to control the temperature of the carrier substrate, as well as a process for cleaning of an exhaust gas emitted from a lean burn engine.

An improved NO.sub.x sensor with an NH.sub.3 oxidation. A sensor module may include a support component, a NO.sub.x sensing material positioned on the support component, and an NH.sub.3 oxidation catalyst. The NH.sub.3 oxidation catalyst may be layered on top of the NO.sub.x sensing material or the NH.sub.3 oxidation catalyst may be positioned upstream of the NO.sub.x sensing material such that the NH.sub.3 oxidation catalyst selectively converts NH.sub.3 to N.sub.2 while permitting NO.sub.x through to the NO.sub.x sensing material.

Disclosed is a method for selective catalytic reduction operating by desorbing ammonia from at least one storage cartridge in an exhaust line at the output of a motor vehicle engine, the cartridge being arranged in at least one bypass branch of a main line of the exhaust line. The exhaust gas flow rate in the bypass branch is controlled according to an estimated or measured temperature in the bypass branch and a desired amount of ammonia to be injected by desorption estimated in the exhaust line to provide a catalytic reduction of the nitrogen oxides present in the exhaust gas, a temperature of the cartridge being estimated according to the gas flow rate at the temperature estimated or measured during a given time interval and corresponding to an amount of desorbed ammonia equal to the desired amount of ammonia.

A method of reducing the emission of nitrogen oxides (NOx) during system startup of a power generating system may include igniting a combustion turbine thereby generating exhaust, supplying the exhaust to a catalyst bed comprising a selective catalytic reduction (SCR) catalyst, injecting an initial pulse of ammonia into the exhaust during a storage period such that the NOx reacts with the ammonia and is stored in the catalyst bed as ammonium nitrate (AN) during the storage period; and injecting a scheduled amount of ammonia into the exhaust during a transition period such that the stored AN is decomposed as temperatures increase and NOx is converted via standard and fast SCR reactions during the transition period.

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.

A catalytic article for treating an exhaust gas stream containing particulate matter, hydrocarbons, CO, and ammonia, the article may include: (a) a substrate having an inlet end and an outlet end defining an axial length; (b) a first catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve; and (c) a second catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve.

An emissions control system for treating exhaust gas containing NO.sub.x emissions from an internal combustion engine comprises a selective catalytic reduction (SCR) device that stores reductant that reacts with the NO.sub.x emissions, a reductant supply system configured to inject the reductant according to a reductant storage model; NO.sub.x module(s) configured to generate an NO.sub.x concentration signal indicating an NO.sub.x concentration, temperature module(s) configured to generate a temperature signal indicating an SCR temperature of the SCR device, and a control module operably connected to the reductant supply system, the NO.sub.x module, and the temperature module. The control module is configured to determine an amount of the reductant that is parasitically oxidized based on the NO.sub.x concentration signal and the temperature signal, and to determine a correction factor based on the amount of parasitically oxidized reductant to modify the reductant storage model.

Provided are a novel synthesis technique for producing pure phase aluminosilicate zeolite and a catalyst comprising the phase pure zeolite in combination with a metal, and methods of using the same.

A vehicle exhaust system includes an injector assembly having a cone positioned adjacent to an injector mount and which extends from an upstream inlet end to a downstream outlet end. Engine exhaust gas and injected spray enter the inlet end of the cone to mix with each other prior to exiting the cone via the outlet end. The cone has a narrowing body portion located downstream of the inlet end to accelerate flow during mixing. A vehicle exhaust component assembly comprising a mixer with the injector assembly and a method for injecting a fluid into an exhaust component using the injector assembly are also disclosed.