A method for desulphurising a nitrogen oxide accumulator catalytic converter of an exhaust gas system that includes the nitrogen oxide accumulator catalytic converter and at least one selective catalytic reduction catalytic converter disposed downstream of the nitrogen oxide accumulator catalytic converter, of an internal combustion engine, where a desulphurisation strategy, on the basis of which the nitrogen oxide accumulator catalytic converter is desulphurised, is adjusted to the ageing of the nitrogen oxide accumulator catalytic converter.

The present invention is applied to an exhaust system provided with a three-way catalyst and a NOx catalyst which are provided in an exhaust passage of an engine and to which sulfur components in exhaust adhere and release the attached sulfur components by rich components in exhaust, and NOx sensors provided downstream of the catalysts. The NOx sensor is a limiting current type sensor. It is determined whether a sulfur release state is present in which a sulfur component is released from the three-way catalyst and the NOx catalyst. When it is determined that it is in the state of sulfur release, reaction suppression processing for suppressing the reaction between oxygen and sulfur components in the pump cell electrodes and the monitor cell electrodes of the NOx sensors is performed.

Systems, apparatuses, and methods include predicting a sulfur exposure of one or more copper-zeolite catalysts deployed in an exhaust aftertreatment system; comparing the predicted sulfur exposure to a predefined sulfur exposure threshold; and responsive to the determination, heating the exhaust aftertreatment catalyst to a predefined heat treatment temperature for a predefined time period to desulfate the one or more copper-zeolite catalysts.

A method for desulphurising a nitrogen oxide accumulator catalytic converter of an exhaust gas system that includes the nitrogen oxide accumulator catalytic converter and at least one selective catalytic reduction catalytic converter disposed downstream of the nitrogen oxide accumulator catalytic converter, of an internal combustion engine, where a desulphurisation strategy, on the basis of which the nitrogen oxide accumulator catalytic converter is desulphurised, is adjusted to the ageing of the nitrogen oxide accumulator catalytic converter.

A compression ignition internal combustion engine system includes an engine and an exhaust system with an upstream exhaust conduit, and an oxidation catalyst device (DOC). Systems and methods of desulfating the oxidation catalyst by the injection of a lightoff fluid to promote ignition of uncombusted fuel in the exhaust stream are disclosed.

An exhaust emission control device for an engine is provided with a first purifying catalyst including an HC adsorbent that adsorbs HC at a low temperature and releases HC at a high temperature and a diesel oxidation catalyst capable of oxidizing HC, a second purifying catalyst including a NOx catalyst capable of storing NOx contained in exhaust, a NOx catalyst regenerator that regenerates the NOx catalyst while raising the temperature of the NOx catalyst, and HC controller that decides whether the amount of adsorbed HC that is HC adsorbed by the HC adsorbent is equal to or more than a preset reference amount and, when the amount of adsorbed HC is decided to be equal to or more than the reference amount, raises the temperature of the first purifying catalyst.

A NOx sensor control device is connected to a NOx sensor mounted in an internal combustion engine. The NOx sensor has a detection cell configured to detect a NOx concentration and having a solid electrolyte body and a pair of electrodes provided on a surface of the solid electrolyte body and a heater heating the detection cell. The NOx sensor control device has a heater control unit. The heater control unit is configured to, at a time when an operation of the internal combustion engine stops, perform a recovery control of the NOx sensor which is an electric current control of the heater for removing SOx adsorbed to the NOx sensor.

The present invention is directed to a method of preparing a synthetic crystalline material, designated as JMZ-12, with a framework built up by the disorder AEI and CHA structures, substantially free of framework phosphorous and prepared preferably in the absence of halides such as fluoride ions. Such method comprises the step of heating a reaction mixture under crystallization conditions for a sufficient period to form a disordered zeolite having both CHA and AEI topologies, wherein the reaction mixture comprises at least one source of aluminum, at least one source of silicon, a source of alkaline or alkaline-earth cations, and a structure directing agent containing at least one source of quaternary ammonium cations and at least one source of alkyl-substituted piperidinium cations in a molar ratio of 0.20 to about 1.4. The resulting zeolites are useful as catalysts, particularly when used in combination with exchanged transition metal(s) and, optionally, rare earth metal(s).

A method for operating a petrol engine, in which air is introduced into an exhaust tract through which exhaust gas from the petrol engine can flow, bypassing the petrol engine, includes introducing the air into the exhaust tract at a point arranged downstream of a first three-way catalytic converter arranged in the exhaust tract and upstream of a second three-way catalytic converter arranged in the exhaust tract downstream of the first three-way catalytic converter, while the petrol engine is operated with a sub-stoichiometric combustion air ratio, where a desulphurization of the second three-way catalytic converter is effected.

An aftertreatment system for reducing constituents of an exhaust gas having a sulfur content includes: an oxidation catalyst; a filter disposed downstream of the oxidation catalyst; and a controller configured to, in response to determining that the filter is to be regenerated and a desulfation condition being satisfied: cause a temperature of the oxidation catalyst to increase to a first regeneration temperature that is greater than or equal to 400 degrees Celsius and less than 550 degrees Celsius, cause the temperature of the oxidation catalyst to be maintained at the first regeneration temperature for a first time period, and after the first time period, cause the temperature of the oxidation catalyst to increase to a second regeneration temperature equal to or greater than 550 degrees Celsius.