Methods and system are provided to heat a catalyst of an after-treatment system for a vehicle. The after-treatment system comprises a heating module having a plurality of heating elements. Each of the plurality of heating elements is independently operable to provide thermal energy to the catalyst of the after-treatment system. One or more of the heating elements of the heating module are selectively operated to provide heat to the catalyst based on an operational parameter of the after-treatment system.

A provision of assemblies and methods for treating exhaust gases from combustion devices to reduce air contaminants in the exhaust gas. The exhaust from a combustion device is cooled, followed by passing the exhaust through first and second catalytic chambers with an oxygen enrichment means in between the catalytic chambers. The catalytic chambers comprise at least one catalyst that substantially reduces nitrogen oxides or carbon monoxide or both.

An exhaust purification system includes: a NOx reduction catalyst for reducing and purifying NOx in an exhaust gas; a catalyst regeneration control module for executing a catalyst regeneration process of restoring a NOx purification capacity of the NOx reduction catalyst by switching an air-fuel ratio of the exhaust gas from a lean state to a rich state by using in parallel an air system control to reduce an intake air amount and an injection system control to increase a fuel injection amount; an exhaust gas temperature sensor that is provided on a downstream side of the NOx reduction catalyst on an exhaust passageway; a catalyst temperature estimating module for estimating a catalyst temperature of the NOx reduction catalyst; a temperature sensor value estimating module for estimating a sensor value of the exhaust gas temperature sensor; and an abnormality determination module for determining on an abnormality of a catalyst regeneration process.

There is provided an exhaust gas purification system including: a NOx storage-reduction catalyst that is provided in an exhaust system of an internal combustion engine to reduce and purify NOx in exhaust gas; a degree of deterioration estimation module 120 for estimating a degree of deterioration of the NOx storage-reduction catalyst; a regeneration control unit 100 for executing a regeneration process in which exhaust gas is enriched so as to restore a NOx storage capacity of the NOx storage-reduction catalyst; an interval setting module for setting a target interval from an end of the regeneration process to a start of the subsequent regeneration process by the regeneration control unit; and an interval target value correction module for correcting the target interval based on the degree of deterioration that is estimated by the degree of deterioration estimation module.

A method for controlling exhaust gas aftertreatment in an exhaust gas aftertreatment system having at least one nitrogen oxide storage catalyst and at least one catalyst for selective catalytic reduction is provided, wherein, in phases of a high load, a combustion engine is operated with a substoichiometric fuel/air mixture, and nitrogen oxides in the exhaust gas are reduced in the nitrogen oxide storage catalyst to ammonia, which is stored in the catalyst for selective catalytic reduction, and, when the storage capacity of the catalyst for selective catalytic reduction is exceeded, the combustion engine is operated with a superstoichiometric fuel/air mixture, thus allowing nitrogen oxides in the catalyst for selective catalytic reduction to be reduced by the stored ammonia.

Methods and systems are provided for conducting an evaporative emissions test diagnostic on a vehicle fuel system and evaporative emissions control system during engine-on conditions. In one example, a first fuel vapor storage device is separated from a second fuel vapor storage device by a one-way check valve, thus preventing loading of the first fuel vapor storage device during conditions such as refueling operations, diurnal temperature fluctuations, or from running-loss vapors from a vehicle fuel tank. In this way, the evaporative emissions test diagnostic may be conducted during a cold-start event where an exhaust catalyst is below a predetermined threshold temperature required for catalytic oxidation of hydrocarbons in the engine exhaust, without increasing undesired exhaust emissions.

An internal combustion engine (ICE) and method of control are provided to determine a value of a catalyst temperature and a value of a quantity of a reducing agent stored in the catalyst. The quantity of gas recirculated by an exhaust gas recirculation (EGR) system of the ICE is calculated on the basis of the value of the catalyst temperature and of the value of the quantity of the reducing agent stored in the catalyst. This solution makes it possible to adjust the quantity of gas recirculated by the EGR system on the basis of parameters linked to an efficiency of a selective catalytic reduction (SCR) system associated with the ICE, in order to reduce the global quantity of pollutants produced by the ICE and released in the environment.

Systems and methods for controlling a gasoline urea selective catalytic reductant catalyst are described. In one example, an observer is provided that corrects an estimate of an amount of NH.sub.3 that is stored in a SCR. The amount of NH.sub.3 that is stored in the SCR is a basis for generating additional NH.sub.3 or ceasing generation of NH.sub.3.

This disclosure is intended to suppress a noble metal supported by a three-way catalyst from being deteriorated by oxidation with the execution of fuel cut processing in a suitable manner. A control apparatus for a naturally aspirated gasoline engine is provided with a three-way catalyst, a first throttle valve, a second throttle valve arranged in the intake passage at the downstream side of the first throttle valve, an EGR valve, and a controller. When the controller carries out fuel cut processing and the temperature of the three-way catalyst is equal to or higher than a predetermined temperature, the controller introduces the EGR gas into a cylinder of the gasoline engine as intake air by fully closing the first throttle valve and by opening the EGR valve, and further controls an amount of the EGR gas by adjusting the degree of opening of the second throttle valve.

A method is provided for operating a vehicle, in particular a watercraft, with at least one combustion engine that emits pollutants contained in an exhaust gas or wastewater. The current position of the vehicle is determined by a location determination. A closed-loop and/or open-loop control device is provided which sets or adjusts the quantity of at least one pollutant emitted by the combustion engine in a self-acting manner or automatically, in accordance with the determined position of the vehicle and with information on local pollutant regulations, in particular exhaust and/or water regulations.