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.

Methods and/or systems for operating an exhaust-gas aftertreatment system of an internal combustion engine include: setting the internal combustion engine to a diagnostic operating mode with relevant diagnostic operating parameters of the internal combustion engine are set to correspond with diagnostic default values; inducing a targeted, defined NH.sub.3 and/or NO.sub.X concentration change upstream of the filter; measuring the NH.sub.3 and/or NO.sub.X concentration change downstream of the filter; providing a correlating concentration comparison value; evaluating the concentration change on the basis of the respective concentration comparison value and predefined limit values; and diagnosing the SCR particle filter as defective if the evaluation yields that the concentration comparison value has overshot a predefined limit value.

A method for controlling the operation of an engine system in a vehicle. The engine system including an engine and an exhaust aftertreatment system having an SCR catalyst and a DPF. The method includes determining preview information of the vehicle operation based at least on an upcoming road event and an engine operation associated with the upcoming road event; performing, in response of the preview information, at least one of: controlling the operation of the engine system by increasing reductant injection to meet an ammonia storage threshold level; controlling the operation of the engine system by increasing the engine out NOx to reduce the ammonia storage in the SCR catalyst to meet an ammonia slip threshold level in the SCR catalyst; controlling the operation of the engine system by decreasing the engine out NOx to increase the amount of engine out particles to meet a soot threshold level in the DPF.

A catalyst deterioration diagnosis method is a method for a system. The system includes a stepped transmission or a continuously variable transmission connected to an internal combustion engine, a catalyst into which an exhaust gas from the internal combustion engine is introduced, and a gas sensor having sensitivity to ammonia that outputs a detection value corresponding to a component of an exhaust gas that has passed through the catalyst. The catalyst deterioration diagnosis method includes the following steps. Monitoring of temporary increase of a detection value of the gas sensor is started, and thereby a temporarily increased amount of the detection value of the gas sensor is acquired. The monitoring is started when upshifting of the stepped transmission or pseudo-upshifting of the continuously variable transmission is performed. Whether or not the temporarily increased amount is larger than a threshold amount is determined.

The present invention provides a fuel supply system, for an eco-friendly ship, which selectively uses an existing fuel and an ammonia fuel or uses a mixture thereof as a fuel for a propulsion engine and a power generation engine of a ship so as to follow ship greenhouse gas regulations to be reinforced in phases at major points until 2050.

A method for controlling the operation of an engine system in a vehicle. The engine system including an engine and an exhaust aftertreatment system having an SCR catalyst and a DPF. The method includes determining preview information of the vehicle operation based at least on an upcoming road event and an engine operation associated with the upcoming road event; performing, in response of the preview information, at least one of: controlling the operation of the engine system by increasing reductant injection to meet an ammonia storage threshold level; controlling the operation of the engine system by increasing the engine out NOx to reduce the ammonia storage in the SCR catalyst to meet an ammonia slip threshold level in the SCR catalyst; controlling the operation of the engine system by decreasing the engine out NOx to increase the amount of engine out particles to meet a soot threshold level in the DPF.

A method includes acquiring nitrogen oxide (NOx) data indicative of a first amount of NOx in an exhaust flow exiting an engine and a second amount of NOx in the exhaust flow exiting an exhaust aftertreatment system coupled to the engine where the exhaust aftertreatment system including a selective catalytic reduction (SCR) system including a SCR catalyst; determining a NOx conversion efficiency fault is present within the exhaust aftertreatment system based on the first amount of NOx and the second amount of NOx; monitoring an actual amount of NOx in the exhaust flow downstream of the SCR catalyst; determining an expected amount of NOx downstream of the SCR catalyst; and determining the SCR catalyst is responsible for the NOx conversion efficiency fault in response to the actual amount of NOx differing from the expected amount of NOx by more than a threshold amount.

A method of monitoring an SCR catalyst in which an area factor (a) of the SCR catalyst is ascertained by means of an observer. It is concluded that there is a fault in the SCR catalyst when a comparison shows that the area factor (a) has gone below a threshold value (S).

A selective catalytic reduction (SCR) system for treating exhaust gas from a diesel engine is provided, along with a method of assembling such a system. The system comprises a frame, a SCR catalyst contained within a SCR canister, and an ammonia oxidation catalyst contained within an ammonia oxidation canister. Each of the SCR and ammonia oxidation canisters is removably attached to the frame.

A method for controlling an exhaust gas purification apparatus including a front three-way catalyst (TWC) and a rear TWC that purify the exhaust gas may include determining an oxygen flow rate and a flow rate of a reducing agent introduced into the front TWC, determining the oxygen storage amount of the front TWC based on the oxygen flow rate and the flow rate of the reducing agent flowing into the front TWC, determining a maximum oxygen storage amount of the front TWC, determining a slip oxygen flow rate and a slip reducing agent flow rate of the front TWC, determining an oxygen storage amount of the rear TWC, comparing a rear TWC oxygen storage amount and a target value of the rear TWC oxygen storage amount, and maintaining a catalyst purge of the front TWC when the rear TWC oxygen storage amount is greater than the target value of the rear TWC oxygen storage amount.