An exhaust treatment system includes an SCRF device, a reductant delivery system, and an SCR storage module. The SCRF device includes a filter portion having a washcoat formed thereon that defines a washcoat thickness (WCT). The reductant delivery system is configured to inject a reductant that reacts with the washcoat based on a reductant storage model. The SCR storage module is in electrical communication with the reductant delivery system to provide the reductant storage model the amount of reductant to be injected based on the reductant storage model. The exhaust treatment system further includes a WCT compensation module configured to electrically communicate a WCT compensation value to the SCR storage module. The SCR storage module modifies the reductant storage model according to the WCT compensation value such that the amount of ammonia that slips from the SCRF device is reduced thereby increasing a storage efficiency of the SCRF device.

A control system includes an electric heater disposed within an exhaust fluid flow pathway, and a control device for receiving at least one input selected from the group consisting of temperature readings along the exhaust fluid flow pathway, alternator power/current/voltage, battery power/current/voltage/state of charge, IAT and EAT profiles, mass flow rate of an exhaust fluid flow, NH.sub.3 slip, TCR characteristics of the heater, alternator speed, engine speed, state of aging of an aftertreatment component, state of aging of engine, aging degradation characteristics, a dosing rate and a temperature of DEF, NH.sub.3 storage condition of aftertreatment system, an ambient temperature, and combinations thereof. The control device modulates power to the heater based on the at least one input such that the heater provides different power output as a function of the at least one input and a continuously variable power output during operation of the exhaust system.

Implementations of systems and methods for detecting the failure of an selective catalytic reduction (SCR) catalyst may include a controller or one or more circuits for acquiring an ammonia to NOx ratio (ANR) value for exhaust gas flowing through an exhaust system, acquiring a conversion inefficiency value indicative of a conversion inefficiency of the SCR catalyst, acquire an NH.sub.3 slip value indicative of an amount of NH.sub.3 slip through the exhaust system downstream of the SCR catalyst, calculate a combined ANR/conversion inefficiency/NH3 slip (ACN) value based on the ANR value, conversion inefficiency value, and NH.sub.3 slip value, and indicating a failure of the SCR catalyst responsive to the calculated ACN value exceeding a predetermined threshold value.

A method for determining a mass flow of ammonia between two SCR catalytic converters disposed one after the other in an SCR catalytic converter system in an exhaust system, which comprises only one reduction agent dosing unit upstream of the first SCR catalytic converter, characterized in that the determination is carried out from the signal of a NOx sensor disposed between the two SCR catalytic converters and the signal of a NOx sensor disposed downstream of the second SCR catalytic converter.

A method and system for mitigating a urea deposit within an SCR system that includes determining a mass of an accumulated urea deposit present within the SCR catalyst and SCR piping, comparing the mass of the accumulated urea deposit with a deposit upper threshold limit, and initiating an SCR regeneration event when the mass of the accumulated urea deposit is greater than the deposit upper threshold limit. The method further includes determining an amount of NH.sub.3 passing through the SCR catalyst downstream of the urea deposit, comparing the amount of NH.sub.3 passing through the SCR catalyst with an NH.sub.3 regeneration threshold limit, and terminating the SCR regeneration event when the level of NH.sub.3 passing through the SCR catalyst is less than the SCR NH.sub.3 regeneration threshold.

An exhaust gas post treatment system for an internal combustion engine, in particular a heavy fuel oil-powered engine, including an SCR catalyst, using ammonia as a reducing agent for the denitration of the exhaust gas, and a device positioned upstream of the SCR catalyst by which ammonia or an ammonia precursor substance, which is converted to ammonia, introduced upstream of the SCR catalyst. Downstream of the SCR catalyst an exhaust gas scrubber is positioned, by which excess ammonia, contained in the exhaust gas leaving the SCR catalyst, together with sulfur oxides, can be scrubbed out of the exhaust gas forming ammonium salts while maintaining a pH value of approximately 6. For the control thereof, a bypass around the SCR catalyst can be provided as a westgate, or comprising an additional SCR catalyst.

A system and method for utilizing fuel as an on-board reductant for selective catalytic reduction of NOx is provided and includes a controller for controlling an engine to produce a lean first exhaust stream and a rich second exhaust stream that are received in respective first and second passageways of a dual path aftertreatment system. The rich second exhaust stream reacts with NOx stored in a NOx storage and reduction catalyst of the second passageway to regenerate this catalyst and generate ammonia. The first exhaust stream and the second exhaust stream having the generated ammonia are combined in a downstream common passageway to form a combined lean exhaust gas stream where the ammonia carried therein is stored or used by an SCR catalyst of the common passageway for NOx reduction. The engine is subsequently controlled to produce a rich first exhaust stream and a lean second exhaust stream.

In a process for adapting an amount of reducing agent for a removal of nitrogen oxides from the gases in an exhaust line, a first alignment of the amounts of nitrogen oxides measured by upstream and downstream sensors is performed without injection of agent and with a catalyst of the system emptied of ammonia. A second alignment of the estimated reduction of nitrogen oxides with the measured reduction is performed by a difference between amounts of nitrogen oxides upstream and downstream during a substoichiometric injection of reducing agent without creating a store of ammonia in a catalyst of the system with a first correction of the amount of agent. A third alignment of an estimated efficiency of retaining nitrogen oxides with a efficiency measured by the sensors is performed, this third alignment taking place via a second correction of the amount of reducing agent injected as an adaptive correction.

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.

An aftertreatment system comprises a selective catalytic reduction (SCR) unit, a reductant injector configured to insert reductant into the aftertreatment system, a first NO.sub.x sensor configured to measure an amount of NO.sub.x gases at a location upstream of the reductant injector, and a second NO.sub.x sensor configured to measure an amount of NO.sub.x gases at a location downstream of the SCR unit. A controller is programmed to estimate an amount of reductant deposits formed in the aftertreatment system based on at least the amount of NO.sub.x gases measured at the location upstream of the reductant injector, the amount of NO.sub.x gases measured at the location downstream of the SCR unit, and an amount of reductant that has been inserted into the aftertreatment system. The controller adjusts an amount of reductant to be inserted into the aftertreatment system based on the estimated amount of reductant deposits formed in the aftertreatment system.