The present invention relates to a method for adaption of an exhaust treatment system arranged for treating an exhaust stream produced by an engine, where the exhaust treatment system includes at least a first additive dosage device, a first selective catalytic reduction catalyst arranged downstream of the first additive dosage device, a second additive dosage device arranged downstream of the first selective catalytic reduction catalyst, and a second selective catalytic reduction catalyst arranged downstream of the second additive dosage device. The method includes initiating an adaption of the second selective catalytic reduction catalyst, and controlling, during the adaption of the second selective catalytic reduction catalyst, the first additive dosage device to inject additive in accordance with at least one injection rule being designed for the adaption.

Methods and systems are provided for maintaining a temperature of exhaust gases of an engine within a temperature range at which catalytic conversion is most efficient. In one example, a method for controlling a temperature of exhaust gases entering a Selective Catalytic Reduction (SCR) system for an engine comprises delivering pressurized air into the exhaust gases upstream of the SCR system, the pressurized air cooled by an air cooler; and adjusting a degree of pressurization by adjusting operation of a turbocharger pressurizing the pressurized air. In one embodiment, the air cooler may be a charge air cooler of a primary turbocharger of the engine, which may flow pressurized air both to the engine and to the SCR system. In other embodiments, the air may be pressurized by an air pump or a secondary dilution turbocharger, and cooled by a secondary charge air cooler.

A method of diagnosing an engine system including an engine and an exhaust aftertreatment system. The engine system comprises a plurality of replaceable engine system components. The method comprises maintaining a database with component data comprising, for each one of the replaceable engine system components, a deterioration efficiency parameter correlating the deterioration status of the replaceable engine system component to emission reducing efficiency, and a utility component parameter comprising component exchangeability data; determining the deterioration status of each one of the replaceable engine system components; estimating the emission reducing efficiency for each one of the replaceable engine system components in response to the determined deterioration status and the deterioration efficiency parameter; based on known relation between component exchangeability data and the resulting emission reducing efficiency of a potential exchange of the replaceable engine system component, identifying a replaceable engine system component to exchange.

A method for operating an SCR catalytic converter in an exhaust gas system of an internal combustion engine with ammonia dosing upstream of the catalytic converter. The method includes: determining, on the basis of a catalytic converter model, the efficiency of nitrogen oxide conversion in the catalytic converter; determining an ammonia fill level in the catalytic converter; determining a nominal ammonia fill level in the catalytic converter, based on the determined efficiency and a pre-definable target nitrogen oxide conversion; and controlling the ammonia dosing depending on the nominal ammonia fill level and the ammonia fill level.

Systems and apparatuses include a circuit structured to receive information indicative of a catalyst health, determine a catalyst health management criteria has been met based on the information, determine a catalyst loading based on the information and the catalyst health management criteria being met, and compare the determined catalyst loading to a predetermined loading limit. A notification circuit is coupled to the circuit and structured to provide a notification when the determined catalyst load exceeds the predetermined loading limit.

A method for ascertaining an exhaust gas composition of an exhaust gas of an internal combustion engine with regard to an ammonia fraction and a nitrogen oxides fraction in an exhaust gas system including an SCR catalytic converter. The method includes detecting, using a sensor, a first signal whose magnitude is a function of the nitrogen oxides fraction of the exhaust gas upstream from the SCR catalytic converter, detecting using a sensor a second signal whose magnitude is a function of the ammonia fraction and the nitrogen oxides fraction of the exhaust gas downstream from the SCR catalytic converter, storing the two signals over an observation period, and ascertaining the ammonia fraction and optionally the nitrogen oxides fraction of the exhaust gas downstream from the at least one SCR catalytic converter using a calculation rule that uses the two signals during the observation period as input variables.

A method that determines a cause for the impaired performance of a catalytic configuration of the exhaust gas of a combustion engine (231), the method including determining (s410) a course of a NOx-conversion ratio; determining (s420) a prevailing temperature of the catalytic configuration; increasing (s430) the temperature of the catalytic configuration from a prevailing temperature below a predetermined temperature value (Te) to a temperature (TSred) above the predetermined temperature value above which sulphur is removed from the catalytic configuration; and/or decreasing (s440) the temperature of the catalytic configuration from a prevailing temperature (TSred) above the predetermined temperature value (Te) to a temperature below the predetermined temperature value so as to impair the performance of the catalytic configuration in case sulphur is present; and determining (s450) one cause out of a set of causes on the basis of the course of the NOx-conversion ratio thus determined.

A control module for an aftertreatment system that includes a selective catalytic reduction (SCR) catalyst and an oxidation catalyst, comprises a controller configured to be operatively coupled to the aftertreatment system. The controller is configured to determine an actual SCR catalytic conversion efficiency of the SCR catalyst. The controller determines an estimated SCR catalytic conversion efficiency based on a test sulfur concentration selected by the controller. In response to the estimated SCR catalytic conversion efficiency being within a predefined range, the controller sets the test sulfur concentration as a determined sulfur concentration in a fuel provided to the engine. The controller generates a sulfur concentration signal indicating the determined sulfur.

Disclosed is a method for diagnosing a first exhaust treatment component for treatment of an exhaust gas stream comprising means for oxidizing nitric oxide into nitrogen dioxide. A first reduction catalytic converter is arranged upstream said means for oxidizing nitric oxide into nitrogen dioxide, and a second reduction catalytic converter is arranged downstream said means. A reagent is for reduction of nitrogen oxides in said first catalytic converter, and a first sensor measures an occurrence of nitrogen oxide downstream said means but upstream said second reduction catalytic converter. The method comprises: causing a supply of reagent upstream said first reduction catalytic converter to an extent exceeding the extent to which reagent is consumed by the first reduction catalytic converter, determining a first measure of the occurrence of reagent downstream said means for oxidizing, and diagnosing said means for oxidizing nitric oxide into nitrogen dioxide based on said first measure.

Systems and apparatuses include a selective catalytic reduction system structured to receive exhaust gases from a dual fuel engine system and include a diesel exhaust fluid dosing unit, an ammonia slip catalyst positioned directly downstream of the selective catalytic reduction catalyst, an oxidation catalyst positioned directly downstream of the ammonia slip catalyst, and one or more processing circuits. The circuits receive a system out NOx value, a space velocity, an ammonia to NOx ratio, an exhaust temperature, a substitution rate, and a conversion efficiency target. The circuits determine a conversion efficiency differential, adjust the substitution rate based on the system out NOx value, adjust the ammonia to NOx ratio based on the space velocity, the ammonia to NOx ratio, the exhaust temperature, the substitution rate, the conversion efficiency target, and the conversion efficiency differential, and determine a diesel exhaust fluid dosing rate for the diesel exhaust fluid dosing unit.