A method for operating an internal combustion engine includes combusting fuel and air within a combustion chamber of an internal combustion engine, thereby forming an exhaust gas, passing the exhaust gas out of the combustion chamber, and performing a startup procedure, the startup procedure including passing the exhaust gas from the combustion chamber through a first aftertreatment system to a pollutant capture unit, capturing criteria pollutants of the exhaust gas with the pollutant capture unit, and heating the first aftertreatment system to a first activation temperature. Subsequent to heating the first aftertreatment system to the first activation temperature a secondary procedure is performed including passing the exhaust gas from the combustion chamber directly to a second aftertreatment system bypassing the pollutant capture unit to heat the second aftertreatment system to a second activation temperature. Subsequently, exhaust gas is passed through the pollutant capture unit to desorb captured criteria pollutants.

A system operates to bypass one or more exhaust purifying devices during deceleration fuel cut-off (DFCO) events in order to avoid hydrocarbon purging. The system includes an internal combustion engine and exhaust purifying system including a first purifying device and a second purifying device. An exhaust gas sensor monitors an exhaust gas feedstream. A diverter valve is disposed to manage the exhaust gas feedstream and fluidly coupled to an exhaust diversion pipe. A controller detects operation of the engine in a DFCO state and monitors the exhaust gas feedstream via the exhaust sensor. The diverter valve is controlled to divert the exhaust gas feedstream away from at least one of the first and second purifying devices during the DFCO event when the exhaust gas feedstream has an air/fuel ratio that is greater than a threshold air/fuel ratio.

A method and a device intended to purify pollutants from an exhaust gas flow of an internal combustion engine operated with sulphur containing fuel, in particular of a ship internal combustion engine operated with heavy fuel oil, are provided. Exhaust gas flow is in contact with a solid adsorption agent of the adsorber in a first step and binding in particular acid pollutants, which comprise sulphur dioxide and sulphur trioxide. The exhaust gas flow is then guided by a second stage of the adsorber realising fine purification of the exhaust gas flow. The adsorption agent of the second stage is used in the first stage as an adsorption agent.

An exhaust purification system includes an electrochemical reactor provided in an engine exhaust passage; a bypass passage bypassing the electrochemical reactor; a flow control valve controlling an amount of exhaust gas, discharged from an engine body, flowing into the electrochemical reactor and the bypass passage; and a control device controlling the flow control valve. The electrochemical reactor includes a holding material holding NO.sub.X or HC and is configured so as to purify NO.sub.X or HC held at the holding material if encrgized. The control device controls the flow control valve so as to control the amount of exhaust gas flowing into the electrochemical reactor so that a temperature of the electrochemical reactor is maintained at less than a desorption start temperature where NO.sub.X or HC starts to be desorbed from the holding material.

A system that may include an exhaust gas source that provides exhaust gas pollutants, a primary catalytic converter coupled downstream of the exhaust gas source, and an adsorption unit, configured to adsorb exhaust gas pollutants. The adsorption unit may be coupled downstream of the exhaust gas source. A process that may include introducing exhaust gas comprising exhaust gas pollutants into a system that includes an adsorption unit, such that the exhaust gas may flow through the adsorption unit and the exhaust gas pollutants may be adsorbed into an adsorption media in the adsorption unit as adsorbed exhaust gas pollutants. A depleted exhaust gas may pass from the adsorption unit.

An engine system includes: an engine including a plurality of combustion chambers generating driving torque by combustion of fuel; an exhaust gas purification apparatus installed at an exhaust line in which exhaust gas exhausted from the combustion chambers flows; a bypass line branched from the exhaust line at an upstream side of the exhaust gas purification apparatus and joining the exhaust line at a downstream side of the exhaust gas purification apparatus so that the exhaust gas flowing in the exhaust line bypasses the exhaust gas purification apparatus; and a bypass valve installed at the bypass line.

Systems and methods described herein relate to generating ammonia from engine exhaust instead of or in addition to using on-board storage tank(s) and/or doser(s) to provide the necessary chemical reagents for purification of the exhaust stream. Systems and methods for generating ammonia and/or hydrogen from engine exhaust in exhaust aftertreatment systems under ambient conditions comprise at least one water-gas shift (WGS) catalyst and at least one ammonia synthesis catalyst (AMS catalyst) positioned downstream of the WGS catalyst. The WGS catalyst is configured, using the engine exhaust gas as an input, to generate hydrogen used by the AMS catalyst as inputs to generate ammonia and/or hydrogen. The ammonia and/or hydrogen thus generated are used downstream in ammonia- and/or hydrogen-based selective catalytic reduction catalysts (SCR).

A method for controlling exhaust flow in an EATS of a vehicle. A NO.sub.x sensor output parameter is monitored. It is determined that the NO.sub.x sensor output parameter is below a limit. When the NO.sub.x sensor output parameter is below the limit, it is determined that a first part of the exhaust flow should bypass at least a first area of the SCR unit and that a second part of the exhaust flow should be inputted to at least the first area of the SCR unit. It is initiated that the first part is bypassed and that the second part is inputted to at least the first area of the SCR unit. An amount of reductant that should be added to the second part of the exhaust flow is determined. Addition of the amount of reductant is initiated.

An internal combustion engine, ICE, system for a vehicle includes an ICE operable on hydrogen; an exhaust gas aftertreatment system, EATS, arranged in an exhaust gas circuit downstream the ICE, said EATS having at least one NOx reduction device and/or a particulate filter, and an exhaust gas water recovery, EWR, system arranged at least partly downstream the EATS in the exhaust gas circuit, said EWR system having at least a primary exhaust cooler and a water separator; a waste heat recovery, WHR, system for providing a rankine cycle, said WHR system being arranged to transport a working fluid, WF, through the primary exhaust cooler of the EWR system; a low temperature coolant circuit in fluid communication with an exhaust condenser of the EWR system; and a water management system arranged to collect water from the EWR system and transport water to at least one combustion chamber of the ICE.

An exhaust emission control system of an engine including a NO.sub.x catalyst for storing NO.sub.x within exhaust gas when an air-fuel ratio thereof is lean, and reducing the NO.sub.x when the air-fuel ratio is approximately stoichiometric or rich, the NO.sub.x catalyst also functioning as an oxidation catalyst for oxidizing HC, is provided. The system includes a SCR catalyst for purifying NO.sub.x by causing a reaction with NH.sub.3, a urea injector, and a processor configured to execute a fuel injection controlling module, and a NO.sub.x reduction controlling module for performing a NO.sub.x reduction control to enrich the air-fuel ratio to a target ratio. When the urea injection is abnormal, the NO.sub.x reduction controlling module performs an NH.sub.3-supplied NO.sub.x reduction control in which the NO.sub.x catalyst supplies NH.sub.3 to the SCR catalyst, by performing the NO.sub.x reduction control, a lean air-fuel ratio operation control, and then the NO.sub.x reduction control again.