An internal combustion engine emissions reduction system in which a emissions passing through a second catalyst element having a second catalyst function are mixed with emissions passing through a first catalyst element having a first catalyst function.

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.

A method of selectively catalysing the reduction of oxides of nitrogen (NO.sub.x) including nitrogen monoxide in an exhaust gas of a stationary source of NO.sub.x emissions also containing oxides of sulfur (SO.sub.x) comprising the steps of passively oxidising nitrogen monoxide to nitrogen dioxide (NO.sub.2) over an oxidation catalyst comprising a platinum group metal so that a NO.sub.2/NO.sub.x content is from 40-60%; introducing a nitrogenous reductant into the exhaust gas; and contacting exhaust gas having the 40-60% NO.sub.2/NO.sub.x content and containing the nitrogenous reductant with a selective catalytic reduction (SCR) catalyst comprising an aluminosilicate zeolite promoted with copper.

An internal combustion engine has an exhaust gas aftertreatment system comprising in the given order in the flow direction of the exhaust gas: a device for metering ammonia and/or a compound that can be decomposed to form ammonia into the exhaust gas to be cleaned, as a reducing agent; one or more SCR catalysts, which form a first SCR unit; one or more SCR and/or ammonia oxidation and/or ammonia slip catalysts, which form a second SCR unit; and a NO.sub.x sensor in the exhaust gas tail pipe. An amount, to be metered into the exhaust gas, of ammonia and/or of the decomposable compound is set using the nitrogen oxide concentration in the exhaust gas tail pipe that is determined by the NO.sub.x sensor, and the occurrence or non-occurrence of an ammonia excess in the region of the NO.sub.x sensor can be determined from the sensor signal of the NO.sub.x sensor by evaluating said sensor signal.

A catalytic composite is formed of a catalytic layered assembly including a porous catalytic fluoropolymer film and one or more felt batts connected with the porous catalytic fluoropolymer film. At least one felt batt is positioned adjacent the upstream side of the porous catalytic fluoropolymer film to form the catalytic composite. The fluoropolymer film is perforated to allow for enhanced airflow therethrough while retaining the capability of catalyzing the reduction or removal of chemical species in fluid flowing through the catalytic composite.

An exhaust aftertreatment unit for cleaning exhaust gases. The exhaust aftertreatment unit includes an emission reducing module being a diesel particulate filter, DPF, and/or a diesel oxidation catalyst, DOC, a selective catalyst reduction, SCR, catalyst, an electrical heating element arranged upstream of the SCR catalyst, a casing housing at least the emission reducing module, and a service lid removably arranged to cover a service opening of the casing through which the emission reducing module may be accessed. The electrical heating element is removably arranged relative the casing and is arranged accessible upon removal of the service lid.

A method includes receiving information indicative of a temperature of exhaust gas emitted from an engine operating at an engine speed, determining that the temperature of the exhaust gas is below a predefined temperature threshold, determining an engine load sized to increase the temperature of the exhaust gas above the predefined temperature threshold, increasing a load on the engine to the determined engine load while maintaining the engine at the engine speed by increasing at least one of a fuel flow rate and a fuel flow pressure of the fuel pump powered by the engine, and diverting the excess fuel from the fuel flow path upstream of the engine. Increasing at least one of the fuel flow rate and the fuel pressure of the fuel pump causes excess fuel to be provided to the engine than is necessary to maintain the engine at the engine speed.

Reductant delivery systems are disclosed that include a dry reductant source and a liquid reductant source which are operable to selectively provide gaseous reductant and liquid reductant to an exhaust aftertreatment system for treatment and reduction of NOx emissions. The gaseous reductant is provided to the exhaust aftertreatment system for treatment of NOx emissions under a first temperature condition associated with the exhaust system and the liquid reductant for treatment of NOx emissions under a second temperature condition associated with the exhaust system.

Subject of the invention is an exhaust gas purification system for a gasoline engine, comprising in consecutive order the following devices: a first three-way-catalyst (TWC1), a gasoline particulate filter (GPF) and a second three-way-catalyst (TWC2), wherein the wash coat load (WCL) of the TWC2 is greater than the WCL of the GPF, wherein the WCL is determined in g/l of the volume of the device,

The invention also relates to methods in which the system is used and uses of the system.

A system includes an aftertreatment system having a catalyst, a heater, at least one sensor configured to determine an exhaust gas temperature, and a controller. The controller is structured to determine whether the exhaust gas temperature is at or below a predefined threshold temperature, provide a first command to start and control the heater in response to the exhaust gas temperature being at or below the predefined threshold temperature, modulate control of the heater as a function of the predefined threshold temperature and an actual temperature, and selectively provide a second command for a close post injection based on the exhaust gas temperature. The controller is further structured to coordinate the first and second commands using a chaining sequence, wherein the first command is provided followed by the second command only if the predefined threshold temperature is not attained by the first command.