Methods and systems are provided for an auto-ignition internal combustion engine comprising an exhaust gas recirculation arrangement, an intake system, and an exhaust gas discharge system for the discharge of exhaust gases, in which the internal combustion engine is operable, at least in a first, stoichiometric operating mode, by way of a spatial ignition method (HCCI mode). For the aftertreatment of the exhaust gas in the first operating mode, a three-way catalytic converter is provided in the exhaust gas discharge system for reducing nitrogen oxides and oxidizing unburned hydrocarbons and carbon monoxide. In this way, the auto-ignition internal combustion engine has a greater window of operation in the HCCI mode than conventional auto-ignition internal combustion engines.

An internal combustion engine system includes an engine and an aftertreatment system that is connected to the engine to receive an exhaust flow from the engine. The aftertreatment system includes a contaminant storage catalyst for storing contaminants produced by the engine during cold start and low temperature operating conditions, and a NO.sub.x reduction catalyst downstream of the storage catalyst for receiving the contaminants released from the storage catalyst when temperature conditions in the exhaust flow and/or NO.sub.x reduction catalyst are above an effective temperature threshold for NO.sub.x reduction. A contaminant amount stored on the storage catalyst can be estimated in response to one or more operating parameters to manage a storage capacity of the storage catalyst. A bypass can used to bypass the storage catalyst to preserve storage capacity for a subsequent cold start condition.

An exhaust system for a combustion engine includes first and second catalytic converters arranged downstream of the combustion engine in a flow direction of exhaust gas. First and second exhaust pipes extend from the combustion engine to the first and second catalytic converters, respectively, with a first valve disposed in the first exhaust pipe, and a second valve disposed in the second exhaust pipe. The first and second valves operate such that in the presence of an exhaust temperature which is equal to or less than a limit value, at least the first valve opens to allow exhaust gas from the combustion engine to flow through the first catalytic converter, and that the first valve closes and the second valve opens, when the exhaust temperature is greater than the limit value to thereby allow exhaust gas from the combustion engine to flow through the second catalytic converter.

An exhaust gas treatment arrangement for an exhaust gas system of an internal combustion engine includes a first exhaust gas flow path leading from an exhaust gas inlet provided on a housing to an exhaust gas outlet provided on the housing and a second exhaust gas flow path leading from the exhaust gas inlet to the exhaust gas outlet. The second exhaust gas flow path is separate from the first exhaust gas flow path. A flow path switching unit changes the exhaust gas stream parts, which are conducted in the first exhaust gas flow path and the second exhaust gas flow path. A reactant supply device supplies reactant into the second exhaust gas flow path downstream of the exhaust gas inlet and an SCR catalyst arrangement is provided in the second exhaust gas flow path upstream of the exhaust gas outlet.

The disclosure relates to an exhaust gas conduction system for a gasoline engine, comprising an exhaust gas line which can be connected to an exhaust manifold of the gasoline engine, an intake line which can be connected to an intake manifold of the gasoline engine, a charge air compressor which is arranged in the intake line, and a turbine which is arranged in the exhaust gas line. The exhaust gas line has at least one bypass line with a bypass throttle valve, said line branching off from the exhaust gas line upstream of the turbine and branching back into the exhaust gas line at an opening downstream of the turbine. At least one exhaust gas recirculation line with an EGR throttle valve is provided, said line opening into the intake line, wherein the exhaust gas recirculation line branches off from the bypass line at a branch, and the bypass throttle valve is arranged upstream of the branch of the exhaust gas recirculation line. At least one particle filter is arranged in the bypass line downstream of the branch of the exhaust gas recirculation line, and an exhaust gas valve is provided in the exhaust gas line upstream of the opening of the bypass line.

An exhaust system for a dual-fuel engine includes an exhaust treatment component in an exhaust passageway. The exhaust treatment component is configured to treat exhaust from the combustion of a second fuel and not from combustion of a first fuel. A thermal enhancement device is in communication with the exhaust passageway and positioned upstream from the exhaust treatment component. A controller activates and deactivates the thermal enhancement device based on switching from the first fuel to the second fuel, wherein the first fuel has a higher sulfur content than the second fuel. The thermal enhancement device increases the temperature of an exhaust to combust a residual amount of the first fuel present in the exhaust passageway during the switch between the first fuel and the second fuel.

An aftertreatment system (100) connected downstream an internal combustion engine arrangement (102) for receiving exhaust gases conveyed from the internal combustion engine arrangement (102) during operation thereof, wherein the aftertreatment system comprises first and second catalytic devices in series, wherein a gap is there between.

An exhaust gas purification device includes a first catalyst, a bypass pipe, a second catalyst, and a switching controller. The first catalyst is provided in an exhaust pipe. The bypass pipe branches from a first portion of the exhaust pipe. The first portion is located upstream of the first catalyst. The bypass pipe is recoupled to a second portion of the exhaust pipe. The second portion is located upstream of the first catalyst. The second catalyst is provided in the bypass pipe. The switching controller is configured to switch a flow path of an exhaust gas to the bypass pipe based on a deterioration degree of the first catalyst.

An engine exhaust aftertreatment device includes a first exhaust treatment unit and/or a second exhaust treatment unit; the first exhaust treatment unit includes a first bypass pipeline and a first connection pipe provided between a DPF and an SCR; the second exhaust treatment unit comprises a second bypass pipeline and a second connection pipeline provided between a DOC and the DPF, one end of the second bypass pipeline being in communication with the turbine front exhaust pipe, and the other end of the second bypass pipeline being in communication with the second connection pipeline; when it is detected that an engine satisfies a starting condition of the first exhaust treatment unit, the first exhaust treatment unit starts; and when it is detected that the engine satisfies a starting condition of the second exhaust treatment unit, the second exhaust treatment unit starts.

A mixer assembly for a vehicle exhaust system includes a mixer shell defining an internal cavity, wherein the mixer shell includes an upstream end configured to receive exhaust gases and downstream end. A reactor is positioned within the internal cavity and has a reactor inlet configured to receive injected fluid and a reactor outlet that directs a mixture of exhaust gas and injected fluid into the internal cavity. A flow diverter is associated with the reactor to direct exhaust gas bypassing the reactor to mix with the mixture exiting the reactor outlet prior to exiting the downstream end of the mixer.