A converter containing a NOx absorbing and reducing catalyst is disposed in the exhaust passage of an internal combustion engine. The upstream half portion (portion of the inlet side) of the substrate of the NOx absorbing and reducing catalyst in the converter carries the oxygen storage component that absorbs oxygen in the exhaust gas when the air-fuel ratio of the exhaust gas is lean and releases the absorbed oxygen when the air-fuel ratio of the exhaust gas flowing in is rich in addition to carrying the NOx absorbing and reducing catalyst. After NOx is absorbed by the NOx absorbing and reducing catalyst as a result of operating the engine at a lean air-fuel ratio, the engine is operated at a rich air-fuel ratio, so that NOx is released from the NOx absorbing and reducing catalyst and is purified by reduction. Here, oxygen is released from the oxygen storage component carried by the upstream half portion of the substrate and is reacted with the H 2 and CO components in the exhaust gas, so that the temperature of the NOx absorbing and reducing catalyst is raised within short periods of time due to the heat of reaction. Therefore, the catalyst exhibits increased activity and the NOx absorbing and reducing catalyst exhibits improved NOx purification capability.

Exhaust gas purification device for an internal combustion engine

An exhaust gas aftertreatment installment and associated exhaust gas aftertreatment method utilizes a nitrogen oxide storage catalytic converter and an SCR catalytic converter. A particulate filter is provided upstream of the nitrogen oxide storage catalytic converter or between the latter and the SCR catalytic converter or downstream of the SCR catalytic converter. The time of regeneration operating phases of the nitrogen oxide storage catalytic converter can be determined as a function of the nitrogen oxide content of the exhaust gas downstream of the nitrogen oxide storage catalytic converter or of the SCR catalytic converter and/or as a function of the ammonia loading of the latter. Moreover, a desired ammonia generation quantity can be determined for a respective regeneration operating phase. The installation and method are adopted for use for motor vehicle internal combustion engines and other engines which are operated predominantly in lean-burn mode.

Exhaust Gas Aftertreatment Installation and Method

One aspect of the invention relates an exhaust treatment system having an SCR reactor following a NOx adsorber. Syn gas is used to regenerate the NOx adsorber. Another aspect relates to an LNT/SCR provided with an ammonia source separate from the LNT. A further aspect relates to a system comprising first and second LNTs and one or more SCRs downstream of the LNTs. A still further aspect relates to a device comprising first and second NOx adsorbers contained in a single housing. Another aspect relates to coating a surface of a moving part in an exhaust system with an oxidation catalyst to mitigate fouling. Additional aspects of the invention relate to strategies for controlling one or more of the time to initiate a regeneration cycle, the time to terminate a regeneration cycle, and the reductant injection rate during regeneration of LNT/SCR exhaust treatment systems.

Hybrid catalyst system for exhaust emissions reduction

A first cylinder and a second cylinder are provided. A first exhaust pipe is connected to the first cylinder and a second exhaust pipe is connected to the second cylinder. A communicating pipe connects together an intermediate portion of the first exhaust pipe with an intermediate portion of the second exhaust pipe. An exhaust gas control catalyst is arranged in the second exhaust pipe downstream of the portion to which the communicating pipe is connected. Exhaust gas amount reducing devices are provided which reduce the amount of exhaust gas that flows from the first exhaust pipe into the second exhaust pipe through the communicating pipe during execution of rich/lean burn control which performs combustion with an air-fuel ratio of an air-fuel mixture that is richer than the stoichiometric air-fuel ratio in one of the first cylinder and second cylinder and performs combustion with an air-fuel ratio of an air-fuel mixture that is leaner than the stoichiometric air-fuel ratio in the other cylinder.

Exhaust Gas Control Apparatus for Internal Combustion Engine

An internal combustion engine comprises an intake tract in which a throttle valve is disposed. The engine also comprises a camshaft which acts on gas inlet valves associated with respective cylinders. A phase-adjustment device is used to adjust a phase between the camshaft and a crankshaft. A desired air mass flow in a combustion chamber of the cylinder is determined depending on a charge requirement requested by the driver. The desired air mass flow is adjusted by varying the phase between the camshaft and the crankshaft if the desired air mass flow can be adjusted by varying the phase while substantially maintaining an actual pressure difference upstream and downstream of the throttle valve. Otherwise, the desired air mass flow is adjusted by varying the opening angle of the throttle valve.

Method and device for controlling an internal combustion engine

The invention relates to a method of controlling the regeneration of at least one NOx catalyst that is mounted in the exhaust gas duct of an internal combustion engine. According to the inventive method, an NOx concentration of an exhaust gas is detected by an NOx sensor that is arranged downstream of the NOx storage catalyst. The inventive method is characterized by the following steps: (a) comparing the measured NOx concentration downstream of the storage catalyst with an NOx theoretical concentration and determining a comparative value that corresponds to a deviation of said NOx concentration from the NOx theoretical concentration; (b) taking a regenerative measure when the comparative value exceeds a predetermined threshold value, said regenerative measure influencing at least temporarily at least one operational parameter of the internal combustion engine (14); (c) selecting the regenerative measure depending on a regenerative measure that has optionally taken place before.

METHOD OF CONTROLLING AN NOx STORAGE CATALYST

The desulfurization is initiated depending on an actual lambda value and/or a ratio of the nitrogen oxides concentration upstream and downstream of the nitrogen oxides storage catalyst (16) depending on nitrogen oxides amount in the storage catalyst and/or an actual temperature of the storage catalyst. Process for desulfurization of a nitrogen oxides storage catalyst arranged in an exhaust gas channel (12) of an IC engine (14) comprises adjusting a lowest desulfurization temperature on the storage catalyst and a working modulus of the engine with lambda less than 1 for desulfurization and/or temporarily influencing an operating parameter of the engine to reach the lowest temperature and/or the working modulus. The desulfurization is initiated depending on an actual lambda value and/or a ratio of the nitrogen oxides concentration upstream and downstream of the nitrogen oxides storage catalyst (16) depending on nitrogen oxides amount in the storage catalyst and/or an actual temperature of the storage catalyst.

Process for desulfurization of a nitrogen oxides storage catalyst arranged in an exhaust gas channel of an IC engine comprises initiating desulfurization depending on an actual

A noise- and/or heat-insulating mat has a channel for the accommodation of cables and or leads. The channel (2) is closed and the cables and/or leads (3) are integrated into the mat (1). The mat material surrounding the cables and/or leads has an almost homogeneous consistency. The mat material surrounding the cables and/or the leads is designed as a one-piece molded body. The channel is implemented by a hollow chamber in the mat and by a tubular component. The component is made from a material differing from the mat. The channel is in the neighborhood of a surface of the mat.

Noise- and/or heat-insulating mat e.g. for vehicles, has channel which is closed, and cables and/or leads integrated into mat

The invention relates to a device for reducing harmful exhaust elements in the exhaust emission control system of an internal combustion engine with an NOx storage catalyst system. Desulfation is carried out in predetermined time intervals by heating the NOx storage catalyst arrangement to a predetermined desulfation temperature in a predetermined temperature range and by flowing exhaust gas through said NOx storage catalyst arrangement. Desulfation is alternately carried out at different desulfation temperatures (ta, tb) of the temperature range (tB) or at a higher desulfation temperature (tb) in the temperature range (tB) after n desulfation phases at the lower desulfation temperature (ta) in the temperature range (tB) including respective time intervals (Zia).

Method and device for reducing harmful exhaust elements in an exhaust emission control system in an internal combustion engine

Die Erfindung betrifft ein Verfahren und eine Vorrichtung zur Steuerung einer
magerlauffahigen Verbrennungskraftmaschine (10), insbesondere zum Antrieb eines
Fahrzeuges, mit mindestens einem nachgeschalteten Katalysator (14, 16), wobei ein
Magerbetrieb der Verbrennungskraftmaschine (10) mit λ > 1 innerhalb eines zulassigen
Magertemperaturbereichs (T M ) fur eine Katalysatortemperatur des mindestens einen
Katalysators (14, 16) zugelassen wird. Es ist vorgesehen, dass eine aktuelle Rohemission mindestens einer Abgaskomponente der
Verbrennungskraftmaschine (10) ermittelt wird und der zulassige Magertemperaturbereich
(T M ) in Abhangigkeit der Rohemission der mindestens einen Abgaskomponente bestimmt
wird.

Ekkehard Pott

Papers

METHOD OF CONTROLLING AN NOx STORAGE CATALYST

Process for desulfurization of a nitrogen oxides storage catalyst arranged in an exhaust gas channel of an IC engine comprises initiating desulfurization depending on an actual

Noise- and/or heat-insulating mat e.g. for vehicles, has channel which is closed, and cables and/or leads integrated into mat

Method and device for reducing harmful exhaust elements in an exhaust emission control system in an internal combustion engine

Verfahren und Vorrichtung zur Steuerung einer magerlauffähigen Verbrennungskraftmaschine