Abstract: A method for operating an exhaust gas purification system of a motor vehicle internal combustion engine is disclosed. The system has an SCR catalyst where a reducing agent containing ammonia is metered into the exhaust gas at a predeterminable metering rate which is produced from a base value and an adaptation factor which corrects the base value. A test procedure checks and, if appropriate, adjusts the adaptation factor where a first nitrogen oxide value is compared with a second nitrogen oxide value of the exhaust gas, where the first and the second nitrogen oxide value are determined by the same nitrogen oxide sensor disposed downstream of the SCR catalyst. The first nitrogen oxide value is determined when the metering of the reducing agent is switched off and the second nitrogen oxide value is determined when the reducing agent is metered at a test metering rate which can be predetermined.

Abstract: In a system with an SCR catalytic converter, a correction by a changeable long term adaption factor to a target dosing rate is provided for the model dosing rate and a correction by a changeable short term adaption factor to an assumed actual filling state for the ammonia filling level value. A dosing unit controllable by a control unit adds an ammonia-containing reducing agent to the exhaust gas and an exhaust gas enriched with ammonia according to the dosing is fed to the SCR catalytic converter. An ammonia filling level value for a filling level of ammonia stored in the SCR catalytic converter and a model dosing rate for dosing the reducing agent into the exhaust gas are calculated by a computer model.

Abstract: A method for operating an exhaust gas purification system of a motor vehicle internal combustion engine is disclosed. The system has an SCR catalyst where a reducing agent containing ammonia is metered into the exhaust gas at a predeterminable metering rate which is produced from a base value and an adaptation factor which corrects the base value. A test procedure checks and, if appropriate, adjusts the adaptation factor where a first nitrogen oxide value is compared with a second nitrogen oxide value of the exhaust gas, where the first and the second nitrogen oxide value are determined by the same nitrogen oxide sensor disposed downstream of the SCR catalyst. The first nitrogen oxide value is determined when the metering of the reducing agent is switched off and the second nitrogen oxide value is determined when the reducing agent is metered at a test metering rate which can be predetermined.

Abstract: 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.

Abstract: 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.

Abstract: A method for operating an exhaust gas treatment system that includes an SCR catalytic converter is provided. Either a model-based filling level regulation for achieving the target filling level or a model-based efficiency control for achieving the target efficiency is performed according to presettable values for certain operating variables such as a temperature of the exhaust gas or of the SCR catalytic converter.

Abstract: In a method for reducing the emission of nitrogen dioxide in a motor vehicle having an exhaust gas purification system having an SCR catalytic converter with adsorption centers for nitrogen oxides, an exhaust gas enriched with ammonia is supplied to the SCR catalytic converter above an operating temperature. Below the operating temperature, the exhaust gas supplied to the SCR catalytic converter is enriched with a material such that an adsorption of nitrogen oxides is inhibited at corresponding adsorption centers of the SCR catalytic converter. In order to reduce the overall NOx emissions below a first, predeterminable amount, an exhaust gas enriched with ammonia is supplied to the SCR catalytic converter and the NO2 portion of the total NOx emissions is reduced below a second, predeterminable amount in that NO2 is converted with hydrocarbons stored in the SCR catalytic converter.

Abstract: In a method for operating an air-compressing fuel-injection internal combustion engine having an exhaust gas post-treatment system with a particle filter and a nitrogen oxide reduction catalytic converter, a plurality of internal combustion engine operating settings are provided, each having respective predefined values for predefined internal combustion engine operating parameters. A heating operating setting is set when the internal combustion engine is warming up, while a basic operating setting is set in the warmed-up state. When the temperature in the exhaust gas system exceeds a predefinable first value, the heating operating setting is changed over to the basic operating setting. In the warmed-up state, at least one further (third) operating setting, with an exhaust gas recirculation rate that is reduced compared to the basic operating setting, is provided in addition to the basic operating setting.

Abstract: In a method for operating an air-compressing fuel-injection internal combustion engine having an exhaust gas post-treatment system with a particle filter and a nitrogen oxide reduction catalytic converter, a plurality of internal combustion engine operating settings are provided, each having respective predefined values for predefined internal combustion engine operating parameters. A heating operating setting is set when the internal combustion engine is warming up, while a basic operating setting is set in the warmed-up state. When the temperature in the exhaust gas system exceeds a predefinable first value, the heating operating setting is changed over to the basic operating setting. In the warmed-up state, at least one further (third) operating setting, with an exhaust gas recirculation rate that is reduced compared to the basic operating setting, is provided in addition to the basic operating setting.

Abstract: 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.

Abstract: 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.

Abstract: The exhaust gas aftertreatment device according to the invention having a reforming unit for generating hydrogen by steam reforming, partial oxidation of hydrocarbons and/or mixed forms thereof is distinguished by the fact that the reforming unit is arranged directly in the main exhaust gas stream from an internal combustion engine. The steam and residual oxygen which are required for the reforming preferably originate from the exhaust gas. The step of providing the required reducing agents consists in briefly switching the internal combustion engine, which is predominantly operated in lean-burn mode and the exhaust gas from which is undergoing the aftertreatment, to rich-burn mode, allowing reforming by means of the reforming reactor according to the invention using the hydrocarbons that are present in the exhaust gas.

Abstract: In a method for operating an air-compressing fuel-injection internal combustion engine having an exhaust gas post-treatment system with a particle filter and a nitrogen oxide reduction catalytic converter, a plurality of internal combustion engine operating settings are provided, each having respective predefined values for predefined internal combustion engine operating parameters. A heating operating setting is set when the internal combustion engine is warming up, while a basic operating setting is set in the warmed-up state. When the temperature in the exhaust gas system exceeds a predefinable first value, the heating operating setting is changed over to the basic operating setting. In the warmed-up state, at least one further (third) operating setting, with an exhaust gas recirculation rate that is reduced compared to the basic operating setting, is provided in addition to the basic operating setting.

Abstract: In a method for operating an air-compressing fuel-injection internal combustion engine having an exhaust gas post-treatment system with a particle filter and a nitrogen oxide reduction catalytic converter, a plurality of internal combustion engine operating settings are provided, each having respective predefined values for predefined internal combustion engine operating parameters. A heating operating setting is set when the internal combustion engine is warming up, while a basic operating setting is set in the warmed-up state. When the temperature in the exhaust gas system exceeds a predefinable first value, the heating operating setting is changed over to the basic operating setting. In the warmed-up state, at least one further, (third) operating setting, with an exhaust gas recirculation rate that is reduced compared to the basic operating setting, is provided in addition to the basic operating setting.

Abstract: In a device and a method for removing nitrogen oxides from the exhaust of an internal combustion engine which is operated predominantly with an excess of air, the internal combustion engine is assigned an exhaust system having a nitrogen oxide reduction catalytic converter which comprises two catalytic converter parts, whose reducing agent filling levels can be determined. Metering of a reducing-agent-containing additive into the exhaust gas of the internal combustion engine takes place as a function of the reducing agent filling level of the first catalytic converter part and/or of the second catalytic converter part.

Abstract: A method for operating an exhaust gas treatment system that includes an SCR catalytic converter is provided. Either a model-based filling level regulation for achieving the target filling level or a model-based efficiency control for achieving the target efficiency is performed according to presettable values for certain operating variables such as a temperature of the exhaust gas or of the SCR catalytic converter.

Abstract: In a system with an SCR catalytic converter, a correction by a changeable long term adaption factor to a target dosing rate is provided for the model dosing rate and a correction by a changeable short term adaption factor to an assumed actual filling state for the ammonia filling level value. A dosing unit controllable by a control unit adds an ammonia-containing reducing agent to the exhaust gas and n exhaust gas enriched with ammonia according to the dosing is fed to the SCR catalytic converter. An ammonia filling level value for a filling level of ammonia stored in the SCR catalytic converter and a model dosing rate for dosing the reducing agent into the exhaust gas are calculated by a computer model.

Abstract: In a method for reducing the emission of nitrogen dioxide in a motor vehicle having an exhaust gas purification system having an SCR catalytic converter with adsorption centers for nitrogen oxides, an exhaust gas enriched with ammonia is supplied to the SCR catalytic converter above an operating temperature. Below the operating temperature, the exhaust gas supplied to the SCR catalytic converter is enriched with a material such that an adsorption of nitrogen oxides is inhibited at corresponding adsorption centers of the SCR catalytic converter. In order to reduce the overall NOx emissions below a first, predeterminable amount, an exhaust gas enriched with ammonia is supplied to the SCR catalytic converter and the NO2 portion of the total NOx emissions is reduced below a second, predeterminable amount in that NO2 is converted with hydrocarbons stored in the SCR catalytic converter.

Abstract: 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.

Abstract: 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.