Abstract: A device for exhaust-gas purification utilizes reduction of nitrogen oxides which are present in the exhaust gas from internal combustion engines by way of gaseous ammonia with an SCR catalytic converter. The functions of the device are monitored with regard to their line paths with connections, valves and sensors by referring to these elements themselves using suitable control circuitry via the evaluation and control unit.

Abstract: A method for determining the storage state of an ammonia-storing SCR catalyst, the change in at least one physical property of the SCR catalyst material, changing with the NH3 storing process, being sensed, the measurement taking place on the SCR catalyst material itself by applying a measuring pickup to the SCR catalyst or bringing it into direct contact with the latter and determining the storage state on the basis of these results.

Abstract: In a method for burning deposited soot particles in a particle filter on an exhaust device of a diesel engine, first of all, in a known way, a catalytic converter produces NO2 from exhaust gas. This NO2 reduces the ignition temperature of soot to such an extent that it burns at normal exhaust-gas temperature. Furthermore, there is provision to add fuel additive, which likewise allows the ignition temperature of the soot to be reduced. The sulphur content in the fuel is determined, and either generation of NO2 or the addition of additive is used as a function of this measurement. This preferably takes place automatically. To determine the sulphur content, it is possible, for example, to use a sulphur sensor in the tank.

Abstract: A device for exhaust-gas purification utilizes reduction of nitrogen oxides which are present in the exhaust gas from internal combustion engines by way of gaseous ammonia with an SCR catalytic converter. The functions of the device are monitored with regard to their line paths with connections, valves and sensors by referring to these elements themselves using suitable control circuitry via the evaluation and control unit.

Abstract: In a method for burning deposited soot particles in a particle filter on an exhaust device of a diesel engine, first of all, in a known way, a catalytic converter produces NO2 from exhaust gas. This NO2 reduces the ignition temperature of soot to such an extent that it burns at normal exhaust-gas temperature. Furthermore, there is provision to add fuel additive, which likewise allows the ignition temperature of the soot to be reduced. The sulphur content in the fuel is determined, and either generation of NO2 or the addition of additive is used as a function of this measurement. This preferably takes place automatically. To determine the sulphur content, it is possible, for example, to use a sulphur sensor in the tank.

Abstract: A device and method for removing nitrogen oxides from the exhaust gas from lean-burn internal combustion engines, e.g., diesel engines used in motor vehicles, includes a feed for a reducing agent, an NH3 sensor for measuring the NH3 concentration in the exhaust gas, and an exhaust pipe with NOx reduction catalytic converter. The arrangement configured to feed in reducing agent includes a control circuit for quantitatively continuously controllable supply of reducing agent to the exhaust gas, the control variable of the control circuit being the NH3 concentration measured by the NH3 sensor, and the guide variable of the control circuit being an NH3 concentration value which may be predetermined as a function of the operating point of the internal combustion engine. The NOx reduction catalytic converter is divided into at least two parts which are separate from one another and are arranged in series in the direction of flow of the exhaust gas.