Abstract: A device and a method for deNOxing exhaust gas from an internal combustion engine includes taking into account an amount of gaseous reducing agent (ammonia) that escapes while the internal combustion engine is at a stand-still as a result of temperature influences in a calculation of the amount of reducing-agent solution (urea) that is to be metered when the internal combustion engine is operating. The gaseous reducing agent is passed to the reduction catalytic converter through a pressure-relief line that includes a pressure-control valve, and, in the method, the amount is recorded by a flowmeter.

Abstract: A device and a method for deNOxing exhaust gas from an internal combustion engine includes taking into account an amount of gaseous reducing agent (ammonia) that escapes while the internal combustion engine is at a stand-still as a result of temperature influences in a calculation of the amount of reducing-agent solution (urea) that is to be metered when the internal combustion engine is operating. The gaseous reducing agent is passed to the reduction catalytic converter through a pressure-relief line that includes a pressure-control valve, and, in the method, the amount is recorded by a flowmeter.

Abstract: A process for catalytic removal of a pollutant from a combustion installation exhaust gas includes calculating, from operationally relevant parameters of the installation, a pollutant concentration using a predetermined characteristic diagram. A predetermined quantity of a reagent is introduced into the exhaust per unit time as a function of the calculated pollutant concentration, the reagent reacting with the pollutant at a catalytic converter. Operating states of the installation with substantially constant pollutant emission levels are determined. The pollutant concentration during an operating state of the installation with a substantially constant pollutant emission level is determined with a sensor and only a pollutant concentration from the installation in a steady operating state is used to correct the diagram. The pollutant concentration from the installation is calculated with the diagram in a non-steady operating state.

Abstract: The invention relates to a filter in which dust-containing silica sand is held together by a polyurethane binder, the polyurethane binder containing an organotin compound with a molecular weight of more than 600 as catalyst and a mixture of highly dispersed silica and/or bentonites with a thickened aluminosilicate as modifier. The filter is particularly suitable for the production of drinking water from ground water in surface mining regions.

Abstract: A process for catalytic removal of a pollutant from a combustion installation exhaust gas includes calculating, from operationally relevant parameters of the installation, a pollutant concentration using a predetermined characteristic diagram. A predetermined quantity of a reagent is introduced into the exhaust per unit time as a function of the calculated pollutant concentration, the reagent reacting with the pollutant at a catalytic converter. Operating states of the installation with substantially constant pollutant emission levels are determined. The pollutant concentration during an operating state of the installation with a substantially constant pollutant emission level is determined with a sensor and only a pollutant concentration from the installation in a steady operating state is used to correct the diagram. The pollutant concentration from the installation is calculated with the diagram in a non-steady operating state.

Abstract: A completely self-contained device reduces the NOx content in the exhaust gas of an internal combustion engine operated with excess air. One or more reduction catalytic converters working according to the SCR principle are provided. A reducing agent control unit need not make any recourse to data present in the control unit of the internal combustion engine. Fitting and retrofitting to a vehicle is greatly simplified, particularly for vehicles that are already in use.

Abstract: An injection valve of a reducing agent metering device is enclosed in a double-walled valve holding element that is connected directly to the exhaust-gas line. It is thereby possible to blow pressurized air into an air gap between an outer wall and an inner wall of the valve holding element and, as a result, to cool at least those parts of the injection valve that are in close vicinity to the exhaust gas.

Abstract: A bypass leads away from the exhaust pipe and the bypass flow is set with an electrically actuable exhaust gas valve. Under certain operating states of the internal combustion engine, in particular when the load is increasing rapidly or during warmup, a portion or the entire exhaust gas flow is diverted through a combined hydrolysis/adsorption catalytic converter in the bypass line. The NOx contained in the exhaust gas is adsorbed in a particularly favorable manner.

Abstract: A method and a device for decomposing nitrogen oxides in an exhaust gas of an internal combustion engine, include feeding the exhaust gas and a reactant which is sprayed into the exhaust gas through the use of compressed air, to a catalytic converter. A compressor for supplying compressed air is associated with the internal combustion engine, and part of the compressed air is diverted and used as the compressed air for injecting the reactant. The sprayed reactant is fed to the catalytic converter, together with the exhaust gas to be purified, which ensures the decomposition of the nitrogen oxides, in particular according to the method of selective catalytic reaction.