Abstract: In a method for exhaust gas aftertreatment, in which an exhaust gas to be aftertreated, which is produced during combustion of a fuel, is treated with a reducing agent. A constituent of the fuel is hereby also used as a constituent of the reducing agent, with the constituent of the fuel which is also used as a constituent of the reducing agent being hydrogen. The hydrogen is produced from water, and the reducing agent is a mixture of hydrogen and ammonia.

Abstract: A method for determining a sulfur trioxide content in a gas. A sample of the gas is taken, and a gas pressure of the sample is reduced. A wave number-resolved transmission measurement is carried out on the sample using a wave number-tunable monochrome light source, and a sulfur trioxide content is derived from the measurement. The measurement is carried out in the sulfur trioxide absorption band between 1360 and 1410 cm?1, in particular in a window around the sulfur trioxide absorption at 1365.49 cm?1. A method for operating a power plant, a measuring system for determining a sulfur trioxide content in a gas, and a power plant are adapted to determine a sulfur trioxide content in a gas.

Abstract: A method for determining a sulfur trioxide content in a gas. A sample of the gas is taken, and a gas pressure of the sample is reduced. A wave number-resolved transmission measurement is carried out on the sample using a wave number-tunable monochrome light source, and a sulfur trioxide content is derived from the measurement. The measurement is carried out in the sulfur trioxide absorption band between 1360 and 1410 cm?1, in particular in a window around the sulfur trioxide absorption at 1365.49 cm?1. A method for operating a power plant, a measuring system for determining a sulfur trioxide content in a gas, and a power plant are adapted to determine a sulfur trioxide content in a gas.

Abstract: In a method for exhaust gas aftertreatment, in which an exhaust gas to be aftertreated, which is produced during combustion of a fuel, is treated with a reducing agent. A constituent of the fuel is hereby also used as a constituent of the reducing agent, with the constituent of the fuel which is also used as a constituent of the reducing agent being hydrogen. The hydrogen is produced from water, and the reducing agent is a mixture of hydrogen and ammonia.

Abstract: A method for reducing the concentration of nitrogen oxide in an exhaust gas from an incomplete combustion of hydrocarbons or hydrocarbon mixtures using a catalyst for reducing nitrogen dioxide by oxidizing non-combusted hydrocarbons or hydrocarbon mixtures, a device for reducing the concentration of nitrogen dioxide in an exhaust gas from an incomplete combustion of hydrocarbons or hydrocarbon mixtures using a catalyst for reducing nitrogen dioxide by oxidizing non-combusted hydrocarbons or hydrocarbon mixtures, and a system including the device is provided.

Abstract: The present invention concerns a method for reducing the concentration of nitrogen oxide in an exhaust gas from an incomplete combustion of hydrocarbons or hydrocarbon mixtures using a catalyst for reducing nitrogen dioxide by oxidising non-combusted hydrocarbons or hydrocarbon mixtures, a device for reducing the concentration of nitrogen dioxide in an exhaust gas from an incomplete combustion of hydrocarbons or hydrocarbon mixtures using a catalyst for reducing nitrogen dioxide by oxidising non-combusted hydrocarbons or hydrocarbon mixtures, and a system comprising said device.

Abstract: Flue gas, in particular from a steam generator, requires cleaning. A catalytic converter for deNOxing the flue gas, which is used, for example, to heat an air preheater, is often employed for this purpose. Residues of a reducing agent react with unconverted sulfur oxide and form a substance which damages the air preheater. To suppress this reaction, there is provided a first mixer for more uniformly mixing the flue gas with the reducing agent downstream of the catalytic converter, as seen in the direction of flow.

Abstract: The process and the device are provided for the selective catalytic reduction of nitrogen oxides in an oxygen-containing gaseous medium. The reducing agent required for the reaction is prepared in a separate preparation reactor. A substance that can be converted into the reducing agent is introduced into a carrier gas in the preparation reactor and, as a result, is converted by substantially thermal conversion. The energy required for the conversion is provided by the carrier gas.

Abstract: With a catalyst that is operated in a dust-containing off-gas, there is a problem with the catalyst becoming blocked by individual particles contained in a gas flowing onto the catalyst. The invention describes a catalyst body with a multiplicity of first longitudinal passages, which also contains second longitudinal passages. The second longitudinal passages have a larger passage cross-section than the first longitudinal passages. As a result, the advantage of a high specific surface area per volume of the catalyst is maintained in combination with simultaneous permeability to individual particles.

Abstract: A method of operating a gas and steam turbine plant includes operating a gas turbine with a fuel to produce an expanded working medium and generating steam for a steam turbine from heat contained in the expanded working medium leaving the gas turbine. A reducing agent and a supply of an adjustable quantity of carrier air are introduced into the working medium with a metering system, for catalytically cleaning the working medium. The quantity of carrier air is adjusted as a function of the type of fuel supplied to the gas turbine. The quantity of carrier air is controlled only with a first air compressor for gas fuel operation of the gas turbine and additionally with a second air compressor, connected in parallel with the first air compressor, for oil fuel operation of the gas turbine. A gas and steam turbine plant is also provided.

Abstract: A combined mixing and deflection unit includes a flow conduit for a medium flowing in a given direction. The flow conduit has a bend region, a given direction downstream of the bend region as seen in the given flow direction, and a cross section. A guide configuration is disposed in the bend region for deflecting the flowing medium from a main flow direction. The guide configuration defines a plane aligned approximately parallel to the given direction downstream of the bend region. The guide configuration has openings formed therein being evenly distributed over the cross section of the flow conduit.

Abstract: Combustion systems have a combustion apparatus, heating surfaces downstream of the combustion apparatus in a flue gas stream, and a deNO.sub.x catalyst. A method for reducing nitrogen oxides in the flue gas of the combustion systems includes selectively assigning the deNO.sub.x catalyst to a position inside and a position outside the flue gas stream as a function of a nitrogen oxide concentration or of a selected energy carrier. An apparatus for reducing nitrogen oxides in the flue gas of the combustion system includes a device for selectively assigning the deNO.sub.x catalyst to a position inside and a position outside a line through which the flue gas flows.

Abstract: A method for operating a gas and steam turbine plant includes producing steam for a steam turbine by utilizing heat contained in pressure-relieved flue gas of a gas turbine, and decreasing the temperature of the pressure-relieved flue gas upon the onset of a critical operating state, by introducing water into the pressure-relieved flue gas. A gas and steam turbine plant includes a gas turbine having a flue gas conduit, a steam turbine having a water-steam loop, a steam generator being connected to the flue gas conduit downstream of the gas turbine for producing steam in the water-steam loop, and a device for introducing water into the flue gas conduit.