Abstract: A process for reducing nitrogen oxides on a SCR catalyst disposed in an exhaust gas system of an internal combustion engine is performed by a device adapted to introduce ammonia (NH3) into the exhaust gas flow of the exhaust gas system before it reaches the SCR catalyst. The device includes a heatable pressure-tight converter, an NH3 store and a control unit with control signals processing engine operating characteristics and determining therefrom the NOx output for controlling a timed valve for injection of an NH3 dose.

Abstract: The invention concerns a process for the preparation of a vanadia SCR-catalyst supported on titania. The process is characterized in that the catalyst is prepared by dispersing titania in an ammonium metavanadate (NH4VO3) solution, adjusting the pH of the solution to a value of 7.0-7.1 by NH4OH and HNO3, stirring the resulting suspension for a time sufficient for complete adsorption of the vanadium compound on titania, filtering the suspension and drying and calcining the resulting catalyst compound.

Abstract: An exhaust gas purification system for denoxing exhaust gases has a converter containing a substance thermolytically separable into NH3, a feed line connecting the converter with an exhaust gas line for supplying NH3 into the exhaust gas flow therein, a dosing device in the feed line for dosing the NH3 to be introduced into the exhaust gas flow, a heatable cold-start store connected to the feed line between the converter and dosing device for providing the substance during starting of a combustion unit connected to the exhaust gas line, an air feeding device having two air conduits provided with valves wherein one conduit is connected to the feed line between the cold-start store and dosing device and the other conduit is connected to a mixing chamber located in the feed line after the dosing device, and a reservoir container for storing the substance connected to a filling pipe terminating in the converter.

Abstract: A process and apparatus for the selective catalyzed NO.sub.x reduction in oxygen-containing exhaust gases of internal-combustion engines. For improving the reduction of nitric oxides, hydrocarbons and air are supplied to the exhaust gas purifier and, for producing reactive short-chained unsaturated hydrocarbons, a defined quantity of fuel from the stored fuel intended for the fuel supply of the internal-combustion engine is catalytically cracked and is oxidized by the simultaneous supply of air. The resulting species are guided into the exhaust gas flow of the exhaust gases which are to be purified.

Abstract: The process of removing dust, sulfur compounds and nitrogen oxides from combustion exhaust gases, comprising mixing a combustion exhaust gas with ammonia; feeding Ca(OH).sub.2 and FeSO.sub.4 to a fluidized bed reactor containing mixed solids including fly ash, iron sulfates and calcium compounds, especially Ca(OH).sub.2, CaCO.sub.3, CaO, CaSO.sub.4 and CaSO.sub.3 ; supplying an ammonia-containing exhaust gas mixture to the fluidized bed reactor as a fluidizing gas; operating the fluidized bed reactor at a temperature between 300.degree. and 450.degree. C. to form a reacted exhaust gas; supplying the reacted exhaust gas to a multistage electrostatic precipitator having a first stage and additional stages; recycling solids collected in the first stage to the fluidized bed reactor; and recycling one portion of additional solids collected in the additional stages to the fluidized bed reactor and discharging another portion of the additional solids.

Abstract: The invention relates to a continuous process for coating bundles of fibers, particularly carbon fibers, with a layer of silicon--which may be present as the carbide, oxide, nitride, or plasma polymer with carbon and hydrogen or in elementary form--by radio-frequency sputtering. The coated fibers are suitable in particular for the manufacture of reinforced plastics.

Abstract: A process is disclosed wherein NO contained in a gas is reduced by means of NH.sub.3 as a reducing agent. A mixture of the NO-containing gas and NH.sub.3 is reacted at 290.degree. to 450.degree. C. in the presence of a catalyst, which comprises a support of SiO.sub.2 and contains 5 to 15% by weight manganese sulfate and iron sulfate. The mole ratio of manganese sulfate and iron sulfate, which is calculated as FeSO.sub.4, is between 1:10 and 10:1. The support has a pore volume of 0.6 to 1.6 ml/g and an average pore diameter of 10 to 100 nm.

Abstract: A process of catalytically reducing NO contained in a gas which contains SO.sub.2. The NO is reduced with NH.sub.3, which is admixed to the gas which contains SO.sub.2 and NO. The mixture is supplied to the catalyst at a rate of 0.2 to 20 standard liters per minute and per gram of catalyst and is reacted with the latter in a fluidized bed at a temperature between 185.degree. and 500.degree. C. and under normal pressure. The catalyst has a particle size between 0.1 and 3 mm and is composed of an acid support and an active component, which consists of V.sub.2 O.sub.5, MnO.sub.2, CuO, Fe.sub.2 O.sub.3, NiO and/or Y.sub.2 O.sub.3 and has been applied to the support in a quantity of 0.5 to 20% by weight. It is proposed that part of the catalyst is removed from the fluidized bed and is regenerated and returned to the fluidized bed.