摘要:
The present invention relates to a method for operating a purification device, to a purification device and to the use of same. To reduce the emission of pollutants, a filter body through which a fluid can flow and comprising a catalyst, is exposed to a stream of gas which is to be purified. Before the gas enters the catalyst, a reducing agent is added in the flow direction of the gas, and after a certain treatment point, during which the gas, which is to be purified, is flowing in the catalyst, reducing agent is added once more to the flowing gas by a feeding mechanism and contact with the catalyst is maintained.
摘要:
A method of catalytically reducing nitrogen oxides (NO.sub.x) and oxidizing hydrocarbons or carbon monoxide in exhaust gases of internal combustion engines or combustion power plants using a catalyst comprising a magnesium oxide/copper oxide/aluminum oxide spinel or a copper-impregnated copper oxide/aluminum oxide spinel.
摘要:
The present invention relates to a method for operating a catalyst for gases, especially for exhaust gases of stoichiometrically operated gasoline engines, wherein a catalyst is exposed to a gas stream and pollutants are catalytically converted. To improve the elimination of pollutants in the starting phase, hydrocarbons present in the gas are temporarily stored by the catalyst at temperatures below a response temperature of the catalyst, particularly below 200.degree. C., and preferably below 150.degree. C. The hydrocarbons are then released at temperatures above the response temperature and the pollutants, such as nitrogen oxides, are catalytically converted with reducing agents, such as hydrocarbons, carbon monoxide and mixtures thereof. The catalyst is a spinel, such as (MgCu)Al.sub.2 O.sub.4, which may also include a catalytically active species, such as WO.sub.3, V.sub.2 O.sub.5 and TiO.sub.2.
摘要翻译:本发明涉及一种用于操作气体催化剂,特别是用于化学计量操作的汽油发动机的废气的方法,其中催化剂暴露于气流并且污染物被催化转化。 为了改善起始阶段污染物的消除,存在于气体中的烃在催化剂的反应温度以下,特别是低于200℃,优选低于150℃的温度下,被催化剂临时储存。然后将烃 在高于响应温度的温度下释放并且诸如氮氧化物的污染物用还原剂如烃,一氧化碳及其混合物进行催化转化。 催化剂是尖晶石,例如(MgCu)Al 2 O 4,其还可以包括催化活性物质,例如WO 3,V 2 O 5和TiO 2。
摘要:
A catalyst and a method for producing the catalyst, for catalytic reduction of NO.sub.x and oxidation of hydrocarbons, the catalyst comprises a zinc, copper and aluminum spinel to which, at least one element selected from palladium, platinum, rhodium, ruthenium, osmium, iridium, rhenium and/or rare earth metals, such as lanthanum and cerium, vanadium, titanium, niobium, molybdenum, tungsten and/or salts thereof and/or oxides thereof has been added.
摘要:
An exhaust-gas cleaning system for cleaning exhaust gas from a combustion source so as to remove at least nitrogen oxides contained therein is provided. An ammonia-generation catalytic converter for generating ammonia uses constituents of at least some of the exhaust gas emitted from the combustion source during ammonia-generation operating phases. A downstream nitrogen oxide reduction catalytic converter is provided for reducing nitrogen oxides which are contained in the exhaust gas emitted from the combustion source using the ammonia generated as the reducing agent. According to the invention, a plasma generator for using plasma technology to generate reactive particles, which promote the ammonia-generation reaction, from constituents of the exhaust gas fed to the ammonia-generation catalytic converter during the ammonia-generation operating phases is connected upstream of the ammonia-generation catalytic converter. This ensures that sufficient ammonia is generated even at relatively low exhaust-gas temperatures.
摘要:
A description is given of superconducting substances having a content of Bi, Sr, Ca and Cu, and of processes for their preparation from the metal oxides within a range which is specified by the overall composition Bi.sub.a (Sr,Ca).sub.b -Cu.sub.6 O.sub.x, where a=3-24 and b=3.23-24, with an Sr/Ca atomic ratio of 1:9-9:1 and a Bi:(Ca+Sr) atomic ratio of 0.3-1.5. The transition temperature is at least 60 K. The principal phase crystallizes in the orthorhombic system. The pure compounds Bi.sub.4 (Sr,Ca).sub.4 Cu.sub.2 O.apprxeq..sub.12 and Bi.sub.4 (Sr,Ca).sub.6 Cu.sub.4 O.apprxeq..sub.20.
摘要:
A method for catalytically reducing pollutants, in particular oxides of nitrogen in oxygen-containing exhaust gases of internal combustion engines, uses a catalyzer unit arranged in the exhaust gas flow of the engine. The catalyzer unit has a catalytic layer, an ion conducting layer and a counterelectrode. The catalytic layer exhibits a non-Faraday modification of the catalytic activity.
摘要:
The invention relates to a method for producing a bearing surface (5) of a radial shaft bearing from electrically conductive material. In said method, the contour of the bearing surface (5) is machined down in a first machining step, and the bearing surface (5) is electrochemically machined in a subsequent step. Also disclosed are an electrode for electrochemical machining as well as a connecting rod (1) to be used in machines.
摘要:
The invention relates to a method for producing heteroepitaxial diamond layers on Si-substrates by means of CVD and standard process gases, in which (a) during the nucleation phase a negative bias voltage is applied to the Si-substrate and (b) following the nucleation phase diamond deposition takes place.
摘要:
A method operates an improved internal combustion engine by heating the fuel before entry into the cylinder, at least during the cold-start phase of the engine. In order to undertake the heating step in a favorable way, at least areas in the region of an intake valve are irradiated with an electromagnetic radiation of radiation source, and thereby heated without contact. As a result, liquid fuel in the valve region is heated by contact with the areas of the valve region, and condensation of the fuel is at least reduced.