摘要:
A material and a process for adsorbing and desorbing nitrogen oxides in exhaust gas systems of engines running on a lean mixture, which does not require a prior oxidation step, wherein a mixed oxide which has an oxygen-rich orthorhombic structure is used which changes to an oxygen-poor tetragonal structure as a function of temperature.
摘要:
A catalyst and a process for producing the catalyst are provided. For the catalytic reduction of NO.sub.x and for the oxidation of hydrocarbons, the catalyst contains a spinel containing the metals copper, zinc and aluminum.
摘要:
A catalyst and a process for producing the catalyst are provided. For the catalytic reduction of NO.sub.x and for the oxidation of hydrocarbons, the catalyst contains a spinel containing the metals copper, zinc and aluminum.
摘要:
The invention provides a catalyst, and a process for preparing the same, for the catalytic reduction of NO.sub.x and for the oxidation of hydrocarbons. The catalyst contains a copper oxide-zinc oxide-aluminum oxide spinel and a zeolitic support material.
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:
An exhaust gas purification device includes a porous body of catalytic material of the general formula AaBbO4 disposed in an exhaust gas stream of an engine. The porous body of catalytic material has a characteristic response temperature above which it is catalytically active to reduce pollutants in the presence of a reducing agent. The porous body stores at least 20% by volume hydrocarbons at temperatures below the response temperature. A represent at least one element selected from Mg, Ca, Mn, Fe, Ni, Co, Cu, Zn, Sn, Ti and A+B is less than 3, A is greater than 0 and B greater than 0.
摘要:
A process for the catalytic reduction of NO.sub.x, the reduction taking place in the presence of a catalyst which comprises(a) from 20 to 97 wt % of A.sub.2 O.sub.3,(b) from 1 to 40 wt % of CuO,(c) from 1 to 50 wt % of ZnO,(d) from 1 to 40 wt % of Ag,(e) from 0 to 2 wt % of Pt,(f) from 0 to 20 wt % of oxides of rare earth metals, elements of the 3rd subgroup of the Periodic Table of the Elements or mixtures thereof,based on the total weight of the components (a) to (e), which adds up to 100 wt %, wherein, in each case, up to half the weight of the component (a) may be replaced by Fe.sub.2 O.sub.3, Cr.sub.2 O.sub.3, Ga.sub.2 O.sub.3 or mixtures thereof, of the component (b) by CoO, of the component (c) by MgO, of the component (d) by Au and of the component (e) by Pd, Ru, Os, Ir, Rh, Re or mixtures thereof, is used for reducing NO.sub.x, especially in combustion off-gases, the components (a), (b) and (c) forming a spinel which is doped with the components (d), (e) and (f).
摘要:
The invention relates to a method and a device for cleaning flowing gases. To reduce the total emissions, nitrogen oxides, especially NO and NOx, are extracted at least partially from the gas to be scrubbed, in the temperature range from 50 and 300° C., preferably between 50 and 150° C. To extract the nitrogen oxides, an intermediate storage medium is used that is composed of a storage material and a supporting material for the storage material. The intermediate storage medium having in particular a composition of the formal chemical formula Ag.CuAl2O4 in an Al2O3 matrix, with the composition being a spinel or being of the spinel type, and with the composition having characteristic spinel lines in the x-ray spectrum, where 0≦x
摘要翻译:本发明涉及清洗流动气体的方法和装置。 为了减少总排放量,氮氧化物,尤其是NO和NO x至少部分地从待洗涤的气体中提取,温度范围为50-300℃,优选为50-150℃。为了提取氮 氧化物,使用由储存材料和用于储存材料的支撑材料组成的中间储存介质。 中间储存介质特别是在Al 2 O 3基质中具有形式化学式Ag.CuAl 2 O 4的组成,其组成为尖晶石或尖晶石型,并且组合物在x射线谱中具有特征尖晶石线, 其中0 <= X <1。
摘要:
The present invention is directed to a purification device that includes a porous body and a catalyst. To reduce the emission of pollutants, a pollutant-containing stream of gas flows through the porous body.
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.