摘要:
A zeolite catalyst and a method for reduction of nitrogen oxides present in waste gas streams is described. The method includes mixing the waste gas containing nitrogen oxides with ammonia. At an elevated temperature, this mixture is passed over a zeolite catalyst. Preferably, the zeolite catalyst is in a monolithic or honeycomb form. The zeolite catalyst includes one or more of the following subgroup metals: copper, iron, molybdeum and cerium. The zeolite catalysts made in accordance with this invention show better conversion of nitrogen oxides and longer life than known catalysts.
摘要:
Titanium dioxide compacts are produced by intensively mixing pyrogenically produced titanium dioxide in the presence of deionized water with a wetting agent and/or with a base and/or optionally with a binder and/or optionally with an auxiliary deformation agent and/or optionally with a pore former, extruding the mass thus obtained at pressures between 5 and 100 bars to form shaped articles, drying the shaped articles at temperatures between 50.degree. and 120.degree. C. and subsequently calcining the shaped articles in the ambient air at temperatures of 400.degree. to 700.degree. C. for 1 to 5 hours.
摘要:
A catalyst is described made of active aluminum oxide with additives of CeO.sub.2, ZrO.sub.2, and Fe.sub.2 O.sub.3 and/or NiO as carrier and an active phase, applied thereon and consisting of platinum, palladium and/or rhodium, and a base metal, which is obtainable by impregnation of the additive-containing carrier with solutions of salts of the metals for the active phase, wherein the base metal of the active phase is cerium, by drying, and by heating to 250.degree. to 650.degree. C. The catalyst can be used for the oxidation and/or reduction of exhaust gases from internal combustion engines.
摘要翻译:催化剂由具有CeO 2,ZrO 2和Fe 2 O 3和/或NiO作为载体的添加剂和施加在其上并由铂,钯和/或铑和贱金属组成的活性相的活性氧化铝制成,其可获得 通过用活性相的金属盐溶液浸渍含添加剂的载体,其中活性相的贱金属是铈,通过干燥,加热至250〜650℃。可以使用催化剂 用于氧化和/或还原来自内燃机的废气。
摘要:
A device for the containment of ceramic catalyst monoliths particularly of four cornered cross sectional area as well as for the combination of a plurality thereof into a package. The device includes elastic gaskets arranged on one of the ends of the monoliths and partitions for the form fitting containment of the elements into a cassette.
摘要:
A coating dispersion is shown for the production of catalysis-promoting coatings on an inert, structure-reinforcing element. The solids of the dispersion are present in various particle fractions and lead to a relatively rough coating surface with improved exchange between the exhaust gas and the catalyst surface. This results in improved heat-up behavior of the catalyst.
摘要:
A coating dispersion is shown for the production of catalysis-promoting coatings on an inert, structure-reinforcing element. The solids of the dispersion are present in various particle fractions and lead to a relatively rough coating surface with improved exchange between the exhaust gas and the catalyst surface. This results in improved heat-up behavior of the catalyst.
摘要:
A process is described for the purification of exhaust gases containing oxides of nitrogen and sulfur obtained from combustion installations and industrial production processes by selective catalytic reduction of the nitric oxides with ammonia, subsequent catalytic oxidation of sulfur dioxide with oxygen and conversion into sulfuric acid of the sulfur trioxide obtained.
摘要:
A catalyst for the selective reduction of nitrous oxide with ammonia contains, in addition to titanium oxide as component (A), at least one oxide of W, Si, B, Al, P, Zr, Ba, Y, La, Ce and at least one oxide of Y, Nb, Mo, Fe, Cu as component (B), whereby the atomic ratio between the elements of components (A) and (B) amounts to 1:0.001 up to 1. The catalyst can be obtained by kneading reactive titanium oxide with a high specific surface of predominantly anatase with the substances of component (B) or their preliminary stages, adding processing agents, winding up with a homogeneous kneaded mass, extruding the latter, drying the extrudate and calcining in air at 300.degree.-800.degree. C.
摘要:
A device for the continuous measurement of the ammonia concentration in gases in the ppm range includes a columnar absorption vessel (1) with a hemispherical bottom (4). The bottom of the column includes an overflow (3) and an outlet (5). The gas introduction pipe (7,8) empties above the bottom (4) and below a sieve bottom (6) arranged in the column (1). A packing material (10) rests on the sieve bottom (6), which packing (10) essentially fills the absorption column (1). A cooling part (11) extends from the absorption column (1). The cooling part (11) includes a cooling zone (15) and a gas collection space (16) above it with a closable connection piece (13). A pipe (14), which may include a serrated crown on each end, runs from the gas collecting space (16) downward in a cooled manner to the packing 10. The liquid absorption agent is introduced through a lateral connection piece (18) into the gas collection space (16). For the measurement of ammonia concentration, a certain volume flow of the gas to be measured is washed in a countercurrent flow with the absorption agent, and the NH.sub.3 content is determined in a part of the ammonia containing absorption agent. The volume flow rate of the absorption agent and of the gas from which NH.sub.3 has been removed is measured (the latter being dried), and the ammonia concentration is thereby calculated.
摘要:
A method for the removal of nitrogen oxides contained in exhaust gases of an optionally fluctuating composition with a temperature of 0.degree.-600.degree. C. by means of catalytic reduction at a preselected stoichiometric ratio between the concentration of reducing agent and the concentration of nitrogen oxide in which the reducing agent is dosed in a pulsed manner.