摘要:
A process and apparatus for accelerating the rate of heating of a fixed bed catalyst to a light-off temperature for a catalytic reaction is disclosed. Supplementary energy from an external energy source is provided to a predetermined area of the catalyst bed for a limited period of time. The fixed bed catalyst may be present as a solid body or in bulk form and has a gas inlet area defined by a cross-section of the flow through channels of the reaction media. The supplementary energy is supplied to one or more isolated sections of the gas inlet area of the catalyst. Such a system significantly reduces the energy required in order to effectuate at least partial conversion of harmful emissions during initial operation of the converter.
摘要:
A method is disclosed for manufacturing a monolithic metal support with a coated, gas-permeable shaped body. The shaped body is formed of one or more smooth and/or corrugated metal foil strips previously coated with a dispersion coating. During or after formation of the shaped body, the metal foil strips are joined by soldering or welding to at least one adjacent metal foil strip or to at least one adjacent layer of the same metal foil strip.
摘要:
A catalyst is described for reducing the quantity of nitrogen oxides in lean exhaust gas of motor vehicle engines. The catalyst contains, on a structure reinforcing body, a first catalytic coating of an aluminum oxide and/or cerium oxide of large surface area impregnated with a mixture of iridium and platinum as catalytically active noble metal components. A second catalytic coating including a zeolite of the mordenite type containing copper and/or iron is applied to the first coating layer.
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:
Monolithic catalysts with a metal carrier that includes a catalytically coated matrix having at least one stack of several sheet-metal strips of corrugated or alternately corrugated and flat metal strips folded or intertwined with one another are described. The free ends of the metal strips are connected by a joining process with a surrounding jacket tube of any required cross-section. The monolithic catalyst is produced very economically and with a catalytic coating that has a uniform thickness. The at least one stack of sheet-metal strips required for the monolithic catalyst with a metal carrier is assembled from coated metal ribbons cut to length so as to form metal stacks. The stacks may be folded and/or intertwined with themselves or with one another so as to form the matrix. The matrix with intertwined and coated strips is inserted into the jacket tube and the free ends of the metal strips are secured by joining to the jacket tube. The coated metal strips may be formed by coating long metal ribbons with catalytic coating in a continuous operation prior to cutting the ribbons to the required length. The metal ribbon is also preferably corrugated prior to the coating step but can also be corrugated after the coating step. In another embodiment, the matrix is formed of a single, continuous and at least partially corrugated metal strip which is folded on to itself so as to form a stack arrangement.
摘要:
A monolithic or honeycomb-catalyst, in particular for purifying the exhaust gases of internal-combustion engines, composed of an inert ceramic or metallic support traversed by parallel flow channels, a layer disposed thereon and composed of catalysis-promoting metal oxide and a catalytically active component supported by the metal oxide, wherein the concentration of the catalysis-promoting metal oxide increases from the periphery to the central axis of the support. Alternatively, the catalysis-promoting metal oxide is essentially equally distributed between central axis and periphery of the support, but concentration of catalytically active component increases from the central axis to the periphery of the support.
摘要:
A catalyst support for detoxifying the exhaust gases of alcohol fueled internal combustion engines contains, besides rare earth metal oxides and palladium, molybdenum silicide on active aluminum oxide in order to improve the conversion of noxious substances and the start up behavior.
摘要:
A catalyst for purifying the exhaust gases of internal combustion engines by means of oxidation and reduction with a reduced tendency to store sulfur oxides and to emit H.sub.2 S contains active Al.sub.2 O.sub.3 as carrier which is charged with CeO.sub.2 and optionally with ZrO.sub.2 as well as with platinum, and/or palladium, and optionally rhodium and also contains in addition 0.7 to 20% by weight B.sub.2 O.sub.3 relative to Al.sub.2 O.sub.3.
摘要翻译:通过氧化和还原的方式来净化内燃机废气的催化剂具有降低的存储硫氧化物的倾向并且排出H 2 S的催化剂,其含有作为载体的活性Al 2 O 3作为载体,其中CeO 2和任选地含有ZrO 2以及铂,并且 /或钯,和任选的铑,并且还相对于Al 2 O 3还含有0.7至20重量%的B 2 O 3。
摘要:
A method for the sealing of flow channels in an annular zone of a cylindrical honeycomb body. The sealing of the flow channels takes place by introduction of a ceramic compound into the flow channels by means of a nozzle, wherein nozzle and honeycomb body are moved relative to one another with simultaneous guiding of the nozzle past the lateral surface and/or past the end face contour of the honeycomb body.