Abstract:
The present invention relates to a process for the preparation of catalyst particles with a particle diameter in the range 20–2000 microns involving the steps of agitating at least two dry catalyst ingredients, spraying a liquid binding agent on the catalyst ingredients while continuing the agitation, and isolating formed catalyst particles with the desired particle diameter and comprising the catalyst ingredients. In contrast to the conventional way of preparing such particles, spray-drying, the present process allows the formation of small particles from slurries with a high solids content. Hence, smaller amounts of liquid have to be evaporated, which makes the process energy efficient.
Abstract:
The invention relates to a device and a method for the aftertreatment of exhaust gases from combustion engines, in particular from internal combustion engines. The device according to the invention and the method are intended to be of simple construction, should be inexpensive to produce and operate and should have less adverse effect on the flow conditions in the exhaust gas stream. To achieve this object, at least one region which is filled with beads is provided in the exhaust-gas stream, the beads preferably being hollow beads. The exhaust gas from the combustion engine is passed through this region, and it is possible to achieve particle agglomeration with simultaneous separation of these particles. In addition, further regions which are filled with metal fibers may follow the at least one region filled with beads, and the exhaust gas is additionally passed through these further regions.
Abstract:
Electrocatalyst powders and methods for producing electrocatalyst powders, such as carbon composite electrocatalyst powders. The powders have a well-controlled microstructure and morphology. The method includes forming the particles from an aerosol of precursors by heating the aerosol to a relatively low temperature, such as not greater than about 400° C.
Abstract:
A composite oxide includes agglomerated particles which have an average particle diameter of 20 μm or less, which are composed of a plurality of metallic element oxides being in form of fine particles having an average diameter of 50 nm or less, and which have a surface and an inner portion whose metallic element distributions differ with each other. The characteristics of the respective metallic elements are exhibited maximally. Hence, it is extremely useful as a support for an exhaust gas purifying catalyst. The catalyst exhibits the activities which degrade less even after it is subjected to a sever durability, is good in terms of the heat and sulfur-poisoning resistance, and can efficiently purify the harmful components in exhaust gases. Moreover, it is possible to produce such a composite oxide and catalyst easily and stably by production processes disclosed herein.
Abstract:
The present invention relates to a reactor for the decomposition of ammonium dinitramide-based liquid monopropellants into hot, combustible gases for combustion in a combustion chamber, and more particularly a rocket engine or thruster comprising such reactor and a combustion chamber. The invention also relates to a process for the decompostion of ammonium dinitramide-based liquid monopropellants.
Abstract:
Catalysts are composed ofa) a magnetizable core,b) which may be coated with a binder andc) which carries catalytically active metals or metal compounds on its surface.
Abstract:
A process for the selective hydrogenation in the gas phase of acetylene compounds containing 2 or 3 carbon atoms to the corresponding ethylene compounds is described. The process uses a catalyst in the form of spherules or extrudates containing palladium, at least one group IB metal, optionally at least one alkaline or alkaline-earth metal and alumina, in which at least 80% of the palladium and at least 80% of the group IB element are present in a volume at the periphery of the catalyst defined between a spherical or cylindrical surface of radius r.sub.1 corresponding to the average spherule or extrudate diameter and a spherical or cylindrical surface of radius r.sub.2 at least equal to 0.8r.sub.1. More particularly, the catalyst comprises an alumina, palladium in a proportion of 0.01% to 0.5% by weight, and group IB metal in a proportion of 0.001 to 0.02% by weight, with a weight ratio of group IB metal/palladium of 0.05 to 0.25.
Abstract:
A process for the preparation of a supported catalyst for the polymerization of .alpha.-olefins, in which(1) a silicon dioxide-containing support gel is prepared by(1.1) introducing a sodium water glass or potassium water glass solution into a swirling stream of an aqueous mineral acid longitudinally and tangentially to the stream, spraying the resultant silica hydrosol in drop form into a gaseous medium and allowing it to solidify to form a hydrogel, and freeing the resultant hydrogel from salts by washing without prior ageing,(1.2) drying the hydrogel resulting from (1.1) to form the support gel,(2) the support gel (1) is charged with chromium trioxide or a chromium compound which can be converted into chromium trioxide under the conditions of process step (3), giving a chromium-containing support gel, and(3) the chromium-containing support gel (2) is heated at from 400.degree. to 1100.degree. C. for from 10 to 1000 minutes in an anhydrous gas stream containing oxygen in a concentration of greater than 10% by volume,comprises drying the hydrogel resulting from step (1.1) in step (1.2) within a time of not more than 60 seconds in a shaping, high-speed dryer at an inlet temperature of from 80.degree. to 400.degree. C.
Abstract translation:一种制备用于α-烯烃聚合的负载催化剂的方法,其中(1)含二氧化硅的载体凝胶通过(1.1)将钠水玻璃或钾水玻璃溶液引入旋流 将水性无机酸纵向和切向于料流,将所得的二氧化硅水溶胶以液滴形式喷雾到气态介质中并使其固化形成水凝胶,并通过在没有预先熟化的情况下洗涤将所得水凝胶从盐中释放,(1.2)干燥 由(1.1)产生的形成支持凝胶的水凝胶,(2)载体凝胶(1)中加入三氧化铬或铬化合物,其可以在工艺步骤(3)的条件下转化为三氧化铬,得到 含铬载体凝胶,(3)含铬载体凝胶(2)在含有浓度浓度的氧的无水气流中在400〜1100℃下加热10〜1000分钟 大于10体积%包括在入口温度为80°至400°的成形高速干燥器中在不超过60秒的时间内将步骤(1.2)中由步骤(1.1)得到的水凝胶干燥 DEG C.
Abstract:
A process to make a small, discrete, spherical magnesium dihalide alcohol adduct is provided. This process comprises: contacting a magnesium dihalide and an alcohol in a high-viscosity liquid that consists of hydrocarbons, to obtain a dispersion; heating and agitating the dispersion to obtain a molten dipersion; cooling the molten dispersion to form said small, discrete, spherical magnesium dihalide alcohol adduct.
Abstract:
A process for producing a spherical zeolite catalyst is disclosed, which comprises dropping a zeolite-containing alumina sol into a surfactant-containing oil phase from a dropping opening directly or through air to thereby form spherical droplets of the sol, and then allowing the droplets to gel in an aqueous alkaline solution phase underlying the oil phase and withdrawing the thus gelled droplets, said dropping of the sol being conducted while the dropping opening is being impulsed to thereby impart a spherical and uniform shape to the resulting zeolite particles containing alumina as a binder, and a novel apparatus therefor.