Basf Aktiengesellschaft

Walter Herrmann

Richard Krabetz

Heinz Engelbach

Norbert Scholz

Peter Palm

Heinrich Spahn

Gerd Duembgen

Bertold Bechert

Fritz Thiessen

Carl-Heinz Willersinn

Walter Schneider

Karl Sommer

Willi Ripperger

Gerd-Juergen Engert

Herbert Geierhaas

Olaf Unbehaun

Uwe Hampel

Horst Gassmann

Heinz Hesser

A coated catalyst comprising (a) an inert carrier having particles of not less than 100 .mu.m diameter and a surface area of up to 20 m.sup.2 /g and (b) a coating which contains the catalytic material and adheres firmly to the outer surface and to the edge zone, near the surface, of the carrier particles, can be prepared by applying the catalytic material as a 10-70% strength suspension in water to the agitated carrier particles, which are at below 70.degree. C., if the suspension is sprayed, at a constant rate of from 0.01 to 2.0 kg of active material/hour/liter of carrier onto the carrier particles, while at the same time uniformly passing from 0.1 to 12 m.sup.3 (S.T.P.)/hour/liter of carrier of an inert gas at from 20.degree. to 300.degree. C. over the carrier particles, under conditions such that the water only evaporates incompletely but the water content of the resulting coating is less than the maximum degree of saturation of the catalytic material.

Preparation of coated catalysts

A coated catalyst comprising (a) an inert carrier having a particle diameter of not less than 100 .mu.m and a surface area of up to 20 m.sup.2 /g and (b) a coating which firmly adheres to the outer surface and in the edge zone, near the surface, of the carrier particles, and which contains the catalytic material, can be prepared by applying the catalytic material in the form of a powder of particle size not more than 300 .mu.m, in the presence of water, to the vigorously agitated carrier by a process wherein catalytically active material in an amount of from 1 to 40 g/minute/liter of carrier, and water in a weight ratio of catalytic material to water of from 1:1 to 30:1, are applied continuously and spatially separate from one another, each at a constant speed, onto the carrier particles, which may or may not have been pre-moistened with water in an amount of up to 95% of the particle absorbency, in such a way that the water content of the coating which forms is less than the maximum degree of saturation of the coating of catalytic material.

Catalysts which consist of a molded carrier, the surface of which is coated with an active catalyst composition of the general formula Mo.sub.12 A.sub.a B.sub.b C.sub.c D.sub.d O.sub.x, where A is V and/or W, B is Cu and/or Fe and/or Mn and/or Ni and/or Cr, C is Nb and/or Ta and/or Bi and/or Sb and/or Sn and/or Th and/or Ce and/or U, D is Li and/or Na and/or K and/or Rb and/or Cs and/or Tl and a is from 0.1 to 18, b is from 0 to 8, c is from 0 to 10, d is from 0 to 2 and x is from 36 to 135, which are particularly active and selective for the oxidation of acrolein and methacrolein with oxygen-containing gases to give acrylic acid and methacrylic acid, respectively, are obtained by first manufacturing the catalyst composition, before applying it to the carrier, from thermally easily decomposed salts of the components by mixing aqueous solutions, slurries or moist solid masses of the salts of the components, drying the mixture and calcining the dried composition at from 140.degree. to 600.degree. C., then milling it to a particle size of less than 150 .mu.m and thereafter applying it, as a mixture with water, as a layer from 10 to 1,500 .mu.m thick, to the premolded carrier, which has a rough surface.

Catalyst for the oxidation of acrolein and methacrolein to acrylic acid

Spherical refining catalysts containing cobalt and/or nickel together with molybdenum on aluminum oxide are prepared in closed mixers provided with mixing elements from spray-dried powders such as catalyst preparations or carriers using peptizing agents. The catalysts thus prepared have a bulk density much higher than that of extrudates of similar composition. Their surface and pore size distribution make them suitable for use in the catalytic refining of hydrocarbon fractions containing metal and asphalt, and particularly for refining vacuum distillates and residues from atmospheric distillation.

Spherical refining catalyst and process for its manufacture

A track or switch tamping machine wherein the machine includes tamping and ramming units having longitudinal ducts for injecting liquid binder into the ballast. The longitudinal ducts terminate in a plate or cavity within the lower portion of the tamping and ramming units. A nozzle is also included in the unit as is means for conveying liquid binder from a storage tank carried on the machine.

Apparatus for consolidating ballast

Growing community of inventors

Mannheim, Germany

Walter Herrmann