Abstract: A process for producing an eggshell catalyst, comprising the coating of the outer surface of a geometric shaped support body with a catalytically active multielement oxide or a powder P, wherein the powder P, after being coated, is converted by thermal treatment to a catalytically active multielement oxide, and one or more liquid binders, wherein the coating is conducted in a horizontal mixer and the Froude number during the coating in the horizontal mixer is from 0.0160 to 0.1200.

Abstract: A porous shaped catalyst support body comprising at least 85% by weight of alpha-alumina, wherein the support has a total pore volume in the range from 0.5 to 2.0 mL/g as determined by mercury porosimetry, and a pore structure characterized by a geometric tortuosity ? in the range from 1.0 to 2.0; and an effective diffusion parameter ? in the range from 0.060 to 1.0; wherein geometric tortuosity ? and effective diffusion parameter ? are determined by image analysis algorithms from computer-assisted 3D reconstructions of focused ion beam scanning electron microscope analyses. The structure of the support has a high total pore volume, such that impregnation with a large amount of silver is possible, while the surface area is kept sufficiently high in order to assure optimal dispersion of the catalytically active species, especially metal species. The support has a pore structure that leads to a maximum rate of mass transfer within the support.

Abstract: A porous alpha-alumina catalyst support is prepared by (i) preparing a precursor material comprising a boehmitic-derived alumina having a pore volume of at least 0.6 mL/g, wherein the boehmitic-derived alumina is obtained by thermal decomposition of a boehmitic starting material and the boehmitic starting material consists predominantly of block-shaped crystals, and optionally an inorganic bond material; (ii) forming the precursor material into shaped bodies; (iii) calcining the shaped bodies to obtain the porous alpha-alumina catalyst support. The support structure has a high overall pore volume, while keeping its surface area sufficiently large so as to provide optimal dispersion of catalytically active species, in particular metal species. The support is useful for a catalyst for producing ethylene oxide by gas-phase oxidation of ethylene.

Abstract: A shaped catalyst body for producing ethylene oxide by gas-phase oxidation of ethylene, having a BET surface area in the range of 2 to 20 m2/g and comprising silver and a rhenium promotor deposited on a porous alpha-alumina catalyst support, characterized in that the support has a calcination history of at least 1460° C. The catalyst support has a high surface area and little ethylene oxide isomerization and/or decomposition activity. The invention further relates to a porous alpha-alumina catalyst support having a BET surface area of 1.7 to 10 m2/g, the porous alpha-alumina catalyst support being obtainable by a) preparing a precursor material comprising a transition alumina and/or an alumina hydrate; b) forming the precursor material into shaped bodies; and c) calcining the shaped bodies at a temperature of 1460° C. to 1700° C. to obtain the porous alpha-alumina support.

Abstract: A process for producing a porous alpha-alumina catalyst support, comprising i) preparing a precursor material comprising, based on inorganic solids content, at least 50 wt.-% of a transition alumina having a loose bulk density of at most 600 g/L, a pore volume of at least 0.6 mL/g and a median pore diameter of at least 15 nm; and at most 30 wt.-% of an alumina hydrate; ii) forming the precursor material into shaped bodies; and iii) calcining the shaped bodies to obtain the porous alpha-alumina catalyst support. The catalyst support has a high overall pore volume, thus allowing for impregnation with a high amount of silver, while keeping its surface area sufficiently large so as to provide optimal dispersion of catalytically active species, in particular metal species. The invention further relates to a shaped catalyst body for producing ethylene oxide by gas-phase oxidation of ethylene, comprising at least 15 wt.

Abstract: A tableted catalyst support, characterized by an alpha-alumina content of at least 85 wt.-%, a pore volume of at least 0.40 mL/g, as determined by mercury porosimetry, and a BET surface area of 0.5 to 5.0 m2/g. The tableted catalyst support is an alpha-alumina catalyst support obtained with high geometrical precision and displaying a high overall pore volume, thus allowing for impregnation with a high amount of silver, while exhibiting a surface area sufficiently large so as to provide optimal dispersion of catalytically active species, in particular metal species. The invention further provides a process for producing a tableted alpha-alumina catalyst support, which comprises i) forming a free-flowing feed mixture comprising, based on inorganic solids content, at least 50 wt.-% of a transition alumina; ii) tableting the free-flowing feed mixture to obtain a compacted body; and iii) heat treating the compacted body at a temperature of at least 1100° C., preferably at least 1300° C.

Abstract: A process for producing a catalytically active multielement oxide comprising the elements Mo, W, V and Cu, wherein at least one source of the elemental constituents W of the multielement oxide is used to produce an aqueous solution, the resultant aqueous solution is admixed with sources of the elemental constituents Mo and V of the multielement oxide, drying of the resultant aqueous solution produces a powder P, the resultant powder P is optionally used to produce geometric shaped precursor bodies, and the powder P is or the geometric shaped precursor bodies are subjected to thermal treatment to form the catalytically active composition, wherein the aqueous solution used for drying comprises from 1.6% to 5.0% by weight of W and from 7.2% to 26.0% by weight of Mo, based in each case on the total amount of aqueous solution.

Abstract: The invention relates to a shaped catalyst body in the form of a tetralobe having four circular through-passages, with the midpoints of the through-passages forming a square and the spacings between in each case two adjacent through-passages being from 0.8 to 1.2 times the thickness of the outer walls of the through-passages. The shaped catalyst body is used for the oxidation of S02 to S03.

Abstract: A process for producing a silver-based epoxidation catalyst, comprising i) impregnating a particulate porous refractory support with a first aqueous silver impregnation solution comprising silver ions and an aminic complexing agent selected from amines, alkanolamines and amino acids; ii) converting at least part of the silver ions impregnated on the refractory support to metallic silver by heating while directing a stream of a first gas over the impregnated refractory support to obtain an intermediate catalyst, wherein the first gas comprises at least 5 vol.

Abstract: A three-dimensional porous catalyst, catalyst carrier or absorbent structure of stacked strands of catalyst, catalyst carrier or absorbent material, composed of layers of spaced-apart parallel strands, wherein parallel strands within a layer are arranged in groups of two or more closely spaced-apart, equidistant strands separated by a small distance, wherein the groups of equidistant strands are separated from adjacent strands or adjacent groups of strands by a larger distance.

Abstract: A process for the continuous production of either acrolein or acrylic acid as the target product from propene comprising a catalyzed gas phase partial oxidation of propene to yield a product gas containing the target product, transferring the target product in a separating zone from the product gas into the liquid phase and conducting out of the separating zone a stream of residual gas the major portion of which is returned into the partial oxidation and the remaining portion of said stream is purged from the process as off-gas from which synthesis gas can be produced or which can be added to synthesis gas produced otherwise.

Abstract: A three-dimensional porous catalyst, catalyst carrier or absorbent monolith of stacked strands of catalyst, catalyst carrier or absorbent material, composed of alternating layers of linear spaced-apart parallel strands, wherein the strands in alternating layers are oriented at an angle to one another, wherein the distance between inner spaced-apart parallel strands is larger than the distance between outer spaced-apart parallel strands in at least a part of the layers of the monolith.

Abstract: The present invention relates to a catalyst bed comprising silver catalyst bodies and a reactor comprising such a catalyst bed. Further, the invention relates to the use of the catalyst bed and the reactor for gas phase reactions, in particular for the oxidative dehydrogenation of organic compounds under exothermic conditions. In a preferred embodiment, the present invention relates to the preparation of olefinically unsaturated carbonyl compounds from olefinically unsaturated alcohols by oxidative dehydrogenation utilizing a catalyst bed comprising metallic silver catalyst bodies.

Abstract: A process for producing ethylene oxide by gas-phase oxidation of ethylene, comprising: directing a feed comprising gaseous ethylene and gaseous oxygen through a packing of individual shaped catalyst bodies, under conditions conducive to obtain a reaction mixture containing at least 2.7 vol.-% of ethylene oxide, wherein each shaped catalyst body comprises silver deposited on a refractory support and is characterized by a content of at least 20 wt.-% of silver, relative to the total weight of the shaped catalyst body; a BET surface area in the range of 1.6 to 3.0 m2/g; a first face side surface, a second face side surface and a circumferential surface with a plurality of passageways extending from the first face side surface to the second face side surface; and a uniform multilobed cross-section; and a longest direct diffusion pathway d, with 2d being in the range of 0.7 to 2.

Abstract: A shaped catalyst body for producing ethylene oxide by gas-phase oxidation of ethylene, comprising silver deposited on a porous refractory support, the shaped catalyst body having a first face side surface, a second face side surface and a circumferential surface, characterized by a content of at least 20 wt.-% of silver, relative to the total weight of the shaped catalyst body; a multilobe structure; a plurality of passageways extending from the first face side surface to the second face side surface, outer passageways being arranged around a central passageway with one outer passageway being assigned to each lobe, wherein neighboring outer passageways are arranged essentially equidistantly to each other and the outer passageways are arranged essentially equidistantly to the central passageway; a minimum wall thickness A between two neighboring passageways in the range of 0.6 to 1.3 mm; a minimum wall thickness B between each outer passageway and the circumferential surface in the range of 1.1 to 1.

Abstract: Process for producing shaped bodies of catalysts, catalyst supports or adsorbents by microextrusion in which a pasty extrusion composition of a shaped body precursor material is extruded through a movable microextrusion nozzle and through movement of the microextrusion nozzle a shaped body precursor is constructed in layerwise fashion and the shaped body precursor is subsequently subjected to a thermal treatment, wherein for construction of each shaped body precursor the pasty extrusion composition is simultaneously extruded through a plurality of microextrusion nozzles.

Abstract: The invention relates to a shaped catalyst body in the form of a tetralobe having four circular through-passages, with the midpoints of the through-passages forming a square and the spacings between in each case two adjacent through-passages being from 0.8 to 1.2 times the thickness of the outer walls of the through-passages. The shaped catalyst body is used for the oxidation of S02 to S03.

Abstract: The invention relates to a die (10) for the extrusion of catalyst molding, catalyst support molding, or adsorbent molding (60) in flow direction (32) of an extrudable composition from an entry side (12) to a discharge side (14) of the die comprising a shell (56) and comprising one or more channel-formers (18) which are displacers of the extrudable composition and which extend in flow direction of the extrudable composition, wherein the channel-formers (18) have been metal-printed. It is preferable that this is free from cavities for receiving extrudable composition which extend at right angles to the flow direction (32) of the extrudable composition, and that this is free from connections running at right angles from channel-formers (18) to the interior side wall (22) of the die (10). The invention further relates to a process for the production, by means of 3D metal printing, of a metal-printed die (10) for the extrusion of catalyst moldings/support moldings (60).

Abstract: The present invention provides a catalyst effective in the oxidative conversion of ethylene to ethylene oxide, comprising an alumina support and 20 to 45%by weight of the catalyst, of silver applied to the support, the catalyst meeting the following limitations (i) to (v): (i) an amount of cesium c(Cs) in mmol per Kg of catalyst of at least 2; (ii) an amount of rhenium c(Re) in mmol per Kg of catalyst of at least 3.0; (iii) an amount of tungsten c(W) in mmol per Kg of catalyst of at least 1.6; (iv) a silicon to alkaline earth metal molar ratio x of not higher than 1.80; (v) c(Cs)?c(Re)?c(W)?4·x?0.5.

Abstract: A method for preparing a silver impregnation solution comprises (a) charging a neutralization reactor R1 with an aqueous organic amine; (b) adding oxalic acid powder through a first feeding conduit to the neutralization reactor R1 to obtain an aqueous oxalic acid-organic amine solution; (c) directing the aqueous oxalic acid-organic amine solution from the neutralization reactor to a complexation reactor R2; (d) adding particulate silver oxide through a second feeding conduit to the complexation reactor R2 to obtain a silver impregnation solution; and, optionally, (e) subjecting the silver impregnation solution to filtration. The silver impregnation solution is used for producing a catalyst effective in the oxidative conversion of ethylene to ethylene oxide. The method allows for the preparation of a silver impregnation solution in an efficient and occupationally and environmentally safe way.