Abstract:
The invention relates to a method for manufacturing geometric catalyst molded bodies K, the active mass of which is a multi-element oxide, which contains the element Mo, the elements Bi and/or V, and one or more of the elements Co, Ni, Fe, Cu, and alkali metals, wherein a fine-particle mixture is produced using sources of the various elements, said fine-particle mixture is coarsened into a powder by compression agglomeration, molded bodies V are formed from the coarsened powder by compression agglomeration, said molded bodies are separated into undamaged molded bodies V+ and damaged molded bodies V-, the undamaged molded bodies V+ are transformed into the catalyst molded bodies K by thermal treatment, and the damaged molded bodies V- are ground and fed back into the production of the fine-particle mixture.
Abstract:
The invention relates to a method for producing a ring-shaped oxidic molded body by mechanically compacting a powdered aggregate introduced into the cavity of a mold, the peripheral surface of the resulting compressed structure corresponding to that of a truncated cone.
Abstract:
The invention relates to a method for producing a geometric oxidic molded body, comprising the step of mechanically compacting a powdered aggregate introduced into the cavity of a mold to give a geometric molded precursor and the step of thermally treating the geometric molded precursor, the components of said precursor decomposing or reacting while producing gaseous components, and the powered aggregate containing metal oxides or metal oxide precursors such as nitrate or ammonium salts and the mold material being in contact with the mold bore being a hard metal of 80% by weight or more of WC and 5% by weight of nickel.
Abstract:
The invention relates to a method for producing a multi-element oxide material containing the element iron in the oxidised form, in which an aqueous iron nitrate solution is also used as a source of the elementary constituent iron. The invention also relates to the production of the melt of a solid hydrate of iron nitrate.
Abstract:
Beschrieben wird ein Katalysator zur Herstellung einer α,&bgr;-ungesättigten Carbonsäure durch Gasphasenoxidation eines α,&bgr;-ungesättigten Aldehyds, umfassend einen Trägerformkörper mit einer darauf aufgebrachten Aktivmasse, dadurch gekennzeichnet, dass die Aktivmassebedeckung qhöchstens 0,3 mg/mm2 beträgt, wobei Q der Aktivmasseanteil des Katalysators in Gew.-% und Sm die spezifische geometrische Oberfläche des Trägerformkörpers in mm2/mg ist. Beschrieben wird ferner ein Verfahren zur Herstellung des Katalysators sowie ein Verfahren zur Herstellung einer α,&bgr;-ungesättigten Carbonsäure durch Gasphasenoxidation eines α,&bgr;-ungesättigten Aldehyds an einem Katalysatorfestbett, das eine Schüttung des Katalysators umfasst. Durch den Katalysator wird bei fortdauernd hohem Umsatz an Acrolein die Überoxidation zu COx verringert und die Selektivität der Acrylsäurebildung erhöht.
Abstract:
A process for preparing a multielement oxide composition comprising the element iron in oxidic form, in which the source of the elemental constituent of iron used is an aqueous iron nitrate solution whose preparation comprises the melting of a solid hydrate of iron nitrate.
Abstract:
The present invention relates to a process for preparing optionally alkyl-substituted 1,4-butanediol by two-stage catalytic hydrogenation in the gas phase of C 4 -dicarboxylic acids and/or of derivatives thereof having the following steps: a) introducing a gas stream of a C 4 -dicarboxylic acid or of a derivative thereof at from 200 to 300° C. and from 10 to 100 bar into a first reactor or into a first reaction zone of a reactor and catalytically hydrogenating it in the gas phase to a product which contains mainly optionally alkyl-substituted gamma-butyrolactone; b) introducing the product stream obtained in this way into a second reactor or into a second reaction zone of a reactor at a temperature of from 140° C. to 260° C. and catalytically hydrogenating it in the gas phase to optionally alkyl-substituted 1,4-butanediol; steps a) and b) being carried out at the same pressure; c) removing the desired product from intermediates, by-products and any unconverted reactants; d) optionally recycling unconverted intermediates into one or both hydrogenation stages, said hydrogenation stages each using a catalyst which comprises =5% by weight, preferably from 5 to 95% by weight, in particular from 20 to 90% by weight, of an oxidic support, and the product mixture removed from the first hydrogenation stage being introduced without further purification into the second hydrogenation stage.