Abstract:
PROBLEM TO BE SOLVED: To provide a method for catalytic gas-phase oxidation of propene to acrylic acid.SOLUTION: A reaction gas starting mixture is oxidized, with an increased propene loading, in a first reaction stage, over a first fixed-bed catalyst, and subsequently the acrolein-containing product gas mixture of the first reaction stage is oxidized, in a second reaction stage, with an increased acrolein loading, over a second fixed-bed catalyst, thereby the catalyst moldings in both reaction stages having an annular geometry.
Abstract:
PROBLEM TO BE SOLVED: To provide a method for catalytic gas-phase oxidation of propene to acrylic acid. SOLUTION: The reaction gas starting mixture is oxidized, with an increased propene loading, in a first reaction stage, over a first fixed-bed catalyst and then the acrolein-containing product gas mixture of the first reaction stage is oxidized, in a second reaction stage, with an increased acrolein loading, over a second fixed-bed catalyst, the catalyst moldings in both reaction stages having an annular geometry. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a continuous heterogeneously catalyzed partial dehydrogenation of a hydrocarbon in the gas phase and in the presence of molecular oxygen, in which a part of a product gas is recirculated to a reaction zone, and a reactor for carrying out such a process. SOLUTION: In the process, a reaction gas containing at least one hydrocarbon to be dehydrogenated is supplied to the reaction zone; the reaction gas is passed in the reaction zone through at least one fixed catalyst bed, wherein the reaction gas is subjected to catalytic dehydrogenation to produce molecular hydrogen and at least one partial dehydrogenated hydrocarbon; the reaction gas, before and/or after entering the reaction zone, is added with a gas containing at least one molecular oxygen-containing gas; the molecular oxygen partially oxidizes the molecular hydrogen contained in the reaction gas in the reaction zone to form water steam; a gas product containing the molecular hydrogen, water steam, at least one dehydrogenated hydrocarbon, and at least one hydrocarbon to be dehydrogenated is withdrawn from the reaction zone; at least one hydrocarbon to be dehydrogenated in the gas phase is partially dehydrogenated by a continuous heterogeneous catalyst. In the partial dehydrogenation method using the continuous heterogeneous catalyst, the reaction gas withdrawn from the reaction zone is divided into two parts being the same in composition, one of which is recycled into reaction zone as a circulating gas. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a new catalytic gas-phase oxidation method of propene to acrylic acid. SOLUTION: There is provided a method for the catalytic gas-phase oxidation of propene to acrylic acid, in which the reaction gas starting mixture is oxidized, with a high propene loading, in a first reaction stage, over a first fixed-bed catalyst which is housed in two successive reaction zones A, B, (the reaction zone B being kept at a higher temperature than the reaction zone A), and the acrolein-containing product gas mixture of the first reaction stage is then oxidized in a second reaction stage, with a high acrolein loading, over a second fixed-bed catalyst which is housed in two successive reaction zones C, D, (the reaction zone D being kept at a higher temperature than the reaction zone C). COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
The invention relates to a process for preparing a catalyst support, in which zirconium dioxide powder is mixed with a binder, if desired a pore former, if desired an acid, water and, if desired, further additives to give a kneadable composition and the composition is homogenized, shaped to produce shaped bodies, dried and calcined, wherein the binder is a monomeric, oligomeric or polymeric organosilicon compound. Suitable binders are monomeric, oligomeric or polymeric silanes, alkoxysilanes, aryloxysilanes, acryloxysilanes, oximinosilanes, halosilanes, aminoxysilanes, aminosilanes, amidosilanes, silazanes or silicones. The invention also provides the catalyst support which has been prepared in this way, a catalyst comprising the support and its use as dehydrogenation catalyst.
Abstract:
The invention relates to a process for preparing butadiene from n-butane comprising the steps (A) providing an n-butane-containing feed gas stream, (B) feeding the n-butane-containing feed gas stream into a first dehydrogenation zone and nonoxidatively catalytically dehydrogenating n-butane to 1-butene, 2-butene and optionally butadiene to obtain a first product gas stream comprising n-butane, 1-butene and 2-butene, with or without butadiene and secondary components, (C) feeding the first product gas stream comprising n-butane, 1-butene and 2-butene, with or without butadiene and secondary components, into a second dehydrogenation zone and oxidatively dehydrogenating 1-butene and 2-butene to butadiene to give a second product gas stream comprising butadiene, n-butane and steam, with or without secondary components, (D) recovering butadiene from the second product gas stream.
Abstract:
Novel catalyst beds comprising a physical mixture of catalytically active and catalytically inactive shaped bodies, in which the catalytically inactive shaped bodies have rounded edges on the external rubbing surfaces.
Abstract:
Procedimiento para la obtención de catalizadores, que contienen cobre pasivado y óxido de cinc y óxido de aluminio, mediante (1) (a) la precipitación de una solución de sales de cinc y de aluminio, estando comprendida la relación atómica Zn : Al entre 3 : 1 y 1 : 3, con una solución de carbonato alcalino a un valor del pH situado en el intervalo comprendido entre 5 y 12 y a una temperatura situada en el intervalo comprendido entre 20 y 100ºC, (b) la separación y el lavado del precipitado para la eliminación de los iones alcalinos, (c) el secado del precipitado, (d) la calcinación del precipitado a una temperatura situada en el intervalo comprendido entre 250 y 800ºC, para dar un óxido mixto, (e) la dispersión del óxido mixto en una solución ácida de sales de sobre y de cinc, estando comprendida la relación atómica Cu : Zn, en la solución, entre 1 : 5 y 20 : 1, (f) la precipitación de la dispersión con una solución de carbonato alcalino a un valor del pH situado en el intervalo comprendido entre 6 y 9 y a una temperatura situada en el intervalo comprendido entre 20 y 100ºC, (g) la realización de las etapas (b) hasta (d), pudiendo contener las soluciones en las etapas (a) y/o (e) sales u óxidos adicionales de uno o varios elementos de los metales del platino de los grupos 4, 5, 11 y de los lantánidos del Sistema Periódico de los Elementos o pueden aplicarse las sales o los óxidos sobre los óxidos mixtos, (2) la calcinación del precursor sólido del catalizador, obtenido en la etapa (1), hasta que se alcance un contenido en aniones a partir del agente de precipitación, especialmente un contenido en carbonato, determinado como CO3, comprendido entre un 0,1 y un 2,5% en peso, (3) el moldeo y, en caso dado, la reducción y la pasivación del precursor calcinado del catalizador procedente de la etapa (2) en un orden arbitrario, para la formación del catalizador.
Abstract:
Procedimiento para la preparación de aldehídos o cetonas ópticamente activos con 3 a 25 átomos de carbono, que al menos presentan un estereocentro racemizable en posición α- y/o β con respecto al grupo carbonilo, mediante deshidrogenación catalítica de los alcoholes primarios o secundarios ópticamente activos correspondientes en presencia de un catalizador, que contiene cinc y calcio en forma oxidada y/o en forma de sus carbonatos, en la fase gaseosa.