Abstract:
PROBLEM TO BE SOLVED: To obtain a low-cost iron oxide-containing catalyst for the dehydrogenation of ethylbenzene to styrene easy to synthesize and having a large pore volume, high activity, selectivity and mechanical stability by using iron oxide obtained by spray-roasting an iron salt solution. SOLUTION: Iron oxide obtained by spray-roasting an iron salt solution is used for producing the objective iron oxide-containing catalyst. At this time, 0.6-1 g/cm3 stamp density and 1-10 m2/g specific surface area are provided. The pore volume of the catalyst is at least 0.2 cm3/g and the average pore diameter (median) is at least 0.3 μm. At least one potassium compound may be incorporated besides the iron oxide. One or more promoters which increase selectivity, activity and stability may further be incorporated and the particularly preferred promoter is a compound of a metal selected form Mg, Ca, Ce, V, Cr, Mo and W.
Abstract:
The invention relates to a device for producing moulded bodies from thermoplastic polymers, starting from monomers that form polymers of this type, in a discontinuous method. Said device comprises a) at least one reactor that is suitable for producing a thermoplastic polymer melt in a discontinuous process starting from monomers that form a polymer of this type, b) a network of pipes that is suitable for circulating the thermoplastic polymer melt and c) at least one device that is suitable for producing moulded bodies from a thermoplastic polymer melt. According to the invention, the reactor or reactors according to a) is/are connected to the network of pipes according to b) and the device or devices according to c) is/are connected to the network of pipes according to b). The invention also relates to a method for producing moulded bodies from thermoplastic polymers in a device of this type.
Abstract:
An apparatus suitable for producing shaped bodies comprising thermoplastic polymers from monomers which form such polymers in a batch process comprises a) at least one reactor suitable for the batchwise preparation of a melt of a thermoplastic polymer from monomers which form such a polymer, b) a piping system suitable as circulation line for the melt of the thermoplastic polymer and c) at least one apparatus suitable for the production of shaped bodies from the melt of a thermoplastic polymer, wherein the reactor or reactors a) is/are connected to the piping system b) and the apparatus or apparatuses c) is/are connected to the piping system b), and an apparatus for producing shaped bodies comprising thermoplastic polymers in such an apparatus.
Abstract:
An apparatus suitable for producing shaped bodies comprising thermoplastic polymers from monomers which form such polymers in a batch process comprises a) at least one reactor suitable for the batchwise preparation of a melt of a thermoplastic polymer from monomers which form such a polymer, b) a piping system suitable as circulation line for the melt of the thermoplastic polymer and c) at least one apparatus suitable for the production of shaped bodies from the melt of a thermoplastic polymer, wherein the reactor or reactors a) is/are connected to the piping system b) and the apparatus or apparatuses c) is/are connected to the piping system b), and an apparatus for producing shaped bodies comprising thermoplastic polymers in such an apparatus.
Abstract:
Heterogeneously-catalysed gas-phase decomposition of N2O involves placing an N2O-decomposing inert material downstream of the fixed bed catalyst.
Abstract:
Catalyst containing iron oxide is produced from an iron oxide obtained by spray roasting an iron salt solution. An Independent claim is also included for the production of the catalyst by using an iron oxide obtained by spray roasting an aqueous iron solution.
Abstract:
The invention relates to a method for producing phthalic anhydride by catalytic vapor-phase oxidation of xylol and/or naphthalene with a gas which contains molecular oxygen, in a fixed bed, at an increased temperature and by means of at least three stacked shell catalysts. A layer comprised of catalytically active metal oxides is deposited on the core of said catalysts, said core being made of supporting material. From layer to layer, the catalyst activity increases from the gas inlet side to the gas outlet side. In addition, the activity of the catalysts of the individual layers is adjusted such that the least active catalyst comprises a smaller active mass quantity and optionally more alkali metal as doping, said alkali metal being selected from the group comprised of potassium, rubidium and cesium, than that of the catalyst of the next layer. The catalyst which is situated thereupon and which is more active comprises the same active mass quantity and less alkali metal, as doping or has a greater active mass quantity and optionally less alkali metal as doping than the catalyst of the second layer.
Abstract:
Copper-containing catalysts for low-temperature conversion at temperatures of from 150 to 300 DEG C and at from 10 to 40 bar which additionally contain aluminium, and zinc, if desired in the form of the compounds or oxides, and are prepared by joint precipitation, the copper-containing catalysts containing potassium and having a BET surface area matched to the potassium content, the potassium content being set to from 0.1 to 3.0% by weight at a BET surface area of from 30 to 160 m /g, and their use for the production of hydrogen and carbon dioxide from carbon monoxide and water.
Abstract:
Phthalic anhydride is prepared by catalytic gas-phase oxidation of xylene and/or naphthalene by a gas comprising molecular oxygen in a fixed bed at elevated temperature and using at least three coated catalysts arranged in superposed zones, which catalysts have a layer of catalytically active metal oxides applied to a core of support material. In the process described, the catalyst activity rises from zone to zone from the gas inlet end to the gas outlet end and the activity of the catalysts of the individual zones is set such that the least active catalyst comprises a lower amount of active composition and, if desired, additionally more alkali metal selected from the group consisting of potassium, rubidium and cesium as dopant than the catalyst of the next zone and the subsequent even more active catalyst comprises the same amount of active composition and even less alkali metal as dopant or a greater amount of active composition and, if desired, less alkali metal as dopant than the catalyst of the second zone, with further conditions.
Abstract:
An apparatus suitable for producing shaped bodies comprising thermoplastic polymers from monomers which form such polymers in a batch process comprises a) at least one reactor suitable for the batchwise preparation of a melt of a thermoplastic polymer from monomers which form such a polymer, b) a piping system suitable as circulation line for the melt of the thermoplastic polymer and c) at least one apparatus suitable for the production of shaped bodies from the melt of a thermoplastic polymer, wherein the reactor or reactors a) is/are connected to the piping system b) and the apparatus or apparatuses c) is/are connected to the piping system b), and an apparatus for producing shaped bodies comprising thermoplastic polymers in such an apparatus.