Abstract: The invention relates to a crossflow tray for a mass transfer column (27) in which a gas is conducted in countercurrent to a liquid, the crossflow tray (1) having passage orifices (3) for the gas and at least two downcomers (5), the downcomers (5) projecting beyond the top surface of the crossflow tray (1) and a collecting cup (13) being disposed beneath each downcomer (5). The downcomer (5) projects into the collecting cup (13), the minimum horizontal cross-sectional area of the collecting cup (13) is 1.2 to 4 times greater than the horizontal cross-sectional area of the downcomer (5) at the outlet, and the collecting cup (13) has a circumferential wall (15) having an overflow (19). The invention further relates to a mass transfer column comprising the crossflow trays and to a use of the mass transfer column.

Abstract: The invention relates to a crossflow tray for a mass transfer column (27) in which a gas is conducted in countercurrent to a liquid, the crossflow tray (1) having passage orifices (3) for the gas and at least two downcomers (5), the downcomers (5) projecting beyond the top surface of the crossflow tray (1) and a collecting cup (13) being disposed beneath each downcomer (5). The downcomer (5) projects into the collecting cup (13), the minimum horizontal cross-sectional area of the collecting cup (13) is 1.2 to 4 times greater than the horizontal cross-sectional area of the downcomer (5) at the outlet, and the collecting cup (13) has a circumferential wall (15) having an overflow (19). The invention further relates to a mass transfer column comprising the crossflow trays and to a use of the mass transfer column.

Abstract: A process for recharging the reaction tubes of a tube bundle reactor with a new fixed catalyst bed, in which a heterogeneously catalyzed partial gas phase oxidation of an organic compound had been performed beforehand in a preceding fixed catalyst bed comprising Mo-comprising multielement oxide active compositions to form a steam-comprising product gas mixture, in which, before the recharge, solid deposit which had been deposited on the tube inner walls and comprises molybdenum oxide and/or molybdenum oxide hydrate is brushed away with the aid of a brush.

Abstract: A process for recharging the reaction tubes of a tube bundle reactor with a new fixed catalyst bed, in which a heterogeneously catalyzed partial gas phase oxidation of an organic compound had been performed beforehand in a preceding fixed catalyst bed comprising Mo-comprising multielement oxide active compositions to form a steam-comprising product gas mixture, in which, before the recharge, solid deposit which had been deposited on the tube inner walls and comprises molybdenum oxide and/or molybdenum oxide hydrate is brushed away with the aid of a brush.

Abstract: A process for recharging the reaction tubes of a tube bundle reactor with a new fixed catalyst bed, in which a heterogeneously catalyzed partial gas phase oxidation of an organic compound had been performed beforehand in a preceding fixed catalyst bed comprising Mo-comprising multielement oxide active compositions to form a steam-comprising product gas mixture, in which, before the recharge, solid deposit which had been deposited on the tube inner walls and comprises molybdenum oxide and/or molybdenum oxide hydrate is brushed away with the aid of a brush.

Abstract: A process for producing geometric shaped catalyst bodies K whose active material is a multielement oxide of stoichiometry [Bi1WbOx]a[Mo12Z1cZ2dFeeZ3fZ4gZ5hOy]1, in which a finely divided oxide Bi1WbOx with the particle size d50A1 and, formed from element sources, a finely divided intimate mixture of stoichiometry Mo12Z1cZ2dFeeZ3fZ4gZ5h with the particle size d90A2 are mixed in a ratio of a:1, this mixture is used to form shaped bodies and these are treated thermally, where (d50A1)0.7·(d90A2)1.5·(a)?1?820. A shaped catalyst body obtained by the process. A catalyst obtained by grinding the shaped catalyst body. A process for heterogeneously catalyzing the partial gas phase oxidation of an alkane, alkanol, alkanal and/or an alkenal of 3 to 6 carbon atoms using the catalyst.

Abstract: A process for producing geometric shaped catalyst bodies K whose active material is a multielement oxide of stoichiometry [Bi1WbOx]a[Mo12Z1cZ2dFeeZ3fZ4gZ5hOy]1, in which a finely divided oxide Bi1WbOx with the particle size d50A1 and, formed from element sources, a finely divided intimate mixture of stoichiometry Mo12Z1cZ2dFeeZ3fZ4gZ5h with the particle size d90A2 are mixed in a ratio of a:1, this mixture is used to form shaped bodies and these are treated thermally, where (d50A1)0.7·(d90A2)1.5·(a)?1?820. A shaped catalyst body obtained by the process. A catalyst obtained by grinding the shaped catalyst body. A process for heterogeneously catalyzing the partial gas phase oxidation of an alkane, alkanol, alkanal and/or an alkenal of 3 to 6 carbon atoms using the catalyst.

Abstract: A process for producing geometric shaped catalyst bodies K whose active material is a multielement oxide of stoichiometry [Bi1WbOx]a[Mo12Z1cZ2dFeeZ3fZ4gZ5nOy]1, in which a finely divided oxide Bi1WbOx with the particle size d50A1 and, formed from element sources, a finely divided intimate mixture of stoichiometry Mo12Z1cZ2dFeeZ3fZ4gZ5h with the particle size d50A2 are mixed in a ratio of a:1, this mixture is used to form shaped bodies and these are treated thermally, where (d50A1)0.7·(d90A1)1.5·(a)?1?820.

Abstract: A process for producing geometric shaped catalyst bodies K whose active material is a multielement oxide of stoichiometry [Bi1WbOx]a[Mo12Z1cZ2dFeeZ3fZ4gZ5hOy]1, in which a finely divided oxide Bi1WbOx with the particle size d50A1 and, formed from element sources, a finely divided intimate mixture of stoichiometry Mo12Z1cZ2dFeeZ3fZ4gZ5h with the particle size d90A2 are mixed in a ratio of a:1, this mixture is used to form shaped bodies and these are treated thermally, where (d50A1)0.7·(d90A2)1.5·(a)?1?820. A shaped catalyst body obtained by the process. A catalyst obtained by grinding the shaped catalyst body. A process for heterogeneously catalyzing the partial gas phase oxidation of an alkane, alkanol, alkanal and/or an alkenal of 3 to 6 carbon atoms using the catalyst.

Abstract: A process for preparing shaped catalyst bodies whose active composition is a multielement oxide, in which a finely divided precursor mixture with addition of graphite having a specific particle size is shaped to the desired geometry and then treated thermally.

Abstract: A process for charging a reactor with a fixed catalyst bed which comprises at least one annular shaped support catalyst body K, in which, before the charging, fragments formed in the preparation of the shaped catalyst bodies K are removed by screening.

Abstract: A process for preparing a coated catalyst in which a finely divided mixture of a multielement oxide comprising the elements Mo and V and a molybdenum oxide or a molybdenum oxide former is applied to the surface of a support body as an active composition.

Abstract: A process for producing geometric shaped catalyst bodies K whose active material is a multielement oxide of stoichiometry [BiaZ1bOx]p[BicMo12FedZ2eZ3fZ4gZ5hZ6iOy]1, in which a finely divided oxide BiaZ1bOx and, formed from element sources, a finely divided mixture of stoichiometry BicMo12FedZ2eZ3fZ4gZ5hZ6i are mixed in a ratio of p:1, this mixture is used to form shaped bodies and these are treated thermally, where 0<c?0.8.

Abstract: The invention discloses a method for producing acetaldehyde and/or acetic acid, according to which method a gaseous flow, containing molecular oxygen, ethanol and at least one impurity selected from sulphur compounds, is brought into contact at a high temperature with a sulphur-resistant oxidation catalyst. The ethanol is preferably obtained from a biomass. Said sulphur-resistant oxidation catalyst comprises, for example, vanadium oxide and at least one oxide of zirconium, titanium and aluminium. In one embodiment, the gaseous flow is converted, on the sulphur-resistant oxidation catalyst, into a first oxidation mixture, acetaldehyde being the predominant oxidation product, and said first oxidation mixture is converted, on another oxidation catalyst, into a second oxidation mixture, acetic acid being the predominant oxidation product. Said other oxidation catalyst comprises, for example, a multi-metal oxide containing at least molybdenum and vanadium.

Abstract: A process for producing geometric shaped catalyst bodies K whose active material is a multielement oxide of stoichiometry [BiaZ1bOx]p[BicMo12FedZ2eZ3fZ4gZ5hZ6iOy]1, in which a finely divided oxide BiaZ1bOx and, formed from element sources, a finely divided mixture of stoichiometry BicMo12FedZ2eZ3fZ4gZ5hZ6i are mixed in a ratio of p:1, this mixture is used to form shaped bodies and these are treated thermally, where 0<c?0.8.

Abstract: A process for the long-term operation of a heterogeneously catalyzed partial gas phase oxidation of an organic starting compound, in which the reaction gas input mixture is partially oxidized over a fixed catalyst bed which is accommodated in two successive temperature zones A, B whose temperature is changed with increasing operating time such that the initially lower temperature increases and the difference between the two temperatures decreases.

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: A process for starting-up a heterogeneously catalyzed partial gas phase oxidation of acrolein to acrylic acid or of methacrolein to methacrylic acid over a fixed catalyst bed disposed in a tube bundle reactor cooled by a heat exchange medium, wherein the temperature of the heat exchange medium is ?290° C. and the temperature of that reactor plate surface which faces the reaction gas entry mixture and the temperature of the reaction gas entry mixture itself are ?285° C.

Abstract: A process for introducing annular coated catalysts K into a reaction tube of a tube bundle reactor, in which adhering pairs of annular coated catalysts K formed in the preparation of the annular coated catalysts K, before the introduction thereof into the reaction tube, are removed at least partly from the annular coated catalysts K.

Abstract: The present invention relates to a process for charging a reactor with a catalyst, to the resulting charged reactors, and to the use thereof for carrying out catalytic gas phase reactions.