Abstract:
The invention relates to a catalytically active composition containing Pd and Bi as active constituents, and at least one element selected from the group (a) consisting of Rh, Au, Sb, V, Cr, W, Mn, Fe, Co, Ni, Na, Cs and Ba; or Pd, Rh and Bi, and optionally an element selected from the group (a') consisting of Au, Sb, V, Cr, W, Mn, Fe, Co, Ni, Pt, Cu, Ag, Na, Cs, Mg, Ca and Ba. The invention also relates to a method for dehydrating hydrocarbons, preferably oxofunctionalised hydrocarbons such as cyclopentanone, cyclohexanone and isovaleraldehyde, by means of the catalytically active composition.
Abstract:
Disclosed is a method for producing a catalyst containing vanadium, phosphorus, and oxygen, which is used for oxidizing the gas phase of a hydrocarbon having at least four carbon atoms to maleic anhydride. According to the inventive method, a corresponding catalyst precursor which contains vanadium, phosphorus, and oxygen and is provided with particles having an average diameter of at least 2 mm is converted into a catalytically active form by means of calcination, and a flow of the catalyst precursor is transported on a conveyor belt across at least one calcination area over a distance ln at an essentially steady speed in order to be calcinated. The variation over time of the gas temperature in relation to the set point value amounts to
Abstract:
Disclosed is a catalyst for gas phase oxidations, comprising an inert carrier and a catalytically active material that is applied thereupon and contains transition metal oxides, or a precatalyst. Said (pre)catalyst is obtained by processing the inert carrier with an aqueous suspension or solution of the transition metal oxides or the precursor compounds thereof. The suspension contains a binder dispersion while the binder is a copolymer of an a-olefin and a vinyl-C 2 -C 4 -carboxylate, the vinyl-C 2 -C 4 -carboxylate content of which amounts to at least 62 mole percent.
Abstract:
The invention relates to a device for the mixing, drying and coating of powdered, granular or moulded bulk material in a fluid bed, in particular, a method for the production of supported catalysts for gas phase oxidations, with a container (10), for holding the bulk goods, whereby a dished recess (17) is provided in a lower region (13) of the container (10), a central tube (27) for the introduction of a gas, whereby the central tube enters in an upper region (12) of the container (10), extending essentially axially downwards into the container (10) and opens out in the recess (17), an essentially annular deflector screen (29), fixed to the central tube (27) in the upper region (12) of the container (10), a guide ring (31), arranged in the lower region (13) of the container (10), which surrounds the central tube (27) over a part of the length thereof essentially concentrically with a separation (L) such that a first passage (34) is formed between the wall of the container (10) at the upper edge of the recess and the lower end (33) of the guide ring (31) and a second outlet (36) is formed between the deflector screen (29) and the upper edge (35) of the guide ring (31) and means for introduction of a fluid into the container (10), such as, for example, nozzles (21). Said device is characterised in that the external wall of the central tube (27) is at least partly provided with a non-stick coating (38). In a preferred embodiment the separation (L) between the wall of the central tube (27) and the wall of the guide ring (27) is greater than the open height (H3) of the first passage (34). The invention further relates to a method for the production of supported catalysts using such a device.
Abstract:
Disclosed is a method for producing a catalyst containing vanadium, phosphorus, and oxygen, which is used for oxidizing the gas phase of a hydrocarbon having at least four carbon atoms to maleic anhydride. According to the inventive method, a corresponding catalyst precursor which contains vanadium, phosphorus, and oxygen and is provided with particles having an average diameter of at least 2 mm is converted into a catalytically active form by means of calcination, and a flow of the catalyst precursor is transported on a conveyor belt across at least one calcination area over a distance ln at an essentially steady speed in order to be calcinated. The variation over time of the gas temperature in relation to the set point value amounts to
Abstract:
The invention relates to a vanadium-, phosphorus- and oxygen-containing catalyst that is used for producing maleic anhydride by heterogeneous catalytic gas phase oxidation of a hydrocarbon carrying at least four carbon atoms in which the ratio of phosphorus/vanadium is 0.9 to 1.5. Said catalyst comprises particles with an average diameter of at least 2 mm and the composition has a x-ray powder diffraction pattern, obtained by irradiation with CuK alpha radiation ( lambda = 1.54 10 m), that produces in the 2 theta range of 10 DEG to 70 DEG a signal/noise ratio of
Abstract:
La invencion se relaciona con un metodo para poner en funcionamiento catalizadores de oxidacion, caracterizado en que el catalizador se pone en funcionamiento a una temperatura de 360 degree C a 400 degree C, con un suministro de aire de 1.0 a 3.5 Nm3/h y una carga de hidrocarburos de 20 a 65 g/Nm3 con formacion de una zona activa en el primer 7 a 20 % del lecho del catalizador a una temperatura de 390 degree C a menos de 450 degree C.
Abstract:
Multimetal oxides corresponding to the general formula (I), processes for their preparation, precatalysts containing such oxides and catalysts made therefrom for gas phase partial oxidation of hydrocarbons: Ag a-c Q b M c V 12 O d .eH 2 O (I) wherein a represents a number having a value of 5 to 9; Q represents an element selected from the group consisting of P, As, Sb, Bi and mixtures thereof; b represents a number having a value of 0.2 to 3; M represents a metal selected from the group consisting of Li, Na, K, Rb, Cs, Tl, Mg, Ca, Sr, Ba, Cu, Zn, Cd, Pb, Cr, Au, Al, Fe, Co, Ni, Ce, Mn, Nb, W, Ta, Mo and mixtures thereof; c represents a number having a value of less than 1; d represents a number having a value of which is determined by the valency and frequency of Ag, Q, M and V in the formula (I); and e represents a number having a value of 0 to 20; wherein the multimetal oxide has a crystal structure wherein its powder X-ray diffractogram includes reflections at at least 5 interplanar spacings selected from the group of 7.13 Å, 5.52 Å, 5.14 Å, 3.57 Å, 3.25 Å, 2.83 Å, 2.79 Å, 2.73 Å, 2.23 Å and 1.71 Å, each interplanar spacing value±0.04 Å.
Abstract:
The invention relates to a method for producing phthalic anhydride during which the catalytic gas phase oxidation of o-xylol and/or naphthalene is carried out over at least three layers of catalysts of increasing activity, whereby only the last layer of the catalyst system contains phosphorous, and the last layer contains at least 10% by weight of vanadium (expressed as V2O5) with regard to the active mass of the catalyst and has a ratio of vanadium (expressed as V2O5) to phosphorous of greater than 35.
Abstract:
Catalyst systems for preparing phthalic anhydride by means of gas-phase oxidation of o-xylene and/or naphthalene, and a process for preparing phthalic anhydride using the catalyst systems.