Catalyst system and method for gas phase oxidation using an upstream layer
AssigneeBASF SE
InventorsHagen Wilmer, Jürgen Zühlke, Thomas Lautensack, Hans-Martin Allmann, Frank Rosowski, Cornelia Dobner
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Abstract
The present invention relates to a process for gas-phase oxidation, in which a gaseous stream comprising an aromatic hydrocarbon and molecular oxygen is passed through two or more catalyst zones. Furthermore, the present invention relates to a catalyst system for gas-phase reaction using a preliminary zone.
Claims20
A catalyst system which comprises at least two catalyst zones containing rings and arranged in series in the flow direction of the gaseous stream and the activities of the catalysts in adjoining catalyst zones are different from one another, wherein a catalyst zone precedes the adjoining catalyst zones in a direction opposite to the flow direction of the gas, and at least one of the following parameters exists:
- a. with the product of diameter times height of the catalyst rings in the preceding zone being smaller than in at least one of the subsequent catalyst zones,
- b. the volume of the catalyst rings in the preceding zone being smaller than in at least one of the subsequent catalyst zones or
- c. the ratio of surface area to volume of the catalyst rings in the preceding zone being greater than in at least one of the subsequent catalyst zones.
A catalyst system which comprises at least two catalyst zones containing rings and arranged in series in the flow direction of the gaseous stream and the activities of the catalysts in adjoining catalyst zones are different from one another, wherein an inert zone precedes the adjoining catalyst zones in a direction opposite to the flow direction of the gas, and at least one of the following parameters exists:
- a. with the product of diameter times height of the inert rings in the preceding zone being smaller than in at least one of the subsequent catalyst zones, or
- b. the volume of the preceding rings in the preceding zone being smaller than in at least one of the subsequent catalyst zones or
- c. the ratio of surface area to volume of the inert rings in the preceding zone being greater than in at least one of the subsequent catalyst zones.
Dependencies are inferred from the claim text.