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Multi-layer catalyst for producing phthalic anhydride

A technology of phthalic anhydride and catalyst, applied in the field of multi-layer catalyst, to achieve the effect of good PSA output

Inactive Publication Date: 2007-05-09
SUD CHEM AG
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] A disadvantage of the inventive catalysts described here is that, despite the use of such structured catalysts, the crude PSA still contains a high proportion of the undesired by-product 2-benzo[c]furanone

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0092] Embodiment 1: the preparation of catalyst A

[0093] For the preparation of catalyst A, it had an active substance proportion of 8% by weight and a composition of 7.5% by weight of vanadium pentoxide, 3.2% by weight of antimony trioxide, 0.40% by weight of cesium (calculated as cesium), 0.2% by weight Phosphorus (calculated as phosphorus) and the rest are titanium dioxide. In a so-called vortex bed coating machine, 2600g of talc in the shape of a hollow cylinder with a size of 8×6×5mm is made of 17.9g of vanadium pentoxide, 7.6 g antimony trioxide, 1.3g cesium sulfate, 1.9g ammonium dihydrogen phosphate, 211.1g have a BET surface area of ​​21m 2 / g of titanium dioxide, 130.5g of 50% water and vinyl acetate / ethylene copolymer (Vinnapas  A binder consisting of a dispersion of EP 65 W from the Wacker company) and a suspension consisting of 2000 g of water are applied at a temperature of 70°C. The active substance is applied in a thin layer.

Embodiment 2

[0094] Embodiment 2: the preparation of catalyst B

[0095] For the preparation of catalyst B, it had an active substance fraction of 8% by weight and a composition of 7.5% by weight of vanadium pentoxide, 3.2% by weight of antimony trioxide, 0.20% by weight of cesium (calculated as cesium), 0.2% by weight Phosphorus (calculated as phosphorus) and the rest are titanium dioxide. In a so-called vortex bed coating machine, 2200g of talc shaped body in the shape of a hollow cylinder with a size of 8×6×5mm is made of 15.4g of vanadium pentoxide, 6.6 g antimony trioxide, 0.5g cesium sulfate, 1.5g ammonium dihydrogen phosphate, the BET surface area of ​​182.9g is 21m 2 / g of titanium dioxide, 110.7g of 50% water and vinyl acetate / ethylene copolymer (Vinnapas  A binder consisting of a dispersion of EP 65 W from the Wacker company) and a suspension consisting of 2000 g of water are applied at a temperature of 70°C. The active substance is applied in a thin layer.

Embodiment 3

[0096] Embodiment 3: the preparation of catalyst C

[0097] To prepare catalyst C, it had an active substance fraction of 8% by weight and a composition of 7.5% by weight of vanadium pentoxide, 3.2% by weight of antimony trioxide, 0.2% by weight of phosphorus (calculated as phosphorus) and the balance titanium dioxide , in the so-called vortex bed coating machine, 2200g 8 × 6 × 5mm size of hollow cylinder shape talc molded body, with 13.35g of vanadium pentoxide, 5.7g of antimony trioxide, 1.34g of ammonium dihydrogen phosphate , 158.65g of BET surface area is 21m 2 / g of titanium dioxide, 109.4g of 50% water and vinyl acetate / ethylene copolymer (Vinnapas  A binder consisting of a dispersion of EP 65 W from the Wacker company) and a suspension consisting of 2000 g of water are applied at a temperature of 70°C. The active substance is applied in a thin layer.

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Abstract

The invention relates to a multi-layered catalyst bed for producing phthalic anhydride by gas phase oxidation of o-xylol and / or naphtaline, which contains at least three differently composed catalyst layers, respectively an active mass, which are characterised as a first, second and / or third catalyst layer which leads from the gas inlet side to the gas outlet side. Said catalyst layers comprise an active mass containing TiO2 having a NA content of less that 0.3 wt. %, and the active mass content decreases from the first catalyst layer, which is placed in the direction of the gas inlet side, to the third catalyst layer, which is placed in the direction of the gas outlet side, under the proviso that (a) the first catalyst layer has an active mass content of between 7 and 12 wt. %, (b) the second catalyst layer has an active mass content in the region of between 6 and 11 wt %. The active mass content of the second catalyst layer is smaller or equal to the active mass content of the first catalyst layer, and (c) the third catalyst layer has an active mass content in the region of between 5 and 10 wt. %. The active mass content of the third catalyst layer is smaller or equal to the active mass content of the second catalyst layer. The invention also relates to a preferred method for producing said type of multi-layered catalyst bed, and to the preferred use of the titanium dioxide which is used according to the invention.

Description

technical field [0001] The present invention relates to a multilayer catalyst, i.e. a catalyst having three or more different layers (layers) for the production of phthalic anhydride ( PSA) in which the active mass (Aktivmasse) content decreases from the first catalyst layer towards the gas inlet side to the catalyst layer towards the gas outlet side. Background technique [0002] The industrial production of phthalic anhydride is achieved by gas-phase catalytic oxidation of o-xylene and / or naphthalene. For this purpose, a catalyst suitable for the reaction is filled into a reactor, preferably a so-called tube-bundle reactor, in which a large number of tubes are arranged in parallel, and the hydrocarbon(s) and the oxygen-containing gas, such as The air-forming mixture flows over the catalyst from above or below. Since this oxidation reaction is highly exothermic, it is necessary to repeatedly flush the reaction tube with a heat transfer medium and thereby dissipate the hea...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J35/10C07C51/265C07C51/31B01J35/00B01J27/198B01J23/22
CPCC07C51/265B01J37/0219B01J23/22B01J27/198B01J37/0221B01J23/002C07C51/313B01J21/063B01J2523/00
Inventor C·古克尔M·涅德梅尔M·埃斯腾费尔德
Owner SUD CHEM AG