Basf Aktiengesellschaft

Peter Reuter

Friedrich Wirth

Kurt Blechschmitt

Guido Voit

Gert Buerger

Paul Hornberger

Manfred Patsch

Ulrich Hammon

Hans Peter Rath

Thomas Heidemann

Helmut Mach

Gerhard Olbert

Heinz Eilingsfeld

Herwig Hoffmann

Hans Diem

Bernd Bessling

Matthias Kummer

Ludwig Wambach

Franz Corr

Werner Peschel

Peter M Lorz

Thomas R&uuml;hl

Rolf Seubert

Bernhard Ulrich

Jean Werner Knab

Willi A Weber

Nikolaus Von Kutepow

Franz J Mueller

A multitube fixed bed reactor and the use of such a reactor for carrying out catalytic gas-phase reactions, in particular for carrying out exothermic and endothermic catalytic gas-phase reactions such as the preparation of phthalic anhydride (PA), acrylic acid, methacrylic acid (MAA), acrolein, maleic anhydride (MA), glyoxal, phosgene, hydrocyanic acid or vinyl formamide (VFA). In a relatively large multitube reactor in which a large amount of heat of reaction is generated owing to the numerous catalyst tubes () and has to be removed, it is proposed that the ratio of tube spacing t to external tube diameter dbe made dependent on the reactor diameter or on the external tube bundle diameter d. At an external diameter of the catalyst tube bundle () of more than 4 meters, a ratio of tube spacing d to external tube diameter dof at least 1.3 is preferred.

Multi-tube fixed-bed reactor, especially for catalytic gas phase reactions

Method for producing phthalic anhydride

On-spec phthalic anhydride is prepared by distillative purification of crude phthalic anhydride by a process in which crude phthalic anhydride is fed to a distillation column which is operated at reduced pressure, the low boilers are removed at the top or in the vicinity of the top of the distillation column and the on-spec phthalic anhydride is removed from the column via a side take-off.

Method for producing phthalic anhylic anhydride according to specifications

In a process for preparing phthalic anhydride by passing a gas stream comprising o-xylene, oxygen and sulfur dioxide at elevated temperature over a catalyst comprising heavy metals, the content of N-acyl compounds in the gas stream is restricted to less than 200 ppm, based on the weight of o-xylene.

Method of producing phthalic acid anhydride

A process for the preparation of N,N-dialkylarylamines (I) by reacting arylamines (II) with alcohols (IIIa) or dialkyl ethers (IIIb) in the presence of an oxygen acid of phosphorus or in the presence of an ammonium salt thereof as catalyst, comprises reacting the oxygen acid of phosphorus with an arylamine (IV) before the reaction is commenced. The invention also relates to the regeneration of the catalyst by occasionally interrupting the reaction and treating the catalyst phase at from 100.degree. to 300.degree. C. with steam or water.

Preparation of N,N-dialkarylamines

A process for the preparation of polyisobutene from isobutene and/or hydrocarbons containing isobutene in the presence of a complex of BF.sub.3 and an alcohol, wherein the free BF.sub.3 is substantially removed from the complex solution and/or from the reaction chamber.

Preparation of polyisobutene

A process for reactivating a vanadium-containing oxidation catalyst, wherein the catalyst is treated first at from 100.degree. to 600.degree. C., with a volatile phosphorus compound in the presence of an oxygen-containing gas, and then at from 50.degree. to 600.degree. C. with sulfur trioxide or a mixture of a volatile sulfur compound and an oxygen-containing gas.

Reactivation of vanadium-containing oxidation catalysts

A supported catalyst, containing vanadium pentoxide, titanium dioxide, phosphorus, rubidium and any optionally added cesium, with or without zirconium dioxide, in which the catalytic material contains from 1 to 40% by weight of V.sub.2 O.sub.5, from 60 to 99% by weight of TiO.sub.2 and/or ZrO.sub.2 and, based on the total amount of TiO.sub.2, ZrO.sub.2 and V.sub.2 O.sub.5, up to 2% by weight of phosphorus and up to 1.5% by weight of rubidium and/or cesium, and which comprises two layers, of which the inner layer contains more than 0.2 and up to 2% by weight of phosphorus, but no rubidium and/or cesium, and the outer layer contains from 0 to 0.2% by weight of phosphorus and from 0.02 to 1.5% by weight of rubidium and/or cesium, the outer layer accounting for from 10 to 90% by weight of the total catalytic material.

Supported catalysts containing vanadium pentoxide, titanium dioxide,

A supported catalyst, containing vanadium and titanium and/or zirconium, obtained by applying a mixture of finely divided titanium dioxide and/or zirconium dioxide, and a solution or suspension of a vanadium compound, to an inert, non-porous, ring-shaped carrier having an external diameter of from 6 to 10 mm, a length of from 4 to 10 mm and a wall thickness of from 0.5 to 3 mm, the two end faces of the ring-shaped carrier being outwardly beveled at an angle such that the length of the outer cylindrical wall is at least 20% shorter than the length of the inner cylindrical wall.

Supported catalyst containing vanadium and titanium and/or zirconium for

A process for the separation of rhodium from a solution containing a rhodium carbonyl complex such as is obtained in the carbonylation of an alkanol or of an olefinically or acetylenically unsaturated compound with carbon monoxide and water and conversion of the separated rhodium into a soluble rhodium carbonyl complex, in which the solution containing the rhodium carbonyl complex is treated with hydrogen in the presence of a carrier substance at a temperature of from 25.degree. to 300.degree. C and at a pressure of from 1 to 700 atmospheres, the solution freed from rhodium is separated and the rhodium precipitated on the carrier is converted into a soluble rhodium carbonyl complex by treatment with carbon monoxide in the presence of a solvent and a compound which can replace the carbon monoxide as a ligand at a temperature of from 20.degree. to 300.degree. C and at a pressure of from 1 to 700 atmospheres.

Separating rhodium from solution containing rhodium carbonyl complexes

A supported catalyst for the oxidation of aromatic or unsaturated aliphatic hydrocarbons, comprising an inert nonporous carrier to which is applied a thin layer of a catalytic composition which contains from 1 to 39.9 percent by weight of vanadium pentoxide, from 60 to 98.9 percent by weight of titanium dioxide and from 0.1 to 10% by weight of rubidium and antimony in an atomic ratio Rb : Sb of from 1:2.5 to 1:30, the vanadium pentoxide content being from 0.05 to 4 percent by weight, based on the supported catalyst.

Supported catalysts containing vanadium pentoxide and titanium dioxide

A process for the manufacture of phthalic anhydride by oxidizing o-xylene and/or naphthalene over a supported catalyst containing vanadium pentoxide and titanium dioxide, at from 350.degree. to 500.degree. C, in which the o-xylene or naphthalene is passed, with an oxygen-containing carrier gas, over the catalyst, and in which the catalyst in the first 25-50 per cent by volume of the total catalyst volume, in the direction of flow of the mixture of o-xylene or naphthalene and carrier gas, contains from 0.01 to 0.3 per cent by weight, based on titanium dioxide, of rubidium, but no phosphorus, in the active composition, while the remainder of the catalyst contains from 0.02 to 0.8 per cent by weight, based on titanium dioxide, of phosphorus, but no rubidium, in the active composition.

Manufacture of phthalic anhydride from o-xylene or naphthalene

A supported catalyst containing vanadium and titanium, comprising a ring-shaped carrier having an external diameter of from 7.3 to 8.6 mm, a length of from 5.3 to 7 mm and a wall thickness of from 0.1 to 2 mm, and an active composition, applied thereto, of from 1 to 30 per cent by weight of vanadium pentoxide and from 70 to 99 per cent by weight of titanium dioxide and/or zirconium dioxide.

Supported catalyst containing vanadium and titanium

Supported catalyst for the oxidation of o-xylene or naphthalene to phthalic anhydride, comprising an inert carrier and the active material applied thereto, which contains from 1 to 40 per cent by weight of vanadium pentoxide, from 60 to 98.84 per cent by weight of titanium dioxide and from 0.16 to 0.6 per cent by weight, based on titanium dioxide, of rubidium in the form of rubidium oxide, the vanadium pentoxide content being from 0.05 to 4 per cent by weight, based on the (complete) catalyst.

Supported catalyst for the oxidation of o-xylene and/or naphthalene to

Anthraquinone is manufactured by oxidation of diphenylmethane compounds in the gas phase, in the presence of vanadium(V) oxide and titanium dioxide in a specific weight ratio. The anthraquinone which may be manufactured by the process of the invention is a valuable starting material for the manufacture of dyes and pesticides.

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Mannheim, Germany

Peter Reuter