KR20110050694A - Catalyst for the catalytic gas phase oxidation of aromatic hydrocarbons to form aldehydes, carboxylic acids and/or carboxylic acid anhydrides, in particular phthalic acid anhydride, and method for producing said type of catalyst - Google Patents

Abstract

FIELD OF THE INVENTION The present invention relates to catalysts for the formation of aldehydes, carboxylic acids and / or carboxylic anhydrides, in particular phthalic anhydrides, from aromatic hydrocarbons by catalytic gas phase oxidation, wherein the active agent of the catalyst is vanadium oxide, preferably pentoxide Vanadium, titanium dioxide, preferably anatase type titanium dioxide, and at least one silver mixed element oxide of silver with certain elements, preferably vanadium and / or molybdenum and / or tungsten and / or niobium and / or antimony, And / or vanadium mixed element oxides of vanadium with certain elements, preferably bismuth and / or molybdenum and / or tungsten and / or antimony and / or niobium, in particular when preparing the catalyst At least one silver and / or barna during the preparation of the powder mixture needed to coat the Mixing element oxide, at least one precursor compound, in particular using at least one multi-core precursor compound as a raw material source.

Description

Catalysts for the formation of aldehydes, carboxylic acids and / or carboxylic anhydrides, in particular phthalic anhydrides, from aromatic hydrocarbons by catalytic gas phase oxidation, and processes for the preparation of catalysts of this type FIELD OF THE CATALYTIC GAS PHASE OXIDATION OF AROMATIC HYDROCARBONS TO FORM ALDEHYDES, CARBOXYLIC ACIDS AND / OR CARBOXYLIC ACID ANHYDRIDES, IN PARTICULAR PHTHALIC ACID ANHYDRIDE, AND METHOD FOR PRODUCING SAID TYPE OF CATALYST}

Catalytic gas phase oxidation of aromatic hydrocarbons, such as benzene, xylene, naphthalene, toluene or durene, in fixed bed reactors, preferably in multi-tube reactors, has been known for a long time and has been described in the literature. In this way, for example, benzoic acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid and pyromellitic anhydride are produced.

To this end, a mixture generally consisting of a gas containing molecular oxygen, for example air, and a mixture of hydrocarbons, for example o-xylene or naphthalene, to be oxidized, is arranged in a reactor comprising at least one catalyst It is introduced through a number of reaction tubes present.

A tube filled with a catalyst is surrounded by a heat transfer medium, for example molten salt, in order to dissipate the heat produced during temperature control or exothermic reaction.

Despite this temperature control, a local maximum temperature (“hot spot”) can be formed in the catalyst stack, which, for example, forms a byproduct that is difficult to completely oxidize or separate from the starting material. Undesired effects can limit the throughput of starting materials.

In order to prevent such hot spots, layers having different activities and chemical compositions actually overlap each other in the reaction tube layer, and layer layers are arranged according to the prior art. This increases the activity.

In general, a so-called shell catalyst has been used, which consists of an inert nonporous carrier material and is coated with a thin film layer of at least one catalytically active mass in the form of a shell.

The composition of the catalyst activator plays an important role with respect to the catalyst properties of the relevant catalyst.

In the past, a number of catalysts have been proposed for producing phthalic anhydride by gas phase oxidation of o-xylene and / or naphthalene with gas containing molecular oxygen on a fixed bed catalyst.

According to the prior art, catalytic activators of phthalic anhydride-catalysts used in practically all industrial fields include anatase-type compounds such as titanium dioxide, vanadium pentoxide and small amounts of other components to improve the conversion, yield, selectivity and long-term stability of the catalyst. It contains a promoter.

Examples of such additives are cesium, antimony, phosphorus, boron, molybdenum, tungsten, tin, bismuth, silver, niobium, iron, potassium, rubidium, chromium and calcium.

Doping with these different materials further increases the performance and stability of the PSA-catalyst. This suggests that over time, to solve the problems of the prior art, the composition of the catalyst gradually becomes more complex, and techniques for combining different catalysts are being developed.

In terms of activity and selectivity, so-called "multi-layered" catalysts are increasingly used on the basis of the composition of the characteristic activators. In this case, a plurality of different catalysts are sequentially layered in the catalyst stack to perform different functions in the catalyst bed according to the layers. The exothermic reactions that take place allow substantially safe control of the high selectivity and stability of the catalyst, with substantially high throughput for the starting materials.

EP A 21 325 has an active material of 60 to 99% by weight of titanium dioxide, 1 to 40% by weight of vanadium pentoxide, and up to 2% by weight of phosphorus and up to 1.5% by weight of rubidium and / or to the total amount of TiO ₂ and V ₂ O ₅ As a catalyst for the preparation of phthalic anhydride containing cesium, a catalyst is described in which the catalytically active agent is applied in two layers on a carrier. The inner layer contains 0 to 2% by weight of phosphorus but no rubidium and / or cesium, and the outer layer contains 0 to 0.2% by weight of phosphorus and 0.02 to 1.5% by weight of rubidium and / or cesium. The catalyst activator of the catalyst contains in addition to the constituents other materials, for example up to 10% by weight of metal molybdenum, tungsten, niobium, tin, silicon, antimony, hafnium. Steatite is used as the inert carrier material.

EP A 286448 describes a process for the preparation of phthalic anhydride, using two different catalysts of similar content for titanium dioxide and vanadium pentoxide. One of these catalysts additionally contains 2 to 5% by weight of cesium compounds, in particular cesium sulfate, but no phosphorus-, tin-antimony-, bismuth-, tungsten- or molybdenum compounds, and the other catalyst 0.1 to 3.0 It is distinguished from each other in that it contains a weight% phosphorus-, tin-, antimony-, bismuth-, tungsten- or molybdenum compound.

US 4,864,036 relates to a catalyst for preparing phthalic anhydride in several steps. In the first step, a 6-sided group metal compound, preferably molybdenum- or tungsten compound, is applied to the anatase-type titanium dioxide and then fired. Thereafter, in the second step, the calcined precursor is added to the vanadium compound and calcined again.

GB 1140264 relates to catalysts for oxidizing aromatic and non-aromatic hydrocarbons to carboxylic acids, which are inert nonporous carriers and layered 0.02 to 2 mm thick and 1 to 15% V ₂ O ₅ and 85 to 99% It consists of an activator consisting of titanium dioxide, the vanadium-content of the total catalyst is in the range of 0.05 to 3%. In addition to titanium dioxide and vanadium pentoxide, an active agent is described which additionally comprises from 0.1 to 3% by weight of at least one metal oxide selected from the group consisting of silver, iron, cobalt, nickel, molybdenum or tungsten.

EP 0447 267 describes a catalyst for the preparation of phthalic anhydride as catalyst activator comprising: (A) 1 to 20% by weight of V ₂ O ₅ and anatase type titanium dioxide having a BET-surface area of 10 to 60 m ² / g. 99 to 80% by weight and (B) 0.05 to 2 parts by weight in terms of silver oxide and an element selected from the group consisting of 0.05 to 1.2 parts by weight of K, Cs, Rb and Ti as oxides based on 100 parts by weight of the mixture (A) Silver of wealth.

EP 0522 871 B1 is at least one element selected from the group consisting of 0.01 to 1% by weight of niobium as niobium pentoxide and 0.05 to 2% by weight of potassium, cesium, rubidium or thallium as oxide, in addition to titanium dioxide and vanadium pentoxide, P ₂ A catalyst containing from 0.2 to 1.2% by weight of phosphorus as O ₅ and from 0.55 to 5.5% by weight of antimony oxide and from 0.05 to 2% by weight of silver as Ag ₂ O, a catalyst using a pentavalent antimony compound as an antimony source. Doing.

CN1108996 relates to a catalyst with two layers based on titanium dioxide / V ₂ O ₅ , which additionally contains at least one rare earth compound and at least one oxide of antimony, phosphorus, tin and silver. The located layer further contains at least one alkali metal compound.

Silver-vanadium oxide compounds having an atomic ratio Ag: V <1 are known as silver-bronze. Examples of using silver-vanadium bronze as an oxidation catalyst are generally known in the literature.

DE 198 51 786 multi-element metal oxide, as described in A1 of the general formula Ag _{a -} is marked with _{b M b V 2 O x *} cH 2 O, wherein a has a value of from 0.3 to 1.9, M is Li, Metal selected from the group consisting of Na, K, Rb, Cs, Tl, Mg, Ca, Sr, Ba, Cu, Zn, Cd, Pb, Cr, Au, Al, Fe, Co, Ni and / or Mo, b has a value from 0 to 0.5 and ab is at least 0.1. The use of such multi-element metal oxides as precursor compounds for preparing procatalysts and catalysts for gas phase oxidation of aromatic hydrocarbons is described.

Finally, WO 2005/092496 A1 discloses a catalyst for the preparation of aldehydes, carboxylic acids and / or carboxylic anhydrides, the actives of which comprise phase A and phase B in the form of three-dimensional expanded compartment regions and Based on titanium and vanadium pentoxide, phase A describes a catalyst which is silver-vanadium oxide-brass and phase B is a mixed element phase. The molar ratio of Ag: V in phase A is in the range of 0.15 to 0.95.

Such catalysts known in the art with various activator compositions are not satisfactory in selectivity, yield or activity, have a short lifespan or are expensive to manufacture industrially.

Accordingly, there has been a continuing need for catalysts that can be manufactured with high raw material throughput, long lifespan and acceptable cost-benefit-ratio while improving selectivity and yield.

SUMMARY OF THE INVENTION An object of the present invention is to provide an improved catalyst for the formation of aldehydes, carboxylic acids and / or carboxylic anhydrides, in particular phthalic anhydrides, from aromatic hydrocarbons by gas phase oxidation, the catalyst having a high raw material throughput and improved selectivity. At the same time, the life is long.

The problem is solved by the features of claim 1. Preferred embodiments are described in the dependent claims, the contents of which are included herein.

Claim 1 describes a catalyst for the formation of aldehydes, carboxylic acids and / or carboxylic anhydrides, in particular phthalic anhydrides, from aromatic hydrocarbons by catalytic gas phase oxidation reactions, wherein the active agent of the catalyst is vanadium oxide, Preferably at least one silver of vanadium pentoxide, titanium dioxide, preferably anatase type titanium dioxide, and silver with certain elements, preferably vanadium and / or molybdenum and / or tungsten and / or niobium and / or antimony Mixing element oxides and / or vanadium mixed element oxides with vanadium and certain elements, preferably bismuth and / or molybdenum and / or tungsten and / or antimony and / or niobium. At least one silver and / or vanadium mixed element oxide, at least one precursor compound, in particular at least one multinuclear precursor compound, as raw material sources, during the preparation of the powder mixtures necessary for coating the catalyst suspension or the carrier, especially when preparing the catalyst use.

Surprisingly, mixed element oxides, preferably of silver and for example vanadium, molybdenum, tungsten, niobium and / or antimony mixed element oxides, preferably of vanadium and for example bismuth, molybdenum, tungsten, niobium and / or antimony Selective when mixed element oxides or precursor compounds thereof are used as raw material sources in the preparation of powder mixtures used in the preparation or application of the catalyst suspension and / or as components of the active agent of the catalyst in addition to the components titanium dioxide and vanadium oxide It has been found that this is obviously increased.

The cause for this is not clearly explained, but perhaps the interaction of silver with other catalytically active constituents, for example titanium dioxide / vanadium oxide monolayer, has a substantial effect and therefore the inherent promoting effect of silver (carbon monoxide from organic raw materials). It is expected that the full oxidation inhibition effect of the furnace is effective.

Many examples of the use of silver as a constituent of an activator are described in the prior art. According to these, besides silver oxide, suitable silver, such as silver nitrate, silver sulfate, silver halide, silver sulfide, silver phosphate, silver salt of organic acid, silver hydroxide, antimony salt of silver, and a silver complex, is used as a raw material source of silver for catalyst suspension manufacture. Most of these feedstock sources are converted to mononuclear silver oxide when they are heated in the reactor and present in the activator as silver oxide, while, for example, silver phosphate and silver halide do not change to active and do not convert to silver oxide even upon heat treatment.

A substantial gist of the present invention includes titanium dioxide and vanadium oxide as active agents and mixed element oxides of silver and vanadium and / or certain other elements and / or mixed element oxides of vanadium and some other elements as additional coating materials. As a catalyst comprising at least one mixed element oxide of silver and / or vanadium and / or at least one mixed element compound of the corresponding precursor compound in the preparation of the powder mixture wherein the catalyst suspension is used for the preparation of the catalyst suspension or for the coating of the carrier. Is added.

The invention also relates to a process for the preparation of the catalyst of the invention described above, comprising preparing a catalyst suspension or a mixture of different components, wherein the catalyst suspension or mixture of different components is at least with anatase titanium dioxide At least one or more of a mixed element oxide or a corresponding precursor compound of a vanadium compound with at least one silver and / or vanadium with a predetermined element is contained as raw material source.

All the components are combined with each other in an aqueous medium and then applied on a ceramic carrier via spraying (preferably vortex- or drum-based). A mixed element oxide phase of silver and / or vanadium or a mixed element oxide-precursor compound thereof is added to the catalyst suspension comprising the main component titanium dioxide and vanadium oxide and other promoters and is generally not present as a phase separated in space It is present as a phase consisting of titanium dioxide and vanadium oxide. All components of the catalyst suspension thus form a single phase, which further contains the corresponding mixed element oxides and optionally other components in addition to titanium dioxide and vanadium oxide.

It may also be possible for a catalyst system in which different layers with different chemical compositions are applied sequentially on an inert carrier and at least one or more layers contain at least one mixed element oxide of silver and / or vanadium with certain elements. In this case, each of the coating-layers of the catalyst according to the invention may consist of a composition according to the invention and a composition not according to the invention.

The mixed element oxide is also used in one or more coating layer (s), alone or in combination with other compounds, which may contain no titanium dioxide and / or vanadium oxide as an active agent.

According to the present invention, catalysts and catalyst precursors for gas phase partial oxidation of aromatic hydrocarbons can be implemented using molecular oxygen-containing gases, which catalysts or catalyst precursors comprise inert nonporous carrier materials and one or more shells thereon. A layer (s) applied in the form of a form is formed, wherein at least one or more of the layers contain one or more of the above-described mixed element oxide or precursor compounds in an amount of 0.01 to 15% by weight, based on the total weight of the layer.

In addition, the present invention claims a specific process for preparing carboxylic acid and / or carboxylic anhydride through gas phase partial oxidation of aromatic hydrocarbon at high temperature by gas containing molecular oxygen on catalyst. The activator is applied in a shell form on the carrier material, and the catalyst activator of the shell catalyst is mixed with 0.01 to 15% by weight of silver and vanadium with respect to the total weight of the shell catalyst, and / or with silver and certain other elements. Elemental oxides and / or 0.01 to 10% by weight of vanadium and bismuth mixed elemental oxides and / or mixed elemental oxides of vanadium with some other element and at the same time anatase type titanium dioxide and vanadium compounds (preferably V ₂ O ₅ ), And the mixed element oxide-compound (s) or precursor compound (s) thereof is activated by heat treatment after carrier coating. An adult is formed and is used for the preparation of the catalyst suspension and / or powder mixture.

In this case, in the oxidation reaction of the aromatic hydrocarbon to carboxylic acid and / or carboxylic anhydride, the active substance contains vanadium oxide, in particular vanadium pentoxide, and titanium dioxide, in particular anatase-type titanium dioxide, but the mixture described below. There may or may not be at least one shell-type catalyst not in accordance with the present invention that does not contain elemental oxides or precursor compounds thereof, and that is a laminate combined with one or more of the catalysts of the present invention as described above (i.e., one Or mixtures thereof).

To this end, it is preferred to introduce an air stream over the catalyst beds of at least two catalyst beds, wherein the catalyst bed located near the gas inlet contains the catalyst according to the invention, and the catalyst bed located downwards along the air stream is the catalyst. The activator contains vanadium oxide and anatase type titanium dioxide, but mixed element oxides and / or vanadium with silver such as vanadium, molybdenum, tungsten, niobium, antimony and / or bismuth, molybdenum, tungsten, niobium, It contains at least one catalyst that does not contain any mixed element oxides with elements such as antimony.

It is also possible to use catalyst stacks composed of at least two layers containing the catalyst according to the invention. In this case, the catalysts according to the invention used can be distinguished by the form and content of the corresponding mixed element oxide in the active.

Preferably at least one catalyst layer, particularly preferably all catalyst layers used in the catalyst zone, including the catalyst of the invention, comprise 1-40% by weight of vanadium oxide (expressed as V ₂ O ₅ ), 50-99% by weight. Titanium dioxide (expressed as TiO ₂ ), up to 1% by weight of alkali metal compound (preferably as cesium compound, alkali metal), up to 1.5% by weight of phosphorus compound (expressed as P) and up to 10% by weight of antimony compound Catalytic actives containing (expressed as Sb ₂ O ₃ ).

According to a particularly preferred embodiment, the catalyst according to the invention is preferably silver and vanadium, niobium, tantalum, titanium, zirconium, chromium, molybdenum, tungsten, cerium, lanthanum, aluminum, boron, manganese, iron, cobalt, nickel, 0.01-15% by weight of at least one mixed element oxide with at least one element selected from the group consisting of copper, zinc, gold, cadmium, tin, lead, bismuth, antimony, arsenic, hafnium, rhenium, ruthenium, rhodium and palladium Vanadium and bismuth, antimony, niobium, tantalum, titanium, zirconium, chromium, molybdenum, tungsten, cerium, lanthanum, aluminum, boron, manganese, iron, cobalt, nickel, copper, zinc, gold, cadmium, tin, At least one mixed element oxide with at least one element selected from the group consisting of lead, arsenic, hafnium, rhenium, ruthenium, rhodium and palladium 0.01 to 10 It contains% by weight.

The content of mixed element oxides of silver with certain elements, in particular vanadium and / or tungsten and / or molybdenum and / or niobium and / or antimony, in the actives of the catalyst is in a preferred embodiment 0.01 to 15% by weight. In the range of 0.01 to 10% by weight, in particularly preferred embodiments, 0.01 to 5% by weight. Mixing of vanadium and certain elements (except silver, see above for mixed element oxides of silver and vanadium) in the active of the catalyst, in particular for example tungsten and / or molybdenum and / or niobium and / or antimony The content of elemental oxides is in the range of 0.01 to 10% by weight in preferred embodiments, and in the range of 0.01 to 5% by weight in particularly preferred embodiments.

In a preferred embodiment, the catalyst of the invention is used in the first catalyst bed, which is the catalyst bed located closest to the gas inlet and having the highest hot spot. At least one other catalyst layer is connected in the direction of the gas outlet, which is generally higher in activity than the first catalyst layer and in which a catalyst corresponding to the prior art can be provided. The catalyst according to the invention then contains at least one mixed element oxide of silver, preferably silver vanadate, and preferably a mixed element oxide of vanadium, preferably bismuth vanadate.

Preference is given to a multilayer catalyst system having at least one hot spot catalyst layer in a bed located forward in the direction of the gas inlet, wherein at least one of the catalyst beds from the gas inlet to the layer with the highest hot spot is present in the present invention. The catalyst according to the invention is used in the layer containing the catalyst according to the rear and / or the catalyst according to the invention is used in a reduced content of the mixed element oxide required for the activator.

In another particularly preferred embodiment, at least one catalyst layer present in front of the layer with the highest hot spot contains a mixed element oxide of silver, preferably a mixed element oxide of silver with molybdenum and / or tungsten, particularly preferably silver While mixed element oxides of and vanadium are present, the layer having the highest hot spot and the layer located downward along the airflow contain no mixed element oxides of silver at all. The layer with the highest hot spot preferably contains a mixed element oxide of vanadium and bismuth. The catalyst layer located behind the hot spot catalyst layer in the direction of the gas outlet preferably corresponds to the prior art and generally does not contain the catalyst according to the invention.

In a particularly preferred embodiment of the catalyst, the compounds AgVO ₃ and / or Ag ₂ MoO ₄ and / or Ag ₂ WO ₄ and / or BiVO ₄ are used in the preparation of the catalyst suspension and / or contained in the active of the catalyst.

It is important that the content of the mixed element oxide serving as a "promoter" is selected to be little or no. When the mixed element oxide content of silver is low, the effect of increasing selectivity is not sufficiently effective, whereas when the mixed element oxide content of silver is high, high activity is observed, which increases the complete oxidation reaction to CO and CO ₂ and thus selectivity. Will be low.

The catalyst according to the invention is particularly preferred for use in all layers from the catalyst bed located close to the gas inlet to the one with the highest hot spot, otherwise the full selectivity increase effect is achieved since almost all of the raw material has already been converted. This is because it can not achieve more.

The high mixed element oxide content of bismuth may adversely affect the selectivity of the catalyst while at the same time forming more byproducts, which may worsen the color stability of the desired product. On the contrary, when the mixed element oxide content of bismuth is small, the effect of increasing selectivity does not appear significantly.

When using a laminate comprising the catalyst according to the invention in at least one or more catalyst layers thereof, at least two or more preferably through a combination of a plurality of catalyst layers, the multilayer catalyst system and a catalyst not according to the invention are used alone. Compared to the above, overall high yield can be obtained.

According to the prior art, in many cases the catalytic activity increases step by step from the first catalyst bed used in the gas inlet to the last catalyst bed closest to the gas outlet. Modulation of activity can be carried out through various methods known to those skilled in the art. For example, by stepwise reducing the content of alkali metals in the actives in the bed from the gas inlet to the gas outlet, increasing the average BET-surface area of the titanium oxide used, or the activity on the total weight of the catalyst Increasing the sieve component can increase the catalytic activity. It is also possible to combine different methods for regulating activity.

The catalyst according to the invention comprises at least one anatase type titanium dioxide, at least one vanadium compound (preferably V ₂ O ₅ ), a mixed element oxide of at least one silver and / or vanadium in the active and optionally antimony It is advantageous to include compounds, compounds of alkali elements and / or phosphorus compounds.

The total content of titanium dioxide in the active agent of the catalyst according to the invention is 50 to 99% by weight, particularly preferably 80 to 99% by weight.

In this case, one anatase-type titanium dioxide having a certain physical property or a mixture of a plurality of titanium dioxides having different physical properties may be used for the preparation of the catalyst suspension and / or for the preparation of the activator of the catalyst.

The average BET-surface area of titanium dioxide used in the catalyst according to the invention is advantageously 10-60 m ² / g, in particular 12-30 m ² / g for one or more titanium dioxide species, whereas for single species BET- The surface area is in the range of 3 to 300 m ² / g.

The average BET-surface area of titanium dioxide used is calculated from the content of the type used and the BET-surface area. At least one titanium dioxide having an average particle size in the range of 0.3 to 0.8 mu m is used.

The content of vanadium oxide (expressed as V ₂ O ₅ ) in the active is preferably in the range from 1 to 40% by weight and in a particularly preferred embodiment in the range from 1 to 20% by weight.

It is advantageous to use vanadium pentoxide and / or vanadium oxalate as raw material sources for preparing the catalysts according to the invention. In general, other vanadium compounds, for example ammonium metavanadate, among them polyvanadium acid or mixtures of different sources are also suitable.

In general, vanadium in the activator is substantially in a tetravalent oxidation step because the precursor compound or source of vanadium is converted to vanadium pentoxide when the catalyst is heat treated or heated in the presence of molecular oxygen in the reactor.

Depending on each layer of the catalyst according to the invention in the catalyst bed, the catalytically active agent is selected from the group consisting of one or more mixed element oxides of silver and / or vanadium in addition to titanium dioxide, vanadium oxide and additionally alkali metals It contains the above elements.

It is generally added as a salt of the catalyst suspension (eg sulphate, carbonate, nitrate, phosphate) and converted to the corresponding oxide upon heating the catalyst or remains unchanged in the activator (after heat treatment of the catalyst).

Alkali metal compounds are used to improve catalytic activity with activity control.

In a preferred embodiment, the alkali metal content in the activator is in the range of 0 to 1.0% by weight and particularly preferably in the range of 0 to 0.6% by weight. It is preferable to use soluble cesium compounds such as cesium sulfate to prepare the catalyst suspension.

The catalyst according to the invention preferably contains an antimony compound as one component of the activator in order to improve thermal stability in the activator of the hot spot catalyst layer. The antimony content in the activator is preferably in the range from 0 to 10% by weight (expressed as Sb ₂ O ₃ ) and in particular in the range from 0 to 5% by weight, depending on the layer of the catalyst in the total catalyst zone and the heat treatment of the catalyst in each layer. .

As starting materials for the powder mixtures of the catalysts according to the invention which are necessary to prepare catalyst suspensions or to coat carriers, different antimony compounds, for example antimony salts or antimony oxides, can be used in different oxidation steps.

In a preferred embodiment of the catalyst according to the invention, antimony-III-oxides are used in the preparation of the catalyst suspension.

In some cases, the catalyst according to the invention may contain a phosphorus compound in the catalyst activator or add the phosphorus compound as a raw material source in the preparation of powder mixtures used for the preparation of catalyst suspensions or carrier coatings. In a particularly preferred embodiment of the catalyst according to the invention, the phosphorus content of the activator is in the range of 0 to 1.5% by weight (expressed as P).

In a catalyst system having a plurality of layers with one or more catalysts according to the invention and / or one or more catalysts not according to the invention in the laminate, increasing the phosphorus content from the gas inlet to the gas outlet Especially good.

The activator of the catalyst according to the invention may contain small amounts of many other compounds which can reduce or increase the activity as an accelerator and / or affect the selectivity of the catalyst.

The prior art describes the use of multilayer catalysts as a means of controlling or reducing the activity or reducing the so-called "hot spots," which are typically layered in the catalyst stack, in particular a plurality of layers being superimposed on one another. The smallest active catalyst is present at the position closest to the inlet and the catalyst activity increases toward the gas outlet.

The catalysts in each layer have different chemical compositions and differ in activity and selectivity.

It is preferred that in the multilayer catalyst system at least one layer contains a catalyst according to the invention containing at least one corresponding mixed element oxide.

The first layer closest to the gas inlet and having the highest hot spot contains the catalyst of the present invention. It is particularly preferred that all layers in the catalyst stage, ie all the layers from the gas inlet to the one with the highest hot spot, contain the catalyst according to the invention. For example, the content and shape of the mixed element oxides of silver in different layers can vary. Other compositions of the activator may be suitably adjusted to suit each layer in the catalyst bed.

In a preferred embodiment, the layer with the highest local maximum temperature contains a mixed element oxide of silver and / or a mixed element oxide of bismuth and vanadium.

In particular, the use of a mixed element oxide of AgVO ₃ and BiVO _{4 in} the layer with the highest hot spot has the effect of increasing the activity of the catalyst according to the invention.

Surprisingly, it has been found that at least one or more of the activators of the catalyst layer upstream along the airflow toward the gas inlet ahead of the layer with the highest hot spots have a lower antimony content in the actives than the layer with the highest hot spots. .

In another preferred embodiment of a catalyst having multiple layers in one or more laminates, at least one catalyst layer located in front of the hot spot-catalyst layer comprises silver and certain elements, particularly advantageously vanadium and / or molybdenum and / or the like. Or at least one of mixed element oxides with tungsten.

In a particularly preferred embodiment of the catalyst according to the invention, at least one or more of all the layers from the gas inlet to the layer with the highest hot spot contains mixed element oxides with silver, in particular silver and vanadium and / or molybdenum and / or While containing mixed element oxides with tungsten, the layer with the highest hot spot contains mixed element oxides of vanadium, in particular mixed element oxides of vanadium and bismuth.

In another particularly preferred embodiment, all the layers from the gas inlet to the layer with the highest hot spot contain mixed element oxides of silver and the layer with the highest hot spot further contain mixed element oxides of vanadium and bismuth.

Particular preference is given to using multinuclear mixed element oxides or their precursor compounds as a source in the preparation of catalyst suspensions or in the preparation of powder mixtures used for carrier coating.

For the catalyst suspension AgVO ₃ for the production and / or production of active substance of the atomic ratio is less than about or may be a larger mixing element silver oxide used. According to the atomic ratio of the elements in the mixed element oxide, the amount of the mixed element oxide and / or its precursor compound in the powder mixture used for the catalyst suspension or coating should be adjusted to suitably control the content of silver in the active material of the prepared catalyst. .

If the mixed element oxide phase or its precursor compound has already been formed, it is preferred to add it in advance to the powder mixture used to coat the catalyst suspension or carrier. It is also possible to add one or more of the corresponding precursor compound / s to the catalyst suspension or powder mixture, which are then converted to the appropriate mixed element oxide upon heat treatment of the catalyst.

As already described, a mixed element oxide of silver and other elements and / or precursor compounds thereof present in an integer molar ratio as raw material source may be used in the preparation of the catalyst suspension or present in the active of the catalyst according to the invention. In addition, binuclear or multinuclear mixed element oxides with silver having a smaller or larger atomic size than silver may be used. Depending on the formula of the mixed element oxide or its silver component, the content of the corresponding mixed element oxide in the catalyst suspension and / or the active is increased or decreased.

Dinuclear or multinuclear mixed element oxides of silver are represented by formula (I) according to claim 11:

Ag _x M _y N _z O _n Formula I

In the mixed element oxide of the formula (I), x particularly preferably has a value of 0 to 5, and the value of the variable y is preferably 0 to 0.3.

Especially preferred are mixed element oxides of the formula:

Ag _x N _z O _n

In the above formula

Ag = silver,

x = a value from 0.1 to 1,

N = element selected from the group consisting of vanadium, molybdenum, tungsten, niobium, antimony,

z = 1,

n = number determined by the valence and frequency of oxygen and other elements in formula (I).

In principle, the catalyst according to the invention in the preparation of the catalyst suspension using one or more precursor compounds of the corresponding mixed element oxides and / or starting compounds thereof and comprising the mixed element oxides is first heated in a reactor and calcined or It can be formed during heating in the interior, which is apparent from the present invention.

In a preferred embodiment of the catalyst of the invention, mixed element oxides AgVO ₃ , Ag ₂ MoO ₄ , Ag ₂ WO ₄ and / or mixed element oxides of these elements with other atomic ratios are used to improve the performance of the catalyst.

For the catalyst suspension a mixed elemental oxide of silver and preferably vanadium, tungsten and molybdenum, for example a "mono-nuclear" silver compound was added and the catalyst and / or oxide (AgO or Ag ₂₎ containing no silver in the active Find that the selectivity is significantly improved compared to catalysts added or contained in the actives as O) or as salts (nitrates, phosphates, sulfates, hydrochlorides, ammonium salts, salts of organic acids) or as hydroxides or as amine-complexes of the catalyst suspension It was. It is expected that silver in the form of mixed element oxides or mixed element compounds will be more effective in the catalytic process compared to salt form or mononuclear oxide.

As a non-limiting example, the compound AgVO ₃ as a component of the catalyst according to the invention can be used as an additive in the preparation of a catalyst suspension or activator, but the activator comprises at least anatase type titanium dioxide and vanadium compounds. Preferably the catalyst according to the invention also comprises at least one compound of at least the first main group. Depending on the layer of the catalyst according to the invention in the catalyst bed the catalyst according to the invention contains an antimony compound, in particular Sb ₂ O ₃ and optionally a phosphorus compound, in the activator.

It has surprisingly been found that multi-layered catalysts prepared using at least one mixed element oxide of silver and vanadium and / or tungsten and / or molybdenum or precursor compounds thereof are very advantageous with regard to the increase in selectivity, according to the present invention. The catalyst is preferably used in one or more of the catalyst beds from the gas inlet to the layer with the highest hot spot.

In a particularly preferred embodiment, one or more or all of the catalyst layers from the gas inlet to the layer with the highest hot spot or all catalyst layers contain 0.01% of the mixed element oxides of silver and vanadium and / or tungsten and / or molybdenum in the active material. To 15% by weight, in particular 0.01 to 10,0% by weight and particularly preferably 0.01 to 5% by weight.

In a particularly preferred embodiment of the catalyst according to the invention, the compound in which the molar ratio of Ag: V in the silver-vanadium-mixed element oxide is 1: 1 is mixed element oxide AgVO ₃ . In this case, so-called silver-vanadium-bronze is not considered because, by definition, the atomic ratio of Ag: V is less than 1: 1.

In addition, vanadium and bismuth, molybdenum, tungsten, antimony, bis, lead, tin, zinc, copper, nickel, cobalt, iron, manganese, chromium, niobium, zirconium, titanium, gold, rhenium, lanthanum, cerium, tantalum, It has been found that the selectivity is improved when mixed elemental oxides of rhenium are used in the preparation of catalysts and / or as constituents of the active.

In particular, bismuth vanadate is used for selectivity improvement as a feedstock source for the preparation of catalyst suspensions or as a constituent of the active agent. In this case, the catalyst BiVO ₄ according to the invention as a constituent of the activator is preferably included in one or more of the layers from the gas inlet to the layer with the highest hot spot.

The catalyst according to the invention comprises, in addition to titanium dioxide and vanadium, one or more mixed element oxides of silver and the above-mentioned elements, and one or more mixed element oxides of vanadium and the above-mentioned elements. In a particularly preferred embodiment, silver vanadate and bismuth vanadate are used to prepare a catalyst suspension of the catalyst according to the invention and / or coexist in the active of the catalyst.

Depending on the layer of the catalyst according to the invention in the catalyst stack, the catalyst according to the invention may contain at least one alkali metal compound, preferably cesium compounds, antimony compounds, preferably antimony-III-oxides and optionally phosphorus compounds. It includes more.

In the preparation of the catalyst suspension, vanadium present in an atomic ratio of integers or mixed element oxides or precursor compounds thereof with the other elements can be used as raw material sources or be present in the actives of the catalyst according to the invention, as well as in vanadium In comparison, binuclear or multinuclear mixed element oxides with vanadium having a smaller or larger atomic size may be used. Depending on the formula of the mixed element oxide or its vanadium constituents, the content of the corresponding mixed element oxide in the catalyst suspension or active is increased or decreased.

Dinuclear or multinuclear mixed element oxides with vanadium are represented by the following formula according to claim 12:

M _a N _b V _c O _d Formula II

As the catalyst according to the invention there may be exemplified a so-called "shell type catalyst", which is a porcelain, magnesium oxide, tin oxide, silicon carbide in which the catalyst activator is generally inert under the reaction conditions in one or more layers. It is applied in the form of a shell on a carrier material such as cerium silicate, magnesium silicate (steatite), zirconium silicate, aluminum oxide, quartz or a mixture of these carrier materials. In the prior art, steatite or silicon carbide were used in particular as carrier material.

Such shell-type catalysts are typically vortexed while a solution or suspension containing an aqueous and / or organic solvent of the active ingredient and / or precursor compounds thereof (hereinafter referred to as "catalyst suspension") is heated on the carrier material. Prepared by (DE-A 2106796) until the desired active ingredient is achieved, based on the total weight of the catalyst. The inert nonporous carrier material may be coated with heating in a dragee-prepared drum heated with an active ingredient or precursor compound thereof as a suspension or powder mixture.

Atomization and / or in part of the catalyst suspension when spraying a catalyst suspension comprising the active ingredient and / or precursor compound thereof contained therein or when coating an inert carrier material in a dragee preparation drum or vortex Since partial erosion of the described carriers results in partial high losses, in this regard in the prior art, organic binders, preferably copolymers, preferably vinylacetate / vinyllaurate, vinylacetate, for the binding of catalyst suspensions It is added in the form of an aqueous dispersion of / acrylate, styrene / acrylate, vinylacetate / maleate and vinylacetate / ethylene, where the amount of conventional binder is 10-20% by weight relative to the solids of the catalyst suspension used. The coating temperature upon addition of the binder material is preferably in the range of 50-450 ° C. The binder material is added to the reactor and then added as soon as it is heated to above its service temperature or at the latest when the effect of the catalyst is initiated and completely separated from the catalyst.

In this case, the catalytically active component remaining on the inert carrier material as a thin shell is considered as active. The components of this activator may be partially derived from the components or raw material sources or precursor compounds used in the catalyst suspension, because they are chemically partially converted through heat treatment of the catalyst and in particular converted to the corresponding metal oxides.

Surprisingly, the performance of the catalyst does not depend entirely on the composition of the catalyst and the amount of activator (after the temperature of the heated or formed catalytically active compound), but the composition of the powder mixture and the amount of activator used in the catalyst suspension or for coating the carrier. It has been found to have a large impact on the selectivity, activity and service life of the catalyst.

The present invention also relates to a process for preparing aldehydes, carboxylic acids and / or carboxylic anhydrides by bringing a gaseous form containing an aromatic hydrocarbon and comprising a molecular oxygen containing gas into contact with a predetermined catalyst in a heated state. .

Mixed element oxides used as feedstock sources for catalyst suspensions can be prepared in a variety of ways and are included directly in the catalyst suspension in the form of discrete compounds or reaction mixtures. If desired, the corresponding precursor compound of the mixed metal oxide of the catalyst suspension can be added. In this case, the multinuclear mixed element compound or the mixed metal oxide compound is generally a mixed element oxide present in the active material and appropriately heat treated, which includes another crystal structure and preferably contains crystal water thereon.

In most cases for the preparation of the mixed element oxides and / or precursor compounds thereof used in the catalysts according to the invention, it may be suitable to convert the solution of the metal compound into a suspension of the metal oxide in an aqueous or non-aqueous solvent at high temperature. have. For example, the silver-vanadium-oxides used for the catalysts according to the invention can be prepared by converting silver nitrate and vanadium pentoxide to the desired atomic ratios, preferably in hot aqueous solutions. At this time, the reaction mixture comprising the mixed metal compound contained therein may be added directly to the catalyst suspension or the mixed metal compound may be separated beforehand and optionally heat treated.

As the solvent, besides water, a polar organic solvent such as polyol, polyether or amine can be used. Metal oxides or many metal oxides (eg vanadium pentoxide and molybdenum trioxide) can be converted together with silver compounds and optionally other compounds (eg phosphorus compounds), usually at room temperature or with heating. The reaction is preferably continued for 20 minutes to 5 days depending on the starting materials used at 50 to 100 ℃ and the reaction conditions.

The mixed metal compound thus formed is separated from the reaction mixture and optionally stored for other uses or added directly as a suspension of a catalyst suspension containing at least titanium dioxide and vanadium compounds. The mixed metal compound obtained and separated through the above reaction can be reacted with heating prior to addition of the catalyst suspension to convert the crystal structure and remove the crystal water.

When the mixed metal compound is separated in advance, the suspension is filtered and the solid obtained is dried, which drying can be carried out in various ways. It is preferred to dry the mixed metal-suspension via spray drying or lyophilization.

Another reaction in solution can also yield a mixed metal compound by co-melting, for example converted to various finely mixed metal oxide-powders in a high temperature solid reaction of 400 to 800 ° C.

The components of the catalyst suspension are generally used in the form of compounds such as oxides and / or salts which, for example, are converted to oxides when heated in the presence of oxygen. Metal salts such as phosphates or halides can also be added to the catalyst suspension, which remains unchanged as the active agent of the catalyst even after heat treatment.

The catalyst according to the invention can generally be prepared from the precursor of the final catalyst, which catalyst precursor can be stored in that state. In this case, the raw material used for the catalyst suspension is preferably sprayed onto the inert ceramic carrier and fixed using an organic binder material.

The active catalyst is generally produced when the catalyst precursor is heat treated or when the catalyst is heated in the reactor. In this case, generally used metal compounds are converted into the corresponding metal oxides. For example, vanadium oxalate is converted to V ₂ O ₅ . In some cases, the compound contained in the catalyst suspension is converted to its oxidized form when the catalyst is heated. Ammonium dihydrogen phosphate is converted to P ₂ O ₅ and is present in the active as it is. In this case, since the crystal water is generally lost during the heat treatment of the catalyst and the crystal structure thereof changes in some cases, an aqueous mixed metal oxide is prepared and used as a raw material source in the preparation of the catalyst suspension.

The conversion of the feedstock source used in the catalyst suspension preferably takes place at a temperature of 200 to 500 ° C, particularly preferably in the range of 300 to 500 ° C.

The shape of the inert carrier material does not depend on the performance of the catalyst according to the invention, but it has been found in the prior art that spherical or cyclic shaped bodies are advantageous.

The layer thickness of the activator or the total layer thickness of the shell containing the activator is generally 20 to 400 μm and depends on the layer of the catalyst according to the invention in the catalyst bed.

Surprisingly it has been found to be generally unnecessary to spatially separate the different components of the catalyst suspension from the mixed metal oxides used to obtain the improved catalyst. All components used in the catalyst suspension are generally mixed or blended with the corresponding mixed metal oxides and at the same time the mixed suspension is applied to the inert carrier. Catalyst suspensions of different compositions may also be applied sequentially to the inert ceramic carrier, since at least one or more layers contain the catalyst according to the invention, an improved catalyst according to the invention can be obtained.

In addition, catalyst suspensions not according to the invention containing titanium dioxide, vanadium compounds and preferably alkali metal compounds are first separated and optionally heat treated, and then the resulting powder is generally at least titanium dioxide, vanadium compounds and It is also possible for improved catalysts to be produced by mixing again (preferably in water) with a powder obtained from a catalyst suspension composed of at least mixed metal oxides or precursor compounds thereof. These new catalyst suspensions may be applied alone as a layer on an inert ceramic carrier or in combination with other coating-layers according to the invention or other coating-layers not according to the invention.

The catalyst according to the invention is generally used for producing aldehydes, carboxylic acids and / or carboxylic anhydrides from aromatic hydrocarbons by partial gas phase oxidation. The catalyst is particularly suitable for the gas phase oxidation of o-xylene and / or naphthalene with phthalic anhydride with a molecular oxygen containing gas.

As already mentioned, the catalyst according to the invention can be used for this purpose either alone or in a variety of other active catalysts, for example catalysts of the prior art (Vanadium pentoxide / Anatase-based without mixed metal oxide component). ) Can be used in combination.

Different catalysts according to the invention and catalysts according to the invention are used in separate catalyst stacks which are generally arranged on at least one catalyst bed. It is then very advantageous to use the catalyst according to the invention in the layer closest to the gas inlet, from the layer closest to the gas inlet to the layer with the highest hot spot.

The use of the catalyst according to the invention in the catalyst bed located next to the layer with the highest hot spot and in the bed located close to the gas outlet also has a positive effect, but in the bed located close to the gas inlet with respect to selectivity. The activity is clearly less than that of the catalyst according to the present invention. The catalyst according to the invention and / or its precursor catalyst is packed in layers in the reactor tubes of the reactor. In this case, different layers can be composed of the catalyst according to the invention and the catalyst not according to the invention.

A layer of a mixture of a mixture of at least one or more catalysts according to the invention and at least one or more catalysts according to the invention is used as a layer and the laminates alone or in accordance with the invention and / or catalysts according to the invention It may also be possible to use in combination with other catalyst layer consisting of.

The reaction tube is generally temperature controlled from the outside by the molten salt surrounding the tube.

Upon heating the reactor with the catalyst-filled reaction tube and / or upon subsequent heat treatment of the catalyst produced from the catalyst precursor with intrinsic catalytic activity, the organic binder is calcined therein and the raw material sources used in the catalyst suspension generally correspond to Is converted into an oxide. The chemical composition and / or crystal structure may vary depending on the form of the mixed metal compound.

In a laminate composed of at least one catalyst according to the invention thus heat treated, the reactor body is introduced at a temperature of 250-550 ° C., in particular at 330-500 ° C. and usually at 0.1-2.5 bar, preferably at 0.3-1.5 bar. The space velocity is usually 1000 to 5000 h (-1).

The reactor introduced into the catalyst is typically an aromatic hydrocarbon to which oxygen may contain appropriate reaction control and / or diluents, such as steam, nitrogen and / or carbon dioxide, through the mixing of a molecular oxygen containing gas, preferably air Wherein the molecular oxygen-containing gas is usually 1 to 100% by volume and particularly preferably 10 to 30% by volume of oxygen, 0 to 30% by volume of water vapor, preferably 0 to 20% by volume of water vapor and 0 to It may contain 50% by volume, preferably 0 to 1% by weight of carbon dioxide, the balance of nitrogen. The molecular oxygen-containing gas is generally 20 to 200 g per Nm ³ of the aromatic hydrocarbon to be oxidized, particularly preferably Nm ³ , to form the reactor gas. At 60 to 120 g per sugar.

In a preferred embodiment of the process for partial oxidation of aromatic hydrocarbons to aldehydes, carboxylic acids and / or carboxylic anhydrides, particularly preferably the aromatic hydrocarbons are oxidized to oxidize o-xylene and / or naphthalene to phthalic anhydride. In the catalyst stack according to the invention, first of all, a portion of the catalyst mixture is converted into a reaction mixture consisting of starting materials, intermediates and final products, and the mixture is optionally at least one additional catalyst of the catalyst according to the invention or a catalyst corresponding to the prior art. Switch by

This reaction may be carried out by one or more reactors, each reactor comprising at least one catalyst stack having at least one catalyst layer and which may be constantly controlled at different reaction temperatures. If at least one reactor comprises a bed with a catalyst according to the invention it is sufficient to carry out the process according to the invention.

In order to produce phthalic anhydride from o-xylene, the reactor body which has been partially converted after passing through one or more catalyst beds with the catalyst according to the present invention, has a substantial amount of unconverted o-xylene in addition to the desired product, phthalic anhydride. For example, intermediates such as o-tolylaldehyde, o-tolyl acid and phthalide will be included.

The product mixture is then generally reached on at least one catalyst bed without further separation and distinguished from the catalyst according to the invention in terms of its chemical composition and activity so that the raw material is completely converted to phthalic anhydride or the microoxide is oxidized to phthalic anhydride Is switched to.

The unconverted o-xylene can also be separated after passing through the catalyst stack with the catalyst according to the invention before the reactor gas is introduced into at least one other catalyst stack. Such a variant is relatively expensive but can be technically realized.

It is therefore desirable to pass the reaction mixture through more catalyst beds without separating the starting materials or intermediates, wherein at least one or more of the catalyst bed layer (s) located near the gas inlet is a stack of catalysts according to the invention. It is preferable to contain.

The catalyst according to the invention is generally used with at least one or more catalyst layers, at least one of all of the catalyst layers from the gas inlet to the layer with the highest hot spot containing the catalyst according to the invention and typically 1 to 40% by weight of vanadium pentoxide represented by ₂ O ₅ , 50 to 99% by weight titanium dioxide represented by TiO ₂ , 1% by weight or less of alkali metal compound represented by alkali metal, 1.5% by weight or less of phosphorus compound represented by P, Sb ₂ O 10 wt% or less of the antimony compound represented by ₃ and 15 wt% or less of silver and at least one mixed element oxide of at least one or more of the aforementioned elements and / or at least one mixed element oxide of vanadium and at least one or more of the aforementioned elements It is composed of up to weight percent.

The catalysts used in this combination are generally used in layers located close to the gas outlet and also in layers behind the layer with the highest hot spots and are not according to the invention based on at least titanium dioxide / V ₂ O ₅ . Does not contain any mixed element oxides of silver and / or vanadium. It is also possible to use the catalyst according to the invention in all layers. In this case, the catalysts are generally distinguished from each other according to the form and content of the mixed metal oxides present in the activator.

Catalysts not according to the invention used in combination with the catalysts according to the invention are generally titanium dioxide-containing 60-99% by weight, vanadium oxide-containing 1-40% by weight, alkali metal contents 1% by weight or less according to the prior art. Phosphorus content up to 1.5 wt% and antimony content up to 10 wt%.

The activator of the catalyst according to the invention and / or the catalyst not according to the invention in the above-mentioned composition may further comprise a small amount of oxidizing compound in order to increase the activity and selectivity.

Example

Preparation of the catalyst

The components of the various catalyst suspensions were added sequentially to the deionized water as solutions and / or powders and the resulting suspension was preferably stirred for at least 12 hours. As a source for the components contained in the catalyst according to the present invention, anatase type titanium dioxide, V ₂ O ₅ or vanadium oxalate, cesium sulfate, ammonium dihydrogen phosphate, antimony trioxide, bismuth vanadate and silver vanadium acid, silver molybdate, Silver tungstic acid and / or other mixed metal oxides of silver and vanadium were used.

The organic binder was then added to the aqueous catalyst suspension in the form of an aqueous dispersion of vinylacetate-copolymer and approximately 20-25% of the suspension was further stirred for 30 minutes.

The activator and / or its precursor compound and organic binder are then placed on an inert carrier (consisting of cyclic steatite having dimensions of 7 x 7 x 4 mm or 8 x 6 x 5 mm) before applying a predetermined amount of adhesive containing suspension. An appropriate amount of the aqueous suspension containing was applied by spraying and calcined to obtain the activators described in the examples.

The activator content (ratio of catalyst activator without binder) is measured after firing at 400 ° C. for 4 hours and refers to the ratio of the catalyst activator to the total weight of the catalyst including the carrier in each catalyst layer.

The phosphorus content mentioned above corresponds to the amount of phosphorus compound added in the preparation of the catalyst suspension. It is known to those skilled in the art that the actual phosphorus content in the active may vary depending on how impure the TiO ₂ used is by the phosphorus compound.

Oxidation reaction

The multilayer catalyst system is added to a reactor surrounded by a salt bath and equipped with a steel reaction tube with a diameter of 25 mm and a length of 3.7 m. Or the R5-layer is the one nearest to the gas outlet.

The reactor was equipped with a 2 mm diameter thermal sleeve in the center with an attachment for temperature measurement. 4 Nm ³ of air was introduced downwards through the reaction tube at a salt bath temperature of 340-380 ° C. every hour, and air Nm ³ About 30-70 g of xylene was added dropwise.

For measuring catalyst performance data, the reactant flowing out of the reaction tube was introduced through an oil cooled condenser, in particular the resulting phthalic anhydride was completely separated and by-products such as benzoic acid, maleic anhydride and phthalide were only partially separated. . The raw material-PSA separated in the condenser was melted by hot oil, collected and weighed, and the content of phthalic anhydride was measured by GC-analysis.

The raw material-PSA yield mentioned in the examples was calculated as follows:

Raw material- PSA  Yield (% by weight) = [raw- PSA  Volume (g) x Raw Material- PSA  Purity (%)] / [o-xylene inflow (g) x o-xylene purity (%)]

The yield of solid PSA measured in this way is expressed in raw material-PSA yield even though the by-products contained therein are excluded, since the product formed after the preheating and distillation retreatment is generally expressed as PSA purity. This is also known to those skilled in the art.

In each case, the conversion of o-xylene is almost 100%, so the raw material-yield thus measured is directly related to the selectivity of the catalyst system.

Example  One( Comparative example ):

Catalytic system  A (the fourth floor)

This catalyst system is substantially a multilayer system with four different layers. Each laminated body of this comparative catalyst does not contain any mixed element oxide of silver.

Composition (% by weight)
Length 1st floor (hot spot)
147 cm 2nd layer
45 cm 3rd floor
70 cm 4th floor
70 cm V ₂ O ₅ 5.0 7.7 8.5 15.0 Sb ₂ O ₃ 2.5 2.2 2.4 0.5 BiVO ₄ 0.31 - - - Cs 0.37 0.20 0.10 0.05 P 0.03 0.05 0.05 0.10 TiO ₂ Balance: up to 100% Balance: up to 100% Balance: up to 100% Balance: up to 100% AM rate 8.3 8.4 8.4 8.0

Air Nm ³ 50-65 g of o-xylene per drop was added and the catalyst system A described in Example 1 was tested at a total air volume of 4 Nm ³ per hour and SBT at 344-347 ° C. After introduction, an average raw material-PSA-yield (based on 100% o-xylene purity) of 113.4% by weight was obtained and the phthalide content in the raw material-PSA was 0.01% by weight.

Example  2 (invention):

Catalytic system  B (the fourth floor)

Composition (% by weight)
Length 1st floor (hot spot)
140 cm 2nd layer
45 cm 3rd floor
70 cm 4th floor
70 cm V ₂ O ₅ 5.0 7.7 8.5 15.0 Sb ₂ O ₃ 2.5 2.2 2.4 0.5 BiVO ₄ 0.31 - - - AgVO ₃ 0.17 - - - Cs 0.40 0.20 0.10 0.05 P 0.03 0.05 0.05 0.10 TiO ₂ Balance: up to 100% Balance: up to 100% Balance: up to 100% Balance: up to 100% AM rate 8.6 8.4 8.4 8.0

Air Nm ³ 58-63 g of o-xylene was added dropwise and the catalyst system B described in Example 2 was tested at a total air volume of 4.0 Nm ³ per hour and SBT at 346-352 ° C. After introduction, an average raw material-PSA-yield (based on 100% o-xylene purity) of 114.0% by weight was obtained and the phthalide content in the raw material-PSA was 0.06% by weight.

Example  3 (invention):

Catalytic system  C (the fourth floor)

Composition (% by weight)
Length 1st floor (hot spot)
140 cm 2nd layer
45 cm 3rd floor
70 cm 4th floor
70 cm V ₂ O ₅ 5.0 7.7 8.5 15.0 Sb ₂ O ₃ 2.5 2.2 2.4 0.5 BiVO ₄ 0.31 - - - AgVO ₃ 0.34 - - - Cs 0.42 0.20 0.10 0.05 P 0.03 0.05 0.05 0.10 TiO ₂ Balance: up to 100% Balance: up to 100% Balance: up to 100% Balance: up to 100% AM rate 8.7 8.4 8.4 8.0

Air Nm ³ 58-65 g of o-xylene was added dropwise and the catalyst system C described in Example 3 was tested at a total air volume of 4.0 Nm ³ per hour and SBT at 346-347 ° C. The average raw material-PSA-yield (based on 100% o-xylene purity) of 115.3 wt% after introduction was obtained and the phthalide content in the raw material-PSA was 0.04 wt%.

Example  4 (invention):

Catalytic system  D (the fourth floor)

Composition (% by weight)
Length 1st floor (hot spot)
145 cm 2nd layer
45 cm 3rd floor
70 cm 4th floor
70 cm V ₂ O ₅ 5.0 7.7 8.5 15.0 Sb ₂ O ₃ 2.5 2.2 2.4 0.5 BiVO ₄ 0.31 - - - Ag ₂ WO ₄ 0.39 - - - Cs 0.40 0.20 0.10 0.05 P 0.03 0.05 0.05 0.10 TiO ₂ Balance: up to 100% Balance: up to 100% Balance: up to 100% Balance: up to 100% AM rate 8.7 8.4 8.4 8.0

Air Nm ³ 57-69 g of o-xylene was added dropwise and the catalyst system D described in Example 4 was tested at a total air volume of 4.0 Nm ³ per hour and SBT at 346-348 ° C. After introduction, an average raw material-PSA-yield (based on 100% o-xylene purity) of 113.9% by weight was obtained and the phthalide content in the raw material-PSA was 0.02% by weight.

Example  5 (invention):

Catalytic system  E (4th floor)

Composition (% by weight)

Length 1st floor (hot spot)
8 x 6 x 5mm
140 cm 2nd layer
7 x 7 x 4mm
45 cm 3rd floor
7 x 7 x 4mm
70 cm 4th floor
7 x 7 x 4mm
70 cm V ₂ O ₅ 5.0 7.7 8.5 15.0 Sb ₂ O ₃ 2.5 2.2 2.4 0.5 BiVO ₄ 0.31 - - - Ag ₂ MoO ₄ 0.16 - - - Cs 0.40 0.20 0.10 0.05 P 0.03 0.05 0.05 0.10 TiO ₂ Balance: up to 100% Balance: up to 100% Balance: up to 100% Balance: up to 100% AM rate 8.6 8.4 8.4 8.0

Air Nm ³ 52-62 g of o-xylene was added dropwise and the catalyst system E described in Example 5 was tested at a total air volume of 4.0 Nm ³ per hour and SBT at 347-348 ° C. After introduction, an average raw material-PSA-yield (based on 100% o-xylene purity) of 114.2% by weight was obtained and the phthalide content in the raw material-PSA was 0.01% by weight.

Example  6 ( Comparative example ):

Catalytic system  F (the fifth floor)

Composition (% by weight)
Length First floor
45 cm 2nd layer (hot spot)
95 cm 3rd floor
50 cm 4th floor
65 cm 5th floor
70 cm V ₂ O ₅ 5.0 5.0 7.7 8.5 15.0 Sb ₂ O ₃ 2.5 2.5 2.2 2.4 0.5 BiVO ₄ 0.31 0.31 - - - Cs 0.36 0.42 0.21 0.10 0.05 P 0.03 0.03 0.05 0.05 0.10 TiO ₂ Balance: up to 100% Balance: up to 100% Balance: up to 100% Balance: up to 100% Balance: up to 100% AM rate 8.8 7.8 8.4 8.4 8.0

Air Nm ³ 58-61 g of o-xylene was added dropwise and the catalyst system F described in Example 6 was tested at a total air volume of 4 Nm ³ per hour and SBT at 350 to 354 ° C. After introduction, an average raw material-PSA-yield (based on 100% o-xylene purity) of 113.1% by weight was obtained and the phthalide content in the raw material-PSA was 0.01% by weight.

Example  6 (invention):

Catalytic system  G (the fifth floor)

Composition (% by weight)
Length First floor
50 cm 2nd layer (hot spot)
90 cm 3rd floor
45 cm 4th floor
70 cm 5th floor
70 cm V ₂ O ₅ 4.0 5.0 7.7 8.5 15.0 Sb ₂ O ₃ 0.2 2.5 2.2 2.4 0.5 BiVO ₄ - 0.31 - - - AgVO ₃ - 0.17 - - - Cs 0.28 0.40 0.21 0.10 0.05 P - 0.03 0.05 0.05 0.10 TiO ₂ Balance: up to 100% Balance: up to 100% Balance: up to 100% Balance: up to 100% Balance: up to 100% AM rate 6.9 7.8 8.4 8.4 8.0

Air Nm ³ 58-75 g of o-xylene was added dropwise and the catalyst system G described in Example 6 was tested at a total air volume of 4 Nm ³ per hour and SBT at 348-350 ° C. After introduction, an average raw material-PSA-yield (based on 100% o-xylene purity) of 114.8% by weight was obtained and the phthalide content in the raw material-PSA was 0.03% by weight.

Performance data of the catalyst according to the invention Catalytic system Salt bath temperature (℃) Φ -raw-PSA-yield
(After the introduction stage) (% by weight) Φ phthalide content (wt%) in raw material-PSA A (comparative example) 344-347 113.4 0.01 B 346-352 114.0 0.06 C 346-347 115.3 0.04 D 346-348 113.9 0.02 E 347-348 114.2 0.01 F (Comparative Example) 350-354 113.1 0.01 G 348-350 114.8 0.03

As can be seen from the comparison of Examples 2 to 5 and Comparative Example 1, a mixed element oxide of silver was used in the first layer closest to the gas inlet as a raw material source for preparing a catalyst suspension for preparing a catalyst, so that the selectivity was obvious. Increased.

As can be seen from the comparison between Example 7 and Comparative Example 6, the use of silver vanadate in the active material of the hot spot-catalyst layer increased selectivity in at least one of the catalyst layers behind the first catalyst layer upon addition.

Claims (38)

As catalyst for the formation of aldehydes, carboxylic acids and / or carboxylic anhydrides, in particular phthalic anhydride, from aromatic hydrocarbons by catalytic gas phase oxidation,
The active agent of the catalyst is vanadium oxide, preferably vanadium pentoxide, titanium dioxide, preferably anatase type titanium dioxide, and silver and certain elements, preferably vanadium and / or molybdenum and / or tungsten and / or niobium and / or Or at least one silver mixed element oxide with antimony, and / or vanadium mixed element oxide with vanadium and certain elements, preferably bismuth and / or molybdenum and / or tungsten and / or antimony and / or niobium, ,
At least one silver and / or vanadium mixed element oxide, at least one precursor compound, in particular at least one multinuclear precursor compound, as raw material sources, during the preparation of the powder mixtures necessary for coating the catalyst suspension or the carrier, especially when preparing the catalyst Catalyst used. 2. The catalyst according to claim 1, wherein the activator comprises 0.01 to 15% by weight, preferably 0.01 to 10% by weight and most preferably 0.01 to 5% by weight of a mixed metal oxide of silver. The method according to claim 1 or 2, wherein at least one of the mixed element oxides of silver is vanadium, molybdenum, tungsten, niobium, tantalum, chromium, titanium, manganese, iron, cobalt, nickel, copper, zinc, cadmium, gold, tin And a zirconium, antimony, arsenic, cerium, lanthanum, bismuth, hafnium, lead, boron, aluminum, ruthenium, rhenium, palladium, rhodium and a mixed metal oxide with at least one additional element selected from the group consisting of . 4. The catalyst according to claim 1, wherein the activator comprises 0.01 to 10% by weight, preferably 0.01 to 5% by weight of mixed element oxides of vanadium. The method according to any one of claims 1 to 4, wherein at least one mixed element oxide of vanadium is bismuth, antimony, molybdenum, tungsten, chromium, lanthanum, cerium, iron, manganese, niobium, tantalum, rhenium, cobalt, Nickel, copper, zinc, gold, cadmium, lead, tin, boron, titanium, zirconium, hafnium, aluminum, arsenic, ruthenium, rhodium, palladium, mixed metal oxides with at least one additional element selected from the group Catalyst. The vanadium oxide-content of V ₂ O ₅ in the active material is 1 to 40% by weight, and the titanium dioxide content is represented by TiO ₂ in the active material. Catalyst, characterized in that 99% by weight. The method according to any one of claims 1 to 6, wherein the active agent is from 0 to 10% by weight of an antimony compound represented by Sb ₂ O ₃ and / or lithium, sodium, potassium, rubidium, cesium represented by an alkali metal. A catalyst comprising 0 to 1% by weight of a compound of at least one or more elements selected and / or 0 to 1.5% by weight of a phosphorus compound represented by P. 8. The catalyst according to claim 1, wherein the activator comprises AgVO ₃ and / or Ag ₂ MoO ₄ and / or Ag ₂ WO ₄ and / or BiVO ₄ . The method according to claim 8, wherein the AgVO ₃ and / or Ag ₂ MoO ₄ and / or Ag ₂ WO ₄ and / or BiVO ₄ and / or at least one precursor compound of these compounds are used as a raw material source in the preparation of the catalyst. A catalyst, characterized in that. The mixed element oxide-precursor compound of the mixed element oxide and / or the mixed element oxide or the mixed element of silver and / or vanadium according to any one of claims 1 to 9, which is used as a raw material source in the preparation of the catalyst. A catalyst, characterized in that the oxide is separated from the reaction mixture before use as a feedstock source in the preparation of the catalyst or the reaction mixture is used directly as feedstock in the preparation of the catalyst. The catalyst according to claim 1, wherein the mixed element oxide of silver comprises formula (I):
Ag _x M _y N _z O _n (Formula 1)
Where
Ag = silver,
x = 0.01 to 100, in particular 0.1 to 10,
M = Li, Na, K, Rb, Cs, P, Mg, Ca, Sr, Ba, Ti, an element selected from the group consisting of
y = 0 to 1,
N = V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ni, Pd, Cu, Au, Zn, Cd, Sn, Pb, B, Al, Bi, Sb, At least one element selected from the group consisting of As, Ti, Zr, Hf, Ce, La,
z = 1,
O = oxygen,
n = number determined by the valence and frequency of oxygen and other elements in formula (I). The catalyst according to any one of claims 1 to 11, wherein the mixed element oxide of vanadium comprises formula (II):
M _a N _b V _c O _d Formula II
Where
M = Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ni, Pd, Cu, Au, Zn, Cd, Sn, Pb, B, Al, Bi, Sb, As, At least one element selected from the group consisting of Ti, Zr, Hf, Ce, La,
a = 0.01 to 100,
At least one element from the group consisting of N = Li, Na, K, Rb, Cs, P, Mg, Ca, Sr, Ba, Ti, P,
b = 0 to 1,
V = vanadium,
c = 1,
O = oxygen,
d = number determined by the valence and frequency of oxygen and other elements in formula (II). The process according to claim 1, wherein V ₂ O ₅ and / or vanadium oxalate and / or V ₆ O ₁₃ and / or NH ₄ VO ₃ and / or poly as vanadium sources for the preparation of the catalyst. Vanadium acid is used, and after the heat treatment of the catalyst, at least a part of the vanadium in the active material is present as vanadium pentoxide. 14. A method according to any one of claims 1 to 13, wherein at least one or more anatase type titanium dioxide species is used for the preparation of the catalyst and is present in the active substance itself, the amount and the surface area of each of the titanium dioxides. A catalyst characterized in that the average BET surface area, calculated as a ratio, is from 10 to 60 m ² / g of the total titanium dioxide. 15. A mixture according to claim 14, wherein a mixture consisting of a plurality of different anatase type titanium dioxide species in said active material is used and at least one anatase type titanium dioxide species has an average particle size of 0.3 to 0.8 mu m and a BET of 13 to 60 m ² / g. A catalyst having a surface area and wherein at least one additional anatase type titanium dioxide species has a BET-surface area of 2 to 15 m ² / g. The antimony compound according to any one of claims 1 to 15, wherein the antimony compound and / or the antimony compound present in the activator of the catalyst is used to prepare a powder mixture necessary for coating the catalyst suspension or carrier. A catalyst characterized in that the III-oxide and / or antimony-V-oxide. 17. The antimony content of claim 1, wherein the catalyst consists of at least three layers and the antimony content in the at least one layer located in the direction of the gas inlet from the hot spot catalyst layer is 20 to more than the antimony content in the hot spot catalyst layer. Catalyst characterized in that 100% low. 18. The process according to any one of the preceding claims, wherein the activator of the catalyst heat-treats the catalyst at 400 ° C. for a predetermined time period, preferably for many hours, particularly preferably for a duration of about 4 hours. A catalyst characterized by having a composition:
Vanadium oxide: 1-40% by weight (expressed as V ₂ O ₅ )
Titanium dioxide: 50-99 wt% (expressed as TiO ₂ )
AgxMyNzOn: 0.01-15% by weight (expressed as AgxMyNzOn)
MaNbVcOd: 0-10% by weight (expressed as MaNbVcOd)
Alkali metal: 0-1.0 wt% (expressed as alkali metal)
Antimony Oxide: 0-10% by weight (expressed as Sb ₂ O ₃ )
Phosphorus: 0-1.5 wt% (expressed as P) 19. The process according to claim 18, wherein the activator of the catalyst has the following composition after heat treatment of the catalyst at 400 ° C. for a predetermined time period, preferably for many hours, particularly preferably for about 4 hours, and at least one silver Catalysts characterized in that mixed element oxides and / or bismuth vanadate are constituents of the active agent of the catalyst:
Vanadium oxide: 1-20% by weight (expressed as V ₂ O ₅ )
Titanium Dioxide: 80-99 wt% (expressed as TiO ₂ )
Vanadium acid is: 0-5% by weight (expressed as AgVO ₃ )
Silver tungstic acid: 0-5% by weight (expressed as Ag ₂ WO ₄ )
Molybdate is: 0-5% by weight (expressed as Ag ₂ MoO ₄ )
Bismuth vanadate: 0-3% by weight (expressed as BiVO ₄ )
Cesium: 0-1% by weight (expressed as Cs)
Antimony Oxide: 0-5% by weight (expressed as Sb ₂ O ₃ )
Phosphorus: 0-1.5% by weight (expressed as P). 20. The method according to any one of claims 1 to 19, characterized in that the activator of the catalyst is in an amount of from 2 to 25% by weight relative to the total weight of the catalyst after the heat treatment of the catalyst at least 400 ℃ for at least 4 hours. Catalyst. 21. The method according to any one of claims 1 to 20, wherein the layer thickness of the activator is 20 to 400 [mu] m on the inert carrier material, and the activator of the catalyst is applied on the inert nonporous carrier and the carrier is preferably A catalyst characterized in that it consists of steatite, in particular cyclic steatite. 22. The method according to any one of claims 1 to 21, wherein at least two or more different layers are preferably applied in shell form on an inert carrier, at least one of said layers being titanium dioxide, vanadium oxide and silver and And / or a mixed element oxide of vanadium. 23. The method according to any one of the preceding claims, wherein at least two or more different layers are preferably applied in a shell form on the ceramic carrier, wherein at least one or more of the layers comprises at least titanium dioxide and vanadium oxide. And at least one or more of the other layers optionally contains at least one silver- and / or vanadium-mixed element oxide comprising additional titanium dioxide and vanadium oxide. 24. A cell catalyst according to any one of the preceding claims, wherein a cell type catalyst is used in at least one of the catalyst beds from the gas inlet to the layer with the highest hot spot, and the active agent of the shell catalyst according to claim 11 A mixed element oxide of silver and / or a mixed element oxide of vanadium according to claim 12, and a mixed element oxide of silver and / or vanadium and / or a mixed element oxide of silver and / or vanadium as a raw material source for preparing the catalyst A precursor compound is used, a shell catalyst for the oxidation of aromatic hydrocarbons is used in at least one of the catalyst beds from the layer having the highest hot spot to the gas outlet, and vanadium pentoxide as a substantial component in the active agent of the shell catalyst. And a catalyst comprising titanium dioxide. The catalyst according to claim 1, wherein a binder, which is an organic polymer or copolymer, in particular a vinylacetate-copolymer, is used in the form of an aqueous dispersion to prepare at least one catalyst layer. 26. A mixed element oxide of silver and vanadium according to any one of claims 1 to 25 wherein the activator of the catalyst comprises a Ag: V ratio of 0.95 (> 0.95): 1 to 10: 1 based on its total weight. A catalyst comprising 0.01 to 15% by weight. 27. A catalyst precursor, in particular a catalyst precursor according to any one of claims 1 to 26, comprising an inert nonporous carrier material and a layer applied in one or more shell forms on the carrier material. The layer contains at least one precursor compound, titanium dioxide and vanadium compounds of the mixed element oxides of formula I according to claim 11 or formula II according to claim 11, wherein the precursor compound is silver when the precursor of the catalyst is heat treated. Or a catalytic precursor converted to a mixed element oxide of vanadium. At least two different layers are preferably catalyst precursors, in particular shell-coated on ceramic supports, in particular catalyst precursors according to any one of claims 1 to 26, wherein at least one of the layers At least one titanium dioxide and vanadium compound, at least one other layer optionally containing a precursor compound of a mixed element oxide having titanium dioxide and a vanadium compound, wherein the precursor compound is a mixed element of silver or vanadium upon heat treatment of the catalyst Catalyst precursor, characterized in that converted to oxide. 27. A process for preparing a catalyst according to any one of claims 1 to 26, comprising at least one titanium dioxide, a vanadium compound and at least one mixed element compound of silver and / or vanadium and / or a mixed element compound of silver and / or vanadium A process for producing a powder or suspension, in particular an aqueous suspension, containing at least one precursor compound of the above and applying the suspension onto an inert carrier. A process for preparing the mixed metal oxide or mixed element oxide according to claim 11, wherein the metal oxide N suspended in a liquid, preferably water, preferably vanadium pentoxide and / or molybdenum trioxide and / or tungsten trioxide, and / or A solution of the metal compound N, preferably a suspension or solution of ammonium metavanadate, preferably an aqueous solution and optionally a solution or suspension of the oxide of the metal compound M, isolating the reaction product and then separating the reaction product It is used as a manufacturing method. 31. A process according to claim 30, wherein said reaction mixture or separated reaction product is used for the preparation of a catalyst or catalyst precursor for gas phase oxidation of aromatic hydrocarbons. A process for preparing the precursor of the mixed metal oxide or mixed element oxide according to claim 12, comprising a vanadium compound suspended in a liquid, preferably water, preferably vanadium pentoxide and / or ammonium vanadate and / or Or a solution or suspension of vanadium oxide (IV, V) and metal compound M, preferably bismuth and / or molybdenum and / or tungsten and / or niobium and / or antimony, preferably an aqueous solution, and optionally metal N A process characterized by heating together a solution or suspension of a salt of an oxide, separating the reaction product or using the reaction mixture as a catalyst feedstock source. 33. The process of claim 32, wherein the separated reaction product and / or reaction mixture is used to prepare a catalyst or catalyst precursor for gas phase oxidation of aromatic hydrocarbons. A process for preparing a mixed element oxide according to claim 11, wherein at least one metal oxide N, preferably vanadium pentoxide and / or molybdenum trioxide and / or tungsten trioxide, and / or at least one metal salt N is an oxide or salt of silver, Preferably in combination dry or in solution with an oxide or salt of AgO and / or Ag ₂ O and optionally metal M, the mixture is optionally preheated and then heated at a temperature between 200 and 900 ° C. over a period of time. And using the reaction product obtained as a feedstock source for the catalyst. 35. The process of claim 34, wherein the reaction product or reaction mixture is used to prepare a catalyst or catalyst precursor for gas phase oxidation of aromatic hydrocarbons. A process for producing a mixed element oxide according to claim 12, wherein at least one salt or oxide of vanadium, preferably vanadium pentoxide and / or ammonium vanadate and / or vanadium (IV, V) oxide, Oxides and / or salts, preferably bismuth oxide and optionally oxides or salts of metal N, dry or in solution, the mixture is optionally preliminarily dried over a period of time at a temperature between 200 and 900 ° C. A production method characterized by using the reaction product obtained by heating as a feedstock source for catalysts. A method for producing aldehydes, carboxylic acids and / or carboxylic anhydrides by partial oxidation of aromatic hydrocarbons at high temperatures using a catalyst having an activator applied on an inert nonporous carrier, wherein the catalysts are based on the total weight Mixed silver and vanadium and / or molybdenum and / or tungsten and / or niobium and / or antimony 0.01 to 15 wt% and / or vanadium and bismuth and / or molybdenum and / or niobium and / or antimony It is a shell catalyst having an activator containing 0.01 to 10% by weight of elemental oxide and simultaneously titanium dioxide and vanadium compounds, preferably V ₂ O _5, and containing vanadium pentoxide and anatase type titanium dioxide as a substantial component in the active material. The mixed element oxide-compound (s) in the presence or absence of at least one other shell type catalyst Or a precursor compound (s) thereof in the preparation of the catalyst suspension and / or powder mixture for the final activator. 27. A process for preparing a catalyst according to any one of claims 1 to 26, wherein the active agent of the catalyst or a compound contained in the catalyst suspension or powder mixture is applied in an inert carrier in a fluid or preferably vortex form. Manufacturing method characterized in that.