DE19859561A1 - Production of shaped bodies, for example containing titanium, silicon, and lithium, using a metal oxide sol - Google Patents

Abstract

Molded bodies having a low content of alkali and alkali earth metal ions can be obtained when in one stage of the process a porous oxide material is mixed with a metal oxide sol and/or a metal oxide. A molded body comprising at least one oxide material and at least one metal oxide is prepared in 5 stages: (i) mixing of at least one metal oxide with at least one metal oxide sol having a low content of alkali and alkali earth metals and/or at least one metal oxide of low alkali and alkali earth metal content; (ii) compaction of the mass; (iii) forming of the mass; (iv) drying of the molded body; and (v) calcining of the dried molded body. Independent claims are included for: (1) A molded body obtained as above; (2) a metal oxide sol having a content of alkali and alkali earth metal ions less than 800 ppm, obtained by hydrolysis of at least one metal acid ester; (3) a process for preparation of at least one alkylene oxide involving the 3 stages: (A) reaction of at least one alkene with hydrogen peroxide in the presence of a molded body obtained as above as catalyst, which can act as catalysts for selective oxidation; (B) preparation of the alkene by dehydration of an alkane; (C) oxidation of the hydrogen produced in (II) to hydrogen peroxide, which is then used in stage (I).

Description

The present invention relates to a method for producing a molded article pers, of at least one porous oxidic material and at least one Contains metal oxide, the molded body itself and its use as a kata analyzer in the implementation of organic compounds, in particular for Epoxidation of organic compounds containing at least one C-C Have double bond.

Shaped bodies that contain porous oxidic materials are used in numerous chemical processes used. This requires a manufacturing process that allows inexpensive large-scale relevant quantities of moldings to manufacture.

As a rule, the porous oxidic material is used to produce molded articles al with a binder, an organic viscosity increasing substance and a Liquid added to make the mass and in a kneader or bowl condensed. The mass obtained is then extruded or Ex truder deformed, and the moldings obtained are dried and calcined.

To produce moldings that are also used to manufacture very reactive products are suitable, it is necessary to use chemically inert binders, the one Prevent further reaction of these products.  

Suitable binders are a number of metal oxides Oxides of silicon, aluminum, titanium or zircon called. Silicon dioxide as a binder is, for example, in the publications US 5,500,199 and US 4,859,785.

With such binders, the content of (earth) alkali metal ions should be as possible be low, which is why the use of (earth) low-alkali metal or (earth) alkali metal-free binder sources is necessary.

To produce the metal oxide binder mentioned above, one can use as starting materials use appropriate metal oxide brines. In the production of, for example the mentioned (earth) low alkali metal or (earth) alkali metal free silicon di Accordingly, oxide binder is used for (earth) low alkali metal or (earth) free of alkali metal Silica sol as a binder source.

In the production of silica sols one can start from alkali silicates, what however, usually to undesirably high levels of alkali metal ions in the Silica sol leads. The production of such silica sols is described, for example, in "Ull mann's Encyclopedia of Industrial Chemistry ", Volume A23 (1993), pp. 614-629 described.

JP-A-07 048 117 discloses silica sol production by hydrolysis of Alkoxysilanes under the influence of ammonia in the presence of a large Excess alcohol, the silica sols obtained having a content of up to have 10% by weight of silicon dioxide.

JP-A-05 085 714 describes the acidic decomposition of alkoxysilanes if in alcoholic medium. In doing so, silica sols are used Silica contents of 1 to 10 wt .-% obtained.  

A disadvantage of the methods disclosed in the last two publications Silica sol production is the low attainable silicon dioxide content of the pebbles sole, which makes the process uneconomical, since both in the production of sol as well as in further processing plant capacity through superfluous what mass is wasted.

Accordingly, an object of the present invention is an industrial scale provide usable process for the production of moldings, the have a low content of (earth) alkali metal ions and as Kataly generators, preferably in a fixed bed, can be used.

It has surprisingly been found that such shaped articles can be obtained NEN, if in a stage of the process with porous oxidic material Metal oxide sol and / or metal oxide is mixed, the metal oxide sol and the metal oxide each have a low content of (earth) alkali metal ions exhibit.

Accordingly, the present invention relates to a process for producing a shaped body, comprising at least one porous oxidic material and at least one metal oxide, which comprises the following step (i):

• a) mixing the at least one porous oxidic material with min least a metal oxide sol, which has a low content of alkali and Has alkaline earth metal ions, and / or at least one metal oxide, which has a low content of alkali and alkaline earth metal ions.

The present invention also relates to a shaped body which can be produced by The method described above, wherein this molded body contains (Earth) alkali metal ions of preferably less than 700 ppm, especially before has less than 600 ppm and in particular less than 500 ppm.  

In a preferred embodiment of the method according to the invention the metal oxide sol is obtained by hydrolysis of at least one metal acid ester manufactured.

Therefore, the present invention also relates to a Ver as described above drive, which is characterized in that the metal oxide sol is produced by hydrolysis of at least one metal acid ester.

The metal acid esters due for hydrolysis can be prior to hydrolysis getting cleaned. All suitable methods are conceivable. Prefers the metal acid esters are subjected to distillation before the hydrolysis.

With regard to the hydrolysis of the metal acid ester, in principle all are possible process. Preference is given to the process according to the invention however, the hydrolysis is carried out in an aqueous medium. This has the advantage that compared to from the literature, for example JP 07,048,117 or JP 05,085,714, known hydrolysis, in which worked with excess alcohol is, much less alcohol has to be distilled off.

The hydrolysis can be catalyzed by adding basic or acidic sub punch. Basic or acidic substances which are preferred are preferred Allow calcining to be removed without residue. Above all, substances are made from selected from the group ammonia, alkylamines, alkanolamines, arylamines, Carboxylic acids, nitric acid and hydrochloric acid are used. In particular, be Ammonia, alkylamines, alkanolamines and carboxylic acids are used.

In the process according to the invention, preference is given to orthokia as the metal acid ester used acid ester.  

The hydrolysis of the metal acid esters takes place in the process according to the invention Temperatures from 20 to 100 ° C, preferably from 60 to 95 ° C and at pH Values from 4 to 10, preferably from 5 to 9, particularly preferably from 7 to 9.

The molar ratio of catalytically active substance / metal acid ester is in general 0.0001 to 0.11, preferably 0.0002 to 0.01 and in particular 0.0005 up to 0.008.

In the process according to the invention, metal oxide brines, preferably obtained silica sols containing (earth) alkali metal ions less than 800 ppm, preferably less than 600 ppm, more preferred less than 400 ppm, more preferably less than 200 ppm, more preferred less than 100 ppm, particularly preferably less than 50 ppm, further particularly which preferably have less than 10 ppm, in particular less than 5 ppm.

Accordingly, the present invention relates to a metal oxide sol having a Ge holds (earth) alkali metal ions of less than 800 ppm, producible by Hydrolysis of at least one metal acid ester.

The metal oxide content of the metal oxide sols produced according to the invention generally carries up to 50% by weight, preferably 10 to 40% by weight.

The alcohol formed during the hydrolysis is in the process according to the invention usually distilled off. However, small amounts of alcohol can Metal oxide sol remain as long as they are in the further steps of the invention show no disruptive effects according to the method.

Advantageous for the industrial use of the products produced according to the invention Metal oxide brine is their property of showing no tendency to gel.  

Special precautions to prevent gel formation are over liquid. The shelf life of the metal oxide sols produced according to the invention is several weeks, which means that the time coordination with other ver driving steps becomes unproblematic.

According to the invention, a mixture comprising at least one is used in the process porous oxidic material and at least one metal oxide, wherein a metal oxide sol is used as the metal oxide source, as described above will be produced.

In principle there are no restrictions with regard to the method for manufacturing position of the mixture. Preference is given to the process according to the invention however, a suspension containing at least one porous oxidic material and metal oxide sol, sprayed.

There are porous oxidic particles in the suspension Material no restrictions as long as the workability of the suspension is guaranteed during manufacture and spraying. Weight is preferred ratio of porous oxidic material to metal oxide of the metal oxide sol selected from 10 to 0.1, particularly preferably from 8 to 1.

The main components of the suspension are generally porous oxidic Material, metal oxide sol and water. Furthermore, the suspension can still have residual contain organic compounds. These can, for example, from the Manufacture of the porous oxidic material. Likewise are alcohols conceivable that arise from the hydrolysis of metal acid esters or substances, which as described above to promote hydrolysis of metal acid esters be set.  

Depending on the humidity of the mixture for further processing processing, drying can follow. Everyone can conceivable procedures are applied. The drying of the Mixtures simultaneously with spraying in a spray drying process. Spray dryers with inert gases are preferred, particularly preferably with Nitrogen or argon operated.

With regard to the process for producing the shaped bodies in the process according to the invention usable porous oxidic materials do not exist restrictions as long as it is possible based on such materials as Manufacture molded articles described herein, and as long as these materials have the necessary catalytic activity.

The porous oxidic material is preferably a zeolite. Zeolites are known to be crystalline aluminosilicates with ordered channel and cage structures that have micropores. The term "micropores" as used in the context of the present invention corresponds to the definition in "Pure Appl. Chem." 45 (1976) p. 71 ff., In particular p. 79, and refers to pores with a pore diameter of less than 2 nm. The network of such zeolites is made up of SiO ₄ - and AlO ₄ tetrahedra, which are connected by common backs of oxygen . An overview of the known structures can be found, for example, in WM Meier, DH Olson and Ch. Baerlocher in "Atlas of Zeolite Structure Types", Elsevier, 4th edition, London 1996.

There are also zeolites that do not contain aluminum and in which Silicate lattice instead of Si (IV) partially titanium is present as Ti (IV). The Titanium zeolites, especially those with a MFI-type crystal structure, as well as possibilities for their production are described for example in the EP-A 0 311 983 or EP-A 0 405 978. In addition to silicon and titanium can  such materials also include additional elements such. B. aluminum, zirconium, Tin, iron, niobium, cobalt, nickel, gallium, boron or small amounts of fluorine contain.

In the zeolites described, the titanium can be partially or partially completely by vanadium, zirconium, chromium, niobium or iron or by a Mixture of two or more of them can be replaced. The molar ratio of titanium and / or vanadium, zirconium, chromium, niobium or iron to the sum of Silicon and titanium and / or vanadium, zirconium, chromium, niobium or iron is usually in the range of 0.01: 1 to 0.1: 1.

Titanium zeolites with an MFI structure are known for being able to be identified via a certain pattern when determining their X-ray diffraction images and also via a framework vibration band in the infrared region (IR) at around 960 cm ^-1 , and are thus different from alkali metal titanates or crystalline and amorphous TiO ₂ -Differentiate phases.

Titanium, vanadium, chromium, niobium, zirconium zeolites, more preferably titanium zeolites and in particular titanium silicalites are used. These include titanium, vanadium, chromium, niobium, zirconium zeolites with a Pentasil zeolite structure, especially the types with X-ray Assignment to BEA, MOR, TON, MTW, FER, MFI, MEL, CHA, ERI, RHO, GIS, BOG, NON, EMT, HEU, KFI, FAU, DDR, MTT, RUT, RTH, LTL, MAZ, GME, NES, OFF, SGT, EUO, MFS, MWW or MFI / MEL mixed structure and ITQ-4. Zeolites of this type are for example in the above-mentioned literature by Meier et al. described. Are also conceivable for use in the inventive method Rite-containing zeolites with the structure of UTD-1, CIT-1 or CIT-5. As another  Titanium-containing zeolites are those with the structure of ZSM-48 or ZSM-12 call.

Such zeolites are described, inter alia, in US Pat. No. 430,000 and WO 94/29408 described, the relevant content in full in the present application is incorporated by reference. As special preferred for the process according to the invention are Ti zeolites with MFI, MEL or MFI / MEL mixed structure. As further preferred are individual the Ti-containing zeolite catalysts, which are generally referred to as "TS- 1 "," TS-2 "," TS-3 ", as well as Ti zeolites with a beta zeolite to call isomorphic framework structure.

Accordingly, the present invention relates to a method for Production of a shaped body as described above, the result is characterized in that the porous oxidic material is a zeolite.

Mixtures can of course also be used in the process according to the invention two or more, especially the above porous oxidic Materials are used.

Usually the titanium, zirconium, chromium, niobium, iron and vanadium zeolites mentioned are prepared by adding an aqueous mixture of a source of metal oxide, preferably an SiO ₂ source, and of a source of titanium, zirconium and chromium -, niobium, iron or vanadium source, such as. B. titanium dioxide or a corresponding vanadium oxide, zirconium alcoholate, chromium oxide, niobium oxide or iron oxide and a nitrogen-containing organic base as a template ("template compound"), such as. B. tetrapropylammonium hydroxide, optionally with the addition of basic compounds, in a pressure vessel at elevated temperature over a period of several hours or a few days, whereby a crystalline product is formed. This is filtered off, washed, dried and baked at elevated temperature to remove the organic nitrogen base. In the powder obtained in this way, the titanium or the zirconium, chromium, niobium, iron and / or vanadium is present at least partially within the zeolite structure in varying proportions with 4-, 5- or 6-fold coordination. To improve the catalytic behavior, a repeated washing treatment with sulfuric acid hydrogen peroxide solution can follow, after which the titanium or zirconium, chromium, niobium, iron, vanadium zeolite powder must be dried and fired again. The titanium or zirconium, chromium, niobium, iron or vanadium zeolite powder thus produced is used in the process according to the invention as a component of the suspension described above.

In particular, the present invention therefore relates to a process as described above in which the at least one porous oxidic material is mixed with at least one metal oxide sol, the at least one porous oxidic material being produced in a process which comprises one or more of the following steps ( a) to (f) include:

• a) producing a preferably aqueous mixture of at least one metal oxide source, preferably an SiO ₂ source, and a further metal source, for example a titanium, zirconium, chromium, niobium, iron or vanadium source,
• b) Crystallization of the mixture from (a) in a pressure vessel with addition at least one template compound, optionally with addition another basic compound,
• c) drying of the suspension contained in (b) crystalline product, preferably by spray drying,
• d) calcining the dried product from (c),  
• e) crushing the calcined product from (d), for example by Grinding to particles with particle sizes smaller than 500 µm, preferably smaller 300 µm, particularly preferably less than 200 µm,
• f) if necessary, repeated washing treatment of the comminuted product from (e) with subsequent drying and calcination.

The pore structure of the porous oxidic materials also exists no special restrictions, d. H. the material can have micropores, Mesopores, macropores, micro and mesopores, micro and macropores, Have meso and macro pores or micro, meso and macro pores, where the definition of the terms "mesopores" and "macropores" also those in the literature mentioned above according to "Pure Appl. Chem." corresponds and with pores a diameter of <2 nm to approximately 50 nm or <approximately 50 nm designated.

However, microporous oxidic materials such as for example, titanium silicalite is used.

In a further preferred embodiment of the method according to the invention rens the at least one porous oxidic material in step (i) mixed at least one metal oxide that has a low content of alkali and has alkaline earth metal ions.

In the event that the porous oxidic material with two or more metal oxides is mixed, it is conceivable that the at least one porous oxidic material first mix with a metal oxide and the resulting mixture with a to mix further metal oxide. If desired, this Ge obtained be mixed with another metal oxide. It is the same  possible the porous oxidic material with a mixture of two or more Mix metal oxides.

The (earth) alkali metal content of this metal oxide or the mixture of two or more metal oxides is generally less than 800 ppm, preferably small ner 600 ppm, particularly preferably less than 500 ppm and particularly preferred less than 200 ppm.

Such metal oxides with a low content of alkali and alkaline earth metal Ions are, for example, pyrogenic metal oxides, an example of a such fumed metal oxide may be called fumed silica.

Of course, it is also possible to invent conventional metal oxides to use methods according to the invention, provided that their content of Alkali and alkaline earth metal ions are correspondingly low, as stated above.

It is also conceivable for one or more conventional metal oxides that a higher than the above-mentioned content of alkali and alkaline earth metal have ions, by washing, extraction or other suitable Measures, of course, by a combination of two or more ge appropriate measures, the content of alkali and alkaline earth metal ions so far lower that the metal oxides used in the process according to the invention can be.

Depending on the measure taken, there may be a reduction in the salary Alkali and alkaline earth metal ions may be necessary, the one or more conven tional metal oxide (s) to be treated accordingly. For example, if Alkali and alkaline earth metal ion content of a conventional metal oxide reduced by washing, it may be necessary to use the conventional  Dry metal oxide after washing it before washing it with at least one porous oxidic material is mixed.

In the context of the method according to the invention, it is of course also possible that Mixture resulting from the mixing of the at least one porous oxidic Material with the metal oxide results with at least one metal oxide sol has a low content of alkali and alkaline earth metal ions . Regarding the production of this mixture, as in the Production of the mixture of porous oxidic material and metal oxide sol, as described above, in principle no restrictions. However, preference is given a suspension comprising the mixture of the at least one porous oxidic material and the at least one metal oxide and the at least a metal oxide sol, sprayed. With regard to the content of this suspension porous oxidic material, there are no restrictions as long as already described above, the processability of the suspension is guaranteed.

Furthermore, it is of course also within the scope of the method according to the invention possible a mixture resulting from the mixing of at least one porous oxidic material with at least one metal oxide sol results, with min least a metal oxide, which has a low content of alkali and Has alkaline earth metal ions to mix. This can cause the mixing with the at least one metal oxide directly to the preparation of the mixture from the at least one porous oxidic material and the at least one egg Connect a metal oxide sol. If, as already described above, after the Production of the mixture from the at least one porous oxidic mate rial and the at least one metal oxide sol, drying may be required it is also possible to dry the metal oxide after drying Mix the mixture.  

It is also possible within the scope of the method according to the invention that the min least a porous oxidic material simultaneously with at least one To mix metal oxide sol and at least one metal oxide.

The mixture according to one of the embodiments described above of the invention is obtained in a further stage of the invention Process condensed. In this compression or deformation step additional metal oxide may optionally be introduced, the metal being Oxide source metal oxide sol is used, which was prepared as described above. This processing step can be carried out in all known equipment, however kneaders, mills or extruders are preferred. Particularly preferred for the industrial use of the method according to the invention Koller used.

According to an embodiment already described above, a Ge mix of at least one porous oxidic material and at least one Metal oxide produced, this mixture is compressed and in the compression step additionally metal oxide sol, which has a low content of alkali and alkaline earth has metal ions added, so in a preferred Embodiment of the present invention 20 to 80 wt .-% porous oxidi cal material, 10 to 60 wt .-% metal oxide and 5 to 30 wt .-% metal oxide sol used. 40 to 70% by weight of porous oxidic are particularly preferred Material, 15 to 30 wt% metal oxide and 10 to 25 wt% metal oxide sol used. These percentages by weight are based in each case on the ultimate produced molded body, as described below. To be favoured here porous oxidic titanium-containing material and silica sol are used.

In a further embodiment of the method according to the invention the mixing of the at least one porous oxidic material with the  at least one metal oxide that has a low alkali and alkaline earth content has limetal ions during the compression step. It is the same accordingly possible in the compression step the at least one porous oxidi cal material containing at least one metal oxide and additionally at least one Mix metal oxide sol.

In this deformation step, one or more viscosities can additionally increasing substances are added as pasting agents, which under others serve the stability of the uncalcined shaped body, as below described to increase. For this all suitable, from the stand substances known in the art can be used. In the invention Processes include water as well as mixtures of water with one or more ren organic substances, if they are miscible with water, as Pastes used. The paste can be used in the later calcine ren of the molded body can be removed again.

Organic, in particular hydrophilic, organic polymers are preferred such as B. cellulose, cellulose derivatives such as methyl cellulose, ethyl cellulose or hexyl cellulose, polyvinyl pyrrolidone, ammonium (meth) acrylates, Tylose or mixtures of two or more of them are used. Especially before methyl cellulose is used.

Ammonia, amines or amine-like compounds can be used as further additives conditions such as B. tetraalkylammonium compounds or amino alcoholates added become. Such further additives are in EP-A 0 389 041, EP-A 0 200 260 and WO 95/19222, which are fully described in this regard the context of the present application incorporated by reference the.  

Instead of basic additives, it is also possible to add acidic additives use. Organic acidic compounds are preferred which differ according to the Let the deformation step burn out by calcining. Especially carboxylic acids are preferred.

The amount of these auxiliaries is preferably 1 to 10% by weight, particularly preferably 2 to 7 wt .-%, are each based on the ultimately produced molded body, as described below.

To influence properties of the shaped body such. B. Transport pores Volume, transport pore diameter and transport pore distribution can be further substances, preferably organic compounds, in particular orga Add African polymers as additional additives that also improve the formability can influence the crowd. Such additives include Algina te, polyvinylpyrolidone, starch, cellulose, polyether, polyester, polyamide, Polyamines, polyimines, polyalkenes, polystyrene, styrene copolymers, polyacrylates, Polymethylacrylate, fatty acids such as stearic acid, high molecular weight Polyalkylene glycols such as polyethylene glycol, polypropylene glycol or polybutylene glycol, or mixtures of two or more thereof become. The total amount of these substances, based on the ultimate amount The shaped body, as described below, is preferably 0.5 to 10% by weight, particularly preferably 1 to 6% by weight.

Accordingly, the present invention also relates to the use of polyal kylene glycol, especially of polyethylene glycol in the manufacture of Titanium silicalite-containing moldings, in particular those which act as catalysts for Selective oxidation can be used.  

In a preferred embodiment, in the method according to the invention Shaped body produced, which are essentially microporous, but beyond can also have mesopores and / or macropores. The pore volume of the Mesopores and macropores in the shaped body according to the invention, determined according to DIN 66133 by mercury porosimetry, is greater than 0.1 ml / g, preferably larger than 0.2 ml / g, particularly preferably greater than 0.3 ml / g, in particular greater than 0.5 ml / g.

The order of addition of the additives described above to the mixture, obtained according to one of the methods described above is not critical table. It is both possible to first add further metal oxide via metal oxide sol, then the viscosity increasing and then the transport properties and / or substances that influence the deformability of the compressed mass as well as any other order.

Optionally, this can usually still be in powder form before compaction Mixture can be homogenized for 10 to 180 min in a kneader or extruder. Here is usually at temperatures in the range of about 10 ° C to Boiling point of the pasting agent and normal pressure or light worked above atmospheric pressure. The mixture is kneaded until an extrudable or extrudable mass has formed.

The mass to be deformed after compression is in invent process according to the invention a proportion of metal oxide of at least 10% by weight %, preferably at least 15% by weight, particularly preferably at least 20% by weight %, in particular at least 30% by weight, based on the total mass. In particular especially when using titanium-containing microporous oxides the mass produced in the process according to the invention is characterized in that it does not cause any problems with the upcoming deformation due to thixotropic Properties leads.  

In principle, all conventional ones can be used for kneading and shaping Kneading and shaping devices or methods, as they are numerous from the State of the art and for the production of z. B. catalyst Moldings are suitable to be used.

Methods are preferably used in which the deformation by Extrusion in conventional extruders, for example to form strands with one pass knife of usually about 1 to about 10 mm, especially about 1.5 to about 5 mm. Such extrusion devices are used in for example in Ullmann's "Encyclopedia of Technical Chemistry", 4th edition, Vol. 2 (1972), pp. 295 ff. In addition to using an extruder an extrusion press is also preferably used. In the case of a big one Technical application of the method is particularly preferred with extruders worked.

The extrudates are either strands or honeycomb bodies. The shape of the honeycomb is any. It can be, for example, round strands, hollow strands, or act star-shaped strands. The diameter of the honeycomb is also arbitrary. The pro usually decide on the outer shape and diameter zeßtechnischen requirements by the process in which the molded body should be used.

Before, during or after the shaping step, the material can be precious metals in the form of suitable precious metal components, for example in the form of water-soluble salts can be applied. This method is preferred applied to oxidation catalysts based on titanium or vanadi to produce silicates with a zeolite structure, catalysts being available, which have a content of 0.01 to 30 wt .-% of one or more precious metals from the group ruthenium, rhodium, palladium, osmium, iridium, platinum, Rhe  nium, gold and silver. Such catalysts are for example in DE-A 196 23 609.6, which are hereby described with respect to those described therein Full scope of catalysts in the context of the present application is incorporated by reference.

In many cases, however, it is cheapest to start with the precious metal components to be applied to the shaped bodies after the shaping step, especially when when a high temperature treatment of the precious metal-containing catalyst is imperative wishes. The noble metal components can in particular by Ion exchange, impregnation or spraying brought onto the molded body become. The application can be by means of organic solvents, aqueous am moniacal solutions or supercritical phases such as carbon dioxide respectively.

By using these aforementioned methods can be quite different like noble metal-containing catalysts are generated. So through Spraying the noble metal solution on the molded body is a kind of coated catalyst be generated. The thickness of this shell containing precious metals can be determined by Im Precise significantly enlarge, while the ion exchange Catalyst particles largely uniform over the cross section of the molded body be covered with precious metal.

After the extrusion or extrusion is finished, they are obtained NEN molded body at generally 50 to 250 ° C, preferably 80 to 250 ° C at Pressures generally 0.01 to 5 bar, preferably 0.05 to 1.5 bar in the course dried from about 1 to 20 hours.

The subsequent calcination takes place at temperatures of 250 to 800 ° C, preferably 350 to 600 ° C, particularly preferably 404 to 500 ° C. The Druckbe  rich is chosen similar to that of drying. It usually comes in oxygen calcined atmosphere, the oxygen content 0.1 to 90 vol.%, is preferably 0.2 to 22% by volume, particularly preferably 0.2 to 10% by volume.

The present invention thus also relates to a process for the production of moldings, as described above, which comprises the following steps (i) to (v):

• a) mixing the at least one porous oxidic material with min least a metal oxide sol, which has a low content of alkali and Has alkaline earth metal ions, and / or at least one metal oxide, which has a low content of alkali and alkaline earth metal ions;
• b) compressing the mixture from stage (i), optionally with the addition of Me tall oxide sol;
• c) (iii deforming the mass from step (ii);
• d) drying the shaped bodies from stage (iii);
• e) calcining the dried moldings from stage (iv).

A special embodiment of the invention is the suspension, the From step (b) described above, the metal oxide sol is added zen to dry the resulting suspension, preferably by Spray drying, and calcining the resulting powder. The dried one and calcined product can then be processed further according to step (iii).

Of course, the strands or extrudates obtained can be made up become. All methods of comminution are conceivable, for example as by splitting or breaking the moldings, as well as others chemical treatments such as described above. Find a Zer smaller instead of, preferably granules or grit with a Particle diameter of 0.1 to 5 mm, in particular 0.5 to 2 mm generated.  

This granulate or grit and other forms produced Bodies contain practically no more fine-grained fractions than those with roughly 0.1 mm minimum particle diameter.

The shaped articles produced or according to the invention can be used as catalysts, in particular for catalytic conversion, especially for the oxidation of organic molecules. Examples of implementation include:
the epoxidation of olefins such as e.g. B. the production of propene oxide from propene and H ₂ O ₂ or from propene and mixtures which provide H ₂ O ₂ in situ;
Hydroxylations such as. B. the hydroxylation of mono-, bi- or polycyclic aromatics to mono-, di- or higher substituted hydroxy aromatics, for example the reaction of phenol and H ₂ O ₂ or of phenol and mixtures which deliver H ₂ O ₂ in situ to hydroquinone ;
the conversion of alkanes to alcohols, aldehydes and acids;
oxime formation from ketones in the presence of H ₂ O ₂ or mixtures which provide H ₂ O ₂ in situ and ammonia (ammonoximation), for example the preparation of cyclohexanone oxime from cyclohexanone;
Isomerization reactions such as B. converting epoxides to aldehydes;
as well as other reactions described in the literature with such shaped bodies, in particular zeolite catalysts, as described, for example, by W. Hoelderich in "Zeolithes: Catalysts for the Synthesis of Organic Compounds", Elsevier, Stud. Surf. Sci. Catal., 49, Amsterdam (1989), pp. 69 to 93, and in particular for possible oxidation reactions by B. Notari in Stud. Surf. Sci. Catal., 37 (1987), pp. 413 to 425, or in Advances in Catalysis, vol. 41, Academic Press (1996), pp. 253 to 334.

Therefore, the present invention relates to the use of a as above wrote produced molded body or a mixture of two or more of which as a catalyst.

The zeolites discussed in detail above are particularly suitable for the epoxidation of alkenes.

Accordingly, the present invention also relates to a process for producing at least one alkene oxide, which comprises the following step (III):

• A) reacting at least one alkene with hydrogen peroxide on one Catalyst,

characterized in that a shaped body, produced in a method as described above, or a shaped body as described above wrote, is used.

Alkenes in question for such functionalization through epoxidation come, for example, ethene, propene, 1-butene, 2-butene, isobutene, Butadiene, pentene, piperylene, hexene, hexadiene, heptene, octene, diisobutene, Trimethylpentene, nonenes, dodecene, tridecene, tetra- to eicosenes, tri- and Tetrapropene, polybutadienes, polyisobutenes, isoprene, terpenes, geraniol, Linalool, linalyl acetate, methylene cyclopropane, cyclopentene, cyclohexene, Norbornene, cycloheptene, vinylcyclohexane, vinyloxirane, vinylcyclohexene, Styrene, cyclooctene, cyclooctadiene, vinyl norbornene, by tetrahydroinden, Methylstyrene, dicyclopentadiene, divinylbenzene, cyclododecene,  Cyclododecatriene, stilbene, diphenylbutadiene, vitamin A, beta-carotene, Vinylidene fluoride, allyl halides, crotyl chloride, methallyl chloride, Dichlorobutene, allyl alcohol, methallyl alcohol, butenols, butenediols, Cyclopentene diols, pentenols, octadienols, tridecenols, unsaturated steroids, Ethoxyethene, isoeugenol, anethole, unsaturated carboxylic acids such as B. Acrylic acid, methacrylic acid, crotonic acid, maleic acid, vinyl acetic acid, unsaturated fatty acids such as As oleic acid, linoleic acid, palmitic acid, of course occurring fats and oils.

The zeolites discussed in detail above are preferably suitable for the Epoxidation of alkenes with 2 to 8 carbon atoms, more preferably of ethene, Propene or butene, and in particular propene to the corresponding Alkene oxides.

Accordingly, the present invention relates in particular to the use of the shaped body described herein as a catalyst for the production of propene oxide, starting from propene and hydrogen peroxide or from propene and mixtures which deliver H ₂ O ₂ in situ.

In a special embodiment of the method, this is to be epoxidized Alkene prepared by dehydration of the corresponding alkane.

Accordingly, the present invention also relates to a method as described above which comprises the additional step (I):

• A) Preparation of the at least one alkene reacted in step (III) by dehydrating at least one alkane.

This dehydration can, in principle, according to all of the prior art known methods are carried out. Such procedures include  in EP-A 0 850 936, which is fully described in this regard in the Context of this application is incorporated by reference.

In a preferred embodiment of the method according to the invention the hydrogen that is produced during the dehydrogenation of the at least one alkane is used to produce hydrogen peroxide, which is used in De Hydrogenation generated, at least one alkene is reacted in step (III).

Accordingly, the present invention also relates to a method as described above, which comprises the following step (II):

• A) Conversion of the hydrogen formed in step (I) to hydrogen per oxide,

wherein the hydrogen peroxide is used for the reaction in step (III).

Accordingly, the present invention also relates to an integrated process for the preparation of an alkene oxide which comprises steps (A) to (C):

• A) dehydrogenation of an alkane to an alkene to give hydrogen,
• B) converting the hydrogen obtained in (A) to hydrogen peroxide,
• C) Reaction of the hydrogen peroxide from (B) with the alkene from (A) below Obtaining the alkene oxide using a form according to the invention body.

The conversion of the hydrogen to hydrogen peroxide can be done here after all Methods which are known from the prior art are carried out. In particular, the hydrogen can be hydrogen with molecular oxygen be implemented peroxide. It is also conceivable to use the Hydrogen from step (A) via the anthraquinone process hydrogen pero to manufacture xid. In both cases it may be necessary to use the Purify hydrogen from step (A) before further use. Prefers  however, the anthraquinone method is used. This is based on to correspond to the catalytic hydrogenation of an anthraquinone compound the anthrahydroquinone compound, subsequent implementation of the same Oxygen with the formation of hydrogen peroxide and subsequent removal tion of the hydrogen peroxide formed by extraction. The catalytic cycle is by renewed hydrogenation of the re-formed anthraquinone compound closed. An overview of the anthraquinone process is provided by "Ullmanns Encyclopedia of Industrial Chemistry ", 5th edition, volume 13, pages 447 to 456.

When using a molded article produced according to the invention or more of these, as a catalyst, can be deactivated by a process after deactivation be regenerated, in which the regeneration by targeted burning of the pads responsible for the deactivation. It is preferred be worked in an inert gas atmosphere, the precisely defined amounts of Contains oxygen-supplying substances. This regeneration process is in described in DE-A 197 23 949.8, which is fully in this regard in the Context of the present application should be incorporated by reference.

Furthermore, the present invention relates in its most general expression staltungform the use of a metal oxide sol, prepared as above described as a binder for the production of a shaped body high chemi shear and mechanical strength.

The following examples are intended to explain the invention.

Examples example 1 Production of a microporous oxidic material

In a four-necked flask (4 l content) 910 g of tetraethyl orthosilicate were pre- puts and from a dropping funnel with 15 g within 30 min Tetraisopropyl orthotitanate was added with stirring (250 rpm. Blade stirrer). It a colorless, clear mixture formed. Then it was mixed with 1600 g a 20% by weight tetrapropylammonium hydroxide solution (alkali metal alloy hold <10 ppm) and stirred for a further 1 h. At 90 to 100 ° C that was the Hydrolysis formed alcohol mixture (about 900 g) distilled off. It was filled with 3 l Water and gave the now slightly opaque sol in a 5 liter Stirred autoclaves made of stainless steel.

With a heating rate of 3 ° C / min the closed autoclave (anchor agitation rer, 200 U / min) brought to a reaction temperature of 175 ° C. After 92 h the reaction was over. The cooled reaction mixture (white suspension) was centrifuged and washed neutral with water several times. The received one Solid was dried at 110 ° C within 24 h (weight: 298 g). The remaining in the zeolite was then in air at 550 ° C in 5 h Template burned off (loss of calcination: 14% by weight).

According to wet chemical analysis, the pure white product had a Ti content of 1.5% by weight and a residual alkali metal content below 100 ppm. The prey on silicon dioxide used was 97%. The crystallites had a size of 0.05 to 0.25 μm and the product showed a typical band at approx. 960 cm ^-1 in the IR.

Example 2 Production of a silica sol

3 l of water were in a 10 l four-necked flask equipped with a stirrer, Thermometer and reflux condenser. With 6 g of 25% ammonia  the pH of the solution was adjusted to 8 to 9. Then that was Water heated to 50 ° C and 1300 g of tetraethyl orthosilicate using a Dropped funnel.

The mixture of water and tetraethyl orthosilicate was refluxed for 3 hours cooked. A further 1304 g of tetraethyl orthosilicate were then passed over one Dropping funnel too. After boiling under reflux for a further 2 h, they were allowed to so Stir the obtained silica sol-water mixture for a further 12 h and then distillate the ethanol formed by the hydrolysis.

The 3618 g of silica sol produced in this way had a silicon dioxide content of approx. 20 % By weight and a content of alkali metal ions of less than 3 ppm.

Example 3 Production of a silica sol

188.6 g of water were placed in a 500 ml four-necked flask equipped with a stirrer, Thermometer and reflux condenser. With 0.3 g of 25% ammonia the pH of the solution was adjusted to 9. Then that was Water heated to 50 ° C and 111.65 g of tetraethyl orthosilicate using a Dropped funnel.

The mixture of water and tetraethyl orthosilicate was refluxed for 2 hours cooked. A further 111.65 g of tetraethyl orthosilicate was then transferred a dropping funnel. After boiling under reflux for a further 2 h, they were allowed to so Stir the resulting silica sol-water mixture for a further 12 h. Then gave 50 g of water were added and the product of the hydrolysis was then distilled Ethanol.  

The 169 g of silica sol produced in this way had a silicon dioxide content of approx. 38 % By weight and a content of alkali metal ions of less than 5 ppm.

Example 4 Spraying titanium silicalite

200 g of ground catalyst, prepared according to Example 1, were first a particle size of <300 µm finely ground and then in 2000 g of water suspended. Then 245 aqueous silica sol with a Silicon dioxide content of 18 wt .-%, prepared according to Example 2, admixed.

The suspension was added with a peristaltic pump with constant stirring a laboratory spray tower made of glass (diameter: 200 mm, height of the cylindrical Partly: 500 mm) conveyed and by means of a two-substance nozzle (diameter of the Liquid supply: 2.5 mm, nozzle gas upstream pressure: 3 bar) atomized.

In the spray tower, the suspension was removed by the dry gas (nitrogen, Throughput: 24 kg / h, inlet temperature: 210 ° C, outlet temperature: 100 ° C) a fine, intimately mixed powder that is then dried in a Glass cyclone was deposited. The yield was 80%.

Example 5 Spraying titanium silicalite

16.1 kg of catalyst, prepared according to Example 1, were first with a Hammer mill roughly pre-ground and then with a baffle plate mill on one Particle size of <300 µm finely ground.

The powder was then added with the addition of 16 kg of aqueous silica sol a silicon dioxide content of 20 wt .-%, produced according to Example 2, in 160 l of water suspended and poured into an open stirred kettle. For this The suspension was stirred with the help of a large container  Peristaltic pump removed and in a spray drying system (from Niro) dried to a fine, intimately mixed powder.

An atomizer disk was used to disperse the suspension Ceramic sleeves (speed 17000 U / min) used. The drying took place at an air inlet temperature of 260 ° C and an air outlet temperature of 110 ° C.

The product was separated from the air flow in a cyclone. The yield was 13 kg.

Comparative Example 1 Deformation of titanium silicalite (catalyst A)

Catalyst A was made by mixing 1665 g of one Spray powder, consisting of 89 wt .-% of a catalyst, prepared according to Example 1, and 11 wt .-% silicon dioxide, with 416 g of a silica sol Silicon dioxide content of approx. 50% by weight (Ludox-TM, from DuPont).

The spray powder mentioned was prepared like that described in Example 4, only that instead of the silica sol produced according to the invention is a commercial one produced silica sol (Ludox AS-40 from DuPont) with one Sodium content of 800 ppm was used.

The mixture was made by adding water and the Extrusion aid methyl cellulose made extrudable and too Extruded strands 1.5 mm in diameter.

These strands were dried at 120 ° C. and annealed at 500 ° C. for 5 hours. The The content of silicon dioxide binder in the shaped body was 20% by weight Sodium content 700 ppm.  

Comparative Example 2 Deformation of titanium silicalite (catalyst B)

Catalyst B was made by mixing 3000 g of one Spray powder, consisting of 78 wt .-% of a catalyst, prepared according to Example 1, and 22 wt .-% silicon dioxide, with 750 g of a silica sol Silicon dioxide content of approx. 43% by weight (Ludox AS-40 from DuPont).

The spray powder mentioned was prepared like that described in Example 4, only that instead of the silica sol produced according to the invention is a commercial one produced silica sol (Ludox AS-40 from DuPont) with one Sodium content of 800 ppm was used.

The mixture was made by adding water and the Extrusion aid methyl cellulose made extrudable and too Extruded strands of 2.5 mm in diameter.

These strands were dried at 120 ° C. and annealed at 500 ° C. for 5 hours. The The content of silicon dioxide binder in the shaped body was 30% by weight Sodium content 910 ppm. The side compressive strength of the strands was 37.9 N, that Cutting hardness 10.25 N.

Comparative Example 3 Deformation of titanium silicalite (catalyst C)

Catalyst C was prepared by crushing 7500 g of one Spray powder, consisting of 78 wt .-% of a catalyst, prepared according to Example 1, and 22 wt .-% silicon dioxide, with 4300 g of a silica sol Silicon dioxide content of approx. 43% by weight (Ludox AS-40 from DuPont).  

The spray powder mentioned was prepared like that described in Example 4, only that instead of the silica sol produced according to the invention is a commercial one produced silica sol (Ludox AS-40 from DuPont) with one Sodium content of 800 ppm was used.

The mixture was made by adding water and the Extrusion aid methyl cellulose made extrudable and too Extruded strands 1.5 mm in diameter.

These strands were dried at 120 ° C. and annealed at 500 ° C. for 5 hours. The The content of silicon dioxide binder in the shaped body was 30% by weight Sodium content 900 ppm.

Example 6 Deformation of titanium silicalite: (catalyst D)

Catalyst D was made by mixing 2200 g of one Spray powder, consisting of 75 wt .-% of a catalyst, prepared according to Example 1, and 25 wt .-% silicon dioxide, with 1037 g of a silica sol a silicon dioxide content of approx. 21% by weight, produced according to Example 2. The spray powder mentioned was prepared analogously to Example 4.

The mixture was made by adding water and the Extrusion aid methyl cellulose made extrudable and too Extruded strands 1.5 mm in diameter.

These strands were dried at 120 ° C. and annealed at 500 ° C. for 5 hours. The The content of silicon dioxide binder in the shaped body was 32% by weight Sodium content 400 ppm.  

Example 7 Deformation of titanium silicalite: (catalyst E)

Catalyst E was prepared by milling 9,700 g of one Spray powder, consisting of 75 wt .-% of a catalyst, prepared according to Example 1, and 25 wt .-% silicon dioxide, with 13000 g of a silica sol a silicon dioxide content of approx. 19% by weight, produced according to Example 2.

The spray powder mentioned was prepared analogously to Example 4.

The mixture was made by adding water and the Extrusion aid methyl cellulose made extrudable and too Strands of 1.5 mm diameter extruded.

These strands were dried at 120 ° C. and annealed at 500 ° C. for 5 hours. The The content of silicon dioxide binder in the shaped body was 40% by weight Sodium content 420 ppm.

Example 8 Deformation of titanium silicalite: (catalyst F)

Catalyst F was made by grinding 8000 g of one Spray powder, consisting of 70 wt .-% of a catalyst, prepared according to Example 1, and 30 wt .-% silicon dioxide, with 4000 g of a silica sol a silicon dioxide content of approx. 19% by weight, produced according to Example 2.

The spray powder mentioned was prepared analogously to Example 4.

The mixture was made by adding water and the Extrusion aid methyl cellulose made extrudable and too Extruded strands 1.5 mm in diameter.  

These strands were dried at 120 ° C. and annealed at 500 ° C. for 5 hours. The The content of silicon dioxide binder in the shaped body was 40% by weight Sodium content 400 ppm. The cutting hardness was 2 N and the Side compressive strength 19 N.

Example 9 Compression and deformation of titanium silicalite (catalyst G)

3.5 kg of TS-1, produced according to Example 1, were in a 1.23 kg pan Aerosil® (DEGUSSA), 6.26 kg of silica sol, produced according to Example 2, and 237 g of methyl cellulose (Walocel®) compacted in a time of 60 min.

Then 48 g of polyethylene glycol (ALKOX-E160®) were added, which Mixture compressed for a further 30 min, 96 g polyethylene glycol (ALKOX-E160®) and 450 g of demineralized water are added and the mixture is again 15 min condensed.

The deformable mass was extruded to 1.5 mm Round strands deformed. The extrusion pressure was 85 to 100 bar, the Squeeze time 15 min. These strands were dried at 120 ° C and at 500 ° C calcined in air for 5 h.

The yield was 5.1 kg. The content of silicon dioxide binder in the Shaped body was 40 wt .-%, the sodium content 500 ppm, the Side compressive strength 17 N and the macro pore volume 0.70 g / ml, determined by mercury porosimetry according to DIN 66133.  

Example 10 Catalytic test series (batch operation)

Each was placed in a steel autoclave with a basket insert and gassing stirrer so many grams of catalyst A to 6 installed that the mass built-in titanium silicalite is 0.5 g each.

The autoclave was filled with 100 g of methanol, sealed and placed on it Tightness checked. The autoclave was then heated to 40 ° C and 11 g of liquid propene are metered into the autoclave.

Now, using an HPLC pump, 9.0 g of a 30% by weight aqueous Hydrogen peroxide solution pumped into the autoclave and the Hydrogen peroxide residues in the feed lines then with 16 ml of methanol rinsed in the autoclave. The initial content of the reaction solution Hydrogen peroxide was 2.5% by weight.

After a reaction time of 2 hours, the autoclave was cooled and let down. The Liquid discharge was examined cerimetrically for hydrogen peroxide. The Analysis and determination of the discharge content of propylene oxide was carried out by gas chromatography.

The table below shows the results of the analysis summarized.  

Table: for example 10 (catalytic test series)

Example 11 Catalytic test (continuous operation)

Through a tubular reactor filled with 28.1 g of the catalyst according to the invention F were flows of 24 hydrogen peroxide (40 wt%) / h, 57 methanol / h and 11.7 ml / h at a reaction temperature of 40 ° C and a pressure of 20 bar passed.

After leaving the reactor, the reaction mixture was in a Sambay Evaporator relaxed against atmospheric pressure. The separated low boilers were analyzed online in a gas chromatograph. The liquid Reaction discharge was collected, weighed and also analyzed by gas chromatography.

The total reaction time was 550 h. During this time the Hydrogen peroxide conversion at well over 90%. The selectivity of Hydrogen peroxide to propylene oxide was also included throughout the period much more than 90%.  

Example 12 Catalytic test (continuous operation)

Through a tubular reactor filled with 20 g of the catalyst according to the invention G, were flows of 9 g hydrogen peroxide (40 wt%) / h, 49 g methanol / h and 8 g propene / h at a reaction temperature of 40 ° C and a pressure headed by 20 bar.

After leaving the reactor, the reaction mixture was in a Sambay Evaporator relaxed against atmospheric pressure. The separated low boilers were analyzed online in a gas chromatograph. The liquid Reaction discharge was collected, weighed and also analyzed by gas chromatography.

The total reaction time was 850 h. During this time the Hydrogen peroxide conversion at well over 90%. The selectivity of Hydrogen peroxide to propylene oxide was also included throughout the period much more than 90%.

Claims (15)

1. A process for producing a shaped body comprising at least one porous oxidic material and at least one metal oxide, which comprises the following step (i):

• a) mixing the at least one porous oxidic material with at least one metal oxide sol which has a low content of alkali and alkaline earth metal ions, and / or at least one metal oxide which has a low content of alkali and alkaline earth metal ions.

2. The method according to claim 1, characterized in that the at least a metal oxide sol is produced by hydrolysis of at least one Metallic acid ester. 3. The method according to claim 2, characterized in that the at least a metallic acid ester is an orthosilicic acid ester. 4. The method according to any one of claims 1 to 3, characterized in that the porous oxidic material is a zeolite. 5. The method according to any one of claims 1 to 4, which additionally comprises one or more of the following steps (ii) to (v):

• a) compressing the mixture from stage (i),
• b) deforming the mass from stage (ii),
• c) drying the shaped bodies from stage (iii),
• d) calcining the dried moldings from stage (iv).

6. Shaped body comprising at least one porous oxidic material and at least one metal oxide, which can be produced by a process which comprises the following step (i):

• a) Mixing the at least one porous oxidic material with at least one metal oxide sol that has a low content of alkali and alkaline earth metal ions and / or a metal oxide that has a low content of alkali and alkaline earth metal ions.

7. Shaped body according to claim 6, characterized in that the content of (Earth) alkali metal ions is less than 700 ppm. 8. Use of a manufactured according to one of claims 1 to 5 Shaped body or a shaped body according to claim 6 or 7 or egg A mixture of two or more of them as a catalyst. 9. Metal oxide sol containing less than (earth) alkali metal ions than 800 ppm, producible by hydrolysis of at least one metal acid esters. 10. Use of a metal oxide sol according to claim 9 as a binder for Production of moldings of high chemical and mechanical Fe consistency.   11. A process for the preparation of at least one alkene oxide which comprises the following step (III):

• A) reacting at least one alkene with hydrogen peroxide over a catalyst,

characterized in that a shaped body produced by a process according to one of claims 1 to 5 or a shaped body according to one of claims 6 or 7 is used as the catalyst. 12. The method of claim 11, comprising the additional step (I):

• A) Preparation of the at least one alkene reacted in step (III) by dehydrogenating at least one alkane.

13. The method according to claim 11 or 12, comprising the following step (II):

• A) converting the hydrogen formed in step (I) to hydrogen peroxide,

wherein the hydrogen peroxide is used for the reaction in step (III). 14. A process for producing an alkene oxide comprising steps (A) to (C):

• A) dehydrogenation of an alkane to an avenue to obtain hydrogen,
• B) converting the hydrogen obtained in (A) to hydrogen peroxide,
• C) reaction of the hydrogen peroxide from (B) with the avenue from (A) to obtain the alkene oxide,

characterized in that a shaped body produced by a process according to one of claims 1 to 5 or a shaped body according to one of claims 6 or 7 is used as the catalyst. 15. Use of polyalkylene glycols in the production of titansili shaped bodies containing potassium.