MXPA00005672A - Moulded body comprising an inert support and at least one porous oxidic material - Google Patents

Abstract

The invention relates to a moulded body comprising an inert support and at least one porous oxidic material applied to said support. The inventive moulded body is obtained by applying a mixture containing the at least one porous oxidic material and at least one metal acid ester or a hydrolyzate thereof or a combination of metal acid esters and hydrolyzate thereof to the inert support.

Description

MOLDED BODY CONSISTING OF AN INERT SUPPORT AND WHEN LESS A POROUS OXIDIC MATERIAL The present invention relates to a molded or formed body consisting of an inert support and at least one porous oxidic material applied thereto, to a process for its production and its use for the conversion of organic compounds, in particular for the epoxidation of compounds organic having at least one CC double bond. The formed body described herein has excellent abrasion resistance and excellent mechanical properties and is economical in comparison to the catalysts used for these purposes up to now.

Abrasion-resistant molded bodies containing catalytically active materials are used in many chemical processes, in particular in processes using a fixed bed.

For the production of solids, a binder, an organic viscosity-improving compound and a liquid for converting the material into a paste are generally added to the catalytically active material, ie the porous oxidic material, and the mixture is compacted in a mixing or kneading apparatus or an extruder. The resulting plastically deformable material is then molded or formed, in particular using an extruder, and the resulting molded bodies are dried and calcined.

Various inorganic compounds are used as binders.

For example, according to US-A 5,430,000, titanium dioxide or titanium dioxide hydrate is used as binders. Examples of other binders of the prior art are: hydrated aluminum oxide or other aluminum-containing binders (WO 94/29408); mixtures of silicon and aluminum compounds (WO 94/13584); silicon compounds (EP-A 0 592 050); clay minerals (JP-A 03 037 156); alkoxysilanes (EP-B 0 102 544).

Another relevant prior art is reviewed in DE 197 23 751. 7 In conversions that exhibit very high intrinsic reaction rates, the performance that can be achieved is technically limited by the diffusion of the initial materials or products in the formed body. In these cases, only the surface layer of the formed body is used for the conversion, while the rest of the formed body is only the support for this surface layer. It will be appreciated that this is economically prohibitive in the case of a catalytically active, expensive material. Therefore, in this case, a supported or coated catalyst is used in the form of a formed body. This catalyst contains an inert core and a surface layer of the catalytically active material.

Catalysts of this type are also prepared using zeolites as the active components. For example, JP 07,241,471 describes the application of the zeolite powder to a support by suspending the zeolite in combination with an inorganic binder in water and organic emulsifiers and the subsequent thin coating on the support. These catalysts are proposed for purification of residual gases. A similar procedure is described in JP 07,155,613, where zeolites and silica sol are suspended in water to form a thin coating suspension that is applied to a monolithic cordierite support. In the same way, JP 02,111,438 describes the application of zeolites to monolithic supports using aluminum sol as binder. This catalyst is used for waste gas purification as well. US 4,692,423 describes the application of zeolites to porous supports first by mixing the zeolite with cyclic oxides which are unstable with respect to the polymerization, coating the surface of the porous support with this suspension and subsequently removing the solvent. US 4,283,583 describes catalysts where a zeolite has been supported on spherical supports from 0.5 to 10 mm in diameter.

It is true that the adhesion of the active component on the support is important for gas phase processes such as the purification of waste gases, but the forces acting on the layer supported in a gaseous phase process are much less abrasive than in a liquid phase process, for example. In the latter case, there are much more requirements on the adhesion of the supported layer. The anchoring of the active material in the inert carrier can be destabilized especially by the permanent presence of liquid or solvent. JP 08,103,659 describes a use for a liquid phase process. In this, titanium silicalite is applied to spheres of 0.2 20 mm in diameter. For this purpose, the titanium silicalite is suspended in an aqueous solution of polyvinyl alcohol and sprayed on the sphere. The sprayed sphere is then calcined to obtain the ready-to-use catalyst which is then used in the epoxidation of propylene with hydrogen peroxide. However, the catalyst generated in this way still exhibits significant abrasion of the active component.

US 5,523,426 describes a form for epoxidizing propylene on titanium silicalite catalysts where titanium silicalite can be applied on inert carriers, inter alia. The procedure of the application is not described in detail.

As can be seen from the prior art, there is a problem that the catalysts used so far are not suitable for use as supported finger abrasion-resistant catalysts where the adhesion of the active component is usually insufficient for these purposes. In addition, a limitation to spherical support bodies is often not sensitive for reasons of fluid dynamics.

Thus, an object of the present invention is to develop a process that makes it possible to apply a zeolite and in particular titanium silicalite in supports of any form, preferably non-monolithic supports, in an abrasion resistant form to obtain catalysts that can be used in chemical processes, in particular in liquid phase processes, and providing such catalysts per se.

We have now found, surprisingly, that this objective is achieved by applying a mixture containing at least one porous oxidic material and at least one metal acid ester or hydrolyzate thereof, or a combination of the metal acid ester and hydrolyzed on a support Inert to obtain a formed body that can be used in liquid phase processes without problems.

Accordingly, the present invention provides a body formed containing an inert support and at least one porous oxidic material applied thereto and which can be obtained by applying a mixture containing at least one porous oxidic material and at least one metal acid ester or a hydrolyzate thereof, or a combination of the metal acid ester and hydrolyzate thereof to an inert support, and a process for the preparation of such formed bodies, which consists in applying a mixture containing at least one porous oxidic material and at least one ester of metallic acid or a hydrolyzate thereof, or a combination of the ester. of metallic acid and the hydrolyzate thereof to an inert support.

The inert supports which may be used, according to the invention, may consist of oxides, carbides, nitrides or other inorganic or organic materials, provided that these do not decompose, melt or otherwise become unstable at the required temperatures. in the preparation processes.

For the purposes of the present invention, "inert" means that the materials used as support have negligible catalytic activity, if any.

The preferred inert carriers used are metal oxides or combined oxides of metals of transition groups III to VIII and major groups III to V of the Periodic Table of the Elements, in combinations of two or more thereof, in particular dioxide silicon, aluminum oxide, titanium dioxide, zirconium dioxide and mixed oxides thereof.

It is also possible to use metals or metal alloys such as steel, aluminum, aluminum, etc., as materials for inert support.

The inert support preferably has an alkali metal or alkaline earth metal content of < 10QD ppm, preferably < 100 ppm, in particular < 10 ppm. The low contents of the alkali metal or the alkaline earth metal of the support are of particular importance when the catalyst of the invention is used for the epoxidation, especially with a titanium silicalite as a porous oxidic material.

The external shape of the inert support or formed body is not crucial and can be selected without restriction depending on the fluid dynamics of the specific reactor chosen for the reaction. The inert support or the formed body can be in the form of extrudates, such as circular extruded, extruded star-shaped, hollow extruded and cylinders, granules, tablets, annular tablets, spherical, non-spherical or spherulitic granules, as a monolith , or in the form of a band-like structure or structure having hollows, for example, in the form of a mesh or fabric, in a pyramidal form or as a wagon wheel profile.

The support or body formed preferably is in the form of non-spherical granulate, an extrudate, a granule, a tablet, a band-like structure or a structure having recesses.

It is also possible to apply the porous oxidic material directly to the reactor wall. In the case of exothermic reactions, this is still beneficial to eliminate heat.

There are no specific limitations with respect to the porous oxidic materials that can be used for the production of the novel shaped body, as long as it is possible to prepare a body formed as described herein starting from these materials and these materials with the activity catalytic not necessary.

The porous oxidic material is preferably a zeolite, particularly preferably a zeolite containing titanium, zirconium, chromium, niobium, iron or vanadium, in particular a titanium silicalite.

Zeolites are known as crystalline aluminosilicates having ordered channels and cage structures having micropores. The term "micropores" as used in the present invention corresponds to the definition provided in Pure Appl. Chem. 4J5 (1976), p. 71ff., In particular p. 79, and refers to pores with a diameter less than 2 nm. The network of these zeolites is composed of tetrahedral Si0 and A10 that are linked by common oxygen bridges. An overview of the known structures is provided in, for example, W. M. Meier and D.H. Olson in "Atlas of Zeolite Structure Tupes", Elsevier, 4th edition, London, 1996.

In addition, there are zeolites that do not contain aluminum and in which some of the Si (IV) has been replaced by titanium as Ti (IV) in the silicate lattice. Titanium zeolites, in particular those having a crystalline structure of the MFI type, and possibilities for their preparation are described, for example, in EP-A 0 311 983 or EP-A 0 405 978. In addition to silicon and titanium, these Materials may contain additional elements, such as aluminum, zirconium, tin, iron, cobalt, nickel, gallium, boron or small amounts of fluorine.

Some or all of the titanium in the described zeolites can be replaced by vanadium, zirconium, chromium, niobium or iron. 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 from 0.001: 1 to 0.1: 1.

It is known that titanium zeolites having the MFI structure can be identified from a particular pattern in their X-ray diffraction patterns and, in addition, by a skeletal infrared (IR) vibration band at approximately 960 cm-1. , and thus they differ from alkali metal titanates or crystalline and amorphous Ti02 phases.

Titanium, zirconium, chromium, niobium, iron and vanadium zeolites are usually prepared by reacting an aqueous mixture of a SiO2 source, a source of titanium, zirconium, chromium, niobium, iron or vanadium, eg, dioxide. of titanium or a vanadium oxide, zirconium alkoxide, chromium oxide, niobium oxide or suitable iron oxide and of a nitrogen-based organic base template, for example, tetrapropylammonium hydroxide, with or without added basic compounds, in a pressure vessel at elevated temperature for a few hours or a few days, giving rise to a crystalline product. The crystalline product is filtered, washed, dried and baked at high temperature to eliminate the nitrogenous or organic base. In the resulting powder, titanium or zirconium, chromium, niobium, iron and / or vanadium is present at least partially within the structure of the zeolite in different proportions - in quadruple, quintuple or sextuple coordination. To improve the catalytic characteristics it is also possible to carry out a subsequent treatment by repeatedly washing with a hydrogen peroxide solution containing sulfuric acid, after which the zeolite powder of titanium, zirconium, chromium, niobium, iron or vanadium must be again dried and baked; this can be followed by a treatment with alkali metal compounds to convert the zeolite from the H form into the cationic form. The resultant titanium, zirconium, niobium, iron or vanadium zeolite powder is then processed in a body formed as described below.

Preferred zeolites are titanium, zirconium, chromium, niobium or vanadium zeolites, the most preferred zeolites are those having a pentasyl zeolite structure, especially the types with X-ray assignment for a BEA, MOR, TON, MTW, FER structure. , MFI, MEL, CHA, ERI, RHO, GIS, BOG, NON, EMT, HEU, KFI, FAU, DDR, MTT, LTL, MAZ, GME, NES, OFF, SGT, EUO, MFS, MCM-22, or the combined structure MFI / MEL. "" Zeolites of this type are described, for example, in the reference of Meier and Olson above. Also possible for the present invention are zeolites containing titanium and with a structure of UTD-1, CIT-1, or CIT-5. Such zeolites are described, inter alia, in US-A 5,430,000 and WO 94/29408, the relevant contents of which are fully incorporated herein by reference. There are no special restrictions on the pore structure of the formed bodies of the invention, that is, the body formed according to the invention can have micropores, mesopores, macropores, micro and esophores, micro and macropores or micro, meso and macropores, The definition of "mesopores" and "macropores" also corresponds to the definition provided in Puré Appl. Chem., Reference which has already been provided and which refers to the pores having a diameter of > 2 nm to 50 nm or > 50 nm, respectively.

In addition, the formed body of the invention can be an oxide-based material containing mesoporous silicon and a silica-containing xerogel. The mesoporous oxides containing silicon which also contain Ti, V, Zr, Sn, Cr, Nb or Fe, in particular Ti, V, Zr, Sn, Cr, Nb or a mixture of two or more thereof, are particularly preferred.

To obtain a shaped body having the desired abrasion resistance, the porous oxidic material described in detail in the foregoing always applies to the inert support in admixture with at least one metal acid ester or a hydrolyzate thereof, or a combination of when minus one metal acid ester and a hydrolyzate thereof (hereinafter often referred to as the metal acid ester (hydrolyzate)). The metals of the metal acid esters can be selected from the main groups III to IV and the transition groups III to VI of the Periodic Table of the Elements. It is also possible to use partial hydrolysates thereof.

Particular examples of these are orthosilicates, alkoxysilanes, tetraalkoxytitanates, trialkoxyaluminates, trialkoxynotates, tetraalkoxy zirconates or a mixture of two or more thereof. However, the particularly preferred metal acid esters used in the present invention are tetraalkoxysilanes. Specific examples are tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane and tetrabutoxy silane, the corresponding tetralkoxytitanium and tetralkoxyzirconium compounds and trimethoxy-, triethoxy-, tripropoxy-, triisopropoxy-, tributoxyaluminium and triisobutoxyaluminum, with tetramethoxysilane and tetraethoxysilane being especially preferred.

According to the invention, the content of metal oxide coming from the metal acid ester or the hydrolyzate thereof is preferably up to about 80% by weight, more preferably from about 1 to about 50% by weight, in particular from about 3 to about 30% by weight, based on the amount of the porous oxide.

The content of the applied mixture is generally from about 1 to about 80% by weight, preferably from about 1 to about 50% by weight, in particular from about 3 to about 30% by weight, in each case based on the amount total of the mixture and the inert support.

As can be seen from the foregoing, it is, of course, also possible to use mixtures of two or more of the aforementioned binders.

There are no particular restrictions with respect to the application of the mixture to the inert support. The application can be made by ± impregnation, spraying or runoff. Some preferred application methods will now be described in more detail.

To apply at least one porous Oxic material, the latter is suspended in a liquid, in the form of a powder or granules, and applied. It is also possible to feed the porous oxidic material in the form of a powder or granules and the liquid required for the adhesion of the porous oxidic material on the inert support at the same time. The oxidic material to be applied preferably is suspended in the liquid and sprayed onto the support.

In one embodiment, the metal acid ester (hydrolyzate) used according to the invention is mixed with the porous oxidic material having the form of a powder or granules. The resulting mixture is then drained onto the inert support which is sprayed with an adhesion liquid at the same time. In this case, preference is given to the use of hydrolysates of the metal acid esters.

In another embodiment of the invention, the metal acid ester (hydrolyzate) is mixed with the adhesion liquid to obtain a mixture which is then applied to the support inert at the same time with the porous oxidic material having the form of a powder or granules. In another embodiment, the metal acid ester (hydrolyzate) is suspended in the adhesion promoting liquid together with the porous oxidic material to obtain a slurry which is sprayed onto the inert support.

The alcohol used in the above preferred mixture corresponds to the alcohol component of the metal acid ester used or hydrolyzate thereof, but it is also not crucial to use another alcohol.

A particularly rapid adhesion of the mixture can be achieved by impregnating the inert support with acidic substances, such as organic or inorganic acids, for example, nitric acid, sulfuric acid, hydrochloric acid, acetic acid, oxalic acid or phosphoric acid.

The mixture to be applied to the inert support may contain other additives, such as viscosity improving, organic and other additives as defined below.

The liquids that favor adhesion include water, different kinds of organic liquids such as alcohols, thiols, polyols, ketones, acids, amines, hydrocarbons and mixtures of two or more of them. If these liquids are used to suspend the porous oxidic material, preference is given to the use of volatilizable liquids at the spray temperatures from about 30 to about 200EC, [sic], preferably from about 50 to about 150EC, [sic], particularly from about 60 to about 120EC, [sic]. If these liquids are added, as adhesion promoters, separately from porous oxidic material, but at the same time, a liquid having a boiling point which is considerably higher than the aforementioned temperatures will be chosen.

In a preferred embodiment, the porous oxidic material is suspended in alcohols, such as methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, tert-butanol and mixtures of two or more thereof. Particular preference is given to the use of a mixture of an alcohol, preferably one of the aforementioned alcohols, with water. Such a mixture generally consists of from about 1 to about 80% by weight, preferably from about 5 to about 70% by weight, in particular from about 10 to about 60% by weight, in each case based on the total weight of the mixture. the mixture of alcohol and water.

High boiling liquids are those that have a boiling point at atmospheric pressure of more than 150EC. Preferred high-boiling liquids are propanediol, glycerol, ethanediol, polyether, polyester, dipropylene glycol, or mixtures of two or more thereof.

The organic substance used in the viscosity used can likewise be any of the substances of the prior art suitable for this purpose. Those preferred are organic, in particular hydrophilic, polymers, for example, cellulose, starch, polyacrylates, polymethacrylates, polyvinyl alcohol, polyvinylpyrrolidone, polyisobutene and polytetrahydrofuran. These substances mainly favor the adhesion of the porous oxidic material to the support in the uncalcined state.

Amines or amine-type compounds, for example, tetraalkylammonium compounds or aminoalcohols and carbonate-containing substances, such as calcium carbonate, can be used, as other additives. These other additives are described in EP-A 0 389 041, EP-A 200 260 and WO 95/19222, the relevant contents of which are fully incorporated herein by reference.

The formed body obtained by applying the mixture containing the porous oxidic material to the inert support can be subjected to a calcination step. This calcination step can be superfluous when the formed body is used as a catalyst in a reaction carried out at high temperatures and in the presence of oxygen. In this case, the calcination is carried out in situ in the reactor.

This applies in particular when the novel mixture of the porous oxidic material and the metal oxide ester (hydrolyzate) is applied directly to the reactor wall and then a reaction is carried out at a high temperature.

Otherwise, the formed bodies are calcined. By this treatment, the formed bodies are provided with the desired hardness and abrasion resistance. Calcination is generally carried out from about 200EC to IOOEC, preferably from 250EC to 900EC, particularly preferably from about 300EC to about 800EC, preferably in the presence of an oxygen-containing gas.

The shaped bodies are preferably dried from about 50 to about 200EC, preferably from about 80 to about 150EC, before calcination.

The bodies formed according to the invention or produced by a process according to the invention have very good catalytic activity and excellent resistance to mechanical abrasion and thus are suitable for use in liquid phase reactions.

The novel shaped bodies have almost no finer particles than those with a minimum particle diameter of about 0.1 nm.

The bodies formed according to the invention or produced according to the invention and containing a porous oxidic material have better mechanical stability and at the same time retain their activity and selectivity in comparison with the corresponding formed bodies of the prior art.

The bodies formed according to the invention or produced according to the invention can be used for the catalytic conversion of organic molecules. Reactions of this type are, for example, oxidations, the epoxidation of olefins, for example, the preparation of propylene oxide from propylene and H202, the hydroxylation of aromatics, for example, phenol from benzene and H202 and hydroquinone. starting from phenol H202, the conversion of alkanes into alcohols, aldehydes and acids, isolating reactions, for example the conversion of epoxides into aldehydes and other reactions described in the literature using such shaped bodies, in particular catalysts of particular zeolites, such as it is described, for example, in W. Holdrich, Zeolites: Catalysts for the Synthesis or Organic Compounds, Elsevier, Stud. Surfing. Sci. Catal., 4_9, Amsterdam 81989), 69-93, and in particular, for possible oxidation reactions, by B. Notari in Stud. Surfing. Sci. Catal., 37 (1987) 413-425. The shaped bodies described in detail in the foregoing are particularly suitable for the epoxidation of olefins, preferably those of 2 to 8 carbon atoms, particularly preferably ethylene, propylene or butene, in particular propene, to obtain the corresponding olefinic oxides. Accordingly, the present invention relates in particular to the use of shaped bodies described herein for the preparation of propylene oxide starting from propylene and hydrogen peroxide as described, for example, in EP-A 0 100 119.

EXAMPLES Preparation example 1 910 g of tetraethyl orthosilicate were initially taken in a four-necked flask, 4 liters, and 15 g of tetraisopropyl orthotitanate were added from a dropping funnel over the course of 30 minutes with stirring (250 rpm, stirrer). palette) . A colorless, transparent mixture formed. 1600 g of a solution at 20% concentration by weight of tetrapropylammonium hydroxide (alkali metal content <10 ppm) were then added and stirring continued for another hour. The alcohol mixture (approximately 900 g) formed from the hydrolysis was distilled from 90 to 100 ° C. The mixture was prepared with 3 1 of water and the slightly opaque sol was transferred to a 5 liter stainless steel stirring autoclave. The closed autoclave (anchor agitator) of 200 rpm) was brought to a reaction temperature of 175 ° C, at a heating rate of 3EC / min. The reaction was complete after 92 hours. The cooled reaction mixture (white suspension) was centrifuged and the pellet was washed several times with water until neutral. The solid obtained was dried to IIOEC over the course of 24 hours (weight obtained 298 g).

The template remaining in the zeolite was then calcined under air at 550EC in 5 hours (loss by calcination: 14% by weight).

According to the wet chemical analysis, the pure white product had a Ti content of 1.3% by weight and a residual alkali content of less than 100 ppm. The yield was 97%, based on the Si02 used. The crystallites had a size from 0.05 to 0.25 μ and the product showed a common band of approximately 960 cm "1 in the IR spectrum.

Comparative example 1 120 g of titanium silicalite powder, synthesized according to Preparation Example 1, were mixed with 48 g of tetramethoxysilane for 2 hours in a kneader. 6 g of Walocel (methylcellulose) were then added. For conversion into a paste, 77 ml of a water / methanol mixture containing 25% by weight of methanol were then added. The material obtained was compacted for another 2 hours in a kneader and then formed in an extruder to obtain 1 mm granules. The extrudates thus obtained were dried at 120 ° C for 16 hours and then calcined at 500 ° C for 5 hours. The epoxidation characteristics of the catalyst VI thus obtained were evaluated in epoxidation experiments.

Comparative Example 2, 120 g of titanium silicalite powder, synthesized according to Preparation Example 1, were mixed with 48 g of tetramethoxysilane for 2 hours in a kneader. 6 g of Walocel (methylcellulose) were then added. For conversion into a paste, 77 ml of a water / methanol mixture containing 25% by weight of methanol were then added. The material obtained was compacted for another 2 hours in the kneader and then formed in an extruder to obtain 3 mm extrudates. The extrudates thus obtained were dried at 120 ° C for 16 h and then calcined at 500 ° C for 5 hours. The epoxidation characteristics of the V2 catalyst thus obtained were evaluated in epoxidation experiments.

Preparation Example 2 _ _ 2500 g of Aerosil 200 obtained from Degussa were compacted together with 150 g of ammonia solution (30%) 100 g of potato starch and 300 g of water in a kneader and then formed in an extruder for get 2mm extruded. The extrudates thus obtained were dried to IIOEC and then calcined at 500EC for 6 hours. The extrudates thus obtained had an alkali metal content of 40 ppm. Half of the extrudates were processed in 1-1.6 mm granules for the following examples.

Example 1 10 g of titanium silicalite powder obtained in Preparation Example 1 (particle sizes <0.1 mm) were suspended in 100 g of methanol and 4 g of tetramethoxysilane. 100 g of the Aerosil granules obtained in Preparation Example 2 were initially taken in a heated splash plate. The suspension of the titanium silicalite in methanol / tetramethoxysilane was sprayed slowly while the splash plate was rotated stably. The granules thus obtained were dried at 120 ° C, screened and calcined at 500 ° C for 5 hours. Approximately 7 g of the TS-1 powder was recovered by the screening procedure after drying. The calcination gave shaped bodies resistant to abrasion suitable for reactions in liquid phase. The formed body contained 2% by weight of Ti silicalite, determined by atomic emission spectroscopy. The epoxidation characteristics of catalyst A thus obtained were evaluated in epoxidation experiments.

Example 2 10 g of titanium silicalite powder obtained in Preparation Example 1 (particle sizes <0.1 mm) were suspended in 100 g of methanol and 4 g of tetramethoxysilane. 100 g of the Aerosil granules obtained in the preparation example 2 were impregnated with acetic acid initially taken in a hotplate, heated. The suspension of the titanium silicalite in methanol / tetramethoxysilane was sprayed by steadily and slowly rotating the splash plate. The granules thus obtained were dried at 120EC, briefly sifted and calcined at 500EC for 5 hours. Approximately 2 g of the TS-1 powder was recovered by the screening procedure after drying. The calcination produced shaped bodies resistant to abrasion suitable for liquid phase reactions. The formed body contained 5% by weight of Ti silicalite, determined by atomic emission spectroscopy. The impregnation of the bodies formed with acetic acid provided better adhesion of the TS-1 during the spraying. The epoxidation characteristics of catalyst B thus obtained were evaluated in epoxidation experiments.

Example 3 20 g of titanium silicalite powder obtained in Preparation Example 1 (particle sizes <0.1 mm) were suspended in 300 g of methanol and 8 g of tetramethoxysilane. 100 g of Aerosil extrudates obtained in Preparation Example 2 were impregnated with acetic acid and initially taken in a splash plate, heated. The suspension of the titanium silicalite in methanol / tetramethoxysilane was slowly sprayed while the splash plate was continuously turned. The extrudates thus obtained were dried at 120 ° C, briefly screened and calcined at 500 ° C for 5 hours. Approximately 3 g of the TS-1 powder was recovered by the sieving procedure after drying. The calcination produced shaped bodies resistant to abrasion suitable for liquid phase reactions. The formed body contained 8.5% by weight of Ti silicalite, determined by atomic emission spectroscopy. The epoxidation characteristics of catalyst C thus obtained were evaluated in epoxidation experiments.

Comparative Example 3 10 g of titanium silicalite powder obtained in Preparation Example 1 (particle sizes <0.1 mm) were suspended in 100 g of methanol and 4 g of tetramethoxysilane. 100 g of silicon dioxide spheres (Siliperl AF-125 obtained from Engelhardt) were initially placed in a hotplate, heated. The suspension of the titanium silicalite in methanol / tetramethoxysilane was sprayed slowly while continuously holding the splash plate. The spheres thus obtained were dried at 120 ° C, briefly screened and calcined at 500 ° C for 5 hours. Approximately 7 g of the TS-1 powder was recovered by the screening procedure after drying. The formed body contained 2% by weight of Ti silicalite, determined by atomic emission spectroscopy, and the alkali metal content was 400 ppm. The epoxidation characteristics of the catalyst V3 thus obtained were evaluated in epoxidation experiments.

Examples 4 to 9 Catalysts A to C and VI to V3 were installed in a steel autoclave with basket insert and gasifier stirrer in the amounts shown in Table 1. The autoclave was filled with 100 g of methanol, closed and revised for leaks. It was then heated to 40 ° C, and 11 g of liquid propene were metered into the autoclave. 9.0 g of an aqueous solution of hydrogen peroxide (hydrogen peroxide content of the solution 30% by weight) were then pumped into the autoclave by means of an HPLC pump, and hydrogen peroxide residues in the feed lines they were then flooded to the autoclave by means of 16 ml of methanol. The initial content of the hydrogen peroxide of the reaction solution was 2.5% by weight. After a reaction time of 2 hours, the autoclave was cooled and depressurized. The liquid efflux was investigated by cerimetry for hydrogen peroxide. The analysis and determination of the content of propylene oxide (OP) were carried out by gas chromatography.

The contents of PO and hydrogen peroxide are shown in table 1.

Catalyst VI (TS-1, extruded 1 mm) is significantly more active than catalyst V2 (TS-1, extruded 3 mm). This indicates a poor utilization of the extruded TS-1 having a diameter of 3 mm (V2). The supported catalysts A to C gave a higher yield of PO although a smaller amount of TS-1 was used. Due to its high alkali metal content of 400 ppm, the V3 catalyst shows almost no epoxidation activity. Despite the high mechanical stress in the shaking steel autoclave, the supported catalysts showed no abrasion (no TS-1 in the effluent).

Table 1 Epoxidation of propene in an autoclave, in batches, to obtain propene oxide.

Examples 10 to 13 Currents of 27.5 g / h of hydrogen peroxide (20% by weight), 65 g / h of methanol and 14 g / h of propene were passed through a battery of reactors consisting of two reactors which had a reaction volume of 98 ml each and a downstream tubular reactor having a volume of 13 ml, filled with the amount of the catalysts VI, V2, A and B shown in Table 2 at a reaction temperature of 40EC and a reaction pressure of 20 bar. The reaction mixture left the tubular reactor and was depressurized at atmospheric pressure in a Sambay evaporator. The low-boiling substances removed were analyzed online by gas chromatography. The effluent of the liquid reaction was collected, weighed and also analyzed by gas chromatography.

The conversion of hydrogen peroxide decreased during the 30 h process time from initial 96% and reached the value given in Table 2. The selectivity of the OP, based on hydrogen peroxide, was always greater than 95%.

Table 2 Continuous epoxidation of propene with hydrogen peroxide to obtain propylene oxide.

In this process, the supported TS-1 catalysts are also significantly more active than the catalysts used in the form of an unsupported (extruded) catalyst, based on the amount of TS-1 used.

Despite the high mechanical stress in the stirred reactors, the catalysts showed no abrasion (no TS-1 in the effluent) in the experiments.

Claims (1)

1. CLAIMS A body formed consisting of an inert support and at least one porous epoxy material applied thereto and obtainable by applying a mixture containing at least one porous oxidic material and at least one metal acid ester or a hydrolyzate thereof, or a combination of the metal acid ester and the hydrolyzate thereof to the inert support, wherein the formed body has micropores, mesopores, micro and mesopores, micro and macropores or micro, meso and macropores. The formed body, as mentioned in claim 1, in the form of non-spherical granules, extruded, granules, tablet, a band-like structure or a structure having holes. The formed body, as mentioned in claim 1 or 2, wherein the porous oxidic material is a zeolite. The formed body, as mentioned in claim 3, wherein the porous oxidic material is a titanium silicalite. The formed body, as mentioned in claim 1 or 4, wherein the metal acid ester is selected from the group consisting of an ortho-skeletal ester, an alkoxysilane, a tetraalkoxytitanate, a trialkoxyaluminate, a tetraalkoxizixconate and a mixture of two or more thereof. A process for the preparation of a body formed as claimed in any of claims 1 to 5, which consists in applying a mixture containing at least one porous oxidic material and at least one metal acid ester or a hydrolyzate thereof, or a combination of the metal acid ester and the hydrolyzate thereof to an inert support. The formed body, as claimed in claim 6, wherein the mixture is applied by spray. The formed body, as claimed in claim 6 or 7, wherein the mixture further comprises at least one alcohol or a mixture of at least one alcohol and water. The use of a body formed as claimed in any of claims 1 to 5 or of a formed body produced by a process as claimed in any of claims 6 to 8, or of a mixture of two or more thereof for epoxidation of organic compounds having at least one CC double bond, for the hydroxylation of aromatic organic compounds, or for the conversion of alkanes to alcohols, ketones, aldehydes and acids. The use of a formed body, as claimed in any of claims 1 to 5 or of a formed body produced by a process as claimed in any of claims 6 to 8 for preparation of propylene oxide starting from propylene and hydrogen peroxide.