WO2000076989A2

WO2000076989A2 - Method for reacting organic compounds with hydrogen peroxide

Info

Publication number: WO2000076989A2
Application number: PCT/EP2000/005319
Authority: WO
Inventors: Joaquim Henrique Teles; Andreas Walch; Norbert Rieber; Gabrielle Iffland
Original assignee: Basf Aktiengesellschaft
Priority date: 1999-06-11
Filing date: 2000-06-08
Publication date: 2000-12-21
Also published as: DE19926725A1; AU5679400A; WO2000076989A3

Abstract

The invention relates to a method for reacting organic compounds with a hydrogen-peroxide solution. The method is characterised in that each concentration of dissolved anions and cations in the hydrogen-peroxide solution which is used, is less than 100 ppm. The invention also relates to methods for reducing the salt concentration in hydrogen-peroxide solutions, to the use of hydrogen-peroxide solutions produced by this method for reacting an organic compound and to an integrated method for producing a hydrogen-peroxide solution, based on a conventional method using anthraquinone, containing one or more stages for reducing the salt concentration.

Description

Process for the implementation of organic compounds with hydrogen peroxide

The invention relates to a process for reacting an organic compound with a hydrogen peroxide solution in the presence of a catalyst containing subgroup metal atoms, the amount of dissolved salts in the reaction mixture being reduced.

The invention further relates to methods for reducing the salt concentration in hydrogen peroxide solutions.

The invention further relates to an integrated method for producing a hydrogen peroxide solution based on a conventional anthraquinone method, which includes one or more steps for reducing the salt concentration.

It is known from the literature that epoxides can be prepared by reacting olefins and hydrogen peroxide in the presence of zeolite catalysts containing titanium atoms (see e.g. EP-A 0 100 1 19).

This reaction always forms by-products that formally result from the addition of water or alcohols to the epoxy (eg diols or their monoethers). In order to suppress these side reactions, the acidity of the catalyst has hitherto either been reduced (for example by pretreatment with basic compounds or by silylation of the surface), or basic, neutral or acid salts have been added to the reaction solution. EP-A 0 230 949 describes, for example, that the number of undesirable by-products resulting from solvolysis in the epoxidation can be considerably reduced by treating the zeolite catalyst containing titanium atoms with suitable acid-neutralizing agents before and / or during the epoxidation reaction. Thus, compounds of the formula X-Si (R) ₃ , with X = CI, Br, I, CH ₃ CON-Si (CH ₃ ) ₃ , CF ₃ COON-Si (CH ₃ ) are suitable for neutralization before the epoxidation reaction ) ₃ , (R) -Si-NH or an imidazolyl group and with R = C alkyl, aryl or C alkaryl.

EP-A 0 230 949 also discloses that the neutralization of the catalyst with water-soluble basic substances can optionally be carried out before and / or during the epoxidation. It is stated here that 0.0001 to 0.1% by weight of such a neutralizing agent is added to the hydrogen peroxide feed in a continuous procedure.

According to EP-A-0 712 852, the selectivity of the titanium silicalite-catalyzed olefin epoxidation can be increased by adding small amounts of non-basic salts, such as LiCl, NaNO ₃ , K SO ₄ and NH ₄ H ₂ PO ₄ . It is stated that the concentration of non-basic salts in the liquid phase of the reaction zone should not be higher than 0.02M, whereas concentrations below 0.0000 IM have little or no effect on the epoxidation selectivity.

According to Clerici et al. (J Catalysis 140, 71-83; 1993), comparatively high concentrations of non-basic salts such as LiCl or NaNO lower the epoxidation rate of certain olefins and also have a disadvantageous effect on the selectivity of the epoxidation. Even higher concentrations of basic salts lead to a strong loss of activity of the TS1 catalyst.

According to EP-A 1-0 757 043, the addition of neutral or acidic salts takes place before or during the titanium silicalite-catalyzed epoxidation of olefins Hydrogen peroxide to reduce by-product formation. In comparison with known processes, in particular basic neutralization according to EP 0 230 949, it is considered advantageous that a variation in the amount of the substance used to treat the catalyst does not have a disadvantageous effect on the catalytic activity of the catalyst in the epoxidation reaction. Example 18 describes a continuous test in which ammonium nitrate (0.1 mol / kg feed = 8000 ppm) is added.

Nowhere in the prior art is it taken into account that commercially available hydrogen peroxide contains salts which have been dissolved from the outset and which are used for the purpose of

Stabilization serve (about 0.01 - 0.025 wt .-% = 100 - 250 ppm = 0.001 -

0.0025 M phosphate and 0.005-0.01 wt% = 50-100 ppm = 0.001-0.002 M.

Nitrate; see. Example 1).

In addition, the methods described in the prior art for increasing the selectivity of epoxidation have various disadvantages. For example, pretreating the catalyst with a basic salt or a silylating agent is complex and must also be repeated regularly. Furthermore, the addition of salts to the reaction mixture causes additional costs. Finally, the salts, and in particular the ammonium salts, form undesired by-products, for example vicinal amino alcohols, by reaction of the free amines which are always present in equilibrium with the epoxide.

Thus, the primary object of the present invention was to provide a method for increasing the selectivity in the reaction of an organic compound with hydrogen peroxide, which does not have the disadvantages of the prior art.

In contrast to the unambiguous teaching contained throughout the prior art, it has now surprisingly been found that an increase selectivity in the reaction of an organic compound with a hydrogen peroxide solution using a catalyst containing subgroup metal atoms without any pretreatment of the catalyst with basic compounds or silylation agents and without the addition of basic, neutral or acidic salts to the reaction solution is possible if the amount of dissolved Salting in the reaction mixture is reduced to a minimum.

Accordingly, the present invention relates to a process for reacting an organic compound with a hydrogen peroxide solution, characterized in that the concentration of dissolved anions and cations in the hydrogen peroxide solution used is in each case less than 100 ppm.

The invention relates in particular to a process in which the reaction of an organic compound takes place in the presence of a catalyst containing secondary group metal atoms.

It has been found that the use of a hydrogen peroxide solution which contains a maximum of 60 ppm phosphate, 30 ppm nitrate, 30 ppm sodium and 5 ppm potassium is particularly advantageous.

An aqueous hydrogen peroxide solution is particularly preferably used in the process according to the invention. The concentration of the aqueous hydrogen peroxide solution preferably used can be between 1 and 70% by weight, a concentration between 5 and 60% by weight is preferred, a concentration between 10 and 50% by weight is particularly preferred.

The following are examples of the reactions which are possible in the process according to the invention: the epoxidation of olefins such as the production of propene oxide from propene and H ₂ O;

Hydroxylations such as the hydroxylation of mono-, bi- or polycyclic aromatics to mono-, di- or higher substituted hydroxy aromatics, for example the conversion of phenol and HO ₂ to hydroquinone;

oxime formation from ketones in the presence of H ₂ O and ammonia (ammonoximation), for example the preparation of cyclohexanone oxime from cyclohexanone;

the Baeyer-Villiger oxidation.

Olefins are preferably reacted in the process according to the invention.

The olefin used can be any organic compound which contains at least one ethylenically unsaturated double bond. It can be aliphatic, aromatic or cycloaliphatic in nature, it can consist of a linear or a branched structure. The olefin preferably contains 2 to 30 carbon atoms. There may be more than one ethylenically unsaturated double bond, for example in dienes or trienes. The olefin can contain additional functional groups such as halogen atoms, carboxyl groups, carboxylic ester functions, hydroxyl groups, ether bridges, sulfide bridges, carbonyl functions, cyano groups or nitro groups.

The following alkenes are mentioned as examples of such organic compounds with at least one C-C double bond:

Ethene, propene, 1-butene, 2-butene, isobutene, butadiene, pentene, piperylene, hexene, hexadiene, heptene, octene, diisobutene, trimethylpentene, nonene, decene,

Undecene, dodecene, tridecene, tetra- to eicosene, tri- and tetrapropene, Polybutadienes, polyisobutenes, isoprene, terpenes, geraniol, linalool, linalyl acetate, methylene cyclopropane, cyclopentene, cyclohexene, norbomene, cycloheptene, vinylcyclohexane, vinyloxirane, vinylcyclohexene, styrene, cyclooctene, cyclooctadiene, methylnorbomenezolodene, dicyclophenylbenzene, dicyclophenylbenzene, dicyclophenylbenzene, dodicyclide, dodicyclophenyl, dodicyclide, dodicyclide, dodicyclide, dodicyclide, dodicyclophenylbenzene, dodecylbenzene, dodecylbenzene, dodecylbenzene, dodecylbenzene, dodecylbenzene, dodecylbenzene, dodecylbenzene, dodecylbenzene, dodecylbenzene, dodecyl benzene cyclododecatriene, stilbene, diphenylbutadiene, vitamin A, beta-carotene, vinylidene fluoride, allyl halides, crotyl chloride, methallyl chloride, dichlorobutene, allyl alcohol, methallyl alcohol, butenols, butenediols, Cyclopentendiole, Pentenole, octadienols, tridecenols, unsaturated steroids, ethoxyethene, isoeugenol, anethole, unsaturated carboxylic acids such as Acrylic acid, methacrylic acid, crotonic acid, maleic acid, vinyl acetic acid, unsaturated fatty acids such as oleic acid, linoleic acid, palmitic acid, naturally occurring fats and oils.

Mixtures of the olefins mentioned can also be epoxidized by the process according to the invention.

Alkenes containing 2 to 8 carbon atoms are preferably used in the process according to the invention. Ethene, propene and butene are particularly preferred. The process according to the invention is particularly suitable for the epoxidation of propene to propylene oxide.

In principle, all heterogeneous catalysts which are suitable for the reaction of an organic compound with a hydrogen peroxide solution are conceivable as catalysts.

Catalysts are preferably used which comprise a porous oxidic material such as a zeolite. Catalysts are preferably used which comprise a zeolite containing titanium, vanadium, chromium, niobium or zirconium as the porous oxidic material. Zeolites containing titanium, vanadium, chromium, niobium, and zirconium with a pentasil zeolite structure, in particular the types with X-ray assignment to ABW, ACO, AEI, AEL, AEN, AET, AFG, AFI, AFN, AFO, AFR, AFS, AFT, AFX, AFY, AHT, ANA, APC, APD, AST, ATN, ATO, ATS , ATT, ATV, AWO, AWW, BEA, BIK, BOG, BPH, BRE, CAN, CAS, CFI, CGF, CGS, CHA, CHI, CLO , CON, CZP, DAC, DDR, DFO, DFT, DOH, DON, EAB, EDI, EMT, EPI, ERI, ESV, EUO, FAU, FER -, GIS, GME, GOO, HEU, IFR, ISV, ITE, JBW, KFI, LAU, LEV, LIO, LOS, LOV, LTA, LTL, LTN, MAZ, MEI, MEL, MEP, MER, MFI, MFS, MON, MOR, MSO, MTF, MTN, MTT, MTW, MWW, NAT , NES, NON, OFF, OSI, PAR, PAU, PHI, RHO, RON, RSN, RTE, RTH, RUT, SAO, SAT, SBE, SBS -, SBT-, SFF-, SGT-, SOD-, STF-, STI-, STT-, TER-, THO-, TON-, TSC-, VET-, VFI-, VNI-, VSV-, WEI-, WEN, YUG, ZON structure and mixed structures of two or more of the aforementioned Structures. Titanium-containing zeolites with the structure of UTD-1, CIT-1 or CIT-5 are also conceivable for use in the process according to the invention. Further titanium-containing zeolites are those with the structure of ZSM-48 or ZSM-12.

Ti zeolites with an MFI, MEL or MFI / MEL mixed structure are to be regarded as particularly preferred for the process according to the invention. The Ti-containing zeolite catalysts, which are generally referred to as "TS-1", "TS-2", "TS-3", and Ti zeolites with a framework structure isomorphous to zeolite are also particularly preferred call.

A heterogeneous catalyst comprising the titanium-containing silicalite TS-1 is particularly preferably used in the process according to the invention.

It is possible in the process according to the invention to use the porous oxidic material per se as the catalyst. Of course, however, it is also possible to use a shaped body as the catalyst which is the porous oxide Material includes. All processes according to the prior art can be used to produce the shaped body, starting from the porous oxidic material.

Before, during or after the one or more shaping steps in these processes, noble metals in the form of suitable noble metal components, for example in the form of water-soluble salts, can be applied to the catalyst material. This method is preferably used to produce oxidation catalysts based on titanium or vanadium silicates with a zeolite structure, it being possible to obtain catalysts which contain from 0.01 to 30% by weight of one or more noble metals from the group ruthenium, rhodium, Palladium, osmium, iridium, platinum, rhenium, gold and silver. Such catalysts are described, for example, in DE-A 196 23 609.6, which is hereby fully incorporated by reference into the context of the present application with respect to the catalysts described therein.

Of course, the moldings can be assembled. All methods of comminution are conceivable, for example by splitting or breaking the shaped bodies, as are other chemical treatments.

Those skilled in the art will appreciate that the catalysts used can contain up to about 60% by weight of binder, based on the total mass of the catalyst.

In principle, the process according to the invention can be carried out with all customary reaction procedures and in all customary reactor types, for example in a suspension procedure or in a fixed bed arrangement. You can work continuously or discontinuously. However, the reaction according to the invention is preferably carried out in a fixed bed apparatus. The process according to the invention is advantageously carried out at a pressure of 1 to 100 bar.

Examples of suitable solvents are water, alcohols, e.g. Methanol, ethanol, iso-propanol or tert-butanol, or mixtures thereof. Mixtures of methanol and water are preferred as solvents, and methanol is particularly preferably used.

The process according to the invention is generally carried out at temperatures from 0 ° C. to 100 ° C., preferably at 20 to 90 ° C. and particularly preferably at 25 to 60 ° C.

A hydrogen peroxide solution suitable for use in the process according to the invention, which contains only small amounts of dissolved salts, can be obtained in various ways. For example, you can reduce the salt concentrations in a finished, such as a commercial hydrogen peroxide solution.

Accordingly, the present invention also relates to processes for reducing the salt concentration in a hydrogen peroxide solution, and in particular to processes which are characterized in that the hydrogen peroxide solution is treated with an ion exchanger.

In principle, cation exchangers and anion exchangers can be used in the process according to the invention.

If only one type of ion exchanger is used, the use of at least one anion exchanger is preferred and that of a weakly basic anion exchanger is particularly preferred. If several ion exchangers are used, they can be used simultaneously or in succession. Sequential treatment with at least one cation exchanger is preferred, followed by treatment with at least one anion exchanger. A weakly basic anion exchanger is preferred as the anion exchanger.

In principle, all ion exchangers known to the person skilled in the art can be used in the context of the present invention, for example organic ion exchangers, for example based on polystyrene, or inorganic ion exchangers, for example hydrotalcites and other phyllosilicates which can contain exchangeable carbonate, hydrogen carbonate or hydroxide groups.

Examples of the weakly basic anion exchangers which are particularly preferred in the context of the present invention are polystyrene resins with tertiary amine groups, for example the commercially available anion exchangers Lewatit MP62 and Lewatit MP 63 (Bayer AG) as well as Dowex MWA / 1 and Dowex AMW-500 (Dow Chemical). In addition, the use of strongly basic ion exchangers, for example polystyrene resins containing quaternary ammonium groups (with hydroxide counterions), is also conceivable. Examples include the commercially available exchangers Lewatit OC-1950 (Bayer AG) and Dowex 1, Dowex 2, Dowex 11, Dowex 21K and Dowex 550A (Dow Chemical).

The conditions in the treatment of the hydrogen peroxide solution with the ion exchanger or the ion exchangers of choice should be chosen so that the hydrogen peroxide solution obtained after this treatment contains the smallest possible amount of anions and cations.

The concentration of dissolved anions or cations is preferably in the

Hydrogen peroxide solution after the treatment in each case less than 100 ppm, particularly preferably contains the hydrogen peroxide solution after the treatment with one or more ion exchangers a maximum of 60 ppm phosphate, 30 ppm nitrate, 30 ppm sodium ions and 5 ppm potassium ions.

The setting of the parameters in the treatment of the hydrogen peroxide solution according to the invention with the ion exchanger or ion exchangers of choice, for example with regard to temperature, pressure, flow rate etc., is within the experience of the person skilled in the art, but should be chosen so that the lowest possible Decomposition takes place.

The present invention further relates to the use of a hydrogen peroxide solution, the concentration of dissolved salts of which has been reduced by means of a method according to the invention, in the method according to the invention for reacting an organic compound.

A hydrogen peroxide solution which is suitable for use in the process according to the invention and which contains only small amounts of dissolved salts can also be obtained by reducing the salt concentration already during the preparation of the hydrogen peroxide solution.

Accordingly, the present invention also relates to an integrated process for the production of hydrogen peroxide based on a conventional anthraquinone process, characterized in that it comprises the following steps: extraction of the (a) working solution with water and (b) treatment with one or more ion exchangers.

The water used for the extraction of the working solution preferably has a phosphate, nitrate and sodium ion content which ensures an extraction which is harmless from a safety point of view, ie generally in each case about 100 ppm to a maximum of about 150 ppm. The anthraquinone process, by means of which practically the entire amount of the hydrogen peroxide produced worldwide (> 2 million t / a) is produced, is based on the catalytic hydrogenation of an anthraquinone compound to the corresponding anthraquinroquinone compound, subsequent reaction thereof with oxygen to form hydrogen peroxide and subsequent separation of the hydrogen peroxide formed by extraction. The catalytic cycle is closed by renewed hydrogenation of the re-formed anthraquinone compound.

The anthraquinone compounds used are usually dissolved in a mixture of several organic solvents. The resulting solution is called a working solution. In the anthraquinone process, this working solution is usually continuously passed through the stages of the process described above.

An overview of the anthraquinone process is given by Ulimann's Encyclopedia of Industrial Chemistry, 5th ed., Vol. AI 3, pp. 447-456.

The present invention further relates to the use of a hydrogen peroxide solution produced by means of the integrated method according to the invention in the method according to the invention for the reaction of an organic compound.

The present invention is to be explained in more detail with the aid of the following examples. However, the invention is by no means restricted to these examples. EXAMPLES

Example 1:

Table 1 shows an example of typical phosphate, nitrate and sodium ion contents 6 of various commercially available aqueous hydrogen peroxide solutions:

Table 1: Overview of the phosphate, nitrate and sodium ion content of some commercially available aqueous hydrogen peroxide solutions

Example 2:

An air-oxidized solution of 2-ethylanthrahydroquinone (approx. 12% by weight in a mixture of alkyl-substituted aromatic hydrocarbons (C ₉ -Cn) and tetrabutylurea) was mixed with water which contained 67 ppm phosphate, 33 ppm nitrate and 33 ppm sodium ions , extracted. The ions contained in the water served as stabilizers to avoid decomposition of the hydrogen peroxide during the extraction. An approximately 39% aqueous hydrogen peroxide solution was obtained which contained 40 ppm phosphate, 20 ppm nitrate, 20 ppm sodium ions and less than 1 ppm potassium ions. Example 3:

The hydrogen peroxide solution from Example 2 was passed at 10-20 ° C. at an empty tube speed of approx. 5 m / h over a column with a height of 80 cm and a diameter of 2 cm (corresponding to a load of 1700 g / h) , which was filled with a weakly basic anion exchanger (Lewatit MP62, Bayer AG). After this treatment, the hydrogen peroxide solution contained only 10-20 ppm phosphate and 10-16 ppm nitrate, the sodium ion and hydrogen peroxide concentrations were unchanged within the measurement accuracy.

Example 4: Comparative example

Approximately 20 g of titanium silicalite-containing catalyst strands produced in accordance with WO 97/46386 were introduced into a tubular reactor (height: 13.0 cm, diameter: 7 cm) without further pretreatment. A mixture of propylene (8 g / h), the 39% strength aqueous hydrogen peroxide solution from Example 2 (9 g / h) and methanol (49 g / h) was passed through the fixed bed reactor thus obtained. The reaction temperature was chosen so that a hydrogen peroxide conversion of about 96% was obtained, and was accordingly between 39 and 45 ° C. The pressure was 20 bar. The selectivity of the conversion to propylene oxide, measured in terms of the amount of hydrogen peroxide converted, was 91% during the first 170 hours of operation.

Example 5:

The procedure was analogous to Example 4, with the difference that the hydrogen peroxide solution with the reduced salt concentration from Example 3 was used. The selectivity of the conversion to propylene oxide, measured in terms of the amount of hydrogen peroxide converted, was 96% during the first 300 hours of operation. Example 6: Comparative example

The procedure was analogous to Example 4, with the difference that a commercial aqueous 20% hydrogen peroxide solution was used which contained 100 ppm phosphate, 30 ppm nitrate and 20 ppm sodium ions. The feed amounts were 16.1 g / h (propene), 33 g / h (hydrogen peroxide solution) and 79.8 g / h (methanol). The selectivity of the conversion to propylene oxide, measured in terms of the amount of hydrogen peroxide converted, was 82% during the first 300 hours of operation.

Example 7:

The procedure was analogous to Example 6, with the difference that the commercial aqueous 20% hydrogen peroxide solution initially at 10 to 20 ° C with an empty tube speed of about 1.3 m / h over a column with a height of 160 cm and a diameter of 2 cm (corresponding to a load of 450 g / h), which was filled with a weakly basic anion exchanger (Lewatit MP62, Bayer AG). After this treatment, the hydrogen peroxide solution contained only 10-20 ppm phosphate and 10-16 ppm nitrate, the sodium ion and hydrogen peroxide concentrations were unchanged within the measuring accuracy. The selectivity of the conversion to propylene oxide, measured in terms of the amount of hydrogen peroxide converted, was 91% during the first 300 hours of operation.

Claims

claims

1. A method for reacting an organic compound with a hydrogen peroxide solution, characterized in that the concentration of dissolved anions and cations in the hydrogen peroxide solution used is in each case less than 100 ppm.

2. The method according to Anspmch 1, characterized in that the reaction of the organic compound takes place in the presence of a catalyst containing secondary group metal atoms.

3. The method according to Anspmch 1 or 2, characterized in that the reaction of the organic compound takes place in the presence of a zeolite catalyst containing titanium atoms.

4. The method according to any one of the preceding claims, characterized in that the hydrogen peroxide solution used in the reaction of the organic compound contains a maximum of 60 ppm phosphate, 30 ppm nitrate, 30 ppm sodium and 5 ppm potassium.

5. The method according to any one of the preceding claims, characterized in that an aqueous hydrogen peroxide solution is used.

6. The method according to any one of the preceding claims, characterized in that the organic compound used is an olefin.

7. The method according to any one of claims 1 to 6, characterized in that the organic compound is propene, the catalyst containing secondary group metal atoms is a silicalite TS-1 and the hydrogen peroxide solution is a is aqueous solution with a concentration of hydrogen peroxide of 1 to 70 wt .-%.

8. A method for reducing the salt concentration of a hydrogen peroxide solution, characterized in that the hydrogen peroxide solution is treated with at least one ion exchanger.

9. Use of a hydrogen peroxide solution, the salt concentration of which has been reduced in accordance with Claim 8, for the reaction of an organic compound.

10. A process for the preparation of a hydrogen peroxide solution based on a conventional anthraquinone process, characterized in that it comprises the following steps:

(a) extraction of the working solution with water which has a phosphate, nitrate and sodium ion content of at most 1000 ppm each, and

(b) treatment with at least one ion exchanger.