CS48692A3 - Supported catalyst based on a noble metal, a process for preparing saidcatalyst and a process for preparing a mixture of cyclohexylamine anddicyclohexylamine by utilizing said catalyst - Google Patents

Description

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Supported noble metal catalyst, process and method for preparing a mixture of cyclohexylamine and dicyclohexylamine using this catalyst

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supported catalyst comprising ruthenium and palladium or a mixture of the two metals and a niobic acid-tantalic acid blender or mixtures thereof. The invention also relates to a process for the preparation of such a catalyst and to the preparation of a mixture of optionally substituted cyclohexylamine and optionally substituted dicyclohexylamine by catalytic hydrogenation of an optionally substituted aniline using a catalyst according to the invention.

Background Art

It is known to produce cyclohexylamine and other hydrogenated amine compounds in the core by catalytic hydrogenation of aniline and other aromatic amino compounds. Catalysts for this purpose are cobalt-based catalysts which contain a basic additive (British Patent 969542), Raney Cobalt (Japanese Patent No. 68/03180), ruthenium; Catalysts (German Patent DE-AAS 10,109), alkali metal compounds doped with ruthenium catalysts (U.S. Pat. No. 3,636,188) and nickel catalysts (DE-PS 805 518). Most of the processes described above are carried out under pressure. and mainly provides cyclohexylamine in addition to a small amount of dicyclo-hexylamine. Therefore, dicyclohexylamine is produced by other methods, for example by pressure hydrogenation of diphenylamine using a ruthenium catalyst (DE-AS 1 106319). In addition, dicyclohexylamide is formed by cyclohexylamine in the reaction of cyclohexanone. in the presence of palladium on carbon as catalyst under a hydrogen pressure of about 0.4 MPa / French Patent No. 1 313W2). The process according to DE-PS 805518 is mainly concerned with obtaining dicyclohesyl-2-amine, however, it is difficult to feed back by-products.

Other drawbacks of the above-mentioned processes include, in part, the severe amount of cyclohexanone waste products, and the lack of stability of the catalysts used. Therefore, it is desirable to develop a process that can be used on a technical scale to reduce the losses caused by the formation of cyclohexane and to improve the stability of the catalyst and to develop a common process: * / production of cyclohexylamine and dicyclohexylamine in each other. Surprisingly, it has now been found that these requirements can be met by the use of a further characterized noble metal catalyst on a support.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION The present invention provides a catalyst comprising ruthenium, palladium, or a mixture thereof on a carrier which comprises a cationic or tantalic acid of formula

Or a mixture thereof comprising a noble metal or noble metals in a total amount of 0.05% by weight; and £ 5%, preferably ·. 0.1 to 4% and especially 0.1 to 3%, and in the case of ruthenium and palladium mixtures both metals in a weight ratio of 1: 9 to 9: 1, S3 preferably 2: 8 to S: 2 and in particular 3 to 7 to 7 : 3, with each percentage being based on the total weight of the catalyst. ~

Thus, the catalysts of the invention are primarily a mixture of palladium and / or ruthenium and niobium or tantalum. Such catalysts provide higher yields of dicyclohexylamine over catalysts known in the art.

The catalysts of the present invention are characterized in particular by the use of niobic acid or tantalic acid as catalyst support; or a substance or a catalyst substance. - 3 -

As is known, niobic acid is a niobium (II) oxide hydrate (Nh 2 O 2), which is formed by, for example, treating the aqueous solution of niobic acid salts with strong mineral acids or treating niobium alcoholates, niobium halide; or niobic acid esters with water, acids or bases. The niobic acid thus precipitated is dried and then constitutes a sparingly soluble solid compound whose residual water content is not defined, although the niobic acid thus prepared appears to be dry; powder, process for producing niobic acid / niobium pentoxide hydrate (described, for example, in Gelsins Handbueh der anorganischen Chemie, 8, Edition, Niobium, Part B1, pg. 49). alcoholates of pentavalent tantalum or other hydrolyzable compounds of pentavalent tantalum. The hydrolysis may be carried out in a manner similar to the hydrolysis of compounds of the pentavalent type. the hydrolysis is well known to those skilled in the art of niobium compounds, and is described, for example, in Gmelins Handbueh der anorganischen Chemie, 8th Edition, Tantal, d 'B1, 1970, p.51 and Ctaem. Flight. 19S8, 3tr. The preparation of compounds of one of these elements also applies to the preparation of compounds of the second element. The great chemical similarity of these two elements and their compounds is manifested in the fact that they occur very often together in nature »

According to a preferred embodiment of the invention, the dream as a carrier or as a component of the carrier uses niobic acids, in particular from raw materials of natural origin with a tantalic acid molar content of 0.0X101 to 10 based on the mol of acid | niobic and tantalic · j

In order for the niobic or tantalic acid to have a favorable piece form for use as a solid catalyst layer, for example, a wet precipitate obtained by hydrolysis, kneading in the kneader and in the granulation apparatus is processed into shaped particles. temperature of 120 ° C and calcine for half an hour to 5 hours at 40 ° C to 400 ° C. Here, a BET surface area of 5 to 36 cm / g is formed. For the preparation of granulates, extrudates or spheres, the niobic or tantalic acid may also be compressed with a binder and granulated. and

Niobium or tantalum acid is an active substance with respect to the catalysts according to the invention, the activity of which is also retained during mixing and other solids. Such suitable solids are, for example, titanium dioxide, zinc oxide, manganese dioxide, iron oxide. , silica, graphite and alumina. These solids can also be used as binders according to the above process.

The mixtures of niobic acid or tantalic acid with such inert solids can be used in a weight ratio of 5: 95 to 99: 1, preferably 50: 50 to 92: 1. niobic acid or tantalic acid or a mixture thereof only as a carrier. Especially suitable as such carriers are alumina and niobium oxide / tantalum oxide carriers which can be prepared by mixing and compressing the components of such a carrier, or by releasing alumina or by precipitating the niobium and tantalum compounds into alumina niobic acid or tantalic acid · Aluminum oxide is preferred as aluminum oxide. The non-acidic or tantalic acid content may vary within wide limits, but is preferably; weight to 10% t based on the weight of the carrier *

The invention further relates to a process for the preparation of such a catalyst, wherein the niobic or tantalic acid or a mixture thereof is impregnated with a solution of ruthenium salt or palladium salt,

or if both metals are used in the case of both metals, the carrier is dried after J filling and the catalyst is used in this form or after treatment with hydrogen at 120 to 4 ° C.

For the preparation of the catalyst, the catalyst support is used in the form of pills, spheres, or fragments of about 1 to 10 microns. The noble metal impregnation 30I is carried out in a manner known to those skilled in the art. The drying is carried out - for example, at a temperature of 100 to 140 and under reduced pressure at a pressure of about 10 to about 1000 microns, for example in a vacuum pump. * Salts of rare earth metals; they may be dissolved in water or

Advantageously, they are dissolved in organic solvents such as simple alcohols, ketones, nitriles or cyclic ethers. Examples of such solvents include methanol, ethanol, acetone, acetonitrile and dioxane. Suitable salts of noble metals include, for example, chlorides, nitrates and acetates.

After impregnation and subsequent drying, the catalyst is substantially ready for use. However, according to a preferred embodiment, the pre-use is still activated by treatment with hydrogen at elevated temperatures. Such an elevated temperature is (120 to 4 ° C, preferably 150 to 34 ° C). Aniline is formed in the core to form a mixture of cyclohexylamine and dicyclohexylamine with optional substituents such as aniline. -b and dicyclohexylamine in large quantities.

The invention also relates to the use of the catalysts according to the invention in the preparation of a mixture of optionally substituted cyclohexylamine of the epopodially substituted dicyclohexylamine; by catalytic hydrogenation of an optionally substituted aniline on a noble metal support plate 5 in which the above catalyst is used at a temperature of 10 ° C to 34 ° C, with a UG of up to 24G ° C at a pressure of 0.5 ° C. to 5G MPa, preferably 0 to 40 HPa, in particular 10 to 4G MPa, and most preferably under pressure: 15 to 35 MPa.

Thus, the process can be carried out in a wide range of pressures; near ambient pressure to very high pressure. Possible embodiments include, for example, gas phase work near - 6 - ambient pressure, high pressure autoclave work, and high pressure scraping stage work,

Hydrogenation on the catalysts of the invention can be carried out both discontinuously and continuously; a continuous process is particularly suitable for technical purposes. According to a preferred embodiment, as mentioned above, a fixed catalyst is employed in the scrubbing phase. An amount of 0.05 to 3 kg, preferably 0.1 to 2 kg, is set, and above all! 15 to 1.5 kg of aniline, optionally substituted per liter of catalyst and hour. Minor changes in the achieved proportion of dicyclohexylamine and the reactivity of the selectivity by the altered catalyst activity over a longer period of time ee can be compensated by a slight adjustment of the resection temperature or other parameters. These ratios can be monitored by reaction mixture analysis. in accordance with the following equation of aniline and substituted anilines, which react to the corresponding cyclohexylamines and dicyclohexyl-amines.

where is R1 and S? hydrogen, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms. Examples of such alkyl substituents include alkoxy, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, methoxy, ethoxy, propoxy, isopropoxy, butoxy and isobutoxy. In a preferred embodiment, the preferred substituents are 1 to 2 carbon atoms, especially methyl or methoxy. Furthermore, it is preferred that one of H 1 and H 2 represents a hydrogen atom and - 7 - a second hydrogen atom, optionally an alkyl group or an alkoxy group as defined above. In a particularly preferred embodiment, the aniline of the unsubstituted 5-substituted aniline is hydrogenated in the core. Such cyclohexylideneniline may also be substituted in the core and correspond to the general formula

Wherein EL and S are as defined above. Finally, it is also possible. , such optionally substituted cyclohexylideneandiline. use t as a mixture of an optionally substituted cyclohexanone and; po-. * for substituted aniline,

The cyclohexylamines and dicyclohexylamines as defined above are used for the preparation of anti-aging compositions of the aplasts as a corrosion preventing agent and as a pre-product for the preparation of plant protection agents and textile assistants. The present invention will be explained in more detail by the following examples. EXAMPLES Example 1 '

75 g of niobic acid, 3.5% by weight of graphite powder, are formed into a 5 mm tablet, whereupon the tablets are impregnated with a solution prepared from 1.56 g palladium acetate and 26.0 g acetonitrile. Thus, niobic acid tablets with 1% palladium are obtained and dried for 1 hour at a temperature of 100 GC in a water pump vacuum. The niobic acid is then charged once more in the same manner with 1% palladium. Bring a 6060 ml / 61 g / catalyst thus prepared into a vertically arranged pressure tube / diameter 14 mm, length 70 cs ^ which is heated by an oil thermostat. Volume between particles with seawater sand (0.2-0.4 mm). The catalyst is first activated for 3 hours at 250 DEG C. and under pressure; 27 KEPa with hydrogen, leaving 40 L of hydrogen per hour at the lower end of the reaction tube. Then it starts under pressure 27. MPa and at 182 ° C and hydrogenation of aniline, the anion and hydrogen being fed upwardly to the catalyst. The liquid flows down the catalyst to the separator. 2 to 26 liters of hydrogen per hour are removed from the separator head. The continuously introduced amount of aniline corresponds to a catalyst load of 0.23 to 0.28 g / ml of catalyst per hour. Under the stationary reaction conditions, the following product composition is obtained, depending on the operating hours: and at the reaction temperature / residue up to 10.0%, by-products.

Boba Temperature BGBA + CHS + h%; <£ 4í7 181 82.0 17.8 nsr 171 84.5 15.3 20, 150: 88.5 ‘11, <3M 125 9T, 8 8.0 + Β6Μ dicyclohexylamine, OBA = cyclohexylamine Example 2

100 g of tablets of niobic acid of the same type as in Example 1 are impregnated with a solution transferable from 2.08 g of palladium acetate and 25 g of dioxane. The niobic acid tablets impregnated with 1 palladium are dried for 18 hours at 100 ° C.

For the hydrogenation of aniline, 60 ml (55.7 g) of the produced catalyst is used in the same manner as in Example 1. The continually introduced amount of aniline is responsible for the load of the catalyst; 0.25 g of aniline per ml of catalyst per hour The dependence of the composition of the product on the catalyst hours of operation and on the hydrogenation temperature is shown in the following table, the remainder being up to 100; % is by-products. - 9 -

Roba fc Temperature ° C; DCM +% ena +% Anilli% 98 179 84.2 15.6 - 219 179 »3.8 16.0 0.05 411 180 86, 77 1X, 1 0.04 57» 189 85, T 13.9 - ' 7748 189 86, -5 13.3 395 189 86.4 13.5 - 940 m 92.2 7.5 + RCEA. Dicyclohexylamine, CHA »Cyclohexylamine

Example X

It is impregnated with 50 g of niobic acid tablets (diameter 5 mm) with a solution consisting of: 3.1 g of ruthenium nitrate (Hti) BG / g and 25 g of methanol. In this way, 2% ruthenium iminated niobic acid was dried for 18 hours at a temperature of 100 ° C in a water pump vacuum. 25 ml (24 g) of catalyst thus prepared are used: for the preparation of aniline hydrogenation hydrogenation products; a 250 ml autoclave fitted with a centrally mounted, fixed, screen-mounted, autoclave in which the catalyst is deposited. 50 g of aniline are hydrogenated each time at a hydrogen pressure of 26 to 28 MPa at different temperatures. The hydrogenation time for each hydrogenation test is three hours. The reaction products exhibit reaction temperature dependence and have the following composition, with the remainder to 100% being by-products:

Temperature / ° G / 110,200 Aniline? 0.4% Q., 5% Cyclohexylamine 90.7% 48.2% Dicyclohexylamine 8.5% 50.0% Example 4

Tablets 80 g of niobic acid Nt2O4 .mu.g are added at a rate of 1.9% graphite / tablet diameter of 5 mm and the tablets are impregnated with a solution prepared from 0.83 g palladium acetate and 17.2 g. acetonitrile. After drying at 10 ° C for 1 hour in a water-jet vacuum, the niobic acid tablets are re-impregnated with a solution prepared from 1.25 g of ruthenium nitrate Bu / W 1 / g and 17.2 g of methanol. for hydrogenation. Niobic acid tablets contain 0.5% palladium and 0.5% ruthenium *

25 ml (25.3 g) of the palladium-ruthenium-based catalyst thus prepared are used for the hydrogenation of aniline in a 0.25 L autoclave # The autoclave has a mesh basket in which the catalyst is arranged. 50 g of aniline are hydrogenated twice in succession at a pressure of 26-28 MPa and at different temperatures. After the individual hydrogenation, the autoclave is cooled to room temperature, the reaction product is removed and the autoclave is again supplied with aniline. Hereby, the temperature dependence at a constant hydrogenacetate time is evident and the following product composition is obtained / the by-products being the remainder to 100% / *

Temperature / ° C / aniline cyclohexylamine, dicyclohexylamine 180 200 0.1 9S '0.5% 65.8% 3.8µ5% 25.4 56.3% Example 5 í 15 ml / 15 is used for gas phase aniline hydrogenation The catalyst is first activated in a hydrogen stream for one hour at 190 ° C under a hydrogen flow (20 L / hr) of the activated catalyst formed in a vertically arranged reaction tube of 17 mm. 1.54 g of aniline together with 2.0 L of hydrogen * The resulting reaction product is condensed and analyzed after various time intervals. The observed dependence of the reaction product composition on the operating hours of the catalyst in the following manner / residue to 1QQ% is by-products / x 11

Test time 116 h 238 h 303 h 438 h cyclohexylamine 22,5 22,1 ts, and 1S, 5 dieclohexylamine 74,2 T4,6 7T, 9 71,9 N-cyclohexylaniline 1,2 1,2 T, 2 1, 4 Aniline M 0.6 1.2 Q, T Attach 6:

25 ml (24.8 g) of Example 2 of the prepared catalyst are used to hydrogenate cyclohexylidene-aniline in a 250 ml autoclave, which has a centrally mounted, screened, autoclave basket filled with catalyst. hydrogenation of 50 g of cyclohexylidene-aniline under hydrogen pressure of 28 SSPa at various temperatures with this catalyst charge. Approximately 95% of cyclohexylidene-aniline is maintained in the feed. The hydrogenation is carried out for 3 hours in all tests in this series. The products of hydrogenation have the following composition (with the remainder to %OS% typhic by-products):

Temperature / ° C / dieclohexylamine,% 2 (Kf 89.1 10. 89.99 cyclohexylamine,% Q, 9 1.25 N 1 -cyclohexylatiline - 3.50 Example 7

In the case of the apparatus described above, including a catalyst (2% palladium on niobic acid NbgO3nB2O), a mixture of cyclohexanone and aniline is used in the molar ratio Q., 9x1 instead of the aniline. 26 g of a mixture / ml of catalyst / h. 50 liters of hydrogen are removed per hour from the blower head. Under stationary reaction conditions, the following product composition was obtained depending on the reaction temperature (with the remainder up to 100% forming by-products):

Temperature 180 ° e 141 Time / 0 z / 4Ψ h / 0 2/24 hr dicyclohexylamine 94.2 92.7 Λ cyclohexylemine 3.7 2.8 N, N -cyclohexylaniline - 2.8 cyclohexanol U7 - - - fc. * Λ..1 Example 8

It inflates. 400 g of aluminum alumina having a diameter of 2-5 mm and a specific surface area of 350 µg / g with a solution of 23.1 g of niobium chloride in 120 g of 31% hydrochloric acid are dried at 120 ° C. Thereafter, the catalyst support was charged with 410 g of 16.9% by weight aqueous ammoniacal solution and washed with water until the chlorides were removed and dried again. 150 g of the solution prepared in this way were prepared from 3; 13 g palladium acetate and 40 g acetonitrile. After re-drying at 120 ° C, the catalyst is ready for use. · Hydrogenation of aniline is carried out with 60 ml / 63 g / catalyst thus prepared. For this purpose, the catalyst is fed into a vertical pressure tube / outside diameter 14 mm, length 7Q. The catalyst is first activated for 3 hours at 250 ° C and at a pressure of 21.6 MPa with hydrogen, while 60 l of hydrogen are withdrawn from the reaction tube per hour.

Then, the temperature is lowered to about 200 ° C and under pressure; 27.5 MPa is fed with aniline and hydrogen from above onto the catalyst. Liquid flows down the catalyst down to the separator. From 60 to 100 liters of hydrogen per hour from the head of the separator ·

Aniline throughput corresponds to a catalyst load of 0.2 and £ 0.1 g of aniline / ml catalyst: x h; this enforcement is maintained as a test.

Hydrogenation product; taken at regular time intervals from the separator and analyzed. reaction temperature 20 ° C / residue to 10G% forms byproducts / c - 13 -

Roba Test Anilin DKA + CEA + &amp; %% 89 .0,2 7 «, 1 22,9 137 - 79,2 20,5 212 - 78,2 21 255 - 80,6 18,7 326 0,1 74,3 2 <, 6 3J < 77.1 22.6 + UBA, dicyclohexylamide CM = cyclohexylamit

Example S

40 g of the alumina used in Example 8 are impregnated with granules; a solution of sodium chloride prepared from 11.64 g of niobium chloride, 11.64. sodium chloride and 1 g of water. This leakage is repeated at a time of drying at 12 ° C. The dried catalyst is treated with 4 g of 8.9% aqueous ammonia for one hour, and the solution is then washed with water to remove chlorides and dried again. 100 g of the catalyst carrier thus prepared are dissolved in a solution prepared from: 4.16 g of palladium acetate and 31 g of methylene chloride. After re-drying, 60 ml (51.1 g / catalyst) was used as in Example 8 to hydrogenate aniline. 368 g of aniline are passed at 20.0 ° C under a pressure of 20 µs of KPs for 21 hours; evenly over the catalyst. At the head of the product separator, 220 liters of hydrogen are removed per hour. The chromatographic analysis of the reaction product shows 23% cyclohexylamine and 76.9% dicyclohexylamine.

Example IQ

4 g of tantalum chloride are dissolved in 6.8 g of 37% hydrochloric acid and then diluted with 25 g of water. The thus prepared tantalum chloride solution is impregnated with 10 g of aluminum oxide granulate (2 to 5 mm in diameter, specific surface area = 14 - 150 m / g). After drying at 100 ° C in a water jet vacuum, the catalyst support is impregnated with 25 g of a 29.3% aqueous α-monovalent solution and then washed with running water to remove chlorides. After further drying, the catalyst support is dissolved in a solution prepared from 4.16 g of palladium acetate and 35 g of methylene chloride. After subsequent drying, the catalyst is ready for use »

6Q ml / 49.4 g is used; the catalyst thus prepared as in Example &amp; for continuous hydrogenation of aniline. The stationary conditions are followed by 935 g of aniline over 24 hours at a temperature of 96 ° C and under a hydrogen pressure of 27 MPa with a catalyst layer. In this process, the product collected is removed from the product by filtration, and the product collected is removed from the product after one hour, containing 18.9% by weight of cyclohexylsine and 1% of dicyclohexylamine.

Industrial usability

Optionally substituted cyclohexylamine and optionally substituted with dicyclohexylamide may be prepared by catalytic hydrogenation of an optionally substituted aniline, employing a catalyst comprising ruthenium, palladium or a mixture thereof, supported on a niobic acid or tantalic acid base or a mixture thereof. still with an inert carrier »

Claims (5)

1 «Carrier-based noble metal catalyst, characterized in that it contains ruthenium, palla? or a mixture thereof on a carrier comprising niobic acid, or a mixture thereof, wherein the content of at least one of said noble metals is 0, From about 5% to about 5%, preferably from about 0% to about 1%, and more preferably from about 0.1% to about 3%, and in the case of a mixture of ruthenium and palladium, the weight ratio of noble metals is preferably about 1: 9%; 2: 8 to 8 and especially 3: 7 to 7: 3, with percentages based on the weight of the catalyst as a whole * 2. Catalyst according to claim 1, characterized in that the carrier comprises niobic acid or is composed of niobic acid, preferably of natural origin having a solubility of 0.0001 to 10% by weight of tantalic acid, based on total weight. mol content of niobic acid and tantalic acid. 3. The catalyst of claim 1. 1, characterized in that prior to use it is treated with hydrogen at a temperature of 120 to 400 ° C, preferably at a temperature of 150 to 340 ° C. 4. Catalyst according to claim 1, characterized in that it comprises alumina carriers, preferably aluminum oxide, with a content of niobic acid, a tantalum or mixtures thereof, of up to 10% by weight. The weight of the catalyst according to claim 1, characterized in that it is applied to niobic acid, tantalum or a mixture thereof or to a carrier containing niobic acid, tantalic acid or a mixture thereof. If the ruthenium or palladium or, when using both crystals, a solution of both salts, the carrier is dried after filling and the catalyst is ready for use or treated with hydrogen at a temperature of 120 to 400 ° C. - - 1 ® - Hexylamine and optionally substituted dicyclohexylamine by catalytic hydrogenation of an optionally substituted aniline using a noble metal catalyst n and carriers according to claim 1 and the hydrogenation is carried out at a temperature of 10 ° C to 340 ° C, preferably from 13 ° C to 240 ° C, and from a pressure of 0.05 to 50 MPa, preferably. 0.2 to 40 MPa and especially 10 to 40 SEPa and most preferably at a pressure of 15 to 35 MPa. her Knows 77. The process of claim 6 wherein the hydrogenation is carried out continuously on a scrubbing phase on a fixed catalyst, with a catalyst load of 0.05 to 5 kg, preferably 0.1 to 2 kg, most preferably 0.15 to 1.5 kg. optionally substituted aniline per liter of catalyst per hour. ffi ,. 4. A process according to claim 6, wherein the aniline of the general formula is hydrogenated. hb independently of one another are hydrogen, alkyl of 1 to 4 carbon atoms or alkoxy and 1 to 4 carbon atoms. 9. A process according to claim 1, wherein the substituted aniline is hydrogenated. when H 1 and R 2 independently of one another are H, C 1 -C 4 alkyl or C 1 -C 4 alkoxy »