JPH09124562A - Production of aromatic amino compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily produce the subject compound in a high yield by hydrogenating an aromatic nitro compound in the presence of a specific highly safe catalyst having a long life. SOLUTION: (B) An aromatic nitro compound such as nitrobenzene, o<-> , m<-> or p-nitrotuluene or α- or β-nitronaphthalene is reacted with (C) hydrogen in the presence of (A) a modified Raney copper catalyst containing Cu, Fe and Al as fundamental components and, if necessary, further V or Si (e.g. a catalyst obtained by developing an alloy containing Cu, Fe, Al and, if necessary, V or Si in an atom molar ratio of 1: (0.05-0.35):(0.02-1.0):(0.01-0.25) or (0.01-0.1) in a 15-30wt.% alkali metal hydroxide aqueous solution at a temperature of 50-95 deg.C under the atmospheric pressure. The alkali metal hydroxide aqueous solution is used in a larger amount than that required for eluting the whole amount of the Al contained in the alloy).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a corresponding aromatic amino compound by reacting an aromatic nitro compound with hydrogen using a modified Raney copper catalyst.

[0002]

2. Description of the Related Art Conventionally, as a catalyst used when a corresponding aromatic amino compound is produced by reacting an aromatic nitro compound with hydrogen, a catalyst of Cu--Cr type oxide generally called "copper chromite catalyst". Are known (for example, Japanese Patent Publication No. 47-27629 and Japanese Patent Publication No. 53-306).
91, JP-A-58-159443).

A method for producing the copper chromite catalyst is described in Industrial and Engineering Chemistry, Vol 26, pp. 878 (1936), but a large amount of hexavalent chromium ions are discharged in the production process. There is a problem, and no major improvements have been made so far on this point. Further, for the purpose of environmental protection, these discharged heavy metals must be collected by an appropriate method, but the final treatment measures for the resulting heavy metal sludge have not been sufficiently established at present.

Therefore, a catalyst other than the copper chromite catalyst was searched for. As an example thereof, a catalyst containing, for example, a Cu—Fe—Al-based metal oxide has been proposed (JP-A-53-53).
92395, JP-A-55-8820, and JP-B-58-50775). These catalysts are superior to conventional copper chromite catalysts in activity, selectivity and durability, but have a problem that the filtration rate is extremely slow when the catalyst is separated from the precipitation slurry during the catalyst production,
In order to overcome this, large-scale and complicated filtration equipment is required (Japanese Patent Laid-Open Nos. 53-92395 and 55-55).
However, when urea is used as a precipitating agent, a large load is applied to treat urea wastewater and ammonia wastewater (see Japanese Patent Publication No. 58-50775). There was a problem.

A further improved catalyst and a method for producing the same are disclosed in JP-A-5-337371. This is a catalyst in which a Cu-Fe-Al-alkali metal (and / or alkaline earth metal) -Zn-based metal oxide is supported on a carrier, but its production process is long and complicated, and as a practical catalyst. There are manufacturing difficulties. In addition to the above, the followings have been proposed as catalysts that can substitute for the copper chromite catalyst. Cu-Mo type oxide (Japanese Patent Publication No. 56-15945) Raney Ni type (Japanese Patent Publication No. 61-20343, Japanese Patent Laid-Open No. 7-53477) Noble metal supporting system (Japanese Patent Publication No. 2-34938, Japanese Patent Laid-Open No. 34938/1983) 6
-71178 gazette) Ni-Al-Zr type oxide (Japanese Patent Publication No. 6-34920 gazette).

[0006]

As described above, various types of catalysts that can replace copper chromite catalysts have been developed in the past, but most of them are metal oxide-based catalysts, and they are different in performance and production. There are problems and I am not satisfied.
In view of the above circumstances, the present inventor has conducted extensive studies on a hydrogen reduction catalyst for an aromatic nitro compound that can be a substitute for a copper chromite catalyst, and as a result, a modified Raney copper catalyst of a multi-component alloy is easy to produce and reproducible. It has been found that the aromatic amino compound can be produced in a high yield with a long catalyst life when used for hydrogen reduction of an aromatic nitro compound.

[0007]

Accordingly, the present invention is directed to a modified Raney copper catalyst containing Cu, Fe and Al as basic components when an aromatic nitro compound is reacted with hydrogen to produce a corresponding aromatic amino compound. A method for producing an aromatic amino compound using is provided. This modified Raney copper catalyst preferably contains V and / or Si in addition to the above. In the method for producing an aromatic amino compound of the present invention, the aromatic nitro compound is nitrobenzene, o-, m-, p-nitrotoluene, or α-, β.
-Nitronaphthalene is preferred.

Here, the term "aromatic" means not only a group of compounds containing a benzene ring in the molecule, but also compounds containing an aromatic cyclic group such as furan, pyridine and thiophene. It should be understood to include so-called "quasi-aromatic". In addition, the “Raney copper catalyst” is basically Cu, as is generally known.
And Al (or Si) alloy is developed with a caustic alkali (or acid) to elute a part of Al (or Si) to increase the active surface area, which means a catalyst mainly composed of Cu.
"Modified Raney copper catalyst" means a catalyst obtained by modifying the Raney copper catalyst described above by addition of another metal.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, the method for producing an aromatic amino compound of the present invention comprises reacting an aromatic nitro compound with hydrogen using a modified Raney copper catalyst containing Cu, Fe and Al as basic components. It is what makes me. Therefore, first, the modified Raney copper catalyst will be described in detail.

The modified Raney copper catalyst (hereinafter referred to as "present catalyst") used in the method for producing an aromatic amino compound of the present invention contains Cu, Fe and Al as basic components, and preferably contains other metal elements, particularly The catalyst of the present invention usually comprises V and / or Si. First, a multi-component alloy containing these metal elements (hereinafter referred to as “R alloy”) is formed, and this R alloy is preferably formed. It is manufactured by developing with caustic to elute a part of Al and expanding the active surface area.

In this catalyst, the basic components Cu, F
As a result of the experiment, the composition ratio of e and Al was 0.05 mol to 0.35 mol of Fe and A in terms of atomic ratio to 1 mol of Cu.
l is preferably in the range of 0.02 mol to 1.0 mol. Therefore, the main component of this catalyst is Cu. Fe is 0.0
If the amount is less than 5 mol, the activity in the hydrogen reduction reaction is hardly improved, and if it exceeds 0.35 mol,
On the contrary, it was found that the activity was decreased. Also, Al is 0.
If it is less than 02 mol, the catalyst strength will decrease, and if it exceeds 1.0, the active specific surface area as a catalyst will decrease.

The present catalyst comprising the above-mentioned basic components is, for example, Fe (1% by weight to 10% by weight), Al (40% by weight to 5% by weight).
5% by weight) and Cu (residual amount) can be prepared by developing an R alloy in an ordinary aqueous solution of an alkali metal hydroxide such as sodium hydroxide.

The present catalyst may contain a metal element other than the above-mentioned basic components as an added metal. Examples of these added metals include Ag, Au, Zn, Bi, Ti,
Zr, Si, Ge, V, Nb, Ta, Ni, Co, M
Examples thereof include o, W, Mn, Re, and noble metals. The content of these additional metals is preferably in the range of 0.01 mol to 0.40 mol in terms of atomic ratio with respect to 1 mol of Cu. The present catalyst containing these added metals in the above proportions develops an R alloy containing these metal elements in an atomic ratio with respect to Cu in the range of 0.01 to 0.40 in a normal aqueous alkali metal hydroxide solution. It can be manufactured by

Of these added metals, V and Si are particularly preferred metals. It has been found that the present catalyst containing any one or both of these has a further improved catalytic activity and an improved yield of the aromatic amino compound as compared with the catalyst composed of only the basic components.

Of these, the ratio of each component in the Cu-Fe-V-Al-based catalyst is 0.05 mol to 0.35 mol of Fe and 0.0 of V in terms of atomic ratio with respect to 1 mol of Cu.
It is preferable that the amount of Al is within the range of 1 mol to 0.25 mol and the amount of Al is within the range of 0.02 mol to 1.0 mol. V is less than 0.01,
Or if it exceeds 0.25, in any case, Fe
It was found that the catalyst activity cannot be expected to improve due to the synergistic effect with.

The present catalyst containing V is, for example, Fe (1
Wt% to 10 wt%), Al (40 wt% to 55 wt%), V (1 wt% to 10 wt%) and Cu (residual amount)
It is possible to produce the R alloy consisting of R in an ordinary aqueous solution of alkali metal hydroxide.

The proportion of each component in the present Cu-Al-Fe-Si catalyst is the atomic ratio of Cu to Fe.
05 to 0.35, Si in the range of 0.01 to 0.10, and Al in the range of 0.02 to 1.0 are preferable. Si
It was found that when the ratio is less than 0.01 or exceeds 0.10, the catalytic activity cannot be expected to improve due to the synergistic effect with Fe in any case.

The present catalyst containing Si is, for example, Fe
(1 wt% to 10 wt%), Al (40 wt% to 55 wt%), Si (0.5 wt% to 10 wt%) and Cu
It can be produced by developing an R alloy consisting of (remaining amount) in a usual aqueous solution of alkali metal hydroxide.

In the production of this catalyst, the alkali metal hydroxide used for development is sodium hydroxide (NaO).
H) or potassium hydroxide (KOH) is preferable, and the concentration of the aqueous solution thereof is selected from the range of 15% by weight to 30% by weight. Aqueous solution of alkali metal hydroxide is A in R alloy
It is preferable to use the total amount of 1 in excess of the amount required for elution. The development temperature of the alkali metal hydroxide aqueous solution is 50 ° C. to 95 ° C., more preferably 65 ° C.
It is preferable to select within the range of 85 ° C. Although it is preferable to use the alkali metal hydroxide in an excess amount over the amount necessary to elute the total amount of Al in the R alloy, it is necessary for Al to remain in the present catalyst. The development time is preferably adjusted so that Al within the range remains.

The manufacturing process of this catalyst is roughly composed of an R alloy forming process, a developing process, and a water washing process, and the process is simplified and reproduced in comparison with the conventional method for producing a hydrogen reduction catalyst for the same purpose. An industrial catalyst can be manufactured with good properties.

In this catalyst, what is considered to be the main catalytic component for hydrogen reduction activity is Cu, Fe, among the basic components,
And, when added, it is V, Si or other added metal, and Al is considered to have a cocatalyst or binder-like action. The presence of all of these metal components in the metallic state, not as an oxide, enhances the adsorptivity of hydrogen and aromatic nitro compounds on the active surface of the catalyst, and at the same time is adsorbed on the active surface of the catalyst. Further, the activity of hydrogen is increased, and excellent hydrogen reducing ability is exhibited.

Next, a method for producing an aromatic amino compound using the present catalyst will be described. In the following description, the term "aromatic" shall include "quasi-aromatic". In the present invention, the aromatic nitro compound that can be used as a raw material for producing an aromatic amino compound is not particularly limited, and examples thereof include benzene, naphthalene, diphenyl, anthraquinone, phenanthrene, furan, thiophene, and pyridine. , Benzotriazoles, diphenyl ethers, carbazoles, benzothiazoles, and nitro compounds of their on-ring hydrogen-substituted derivatives. Especially benzene, toluene,
The nitro compounds of naphthalene, phenol, aniline, 5-membered or 6-membered aromatic heterocyclic compounds and their on-ring hydrogen-substituted derivatives can suitably be hydrogen-reduced to the corresponding amino compounds by the process of the invention. Examples include nitrobenzene, alkyl-substituted nitrobenzenes,
Nitronaphthalenes, 4-nitrodiphenyl, nitroanthraquinones, nitrophenanthrenes, 2-nitrofuran, 2-nitrothiophene, 3-nitropyridine,
5-nitro-1H-benzotriazole, 2-nitrodiphenyl ether, isomeric dinitrobenzenes, isomeric nitroanilines, p-nitrobenzoic acid, m-nitrobenzoic acid, o-nitrobenzoic acid, isomeric nitrophenols, o-, m-, p-nitrochlorobenzene, 5-nitro-2-chlorobenzonitrile, 3,4-dichloronitrobenzene, 2-nitro-1,4-phenylenediamine, 2,4-dinitroaniline, 2,4- Examples include dinitrochlorobenzene and isomers of dinitroalkyl-substituted benzenes. Among these, especially nitrobenzene, o-, m-, p-nitrotoluene, and α-
Alternatively, β-nitronaphthalene is a nitro compound suitable for applying the production method of the present invention.

In the method of the present invention, the reaction mode for reacting the above aromatic nitro compound with hydrogen in the presence of the present catalyst to obtain the corresponding aromatic amino compound is not particularly limited, Any of a gas phase method or a liquid phase method, a batch method or a continuous method, which has been generally adopted for hydrogen reduction, can be applied. At this time, the catalyst may be used in any system such as a fixed bed, a moving bed or a suspension bed.

Further, the shape and size of the present catalyst are powdery, particulate, granular, lumpy, depending on the selected reaction system.
A spherical shape, a pellet shape, or the like can be selected at any time. In general, the present catalyst is produced by forming an R alloy ingot, crushing the ingot to obtain an appropriate particle size distribution, and then expanding the crushed ingot. In this case, the catalyst shape becomes irregular, but the catalyst strength is sufficiently high, so even if it is packed in a catalyst tower or the like and used in a fixed bed system, it will not be crushed due to its own weight or vibration, etc. Can be used as a catalyst. For example, when the catalyst is used as a fixed bed, the ingot of R alloy is crushed to have a particle size of, for example, 1 mm to 7 mm, and the developed catalyst is preferably used.

When the present catalyst is used in a suspension bed system in a liquid phase or a gas phase, if the catalyst is irregular in shape, it may rub against each other into fine powder, and separation and recovery after the reaction may be difficult. In this case, it is preferable that the R alloy is formed into a spherical shape and then expanded to be used as a spherical main catalyst. For example, when a spherically shaped R alloy having a particle size of 10 μm to 200 μm is developed, the spherical particles are hardly pulverized by this operation, and the particle size distribution is maintained and used for a suspension bed reaction. It is possible to maintain sufficient mechanical strength. Further, in separation and recovery after the reaction, the catalyst has excellent settling property and filterability, and workability is good.

After being developed, the present catalyst is usually stored in a water-sealed state. In use, it is preferable to use after drying in an inert gas after draining. Since this catalyst is in a reduced state at the time of development, it can be used for the reaction without performing preliminary reduction again. However, 100
If the hydrogen treatment is carried out in the temperature range of ℃ to 300 ℃, the catalytic activity may be further improved.

When the aromatic nitro compound is reacted with hydrogen by the method of the present invention to produce an aromatic amino compound, the reaction temperature is preferably 100 ° C to 300 ° C. The hydrogen pressure is 1 kgG / cm ^{2 to} 30 k.
It is preferably within the range of gG / cm ² . When used in a suspension bed system, the amount of the catalyst used is in the range of 0.1% by weight to 20% by weight, more preferably 0.5% by weight to 10% by weight, based on the aromatic nitro compound as a raw material. It is preferable that In the gas phase method, when the catalyst is used as a fixed bed, the liquid hourly space velocity (LHSV) of the aromatic nitro compound with respect to the fixed catalyst bed is within the range of 0.1 to 10.0, and the aromatic nitro compound is To hydrogen molar ratio is 1/1
It is preferably in the range of 0 to 1/50.

[0028]

The present invention will be described below in more detail with reference to examples. However, the present invention is not limited to the following examples. (Example 1) Production of catalyst: The present catalyst (present catalyst 1) composed of Cu, Fe, V and Al was produced by the following method. The composition is Cu (4
1.7% by weight), Fe (3.8% by weight), V (3.5% by weight) and Al (51.0% by weight) and classified into a particle size range of 4.76 mm to 5.60 mm. Formed R alloy particles, which are added to 65 wt% in a 20 wt% NaOH aqueous solution.
After being developed at from ℃ to 75 ℃, thoroughly washed with water to obtain the present catalyst 1. This catalyst was stored in a water-sealed state until use.

As a result of analysis, the composition of this catalyst 1 was found to be Cu (6
5.05 wt%), Fe (5.93 wt%), V (5.
46% by weight), Al (23.56% by weight), and Cu
The atomic ratio to 1 mol is Fe (0.146 mol), V (0.107 mol), Al (0.105 mol), respectively.
Met. When the R alloy was developed, the fine powder of the catalyst was negligibly small, and almost no difference in particle size distribution was observed between the R alloy and the present catalyst 1.

Hydrogen reduction reaction: Using the main catalyst 1 described above, a hydrogen reduction reaction of nitrobenzene was performed. A cylindrical reactor (SUS-316, inner diameter 18 mmφ) was filled with 15 ml of the drained main catalyst 1 described above, and N ₂ gas was ventilated at 120 ° C. until water was not detected from the reactor outlet.
Dry well.

Then, nitrobenzene and hydrogen were reacted under the following reaction conditions. Reaction temperature: 230 ° C. Reaction pressure: 1 kgG / cm ² Nitrobenzene / hydrogen molar ratio: 1/20 Liquid hourly space velocity of nitrobenzene (LHS)
V); 1.0 hr ^-1

Test results: As a result of analyzing the reaction product by liquid chromatography, the conversion rate of nitrobenzene was 100% and the aniline yield was 99.4%.
This result shows that Cu, Fe and Al are the basic components, and V
It is shown that aniline, which is an aromatic amino compound, was obtained in a very high yield by a gas phase reduction reaction of nitrobenzene using the present catalyst 1 containing the above in a fixed bed system.

(Example 2) Using the same catalyst 1 as in Example 1, the hydrogen reduction reaction of nitrobenzene was carried out in the same manner as in Example 1 except that the reaction conditions were changed as follows. In Example 2, a reaction duration time, that is, a catalyst life test was also performed. Reaction temperature: 250 ° C. Reaction pressure: 1 kgG / cm ² Nitrobenzene / hydrogen molar ratio: 1/20 Liquid hourly space velocity of nitrobenzene with respect to the present catalyst 1 (LHS
V); 1.5 hr ^-1 reaction duration time: 100 hours

Test result: As a result of analysis in the same manner as in Example 1, the conversion of nitrobenzene was 10 at the initial stage of the reaction.
The yield was 0% and the aniline yield was 99.1%, and these values did not change even after 100 hours of reaction. This result indicates that high nitrobenzene conversion and high aniline yield were maintained without decay from the initial reaction to 100 hours later.
It shows that the catalyst life is sufficiently long.

Example 3 Instead of nitrobenzene,
The hydrogen reduction reaction of o-nitrotoluene was performed in the same manner as in Example 1 except that o-nitrotoluene was used. o-
The yield of toluidine was 95.4 mol%, which shows that the aromatic amino compound was obtained in high yield by the method of the present invention even when o-nitrotoluene was used as a raw material.

(Example 4) Instead of nitrobenzene,
The hydrogen reduction reaction of α-nitronaphthalene was carried out in the same manner as in Example 1 except that α-nitronaphthalene was used.
The yield of α-naphthylamine was 94.0 mol%,
Even when -nitronaphthalene is used as a raw material, it is shown that the aromatic amino compound was obtained in high yield by the method of the present invention.

(Example 5) Production of catalyst: Cu, Fe, Si and Al were prepared by the following method.
To produce a main catalyst (main catalyst 2). The composition is Cu
(42.9% by weight), Fe (3.8% by weight), Si
(0.95% by weight) and Al (52.35% by weight), and formed into R alloy particles classified into a particle size of 4.76 mm to 5.60 mm, and added in a 20% by weight NaOH aqueous solution of 65 After being developed at ℃ to 75 ℃, washed thoroughly with water to obtain the present catalyst 2. This catalyst was stored in a water-sealed state until use.

As a result of analysis, the composition of this catalyst 2 was found to be Cu (8
9.37% by weight), Fe (7.95% by weight), Si
(0.54% by weight), Al (2.14% by weight),
The atomic ratio to Cu was Fe (0.10 mol), Si (0.02 mol), and Al (0.06 mol), respectively. When the R alloy was developed, the fine powder of the catalyst was negligibly small, and almost no difference in particle size distribution was observed between the R alloy and the present catalyst 1.

Reduction reaction: Using the above catalyst 2, hydrogen reduction reaction of nitrobenzene was carried out in the same manner as in Example 1. The conversion rate of nitrobenzene in this reaction is 100.
%, And the aniline yield was 98.9%. This result shows that aniline, an aromatic amino compound, was obtained in a very high yield by a gas phase reduction reaction of nitrobenzene using Cu, Fe and Al as basic components and the present catalyst 2 containing Si in a fixed bed system. Has been shown.

Example 6 A main catalyst (main catalyst 3) having a catalyst composition consisting of only basic components of Cu, Fe and Al was produced. The composition is Cu (41.6 wt%), Fe (7.
6% by weight) and Al (50.8% by weight),
An R alloy particle having a particle size of 4.76 mm to 5.60 mm was formed, and the particle size was adjusted to 65 in a 20 wt% NaOH aqueous solution.
After being developed at ℃ to 75 ℃, thoroughly washed with water to obtain the present catalyst 3. This catalyst was stored in a water-sealed state until use.

The composition of this catalyst 3 is as follows: Cu (81.7% by weight), Fe (15.5% by weight), Al (2.8% by weight)
And the atomic ratio to 1 mol of Cu is Fe
(0.081 mol) and Al (0.216 mol).

Reduction reaction: Using the catalyst 3 described above, a hydrogen reduction reaction of nitrobenzene was carried out in the same manner as in Example 1. As a result of the reaction, the conversion rate of nitrobenzene was 100% and the aniline yield was 96.4%. This result shows that the conversion rate of nitrobenzene was 100% and the aniline was also obtained in a high yield even in the present catalyst 3 including only basic components of Cu, Fe and Al.

Comparative Example 1 Nitrobenzene was hydrogen-reduced using a commercially available copper chromite catalyst (comparative catalyst). The composition of Comparative _{Catalyst: CuO-Cr 2 O 3 -Mn} 2 O 3 -B
aO The metal atom ratio of this comparative catalyst was as follows. Metal atomic ratio: Cu (1 mol), Cr (1.02 mol),
Mn (0.05 mol), Ba (0.03 mol) The shape of this comparative catalyst was a pellet having a height of 5 mm and an outer diameter of 5 mmφ.

A cylindrical reactor similar to that of Example 1 (SUS-
316, inner diameter 18 mmφ) with 15 m of the above comparative catalyst
It was filled with 1 L, and N ₂ gas was bubbled at 150 ° C., and it was sufficiently dried until no water was detected from the outlet of the reactor. Then, the temperature of the comparative catalyst layer was raised to 200 ° C., H ₂ was aerated, and a sufficient pretreatment with H ₂ was performed until no water was detected from the outlet of the reactor. Then, nitrobenzene and hydrogen were reacted under the same conditions as in Example 1.

As a result of this reaction, the conversion rate of nitrobenzene after 2 hours from the start of the reaction was 90% and the yield of aniline was 89.
Although it was 3%, after 100 hours, a remarkable decrease in activity was observed with a nitrobenzene conversion rate of 55% and an aniline yield of 54.6%.

[0046]

Industrial Applicability The method for producing an aromatic amino compound of the present invention uses Cu, Fe and Al as basic components, and preferably uses a modified Raney copper containing other metal components, particularly V or Si as a catalyst, Since a nitro compound is reacted with hydrogen, hydrogen is produced in a higher yield and for a longer period of time than when using a commercially available copper chromite catalyst while using a catalyst that is easy to manufacture and highly safe. A reduction reaction becomes possible.

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Claims (4)

[Claims] 1. When producing a corresponding aromatic amino compound by reacting an aromatic nitro compound with hydrogen, C
A method for producing an aromatic amino compound, which comprises using a modified Raney copper catalyst containing u, Fe and Al as basic components. 2. The method for producing an aromatic amino compound according to claim 1, wherein the modified Raney copper catalyst contains V. 3. The method for producing an aromatic amino compound according to claim 1, wherein the modified Raney copper catalyst contains Si. 4. The aromatic nitro compound is nitrobenzene,
It is o-, m-, p-nitrotoluene, or (alpha)-(beta) -nitro naphthalene, The manufacturing method of the aromatic amino compound of Claim 1 characterized by the above-mentioned.