JP2002179636A - Method for producing aromatic nitrile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method that can produce an aromatic nitrile in high yield and high selectivity with reduced consumption of ammonia in the process for producing the aromatic nitrile through a vapor phase catalytic reaction between an aromatic aldehyde and ammonia. SOLUTION: The vapor-phase catalytic reaction between an aromatic aldehyde and ammonia is carried out in the presence of a catalyst including copper oxide and zinc oxide and/or chromium oxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing an aromatic nitrile, and more particularly to a method for producing an aromatic nitrile by subjecting an aromatic aldehyde to a gas-phase catalytic reaction with ammonia in the presence of a catalyst.

[0002]

2. Description of the Related Art A method for producing an aromatic nitrile by reacting an aromatic aldehyde with ammonia in the presence of a catalyst in the presence of a catalyst has been known. For example, a method of producing a catalyst having 15% copper supported on alumina is known. Benzaldehyde in the presence
A method for producing benzonitrile by reacting gas phase with 20 moles of ammonia per mole of benzaldehyde [J. Org. Chem. , 46, 754-757
(1981)], in the presence of a catalyst containing molybdenum, oxygen and nitrogen, a gas phase catalytic reaction of an aromatic aldehyde such as benzaldehyde and an alkyl-substituted benzaldehyde with 10 to 15 mol of ammonia per 1 mol of the aromatic aldehyde. A method for producing aromatic nitriles such as benzonitrile and alkyl-substituted benzonitrile (West German Patent Publication No. 19647779) is known.

[0003]

However, the conventional method uses a large amount of ammonia, and cannot be said to be a method suitable for industrialization. Therefore, an object of the present invention is to provide a method for producing a target nitrile with a smaller amount of ammonia used in a high yield and a high selectivity.

[0004]

Means for Solving the Problems The present inventor has made intensive studies to solve the above-mentioned problems. As a result, in a method of producing an aromatic nitrile by reacting an aromatic aldehyde with ammonia in a gas phase, when a catalyst containing copper oxide and zinc oxide and / or chromium oxide is used as a catalyst, the amount of ammonia used becomes lower than before. The present inventors have found that an aromatic nitrile can be produced with a high yield and a good selectivity even if the amount is small, and have completed the present invention.

That is, the present invention relates to a method for producing an aromatic nitrile by reacting an aromatic aldehyde with ammonia in a gas phase, wherein copper oxide, zinc oxide and / or zinc oxide are used as a catalyst.
Alternatively, the present invention relates to a method for producing an aromatic nitrile, which comprises using a catalyst containing chromium oxide.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the present invention, a catalyst containing copper oxide and zinc oxide and / or chromium oxide is used as a catalyst when an aromatic aldehyde is reacted with ammonia in a gas phase to produce an aromatic nitrile. The ratio of copper oxide to zinc oxide and / or chromium oxide in the catalyst is usually 0.05 to 9 copper oxide.
9.5 parts by weight and zinc oxide and / or chromium oxide in total 9
9.5 to 0.05 parts by weight, preferably copper oxide 10
Total of 9 to 80 parts by weight and zinc oxide and / or chromium oxide
0 to 20 parts by weight, more preferably 20 to 70 parts by weight of copper oxide and 80 to 30 parts by weight of zinc oxide and / or chromium oxide in total. The catalyst containing copper oxide and zinc oxide and / or chromium oxide of the present invention may contain an alkali metal and / or an alkaline earth metal, which are contained as ions and / or compounds (such as oxides). . As long as the object of the present invention can be achieved, the catalyst of the present invention is at least one selected from the group consisting of metal elements belonging to Group 1, Group 2, Group 3, Group 4, Group 5, and Group 6 of the periodic table. May be contained as a metal, an ion and / or a compound.

[0007] The compounds of copper, zinc and chromium used as raw materials for preparing the catalyst of the present invention include complexes, acetates, carbonates, halides, hydroxides, nitrates, phosphates, sulfates, oxalates. A variety of compounds can be used, such as, lactate and formate. Further, in the preparation of a catalyst containing at least one metal element selected from the group consisting of metal elements belonging to Group 1, Group 2, Group 3, Group 4, Group 5, and Group 6 of the periodic table, Acetates, carbonates, halides, hydroxides, nitrates, phosphates, sulfates, oxalates, lactates and formates of the respective metal elements can be used as raw materials.

The catalyst of the present invention can be prepared by a known method such as a coprecipitation method, an impregnation method, a dipping method, and a kneading method. As a specific example of catalyst preparation, for example, when preparing by a coprecipitation method, after mixing the above raw material compounds in a suitable solvent such as water, concentrating, drying and calcining in air The catalyst of the present invention can be obtained. The catalyst of the present invention can be obtained as a commercial product.

The catalyst containing copper oxide and zinc oxide and / or chromium oxide of the present invention can be used as it is or supported on a carrier. As the carrier, a known carrier used as a catalyst can be widely used, and examples thereof include silica and alumina. For a catalyst in which copper oxide, zinc oxide and / or chromium oxide is supported on a carrier, a conventionally known method can be applied as a method for preparing a carrier-supported catalyst. The content of copper oxide, zinc oxide and / or chromium oxide in the catalyst supported on the carrier is usually 0.01 to 60% by weight, preferably 1 to 50% by weight, more preferably 10 to 50% by weight based on the weight of the carrier.
４０40% by weight.

The catalyst of the present invention is formed into a desired shape such as a powder, a column, a cylinder, a sphere, and a granule, and is used in the gas phase contact reaction of the present invention.

The aromatic aldehyde used in the present invention includes, for example, a compound represented by the following general formula (1):

[0012]

Embedded image (Wherein, R represents an alkyl group, and n is an integer of 0 to 5). In the general formula (1), R of the formyl group and the substituent is a group bonded to a carbon atom of an aromatic ring. Examples of the alkyl group represented by R include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and s.
ec-butyl group, tert-butyl group, n-butyl group,
Linear or branched alkyl having 1 to 6 carbon atoms such as isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, isohexyl group, and neohexyl group. And a linear or branched alkyl group having 1 to 4 carbon atoms. When n is an integer of 2 or more, the plurality of substituents R may be the same alkyl group or different alkyl groups. Particularly preferred aromatic aldehydes are those in which R is a methyl group and n is 0 or 1 in the general formula (1). For example, benzaldehyde, p-tolualdehyde, o-tolualdehyde, and m-tolualdehyde are preferred. No.

The gas phase catalytic reaction of the present invention may be carried out by supplying an aromatic aldehyde and ammonia to a reactor in which the catalyst of the present invention is present. According to the present invention, an aromatic nitrile can be produced in high yield even if the amount of ammonia used is smaller than that in the conventional method. Therefore, the amount of ammonia used is usually 1 to 9 moles per mole of aromatic aldehyde,
Preferably, 2 to 5 mol is sufficient.

In the reaction, an inert gas such as nitrogen, helium, steam or the like may be further used as a diluent, and a preferred diluent is nitrogen. When a diluent is used, the amount of the diluent used is usually 0.1 mol per mol of aromatic aldehyde.
１００100 mol, preferably 1-40 mol.

The reaction of the present invention may be carried out in a fixed bed reactor or a fluidized bed.
It can be performed in a reactor. Gas phase catalytic reaction of the present invention
Is carried out using a fixed-bed reactor.
And filling the reaction tube with a catalyst, for example,
Parts, usually from 250 to 550 ° C, preferably from 300 to 50 ° C.
Heat to 0 ° C. Next, a fragrance was added to the catalyst filling section of the reaction tube.
Supply of aromatic aldehyde and ammonia and optional diluent
To perform a gas phase contact reaction. Liquid space velocity of aromatic aldehyde
The degree (hereinafter referred to as LHSV) is usually 0.01 to 5.0.
g / (ml catalyst · hr), preferably 0.1 to 2.0 g
/ (Ml catalyst · hr). Also aromatic aldehydes
Gas mixture of gas, ammonia and, if desired, diluent
Is usually 1-220.
000hr ^-1, Preferably 10-26000 hr^-1In
You. The reaction is carried out under normal pressure, reduced pressure or increased pressure.
Can be

When the reaction is carried out as described above, an aromatic nitrile in which the formyl group of the aromatic aldehyde used has been converted to a cyano group can be produced. For example, from the aromatic aldehyde represented by the general formula (1), the general formula (2):

[0017]

Embedded image (Wherein, R and n are the same as described above). Specifically, from the particularly preferred aromatic aldehydes benzaldehyde, p-tolualdehyde, o-tolualdehyde, and m-tolualdehyde,
Benzonitrile, p-tolunitrile, o-tolunitrile and m-tolunitrile are obtained respectively.

When the reaction is carried out as described above, and the reaction gas flowing out of the reactor is cooled and / or passed through a suitable solvent as it is, an aggregate and / or a solution containing an aromatic nitrile is obtained. From the obtained condensate or collected liquid, concentration,
An aromatic nitrile can be isolated by combining unit operations such as distillation.

[0019]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited to only the Examples. The conversion, yield and selectivity in the following examples were calculated according to the following definitions.

Conversion (%) = reacted aromatic aldehyde (mol) × 100 / aromatic aldehyde supplied (mol)

Yield (%) = Aromatic nitrile (mol) generated by reaction × 100 / Aromatic aldehyde supplied (mol)

Selectivity (%) = Aromatic nitrile formed by the reaction (mol) × 100 / Aromatic aldehyde reacted (mol)

Example 1 Copper oxide / zinc oxide / alumina (weight ratio) = 4 as a catalyst
2/47/10 [0.6cm × 0.3cm tablet,
Toyo CCI Co., Ltd.] (hereinafter, catalyst A) was charged into a Pyrex (registered trademark) reaction tube having an inner diameter of 18 mmφ, and the temperature of the catalyst-filled portion of the reaction tube was increased to 360 ° C. L-HSV = p-tolualdehyde was added to the catalyst-filled portion.
0.4 g / (ml catalyst · hr) and ammonia
3 moles per mole of tolualdehyde (37.3 ml /
Min) supplied. The reaction product gas flowing out of the reaction
The mixture was passed through 100 ml of acetonitrile for one minute to dissolve the soluble components in the reaction product gas in acetonitrile. The obtained solution was analyzed by gas chromatography. As a result, the conversion of p-tolualdehyde was 97.2%, the yield of p-tolunitrile was 91.8%, and the selectivity was 94.5%.

Example 2 In Example 1, copper / zinc oxide (weight ratio) = 42/48 [0.6 cm × 0.6 cm tablet, manufactured by Toyo CCI Co., Ltd.] was used in place of catalyst A. Performed in the same manner as in Example 1. As a result, the conversion of p-tolualdehyde was 97.3%, the yield of p-tolunitrile was 89.3%,
The selectivity was 91.8%.

Example 3 In Example 1, except that the catalyst A was replaced by copper oxide / zinc oxide (weight ratio) = 33/65 [0.6 cm × 0.3 cm tablet, manufactured by Nissan Gardler Co., Ltd.] Example 1
The same was done. As a result, the conversion of p-tolualdehyde was 97.3% and the yield of p-tolunitrile was 88.4.
% And selectivity was 90.9%.

Example 4 10.0 ml of the catalyst A was charged into a Pyrex reaction tube having an inner diameter of 18 mmφ, and the temperature of the catalyst-filled portion of the reaction tube was raised to 360 ° C. Benzaldehyde is added to this catalyst filled part by LHS
V = 0.4 g / (ml catalyst · hr), and 3 moles (42.2 ml) of ammonia to 1 mole of benzaldehyde
/ Min). The reaction product gas flowing out of the reaction tube is 1
The mixture was passed through 100 ml of methanol for 0 minutes to dissolve the soluble components in the reaction product gas in methanol. The obtained solution was analyzed by gas chromatography. As a result, the conversion of benzaldehyde was 100.0%, the yield of benzonitrile was 95.8%, and the selectivity was 95.8%.

Example 5 In Example 4, copper oxide / zinc oxide (weight ratio) = 33/65 [0.6 cm × 0.3 cm tablet, manufactured by Nissan Gardler Co., Ltd.] was used instead of the catalyst A. The same operation as in Example 4 was performed except that the temperature of the filling section was changed to 410 ° C. As a result, the conversion of benzaldehyde was 100.0%.
%, The yield of benzonitrile is 93.7%, and the selectivity is 9
3.7%.

Example 6 In Example 4, copper oxide / zinc oxide / alumina (weight ratio) = 30/60/10 [0.6 cm ×
0.3 cm tablet, manufactured by Nissan Gardler Co., Ltd.], and the temperature of the catalyst-filled part was changed to 435 ° C. As a result, the conversion of benzaldehyde was 100.0% and the yield of benzonitrile was 85.0.
% And selectivity was 85.0%.

Example 7 In Example 4, copper oxide / zinc oxide (weight ratio) = 49/45 [cylindrical molded product manufactured by JGC Corporation] in place of catalyst A
And the same procedure as in Example 1 was carried out except that the temperature of the catalyst charging section was changed to 380 ° C. As a result, the conversion of benzaldehyde was 98.0%, and the yield of benzonitrile was 96.
The selectivity was 18.0% and the selectivity was 98.0%.

Example 8 In Example 4, copper oxide / chromium oxide (weight ratio) = 40 / 26.5 [0.5 cm × 0.3 c] in place of catalyst A
m, 0.5cm × 0.5cm, 0.6cm × 0.6cm
Tablet, manufactured by Nissan Gardler Co., Ltd.], and the temperature was changed to 380 ° C. in the catalyst-filled portion, and the same procedure was performed as in Example 1. As a result, the conversion of benzaldehyde was 10
0.0%, the yield of benzonitrile was 96.4%, and the selectivity was 96.4%.

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Claims (1)

[Claims] 1. A process for producing an aromatic nitrile by reacting an aromatic aldehyde with ammonia in the presence of a catalyst in the gas phase, wherein a catalyst containing copper oxide and zinc oxide and / or chromium oxide is used as the catalyst. A method for producing an aromatic nitrile.