JPH11209332A - Method for producing nitrile compound and catalyst for production - Google Patents

Abstract

(57) Abstract: A nitrile compound is produced in a high yield in a contact reaction between an alkyl-substituted aromatic compound or an alkyl-substituted heterocyclic compound and a mixed gas containing ammonia and oxygen. A catalyst comprising vanadium oxide, chromium oxide, boron oxide, molybdenum oxide and an alkali metal or alkaline earth oxide is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a corresponding nitrile compound from a mixed gas containing an alkyl-substituted aromatic compound or an alkyl-substituted heterocyclic compound and ammonia and oxygen. Nitrile compounds derived from alkyl-substituted aromatic compounds are important intermediates in the organic chemical industry.For example, phthalonitrile is a raw material for synthetic resins, agricultural chemicals, and xylylenediamine, which is useful as a curing agent for diisocyanates and epoxy resins. Used for On the other hand, cyanopyridine derived from an alkyl-substituted heterocyclic compound is used as a raw material for nicotinamide or nicotinic acid, which is a useful substance in the fields of pharmaceuticals, feed additives, food additives and the like.

[0002]

2. Description of the Related Art Various methods have been proposed for producing an aromatic nitrile by ammoxidizing an alkyl-substituted aromatic compound with ammonia and oxygen. For example, Japanese Patent Publication No. 45-1
No. 9284 describes a ternary catalyst of vanadium, chromium and boron. In JP-B-49-45860, silica is used as a carrier for this three-component catalyst, and the atomic ratio of vanadium oxide, chromium oxide, and boron oxide is 1: (0.5 to 2.0) :( 0.1-1.2)
Describes 30 to 60% by weight of a supported catalyst based on silica. In Japanese Patent Publication No. 51-15028,
The atomic ratio of vanadium oxide, chromium oxide, boron oxide and phosphorus oxide is 1: (0.5-2.0) :( 0.
1-1.2): (0.01-0.3), and JP-A-1-275551 discloses vanadium oxide, chromium oxide, molybdenum oxide and boron oxide. The atomic ratio is 1: (0.5 to 2.0) :( 0.01
To 1.2): (0.01 to 1.2). On the other hand, as an example of producing a corresponding nitrile compound by ammoxidizing an alkyl-substituted heterocyclic compound, Japanese Patent Application Laid-Open No. 1-275564 discloses a method for producing cyanopyridine by reacting methylpyridine with ammonia and an oxygen-containing gas. Vanadium oxide supported on silica,
It is described that a catalyst composed of chromium oxide and boron oxide is used.

[0003]

The ammoxidation reaction in which ammonia and oxygen are reacted with an alkyl-substituted compound in the gas phase with an alkyl-substituted compound generates a large amount of heat of reaction, so that the control of the reaction temperature is extremely difficult. Is particularly effective. JP-B-51-15028 and JP-A-1-275
No. 551 is a catalyst for a fluidized bed reactor,
No. 19284 and JP-B-49-45860 have improved the yield of nitrile compounds by adding phosphorus oxide and molybdenum oxide to vanadium oxide, chromium oxide and boron oxide. However,
These catalysts do not always have a sufficient nitrile compound yield, and further improvement is desired. The purpose of the present invention is
An object of the present invention is to provide a method for producing a nitrile compound in a high yield in a contact reaction between an alkyl-substituted aromatic compound or an alkyl-substituted heterocyclic compound and a mixed gas containing ammonia and oxygen.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have conducted intensive studies to further improve the yield of a nitrile compound in an ammoxidation reaction of an alkyl-substituted aromatic compound or an alkyl-substituted heterocyclic compound. Use a four-component catalyst composed of vanadium oxide, chromium oxide, boron oxide, and molybdenum oxide, and a five-component catalyst having a specific composition further added with an alkali metal oxide or an alkaline earth metal oxide. As a result, it has been found that the nitrile yield is remarkably improved, and the present invention has been achieved.

That is, the present invention provides a method for producing a nitrile compound by contacting an alkyl-substituted aromatic compound or an alkyl-substituted heterocyclic compound with a mixed gas containing ammonia and oxygen on a catalyst. , A method for producing a nitrile compound, comprising using a catalyst comprising a boron oxide, a molybdenum oxide and an oxide of an alkali metal or an alkaline earth metal; and vanadium oxide, chromium oxide, boron oxide, and molybdenum. A catalyst for producing a nitrile compound, comprising an oxide and an oxide of an alkali metal or an alkaline earth metal supported on silica.

[0006]

DETAILED DESCRIPTION OF THE INVENTION The starting materials for the vanadium oxide, chromium oxide, boron oxide and molybdenum oxide components used in the catalyst of the present invention include, for example, vanadium such as ammonium metavanadate, vanadyl sulfate and oxalic acid. , Vanadium salts of organic acids such as tartaric acid are used,
Chromium includes chromic acid, chromium nitrate, chromium hydroxide, ammonium chromate, ammonium bichromate,
And chromium salts of organic acids such as oxalic acid and tartaric acid; boron as boric acid, ammonium borate; and molybdenum as molybdic acid, ammonium paramolybdate, and molybdenum salts of organic acids such as oxalic acid and tartaric acid. used.

A feature of the present invention is that an alkali metal or an alkaline earth metal is added in addition to the above four-component metal oxide. As the raw material of the alkali metal, lithium, sodium, potassium, rubidium, cesium hydroxides, carbonates, nitrates, and organic acid salts such as oxalic acid, tartaric acid, and acetic acid are preferably used. As the raw material of the alkaline earth metal, hydroxides, nitrates of magnesium, calcium, strontium and barium, and organic acid salts such as oxalic acid, tartaric acid and acetic acid are preferably used.

The atomic ratio of the catalyst components vanadium, chromium, boron, molybdenum, alkali metal or alkaline earth metal is 1: (0.5-2.0) :( 0.01-1.
5): (0.01 to 1.5): (0.005 to 0.2)
When the atomic ratio of each catalyst component is out of the range, the yield of the nitrile compound decreases.

In the present invention, a catalyst comprising the above catalyst component supported on silica is preferably used. Examples of the silica used for the carrier include, for example, Chemical Handbook, Applied Chemistry Edition I (Maruzen 198)
Silica gel, colloidal silica, anhydrous silica and the like described on pages 256 to 258) are used. The concentration of the catalyst component was determined using oxides (V ₂ O ₅ , Cr ₂ O ₃ , B ₂ O ₃ ,
(MoO ₃ , XeO) 20 to 80% by weight, preferably 30 to 80% by weight,
60% by weight (where X is Li, Na, K, R
b, at least one element selected from the group consisting of Cs, Mg, Ca, Sr, and Ba, and e is an integer of 2 for an alkali metal oxide and 1 for an alkaline earth metal).

[0010] The catalyst of the present invention can be produced by a known method. For example, an aqueous solution of ammonium paramolybdate, an aqueous solution of boric acid and potassium or calcium acetate are added to a solution of vanadium oxide and chromium oxide dissolved in oxalic acid, and then a silica sol is added to obtain a slurry mixture. In this case, if necessary, a dissolution aid for boric acid is used. Polyhydric alcohol, α-monooxycarboxylic acid, and dioxycarboxylic acid are used as a dissolution aid for boric acid. In the case of a fluidized bed catalyst, this mixture is spray-dried and, if necessary, further dried at 110 to 150 ° C.
Bake. In the case of a fixed bed catalyst, the mixture is evaporated to dryness and then calcined. The calcination is performed at 400 to 700 ° C., preferably 450 to 650 ° C., for several hours or more while flowing air. It is to be noted that a more preferable result can be obtained by performing preliminary firing at 200 to 400 ° C. prior to the firing.

In the present invention, the starting alkyl-substituted aromatic compound subjected to the ammoxidation reaction includes toluene,
Ethylbenzene, polymethylbenzene (xylene, mesitylene, cymene, durene, etc.), diethylbenzene,
Methyl naphthalene and the like can be mentioned. Examples of the alkyl-substituted heterocyclic compound include methylpyridine, ethylpyridine, dimethylpyridine, methylquinoline and the like. The concentration of these raw material alkyl compounds in the gas supplied to the reactor is 0.5 to 0.5 when air is used as an oxygen source.
A range of 5 vol% is appropriate.

The amount of ammonia used may be at least the theoretical amount (1 mole of ammonia per mole of alkyl group). The higher the molar ratio of the ammonia / alkyl-substituted compound in the raw material gas is, the more advantageous the nitrile yield from the raw material alkyl is. Preferably about 2 to 10 times the theoretical value is economically advantageous. As the oxygen source, air is usually used, but other inert diluents such as nitrogen, carbon dioxide, water vapor and the like may be used. The amount of oxygen to be supplied needs to be at least 1.5 times the stoichiometric amount, and preferably 2 to 50 times the stoichiometric amount.
It is twice.

The reaction temperature can be carried out in a wide range from 300 to 500 ° C., preferably from 330 to 470 ° C. At a temperature lower than 300 ° C., the conversion of the starting alkyl compound is small, and at a temperature higher than 500 ° C., carbon dioxide,
Production of hydrogen cyanide and the like increases, and the yield of the nitrile compound decreases. The reaction temperature at which the highest yield is obtained varies depending on the type of the raw material alkyl-substituted compound, the raw material concentration, the contact time, the calcination temperature of the catalyst, and the like. The reaction of the present invention is generally
The reaction is carried out at normal pressure, but can be carried out under increased or reduced pressure. The contact time between the reaction gas and the catalyst can be quite wide, but is generally in the range of 0.5 to 30 seconds.

The collection of the reaction product may be performed by any appropriate method,
For example, a method of collecting the product by cooling to a temperature sufficient to precipitate the product, a method of washing and collecting the reaction product gas with water or another suitable solvent, and the like are used. As described above, since the reaction of the present invention is accompanied by intense heat generation, removal of reaction heat,
In order to prevent partial heating, it is advantageous to carry out the reaction in a fluidized bed or a moving bed, but even if the reaction is carried out in a fixed bed, the characteristics of the catalyst of the present invention are exhibited and excellent performance is maintained. .

[0015]

Next, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited by these examples.

Comparative Example 1 (Preparation of catalyst) 500 ml of water was added to 229 g of vanadium pentoxide V ₂ O ₅ , heated to 80 to 90 ° C., and 477 g of oxalic acid was added and dissolved with good stirring. Also, 400 ml of water was added to 963 g of oxalic acid and heated to 50 to 60 ° C.
A solution prepared by adding 252 g of chromic anhydride CrO ₃ to 200 ml of water was added thereto with good stirring and dissolved. The solution of vanadyl oxalate thus obtained was mixed with a solution of chromium oxalate at 50 to 60 ° C. to obtain a vanadium-chromium solution. Meanwhile 44g of ammonium paramolybdate _{(NH 4) 6 Mo 7 O} 24 · 4H 2 O and 300ml of water was added to and mixed well at 30 to 40 ° C.. The aqueous solution of ammonium paramolybdate was added to the above vanadium and chromium solution, and 2501 g of a 20 wt% aqueous silica sol was further added. 78 g of boric acid H ₃ BO ₃ was added to the slurry solution.
Was added and mixed well, and the mixture was concentrated until the liquid amount became about 3800 g. This catalyst solution was heated at an inlet temperature of 250 ° C. and an outlet temperature of 13 ° C.
Spray drying was performed while maintaining the temperature at 0 ° C. 1 spray-dried catalyst
After being dried in a dryer at 30 ° C. for 12 hours, it was temporarily fired at 400 ° C. for 0.5 hour, and then fired at 550 ° C. for 8 hours in an air stream. The atomic ratio of this catalyst is such that V: Cr: B: Mo is 1:
1: 0.5: 0.1, and the catalyst concentration is 5
0 wt%.

(Catalyst activity test) A reactor having an inner diameter of 23 mm heated by a resistance heating element was charged with 40 ml of this catalyst, and a metaxylene concentration of 3.0 vol% and ammonia 2 were added.
A gas consisting of 1.0 vol% and 76.0 vol% air was subjected to a space time SV750Hr at 370 ° C., the temperature at which the catalyst gave the highest isophthalonitrile yield.
^A fluid contact reaction was performed under the conditions of ^-1 . As a result, the yield of isophthalonitrile based on meta-xylene was 72.6 mol.
%, The yield of metatolunitrile was 2.9 mol%, and the selectivity of isophthalonitrile to reacted meta-xylene was 72.7 mol%.

Example 1 (Preparation of catalyst) 500 ml of water was added to 229 g of vanadium pentoxide V ₂ O ₅ , heated to 80 to 90 ° C., and 477 g of oxalic acid was added and dissolved with good stirring. Also, 400 ml of water was added to 963 g of oxalic acid and heated to 50 to 60 ° C.
A solution obtained by adding 252 g of chromic anhydride CrO ₃ to 200 ml of water was added and dissolved with good stirring. The solution of vanadyl oxalate thus obtained was mixed with a solution of chromium oxalate at 50 to 60 ° C. to obtain a vanadium-chromium solution. Meanwhile 44g of ammonium paramolybdate _{(NH 4) 6 Mo 7 O} 24 · 4H 2 O and 300ml of water was added to and mixed well at 30 to 40 ° C.. This aqueous solution of ammonium paramolybdate is added to the above vanadium and chromium solution, then 100 ml of water is added to 9.05 g of lithium carbonate Li ₂ CO ₃ and dissolved, and then added to the above mixed solution. Further, 2501 g of a 20 wt% aqueous silica sol is added. To this slurry solution, 78 g of boric acid H ₃ BO ₃ is added, mixed well, and concentrated until the liquid amount becomes about 3800 g. This catalyst solution was heated at an inlet temperature of 250 ° C. and an outlet temperature of 130 ° C.
Spray drying was carried out while maintaining the temperature. 13 spray-dried catalysts
After being dried in a dryer at 0 ° C. for 12 hours, it was temporarily fired at 400 ° C. for 0.5 hour, and then fired at 550 ° C. for 8 hours in an air stream. The atomic ratio of this catalyst is V: Cr: B: Mo: Li in a ratio of 1: 1: 0.5: 0.1: 0.077, and the catalyst concentration is 50 wt%.

(Activity test of catalyst) An activity test was carried out in the same manner as in Comparative Example 1 using the catalyst prepared as described above. A gas consisting of 3.0 vol% of meta-xylene, 21.0 vol% of ammonia, and 76.0 vol% of air was passed through 390 ° C., the temperature at which the catalyst gave the highest isophthalonitrile yield.
The reaction was performed under the condition of SV750Hr- ¹ . As a result, the yield of isophthalonitrile based on meta-xylene was 82.3.
mol%, the yield of metatolunitrile was 2.2 mol%, and the selectivity of isophthalonitrile to reacted metaxylene was 82.5 mol%.

Example 2 Sodium carbonate Na ₂ was used instead of lithium carbonate in Example 1.
Example 1 A catalyst using CO ₃ and having an atomic ratio of V: Cr: B: Mo: Na of 1: 1: 0.5: 0.2: 0.046 was used.
And an activity test of the catalyst was carried out. Meta-xylene 3.0 vol%, ammonia 21.0 vol%,
A gas consisting of 76.0 vol% of air is heated to 410 ° C., the temperature at which this catalyst gives the highest isophthalonitrile yield.
The reaction was carried out under the conditions of ° C and SV750Hr- ¹ . As a result,
The isophthalonitrile yield based on meta-xylene is 8
1.7 mol%, the yield of metatolunitrile is 2.8 mol
1%, and the selectivity of isophthalonitrile to reacted meta-xylene was 81.9 mol%.

Example 3 Potassium acetate CH ₃ C in place of lithium carbonate in Example 1
Using OOK, V: Cr: B: Mo: K is an atomic ratio of 1:
A catalyst of 1: 0.5: 0.2: 0.027 was prepared in the same manner as in Example 1, and an activity test of the catalyst was performed. A gas consisting of 3.0 vol% of meta-xylene, 21.0 vol% of ammonia and 76.0 vol% of air was supplied at 410 ° C., which is the temperature at which the catalyst gives the highest isophthalonitrile yield.
The reaction was performed under the condition of V750Hr- ¹ . As a result, the yield of isophthalonitrile based on meta-xylene was 86.4 m.
ol%, the yield of metatolunitrile was 2.6 mol%, and the selectivity of isophthalonitrile to reacted meta-xylene was 86.7 mol%.

Example 4 In place of lithium carbonate in Example 1, calcium acetate (CH
A catalyst having an atomic ratio of V: Cr: B: Mo: Ca of 1: 1: 0.5: 0.2: 0.039 using ₃ COO) ₂ Ca was prepared in the same manner as in Example 1. Was tested for activity. Meta-xylene 3.0 vol%, ammonia 21.0
A gas consisting of 76.0 vol% of air and 76.0 vol% of air was reacted under the conditions of 410 ° C. and SV 750 Hr ⁻¹ , which are the temperatures at which this catalyst gives the highest isophthalonitrile yield. As a result, the yield of isophthalonitrile relative to meta-xylene was 85.1 mol%, and the yield of metatolunitrile was 1.
9 mol%, and the selectivity of isophthalonitrile to reacted meta-xylene was 85.5 mol%.

Example 5 The catalyst prepared in Example 3 was used instead of meta-xylene
Using para-xylene, the activity of the catalyst was the same as in Example 1.
The test was performed. 3.2 vol% of para-xylene, ammonium
A Gas consisting of 19.5 vol% and air 77.3 vol%
This catalyst gives the highest terephthalonitrile yield
400 ℃, SV800Hr ^-1Reaction under the conditions
I let it. As a result, terephthaloni
The yield of tolyl is 85.9 mol%,
The yield is 1.5 mol%, and
The selectivity of terephthalonitrile to 86.1 mol%
Met.

Example 6 An activity test of the catalyst was carried out in the same manner as in Example 1 except that the catalyst prepared in Example 3 was replaced with toluene in place of meta-xylene. Toluene 5.1 vol%, ammonia 25.
A gas consisting of 0 vol% and 69.9 vol% air was reacted under the conditions of 410 ° C. and SV840 Hr ⁻¹ , which are the temperatures at which the catalyst gives the highest benzonitrile yield. As a result, the yield of benzonitrile based on toluene was 83.30.
5 mol%, and the selectivity of benzonitrile to the reacted toluene was 83.9 mol%.

Example 7 Using the catalyst prepared in Example 1 instead of meta-xylene
A catalyst activity test was performed in the same manner as in Example 1 using 3-methylpyridine. 3.0 vol% of 3-methylpyridine,
A gas consisting of 12.0 vol% of ammonia and 85.0 vol% of air was reacted under the conditions of 390 ° C. and SV 750 Hr ⁻¹ , which are the temperatures at which this catalyst gives the highest yield of 3-cyanopyridine. As a result, 3-methylpyridine
The yield of cyanopyridine was 93.3 mol%, and the selectivity of 3-cyanopyridine to reacted 3-methylpyridine was 93.6 mol%.

[0026]

As is clear from the above embodiments, the present invention supports vanadium oxide, chromium oxide, boron oxide, molybdenum oxide and alkali metal oxide or alkaline earth metal oxide. By using the above catalyst, an alkyl-substituted aromatic compound or an alkyl-substituted heterocyclic compound is ammoxidized to obtain a corresponding nitrile compound in an extremely high yield. Therefore, according to the present invention, a nitrile compound can be industrially extremely advantageously produced,
The industrial significance of the present invention is great.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // C07B 61/00 300 C07B 61/00 300 (72) Inventor Kinya Tsuji Kinuya 182, Tayuhama-ji, Niigata City, Niigata Prefecture Mitsubishi Gas Niigata Research Laboratory

Claims (5)

[Claims] 1. A vanadium oxide, a chromium oxide, a boron oxide, etc., for producing a nitrile compound by contacting an alkyl-substituted aromatic compound or an alkyl-substituted heterocyclic compound with a mixed gas containing ammonia and oxygen on a catalyst. A method for producing a nitrile compound, comprising using a catalyst comprising a substance, molybdenum oxide and an oxide of an alkali metal or an alkaline earth metal. 2. The method for producing a nitrile compound according to claim 1, wherein the alkali metal or alkaline earth metal is at least one element selected from lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium and barium. . 3. The atomic ratio of vanadium, chromium, boron, molybdenum, alkali metal or alkaline earth metal is 1:
(0.5 to 2.0): (0.01 to 1.5): (0.0
The method for producing a nitrile compound according to claim 1, wherein the ratio is in the range of (1 to 1.5): (0.005 to 0.2). 4. A catalyst in which an oxide of a vanadium oxide, a chromium oxide, a boron oxide, a molybdenum oxide and an alkali metal or an alkaline earth metal is supported on silica in an amount of 20 to 80% by weight. The manufacturing method as described. 5. A catalyst for producing a nitrile compound, comprising vanadium oxide, chromium oxide, boron oxide, molybdenum oxide and an alkali metal or alkaline earth metal oxide supported on silica.