JP2002292283A - Compound metal oxide catalyst and method for gaseous phase catalytic oxidizing reaction using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compound metal oxide catalyst for gaseous phase catalytic oxidizing reaction which keeps a high yield for a long term. SOLUTION: The compound metal oxide catalyst is represented by formula (1): Mo1 Vb Tec Nbd Xx On . Therein, X is an element of group 1 to 14 in periodic table, represents at least one or more elements which are selected from the elements other than Mo, V, Nb, Te and O, 0.2<b<0.3, 0.01<c<0.3, 0.15<d<0.2, 0<=x<0.8 and (n) is a value which is determined by oxidation states of other elements.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel composite metal oxide catalyst and a method for the gas phase catalytic oxidation of alkanes using the same.

[0002]

2. Description of the Related Art There have been many reports on catalysts used in the production of unsaturated nitriles from alkanes by gas phase catalytic oxidation. For example, for the production of acrylonitrile by a gas phase catalytic oxidation reaction of propane and ammonia, a composite metal oxide catalyst containing Mo, V, and Te as essential components proposed by the present inventor (JP-A-2-257) JP-A-5-148212, JP-A-5-208
136) and a composite metal oxide catalyst containing Mo, V, and Sb as essential components (JP-A-9-157241) exhibit excellent performance.

Japanese Patent Application Laid-Open No. H11-124361 discloses a Mo-Te-V-Nb-based composite metal oxide catalyst, but a tellurium-containing composite metal oxide catalyst is used for an ammoxidation reaction. to be as the useful nitrites yield and catalyst deterioration over time is reduced, a method of adding a tellurium compound as an activator is proposed during the reaction.

[0004]

When industrially carrying out the THE INVENTION It is an object to solve gas phase catalytic oxidation reaction is not only the initial yield, a method capable of maintaining a high nitrile yield over a long period of time is extremely important. However, Japanese Patent Application Laid-Open No. 11-12 / 1999
In the method of No. 4361, a useful nitrile yield may not always be maintained depending on the specifications and operating conditions of the reactor to be used, and it cannot be said that the method is generally effective. An object of the present invention is to provide a catalyst which can maintain a high yield over a long period of time.

[0005]

DISCLOSURE OF THE INVENTION The present inventors have conducted intensive studies on Mo-Te-V-Nb-based composite metal oxide catalysts while taking the above-mentioned problems into consideration. The inventors have found that composite metal oxide catalysts each having a specific composition ratio can maintain a high nitrile yield for a long period of time, and have completed the present invention.

That is, the gist of the present invention is to provide the following composition formula (1)
And a gas-phase catalytic oxidation reaction method comprising subjecting an alkane to a gas-phase catalytic oxidation reaction with a nitrogen source in the presence of the oxide catalyst.

[0007]

## STR2 ## _{Mo 1 V b Te c Nb d} X x O n
(1) (In the formula (1), X is 1 to 3 in the periodic table.
Group 16 element, which represents one or more elements selected from the group other than Mo, V, and Nb, and 0.2 <b <0.3, 0.01 <c <
0.3 a 0.15 <d <0.2,0 ≦ x <0.8, n is a value determined by the oxidation states of the other elements)

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. (Description of Composite Metal Oxide Catalyst) The composite metal oxide catalyst of the present invention has the following composition formula (1) before use in the gas phase catalytic oxidation reaction. Have a specific composition ratio.

[0009]

Embedded image in _{Mo 1 V b Te c Nb d} X x O n (1) ( Formula (1), X is an element of the 1 to 16 of the periodic table, Mo, V, 1 or more selected from other than Nb Represents an element of 0.2 <b <0.3, 0.01 <c <0.3, 0.
15 is a <d <0.2,0 ≦ x <0.8, n is a value determined by the oxidation states of the other elements) X is specifically a rare earth, yttrium, bismuth,
Selected tantalum, gallium, germanium, cobalt, manganese, nickel, iron, lead, tungsten, rhenium, ruthenium, rhodium, zinc, tin, titanium, zirconium, boron, indium, chromium, phosphorus, aluminum, alkali, alkaline earth metal At least one element selected from zirconium and rare earths, and more preferably yttrium or cerium.

The composition of each element of the composite metal oxide catalyst of the present invention will be described. Molar ratio of V to Mo (b)
Is greater than 0.2, more preferably 0.22 or more. Also, the upper limit is less than 0.3, preferably 0.1.
28 or less. The molar ratio of Te to Mo (c) is
It is larger than 0.01, preferably larger than 0.03, more preferably larger than 0.05, particularly preferably larger than 0.08. The upper limit is less than 0.3, preferably less than 0.2, more preferably less than 0.17, particularly preferably 0.13 or less. The molar ratio (d) of Nb to Mo is greater than 0.15, preferably 0.16 or more, and the upper limit is less than 0.2, preferably 0.18 or less. The molar ratio of X to Mo is 0 or more, preferably 0.02 or more, more preferably 0.03 or more, and the upper limit is less than 0.8.
Preferably it is less than 0.30, more preferably less than 0.20. By setting the content in such a range, the yield of the target product is improved, and a high yield can be maintained over a long period of time. Oxide catalyst of the present invention, and strength improvement of the catalyst, in order to prevent aggregation of the catalyst particles may also contain SiO _2, the SiO ₂ content, 3 in a weight ratio to the total oxide after the normal firing 50 percent by weight, preferably from 5 to
25% by weight. (Method for Producing Composite Metal Oxide Catalyst) A method for producing the composite metal oxide catalyst of the present invention is generally as follows. A predetermined amount of Mo raw material, V raw material, Te material, Nb raw material, the solution or slurry containing X raw material and SiO2 sol solution - the atomic ratio of the respective metal elements were blended in proportions such that the predetermined ratio Then, the solvent is dried, and finally, the remaining dried product is subjected to a thermal decomposition step, and then calcined to obtain a target composite metal composite metal oxide catalyst.

Among the above catalyst raw materials, molybdenum (M
o) Raw materials include ammonium paramolybdate,
MoO3, MoCl5, Mo (OR) 5, (R is carbon number 1
Alkyl group 5), such as molybdenum acetylacetonate is available. The vanadium (V) starting material, ammonium metavanadate salt, VOSO4, V2
O5, V2 O3, VCl4, VOCl3, VO (OR) 3
(R is an alkyl group having 1 to 5 carbon atoms), and the like.

As the tellurium (Te) raw material, telluric acid,
TeO2, Te alone, or the like can be used. If necessary, a dissolving method using oxometalate described in JP-A-11-226408 may be used. Niobium (N
The b) the raw material, niobium oxide (Nb ₂ O ₅₎ sol, available like niobium ammonium oxalate is particularly niobium oxide (Nb ₂ O ₅₎ sol is preferred. It is preferable that the Nb source be soluble or colloidal in water. At least a part of the Nb source used is preferably an Nb raw material to which no carboxylic acid is coordinated. Specifically, it is also possible to simultaneously use Nb ammonium oxalate and the like and niobium oxide sol. Here, commercially available niobium ammonium oxalate can be used, for example, X ₃ NbO (C ₂ O ₄ ) ₃ and X ₂ N
_{bO (OH) (C 2 O} 4) 2 mixture [wherein, X = N
H ₄ ⁺ or H ⁺ ] can be used. Instead of niobium ammonium oxalate, it is also possible to use niobium hydrate or the like dissolved in an aqueous solution of a dicarboxylic acid such as oxalic acid in the presence or absence of ammonium ions.
Typified by those of ammonium niobium oxalate and the like, the characteristics of Nb raw material which is dissolved by the dicarboxylic acid consists in the majority of niobium is present as complexes which dicarboxylic acid and hydroxyl group is bonded, such as oxalic acid. on the other hand,
Niobium oxide sol is a kind of dispersed colloid in which fine particles of niobium oxide (Nb ₂ O ₅ ) are dispersed in a medium such as an aqueous solution, and niobium oxide having an average particle diameter of 1 nm to 100 nm can be used. The average particle size is 3 to 8 nm, particularly 5 nm ±, from the viewpoint of long-term stability and availability.
It is the most preferred of 1nm. The characteristic of this niobium oxide sol is that although it is homogeneously dispersed in a medium such as water and is translucent, most of the niobium is in a state where a dicarboxylic acid group such as oxalic acid is not bonded.

The raw material X does not need to be particularly water-soluble as long as it has good dispersibility in water. Oxide sols, hydroxides, water-soluble oxo acids or salts thereof, carboxylate salts, sulfate salts of these elements are usually used. , ammonium carboxylate, alkoxide, acetylacetonate, and the like can be used. Preferably oxide sol or hydroxide, fine powder such as oxide. Various methods can be selected for the manner in which the X raw material is added to the slurry containing another catalyst component. However, the average particle size for industrial use in a fluidized layer 40-6
To obtain a spherical catalyst 0 .mu.m, a method of granulating a slurry containing catalyst components to dry particles of fine spherical by spray drying is most suitably implemented. From the standpoint of such industrial use, it is preferable that the slurry to be subjected to spray drying contains all the catalyst constituent elements except oxygen.

[0014] X component, by co-exist with other catalyst components, has the effect of improving the yield of useful nitriles, depending mode of addition result of undesirable interactions with other components in the slurry However, the effect may not be sufficiently exhibited. When it is necessary to suppress such an undesired interaction between the slurry and the X component, the mixed slurry is controlled to a certain temperature or lower, or line mixing or the like for shortening the time from mixing to the drying step. method can also be employed. Alternatively, as the X component to be added, oxide fine particles fired at a high temperature of 500 ° C. or higher, preferably 1000 ° C. or higher are used.
using oxide particles having a diameter of not less than m and not more than 40 μm;
Specific surface area measured by the ET method 0.1 m ² g ^-1 to 200
m ² g ⁻¹ or less, preferably 0.1 m ² g ⁻¹ or more and 5 m ² g ⁻¹
As long as the dispersibility in the medium is satisfied, such as using the following raw materials or using a raw material having a loss on ignition of 5% or less, preferably 1% or less, a chemically inert X component should be selected. Is also possible. Here, burning loss means 1 in the atmosphere
It is a weight reduction rate when the temperature is kept at 000 ° C. for 30 minutes.

[0015] obtaining a solution or slurry of these respective materials described above were mixed in a solvent such as water. The ratio of each element component used as a raw material, except for tellurium, is usually blended so as to be the same as the composition ratio of the composite metal oxide catalyst finally obtained as described above. Temperature during mixing of the raw material is usually 30 to 80 ° C., preferably from 40 to 50 ° C..

The slurry containing the raw material compound of each metal element contains a substance having a reducing action in the slurry state or in the thermal decomposition step or the firing step. Examples of the substance having a reducing action include organic acids such as oxalic acid, citric acid, tartaric acid, malic acid, and ascorbic acid or salts thereof, aldehydes such as aliphatic aldehyde and aromatic aldehyde, and alcohols such as butanol and benzyl alcohol. Or reducing sugars such as glucose, inorganic amines such as hydroxylamine and salts thereof, organic amines or salts thereof, hydrazines and salts thereof or diimides, and preferably organic acids or aldehydes or alcohols. And more preferably oxalic acid or citric acid, most preferably oxalic acid.

These substances having a reducing action, such as oxalates in niobium ammonium oxalate, are contained in the raw materials of the catalyst constituent elements or are separately combined with oxalic acid dihydrate even if they are combined. May be added in any form. The amount of substance having the reduction action, the average valence of the intended double metal oxide, because it is determined by the balance of the utilization efficiency of the average valence and a reducing agent of the starting compounds, the preferred amount is sweepingly Although not be determined, it is 0.01 to 10 moles per mol of the normal metal element total number of moles of charged excluding carrier component such as Si. Here, the average valence refers to a value obtained by adding by multiplying the existing ratio to the valence of the element. Case of containing the oxalic acid radical as the reducing agent, the number of moles of oxalic acid radical, relative to metal molar number of charged, usually 0.05 to 1 times, preferably 0.1 to 0.5 times.

The valence of the respective elements after the reducing agent is applied may, Mo is less than an average of 5 or more 6, V is less than 5 average 4 or more,
Te is less than an average of 4 or more 6, Sb less than the average 3 or more 5, N
b is pentavalent, and the average valence of the constituent elements excluding the carrier component such as Si is usually 4 or more and less than 6, preferably 4.5 or more and 5.
9 or less, particularly preferably 5 or more 5.8 or less. In the present invention, the reducing agent may act in any of the steps of slurry state, thermal decomposition, and calcination. However, usually, the reducing agent acts in the thermal decomposition or calcination step to adjust the valence. It is particularly preferred, and particularly preferred, that this adjustment takes place mainly in the pyrolysis step.

The resulting solution or slurry is then sent to a drying step for solvent removal, the solid was removed the solvent. If the temperature at which the solution or slurry is held until the drying step is increased, the performance of the produced catalyst tends to decrease. Therefore, the holding temperature is usually 80 ° C. or less, preferably less than 60 ℃. When the slurry is held at a low temperature, a crystalline solid tends to precipitate and the generated catalyst tends to deteriorate, so the holding temperature is usually 10 ° C. or higher, preferably 30 ° C. or higher.

Drying for removing the solvent from the solution or slurry may be carried out according to a conventional method such as an evaporation to dryness method, a spray drying method, and a vacuum drying method. In the case of using the finally obtained composite metal oxide catalyst as a fluidized bed catalyst is preferably spray drying. According to the spray drying method, the average particle diameter 40~60μ
It is possible to easily obtain a spherical catalyst having a size of about m and suitable as a fluidized bed catalyst. In the first stage of the spray-drying process, the slurry subjected to spray-drying passes through a suitable atomizer to produce sprays or droplets of the liquid mixture. As the atomizer, a disk rotary type or a nozzle type atomizer is preferably used. To obtain the average particle diameter 40~60μm about spherical catalyst as in the present invention, a disk rotary atomizer is more preferable. When a disk rotary atomizer is used, the particle diameter of droplets generated by spraying a certain slurry at a certain liquid sending speed is generally controlled by the disk rotation speed.

The spray drying may be performed according to a conventional method. For example, the inlet gas temperature is usually 100 to 400 ° C., preferably 150 to 300 ° C., more preferably 200 to 250 ° C.
, And the outlet gas temperature is usually 80 to 200 ° C., preferably 120 to 180 ° C., more preferably 140 to 160 ° C.
Is adopted. Drying time is usually 0.01 seconds to 10 minutes, preferably from 0.01 seconds to 1 minute, more preferably from 0.05 seconds to 10 seconds.

From the viewpoints of the strength and fluidity of the fluidized bed catalyst, the flow rate, inlet / outlet gas temperature, dry gas flow rate, etc. are selected so that solid, not hollow, dry particles are obtained. . Normally, a gas containing dried particles obtained by spray drying is led to a classifier represented by a cyclone or the like, where the particles are collected and classified. The operating conditions such as the linear velocity of the gas in the cyclone are selected so as to have an average particle size and a particle size distribution suitable for use in a fluidized bed.

The solid obtained in the drying step, then calcined after pyrolyzed to release ammonia and carbon dioxide gas and a complex metal oxide catalyst by a conventional method. Although various forms can be adopted for the method of thermal decomposition, it is advantageous industrially to carry out the method continuously using a rotary kiln or the like. Although the thermal decomposition temperature is preferably 150 to 400 ° C., more preferably from 200 to 300 [° C.. The residence time of the pyrolysis step is preferably in the range of several seconds to tens of minutes. The residence time referred to here is, in the case of the kiln, the temperature of the catalyst precursor during decomposition when the catalyst precursor moves on the retort of the kiln, and the temperature reached by the maximum attainment temperature and 5 ° C lower than that. It is the time during which it has passed through an area that is between This dwell time is more preferably in the range of 2 minutes to 10 minutes.

The heating rate of the catalyst precursor during pyrolysis, the strength of the catalyst particles with good reproducibility, to keep to a high value, 2 ° C. /
It is preferable to set the temperature to 40 ° C./min or more.
In the case of a kiln, the rate of temperature rise in this case is such that decomposition does not substantially proceed at a certain point at the kiln entrance.
The time required for the catalyst precursor at a certain temperature of about 0 ° C. or lower to reach a certain temperature of the maximum pyrolysis temperature at which the catalyst precursor moves through the retort of the kiln and is exposed to a higher temperature and decomposition proceeds. It is typically (the highest temperature reached by the precursor-the temperature at the kiln inlet) / (the average moving time of the precursor during that time). This temperature rising rate is preferably 2 to 30 ° C./min, more preferably 10 to 2 ° C.
0 ° C./min. The heating rate of the thermal decomposition has a great influence on the strength of the obtained catalyst. If the temperature rise rate of the thermal decomposition is too high, the particles tend to be crushed or cracked due to rapid generation of decomposition gas inside the particles, and the strength tends to decrease. Besides the Atsushi Nobori rate of the thermal decomposition is too slow the activity of the catalyst is impaired, there is a tendency that the efficiency in producing the catalyst becomes low. The thermal decomposition step is usually performed under a gas flow in order to quickly remove generated decomposition gas.

The atmosphere in the pyrolysis process, since the volatile components is prevented from forming explosive mixture with oxygen-containing atmosphere, low oxygen concentration than normal air atmosphere, preferably an oxygen concentration of 50
0 ppm or less, more preferably oxygen concentration 100 ppm or less, most preferably substantially oxygen-free nitrogen, argon,
An atmosphere of an inert gas such as helium or CO2. When the thermal decomposition step is performed continuously, the gas flows at a rate of 500 to 10,000 Nl per 1 kg of the supplied precursor. Preferably it is 1000-6000 Nl. If disassembly in a fixed bed, the spatial velocity of the gas (SV) is
It is usually 100 to 10,000 hr ^-1 , preferably 50 to
A 0~6000hr ^-1, more preferably 1000 to
6000 hr ^-1 . Residence time of the pyrolysis process is preferably performed in a range of several seconds to several tens of minutes, more preferably in the range of 2 minutes to 10 minutes.

The firing method can take various forms such as a fixed bed method, a fluidized bed method, a rotary kiln, a tunnel furnace, and the like, but a fluidized bed, a rotary kiln and the like are industrially advantageous. The firing temperature is usually 300 to 700 ° C, preferably 550 to 650 ° C, more preferably 580 to 630 ° C.
It is. Calcination time is usually 5 minutes to 20 hours, 6 hours preferably 30 minutes, particularly preferably 1 to 3 hours. The time required to reach a predetermined firing temperature from room temperature is usually 3 hours or less, preferably 2 hours or less. The firing atmosphere is an atmosphere having an oxygen concentration lower than that of ordinary air, preferably an oxygen concentration of 500 ppm or less, more preferably an oxygen concentration of 100 p.
pm or less, and most preferably substantially free of oxygen nitrogen, noble gases, an inert gas atmosphere such as CO2. The inert gas is preferably nitrogen, a noble gas, more preferably nitrogen, argon, helium. Also, Japanese Patent Laid-Open No. 7-2
Again oxygen 500ppm or less nitrogen after contact with oxygen and cooled after the sintering, as described in 89907 JP, argon, helium, and preferably calcined in an inert atmosphere such as CO2. Gas space velocity (SV)
Is usually 100～10000Hr ^-1, preferably 500～6000Hr ^-1, more preferably 500
６6000 hr ⁻¹ .

At the time of fluidized firing, it is preferable to confirm that the catalyst is in a fluidized state by measuring the temperature distribution of the catalyst layer. At that time, the flow rate of the inert gas is usually adjusted so that the linear velocity (LV) is about 2 cm / sec or more at a predetermined firing temperature. It is also possible to install a separation device such as a cyclone in order to prevent the catalyst from scattering from the firing device. By heating the entire sintering apparatus, it is possible to prevent the volatile components adhering to the vessel wall from dropping onto the catalyst and from mixing into the catalyst.

The catalyst may be cooled during the drying and thermal decomposition steps, or may be immediately transferred to the decomposition step without cooling. 100% solid before thermal decomposition during transfer, storage, etc.
It is not preferable that the temperature is kept at 30 ° C. or more for 30 minutes or more. The solid after pyrolysis can be cooled before the firing step. A solid before calcination or a catalyst at 300 ° C
At the above temperature, it is not preferable to maintain the atmosphere having an oxygen concentration of 500 ppm or more for 30 minutes or more. At the time of baking, it is preferable that the inside of the baking apparatus is sufficiently replaced with an inert gas before the start of temperature rise, and that the residual oxygen concentration is 300 ppm or less. Composite metal oxide catalyst obtained by the method of the present invention (description of gas-phase catalytic oxidation reaction) is used in the preparation of organic compounds by catalytic oxidation of an alkane. The gas phase catalytic oxidation reaction of alkanes is a reaction in which an alkane is oxidized in gas phase with oxygen, and also includes a reaction in which a nitrogen source such as ammonia or urea or water vapor is present in the reaction system in addition to oxygen. It is used for the production of various organic compounds such as organic compounds, dehydrogenated organic compounds, and nitriles.

The composite metal oxide catalyst obtained according to the present invention has extremely high performance especially as a catalyst for gas phase oxidation or ammoxidation of lower alkanes. For example, n-
Maleic anhydride from butane, acrylic acid from propane,
It is useful as a catalyst in a reaction for producing acrylonitrile from propane, acrylic acid and acrylonitrile from propane, and ethylene from ethane.

Since the composite metal oxide catalyst obtained by the production method of the present invention has a property that the selective oxidation activity of alkanes is high even at a relatively low temperature of 500 ° C. or less, the reaction temperature is usually 300 to 500 ° C., preferably Is 350-48
0 ° C. and the gas hourly space velocity (SV) is usually 100 to 10
000hr ^-1, preferably in the range of 300~6000hr ^-1. The pressure of the reaction is not particularly restricted, usually 1
3 atmospheres pressure, preferably 2 atm 1 atm.
In addition, nitrogen, helium, argon, CO
It is also possible to use an inert gas _2. The reaction is a fixed bed, but may employ either of the fluidized bed, preferably is easy more temperature control fluid layer. In addition, the removal of heat of reaction in the fluidized bed can be further facilitated by the presence of oxide particles inert to the reaction in the reaction system.

The composite metal oxide catalyst of the present invention, among others,
It is particularly effective for producing acrylonitrile from propane. In this case, in the reaction feed gas, oxygen is preferably in a range of 0.2 to 4 moles per mole of propane, and ammonia is preferably in a range of 0.1 to 3 moles per mole of propane. When used in this way as a catalyst, the conversion of the starting material kept low, and recycling separated unreacted raw material at the reactor outlet in order to realize a high product selectivity, adopting a method to use again as a raw material be able to.

[0032] The present invention composite metal oxide catalyst can unsaturated carboxylic acid by partial oxidation of alkanes, also possible to obtain the acrylic acid, especially in high yield by partial oxidation reaction of propane. The reaction raw material gas, propane, but using oxygen-containing gas, it is possible to further further enhance it is preferable to use water vapor, to suppress the formation of such carbon dioxide selectivity of acrylic acid. Acrylic acid, propane / steam / oxygen /
Molar ratio of nitrogen, a 1.0 / 0.1 to 20 / 0.1 to 10.0 / 0 to 50.0 at which the reaction gas is produced by supplying to the reactor under the conditions of a space velocity SV described above.

Furthermore, the composite metal oxide catalyst according to the present invention can control acrylonitrile by controlling the reaction conditions of the partial oxidation reaction of propane in the presence of ammonia, in particular, the molar ratio of ammonia and oxygen to propane, and the reaction temperature. And acrylic acid can be simultaneously produced, and the molar ratio of propane / ammonia / oxygen / nitrogen is usually 1.0 /
It is manufactured by supplying a reaction gas having a space velocity of 0.1 to 3.0 / 0.1 to 10.0 / 0 to 50.0 to the reactor under the condition of the space velocity SV described above.

[0034]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples unless it exceeds the gist. Propane (PPA) conversion, acrylonitrile (AN) yield, and WWH are calculated as follows.

[0035]

## EQU1 ## Propane conversion (%): moles of reacted propane / moles of propane supplied × 100 Acrylonitrile yield (%): moles of acrylonitrile generated / moles of propane supplied × 100 WWH (hr) ^-1 ): Propane supply per hour (k
g) / catalyst weight (kg)

(Example 1) _{Mo 1 V 0.25 Nb 0.16 Te 0.125} Ce 0.04 O n / SiO 2 -
Production of 10wt% Heat 21740 g of ion-exchanged water to 75 ° C,
5782 g of ammonium ribate, metavanadate
958 g of ammonium and 1504 g of telluric acid in this order
No. and the mixture was stirred and dissolved. Release this solution to 70 ° C.
After cooling, silica sol (Catalyzed Chemical Industry S-20L: SiO
_Two 4119 g was added and stirred at 60 ° C.
Kept. This is designated as solution A. Separately, ion-exchanged water 529
2 g is heated to 50 ° C. and niobium ammonium oxalate
(Starck Co., Ltd.; X_ThreeNbO (C_TwoO _Four)_ThreeAnd X_TwoNbO
(OH) (C_TwoO_Four)_TwoMixture [wherein, X = NH_Four ⁺
Or H⁺], Nb: 20.1 wt%, C_TwoO_Four: 51.
8 wt%, NH_Three: 5.0 wt%) 1322.9g
Was added and stirred while heating to 70 ° C. to dissolve.
The solution is allowed to cool to 50 ° C., and niobium oxide sol (Takika
Gaku; Nb_TwoO_Five: 10 wt%, (NH_Three+ NH_Four ⁺)
Amount: N / Nb = 0.44 (mol / mol), (CO
OH)_Two/Nb=0.338 (mol / mol)) 3
Add 157 g and 872 g of ion-exchanged water to 60 ° C
After heating and stirring for 10 minutes, the temperature was maintained at 40 ° C. This is B
And liquid. Mix liquid B and liquid A quickly and immediately BET
Specific surface area 1.3 m^Twog^-1Cerium oxide (CeO)_Two:
Nippon Metal Chemical Co., Ltd. Cerium oxide-100 in air
1100 ° C firing, CeO in oxide_TwoPurity: 99.9%
Above, the average particle diameter: 6 [mu] m, loss on ignition: 1% or less) 2
Add 25.5 g to prevent sedimentation of the cerium oxide particles.
And then spray-dried under the following conditions. Spray conditions: a disk-type spray dryer, the disk
Rotation speed: 6600rpm, feed rate: 7L / hr, dry gas
(Air) inlet temperature: 220 ° C., outlet temperature: 160 ° C. The solid after spray drying was immediately cooled to room temperature.

[0037] Next, the solid obtained by spray drying in a rotary kiln (259mmφx2170mm)
1kg / hr, retort speed: 1rpm
m, Nitrogen: 2580 NL / hr circulation, thermal decomposition treatment at 250 ° C. for 8 min, at a heating rate of 20 ° C./min. After completion of the pyrolysis, the solid was immediately cooled to room temperature. Then, the obtained catalyst precursor was calcined by repeating 3 times the following operations. The catalyst precursor 3kg packed in a cylindrical fluidized calciner (150mmφX520mm), nitrogen stream oxygen concentration is 300ppm or less,
The temperature was raised from room temperature to 600 ° C. in 2 hours, kept at 600 ° C. for 2 hours, and then allowed to cool to room temperature. The flow rate of nitrogen, 6
At 00 ° C., the linear velocity (LV) is 2c in the fluidized firing device.
m / sec. X-ray fluorescence analysis (XRF)
The composition of the obtained catalyst was determined to be Mo ₁
V _0.25 Nb _0.16 Te _0.125 Ce _0.04 On / SiO ₂ -10
wt%.

Ammoxidation reaction of propane 550 mg of the catalyst prepared as described above was mixed with an inner diameter of 6 mm.
In a Pyrex (registered trademark) was charged into a glass tube, P
PA / NH ₃ / O ₂ / N ₂ = 1 / 1.2 / 3.14 / 5.
86 mixed gas at normal pressure, 500 Nml / hr (W
WH = 0.16 kg-PPA / kg-cat / hr,
Space velocity SV was supplied at a flow rate of 1041 h-1), and an ammoxidation reaction of propane was performed at a reaction temperature of 455 ° C.
After 16 hours, the yield of acrylonitrile (AN) was 52.
The yield of acrylic acid (AA) was 0.87%, and the conversion of propane (PPA) was 87.5%. The reaction test was continued under the same reaction conditions. After 3019 hours, AN
The yield was 51.2% and the PPA conversion was 86.9%. After 5035 hours, the AN yield was 49.6%, PP
A conversion of 85.9% after 8140Hr, AN yield 47.3% PPA conversion was 85.1%. Table 1 shows the results.

[0039] (Example _{2) Mo 1 V 0.25 Nb 0.16} Te 0.11 On / SiO 2 -10wt
% The production of a catalyst was carried out in the same manner as in Example 1 except that cerium oxide was not added. When the composition was analyzed in the same manner as in Example 1, Mo ₁ V _0.25 Nb _0.16 Te _0.11 On / SiO ₂ −
It was 10 wt%.

[0040] Using the same reactor as in ammoxidation Example 1 propane, filled with a catalyst 550mg prepared as described above, SV = 1106h-1, at a reaction temperature of 445 ° C.. After 15 hours, the AN yield was 50.3% and the PPA conversion was 83.3%. The reaction test was continued under the same reaction conditions. After 3020hr elapsed,
AN yield 50.6%, PPA conversion was 86.7%. After 5036 hours, the AN yield was 48.6% and P
The PA conversion was 86.9% and after 8117 hours, the AN yield was 46.3% and the PPA conversion was 84.9%.
Table 1 shows the results.

Example 3 Mo ₁ V _0.26 Nb _0.18 Te _0.13 On / SiO ₂ -10 wt
% Catalyst Production A catalyst was produced in the same manner as in Example 2 except that 1654 g of telluric acid, 996.3 g of ammonium metavanadate, 3551 g of niobium oxide sol, and 1488 g of niobium ammonium oxalate were used. When the composition was analyzed in the same manner as in Example 1, Mo ₁ V _0.26 Nb _0.18 Te _0.13 On / S
iO ₂ -10 wt%.

Ammoxidation reaction of propane Using the same reactor as in Example 1, 550 mg of the catalyst produced as described above was charged, and the reaction was carried out at SV = 1104 h ^-1 and a reaction temperature of 447 ° C. After 26 hours, the AN yield was 5
0.2%, PPA conversion was 83.5%. The reaction test was continued under the same reaction conditions. After 3015 hours, A
The N yield was 50.5% and the PPA conversion was 86.9%. After 5040 hours, the AN yield was 49.4%, PP
The A conversion was 86.6%. Table 1 shows the results.

Example 4 Mo ₁ V _0.28 Nb _0.17 Te _0.12 On / SiO ₂ -10 wt
% Of 1579g manufacturing telluric acid, 1035 g of ammonium metavanadate, except that the niobium oxide sol 3354G, was 1406g of ammonium niobium oxalate, Example 2
A catalyst was produced in the same manner as described above. When the composition was analyzed in the same manner as in Example _{1, Mo 1 V 0.28 Nb 0.17} Te 0.12 On / Si
O ₂ -10 wt%.

Ammoxidation reaction of propane Using the same reactor as in Example 1, 550 mg of the catalyst produced as described above was charged, and the reaction was carried out at SV = 1107 h ^-1 and at a reaction temperature of 444 ° C. After 24 hours, the AN yield is 5
1.9% and PPA conversion was 86.1%. The reaction test was continued under the same reaction conditions. After 3010 hours, A
N yield: 51.0%, PPA conversion: 86.5%. After 5045 hours, AN yield: 49.2%, PP
A conversion: 86.7%. Table 1 shows the results.

Comparative Example 1 Mo ₁ V _0.30 Nb _0.12 Te _0.17 On / SiO ₂ -10 wt
21740 g of the prepared ion-exchanged water was heated to 75 ° C., and 5782 g of ammonium paramolybdate, 1150 g of ammonium metavanadate, and 1729 g of telluric acid were charged in this order and dissolved by stirring. 70 ° C
And cooled to silica sol (Catalyst Chemical Industry S-20L: S
(20 wt% of iO2) 4076 g was added and stirred, and 6
It was kept at 0 ° C. This is designated as solution A. Separately ion-exchanged water 5
After heating 896 g to 50 ° C., ammonium niobium oxalate (manufactured by Starck; X ₃ NbO (C ₂ O ₄ ) ₃ and X ₂ NbO)
(OH) (C ₂ O ₄ ) ₂ [where X = NH ₄ ⁺
Or H +], Nb: 20.1 wt%, C ₂ O ₄ : 51.
_{8 wt%, NH 3: 5.0} wt%) 1766g added and dissolved by stirring while heating to 70 ° C., 40
C. This is referred to as B solution. Solution B and Solution A were immediately mixed, immediately stirred for 15 minutes, and dried, decomposed and calcined in the same manner as in Example 1 except that the temperature of the thermal decomposition treatment in the rotary kiln was changed to 350 ° C. to obtain a catalyst. Was. The composition of the resulting catalyst was analyzed by XRF method, Mo ₁
V _0.30 Nb _0.12 Te _0.17 On / SiO ₂ -10 wt%.

Ammoxidation reaction of propane 550 mg of the catalyst prepared as described above was mixed with an inner diameter of 6 mm.
Into a Pyrex glass tube, PPA / NH ₃
/ O ₂ / N ₂ = 1 / 1.2 / 3.14 / 5.86 mixed gas at normal pressure, 500 Nml / hr (WWH = 0.1
6 kg-PPA / kg-cat / hr, space velocity S
Supplied with V = flow velocity of 1041h ^-1), reaction temperature 435 ° C.
In was ammoxidation reaction of propane. After 9 hours, the yield of acrylonitrile (AN) was 53.5% and the conversion of propane (PPA) was 88.9%. 3018h
After 4 hours, the AN yield was 48.4% and the PPA conversion was 9
0.2%. After 5034 hours, the AN yield was 4
4.5%, PPA conversion rate is 91.4%, after 8094 hours, AN yield is 38.1%, PPA conversion rate is 90.0%.
%Met. Table 1 shows the results.

Comparative Example 2 Mo ₁ V _0.20 Nb _0.15 Te _0.13 On / SiO ₂ -10 wt
% Of the production of ion exchange water 1564g was heated to 75 ° C., ammonium paramolybdate 462.8G, ammonium metavanadate 61.3 g, telluric acid 90.3
g was added in this order and stirred to dissolve. The solution was allowed to cool to 70 ° C.,
L: added and stirred SiO ₂ 20wt%) 300g, was maintained at 60 ° C.. This is designated as solution A. Separately, 275.5 g of ion-exchanged water was heated to 50 ° C., and a mixture of ammonium niobium oxalate (manufactured by Starck; X ₃ NbO (C ₂ O ₄ ) ₃ and X ₂ NbO (OH) (C ₂ O ₄ ) ₂ was used. [Where X
= NH ₄ ⁺ or H ⁺ ], Nb: 20.1 wt%, C 2 O
4: 51.8 wt%, NH3: 5.0 wt%) 11
1.8 g was added, and the mixture was stirred and dissolved while heating to 70 ° C, and kept at 40 ° C. Niobium oxide sol (manufactured by Taki Kagaku; Nb ₂ O ₅ : 10 wt%, (NH ₃ + NH ₄ ⁺ ) content: N / Nb = 0.44 (mol / mol), (CO
OH) ₂ /Nb=0.338 (mol / mol)) 1
91 g were added. This is called liquid B.

[0048] Solution B and solution A are mixed rapidly and was subjected to the same spray-dried as in Example 1. 2 g of the solid after spray drying is filled in a quartz tube having an inner diameter of 20 mm, and while flowing at 100 ml / min of air, the solid is cooled until the temperature of the solid reaches 350 ° C.
The temperature was raised at 0 minutes, was subjected to thermal decomposition treatment. Solid temperature of 35
After reaching 0 ° C., it was rapidly cooled to room temperature within 10 minutes. Next, while flowing nitrogen at a flow rate of 100 ml / min, the temperature was raised from room temperature until the temperature of the solid reached 600 ° C. in one hour,
Calcination was performed at that temperature for 2 hours to obtain a catalyst. When analyzed in the same manner as in Example 1, the composition was Mo ₁ V _0.20 Nb _0.15 Te.
It was _0.13 On / SiO _{2 -10wt%.}

Ammoxidation reaction of propane 550 mg of the catalyst produced as described above was mixed with an inner diameter of 6 mm.
Into a Pyrex glass tube, PPA / NH ₃
A mixed gas of / O ₂ / N ₂ = 1 / 1.2 / 3.15 / 11.85 was applied at a pressure of 0.9 kG and 500 Nml / hr.
(WWH = 0.18kg-PPA / kg-cat / h
r, space velocity SV = 1106h ^-1 )
An ammoxidation reaction of propane was performed at a reaction temperature of 430 ° C. After 110 hours, the yield of acrylonitrile (AN) is 49.0% and the conversion of propane (PPA) is 91.0%
Met. After 2280 hours, AN yield 40.0%, P
The PA conversion was 86.0%.

[0050] (Comparative Example _{3) Mo 1 V 0.30 Nb 0.20} Te 0.13 On / SiO 2 -10wt
% Of the production of ion exchange water 1692g was heated to 75 ° C., poured ammonium paramolybdate 415 g, ammonium metavanadate 82.5 g, telluric acid 108g in this order and stirred to dissolve. 70 ° C
And the silica sol (Catalyst Chemical Industry S-20L: Si
O ₂ 20 wt%) was stirred with 300 g, 60 ° C.
Kept. This is designated as solution A. 275 g of ion exchange water
Was heated to 70 ° C., and 92.1 g of niobium ammonium oxalate and 70 g of oxalic acid dihydrate were added and dissolved as in Example 1. After cooling to 50 ° C., niobium oxide sol (manufactured by Taki Chemical; Nb; ₂ O ₅ : 10 wt%, (NH ₃ + NH ₄ ⁺ ) content: N / Nb = 0.44 (mol / mol), (C
OOH) 2 / Nb = 0.338 (mol / mol))
351g were mixed. This is referred to as B solution. The solution B and the solution A were promptly mixed and spray-dried in the same manner as in Example 1.
2 g of the solid after spray drying was pyrolyzed and calcined in the same manner as in Comparative Example 2 to obtain a catalyst. When the composition was analyzed in the same manner as in Example 1, Mo ₁ V _0.30 Nb _0.20 Te _0.13 On / SiO ₂ -10
wt%. Was life tested in the same manner as ammoxidation Comparative Example 2 propane. After 1 hour, the AN yield was 45.0% and the PPA conversion was 72.0%.
After 3000 hours, the AN yield was 44.0% and the PPA conversion was 74.0%. Table 1 shows the results.

[0051]

[Table 1]

As is apparent from Table 1, in the composition formula (1) of the present invention, 0.2 <b <0.3 and 0.1
5 <When using a composite metal oxide catalyst having the composition in the range of d <0.2, higher AN yields and be continued for a long time reaction, it can be seen that maintaining a high AN yield .

[0053]

The catalyst having the composition range of the present invention can maintain a high α, β unsaturated nitrile yield for a long period of time.

────────────────────────────────────────────────── ─── of the front page continued (51) Int.Cl. ⁷ identification mark FI theme Court Bu (reference) // C07B 61/00 300 C07B 61/00 300 (72) inventor Kazunori Oshima Kanagawa Prefecture, Aoba-ku, Yokohama City Kamoshida No. 1000 Town Mitsubishi Chemical Corporation Yokohama Research Laboratory (72) Inventor Noboru Watanabe No. 1000 Kamoshidacho, Aoba-ku, Aoba-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Chemical Corporation Yokohama Research Laboratory F-term 4G069 AA02 AA03 BA02B BB06A BB06B BC01A BC08A BC15A BC16A BC17A BC18A BC21A BC22A BC23A BC24A BC25A BC30A BC34A BC35A BC38A BC40A BC43A BC43B BC50A BC51A BC53A BC54A BC54B BC55A BC55B BC56A BC57A BC58A BC59A BC59B BC60A BC61A BC62A BC64A BC65A BC66A BC67A BC68A BC69A BC70A BC71A BD03A BD07A BD10A BD10B CB53 CB54 EA02Y EB18Y FC08 4H006 AA02 AC12 AC54 BA12 BA14 BA15 BA33 BA60 BA81 BC13 BE14 BE30 QN24 4 H039 CA65 CA70 CC10 CC30 CC90

Claims (9)

[Claims] 1. A composite metal oxide catalyst represented by the following composition formula (1). ## STR1 ## In _{Mo 1 V b Te c Nb d} X x O n (1) ( Formula (1), X is an element of the 1 to 16 of the periodic table, Mo, V, Nb, Te , from outside O Represents at least one or more selected elements, and 0.2 <b <0.3, 0.0
1 <c <0.3, 0.15 <d <0.2, 0 ≦ x <
0.8 and n are values determined by the oxidation state of other elements) 2. In the composition formula (1), 0.22 ≦ b ≦
0.28 a composite metal oxide catalyst according to claim 1. 3. In the composition formula (1), 0.16 ≦ d ≦
0.18 a composite metal oxide catalyst according to claim 1 or 2. 4. In the composition formula (1), 0.03 <c <
0.17 a composite metal oxide catalyst according to any of claims 1 to 3. 5. In the composition formula (1), 0.05 <c ≦
5. The composite metal oxide catalyst according to claim 4, which is 0.13. 6. The composite metal oxide catalyst according to claim 1, wherein in the composition formula (1), X is an element selected from Group 3 of the periodic table. 7. A gas phase catalytic oxidation reaction method comprising subjecting an alkane to a nitrogen source in a gas phase catalytic oxidation reaction in the presence of the composite metal oxide catalyst according to any one of claims 1 to 6. 8. The method according to claim 7, wherein the alkane is propane. 9. The gas-phase catalytic oxidation reaction process according to claim 7 or 8 alpha by gas-phase catalytic oxidation, beta-unsaturated nitrile compound to produce an alkane with a nitrogen source.