JP2001055355A - Vapor phase catalytic oxidation reaction of hydrocarbon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of reactional operation enabling the objective product to be obtained favorably in vapor phase catalytic oxidation reaction of a hydrocarbon. SOLUTION: This method of reactional operation in producing unsaturated nitrile and/or unsaturated carboxylic acid by vapor phase catalytic oxidation reaction of a hydrocarbon in the presence of a multicomponent metal oxide catalyst containing as the essential component at least one element among molybdenum, vanadium, tellurium and antimony, comprises the following practice: temperature is raised in an atmosphere substantially containing neither oxygen nor combustible gas until the temperature of the catalytic bed reaches a temperature capable of initiating the reaction. By this method, unsaturated nitrile and/or unsaturated carboxylic acid can be produced in high yield and selectivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for catalytically oxidizing hydrocarbons in the gas phase. In particular, the present invention relates to a method for producing an unsaturated nitrile and / or an unsaturated carboxylic acid by subjecting an alkane to a gas phase catalytic oxidation reaction in the presence of a specific catalyst.

[0002]

2. Description of the Related Art Unsaturated nitriles such as acrylonitrile and methacrylonitrile are used as intermediate materials for synthetic resins, synthetic fibers and synthetic rubbers, while unsaturated carboxylic acids such as acrylic acid and methacrylic acid are used for synthetic resins, paints and adhesives. It is industrially important as a raw material for plasticizers and the like. Conventionally, these unsaturated nitriles and unsaturated carboxylic acids are produced by a gas-phase catalytic oxidation reaction of an alkene as a raw material. For example, it is economically advantageous to use inexpensive propane or isobutane with propylene or isobutene. Extensive research has been conducted on catalysts that make this possible, and as a result, many catalysts have been reported. Among these catalysts, a composite metal oxide catalyst containing molybdenum, vanadium, and at least one element of tellurium or antimony as an essential component is known as an alkane gas phase catalytic oxidation reaction catalyst.

The present inventors have also disclosed in JP-A-2-257 and JP-A-5-148212 that a catalyst containing Mo, V, and Te as essential components is effective for producing acrylonitrile by an ammoxidation reaction of propane. JP-A-5-208
No. 136, and Japanese Patent Application Laid-Open No. 6-2 / 1993 discloses that it is effective for the production of acrylic acid by an oxidation reaction of propane.
No. 79351 discloses this. Further, M
Japanese Patent Application Laid-Open No. 9-157241 discloses that a catalyst containing o, V, and Sb as essential components is effective for producing acrylonitrile by an ammoxidation reaction from propane.

The inventor of the present invention has continued research on the catalysts disclosed in these publications. As a result, depending on the reaction operation method, in particular, the selection of the atmosphere until the temperature of the reactor loaded with the catalyst reaches the temperature at which the reaction is carried out, the catalyst may vary. May not be sufficiently exhibited, and selection of a preferable reaction operation method is required. In order to solve this problem, when the temperature of the catalyst layer is higher than 300 ° C. and lower than the reaction temperature, a combustible gas such as oxygen and hydrocarbons and / or ammonia is supplied, and the reaction temperature is increased. It has been proposed to increase the temperature up to the target reaction temperature, and to switch to the supply of the reactant gas when the target reaction temperature is reached.However, there is insufficient consideration on the chemical properties of the catalyst, Depending on the selection of the temperature and the state of supplying the flammable gas and oxygen, the performance of the catalyst may be rather deteriorated, the operation is complicated, and there is the danger of explosion. There is.

[0005]

SUMMARY OF THE INVENTION
The performance of the catalyst described in the above publication is fully exhibited,
There is also a demand for an operation method which is excellent in workability and suitably selects an atmosphere in which a catalyst is placed until a temperature at which a reaction can be started is reached. The present invention provides molybdenum, vanadium,
And in the presence of a composite metal oxide catalyst having at least one element of tellurium or antimony as an essential component,
It is an object of the present invention to appropriately set a reaction operation method in order to obtain a desired product when a hydrocarbon is subjected to a gas phase catalytic oxidation reaction.

[0006]

In order to solve this problem, the present inventor has proposed a method in which molybdenum, vanadium, and a composite metal oxide catalyst containing at least one of tellurium and antimony as essential components. As a result of repeated studies on the selective oxidation reaction of hydrocarbons, the conversion rate of hydrocarbons, selectivity to target products, and catalyst The present inventors have found that the life of the aluminum alloy is improved, and reached the present invention. That is, the gist of the present invention is to provide a gas phase catalytic oxidation reaction of a hydrocarbon in the presence of a composite metal oxide catalyst containing at least one of molybdenum, vanadium, and tellurium or antimony as an essential component to obtain unsaturated nitrile. And / or a method for producing an unsaturated carboxylic acid, until the temperature of the catalyst layer reaches a reaction startable temperature.
The temperature is raised in an atmosphere substantially free of oxygen and / or flammable gas. Preferably, under such conditions, the temperature of the catalyst layer is equal to or lower than the reaction execution temperature, and a gas containing hydrocarbon and oxygen, or A hydrocarbon which supplies a gas containing ammonia and oxygen, or raises the temperature in an atmosphere substantially free of oxygen and / or flammable gas until the temperature of the catalyst layer reaches or exceeds the reaction temperature. Gas phase catalytic oxidation reaction method.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the present invention, a composite metal oxide catalyst containing molybdenum, vanadium, and at least one element of tellurium or antimony as an essential component is used. More specifically, molybdenum, vanadium, X, Y and oxygen (X
Is at least one of tellurium and antimony, Y
Is niobium, tantalum, tungsten, titanium, aluminum, zirconium, chromium, manganese, iron, ruthenium, cobalt, rhodium, nickel, palladium, platinum, bismuth, boron, indium, phosphorus, germanium, rare earth elements, alkali metals, alkaline earths (Indicating one or more elements selected from the group consisting of metals) as an essential component. Further, the proportion of these catalyst constituent elements is determined by the following formula: 0.25 <rMo <0.98 0.003 <rV <0.5 0.003 <rX <0.50 ≦ rY <0.5 (where rMo , RV, rX, and rY represent the mole fractions of Mo, V, X, and Y with respect to the sum of the above essential components excluding oxygen).

In the present invention, the temperature is usually from 300 ° C. to 49 ° C.
A gas phase catalytic oxidation reaction of hydrocarbons is carried out at a reaction temperature of 0 ° C. An atmosphere substantially free of oxygen and / or a flammable gas up to a temperature at which the reaction can be started is provided by loading the above catalyst into a reactor. And raise the temperature in an atmosphere substantially free of oxygen and / or flammable gas until the temperature of the catalyst layer reaches or exceeds the reaction execution temperature, or the temperature of the catalyst layer reaches a reaction startable temperature. Up to an atmosphere substantially free of oxygen and / or flammable gas, and a gas containing hydrocarbons and oxygen until the reaction temperature is reached;
Alternatively, by supplying a gas containing hydrocarbon, ammonia and oxygen, the catalyst performance is sufficiently exhibited and unsaturated carboxylic acid and / or unsaturated nitrile is suitably produced.

Further, a gas containing a hydrocarbon and oxygen, wherein the temperature of the catalyst layer is equal to or higher than the reaction startable temperature,
Alternatively, the concentration of oxygen in the gas at the outlet of the reactor is controlled to 0.1% or more, preferably 1% by controlling the amount of supply of gas containing hydrocarbon, ammonia and oxygen to the reactor.
When it is maintained at not less than 25% or less, generation of unsaturated carboxylic acid and / or unsaturated nitrile is further promoted, which is preferable. Here, the reaction-startable temperature is defined as an unsaturated carboxylic acid and / or an unsaturated carboxylic acid when hydrocarbon and oxygen or hydrocarbon, ammonia and oxygen are supplied in the presence of the specific catalyst used in the present invention. Shows the temperature at which the production of saturated nitrile starts, which differs depending on the type of catalyst and hydrocarbon, etc., but if a catalyst proposed by the present invention is used and propane and oxygen or propane and ammonia and oxygen are reacted, it is usually The range is from 200 ° C to 450 ° C.

According to the method proposed in the present invention, acrylic acid or methacrylic acid by gas phase catalytic oxidation reaction of lower alkane among hydrocarbons, especially propane or isobutane, and / or acrylonitrile or methacrylonitrile by ammoxidation reaction. Production can proceed advantageously. The term "atmosphere substantially free of oxygen and / or flammable gas" as used herein means an atmosphere which is actually inert to the gas phase catalytic oxidation reaction of hydrocarbons at a temperature not lower than the reaction initiation temperature. Specifically, it refers to a single or mixed atmosphere of nitrogen, argon, helium, carbon dioxide, water vapor, and the like. Here, the flammable gas refers to hydrocarbons, ammonia, hydrogen, carbon monoxide and the like, and more specifically, alkanes having 8 or less carbon atoms, alkenes, cycloalkanes, cycloalkenes, aromatic hydrocarbons, Alcohols, ethers, esters, nitriles,
Shows carboxylic acids, acid anhydrides, aldehydes, ketones and the like. Furthermore, those most commonly used in the present invention include propane, isobutane, and ammonia alone or as a mixture. Even if a small amount of these combustible gases and / or oxygen are present, they are substantially inert if they are inert to the gas phase catalytic oxidation reaction of hydrocarbons.

As the reaction system, any of a fixed bed, a fluidized bed and the like can be adopted. However, since the reaction is an exothermic reaction, the fluidized bed system is preferable because the reaction temperature can be easily controlled. For example, when the gas phase catalytic oxidation reaction between propane and ammonia is carried out using a fluidized-bed reactor, the reactor filled with the catalyst as described above may contain substantially oxygen and / or combustible gas. In a non-atmosphere, the temperature of the catalyst layer was raised until the temperature reached the reaction temperature or higher.
Propane and oxygen or propane and ammonia and oxygen
The reactor outlet oxygen concentration is supplied with careful monitoring. At this time, propane or propane and ammonia may be supplied coexisting with oxygen under conditions that avoid explosion, or may be supplied separately from oxygen from a pipe connected to the reactor. Alternatively, the temperature is raised in an atmosphere substantially free of oxygen and / or flammable gas until the temperature of the catalyst layer reaches the reaction startable temperature, and when the reaction startable temperature is reached, propane and oxygen or Propane, ammonia and oxygen are supplied while carefully monitoring the reactor outlet oxygen concentration.

The present inventor has already reported that the above-mentioned catalyst exhibits a good catalytic action on the gas phase catalytic oxidation reaction of hydrocarbons. However, in order to obtain more excellent performance, the characteristics of the catalyst should be examined in detail. As a result, the reaction operation method proposed in the present invention has been found. Although the details of the reason why the reaction result is improved by adopting this reaction operation method are not clear, since the activity of the catalyst is very high, the chemical state of the catalyst depends on the atmosphere when the catalyst layer is heated. Is assumed to change.

In the gas phase catalytic reaction of hydrocarbons, a side reaction proceeds in addition to the desired reaction. For example, in the production of acrylonitrile from propane, hydrogen cyanide, acetonitrile, carbon dioxide And carbon monoxide. These production routes include a route produced directly from propane and a route produced by decomposition of acrylonitrile produced. When the change over time in the formation behavior of these by-products is tracked, the amount of formation is large at the beginning of the reaction, but may be observed to decrease with time. This is presumably because the action of the active site that promotes this side reaction is weakened immediately after the start of the reaction. Here, when the reaction is started at a temperature higher than the reaction temperature for the purpose of the gas phase oxidation reaction, that is, the oxygen and / or flammable gas is substantially reduced to a temperature higher than the reaction temperature as proposed in the present invention. When the temperature is increased in an air stream that does not contain the gas, and the gas is changed to a gas composed of propane and oxygen, the effect of the side reaction active site can be rapidly reduced because the initial reaction temperature at which the reaction started is high, As a result, it is expected that stable and good selectivity can be achieved in a short time. In addition, when the temperature reaches a temperature higher than the reaction temperature, the heater for heating the reactor is weakened to balance the heat generated by the reaction to reach the reaction temperature. Can be done in many cases.

Further, since the gas phase catalytic oxidation reaction of hydrocarbons is an exothermic reaction, the temperature is raised to a temperature at which the reaction can be started by a gas stream containing no oxygen and / or flammable gas. When a gas containing hydrocarbon and oxygen, or a gas containing hydrocarbon, ammonia and oxygen is supplied, the reaction can proceed if the temperature of the catalyst layer is equal to or higher than the reaction startable temperature, and the temperature of the catalyst layer can be increased. . That is, the energy for raising the temperature of the reactor becomes unnecessary or can be reduced. Furthermore, if the reaction gas is supplied in a desired composition of the reaction gas, while the temperature rises to the reaction execution temperature, the reaction gas composition giving a suitable reaction result can be easily reached by adjusting the flow rate of the constituent components and the like. Therefore, there is no need to perform a risky operation such as switching the gas near the reaction temperature.

When a gas containing hydrocarbon and ammonia or a gas containing hydrocarbon, ammonia and oxygen is supplied under the condition that the temperature of the catalyst layer is equal to or higher than the reaction startable temperature, the gas is discharged from the reactor outlet. The oxygen concentration in the gas is 0.
When it is maintained at 1% or more, preferably 1% or more and 25% or less, it is presumed that the chemical state of the catalyst is adjusted to a state suitable for the gas phase catalytic oxidation reaction of hydrocarbons, which is even better.

The present invention is a method for raising the temperature of the catalyst layer, and any method can be selected to obtain the required effect. For example, when the reaction operation method proposed in the present invention is employed in the production of acrylic acid or acrylonitrile from propane, not only the reaction results and the service life of the catalyst are good, but also the gas supplied at the reaction temperature is high. By avoiding complicated and dangerous operations such as switching types, and by arbitrarily supplying oxygen and propane, or oxygen, propane and ammonia to reach a predetermined reaction temperature, a desired reaction raw material gas composition is obtained. It is possible to easily and safely start the reaction by adjusting the flow rate.

As the conditions for the gas phase catalytic oxidation reaction of hydrocarbons, the reaction temperature is usually from 200 to 500 ° C., preferably from 300 to 490 ° C., and the gas hourly space velocity SV in the gas phase reaction is usually from 100 to 10,000 h. ⁻¹ , preferably in the range of 300 to 6000 h ⁻¹ . The gas phase contact reaction is
Usually, the reaction is carried out under atmospheric pressure, but may be carried out under low pressure or low pressure. As a diluent gas for adjusting the space velocity and the oxygen partial pressure, an inert gas such as nitrogen, argon, helium, or carbon dioxide can be used. In addition, the reaction is carried out while controlling the conversion of hydrocarbons to about 70% or less so that the selectivity to the target product is increased, and unreacted hydrocarbons are separated and recovered, and supplied to the reactor again. It is also possible to employ.

Specifically, when acrylonitrile is produced from propane, the proportion of oxygen supplied to the reaction system has a large effect on the selectivity of acrylonitrile to be produced, and the proportion of oxygen is 0.2 to 4 relative to propane. The range of the molar amount is preferable. Within this range, a high acrylonitrile selectivity can be exhibited. The ratio of ammonia supplied to the reaction system is 0.1 to 3 with respect to propane.
A molar range is preferred.

When acrylic acid is produced from propane, the proportion of oxygen supplied to the reaction system is preferably in the range of 0.1 to 5 times the molar amount of propane. Furthermore,
By supplying water vapor to the reaction system, the selectivity of acrylic acid may be improved, and the ratio of the water vapor is 40 mol times or less with respect to propane. Furthermore, when trying to produce unsaturated nitrile and unsaturated carboxylic acid, for example, acrylonitrile and acrylic acid at the same time, the composition of the gas supplied to the reactor is such that the molar ratio of ammonia / propane is:
Usually 0.1-5, preferably 0.1-4, oxygen /
The molar ratio of ammonia is usually 1 to 10, preferably 2 to
8 Within this range, the total selectivity of the unsaturated nitrile and the unsaturated carboxylic acid is excellent.

The method for preparing the catalyst used in the present invention is not particularly limited, and includes a method of preparing a solution or a slurry of water or an organic solvent as a raw material of the composite oxide, and a method of mixing the raw material of the composite oxide to a high temperature. Two methods of preparing by solid-phase reaction are well known. In order to obtain a catalyst having better performance, the former method, particularly a method of preparing a solution or a slurry-like aqueous liquid containing each component, followed by drying and calcining, is preferred.

As raw materials for preparing the catalyst of the present invention,
Carboxylate, carboxylate ammonium salt, ammonium halide salt, oxide, hydrated oxide, oxyacid and its salt, halide, hydrogen acid, acetylacetonate,
Compounds such as alkoxides and halides, or metals can be used after being solubilized or slurried with an appropriate reagent.

For example, as a method for producing a catalyst comprising a composite oxide containing molybdenum, vanadium, tellurium and niobium, an aqueous solution of ammonium metavanadate, an aqueous solution of telluric acid, a water-soluble slurry containing a niobium compound, or niobium oxalate An aqueous solution of an ammonium salt and an aqueous solution of an ammonium paramolybdate are sequentially added in a quantitative ratio such that the atomic ratio of each metal element becomes a predetermined ratio,
It can be obtained by drying by an evaporation to dryness method, a spray drying method, a freeze drying method, a vacuum drying method or the like to obtain a dried product, and then baking the obtained dried product. The firing temperature is usually 200 to 700 ° C, preferably 250 to 650 ° C, and the time is generally 0.5 to 30 hours, preferably 1 to 10 hours. The firing may be performed in an oxygen atmosphere, but is preferably performed in the absence of oxygen.
It is performed in an atmosphere of an inert gas such as nitrogen, argon, helium, or in a vacuum.

The catalyst comprising the composite oxide thus produced may be used alone, but may be any of well-known carrier components,
For example, it may be used as a mixture containing about 1 to 90% by weight of silica, alumina, titania, zirconia, aluminosilicate, diatomaceous earth and the like. Such a carrier component may be added at the same time as preparing the solution or slurry of the catalyst raw material, or may be added after the solution or slurry is dried. Alternatively, the catalyst particles after calcination and these carrier component particles may be physically mixed and used.

[0024]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples unless it exceeds the gist. The alkane conversion (%), target product selectivity (%), and target product yield (%) in the following Examples and Comparative Examples are each calculated by the following formulas.

[0025]

## EQU1 ## Alkane conversion (%) = (moles of alkane consumed / moles of supplied alkane) × 100 Selectivity (%) of target product = (moles of target product formed / moles of alkane consumed) Number) × 100 Yield (%) of target product = (moles of target product generated /
Number of moles of supplied alkane) x 100

Reference Example 1 Preparation of Mo-V-Te-Nb composite metal oxide catalyst The charged metal element ratio was Mo ₁ V _0.3 Te _0.23 Nb _0.12
The composite metal oxide catalyst was prepared as follows. 1.38 kg of ammonium paramolybdate, 0.275 kg of ammonium metavanadate, and 0.413 kg of telluric acid were dissolved in 5.68 liters of warm water to prepare a uniform aqueous solution. Furthermore, the silica content is 20
An aqueous solution containing niobium prepared by dissolving 0.658 kg of a wt.% silica sol and an aqueous oxalic acid solution heated to 70 ° C. in an aqueous oxalic acid solution (niobium concentration 0.4
(mol / kg) to prepare a slurry. The slurry was dried to remove water. Next, the dried product was heated at about 300 ° C. until the smell of ammonia disappeared, and then calcined at 600 ° C. for 2 hours in a nitrogen stream.

Reference Example 2 Preparation of Mo-V-Sb-Nb Composite Metal Oxide Catalyst A composite oxide was prepared as follows so that the charged metal element ratio was Mo ₁ V _0.3 Sb _0.2 Nb _0.05 . 122 g of ammonium metavanadate and 102 g of antimony trioxide were added to 2.1 liters of warm water, and the slurry was heated at 90 ° C. for 6 hours to remove water and concentrated to about ３. This is called slurry A. Separately, ammonium paramolybdate 614 was added to 1.23 kg of warm water.
g was added and dissolved, and then heated to 40 ° C. to prepare an aqueous solution containing molybdenum. Further, 77 g of niobium ammonium oxalate was dissolved in 4.62 kg of warm water, and then heated to 40 ° C. to prepare an aqueous solution containing niobium. These slurries,
Alternatively, the aqueous solution is cooled to about 30 ° C., and the aqueous solution containing molybdenum in the slurry A, and then the silica content is 20 wt.
% Silica sol and an aqueous solution containing the above-mentioned niobium were added with stirring to prepare an aqueous slurry.
Then, the dried product is removed for about 30 minutes until the smell of ammonia disappears.
After heat treatment at 0 ° C., it was baked at 600 ° C. for 2 hours in a nitrogen stream.

Example 1 A fixed-bed flow reactor was charged with 0.25 g of the composite metal oxide catalyst prepared as in Reference Example 1, and the gas space velocity SV was set at about 2000 h ^-1 to reduce nitrogen. To distribute,
The temperature of the catalyst layer was raised from room temperature to 350 ° C. in 30 minutes. When the temperature reaches 350 ° C, the SV is increased to about 200
At 0 h ^-1 , propane: ammonia: oxygen: nitrogen =
A gas was supplied at a molar ratio of 1: 1.2: 3: 12, and the temperature was increased in 20 minutes until the temperature of the catalyst layer reached 430 ° C.
When the oxygen concentration at the reactor outlet at this time was analyzed, it changed from 13.5% (350 ° C.) to 2.4% (430 ° C.). In this state, a gas phase catalytic oxidation reaction was performed at 430 ° C. Table 1 shows the results.

Example 2 0.25 g of the composite metal oxide catalyst prepared as in Reference Example 1 was charged into a fixed bed flow type reactor, and the gas space velocity SV was set to about 2000 h ^-1 to reduce nitrogen. To distribute,
The temperature of the catalyst layer was raised from room temperature to 430 ° C. in 50 minutes. When the temperature reaches 430 ° C., the power supplied to the electric heater heating the reactor is reduced, and the SV is reduced to about 2
In a state of 000 h ⁻¹ , a gas was supplied at a molar ratio of propane: ammonia: oxygen: nitrogen = 1: 1.2: 3: 12, and the temperature of the catalyst layer was maintained at 430 ° C. 43 as it is
A gas phase catalytic oxidation reaction was performed at 0 ° C. Table 1 shows the results.
Shown in

Comparative Example 1 0.25 g of the composite metal oxide catalyst prepared as in Reference Example 1 was charged into a fixed bed flow type reactor, and the gas space velocity SV was set to about 2000 h ^-1 to release air. To distribute,
The temperature of the catalyst layer was raised from room temperature to 350 ° C. in 30 minutes. When the temperature reaches 350 ° C, the SV is increased to about 200
At 0 h ^-1 , propane: ammonia: oxygen: nitrogen =
A gas was supplied at a molar ratio of 1: 1.2: 3: 12, and the temperature was increased in 20 minutes until the temperature of the catalyst layer reached 430 ° C.
When the oxygen concentration at the reactor outlet at this time was analyzed, it was changed from 14.8% to 5.8%. In this state, a gas phase catalytic oxidation reaction was performed at 430 ° C. Table 1 shows the results.

COMPARATIVE EXAMPLE 2 0.25 g of the composite metal oxide catalyst prepared as in Reference Example 1 was charged into a fixed bed flow reactor, and the gas space velocity SV was set at about 2000 h ^-1 to obtain ammonia: A gas was passed at a molar ratio of oxygen: nitrogen = 1.5: 20.5: 78, and the temperature of the catalyst layer was raised from room temperature to 350 ° C. for 30 minutes. When the temperature reaches 350 ° C., a gas is supplied at a SV of about 2000 h ⁻¹ at a molar ratio of propane: ammonia: oxygen: nitrogen = 1: 1.2: 3: 12, and the temperature of the catalyst layer reaches 430 ° C. The temperature was raised in 20 minutes until it became. In this state, a gas phase catalytic oxidation reaction was performed at 430 ° C. Table 1 shows the results.

Example 3 0.25 g of the composite metal oxide catalyst prepared as in Reference Example 1 was charged into a fixed bed flow type reactor, and the gas space velocity SV was set at about 2000 h ^-1 to reduce nitrogen. To distribute,
The temperature of the catalyst layer was raised from room temperature to 350 ° C. in 30 minutes. When the temperature reaches 350 ° C, the SV is increased to about 900
In the state of h- ¹ , ammonia: oxygen: nitrogen = 2: 2: 96
And the temperature was increased in 20 minutes until the temperature of the catalyst layer reached 430 ° C. At this time, the oxygen concentration at the outlet of the reactor was analyzed to be from 1.8% to 0.1%.
%. When the temperature reaches 430 ° C, the SV is increased to about 2000
In the state of h- ¹ , propane: ammonia: oxygen: nitrogen =
Gas was supplied at a molar ratio of 1: 1.2: 3: 12 to perform a gas phase catalytic oxidation reaction. Table 1 shows the results.

[0033]

[Table 1]

Example 4 0.55 g of the composite metal oxide catalyst prepared as in Reference Example 1 was charged into a fixed bed flow type reactor, and the gas space velocity SV was set at about 1870 h ^-1 to remove nitrogen. To distribute,
The temperature of the catalyst layer was raised from room temperature to 300 ° C. in 30 minutes. When the temperature reaches 300 ° C., the SV is increased to about 187.
At 0 h ^-1 , propane: oxygen: water vapor: nitrogen = 1:
The gas was supplied at a molar ratio of 3:12:14, and the temperature was increased in 20 minutes until the temperature of the catalyst layer reached 430 ° C. 8. The oxygen concentration at the reactor outlet at this time was analyzed.
It changed from 5% to 2.2%. 430 ° C as it is
For a gas phase catalytic oxidation reaction. Table 2 shows the results.

Comparative Example 3 0.55 g of the composite metal oxide catalyst prepared as in Reference Example 1 was charged into a fixed bed flow type reactor, and the gas space velocity SV was set at about 1870 h ^-1 to remove air. To distribute,
The temperature of the catalyst layer was raised from room temperature to 300 ° C. in 30 minutes. When the temperature reaches 300 ° C., the SV is increased to about 187.
At 0 h ^-1 , propane: oxygen: water vapor: nitrogen = 1:
The gas was supplied at a molar ratio of 3:12:14, and the temperature was increased in 20 minutes until the temperature of the catalyst layer reached 430 ° C. When the oxygen concentration at the reactor outlet at this time was analyzed, it was 1
It changed from 0.5% to 3.3%. 43 as it is
A gas phase catalytic oxidation reaction was performed at 0 ° C. Table 2 shows the results.
Shown in

Example 5 0.55 g of the composite metal oxide catalyst prepared as in Reference Example 1 was charged into a fixed bed flow type reactor, and the gas space velocity SV was set to about 1870 h ^-1 to remove nitrogen. To distribute,
The temperature of the catalyst layer was raised from room temperature to 300 ° C. in 30 minutes. When the temperature reaches 300 ° C, the SV is increased to about 900
In the state of h- ¹ , gas was supplied at a molar ratio of propane: oxygen: nitrogen = 2: 2: 96, and the temperature was increased in 20 minutes until the temperature of the catalyst layer reached 430 ° C. When the oxygen concentration at the reactor outlet at this time was analyzed, it was 1.9% to 0.1%.
Changed to When the temperature reaches 430 ° C., the SV is increased to about 1870 h ⁻¹
, Propane: oxygen: water vapor: nitrogen = 1: 3: 1
Gas was supplied at a molar ratio of 2:14 to perform a gas phase catalytic oxidation reaction. Table 2 shows the results.

[0037]

[Table 2]

Example 6 0.55 g of the composite metal oxide catalyst prepared as in Reference Example 2 was charged into a fixed bed flow reactor, and the gas space velocity SV was set at about 900 h ^-1 to reduce nitrogen. The temperature was raised for 30 minutes until the temperature of the catalyst layer reached 350 ° C. from room temperature. When the temperature reaches 350 ° C, the SV is increased for about 900 hours.
^In the state of ^-1 , propane: ammonia: oxygen: nitrogen = 1:
The gas was supplied at a molar ratio of 1.2: 3: 12, and the temperature was increased in 20 minutes until the temperature of the catalyst layer reached 430 ° C. When the oxygen concentration at the reactor outlet at this time was analyzed, it was 1
It changed from 3.8% to 2.7%. 43 as it is
A gas phase catalytic oxidation reaction was performed at 0 ° C. Table 3 shows the results.
Shown in

Comparative Example 5 0.55 g of the composite metal oxide catalyst prepared as in Reference Example 2 was charged into a fixed bed flow type reactor, and the gas space velocity SV was set to about 900 h ^-1 to release air. The temperature was raised for 30 minutes until the temperature of the catalyst layer reached 350 ° C. from room temperature. When the temperature reaches 350 ° C, the SV is increased for about 900 hours.
^In the state of ^-1 , propane: ammonia: oxygen: nitrogen = 1:
The gas was supplied at a molar ratio of 1.2: 3: 12, and the temperature was increased in 20 minutes until the temperature of the catalyst layer reached 430 ° C. When the oxygen concentration at the reactor outlet at this time was analyzed, it was 1
It changed from 4.9% to 5.7%. 43 as it is
A gas phase catalytic oxidation reaction was performed at 0 ° C. Table 3 shows the results.
Shown in

Comparative Example 6 0.55 g of the composite metal oxide catalyst prepared as in Reference Example 2 was charged into a fixed bed flow type reactor, and the gas space velocity SV was set at about 900 h ^-1 to adjust ammonia: oxygen:
Nitrogen was passed at a molar ratio of 1.5: 20.5: 78 and the temperature of the catalyst layer was increased from room temperature to 350 ° C. until the temperature reached 350 ° C.
The temperature rose in minutes. When the temperature reaches 350 ° C., the SV is reduced to about 90
At 0 h ^-1 , propane: ammonia: oxygen: nitrogen =
A gas was supplied at a molar ratio of 1: 1.2: 3: 12, and the temperature was increased in 20 minutes until the temperature of the catalyst layer reached 430 ° C.
In this state, a gas phase catalytic oxidation reaction was performed at 430 ° C. Table 3 shows the results.

Example 7 0.55 g of the composite metal oxide catalyst prepared as in Reference Example 2 was charged into a fixed bed flow reactor, and the gas space velocity SV was set at about 900 h ^-1 to reduce nitrogen. The temperature was raised for 30 minutes until the temperature of the catalyst layer reached 350 ° C. from room temperature. When the temperature reaches 350 ° C, the SV is increased for about 900 hours.
^Under the condition of ^-1 , a gas was supplied at a molar ratio of ammonia: oxygen: nitrogen = 2: 2: 96, and the temperature was increased in 20 minutes until the temperature of the catalyst layer reached 430 ° C. When the oxygen concentration at the reactor outlet at this time was analyzed, it was 1.9% to 0.1%.
Changed to When the temperature reaches 430 ° C., the SV is reduced to about 900 h ⁻¹
And propane: ammonia: oxygen: nitrogen = 1:
Gas was supplied at a molar ratio of 1.2: 3: 12 to perform a gas phase catalytic oxidation reaction. Table 3 shows the results.

[0042]

[Table 3]

Example 8 The average diameter prepared as described in Reference Example 1 was about 50 μm.
m of the composite metal oxide catalyst particles having an average diameter of about 5 g.
480 g of spherical silica particles having a particle diameter of 50 μm were mixed.
mm stainless steel fluidized bed reactor. Nitrogen gas was introduced from the lower part of the reactor at a flow rate of 890 NL / hr,
The temperature of the catalyst layer was increased to 390 ° C. in an electric furnace while maintaining the pressure at the reactor outlet at 0.9 kg / cm ² G. Thereafter, the supply of oxygen, ammonia and propane was started as follows. That is, while keeping the supply gas amount and the reactor outlet pressure almost constant, the oxygen, ammonia, and propane gas are adjusted so that the oxygen concentration in the gas at the reactor outlet becomes about 5% in a state where all components are vaporized. The supply amount of nitrogen was increased and the supply amount of nitrogen was decreased. This operation was repeated so that finally propane: ammonia: oxygen: nitrogen = 1: 0.3: 1.68: 6.32. In the operation of changing the supply ratio, the temperature of the catalyst layer rises due to heat generation due to the gas phase catalytic oxidation reaction of propane and ammonia. The temperature was raised to 460 ° C. by controlling the temperature of the electric furnace. Where 4
No operation was performed to switch the gas supplied to the reactor until the temperature reached 60 ° C. At the reaction temperature, S
V = 1187 h ⁻¹ . Start the reaction in this way,
When the reaction results after about 2 hours were determined, the propane conversion was 44.0% and the acrylonitrile selectivity was 58.6.
%, Acrylic acid selectivity was 8.6%.

Example 9 The average diameter prepared as described in Reference Example 1 was about 50 μm.
m of mixed metal oxide catalyst particles of 600 m were charged into a fluidized bed reactor having an inner diameter of 50 mm, and nitrogen gas 108
8NL / hr was passed, and the pressure at the reactor outlet was 0.9k.
g / cm ² G and the temperature of the catalyst layer was 39 in an electric furnace.
The temperature was raised to 0 ° C. Thereafter, the supply of oxygen, ammonia and propane was started as follows. That is, while keeping the supply gas amount and the reactor outlet pressure almost constant, the oxygen, ammonia, and propane gas are adjusted so that the oxygen concentration in the gas at the reactor outlet becomes about 5% in a state where all components are vaporized. The supply amount of nitrogen was increased and the supply amount of nitrogen was decreased. This operation was repeated to finally make propane: ammonia: air = 1: 1.2: 15. In the operation of changing the supply ratio, the temperature of the catalyst layer rises due to heat generation due to the gas phase catalytic oxidation reaction of propane and ammonia. The temperature was raised to 445 ° C. by controlling the temperature of the electric furnace. Here, the operation of switching the gas supplied to the reactor until the temperature reached 445 ° C. was not performed at all. At the reaction temperature, SV = 1451h ^-1 . The reaction was started in this manner, and the reaction results after about 2 hours were determined. The propane conversion was 87.9% and the acrylonitrile selectivity was 50.
5% and selectivity of acrylic acid was 0.8%.

Example 10 The average diameter prepared as described in Reference Example 2 was about 50 μm.
240 g of a composite oxide catalyst having an average diameter of about 50 μm
360 g of spherical silica particles having an inner diameter of 50 mm
Of a stainless steel fluidized bed reactor. Nitrogen gas was introduced from the lower part of the reactor at a flow rate of 969 NL / hr, and the temperature of the catalyst layer was raised to 390 ° C. in an electric furnace while maintaining the pressure at the reactor outlet at 0.9 kg / cm ² G. afterwards,
The supply of oxygen, ammonia and propane was started as follows. That is, while keeping the supply gas amount and the reactor outlet pressure almost constant, the oxygen, ammonia, and propane gas are adjusted so that the oxygen concentration in the gas at the reactor outlet becomes about 5% in a state where all components are vaporized. The supply amount of nitrogen was increased and the supply amount of nitrogen was decreased. This operation was repeated so that finally propane: ammonia: oxygen: nitrogen = 1: 0.3: 1.68: 6.32. In the operation of changing the supply ratio, the temperature of the catalyst layer rises due to heat generation due to the gas phase catalytic oxidation reaction of propane and ammonia. The temperature was raised to 460 ° C. by controlling the temperature of the electric furnace. Where 4
No operation was performed to switch the gas supplied to the reactor until the temperature reached 60 ° C. At the reaction temperature, S
V = 1292 h ⁻¹ . Start the reaction in this way,
When the reaction results after about 2 hours were determined, the conversion of propane was 50.0% and the selectivity of acrylonitrile was 52.0%.
% And acrylic acid selectivity was 14.0%.

Example 11 A fixed-bed flow reactor was charged with 0.25 g of the composite metal oxide catalyst prepared as in Reference Example 1, and the gas space velocity SV was set to about 2000 h ^-1 to reduce nitrogen. To distribute,
The temperature of the catalyst layer was raised from room temperature to 440 ° C. in 40 minutes. When the temperature reaches 440 ° C, the SV is increased to about 200
At 0 h ^-1 , propane: ammonia: oxygen: nitrogen =
Gas was supplied at a molar ratio of 1: 1.2: 3: 12, and the temperature was adjusted such that the temperature of the catalyst layer became 430 ° C. The oxygen concentration at the reactor outlet at this time was analyzed.
It changed from 0% to 2.4%. 430 ° C as it is
For a gas phase catalytic oxidation reaction. The reaction was started in this way, and the reaction results after about 2 hours were determined. The conversion of propane was 82.5% and the selectivity of acrylonitrile was 56.
The acrylonitrile yield was 86.9%, and the acrylonitrile yield was 46.9%.

[0047]

According to the present invention, acrylonitrile useful as an industrial raw material by a gas phase catalytic oxidation reaction of hydrocarbons,
Unsaturated nitriles such as acrylic acid and unsaturated carboxylic acids can be produced with high yield and selectivity.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C07C 255/08 C07C 255/08 // C07B 61/00 300 C07B 61/00 300 F-term (Reference) 4H006 AA02 AC12 AC46 AC54 BA05 BA06 BA08 BA09 BA10 BA11 BA12 BA13 BA14 BA15 BA16 BA19 BA20 BA21 BA23 BA24 BA25 BA26 BA30 BC10 BC18 BC40 BE14 BE30 BS10 4H039 CA65 CC20 CC30 CL50

Claims (8)

[Claims] A hydrocarbon is subjected to a gas phase catalytic oxidation reaction in the presence of a composite metal oxide catalyst containing molybdenum, vanadium, and at least one element of tellurium or antimony as an essential component, thereby obtaining unsaturated nitrile and / or unsaturated nitrile. In the method for producing an unsaturated carboxylic acid, the temperature of the catalyst layer is raised in an atmosphere substantially free of oxygen and / or a flammable gas until the temperature of the catalyst layer reaches a temperature at which reaction can be started. Catalytic oxidation reaction method. 2. The hydrocarbon according to claim 1, wherein a gas containing hydrocarbon and oxygen or a gas containing hydrocarbon, ammonia and oxygen is supplied when the temperature of the catalyst layer is lower than the reaction temperature. Gas phase catalytic oxidation reaction method. 3. A gas containing hydrocarbons and oxygen at a temperature higher than the reaction temperature by raising the temperature in an atmosphere substantially free of oxygen and / or flammable gas until the temperature of the catalyst layer reaches a temperature higher than the reaction temperature. 2. The method according to claim 1, wherein a gas containing hydrocarbon, ammonia and oxygen is supplied. 4. The method according to claim 1, wherein the reaction start temperature is from 200 ° C. to 450 ° C., and the reaction temperature is from 300 ° C. to 490 ° C. in the gas phase catalytic oxidation reaction of hydrocarbons. 2. A method for the gas phase catalytic oxidation reaction of hydrocarbon according to claim 1. 5. A gas containing hydrocarbon and oxygen, or a mixture of hydrocarbon, ammonia and oxygen at a temperature of a catalyst layer higher than a temperature at which a reaction can be initiated in a gas phase catalytic oxidation reaction of hydrocarbons. The gas containing is supplied while maintaining the oxygen concentration in the gas at the outlet of the reactor at 0.1% or more, and the reaction is carried out by adjusting the temperature of the catalyst layer to the reaction execution temperature. A method for the gas phase catalytic oxidation reaction of hydrocarbons according to any one of the preceding claims. 6. The method for catalytically oxidizing hydrocarbons in the gas phase, wherein the composite metal oxide catalyst comprises molybdenum, vanadium, X, Y and oxygen (X is at least one of tellurium and antimony, Y is niobium, Tantalum, tungsten, titanium, aluminum, zirconium, chromium, manganese, iron, ruthenium, cobalt, rhodium,
Nickel, palladium, platinum, bismuth, boron, indium, phosphorus, germanium, a rare earth element, an alkali metal, or an alkaline earth metal). The method for gas phase catalytic oxidation of hydrocarbons according to any one of claims 1 to 5, characterized in that: 7. In the gas phase catalytic oxidation reaction of hydrocarbons, the proportion of the essential component of the catalyst is determined by the following formula: 0.25 <rMo <0.98 0.003 <rV <0.5 0.003 <rX <0.5 0 ≦ rY <0.5 (where rMo, rV, rX, rY represent the mole fraction of Mo, V, X and Y with respect to the sum of the above essential components excluding oxygen) The method for gas phase catalytic oxidation reaction of hydrocarbon according to claim 6, characterized in that: 8. The gas phase catalytic hydrocarbon oxidation method according to claim 1, wherein the hydrocarbon is propane and / or isobutane. Oxidation reaction method.