JPH04202171A - Apparatus for producing alpha,beta-unsaturated nitrile - Google Patents

Abstract

PURPOSE:To obtain a fluidized bed reactor having improved conversion degree at the outer circumferential part of the reactor to increase the overall yield by providing gas blasting nozzles connected to a raw material gas supplying device and an oxygen-containing gas supplying device placed at the lower part in a reactor and arranging the gas blasting nozzle to satisfy a specific positional relationship. CONSTITUTION:A raw material gas supplying device having plural raw material gas blasting nozzles 5 arranged at nearly uniform spacings on the lower face is horizontally placed at the lower part of a reactor. Opposite to the raw material gas blasting nozzles 5, the same number of oxygen-containing gas blasting pipes 6 are opened on the upper surface of an oxygen-containing gas supplying device 4 below the raw material gas blasting nozzles 5. The distance between the tip of the nozzle 5 and the tip of the pipe 6 is 25-300mm, the distance between the pipes 6 is 90-250mm and the number of the pipes 6 per unit cross-sectional area of the reactor is 16-120/m<2>. An alpha,beta-unsaturated nitrile is produced by the reaction of propylene, isobutylene or tert. butyl alcohol with ammonia and an oxygen-containing gas using the above reactor.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a reaction apparatus for producing acrylonitrile or methacrylonitrile using propylene, isobutylene, or tertiary butyl alcohol, ammonia, and an oxygen-containing gas as raw materials.

[Conventional technology]

Conventionally, when producing an α,β-unsaturated nitrile by reacting an olefin or tertiary butyl alcohol, ammonia, and an oxygen-containing gas by a gas phase catalytic reaction,
Fluidized bed reactors are widely adopted. The composition of the gas supplied to this reactor is within the explosive range if they are mixed in advance. ) must be supplied from a separate supply port from that of the oxygen-containing gas. Ikeda Rice -; Chemical Engineering 1st No. 10.1013 (
(1970), it is known that reducing the bubble diameter in a fluidized bed improves the contact efficiency between gas and solid (ie, catalyst). It is also known from the above-mentioned literature that in the acrylonitrile synthesis reaction by ammoxidation of propylene, the selectivity of acrylonitrile is improved by reducing the bubble diameter. and,
In order to reduce the bubble diameter, a method of inserting an insert into the reactor has conventionally been adopted, but this method increases equipment costs and is not desirable. Normally, when producing acrylonitrile or methacrylonitrile using a fluidized bed reactor, high-boiling substances produced by side reactions are heated by a feed air preheater and a boiler water heater installed at the reactor outlet. block the exchanger,
As a result, there is a problem that the reactor cannot be operated continuously for a long period of time. Furthermore, as the reaction gas flow side of these heat exchangers becomes clogged and the pressure difference between the outlet and inlet of the exchanger increases, the reaction pressure of the reactor gradually increases. Catalysts used in the production of acrylonitrile or methacrylonitrile generally tend to reduce the yield of acrylonitrile or methacrylonitrile as the reaction pressure increases, so even during normal operation, these heat exchangers It is not desirable that the pressure increases and the reaction pressure increases. Inside a large fluidized bed reactor, the fluidized catalyst rises in the center of the reactor and descends near the reactor main wall.
It is generally known that a so-called particle circulation flow is formed (Miyauchi et al.
sport Phenomena and React
ion in Fluidized Catalys
t Beds - 8 advancements in C
hem, Eng. , VolII p279-280. Academ
ic Press (1981)). It is known that the strength of the circulation flow increases as the radius of the reactor increases (ibid. References 311-3
p. 17, Whichi et al., “Reaction Engineering of Fluidized Beds”, 115-116
Page, Baifukan, 1981). In large fluidized bed reactors with a radius of more than 3 m, the so-called particle circulation flow is strong, which is formed when the fluidized catalyst rises in the center of the reactor and descends near the reactor main wall.
This has the serious drawback that the efficiency of contact with the catalyst, such as back-mixing and blow-by of the reaction gas, decreases, leading to a decrease in the reaction rate, and the ability of the catalyst cannot be fully demonstrated. Therefore, for the purpose of improving flow, structures such as perforated plates have been installed inside the fluidized bed to redisperse the air bubbles. but,
If air bubbles are redispersed using a perforated plate, etc., the pressure drop in this area will increase, or the catalyst particles will not fall enough, etc.
This is not suitable because a reaction gas stagnation part is generated in the lower part of the internal structure, resulting in a decrease in the yield of the target product. In a fluidized bed reactor, it is extremely important to quickly mix the raw material gas and the oxygen-containing gas to form a homogeneous mixed gas before reacting, so US Patent No. 480
No. 1731 proposes a method of countercurrent mixing in the production of acrylonitrile by arranging the blowing pipe of an oxygen-containing gas supplier and the blowing nozzle of a propylene/ammonia mixed gas supplier in a straight line. However, in large-scale fluidized bed reactors with a diameter of 3 m or more that are usually used commercially, the presence of a circulating flow of catalyst particles becomes noticeable, and the influence of the downward flow near the wall of the reactor body causes The oxygen-containing gas jet at the outer periphery is bent towards the center of the reactor. Therefore, when using a large reactor with a diameter of 3 m or more, US Pat.
The method of No. 01731 has the disadvantage that the mixing of the "raw material gas" and the oxygen-containing gas at the outer periphery is insufficient, resulting in a decrease in the tolyl for α,β-unsaturation in the reactor as a whole.

[Problem to be solved by the invention]

The object of the present invention is to improve the tolyl for α,β-unsaturation, to enable continuous operation of the reactor, and to further improve the tolyl content of the raw material olefin or tertiary butyl alcohol in the outer periphery of the reactor. An object of the present invention is to provide a fluidized bed reactor that improves the tolyl for α,β-unsaturation as a whole by improving the reaction rate.

[Means to solve the problem]

The present inventors have completed the present invention as a result of diligently improving the reaction apparatus by paying attention to the diameter of generated bubbles and the circulating flow of catalyst around the outer periphery of the reactor. To explain the structure of the present invention, as shown in FIG. 1, a raw material gas supply device 3 is provided at the lower part of the reactor, and an oxygen-containing gas supply device 4 is formed below it. The raw material gas supply device 3 is provided horizontally, and has a plurality of raw material gas blowing nozzles 5 on its lower surface at substantially uniform intervals toward the bottom of the reactor. It is desirable that this raw material gas supply device has a diameter slightly smaller than the diameter of the reactor. The oxygen-containing gas supply device 4 is also provided horizontally, and has the same number of oxygen-containing gas blow-off pipes 6 on its upper surface facing the raw material gas blow-off nozzles 5. This oxygen-containing gas supply device desirably has a diameter that is approximately the same as the diameter of the reactor. The relative positional relationship between the raw material gas blowing nozzle 5 and the oxygen-containing gas blowing pipe 6 is that the relative position is that between the tip of the raw material gas blowing nozzle 5 and the tip of the oxygen-containing gas blowing pipe 6. The distance is 25~3
00mm, the distance between the oxygen-containing gas blowing pipes is 90mm
250 mm, and the number of tubes is 16 to 120/2 per cross-sectional area of the reactor. The present invention is characterized in that it consists of the above-mentioned structure, and is produced by reacting propylene, isobutylene, or tertiary butyl alcohol with ammonia and oxygen-containing gas to obtain α having the same number of carbon atoms as the raw material olefin or tertiary butyl alcohol. , β-, β-nitrile production equipment,
In the above configuration, it is further preferable that the distance between the series of oxygen-containing gas blowing pipes 6 closest to the inner wall of the reactor and the inner wall be 300 mm or less, and , among the raw material gas blowing nozzles 5, a series of nozzles located on the outer periphery of the reactor are
The position of the series of oxygen-containing gas blow-off pipes 6, which are arranged opposite to each other, is shifted to the center of the reactor, and the positional shift is 40 when expressed as a relative angle θ.
It is preferable that the temperature is set so that the temperature is less than or equal to 1. In the present invention, the outer periphery of the reactor refers to the ratio of the distance from the center of the reactor to the radius of the reactor (r/R
) is in the range of 0.8 to 1.0. To explain the present invention in more detail, in the tolyle for α,β-unsaturation produced by the apparatus of the present invention, the catalyst used for the reaction can be selected from ammoxide catalysts commonly used in the production of acrylonitrile or methacrylonitrile. For example, for the production of acrylonitrile, Japanese Patent Publication No. 36-5870, Japanese Patent Publication No. 38-17967,
Catalysts described in Japanese Patent Publication No. 50667/1983, Japanese Patent Publication No. 58462/1986, US Pat. No. 4,495,109, and Japanese Patent Publication No. 1-34221 and Japanese Patent Publication No. 1-34222 can be used for the production of methacrylonidril. When producing acrylonitrile or methacrylonitrile, the reaction temperature is between 400°C and 500°C, and the reaction pressure is between 0°2 kg/am2G and 2kg/cm2G. Propylene, isobutylene or tertiary butylene-10
= The mixing molar ratio of alcohol and ammonia is from equimolar to a slight excess of ammonia of 1.0 to 1.3. The oxygen-containing gas must contain molecular oxygen; for example, pure oxygen or diluted oxygen with an inert gas such as nitrogen gas is used, and air is particularly preferred. used. When using air as the oxygen-containing gas, the reactor contains (Jl
The raw material air to be used is supplied in a molar amount ranging from 7 to 14 times that of propylene, isobutylene, or tertiary butyl alcohol. The distance between the oxygen-containing gas blowing pipes is 90 to 250
mm is better. However, if the distance between the blow-off tubes is made too small, the bubbles generated from the blow-off tubes adjacent to each other will come together and the effect will be reduced. The distance between the blowoff pipes can be constant, but it does not have to be constant. Also, the outlet tubes can be arranged in a square, rectangle or triangle. The density of the oxygen-containing gas blowing tubes is preferably 16 or more and 1201 or less per 1 m2 of cross-sectional area of the reactor. The diameter of bubbles generated on the oxygen-containing gas supply device or in the blow-off pipe can be determined by calculation according to the following formula [Miwa et al., Chemical Engineering 35770 (1971)]. Dbo=3.77g −'(Uo −Umf) 2
■The diameter of the generated bubbles is the larger value of the values calculated from formulas ■ and ■. Dbo: diameter of generated bubbles (Cm) Uo: gas superficial velocity (m/sec) Umf: fluidization start velocity (m/sec) At: reactor cross-sectional area [
m2] Nov: Number of blowoff pipes [pieces] g: Gravitational acceleration (m/5ec2) The blowoff pipes are arranged in a square, Uo=Q, 5m/sec
Calculating the diameter of the generated bubbles in case c is as follows. If the distance between the blowout tubes is less than 90 mm, the diameter of the bubbles will be larger than the distance between the blowout tubes, and the bubbles will join together and become larger, which is not preferable. Moreover, if the same distance exceeds 250 mm, the bubble diameter will significantly exceed 200 mm, which is also not preferable. Therefore, from 90mm to 250mm
It is desirable to select within the range of . Although the inner diameter of the oxygen-containing gas blowing tube can be made uniform, it does not have to be particularly uniform. However, it is preferable that the tip of the catalyst be constricted to prevent the catalyst from entering the oxygen-containing gas supply device. The blowing speed from the oxygen-containing gas blowing pipe is 10 m/
The range is preferably from 30 m/s to 60 m/s, preferably from 30 m/s to 60 m/s. If the blowing speed is too high,
This is not preferable because it will wear out the catalyst. Although the hole diameter of the raw material gas blowing nozzle can be made uniform, it does not have to be particularly uniform. The blowing speed from the raw material gas blowing nozzle is 10 m/
A good range is from 30 m/s to 60 m/s, preferably from 30 m/s to 60 m/s. If the blowing speed is too high,
This is not preferable because it will wear out the catalyst. The number of raw material gas blowing nozzles and oxygen-containing gas blowing pipes is preferably the same, and their relative positions are opposite to each other. The distance from the tip is preferably 25 to 300 mm. If the relative distance is too short, the raw material gas blow-off nozzle or oxygen-containing gas blow-off pipe may be eroded due to an abnormal reaction, and if the relative distance is too long, the raw material gas and the oxygen-containing gas will not be sufficiently mixed. , α, β-unsaturation The tolyl for unsaturation decreases. In order to suppress the circulating flow of catalyst particles in the outer circumference of the reactor and to sufficiently mix the raw material gas and the oxygen-containing gas, the distance between the inner wall of the reactor and the oxygen-containing gas blowing pipe closest to the inner wall of the reactor must be adjusted. (hereinafter referred to as wall distance) is 300m
m or less, preferably 50 to 200 mm, to suppress the downward flow of the fluidized catalyst near the inner wall of the reactor, and furthermore, due to the influence of the downward flow of the catalyst near the inner wall of the reactor, a jet of oxygen-containing gas at the outer periphery. Considering that the gas is bent toward the center of the reactor, the raw material gas blow-off nozzle located on the outer periphery is placed closer to the center of the reactor than the oxygen-containing gas blow-off pipe located opposite to the lower part of the raw material gas blow-off nozzle. By arranging them, the reaction rate of propylene, isobutylene, or tertiary butyl alcohol in the outer periphery is dramatically improved, and the yield of acrylonitrile or methacrylonitrile in the reactor as a whole is improved. In addition, the degree to which the raw material gas blowing nozzle located on the outer periphery is placed closer to the center of the reactor than the oxygen-containing gas blowing pipe placed opposite to the lower part of the nozzle depends on the strength of the catalyst particle circulation flow and the raw material gas blowing nozzle. Although it depends on the relative distance between the gas blow-off nozzle and the oxygen-containing gas blow-off tube, the distance between the line connecting the center of the tip of the oxygen-containing gas blow-off tube and the center of the tip of the raw material gas blow-off tube and the tip of the oxygen-containing gas blow-off tube The angle θ where the vertical lines passing through the center intersect (hereinafter,
It is preferable that the relative angle θ) is 40° or less, more preferably 30° or less, toward the center of the reactor.

【Effect of the invention】

According to the apparatus of the present invention, by inserting an insert inside the reactor or providing a structure such as a perforated plate, pressure drop increases in that part, or insufficient falling of catalyst particles, etc.
To improve the trill for α,β-unsaturation with a simple structural device without causing a reaction gas retention part to occur in the lower part of the internal structure and causing a decrease in the trill for α,β-unsaturation. Moreover, a great industrial advantage can be expected in that the reactor can be operated continuously for a long period of time without clogging the heat exchanger installed at the reactor outlet.

【Example】

An example of implementation of the device of the present invention will be described based on the drawings. 1 is a fluidized bed reactor main body with an inner diameter of 3.7 m, 2 is a heat removal coil, and a raw material gas supply device 3 having a plurality of raw material gas blowing nozzles 5 on the lower surface is installed horizontally at the lower part of the fluidized bed reactor main body 1. It is set in. This raw material gas supply device 3 is formed to be slightly smaller than the diameter of the fluidized bed reactor main body 1. An oxygen-containing gas supplier 4 having the same number of oxygen-containing gas blow-off pipes 6 on its upper surface facing the source gas blow-off nozzles 5 is formed below the raw material gas supplier 3. , the diameter is almost the same as the diameter of the fluidized bed reactor main body 1. Then, the relative distance is 100 mm, and the mutual capacity of the oxygen-containing gas blowing pipe 6 is ftl! t140mm, the number of oxygen-containing gas blowing pipes 6 is 5 per cross-sectional area of the fluidized bed reactor main body 1.
1 piece/m2, and the distance between the series of oxygen-containing gas blow-off pipes 6 closest to the inner wall of the fluidized bed reactor main body 1 and the inner wall is 150 mm. In addition, a series of raw material gas blowing nozzles 5 located on the outer periphery of the fluidized bed reactor main body 1 are connected to the fluidized bed from a position of a series of oxygen-containing gas blowing pipes 6 provided opposite to each other. It is arranged offset to the center of the reactor main body 1, and the positional offset is 15 degrees when expressed as a relative angle θ. In the figure, 7 indicates a jet formed by an oxygen-containing gas blowing pipe, and 8 indicates a catalyst particle circulation flow. Next, Examples and Comparative Examples in which α, β-unsaturated nitriles are produced using the apparatus of the present invention will be described. In addition, the fluidized catalyst bed density is 750 mm above the oxygen-containing gas blowing pipe.
and static −18= pressure taps at 1250 mm are installed at the center of the fluidized bed reactor at r/R=0.0 and at the outer periphery at r/R=0.9. , - used a method that calculates the density using a known pressure difference within the membrane. Here, the driving force for forming the particle circulation flow is the density difference in the radial direction of the fluidized bed ('FLUI
DIZATION ENG4NEERING J
(D, Kunii, 0, Levenspie
(author) p. 354]. Therefore, it is obvious that if the density of the fluidized catalyst bed is uniform in the radial direction, no particle circulation flow is formed. In addition, gas sampling nozzles were installed at the center of the unreacted olefin at a height of 9 m at r/R-〇, 0, and at the outer periphery at the same height at r/R = 0.9, and the gas coming out of the nozzles was collected. It was washed with water, taken out, and analyzed using a gas chromatograph. Instruments and other auxiliary equipment are those normally used. Comparative Example 1 An oxygen-containing gas supply device was installed at the bottom of a fluidized bed reactor with an inner diameter of 3.7 m, and blow-off pipes were arranged in a square with a side of 300 mm. A raw material gas supply device is installed above it, and its model is a pipe grid type, with three blowout nozzles on each side.
The balloons were arranged in a 00 mm square, with the blowing direction facing straight down. The number of oxygen-containing gas blow-off tubes and raw material gas blow-off nozzles was the same, and the raw material gas blow-off nozzles were positioned 100 mm directly above the opposing oxygen-containing gas blow-off tubes. The relative angle θ of the outer peripheral portion is Oo. The walls were arranged so that the distance between them was 150 mm. The blowing speed from the oxygen-containing gas blowing pipe is 46 m/
The inner diameter of the pipes was determined so that the inner diameter of the pipes was 1.5 seconds, and all the inner diameters were uniform. The blowing speed from the raw material gas blowing nozzle is 40 m/
The inner diameter of the nozzle was determined so that the inner diameter of the nozzle was 1.5 seconds, and the inner diameter of all nozzles was uniform. A reactor was filled with 25 tons of a molybdenum-bismuth-iron fluidized bed catalyst having silica as a carrier. 9,10100N/H1 of air to the oxygen-containing gas supplier and 1000% of propylene with a purity of 96 mol% to the raw material gas supplier.
Nm3/H and ammonia were supplied at 115ONm3/H, and the reaction was carried out at a reaction temperature of 470°C. Table 1 shows the reaction results obtained two weeks after the start of the reaction. The definitions of reaction rate, yield, and high boiling point substance in the table are as follows. Total of acetic acid, acrylic acid, fumaronitrile, 3-cyanopyridine and "other" analyzed by secondary gas chromatographic analysis of high-boiling substances. Here, the carbon weight of "others" was calculated from the sum of the areas of peaks other than acetic acid, acrylic acid, fumaronitrile, and 3-cyanopyridine on a gas chromatograph using a conversion factor for fumaronitrile. Gas chromatography analysis column: Glass 3mm x 3m -20 = Packing material: Wako Tsumugi Co., Ltd. FON 10%/Shimalite TPA Column temperature =
While the reaction continues at 160°C, the differential pressure on the reaction gas flow side of the feed air preheater (not shown) and the boiler water heater (not shown) installed at the reactor outlet increases, and the reactor The reaction pressure became high and it became difficult to supply raw material air, so the reaction was stopped 4.2 months after the start of the reaction. Examples 1 to 4 Except for changing the length of each side of the square arrangement,
Using the same reactor as Comparative Example 1, the same catalyst as Comparative Example 1,
The reaction was carried out under the following reaction conditions. However, in Example 3, the array was rectangular, with a short side of 90 mm and a long side of 180 mm. Table 1 shows the reaction results obtained two weeks after the start of the reaction. Comparative Example 2 An oxygen-containing gas supply device was installed at the bottom of a fluidized bed reactor with an inner diameter of 7.8 m, and the blowoff pipes were arranged in a square with a side of 1'60 mm. A raw material gas supply device was installed above it, and its model was a vibrator grid type, the blowing nozzles were arranged in a square of 160 mm on a side, and the blowing direction was directed directly downward. The number of oxygen-containing gas blowing pipes and raw material gas blowing nozzles was the same, and the relative distance was 75 mm. The relative angle θ of the outer periphery was Oo, and the distance between the walls was 500 mm. Particle size 10-100μm, average particle size 5
A 0 μm molybdenum-bismuth-iron silica-supported catalyst was packed to a static bed height of 3 m, and 41000 Nm3/H of air was supplied to the oxygen-containing gas disperser. , ammonia was supplied at 4800 Nm'/H, and the reaction temperature was 450 Nm'/H.
When the reaction was carried out at a temperature of 1 kg/cm2G and a pressure of 1 kg/cm2G, the results shown in Table 2 were obtained. Examples 5 to 7 In the same reactor as Comparative Example 2, the same oxygen-containing gas supply device and raw material gas supply device were used, except that the wall distance = 24- and the relative angle θ were set as shown in Table 2. When the reaction was carried out under the same reaction conditions as in Comparative Example 2, as shown in Table 2, a significant decrease in the catalyst particle circulation flow and unreacted propylene in the outer periphery was observed, and the propylene reaction rate in the entire reactor and Acrylonitrile yield improved. Example 8 An oxygen-containing gas supply device was installed at the bottom of a fluidized bed reactor with an inner diameter of 5.3 m, and blow-off pipes were arranged in a square with a side of 180 mm. A raw material gas supply device is installed above it, and its model is a pipe grid type, with one blowout nozzle on each side.
They were arranged in a square of 80 mm, and the blowing direction was directed downward. The number of oxygen-containing gas blow-off tubes and raw material gas blow-off nozzles was the same, and the relative distance between the oxygen-containing gas blow-off tubes disposed outside the outer periphery and the raw material gas blow-off nozzles opposed thereto was 100 mm. Relative angle θ of outer periphery
was set at 15°, and the distance between the walls was 120 mm. A molybdenum-bismuth-iron-based silica-supported catalyst having a particle size of 10 to 100 pm and an average particle size of 5 to 9 G and -0 μm was packed to a static bed height of 3 m. 28000 Nm3/H8 of air to the oxygen-containing gas supplier
230ONm3/H of inbutylene to the raw material gas supply device,
Ammonia was supplied at 3000 Nm3/H, and the reaction was carried out at a reaction temperature of 430°C and a pressure of 1 kg/cm2G. The results are shown in Table 2. 2G- From the results shown in Table 2, the effects of the device of the present invention will become clearer. Example 6 shows that, compared to Comparative Example 2, by setting the distance between the walls to 150 mm, unreacted propylene in the outer periphery is reduced and the yield of acrylonitrile in the entire reactor is improved. Furthermore, it is clear from the results of Examples 5 and 6 that it is preferable to provide a relative angle when the distance between walls is the same. That is, compared to Example 6, Example 5 has
The effect of setting the relative angle of the outer periphery to 15 degrees is obtained. Furthermore, when the distance between the walls is large as seen in Example 7, it is clear that increasing the relative angle θ is effective. Example 9 Using the same reactor and catalyst as in Example 8, air was supplied to the oxygen-containing gas supply device at 24,000 Nm”/H1, and a tertiary butyl alcohol aqueous solution with a purity of 84% by weight was gasified to the raw material gas supply device. 3600 Nm"/H, ammonia was supplied at 2600 Nm"/H, and the reaction temperature was 440°C1.
When the reaction was carried out at a pressure of 1 kg/cm2G, the following results were obtained. Center part Outer part fluidized catalyst density (kg/m3) 580 600
Unreacted isobutylene (vol) 0.1
0 0.13

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main parts of a fluidized bed reactor showing an embodiment of the present invention, and FIG. 2 shows the oxygen-containing gas blowing pipe of the oxygen-containing gas supply device and the raw material of the raw material gas supply device in the same reactor. FIG. 3 is a plan view of the oxygen-containing gas supply device, and FIG. 4 is a plan view of the raw material gas supply device. 1...Fluidized bed reactor main body 2...Heat removal coil 3...Raw material gas supply device 4...Oxygen-containing gas supply device 5...Raw material gas blow-off nozzle 6...Oxygen-containing gas blow-off pipe 7... Jet formed by the oxygen-containing gas blowing pipe 8... Catalyst particle circulation flow Figure 2

Claims (4)

[Claims] (1) A raw material gas supply device having a plurality of raw material gas blowing nozzles on the lower surface is installed horizontally in the lower part of the reactor,
An oxygen-containing gas supply device having the same number of oxygen-containing gas blow-off pipes on its upper surface facing oppositely to the raw material gas blow-off nozzle is formed below the raw material gas blow-off nozzle. The distance from the tip was 25 to 300 mm, the distance between the oxygen-containing gas blowing tubes was 90 to 250 mm, and the number of tubes was 16 to 120/m^2 per cross-sectional area of the reactor. Propylene, isobutylene, or tertiary butyl alcohol is reacted with ammonia and an oxygen-containing gas to produce an α,β-unsaturated nitrile having the same number of carbon atoms as the raw material olefin or tertiary butyl alcohol. Device. (2) The distance between the series of oxygen-containing gas blowing pipes closest to the inner wall of the reactor and the inner wall is 300 mm.
2. The apparatus of claim 1, wherein: (3) Among the raw material gas blow-off nozzles, a series of nozzles located on the outer periphery of the reactor are shifted to the center of the reactor from the position of a series of oxygen-containing gas blow-off pipes that are provided facing each other. 3. The device according to claim 1 or 2, wherein: (4) Among the raw material gas blow-off nozzles, the positional deviation between a series of nozzles located on the outer periphery of the reactor and a series of oxygen-containing gas blow-off pipes provided opposite to these nozzles is expressed as a relative angle θ. 4. The device according to claim 3, wherein the angle is 40 degrees or less.