Nitrile manufacturing method with improved ammonia absorption effect

Abstract

This invention relates to a nitrile manufacturing process with improved ammonia absorption effect. This process atomizes the spray liquid, increases the contact area with ammonia, and improves mass transfer efficiency. The nitrile manufacturing process includes a step of subjecting hydrocarbon raw materials to an ammoxidation reaction to produce a reaction product containing nitrile (referred to as the reaction step), and a step of supplying the reaction product from a gas inlet to an absorption device, spraying the reaction product with a spray liquid via a spray device in the absorption device to cool the reaction product and form an absorption atmosphere (referred to as the cooling step). Here, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorption atmosphere is 0.004 to 0.02 m -1 That is the case.

Description

Detailed description of the invention

[0001] [Technical Field] The present invention relates to the technical field of gas absorption, and more specifically to a method for producing nitriles with improved ammonia absorption effect.

[0002] 〔background〕 In process routes for producing the corresponding nitriles by ammoniation or ammoxidation, ammonia, the raw material gas, is usually used in excess to maximize the conversion rate of the raw material gas, such as hydrocarbons. That is, the molar ratio of ammonia to hydrocarbon raw material gas is greater than 1. For example, in the ammoxidation of propylene, the ammonia ratio (molar ratio of ammonia to propylene) is 1.10 to 1.35, and in the ammoxidation of aromatic hydrocarbons, the ammonia ratio (molar ratio of ammonia to aromatic hydrocarbons) is 4 to 8. Therefore, the exhaust gas (tail gas) at the reactor outlet inevitably contains unreacted ammonia. On the other hand, in processes such as acrylonitrile production, reaction gases such as acrylonitrile are prone to polymerization under alkaline conditions. On the other hand, the dissipation of even small amounts of unreacted ammonia can easily cause environmental pollution. Therefore, in ammoniation or ammoxidation processes, it is desirable and essential to remove unreacted ammonia from the gas phase using an absorption device (generally called an ammonia absorption tower or quench tower) with acid or water.

[0003] With advancements in production technology, production loads are continuously increasing, and the trend towards larger equipment indicates the direction of future development. The higher the equipment load, the larger the equipment, including the absorption device. In absorption devices, it is known that a circulating liquid (spray liquid) is distributed into the absorption device via a spray device, and the objective of removing residual ammonia from the gas phase is achieved by countercurrent contact with the ammonia-containing gas to be absorbed.

[0004] CN105425849 teaches that residual ammonia can be removed by adjusting the amount of acid added based on the pH value of the wastewater from the absorber. CN1199940 teaches that mass transfer and heat transfer effects between the gas and liquid phases can be improved by adding internal components to the bottom of the absorber, which in practice solves the problem of uniform distribution of the ammonia-containing gas phase. However, the absorber still cannot avoid ammonia breakthrough, meaning that small amounts of ammonia dissipation still exist, causing product loss or environmental pollution in subsequent purification and separation equipment.

[0005] In conventional ammonia absorption methods, the ammonia content in the absorbed exhaust gas increases significantly after the absorption device has been operated for a long period of time compared to the initial stage of operation.

[0006] [Summary of the Invention] In an ammonia absorption tower, the spray liquid is supplied to the nozzle by a pump. Because the spray liquid is under high pressure, it is sent into the nozzle cavity from a tangential inlet, causing rotational motion. After passing through a specially structured nozzle, the spray liquid is ejected from the nozzle at high speed and broken down into countless fine droplets. Most of the droplets move downward within the tower due to their own gravity and centrifugal force from the rotational motion. These droplets come into contact with the rising airflow in a countercurrent. At the same time, a small number of droplets may be caught in the airflow and rise within the tower. Spraying devices consisting of multiple layers are arranged inside the column. Each spraying device consists of tens to hundreds of nozzles uniformly distributed across its cross-section. While the device is operating, the internal space of the column occupied by the spraying device is filled with countless fine droplets due to the influence of the airflow. The droplets strongly attenuate both visible light and infrared light. By measuring the extinction coefficient of the droplets in the column using infrared spectroscopy or forward scattering, it is possible to comprehensively evaluate the size, quantity, and distribution of the droplets. Generally, the larger the droplet, and the fewer the droplets, the less light is absorbed, the higher the light transmittance, and the smaller the extinction coefficient. Conversely, the opposite is true, and the extinction coefficient is higher.

[0007] The inventor of the present invention has discovered that this problem can be solved by setting the extinction coefficient in the absorption atmosphere within a specific numerical range. The present invention has been completed based on this discovery.

[0008] Specifically, the present invention relates to the following aspects.

[0009] 1. A method for producing nitrile, comprising a step of subjecting a hydrocarbon raw material to an ammoxidation reaction to produce a reaction product containing nitrile (referred to as a reaction step), and supplying the reaction product from a gas inlet to an absorption device, spraying a spraying liquid onto the reaction product through a spraying device in the absorption device to cool the reaction product and form an absorption atmosphere (referred to as a cooling step). Here, when measured at a position 3000 mm vertically from the gas inlet, the extinction coefficient of the absorption atmosphere is 0.004 - 0.02 m -1 (preferably 0.006 - 0.018 m -1 )

[0010] 2. In a manufacturing process according to any of the foregoing or following aspects, when measured at a position 3000 mm vertically from the gas inlet, the average droplet diameter D of the absorption atmosphere 32 is 400 - 2600 μm (preferably 600 - 24 μm). Also, when measured at a position 3000 mm vertically from the gas inlet, the droplet size distribution in the absorption atmosphere is D 10 is 150 - 1500 μm, D 50 is 700 - 3000 μm, D 90 is 1400 - 3600 μm (preferably D 10 is 250 - 1400 μm, D 50 is 800 - 2800 μm, D 90 is 1600 - 3500 μm)

[0011] 3. In a manufacturing process according to any of the foregoing or following aspects, when measured at a position 8500 mm vertically from the gas inlet, the absorption atmosphere has an extinction coefficient of 0.001 - 0.004 m -1 (preferably 0.0015 - 0.0035 m -1) and / or, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere has an average droplet diameter D of 200-1400 μm (preferably 400-1000 μm). 32 It has and / or, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere is D 10 is 100-1000 μm, D 50 is 300-1800 μm, D 90 The thickness is 500-2200 μm (preferably D 10 is 200-600 μm, D 50 is 400~1400μm, D 90 (The thickness is 600-1800 μm).

[0012] 4. In a manufacturing process according to either of the embodiments described above or below, the spraying device comprises a spray liquid inlet, a first spray pipe in fluid communication with the spray liquid inlet, a plurality of (e.g., 10 to 26, preferably 12 to 22) second spray pipes in fluid communication with the first spray pipe and extending perpendicularly to the first spray pipe along both sides of the first spray pipe, a plurality of (e.g., 4 to 26, preferably 6 to 22) third spray pipes in fluid communication with the second spray pipe and extending perpendicularly to the second spray pipe along both sides of the second spray pipe, and a nozzle.

[0013] 5. In the manufacturing process according to any of the preceding or following paragraphs, the straight-line distance M between any end of a third spray pipe on one second spray pipe and any end of a third spray pipe on the other adjacent second spray pipe is 320 mm or more (preferably 350 mm or more). Furthermore, the nozzles are identical or different from each other and each independently has a spray liquid discharge rate of 0.5 to 7.5 tons / hour (preferably 0.9 to 6.5 tons / hour), and / or the nozzles are identical or different from each other and each independently has a spray liquid discharge pressure of 0.03 to 0.85 MPaG (preferably 0.04 to 0.65 MPaG) at the nozzle outlet, and / or the spray liquid input pressure at the spray liquid inlet is controlled to 0.06 to 1.00 MPaG (preferably 0.12 to 0.90 MPaG, more preferably 0.18 to 0.80 MPaG), and / or the difference (absolute value) of the spray liquid input pressure at the spray liquid inlets of any two spraying devices is less than 0.024 MPa (preferably less than 0.018 MPa, more preferably less than 0.012 MPa).

[0014] 6. In a manufacturing process according to either the preceding or following paragraph, a plurality of (e.g., 2 to 10, preferably 4 to 8) spraying devices are arranged in layers within the absorber at predetermined vertical intervals along the central axis of the absorber, and / or the vertical distance between two adjacent spraying devices (calculated as the vertical distance between the spray liquid inlets of the spraying devices) is 650 to 1350 mm (preferably 750 to 1200 mm).

[0015] 7. In a manufacturing process having the characteristics of either the preceding or following paragraph, in a cross-section obtained by cutting the absorption device in a direction perpendicular to its central axis, at least one (preferably all) of the first, second, and third spray tubes in one of the plurality of spray devices and at least one (preferably all) of the first, second, and third spray tubes in another spray device substantially coincide in the cross-sectional projection. At least one (preferably all) of the second and third spray tubes substantially coincide in the projection in the said cross-section.

[0016] 8. In the manufacturing method described in either the preceding or following paragraph, all nozzles of one spraying device and all nozzles of any other spraying device substantially coincide in cross-sectional projection, and / or two nozzles whose projections substantially coincide have the same spray diameter, and / or two nozzles whose projections substantially coincide have the same spray liquid rotation direction.

[0017] 9. In a manufacturing process according to either of the aspects described above or below, the vertical distance between the gas inlet and the spray liquid inlet of the spraying device (if there are multiple spraying devices, this refers to the spraying device closest to the gas inlet) is 800 to 6000 mm (preferably 1000 to 5000 mm), and / or the inner diameter of the gas inlet is 800 to 1900 mm (preferably 900 to 1700 mm), and / or the linear velocity of the reaction product in the absorption device is 0.6 to 1.5 m / s (preferably 0.7 to 1.3 m / s), and / or the weight ratio of the spray liquid to the reaction product is 15 to 25:1.

[0018] 10. In a manufacturing process that conforms to either of the preceding or following aspects, no mechanical components that could substantially affect the gas flow are located within the internal space of the absorption device between the gas inlet and the spraying device (referring to the spraying device closest to the gas inlet, if multiple spraying devices exist).

[0019] 11. In a manufacturing process according to either of the aspects described above or below, the angle between the projection of the spray liquid inlet of one spraying device and the projection of the spray liquid inlet of any other spraying device is 180° in cross-section.

[0020] 12. In an absorption apparatus according to either of the embodiments described above or below, the angle between the cross-sectional projections of the spray liquid inlets of any two odd-numbered spray devices is 0 degrees. The angle on the projection plane of the spray liquid inlets of any two even-numbered spray devices is 0°, and the angle between the projection plane of the spray liquid inlet of any odd-numbered spray device and the projection plane of the spray liquid inlet of any even-numbered spray device is 180°.

[0021] 13. In an absorption device according to either the preceding or following embodiment, the nozzle comprises a nozzle inlet, a rotating chamber, and a nozzle outlet, wherein the rotating chamber is configured such that the spray liquid supplied from the nozzle inlet passes through the rotating chamber and is then discharged from the nozzle outlet while rotating.

[0022] 14. In an absorption device according to either of the embodiments described above or below, in at least one (preferably all) second spray tube, two adjacent (preferably all) nozzles located on the same side of the second spray tube are configured to spray the spray liquid in the same rotational direction.

[0023] 15. In an absorption device according to either the above or below embodiment, all nozzles facing opposite sides of two adjacent second spray pipes are configured such that the spray liquid is ejected in opposite rotational directions.

[0024] 16. In an absorption device according to any of the features described above or the features described below, in at least one (preferably all) second spray tubes, at least one (preferably all) nozzles located on one side of the second spray tubes are configured to eject the spray liquid in rotational direction A. On the other hand, at least one (preferably all) nozzles located on the opposite side of the second spray tubes are configured to eject the spray liquid in rotational direction B. Here, rotational direction A is opposite to rotational direction B.

[0025] 17. In an absorption device according to either the above or below description, the number of nozzles that spray the spray liquid in rotation direction A is equal to, or substantially equal to, the number of nozzles that spray the spray liquid in rotation direction B among all the nozzles of the spraying device.

[0026] 18. In a manufacturing process according to either the preceding or following embodiment, a plurality of second spray tubes extend perpendicular to the first spray tube and substantially parallel to the opposite side in the horizontal direction, and / or a plurality of third spray tubes extend perpendicular to the second spray tube and substantially parallel to the opposite side in the horizontal direction.

[0027] 19. In a manufacturing process according to either the above or below description, the inner diameter of the first spray pipe is 160 to 480 mm (preferably 200 to 450 mm) and the length is 4500 to 11500 mm (preferably 4800 to 10500 mm). The plurality of second spray pipes are identical or different from each other, each independently having an inner diameter of 30 to 150 mm (preferably 40 to 120 mm) and each independently having a length of 1200 to 5750 mm (preferably 1800 to 5250 mm). The plurality of third spray pipes are identical or different from each other, each independently having an inner diameter of 10 to 60 mm (preferably 15 to 50 mm) and each independently having a length of 160 to 325 mm (preferably 175 to 300 mm).

[0028] 20. In a manufacturing process according to either of the aspects described above or below, the nozzles are identical or different from each other, and each nozzle independently has an inner diameter (see nozzle outlet) of 3 to 20 mm (preferably 6 to 14 mm), a rotating chamber diameter of 10.0 to 55.0 mm (preferably 13.0 to 45.0 mm), and a spray angle of 65 to 120 degrees (preferably 70 to 100 degrees).

[0029] 21. In a manufacturing process according to either the above or below description, on the first spray pipe, the horizontal distance between two adjacent second spray pipes is 640 to 1300 mm (preferably 700 to 1200 mm), and / or, on the same second spray pipe, the horizontal distance between two adjacent third spray pipes is 320 to 650 mm (preferably 350 to 600 mm).

[0030] 22. In a manufacturing process according to either of the embodiments described above or below, the spray liquid and the reaction product come into contact in a countercurrent manner during the cooling step.

[0031] 23. In a manufacturing process according to either of the embodiments described above or below, the inner diameter of the absorption device is 4.5 to 11.5 m (preferably 4.8 to 10.5 m).

[0032] 24. In a manufacturing process based on any of the points described above or below, the gas inlet is located below the spraying device along the central axis of the absorption device.

[0033] 25. In a manufacturing process that follows either of the aspects described above or below, in the reaction step, the hydrocarbon raw material is propylene, the molar ratio of propylene / ammonia / air (calculated as molecular oxygen) is 1:1.1~1.3:1.8~2.0, the reaction takes place at a temperature of 420~440°C, the reaction pressure (gauge pressure) is 0.03-0.14 MPa, and the catalyst gravimetric space-time velocity is 0.06-0.15 h. -1 Alternatively, the hydrocarbon raw material is isobutylene, and the molar ratio of isobutylene / ammonia / air (calculated as molecular oxygen) is 1:1.3-1.6:2.2~2.8, and the reaction takes place at a temperature of 395~420°C, a reaction pressure of 0.03~0.14 MPa (gauge pressure), and 0.08~0.17 hours. -1 This includes the catalytic gravitational space velocity.

[0034] 26. In a manufacturing process according to either of the aspects described above or below, in the cooling step, the spray liquid cools the reaction product from a temperature of 195-235°C to 81-86°C, and / or, in the cooling step, the spray liquid reduces the ammonia content of the reaction product to 150 ppm or less.

[0035] 27. In an absorption device according to either of the aspects described above or below, the rotation direction A is clockwise and the rotation direction B is counterclockwise.

[0036] [Technical effects] According to the present invention, even after long-term operation (for example, continuous operation for 18 months or more), the ammonia content in the absorbed exhaust gas does not increase significantly compared to the initial stage of operation, allowing for the maintenance of a good ammonia absorption effect over a long period and reducing ammonia dissipation.

[0037] According to the present invention, even after long-term operation (for example, after 18 months or more of continuous operation), the total acid consumption remains at a low level and increases only slightly (for example, less than 3%).

[0038] According to the present invention, ammonia gas is uniformly distributed within the absorption tower. This is advantageous for ammonia absorption.

[0039] According to the present invention, sufficient gas-liquid contact is achieved, the ammonia absorption effect is excellent, and the amount of acid used can be reduced.

[0040] [Brief explanation of the drawing] Figure 1 is a schematic front view of a conventional ammonia absorption tower.

[0041] Figure 2 is a schematic front view of a conventional ammonia absorption tower.

[0042] Figures 3a and 3b are schematic front views of the ammonia absorption tower of the present invention.

[0043] Figures 4A and 4B are schematic front views of the ammonia absorption tower of the present invention.

[0044] Figure 5 is a schematic top view of the spraying apparatus of the present invention.

[0045] Figures 6A and 6B are schematic top views of the spraying apparatus of the present invention.

[0046] Figure 7 is a schematic top view of the spraying apparatus of the present invention.

[0047] Figures 8A and 8B are schematic top views of a spraying apparatus according to a comparative example.

[0048] Figures 9A and 9B are schematic top and front views, respectively, of a conventional nozzle.

[0049] Figures 10A and 10B are schematic and detailed top views, respectively, of a conventional spraying device.

[0050] Figure 11A is a schematic top / front view showing two rotation modes of the nozzle of the present invention.

[0051] Figure 11B is a schematic top view of the spraying device.

[0052] Figure 11C is a detailed schematic top view of one spraying device according to the present invention.

[0053] Figure 11D is a detailed schematic top view of another spraying apparatus of the present invention.

[0054] Figure 11E is a detailed schematic top view of another spraying apparatus of the present invention.

[0055] [Explanation of reference symbols] 1: Ammonia absorption tower 2: Demister, an internal component of an ammonia absorption tower 3: Spraying device, an internal component of the ammonia absorption tower; 3a to 3f are spraying devices. 4: Gas distributor, an internal component of an ammonia absorption tower. 5: Spraying device, an internal component of the ammonia absorption tower; 5a-5b are spraying devices. 6: Upper circulation pump 7: Lower circulation pump 8: Ammonia-containing gas supply port 9: Gas phase outlet of ammonia absorption tower 10: Upper water supply 11: Lower wastewater outlet 12: Upper ammonium salt-containing solution outlet 13: Lower circulating fluid 14: Upper circulating fluid 15: Acid-containing solution 16: Circulating fluid 17: Circulation pump 18: Spray device inlet 19: First spray pipe of the spraying device 20a, 20b: Second spray pipe of the spraying device 21: Third spray pipe of the spraying device 22: Atomizing nozzle for spraying device 23: Gas distributor P1, P2, P3, P4, P5, P6: Inlet pressure of the spray liquid in the spraying device. [Embodiment] Embodiments of the present invention will be described in detail below. However, the scope of protection of the present invention is not limited to these embodiments, but is determined by the appended claims.

[0056] All publications, patent applications, patents, and other references mentioned herein are incorporated herein by reference in their entirety. Unless otherwise defined, all technical and scientific terms used herein are to be understood as having the same meaning as those commonly known to those skilled in the art. In case of any conflict, the definitions herein shall prevail.

[0057] Where this specification introduces materials, substances, processes, procedures, apparatus, components, etc., that begin with phrases such as "well known to those skilled in the art" or "prior art," the subject matter is intended to include not only those that have been conventionally used in the art at the time of filing, but also those that are not currently in common use but will become known in art suitable for similar purposes.

[0058] In the context of this specification, the term “substantially” means a deviation of 10%, preferably 5%, or 2% or less.

[0059] In this specification, the method for measuring the extinction coefficient is forward near-infrared scattering spectroscopy. In a region of strong visible light emission, a sample volume of approximately 100 ml is irradiated using a near-infrared LED light source, and the scattered light intensity I(θ) in the forward 25°-45° range is measured. From this, the extinction coefficient σ is calculated using the formula σ = I(θ) / k, where k is the scattering extinction ratio and can be calibrated with a high-precision transmittance meter.

[0060] In this specification, the average droplet diameter D 32 The measurement method is based on laser imaging for measuring the size of a planar droplet. The Sauter mean diameter D has two-dimensional spatial resolution. 32 teeth 、The size is obtained from image information of mist droplets. For planar total droplet size measurement, it is necessary to simultaneously record images of laser-induced fluorescence (LIF) and Mie scattering (MIE) signals for the droplet being measured. The two-dimensional Sauter mean diameter is calculated from the ratio of these two image signals. The LIF image represents the droplet volume, and the MIE light is basically proportional to the total volume of the droplet.

[0061] D 32 =Total droplet volume / Total droplet surface area = LIF signal / MIE signal.

[0062] In this specification, a method for measuring droplet size distribution is provided, which is based on laser imaging for droplet size distribution measurement, and the average droplet diameter D 32 This is the same measurement method as D 10 , D 50 , D 90 Particle size distributions with two-dimensional spatial resolution, such as those described above, can be obtained from image information of mist droplets.

[0063] All percentages, parts, ratios, etc., stated in the specification are based on weight, and pressures are gauge pressures unless explicitly stated.

[0064] In the context of the present invention, two or more embodiments or aspects of the present invention can be arbitrarily combined, and the resulting technical solutions are part of the original disclosure of this specification and are within the scope of the present invention.

[0065] In the context of this specification, for any technical details not described herein, relevant information known in the art shall apply directly.

[0066] One embodiment of the present invention involves a process for producing nitriles, particularly (meth)acrylonitrile.

[0067] According to one embodiment of the present invention, the absorption device comprises a housing and a plurality of spraying devices (for example, 2 to 10, preferably 4 to 8) arranged in layers at predetermined vertical intervals along the central axis of the absorption device.

[0068] According to one embodiment of the present invention, a nitrile production process includes a step of subjecting a hydrocarbon raw material to an ammoxidation reaction to produce a reaction product containing nitrile (called the reaction step), and a step of supplying the reaction product from a gas inlet to an absorption device, spraying a spray liquid onto the reaction product via a spray device in the absorption device to cool the reaction product and form an absorption atmosphere (called the cooling step). In this field, the absorption device is also commonly called an ammonia absorption tower or quench tower.

[0069] According to the present invention, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere has an extinction coefficient of 0.004 to 0.02 m. -1 (Preferably 0.006~0.018m) -1 The inventors of this invention have found that because droplets strongly attenuate both visible light and infrared signals, the dispersion effect of droplets after being sprayed at high speed from a nozzle can be comprehensively evaluated by measuring the attenuation of light and calculating its extinction coefficient. For a certain amount of liquid dispersed into multiple minute droplets by a nozzle, generally, the larger the droplet size and the relatively small the number of droplets, the less light absorption, the higher the light transmittance, and the smaller the extinction coefficient. Conversely, the smaller the droplet size and the larger the number of droplets, the greater the light absorption, the lower the light transmittance, and the larger the extinction coefficient. A small extinction coefficient means that the droplet size is large and the number of droplets is small. As a result, the total surface area of ​​the droplets is relatively small. Because the contact area with gaseous ammonia is insufficient, the absorption efficiency of ammonia decreases and the amount of ammonia that penetrates increases. Conversely, a large extinction coefficient means that the droplet size is small and the number of droplets is large. However, these excessively small droplets are lifted up by the gas and easily discharged from the column. In an ammonia absorption column, ammonium salts contained in droplets are carried by the gas and transferred to subsequent processes, increasing the environmental burden. This should be avoided as much as possible.

[0070] According to a preferred embodiment of the present invention, when measured at a vertical distance of 3000 mm from the gas inlet, the average droplet diameter D of the absorption atmosphere is 32The average droplet size is 400 to 2600 μm (preferably 600 to 2400 μm). The inventors discovered that at the moment the liquid is ejected from the nozzle, the liquid film breaks into tiny droplets. During the descent process, when these tiny droplets collide with other droplets, phenomena such as separation, merging, and fragmentation occur. The average droplet size can be measured by optical methods. When the average droplet size exceeds 2600 μm, gravity increases the descent speed of the droplets, significantly shortening their residence time in the column. This results in insufficient contact time with the gas, which tends to lead to a decrease in absorption efficiency. On the other hand, for two droplets of the same volume, the surface area of ​​one large droplet is smaller than the combined surface area of ​​the two smaller droplets formed by the splitting. In other words, one large droplet has fewer opportunities to come into contact with the gas compared to two smaller droplets, which also leads to a decrease in absorption efficiency. When the average droplet size is less than 400 μm, the upward lift force of the gas on the droplet exceeds the gravity of the droplet itself, so the droplet is more easily drawn in. At the same time, greater power is required, such as the inlet pressure of the spraying device, and the liquid must be broken down into finer particles when sprayed from the nozzle.

[0071] According to a preferred embodiment of the present invention, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere is 150-1500 μm D 10 , 700-3000 μm D 50 , D 1400-3600 μm 90 (Preferably 250-300 μm D 10 ) has a droplet size distribution. 50 is 700-3000 μm, D 90 The thickness is 1400 to 3600 μm (preferably D 10 is 250~1400μm, D 50 is 800-2800 μm, D 90(The diameter is 1600-3500 μm). The inventors of this invention have discovered that after a liquid is sprayed from a nozzle, it is divided into numerous microdroplets of various sizes. At the same time, during the collision of two droplets, the particle size may increase due to merging, decrease due to fragmentation, or remain unchanged due to separation. In certain embodiments, the circulating liquid is an acid-containing liquid, and the absorption atmosphere is an ammonia-containing gas. The acid in the droplets absorbs ammonia from the gas phase, forming ammonium salts present in the droplets. 10 and / or D 50 and / or D 90 If the droplet is small, 32 This also means that the volume is small. As a result, droplets containing ammonium salts can easily be drawn into the gas and escape from the column, creating new problems in subsequent processing steps. For example, if the circulating fluid contains sulfuric acid, SO2-containing gas is generated when the wastewater is incinerated. On the other hand, if the circulating fluid contains phosphoric acid, P2O5 is generated. These are harmful to the environment and should be avoided whenever possible.

[0072] According to a more preferred embodiment of the present invention, when measured at a vertical distance of 8500 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere is 0.001-0.004 m -1 (Preferably 0.0015-0.0035m) -1 The inventors of this invention discovered that the measurement position is located above the spraying device of the absorption tower, and that droplets in this region are caused by gas entrainment. Compared to the droplet size at the aforementioned measurement position, the droplet size in this region is relatively small, and the amount of gas entrainment is within a controllable range. The extinction coefficient of the absorption atmosphere is 0.001 m -1 A value less than 0.004 m² indicates that the droplet size in the spraying device region is relatively large, and the upward thrust of the gas acting on the droplet is less than gravity, resulting in relatively little droplet entrainment. However, a large droplet size in the spraying device region can lead to insufficient gas-liquid contact, making it easy for absorbent gases (e.g., ammonia) to penetrate. -1If the value exceeds a certain threshold, assuming a normal droplet size, it indicates that a large amount of droplets are being drawn into the gas. This suggests a high gas flow rate in the column or insufficient retention time for the gas within the column. This can lead to incomplete absorption, reduced efficiency, and the possibility of absorption gases (e.g., ammonia) breaking through.

[0073] According to a preferred embodiment of the present invention, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere is equal to the average droplet diameter D 32 The droplet size is 200-1400 μm (preferably 400-1000 μm). More preferably, when measured at a vertical distance of 8500 mm from the gas inlet, the droplet size distribution of the absorption atmosphere is D 10 is 100-1000 μm, D 50 is 300-1800 μm, D 90 is 500-2200 μm (preferably D 10 is 200-600 μm, D 50 is 400~1400μm, D 90 (More preferably, the droplet average diameter D is 600 to 1800 μm). The inventors of the present invention have determined that the droplet average diameter D measured at the measurement position is 32 The droplet size distribution is the average droplet diameter D in the spray device area. 32 We also found that it is closely related to the droplet size distribution in the spraying device area. Generally, the average droplet diameter D of large droplets in the spraying device area 32 This is the relatively large average droplet diameter D in this region. 32 The same applies to droplet size distribution. When the average droplet diameter and droplet size distribution are below the lower limit, it indicates that the droplets in the spraying device area are relatively small and easily drawn in. Conversely, when the average droplet diameter and droplet size distribution exceed the upper limit, the droplets in the spraying device area are relatively large, resulting in insufficient gas-liquid contact and reduced absorption efficiency.

[0074] According to embodiments of the present invention, the spraying device comprises a spray liquid inlet, a first spray pipe that is in fluid communication with the spray liquid inlet, a plurality of (e.g., 10 to 26, preferably 12 to 22) second spray pipes that are in fluid communication with the first spray pipe and extend perpendicularly to the first spray pipe along both sides of the first spray pipe, a plurality of (e.g., 4 to 26, preferably 6 to 22) third spray pipes that are in fluid communication with the second spray pipe and extend perpendicularly to the second spray pipe along both sides of the second spray pipe, and a nozzle disposed at the end of the third spray pipe and in fluid communication with it.

[0075] The means of connecting the various spray tubes and the third spray tube and nozzles are not particularly limited by the present invention, and conventional connecting means can be used in this technology. For example, fixed connections or detachable connections can be used, preferably screw connections or other detachable connecting means, and are not particularly limited.

[0076] According to one embodiment, the spray liquid is water or an acidic aqueous solution. Preferably, the ammonia-containing gas is brought into countercurrent contact with the acidic aqueous solution flowing from bottom to top as the spray liquid, and the acidic H contained in the aqueous solution is released. + This neutralizes and removes ammonia. Here, an acidic aqueous solution is an aqueous solution of an acidic substance. Examples of acidic substances include, but are not limited to, inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid, or organic acids such as acrylic acid and acetic acid, or acidic salts such as ammonium sulfate.

[0077] According to one embodiment of the present invention, in the cooling process, the input pressure of the spray liquid at the spray liquid inlet is controlled to 0.06 to 1.00 MPaG (preferably 0.12 to 0.90 MPaG, more preferably 0.18 to 0.80 MPaG). The inventors of the present invention have discovered that the circulating liquid is supplied to the spray device from the spray device inlet, passes through the first spray pipe, the second spray pipe, and the third spray pipe, and is supplied into the absorption tower from the nozzle at the end of the third spray pipe. Generally, the larger the droplet particles, the weaker the light absorption by the particles and the lower the quenching efficiency. Also, the size of the droplet particles is inversely proportional to the pressure. As the pressure gradually decreases along the direction of fluid flow, the droplet particles continuously increase in size along the direction of circulating liquid flow. The droplet size D formed at the spray nozzle distal to the spray inlet along the direction of fluid flow. 32 The droplet size is larger than that formed at the spray nozzles proximal to the spray inlet along the fluid flow direction. As a result, the ammonia absorption efficiency decreases at positions distal to the spray inlet along the fluid flow direction compared to positions proximal to the spray inlet. By controlling the spray liquid input pressure at the spray liquid inlet within the aforementioned range, sufficient pressure is ensured at the distal nozzles, meeting the requirements for average droplet size and size distribution required by the device, and guaranteeing the spraying effect. Furthermore, with long-term operation of the device, viscous polymers are generated during the reaction process and mix with ammonium salts in the circulating fluid, adhering to the walls of the spray piping. This increases resistance along the piping path, and the rate of increase in resistance along the piping path becomes more pronounced, especially after operation for 18 months or more, further decreasing the pressure at the far-end nozzles. As a result, the droplet particles at the far-end nozzles become even larger, the particle size distribution becomes wider and more non-uniform, and the spraying effect decreases. According to the present invention, by controlling the spray liquid input pressure at the spray liquid inlet within the specified range, sufficient pressure can be maintained at the far-end nozzles even after long-term continuous operation, and the spraying effect can be ensured.

[0078] According to embodiments of the present invention, the plurality of second spray tubes extend substantially parallel to the first spray tube in both opposite directions in a horizontal direction perpendicular to the first spray tube.

[0079] According to one embodiment, a plurality of third spray pipes extend toward the opposite side of the second spray pipe, substantially parallel to it in the horizontal direction.

[0080] According to one embodiment, the inner diameter of the first spray pipe is 160 to 480 mm (preferably 200 to 450 mm), and its length is 4500 to 11500 mm (preferably 4800 to 10500 mm).

[0081] According to one embodiment, the multiple second spray pipes are identical or different from each other, and each independently has an inner diameter of 30 to 150 mm (preferably 40 to 120 mm) and a length of 1200 to 5750 mm (preferably 1800 to 5250 mm).

[0082] According to one embodiment, the multiple third spray tubes may be identical or different from one another, and each independently has an inner diameter of 10 to 60 mm (preferably 15 to 50 mm) and a length of 160 to 325 mm (preferably 175 to 300 mm).

[0083] According to one embodiment of the present invention, the nozzle comprises a nozzle inlet, a rotating chamber, and a nozzle outlet, wherein the rotating chamber is configured such that the spray liquid supplied from the nozzle inlet passes through the rotating chamber and is then discharged from the nozzle outlet while rotating. According to the present invention, the rotating chamber may employ any rotating chamber structure known in the art, and is not particularly limited, as long as it allows the spray liquid to pass through the rotating chamber and be discharged from the nozzle outlet while rotating.

[0084] According to one embodiment of the present invention, the nozzles may be identical or different from each other, and each may independently have an inner diameter (see nozzle outlet) of 3 to 20 mm (preferably 6 to 14 mm), a rotating chamber diameter of 10.0 to 55.0 mm (preferably 13.0 to 45.0 mm), and a spray angle of 65 to 120 degrees (preferably 70 to 100 degrees). According to the present invention, the rotating chamber may employ any rotating chamber structure known in the art, as long as it allows the spray liquid to be discharged from the nozzle outlet while rotating after passing through the rotating chamber, and is not particularly limited.

[0085] According to an embodiment of the present invention, the horizontal distance between two adjacent second spray pipes on the first spray pipe is 640 to 1300 mm (preferably 700 to 1200 mm).

[0086] According to one embodiment of the present invention, the horizontal distance between two adjacent third spray pipes on the same second spray pipe is 320 to 650 mm (preferably 350 to 600 mm).

[0087] According to one embodiment of the present invention, in two adjacent second spray pipes, the straight-line distance M (as shown in Figures 6A and 6B) between any end of a third spray pipe on one second spray pipe and any end of a third spray pipe on the other adjacent second spray pipe is 320 mm or more, preferably 350 mm or more. The inventors of the present invention have found that in order to improve ammonia absorption efficiency, it is generally necessary that any position in the internal cross-section of the column be covered by at least two or more overlapping conical liquid surfaces formed around the nozzle. The same situation applies to the column wall. If the distance between the ends of two spray pipes is too large due to constraints on the nozzle structure, it is difficult to satisfy the requirement that any position on the column wall be covered by overlapping liquid surfaces sprayed from two or more nozzles. In other words, this means that the number of droplets in the column decreases, which is indicated by a decrease in the light absorption rate and weakening of the quenching ability of the droplets, and as a result the probability of ammonia leakage from "gaps" increases. If the distance between the ends of the two spray pipes is too small, the amount of circulating liquid in the ammonia absorption tower must be increased to ensure the atomization quality of the spray liquid. This means that the energy consumption of the pump will increase. Furthermore, as shown in Figures 6A and 6B, if the vertical projections of the upper and lower layers of the spraying apparatus coincide, only the spray liquid inlet located opposite the upper spraying apparatus will be visible.

[0088] According to one embodiment of the present invention, the nozzles may be the same or different from each other, and each has an independent spray liquid discharge rate of 0.5 to 7.5 tons / hour (preferably 0.9 to 6.5 tons / hour).

[0089] According to a preferred embodiment of the present invention, the nozzles may be identical or different from each other, and each nozzle independently has a spray liquid discharge pressure of 0.03 to 0.85 MPag (preferably 0.04 to 0.65 MPag) at the nozzle outlet. The inventors of the present invention have found that pressure is one of the main factors that cause liquid to form droplets in spray nozzles in an ammonia absorption tower. Within a certain pressure range, the droplet size increases as the pressure decreases. Generally, smaller droplets are considered to have better mass and heat transfer efficiency than larger droplets. Generally, the smaller the droplet, and the "narrower" the particle size distribution, the greater the light absorption and the stronger the quenching ability. When the spray liquid discharge pressure at the nozzle outlet is less than 0.03 MPaG, the atomization effect of the acidic circulating liquid that has passed through the spraying device is poor, and the droplet size becomes large, resulting in insufficient contact with ammonia. When the spray liquid discharge pressure at the nozzle outlet exceeds 0.85 MPaG, the atomization effect of the acidic circulating liquid after passing through the spraying device is good, but the droplet size is too small, causing the liquid to be easily drawn into the gas and discharged from the ammonia absorption tower. This causes ammonium salts dissolved in the liquid to cause unnecessary problems in subsequent processes. Furthermore, if the device is operated for a long period of time, viscous polymers generated during operation adhere to the inside of the nozzle lumen, increasing nozzle resistance and lowering the pressure at the nozzle outlet. For example, after 18 months of continuous operation, dirt adheres to the inside of the nozzle, changing the flow behavior of the spray liquid within the nozzle. In particular, the instability of spraying at the far-end nozzle increases, and this instability becomes more pronounced as the operating time of the device increases. According to the present invention, by controlling the spray pressure of the spray liquid at the nozzle outlet within the above range, the spraying at the far-end nozzle can be stabilized even after long-term continuous operation, and the spraying effect can be ensured.

[0090] According to one embodiment of the present invention, in the cooling process, the spray liquid and the reaction product are brought into contact in a countercurrent manner.

[0091] According to embodiments of the present invention, in the cooling step, the weight ratio of the spray liquid to the reaction product is 15 to 25:1.

[0092] According to embodiments of the present invention, the cooling process is carried out within the absorption device, and a plurality of (e.g., 2 to 10, preferably 4 to 8) spraying devices are arranged in layers within the absorption device at predetermined vertical intervals along the central axis of the absorption device.

[0093] According to embodiments of the present invention, in a cross-section obtained by cutting the absorption device in a direction perpendicular to its central axis, at least one (preferably all) of the first, second, and third spray tubes of one of the plurality of spray devices and at least one (preferably all) of the first, second, and third spray tubes of another spray device substantially coincide in cross-sectional projection. That is, the projections of the nozzles (centers of the cones) of each spray device coincide in the cross-section. At least one (preferably all) of the second and third spray tubes substantially coincide in projection in the said cross-section. That is, the projections of the nozzles (centers of the cones) of each layer coincide in the cross-section. As a result, the distribution of ammonia in the gas passage becomes uniform.

[0094] According to one embodiment of the present invention, all nozzles of one spraying device and all nozzles of any other spraying device substantially coincide in cross-sectional projection. The inventors of the present invention have found that the multiple spraying devices within the absorption device are not only relatively independent entities but are also integrated as a single unit. The circulating liquid is supplied to the nozzles of each spraying device via the first, second, and third spraying pipes of each spraying device, forming a hollow conical liquid surface centered on the nozzle. The gas comes into contact with the circulating liquid in a countercurrent. The gas cannot come into contact with the conical liquid surface formed by the next upper spraying device unless it passes through the conical liquid surface formed by the lower spraying device. At the moment the gas passes through the conical liquid surface, the ammonia in the gas neutralizes with the acid in the liquid.

[0095] As the ammonia-containing gas passes through multiple hollow conical liquid surfaces formed by multiple spraying devices, it is eventually completely neutralized by the acid in the circulating liquid. The space between the two layers of the spraying device, namely the upper and lower hollow conical liquid surfaces, can be considered as a gas upward path. Since each stage requires an independent liquid-phase circulating spraying device, the upward gas path has a certain height. The projections of at least one (preferably all) of the first, second, and third spraying tubes substantially coincide in cross-section. This means that the projections of the nozzles (centers of the cones) of each layer coincide in cross-section. This results in a more uniform ammonia distribution within the gas path, leading to better mixing with the droplets and more stable quenching efficiency. If the projections of the upper and lower nozzles do not coincide in cross-section, the upward gas path changes because the upper and lower hollow conical liquid surfaces are not in the same position. After the upward gas passes through such a gas path, differences in quenching efficiency in the different paths can lead to non-uniformity of the gas distribution between the gas paths, reducing the ammonia absorption effect. According to one embodiment of the present invention, the vertical distance between two adjacent spraying devices (calculated as the vertical distance between the spray liquid inlets of the spraying devices) is 650 to 1350 mm, preferably 750 to 1200 mm.

[0096] The inventors of this invention discovered that when the projections of the upper and lower nozzles do not coincide in cross-section, the upper and lower hollow conical liquid surfaces are not in the same position, which alters the upward gas flow path. Some flow paths become "wider," while others become "narrower." A "wider" passage means fewer droplets inside, resulting in reduced quenching capacity. Conversely, a "narrower" passage enhances quenching capacity. After the upward gas passes through gas passages at different heights, the gas residence times within the passages differ, making it easy for non-uniformity of the gas distribution within the passages to occur. In other words, when ammonia-containing gas passes through a hollow conical liquid surface, some areas of the liquid surface have an excess of acid, while other areas lack sufficient acid, allowing ammonia to penetrate and reducing the ammonia absorption effect.

[0097] The inventors of this invention also discovered that when the projections of the upper and lower nozzles do not coincide in cross-section, the spray liquid sprayed from the upper nozzle and the spray liquid sprayed from the lower nozzle undergo more collisions. When two droplets collide, behaviors such as separation, merging, and splitting can occur. The inventors found that when the projections of the upper and lower nozzles do not coincide, the droplets generated by the upper nozzle and the droplets generated by the lower nozzle are more likely to merge upon collision, forming larger droplets, while the number of droplets relatively decreases. This is represented by a decrease in quenching efficiency, which is undesirable for ammonia absorption.

[0098] The inventors of this invention also discovered that the circulating fluid in each spraying device flows along the first spray pipe to the second spray pipe, and further through the third spray pipe to the nozzle. During fluid flow, the pressure continuously decreases along the pipeline due to the effect of pipe wall resistance. The pressure at nozzles farther from the spray liquid inlet is lower than the pressure at nozzles closer to the spray liquid inlet. Because the pressure at the furthest nozzle is relatively lowest, the average droplet size there is relatively large, the droplet size distribution is broad, the light absorption efficiency by the droplets is lowest, and the spraying effect is the worst. As a result, gas-liquid contact at the furthest nozzle is insufficient. This easily causes ammonia to escape. As the operating cycle of the device lengthens, for example, if the device is operated continuously for more than 18 months, solid impurities and viscous heavy components adhere to the inner walls of the pipes, further increasing pipe wall resistance. This further reduces the light absorption efficiency by the droplets, i.e., further reduces the quenching efficiency, further worsens the atomization effect at the end nozzles, and more ammonia leaks out. When the spray liquid inlets of a multi-layered spraying device are on the same side, the distal nozzles of each layer are also on the same side. As a result, gas-liquid contact is weakest in this region, and ammonia in the gas phase is more likely to escape the ammonia absorption tower from this region.

[0099] Based on these findings, according to one embodiment of the present invention, the angle between the projection of the spray liquid inlet of one spraying device and the projection of the spray liquid inlet of any other spraying device is 180° in cross-section. In the initial stages of operation of the device, the piping of the spraying devices is relatively clean, so the distal nozzles of the spraying devices are sufficient to atomize the spray liquid into droplets of appropriate size. After the device has been in continuous operation for 18 months or more, the atomization effect of the nozzle at the furthest end of one spraying device decreases, and ammonia escape occurs due to poor gas-liquid contact. However, the escaped ammonia is captured by the spray liquid from the proximal nozzle of the upper spraying device and forms a corresponding salt through a neutralization reaction. As a result, the average droplet diameter and droplet diameter distribution near the inlet ends of the vertically opposed spraying devices are similar, and the quenching efficiency is also equivalent. Typically, ammonia absorption towers are equipped with multiple layers of spraying devices, for example, 3 layers, 4 layers, 5 layers or more. In a cross-section, if the projection angle between the spray liquid inlet of the upper (or double) spraying device and the spray liquid inlet of the lower (or double) spraying device is 180°, more ammonia can be absorbed, thus reducing ammonia escape and further reducing acid consumption.

[0100] According to embodiments of the present invention, two nozzles having substantially identical spray angles have the same spray diameter.

[0101] According to embodiments of the present invention, in all spraying devices, the angle between the projections in the cross-section of the spray liquid inlet of any two odd-numbered spraying devices is 0 degrees. The angle between the projections on the cross-section of the spray liquid inlet of any even-numbered spraying device is 0°, and the angle between the projection on the cross-section of the spray liquid inlet of any odd-numbered spraying device and the projection on the cross-section of the spray liquid inlet of any even-numbered spraying device is 180°. The inventors of the present invention have found that such an arrangement maximizes the uniform distribution of ammonia in the gas phase within the gas channel.

[0102] According to one embodiment of the present invention, in at least one (preferably all) second spray tubes, two adjacent (preferably all) nozzles located on the same side of the second spray tube are configured to spray the spray liquid in the same rotational direction. The inventors of the present invention have discovered that the spray liquid is supplied to the rotational chamber tangentially to the nozzle, and after passing through the nozzle outlet, forms a hollow cone with the nozzle outlet as the apex of the cone. In order to achieve uniformity of the spray liquid in the column, two adjacent nozzles must be positioned at equal intervals on the cross-section of the column. That is, the spray liquid enters the nozzles in the same tangential direction. Therefore, the spray liquid on the same side of the second spray tube is ejected in the same rotational direction, while the two spray liquids on opposite sides of the second spray tube are ejected in opposite rotational directions. Thus, after the spray liquids ejected from nozzles on the same second spray tube merge and collide, more droplets continue to descend along their original direction of motion without changing their light absorption state.

[0103] According to one embodiment of the present invention, all nozzles facing opposite sides of two parallel, adjacent second spray tubes are configured to eject the spray liquid in opposite rotational directions. Here, "adjacent" means that they are located on the same side of the first spray tube and adjacent to each other, and "facing opposite sides" means that, as shown in Figure 11C, the respective sides of the two opposing second spray tubes and the other second spray tube. Even after the spray liquids sprayed from the nozzles of the two adjacent second spray tubes collide during their respective descent, the droplets continue to descend while maintaining their original state. The droplets are less likely to combine into larger droplets and less likely to break down into smaller droplets.

[0104] According to embodiments of the present invention, in at least one (preferably all) second spray tubes, at least one (preferably all) nozzles located on one side of the second spray tubes are configured to eject the spray liquid in rotational direction A. On the other hand, at least one (preferably all) nozzles located on the opposite side of the second spray tubes are configured to eject the spray liquid in rotational direction B. Here, rotational direction A is opposite to rotational direction B.

[0105] According to one embodiment of the present invention, rotation direction A is clockwise, and rotation direction B is counterclockwise.

[0106] According to one embodiment of the present invention, in all nozzles of the spraying device, the number of nozzles spraying the spray liquid in rotation direction A is equal to, or substantially equal to, the number of nozzles spraying the spray liquid in rotation direction B. As mentioned above, the premise for uniform spraying is a uniform distribution of nozzles in the column, and an axially symmetric distribution is usually preferred. Therefore, the inventors of the present invention have found that the rotation directions of the nozzles appear in axially symmetric pairs. When the rotation directions of all paired nozzles are the same, it means that all nozzles have the same rotation direction. This is likely to cause the spray liquid sprayed from two adjacent nozzles to collide and become larger during rotation and descent, leading to a decrease in quenching efficiency. In this process, the total effective contact area with gaseous ammonia decreases, and the ammonia absorption efficiency decreases.

[0107] According to one embodiment of the present invention, in at least one (preferably all) second spray tube, two adjacent (preferably all) nozzles located on the same side of the second spray tube are configured to spray the spray liquid in opposite rotational directions. The third spray tube extends substantially parallel to the second spray tube in a horizontal direction perpendicular to it, to two opposite directions. As shown in Figure 11E, all nozzles on the same horizontal extension of the second spray tube are configured to spray the spray liquid in the same rotational direction.

[0108] According to embodiments of the present invention, in at least one (preferably all) second spray tubes, one nozzle positioned on the second spray tube is configured to spray the spray liquid in rotational direction A. Meanwhile, at least another adjacent nozzle on the same side is configured to spray the spray liquid in rotational direction B. At least one (preferably all) nozzles on the opposite side of the second spray tube are configured to spray the spray liquid in rotational direction A, where rotational direction A is opposite to rotational direction B.

[0109] According to one embodiment, the nozzle includes a nozzle inlet, a nozzle cavity, and a nozzle outlet. The cavity has a special structure, and when the spraying liquid supplied from the nozzle inlet passes through the cavity and is discharged from the nozzle outlet, droplets are formed. As shown in FIG. 9. The cavity can adopt any structure known in the technical field as long as it can form droplets when the spraying liquid is discharged from the nozzle outlet, and is not particularly limited.

[0110] According to one embodiment, the spraying liquid is supplied from the upper part of the nozzle to the cavity, and after passing through the nozzle outlet, a solid cone with the nozzle outlet as the apex is formed. Usually, two adjacent nozzles are arranged at equal intervals in the cross-section of the column, and the nozzle projections of a plurality of spraying devices substantially coincide. After the spraying liquids sprayed from two adjacent nozzles collide during their respective descending processes, the droplets can continue to descend while maintaining their original state.

[0111] According to one embodiment, the vertical interval between two adjacent spraying devices (calculated as the vertical interval between the spraying liquid inlets of the spraying devices) is between 650 and 1350 mm (preferably between 750 and 1200 mm). The inventor of the present invention has found that when the vertical interval between two adjacent spraying devices is less than 650 mm, in an ammonia absorption tower having a predetermined number of spraying devices, the contact time between the ascending ammonia-containing gas and the descending circulating liquid is insufficient, the gas-liquid mixing is insufficient, and the extinction efficiency decreases. In addition, since a part of the ammonia in the gas phase directly passes through the hollow conical liquid surface formed by the circulating liquid, the ammonia absorption efficiency decreases. Increasing the number of spraying devices can ensure sufficient gas-liquid contact time and completely absorb the ammonia in the gas phase, but this increases the total amount of the circulating liquid and the energy consumption of the pump. This is clearly uneconomical. When the vertical interval between two adjacent spraying devices exceeds 1350 mm, if the number of spraying devices is the same, the height of the tower increases. That is, the equipment investment cost increases. Furthermore, the difficulty of maintenance and repair also increases.

[0112] According to one embodiment, the difference (absolute value) in the spraying liquid input pressure at the spraying liquid inlets of any two spraying devices is less than 0.024 MPa (preferably less than 0.018 MPa, more preferably less than 0.012 MPa). The inventor of the present invention has discovered that the particle size of the spraying liquid droplets is closely related to the pressure at the nozzle. Whether the pressure is too high or too low is disadvantageous for the operation of the device. Since the nozzle pressure is derived from the spraying liquid input pressure at the spraying liquid inlet, theoretically it is desirable that the spraying liquid input pressures at the spraying liquid inlets are the same. However, in practice, since a plurality of spraying device layers are arranged vertically, pressure loss occurs when the circulation pump supplies the circulating liquid to each spraying device layer. Therefore, the pressure difference between the spraying liquid inlets of any two spraying devices should be minimized as much as possible. Thereby, all nozzles of the uppermost and lowermost spraying devices satisfy the optimal pressure conditions, ensuring that the average droplet diameter and the droplet diameter distribution in the longitudinal section of the device are similar. This means that the extinction efficiency along the longitudinal direction of the device is also the same.

[0113] According to one embodiment of the present invention, the inner diameter of the absorption device is 4.5 to 11.5 m (preferably 4.8 to 10.5 m).

[0114] According to one embodiment of the present invention, the absorption device further includes a housing and a gas inlet. According to the present invention, the spraying device is arranged inside the housing of the absorption device. Further, the reaction product is supplied to the absorption device through the gas inlet.

[0115] According to one embodiment of the present invention, the gas introduction part is located below the spraying device along the central axis direction of the absorption device.

[0116] In one embodiment, the vertical distance between the gas inlet and the spray liquid inlet of the spraying device (if multiple spraying devices exist, this refers to the spraying device closest to the gas inlet) is 800 to 6000 mm (preferably 1000 to 5000 mm). The inventors of the present invention discovered that the gas is introduced into the column through a downwardly curved semicircular introduction tube and then supplied from bottom to top. Relatively, the gas concentration is highest in the introduction tube. As the gas rises, the difference in gas concentration causes the gas to diffuse to the periphery, and eventually the gas concentration on the column cross-section becomes uniform. If the vertical distance is less than 800 mm, the gas concentration does not diffuse sufficiently, resulting in an uneven concentration distribution and gas-liquid mixing, which can lead to uneven quenching efficiency. This can easily result in localized insufficient ammonia absorption or localized excess acid. On the other hand, if the vertical distance is too large, the tangential height of the ammonia absorption tower becomes excessive, increasing capital investment. Meanwhile, as the spray liquid rotates and falls, the colliding droplets exhibit behaviors such as separation, merging, and crushing. When droplets coalesce, larger droplets are formed, and when they break down, smaller droplets are formed. The longer the spray distance of the droplets, the more likely coalescing and splitting are to occur, potentially leading to a wider droplet size distribution. This can reduce quenching efficiency, which is also detrimental to ammonia absorption.

[0117] According to one embodiment of the present invention, the inner diameter of the gas inlet is 800 to 1900 mm (preferably 900 to 1700 mm).

[0118] According to one embodiment, the linear velocity of the gas inside the enclosure is 0.6 to 1.5 m / s (preferably 0.7 to 1.3 m / s). The inventors of the present invention have discovered that the operating speed inside the enclosure affects the gas diffusion speed. The higher the operating speed inside the enclosure, the stronger the turbulent effect, the more droplets are drawn in, and the higher the quenching efficiency. This is advantageous for gas diffusion, and therefore the diffusion distance is shortened. When the velocity inside the enclosure is less than 0.6 m / s, the time required for the gas to diffuse uniformly is relatively longer. In other words, the distance from the inlet to the first layer of the spraying device increases. However, when the linear velocity inside the enclosure exceeds 1.5 m / s, the droplets of the spray liquid from the spraying device are usually in the form of mist, and these mist droplets are easily drawn into the gas. The higher the velocity inside the enclosure, the more severe the mist entrainment phenomenon becomes, and as a result, more mist droplets containing ammonium salts are carried out of the ammonia absorption tower by the gas.

[0119] According to one embodiment, no mechanical components that could substantially affect the gas flow, particularly baffles, trays, packing materials, or other mechanical components that obstruct the gas flow, are placed in the internal space of the absorption device between the gas inlet and the spraying device (or, if multiple spraying devices exist, the spraying device closest to the gas inlet). The inventors of the present invention have found that while it is possible to add internal components to ensure uniform distribution of gaseous ammonia on the cross-section before contact with the first layer of spray liquid, any kind of mechanical component increases the system pressure of the device, which ultimately reflects as an increase in reaction pressure and reduces the yield of the target product. Smaller droplet sizes result in a larger contact area between the droplet and gaseous ammonia, improving the absorption effect. Conversely, larger droplet sizes result in a reduced ammonia absorption effect. Gases are relatively diffusive. Even if gaseous ammonia is not perfectly and uniformly dispersed at the initial spraying position, as long as the quenching efficiency is only slightly inferior, the gaseous ammonia will continue to diffuse during the upward process and be captured and absorbed by the spray liquid of subsequent spraying devices. Therefore, while the objective of rapid and uniform dispersion of gaseous ammonia is achieved by adding components here, the vertical distance from the first-layer spraying device to the inlet should be 800 to 6000 mm, preferably 1000 to 5000 mm. This satisfies both the efficient reaction of the preceding reaction section and the quenching efficiency of the column, thereby achieving ammonia absorption efficiency. As a result, the overall economic efficiency of the apparatus is improved.

[0120] According to one embodiment of the present invention, in the reaction step, the hydrocarbon raw material is propylene, and the molar ratio of propylene / ammonia / air (calculated as molecular oxygen) is 1:1.1~1.3:1.8~2.0. The reaction takes place at a temperature of 420-440°C, a reaction pressure (gauge pressure) of 0.03-0.14 MPa, and a catalyst gravimetric space-time velocity of 0.06-0.15 h. -1 Alternatively, the hydrocarbon raw material is isobutylene, and the molar ratio of isobutylene / ammonia / air (calculated as molecular oxygen) is 1:1.3~1.6:2.2~2.8. In this case, the reaction takes place at a temperature of 395~420°C, a reaction pressure (gauge pressure) of 0.03~0.14 MPa, and a catalyst weight space velocity of 0.08~0.17 h. -1 It is composed of.

[0121] According to one embodiment, depending on the various reaction steps, the composition of the reaction product is generally about 10-20% by weight of C 1-4 Nitrile (e.g., acrylonitrile), approximately 0.1-5% by weight of C 1-4 The reaction product contains an oxygen-containing compound (e.g., acrolein), approximately 0.1 to 5% by weight of O2, approximately 0.1 to 2% by weight of ammonia, and the remaining impurities, with the total weight of the reaction product being 100% by weight. After pre-cooling, the temperature of the reaction product is approximately 195 to 235°C, and the pressure is approximately 0.03 to 0.14 MPaG. According to the present invention, the technical effects of the manufacturing process of the present invention described above are particularly excellent for this specific reaction product.

[0122] According to one embodiment of the present invention, in the cooling step, the spray liquid cools the reaction product from 195-235°C to 81-86°C. More preferably, the spray liquid reduces the ammonia content of the reaction product to 150 ppm or less.

[0123] Specific embodiments of the present invention will be described in detail illustratively with reference to the drawings.

[0124] For example, as shown in Figure 4A, according to the present invention, a reaction gas at 225°C and unreacted ammonia are supplied to the ammonia absorption tower 1 through the ammonia-containing gas supply port 8. The circulating liquid is drawn out from the bottom of the tower and sent to the multi-layered sprayers 3a to 3f by the circulation pump 17. The sprayers 3a to 3f are arranged in order from top to bottom within the tower, with sprayers 3a, 3c, and 3e located on the same side, and sprayers 3b, 3d, and 3f located on the opposite side from sprayers 3a, 3c, and 3e. The vertical distance between the ammonia-containing gas supply port 8 and sprayer 3f is 1800 mm. The spray liquid input pressures at the spray liquid inlets of sprayers 3a, 3c, and 3e are 0.327 MPaG, 0.330 MPaG, and 0.334 MPaG, respectively. Sulfuric acid is added to the outlet piping of the circulation pump through the acid-containing solution inlet 15. The circulating liquid is supplied through the spraying device 3, flowing in from the inlet 18 of the spraying device 3 and reaching the spray nozzle 22 via the first spray pipe 19, the second spray pipe 20a (20b), and the third spray pipe 21 along the fluid direction. The circulating liquid sprayed from the nozzle 22 forms an acid mist layer in the ammonia absorption tower and absorbs gaseous ammonia flowing in from the gas supply inlet 8. The tail gas is discharged from the gas phase outlet 9 of the ammonia absorption tower. The temperature of the top tail gas is 84°C. As shown in Figure 5, the protruding ends of the third spray pipes of the spraying devices 3a to 3f coincide on the tower cross-section.

[0125] Furthermore, as shown in Figure 4B, for example, according to the present invention, the reaction gas at 225°C and unreacted ammonia are supplied to the ammonia absorption tower 1 from the ammonia-containing gas supply port 8. The circulating liquid is drawn from the bottom of the tower and sent to the sprayers 3a-3f by the circulation pump 17. Here, the sprayers 3a, 3c, and 3e are located on the same side, while the sprayers 3b, 3d, and 3f are located on the side opposite to the sprayers 3a, 3c, and 3e. The acid-containing liquid is added to the outlet piping of the circulation pump through the acid-containing solution inlet 15. The circulating liquid is supplied through the sprayer 3, flows in from the inlet 18 of the sprayer, and reaches the spray nozzle 22 via the first spray pipe 19, the second spray pipe 20a (20b), and the third spray pipe 21 along the fluid direction. The ratio of left-rotating spray nozzles to right-rotating spray nozzles is 1:1. The circulating liquid sprayed from the nozzle 22 forms an acidic mist layer in the ammonia absorption tower and absorbs the gaseous ammonia supplied from the gas supply inlet 8. The tail gas is discharged from the gas phase outlet 9 of the ammonia absorption tower. The temperature of the top tail gas is 84°C. The projection of the third spray tube end of sprayers 3a-3f coincides on the column cross-section as shown in Figure 6A. A schematic diagram of the nozzle structure of the sprayer and a plan view of the sprayer are shown in Figures 11C and 11B, respectively.

[0126] [Examples] The present invention will be described in more detail with reference to the following embodiments. However, the present invention is not limited to these embodiments.

[0127] In the following examples and comparative examples, the residual ammonia concentration in the tail gas can be measured by offline analysis. Specifically, a fixed volume (V) of gas is sampled from the top of the ammonia absorption tower, and this gas is absorbed with a fixed amount of water. The amount of ammonia in the water is analyzed and converted to the amount of gaseous ammonia (v). The residual ammonia concentration in the tail gas is calculated as v / V. In addition, the acid consumption of the ammonia absorption tower is measured with an acid flow meter.

[0128] [Example 1] As shown in Figure 3b, the ammonia absorption tower had a two-stage structure. The inner diameter of the absorption tower was 7200 mm, and no gas distributor 23 was located inside the tower. The linear velocity of the reaction gas inside the tower was 1.1 m / s. The acid added to the circulating liquid was sulfuric acid. The circulating liquid containing the acid was supplied to the absorption tower via an upper circulation pump and four sprayers. The fluid direction of the first spray pipes of sprayers 3a and 3c was opposite to that of 3b and 3d, and the projection angle between the two spray liquid inlets of adjacent sprayers was 180°. The spray liquid input pressure at the spray liquid inlets of sprayers 3a(b) and 3c(d) was 0.440 MPaG and 0.446 MPaG, respectively. The spray liquid discharge pressure was 0.051 MPaG. The distance between two adjacent sprayers was 1200 mm. Each sprayer was provided with 16 second spray pipes, and each second spray pipe was equipped with 11 to 18 third spray pipes. The projections of the ends of the third spray tubes of the spraying device matched, and their rotation directions were identical. All nozzles on the same side of the second spray tube had the same rotation direction. The two nozzles on opposite sides of the second spray tube had opposite rotation directions, and all nozzles facing opposite sides of two adjacent second spray tubes had opposite rotation directions. The number of nozzles with the same rotation direction was 480 and 480, respectively. The first spray tube of the spraying device had an inner diameter of 250 mm and a length of 7000 mm. The spacing between the second spray tubes of the spraying device was 820 mm. The second spray tubes had an inner diameter of 100 mm and a length of 2100 mm to 3450 mm. The spacing between the third spray tubes of the spraying device was 410 mm. The inner diameter of the third spray tube was 40 mm and its length was 205 mm. A total of 960 nozzles were installed in the spraying device. As shown in Figure 6B, the distance between the ends of two adjacent third spray tubes was 580 mm. The nozzle outlet diameter was 11.5 mm, the nozzle rotation chamber diameter was 40 mm, and the nozzle spray angle was 75°. The vertical distance from the gas supply port 8 to the spraying device 3d was 4000 mm, and the inner diameter of the supply port was 1300 mm. The reaction product gas supplied from the supply port contained approximately 0.71 wt% ammonia and 13.2 wt% acrylonitrile, with the remainder consisting of impurities such as O2, acrolein, and nitrogen, at a temperature of 225°C and a pressure of 0.06 MPaG.The spray liquid discharge rate per nozzle was 4.8 tons / hour, and the weight ratio of the spray liquid to the reaction product gas supplied from the gas inlet was 20. In the initial stages of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 41 ppm. After 24 months of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 52 ppm. The ratio of acid consumption after 24 months to acid consumption after 1 month of operation was 1.02.

[0129] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.011 m. -1 , droplet average diameter D 32 The droplet size is 1130 μm, and the droplet size distribution is D 10 is 625 μm, D 50 is 1328 μm, D 90 The value was 2195 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0021 m -1 , droplet average diameter D 32 The droplet size is 462 μm, and the droplet size distribution is D 10 406 μm, D 50 593 μm, D 90 The size was 894 μm.

[0130] [Example 2] As shown in Figure 4B, the ammonia absorption tower had a single-stage structure. The inner diameter of the absorption tower was 7200 mm, and no gas distributor 23 was located inside the tower. The linear velocity of the reaction gas inside the tower was 1.1 m / s. The acid added to the circulating liquid was sulfuric acid. The circulating liquid containing the acid was supplied to the absorption tower via a circulation pump through six sprayers. The fluid direction in the first spray pipes of sprayers 3a, 3c, and 3e was opposite to that of sprayers 3b, 3d, and 3f, and the projection angle between two adjacent spray liquid inlets was 180°. A plan view of the sprayers is shown in Figure 11B, and a detailed plan view of the sprayers is shown in Figure 11C. The spray liquid input pressures at the spray liquid inlets of sprayers 3a(b), 3c(d), and 3e(f) were 0.425 MPaG, 0.430 MPaG, and 0.435 MPaG, respectively. The spray pressure of the spray liquid was 0.055 MPaG, respectively. The vertical distance between two adjacent sprayers was 880 mm. Each sprayer was equipped with 14 second spray tubes, each of which had 6 to 14 third spray tubes. The projections of the ends of the third spray tubes of the sprayers coincided, and their rotation directions were identical. All nozzles on the same side of the second spray tubes had the same rotation direction. The two nozzles on opposite sides of the second spray tubes had opposite rotation directions, and all nozzles facing opposite sides of two adjacent second spray tubes had opposite rotation directions. The number of nozzles with the same rotation direction was 456 and 456, respectively. The first spray tube of the sprayer had an inner diameter of 200 mm and a length of 7000 mm. The distance between the second spray tubes of the sprayers was 1000 mm, and the second spray tubes had an inner diameter of 100 mm and lengths of 1850-3450 mm. The distance between the third spray tubes of the sprayers was 500 mm. The inner diameter of the third spray pipe was 40 mm, and its length was 250 mm. The protrusions at the ends of the third spray pipes of the spraying device were aligned, and as shown in Figure 6A, the distance between two adjacent third spray pipe ends was 500 mm. A total of 912 nozzles were installed in the spraying device. The nozzle outlet diameter of the spraying device was 11.7 mm, the nozzle rotation chamber diameter was 36 mm, and the spray angle was 80°. The vertical distance from the gas supply inlet 8 to spraying device 3f was 1500 mm, and the vertical distance from the gas supply inlet 8 to spraying device 3d was 4000 mm. The diameter of the gas supply inlet was 1200 mm.The reaction product gas supplied from the inlet contained approximately 0.71% by weight of ammonia, 13.2% by weight of acrylonitrile, and the remainder consisted of impurities such as O2, acrolein, and nitrogen, at a temperature of 225°C and a pressure of 0.06 MPaG. The spray liquid discharge rate per nozzle was 5.1 tons / hour, and the weight ratio of spray liquid to reaction product gas passing through the gas inlet was 20. In the initial stages of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 27 ppm. After 24 months of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 34 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.01.

[0131] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0128 m. -1 , droplet average diameter D 32 The droplet size is 1054 μm, and the droplet size distribution is D 10 is 832 μm, D 50 is 1242 μm, D 90 The value was 1956 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0019 m -1 , droplet average diameter D 32 The droplet size is 412 μm, and the droplet size distribution is D 10 is 386 μm, D 50 is 574 μm, D 90 It was 878 μm.

[0132] [Example 3] Example 2 was repeated, but the spray liquid input pressure at the spray liquid inlet of sprayers 3a(b), 3c(d), and 3e(f) was set to 0.152 MPaG, 0.160 MPaG, and 0.168 MPaG, respectively, and the spray liquid pressure was set to 0.04 MPaG for each, and the nozzle outlet diameter of the sprayer was set to 11.9 mm. At the beginning of the operation of the apparatus, the residual ammonia concentration in the exhaust gas at the reaction outlet was 72 ppm. After 24 months of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 98 ppm.

[0133] In this embodiment, when measured at a position 3000 mm vertically from the gas inlet, the absorption atmosphere has an extinction coefficient of 0.0058 m -1 , the average droplet diameter D 32 is 2226 μm, the droplet size distribution D 10 is 1298 μm, D 50 is 2384 μm, D 90 is 3203 μm. Further, when measured at a position 8500 mm vertically from the gas inlet, the absorption atmosphere has an extinction coefficient of 0.0013 m -1 , the average droplet diameter D 32 is 542 μm, the droplet size distribution is D 10 is 427 μm, D 50 is 671 μm, D 90 is 914 μm.

[0134] 〔Example 4〕 Example 2 was repeated. However, the spray liquid input pressures at the spray liquid inlets of the spray devices 3a(b), 3c(d), and 3e(f) were 0.838 MPaG, 0.844 MPaG, and 0.85 MPaG respectively, the spray liquid spray pressures of the spray devices were 0.42 MPaG respectively, and the nozzle outlet diameters of the spray devices were 12.1 mm. At the initial stage of the device operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 84 ppm. After 24 months of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 92 ppm.

[0135] In this embodiment, when measured at a position 3000 mm vertically from the gas inlet, the extinction coefficient of the absorption atmosphere is 0.018 m -1 , the average droplet diameter D 32 is 726 μm, the droplet size distribution is D 10 is 422 μm, D 50 is 989 μm, D 90 is 1803 μm. Further, when measured at a position 8500 mm vertically from the gas inlet, the extinction coefficient of the absorption atmosphere is 0.0035 m -1 , the average droplet diameter D 32 is 321 μm, the droplet size distribution is D 10 is 267 μm, D 50 is 389 μm, D 90 is 543 μm.

[0136] [Example 5] Example 2 was repeated, but the spray liquid input pressure at the spray liquid inlet of sprayers 3a(b), 3c(d), and 3e(f) was set to 0.950 MPaG, 0.954 MPaG, and 0.959 MPaG, respectively, and the spray liquid pressure was set to 0.42 MPaG for each sprayer, with a nozzle outlet diameter of 11.1 mm. At the beginning of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 105 ppm. 24 months after the start of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 116 ppm.

[0137] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.01925 m -1 , droplet average diameter D 32 The droplet size is 432 μm, and the droplet size distribution is D 10 392 μm, D 50 is 750 μm, D 90 The value was 1439 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0038 m -1 , droplet average diameter D 32 The droplet size is 280 μm, and the droplet size distribution is D 10 is 159 μm, D 50 is 345 μm, D 90 The size was 511 μm.

[0138] [Example 6] Example 2 was repeated, with the spray liquid input pressure at the spray liquid inlet of sprayers 3a(b), 3c(d), and 3e(f) being 0.098 MPaG, 0.103 MPaG, and 0.108 MPaG, respectively, and the spray liquid pressure being 0.04 MPaG, respectively, and the nozzle outlet diameter of the sprayers being 12.3 mm. In the initial stages of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 132 ppm. 24 months after the start of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 181 ppm.

[0139] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere has a extinction coefficient of 0.0042 m -1 , droplet average diameter D 32 2426 μm, droplet size distribution D 10 1398 μm, D 50 is 2434 μm, D 90 The value was 3390 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0012 m. -1 , droplet average diameter D 32 The droplet size is 692 μm, and the droplet size distribution is D 10 is 547 μm, D 50 is 682 μm, D 90 The size was 950 μm.

[0140] [Example 7] Example 2 was repeated, but the vertical distance between two adjacent sprayers was set to 1200 mm, and the distance between the ends of two adjacent third spray pipes was set to 707 mm, as shown in Figure 6B. The nozzle outlet diameter of the sprayer was 11.8 mm, and the spray liquid discharge rate per nozzle was 5.8 t / h. In the initial stages of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 68 ppm. After 24 months of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 96 ppm.

[0141] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.005 m. -1 , droplet average diameter D 32 The droplet size is 1623 μm, and the droplet size distribution D 10 is 1189 μm, D 50 is 2148 μm, D 90 The value was 2415 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0021 m -1 , droplet average diameter D 32 The droplet size is 432 μm, and the droplet size distribution is D 10 387 μm, D 50 is 601 μm, D 90 The size was 914 μm.

[0142] [Example 8] The procedure for Example 2 was repeated, but with a vertical distance of 1200 mm between two adjacent spraying devices. Each spraying device was equipped with 18 second spray pipes, and each second spray pipe was fitted with 7 to 20 third spray pipes. The distance between the second spray pipes in the spraying device was 670 mm, the inner diameter of the second spray pipe was 80 mm, and as shown in Figure 6A, the distance between the ends of two adjacent third spray pipes was 335 mm. The total number of nozzles in the spraying device was 2000. The nozzle outlet diameter was 11.3 mm, the nozzle rotation chamber diameter was 30 mm, and the spray angle was 65°. The spray liquid discharge rate per nozzle was 2.64 tons / hour. In the initial stage of device operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 86 ppm. After 24 months of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 105 ppm.

[0143] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0078 m -1 , droplet average diameter D 32 The droplet size is 1814 μm, and the droplet size distribution D 10 is 1075 μm, D 50 is 2184 μm, D 90 The value was 2851 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0015 m -1 , droplet average diameter D 32 The droplet size is 460 μm, and the droplet size distribution is D 10 437 μm, D 50 651 μm, D 90 The size was 893 μm.

[0144] [Example 9] Example 2 was repeated, and the spray liquid input pressures at the spray liquid inlets of sprayers 3a(b), 3c(d), and 3e(f) were 0.376 MPaG, 0.380 MPaG, and 0.385 MPaG, respectively. The spray liquid discharge pressure was 0.045 MPaG, the vertical distance between two adjacent sprayers was 550 mm, and the distance between the ends of two adjacent third spray pipes was 707 mm, as shown in Figure 6B. In the initial stages of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 120 ppm. After 24 months of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 162 ppm.

[0145] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0042 m -1 , droplet average diameter D 32 The droplet size is 2154 μm, and the droplet size distribution is D 10 is 1096 μm, D 50 It is 2628 μm, D 90 The value was 2865 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0011 m -1 , droplet average diameter D 32 The droplet size is 367 μm, and the droplet size distribution is D 10 316 μm, D 50 is 484 μm, D 90 The thickness was 616 μm.

[0146] [Example 10] Example 2 was repeated, but the vertical distance between two adjacent sprayers was 1200 mm, each sprayer had 24 second spray pipes, each second spray pipe had 9 to 24 third spray pipes, the spacing between the second spray pipes of the sprayers was 580 mm, the inner diameter of the second spray pipes was 80 mm, and as shown in Figure 6A, the distance between the ends of adjacent third spray pipes was 290 mm. The total number of nozzles in the sprayers was 2640. The nozzle outlet diameter of the sprayers was 9.1 mm, the nozzle rotation chamber diameter was 30 mm, and the spray angle was 65°. The spray liquid discharge rate per nozzle was 2.0 tons / hour. In the initial stage of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 146 ppm. After 24 months of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 185 ppm.

[0147] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0059 m -1 , droplet average diameter D 32 The droplet size is 1934 μm, and the droplet size distribution is D. 10 It is 1738 μm, D 50 is 2128 μm, D 90 The value was 2665 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0013 m -1 , droplet average diameter D 32 The droplet size is 347 μm, and the droplet size distribution is D 10 is 284 μm, D 50 is 482 μm, D 90 The thickness was 615 μm.

[0148] [Example 11] Example 2 was repeated, with a spray liquid discharge rate of 8.5 t / h per nozzle and a weight ratio of spray liquid to reaction product gas supplied from the gas inlet of 32. After 1 month of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 85 ppm. After 24 months of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 99 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.03.

[0149] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0016 m -1 , droplet average diameter D 32 The droplet size is 1712 μm, and the droplet size distribution is D 10 is 1138 μm, D 50 is 2324 μm, D 90 The value was 2765 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0014 m -1 The average droplet diameter D was shown. 32 The droplet size is 787 μm, and the droplet size distribution is D 10 556 μm, D 50 is 832 μm, D 90 The size was 1042 μm.

[0150] [Example 12] Example 2 was repeated, but the spray liquid discharge rate per nozzle was set to 1.5 t / h, and the weight ratio of the spray liquid to the reaction product gas supplied from the gas inlet was set to 11. After 1 month of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 145 ppm. After 24 months of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 178 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.05.

[0151] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere is 0.005 m -1 , droplet average diameter D 32 The droplet size is 469 μm, and the droplet size distribution is D 10 409 μm, D 50 is 772 μm, D 90 The value was 1091 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0012 m -1 , droplet average diameter D 32 The droplet size is 348 μm, and the droplet size distribution is D 10 is 159 μm, D 50 393 μm, D 90 The size was 604 μm.

[0152] [Example 13] Example 2 was repeated, but the inlets of the sprayers 3a to 3f were positioned in different orientations. Here, the first spray tubes of sprayers 3a to 3f coincided in cross-sectional projection, but the second spray tube, third spray tube, and nozzles did not coincide in cross-sectional projection. After 1 month of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 137 ppm. After 24 months of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 148 ppm.

[0153] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere is 0.0063 m -1 , droplet average diameter D 32 The droplet size is 1852 μm, and the droplet size distribution is D 10 1593 μm, D 50 1882 μm, D 90 The value was 2191 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.001 m. -1 , droplet average diameter D 32 The droplet size is 430 μm, and the droplet size distribution is D 10 392 μm, D 50 575 μm, D 90 The size was 783 μm.

[0154] [Example 14] Example 2 was repeated, but the nozzle diameters of the 1st to 11th second spray pipes of the first spray pipe were set to 36 mm along the fluid direction, and the nozzle diameters of the 12th to 14th second spray pipes of the first spray pipe were set to 32 mm. After 1 month of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 63 ppm. After 24 months of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 99 ppm.

[0155] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0127 m -1 , droplet average diameter D 32 The droplet size is 824 μm, and the droplet size distribution is D 10 598 μm, D 50 is 1198 μm, D90 The value was 1976 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0018 m -1 , droplet average diameter D 32 The droplet size is 411 μm, and the droplet size distribution is D 10 is 375 μm, D 50 586 μm, D 90 The size was 880 μm.

[0156] [Example 15] Example 2 was repeated, but the vertical distance between two adjacent spraying devices was set to 1250 mm. In the initial stages of device operation, the residual ammonia concentration in the tail gas at the reaction outlet was 77 ppm. After 24 months of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 85 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.04.

[0157] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere is 0.0094 m -1 , droplet average diameter D 32 The droplet size is 1408 μm, and the droplet size distribution is D 10 is 1009 μm, D 50 is 2083 μm, D 90 The value was 2362 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0016 m -1 , droplet average diameter D 32 The droplet size is 469 μm, and the droplet size distribution is D 10 372 μm, D 50 579 μm, D 90 The size was 880 μm.

[0158] [Example 16] Example 2 was repeated, but the vertical distance between two adjacent spraying devices was set to 720 mm. In the initial stages of device operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 111 ppm. After 24 months of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 129 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.07.

[0159] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0143 m -1 , droplet average diameter D 32 The droplet size is 935 μm, and the droplet size distribution is D 10 is 616 μm, D 50 is 1323 μm, D 90 The value was 1950 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0015 m -1 , droplet average diameter D 32 The droplet size is 420 μm, and the droplet size distribution is D 10 389 μm, D 50 is 480 μm, D 90 The thickness was 632 μm.

[0160] [Example 17] Example 2 was repeated, but the vertical distance between two adjacent spraying devices was set to 1650 mm. In the initial stages of device operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 177 ppm. After 24 months of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 195 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.05.

[0161] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0053 m -1 , droplet average diameter D 32 The droplet size is 2215 μm, and the droplet size distribution is D 10 is 1295 μm, D 50 It is 2489 μm, D 90The value was 3125 μm. Furthermore, when measured at a vertical distance of 10350 mm from the gas inlet (located above the spraying device), the extinction coefficient of the absorbing atmosphere was 0.0011 m -1 , droplet average diameter D 32 The droplet size is 580 μm, and the droplet size distribution is D 10 319 μm, D 50 is 645 μm, D 90 The thickness was 711 μm.

[0162] [Example 18] Example 2 was repeated, but the vertical distance between two adjacent spraying units was set to 550 mm. After operating the unit for one month, the residual ammonia concentration in the exhaust gas at the reaction outlet was 129 ppm. After operating the unit for 24 months, the residual ammonia concentration in the exhaust gas at the reaction outlet was 145 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.04.

[0163] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0187 m -1 , droplet average diameter D 32 The droplet size is 895 μm, and the droplet size distribution is D 10 566 μm, D 50 is 1129 μm, D 90 The value was 1921 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0011 m. -1 , droplet average diameter D 32 The droplet size is 350 μm, and the droplet size distribution is D 10 is 219 μm, D 50 is 445 μm, D 90 The size was 511 μm.

[0164] [Example 19] The procedure for Example 2 was repeated, and the spray liquid input pressures at the spray liquid inlets of sprayers 3a(b), 3c(d), and 3e(f) were 0.405 MPaG, 0.421 MPaG, and 0.435 MPaG, respectively. In the initial stages of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 65 ppm. After 24 months of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 89 ppm.

[0165] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0135 m. -1 , droplet average diameter D 32 The droplet size is 992 μm, and the droplet size distribution is D 10 is 735 μm, D 50 is 1112 μm, D 90 The value was 1601 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0025 m -1 , droplet average diameter D 32 The droplet size is 402 μm, and the droplet size distribution is D 10 is 366 μm, D 50 is 580 μm, D 90 The size was 808 μm.

[0166] [Example 20] Example 2 was repeated, except that the spray liquid input pressure at the spray liquid inlet of sprayers 3a(b), 3c(d), and 3e(f) was 0.327 MPaG, 0.352 MPaG, and 0.376 MPaG, respectively. At the beginning of the operation of the apparatus, the residual ammonia concentration in the exhaust gas at the reaction outlet was 112 ppm. After 24 months of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 145 ppm.

[0167] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere is 0.0094 m -1 , droplet average diameter D 32 The droplet size is 1432 μm, and the droplet size distribution is D 10 is 1032 μm, D 50 1789 μm, D 90The value was 2647 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0012 m -1 , droplet average diameter D 32 The droplet size is 497 μm, and the droplet size distribution is D 10 is 452 μm, D 50 is 620 μm, D 90 The size was 913 μm.

[0168] [Example 21] Example 1 was repeated, but the vertical distance from the gas inlet to the spraying device 3f was set to 6000 mm. In the initial stages of device operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 77 ppm. After 24 months of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 85 ppm.

[0169] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0093 m -1 , droplet average diameter D 32 The droplet size is 1132 μm, and the droplet size distribution is D 10 932 μm, D 50 It is 1248 μm, D 90 The value was 2101 μm. Furthermore, when measured at a vertical distance of 13500 mm from the gas inlet (located above the spraying device), the extinction coefficient of the absorbing atmosphere was 0.0016 m -1 , droplet average diameter D 32 The droplet size is 372 μm, and the droplet size distribution is D 10 416 μm, D 50 491 μm, D 90 The thickness was 638 μm.

[0170] [Example 22] Example 2 was repeated, but the vertical distance from the gas inlet to the spraying device 3f was set to 8000 mm. In the initial stages of device operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 90 ppm. After 24 months of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 106 ppm.

[0171] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere has a extinction coefficient of 0.0062 m -1 , droplet average diameter D 32 The droplet size is 1520 μm, and the droplet size distribution is D. 10 is 1249 μm, D 50 is 1742 μm, D 90 The value was 2345 μm. Furthermore, when measured at a vertical distance of 16000 mm from the gas inlet (above the spraying device), the extinction coefficient of the absorbing atmosphere was 0.0015 m -1 , droplet average diameter D 32 The droplet size is 326 μm, and the droplet size distribution is D 10 is 291 μm, D 50 is 485 μm, D 90 The size was 794 μm.

[0172] However, the increased overall height of the column apparatus led to higher equipment investment costs and simultaneously increased the difficulty of maintaining the equipment.

[0173] [Example 23] Example 2 was repeated, but the vertical distance from the gas inlet to the spraying device 3f was set to 900 mm. In the initial stages of device operation, the residual ammonia concentration in the tail gas at the reaction outlet was 125 ppm. After 24 months of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 142 ppm.

[0174] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0055 m -1 , droplet average diameter D 32 The droplet size is 1220 μm, and the droplet size distribution is D 10 is 749 μm, D 50 It is 1468 μm, D 90 The value was 2845 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0016 m -1 , droplet average diameter D 32 The droplet size is 486 μm, and the droplet size distribution is D 10 419 μm, D 50 685 μm, D 90 It was 898 μm.

[0175] [Example 24] Example 2 was repeated, but the vertical distance from the gas inlet to the spraying device 3f was set to 500 mm. In the initial stages of device operation, the residual ammonia concentration in the tail gas at the reaction outlet was 182 ppm. After 24 months of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 219 ppm.

[0176] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere is 0.0043 m -1 , droplet average diameter D 32 The droplet size is 1143 μm, and the droplet size distribution is D 10 is 648 μm, D 50 2163 μm, D 90 The value was 3556 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0018 m -1 , droplet average diameter D 32 The droplet size is 402 μm, and the droplet size distribution is D 10 is 284 μm, D 50 575 μm, D 90 It was 969 μm.

[0177] [Example 25] Example 2 was repeated, but with a gas distributor 23 placed inside the column as shown in Figure 4B. The residual ammonia concentration in the tail gas at the reaction outlet was 35 ppm. After adding the internal components of the gas distributor, the pressure at the bottom of the ammonia absorption column increased by 10 kPa. This increased the reaction pressure of the system preceding the ammonia absorption column by 10 kPa, resulting in a 1.5% decrease in the yield of the target product, nitrile.

[0178] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0127 m -1 , droplet average diameter D 32 The droplet size is 1068 μm, and the droplet size distribution is D 10 is 790 μm, D 50 is 1222 μm, D 90The value was 1960 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.002 m -1 , droplet average diameter D 32 The droplet size is 398 μm, and the droplet size distribution is D 10 is 376 μm, D 50 is 572 μm, D 90 The size was 864 μm.

[0179] [Example 26] Example 2 was repeated, but the linear velocity of the reaction gas in the tower was set to 0.6 m / s, and the spray liquid discharge rate per nozzle was set to 2.8 t / h. At the beginning of the operation of the apparatus, the residual ammonia concentration in the tail gas at the reaction outlet was 82 ppm. After 24 months of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 99 ppm.

[0180] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.009 m. -1 , droplet average diameter D 32 The droplet size is 1254 μm, and the droplet size distribution is D 10 895 μm, D 50 is 1405 μm, D 90 The value was 2084 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0016 m -1 , droplet average diameter D 32 The droplet size is 486 μm, and the droplet size distribution is D 10 385 μm, D 50 is 568 μm, D 90 The size was 880 μm.

[0181] [Example 27] Example 2 was repeated, but the linear velocity of the reaction gas in the tower was 1.4 m / s, the spray liquid discharge rate per nozzle was 5.1 t / h, and the weight ratio of the spray liquid to the reaction product gas supplied from the gas inlet was 17. In the initial stages of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 132 ppm. After 24 months of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 154 ppm.

[0182] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0191 m. -1 , droplet average diameter D 32 The droplet size is 954 μm, and the droplet size distribution is D 10 595 μm, D 50 It is 1389 μm, D 90 The value was 2052 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0029 m -1 , droplet average diameter D 32 The droplet size is 390 μm, and the droplet size distribution is D 10 is 336 μm, D 50 is 564 μm, D 90 The size was 882 μm.

[0183] [Example 28] Example 2 was repeated, but the linear velocity of the reaction gas in the tower was set to 0.4 m / s, and the spray liquid discharge rate per nozzle was set to 2.0 t / h. At the beginning of the operation of the apparatus, the residual ammonia concentration in the tail gas at the reaction outlet was 173 ppm. After 24 months of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 195 ppm.

[0184] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere is 0.006 m -1 , droplet average diameter D 32 The droplet size is 1350 μm, and the droplet size distribution is D 10 985 μm, D 50 1549 μm, D 90 The value was 2256 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.001 m. -1 This shows the average droplet diameter D 32 The droplet size is 416 μm, and the droplet size distribution is D 10 385 μm, D 50 581 μm, D 90 The size was 872 μm.

[0185] [Example 29] Example 2 was repeated, but the linear velocity of the reaction gas in the tower was 1.9 m / s, the spray liquid discharge rate per nozzle was 6.2 t / h, and the weight ratio of the spray liquid to the reaction product gas supplied from the gas inlet was 15. In the initial stages of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 182 ppm. After 24 months of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 199 ppm.

[0186] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.02 m. -1 , droplet average diameter D 32 The droplet size is 890 μm, and the droplet size distribution is D 10 is 522 μm, D 50 It is 1234 μm, D 90 The value was 2043 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0039 m -1 , droplet average diameter D 32 The droplet size is 361 μm, and the droplet size distribution is D 10 306 μm, D 50 514 μm, D 90 The size was 847 μm.

[0187] [Example 30] Example 2 was repeated, but the ammonia absorption tower used was a single-stage structure as shown in Figure 4A. The fluid direction of the first spray pipes of sprayers 3a, 3b, and 3c was opposite to that of sprayers 3d, 3e, and 3f. That is, the projection of the spray inlets of the upper three layers of sprayers 3a, 3b, and 3c substantially coincided with the projection of the spray nozzles of the upper three layers of sprayer 3c, and substantially coincided with the projection of the spray nozzles of the lower three layers of sprayers 3d, 3e, and 3f. The projection angle between the spray nozzles of the upper three layers and the lower three layers was 180°. After operating the apparatus for one month, the residual ammonia concentration in the exhaust gas at the reaction outlet was 42 ppm. After operating the apparatus for 24 months, the residual ammonia concentration in the exhaust gas at the reaction outlet was 61 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.03.

[0188] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0118 m -1 , droplet average diameter D 32 The droplet size is 934 μm, and the droplet size distribution is D 10 698 μm, D 50 1367 μm, D 90 The value was 2182 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0019 m -1 , droplet average diameter D 32 The droplet size is 417 μm, and the droplet size distribution is D 10 392 μm, D 50 584 μm, D 90 It was 898 μm.

[0189] [Example 31] Example 2 was repeated, but as shown in Figure 7, the projections of the first spray pipes of sprayers 3a, 3c, and 3e and the first spray pipes of sprayers 3b, 3d, and 3f coincided in cross-section, while the projections of the second spray pipe, third spray pipe, and nozzles did not coincide in cross-section. After operating the apparatus for one month, the residual ammonia concentration in the exhaust gas at the reaction outlet was 78 ppm. After operating the apparatus for 24 months, the residual ammonia concentration in the exhaust gas at the reaction outlet was 95 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.05.

[0190] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0103 m -1 , droplet average diameter D 32 The droplet size is 1146 μm, and the droplet size distribution is D 10 is 790 μm, D 50 is 1742 μm, D 90 The value was 1956 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.002 m. -1 , droplet average diameter D 32 The droplet size is 442 μm, and the droplet size distribution is D 10 is 401 μm, D 50 is 612 μm, D 90It was 934 μm.

[0191] [Example 32] Example 2 was repeated, but in each spraying apparatus, the nozzles on the opposite side of the eight second spray tubes had the opposite direction of rotation in the chamber, whereas the nozzles on the opposite side of another eight second spray tubes had the same direction of rotation in the chamber. After operating the apparatus for one month, the residual ammonia concentration in the exhaust gas at the reaction outlet was 90 ppm. After operating the apparatus for 24 months, the residual ammonia concentration in the exhaust gas at the reaction outlet was 105 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.04.

[0192] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0103 m -1 , droplet average diameter D 32 The droplet size is 1231 μm, and the droplet size distribution is D 10 is 778 μm, D 50 It is 1692 μm, D 90 The value was 1923 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0018 m -1 , droplet average diameter D 32 The droplet size is 449 μm, and the droplet size distribution is D 10 is 420 μm, D 50 643 μm, D 90 The size was 946 μm.

[0193] [Example 33] Example 2 was repeated, but the projection of the end of the third spray pipe of the spraying device matched, while the projection-matching nozzle of the adjacent spraying device had the opposite rotation direction. The residual ammonia concentration in the exhaust gas at the reaction outlet after the device had been running for one month was 85 ppm. The residual ammonia concentration in the exhaust gas at the reaction outlet after the device had been running for 24 months was 110 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.05.

[0194] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0100 m. -1 , droplet average diameter D 32 The droplet size is 1327 μm, and the droplet size distribution is D 10 is 808 μm, D 50 is 1700 μm, D 90 The value was 1906 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0018 m -1 , droplet average diameter D 32 The droplet size is 452 μm, and the droplet size distribution is D 10 is 424 μm, D 50 656 μm, D 90 It was 989 μm.

[0195] [Example 34] Example 2 was repeated, but in the spraying apparatus, two adjacent nozzles on the same side of the second spray pipe rotated in opposite directions. On the other hand, all nozzles on the same horizontal extension of the second spray pipe rotated in the same direction. A plan view of the spraying apparatus is shown in Figure 11B, and a detailed plan view of the spraying apparatus is shown in Figure 11E. After operating the apparatus for one month, the residual ammonia concentration in the exhaust gas at the reaction outlet was 106 ppm. After operating the apparatus for 24 months, the residual ammonia concentration in the exhaust gas at the reaction outlet was 125 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.05.

[0196] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere is 0.0074 m -1 , droplet average diameter D 32 The droplet size is 1291 μm, and the droplet size distribution is D 10 is 728 μm, D 50 is 1702 μm, D 90 The value was 2011 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.00145 m -1 , droplet average diameter D 32 The droplet size is 519 μm, and the droplet size distribution is D 10 436 μm, D50 is 672 μm, D 90 The size was 1046 μm.

[0197] [Example 35] Example 2 was repeated, but all nozzles on opposite sides of two adjacent second spray tubes of the spraying apparatus had the same spray rotation direction, while nozzles on both sides of the same second spray tube had opposite spray rotation directions. After operating the apparatus for one month, the residual ammonia concentration in the exhaust gas at the reaction outlet was 108 ppm. After operating the apparatus for 24 months, the residual ammonia concentration in the exhaust gas at the reaction outlet was 121 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.04.

[0198] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0072 m -1 , droplet average diameter D 32 The droplet size is 1345 μm, and the droplet size distribution is D 10 is 723 μm, D 50 is 1726 μm, D 90 The value was 2071 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.00143 m -1 , droplet average diameter D 32 The droplet size is 503 μm, and the droplet size distribution is D 10 438 μm, D 50 699 μm, D 90 The size was 1167 μm.

[0199] [Example 36] Example 2 was repeated, but the two adjacent nozzles on one side of the second spray pipe of the spraying device rotated in opposite directions, and the two nozzles on the opposite side of the same second spray pipe also rotated in opposite directions. After operating the device for one month, the residual ammonia concentration in the exhaust gas at the reaction outlet was 125 ppm. After operating the device for 24 months, the residual ammonia concentration in the exhaust gas at the reaction outlet was 148 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.05.

[0200] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0064 m -1 , droplet average diameter D 32 The droplet size is 1446 μm, and the droplet size distribution is D 10 is 723 μm, D 50 is 1825 μm, D 90 The value was 2270 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.00141 m -1 , droplet average diameter D 32 The droplet size is 513 μm, and the droplet size distribution is D 10 is 420 μm, D 50 739 μm, D 90 The size was 1190 μm.

[0201] [Example 37] Example 1 was repeated, except that all nozzles in the spraying apparatus had the same rotation chamber direction. After operating the apparatus for one month, the residual ammonia concentration in the exhaust gas at the reaction outlet was 129 ppm. After operating the apparatus for 24 months, the residual ammonia concentration in the exhaust gas at the reaction outlet was 149 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.06.

[0202] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere is 0.0052 m -1 , droplet average diameter D 32 The droplet size is 1586 μm, and the droplet size distribution is D 10 is 723 μm, D 50 is 1825 μm, D 90 The value was 2331 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0012 m -1 , droplet average diameter D 32 The droplet size is 545 μm, and the droplet size distribution is D 10 is 430 μm, D 50 is 780 μm, D 90 The size was 1254 μm.

[0203] [Example 38] Example 2 was repeated, but the distance between adjacent third spray tubes was set to 300 mm, and the distance between the ends of two adjacent third spray tubes was set to 300 mm, as shown in Figure 6A. The residual ammonia concentration in the tail gas at the reaction outlet was 76 ppm.

[0204] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0051 m -1 , droplet average diameter D 32 The droplet size is 1620 μm, and the droplet size distribution is D 10 is 1182 μm, D 50 It is 2145 μm, D 90 The value was 2405 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0022 m -1 , droplet average diameter D 32 The droplet size is 430 μm, and the droplet size distribution is D 10 382 μm, D 50 is 604 μm, D 90 The size was 924 μm.

[0205] [Example 39] Example 2 was repeated, but the distance between the ends of the two adjacent third spray tubes was set to 340 mm, as shown in Figure 6A. The residual ammonia concentration in the tail gas at the reaction outlet was 105 ppm.

[0206] In this example, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0079 m. -1 , droplet average diameter D 32 The droplet size is 1821 μm, and the droplet size distribution D 10 is 1077 μm, D 50 is 2180 μm, D 90 The value was 2855 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.00156 m -1 , droplet average diameter D 32 The droplet size is 461 μm, and the droplet size distribution is D 10 is 427 μm, D 50 654 μm, D90 It was 883 μm.

[0207] [Example 40] Example 2 was repeated, but the nozzle outlet diameters of the 1st to 11th 2nd spray tubes of the 1st spray tube were set to 11.7 mm along the fluid direction, and the nozzle outlet diameters of the 12th to 14th 2nd spray tubes of the 1st spray tube were set to 11.9 mm. After operating the apparatus for one month, the residual ammonia concentration in the exhaust gas at the reaction outlet was 85 ppm. After operating the apparatus for 24 months, the residual ammonia concentration in the exhaust gas at the reaction outlet was 99 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.03.

[0208] In this embodiment, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.00161 m -1 , droplet average diameter D 32 The droplet size is 1722 μm, and the droplet size distribution is D 10 is 1128 μm, D 50 is 2310 μm, D 90 The value was 2785 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0014 m -1 , droplet average diameter D 32 The droplet size is 777 μm, and the droplet size distribution is D 10 536 μm, D 50 is 841 μm, D 90 It was 998 μm.

[0209] [Comparative Example 1] Example 1 was repeated, but the ammonia absorption tower was configured in a two-stage structure as shown in Figure 1. The spray liquid input pressures at the spray liquid inlets of sprayers 3a, 3b, 3c, and 3d were 0.04 MPaG, 0.044 MPaG, 0.046 MPaG, and 0.051 MPaG, respectively. The spray liquid discharge pressure was 0.02 MPaG, and the nozzle outlet diameter was 14.2 mm. In the initial stages of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 400 ppm. After 24 months of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 529 ppm.

[0210] In this comparative example, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0033 m -1 , droplet average diameter D 32 The droplet size is 2976 μm, and the droplet size distribution is D 10 is 1298 μm, D 50 3174 μm, D 90 The value was 3990 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0008 m -1 , droplet average diameter D 32 The droplet size is 742 μm, and the droplet size distribution is D 10 523 μm, D 50 is 882 μm, D 90 The size was 1050 μm.

[0211] [Comparative Example 2] Example 2 was repeated, but the ammonia absorption tower was a single-stage structure as shown in Figure 2. The spray liquid input pressures at the spray liquid inlets of sprayers 3a, 3b, 3c, 3d, 3e, and 3f were 1.202 MPaG, 1.205 MPaG, 1.209 MPaG, 1.214 MPaG, 1.217 MPaG, and 1.220 MPaG, respectively, and the spray liquid spray pressure was 0.076 MPaG. In the initial stages of operation, the residual ammonia concentration in the exhaust gas at the reaction outlet was 85 ppm. After 24 months of operation, the residual ammonia concentration in the tail gas at the reaction outlet was 96 ppm. However, 1.5% ammonium sulfate was detected in the condensate of the tail gas from the ammonia absorption tower outlet.

[0212] In this comparative example, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0263 m -1 , droplet average diameter D 32 The droplet size is 369 μm, and the droplet size distribution is D 10 is 232 μm, D 50 is 550 μm, D 90 The value was 1239 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0052 m -1 , droplet average diameter D 32The droplet size is 231 μm, and the droplet size distribution is D 10 is 149 μm, D 50 315 μm, D 90 The size was 436 μm.

[0213] [Comparative Example 3] The procedure for Example 1 was repeated, and the spray inlets 18 of sprayers 3a, 3c and 3b, 3d were located on the same side of the ammonia absorption tower, meaning the fluid direction in the first spray tube was the same, and the positions of the spray nozzles of sprayers 3a, 3b, 3c, 3d were substantially the same (see Figure 1). In addition, the nozzle positions at the ends of the third spray tubes of sprayers 3a, 3c and sprayers 3b, 3d coincided in cross-section (see Figure 5). The residual ammonia concentration in the exhaust gas at the reaction outlet after the apparatus was operated for one month was 85 ppm. The residual ammonia concentration in the exhaust gas at the reaction outlet after the apparatus was operated for 24 months was 253 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.13.

[0214] In this comparative example, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0038 m. -1 , droplet average diameter D 32 The droplet size is 1386 μm, and the droplet size distribution is D 10 523 μm, D 50 is 1725 μm, D 90 The value was 2831 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0008 m -1 , droplet average diameter D 32 The droplet size is 545 μm, and the droplet size distribution is D 10 is 130 μm, D 50 is 680 μm, D 90 The size was 1454 μm.

[0215] [Comparative Example 4] The procedure for Example 2 was repeated, but the spray inlets 18 of sprayers 3a, 3c, and 3e and the spray inlets 18 of sprayers 3b, 3d, and 3f were positioned on the same side of the ammonia absorption tower, i.e., the fluid direction within the first spray pipe was the same. The projections of the spray inlets of sprayers 3a, 3b, 3c, 3d, 3e, and 3f were made to substantially coincide (see Figure 2). In addition, the nozzle projections at the ends of the third spray pipes of sprayers 3a and 3c and the nozzle projections at the ends of the third spray pipes of sprayers 3b and 3d were made to coincide in cross-section (see Figure 5). After operating the apparatus for one month, the residual ammonia concentration in the exhaust gas at the reaction outlet was 73 ppm. After operating the apparatus for 24 months, the residual ammonia concentration in the exhaust gas at the reaction outlet was 223 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.13.

[0216] In this comparative example, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0039 m -1 , droplet average diameter D 32 The droplet size is 1356 μm, and the droplet size distribution is D 10 is 521 μm, D 50 1856 μm, D 90 The value was 2913 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0008 m -1 , droplet average diameter D 32 The droplet size is 536 μm, and the droplet size distribution is D 10 It is 137 μm, D 50 649 μm, D 90 The size was 1450 μm.

[0217] [Comparative Example 5] The procedure for Example 2 was repeated, but the projection angles of the spray inlets 18 of sprayers 3a, 3c, and 3e and the spray inlets 18 of sprayers 3b, 3d, and 3f were 30°. That is, the fluid direction of the first spray pipe of the corresponding sprayer was set to 30°, so that the projection of the tip of the third spray pipe of the sprayer did not coincide, as shown in Figure 8B. After operating the apparatus for one month, the residual ammonia concentration in the exhaust gas at the reaction outlet was 130 ppm. After operating the apparatus for 24 months, the residual ammonia concentration in the tail gas at the reaction outlet was 343 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.15.

[0218] In this comparative example, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0034 m -1 , droplet average diameter D 32 The droplet size is 1672 μm, and the droplet size distribution is D 10 is 540 μm, D 50 1738 μm, D 90 The value was 3213 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0008 m -1 , droplet average diameter D 32 The droplet size is 436 μm, and the droplet size distribution is D 10 is 189 μm, D 50 649 μm, D 90 The size was 1550 μm.

[0219] [Comparative Example 6] Example 2 was repeated, but the projection angles of the spray inlets 18 of sprayers 3a, 3c, and 3e and the spray inlets 18 of sprayers 3b, 3d, and 3f were 90°. That is, the fluid direction of the first spray pipe of the corresponding sprayer was 90°. The projection of the end of the third spray pipe of the sprayer was made not to match. After operating the apparatus for one month, the residual ammonia concentration in the exhaust gas at the reaction outlet was 110 ppm. After operating the apparatus for 24 months, the residual ammonia concentration in the exhaust gas at the reaction outlet was 293 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.10.

[0220] In this comparative example, when measured at a vertical distance of 3000 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0035 m -1 , droplet average diameter D 32 The droplet size is 1582 μm, and the droplet size distribution is D 10 is 640 μm, D 50 is 1714 μm, D 90 The value was 3138 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0009 m. -1 , droplet average diameter D 32 The droplet size is 461 μm, and the droplet size distribution is D 10 is 259 μm, D 50 is 618 μm, D 90 The size was 1489 μm.

[0221] [Comparative Example 7] Example 2 was repeated, except that the projection angle of the spray inlet 18 of sprayers 3a, 3c, and 3e and the spray inlet 18 of sprayers 3b, 3d, and 3f was 120°. That is, the fluid direction of the corresponding first spray tube of the sprayer was 90°. The projection angle of the spray inlet 18 of sprayer 3f was set to 120°, that is, the fluid direction of the corresponding first spray tube of the sprayer was set to 90°, as shown in Figure 8B, so that the projection of the end of the third spray tube of the sprayer did not coincide. After operating the apparatus for one month, the residual ammonia concentration in the tail gas at the reaction outlet was 132 ppm. After operating the apparatus for 24 months, the residual ammonia concentration in the tail gas at the reaction outlet was 353 ppm. The ratio of acid consumption after 24 months of operation to acid consumption after 1 month of operation was 1.15.

[0222] In this comparative example, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere was 0.0032 m -1 , droplet average diameter D 32 The droplet size is 2522 μm, and the droplet size distribution is D 10 is 678 μm, D 50 is 2924 μm, D 90 The value was 3738 μm. Furthermore, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere had a extinction coefficient of 0.0006 m -1, droplet average diameter D 32 The droplet size is 491 μm, and the droplet size distribution is D 10 is 259 μm, D 50 876 μm, D 90 The size was 1573 μm. [Brief explanation of the drawing]

[0223] [Figure 1] This is a schematic front view of a conventional ammonia absorption tower. [Figure 2] This is a schematic front view of a conventional ammonia absorption tower. [Figure 3a] This is a schematic front view of the ammonia absorption tower of the present invention. [Figure 3b] This is a schematic front view of the ammonia absorption tower of the present invention. [Figure 4A] This is a schematic front view of the ammonia absorption tower of the present invention. [Figure 4B] This is a schematic front view of the ammonia absorption tower of the present invention. [Figure 5] This is a schematic top view of the spraying device of the present invention. [Figure 6A] This is a schematic top view of the spraying device of the present invention. [Figure 6B] This is a schematic top view of the spraying device of the present invention. [Figure 7] This is a schematic top view of the spraying device of the present invention. [Figure 8A] This is a schematic top view of a spraying apparatus in a comparative example. [Figure 8B] This is a schematic top view of a spraying apparatus in a comparative example. [Figure 9A] This is a schematic top view of a conventional nozzle. [Figure 9B] This is a schematic front view of a conventional nozzle. [Figure 10A] This is a schematic top view of a conventional spraying device. [Figure 10B] This is a detailed top view of a conventional spraying device. [Figure 11A] This is a schematic top / front view showing two rotation modes of the nozzle of the present invention. [Figure 11B] This is a schematic top view of the spraying device. [Figure 11C] This is a detailed diagram of a schematic top view of one of the spraying devices of the present invention. [Figure 11D] This is a detailed diagram of a schematic top view of another spraying device of the present invention. [Figure 11E] This is a detailed diagram of a schematic top view of another spraying device of the present invention.

Claims

1. A process for manufacturing nitriles, The process involves subjecting hydrocarbon raw materials to an ammoxidation reaction to produce a reaction product containing nitriles (called the reaction process), The process includes supplying the reaction product from a gas inlet to an absorption device, spraying a spray liquid onto the reaction product via a spray device within the absorption device to cool the reaction product and form an absorption atmosphere (referred to as a cooling step), Here, when measured at a vertical distance of 3000 mm from the gas inlet, the extinction coefficient of the absorbing atmosphere is 0.004–0.02 m. －１ (Preferably 0.006-0.018 m) －１ ) is a process.

2. When measured at a position 3000 mm vertically from the gas inlet, the absorption atmosphere has a droplet average diameter D ３２ of 400 - 2600 μm (preferably 600 - 2400 μm), and / or when measured at a position 3000 mm vertically from the gas inlet, the absorption atmosphere has a droplet size distribution D １０ of 150 - 1500 μm, D ５０ of 700 - 3000 μm, D ９０ of 1400 - 3600 μm (preferably D １０ of 250 - 1400 μm, D ５０ of 800 - 2800 μm, D ９０ of 1600 - 3500 μm). The manufacturing process according to claim 1.

3. When measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere has an extinction coefficient of 0.001 to 0.004 m. －１ (Preferably 0.0015 to 0.0035 m) －１） The absorption atmosphere has and / or, when measured at a vertical distance of 8500 mm from the gas inlet, the average droplet diameter D ３２ The droplet size distribution D is 200-1400 μm (preferably 400-1000 μm), and / or, when measured at a vertical distance of 8500 mm from the gas inlet, the absorption atmosphere is 200-1400 μm, and / or the droplet size distribution D is 200-1400 μm, and / or the absorption atmosphere is 200-1400 μm, and / or the droplet size distribution D is 200-1 １０ is 100-1000 μm, D ５０ is 300-1800 μm, D ９０ The thickness is 500 to 2200 μm (preferably D １０ is 200-600 μm, D ５０ 400-1400 μm, D ９０ The manufacturing process according to claim 1, wherein the thickness is 600 to 1800 μm.

4. The spraying device has a spray liquid inlet and A first spray pipe that communicates with the spray liquid inlet, Multiple second spray pipes that are in fluid communication with the first spray pipe and extend perpendicularly to the first spray pipe along both sides of the first spray pipe, Multiple third spray pipes are in fluid communication with the second spray pipe and extend perpendicularly to the second spray pipe along both sides of the second spray pipe, The manufacturing process according to claim 1, further comprising a nozzle located at the end of the third spray pipe and in fluid communication with it.

5. Between two adjacent second spray pipes, the straight-line distance M between any end of a third spray pipe on one second spray pipe and any end of a third spray pipe on the other adjacent second spray pipe is 320 mm or more (preferably 350 mm or more), and / or, the nozzles are identical or different from each other and each independently has a spray liquid discharge rate of 0.5 to 7.5 tons / hour (preferably 0.9 to 6.5 tons / hour), and / or, the nozzles are identical or different from each other and each independently has a discharge rate of 0.0 at the nozzle outlet. The manufacturing process according to claim 4, wherein the spray liquid discharge pressure is 3 to 0.85 MPaG (preferably 0.04 to 0.65 MPaG), and / or the spray liquid input pressure at the spray liquid inlet is controlled to 0.06 to 1.00 MPaG (preferably 0.12 to 0.90 MPaG, more preferably 0.18 to 0.80 MPaG), and / or the difference (absolute value) of the spray liquid input pressure between the spray liquid inlets of any two spraying devices is less than 0.024 MPa (preferably less than 0.018 MPa, more preferably less than 0.012 MPa).

6. The manufacturing process according to claim 1, wherein a plurality of (e.g., 2 to 10, preferably 4 to 8) spraying devices are arranged in layers within the absorber at predetermined vertical intervals along the central axis of the absorber, and / or the vertical distance between two adjacent spraying devices (calculated as the vertical distance between the spray liquid inlets of the spraying devices) is 650 to 1350 mm (preferably 750 to 1200 mm).

7. The manufacturing process according to claim 4, wherein in a cross-section obtained by cutting the absorbent device in a direction perpendicular to its central axis, at least one (preferably all) selected from the first spray tube, second spray tube, and third spray tube of any one of the plurality of spray devices and at least one (preferably all) selected from the first spray tube, second spray tube, and third spray tube of the other plurality of spray devices substantially coincide in the projection in said cross-section.

8. The manufacturing process according to claim 7, wherein all nozzles of one spraying device and all nozzles of any other spraying device substantially coincide in the projection on the cross-section, and / or two nozzles whose projections substantially coincide have the same spray diameter, and / or two nozzles whose projections substantially coincide have the same spray liquid rotation direction.

9. The manufacturing process according to claim 1, wherein the vertical distance between the gas inlet and the spray liquid inlet of the spraying device (if there are multiple spraying devices, this refers to the spraying device closest to the gas inlet) is 800 to 6000 mm (preferably 1000 to 5000 mm), and / or the inner diameter of the gas inlet is 800 to 1900 mm (preferably 900 to 1700 mm), and / or the linear velocity of the reaction product in the absorption device is 0.6 to 1.5 m / s (preferably 0.7 to 1.3 m / s), and / or the weight ratio of the spray liquid to the reaction product is 15 to 25:

1.

10. The manufacturing process according to claim 1, wherein no mechanical components that could substantially affect the gas flow are located in the internal space between the gas inlet and the spraying device of the absorber (or, if there are multiple spraying devices, the spraying device closest to the gas inlet).

11. The manufacturing process according to claim 7, wherein the angle between the projection on the cross-section of the spray liquid inlet of one spraying device and the projection on the cross-section of the spray liquid inlet of any other spraying device is 180 degrees.

12. The absorption device according to claim 11, wherein, among all spraying devices, the angle between the cross-sectional projections of the spray liquid inlet of any two odd-numbered spraying devices is 0°, the angle between the cross-sectional projections of the spray liquid inlet of any two even-numbered spraying devices is 0°, and the angle between the cross-sectional projection of the spray liquid inlet of any odd-numbered spraying device and the cross-sectional projection of the spray liquid inlet of any even-numbered spraying device is 180°.

13. The absorption device according to claim 11, wherein the nozzle comprises a nozzle inlet, a rotating chamber, and a nozzle outlet, and the rotating chamber is configured such that the spray liquid supplied from the nozzle inlet passes through the rotating chamber and is then discharged from the nozzle outlet while rotating.

14. The absorption device according to claim 11, wherein in at least one (preferably all) second spray tubes, two adjacent (preferably all) nozzles located on the same side of the second spray tube are configured to eject the spray liquid in the same rotational direction.

15. The absorption device according to claim 14, wherein all nozzles positioned on opposite sides of two adjacent second spray pipes are configured to eject the spray liquid in opposite rotational directions.

16. The absorption device according to claim 14, wherein in at least one (preferably all) second spray tubes, at least one (preferably all) nozzles located on one side of the second spray tube are configured to eject the spray liquid in rotational direction A, while at least one (preferably all) nozzles located on the opposite side of the second spray tube are configured to eject the spray liquid in rotational direction B, where rotational direction A is opposite to rotational direction B.

17. The absorption device according to claim 16, wherein, among all the nozzles of the spraying device, the number of nozzles that spray the spraying liquid in rotation direction A is equal to, or substantially equal to, the number of nozzles that spray the spraying liquid in rotation direction B.

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