Gas replacement process, gas replacement apparatus, and hydrogenation reaction process of nitro compounds

Abstract

The present invention relates to a gas replacement process, a gas replacement device, and the use of the gas replacement process or device in a hydrogenation reaction process for nitro compounds. The gas replacement process includes at least a first step of subjecting a stream to gas replacement in the presence of a first replacement gas, and then a second step of subjecting the stream to gas replacement in the presence of a second replacement gas, where V1 is the superficial velocity of the first replacement gas and V2 is the superficial velocity of the second replacement gas, and V2 / V1 is 1.5 or greater. The gas replacement process or device has advantages such as high gas replacement efficiency.

Description

[Technical Field]

[0001] The present invention relates to a gas replacement process, and more particularly to a degassing process. Furthermore, the present invention relates to a gas replacement apparatus, and to the use of a gas replacement process or apparatus in the hydrogenation reaction process of nitro compounds. [Background technology]

[0002] Aniline is an important basic organic chemical raw material and fine chemical intermediate, and can be used in the manufacture of more than 300 downstream products. It is widely used in industries such as dyes, pharmaceuticals, pesticides, explosives, spices, rubber, and synthetic materials. In recent years, with the rapid development of the polyurethane industry in China and around the world, aniline, one of the unsubstituted basic raw materials for its main raw material MDI (4,4-diphenylmethane diisocyanate), has seen remarkable and rapid development.

[0003] There are three commercial processes for producing aniline: the nitrobenzene catalytic hydrogenation process, the phenol ammonia process, and the iron powder reduction process. In particular, the iron powder reduction process is being gradually phased out due to the poor quality of the aniline produced. The phenol ammonia process is highly dependent on the source of phenol. The current nitrobenzene catalytic hydrogenation process is employed by most manufacturers. The nitrobenzene catalytic hydrogenation process is further divided into gas-phase catalytic hydrogenation and liquid-phase catalytic hydrogenation. The nitrobenzene liquid-phase catalytic hydrogenation process is mainly carried out by employing a noble metal catalyst in an anhydrous state and has the advantages of low reaction temperature, high catalyst support, long service life, and large plant production capacity, but has the disadvantages of high pressure requirements, the need to separate reactants from the catalyst and solvent, high plant operating costs, high catalyst prices, and a relatively large number of byproducts caused by excessively high catalytic activity. The fluidized bed gas-phase catalytic hydrogenation process is characterized by heating and vaporizing the raw material, nitrobenzene, and mixing it with hydrogen gas, then feeding it into a fluidized bed reactor containing a copper-silica gel catalyst to carry out hydrogenation and reduction reactions. This process has the advantages of improving heat transfer, controlling reaction temperature, avoiding localized overheating, reducing the formation of side reactions, and extending the service life of the catalyst, but it also has the disadvantages of relatively complex operation, severe catalyst wear, and relatively high operating and maintenance costs.

[0004] The gas-phase hydrogenation process for preparing aniline from nitrobenzene has been used in China for several decades, and the fluidized bed gas-phase catalytic hydrogenation process is employed by many aniline manufacturers in China.

[0005] Chinese patent application CN1528737A discloses an apparatus mainly comprising a fluidized bed reactor; a reaction feed gas inlet located at the bottom of the reactor; a first gas distributor located above the inlet; a second gas distributor located midway in the axial height of the reactor and dividing the reactor into two catalyst-concentrated phase regions; heat exchangers located in the two catalyst-concentrated phase regions inside the reactor; catalyst overflow devices located outside or inside the reactor and connected to the upper or lower catalyst-concentrated phase regions, respectively; and a gas-solid separation device.

[0006] Chinese patent application CN1634860A discloses a gas distributor in a fluidized bed for aniline synthesis and a process for synthesizing aniline, the gas distributor comprising a main pipe for transporting gas, branch pipes and annular pipes connected thereto for distributing the gas, and nozzles for injecting gas downward and nozzles for injecting gas upward, both of which are located on the annular pipe. [Overview of the Initiative]

[0007] The inventors of the present invention have found that in conventional fluidized bed reactors for aniline preparation, the reaction gas raw materials enter the fluidized bed from a distributor at the bottom, come into contact with the catalyst and react to produce aniline as the product gas, and the catalyst is prone to carbon deposition and deactivation. As a result, the fluidized bed reactor needs to be stopped at intervals for regeneration and activation, making long-term operation difficult. Therefore, the key to solving the problem of long-term operation of aniline reactors is the ability to complete the regeneration and activation of the aniline catalyst in a timely manner and on the line.

[0008] The inventors of this invention also found that in the reaction, regeneration, and activation processes, it is necessary to introduce three different components, namely nitrobenzene and hydrogen, and oxygen and hydrogen, respectively, and that if oxygen comes into contact with flammable and explosive gases, the risk of explosion easily arises, and therefore, after these three stages are completed, it is necessary to efficiently degass the preceding stage. As a result, the raw material gas and product gas encompassed with the catalyst particles coming from the reactor are effectively removed, the catalyst particles enter the regeneration unit and are regenerated, the air (oxygen) encompassed with the catalyst particles flowing out of the regeneration reactor is removed, and then the catalyst particles enter the activation unit. This invention is completed based on these findings.

[0009] Specifically, the present invention relates to the following aspects: 1. A gas replacement (e.g., volatilization or degassing) process, A first step (referred to as the first gas replacement step) for gas replacement of a stream (e.g., a liquid stream or, in particular, a solid stream of solid particles) to be replaced in the presence of a first replacement gas (e.g., gas or vapor or water vapor), The process includes at least a second step (referred to as the second gas replacement step) for gas replacement in the presence of a second replacement gas (e.g., gas, vapor, or water vapor), A gas replacement process in which, if V1 is the empty column velocity (absolute value, in m / s) of the first replacement gas and V2 is the empty column velocity (absolute value, in m / s) of the second replacement gas, then V2 / V1 ≥ 1.5, 100 ≥ V2 / V1 ≥ 2, 20 ≥ V2 / V1 ≥ 2.5, or 15 ≥ V2 / V1 ≥ 5.

[0010] 2. The first gas replacement step has an operating temperature of 0 to 700°C (preferably 80 to 400°C) and an operating pressure of 0 to 3 MPaG (preferably 0.01 to 1 MPaG), and / or In the first gas replacement step, the empty tower velocity (absolute value) V1 of the first replacement gas is 0.05 to 0.6 m / s (preferably 0.1 to 0.3 m / s), and the empty tower velocity (absolute value) of the stream being replaced is 0.02 to 0.2 m / s (preferably 0.05 to 0.1 m / s), and / or The second gas replacement step has an operating temperature of 0 to 700°C (preferably 80 to 400°C) and an operating pressure of 0 to 3 MPaG (preferably 0.01 to 1 MPaG), and / or A gas replacement process according to either of the above or below embodiments, wherein in the second gas replacement step, the empty tower velocity (absolute value) V2 of the second replacement gas is 0.8 to 10 m / s (preferably 1 to 3 m / s), and the empty tower velocity (absolute value) of the stream being replaced is 0.4 to 6 m / s (preferably 0.6 to 2.4 m / s).

[0011] 3. A gas replacement process according to either of the above or below embodiments, wherein in the first gas replacement step, the gas-solid fluidization characteristics are bubbling fluidization or turbulent fluidization, and the solid content is in the range of 0.25 to 0.6, and / or in the second gas replacement step, the gas-solid fluidization characteristics are turbulent fluidization or fast fluidization, and the solid content is in the range of 0.02 to 0.3.

[0012] 4. A gas replacement process according to any of the above or below embodiments, wherein the first replacement gas and the stream to be replaced are in countercurrent or parallel contact (preferably in countercurrent contact), and the second replacement gas and the stream to be replaced are in countercurrent or parallel contact (preferably in parallel contact).

[0013] 5. The first gas replacement step and the second gas replacement step are performed in the same vessel (e.g., in different regions) or in different vessels, preferably in the same vessel (e.g., in different regions), and / or the first gas replacement step and the second gas replacement step are in gas-phase communication (particularly headspace gas-phase communication), and / or A gas replacement process according to either of the above or below embodiments, wherein the operating pressure of the first gas replacement step and the operating pressure of the second gas replacement step are basically the same.

[0014] 6. A gas replacement process according to any of the above or subsequent embodiments, further comprising one or more gas replacement steps (referred to as additional gas replacement steps) performed before the first gas replacement step, after the first gas replacement step, and before the second gas replacement step, and / or after the second gas replacement step.

[0015] 7. Gas replacement equipment (e.g., stripper or degassing tank), The system comprises at least a first gas displacement region (in particular a first vertical gas displacement region) and a second gas displacement region (in particular a second vertical gas displacement region) (for example, connected in a series or sequence), The inlet for the stream to be replaced in the first gas replacement area is located at the top of the first gas replacement area, and the exhaust port for the replaced stream in the second gas replacement area is located at the top of the second gas replacement area; and the cross-sectional area of ​​the central part of the first gas replacement region (unit: m²) 2 Let A1 be the central part of the second gas replacement region, and the cross-sectional area (in units of m²) of the central part of the second gas replacement region. 2 A gas replacement device where, if A2 is the value of A2, then 100 ≥ A2 / A1 ≥ 1.5, 50 ≥ A2 / A1 ≥ 2.5, or 15 ≥ A2 / A1 ≥ 5.

[0016] 8. The inlet for the replacement gas in the first gas replacement area is located at the bottom of the first gas replacement area, and the inlet for the replacement gas in the second gas replacement area is located at the bottom of the second gas replacement area, and / or The exhaust port for the replaced stream of the first gas replacement area is located at the bottom or base (e.g., the bottom) of the first gas replacement area, and the inlet for the stream being replaced in the second gas replacement area (the replaced stream from the previous gas replacement area, e.g., the replaced stream from the first gas replacement area) is located at the bottom or base (e.g., the bottom) of the second gas replacement area, and / or A gas replacement apparatus according to either the above or below embodiment, wherein the exhaust port for the gas phase of the first gas replacement area is located at the top of the first gas replacement area, and the exhaust port for the gas phase of the second gas replacement area is located at the top of the second gas replacement area.

[0017] 9. The exhaust port for the gas phase of the first gas replacement region is in contact with the exhaust port for the gas phase of the second gas replacement region (preferably, the exhaust port for the gas phase of the first gas replacement region is in direct contact with the exhaust port for the gas phase of the second gas replacement region, more preferably, there is at least one passage between the headspace of the first gas replacement region and the headspace of the second gas replacement region, and, The at least one passage is configured such that the headspace gas phase of the first gas replacement region enters the headspace of the second gas replacement region, and / or the headspace gas phase of the second gas replacement region enters the headspace of the first gas replacement region, more preferably the first gas replacement region and the second gas replacement region share a headspace), and / or, The exhaust port for the replaced stream of the first gas replacement region is in contact with the inlet for the stream being replaced in the second gas replacement region (preferably the exhaust port for the replaced stream of the first gas replacement region is in direct contact with the inlet for the stream being replaced in the second gas replacement region, more preferably there is at least one passage between the first gas replacement region and the second gas replacement region, and, A gas replacement apparatus according to either of the above or below embodiments, wherein the at least one passage is configured to allow the replaced stream of the first gas replacement region to enter the second gas replacement region as a stream to be replaced.

[0018] 10. The first gas replacement area and the second gas replacement area may be separated and arbitrarily arranged in different containers (e.g., different strippers or degassing tanks), or the first gas replacement area and the second gas replacement area may be arranged together in the same container (e.g., in the same stripper or degassing tank), and / or A gas replacement apparatus according to either of the above or below embodiments, wherein the first gas replacement region and the second gas replacement region are arranged together in the same container, and at least one partition structure member (e.g., a plate-shaped or ring-shaped partition structure member) is present between the first gas replacement region and the second gas replacement region.

[0019] 11. A gas replacement apparatus according to any of the above or subsequent embodiments, wherein the central axis direction of the first gas replacement area is substantially parallel to the central axis direction of the second gas replacement area, and / or, in a direction perpendicular to the horizontal plane, the inlet for the replacement gas of the first gas replacement area is at substantially the same height as or above the inlet for the replacement gas of the second gas replacement area, or the bottom of the first gas replacement area is at substantially the same height as or above the bottom of the second gas replacement area.

[0020] 12. A gas replacement apparatus according to any of the above or subsequent embodiments, further comprising one or more gas replacement areas (referred to as additional gas replacement areas) before the first gas replacement area, after the first gas replacement area, and before the second gas replacement area, and / or after the second gas replacement area.

[0021] 13. The flow disturbance structural member is positioned within the first gas displacement region and / or the second gas displacement region and / or an additional gas displacement region. A gas replacement device according to any of the above or subsequent embodiments, wherein the flow disturbance structural member comprises at least one (e.g., 1 to 1000 or 4 to 100) flow rectifiers (e.g., selected from at least one of streamlined flow rectifiers, diamond flow rectifiers, and inclined baffle mixed flow flow rectifiers) and connecting components for fixing the at least one flow rectifier to a corresponding gas replacement region (e.g., the first gas replacement region or the second gas replacement region) and / or to each other (if there are multiple flow rectifiers).

[0022] 14. The streamlined flow rectifier is selected from at least one of the following: a combination of two semiellipsoids, a combination of one semiellipsoid and one cone, a combination of one semiellipsoid and one arc-shaped streamlined body, and a combination of one semiellipsoid and one projectile, preferably a combination of one semiellipsoid and one projectile, and / or The diamond-shaped flow rectifier is selected from at least one of a combination of two pyramids, a combination of two truncated pyramids, and a combination of one pyramid and one truncated pyramid, preferably a combination of two pyramids, and / or The aforementioned inclined baffle mixed-flow type flow rectifier is a baffle inclined with respect to a horizontal plane (for example, the inclination angle with respect to the horizontal plane is 0 to 60°, preferably 10 to 40°), and the gas replacement device is according to either the above or below embodiment.

[0023] 15. The central axis direction of at least one flow rectifier substantially coincides with the central axis direction of the corresponding gas displacement region (e.g., the first gas displacement region or the second gas displacement region), and / or At least one of the flow rectifiers is at least one through Flow channel(For example, through holes) (preferably arranged along the central axis direction of the corresponding gas replacement region (for example, the first gas replacement region or the second gas replacement region)), preferably having a cross-sectional area of ​​the through passage (if there are multiple such through passages, the sum of the cross-sectional areas of the multiple such through passages, in units of m 2 The maximum cross-sectional area of ​​the corresponding flow rectifier (in units of m²) 2 The ratio to ) is 1-30:100 or 3-15:100, and / or, In each flow disturbance structural member, the maximum cross-sectional area of ​​the flow rectifier (if there are multiple flow rectifiers, this is the sum of the maximum cross-sectional areas of the multiple flow rectifiers, and the unit is m) is specified. 2 The corresponding cross-sectional area (in units of m²) of the corresponding gas replacement region (for example, the first gas replacement region or the second gas replacement region) 2 The ratio to ) is 20-90:100 (preferably 45-65:100), and / or, In each flow disturbance structural member, if there are multiple flow rectifiers, the multiple flow rectifiers are arranged relative to each other in a predetermined manner (for example, in a random, triangular, square, rectangular, circular, or annular arrangement), and / or, One or more (e.g., 2 to 20, or 4 to 10) of the flow disturbance structural members are arranged along the central axis of the corresponding gas displacement region (e.g., the first gas displacement region or the second gas displacement region), and / or The perpendicular distance (in meters) between any two adjacent flow disturbance structural members along the central axis of the corresponding gas displacement region (e.g., the first gas displacement region or the second gas displacement region) is 2%H to 20%H. Herein, H is the height (in meters) of the corresponding gas replacement area (e.g., the first gas replacement area or the second gas replacement area), and / or if the height (in meters) of the first gas replacement area is H1 and the height (in meters) of the second gas replacement area is H2, then H2 / H1 ≥ 1 or 2 ≥ H2 / H1 ≥ 1, a gas replacement apparatus according to either of the above or below embodiments.

[0024] 16. Reaction systems (especially hydrogenation reaction systems for nitro compounds), The system comprises at least one reactor (preferably a fluidized bed reactor, particularly a reactor having a fluidized bed of catalyst particles) and at least one (e.g., 1 to 3 or 2) gas replacement devices communicating with the at least one reactor (e.g., configured to receive effluent from the at least one reactor, and particularly configured to receive spent catalyst particles from the at least one reactor) (e.g., communicating downstream), A reaction system in which at least one of the gas replacement devices is configured to carry out a gas replacement device for a gas replacement process according to either of the above or below embodiments, or is a gas replacement device according to either of the above or below embodiments.

[0025] 17. A hydrogenation process of nitro compounds, The process involves contacting a nitro compound (particularly nitrobenzene) as a reaction raw material with hydrogen gas and a hydrogenation catalyst to obtain a reaction product (e.g., an amino compound, particularly aniline) and a spent catalyst (called the hydrogenation reaction step), The process includes at least the step of subjecting a spent catalyst to gas replacement (e.g., degassing) in the presence of a replacement gas (referred to as the gas replacement step), The gas replacement step is carried out according to either the above-described or the following embodiment, or is carried out in a gas replacement apparatus according to either the above-described or the following embodiment, in which case the hydrogenation reaction process of a nitro compound is carried out.

[0026] 18. The reaction conditions for the hydrogenation reaction step are: an empty tower gas velocity of 0.2 to 0.8 m / s, a molar ratio of hydrogen gas to the reaction raw material (e.g., nitrobenzene) of 6 to 21, a reaction temperature of 220 to 280°C, a reaction pressure of 0.05 to 1 MPa (gauge pressure), the hydrogenation catalyst being selected from at least one of a copper-based supported catalyst, a nickel-based supported catalyst, and a precious metal-based supported catalyst, and / or the bulk density of the hydrogenation catalyst being 300 to 1200 kg / m³. 3and / or the average particle diameter of the hydrogenation catalyst is 30 to 800 μm (preferably 40 to 500 μm or 50 to 600 μm), and the mass percentage of catalyst particles having a particle diameter of less than 80 μm with respect to the total catalyst particles is 2% by weight or more (preferably 5 to 15% by weight), and / or the substitution gas is a gas or vapor (particularly, at least one selected from nitrogen gas, water vapor, carbon dioxide, methane, oxygen gas, and argon gas), and / or the nitro compound is at least one selected from compounds represented by the following formula (1), a hydrogenation reaction process according to any of the above or below-described embodiments.

[0027] R-NO2(1) In structural formula (1), R is an optionally substituted C 2-20 linear, branched or cyclic hydrocarbyl (preferably an optionally substituted C 4-20 cyclic hydrocarbyl, particularly an optionally substituted C 6-20 aryl, particularly an optionally substituted phenyl).

[0028] On the other hand, the present invention relates to the following embodiments: 1. A reactor for producing aniline by hydrogenation of nitrobenzene, comprising a fluidized bed reactor (3), a degassing tank (12) for used catalyst, a regenerator (13), a degassing tank (16) for activated catalyst, an activator (19), and an upflow pipe (21), wherein a dense phase reaction zone (4) located at the lower part, a particle sputtering transition zone (5) located in the middle part, and a dilute phase zone (7) located at the upper part are included in the fluidized bed reactor (3), the degassing tank (12) for used catalyst communicates with the fluidized bed reactor (3) and the regenerator (13) respectively, the degassing tank (16) for activated catalyst communicates with the regenerator (13) and the activator (19) respectively, and the upflow pipe (21) communicates with the activator (19) and the fluidized bed reactor (3) respectively.

[0029] 2. A reactor for producing aniline by hydrogenation of nitrobenzene, according to either of the above or below embodiments, characterized in that the fluidized bed reactor (3) includes a gas distributor (2), a heat exchange pipe (11), a sputter separation structural member (6), and a cyclone separator (9).

[0030] 3. A reaction apparatus for producing aniline by hydrogenation of nitrobenzene, characterized in that the degassing tank (12) for used catalyst includes a degassing downward flow region (31) and a degassing upward parallel flow region (32), and degassing baffle structural members (33) are provided in both the degassing downward flow region (31) and the degassing upward parallel flow region (32); and the degassing tank (16) for the catalyst to be activated includes a regenerating degassing downward flow region (51) and a regenerating degassing upward parallel flow region (52), and degassing baffle structural members (33) are provided in both the regenerating degassing downward flow region (51) and the regenerating degassing upward parallel flow region (52), according to either the above or the following embodiment.

[0031] 4. The degassing baffle structural member (33) is made up of multiple sets of flow rectifiers connected via connecting parts, and the flow rectifier is one or more of the following: a streamlined flow rectifier (41), a diamond-type flow rectifier (42), and an inclined baffle mixed-flow type flow rectifier (43), wherein the reaction apparatus for producing aniline by hydrogenation of nitrobenzene is according to any of the embodiments described above or below.

[0032] 5. A reaction method for producing aniline by hydrogenation of nitrobenzene, as described in either of the above or subsequent embodiments, characterized by comprising the following steps: (a) Vaporized nitrobenzene and hydrogen gas are introduced into the gas chamber as raw materials, and the catalyst is then pushed into the fluidized bed reactor (3) through a gas distributor (2) and fluidized, and subsequently reacted in the dense phase reaction region (4) to produce aniline products. Particle sputtering occurs at the top of the dense phase reaction region (4), forming a particle sputtering transition region (5), where the sputtered particles are efficiently blocked by the sputtering separation structure member (6) and return to the dense phase reaction region (4), allowing the catalytic action to proceed. A small portion of the unblocked particles passes through the sputtering separation structure member and enters the dilute phase region (7), where they are separated by the cyclone separator (9), and the particles return to the dense phase reaction region (4), and the crude product gas (8) flows out of the fluidized bed reactor (3) and is sent to the subsequent separation section; (b) After the catalyst is partially coked during the reaction, the coked catalyst is degassed in a degasser (12) for spent catalysts and introduced into a regenerator (13) into which oxygen is introduced, and the catalyst is regenerated by carbon combustion; (c) The regenerated catalyst is then introduced into a degasser (16) for the catalyst to be activated, where it is degassed, and then introduced into an activator (19) into which hydrogen gas is introduced, where the catalyst is activated, and the activated catalyst is introduced into a riser pipe (21), lifted up and returned to the fluidized bed reactor (3) to carry out the catalytic action.

[0033] 6. A reaction process for producing aniline by hydrogenation of nitrobenzene, as described in any of the above or below embodiments, characterized in that the catalyst is a metal-supported catalyst with copper as the main active component, the support is alumina or silica, the catalyst has an average particle size of 50 to 600 μm, and the content of particles smaller than 80 μm is 2% or more.

[0034] 7. A reaction process for producing aniline by hydrogenation of nitrobenzene, as described in any of the above or below embodiments, characterized in that the reaction conditions in the fluidized bed reactor (3) include the following: the empty tower gas velocity is 0.2 to 0.8 m / s, the molar ratio of hydrogen gas to nitrobenzene is 6 to 21, the average reaction temperature in the dense phase reaction region (4) is controlled to 220 to 280°C, the temperature near the gas distributor (2) is controlled to 320°C or less, and the reaction pressure in the dense phase reaction region (4) is 0.05 to 1 MPa.

[0035] 8. A reaction process for producing aniline by hydrogenation of nitrobenzene, as described in any of the embodiments described above or below, characterized in that the reaction conditions in the regenerator (13) include: an empty tower gas velocity of 0.1 to 0.6 m / s and an average regeneration temperature of 350 to 450°C; and the reaction conditions in the activator (19) include: an empty tower gas velocity of 0.1 to 0.6 m / s and an average activation temperature of 200 to 250°C.

[0036] 9. A reaction process for producing aniline by hydrogenation of nitrobenzene, as described in any of the above or below embodiments, characterized in that the ratio of the empty tower gas velocity in the degassing downward flow region (31) to the empty tower gas velocity in the degassing upward flow region (32) in the degassing tank (12) for used catalyst is 1 / 15 to 1, the degassing agent is one or more of nitrogen gas, water vapor, carbon dioxide, methane, and argon gas (as a mixture), and the gas components delivered from the fluidized bed reactor (3) are replaced.

[0037] 10. A reaction process for producing aniline by hydrogenation of nitrobenzene, as described in either of the above or below embodiments, wherein the ratio of the empty tower gas velocity in the regenerative degassing downward flow region (51) to the empty tower gas velocity in the regenerative degassing upward flow region (52) in the degassing tank (16) for the activated catalyst is 1 / 15 to 1, the degassing agent is one or more of nitrogen gas, water vapor, carbon dioxide, oxygen gas, and argon gas (as a mixture), and the oxygen-containing gas component carried from the regenerator (13) is replaced. [Effects of the Invention]

[0038] According to the gas replacement process or gas replacement apparatus of the present invention, the gas replacement efficiency (particularly the degassing efficiency) can generally be 90% or more, preferably 94% or more.

[0039] When used in the hydrogenation reaction of nitro compounds (e.g., the production of aniline by hydrogenation of nitrobenzene), the gas replacement process or gas replacement apparatus according to the present invention can achieve the objective of long-cycle production of continuous reaction, regeneration, and activation, while also achieving technical effects such as improved degassing efficiency (e.g., an increase of 7% or more) and a controllable amount of carbon deposition on the catalyst in the fluidized bed reactor. [Brief explanation of the drawing]

[0040] [Figure 1] Figure 1 is a schematic flow diagram of the hydrogenation reaction system of nitro compounds according to the present invention, and the hydrogenation of nitrobenzene, which produces aniline, is given as an example.

[0041] In Figure 1, 1: raw materials for vaporized nitrobenzene and hydrogen gas, 2: gas distributor, 3: fluidized bed reactor, 4: dense phase reaction region, 7: dilute phase region, 8: crude product gas, 9: cyclone separator, 10: dip leg, 11: heat exchange pipe, 12: degasser for spent catalyst, 13: regenerator, 15: fluidized gas for regeneration, 16: degasser for catalyst to be activated, 17: fluidized gas for activation, 19: activator, 20: rising gas, 21: rising pipe. Here, the degasser for spent catalyst or the degasser for catalyst to be activated is either the gas replacement apparatus of the present invention or the gas replacement process of the present invention is carried out. [Figure 2] Figure 2 is a schematic flow diagram of an embodiment of the gas replacement process (particularly the degassing process) of the present invention.

[0042] In Figure 2, 21 represents the first gas replacement process and 22 represents the second gas replacement process, separated by a partition. Furthermore, the black triangular arrows represent the main flow direction of the replacement gas; the hollow triangular arrows represent the main flow direction of the stream being replaced, for example, solid particles. The empty column velocity of the first replacement gas is denoted as V1, and the empty column velocity of the second replacement gas is denoted as V2. Depending on the situation, the first gas replacement process and / or the second gas replacement process can be carried out in the presence of a flow disturbance structure member (number 4 in the figure, for example, the flow disturbance structure member 33 described later in the present invention). [Figure 3] Figure 3 is a schematic flow diagram of an embodiment of the gas replacement apparatus of the present invention (particularly a degassing tank for spent catalysts or a degassing tank for activated catalysts).

[0043] Figure 3, 30: Partition structural member; 31: First gas replacement region; 321: Second gas replacement region; 33: Flow disturbance structural member (number in the figure: 4); 34: Inlet for the stream to be replaced in the first gas replacement region; 35: Exhaust port for the stream to be replaced in the second gas replacement region; 36: Inlet for the stream to be replaced in the second gas replacement region; 37: Exhaust port for the stream to be replaced in the first gas replacement region; 38: Exhaust port for the gas phase of the first gas replacement region; 39: Exhaust port for the gas phase of the second gas replacement region; 40: Shared headspace; 41: Flow rectifier (number in the figure: greater than 1). Furthermore, black triangular arrows represent the main flow direction of the replacement gas; hollow triangular arrows represent the main flow direction of the stream being replaced, for example, solid particles. The cross-sectional area of ​​the central part of the first gas replacement region is denoted as A1, and the cross-sectional area of ​​the central part of the second gas replacement region is denoted as A2. [Figure 4] Figure 4 is a schematic diagram of one embodiment of the streamlined flow rectifier of the present invention, where 42 represents the through-flow channel. [Figure 5] Figure 5 is a schematic diagram of one embodiment of the diamond-shaped flow rectifier of the present invention, where 42 represents the through-flow channel. [Figure 6] Figure 6 is a schematic diagram of one embodiment of the inclined baffle diagonal flow type flow rectifier of the present invention. [Modes for carrying out the invention]

[0044] [Detailed explanation] Embodiments of the present invention will be described in detail below. However, it should be understood that the scope of the present invention is not limited by the embodiments but is defined by the appended claims.

[0045] All publications, patent applications, patents, and other references referenced herein are incorporated herein by reference in their entirety. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the invention pertains. In case of any conflict, this specification, including its definitions, shall prevail.

[0046] Where this specification derives materials, substances, processes, procedures, apparatus, elements, etc., using expressions such as "known to those skilled in the art," "prior art," or similar terms, the subject matter thus derived includes those that were conventionally used in the art at the time of filing of this application. It is also intended to include those that, even if not currently in common use, will become known in the art as being suitable for similar purposes.

[0047] In the context of this Specified, the term “substantially” means the tolerance of deviations that are acceptable to or reasonable to a person skilled in the art, such as deviations of ±10%, ±5%, ±1%, ±0.5%, or ±0.1%.

[0048] In the context of this specification, the term "gas replacement" refers to the replacement of gaseous or easily vaporizable substances (collectively referred to as hazardous substances) contained in a stream (referred to as the stream being replaced) with a gas (referred to as the replacement gas) in order to remove hazardous substances from the stream being replaced. Here, gas replacement usually includes degassing, water vapor evaporation, etc., and in particular refers to degassing.

[0049] In the context of this specification, gas replacement efficiency (e.g., degassing efficiency) refers to the ratio of the replacement gas (e.g., degassing agent) remaining in the gas replacement apparatus (e.g., degassing tank) after gas replacement is completed, to the total amount of gas. The closer the gas replacement efficiency is to 1, the better the effect of gas replacement. Here, a process for measuring gas replacement efficiency may be, for example, a process of analyzing the ratio of the amount of replacement gas to the total amount of gas in the gas replacement apparatus using a gas analyzer such as a gas-phase chromatograph.

[0050] In the context of this specification, the term "empty tower velocity" refers to the velocity at which a gas flows through a region, obtained by dividing the flow rate per unit time through that region by the cross-sectional area of ​​that region, without considering solids such as solid catalyst particles.

[0051] In the context of this specification, the term "solids content" refers to the volume fraction of solid particles in a gas-solid two-phase mixture. The solids content at any given position is given by the formula

[0052]

number

[0053] It can be calculated by the following: Here, ΔP is the difference (in Pa) between the pressure (gauge pressure) at the lower position Δz / 2 and the pressure (gauge pressure) at the upper position Δz / 2, Δz is the distance (in m) between the point at the lower position Δz / 2 and the point at the upper position Δz / 2, ρ P This is the particle density of solid particles (unit: kg / m³). 3 ), ρ is the density of the gas (unit: kg / m³). 3 ), 1-ε is the solids content, ε is the gaseous content, the sum of the solids and gaseous content is 1, and g is the acceleration due to gravity (generally 9.8 m / s²). 2 It is the absolute value of (which takes the value of ).

[0054] In the context of this specification, “vertical” means that the central axis is substantially perpendicular to the horizontal plane.

[0055] In the context of this specification, if H is the vertical distance (in meters) from the bottom to the top of a gas-displaced region along the central axis of a gas-displaced region, then the portion above and below the 1 / 2H point, for example between 25%H, is called the middle portion, the portion between the middle portion and the top is called the upper portion, and the portion between the middle portion and the bottom is called the lower portion.

[0056] In the context of this specification, the expression "optionally substituted" means halogen, hydroxy, mercapto, amino, aminocarbonyl, nitro, oxo, thio, cyano, C 1-6 Linear or branched (halo)alkane (oxy, thio, amino, carbonyl) group, C 2-6 Linear or branched (halo)alkene (oxy, thio, amino, carbonyl) group, C 2-6 Linear or branched (halo) alkyne (oxy, thio, amino, carbonyl) group, C 3-20 Cycloalkyl, C 3-20 Cycloalkane (oxy, thio, amino) group, C 3-20 Cycloalkyl C 1-6 Linear or branched (halo)alkane (oxy, thio, amino, carbonyl) group, C 3-20 Cycloalkyl C 2-6 Linear or branched (halo)alkene (oxy, thio, amino, carbonyl) group, C 3-20 Cycloalkyl C 2-6 Linear or branched (halo) alkyne (oxy, thio, amino, carbonyl) group, C 3-20 Cycloalkenyl, C 3-20 Cycloalkene (oxy, thio, amino) group, C 3-20 Cycloalkenyl C 1-6 Linear or branched (halo)alkane (oxy, thio, amino, carbonyl) group, C 3-20 Cycloalkenyl C 2-6 Linear or branched (halo)alkene (oxy, thio, amino, carbonyl) group, C 3-20 Cycloalkenyl C 2-6 Linear or branched (halo) alkyne (oxy, thio, amino, carbonyl) group, C 6-20 Ariel, C 6-20Arene (oxy, thio, amino) group, C 6-20 Aryl C 1-6 Linear or branched (halo)alkane (oxy, thio, amino, carbonyl) group, C 6-20 Aryl C 2-6 Linear or branched (halo)alkene (oxy, thio, amino, carbonyl) group, C 6-20 Aryl C 2-6 Linear or branched (halo) alkyne (oxy, thio, amino, carbonyl) group, C 4-20 Heteroaryl, C 4-20 Heterearene (oxy, thio, amino) group, C 4-20 Heteroaryl C 1-6 Linear or branched (halo)alkane (oxy, thio, amino, carbonyl) group, C 4-20 Heteroaryl C 2-6 Linear or branched (halo)alkene (oxy, thio, amino, carbonyl) group, C 4-20 Heteroaryl C 2-6 Linear or branched (halo) alkyne (oxy, thio, amino, carbonyl) group, C 2-20 Heterocyclyl, C 2-20 Heterocycle (oxy, thio, amino) groups, C 2-20 Heterocyclyl C 1-6 Linear or branched (halo)alkane (oxy, thio, amino, carbonyl) group, C 2-20 Heterocyclyl C 2-6 Linear or branched (halo)alkene (oxy, thio, amino, carbonyl) groups and C 2-20 Heterocyclyl C 2-6 This indicates that the molecule is optionally substituted with one or more substituents (e.g., 1-5, 1-4, 1-3, 1-2, or 1) selected from linear or branched (halo) alkyne (oxy, thio, amino, carbonyl) groups. When multiple substituents are present, two adjacent substituents (e.g., the molecular chain ends of two substituents) can bond to each other to form a divalent substituent group structure. For example, two adjacent C 1-6 Linear or branched alkyl groups can be bonded to each other to form the corresponding alkylene structure. Alternatively, for example, two adjacent C 1-6Linear or branched alkyloxy groups can form the corresponding alkylenedioxy group structure, for example, two adjacent C 1-6 Linear or branched alkylamino groups can form the corresponding alkylenediamino structure, for example, two adjacent C 1-5 Linear or branched alkylthio groups can form the corresponding alkylenedithio structure, and so on. Preferred substituents include, for example, halogen, hydroxy, mercapto, amino, thio, oxo, or C 1-6 Examples include linear or branched (halo)alkane (oxy, thio, amino, carbonyl) groups. Here, "(halo)alkane (oxy, thio, amino, carbonyl) group" means alkyl, haloalkyl, alkyloxy, alkylthio, alkylamino, alkylcarbonyl, haloalkyloxy, haloalkylthio, haloalkylamino, or haloalkylcarbonyl, and "(halo)alkene (oxy, thio, amino, carbonyl) group" means alkenyl, haloalkenyl, alkenyloxy, alkenylthio, alkenylamino, alkenylcarbonyl, haloal This refers to alkennyoxy, haloalkenylthio, haloalkenylamino, or haloalkenylcarbonyl. "(halo)alkyne (oxy, thio, amino, carbonyl) group" refers to alkynyl, haloalkynyl, alkynyloxy, alkynylthio, alkynylamino, alkynylcarbonyl, haloalkynyloxy, haloalkynylthio, haloalkynylamino, or haloalkynylcarbonyl. "(oxy, thio, amino) group" refers to oxy, thio, or amino. Here, the expression "halo" includes monohalo, dihalo, trihalo, or perhalo, etc.

[0057] All percentages, proportions, ratios, etc., mentioned herein are in weight unless explicitly stated, and pressures are gauge pressures.

[0058] In the context of this specification, any two or more embodiments of the present invention can be combined in any combination, and the resulting technical solutions are part of the original disclosures herein and are within the scope of the invention.

[0059] According to one embodiment of the present invention, the present invention relates to a gas replacement process. Examples of gas replacement processes include water vapor volatilization or degassing, particularly degassing.

[0060] According to one embodiment of the present invention, the gas replacement process includes at least a first step (first gas replacement step) of subjecting the stream to be replaced to gas replacement in the presence of a first replacement gas, and a second step (referred to as the second gas replacement step) of subjecting the stream to be replaced to gas replacement in the presence of a second replacement gas. Here, the stream to be replaced can be, for example, a liquid stream or a solid stream, in particular solid particles, more specifically solid catalyst particles, and even more specifically solid catalyst particles having an average particle diameter of 30 to 800 μm. Furthermore, the average particle diameter is preferably 40 to 500 μm or 50 to 600 μm. For example, the average particle diameter can be determined by analyzing sampled solid catalyst particles using a particle size analyzer.

[0061] According to one embodiment of the present invention, the first replacement gas and the second replacement gas are identical or different from each other, independently selected from any gas, vapor, or water vapor that can be used in the art during gas replacement (particularly degassing), and may include, without limitation, nitrogen gas, water vapor, carbon dioxide, methane, oxygen gas, argon gas, air, or hydrogen gas.

[0062] According to one embodiment of the present invention, the gas replacement process further includes one or more gas replacement steps (referred to as additional gas replacement steps) performed before the first gas replacement step, after the first gas replacement step, and before and / or after the second gas replacement step. For this purpose, the first and second gas replacement steps are performed in a consecutive order, but one or more additional gas replacement steps may be inserted between these two steps as circumstances permit. Here, the additional gas replacement steps can be performed according to any process known in the art, or without particular limitation, according to the first gas replacement step or according to the second gas replacement step. Preferably, the first and second gas replacement steps are performed consecutively and directly. That is, no other gas replacement steps are inserted between the first and second gas replacement steps, the stream to be replaced passes through the first and second gas replacement steps, and the gas replacement is performed consecutively.

[0063] According to one embodiment, if the empty column velocity (absolute value, in m / s) of the first replacement gas is V1 and the empty column velocity (absolute value, in m / s) of the second replacement gas is V2, then V2 / V1 ≥ 1.5. Preferably, 100 ≥ V2 / V1 ≥ 2 or 20 ≥ V2 / V1 ≥ 2.5, and particularly 15 ≥ V2 / V1 ≥ 5.

[0064] According to one embodiment of the present invention, the operating temperature of the first gas replacement step is not particularly limited, but is generally 0 to 700°C, preferably 80 to 400°C.

[0065] According to one embodiment of the present invention, the operating pressure of the first gas replacement step is not particularly limited, but is generally 0 to 3 MPaG, preferably 0.01 to 1 MPaG.

[0066] According to one embodiment of the present invention, in the first gas replacement step, the empty column velocity (absolute value) V1 of the first replacement gas is generally 0.05 to 0.6 m / s, preferably 0.1 to 0.3 m / s.

[0067] According to one embodiment of the present invention, in the first gas replacement step, the empty tower velocity (absolute value) of the stream being replaced is generally 0.02 to 0.2 m / s, preferably 0.05 to 0.1 m / s.

[0068] According to one embodiment of the present invention, the operating temperature of the second gas replacement step is not particularly limited, but is generally 0 to 700°C, preferably 80 to 400°C.

[0069] According to one embodiment of the present invention, the operating pressure of the second gas replacement step is not particularly limited, but is generally 0 to 3 MPaG, preferably 0.01 to 1 MPaG.

[0070] According to one embodiment of the present invention, in the second gas replacement step, the empty column velocity (absolute value) V2 of the second replacement gas is generally 0.8 to 10 m / s, preferably 1 to 3 m / s.

[0071] According to one embodiment of the present invention, in the second gas replacement step, the empty tower velocity (absolute value) of the stream being replaced is generally 0.4 to 6 m / s, preferably 0.6 to 2.4 m / s.

[0072] According to one embodiment of the present invention, in the first gas replacement step, the gas-solid fluidization is characterized by bubbling fluidization or turbulent fluidization, and the solid content is generally in the range of 0.25 to 0.6.

[0073] According to one embodiment of the present invention, in the second gas replacement step, the gas-solid fluidization is characterized by turbulent fluidization or high-speed fluidization, and the solid content is generally in the range of 0.02 to 0.3.

[0074] According to one embodiment of the present invention, the first replacement gas and the stream being replaced are in countercurrent or parallel flow contact, preferably in countercurrent contact.

[0075] According to one embodiment of the present invention, the second replacement gas and the stream being replaced are in countercurrent or parallel contact, preferably parallel contact.

[0076] According to one embodiment of the present invention, the first gas replacement step and the second gas replacement step are performed in the same vessel (e.g., different regions) or in different vessels, respectively. Here, the first gas replacement step and the second gas replacement step are preferably performed in the same vessel (e.g., different regions).

[0077] According to one embodiment of the present invention, the first gas replacement step and the second gas replacement step are gas-phase communication, particularly headspace gas-phase communication. For this purpose, preferably the operating pressure of the first gas replacement step and the operating pressure of the second gas replacement step are basically the same.

[0078] One embodiment of the present invention also relates to a gas replacement device. Here, examples of gas replacement devices include, for example, a stripper and a degassing tank, and more specifically, a degassing tank.

[0079] According to one embodiment of the present invention, the gas replacement apparatus comprises at least a first gas replacement region and a second gas replacement region. Here, the first gas replacement region and the second gas replacement region can be connected according to any process known in the art, specifically, for example, connected sequentially or in a series. In addition, a first vertical gas replacement region may be specifically cited as the first gas replacement region; or a second vertical gas replacement region may be specifically cited as the second gas replacement region.

[0080] According to one embodiment of the present invention, the operating conditions of the first gas replacement region are not particularly limited and those well known to those skilled in the art can be directly applied, for example, the operating temperature is generally 0 to 700°C, preferably 80 to 400°C, and the operating pressure is generally 0 to 3 MPaG, preferably 0.01 to 1 MPaG.

[0081] According to one embodiment of the present invention, the empty tower velocity of the replacement gas in the first gas replacement region is not particularly limited and can be directly applied as is well known to those skilled in the art. For example, the empty tower velocity (absolute value) is generally 0.05 to 0.6 m / s, preferably 0.1 to 0.3 m / s.

[0082] According to one embodiment of the present invention, the operating conditions of the second gas replacement region are not particularly limited and those well known to those skilled in the art can be directly applied, for example, the operating temperature is generally 0 to 700°C, preferably 80 to 400°C, and the operating pressure is generally 0 to 3 MPaG, preferably 0.01 to 1 MPaG.

[0083] According to one embodiment of the present invention, the empty tower velocity of the replacement gas in the second gas replacement region is not particularly limited and can be directly applied as is well known to those skilled in the art. For example, the empty tower velocity (absolute value) is generally 0.05 to 10 m / s, 0.1 to 10 m / s, or 0.8 to 10 m / s, preferably 1 to 3 m / s.

[0084] According to one embodiment of the present invention, the gas replacement process carried out in the first gas replacement region is not particularly limited and can be carried out according to any process known to those skilled in the art, but is preferably carried out according to the first gas replacement step mentioned in any of the earlier embodiments of the present invention.

[0085] According to one embodiment of the present invention, the gas replacement process carried out in the second gas replacement region is not particularly limited and can be carried out according to any process known to those skilled in the art, but is preferably carried out according to the second gas replacement step mentioned in any of the earlier embodiments of the present invention.

[0086] According to one embodiment of the present invention, the inlet for the stream to be replaced in the first gas replacement region is located at the top of the first gas replacement region, and the exhaust port for the stream replaced in the second gas replacement region is located at the top of the second gas replacement region.

[0087] According to one embodiment of the present invention, the cross-sectional area of ​​the central portion of the first gas replacement region (unit is m 2 Let A1 be the central part of the second gas replacement region (unit: m²). 2If we let A2 be the value of A2 / A1, then 100 ≥ A2 / A1 ≥ 1.5. Preferably, 50 ≥ A2 / A1 ≥ 2.5 or 15 ≥ A2 / A1 ≥ 5.

[0088] According to one embodiment of the present invention, the inlet for the replacement gas of the first gas replacement area is located at the bottom of the first gas replacement area, and the inlet for the replacement gas of the second gas replacement area is located at the bottom of the second gas replacement area.

[0089] According to one embodiment of the present invention, the exhaust port of the replaced stream in the first gas replacement region is located at the bottom or base of the first gas replacement region, particularly at the bottom. The inlet of the replaced stream in the second gas replacement region is located at the bottom or base of the second gas replacement region, particularly at the bottom. Here, the replaced stream corresponds to the replaced material from the previous gas replacement region, for example, the replaced stream from the first gas replacement region.

[0090] According to one embodiment of the present invention, the exhaust port for the gas phase of the first gas replacement region is located at the top of the first gas replacement region, and the exhaust port for the gas phase of the second gas replacement region is located at the top of the second gas replacement region.

[0091] According to one embodiment of the present invention, an exhaust port for the gas phase of a first gas replacement region is in contact with an exhaust port for the gas phase of a second gas replacement region. Preferably, the exhaust port for the gas phase of the first gas replacement region is in direct contact with an exhaust port for the gas phase of the second gas replacement region, more preferably there is at least one passage between the headspace of the first gas replacement region and the headspace of the second gas replacement region, and the at least one passage is configured so that the headspace gas phase of the first gas replacement region enters the headspace of the second gas replacement region and / or the headspace gas phase of the second gas replacement region enters the headspace of the first gas replacement region, more preferably the first gas replacement region and the second gas replacement region share a headspace.

[0092] According to one embodiment of the present invention, the exhaust port for the replaced stream of the first gas replacement region is in contact with the inlet for the stream being replaced in the second gas replacement region. Preferably, the exhaust port for the replaced stream of the first gas replacement region is in direct contact with the inlet for the replaced stream of the second gas replacement region, and more preferably, there is at least one passage between the first gas replacement region and the second gas replacement region, and the at least one passage is configured such that the replaced stream of the first gas replacement region enters the second gas replacement region as the stream being replaced.

[0093] According to one embodiment of the present invention, the first gas replacement region and the second gas replacement region are each located in different containers, for example, in different strippers or degassing tanks. Alternatively, the first gas replacement region and the second gas replacement region are both located in the same container, for example, in the same stripper or degassing tank.

[0094] According to one embodiment of the present invention, a first gas replacement region and a second gas replacement region are arranged together in the same container, and at least one partition structural member exists between the first gas replacement region and the second gas replacement region. Here, the partition structural member can be specifically exemplified by a plate-shaped or ring-shaped partition structural member.

[0095] According to one embodiment of the present invention, the central axis direction of the first gas replacement region is basically parallel to the central axis direction of the second gas replacement region.

[0096] According to one embodiment of the present invention, in a direction perpendicular to the horizontal plane, the inlet for the replacement gas of the first gas replacement area is at substantially the same height as or above the inlet for the replacement gas of the second gas replacement area, or the bottom of the first gas replacement area is at substantially the same height as or above the bottom of the second gas replacement area.

[0097] According to one embodiment of the present invention, the gas replacement device further comprises one or more gas replacement areas (referred to as additional gas replacement areas) before the first gas replacement area, after the first gas replacement area, and before and / or after the second gas replacement area. For this purpose, even if the first gas replacement area and the second gas replacement area are connected in a continuous order, one or more additional gas replacement areas may be inserted between these two areas depending on the circumstances. Here, the additional gas replacement area may be any known structural form of a gas replacement area and is not particularly limited, but may be identical to the first gas replacement area or identical to the second gas replacement area. Preferably, the first gas replacement area is directly connected to the second gas replacement area. That is, no other gas replacement area is inserted between the first gas replacement area and the second gas replacement area, and the stream to be replaced passes through the first gas replacement area and the second gas replacement area to continuously perform gas replacement.

[0098] According to one embodiment of the present invention, a flow disturbance structural member is provided in the first gas replacement region.

[0099] According to one embodiment of the present invention, a flow disturbance structural member is provided in the second gas replacement region.

[0100] According to one embodiment of the present invention, a flow disturbance structural member is provided in an additional gas replacement region.

[0101] According to one embodiment of the present invention, the flow disturbance structural member comprises at least one flow rectifier and a connecting component for fixing at least one flow rectifier to and / or to a corresponding gas displacement region (if multiple flow rectifiers exist). Here, the number of flow rectifiers can be, for example, 1 to 1000 or 4 to 100, but is not limited to these.

[0102] According to one embodiment of the present invention, the connecting component can be any structural form of structural member used in the art to connect or fix a flow rectifier or flow disturbance structural member, without particularly limiting it, and specifically include, for example, grids, screen meshes, metal strips, metal rods, metal wires, and metal plates.

[0103] According to one embodiment of the present invention, the flow rectifier may be any structural style of flow rectifier used in the art to change or guide a gas flow, for example, but preferably the flow rectifier is selected from at least one of a streamlined flow rectifier, a diamond flow rectifier, and an inclined baffle mixed flow flow rectifier.

[0104] According to one embodiment of the present invention, the streamlined flow rectifier is selected from at least one of the following: a combination of two semiellipsoids, a combination of one semiellipsoid and one cone, a combination of one semiellipsoid and one arc-shaped streamlined body, and a combination of one semiellipsoid and one projectile, preferably a combination of one semiellipsoid and one projectile. Here, preferably, the generalatrix of the projectile is a curved equation.

[0105]

number

[0106] The following conditions must be met, where d is the maximum cross-sectional diameter (in mm) and b is a value between 0.5 and 8.

[0107] According to one embodiment of the present invention, the diamond-shaped flow rectifier is selected from at least one of a combination of two pyramids, a combination of two truncated pyramidal structures, and a combination of one pyramid and one truncated pyramidal structure, preferably a combination of two pyramids.

[0108] According to one embodiment of the present invention, the inclined baffle diagonal flow type flow rectifier is a plurality of baffles inclined with respect to a horizontal plane. Here, the inclination angle with respect to the horizontal plane is generally 0 to 60°, preferably 10 to 40°.

[0109] According to one embodiment of the present invention, the central axis direction of at least one flow rectifier substantially coincides with the central axis direction of the corresponding gas displacement region. In the context of the present invention, the so-called corresponding gas displacement region refers to a gas displacement region in which a flow disturbance structural member or a flow rectifier is provided, such as a first gas displacement region or a second gas displacement region.

[0110] According to one embodiment of the present invention, at least one (e.g., each) flow rectifier has at least one through-flow channel. Preferably, the maximum cross-sectional area of ​​the corresponding flow rectifier (in units of m²) 2 ) relative to the cross-sectional area of ​​the through-channel (in cases where there are multiple through-channels, refer to the sum of the cross-sectional areas of the multiple through-channels, unit is m 2 The ratio of ) is 1 to 30:100 or 3 to 15:100. Here, the through-channels generally include through-holes or through-slits. Furthermore, the through-channels may be arranged on the flow rectifier in any process known in the art, but are preferably arranged along the central axis of the corresponding gas replacement region.

[0111] According to one embodiment of the present invention, in each flow disturbance structural member, the corresponding cross-sectional area of ​​the corresponding gas replacement region (unit is m 2 ) Maximum cross-sectional area of ​​the flow rectifier (If multiple flow rectifiers exist, refer to the sum of the maximum cross-sectional areas of the multiple flow rectifiers, unit is m 2 The ratio of ) is 20-90:100, preferably 45-65:100.

[0112] According to one embodiment of the present invention, when multiple flow rectifiers are present in each flow disturbance structural member, the multiple flow rectifiers are arranged relative to each other in a predetermined manner. Here, any conventionally known manner can be used as the manner of arrangement, and specifically, examples include random, triangular, square, rectangular, circular, and annular shapes.

[0113] According to one embodiment of the present invention, one or more flow disturbance structural members are arranged along the central axis direction of the corresponding gas displacement region. Here, the number of flow disturbance structural members may be, for example, 2 to 20 or 4 to 10, but is not limited to these.

[0114] According to one embodiment of the present invention, when a plurality of flow disturbance structural members are arranged along the central axis direction of the corresponding gas displacement region, the vertical distance (in m) between any two adjacent flow disturbance structural members that are related to each other along the central axis direction of the corresponding gas displacement region can be 2%H to 20%H, where H is the height (in m) of the corresponding gas displacement region.

[0115] According to one embodiment of the present invention, if the height (in meters) of the first gas replacement region is H1 and the height (in meters) of the second gas replacement region is H2, then H2 / H1 ≥ 1 or 2 ≥ H2 / H1 ≥ 1.

[0116] According to one embodiment of the present invention, a reaction system, and more particularly a hydrogenation reaction system for nitro compounds, is also relating. The reaction system comprises at least one reactor and at least one (e.g., 1 to 3 or 2) gas replacement devices communicating with the at least one reactor (e.g., communicating downstream). Herein, the gas replacement devices are generally configured to receive effluent from the at least one reactor, and in particular to receive spent catalyst particles from the at least one reactor. In addition, the at least one gas replacement device is configured to implement a gas replacement device for a gas replacement process according to any embodiment of the present invention described above, or is a gas replacement device according to any embodiment of the present invention described above.

[0117] According to one embodiment of the present invention, the reactor is preferably a fluidized bed reactor, more particularly a reactor having a fluidized bed of catalyst particles, more specifically a fluidized bed reactor for the hydrogenation of nitro compounds, and more specifically a fluidized bed reactor for producing aniline by hydrogenation of nitrobenzene.

[0118] According to one embodiment of the present invention, spent catalyst particles are subjected to gas replacement (particularly degassing) in the at least one gas replacement device, then further regenerated / activated, and then recirculated back to the at least one reactor.

[0119] According to one embodiment of the present invention, the present invention also relates to a hydrogenation reaction process for nitro compounds. Preferably, the hydrogenation reaction process for nitro compounds is carried out in a hydrogenation reaction system for nitro compounds according to any of the earlier embodiments of the present invention.

[0120] According to one embodiment of the present invention, the hydrogenation reaction process of a nitro compound includes at least the steps of contacting a hydrogenation catalyst with a nitro compound, which is a reaction raw material, and hydrogen gas to obtain a reaction product and a spent catalyst (referred to as the hydrogenation reaction step), and the step of gas-replacing the spent catalyst in the presence of a substitution gas (referred to as the gas replacement step).

[0121] According to one embodiment of the present invention, the gas replacement step is performed in accordance with the gas replacement process described in any of the earlier embodiments of the present invention, or in a gas replacement apparatus according to any of the earlier embodiments of the present invention.

[0122] According to one embodiment of the present invention, spent catalyst particles are gas-purged in a gas-purging step, then further regenerated / activated, and then recycled back to the hydrogenation reaction step.

[0123] Referring to Figure 1, the hydrogenation reaction system or process of nitro compounds will be described in detail. Specifically, the main apparatus of the hydrogenation reaction system or process of nitro compounds comprises: a fluidized bed reactor 3, a degasser 12 for spent catalyst, a regenerator 13, a degasser 16 for the catalyst to be activated, an activator 19, and a riser pipe 21. Here, the fluidized bed reactor 3 includes a dense phase reaction region 4 located in the lower section, a particle sputtering transition region 5 located in the middle section, and a dilute phase region 7 located in the upper section. The degasser 12 for spent catalyst is connected to the fluidized bed reactor 3 and the regenerator 13, respectively. The degasser 16 for the catalyst to be activated is connected to the regenerator 13 and the activator 19, respectively. The riser pipe 21 is connected to the activator 19 and the fluidized bed reactor 3, respectively. The fluidized bed reactor 3 is equipped with a gas distributor 2, a heat exchange pipe 11, and a cyclone separator 9. Here, the degassing tank 12 for the spent catalyst comprises a degassing downward flow region (corresponding to the first gas replacement region or first gas replacement step of the present invention) and a degassing upward flow region (corresponding to the second gas replacement region or second gas replacement step of the present invention), and a flow disturbance structural member 33 is provided in both the degassing downward flow region and the degassing upward flow region; the degassing tank 16 for the catalyst to be activated comprises a regenerative degassing downward flow region (corresponding to the first gas replacement region or first gas replacement step of the present invention) and a regenerative degassing upward flow region (corresponding to the second gas replacement region or second gas replacement step of the present invention), and a flow disturbance structural member 33 is provided in both the regenerative degassing downward flow region and the regenerative degassing upward flow region. The degassing tank 12 for the spent catalyst and the degassing tank 16 for the catalyst to be activated carry out the gas replacement apparatus or gas replacement process of the present invention.

[0124] According to one embodiment of the present invention, in a hydrogenation reaction system or hydrogenation reaction process of a nitro compound, vaporized nitrobenzene and hydrogen gas, which are the raw materials, are introduced into a gas chamber, then into a fluidized bed reactor 3 via a gas distributor 2, where the catalyst in the reactor is pushed in and fluidized, and then reacts in a dense phase reaction region 4 to produce aniline products. A portion of the gas phase forms bubbles, particle sputtering occurs at the top of the dense phase reaction region 4 to form a particle sputtering transition region 5, where particles enter a dilute phase region 7 and are separated in a cyclone separator 9, returning to the dense phase reaction region 4, and the crude product gas 8 flows out of the fluidized bed reactor 3 and is sent to a subsequent separation section. After the catalyst is partially coked in the reaction, the coked catalyst is degassed in a degasser 12 for spent catalysts and introduced into a regenerator 13 where oxygen is introduced, and the catalyst is regenerated by carbon combustion. The regenerated catalyst is introduced into a degassing tank 16 for the catalyst to be activated. After degassing, it is introduced into an activator 19, where hydrogen gas is introduced to activate the catalyst. The activated catalyst is then introduced into a rising pipe 21, where it is raised and lowered and returned to the fluidized bed reactor 3, where the catalytic action continues.

[0125] According to one embodiment of the present invention, in the hydrogenation reaction step or the fluidized bed reactor 3, the gas emptying velocity is generally 0.2 to 0.8 m / s, and the molar ratio of hydrogen gas to the reaction raw material (e.g., nitrobenzene) is generally 6 to 21.

[0126] According to one embodiment of the present invention, in the hydrogenation reaction process or the fluidized bed reactor 3, the reaction temperature (generally referring to the average reaction temperature in the dense phase reaction region) is 220 to 280°C, and the reaction pressure (generally referring to the pressure in the dense phase reaction region) is 0.05 to 1 MPa (gauge pressure). In addition, the temperature near the gas distributor is usually controlled to 320°C or lower.

[0127] According to one embodiment of the present invention, the reaction conditions in the regenerator 13 include a gas emptying velocity of 0.1 to 0.6 m / s and an average regeneration temperature of 350 to 450°C; the reaction conditions in the activator 19 include a gas emptying velocity of 0.1 to 0.6 m / s and an average activation temperature of 200 to 250°C.

[0128] According to one embodiment of the present invention, the ratio of the gas empty column velocity in the degassing downward flow region to the gas empty column velocity in the degassing upward parallel flow region of the degassing tank 12 for used catalyst is 1 / 15 to 1, and the degassing agent is one or more of nitrogen gas, water vapor, carbon dioxide, methane, and argon gas (as a mixture), and the gas components carried from the fluidized bed reactor 3 are replaced. The ratio of the gas empty column velocity in the regenerating degassing downward flow region to the gas empty column velocity in the regenerating degassing upward parallel flow region of the degassing tank 16 for the catalyst to be activated is 1 / 15 to 1, and the degassing agent is one or more of nitrogen gas, water vapor, carbon dioxide, oxygen gas, and argon gas (as a mixture), and the oxygen-containing gas components carried from the regenerator 13 are replaced.

[0129] According to one embodiment of the present invention, the degassing efficiency of the degassing tank for used catalyst and the degassing tank for the catalyst to be activated can generally reach 90% or more, preferably 94% or more. In addition, these two degassing tanks have a large contact area, high levels of mass transfer and heat transfer, and degassing efficiency that meets the requirements of production safety.

[0130] According to one embodiment of the present invention, any catalyst used in the art for the hydrogenation reaction of nitro compounds can be cited as the hydrogenation catalyst, and at least one selected from copper-based supported catalysts, nickel-based supported catalysts, and precious metal-based supported catalysts can be cited, more specifically a copper-based supported catalyst. Here, copper-based supported catalysts generally use copper as the main active component, and alumina or silica as the support.

[0131] According to one embodiment of the present invention, the average particle size of the hydrogenation catalyst is generally 30 to 800 μm, preferably 40 to 500 μm or 50 to 600 μm. Preferably, in the hydrogenation catalyst, catalyst particles having a particle size of less than 80 μm constitute 2% by weight or more, preferably 5 to 15% by weight, of all catalyst particles. For example, the average particle diameter can be determined by analyzing sampled solid catalyst particles using a particle size analyzer.

[0132] According to one embodiment of the present invention, the substitution gas is generally a gas, vapor, or water vapor. Here, the substitution gas can be at least one selected from nitrogen gas, water vapor, carbon dioxide, methane, oxygen gas, and argon gas, with nitrogen gas being particularly noteworthy. Those skilled in the art can proceed with conventional selections according to their actual requirements without being particularly limited.

[0133] According to one embodiment of the present invention, the nitro compound is selected from at least one compound represented by the following formula (1), particularly from nitrobenzene.

[0134] R-NO2(1) According to one embodiment of the present invention, in structural formula (1), R is optionally substituted with C 2-20 Linear, branched, or cyclic hydrocarbyl, preferably optionally substituted C 4-20 Cyclic hydrocarbyl, especially optionally substituted C 6-20 Aryl compounds, particularly optionally substituted phenyl compounds or phenyl compounds. [Examples] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0135] In the following examples and comparative examples, the amount of carbon precipitate was measured and analyzed using a thermogravimetric analyzer. <Example 1> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. Degassing was performed in the degassing tank for the spent catalyst and the degassing tank for the activated catalyst according to the degassing process as shown in Figure 2. The flow rectifier of the flow disturbance structure member was a streamlined flow rectifier.

[0136] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solid content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solid content was 0.12. In this example, V1 = 0.25 m / s and V2 = 1.25 m / s.

[0137] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 98.7%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitate could be controlled to 0.5% or less, and the results are shown in Table 1. <Example 2> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. Degassing was performed in the degassing tank for the spent catalyst and the degassing tank for the activated catalyst according to the degassing process as shown in Figure 2. The flow rectifier of the flow disturbance structure member is a diamond-type flow rectifier.

[0138] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.12.

[0139] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 97.3%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitate could be controlled to 0.5% or less, and the results are shown in Table 1. <Example 3> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. Degassing was performed in the degassing tank for the spent catalyst and the degassing tank for the activated catalyst according to the degassing process as shown in Figure 2. The flow rectifier of the flow disturbance structure member was an inclined baffle mixed-flow type flow rectifier.

[0140] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.12.

[0141] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 97.1%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitate could be controlled to 0.5% or less, and the results are shown in Table 1. <Example 4> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. Degassing was performed in the degassing tank for the spent catalyst and the degassing tank for the activated catalyst according to the degassing process as shown in Figure 2. The flow rectifier of the flow disturbance structure member was a streamlined flow rectifier.

[0142] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.1 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.12.

[0143] The degassing efficiency of both the degassing tank for used catalysts and the degassing tank for activated catalysts was 98.7%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitate could be controlled to 0.7% or less, and the results are shown in Table 1. <Example 5> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. Degassing was performed in the degassing tank for the spent catalyst and the degassing tank for the activated catalyst according to the degassing process as shown in Figure 2. The flow rectifier of the flow disturbance structure member was a streamlined flow rectifier.

[0144] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.6 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.12.

[0145] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 98.7%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitated could be controlled to 0.3% or less, and the results are shown in Table 1. <Example 6> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. Degassing was performed in the degassing tank for the spent catalyst and the degassing tank for the activated catalyst according to the degassing process as shown in Figure 2. The flow rectifier of the flow disturbance structure member was a streamlined flow rectifier.

[0146] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 350°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.12.

[0147] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 98.7%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitated could be controlled to less than 1%, and the results are shown in Table 2. <Example 7> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. Degassing was performed in the degassing tank for the spent catalyst and the degassing tank for the activated catalyst according to the degassing process as shown in Figure 2. The flow rectifier of the flow disturbance structure member was a streamlined flow rectifier.

[0148] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 450°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.12.

[0149] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 98.7%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitate could be controlled to 0.15% or less, and the results are shown in Table 2. <Example 8> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. Degassing was performed in the degassing tank for the spent catalyst and the degassing tank for the activated catalyst according to the degassing process as shown in Figure 2. The flow rectifier of the flow disturbance structure member was a streamlined flow rectifier.

[0150] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 15, and the degassing agent was nitrogen gas. In the degassing tank for activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 15, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.59; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.065.

[0151] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 98.2%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitated could be controlled to 0.5% or less, and the results are shown in Table 2. <Example 9> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. Degassing was performed in the degassing tank for the spent catalyst and the degassing tank for the activated catalyst according to the degassing process as shown in Figure 2. The flow rectifier of the flow disturbance structure member was a streamlined flow rectifier.

[0152] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 2, and the degassing agent was nitrogen gas. In the degassing tank for activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 2, and the degassing agent was nitrogen gas. The average solid content was 0.46 in both the first gas replacement step for the degassing tank for spent catalysts and the degassing tank for activated catalysts; and the average solid content was 0.18 in both the second gas replacement step for the degassing tank for spent catalysts and the degassing tank for activated catalysts.

[0153] The degassing efficiency of both the degassing tank for used catalysts and the degassing tank for activated catalysts was 96.8%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitated could be controlled to 0.5% or less, and the results are shown in Table 2. <Example 10> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. Degassing was performed in the degassing tank for the spent catalyst and the degassing tank for the activated catalyst according to the degassing process as shown in Figure 2. The flow rectifier of the flow disturbance structure member was a streamlined flow rectifier.

[0154] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 20, and the degassing agent was nitrogen gas; in the degassing tank for activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 20, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.61; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.058.

[0155] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 98.9%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitated could be controlled to 0.5% or less, and the results are shown in Table 2. <Example 11> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0156] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 7, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are streamlined flow rectifiers, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 10:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 50:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0157] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.12.

[0158] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 98.8%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitate could be controlled to 0.5% or less, and the results are shown in Table 3. <Example 12> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0159] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 1.5, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are streamlined flow rectifiers, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 10:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 50:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0160] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. The average solid content was 0.55 in both the first gas replacement step for the degassing tank for spent catalysts and the degassing tank for the activated catalysts; and the average solid content was 0.12 in both the second gas replacement step for the degassing tank for spent catalysts and the degassing tank for the activated catalysts.

[0161] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 96.7%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitate could be controlled to 0.5% or less, and the results are shown in Table 3. <Example 13> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0162] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 15, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are streamlined flow rectifiers, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 10:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 50:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0163] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5; the degassing agent was nitrogen gas. In the degassing tank for activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5; the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.12.

[0164] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 98.6%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitate could be controlled to 0.5% or less, and the results are shown in Table 3. <Example 14> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0165] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 30, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are streamlined flow rectifiers, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 10:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 50:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0166] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.12.

[0167] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 98.6%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitate could be controlled to 0.5% or less, and the results are shown in Table 3. <Example 15> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0168] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 7, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 12, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are streamlined flow rectifiers, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 10:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 50:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0169] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.12.

[0170] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 99.1%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitate could be controlled to 0.5% or less, and the results are shown in Table 3. <Example 16> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0171] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 7, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 36, the flow rectifiers are streamlined flow rectifiers, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 10:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 50:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0172] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.12.

[0173] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 98.9%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitate could be controlled to 0.5% or less, and the results are shown in Table 4. <Example 17> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0174] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 7, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are diamond-shaped flow rectifiers, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 10:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 50:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0175] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. The average solid content was 0.55 in both the first gas replacement step for the degassing tank for spent catalysts and the degassing tank for the activated catalysts; and the average solid content was 0.12 in both the second gas replacement step for the degassing tank for spent catalysts and the degassing tank for the activated catalysts.

[0176] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 98.2%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitate could be controlled to 0.5% or less, and the results are shown in Table 4. <Example 18> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0177] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 7, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are inclined baffle diagonal flow type flow rectifiers, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 10:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 50:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0178] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the degassing tank for activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.12.

[0179] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 97.9%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitate could be controlled to 0.5% or less, and the results are shown in Table 4. <Example 19> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0180] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 7, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are flow rectifier type 1, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 15:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 50:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0181] The catalyst is a metal-supported catalyst with copper as the main active component, the carrier is silica, the average particle size of the catalyst is 400 μm, and the content of particles less than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas superficial velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense-phase reaction zone was controlled at 240 °C, and the reaction pressure in the dense-phase reaction zone was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas superficial velocity was 0.3 m / s and the average regeneration temperature was 410 °C; the reaction conditions in the activator were as follows: the gas superficial velocity was 0.3 m / s and the average activation temperature was 220 °C. The ratio of the superficial velocity of the first gas replacement step to the superficial velocity of the second gas replacement step in the degassing tank for the used catalyst was 1 / 5, and the degassing agent was nitrogen gas; the ratio of the superficial velocity of the first gas replacement step to the superficial velocity of the second gas replacement step in the degassing tank for the catalyst to be activated was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for the degassing tank for the used catalyst and the degassing tank for the catalyst to be activated, the average solid fraction was both 0.55; in the second gas replacement step for the degassing tank for the used catalyst and the degassing tank for the catalyst to be activated, the average solid fraction was both 0.12.

[0182] The degassing efficiency of both the degassing tank for the used catalyst and the degassing tank for the catalyst to be activated was 97.2%, and the carbon deposition amount could be controlled to 0.5% or less when the reaction time under the high space velocity condition (0.9 h -1 ) was 90 minutes, and the results are shown in Table 4. <Example 20> A reaction system for producing aniline by hydrogenation of nitrobenzene as shown in FIG. 1 was used. The degassing tank for the used catalyst and the degassing tank for the catalyst to be activated used the gas replacement device shown in FIG. 3. The degassing tank for the used catalyst and the degassing tank for the catalyst to be activated were degassed according to the degassing process as shown in FIG. 2.

[0183] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 7, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are flow rectifier type 1, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 3:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 50:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0184] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.12.

[0185] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 98.9%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitate could be controlled to 0.5% or less, and the results are shown in Table 4. <Example 21> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0186] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 7, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are flow rectifier type 1, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 28:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 50:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0187] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. The average solid content was 0.55 in both the first gas replacement step for the degassing tank for spent catalysts and the degassing tank for the activated catalysts; and the average solid content was 0.12 in both the second gas replacement step for the degassing tank for spent catalysts and the degassing tank for the activated catalysts.

[0188] The degassing efficiency of both the degassing tank for spent catalyst and the degassing tank for the activated catalyst was 96.8%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitated could be controlled to 0.5% or less, and the results are shown in Table 5. <Example 22> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0189] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 7, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are flow rectifier type 1, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 10:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 40:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0190] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.12.

[0191] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 98.3%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitate could be controlled to 0.5% or less, and the results are shown in Table 3. <Example 23> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0192] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 7, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are flow rectifier type 1, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 10:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 65:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0193] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.12.

[0194] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 99.0%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitated could be controlled to 0.5% or less, and the results are shown in Table 5. <Example 24> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0195] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 7, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are flow rectifier type 1, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 10:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 30:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0196] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.12.

[0197] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 97.9%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitated could be controlled to 0.5% or less, and the results are shown in Table 5. <Example 25> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0198] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 7, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are flow rectifier type 1, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 10:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 50:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 4. The number of flow disturbance structural members placed within the second gas displacement region was 4, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0199] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.12.

[0200] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 99.1%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitated could be controlled to 0.5% or less, and the results are shown in Table 5. <Example 26> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0201] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 7, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are flow rectifier type 1, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 10:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 50:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 10. The number of flow disturbance structural members placed within the second gas displacement region was 10, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0202] The catalyst is a metal-supported catalyst with copper as the main active component, the carrier is silica, the average particle size of the catalyst is 400 μm, and the content of particles less than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas superficial velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense-phase reaction zone was controlled at 240 °C, and the reaction pressure in the dense-phase reaction zone was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas superficial velocity was 0.3 m / s, and the average regeneration temperature was 410 °C; the reaction conditions in the activator were as follows: the gas superficial velocity was 0.3 m / s, and the average activation temperature was 220 °C. The ratio of the superficial velocity of the first gas replacement step to the superficial velocity of the second gas replacement step in the degassing tank for the used catalyst was 1 / 5, and the degassing agent was nitrogen gas; the ratio of the superficial velocity of the first gas replacement step to the superficial velocity of the second gas replacement step in the degassing tank for the catalyst to be activated was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for the degassing tank for the used catalyst and the degassing tank for the catalyst to be activated, the average solid fraction was 0.55 for both; in the second gas replacement step for the degassing tank for the used catalyst and the degassing tank for the catalyst to be activated, the average solid fraction was 0.12 for both.

[0203] The degassing efficiency of the degassing tank for the used catalyst and the degassing tank for the catalyst to be activated was 99.2% for both. When the reaction time under high space velocity conditions (0.9 h -1 ) was 90 minutes, the carbon deposition amount could be controlled to 0.5% or less, and the results are shown in Table 6. <Example 27> A reaction system for producing aniline by hydrogenation of nitrobenzene as shown in FIG. 1 was used. The degassing tank for the used catalyst and the degassing tank for the catalyst to be activated used the gas replacement device shown in FIG. 3. The degassing tank for the used catalyst and the degassing tank for the catalyst to be activated were degassed according to the degassing process as shown in FIG. 2.

[0204] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 7, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are flow rectifier type 1, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 10:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 50:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.02, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0205] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the degassing tank for activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.12.

[0206] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 99.1%, under high space velocity conditions (0.9h). -1 With a reaction time of 90 minutes, the amount of carbon precipitate could be controlled to 0.5% or less, and the results are shown in Table 6. <Example 28> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0207] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 7, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are flow rectifier type 1, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 10:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 50:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.1, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.5.

[0208] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.12.

[0209] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 97.6%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitated could be controlled to 0.5% or less, and the results are shown in Table 6. <Example 29> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0210] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 7, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are flow rectifier type 1, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 10:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 50:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 1.

[0211] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the degassing tank for activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for activated catalysts, the average solids content was 0.12.

[0212] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 97.6%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitated could be controlled to 0.5% or less, and the results are shown in Table 6. <Example 30> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. The degassing tanks for the spent catalyst and the activated catalyst were operated using the gas replacement apparatus shown in Figure 3. The degassing tanks for the spent catalyst and the activated catalyst were degassed according to the degassing process shown in Figure 2.

[0213] In a degassing tank for spent catalysts and a degassing tank for activated catalysts, the ratio of the cross-sectional area of ​​the central part of the second gas replacement region to the cross-sectional area of ​​the central part of the first gas replacement region is 7, the number of flow rectifiers included in any flow disturbance structural member in the first gas replacement region is 4, the number of flow rectifiers included in any flow disturbance structural member in the second gas replacement region is 20, the flow rectifiers are flow rectifier type 1, the ratio of the cross-sectional area of ​​the through-flow channel to the maximum cross-sectional area of ​​the corresponding flow rectifier is 10:100, the ratio of the sum of the maximum cross-sectional areas of the multiple flow rectifiers to the corresponding cross-sectional area of ​​the corresponding gas replacement region is 50:100, and the number of flow disturbance structural members arranged in the first gas replacement region is 2. The number of flow disturbance structural members placed within the second gas displacement region was 2, the ratio of the vertical distance between any two flow disturbance structural members to the corresponding gas displacement region (height) was 0.5, and the ratio of the height of the second gas displacement region to the height of the first gas displacement region was 3.

[0214] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas; in the degassing tank for the activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1 / 5, and the degassing agent was nitrogen gas. In the first gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.55; in the second gas replacement step for both the degassing tank for spent catalysts and the degassing tank for the activated catalysts, the average solids content was 0.12.

[0215] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 98.9%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitated could be controlled to 0.5% or less, and the results are shown in Table 6. <Comparative Example 1> A reaction system for producing aniline by hydrogenation of nitrobenzene, as shown in Figure 1, was used. Degassing was performed in the degassing tank for the spent catalyst and the degassing tank for the activated catalyst according to the degassing process shown in Figure 2. The flow rectifier of the flow disturbance structure member was a streamlined flow rectifier.

[0216] The catalyst was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%. The reaction conditions in the fluidized bed reactor were as follows: the gas emptying velocity was 0.4 m / s, the molar ratio of hydrogen gas to nitrobenzene was 11, the average reaction temperature in the dense phase reaction region was controlled to 240°C, and the reaction pressure in the dense phase reaction region was 0.1 MPa. The reaction conditions in the regenerator were as follows: the gas emptying velocity was 0.3 m / s, and the average regeneration temperature was 410°C; the reaction conditions in the activator were as follows: the gas emptying velocity was 0.3 m / s, and the average activation temperature was 220°C. In the degassing tank for spent catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1.1, and the degassing agent was nitrogen gas; in the degassing tank for activated catalysts, the ratio of the empty column velocity in the first gas replacement step to the empty column velocity in the second gas replacement step was 1.1, and the degassing agent was nitrogen gas. The average solid content was 0.36 in both the first gas replacement step for the degassing tank for spent catalysts and the degassing tank for activated catalysts; and the average solid content was 0.41 in both the second gas replacement step for the degassing tank for spent catalysts and the degassing tank for activated catalysts.

[0217] The degassing efficiency of both the degassing tank for spent catalysts and the degassing tank for activated catalysts was 93.1%, under high space velocity conditions (0.9h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitate could be controlled to 0.5% or less, and the results are shown in Table 7. <Comparative Example 2> A conventional reaction system for producing aniline by hydrogenating nitrobenzene without using a regenerator or activator was used. The catalyst used was a metal-supported catalyst with copper as the main active component, the support was silica, the average particle size of the catalyst was 400 μm, and the content of particles smaller than 80 μm was 6%, and the reaction was carried out under high space velocity conditions (0.9 h). -1 When the reaction time in ) was set to 90 minutes, the amount of carbon precipitated was 3.7%, and the results are shown in Table 2.

[0218] Obviously, the gas replacement device or process of the present invention can solve problems such as catalysts that are prone to coking and deactivation, and difficulties in long-term operation, and can be used in the industrial operation of the hydrogenation of nitrobenzene to produce aniline.

[0219]

Table 1

[0220]

Table 2

[0221]

Table 3

[0222] JPEG0007851123000006.jpg21169

[0223]

Table 4

[0224] JPEG0007851123000008.jpg62169

[0225]

Table 5

[0226] JPEG0007851123000010.jpg98169

[0227]

Table 6

[0228] JPEG0007851123000012.jpg136169

[0229] Table 7

Claims

1. A hydrogenation reaction process of nitro compounds, The process includes contacting a nitro compound as a reaction raw material with hydrogen gas and a hydrogenation catalyst to obtain an amino compound and a spent catalyst (called the hydrogenation reaction step), Next, the used catalyst is degassed, regenerated, degassed again, activated, and then recycled back to the hydrogenation reaction step as the hydrogenation catalyst. Each of the degassing processes is: A first step (referred to as the first degassing step) for degassing the catalyst in the presence of a first degassing gas, Next, the process includes at least a second step (referred to as the second degassing step) for degassing in the presence of a second degassing gas, Let V1 be the empty tower velocity of the first degassed gas, expressed as an absolute value in units of m / s, and let V2 be the empty tower velocity of the second degassed gas, also expressed as an absolute value in units of m / s. Then V2 / V1 ≥ 1.

5. A hydrogenation reaction process for a nitro compound, which proceeds according to a degassing process in which the first degassed gas and the catalyst are in countercurrent contact and the second degassed gas and the catalyst are in parallel contact.

2. The first degassed gas is a gas, vapor, or water vapor. The second degassed gas is a gas, vapor, or water vapor, and The process according to claim 1, wherein 20 ≥ V2 / V1 ≥ 2.

5.

3. The process according to claim 1, wherein 15 ≥ V2 / V1 ≥ 5.

4. The first degassing step has an operating temperature of 0 to 700°C and an operating pressure of 0 to 3 MPaG, and / or In the first degassing step, the empty column velocity (absolute value) V1 of the first degassed gas is 0.05 to 0.6 m / s, and the empty column velocity (absolute value) of the catalyst is 0.02 to 0.2 m / s, and / or The second degassing step has an operating temperature of 0 to 700°C and an operating pressure of 0 to 3 MPaG, and / or The process according to claim 1, wherein in the second degassing step, the empty column velocity (absolute value) V2 of the second degassed gas is 0.8 to 10 m / s, and the empty column velocity (absolute value) of the catalyst is 0.4 to 6 m / s, and / or 100 ≥ V2 / V1 ≥ 2.

5. The first degassing step has an operating temperature of 80 to 400°C and an operating pressure of 0.01 to 1 MPaG, and / or In the first degassing step, the empty tower velocity (absolute value) V1 of the first degassed gas is 0.1 to 0.3 m / s, and / or The empty velocity (absolute value) of the catalyst is 0.05 to 0.1 m / s, and / or, The second degassing step has an operating temperature of 80 to 400°C and an operating pressure of 0.01 to 1 MPaG, and / or The process according to claim 1, wherein in the second degassing step, the empty column velocity (absolute value) V2 of the second degassed gas is 1 to 3 m / s, and the empty column velocity (absolute value) of the catalyst is 0.6 to 2.4 m / s.

6. The process according to claim 1, wherein in the first degassing step, the solid content is in the range of 0.25 to 0.6, and / or in the second degassing step, the solid content is in the range of 0.02 to 0.

3.

7. The first degassing step and the second degassing step are performed in the same container or in different containers, and / or the first degassing step and the second degassing step are in gas phase communication, and / or The process according to claim 1, wherein the operating pressure of the first degassing step and the operating pressure of the second degassing step are the same.

8. The first degassing step and the second degassing step are performed in different areas within the container, and / or The process according to claim 1, wherein the first degassing step and the second degassing step are in headspace gas phase communication.

9. The process according to claim 1, further comprising one or more degassing steps called additional degassing steps, which are performed before the first degassing step, after the first degassing step, and before the second degassing step and / or after the second degassing step.

10. The reaction conditions for the hydrogenation reaction step are: an empty tower gas velocity of 0.2 to 0.8 m / s, a molar ratio of hydrogen gas to reaction material of 6 to 21, a reaction temperature of 220 to 280°C, a reaction pressure of 0.05 to 1 MPa (gauge pressure), the hydrogenation catalyst being selected from at least one of a copper-based supported catalyst, a nickel-based supported catalyst, and a precious metal-based supported catalyst, and / or the bulk density of the hydrogenation catalyst being 300 to 1200 kg / m³. ３ The process according to claim 1, wherein the average particle size of the hydrogenation catalyst is 30 to 800 μm, and the mass percentage of catalyst particles having a particle size of less than 80 μm relative to the total number of catalyst particles is 2% by weight or more, and / or the degassed gas is a gas or vapor, and / or the nitro compound is selected from at least one of the compounds represented by the following formula (1). R-NO ２ (1) In structural formula (1), R is a C which can be arbitrarily substituted. ６－２０ It is Ariel.

11. The average particle size of the hydrogenation catalyst is 50 to 600 μm, and / or The mass percentage of catalyst particles having a particle size of less than 80 μm relative to the total number of catalyst particles is 5 to 15% by weight, and / or, The degassed gas is selected from at least one of nitrogen gas, water vapor, carbon dioxide, methane, oxygen gas, and argon gas, and / or The process according to claim 10, wherein in structural formula (1), R is an optionally substituted phenyl.

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