CN111056958A

CN111056958A - Coupling reaction device and reaction method for preparing aniline by nitrobenzene hydrogenation

Info

Publication number: CN111056958A
Application number: CN201811207013.0A
Authority: CN
Inventors: 钟思青; 徐俊; 屠功毅
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2018-10-17
Filing date: 2018-10-17
Publication date: 2020-04-24
Anticipated expiration: 2038-10-17
Also published as: CN111056958B

Abstract

The invention relates to a coupling reaction device and a coupling reaction method for preparing aniline by nitrobenzene hydrogenation, which mainly solve the problems that the content of nitrobenzene in crude aniline is high, a catalyst is easy to deposit carbon and cannot be regenerated and activated on line, the device cannot run for a long period and the like. The invention provides a coupling reaction device and a coupling reaction method for preparing aniline by nitrobenzene hydrogenation, which utilize three reaction zones to carry out refined control on the reaction, and adopt the arrangement of two degassing tanks to solve the problems of on-line regeneration and activation of a coking catalyst, thereby achieving the technical scheme of long-period production target of low nitrobenzene content in crude aniline, continuous reaction, regeneration and activation, better solving the technical problems and being applicable to the industrial production of preparing aniline by nitrobenzene hydrogenation.

Description

Coupling reaction device and reaction method for preparing aniline by nitrobenzene hydrogenation

Technical Field

The invention relates to a reaction device and a reaction method for preparing aniline by nitrobenzene hydrogenation

Background

Aniline is an important basic organic chemical raw material and a fine chemical intermediate, and downstream products produced by aniline can be more than 300, so that the aniline is widely applied to industries such as dyes, medicines, pesticides, explosives, spices, rubber, synthetic materials and the like. In recent years, with the rapid rise of polyurethane industry in China and worldwide, aniline, which is one of the basic raw materials irreplaceable to MDI (4, 4-diphenylmethane diisocyanate), which is the main raw material, has been remarkably and rapidly developed.

Three methods for industrially producing aniline currently exist, namely a nitrobenzene catalytic hydrogenation method, a phenol ammoniation method and an iron powder reduction method. Wherein, the iron powder reduction method is gradually eliminated due to the poor quality of the generated aniline. The phenol amination process is strongly dependent on the source of the phenol. The prior nitrobenzene catalytic hydrogenation method is adopted by most manufacturers. The nitrobenzene catalytic hydrogenation method is divided into a gas-phase catalytic hydrogenation process and a liquid-phase catalytic hydrogenation process. The nitrobenzene liquid-phase catalytic hydrogenation process is firstly developed successfully by DuPont company in America, and is mainly carried out under the anhydrous condition by adopting a noble metal catalyst. The fluidized bed gas phase catalytic hydrogenation method is that the nitrobenzene as raw material is heated and vaporized and mixed with hydrogen, and then enters a fluidized bed reactor filled with a copper-silica gel catalyst to carry out hydrogenation reduction reaction.

The method for preparing aniline by gas phase hydrogenation of nitrobenzene has been in production history for decades in China, and fluidized bed gas phase catalytic hydrogenation process is adopted by many aniline manufacturers in China.

Document CN1528737A discloses a device and a method for preparing aniline by gas phase hydrogenation of nitrobenzene. The device comprises a fluidized bed reactor, a reaction raw material gas inlet arranged at the bottom of the reactor, a first gas distributor arranged at the upper part of the inlet, a second gas distributor which is arranged at the middle part of the axial height of the reactor and divides the reactor into two catalyst dense-phase areas, and a catalyst overflow device which is arranged outside or inside the reactor and is respectively connected with the upper catalyst dense-phase area and the lower catalyst dense-phase area.

Document CN1634860A discloses a gas distributor in fluidized bed for aniline synthesis and a method for synthesizing aniline. The gas distributor consists of a main pipe for conveying gas, branch pipes, an annular pipeline connected with the main pipe and the branch pipes for distributing gas, and a nozzle for spraying gas downwards and a nozzle for spraying gas upwards, which are arranged on the annular pipeline.

In the fluidized bed reactor for preparing aniline of the prior art, the reaction gas raw materials enter the fluidized bed from the distributor at the bottom, so that the nitrobenzene concentration near the distributor area at the bottom is higher, and the reaction is relatively violent. The nitrobenzene hydrogenation reaction belongs to a strong exothermic reaction, so that the area near the distributor has excessive heat and forms a local high-temperature area. The mass and heat transfer level of the existing fluidized bed does not completely reach the capability of timely transferring excessive heat away, so that on one hand, byproducts are easily generated at the position and the product purity of aniline is influenced; on the other hand, the catalyst is very easy to deposit carbon, and the deactivation of the catalyst is accelerated.

Disclosure of Invention

The invention mainly solves the technical problems that in the prior art, the content of nitrobenzene in crude aniline at the outlet of a fluidized bed reactor is high, a catalyst is easy to deposit carbon and cannot be regenerated and activated on line, the device cannot run for a long period and the like, and provides a novel device and a method for preparing aniline by nitrobenzene hydrogenation. The device and the method are used in the nitrobenzene hydrogenation process, three reaction zones are utilized to carry out refinement control on the reaction, the problem of on-line regeneration and activation of the coking catalyst is solved by adopting the arrangement of two degassing tanks, and the technical scheme of the long-period production target of low nitrobenzene content in the crude aniline, continuous reaction, regeneration and activation is achieved.

The second technical problem to be solved by the present invention is to provide a reaction method corresponding to the first technical problem.

In order to solve one of the above technical problems, the technical scheme adopted by the invention is as follows: a coupling reaction device for preparing aniline by nitrobenzene hydrogenation mainly comprises: the system comprises a fluidized bed reactor 3, a to-be-regenerated degassing tank 12, a regenerator 13, a to-be-activated degassing tank 16 and an activator 19, wherein the fluidized bed reactor 3 comprises a first reaction zone 4 at the lower part, a second reaction zone 5 at the middle section and a third reaction zone 6 at the upper part, the to-be-regenerated degassing tank 12 is respectively communicated with the fluidized bed reactor 3 and the regenerator 13, the to-be-activated degassing tank 16 is respectively communicated with the regenerator 13 and the activator 19, and the activator 19 is communicated with the fluidized bed reactor 3.

In the above technical scheme, gas raw material gas inlet devices are respectively arranged at the bottoms of the first reaction zone 4, the second reaction zone 5 and the third reaction zone 6 in the fluidized bed reactor 3. The ratio of the cross-sectional area of the first reaction zone 4 to the cross-sectional area of the second reaction zone 5 is 1.2 to 5. The ratio of the cross-sectional area of the third reaction zone 6 to the cross-sectional area of the second reaction zone 5 is 1.5 to 8.

In order to solve the second problem, the invention adopts the following technical scheme: a method for preparing aniline by nitrobenzene hydrogenation coupling reaction adopts the reaction device, and comprises the following steps:

a. the vaporized nitrobenzene and hydrogen raw materials enter a gas chamber and then enter a fluidized bed reactor 3 through a gas distributor 2, catalyst particles in the reactor are pushed to be fluidized and then are fluidized and contacted in a first reaction zone 4, the initial slow reaction is carried out, and gas and part of the catalyst particles enter a second reaction zone 5 to further react with the raw materials containing hydrogen and nitrobenzene from a second feeding pipeline 11 violently;

b. the incompletely reacted feedstock and catalyst particles then flow into the third reaction zone 6 for further reaction after mixing with the hydrogen-rich gas from the third feed line 10; then the reaction product and a small part of catalyst particles are separated by a cyclone separator 9, the small part of particles returns to the first reaction zone 4, and the crude product gas 8 flows out of the fluidized bed reactor 3 and enters a subsequent separation section;

c. after the catalyst is partially coked in the reaction process, the coked catalyst is degassed by a to-be-regenerated degassing tank 12 from a third reaction zone 6 and then enters a regenerator 13 to be introduced with oxygen for carbon burning regeneration; the regenerated catalyst is degassed by a degassing tank 16 to be activated and enters an activator 19 to be activated by introducing hydrogen, and the activated catalyst returns to the fluidized bed reactor 3 to continuously perform catalytic action.

In the technical scheme, the catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is aluminum oxide or silicon dioxide, the average particle size of the catalyst is 50-600 mu m, and the content of particles below 80 mu m is not less than 2%.

In the above technical scheme, the reaction conditions of the first reaction zone in the fluidized bed reactor 3 are as follows: the superficial gas velocity is 0.2-0.8m/s, the molar ratio of the hydrogen to the nitrobenzene is 2-10, and the average reaction temperature is controlled at 220 ℃ of 180 ℃; the reaction conditions of the second reaction zone are as follows: the superficial gas velocity is 0.6-5.0m/s, the molar ratio of the hydrogen to the nitrobenzene is 8-15, and the average reaction temperature is controlled at 220-280 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity is 0.2-0.8m/s, the molar ratio of the hydrogen to the nitrobenzene is 10-20, and the average reaction temperature is controlled at 220-260 ℃.

In the above technical scheme, the reaction conditions in the regenerator 13 are as follows: the apparent gas velocity is 0.1-0.6m/s, and the average regeneration temperature is 350-450 ℃; the reaction conditions in the activator 19 are as follows: the apparent gas velocity is 0.1-0.6m/s, and the average activation temperature is 200-.

In the technical scheme, the superficial gas velocity in the degassing tank 12 to be regenerated is 0.05-0.5m/s, the degassing agent is one or a mixture of a plurality of inert gases such as nitrogen, water vapor, carbon dioxide and the like, and gas components brought out from the fluidized bed reactor 3 are replaced. The superficial gas velocity in the degassing tank 16 to be activated is 0.05-0.5m/s, the degassing agent is one or a mixture of several of inert gases such as nitrogen, water vapor, carbon dioxide and the like, and oxygen-containing gas components brought out from the regenerator 13 are replaced.

By adopting the technical scheme of the invention, the coupling reaction device and the reaction method for preparing aniline by nitrobenzene hydrogenation are applied to aniline by nitrobenzene hydrogenation, the internal reaction condition and coking environment are changed by a three-region fine control technology, the coke content is effectively controlled while the safe production is ensured by adding the degassing tank and the regenerator and activator, compared with the prior art, the content of nitrobenzene in crude aniline at the outlet of a fluidized bed is reduced by 23%, the carbon deposition amount is greatly reduced, and a better technical effect is obtained.

Drawings

FIG. 1 is a schematic view of a coupling reaction device for preparing aniline by nitrobenzene hydrogenation according to the present invention and a process thereof:

in FIG. 1, 1 is the vaporized nitrobenzene and hydrogen feed; 2 is a gas distributor; 3 is a fluidized bed reactor; 4 is a first reaction zone; 5 is a second reaction zone; 6 is a third reaction zone; 8 is crude product gas; 9 is a cyclone separator; 10 is a third feed line; 11 is a second feed line; 12 is a degassing tank to be regenerated; 13 is a regenerator; 15 is regenerated fluidizing gas; 16 is a degassing tank to be activated; 17 is activated fluidizing gas; an activator is shown at 19.

The present invention will be further illustrated by the following examples, but is not limited to these examples.

Detailed Description

[ example 1 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.8mg/kg, the fluidized bed was closed and the reaction was stoppedHigh space velocity conditions (0.9 h) after valves between reactor and regenerator and activator^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.3%; the carbon deposition content can be controlled to be not more than 0.5% when the regenerator and the activator are used and the reaction time is 90min at high space velocity, and the results are detailed in table 1.

[ example 2 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 1.2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 4.0mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the high space velocity was achieved (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.5%; the carbon deposition content can be controlled to be not more than 0.5% when the regenerator and the activator are used and the reaction time is 90min at high space velocity, and the results are detailed in table 1.

[ example 3 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 5. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst,copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 mu m, and the content of particles below 80 mu m is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.9mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the high space velocity was achieved (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.4%; the carbon deposition content can be controlled to be not more than 0.5% when the regenerator and the activator are used and the reaction time is 90min at high space velocity, and the results are detailed in table 1.

[ example 4 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 1.5. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank is 0.2m/s, the degassing agent is nitrogen, and the nitrogen is replaced by the fluidized gasThe gaseous components carried over from the bed reactor. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.9mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the high space velocity was achieved (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.4%; the carbon deposition content can be controlled to be not more than 0.5% when the regenerator and the activator are used and the reaction time is 90min at high space velocity, and the results are detailed in table 1.

[ example 5 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 8. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.8mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the space velocity was high (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.3%; the carbon deposition content can be controlled to be not more than 0.5% when the regenerator and the activator are used and the reaction time is 90min at high space velocity, and the results are detailed in table 1.

[ example 6 ]

As shown in fig. 1The nitrobenzene hydrogenation aniline preparation device. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.2m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.7mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the space velocity was high (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.5%; the carbon deposition content can be controlled to be not more than 0.5% when the regenerator and the activator are used and the reaction time is 90min at high space velocity, and the results are detailed in table 2.

[ example 7 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.8m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the superficial gas velocity is 2m/s, the molar ratio of hydrogen to nitrobenzene is 13, and the average reaction temperatureControlling the temperature at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.9mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the high space velocity was achieved (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.3%; the carbon deposition content can be controlled to be not more than 0.5% when the regenerator and the activator are used and the reaction time is 90min at high space velocity, and the results are detailed in table 2.

[ example 8 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the apparent gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 2, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 4.4mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the space velocity was high (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.2%; make itThe carbon deposition content can be controlled to be not more than 0.5% when the regenerator and the activator are used and the reaction time is 90min under high space velocity, and the results are detailed in Table 2.

[ example 9 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 10, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.7mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the space velocity was high (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.6%; the carbon deposition content can be controlled to be not more than 0.5% when the regenerator and the activator are used and the reaction time is 90min at high space velocity, and the results are detailed in table 2.

[ example 10 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. First reactionThe reaction conditions of the reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 180 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.9mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the high space velocity was achieved (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.2%; the carbon deposition content can be controlled to be not more than 0.5% when the regenerator and the activator are used and the reaction time is 90min at high space velocity, and the results are detailed in table 2.

[ example 11 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 220 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated is 0.2m/s, the degassing agent is nitrogen, and the oxygen carried out from the regenerator is replacedA gas component. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.7mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the space velocity was high (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.7%; the carbon deposit content at a high space velocity and a reaction time of 90min using a regenerator and an activator can be controlled to be not more than 0.5%, and the results are detailed in table 3.

[ example 12 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.7mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the space velocity was high (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.4%; the carbon deposit content at a high space velocity and a reaction time of 90min using a regenerator and an activator can be controlled to be not more than 0.5%, and the results are detailed in table 3.

[ example 13 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. Cross section of the third reaction zoneThe ratio of the product to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 5m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 4.0mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the high space velocity was achieved (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.2%; the carbon deposit content at a high space velocity and a reaction time of 90min using a regenerator and an activator can be controlled to be not more than 0.5%, and the results are detailed in table 3.

[ example 14 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity is 0.4m/s, the molar ratio of the hydrogen to the nitrobenzene is 15, and the average reaction temperature is controlled to beAt 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.9mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the high space velocity was achieved (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.3%; the carbon deposit content at a high space velocity and a reaction time of 90min using a regenerator and an activator can be controlled to be not more than 0.5%, and the results are detailed in table 3.

[ example 15 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 15, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.7mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the space velocity was high (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.3%; the carbon deposit content at a high space velocity and a reaction time of 90min using a regenerator and an activator can be controlled to be not more than 0.5%, and the results are detailed in table 3.

[ example 16 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 220 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 4.0mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the high space velocity was achieved (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.2%; the carbon deposit content at a high space velocity and a reaction time of 90min using a regenerator and an activator can be controlled to be not more than 0.5%, and the results are detailed in table 4.

[ example 17 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; second reaction zoneThe reaction conditions are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 280 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.5mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the space velocity was high (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.4%; the carbon deposit content at a high space velocity and a reaction time of 90min using a regenerator and an activator can be controlled to be not more than 0.5%, and the results are detailed in table 4.

[ example 18 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.2m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.9mg/kg, and the valves between the fluidized bed reactor and the regenerator and activator were closedHigh airspeed condition behind door (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.4%; the carbon deposit content at a high space velocity and a reaction time of 90min using a regenerator and an activator can be controlled to be not more than 0.5%, and the results are detailed in table 4.

[ example 19 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.8m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.7mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the space velocity was high (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.2%; the carbon deposit content at a high space velocity and a reaction time of 90min using a regenerator and an activator can be controlled to be not more than 0.5%, and the results are detailed in table 4.

[ example 20 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, and a carrier is twoSilicon oxide, the average particle diameter of the catalyst is 400 μm, and the content of particles below 80 μm is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 10, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.9mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the high space velocity was achieved (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.3%; the carbon deposit content at a high space velocity and a reaction time of 90min using a regenerator and an activator can be controlled to be not more than 0.5%, and the results are detailed in table 4.

[ example 21 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 20, and the average reaction temperature was controlled at 240 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. To be aliveThe superficial gas velocity in the chemical degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.6mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the space velocity was high (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.2%; the carbon deposit content at a high space velocity and a reaction time of 90min using a regenerator and an activator can be controlled to be not more than 0.5%, and the results are detailed in table 5.

[ example 22 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 220 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.9mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the high space velocity was achieved (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.2%; the carbon deposit content at a high space velocity and a reaction time of 90min using a regenerator and an activator can be controlled to be not more than 0.5%, and the results are detailed in table 5.

[ example 23 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. First of allThe ratio of the cross-sectional area of the reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 260 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.6mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the space velocity was high (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.3%; the carbon deposit content at a high space velocity and a reaction time of 90min using a regenerator and an activator can be controlled to be not more than 0.5%, and the results are detailed in table 5.

[ example 24 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; third reaction zone reaction stripThe parts are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The average regeneration temperature in the regenerator was 380 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.8mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the space velocity was high (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 1.3%; the carbon deposit content at a high space velocity and a reaction time of 90min using a regenerator and an activator can be controlled to be not more than 0.75%, and the results are detailed in table 5.

[ example 25 ]

The device for preparing aniline by nitrobenzene hydrogenation is shown in figure 1. The ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone was 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The average regeneration temperature in the regenerator was 450 ℃. The superficial gas velocity in the spent degassing tank was 0.2m/s, and the degassing agent was nitrogen gas, and the gas components carried out from the fluidized bed reactor were replaced. The superficial gas velocity in the degassing tank to be activated was 0.2m/s, and the degassing agent was nitrogen gas, and the oxygen-containing gas component carried out from the regenerator was replaced. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 3.8mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the space velocity was high (0.9 h)^-1) At the time of reactionThe carbon deposition amount is 1.3% when the time is 90 minutes; the carbon deposit content at a high space velocity and a reaction time of 90min using a regenerator and an activator can be controlled to be not more than 0.15%, and the results are detailed in table 5.

[ COMPARATIVE EXAMPLE 1 ]

The fluidized bed reactor device for preparing aniline by nitrobenzene hydrogenation in the prior art is adopted, the reactor has only one zone, and the regenerator and the activator which are the same as those in the example 1 are adopted. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 5%. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 4.8mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the space velocity was high (0.9 h)^-1) The carbon deposition amount at the time of the next reaction time of 90 minutes was 3.7%; the carbon deposit content at a high space velocity and a reaction time of 90min using a regenerator and an activator can be controlled to be not more than 0.5%, and the results are detailed in table 6.

[ COMPARATIVE EXAMPLE 2 ]

The fluidized bed reactor device for preparing aniline by nitrobenzene hydrogenation of the invention adopts the same reaction conditions as the example 1, and the ratio of the cross-sectional area of the first reaction zone to the cross-sectional area of the second reaction zone is 2. The ratio of the cross-sectional area of the third reaction zone to the cross-sectional area of the second reaction zone was 4. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 6%. The reaction conditions of the first reaction zone are as follows: the superficial gas velocity is 0.6m/s, the molar ratio of the hydrogen to the nitrobenzene is 8, and the average reaction temperature is controlled at 200 ℃; the reaction conditions of the second reaction zone are as follows: the apparent gas velocity is 2m/s, the molar ratio of the hydrogen to the nitrobenzene is 13, and the average reaction temperature is controlled at 250 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity was 0.4m/s, the molar ratio of hydrogen to nitrobenzene was 15, and the average reaction temperature was controlled at 240 ℃. The regenerator and the activator are not provided. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 4.0mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the high space velocity was achieved (0.9 h)^-1) The amount of carbon deposition at 90 minutes was 3.7%, and the results are shown in Table 6.

[ COMPARATIVE EXAMPLE 3 ]

The fluidized bed reactor device for preparing aniline by nitrobenzene hydrogenation in the prior art is adopted, and the reactor has only one zone and is not provided with a regenerator and an activator. The catalyst is a metal-loaded catalyst, copper is used as a main active component, a carrier is silicon dioxide, and the average particle size of the catalyst is 400 microns, and the content of particles below 80 microns is 5%. The nitrobenzene content in the crude aniline at the outlet of the fluidized bed was 4.8mg/kg, and after closing the valves between the fluidized bed reactor and the regenerator and activator, the space velocity was high (0.9 h)^-1) The amount of carbon deposition at 90 minutes was 3.7%, and the results are shown in Table 6.

Obviously, the method has great technical advantages and can be used for industrial production of aniline by nitrobenzene hydrogenation.

TABLE 1

TABLE 2

TABLE 3

TABLE 4

TABLE 5

TABLE 6

Claims

1. A coupling reaction device for preparing aniline by nitrobenzene hydrogenation comprises: the device comprises a fluidized bed reactor (3), a degassing tank to be regenerated (12), a regenerator (13), a degassing tank to be activated (16) and an activator (19), wherein the fluidized bed reactor (3) comprises a first reaction zone (4) at the lower part, a second reaction zone (5) at the middle section and a third reaction zone (6) at the upper part, the degassing tank to be regenerated (12) is respectively communicated with the fluidized bed reactor (3) and the regenerator (13), the degassing tank to be activated (16) is respectively communicated with the regenerator (13) and the activator (19), and the activator (19) is communicated with the fluidized bed reactor (3).

2. The coupling reaction device for hydrogenation of nitrobenzene to aniline according to claim 1, wherein the bottoms of the first reaction zone (4), the second reaction zone (5) and the third reaction zone (6) in the fluidized bed reactor (3) are respectively provided with a gas raw material inlet device.

3. The coupling reaction device for hydrogenation of nitrobenzene to aniline according to claim 1, wherein the ratio of the cross-sectional area of the first reaction zone (4) to the cross-sectional area of the second reaction zone (5) is 1.2 to 5.

4. The coupled reaction device for hydrogenation of nitrobenzene to aniline according to claim 1, wherein the ratio of the cross-sectional area of the third reaction zone (6) to the cross-sectional area of the second reaction zone (5) is between 1.5 and 8.

5. A coupling reaction method for preparing aniline by nitrobenzene hydrogenation, which adopts the device of claims 1-4, comprises the following steps:

(a) the vaporized nitrobenzene and hydrogen raw materials enter a gas chamber and then enter a fluidized bed reactor (3) through a gas distributor (2), catalyst particles in the reactor are pushed to be fluidized, then are fluidized and contacted in a first reaction zone (4), and are subjected to preliminary slow reaction, and gas and part of the catalyst particles enter a second reaction zone (5) to further react violently with raw materials containing hydrogen and nitrobenzene from a second feeding pipeline (11);

(b) the incompletely reacted starting material and the catalyst particles then flow into the third reaction zone (6) and are mixed with a hydrogen-rich gas from the third feed line (10) for further reaction; then the reaction product and a small part of catalyst particles are separated by a cyclone separator (9), the small part of particles returns to the first reaction zone (4), and the crude product gas (8) flows out of the fluidized bed reactor (3) and enters a subsequent separation section;

(c) after the catalyst is partially coked in the reaction process, the coked catalyst is degassed by a to-be-regenerated degassing tank (12) in a third reaction zone (6) and then enters a regenerator (13) to be introduced with oxygen for carbon burning regeneration; the regenerated catalyst is degassed by a degassing tank (16) to be activated and enters an activator (19) to be activated, hydrogen is introduced for activation, and the activated catalyst returns to the fluidized bed reactor (3) to continue catalytic action.

6. The coupling reaction method for preparing aniline by nitrobenzene hydrogenation according to claim 5, wherein the catalyst is a metal-supported catalyst, copper is used as a main active component, the carrier is alumina or silicon dioxide, the average particle size of the catalyst is 50-600 μm, and the content of particles below 80 μm is not less than 2%.

7. The coupled reaction method for preparing aniline by nitrobenzene hydrogenation according to claim 5, wherein the reaction conditions in the first reaction zone in the fluidized bed reactor (3) are as follows: the superficial gas velocity is 0.2-0.8m/s, the molar ratio of the hydrogen to the nitrobenzene is 2-10, and the average reaction temperature is controlled at 220 ℃ of 180 ℃; the reaction conditions of the second reaction zone are as follows: the superficial gas velocity is 0.6-5.0m/s, the molar ratio of the hydrogen to the nitrobenzene is 8-15, and the average reaction temperature is controlled at 220-280 ℃; the reaction conditions of the third reaction zone are as follows: the superficial gas velocity is 0.2-0.8m/s, the molar ratio of the hydrogen to the nitrobenzene is 10-20, and the average reaction temperature is controlled at 220-260 ℃.

8. The coupled reaction method for preparing aniline by nitrobenzene hydrogenation according to claim 5, characterized in that the reaction conditions in the regenerator (13) are as follows: the apparent gas velocity is 0.1-0.6m/s, and the average regeneration temperature is 350-450 ℃; the reaction conditions in the activator (19) are as follows: the apparent gas velocity is 0.1-0.6m/s, and the average activation temperature is 200-.

9. The coupling reaction method for preparing aniline by nitrobenzene hydrogenation according to claim 4, characterized in that the superficial gas velocity in the degassing tank (12) is 0.05-0.5m/s, the degassing agent is one or a mixture of several inert gases such as nitrogen, water vapor and carbon dioxide, and the gas components brought out from the fluidized bed reactor (3) are replaced.

10. The coupled reaction method for preparing aniline by nitrobenzene hydrogenation according to claim 4, characterized in that the superficial gas velocity in the degassing tank (16) to be activated is 0.05-0.5m/s, the degassing agent is one or a mixture of several inert gases such as nitrogen, water vapor and carbon dioxide, and the oxygen-containing gas component carried out from the regenerator (13) is replaced.