CN115636752A - Method for preparing o-phenylenediamine by using jet loop reactor - Google Patents

Abstract

The invention discloses a method for preparing o-phenylenediamine by using a jet loop reactor. Catalyst, o-nitroaniline and water are added into the reactor, hydrogen gas is continuously fed into the reactor, and hydrogen gas is continuously pumped into the reactor. A certain mass ratio of o-nitroaniline and water, the raw materials in the reactor form a liquid phase material, and a part of the liquid phase material enters the reactor from the top inlet of the injector after passing through the reactor, filter, circulation pump, heat exchanger and static mixer Circulating mixed reaction is carried out in the reactor, a part of the liquid phase material is extracted through the extraction pump and the gas-liquid separator, and the o-phenylenediamine product is prepared. The liquid phase material can realize the circular reaction in the reactor, realize continuous production, and use water as the Solvent, compared with the traditional organic solvent method, can effectively reduce the impurity content and improve the reaction selectivity. The product content of o-phenylenediamine is high, and the reaction yield is high. Economical and environmentally friendly, suitable for industrial production.

Description

A kind of method utilizing jet loop reactor to prepare o-phenylenediamine

technical field

The invention relates to the technical field of preparing o-phenylenediamine by using a jet loop reactor.

Background technique

O-phenylenediamine is an aromatic amine. It is a colorless monoclinic crystal. It becomes darker in air and sunlight. O-phenylenediamine is usually used as a raw material for dyes, a pesticide intermediate, and pesticides such as carbendazim, benomyl, (methyl ) The main raw material of systemic fungicides such as thiophanate.

The traditional process mostly uses methanol as a solvent. During the preparation process, continuous hydrogenation is used to reduce and prepare o-phenylenediamine. During the hydrogenation process, impurities as shown in the figure below will be produced. These impurities are difficult to separate from the o-phenylenediamine product. The prepared o-phenylenediamine product has low purity and is easy to change color.

X is -CH ₃ , -C ₂ H ₅ , etc., Y is -Cl, -NH ₂ , -OH, etc.

In addition, there are currently many ways to synthesize o-phenylenediamine. The common preparation method is to synthesize o-phenylenediamine using o-nitroaniline as a raw material, using sodium sulfide reduction method or catalytic hydrogenation reduction method, specifically including the following :

(1) Patent US4207261A discloses that 1,4-dichlorobenzene is used as raw material, and nitration is carried out under mixed acid to obtain 2,5-dichloronitrobenzene, which is then reacted with ammonium hydroxide aqueous solution to obtain 4-chloro-2-nitrobenzene phenylenediamine, then 4-chloro-2-nitroaniline is subjected to catalytic hydrogenation, and after dechlorination reaction, o-phenylenediamine is obtained. In this method, mixed acid is added in the nitrification process, which will produce a large amount of waste water and waste residue, which is easy to cause pollution, and the yield of o-phenylenediamine is as low as about 90%.

(2) Patent GB440697A discloses that o-dichlorobenzene is treated with ammonia water in the presence of copper or cuprous chloride and copper, and ammonolysis reaction is carried out. By acidification, copper is precipitated as sulfide and alkalized filtrate, and the product is mixed with copper Compounds are separated to prepare o-phenylenediamine. This method needs to be reacted under high temperature and high pressure conditions, which requires high equipment reaction conditions and long reaction time.

(3) Patent CN112194583A discloses a preparation method of o-phenylenediamine. In the presence of a copper catalyst and a ligand, o-dichlorobenzene reacts with ammonia to obtain o-phenylenediamine. The method adds a catalyst ligand to the reaction system , the reaction conditions are mild, and the reaction efficiency is high, but the product purity of o-phenylenediamine is low, and the yield of o-phenylenediamine is as low as 86.3% to 88.5%.

Contents of the invention

In order to solve the problems in the prior art, there are high impurity content of o-phenylenediamine products in the preparation process of o-phenylenediamine, low content of finished products, low product yield, high production reaction conditions, high production cost, easy to cause environmental pollution in the production process, and difficult Problems in the industrial production of high-purity o-phenylenediamine.

The invention discloses a method for preparing o-phenylenediamine using a jet loop reactor, comprising the following steps:

Step 1: Add catalyst, o-nitroaniline and water into the reactor through the feed pipe, open the inlet pipe and feed nitrogen into the reactor to repeatedly replace the air in the reactor, and then feed hydrogen into the reactor to repeatedly replace the reactor In the inner air step, adjust the temperature in the reactor, open the inlet pipe to continuously feed hydrogen into the reactor, adjust the pressure in the reactor, turn on the circulation pump, and then continuously add the mass ratio of 1:1 to the reactor through the feed pipe. 10 o-Nitroaniline and water, the raw materials in the reactor form a liquid phase material, turn on the circulation pump, the liquid phase material is filtered through the filter, pressurized by the circulation pump, heat exchange control temperature of the heat exchanger, and then sprayed from the static mixer The top inlet of the reactor enters the reactor, and the liquid phase materials are mixed and reacted in the reactor;

Step 2: Part of the liquid phase material after the mixed reaction passes through the reactor, filter, circulating pump, heat exchanger and static mixer, and then enters the reactor from the top inlet of the injector to form a circulating material, which is circulated and mixed in the reactor reaction, the other part of the liquid phase material is extracted through the extraction pump and the gas-liquid separator to obtain a solution of o-phenylenediamine, and the solution of o-phenylenediamine is dehydrated and rectified to prepare the o-phenylenediamine product.

The jet loop reactor comprises: a reactor 1, a filter 2, a circulation pump 3, a heat exchanger 4, a static mixer 5, an ejector 6, a production pump 7, a gas-liquid separator 8, a feed pipe 9 and Intake pipe 10, above the reactor 1 is provided with an injector 6, the static mixer 5 is installed on the upper part of the injector 6, the outlet below the reactor 1 is connected with the inlet of the filter 2 and the circulation pump 3 in turn through the pipeline The outlet on one side of the circulation pump 3 is connected to the inlet of the heat exchanger 4 through a pipeline, and the outlet of the heat exchanger 4 is connected to the inlet of the static mixer 5 through a pipeline, and the outlet of the static mixer 5 is connected to the inlet of the static mixer 5 through a pipeline. The pipe is connected to the top inlet of the injector 6;

The outlet on the other side of the circulation pump 3 is connected to the inlet of the production pump 7 and the gas-liquid separator 8 through pipelines in turn;

One side of the injector 6 is sequentially provided with a feed pipe 9 and an air intake pipe 10;

In some embodiments of the present invention, the mass ratio of the catalyst, o-nitroaniline and water is 0.01-0.1:1:1-10;

In some embodiments of the present invention, the volume of the circulating material in the step 2 is determined by the material volume of the catalyst, o-nitroaniline and water added to the reactor through the feed pipe in the step 1. The volume of diamine solution is determined by the material volume of o-nitroaniline and water continuously added to the reactor with a mass ratio of 1:1 to 10 through the feed pipe in step 1;

In some embodiments of the present invention, the catalyst is one of Raney nickel catalyst, palladium carbon catalyst and platinum carbon catalyst;

In some embodiments of the present invention, in the first step, open the inlet pipe and feed nitrogen into the reactor to repeatedly replace the air in the reactor, and then feed hydrogen into the reactor to repeatedly replace the air in the reactor. for:

Open the air inlet pipe and feed nitrogen into the reactor to replace the air in the reactor repeatedly for more than five times, then feed hydrogen into the reactor and repeat the steps of replacing the air in the reactor, and feed 0.2Mpa nitrogen or hydrogen into the reactor each time ;

In some embodiments of the present invention, the temperature in the reactor in the step 1 is 80-180°C;

In some embodiments of the present invention, the pressure inside the reactor in the first step is 0.5-5.0Mpa;

In some embodiments of the present invention, in the first step, the time for the liquid-phase materials to be mixed and reacted in the reactor is 1-30 minutes;

In some embodiments of the present invention, the heat exchanger (4) is one of a jacketed kettle heat exchanger, a plate heat exchanger, or a shell-and-tube heat exchanger;

In some embodiments of the present invention, the injector (6) is a jet-type Venturi injector.

The beneficial effects produced by adopting the above-mentioned technical scheme are as follows:

(1) In this application, water is used as a solvent, and a catalyst, o-nitroaniline and water with a mass ratio of 0.01 to 0.1:1:1 to 10 are added to the reactor, and nitrogen and hydrogen are introduced into the reactor to replace the reactor. Air, and then continue to feed hydrogen into the reactor, and continuously pump o-nitroaniline and water into the reactor with a mass ratio of 1:1~10. Under the condition of water as the solvent, o-nitroaniline is continuously In the process of hydrogenation, it is reduced to o-phenylenediamine. After dehydration and rectification, o-phenylenediamine products with high content and high yield are prepared. O-phenylenediamine products have high purity, are not easy to change color, and have good quality. Compared with traditional The process can effectively reduce the generation of impurities that affect the quality of o-phenylenediamine, the content of o-phenylenediamine products can reach as high as 99.995%, and the yield can reach as high as 98.08%.

(2) In this application, catalyst, o-nitroaniline and water are added to the reactor, hydrogen is continuously fed into the reactor, and o-nitroaniline with a mass ratio of 1:1 to 10 is continuously pumped into the reactor With water, the raw materials in the reactor form a liquid phase material, turn on the circulation pump, a part of the liquid phase material passes through the reactor, filter, circulation pump, heat exchanger and static mixer, and then enters the reactor from the top inlet of the injector for circulation and mixing Reaction, a part of the liquid phase material is extracted through the extraction pump and the gas-liquid separator to obtain a solution of o-phenylenediamine. The solution of o-phenylenediamine is dehydrated and rectified to prepare the o-phenylenediamine product. The liquid phase material is in the reaction The cyclic reaction can be realized in the device, and then the continuous production can be realized. The reaction mass and heat transfer is good, the reaction time is short, the selectivity is high, the safety of the device is high, and the o-phenylenediamine product with high content and high yield can be prepared; As a solvent, compared with the traditional organic solvent method, it can effectively reduce the impurity content and improve the reaction selectivity. At the same time, it prevents difficult-to-separate impurities from entering the post-processing process, greatly reducing the difficulty of post-processing. The product has high purity, good quality, is not easy to change color, low production cost, economical and environmentally friendly, and has high reaction safety. It is suitable for industrial production.

(3) Open the inlet pipe and continue to feed hydrogen into the reactor, so that the liquid phase materials in the reactor can be mixed and reacted in the reactor, the effect of mass transfer and heat transfer is good, the reaction time is greatly shortened, the side reaction is low, and the product of o-phenylenediamine High content, high reaction yield, large heat exchange area, easy control of reaction temperature and high safety.

(4) A static mixer and a gas-liquid separator are installed in the jet loop reactor, which can effectively enhance the material mixing effect, effectively shorten the reaction time, improve the utilization rate of hydrogen, and reduce consumption.

Description of drawings

In order to illustrate the technical solution of the present application more clearly, the accompanying drawings that need to be used in the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, on the premise of not paying creative work, there are also Additional figures can be derived from these figures.

Fig. 1 is a schematic structural view of the jet loop reactor of the present invention.

Reference signs: 1-reactor; 2-filter; 3-circulation pump; 4-heat exchanger; 5-static mixer; 6-ejector; 7-production pump; 8-gas-liquid separator; 9 - feed pipe; 10 - air intake pipe.

Detailed ways

In order to make the above objects, features and advantages of the present application more obvious and understandable, the present application will be further described in detail below in conjunction with specific embodiments.

Embodiment one

A kind of method utilizing jet loop reactor to prepare o-phenylenediamine, comprises the following steps:

One: As shown in Figure 1, a jet loop reactor is used to prepare o-phenylenediamine. The jet loop reactor includes: reactor 1, filter 2, circulation pump 3, heat exchanger 4, static mixer 5, Ejector 6, production pump 7, gas-liquid separator 8, feed pipe 9 and inlet pipe 10, above the reactor 1 is provided with an ejector 6, and the static mixer 5 is installed on the top of the ejector 6, so The lower outlet of the reactor 1 is connected to the inlet of the filter 2 and the circulation pump 3 in turn through a pipeline, and the outlet on one side of the circulation pump 3 is connected to the inlet of the heat exchanger 4 through a pipeline, and the outlet of the heat exchanger 4 Be connected with the inlet of static mixer 5 by pipeline, the outlet of described static mixer 5 is connected with the top inlet of ejector 6 by pipeline;

The outlet on the other side of the circulation pump 3 is connected to the inlet of the production pump 7 and the gas-liquid separator 8 through pipelines in turn;

One side of the injector 6 is sequentially provided with a feed pipe 9 and an air intake pipe 10;

The injector 6 is a jet-type Venturi injector;

The heat exchanger 4 is a jacketed tank heat exchanger.

Two: the method for preparing o-phenylenediamine by using a jet loop reactor specifically comprises the following steps:

Step 1: Add palladium carbon catalyst, o-nitroaniline and water into the reactor through the feed pipe, the mass ratio of palladium carbon catalyst, o-nitroaniline and water is 0.05:1:4, open the inlet pipe to the reactor Pass nitrogen to replace the air in the reactor repeatedly five times, each time pass 0.2Mpa nitrogen into the reactor, and then pass hydrogen into the reactor to repeatedly replace the air in the reactor five times, each time pass into the reactor 0.2Mpa of hydrogen; adjust the temperature in the reactor to 110°C, open the inlet pipe to continuously feed hydrogen into the reactor, adjust the pressure in the reactor to 2Mpa, and continuously add the mass ratio of 1:4 to the reactor through the feed pipe The o-nitroaniline and water, the raw materials in the reactor form a liquid phase material, the circulation pump is turned on, the liquid phase material is filtered through the filter, the circulation pump is pressurized, the heat exchange is controlled by the heat exchanger, and the static mixer is discharged from the injector. The top inlet enters the reactor, and the liquid phase materials are mixed and reacted in the reactor for 5 minutes;

Step 2: Part of the liquid phase material after the mixed reaction passes through the reactor, filter, circulating pump, heat exchanger and static mixer, and then enters the reactor from the top inlet of the injector to form a circulating material, which is circulated and mixed in the reactor Reaction, a part of the liquid phase material is extracted through the extraction pump and the gas-liquid separator to obtain a solution of o-phenylenediamine. The solution of o-phenylenediamine is dehydrated and rectified under reduced pressure to obtain the o-phenylenediamine product, which is normalized by GC The content is 99.993%, and the yield is 97.58% (calculated based on o-phenylenediamine product).

The volume of the circulating material in the step 2 is determined by the material volume of the palladium carbon catalyst, o-nitroaniline and water added to the reactor through the feed pipe in the step 1, and the solution volume of the o-phenylenediamine in the step 2 is determined by the One is determined by the material volume of o-nitroaniline and water with a mass ratio of 1:4 continuously added to the reactor through the feed pipe.

Said step one and step two utilize jet loop reactor to prepare the chemical reaction formula of o-phenylenediamine as follows:

Embodiment two

A kind of method utilizing jet loop reactor to prepare o-phenylenediamine, comprises the following steps:

One: As shown in Figure 1, a jet loop reactor is used to prepare o-phenylenediamine. The difference between the jet loop reactor and Example 1 is that the heat exchanger 4 is a jacketed plate heat exchanger.

Two: the method for preparing o-phenylenediamine by using a jet loop reactor specifically comprises the following steps:

Step 1: Add Raney nickel catalyst, o-nitroaniline and water into the reactor through the feed pipe, the mass ratio of Raney nickel catalyst, o-nitroaniline and water is 0.1:1:2, open the inlet pipe to the reaction Introduce nitrogen into the reactor to replace the air in the reactor repeatedly six times, each time inject 0.2Mpa nitrogen into the reactor, and then inject hydrogen into the reactor to repeatedly replace the air in the reactor six times, each time into the reactor Introduce hydrogen at 0.2Mpa; adjust the temperature inside the reactor to 90°C, open the inlet pipe and continuously feed hydrogen into the reactor, adjust the pressure inside the reactor to 1Mpa, and continuously add a mass ratio of 1 to the reactor through the feed pipe : 2 o-Nitroaniline and water, the raw materials in the reactor form a liquid phase material, turn on the circulating pump, the liquid phase material is filtered through the filter, the circulating pump is pressurized, the heat exchange is controlled by the heat exchanger, and then the static mixer is used. The top inlet of the injector enters the reactor, and the liquid phase materials are mixed and reacted in the reactor for 30 minutes;

Step 2: Part of the liquid phase material after the mixed reaction passes through the reactor, filter, circulating pump, heat exchanger and static mixer, and then enters the reactor from the top inlet of the injector to form a circulating material, which is circulated and mixed in the reactor Reaction, a part of the liquid phase material is extracted through the extraction pump and the gas-liquid separator to obtain a solution of o-phenylenediamine. The solution of o-phenylenediamine is dehydrated and rectified under reduced pressure to obtain the o-phenylenediamine product, which is normalized by GC The content is 99.992%, and the yield is 96.35% (calculated based on o-phenylenediamine product).

The volume of the circulating material in the step 2 is determined by the material volume of the Raney nickel catalyst, o-nitroaniline and water added to the reactor through the feed pipe in the step 1, and the solution volume of the o-phenylenediamine in the step 2 is determined by In step 1, the material volume of o-nitroaniline and water with a mass ratio of 1:2 is continuously added to the reactor through the feed pipe.

The chemical reaction formula for preparing o-phenylenediamine in step 1 and step 2 using a jet loop reactor is the same as that in embodiment 1.

Embodiment three

A kind of method utilizing jet loop reactor to prepare o-phenylenediamine, comprises the following steps:

One: As shown in Figure 1, a jet loop reactor is used to prepare o-phenylenediamine. The difference between the jet loop reactor and Example 1 is that the heat exchanger 4 is a shell-and-tube heat exchanger with a jacket.

Two: the method for preparing o-phenylenediamine by using a jet loop reactor specifically comprises the following steps:

Step 1: Add palladium carbon catalyst, o-nitroaniline and water into the reactor through the feed pipe, the mass ratio of palladium carbon catalyst, o-nitroaniline and water is 0.03:1:1, open the inlet pipe to the reactor Pass nitrogen to replace the air in the reactor repeatedly seven times, each time pass 0.2Mpa nitrogen into the reactor, and then pass hydrogen into the reactor to repeatedly replace the air in the reactor seven times, each time pass into the reactor 0.2Mpa of hydrogen; adjust the temperature in the reactor to 150°C, open the inlet pipe to continuously feed hydrogen into the reactor, adjust the pressure in the reactor to 3.5Mpa, and continuously add a mass ratio of 1 to the reactor through the feed pipe: 1 o-Nitroaniline and water, the raw materials in the reactor form a liquid phase material, turn on the circulation pump, the liquid phase material is filtered through the filter, the circulation pump is pressurized, the heat exchange is controlled by the heat exchanger, and then the static mixer is sprayed. The top inlet of the reactor enters the reactor, and the liquid phase material is mixed and reacted in the reactor for 10 minutes;

Step 2: Part of the liquid phase material after the mixed reaction passes through the reactor, filter, circulating pump, heat exchanger and static mixer, and then enters the reactor from the top inlet of the injector to form a circulating material, which is circulated and mixed in the reactor Reaction, a part of the liquid phase material is extracted through the extraction pump and the gas-liquid separator to obtain a solution of o-phenylenediamine. The solution of o-phenylenediamine is dehydrated and rectified under reduced pressure to obtain the o-phenylenediamine product, which is normalized by GC The content is 99.989%, and the yield is 97.18% (calculated based on o-phenylenediamine product).

The volume of the circulating material in the step 2 is determined by the material volume of the palladium carbon catalyst, o-nitroaniline and water added to the reactor through the feed pipe in the step 1, and the solution volume of the o-phenylenediamine in the step 2 is determined by the One is determined by the material volume of o-nitroaniline and water continuously added to the reactor with a mass ratio of 1:1 through the feed pipe.

The chemical reaction formula for preparing o-phenylenediamine in step 1 and step 2 using a jet loop reactor is the same as that in embodiment 1.

Embodiment four

A kind of method utilizing jet loop reactor to prepare o-phenylenediamine, comprises the following steps:

One: As shown in Figure 1, a jet loop reactor is used to prepare o-phenylenediamine. The difference between the jet loop reactor and Example 1 is that the heat exchanger 4 is a jacketed plate heat exchanger.

Two: the method for preparing o-phenylenediamine by using a jet loop reactor specifically comprises the following steps:

Step 1: Add platinum carbon catalyst, o-nitroaniline and water into the reactor through the feed pipe, the mass ratio of platinum carbon catalyst, o-nitroaniline and water is 0.08:1:3, open the inlet pipe to the reactor Repeatedly replace the air in the reactor with nitrogen for eight times, each time feed 0.2Mpa nitrogen into the reactor, and then feed hydrogen into the reactor to repeatedly replace the air in the reactor eight times, each time feed into the reactor 0.2Mpa of hydrogen; adjust the temperature in the reactor to 80°C, open the inlet pipe to continuously feed hydrogen into the reactor, adjust the pressure in the reactor to 5Mpa, and continuously add the mass ratio of 1:3 to the reactor through the feed pipe The o-nitroaniline and water, the raw materials in the reactor form a liquid phase material, the circulation pump is turned on, the liquid phase material is filtered through the filter, the circulation pump is pressurized, the heat exchange is controlled by the heat exchanger, and the static mixer is discharged from the injector. The top inlet enters the reactor, and the liquid phase materials are mixed and reacted in the reactor for 3 minutes;

Step 2: Part of the liquid phase material after the mixed reaction passes through the reactor, filter, circulating pump, heat exchanger and static mixer, and then enters the reactor from the top inlet of the injector to form a circulating material, which is circulated and mixed in the reactor Reaction, a part of the liquid phase material is extracted through the extraction pump and the gas-liquid separator to obtain a solution of o-phenylenediamine. The solution of o-phenylenediamine is dehydrated and rectified under reduced pressure to obtain the o-phenylenediamine product, which is normalized by GC The content is 99.995%, and the yield is 98.08% (calculated by o-phenylenediamine product).

The volume of the circulating material in the step 2 is determined by the material volume of the platinum carbon catalyst, o-nitroaniline and water added to the reactor through the feed pipe in the step 1, and the solution volume of the o-phenylenediamine in the step 2 is determined by the One is determined by the material volume of o-nitroaniline and water with a mass ratio of 1:3 continuously added to the reactor through the feed pipe.

The chemical reaction formula for preparing o-phenylenediamine in step 1 and step 2 using a jet loop reactor is the same as that in embodiment 1.

Embodiment five

A kind of method utilizing jet loop reactor to prepare o-phenylenediamine, comprises the following steps:

One: As shown in Figure 1, the jet loop reactor is used to prepare o-phenylenediamine. The difference between the jet loop reactor and Example 1 is that the heat exchanger 4 is a jacketed shell and tube heat exchanger;

Two: the method for preparing o-phenylenediamine by using a jet loop reactor specifically comprises the following steps:

Step 1: Add palladium carbon catalyst, o-nitroaniline and water into the reactor through the feed pipe, the mass ratio of palladium carbon catalyst, o-nitroaniline and water is 0.06:1:10, open the inlet pipe to the reactor Pass nitrogen to replace the air in the reactor repeatedly five times, each time pass 0.2Mpa nitrogen into the reactor, and then pass hydrogen into the reactor to repeatedly replace the air in the reactor five times, each time pass into the reactor 0.2Mpa of hydrogen; adjust the temperature in the reactor to 180°C, open the inlet pipe to continuously feed hydrogen into the reactor, adjust the pressure in the reactor to 3Mpa, and continuously add the mass ratio of 1:10 to the reactor through the feed pipe The o-nitroaniline and water, the raw materials in the reactor form a liquid phase material, the circulation pump is turned on, the liquid phase material is filtered through the filter, the circulation pump is pressurized, the heat exchange is controlled by the heat exchanger, and the static mixer is discharged from the injector. The top inlet enters the reactor, and the liquid phase materials are mixed and reacted in the reactor for 15 minutes;

Step 2: Part of the liquid phase material after the mixed reaction passes through the reactor, filter, circulating pump, heat exchanger and static mixer, and then enters the reactor from the top inlet of the injector to form a circulating material, which is circulated and mixed in the reactor Reaction, a part of the liquid phase material is extracted through the extraction pump and the gas-liquid separator to obtain a solution of o-phenylenediamine. The solution of o-phenylenediamine is dehydrated and rectified under reduced pressure to obtain the o-phenylenediamine product, which is normalized by GC The content is 99.991%, and the yield is 96.93% (calculated by o-phenylenediamine product).

The volume of the circulating material in the step 2 is determined by the material volume of the palladium carbon catalyst, o-nitroaniline and water added to the reactor through the feed pipe in the step 1, and the solution volume of the o-phenylenediamine in the step 2 is determined by the One is determined by the material volume of o-nitroaniline and water continuously added to the reactor with a mass ratio of 1:10 through the feed pipe.

The chemical reaction formula for preparing o-phenylenediamine in step 1 and step 2 using a jet loop reactor is the same as that in embodiment 1.

Embodiment six

A kind of method utilizing jet loop reactor to prepare o-phenylenediamine, comprises the following steps:

One: As shown in Figure 1, the jet loop reactor is used to prepare o-phenylenediamine. The difference between the jet loop reactor and Example 1 is that the heat exchanger 4 is a jacketed shell and tube heat exchanger;

Two: the method for preparing o-phenylenediamine by using a jet loop reactor specifically comprises the following steps:

Step 1: Add platinum carbon catalyst, o-nitroaniline and water into the reactor through the feed pipe, the mass ratio of platinum carbon catalyst, o-nitroaniline and water is 0.01:1:2, open the inlet pipe to the reactor Repeatedly replace the air in the reactor with nitrogen for nine times, each time feed 0.2Mpa nitrogen into the reactor, and then feed hydrogen into the reactor to repeatedly replace the air in the reactor nine times, each time feed into the reactor 0.2Mpa of hydrogen; adjust the temperature in the reactor to 130°C, open the inlet pipe to continuously feed hydrogen into the reactor, adjust the pressure in the reactor to 2.5Mpa, and continuously add a mass ratio of 1 to the reactor through the feed pipe: 2 o-Nitroaniline and water, the raw materials in the reactor form a liquid phase material, turn on the circulation pump, the liquid phase material is filtered through the filter, the circulation pump is pressurized, the heat exchange is controlled by the heat exchanger, and the static mixer is sprayed. The top inlet of the reactor enters the reactor, and the liquid phase material is mixed and reacted in the reactor for 20 minutes;

Step 2: Part of the liquid phase material after the mixed reaction passes through the reactor, filter, circulating pump, heat exchanger and static mixer, and then enters the reactor from the top inlet of the injector to form a circulating material, which is circulated and mixed in the reactor Reaction, a part of the liquid phase material is extracted through the extraction pump and the gas-liquid separator to obtain a solution of o-phenylenediamine. The solution of o-phenylenediamine is dehydrated and rectified under reduced pressure to obtain the o-phenylenediamine product, which is normalized by GC The content is 99.993%, and the yield is 96.56% (calculated by o-phenylenediamine product).

The volume of the circulating material in the step 2 is determined by the material volume of the platinum carbon catalyst, o-nitroaniline and water added to the reactor through the feed pipe in the step 1, and the solution volume of the o-phenylenediamine in the step 2 is determined by the One is determined by the material volume of o-nitroaniline and water with a mass ratio of 1:2 continuously added to the reactor through the feed pipe.

The chemical reaction formula for preparing o-phenylenediamine in step 1 and step 2 using a jet loop reactor is the same as that in embodiment 1.

Comparative example one

Put palladium carbon catalyst, o-nitroaniline and methanol into the autoclave to prepare liquid phase materials, the mass ratio of palladium carbon catalyst, o-nitroaniline and methanol is 0.05:1:4, seal the lid of the kettle, open the inlet pipe to the high pressure Feed nitrogen into the autoclave to replace the air in the autoclave, then vent, and replace 6 times repeatedly, each time feed 0.2Mpa nitrogen into the reactor, then feed hydrogen into the autoclave to repeatedly replace the air in the reactor 6 times, each time Introduce 0.2Mpa hydrogen into the reactor for the first time; after the replacement, adjust the temperature in the autoclave to 110°C, open the inlet pipe and continuously feed hydrogen into the autoclave, adjust the pressure in the autoclave to 2Mpa, and the liquid phase material in the autoclave The mixed reaction was carried out in the autoclave for 2 hours, and the pressure in the autoclave was continued to be kept at 2Mpa. After the mixed reaction for 0.5h, the temperature was lowered to 50°C, the air inlet pipe was opened, and 0.2Mpa nitrogen gas was introduced into the autoclave to replace the air in the autoclave, and the material was discharged while it was hot. The palladium-carbon catalyst was filtered out to prepare a solution of o-phenylenediamine, and the o-phenylenediamine product was prepared by dehydration and rectification under reduced pressure. The GC normalized content was 99.68%, and the impurity content affecting the quality of o-phenylenediamine was 0.28% %, the yield is 90.51%, (calculated with o-phenylenediamine product).

Using methanol as a solvent, o-nitroaniline can also be reduced to o-phenylenediamine under the condition of a catalyst and hydrogen gas continuously flowing in, but the following impurity components will be produced at the same time:

X is -CH ₃ , -C ₂ H ₅ , etc., Y is -Cl, -CH ₂ , -OH, etc.

Comparative example two

A kind of method utilizing jet loop reactor to prepare o-phenylenediamine, comprises the following steps:

One: As shown in Figure 1, a jet loop reactor is used to prepare o-phenylenediamine, and the jet loop reactor is the same as that in Example 1.

Two: the method for preparing o-phenylenediamine by using a jet loop reactor specifically comprises the following steps:

Step 1: Add palladium carbon catalyst, o-nitroaniline and methanol into the reactor through the feed pipe, the mass ratio of palladium carbon catalyst, o-nitroaniline and methanol is 0.05:1:4, open the inlet pipe to the reactor Pass nitrogen to replace the air in the reactor repeatedly five times, each time pass 0.2Mpa nitrogen into the reactor, and then pass hydrogen into the reactor to repeatedly replace the air in the reactor five times, each time pass into the reactor 0.2Mpa of hydrogen; adjust the temperature in the reactor to 110°C, open the inlet pipe to continuously feed hydrogen into the reactor, adjust the pressure in the reactor to 2Mpa, and continuously add the mass ratio of 1:4 to the reactor through the feed pipe The o-nitroaniline and water, the raw materials in the reactor form a liquid phase material, the circulation pump is turned on, the liquid phase material is filtered through the filter, the circulation pump is pressurized, the heat exchange is controlled by the heat exchanger, and the static mixer is discharged from the injector. The top inlet enters the reactor, and the liquid phase materials are mixed and reacted in the reactor for 5 minutes;

Step 2: Part of the liquid phase material after the mixed reaction passes through the reactor, filter, circulating pump, heat exchanger and static mixer, and then enters the reactor from the top inlet of the injector to form a circulating material, which is circulated and mixed in the reactor Reaction, a part of the liquid phase material is extracted through the extraction pump and the gas-liquid separator to obtain a solution of o-phenylenediamine. The solution of o-phenylenediamine is dehydrated and rectified under reduced pressure to obtain the o-phenylenediamine product, which is normalized by GC The content is 99.72%, wherein the impurity content affecting the quality of o-phenylenediamine is 0.23%, and the yield is 94.28% (calculated based on the o-phenylenediamine product).

The volume of the circulating material in the step 2 is determined by the material volume of the palladium carbon catalyst, o-nitroaniline and water added to the reactor through the feed pipe in the step 1, and the solution volume of the o-phenylenediamine in the step 2 is determined by the One is determined by the material volume of o-nitroaniline and water with a mass ratio of 1:4 continuously added to the reactor through the feed pipe.

Using methanol as a solvent, continuously feeding hydrogen into the catalyst, and allowing the liquid phase materials to be circulated and mixed in the reactor, can reduce o-nitroaniline to o-phenylenediamine, but at the same time it will produce as given in Comparative Example 1 impurity components.

By comparing the content and yield results of o-phenylenediamine products in the examples and comparative examples, it can be seen that the present application uses water as a solvent, and adds a catalyst, o-nitroaniline, and o-nitroaniline in a mass ratio of 0.01 to 0.1:1:1 to 10 in the reactor. and water, continue to feed hydrogen into the reactor, and continuously pump o-nitroaniline and water into the reactor with a mass ratio of 1:1 to 10, the raw materials in the reactor form a liquid phase material, and a part of the liquid phase material passes through After the reactor, filter, circulation pump, heat exchanger and static mixer enter the reactor from the top inlet of the injector to carry out the circulation and mixing reaction, a part of the liquid phase material is extracted through the extraction pump and the gas-liquid separator to produce ortho-benzene The diamine solution and the o-phenylenediamine solution are dehydrated and rectified to prepare the o-phenylenediamine product, and the liquid phase material can realize circular reaction in the reactor, thereby realizing continuous production.

Under the condition of water as the solvent and the liquid phase materials are circulated and mixed in the reactor, o-nitroaniline is reduced to o-phenylenediamine during the continuous hydrogenation process, and o-phenylenediamine with high content and high yield can be prepared. Phenylenediamine products, and its impurity content is significantly reduced. O-phenylenediamine products have high purity, are not easy to change color, and have good quality. Compared with traditional processes, the content of o-phenylenediamine products can reach 99.995%, and the yield can reach 98.08% %.

The present application has been described in detail above in conjunction with specific implementations and illustrative examples, but these descriptions should not be construed as limiting the present application. Those skilled in the art understand that without departing from the spirit and scope of the present application, various equivalent replacements, modifications or improvements can be made to the technical solutions and implementations of the present application, all of which fall within the scope of the present application. The scope of protection of the present application is subject to the appended claims.

Claims (10)

1. A method utilizing a jet loop reactor to prepare o-phenylenediamine, characterized in that, the jet loop reactor comprises: reactor (1), filter (2), circulation pump (3), heat exchanger (4), static mixer (5), ejector (6), production pump (7), gas-liquid separator (8), feed pipe (9) and inlet pipe (10), described reactor ( 1) An injector (6) is arranged above, and the static mixer (5) is installed on the upper part of the injector (6), and the lower outlet of the reactor (1) is sequentially connected with the filter (2) and the circulation pump through the pipeline The inlet of (3) is connected, and the one side outlet of described circulation pump (3) is connected with the inlet of heat exchanger (4) through pipeline, and the outlet of described heat exchanger (4) is connected with static mixer (5) through pipeline. The inlet of said static mixer (5) is connected to each other by the top inlet of injector (6) through pipeline; The outlet on the other side of the circulating pump (3) is connected to the inlet of the production pump (7) and the gas-liquid separator (8) through pipelines; One side of the injector (6) is sequentially provided with a feed pipe (9) and an air inlet pipe (10); The method for preparing o-phenylenediamine by using a jet loop reactor comprises the following steps: Step 1: Add catalyst, o-nitroaniline and water into the reactor through the feed pipe, open the inlet pipe and feed nitrogen into the reactor to repeatedly replace the air in the reactor, and then feed hydrogen into the reactor to repeatedly replace the reactor In the inner air step, adjust the temperature in the reactor, open the inlet pipe to continuously feed hydrogen into the reactor, adjust the pressure in the reactor, turn on the circulation pump, and then continuously add the mass ratio of 1:1 to the reactor through the feed pipe. 10 o-Nitroaniline and water, the raw materials in the reactor form a liquid phase material, turn on the circulation pump, the liquid phase material is filtered through the filter, pressurized by the circulation pump, heat exchange control temperature of the heat exchanger, and then sprayed from the static mixer The top inlet of the reactor enters the reactor, and the liquid phase materials are mixed and reacted in the reactor; Step 2: Part of the liquid phase material after the mixed reaction passes through the reactor, filter, circulating pump, heat exchanger and static mixer, and then enters the reactor from the top inlet of the injector to form a circulating material, which is circulated and mixed in the reactor reaction, the other part of the liquid phase material is extracted through the extraction pump and the gas-liquid separator to obtain a solution of o-phenylenediamine, and the solution of o-phenylenediamine is dehydrated and rectified to prepare the o-phenylenediamine product. 2 . The method for preparing o-phenylenediamine using a jet loop reactor according to claim 1 , wherein the mass ratio of the catalyst, o-nitroaniline and water is 0.01˜0.1:1:1˜10. 3. the method utilizing jet loop reactor to prepare o-phenylenediamine according to claim 1, is characterized in that, in described step 2, circulation material volume is added catalyst, o-phenylenediamine in step 1 by feed pipe in reactor. The material volume of nitroaniline and water is determined, and the solution volume of o-phenylenediamine in the step 2 is continuously added into the reactor through the feed pipe in the step 1 with a mass ratio of 1:1 to 10. The material volume of water is determined. 4. the method utilizing jet loop reactor to prepare o-phenylenediamine according to claim 1, is characterized in that, described catalyst is the one in Raney nickel catalyst, palladium carbon catalyst and platinum carbon catalyst. 5. the method utilizing jet loop reactor to prepare o-phenylenediamine according to claim 1, is characterized in that, in described step 1, open inlet pipe and feed nitrogen into reactor to repeatedly replace air in reactor, and then The specific steps of introducing hydrogen into the reactor to repeatedly replace the air step in the reactor are: Open the air inlet pipe and feed nitrogen into the reactor to replace the air in the reactor repeatedly for more than five times, then feed hydrogen into the reactor and repeat the steps of replacing the air in the reactor, and feed 0.2Mpa nitrogen or hydrogen into the reactor each time . 6 . The method for preparing o-phenylenediamine using a jet loop reactor according to claim 1 , wherein the temperature in the reactor in the first step is 80-180° C. 7 . The method for preparing o-phenylenediamine using a jet loop reactor according to claim 1 , wherein the pressure inside the reactor in the first step is 0.5-5.0 Mpa. 8 . The method for preparing o-phenylenediamine using a jet loop reactor according to claim 1 , characterized in that, in the first step, the time for mixing and reacting the liquid phase materials in the reactor is 1 to 30 minutes. 9. the method utilizing jet loop reactor to prepare o-phenylenediamine according to claim 1, is characterized in that, described heat exchanger (4) is the still type heat exchanger of band jacket, plate heat exchanger or One of the shell and tube heat exchangers. 10. The method for preparing o-phenylenediamine using a jet loop reactor according to claim 1, characterized in that the injector (6) is a jet-type Venturi injector.

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