A 1,5-diaminonaphthalene production apparatus

Abstract

The utility model relates to the technical field of chemical equipment relates to a 1, 5 -diaminonaphthalene production device, including the reaction kettle that is equipped with heat exchange device and stirring device, the feed inlet of reaction kettle is communicated to the material preparation tank and liquid ammonia storage tank through pipeline, valve and pump respectively, and the discharge port of reaction kettle is communicated to crystallization kettle, first filtering device, reflux kettle, second filtering device and drying device in proper order through pipeline, valve and pump. The utility model production process is simple, and the reaction process is easy to control, and the production product yield is high, and the quality is good, and is easy to industrial production.

Description

Technical Field

[0001] This utility model relates to the field of chemical equipment technology, and in particular to a 1,5-diaminonaphthalene production device. Background Technology

[0002] 1,5-Diaminonaphthalene (NDA), also known as 1,5-naphthyldiamine, is an important aromatic amine compound. As an intermediate in organic synthesis, it has wide applications in pigments, dyes, pharmaceuticals, rubber additives, resins, and photosensitive materials. In particular, 1,5-diaminonaphthalene can be used to synthesize 1,5-naphthalene diisocyanate (NDI), which can be further used to synthesize high-performance polyurethanes, thus creating a significant market demand.

[0003] Currently, the main synthetic methods for producing 1,5-diaminonaphthalene include halogenation ammoniation, naphthoquinone ammonolysis, nitration reduction, and cyclization. Among these, halogenation ammoniation produces a large amount of the byproduct 1,4-dibromonaphthalene, which is difficult to separate and purify. Nitration reduction requires a precious metal catalyst (Pd / C – expensive) or a specially treated non-precious metal catalyst (such as modified Raney nickel – highly flammable and dangerous when exposed to air), and the residual nitro compounds after hydrogenation reduction affect the appearance and yield of the product in subsequent NDI production. Cyclation is a complex process with difficult-to-control reaction. Naphthoquinone ammonolysis can effectively overcome the shortcomings of the above-mentioned production methods. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a 1,5-diaminonaphthalene production device that addresses the shortcomings of the existing technology. The production process is simple, the reaction process is easy to control, and the produced products have high yield and good quality, making them easy to industrially produce.

[0005] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0006] A 1,5-diaminonaphthalene production apparatus includes a reactor equipped with a heat exchange device and a stirring device. The feed inlet of the reactor is connected to a preparation tank and a liquid ammonia storage tank via pipes, valves and pumps. The discharge outlet of the reactor is connected in sequence to a crystallization vessel, a first filtration device, a reflux vessel, a second filtration device and a drying device via pipes, valves and pumps.

[0007] Preferably, the preparation tank is a raw material pre-mixing tank, which is equipped with a stirring device and a temperature exchange device; the raw material pre-mixing tank is also connected to a solid material storage tank and a liquid material storage tank through pipes, valves and pumps respectively. The flow meter is a Promass series mass flow meter.

[0008] Preferably, the liquid ammonia storage tank is connected to the reaction vessel via a pressure reducing valve, a flow meter, a weighing device, and corresponding pipelines (ammonia is introduced before the material is heated, but not after the heating begins).

[0009] Preferably, the reactor is a high-pressure reactor, equipped with a solid material inlet, a material outlet, and a pressure relief port; the material outlet is connected to the crystallization reactor via a pipe and a valve, and the pressure relief port is connected to the crystallization reactor via a pipe and a high-pressure buffer. The reactor is a Weihai Chemical Machinery Co., Ltd. FCH-530 / 16 magnetically driven reactor.

[0010] Preferably, the crystallization vessel is equipped with a heat exchange device, a stirring device, and a nitrogen protection device. Jiangsu Gongtang Chemical Equipment Co., Ltd.'s PT series glass-lined crystallization tanks.

[0011] Preferably, both the first and second filtration devices are plate and frame filters.

[0012] Preferably, the reflux vessel is equipped with a temperature exchange device, a stirring device, a material circulation device, and a solvent reflux circulation device, with a condenser installed on the circulation pipe of the solvent reflux circulation device; it also has a solid material inlet, a solvent inlet, and a discharge outlet. Organic impurities in the material are dissolved and removed in the solvent.

[0013] Preferably, the drying device is a vacuum drying oven equipped with a nitrogen protection device. The DZG series drying ovens are from Shanghai Dongfulong Technology Co., Ltd.

[0014] After adopting the above technical solution, the beneficial effects of this utility model are:

[0015] This invention first reacts 1,5-naphthol with ammonia under high pressure to generate 1,5-diaminonaphthalene. To facilitate material recovery and separation, the material is transported to a crystallization kettle for crystallization. After crystallization, most of the material forms small granular crystals, while a small amount forms small powder. This powder forms a suspension with water that cannot separate into layers in a short time. Therefore, the 1,5-diaminonaphthalene and water are separated by a first filtration device. Then, the material is transported to a reflux kettle where a solvent is added for washing. The temperature difference generated by the solvent heating and reflux affects the solubility of the material, causing the powder and some granular material to dissolve. The material is then re-crystallized or continues to grow crystals on the original crystals. At the same time, organic impurities are removed by dissolving and passing through a second filtration device. The solid material obtained from the second filtration device is dried to obtain the finished 1,5-diaminonaphthalene product.

[0016] In summary, the production process of this utility model is simple, the reaction process is easy to control, and the produced products have high yield and good quality, making them suitable for industrial production. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0018] The components include: 1. Reactor; 2. Material preparation tank; 3. Liquid ammonia storage tank; 4. Crystallization vessel; 5. First filtration device; 6. Reflux vessel; 7. Second filtration device; and 8. Drying device. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Example 1:

[0021] like Figure 1 As shown, a 1,5-diaminonaphthalene production apparatus includes a reactor 1 equipped with a heat exchange device (not shown) and a stirring device (not shown). The feed inlet of the reactor 1 is connected to a preparation tank 2 and a liquid ammonia storage tank 3 via pipes (not shown), valves (not shown) and pumps (not shown). The discharge outlet of the reactor 1 is connected to a crystallization vessel 4, a first filter device 5, a reflux vessel 6, a second filter device 7 and a drying device 8 in sequence via pipes, valves and pumps.

[0022] In practical applications, firstly, the raw materials are added to the preparation tank 2 (the jacket of the preparation tank 2 is made of chilled brine) according to the proportion. First, 1,5-naphthol powder (stored in the solid material storage tank) is added, followed by a portion of sodium bisulfite ammonia solution (stored in the liquid material storage tank). After stirring into a paste or suspension, it is transferred to the reaction vessel 1 (pre-cooled to prevent ammonia volatilization). The remaining ammonia water is added to the preparation tank 2 to wash the remaining materials in the preparation tank 2 and pipelines, and then fed into the reaction vessel 1. The feed valve of the reaction vessel 1 is closed, and liquid ammonia is replenished from the liquid ammonia storage tank 3 according to the material detection data (ammonia water concentration) (no replenishment is required if the needs are met).

[0023] During the reaction, the reaction temperature, pressure, and material stirring speed are controlled by a heat exchanger and a stirring device. A pressure relief pipe (not shown) is installed on the top of reactor 1, and a filter screen (not shown) is installed below the pipe to prevent large amounts of material from overflowing. The pressure relief pipe is connected to crystallizer 4 via a high-pressure buffer (not shown). The gas thereafter is treated by a subsequent ammonia removal device. The material remaining after the reaction in reactor 1 (the material pipe inside the reactor is fixed to the reactor wall, with its upper end connected to the discharge port at the top of the reactor and its lower end extending to the bottom of the reactor) after the reaction and pressure relief are completed, remains... The material is forced into the crystallizer 4 by pressure from the feed pipe port at the bottom of the reactor, and then transported through the pipeline to the discharge port at the top of the reactor for cooling and crystallization. When the material temperature drops to about 90°C, the nitrogen valve at the bottom of the crystallizer is opened to purge for 15 minutes to reduce the ammonia concentration. At the same time, the stirring speed is controlled at 25 rpm. When the material temperature drops to about 40°C, crystallization is complete. The material is then discharged into the first filtration device 5 to separate the crystals and the mother liquor. During the discharge process, stirring is continuous, and the nitrogen protection device at the bottom of the reactor needs to be turned on to prevent the material crystals from settling and clogging the feed pipe. After collection, the filter cake material is transferred to the reflux reactor 6, where solvent (approximately 1-2 times the weight of the raw material, which can be reused) is added. The mixture is stirred and heated, refluxed for 30 minutes, and cooled to below 40°C before being sent to the second filtration device 7 for filtration to separate the solvent and the filter cake material. The filter cake material is then put into the drying device 8 for drying to obtain the 1,5-diaminonaphthalene product.

[0024] It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A production apparatus for 1,5-diaminonaphthalene, characterized in that: The reactor includes a heat exchanger and a stirring device. The feed inlet of the reactor is connected to a preparation tank and a liquid ammonia storage tank via pipes, valves and pumps. The discharge outlet of the reactor is connected in sequence to a crystallization vessel, a first filtration device, a reflux vessel, a second filtration device and a drying device via pipes, valves and pumps.

2. The 1,5-diaminonaphthalene production apparatus according to claim 1, characterized in that: The preparation tank is a raw material pre-mixing tank, which is equipped with a stirring device and a temperature exchange device.

3. The 1,5-diaminonaphthalene production apparatus according to claim 1, characterized in that: The liquid ammonia storage tank is connected to the reaction vessel via a pressure reducing valve, flow meter, weighing device and corresponding pipelines.

4. The 1,5-diaminonaphthalene production apparatus according to claim 1, characterized in that: The reactor is a high-pressure reactor, equipped with a solid material inlet, a material outlet, and a pressure relief port; the material outlet is connected to the crystallization reactor through a pipe and a valve, and the pressure relief port is connected to the crystallization reactor through a pipe and a high-pressure buffer.

5. The 1,5-diaminonaphthalene production apparatus according to claim 1, characterized in that: The crystallization vessel is equipped with a heat exchange device, a stirring device, and a nitrogen protection device.

6. The 1,5-diaminonaphthalene production apparatus according to claim 1, characterized in that: Both the first and second filtration devices are plate and frame filters.

7. The 1,5-diaminonaphthalene production apparatus according to claim 1, characterized in that: The reflux kettle is equipped with a temperature exchange device, a stirring device, and a material circulation device. A condenser is installed on the circulation pipe of the material circulation device.

8. The 1,5-diaminonaphthalene production apparatus according to claim 1, characterized in that: The drying device is a vacuum drying oven equipped with a nitrogen protection device.

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