A continuous hydrogenated h-acid production system and method

Abstract

The application provides a continuous hydrogenation H-acid production system and a production method. The production system comprises a preheater, a premixer and a reactor. The inlet of the preheater is communicated with a first pipeline. The outlet of the preheater is communicated with the first inlet of the premixer through a second pipeline. The second inlet of the premixer is communicated with a third pipeline. The outlet of the premixer is communicated with the first inlet of the reactor through a fourth pipeline. The second inlet of the reactor is communicated with a fifth pipeline. The first pipeline is used for inputting a suspended liquid catalyst. The third pipeline is used for inputting hydrogen. The fifth pipeline is used for inputting nitro T-acid. Pumps are arranged on the first pipeline and the fifth pipeline. A compressor is arranged on the third pipeline. The application provides a continuous hydrogenation H-acid production system and a production method. The hydrogenation is continuous. The catalytic reaction time is shortened. The reaction efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of H-acid production technology, specifically, it relates to a continuous hydrogenation H-acid production system and production method. Background Technology

[0002] H-acid (1-amino-8-naphthol-3,6-disulfonic acid) is an important dye intermediate in the production of reactive dyes, acid dyes, and direct dyes. It is readily soluble in alkaline solutions such as sodium hydroxide, sodium carbonate, and ammonia. H-acid has a wide range of applications and has remained a popular product since its introduction. Currently, most H-acid production processes in my country utilize traditional batch processes and iron powder reduction methods. The batch process suffers from problems such as low catalytic efficiency, long reaction times, low catalyst utilization, cumbersome catalyst application, and large amounts of solid waste. The iron powder reduction method uses refined naphthalene as the main raw material and includes processes such as sulfonation, nitration, denitration, neutralization, reduction, pressure filtration, separation, filtration, dissolution, alkali fusion, separation, filtration, and drying. This process is primarily batch-based, with a long process route, low production capacity, low yield, and large amounts of waste.

[0003] Currently, there is another process for producing H-acids, which uses catalytic hydrogenation technology to replace the reduction of nitro-T-acids to amino-T-acids by iron filings in the iron powder reduction method. Specifically, in a batch high-pressure reactor, an appropriate amount of nitro-T-acid is first added to the reactor along with a certain amount of catalyst. After purging the air, hydrogen gas is introduced, and then the temperature is raised to carry out the hydrogenation catalytic reaction of the nitro-T-acids. This can improve the yield and reduce the emission of waste gas, wastewater, and solid waste. However, in the hydrogenation reaction in the batch high-pressure reactor, there is a problem of catalyst wear and loss, resulting in large catalyst consumption and high cost. Moreover, hydrogen, as a raw material participating in the reaction, is in a discontinuous phase, meaning the contact between hydrogen and the catalyst is discontinuous, leading to low reaction efficiency and long reaction time. Summary of the Invention

[0004] To address the aforementioned shortcomings, this invention provides a continuous hydrogenation H-acid production system and method, which enables continuous hydrogenation, shortens the catalytic reaction time, and improves reaction efficiency.

[0005] To solve the above-mentioned technical problems, the embodiments of the present invention adopt the following technical solutions: In a first aspect, embodiments of the present invention provide a continuous hydrogenation H-acid production system, comprising a preheater, a premixer, and a reactor. The inlet of the preheater is connected to a first pipeline, the outlet of the preheater is connected to the first inlet of the premixer via a second pipeline, the second inlet of the premixer is connected to a third pipeline, the outlet of the premixer is connected to the first inlet of the reactor via a fourth pipeline, and the second inlet of the reactor is connected to a fifth pipeline. The first pipeline is used to input a suspended catalyst, the third pipeline is used to input hydrogen gas, and the fifth pipeline is used to input nitro-T-acid. Pumps are provided on both the first and fifth pipelines, and a compressor is provided on the third pipeline.

[0006] As a further improvement of the embodiments of the present invention, it also includes a cooler, a gas-liquid separator, and a solid-liquid separator. The outlet of the reactor is connected to the inlet of the cooler through a sixth pipeline, the outlet of the cooler is connected to the inlet of the gas-liquid separator through a seventh pipeline, and the liquid outlet of the gas-liquid separator is connected to the inlet of the solid-liquid separator through an eighth pipeline.

[0007] As a further improvement of this embodiment of the invention, the pressure in the preheater, premixer, reactor and cooler is 9-20 MPa.

[0008] As a further improvement of this embodiment of the invention, it also includes a catalyst preparation vessel and a catalyst buffer tank. The first inlet of the catalyst preparation vessel is connected to the ninth pipeline, and the second inlet is connected to the tenth pipeline. The ninth pipeline is used to input amino T-acid, and the tenth pipeline is used to input solid catalyst. The outlet of the catalyst preparation vessel is connected to the inlet of the catalyst buffer tank through the twelfth pipeline, and the outlet of the catalyst buffer tank is connected to the first pipeline.

[0009] As a further improvement of this embodiment of the invention, the solid outlet of the solid-liquid separator is connected to the inlet of the catalyst buffer tank.

[0010] As a further improvement of this embodiment of the invention, the temperature in the reactor is 100-200°C.

[0011] Secondly, embodiments of the present invention also provide a continuous hydrogenation method for producing H-acid, employing the above-mentioned H-acid production system, the method comprising: Step 10) The suspended catalyst is continuously fed into the preheater under pressure for preheating, so that the temperature of the suspended catalyst is raised to 80-150°C; Step 20) The preheated suspension of catalyst is continuously fed into the premixer, and hydrogen is continuously introduced into the premixer at the same time. The hydrogen and the catalyst are fully mixed and adsorbed in the premixer. Step 30) The mixture in the premixer is continuously fed into the reactor, and nitro T-acid is continuously fed into the reactor under pressure. The catalytic reduction reaction is carried out under the conditions of pressure of 9-20 MPa and temperature of 100-200℃. The reactor outputs a mixed product of catalyst, hydrogen and amino T-acid.

[0012] As a further improvement to the embodiments of the present invention, it also includes: Step 40) The mixed product output from the reactor is continuously fed into a cooler for cooling, so that the temperature of the mixed product is reduced to 60-90°C; then the cooled mixed product is continuously fed into a gas-liquid separator for gas-liquid separation, the separated hydrogen is pressurized and continuously fed into a premixer, and the separated liquid is fed into a solid-liquid separator for solid-liquid separation to obtain amino T-acid and catalyst.

[0013] As a further improvement to this embodiment of the invention, the method further includes the following step before step 10): Solid catalyst and amino T-acid are added to catalyst preparation vessel for mixing to obtain catalyst suspension. The catalyst suspension is then fed into catalyst buffer tank. The catalyst suspension in the catalyst buffer tank is pressurized and continuously fed into preheater. The mass percentage of catalyst in the catalyst suspension is 1-10%.

[0014] As a further improvement of this embodiment of the invention, in step 40), the catalyst separated by the solid-liquid separator is input into the catalyst buffer tank; by controlling the amount of catalyst suspension input into the catalyst buffer tank, the liquid level in the catalyst buffer tank is maintained at a preset liquid level.

[0015] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: (1) In this invention, the preheater, premixer and reactor all adopt a continuous input and output mode to realize the continuous input of nitro T-acid, hydrogen and catalyst for reaction, and the hydrogenation reduction is carried out by fluidized bed reaction mode, which has short reaction time and high efficiency.

[0016] (2) Use a suspended catalyst to enable continuous input in the preheater, premixer and reactor.

[0017] (3) The catalyst is continuously fed into the preheater for preheating so that the catalyst can quickly reach the reaction temperature in the reactor and react, thereby improving the reaction efficiency.

[0018] (4) The preheated catalyst and hydrogen are continuously fed into the premixer for mixing, so that the contact between hydrogen and catalyst is continuous. The hydrogen adheres well to the surface of the catalyst and can fully contact the nitro T-acid after entering the reactor, thereby improving the catalytic efficiency and yield. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a continuous hydrogenation H-acid production system according to an embodiment of the present invention.

[0020] The diagram includes: preheater 1, premixer 2, reactor 3, cooler 4, gas-liquid separator 5, solid-liquid separator 6, catalyst buffer tank 7, catalyst preparation vessel 8, first pipeline 101, second pipeline 102, third pipeline 103, fourth pipeline 104, fifth pipeline 105, sixth pipeline 106, seventh pipeline 107, eighth pipeline 108, ninth pipeline 109, tenth pipeline 110, eleventh pipeline 111, twelfth pipeline 112, nitro T-acid A, hydrogen B, catalyst C, and amino T-acid D. Detailed Implementation

[0021] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings.

[0022] This invention provides a continuous hydrogenation H-acid production system, such as... Figure 1 As shown, the reactor includes a preheater 1, a premixer 2, and a reactor 3. The inlet of the preheater 1 is connected to a first pipeline 101, which is equipped with a pump and is used to input a suspended catalyst. The outlet of the preheater 1 is connected to the first inlet of the premixer 2 via a second pipeline 102. The second inlet of the premixer 2 is connected to a third pipeline 103, which is equipped with a compressor and is used to input hydrogen. The outlet of the premixer 2 is connected to the first inlet of the reactor 3 via a fourth pipeline 104. The second inlet of the reactor 3 is connected to a fifth pipeline 105, which is equipped with a pump and is used to input nitro-T-acid. Preferably, the pump on the first pipeline 101 is a high-pressure plunger diaphragm pump, and the pump on the fifth pipeline 105 is a high-pressure plunger pump. Preferably, the temperature in the reactor 3 is 100–200°C, and the pressure is 9–20 MPa. Preferably, the catalyst is a nickel catalyst, such as Raney nickel.

[0023] In this embodiment of the H-acid production system, the preheater 1, premixer 2, and reactor 3 all employ a continuous input-output method, enabling the continuous input of nitro-T-acid, hydrogen, and catalyst for reaction. A fluidized bed reaction is used for hydrogenation reduction, resulting in a short reaction time and high efficiency. The catalyst is input in a suspended liquid state to ensure continuous input in the preheater, premixer, and reactor. A preheater is installed before the reactor, where the catalyst is continuously fed and preheated, ensuring it quickly reaches the reaction temperature upon entering the reactor, thus improving reaction efficiency. A premixer is installed between the preheater and reactor, where the preheated catalyst and hydrogen are continuously mixed, ensuring continuous contact between hydrogen and catalyst. The hydrogen adheres well to the catalyst surface, allowing for sufficient contact with the nitro-T-acid upon entering the reactor, improving catalytic efficiency and yield.

[0024] As a preferred embodiment, the H-acid production system of this invention further includes a cooler 4, a gas-liquid separator 5, and a solid-liquid separator 6. The outlet of the reactor 3 is connected to the inlet of the cooler 4 via a sixth pipe 106. The outlet of the cooler 4 is connected to the inlet of the gas-liquid separator 5 via a seventh pipe 107, and the liquid outlet of the gas-liquid separator 5 is connected to the inlet of the solid-liquid separator 6 via an eighth pipe 108.

[0025] In this embodiment of the H-acid production system, a suspended catalyst is first continuously injected into a preheater via a high-pressure pump for heating. The preheated catalyst and hydrogen are then fully mixed and adsorbed in a premixer before entering the reactor. Simultaneously, nitro-T-acid is continuously introduced into the reactor via a high-pressure plunger pump. The reaction is carried out under conditions of 9–20 MPa and 100–200 °C, yielding a mixed suspension of hydrogen, catalyst, and amino-T-acid. This suspension is then cooled to 60–90 °C by a cooler before entering a gas-liquid separator for gas-liquid separation. The separated hydrogen can be repressurized by a compressor and reintroduced into the premixer. The separated mixed suspension of catalyst and amino-T-acid then enters a solid-liquid separator for solid-liquid separation. The separated catalyst can then be reintroduced into the H-acid production system, and the separated amino-T-acid is the product.

[0026] Preferably, the pressures in preheater 1, premixer 2, reactor 3, and cooler 4 are all 9–20 MPa, but not equal, with a pressure difference between adjacent units. Under the action of a high-pressure plunger diaphragm pump on the first pipeline connected to preheater 1, a compressor on the third pipeline connected to premixer 1, and a high-pressure plunger pump on the fifth pipeline connected to reactor 3, the material in preheater 1 can flow to premixer 2, the material in premixer 2 can flow to reactor 3, and the material in reactor 3 can flow to cooler 4. This ensures continuous material transfer between preheater 1, premixer 2, reactor 3, and cooler 4, achieving a fluidized bed hydrogenation reduction reaction. Preheater 1, premixer 2, reactor 3, and cooler 4 all employ structures with high pressure resistance. Preheater 1 uses a hot medium to exchange heat with the catalyst, raising the catalyst temperature to 80–150°C. Cooler 4 uses a cold medium to exchange heat with the catalyst, lowering the temperature of the mixed suspension to 60–90°C.

[0027] As a preferred embodiment, the H-acid production system of this invention further includes a catalyst preparation vessel 8 and a catalyst buffer tank 7. The first inlet of the catalyst preparation vessel 8 is connected to a ninth pipeline 109, which is used to input amino-T-acid. The second inlet of the catalyst preparation vessel 8 is connected to a tenth pipeline 110, which is used to input solid catalyst. The outlet of the catalyst preparation vessel 8 is connected to the inlet of the catalyst buffer tank 7 through a twelfth pipeline, and the outlet of the catalyst buffer tank 7 is connected to a first pipeline. In this embodiment, the catalyst preparation vessel 8 is provided to prepare a catalyst suspension of a preset concentration from solid catalyst and amino-T-acid. Since the catalyst suspension of the preset concentration cannot be obtained continuously during the preparation process, but is prepared in batches, in this embodiment, the prepared catalyst suspension is input into the catalyst buffer tank 7, and then the catalyst suspension in the catalyst buffer tank 7 is continuously input into the preheater 1 through a high-pressure plunger diaphragm pump, so that the catalyst is continuously input into the production system, realizing continuous production. The product is prepared using amino-T-acids, which are products of the system, thus avoiding the introduction of new impurities into the system and improving the purity of the product.

[0028] As a preferred example, the solid outlet of the solid-liquid separator 6 is connected to the inlet of the catalyst buffer tank 7.

[0029] In this embodiment, the catalyst obtained after solid-liquid separation by the solid-liquid separator 6 is input into the catalyst buffer tank 7. All the catalyst in the production system is input into the catalyst buffer tank 7 after solid-liquid separation. By controlling the amount of catalyst suspension prepared by the catalyst preparation vessel 8, the liquid level in the catalyst buffer tank 7 is maintained at a preset liquid level, thereby ensuring that the catalyst in the catalyst buffer tank has a stable concentration, that is, the catalyst input into the production system has a stable concentration.

[0030] This invention also provides a continuous hydrogenation method for producing H-acids, using the aforementioned H-acid production system. The method includes: Step 10) The suspended catalyst is continuously pressurized and fed into the preheater 1 for preheating, so that the temperature of the suspended catalyst rises to 80-150°C.

[0031] Step 20) The preheated suspension of catalyst is continuously fed into the premixer 2, and hydrogen is continuously introduced into the premixer 2. The hydrogen and the catalyst are fully mixed and adsorbed in the premixer 2.

[0032] Step 30) The mixture in the premixer 2 is continuously fed into the reactor 3, and nitro T-acid is continuously fed into the reactor 3 under pressure. The catalytic reduction reaction is carried out under the conditions of pressure of 9-20 MPa and temperature of 100-200℃. The reactor 3 outputs a mixed product of catalyst, hydrogen and amino T-acid.

[0033] The production method of this invention is described according to the flow direction of the material after it enters the system. Since the material is continuously fed into the system, the process flow is repetitive. In this method, the preheater, premixer, and reactor all employ a continuous input-output method to achieve continuous input of nitro-T-acid, hydrogen, and catalyst for reaction. A fluidized bed reaction is used for hydrogenation reduction, resulting in a short reaction time and high efficiency. A suspended catalyst is used to ensure continuous input in the preheater, premixer, and reactor. The catalyst is continuously fed into the preheater for preheating, allowing it to quickly reach the reaction temperature in the reactor and improve reaction efficiency. The preheated catalyst is continuously mixed with hydrogen in the premixer, ensuring continuous contact between hydrogen and catalyst. The hydrogen adheres well to the catalyst surface and, upon entering the reactor, can fully contact the nitro-T-acid, improving catalytic efficiency and yield.

[0034] As a preferred example, the method in this embodiment further includes: Step 40) The mixed product output from reactor 3 is continuously fed into cooler 4 for cooling, so that the temperature of the mixed product is reduced to 60-90°C. The cooled mixed product is then continuously fed into gas-liquid separator 5 for gas-liquid separation. The separated hydrogen is then pressurized and continuously fed into premixer 2, and the separated liquid is fed into solid-liquid separator 6 for solid-liquid separation to obtain amino T-acid and catalyst.

[0035] As a preferred example, the method further includes the following step before step 10): Solid catalyst and amino-T-acid are added to catalyst preparation vessel 8 for mixing to obtain catalyst suspension. The catalyst suspension is then fed into catalyst buffer tank 7, and the catalyst suspension in catalyst buffer tank 7 is continuously fed into preheater 1 under pressure. The mass percentage of catalyst in the catalyst suspension is 1-10%.

[0036] Preferably, in step 40), the catalyst separated by the solid-liquid separator 6 is input into the catalyst buffer tank 7. By controlling the amount of catalyst suspension input into the catalyst buffer tank 7, the liquid level in the catalyst buffer tank 7 is maintained at a preset level.

[0037] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the specific embodiments described above. The specific embodiments and descriptions in the specification are merely for further illustrating the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A continuous hydrogenation system for producing H-acids, characterized in that, The reactor includes a preheater (1), a premixer (2), and a reactor (3). The inlet of the preheater (1) is connected to a first pipeline, the outlet of the preheater (1) is connected to the first inlet of the premixer (2) via a second pipeline, the second inlet of the premixer (2) is connected to a third pipeline, the outlet of the premixer (2) is connected to the first inlet of the reactor (3) via a fourth pipeline, and the second inlet of the reactor (3) is connected to a fifth pipeline. The first pipeline is used to input a suspended catalyst, the third pipeline is used to input hydrogen, and the fifth pipeline is used to input nitro T-acid. Pumps are installed on both the first and fifth pipelines, and a compressor is installed on the third pipeline.

2. The continuous hydrogenation H-acid production system according to claim 1, characterized in that, It also includes a cooler (4), a gas-liquid separator (5) and a solid-liquid separator (6). The outlet of the reactor (3) is connected to the inlet of the cooler (4) through a sixth pipeline, the outlet of the cooler (4) is connected to the inlet of the gas-liquid separator (5) through a seventh pipeline, and the liquid outlet of the gas-liquid separator (5) is connected to the inlet of the solid-liquid separator (6) through an eighth pipeline.

3. The continuous hydrogenation H-acid production system according to claim 2, characterized in that, The pressure in the preheater (1), premixer (2), reactor (3) and cooler (4) is 9-20 MPa.

4. The continuous hydrogenation H-acid production system according to claim 2, characterized in that, It also includes a catalyst preparation vessel (8) and a catalyst buffer tank (7). The first inlet of the catalyst preparation vessel (8) is connected to the ninth pipeline, and the second inlet is connected to the tenth pipeline. The ninth pipeline is used to input amino T-acid, and the tenth pipeline is used to input solid catalyst. The outlet of the catalyst preparation vessel (8) is connected to the inlet of the catalyst buffer tank (7) through the twelfth pipeline, and the outlet of the catalyst buffer tank (7) is connected to the first pipeline.

5. The continuous hydrogenation H-acid production system according to claim 4, characterized in that, The solid outlet of the solid-liquid separator (6) is connected to the inlet of the catalyst buffer tank (7).

6. The continuous hydrogenation H-acid production system according to claim 1, characterized in that, The temperature in the reactor (3) is 100-200℃.

7. A method for producing H-acid by continuous hydrogenation, characterized in that, The method of using the H-acid production system according to any one of claims 1 to 6 includes: Step 10) The suspended catalyst is continuously pressurized and fed into the preheater (1) for preheating, so that the temperature of the suspended catalyst rises to 80-150°C; Step 20) The preheated suspension of the catalyst is continuously fed into the premixer (2), and hydrogen is continuously introduced into the premixer (2) at the same time. The hydrogen and the catalyst are fully mixed and adsorbed in the premixer (2). Step 30) The mixture in the premixer (2) is continuously fed into the reactor (3), and nitro T-acid is continuously fed into the reactor (3) under pressure. The catalytic reduction reaction is carried out under the conditions of pressure of 9-20 MPa and temperature of 100-200℃. The reactor (3) outputs a mixture of catalyst, hydrogen and amino T-acid.

8. The method for producing H-acid by continuous hydrogenation according to claim 7, characterized in that, Also includes: Step 40) The mixed product output from the reactor (3) is continuously fed into the cooler (4) for cooling, so that the temperature of the mixed product is reduced to 60-90°C; then the cooled mixed product is continuously fed into the gas-liquid separator (5) for gas-liquid separation, the separated hydrogen is pressurized and continuously fed into the premixer (2), and the separated liquid is fed into the solid-liquid separator (6) for solid-liquid separation to obtain amino T-acid and catalyst.

9. The method for producing H-acid by continuous hydrogenation according to claim 8, characterized in that, The steps preceding step 10) also include: The solid catalyst and amino T-acid are added to the catalyst preparation vessel (8) for mixing to obtain a catalyst suspension. The catalyst suspension is then fed into the catalyst buffer tank (7). The catalyst suspension in the catalyst buffer tank (7) is pressurized and continuously fed into the preheater (1). The mass percentage of the catalyst in the catalyst suspension is 1-10%.

10. The method for producing H-acid by continuous hydrogenation according to claim 9, characterized in that, In step 40), the catalyst separated by the solid-liquid separator (6) is input into the catalyst buffer tank (7); by controlling the amount of catalyst suspension input into the catalyst buffer tank (7), the liquid level in the catalyst buffer tank (7) is maintained at the preset liquid level.

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