A device for synthesizing and producing pyridine base

Abstract

The utility model discloses a pyridine base synthetic production device belongs to pyridine base synthetic technical field, including first preheater and second preheater, first preheater and second preheater all are connected with mixer, the air inlet of mixer is connected liquid nitrogen tank, the discharge port of mixer is connected fixed bed reactor, the discharge port of fixed bed reactor is connected absorption tower, absorption tower is connected extraction column through the pipeline, the first rectifying column is connected through the pipeline to extraction column, the first rectifying column is connected through the pipeline to second rectifying column. The utility model can solve the problem that the existing reaction byproduct is more and miscellaneous, and is not easy to separate. The utility model can reduce the treatment of waste gas, promote the full mixing of feed liquid and extraction liquid, improve extraction efficiency and separation effect, improve the production capacity of extraction tower, reduce the steam energy consumption required for rectification, realize pyridine recovery, improve product separation efficiency and reduce production cost.

Description

Technical Field

[0001] This utility model relates to the field of pyridine base synthesis technology, specifically to a pyridine base synthesis production apparatus. Background Technology

[0002] Pyridine bases include 2-methylpyridine, 3-methylpyridine, 2,6-dimethylpyridine, 3,5-dimethylpyridine, and 2,4,6-trimethylpyridine. They are important chemical raw materials, organic intermediates, and solvents, and can be used to manufacture pesticides, pharmaceuticals, veterinary drugs, fragrances, dyes, and rubber.

[0003] Currently, the main method for synthesizing pyridine bases is the aldehyde-ketone-amine process, which controls the formation of different alkylpyridines by adjusting the aldehyde / ketone-amine ratio. However, the reaction produces numerous and complex byproducts that are difficult to separate. Therefore, improving separation efficiency and reducing energy consumption by directly alkylating pyridine for production followed by separation and purification is a key focus of the industry. Utility Model Content

[0004] The purpose of this invention is to provide a pyridine base synthesis production apparatus that uses pyridine and methanol as raw materials to achieve the recovery of pyridine and the purification of the product alkylpyridine during the reaction, thereby reducing costs and improving efficiency, and thus solving the problems in the prior art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A pyridine base synthesis production apparatus includes a first preheater and a second preheater, both of which are connected to a mixer. The inlet of the mixer is connected to a liquid nitrogen tank, and the outlet of the mixer is connected to a fixed-bed reactor. The outlet of the fixed-bed reactor is connected to an absorption tower, which is connected to an extraction tower via a pipeline. The extraction tower is connected to a first distillation tower via a pipeline, and the first distillation tower is connected to a second distillation tower via a pipeline.

[0007] Preferably, the inlet of the first preheater is connected to the pyridine storage tank, the inlet of the second preheater is connected to the methanol storage tank, the interior of the first and second preheaters is provided with serpentine pipelines, and the thermal catalyst is a mixture of steam and water.

[0008] Preferably, the mixer is provided with a first feed inlet, a second feed inlet and an air inlet at its upper end. The mixer is connected to a first preheater through the first feed inlet, a second preheater through the second feed inlet, and a liquid nitrogen tank through the air inlet. Flow control valves are provided on the first feed inlet, the second feed inlet and the air inlet.

[0009] Preferably, the fixed bed reactor has a feed inlet at the top, a catalyst bed in the middle, and a discharge outlet at the bottom; the feed inlet of the fixed bed reactor is connected to the discharge outlet of the mixer, and a gas distributor is installed on the feed inlet.

[0010] Preferably, the absorption tower has a fixed water spray coil inside, a gas distributor installed on the air inlet, a liquid distributor installed at the bottom, and an exhaust gas treatment device at the top.

[0011] Preferably, the extraction tower is equipped with a spray system and a liquid distributor at the top, rectangular saddle-shaped packing at the top and bottom, a liquid redistributor in the middle, an air inlet on the lower left side of the tower bottom connected to an air pump, a liquid outlet on the lower right side, and a grid plate at the bottom.

[0012] Preferably, the top pipes of the first and second distillation columns are both connected to external condensers, the condensers are connected to reflux tanks, the reflux tanks are connected to vacuum pumps, and vertical reboilers are provided at the bottom of the first and second distillation columns, which are heated by steam.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0014] The mixer of this invention uses a flow control valve to intelligently regulate the feed ratio. A gas distributor is installed at the inlet of the absorption tower to promote uniform absorption of gas by water, reduce waste gas treatment, and maximize the absorption of unreacted pyridine, laying the groundwork for subsequent recovery. For the packed extraction tower, a liquid redistributor is placed in the middle, and rectangular saddle-shaped packing is distributed above and below. Gas is pumped in from the inlet to promote thorough mixing of the feed liquid and the extract liquid, improve extraction efficiency and separation effect, and increase the production capacity of the extraction tower. Two sets of series-connected vacuum distillation equipment are used to reduce the steam energy required for the first and second distillation towers, realize pyridine recovery, improve product separation efficiency, and reduce production costs. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the pyridine base synthesis and production apparatus of this utility model;

[0016] Figure 2 This is a schematic diagram of the extraction tower of this utility model.

[0017] In the diagram: 1. First preheater; 2. Second preheater; 3. Mixer; 4. Liquid nitrogen tank; 5. Fixed bed reactor; 6. Absorber; 7. Extraction tower; 71. Spray system; 72. Liquid distributor; 73. Rectangular saddle packing; 74. Liquid redistributor; 75. Grid plate; 76. Air pump; 8. First distillation column; 9. Second distillation column. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] To address the problem of numerous and complex reaction byproducts that are difficult to separate, please refer to [link / reference needed]. Figure 1-2 The following technical solution is provided in this embodiment:

[0020] A pyridine base synthesis production apparatus includes a first preheater 1 and a second preheater 2.

[0021] In this embodiment, the inlet of the first preheater 1 is connected to the pyridine storage tank, and the inlet of the second preheater 2 is connected to the methanol storage tank. The interiors of the first preheater 1 and the second preheater 2 are equipped with serpentine pipelines, and the thermal catalyst is a mixture of steam and water.

[0022] The first preheater 1 and the second preheater 2 are both connected to the mixer 3, and the air inlet of the mixer 3 is connected to the liquid nitrogen tank 4.

[0023] In this embodiment, the mixer 3 is provided with a first feed port, a second feed port and an air inlet at its upper end. The mixer 3 is connected to the first preheater 1 through the first feed port, the mixer 3 is connected to the second preheater 2 through the second feed port, and the mixer 3 is connected to the liquid nitrogen tank 4 through the air inlet. Flow control valves are provided on the first feed port, the second feed port and the air inlet. The liquid nitrogen tank 4 is provided with a liquid nitrogen valve.

[0024] Specifically, pyridine and methanol are heated and vaporized by the first preheater 1 and the second preheater 2, respectively, and then enter the mixer 3 to be fully mixed with nitrogen.

[0025] The outlet of mixer 3 is connected to fixed-bed reactor 5.

[0026] In this embodiment, the fixed bed reactor 5 has a feed inlet at the top, a catalyst bed in the middle, and a discharge outlet at the bottom. The feed inlet of the fixed bed reactor 5 is connected to the discharge outlet of the mixer 3, and a gas distributor is installed on the feed inlet, which can make the reaction mixed gas flow evenly around the fixed bed reactor 5, achieve better distribution effect, and fully contact the catalyst, thereby improving the reaction effect.

[0027] The outlet of the fixed-bed reactor 5 is connected to the absorption tower 6.

[0028] In this embodiment, the absorption tower 6 has a fixed water spray coil inside, a gas distributor installed on the air inlet, a liquid distributor installed at the bottom, and an exhaust gas treatment device at the top of the tower.

[0029] Specifically, the top of the absorption tower 6 is equipped with a feed inlet, which is connected to the outlet of the fixed-bed reactor 5. After the reaction is completed, the reaction product gas enters the top of the absorption tower 6 from the outlet of the fixed-bed reactor 5 and is fully absorbed by water. The absorption tower 6 has a fixed water spray coil inside, a gas distributor installed on the gas inlet, and a liquid distributor installed at the bottom to promote the uniform absorption of gas by water, reduce the treatment of waste gas, maximize the absorption of reaction products, improve the absorption effect, ensure the recovery of unreacted raw materials, and reduce costs.

[0030] Absorption tower 6 is connected to extraction tower 7 via pipeline.

[0031] In this embodiment, the top of the extraction tower 7 is equipped with a spraying facility 71 and a liquid distributor 72. The upper and lower parts are both rectangular saddle-shaped packing 73, the middle part is equipped with a liquid redistributor 74, the lower left side of the tower bottom is equipped with an air inlet connected to an air pump 76, the lower right side is equipped with a liquid outlet, and the bottom is equipped with a grid plate 75.

[0032] Specifically, the liquid from the outlet of the absorption tower 6 enters the extraction tower 7 and is sprayed into the extraction tower 7. The liquid passes through the rectangular saddle packing 73 and the liquid redistributor 74 to increase the liquid-liquid contact area. At the same time, the gas is pumped in from the air inlet by the air pump 76 to promote the full mixing of the liquid and the extract, improve the extraction efficiency and separation effect, and enhance the production capacity of the extraction tower 7.

[0033] Extraction column 7 is connected to first distillation column 8 via pipeline, and first distillation column 8 is connected to second distillation column 9 via pipeline.

[0034] In this embodiment, the top pipes of the first distillation column 8 and the second distillation column 9 are both externally connected to condensers. The condensers are connected to reflux tanks, which are connected to vacuum pumps. The bottom of the reflux tanks is connected to the first distillation column 8 and the second distillation column 9. Vertical reboilers are provided at the bottom of the first distillation column 8 and the second distillation column 9, which are heated by steam.

[0035] Specifically, the feed liquid enters the first distillation column 8 through the outlet of the extraction column 7 for purification and separation. The pyridine distillate from the top of the column is recovered to the pyridine storage tank through a pipeline, and the distillate from the bottom of the column enters the second distillation column 9 through the outlet for further distillation and purification of alkylpyridine. The use of two sets of series-connected vacuum distillation equipment reduces the required steam energy consumption, realizes pyridine recovery, improves product separation efficiency, and reduces production costs.

[0036] Working Principle: To synthesize alkylpyridine using this device, firstly, the first preheater 1 and the second preheater 2 are opened. Pyridine and methanol enter the first preheater 1 and the second preheater 2 respectively through pipelines, vaporizing into pyridine and methanol gases. These gases then enter the mixer 3 from the outlets of the first preheater 1 and the second preheater 2, respectively. Simultaneously, nitrogen gas from the liquid nitrogen tank 4 is introduced into the mixer 3. The three gases are thoroughly mixed, and their ratio can be controlled by a flow regulating valve. The fixed-bed reactor 5 is heated. At a suitable temperature, the reaction gases enter the fixed-bed reactor 5 through the gas distributor at the feed inlet, where they fully contact and react with the catalyst. Pyridine and methanol... Alkylation reaction yields alkylpyridine. The resulting reactants are discharged into absorption tower 6, where a water spray coil ensures thorough contact between the reactant gas and cooling water, resulting in absorption. The liquid feed is discharged from the bottom of the tower into extraction tower 7, where it falls through a spray system 71 at the top and passes through a rectangular saddle packing 73 and a liquid redistributor 74 to increase the liquid-liquid contact area and mix thoroughly with the extract. The liquid is then discharged into the first distillation tower 8 for purification and separation. The pyridine distillate from the top of the tower is recovered to a pyridine storage tank via a pipeline, while the distillate from the bottom of the tower is discharged into the second distillation tower 9 for further distillation and purification to obtain the final alkylpyridine product.

[0037] In summary, the mixer uses a flow control valve to intelligently regulate the feed ratio, and a gas distributor is installed at the inlet of the absorption tower to promote uniform absorption of gas by water, reduce waste gas treatment, and maximize the absorption of unreacted pyridine, laying the groundwork for subsequent recovery. For the packed extraction tower, a liquid redistributor is placed in the middle, with rectangular saddle-shaped packing distributed above and below. An air pump is used to inject gas from the inlet to promote thorough mixing of the feed liquid and the extract liquid, improve extraction efficiency and separation effect, and increase the production capacity of the extraction tower. Two sets of series-connected vacuum distillation equipment are used to reduce the steam energy required for the first and second distillation towers, achieve pyridine recovery, improve product separation efficiency, and reduce production costs.

[0038] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A pyridine base synthesis production apparatus, comprising a first preheater (1) and a second preheater (2), characterized in that: The first preheater (1) and the second preheater (2) are both connected to the mixer (3). The inlet of the mixer (3) is connected to the liquid nitrogen tank (4). The outlet of the mixer (3) is connected to the fixed bed reactor (5). The outlet of the fixed bed reactor (5) is connected to the absorption tower (6). The absorption tower (6) is connected to the extraction tower (7) through a pipeline. The extraction tower (7) is connected to the first distillation tower (8) through a pipeline. The first distillation tower (8) is connected to the second distillation tower (9) through a pipeline.

2. The pyridine base synthesis production apparatus according to claim 1, characterized in that: The inlet of the first preheater (1) is connected to the pyridine storage tank, and the inlet of the second preheater (2) is connected to the methanol storage tank. The interior of the first preheater (1) and the second preheater (2) is equipped with serpentine pipelines, and the thermal catalyst is a mixture of steam and water.

3. The pyridine base synthesis production apparatus according to claim 1, characterized in that: The mixer (3) is provided with a first feed inlet, a second feed inlet and an air inlet at its upper end. The mixer (3) is connected to the first preheater (1) through the first feed inlet, the mixer (3) is connected to the second preheater (2) through the second feed inlet, and the mixer (3) is connected to the liquid nitrogen tank (4) through the air inlet. Flow control valves are provided on the first feed inlet, the second feed inlet and the air inlet.

4. The pyridine base synthesis production apparatus according to claim 1, characterized in that: The fixed bed reactor (5) has a feed inlet at the top, a catalyst bed in the middle, and a discharge outlet at the bottom. The feed inlet of the fixed bed reactor (5) is connected to the discharge outlet of the mixer (3), and a gas distributor is installed on the feed inlet.

5. The pyridine base synthesis production apparatus according to claim 1, characterized in that: The absorption tower (6) has a fixed water spray coil inside, a gas distributor installed on the air inlet, a liquid distributor installed at the bottom, and a tail gas treatment device at the top.

6. The pyridine base synthesis production apparatus according to claim 1, characterized in that: The extraction tower (7) is equipped with a spray system (71) and a liquid distributor (72) at the top. The upper and lower parts are filled with rectangular saddle-shaped packing (73). The middle part is equipped with a liquid redistributor (74). The bottom left side of the tower is equipped with an air inlet connected to an air pump (76). The bottom right side is equipped with a liquid outlet. The bottom is equipped with a grid plate (75).

7. The pyridine base synthesis production apparatus according to claim 1, characterized in that: The top pipes of the first distillation column (8) and the second distillation column (9) are both connected to external condensers. The condensers are connected to the reflux tank, which is connected to the vacuum pump. The bottom of the first distillation column (8) and the second distillation column (9) are equipped with vertical reboilers, which are heated by steam.

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