Low-carbon fatty amine production device and low-carbon fatty amine production method

Abstract

The invention discloses a low-carbon fatty amine production device and a low-carbon fatty amine production method. The production device comprises a low-carbon fatty amine reaction unit and a reactive distillation unit, the reactive distillation unit comprises a distillation deamination tower; the rectification deamination tower is provided with a reaction liquid inlet, and the reaction liquid inlet is connected with the low-carbon fatty amine reaction unit; a rectifying section and a stripping section are sequentially arranged in the rectifying deamination tower from top to bottom, and a gas phase reaction zone is arranged in the stripping section; a raw material inlet is formed in the side wall of the rectification deamination tower and is positioned below the stripping section; and the reaction liquid inlet is positioned between the stripping section and the rectifying section. According to the reactive distillation unit and the method for producing the low-carbon fatty amine by using the reactive distillation unit, the selectivity of polyalkylamine in a low-carbon fatty amine product can be improved by 10% or above.

Description

Technical Field

[0001] The present application relates to a low-carbon fatty amine production device and a low-carbon fatty amine production method, belonging to the field of low-carbon nitrogen-containing chemical production. Background Art

[0002] Low-carbon fatty amines are an important type of organic chemical raw materials. Common ones include ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, etc. They are widely used in downstream industries such as pesticides, medicines, new energy materials, coatings, dyes, catalysts, curing agents, cosmetics, food additives, fertilizer sustained-release agents, preservatives, etc.

[0003] Low-carbon fatty amines are generally prepared by reacting ammonia with corresponding ketones or alcohols. The reaction is usually an exothermic reaction. Both fixed bed reactors and tubular reactors are used. The organic amines in the product are mostly a mixture of two or more amines. Limited by the thermodynamic equilibrium of the reaction, it is difficult to improve the selectivity of polyalkylamines with added value. In industry, a large amount of purified low-alkylamines are usually used in a cyclic reaction to improve the selectivity of polyalkylamines, resulting in a large amount of energy waste.

[0004] Patent CN202210415190.8 discloses a method for continuously preparing triethylamine, and the steps are as follows: S1. The multiphase catalyst is hydrogenated and activated and loaded into the middle section of the reactor; S2. Liquid ammonia and ethanol are sent into the mixer through a feed pump, mixed and then enter the reactor for hydrogenation reduction reaction to obtain a reaction liquid and unreacted hydrogen; S3. The unreacted hydrogen and the reaction liquid are separated into gas and liquid in a gas-liquid separation tank, and the reaction liquid is sent to a deammoniation tower for deammoniation to obtain a deaminated reaction liquid and unreacted ammonia; S4. The unreacted ammonia is condensed and then reused, and the deaminated reaction liquid enters a six-stage distillation tower for separation, and the obtained diethylamine and ethanol are returned to the mixer for continued reuse, and the triethylamine is also obtained.

[0005] Patent CN202010606411.0 discloses a method for selectively producing triethylamine, comprising the following steps: (1) a mixed solution of ethanol and liquid ammonia in a mass ratio of 4.5-7.8:1 is preheated, vaporized, and heat-exchanged before entering a reactor, and a gas-phase catalytic reaction is carried out in the presence of hydrogen, and monoethylamine, diethylamine, and triethylamine are obtained by multiple fractionation; (2) a portion of the diethylamine obtained in step (1) is mixed with ethanol in a molar ratio of diethylamine to ethanol of 1:1, heated to 150°C, and reacted to obtain triethylamine. Summary of the invention

[0006] Reactive distillation is the process of separating products by distillation while carrying out the reaction. It is one of the important methods of chemical process intensification. It has been used in reactions such as esterification, etherification, hydrogenation and aromatic alkylation. It has the advantages of high conversion rate, good selectivity, low investment and low energy consumption. It has been widely used in recent years.

[0007] In view of the existing problems, the present invention proposes a reaction distillation device and a method for producing low-carbon fatty amines using the same. A catalyst bed is set at an appropriate position in a distillation deamination tower, and a raw material ketone or alcohol is added to the bottom of the tower. The selectivity of the target product is improved by coupling reaction and distillation, and the reaction heat is effectively utilized to reduce the separation energy consumption.

[0008] The purpose of the present application is to provide a reactive distillation device and a method for producing low-carbon fatty amines using the same. The method is to set up multiple gas phase reaction zones in the gas phase zone at appropriate positions of the stripping section of the distillation deamination tower, and add raw material ketone or alcohol to the bottom of the tower to increase the concentration of the raw material ketone or alcohol and low alkylamine in the catalyst bed area. By reactive distillation, the selectivity of the current product polyalkylamine is improved, and the reaction heat is effectively utilized to reduce the separation energy consumption.

[0009] According to one aspect of the present application, a low-carbon fatty amine production device is provided, the low-carbon fatty amine production device comprising a low-carbon fatty amine reaction unit and a reactive distillation unit;

[0010] The reactive distillation unit comprises a distillation deamination tower;

[0011] The rectification and deamination tower is provided with a reaction liquid inlet, and the reaction liquid inlet is connected to the low-carbon fatty amine reaction unit;

[0012] The rectifying and deamination tower is composed of a rectifying section and a stripping section from top to bottom, and a gas phase reaction zone is provided in the stripping section;

[0013] The side wall of the rectification and deamination tower is provided with a raw material inlet, and the raw material inlet is located below the stripping section;

[0014] The reaction liquid inlet is located between the stripping section and the rectifying section.

[0015] Optionally, the stripping section is provided with N+1 layers of trays or N+1 layers of packing;

[0016] The gas phase reaction zone is composed of N gas phase reaction layers, N≥2;

[0017] The gas phase reaction layer is located below the tray or packing.

[0018] Optionally, 2≤N≤30.

[0019] Optionally, the height of the gas phase reaction layer is 100 to 1000 mm.

[0020] Optionally, when a tray is provided in the stripping section,

[0021] In the stripping section, the spacing between the tower plates is 600 to 2000 mm;

[0022] The distance between the gas phase reaction layer and the upper tower plate is 200-800 mm.

[0023] Optionally, when a filler is provided in the stripping section,

[0024] The gas phase reaction layer is provided with a liquid channel, and the liquid collected by the upper packing layer flows into the lower packing layer through the liquid channel.

[0025] Optionally, the reactive distillation unit further comprises a condenser, a reboiler, and a gas-liquid separation component;

[0026] A reboiler is provided at the bottom of the rectification and deamination tower;

[0027] The top of the rectification and deamination tower is provided with a light component outlet, which is connected to the condenser and the gas-liquid separation component in sequence, and the gas-liquid separation component is provided with a gas phase outlet and a liquid phase outlet, and the liquid phase outlet is connected to the rectification and deamination tower;

[0028] A deamination liquid outlet is provided at the bottom of the rectification deamination tower.

[0029] Optionally, at least one layer of tower plates or at least one layer of packing is provided in the distillation section.

[0030] As a specific implementation method, the low-carbon fatty amine production device includes a reactive distillation device, which includes a distillation deamination tower, a condenser, a reboiler, and a gas-liquid separation tank. The gas phase outlet of the distillation deamination tower is connected to the inlet of the condenser, and the gas phase enters the gas-liquid separation tank after being partially condensed by the condenser. The gas phase outlet of the gas-liquid separation tank is ammonia, and the liquid phase of the gas-liquid separation tank is returned to the distillation deamination tower as a reflux liquid. The tower kettle of the distillation deamination tower is provided with a reboiler.

[0031] The distillation deamination tower comprises a distillation section and a stripping section, wherein the distillation section is composed of tower plates or fillers, and the stripping section is provided with a plurality of tower plates or fillers; when the stripping section of the distillation deamination tower is provided with a plurality of tower plates, a plurality of gas phase reaction zones are provided in the gas phase region below the tower plates, the gas phase reaction zones are 200 to 800 mm away from the upper tower plates, and the distance between the tower plates is 600 to 2000 mm; when the stripping section of the distillation deamination tower is provided with fillers, a gas phase reaction zone is provided in the gas phase region below the fillers, and a liquid channel is provided in the gas phase reaction zone, and the liquid collected in the upper filler layer flows into the lower filler layer through the liquid channel.

[0032] The gas phase reaction zone is arranged below the tower plate or filler with an operating temperature of 120-180°C in the distillation section. The gas phase reaction zone is arranged in two or more layers. The gas phase reaction zone is filled with solid catalyst. To control the pressure drop of the catalyst bed, the height of the gas phase reaction zone is 100-1000mm.

[0033] Another aspect of the present application provides a method for producing low-carbon fatty amines using the above-mentioned low-carbon fatty amine production device, the method comprising:

[0034] (1) A raw material I containing ammonia is introduced into a low-carbon fatty amine reaction unit for reaction to obtain a reaction solution;

[0035] Wherein, the raw material I also contains ketone or alcohol;

[0036] (2) The reaction liquid is introduced into a distillation deamination tower containing a solid catalyst through a reaction liquid inlet, and the raw material II is introduced into the distillation deamination tower through a raw material inlet, contacts with the reaction liquid, reacts, and is distilled and separated to obtain a low-carbon fatty amine product;

[0037] Wherein, the raw material II includes ketone or alcohol.

[0038] Optionally, in the rectification and deamination tower, the operating temperature of the stripping section is 120-180°C.

[0039] Optionally, the operating pressure of the distillation deamination tower is 1.3-1.9 MPaG.

[0040] Optionally, the ratio of the mass flow rate of the raw material II to the mass flow rate of the reaction liquid is 0.05 to 0.5.

[0041] Optionally, the solid catalyst is loaded in the gas phase reaction zone.

[0042] As a specific embodiment, the production method includes:

[0043] The liquid phase product of the reaction from the upstream reactor enters the middle part of the distillation deamination tower. After separation in the distillation section, the light component (mainly ammonia) at the top of the tower is condensed by the condenser and enters the gas-liquid separation tank. The ammonia is discharged from the gas phase port of the gas-liquid separation tank, and the liquid phase of the gas-liquid separation tank is refluxed to the top of the distillation deamination tower. The stripping section of the distillation deamination tower is provided with multiple plates or fillers, and a gas phase reaction zone. The heavier components in the liquid phase product of the reaction enter the stripping section. Under the action of distillation, within a suitable temperature range, the concentration ratio of low-carbon fatty amines in the gas phase changes, the concentration of polyalkylamines is lower and the concentration of low alkylamines is higher, which is conducive to the reaction of low alkylamines with raw material ketones or alcohols to produce polyalkylamines, and can effectively utilize the reaction heat to reduce the energy consumption of the reboiler. A reboiler is provided at the bottom of the distillation deamination tower, which is heated by a heat medium to supplement the energy required for distillation separation. The deammoniation liquid discharged from the bottom of the distillation deamination tower is sent to the downstream separation process.

[0044] The beneficial effects of this application include:

[0045] The present application provides a reactive distillation device and a method for producing low-carbon fatty amines using the same. Multiple gas phase reaction zones are set up in the gas phase zone at an appropriate position of the stripping section of the distillation deamination tower, and raw material ketones or alcohols are added to the bottom of the tower to increase the concentration of raw material ketones or alcohols and low alkylamines in the catalyst bed area. The selectivity of the current product polyalkylamines is improved by reactive distillation, and the reaction heat is effectively utilized to reduce separation energy consumption. Using a reactive distillation device and a method for producing low-carbon fatty amines using the same of the present application, the selectivity of polyalkylamines in the low-carbon fatty amine product can be increased by 10% or more. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a connection diagram of a reaction distillation unit (plate tower) in one embodiment of the present application.

[0047] Figure 2 This is a connection diagram of a reaction distillation unit (packed tower) in one embodiment of the present application.

[0048] List of parts and reference numerals:

[0049] 1-tower plate; 2-gas phase reaction zone of plate tower; 3-packing; 4-gas phase reaction zone of packed tower; 5-liquid flow channel;

[0050] T01-distillation and deamination tower; E01-condenser; E02-reboiler; V01-gas-liquid separation tank. DETAILED DESCRIPTION

[0051] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0052] Unless otherwise specified, the raw materials and catalysts in the examples of this application were purchased through commercial channels.

[0053] The analysis method in the examples of this application is as follows:

[0054] The analysis of low-carbon fatty amines is carried out by gas chromatography, and the specific operation refers to the specification GB / T23961-2023.

[0055] Figure 1 , Figure 2 This is an example of equipment connection using the reactive distillation unit in the low-carbon fatty amine production device of the present application, the difference is Figure 1 In the distillation deamination tower T01, a plate tower is used. Figure 2 In the distillation deamination tower T01 is a packed tower. Figure 1As shown, the reaction liquid phase product from the upstream reactor enters the middle part of the distillation deamination tower T01, and after separation in the distillation section, the light component at the top of the tower (mainly ammonia) is condensed by the condenser E01 and enters the gas-liquid separation tank V01, and the ammonia is discharged from the gas phase port of the gas-liquid separation tank V01, and the liquid phase of the gas-liquid separation tank V01 is refluxed to the top of the distillation deamination tower T01; the stripping section of the distillation deamination tower T01 is provided with multiple tower plates 1 or packings 3, and is provided with a gas phase reaction zone (plate tower gas phase reaction zone 2 and packed tower gas phase reaction zone 4), and the reaction The heavier components in the liquid phase product enter the stripping section. Under the action of distillation, within the appropriate temperature range, the concentration ratio of low-carbon fatty amines in the gas phase changes, and the concentration of polyalkylamines is low, which is conducive to the reaction of low-alkylamines with raw ketones or alcohols to produce polyalkylamines, and can effectively utilize the reaction heat to reduce the energy consumption of the reboiler; a reboiler E02 is provided at the bottom of the distillation deamination tower T01, which is heated by a heat medium to supplement the energy required for distillation separation; the deammoniation liquid discharged from the bottom of the distillation deamination tower T01 is sent to the downstream separation process. When the distillation deamination tower T01 is a packed tower, a liquid flow channel 5 is provided in the gas phase reaction zone 4 of the packed tower, which is used to flow the liquid collected in the upper packing layer into the lower packing through the liquid channel.

[0056] use Figure 1 or Figure 2 The device connection method and the method described in this application can increase the selectivity of polyalkylamines in low-carbon fatty amine products by 10% or more.

[0057] Example 1

[0058] The reactive distillation unit of the present application is used for the liquid phase deamination and reaction process of ethanol amination to ethylamine. The equipment connection example diagram is as follows Figure 1 As shown, a 500mm high gas phase reaction zone is set below the tower plate with an operating temperature in the range of 130-170°C in the distillation section. There are 20 layers of tower plates with a plate spacing of 1200mm. The operating pressure of the distillation deamination tower is 1.6MPaG, and the ratio of the mass flow rate of raw ethanol in the tower bottom to the mass flow rate of the reaction liquid is 0.2.

[0059] The mass ratio of monoethylamine, diethylamine and triethylamine in the reaction liquid phase is 1.5:3.5:5.5. After passing through the reaction distillation unit of the present application, the mass ratio of monoethylamine, diethylamine and triethylamine in the bottom liquid phase becomes 0.5:2.5:7.0, and the selectivity of triethylamine is significantly improved.

[0060] Comparative Example 1

[0061] A conventional distillation tower was used for the deamination process of the reaction liquid phase of ethanol amination to ethylamine, and the operating conditions of the distillation tower were the same as those in Example 1. The mass ratio of monoethylamine, diethylamine, and triethylamine in the reaction liquid phase was 1.5:3.5:5.5, and since no reaction zone was set in the tower, the mass ratio of the three ethylamines in the distillation tower reactor discharge did not change significantly.

[0062] By comparing Example 1 with Comparative Example 1, it can be seen that the use of the reactive distillation apparatus of the present application significantly improves the selectivity of triethylamine in the product.

[0063] Example 2

[0064] The reactive distillation unit applied for isopropyl alcohol amination to isopropylamine reaction liquid phase deamination, reaction process, equipment connection example diagram as shown Figure 2 As shown, 5 layers of perforated corrugated packing are arranged below the packing in the operating temperature range of 140-180°C in the distillation section, a gas phase reaction zone with a height of 800mm is arranged between the packings, the operating pressure of the distillation deamination tower is 1.7MPaG, and the ratio of the mass flow rate of the raw material isopropanol in the bottom of the tower to the mass flow rate of the reaction liquid is 0.3.

[0065] The mass ratio of isopropylamine to diisopropylamine in the reaction liquid phase is 4.5:5.5. After passing through the reaction distillation unit of the present application, the mass ratio of isopropylamine to diisopropylamine in the bottom liquid phase becomes 3.5:6.5, and the selectivity of diisopropylamine is significantly improved.

[0066] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A low-carbon fatty amine production device, characterized in that: The low-carbon fatty amine production device comprises a low-carbon fatty amine reaction unit and a reactive distillation unit; The reactive distillation unit comprises a distillation deamination tower; The rectification and deamination tower is provided with a reaction liquid inlet, and the reaction liquid inlet is connected to the low-carbon fatty amine reaction unit; The rectifying and deamination tower is composed of a rectifying section and a stripping section from top to bottom, and a gas phase reaction zone is provided in the stripping section; The side wall of the rectification and deamination tower is provided with a raw material inlet, and the raw material inlet is located below the stripping section; The reaction liquid inlet is located between the stripping section and the rectifying section.

2. The low-carbon fatty amine production device according to claim 1, characterized in that: The stripping section is provided with N+1 layers of trays or N+1 layers of fillers; The gas phase reaction zone is composed of N gas phase reaction layers, N≥2; The gas phase reaction layer is located below the tower plate or packing; Preferably, 2≤N≤30; Preferably, the height of the gas phase reaction layer is 100 to 1000 mm.

3. The low-carbon fatty amine production device according to claim 2, characterized in that: When a tray is set in the stripping section, In the stripping section, the spacing between the tower plates is 600 to 2000 mm; The distance between the gas phase reaction layer and the upper tower plate is 200-800 mm.

4. The low-carbon fatty amine production device according to claim 2, characterized in that: When packing is provided in the stripping section, The gas phase reaction layer is provided with a liquid channel, and the liquid collected by the upper packing layer flows into the lower packing layer through the liquid channel.

5. The low-carbon fatty amine production device according to claim 1, characterized in that: The reactive distillation unit also includes a condenser, a reboiler, and a gas-liquid separation component; A reboiler is provided at the bottom of the rectification and deamination tower; The top of the rectification and deamination tower is provided with a light component outlet, which is connected to the condenser and the gas-liquid separation component in sequence, and the gas-liquid separation component is provided with a gas phase outlet and a liquid phase outlet, and the liquid phase outlet is connected to the rectification and deamination tower; A deamination liquid outlet is provided at the bottom of the rectification deamination tower.

6. The low-carbon fatty amine production device according to claim 1, characterized in that: At least one layer of tower plates or at least one layer of fillers is arranged in the rectification section.

7. A method for producing low-carbon fatty amines using the low-carbon fatty amine production device according to any one of claims 1 to 6, characterized in that: The method comprises: (1) A raw material I containing ammonia is introduced into a low-carbon fatty amine reaction unit for reaction to obtain a reaction solution; Wherein, the raw material I also contains ketone or alcohol; (2) The reaction liquid is introduced into a distillation deamination tower containing a solid catalyst through a reaction liquid inlet, and the raw material II is introduced into the distillation deamination tower through a raw material inlet, contacts with the reaction liquid, reacts, and is distilled and separated to obtain a low-carbon fatty amine product; Wherein, the raw material II includes ketone or alcohol.

8. The method according to claim 7, characterized in that In the rectification and deamination tower, the operating temperature of the stripping section is 120-180°C. Preferably, the operating pressure of the distillation deamination tower is 1.3-1.9 MpaG.

9. The method according to claim 7, characterized in that: The ratio of the mass flow rate of the raw material II to the mass flow rate of the reaction liquid is 0.05 to 0.

5.

10. The method according to claim 7, characterized in that The solid catalyst is loaded in the gas phase reaction zone.

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