A synthesis system of triethylenetetramine

Abstract

A triethylenetetramine synthesis system, relating to the field of triethylenetetramine production technology, includes an amination reactor, a circulating gas heater, a product collection tank, a liquid-phase mixture separation mechanism, and a gas-phase mixture separation mechanism. The amination reactor has a gas inlet and a liquid outlet at its top and bottom, respectively, and a liquid inlet and a gas outlet on its upper and lower outer walls, respectively. The liquid-phase mixture separation mechanism is connected to the liquid outlet, the gas-phase mixture separation mechanism, the product collection tank, and the cold fluid inlet of the circulating gas heater. The gas-phase mixture separation mechanism is connected to the gas outlet and the cold fluid inlet of the circulating gas heater. The cold fluid outlet of the circulating gas heater is connected to the gas inlet. This invention solves the problem of high circulating gas and product loss rates in existing triethylenetetramine synthesis systems.

Description

Technical Field

[0001] This invention relates to the field of triethylenetetramine production technology, specifically a triethylenetetramine synthesis system. Background Technology

[0002] Triethylenetetramine (TETA) is an important aliphatic polyamine compound. At room temperature, it is a viscous yellow liquid with an ammonia-like odor. It is readily soluble in water and most organic solvents. Due to the presence of four amine groups (primary and secondary amines) in its molecule, it exhibits strong basicity and high reactivity, and is widely used as an epoxy resin curing agent, metal chelating agent, lubricant additive, and an important intermediate in the preparation of polyamides and other chemical products. In industrial production, it is commonly prepared using the hydroamination method with ethylenediamine (EDA), diethylenetriamine (DETA), and hydrogen as raw materials.

[0003] The existing triethylenetetramine synthesis system has gradually revealed its shortcomings during use, mainly in the following aspects: High losses of both recycle gas and product are a significant issue. Specifically, in the hydroammoniation process, hydrogen is recycled as a key reducing and protecting agent. However, this recycling process also leads to high losses of both the recycle gas and the target product, triethylenetetramine. The material discharged from the amination reactor after the reaction consists of a liquid mixture and a gas mixture. The target product, triethylenetetramine, is mainly present in the liquid phase, but the liquid phase dissolves some of the recycle gas. This dissolved recycle gas is released as tail gas during subsequent purification and separation processes and is lost. On the other hand, the gas mixture also carries some vaporized triethylenetetramine product. Before the recycle gas can be reused, these gaseous product impurities need to be removed through purification, resulting in product loss. This bidirectional loss leads to high losses of both the recycle gas and the target product, severely impacting economic efficiency.

[0004] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a synthesis system for triethylenetetramine. This synthesis system, through an integrated separation mechanism, achieves efficient separation and recovery of dissolved circulating gas in a liquid-phase mixture, as well as effective separation and collection of the target product entrained in a gas-phase mixture, thereby significantly reducing the dual losses of circulating gas and target product.

[0006] To address the above problems, the present invention provides the following technical solution: A synthesis system for triethylenetetramine includes an amination reactor, a circulating gas heater, a product collection tank, a liquid-phase mixture separation mechanism, and a gas-phase mixture separation mechanism. The amination reactor has an inlet and an outlet at its top and bottom, respectively, and an inlet and an outlet on its upper and lower outer walls. The liquid-phase mixture separation mechanism is connected to the outlet, the gas-phase mixture separation mechanism, the product collection tank, and the cold fluid inlet of the circulating gas heater. The gas-phase mixture separation mechanism is connected to the outlet and the cold fluid inlet of the circulating gas heater. The cold fluid outlet of the circulating gas heater is connected to the inlet.

[0007] As an optimized solution, the liquid phase mixture separation mechanism includes a hot low-pressure separation tank, a cold low-pressure gas water cooler, a cold low-pressure separation tank, a cold low-pressure gas deep cooler, a gas-liquid separation tank, and a liquid ammonia tank. The liquid inlet, liquid outlet, and gas outlet of the hot low-pressure separation tank are connected to the liquid outlet, the product collection tank, and the hot fluid inlet of the cold low-pressure gas water cooler, respectively. The inlet, liquid outlet, and gas outlet of the cold low-pressure separation tank are connected to the hot fluid outlet of the cold low-pressure gas water cooler, the product collection tank, and the hot fluid inlet of the cold low-pressure gas deep cooler, respectively. The inlet, liquid outlet, and gas outlet of the gas-liquid separation tank are connected to the hot fluid outlet of the cold low-pressure gas deep cooler, the liquid ammonia tank, and the circulating gas heater, respectively.

[0008] As an optimized solution, the gas-phase mixture separation mechanism includes a hot high-pressure gas water cooler, a hot high-pressure separator, a hot high-pressure gas cryostat, and a cold high-pressure separator. The hot fluid inlet of the hot high-pressure gas water cooler is connected to the gas outlet. The inlet, liquid outlet, and gas outlet of the hot high-pressure separator are connected to the hot fluid outlet of the hot high-pressure gas water cooler, the inlet of the cold low-pressure separator, and the hot fluid inlet of the hot high-pressure gas cryostat, respectively. The inlet, liquid outlet, and gas outlet of the cold high-pressure separator are connected to the hot fluid outlet of the hot high-pressure gas cryostat, the inlet of the gas-liquid separator, and the circulating gas heater, respectively.

[0009] As an optimized solution, the amination reactor is provided with a raw material heater and a product-raw material heat exchanger on the side. The cold fluid inlet of the product-raw material heat exchanger is connected to a liquid inlet pipe. The cold fluid outlet, hot fluid inlet, and hot fluid outlet of the product-raw material heat exchanger are respectively connected to the cold fluid inlet and gas outlet of the raw material heater and the hot fluid inlet of the hot high-temperature gas water cooler. The cold fluid outlet of the raw material heater is connected to the liquid inlet.

[0010] As an optimized solution, the external hydrogen replenishment system is connected to the cold fluid inlet of the circulating gas heater via a hydrogen replenishment pipeline.

[0011] Compared with the prior art, the beneficial effects of the present invention are: 1. The liquid-phase mixture in the amination reactor enters the hot low-pressure separator through the outlet. After depressurization, a large amount of light components (hydrogen, ammonia, and low-boiling-point ethylenediamine) rapidly vaporizes and separates from the high-boiling-point liquid-phase products (such as diethylenetriamine and triethylenetetramine). At this point, the gas phase still contains some diethylenetriamine and triethylenetetramine components. The separated liquid phase enters the product collection tank, while the gas phase enters the cold low-pressure water cooler for preliminary cooling and condensation. The higher-boiling-point organic amines (such as ethylenediamine, diethylenetriamine, and triethylenetetramine) are then... After condensation into a liquid, the gas-liquid mixture enters a cold low-pressure separator for sedimentation and separation. The liquid organic amine mixture at the bottom of the cold low-pressure separator enters a product collection tank, while the gas phase (hydrogen and ammonia) at the top enters a cold low-pressure gas separator for deep condensation, causing the ammonia to condense into liquid ammonia. The low-temperature gas-liquid mixture then enters a gas-liquid separator for final separation. The liquid ammonia is collected in a liquid ammonia tank, and the hydrogen is pressurized and heated by a circulating gas heater before being returned to the amination reactor for recycling. Through the above process, efficient separation and recovery of dissolved circulating gas in the liquid phase mixture are achieved. 2. After the gaseous mixture generated in the amination reactor is discharged through the outlet, it first undergoes heat exchange in the product-origin heat exchanger, and then enters the hot high-pressure gas water cooler for preliminary cooling. This causes the organic amines with higher boiling points (such as ethylenediamine, diethylenetriamine, and triethylenetetramine) to condense into liquids, forming a gas-liquid mixture that enters the hot high-pressure separator. After gas-liquid separation in the hot high-pressure separator, the bottom liquid phase (organic amine mixture) enters the cold low-pressure separator, while the top gas phase (hydrogen and ammonia) enters the hot high-pressure gas cryostat for deep condensation. Under these low-temperature conditions, the ammonia is further condensed into liquid ammonia, forming a low-temperature gas-liquid mixture that enters the cold high-pressure separator for final separation. The separated liquid ammonia then enters the gas-liquid separator, while the hydrogen... The gas is heated by the circulating gas heater and then returned to the amination reactor for recycling. When the liquid phase in the hot high-pressure separator enters the cold low-pressure separator, the pressure is significantly reduced, causing the hydrogen and ammonia dissolved in the liquid organic amine to overflow. They then continue to be separated along with the above-mentioned stage separation process of the liquid phase mixture. Similarly, when the liquid ammonia in the cold high-pressure separator enters the gas-liquid separator, the pressure is significantly reduced, causing the hydrogen dissolved in the liquid ammonia to overflow, thus achieving a more thorough separation. In summary, this synthesis system, through the integrated separation mechanism, achieves efficient separation and recovery of dissolved circulating gas in the liquid phase mixture, as well as effective separation and collection of target products entrained in the gas phase mixture, thereby significantly reducing the dual loss of circulating gas and target products. 3. The raw material in the inlet pipe passes through the heat exchanger of the product-raw material heat exchanger and the heating of the raw material heater in sequence before entering the amination reactor through the inlet. At the same time, the gas phase mixture in the amination reactor is discharged through the outlet and enters the hot high-temperature gas water cooler after passing through the product-raw material heat exchanger. In this process, the waste heat of the gas phase mixture is used to preheat the raw material, which reduces the energy consumption of raw material heating. 4. The external hydrogen replenishment system replenishes the lost hydrogen in the hydrogen circulation path through the hydrogen replenishment pipeline. Attached Figure Description

[0012] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0013] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the liquid phase mixture separation mechanism of the present invention; Figure 3 This is a schematic diagram of the gas phase mixture separation mechanism of the present invention.

[0014] In the diagram: 1-Amination reactor; 2-Liquid inlet; 3-Gas inlet; 4-Circulating gas heater; 5-Hydrogen replenishment pipeline; 6-Liquid phase mixture separation mechanism; 7-Product collection tank; 8-Gas phase mixture separation mechanism; 9-Liquid inlet pipe; 10-Product-raw material heat exchanger; 11-Raw material heater; 12-Gas outlet; 13-Liquid outlet; 14-Hot low-pressure separator; 15-Cold low-pressure gas water cooler; 16-Cold low-pressure separator; 17-Cold low-pressure gas cryostat; 18-Gas-liquid separator; 19-Liquid ammonia tank; 20-Hot high-pressure separator; 21-Hot high-pressure gas water cooler; 22-Hot high-pressure gas cryostat; 23-Cold high-pressure separator. Detailed Implementation

[0015] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0016] like Figures 1 to 3 As shown, a triethylenetetramine synthesis system includes an amination reactor 1, a circulating gas heater 4, a product collection tank 7, a liquid phase mixture separation mechanism 6, and a gas phase mixture separation mechanism 8. The amination reactor 1 is provided with an inlet 3 and a liquid outlet 13 at its top and bottom, respectively. The upper outer wall and lower outer wall of the amination reactor 1 are provided with an inlet 2 and a gas outlet 12, respectively. The liquid phase mixture separation mechanism 6 is connected to the liquid outlet 13, the gas phase mixture separation mechanism 8, the product collection tank 7, and the cold fluid inlet of the circulating gas heater 4. The gas phase mixture separation mechanism 8 is connected to the outlet 12 and the cold fluid inlet of the circulating gas heater 4. The cold fluid outlet of the circulating gas heater 4 is connected to the inlet 3.

[0017] The liquid phase mixture separation mechanism 6 includes a hot low-pressure separator 14, a cold low-pressure gas water cooler 15, a cold low-pressure separator 16, a cold low-pressure gas deep cooler 17, a gas-liquid separator 18, and a liquid ammonia tank 19. The liquid inlet, liquid outlet, and gas outlet of the hot low-pressure separator 14 are connected to the liquid outlet 13, the product collection tank 7, and the hot fluid inlet of the cold low-pressure gas water cooler 15, respectively. The inlet, liquid outlet, and gas outlet of the cold low-pressure separator 16 are connected to the hot fluid outlet of the cold low-pressure gas water cooler 15, the product collection tank 7, and the hot fluid inlet of the cold low-pressure gas deep cooler 17, respectively. The inlet, liquid outlet, and gas outlet of the gas-liquid separator 18 are connected to the hot fluid outlet of the cold low-pressure gas deep cooler 17, the liquid ammonia tank 19, and the circulating gas heater 4, respectively.

[0018] The gas phase mixture separation mechanism 8 includes a hot high-pressure gas separator 21, a hot high-pressure separator 20, a hot high-pressure gas cryostat 22, and a cold high-pressure separator 23. The hot fluid inlet of the hot high-pressure gas separator 21 is connected to the gas outlet 12. The inlet, liquid outlet, and gas outlet of the hot high-pressure separator 20 are connected to the hot fluid outlet of the hot high-pressure gas separator 21, the inlet of the cold low-pressure separator 16, and the hot fluid inlet of the hot high-pressure gas cryostat 22, respectively. The inlet, liquid outlet, and gas outlet of the cold high-pressure separator 23 are connected to the hot fluid outlet of the hot high-pressure gas cryostat 22, the inlet of the gas-liquid separator 18, and the circulating gas heater 4, respectively.

[0019] A raw material heater 11 and a product-raw material heat exchanger 10 are provided on the side of the amination reactor 1. The cold fluid inlet of the product-raw material heat exchanger 10 is connected to the liquid inlet pipe 9. The cold fluid outlet, hot fluid inlet and hot fluid outlet of the product-raw material heat exchanger 10 are respectively connected to the cold fluid inlet, gas outlet 12 and hot fluid inlet of the hot high-temperature gas water cooler 21. The cold fluid outlet of the raw material heater 11 is connected to the liquid inlet 2.

[0020] The external hydrogen replenishment system is connected to the cold fluid inlet of the circulating gas heater 4 via hydrogen replenishment pipeline 5.

[0021] The working principle of this device is as follows: The liquid-phase mixture in amination reactor 1 enters the hot low-pressure separator 14 through outlet 13. After depressurization, a large amount of light components (hydrogen, ammonia, and low-boiling-point ethylenediamine) rapidly vaporizes and separates from the high-boiling-point liquid-phase products (such as diethylenetriamine and triethylenetetramine). At this point, the gas phase still contains some diethylenetriamine and triethylenetetramine components. The separated liquid phase enters the product collection tank 7, while the gas phase enters the cold low-pressure water cooler 15 for preliminary cooling and condensation. The organic amines with higher boiling points (such as ethylenediamine, diethylenetriamine, and triethylenetetramine) are condensed into liquid. After forming a gas-liquid mixture, the mixture enters a cold low-pressure separator 16 for sedimentation and separation. The liquid organic amine mixture at the bottom of the cold low-pressure separator 16 enters a product collection tank 7, while the gas phase (hydrogen and ammonia) at the top enters a cold low-pressure gas cryostat 17 for deep condensation, causing the ammonia to condense into liquid ammonia. The low-temperature gas-liquid mixture then enters a gas-liquid separator 18 for final separation. The liquid ammonia is collected in a liquid ammonia tank 19, and the hydrogen is pressurized and heated by a circulating gas heater 4 before returning to the amination reactor 1 for recycling. Through the above process, efficient separation and recovery of dissolved circulating gas in the liquid phase mixture are achieved. After the gaseous mixture generated in the amination reactor 1 is discharged through the outlet 12, it first undergoes heat exchange through the product-origin heat exchanger 10, and then enters the hot high-pressure gas water cooler 21 for preliminary cooling, causing the organic amines with higher boiling points (such as ethylenediamine, diethylenetriamine, and triethylenetetramine) to condense into liquid, forming a gas-liquid mixture that enters the hot high-pressure separator 20. After gas-liquid separation in the hot high-pressure separator 20, the bottom liquid phase (organic amine mixture) enters the cold low-pressure separator 16, while the top gas phase (hydrogen and ammonia) enters the hot high-pressure gas deep cooler 22 for deep condensation. Under this low-temperature condition, the ammonia is further condensed into liquid ammonia, forming a low-temperature gas-liquid mixture that enters the cold high-pressure separator 23 for final separation. The separated liquid ammonia then enters the gas-liquid separator 1. 8. Hydrogen is heated by the circulating gas heater 4 and then returned to the amination reactor 1 for recycling. When the liquid phase in the hot high-pressure separator 20 enters the cold low-pressure separator 16, the pressure is greatly reduced, causing the hydrogen and ammonia dissolved in the liquid organic amine to overflow and continue to be separated with the above-mentioned stage separation process of the liquid phase mixture. Similarly, when the liquid ammonia in the cold high-pressure separator 23 enters the gas-liquid separator 18, the pressure is greatly reduced, causing the hydrogen dissolved in the liquid ammonia to overflow, thus achieving a more thorough separation. In summary, this synthesis system, through the integrated separation mechanism, achieves efficient separation and recovery of dissolved circulating gas in the liquid phase mixture, as well as effective separation and collection of target products entrained in the gas phase mixture, thereby significantly reducing the dual loss of circulating gas and target products. The raw material in the inlet pipe 9 passes through the heat exchanger 10 and the raw material heater 11 in sequence before entering the amination reactor 1 through the inlet 2. At the same time, the gaseous mixed components in the amination reactor 1 are discharged through the outlet 12 and enter the hot high-temperature gas water cooler 21 after passing through the heat exchanger 10. In this process, the waste heat of the gaseous mixed components is used to preheat the raw material, which reduces the energy consumption for heating the raw material. The external hydrogen replenishment system replenishes the lost hydrogen in the hydrogen circulation path through hydrogen replenishment pipeline 5.

[0022] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A system for synthesizing triethylenetetramine, characterized in that: The device includes an amination reactor (1), a circulating gas heater (4), a product collection tank (7), a liquid phase mixture separation mechanism (6), and a gas phase mixture separation mechanism (8). The amination reactor (1) is provided with an air inlet (3) and a liquid outlet (13) at the top and bottom respectively. The amination reactor (1) is provided with an liquid inlet (2) and a gas outlet (12) at the upper and lower outer walls respectively. The liquid phase mixture separation mechanism (6) is connected to the liquid outlet (13), the gas phase mixture separation mechanism (8), the product collection tank (7), and the cold fluid inlet of the circulating gas heater (4). The gas phase mixture separation mechanism (8) is connected to the gas outlet (12) and the cold fluid inlet of the circulating gas heater (4). The cold fluid outlet of the circulating gas heater (4) is connected to the air inlet (3).

2. The synthesis system for triethylenetetramine according to claim 1, characterized in that: The liquid phase mixture separation mechanism (6) includes a hot low-pressure separator (14), a cold low-pressure gas water cooler (15), a cold low-pressure separator (16), a cold low-pressure gas deep cooler (17), a gas-liquid separator (18), and a liquid ammonia tank (19). The liquid inlet, liquid outlet, and gas outlet of the hot low-pressure separator (14) are connected to the liquid outlet (13), the product collection tank (7), and the hot fluid inlet of the cold low-pressure gas water cooler (15), respectively. The inlet, liquid outlet, and gas outlet of the cold low-pressure separator (16) are connected to the hot fluid outlet of the cold low-pressure gas water cooler (15), the product collection tank (7), and the hot fluid inlet of the cold low-pressure gas deep cooler (17), respectively. The inlet, liquid outlet, and gas outlet of the gas-liquid separator (18) are connected to the hot fluid outlet of the cold low-pressure gas deep cooler (17), the liquid ammonia tank (19), and the circulating gas heater (4), respectively.

3. The synthesis system for triethylenetetramine according to claim 2, characterized in that: The gas phase mixture separation mechanism (8) includes a hot high-pressure gas water cooler (21), a hot high-pressure separator (20), a hot high-pressure gas deep cooler (22), and a cold high-pressure separator (23). The hot fluid inlet of the hot high-pressure gas water cooler (21) is connected to the gas outlet (12). The inlet, liquid outlet, and gas outlet of the hot high-pressure separator (20) are connected to the hot fluid outlet of the hot high-pressure gas water cooler (21), the inlet of the cold low-pressure separator (16), and the hot fluid inlet of the hot high-pressure gas deep cooler (22), respectively. The inlet, liquid outlet, and gas outlet of the cold high-pressure separator (23) are connected to the hot fluid outlet of the hot high-pressure gas deep cooler (22), the inlet of the gas-liquid separator (18), and the circulating gas heater (4), respectively.

4. The synthesis system for triethylenetetramine according to claim 3, characterized in that: The amination reactor (1) is provided with a raw material heater (11) and a product-raw material heat exchanger (10) on the side. The cold fluid inlet of the product-raw material heat exchanger (10) is connected to a liquid inlet pipe (9). The cold fluid outlet, hot fluid inlet and hot fluid outlet of the product-raw material heat exchanger (10) are respectively connected to the cold fluid inlet of the raw material heater (11), the gas outlet (12) and the hot fluid inlet of the high-temperature gas water cooler (21). The cold fluid outlet of the raw material heater (11) is connected to the liquid inlet (2).

5. The synthesis system for triethylenetetramine according to claim 1, characterized in that: The external hydrogen replenishment system is connected to the cold fluid inlet of the circulating gas heater (4) via the hydrogen replenishment pipeline (5).

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