Deamination system for product refining

Abstract

A deamination system for product refining relates to the technical field of deamination and comprises a deamination tower, the top and the bottom of the deamination tower are respectively provided with an exhaust port and a liquid discharge port, the upper outer wall and the lower outer wall of the deamination tower are respectively provided with a liquid inlet and a reflux inlet, a falling film reboiler is arranged on the side of the deamination tower, the liquid discharge port is communicated with the inlet end of the falling film reboiler through a reflux circulating pump, and the reflux circulating pump is communicated with the liquid discharge port. The outlet end of the falling film reboiler is communicated with the reflux inlet, and a condensation assembly communicated with the exhaust port is arranged on the side of the deamination tower. The problem that the content of entrained products is high when an existing deamination system separates ammonia is solved; the deamination effect is poor.

Description

Technical Field

[0001] This invention relates to the field of deammoniation technology, specifically to a deammoniation system for product refining. Background Technology

[0002] Polyethylene polyamines are an important class of aliphatic amine compounds, typically including diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, and other series of products. They have wide applications in various industrial fields such as epoxy resin curing agents, chelating agents, lubricant additives, and surfactants. During industrial production, ammonia is generated as a byproduct in the reaction system. Therefore, to ensure the purity and performance stability of the final product and to meet the stringent low ammonia content requirements of downstream applications, the dissolved or residual ammonia must be effectively removed through distillation in the subsequent refining process. This step is also crucial for optimizing the product's amine value, color, and storage stability.

[0003] The existing ammonia removal system has gradually revealed its shortcomings during use, mainly in the following aspects: First, the ammonia separation process suffers from high levels of entrained products. Specifically, during the distillation process to separate ammonia from the product, due to the intense boiling and gas-liquid entrainment effect, some high-boiling-point products escape as mist or droplets along with the gaseous ammonia into the gas phase fraction. When this mixed gas enters the condenser and is cooled, the gaseous ammonia is condensed into liquid ammonia, while the entrained liquid products remain in the condensed liquid ammonia. Ultimately, this results in the condensed and recovered liquid ammonia containing a high concentration of other product components. This not only leads to impure ammonia separation and a high content of entrained products, but also means that valuable products are lost in the ammonia phase, thus seriously affecting the separation effect and economic benefits.

[0004] Secondly, the ammonia removal effect is poor. Specifically, in the process of separating ammonia from liquid products by distillation, the material in the vessel is continuously fed and heated to remove ammonia: the high-temperature liquid product at the bottom of the vessel is heated and vaporized and flows upward, while the fresh liquid product at a lower temperature flows in from the top of the vessel. The two are in countercurrent contact at the packing to transfer heat and mass, thereby continuously vaporizing and carrying out the ammonia component in the liquid. However, existing distillation vessels generally use coils or tubes fixedly installed inside to heat the liquid at the bottom. This static heating method is very likely to cause uneven distribution of components inside the liquid in the vessel, which seriously affects the removal effect of ammonia components from the liquid phase.

[0005] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide an ammonia removal system for product refining. This system can perform repeated distillation and condensation purification on liquid ammonia after initial condensation and separation, which greatly reduces the content of other products entrained in the final recovered liquid ammonia and significantly improves the separation effect of ammonia components in the initial liquid product and the purity of the product. This system enables the liquid product at the bottom of the vessel to circulate and be heated. This dynamic heating method effectively promotes the uniformity of the internal component distribution of the liquid product in the vessel, which is conducive to the removal of ammonia components from the liquid phase and significantly improves the removal effect of ammonia components from the liquid product.

[0007] To address the above problems, the present invention provides the following technical solution: A deammoniation removal system for product refining includes a deammoniation removal tower. The top and bottom of the deammoniation removal tower are respectively provided with an exhaust port and a liquid discharge port. The upper and lower outer walls of the deammoniation removal tower are respectively provided with a liquid inlet and a reflux port. A falling film reboiler is provided on the side of the deammoniation removal tower. The liquid discharge port is connected to the inlet end of the falling film reboiler through a reflux circulation pump. The outlet end of the falling film reboiler is connected to the reflux port. A condensation component connected to the exhaust port is provided on the side of the deammoniation removal tower.

[0008] As an optimized solution, the condensation assembly includes a primary condenser, a secondary condenser, and a temporary storage tank arranged in sequence. The exhaust port is connected to the primary condenser. A return port is provided on the outer wall of the deammoniation tower above the liquid inlet. The liquid outlet on the lower outer wall of the temporary storage tank is connected to the return port through a return circulation pump.

[0009] As an optimized solution, a first liquid distributor is fixedly installed on the inner wall of the deammoniation tower below the liquid inlet, and a first packing layer is provided below the first liquid distributor. The liquid inlet is connected to the first liquid distributor, and the first packing layer is located above the reflux port.

[0010] As an optimized solution, a second liquid distributor is fixedly installed on the inner wall of the deammoniation tower below the return liquid port, and a second packing layer is provided below the second liquid distributor. The return liquid port is connected to the second liquid distributor.

[0011] As an optimized solution, a liquid collector is provided on the inner wall of the deammoniation tower below the second packing layer, and the liquid collector is connected to the first liquid distributor.

[0012] As an optimized solution, a product tank is provided on the side of the deammoniation tower, and a pneumatic three-way valve is connected to the outlet end of the reflux circulation pump. The pneumatic three-way valve is a one-inlet, two-outlet type, and the two outlet ends of the pneumatic three-way valve are connected to the falling film reboiler and the product tank respectively.

[0013] As an optimized solution, a collection tank is provided on the side of the temporary storage tank. The air outlet on the outer wall of the temporary storage tank is connected to the collection tank. An electric three-way valve is connected to the outlet end of the return liquid circulation pump. The electric three-way valve is a one-in-two-out type, and the two outlet ends of the electric three-way valve are connected to the return liquid port and the collection tank respectively.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. During the ammonia removal process of the liquid product, the liquid product at the bottom of the ammonia removal tower is heated and vaporized, then moves upward. Simultaneously, fresh liquid product enters through the inlet and is evenly distributed in the first packing layer under the action of the first liquid distributor. The rising vapor and fresh liquid fully contact and transfer heat and mass within the first packing layer, thereby transferring the ammonia component from the liquid phase to the gas phase. The ammonia-containing gas phase is then discharged through the exhaust port and sequentially cooled by the primary and secondary condensers. Most of the gas phase condenses into a liquid phase dominated by ammonia and containing a small amount of entrained products, which, along with a very small amount of non-condensable gas, enters the temporary storage tank. The return circulation pump then... The liquid phase in the temporary storage tank is extracted and sent to the second liquid distributor in the deammoniation tower through the return liquid port. It is evenly distributed to the second packing layer, where it undergoes heat and mass transfer again with the rising gas phase after passing through the first packing layer. The ammonia component in the condensed liquid phase of the second packing layer is further transferred to the gas phase. This gas phase can be re-entered for condensation recovery and circulation. This system can perform repeated distillation and condensation purification on the liquid ammonia after the initial condensation separation, which greatly reduces the content of other products entrained in the final recovered liquid ammonia and significantly improves the separation effect and product purity of the ammonia component in the initial liquid product. 2. The return liquid port is located above the inlet. This structure ensures that the temperature at the return liquid port of the deammoniation tower and the temperature of the gas phase components rising to this point are both lower than the temperature at the inlet. This creates heat and mass transfer conditions favorable for the separation of ammonia components within the second packing layer. Under this temperature gradient, the ammonia components in the condensed liquid phase within the second packing layer, due to their high volatility, can continuously transfer to the gas phase. Meanwhile, other high-boiling-point or non-volatile products entrained in the condensed liquid phase are not easily carried up with the gas phase and are effectively retained in the liquid phase. This process significantly inhibits the entrainment and transfer of non-ammonia components, thereby ensuring the efficient and selective separation of ammonia components and improving the purity and effectiveness of the entire deammoniation process. 3. With the cooperation of the reflux circulation pump, the liquid product at the bottom of the deammoniation tower is circulated through the falling film reboiler for heating and vaporization. This system enables the liquid product at the bottom of the vessel to circulate and be heated. This dynamic heating method effectively promotes the uniformity of the internal component distribution of the liquid product in the vessel, which is conducive to the removal of ammonia components from the liquid phase and significantly improves the removal effect of ammonia components in the liquid product. 4. The liquid collector can collect the liquid phase components flowing through the second packing layer and allow them to pass through the first liquid distributor again into the first packing layer, thereby removing the residual ammonia components inside. This process improves the separation effect of ammonia components during the repurification of the liquid phase components after condensation. Attached Figure Description

[0015] 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.

[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the ammonia removal tower of the present invention.

[0017] In the diagram: 1-Ammonia removal tower; 2-Exhaust port; 3-Return liquid port; 4-First-stage condenser; 5-Condensation assembly; 6-Second-stage condenser; 7-Temporary storage tank; 8-Collection tank; 9-Return liquid circulation pump; 10-Electric three-way valve; 11-Inlet; 12-Drain; 13-Return circulation pump; 14-Product tank; 15-Pneumatic three-way valve; 16-Return port; 17-Falling film reboiler; 18-First packing layer; 19-First liquid distributor; 20-Liquid collector; 21-Second packing layer; 22-Second liquid distributor. Detailed Implementation

[0018] 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.

[0019] like Figures 1 to 2 As shown, an ammonia removal system for product refining includes an ammonia removal tower 1. The top and bottom of the ammonia removal tower 1 are respectively provided with an exhaust port 2 and a liquid discharge port 12. The upper outer wall and lower outer wall of the ammonia removal tower 1 are respectively provided with a liquid inlet 11 and a reflux port 16. A falling film reboiler 17 is provided on the side of the ammonia removal tower 1. The liquid discharge port 12 is connected to the inlet end of the falling film reboiler 17 through a reflux circulation pump 13. The outlet end of the falling film reboiler 17 is connected to the reflux port 16. A condensation component 5 connected to the exhaust port 2 is provided on the side of the ammonia removal tower 1.

[0020] The condensation assembly 5 includes a primary condenser 4, a secondary condenser 6, and a temporary storage tank 7 arranged in sequence. The exhaust port 2 is connected to the primary condenser 4. The outer wall of the deammoniation tower 1 is provided with a return port 3 above the liquid inlet 11. The liquid outlet on the lower outer wall of the temporary storage tank 7 is connected to the return port 3 through a return circulation pump 9.

[0021] A first liquid distributor 19 is fixedly installed on the inner wall of the deammoniation tower 1 below the liquid inlet 11. A first packing layer 18 is provided below the first liquid distributor 19. The liquid inlet 11 is connected to the first liquid distributor 19. The first packing layer 18 is located above the reflux port 16.

[0022] A second liquid distributor 22 is fixedly installed on the inner wall of the deammoniation tower 1 below the return liquid port 3. A second packing layer 21 is installed below the second liquid distributor 22. The return liquid port 3 is connected to the second liquid distributor 22.

[0023] A liquid collector 20 is provided on the inner wall of the deammoniation tower 1 below the second packing layer 21. The liquid collector 20 is connected to the first liquid distributor 19.

[0024] A product tank 14 is located on the side of the deammoniation tower 1. A pneumatic three-way valve 15 is connected to the outlet end of the reflux circulation pump 13. The pneumatic three-way valve 15 is a one-in-two-out type, and the two outlet ends of the pneumatic three-way valve 15 are connected to the falling film reboiler 17 and the product tank 14 respectively.

[0025] A collection tank 8 is provided on the side of the temporary storage tank 7. The air outlet on the outer wall of the temporary storage tank 7 is connected to the collection tank 8. An electric three-way valve 10 is connected to the outlet of the return liquid circulation pump 9. The electric three-way valve 10 is a one-in-two-out type. The two outlets of the electric three-way valve 10 are connected to the return liquid port 3 and the collection tank 8 respectively.

[0026] The working principle of this device is as follows: During the ammonia removal process of the liquid product, the liquid product at the bottom of the ammonia removal tower 1 is heated and vaporized, then moves upward. Simultaneously, fresh liquid product enters through the inlet 11 and is evenly distributed in the first packing layer 18 under the action of the first liquid distributor 19. The rising vapor and fresh liquid fully contact and transfer heat and mass within the first packing layer 18, thereby transferring the ammonia component from the liquid phase to the gas phase. The ammonia-containing gas phase is then discharged through the exhaust port 2 and sequentially cooled by the primary condenser 4 and the secondary condenser 6. Most of the gas phase condenses into a liquid phase mainly composed of ammonia and containing a small amount of entrained products, which, along with a very small amount of non-condensable gas, enters the temporary storage tank 7. The return liquid circulation pump 9 then... The liquid phase in the temporary storage tank 7 is extracted and sent to the second liquid distributor 22 in the deammoniation tower 1 through the return liquid port 3. It is evenly distributed to the second packing layer 21, where it undergoes heat and mass transfer again with the rising gas phase after passing through the first packing layer 18. The ammonia component in the condensed liquid phase of the second packing layer 21 is further transferred to the gas phase. This gas phase can be re-entered for condensation recovery and recycling. This system can perform repeated distillation and condensation purification of liquid ammonia after the initial condensation separation, which greatly reduces the content of other products entrained in the final recovered liquid ammonia and significantly improves the separation effect and product purity of the ammonia component in the initial liquid product. The return port 3 is located above the inlet 11. This structure ensures that the temperature at the return port 3 of the deammoniation tower 1 and the temperature of the gas phase components rising to this point are both lower than the temperature at the inlet 11. This creates heat and mass transfer conditions favorable for the separation of ammonia components within the second packing layer 21. Under this temperature gradient, the ammonia components in the condensed liquid phase within the second packing layer 21, due to their high volatility, can continuously transfer to the gas phase. Meanwhile, other high-boiling-point or non-volatile products entrained in the condensed liquid phase are not easily carried up with the gas phase and are effectively retained in the liquid phase. This process significantly inhibits the entrainment and transfer of non-ammonia components, thereby ensuring the efficient and selective separation of ammonia components and improving the purity and effectiveness of the entire deammoniation process. With the cooperation of the reflux circulation pump 13, the liquid product at the bottom of the deammoniation tower 1 is circulated through the falling film reboiler 17 for heating and vaporization. This system can make the liquid product at the bottom of the vessel circulate and be heated. This dynamic heating method effectively promotes the uniformity of the internal component distribution of the liquid product in the vessel, which is conducive to the ammonia component being removed from the liquid phase and significantly improves the removal effect of the ammonia component in the liquid product. The liquid collector 20 can collect the liquid phase component flowing through the second packing layer 21 and make it pass through the first liquid distributor 19 again into the first packing layer 18, thereby removing the residual ammonia component inside again. This process improves the separation effect of ammonia component in the repurification process of the condensed liquid phase component. When the liquid product at the bottom of the deammoniation tower 1 reaches a certain height, the pneumatic three-way valve 15 connects the drain port 12 and the product tank 14. The reflux circulation pump 13 pumps the deammoniation-removed liquid product in the deammoniation tower 1 to the product tank 14. The non-condensable gas (mainly composed of ammonia) in the temporary storage tank 7 enters the collection tank 8 for collection. When the liquid ammonia in the temporary storage tank 7 reaches a certain height, the electric three-way valve 10 connects the temporary storage tank 7 and the collection tank 8. The return circulation pump 9 transports the liquid ammonia in the temporary storage tank 7 to the collection tank 8 for collection.

[0027] 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 deammoniation system for product refining, characterized in that: The ammonia removal tower (1) is provided with an exhaust port (2) and a liquid discharge port (12) at the top and bottom of the ammonia removal tower (1), respectively. The upper outer wall and lower outer wall of the ammonia removal tower (1) are provided with a liquid inlet (11) and a reflux port (16), respectively. A falling film reboiler (17) is provided on the side of the ammonia removal tower (1). The liquid discharge port (12) is connected to the inlet end of the falling film reboiler (17) through a reflux circulation pump (13). The outlet end of the falling film reboiler (17) is connected to the reflux port (16). A condensation component (5) connected to the exhaust port (2) is provided on the side of the ammonia removal tower (1).

2. The deammoniation system for product refining according to claim 1, characterized in that: The condensation assembly (5) includes a primary condenser (4), a secondary condenser (6) and a temporary storage tank (7) connected in sequence. The exhaust port (2) is connected to the primary condenser (4). The outer wall of the deammonia tower (1) is provided with a return port (3) above the inlet (11). The outlet of the lower outer wall of the temporary storage tank (7) is connected to the return port (3) through a return circulation pump (9).

3. The deammoniation system for product refining according to claim 2, characterized in that: The inner wall of the deammoniation tower (1) is fixedly provided with a first liquid distributor (19) below the liquid inlet (11). A first packing layer (18) is provided below the first liquid distributor (19). The liquid inlet (11) is connected to the first liquid distributor (19). The first packing layer (18) is located above the reflux port (16).

4. The deammoniation system for product refining according to claim 3, characterized in that: The inner wall of the deammoniation tower (1) is fixedly provided with a second liquid distributor (22) below the return liquid port (3). A second packing layer (21) is provided below the second liquid distributor (22). The return liquid port (3) is connected to the second liquid distributor (22).

5. A deammoniation system for product refining according to claim 4, characterized in that: The inner wall of the deammoniation tower (1) is provided with a liquid collector (20) located below the second packing layer (21), and the liquid collector (20) is connected to the first liquid distributor (19).

6. The deammoniation system for product refining according to claim 1, characterized in that: The deammonia removal tower (1) is provided with a product tank (14) on its side. The outlet end of the reflux circulation pump (13) is connected to a pneumatic three-way valve (15). The pneumatic three-way valve (15) is a one-in-two-out type. The two outlet ends of the pneumatic three-way valve (15) are connected to the falling film reboiler (17) and the product tank (14).

7. A deammoniation system for product refining according to claim 2, characterized in that: The temporary storage tank (7) is provided with a collection tank (8) on its side. The air outlet on the outer wall of the temporary storage tank (7) is connected to the collection tank (8). The outlet end of the return circulation pump (9) is connected to an electric three-way valve (10). The electric three-way valve (10) is a one-in-two-out type. The two outlet ends of the electric three-way valve (10) are connected to the return port (3) and the collection tank (8) respectively.

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