A device for recovering ammonia in the production of ethanolamine

Abstract

The present invention discloses a device for recovering ammonia in the production of ethanolamine, comprising an ammonia absorption unit, a reaction product input interface is provided at the upper part of the ammonia absorption unit, an absorbent input interface is provided at the left side of the ammonia absorption unit, a non-absorbed gas output interface is provided at the top of the ammonia absorption unit, and an ammonia-rich absorption liquid output interface is provided at the bottom of the ammonia absorption unit. The present invention realizes efficient recovery and refining of ammonia by arranging an ammonia absorption unit, an ammonia desorption unit, an ammonia separation unit, an ammonia refining unit and a liquid ammonia storage unit, and each unit works in synergy, which can effectively solve the problem that impurities and moisture are difficult to completely remove in the ammonia recovery process in the prior art, and improve the purity and quality of the ethanolamine product.

Description

Technical Field

[0001] The invention relates to the field of ethanolamine production, in particular to a device for recovering ammonia in ethanolamine production. Background Art

[0002] As an important chemical raw material, ethanolamine is widely used in many fields such as pharmaceuticals, printing and dyeing, and surfactants. In the production process of ethanolamine, ammonia is a key raw material and also a substance that needs to be effectively recycled and reused. This is because the effective recycling of ammonia can not only reduce production costs, but also reduce environmental pollution, which meets the requirements of sustainable development.

[0003] For example, the ammonia recovery method in the production of ethanolamine disclosed in the authorization announcement number CN101560159B includes three steps: the first step is that the reaction liquid with a large amount of ammonia enters a flash evaporation and evaporation integrated deammoniation device, in which 98-99% of the ammonia in the reaction liquid is removed, and the evaporated ammonia is condensed and recovered to the liquid ammonia turnover tank; the second step is that the reaction liquid with a small amount of ammonia is flashed for the second time, and the flashed ammonia and water are condensed and returned to the water catalytic tank, at which time the ammonia removal rate reaches more than 99.8%; the third step is that the reaction liquid with trace ammonia is completely evaporated in the dehydration tower. The beneficial effect of adopting the above technical solution is: in the integrated deammoniation equipment, the ammonia removal rate can reach more than 99.8%. Compared with the same process, it can also be continuously produced without adding equipment, and it is closed-loop and does not cause pollution to the environment.

[0004] Although the above patent improves the ammonia recovery rate, some impurities or moisture may be introduced during the multiple flash distillation, evaporation and condensation processes, affecting the purity of the final ethanolamine product. For example, a small amount of water will flash out during the flash distillation of ammonia. If this water cannot be completely removed, it will remain in the product and reduce the product quality. Summary of the invention

[0005] The object of the present invention is to provide a device for recovering ammonia in the production of ethanolamine to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A device for recovering ammonia in the production of ethanolamine, comprising:

[0008] An ammonia absorption unit, wherein a reaction product input interface is provided at the upper portion of the ammonia absorption unit, an absorbent input interface is provided at the left side of the ammonia absorption unit, an unabsorbed gas output interface is provided at the top of the ammonia absorption unit, and an ammonia-rich absorption liquid output interface is provided at the bottom of the ammonia absorption unit;

[0009] An ammonia desorption unit, wherein an ammonia-rich absorption liquid input interface is provided at the upper part of the ammonia desorption unit, a post-desorption absorbent output interface is provided at the right side of the ammonia desorption unit, an ammonia gas output interface is provided at the top of the ammonia desorption unit, and the ammonia-rich absorption liquid input interface is connected to the ammonia-rich absorption liquid output interface through a pipeline;

[0010] An ammonia separation unit, wherein an ammonia gas input interface is provided on the left side of the ammonia separation unit, and a high-purity ammonia output interface is provided on the right side of the ammonia separation unit, wherein the ammonia gas input interface is connected to the ammonia gas output interface through a pipeline;

[0011] An ammonia refining unit, wherein a high-purity ammonia input interface is provided at the top of the ammonia refining unit, a high-purity liquid ammonia output interface is provided at the bottom of the ammonia refining unit, an impurity wastewater output interface is provided on the right side of the ammonia refining unit, and the high-purity ammonia input interface is connected to the high-purity ammonia output interface through a pipeline;

[0012] A liquid ammonia storage unit is provided with a liquid ammonia input interface at the upper part of the liquid ammonia storage unit, and a liquid ammonia discharge port is provided at the lower part of the liquid ammonia storage unit, and the liquid ammonia input interface is connected to the high-purity liquid ammonia output interface through a pipeline.

[0013] Furthermore, the ammonia absorption unit is an absorption tower, which is provided with a cavity for accommodating an absorbent; the ammonia desorption unit is a desorption tower, and a condenser is provided at the top of the desorption tower; the ammonia separation unit is a membrane separation unit, and a separation membrane is provided in the membrane separation unit.

[0014] Furthermore, the ammonia refining unit is a refining tower, and a second condenser is provided on the top of the refining tower; and the post-desorption absorbent output interface is connected to the absorbent input interface through a pipeline.

[0015] Furthermore, a filtering component and a condensing component are also provided inside the ammonia absorption unit. The filtering component is close to the bottom of the reaction product input interface, and the condensing component is close to the top of the ammonia-rich absorption liquid output interface.

[0016] Furthermore, a decompression component is also provided inside the ammonia desorption unit, and the decompression component is located in the middle of the ammonia desorption unit and close to the bottom where the condenser 1 is provided.

[0017] Furthermore, the ammonia separation unit is also provided with an impurity discharge port, and the impurity discharge port is located at the bottom of the ammonia separation unit.

[0018] Furthermore, a packing component is provided inside the ammonia refining unit, and the packing component is located in the middle and upper part of the ammonia refining unit. A reboiler is provided below the ammonia refining unit, and the reboiler is connected to the bottom of the ammonia refining unit through a pipeline.

[0019] Furthermore, a liquid level display component is also provided on the outside of the liquid ammonia storage unit, and the liquid level display component is located on the right front side of the liquid ammonia storage unit.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention realizes efficient recovery and refining of ammonia by arranging an ammonia absorption unit, an ammonia desorption unit, an ammonia separation unit, an ammonia refining unit and a liquid ammonia storage unit. The units work together to achieve efficient recovery and refining of ammonia. Specifically, the ammonia absorption unit can perform preliminary treatment on the incoming reaction products and reduce the influence of impurities by arranging a filtering component and a condensing component. The decompression component of the ammonia desorption unit is helpful for the desorption of ammonia. The membrane separation technology of the ammonia separation unit can effectively separate ammonia and impurities. The packing component and the reboiler of the ammonia refining unit further purify ammonia. The liquid level display component of the liquid ammonia storage unit facilitates the monitoring of the storage of liquid ammonia. Through such a complete set of devices, the problem that impurities and moisture are difficult to be completely removed in the ammonia recovery process in the prior art can be effectively solved, and the purity and quality of the ethanolamine product can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The present invention is a schematic diagram of the overall structure of an ammonia recovery device in the production of ethanolamine.

[0023] In the figure: 1. Ammonia absorption unit; 101. Reaction product input interface; 102. Absorbent input interface; 103. Unabsorbed gas output interface; 104. Ammonia-rich absorption liquid output interface; 105. Filter component; 106. Condensation component; 2. Ammonia desorption unit; 201. Ammonia-rich absorption liquid input interface; 202. Absorbent output interface after desorption; 203. Ammonia gas output interface; 204. Condenser 1; 205. Decompression component; 3 ... Isolation unit; 301, ammonia gas input interface; 302, high-purity ammonia output interface; 303, impurity discharge port; 4, ammonia refining unit; 401, high-purity ammonia input interface; 402, high-purity liquid ammonia output interface; 403, impurity wastewater output interface; 404, condenser 2; 405, packing component; 406, reboiler; 5, liquid ammonia storage unit; 501, liquid ammonia input interface; 502, liquid ammonia discharge port; 503, liquid level display component. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] like Figure 1 As shown, the present invention provides a technical solution:

[0026] A device for recovering ammonia in the production of ethanolamine comprises an ammonia absorption unit 1, wherein a reaction product input interface 101 is provided at the upper part of the ammonia absorption unit 1, an absorbent input interface 102 is provided at the left side of the ammonia absorption unit 1, an unabsorbed gas output interface 103 is provided at the top of the ammonia absorption unit 1, and an ammonia-rich absorption liquid output interface 104 is provided at the bottom of the ammonia absorption unit 1. The ammonia absorption unit 1 is an absorption tower, and a cavity for accommodating the absorbent is provided in the absorption tower. A filtering component 105 and a condensing component 106 are further provided inside the ammonia absorption unit 1, wherein the filtering component 105 is close to the bottom of the reaction product input interface 101, and the condensing component 106 is close to the top of the ammonia-rich absorption liquid output interface 104;

[0027] In this embodiment, the filter component 105 arranged inside the ammonia absorption unit 1 is close to the bottom of the reaction product input interface 101, and can perform preliminary filtration on the incoming reaction products, effectively intercepting solid impurities therein, such as possible catalyst particles, etc., to prevent these impurities from entering the subsequent process, thereby ensuring the stability of the subsequent ammonia recovery process and the product quality.

[0028] Preferably, the condensation component 106 is close to the top of the ammonia-rich absorption liquid output interface 104, which helps to condense the gas generated during the absorption process, so that the ammonia and other substances therein are converted into liquid as much as possible to form an ammonia-rich absorption liquid, thereby improving the absorption efficiency of ammonia and reducing ammonia losses.

[0029] Furthermore, the reaction product input interface 101 is located at the top, the absorbent input interface 102 is located on the left, the unabsorbed gas output interface 103 is located at the top, and the ammonia-rich absorption liquid output interface 104 is located at the bottom. This design allows the reaction product to be fully in contact with the absorbent, which is beneficial to the absorption of ammonia, while facilitating the discharge of unabsorbed gas and the collection of ammonia-rich absorption liquid.

[0030] The ammonia desorption unit 2 is provided with an ammonia-rich absorption liquid input interface 201 at the upper part of the ammonia desorption unit 2, a post-desorption absorbent output interface 202 is provided on the right side of the ammonia desorption unit 2, and an ammonia gas output interface 203 is provided at the top of the ammonia desorption unit 2. The ammonia-rich absorption liquid input interface 201 is connected to the ammonia-rich absorption liquid output interface 104 through a pipeline. The ammonia desorption unit 2 is a desorption tower, and a condenser 204 is provided on the top of the desorption tower. A decompression component 205 is also provided inside the ammonia desorption unit 2, and the decompression component 205 is located in the middle of the ammonia desorption unit 2 and close to the bottom where the condenser 204 is provided;

[0031] In this embodiment, the pressure reducing component 205 arranged inside the ammonia desorption unit 2 is located in the middle position and close to the bottom of the condenser. By reducing the pressure conditions for ammonia desorption, the ammonia in the ammonia-rich absorption liquid is easier to desorb, thereby improving the ammonia desorption efficiency, which is beneficial to the subsequent further recovery and treatment of ammonia.

[0032] Preferably, the condenser 204 arranged at the top of the desorption tower can condense the desorbed ammonia gas and convert it into liquid ammonia, which is easy to collect and transport. It can also prevent the volatilization and loss of ammonia gas and improve the recovery rate of ammonia.

[0033] The ammonia separation unit 3 has an ammonia gas input interface 301 on the left side of the ammonia separation unit 3, and a high-purity ammonia output interface 302 on the right side of the ammonia separation unit 3. The ammonia gas input interface 301 is connected to the ammonia gas output interface 203 through a pipeline. The ammonia separation unit 3 is a membrane separation unit, and a separation membrane is provided in the membrane separation unit. The ammonia separation unit 3 is also provided with an impurity discharge port 303, and the impurity discharge port 303 is located at the bottom of the ammonia separation unit 3;

[0034] In this embodiment, membrane separation technology is used to separate and purify ammonia gas using a separation membrane, which can effectively remove impurities therein and obtain high-purity ammonia. This separation method has the advantages of high selectivity and high separation efficiency, can improve the purity of ammonia, and provide high-quality raw materials for subsequent ammonia refining.

[0035] Preferably, the impurity discharge port 303 disposed at the bottom can discharge the impurities generated during the separation process in a centralized manner, thereby preventing the impurities from accumulating in the system and affecting the recovery and refining effects of ammonia, thereby ensuring the stable operation of the entire device.

[0036] An ammonia refining unit 4 is provided with a high-purity ammonia input interface 401 at the upper part of the ammonia refining unit 4, a high-purity liquid ammonia output interface 402 is provided at the bottom of the ammonia refining unit 4, and an impurity wastewater output interface 403 is provided on the right side of the ammonia refining unit 4. The high-purity ammonia input interface 401 is connected to the high-purity ammonia output interface 302 through a pipeline. A packing component 405 is also provided inside the ammonia refining unit 4, and the packing component 405 is located in the middle and upper part of the ammonia refining unit 4. A reboiler 406 is provided below the ammonia refining unit 4, and the reboiler 406 is connected to the bottom of the ammonia refining unit 4 through a pipeline. The ammonia refining unit 4 is a refining tower, and a condenser 2 404 is provided at the top of the refining tower; and the absorbent output interface 202 after desorption is connected to the absorbent input interface 102 through a pipeline;

[0037] In this embodiment, the packing component 405 disposed inside the ammonia refining unit 4 is located in the middle and upper part, which increases the gas-liquid contact area and is conducive to further separation of ammonia from impurities and water. During the ammonia refining process, ammonia gas fully contacts with impurities and water in the liquid phase on the surface of the packing, so that impurities and water are better separated from ammonia, thereby improving the purity of ammonia.

[0038] Preferably, the reboiler 406 disposed below is connected to the bottom through a pipeline, providing necessary heat for the ammonia refining process, so that ammonia can be more fully volatilized from the mixed liquid, while impurities such as moisture remain in the liquid phase, further improving the refining effect of ammonia and ensuring that a high-purity liquid ammonia product is finally obtained.

[0039] Furthermore, the condenser 2 404 arranged at the top of the refining tower can condense the refined ammonia gas and convert it into liquid high-purity ammonia, which is easy to collect and store. It can also prevent the volatilization and loss of ammonia gas, thereby ensuring the recovery rate of ammonia and the product quality.

[0040] The liquid ammonia storage unit 5 is provided with a liquid ammonia input interface 501 at the upper part of the liquid ammonia storage unit 5, and a liquid ammonia discharge outlet 502 is provided at the lower part of the liquid ammonia storage unit 5. The liquid ammonia input interface 501 is connected to the high-purity liquid ammonia output interface 402 through a pipeline. A liquid level display component 503 is also provided on the outside of the liquid ammonia storage unit 5, and the liquid level display component 503 is located on the right front side of the liquid ammonia storage unit 5.

[0041] In this embodiment, the liquid level display component 503 disposed outside the liquid ammonia storage unit 5 is located on the right front side, and can display the storage amount of liquid ammonia in real time. The operator can adjust the production and storage strategy in time according to the liquid level to ensure the stable storage and supply of liquid ammonia. For example, when the liquid level is too low, the liquid ammonia can be replenished in time; when the liquid level is too high, the use or storage of liquid ammonia can be reasonably arranged to facilitate the monitoring and management of the production process.

[0042] Working principle: In the ammonia recovery process of ethanolamine production, the reaction product containing ammonia first enters the absorption tower from the reaction product input interface 101 at the top of the ammonia absorption unit 1, and after filtering out the solid impurities therein through the filter component 105, it fully contacts with the absorbent entering from the absorbent input interface 102 on the left, and the ammonia is absorbed by the absorbent to form an ammonia-rich absorption liquid. The gas generated during the absorption process is condensed by the condensation component 106 and merged into the ammonia-rich absorption liquid. The unabsorbed gas is discharged from the unabsorbed gas output interface 103 at the top, and the ammonia-rich absorption liquid flows out from the ammonia-rich absorption liquid output interface 104 at the bottom and enters the ammonia desorption unit 2. In the ammonia desorption unit 2, the ammonia-rich absorption liquid enters the desorption tower from the ammonia-rich absorption liquid input interface 201 at the top, and the pressure reduction component 205 reduces the pressure to desorb the ammonia and convert it into ammonia gas. The absorbent after desorbing ammonia is discharged from the desorbed absorbent output interface 202 on the right and circulated to the ammonia absorption unit 1, and the ammonia gas is discharged from the ammonia gas output interface 203 at the top. At the same time, the condenser 204 at the top of the desorption tower condenses the ammonia gas. Next, the ammonia gas is transported from the ammonia gas output interface 203 to the ammonia gas input interface 301 on the left side of the ammonia separation unit 3 through a pipeline, and is separated and purified by a separation membrane in the membrane separation unit. Impurities are discharged from the impurity discharge port 303 at the bottom, and high-purity ammonia is discharged from the high-purity ammonia output interface 302 on the right side and enters the ammonia refining unit 4. In the ammonia refining unit 4, high-purity ammonia enters the refining tower from the high-purity ammonia input interface 401 at the top, and the packing component 405 and the reboiler 406 cooperate to further refine the ammonia, and the impurity wastewater is discharged from the impurity wastewater output interface 403 on the right side, and the high-purity liquid ammonia flows out from the high-purity liquid ammonia output interface 402 at the bottom. The condenser 2 404 at the top of the refining tower condenses the ammonia gas. Finally, high-purity liquid ammonia is transported from the high-purity liquid ammonia output interface 402 through a pipeline to the liquid ammonia input interface 501 at the top of the liquid ammonia storage unit 5 for storage. The liquid level display component 503 displays the liquid ammonia storage amount in real time. When necessary, the liquid ammonia is discharged from the liquid ammonia discharge port 502 at the bottom.

[0043] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0044] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for recovering ammonia in the production of ethanolamine, characterized in that: include An ammonia absorption unit (1), wherein a reaction product input interface (101) is provided at the top of the ammonia absorption unit (1), an absorbent input interface (102) is provided at the left side of the ammonia absorption unit (1), an unabsorbed gas output interface (103) is provided at the top of the ammonia absorption unit (1), and an ammonia-rich absorption liquid output interface (104) is provided at the bottom of the ammonia absorption unit (1); An ammonia desorption unit (2), wherein an ammonia-rich absorption liquid input interface (201) is provided at the upper part of the ammonia desorption unit (2), a post-desorption absorbent output interface (202) is provided at the right side of the ammonia desorption unit (2), and an ammonia gas output interface (203) is provided at the top of the ammonia desorption unit (2), and the ammonia-rich absorption liquid input interface (201) is connected to the ammonia-rich absorption liquid output interface (104) through a pipeline; An ammonia separation unit (3), wherein an ammonia gas input interface (301) is provided on the left side of the ammonia separation unit (3), and a high-purity ammonia output interface (302) is provided on the right side of the ammonia separation unit (3), and the ammonia gas input interface (301) is connected to the ammonia gas output interface (203) through a pipeline; An ammonia refining unit (4), wherein a high-purity ammonia input interface (401) is provided at the top of the ammonia refining unit (4), a high-purity liquid ammonia output interface (402) is provided at the bottom of the ammonia refining unit (4), and an impurity wastewater output interface (403) is provided on the right side of the ammonia refining unit (4), and the high-purity ammonia input interface (401) is connected to the high-purity ammonia output interface (302) through a pipeline; A liquid ammonia storage unit (5), wherein a liquid ammonia input interface (501) is provided at the upper portion of the liquid ammonia storage unit (5), and a liquid ammonia discharge outlet (502) is provided at the lower portion of the liquid ammonia storage unit (5), wherein the liquid ammonia input interface (501) is connected to the high-purity liquid ammonia output interface (402) via a pipeline.

2. The device for recovering ammonia in the production of ethanolamine according to claim 1, characterized in that: The ammonia absorption unit (1) is an absorption tower, wherein a cavity for accommodating an absorbent is provided inside the absorption tower; the ammonia desorption unit (2) is a desorption tower, wherein a condenser (204) is provided at the top of the desorption tower; the ammonia separation unit (3) is a membrane separation unit, wherein a separation membrane is provided inside the membrane separation unit.

3. The device for recovering ammonia in the production of ethanolamine according to claim 1, characterized in that: The ammonia refining unit (4) is a refining tower, and a second condenser (404) is provided on the top of the refining tower; and the post-desorption absorbent output interface (202) is connected to the absorbent input interface (102) through a pipeline.

4. The device for recovering ammonia in the production of ethanolamine according to claim 1, characterized in that: The interior of the ammonia absorption unit (1) is also provided with a filtering component (105) and a condensing component (106), wherein the filtering component (105) is located below the reaction product input interface (101), and the condensing component (106) is located above the ammonia-rich absorption liquid output interface (104).

5. The device for recovering ammonia in the production of ethanolamine according to claim 1, characterized in that: A decompression component (205) is also provided inside the ammonia desorption unit (2). The decompression component (205) is located in the middle of the ammonia desorption unit (2) and close to the bottom where the condenser 1 (204) is provided.

6. The device for recovering ammonia in the production of ethanolamine according to claim 1, characterized in that: The ammonia separation unit (3) is also provided with an impurity discharge port (303), and the impurity discharge port (303) is located at the bottom of the ammonia separation unit (3).

7. The device for recovering ammonia in the production of ethanolamine according to claim 1, characterized in that: A packing component (405) is also provided inside the ammonia refining unit (4), and the packing component (405) is located in the upper middle part of the ammonia refining unit (4). A reboiler (406) is provided below the ammonia refining unit (4), and the reboiler (406) is connected to the bottom of the ammonia refining unit (4) through a pipeline.

8. The device for recovering ammonia in the production of ethanolamine according to claim 1, characterized in that: A liquid level display component (503) is also provided on the outside of the liquid ammonia storage unit (5), and the liquid level display component (503) is located on the right front side of the liquid ammonia storage unit (5).

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