Device for efficiently trapping CO2 in urea hydrolysis gas

Abstract

The utility model discloses a device for efficiently trapping CO2 in urea hydrolysis gas, which comprises an upper cabin, a middle cabin and a lower cabin which are sequentially connected, and an absorption liquid distributor is arranged in the upper cabin; a first dividing fencing is fixedly arranged at the upper part in the middle cabin, a second dividing fencing is fixedly arranged at the lower part in the middle cabin, and a hollow ball is arranged between the first dividing fencing and the second dividing fencing; a wire mesh demister and a mixed gas distributor are sequentially arranged at the upper part in the lower cabin from top to bottom; the top of the upper cabin is provided with an air outlet pipe, and the bottom of the lower cabin is provided with a liquid return pipe. According to the device disclosed by the utility model, the absorption liquid distributor is arranged at the upper part, the mixed gas distributor is arranged to uniformly mix gas and absorption liquid, and the hollow balls are added in the middle to increase the contact area, so that the reaction effect is improved, CO2 is effectively absorbed, the ammonia concentration is increased, the product quality is improved, the absorption liquid can be recycled as a chemical raw material, and the cost is saved.

Description

Technical Field

[0001] This utility model relates to the field of urea hydrolysis ammonia production technology, specifically to a method for efficiently capturing CO in urea hydrolysis gas. 2 The device. Background Technology

[0002] Ammonia, a key chemical raw material, has traditionally been supplied primarily through liquid ammonia or ammonia water. However, both liquid ammonia and ammonia water are high-risk chemicals, and their storage and transportation must adhere to strict safety regulations. Given their high explosive potential and the serious threat they pose to production safety, most companies have abandoned this approach and instead adopted the method of directly producing ammonia from urea.

[0003] Currently, ammonia production technology mainly uses urea hydrolysis. This method is energy-efficient and produces a large amount of ammonia. However, it also has several drawbacks: the product gas is affected by CO2, resulting in a lower ammonia concentration. Carbon dioxide and ammonia are relatively difficult to separate. Firstly, ammonia has a high solubility in solutions that absorb carbon dioxide. Secondly, the surface area of ​​the gas-liquid interface directly affects carbon dioxide absorption. While some methods use solid adsorption, this leads to significant waste. Utility Model Content

[0004] The purpose of this invention is to solve the problems mentioned in the background art and to propose a device for efficiently capturing CO2 in urea hydrolysis gas. The device disclosed in this invention has an absorbent distributor at the top and a mixed gas distributor at the bottom to ensure uniform distribution of the mixed gas and absorbent. A hollow sphere is set in the middle to increase the contact area between the absorbent and the mixed gas, thereby increasing the reaction effect, absorbing CO2 from the mixed gas, increasing the ammonia concentration, improving product quality, and the absorbent can be used as a chemical raw material, saving costs.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] A highly efficient device for capturing CO2 from urea hydrolysis gas includes an upper chamber, a middle chamber, and a lower chamber connected in sequence. An absorbent distributor is installed in the upper chamber, and the absorbent distributor is externally connected to an absorbent circulation assembly via an outlet pipe. The absorbent is an amine-based absorbent, such as N-methyldiethanolamine (MDEA) or ethanolamine (MEA). A first segmented barrier is fixedly installed in the upper part of the middle chamber, and a second segmented barrier is fixedly installed in the lower part of the middle chamber. A perforated sphere is installed between the first and second segmented barriers. The first and second segmented barriers allow the mixed gas and absorbent to pass through while simultaneously fixing the perforated sphere in the middle chamber, ensuring that the mixed gas is effectively purified. The CO2 process proceeds smoothly. A wire mesh demister and a mixed gas distributor are sequentially installed from top to bottom in the upper part of the lower chamber. The mixed gas distributor is connected to a urea hydrolysis device via an inlet pipe. The wire mesh demister removes water vapor from the mixed gas. An outlet pipe is installed at the top of the upper chamber. A CO2 concentration monitor is installed at the connection point between the top of the upper chamber and the outlet pipe. The CO2 concentration monitor detects the CO2 concentration in the treated gas in real time. If the CO2 concentration exceeds a set value, the absorbent is considered saturated and needs to be replaced with new absorbent. An ammonia storage device is connected to the outlet pipe. A return pipe is installed at the bottom of the lower chamber, connected to an absorbent circulation assembly. The absorbent is recycled before it becomes saturated.

[0007] Preferably, the upper compartment, middle compartment, and lower compartment are connected by threads for easy loading and unloading. Sealing gaskets are provided at the connection surfaces of the upper compartment, middle compartment, and lower compartment to ensure that the internal space is sealed.

[0008] As a preferred option, a maintenance port is provided on the side of the middle compartment, which can be used to load and replace the hollow spheres.

[0009] Preferably, a support frame is installed below the lower compartment to improve the stability of the device.

[0010] Preferably, the absorbent circulation assembly includes an absorbent circulation machine. A new liquid tank is located on the right side of the absorbent circulation machine, and the top surface of the absorbent circulation machine is connected to an outlet pipe. The outlet pipe is connected to the new liquid tank through a pipe inside the absorbent circulation machine. A waste liquid tank is located on the front of the absorbent circulation machine, and a return liquid pipe is connected to the left side of the absorbent circulation machine. The return liquid pipe is connected to the waste liquid tank through a pipe inside the absorbent circulation machine. After the absorbent is saturated, it is stored in the waste liquid tank. New absorbent is taken from the new liquid tank and enters the device to start the CO2 removal process.

[0011] Preferably, a new liquid tank inlet is provided on the top surface of the new liquid tank. When the absorbent is almost used up, the absorbent is replenished through the new liquid tank inlet. A waste liquid tank outlet is provided at the bottom front of the waste liquid tank. When the saturated absorbent in the waste liquid tank is almost full, the saturated absorbent is discharged through the waste liquid tank outlet. The discharged saturated absorbent is used as a chemical raw material.

[0012] Preferably, the absorbent distributor includes multiple liquid nozzles and a first interconnecting pipe connecting the liquid nozzles in series. The liquid nozzles are arranged in a circular pattern with multiple rings, resulting in a large and dense distribution of the absorbent liquid and thus improving the CO2 removal effect. The innermost ring of liquid nozzles is connected to the first interconnecting pipe at only one end, while the outermost ring of liquid nozzles is connected to the first interconnecting pipe at one end and to the inlet pipe at the other end. The outlet of the liquid nozzle faces downward, and the inlet pipe is connected to the outlet pipe.

[0013] Preferably, the gas distributor includes multiple gas nozzles and a second interconnecting pipe connecting the gas nozzles in series. The gas nozzles are arranged in a circular pattern with multiple rings, resulting in a large and dense distribution of the gas mixture and thus improving the removal of CO2 and water vapor. The innermost gas nozzle is connected to the second interconnecting pipe at only one end, while the outermost gas nozzle is connected to the second interconnecting pipe at one end and to the inlet pipe at the other end. The outlet of the gas nozzle faces downward, and the inlet pipe is connected to the gas supply pipe.

[0014] Preferably, the hollow sphere has multiple through holes inside, which increases both the contact area and the contact time between the mixed gas and the absorbent, thereby enhancing the reaction effect. The hollow sphere is made of plastic and rubber, does not participate in the CO2 removal chemical reaction, and does not react with ammonia, thus exhibiting stable chemical properties.

[0015] Preferably, multiple sets of positioning rings are fixedly installed on the inner walls of the upper, middle and lower compartments, and the positioning rings are located below the absorbent distributor, the first dividing barrier, the second dividing barrier, the wire mesh demister and the mixed gas distributor.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] 1. The device disclosed in this utility model has an absorbent distributor at the top and a mixed gas distributor at the bottom to ensure uniform distribution of the mixed gas and absorbent. A hollow ball is set in the middle to increase the contact area between the absorbent and the mixed gas, thereby increasing the reaction effect, absorbing CO2 inside the mixed gas, increasing the ammonia concentration, improving product quality, and the absorbent can be used as a chemical raw material, saving costs.

[0018] 2. The device disclosed in this utility model is designed with an upper compartment, a middle compartment, and a lower compartment that are easy to load and unload. Sealing gaskets are provided at the connection points to ensure that the internal space is sealed, preventing the leakage of internal chemical materials, avoiding resource waste and environmental pollution, and improving production safety.

[0019] 3. The device disclosed in this utility model has a maintenance port on the side of the middle compartment, which can be used to fill and replace the hollow ball, thus improving work efficiency.

[0020] 4. The device disclosed in this utility model has a support frame installed below the lower compartment, which improves the stability of the device and enhances production safety.

[0021] 5. The device disclosed in this utility model realizes the recycling of absorbent liquid through the absorbent liquid circulation component. At the same time, after the absorbent liquid is saturated, it is stored in the waste liquid tank. New absorbent liquid is taken from the waste liquid tank and put into the device to start the CO2 removal process, which saves resources, reduces production costs, and improves production efficiency.

[0022] 6. The absorbent distributor and mixed gas distributor provided in the device disclosed in this utility model increase the distribution area of ​​the mixed gas and absorbent, improve the contact area, thereby enhancing the CO2 absorption effect and improving the quality of ammonia production.

[0023] 7. The hollow sphere in the device disclosed in this utility model increases both the contact area and the contact time between the mixed gas and the absorbent, thereby enhancing the reaction effect and improving the quality of ammonia production. It does not participate in the CO2 removal chemical reaction, nor does it react with ammonia. It has stable chemical properties, can be used for a long time, and saves costs. Attached Figure Description

[0024] Figure 1 This is an isometric structural diagram of the device disclosed in this utility model;

[0025] Figure 2 This is an exploded view of the device disclosed in this utility model;

[0026] Figure 3 This is a cross-sectional view of the device disclosed in this utility model;

[0027] Figure 4 This is a schematic diagram of the absorbent distributor structure of the device disclosed in this utility model;

[0028] Figure 5 This is a schematic diagram of the gas distributor structure of the device disclosed in this utility model;

[0029] Figure 6 This is a schematic diagram of the hollow ball structure of the device disclosed in this utility model.

[0030] The components include: 1. Upper compartment; 2. Middle compartment; 201. Maintenance port; 3. Lower compartment; 4. Support frame; 5. Absorbent liquid circulation assembly; 501. Absorbent liquid circulation machine; 502. New liquid tank; 5021. New liquid tank inlet; 503. Waste liquid tank; 5031. Waste liquid tank outlet; 6. Gas outlet pipe; 7. Gas supply pipe; 8. CO2 concentration monitor; 9. Absorbent liquid distributor; 901. Liquid nozzle; 902. First interconnecting pipe; 903. Liquid inlet pipe; 10. First dividing barrier; 11. Second dividing barrier; 12. Wire mesh demister; 13. Mixed gas distributor; 1301. Gas nozzle; 1302. Second interconnecting pipe; 1303. Gas inlet pipe; 14. Positioning ring; 15. Hollowed-out ball; 16. Liquid outlet pipe; 17. Liquid return pipe. Detailed Implementation

[0031] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0032] like Figure 1-6 As shown, an efficient device for capturing CO2 from urea hydrolysis gas includes an upper chamber 1, a middle chamber 2, and a lower chamber 3 connected in sequence. An absorbent distributor 9 is installed in the upper chamber 1, and the absorbent distributor 9 is externally connected to an absorbent circulation assembly 5 via an outlet pipe 16. The absorbent is an alcoholamine-based absorbent, such as N-methyldiethanolamine (MDEA) or ethanolamine (MEA). A first dividing barrier 10 is fixedly installed in the upper part of the middle chamber 2, and a second dividing barrier 11 is fixedly installed in the lower part of the middle chamber 2. A perforated sphere 15 is placed between the first dividing barrier 10 and the second dividing barrier 11. The first dividing barrier 10 and the second dividing barrier 11 allow the mixed gas and absorbent to pass through while simultaneously fixing the perforated sphere 15 in the middle chamber 2, ensuring the mixing... The CO2 removal process proceeds smoothly. A wire mesh demister 12 and a mixed gas distributor 13 are sequentially installed from top to bottom in the upper part of the lower chamber 3. The mixed gas distributor 13 is connected to a urea hydrolysis device via an inlet pipe 1303. The wire mesh demister 12 removes water vapor from the mixed gas. An outlet pipe 6 is installed at the top of the upper chamber 1. A CO2 concentration monitor 8 is installed at the connection point between the top of the upper chamber 1 and the outlet pipe 6. The CO2 concentration monitor 8 detects the CO2 concentration in the treated gas in real time. If the CO2 concentration is higher than a set value, the absorbent is considered saturated and needs to be replaced with a new absorbent. An ammonia storage device is connected to the outlet pipe 6. A return pipe 17 is installed at the bottom of the lower chamber 3. The return pipe 17 is connected to an absorbent circulation assembly 5, allowing the absorbent to be recycled before it becomes saturated.

[0033] like Figures 1-3As shown, the upper compartment 1, middle compartment 2 and lower compartment 3 are connected by threads for easy loading and unloading. Sealing gaskets are provided at the connection surfaces of the upper compartment 1, middle compartment 2 and lower compartment 3 to ensure that the internal space is sealed. A maintenance port 201 is provided on the side of the middle compartment 2 for loading and replacing the hollow ball 15. A support 4 is provided below the lower compartment 3 to improve the stability of the device.

[0034] like Figure 1 As shown, the absorbent circulation assembly 5 includes an absorbent circulation machine 501. A new liquid tank 502 is provided on the right side of the absorbent circulation machine 501. The top surface of the absorbent circulation machine 501 is connected to the outlet pipe 16, which is connected to the new liquid tank 502 through a pipe inside the absorbent circulation machine 501. A waste liquid tank 503 is provided on the front of the absorbent circulation machine 501. A return liquid pipe 17 is connected to the left side of the absorbent circulation machine 501, which is connected to the waste liquid tank 503 through a pipe inside the absorbent circulation machine 501. After the absorbent is saturated, it is stored in the waste liquid tank 503. New absorbent is taken from the new liquid tank 502 and enters the device to start the CO2 removal process. The absorbent circulation machine 501 uses a conventional liquid extraction or conveying motor, which will not be described in detail here. The top surface of the new liquid tank 502 is provided with a new liquid tank inlet 5021. When the absorbent is almost used up, the absorbent is replenished through the new liquid tank inlet 5021. The bottom front of the waste liquid tank 503 is provided with a waste liquid tank outlet 5031. When the saturated absorbent in the waste liquid tank 503 is almost full, the saturated absorbent is discharged through the waste liquid tank outlet 5031. The discharged saturated absorbent is used as a chemical raw material.

[0035] like Figure 3 and Figure 4 As shown, the absorbent distributor 9 includes multiple liquid nozzles 901 and a first interconnecting pipe 902 that connects the liquid nozzles 901 in series. The liquid nozzles 901 are arranged in a circular pattern, with multiple rings of liquid nozzles. The large number and density of liquid nozzles 901 increase the distribution area of ​​the absorbent liquid, thereby improving the CO2 removal effect. The innermost ring of liquid nozzles 901 is connected to the first interconnecting pipe 902 at only one end, while the outermost ring of liquid nozzles 901 is connected to the first interconnecting pipe 902 at one end and to the inlet pipe 903 at the other end. The outlet of the liquid nozzle 901 faces downward, and the inlet pipe 903 is connected to the outlet pipe 16.

[0036] like Figure 3 and Figure 5 As shown, the gas distributor 13 includes multiple gas nozzles 1301 and a second interconnecting pipe 1302 connecting the gas nozzles 1301 in series. The gas nozzles 1301 are arranged in a circular pattern with multiple rings. The large number and density of the gas nozzles 1301 increase the dispersion area of ​​the mixed gas, thereby improving CO removal efficiency. 2The effect of water vapor is that the innermost gas nozzle 1301 is connected to the second interconnecting pipe 1302 at only one end, while the outermost gas nozzle 1301 is connected to the second interconnecting pipe 1302 at one end and to the air inlet pipe 1303 at the other end. The outlet of the gas nozzle 1301 is downward, and the air inlet pipe 1303 is connected to the air supply pipe 7.

[0037] like Figure 6 As shown, the hollow sphere 15 has multiple through holes inside, which increases both the contact area between the mixed gas and the absorbent liquid and the contact time between the mixed gas and the absorbent liquid, thereby enhancing the reaction effect. The hollow sphere 15 is made of plastic and rubber, does not participate in the CO2 removal chemical reaction, and does not react with ammonia, so its chemical properties are stable.

[0038] like Figure 2 As shown, multiple sets of positioning rings 14 are fixedly installed on the inner walls of the upper compartment 1, the middle compartment 2 and the lower compartment 3. The positioning rings 14 are located below the absorbent distributor 9, the first dividing barrier 10, the second dividing barrier 11, the wire mesh demister 12 and the mixed gas distributor 13.

[0039] Specific embodiments of the device disclosed in this utility model are as follows:

[0040] 1. Urea solution hydrolyzes to produce NH3 and CO under the action of a catalyst and heating. 2， A mixed gas is generated, which contains NH3, CO2 and water vapor. The mixed gas enters the lower compartment 3 through the gas supply pipe 7 and the mixed gas distributor 13.

[0041] 2. The absorbent circulation assembly controls the absorbent, which enters the upper chamber 1 through the outlet pipe 16 and is sprayed downwards through the absorbent distributor 9;

[0042] 3. The mixed gas moves upward and passes through the wire mesh demister 12 to remove water vapor;

[0043] 4. The mixed gas and absorbent liquid meet and come into contact in the middle chamber 2. The contact area and contact time are increased by the hollow ball 15, so that CO2 and absorbent liquid can react fully.

[0044] 5. The absorbed liquid after the reaction returns from the lower chamber 3 to the absorbed liquid circulation assembly 5 through the return pipe 17, and the purified ammonia gas is discharged to the ammonia storage device through the outlet pipe 6.

[0045] It should be noted that the device disclosed in this utility model is one of the devices on an ammonia production line and needs to be used in conjunction with other ammonia production devices. The other ammonia production devices use existing conventional equipment, which will not be described in detail here.

[0046] In the description of this utility model, the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for describing this utility model and do not require that this utility model be constructed or operated in a specific orientation, and therefore should not be construed as limiting this utility model. The terms "connected" and "linked" in this utility model should be interpreted broadly. For example, they can refer to a connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0047] The above description represents the preferred operating mode of this utility model. The specific operating mode description is only for better understanding the concept of this utility model. For those skilled in the art, several improvements or equivalent substitutions can be made based on the principles of this utility model, and these improvements or equivalent substitutions are also considered to fall within the protection scope of this utility model.

Claims

1. A device for efficiently capturing CO2 in urea hydrolysis gas, comprising an upper cabin (1), a middle cabin (2) and a lower cabin (3) connected in sequence, characterized in that, The upper cabin (1) is provided with an absorption liquid distributor (9) which is connected with an absorption liquid circulating assembly (5) through a liquid outlet pipe (16); the middle cabin (2) is fixedly provided with a first partition dam (10) at the upper part and a second partition dam (11) at the lower part, and a hollow ball (15) is arranged between the first partition dam (10) and the second partition dam (11); the lower cabin (3) is sequentially provided with a wire mesh demister (12) and a mixed gas distributor (13) from top to bottom at the upper part, and the mixed gas distributor (13) is connected with a urea hydrolysis device through an air inlet pipe (1303); the upper cabin (1) is provided with an air outlet pipe (6) at the top, a CO2 concentration monitor (8) is arranged at the position where the upper cabin (1) top and the air outlet pipe (6) are connected, the air outlet pipe (6) is connected with an ammonia gas storage device, and the lower cabin (3) is provided with a liquid return pipe (17) at the bottom, which is connected with the absorption liquid circulating assembly (5).

2. The device for efficiently capturing CO2 in urea hydrolysis gas according to claim 1, wherein The upper cabin (1), the middle cabin (2) and the lower cabin (3) are connected by threads, and sealing gaskets are arranged at the connecting surfaces of the upper cabin (1), the middle cabin (2) and the lower cabin (3).

3. The device for efficiently capturing CO2 in urea hydrolysis gas according to claim 1, wherein A maintenance opening (201) is arranged on the side of the middle cabin (2).

4. The device for efficiently capturing CO2 in urea hydrolysis gas according to claim 1, wherein A support (4) is arranged below the lower cabin (3).

5. The device for efficiently capturing CO2 in urea hydrolysis gas according to claim 1, wherein The absorption liquid circulating assembly (5) comprises an absorption liquid circulating machine (501), a new liquid tank (502) is arranged on the right side of the absorption liquid circulating machine (501), the top surface of the absorption liquid circulating machine (501) is connected with the liquid outlet pipe (16), the liquid outlet pipe (16) is connected with the new liquid tank (502) through the pipeline inside the absorption liquid circulating machine (501); a waste liquid tank (503) is arranged on the front surface of the absorption liquid circulating machine (501), and the left surface of the absorption liquid circulating machine (501) is connected with the liquid return pipe (17), and the liquid return pipe (17) is connected with the waste liquid tank (503) through the pipeline inside the absorption liquid circulating machine (501).

6. The device for efficiently capturing CO2 in urea hydrolysis gas according to claim 5, characterized in that, A new liquid tank liquid inlet (5021) is arranged on the top surface of the new liquid tank (502), and a waste liquid tank liquid outlet (5031) is arranged on the front bottom surface of the waste liquid tank (503).

7. The device for efficiently capturing CO2 in urea hydrolysis gas according to claim 1, wherein The absorption liquid distributor (9) comprises a plurality of liquid spray heads (901) and a first intercommunication pipe (902) connected in series with the liquid spray heads (901), the liquid spray heads (901) are circularly distributed, and the liquid spray heads (901) are arranged in multiple circles, wherein the liquid spray heads (901) in the innermost circle are connected with the first intercommunication pipe (902) at one end, and any one of the liquid spray heads (901) in the outermost circle is connected with the first intercommunication pipe (902) at one end and connected with a liquid inlet pipe (903) at the other end, and the liquid inlet pipe (903) is connected with the liquid outlet pipe (16).

8. The device for efficiently capturing CO2 in urea hydrolysis gas according to claim 1, wherein The mixed gas distributor (13) comprises a plurality of gas nozzles (1301) and a second intercommunication pipe (1302) connected in series with the gas nozzles (1301), the gas nozzles (1301) are distributed in a circular manner, and the gas nozzles (1301) are arranged in multiple circles, wherein the gas nozzles (1301) in the innermost circle are connected to the second intercommunication pipe (1302) at one end, and any one of the gas nozzles (1301) in the outermost circle is connected to the second intercommunication pipe (1302) at one end and to a gas inlet pipe (1303) at the other end, and the gas inlet pipe (1303) is connected to the gas supply pipe (7).

9. The device for efficiently capturing CO2 in urea hydrolysis gas according to claim 1, wherein The hollow ball (15) is internally provided with a plurality of through holes, and the hollow ball (15) is made of plastic and rubber.

10. The device for efficiently capturing CO2 in urea hydrolysis gas according to claim 1, wherein A plurality of groups of positioning rings (14) are fixedly arranged on the inner walls of the upper cabin (1), the middle cabin (2) and the lower cabin (3), and the positioning rings (14) are located below the absorption liquid distributor (9), the first dividing baffle (10), the second dividing baffle (11), the wire mesh demister (12) and the mixed gas distributor (13).

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