System for synthesizing ammonia by liquid phase method

Abstract

The utility model provides a system for synthesizing ammonia by a liquid phase method. The system comprises a hydrogen pipeline, a nitrogen pipeline, a liquid ammonia pipeline, a catalyst pipeline, a gas mixer, a solid-liquid mixer, a reactor and a buffer tank, the catalyst pipeline and the liquid ammonia pipeline are both connected with the solid-liquid mixer; the hydrogen pipeline and the nitrogen pipeline are connected with a gas inlet of the gas mixer; two pneumatic enhanced mass transfer devices are arranged in the reactor, are positioned below the liquid level of the reactor, and have the same mounting height; the radial outlets of the two pneumatic reinforced mass transfer devices are staggered, and the tangential outlets face opposite directions; an outlet of the gas mixer is connected with the pneumatic enhanced mass transfer device; the outlet of the reactor is connected with the inlet of the buffer tank, the side wall of the buffer tank is provided with a product extraction port, the bottom of the buffer tank is provided with a reflux port, and the reflux port is connected with the reactor to reflux a catalyst deposited at the bottom of the buffer tank to the reactor. The system can be used for synthesizing ammonia at lower temperature and pressure.

Description

Technical Field

[0001] This utility model relates to the field of ammonia synthesis technology, and more specifically, to a system for ammonia synthesis via a liquid phase method. Background Technology

[0002] The ammonia synthesis industry occupies a pivotal position in modern chemical industry. Ammonia, as an important chemical raw material, is widely used in fertilizer production, pharmaceuticals, synthetic fibers, and many other fields. Traditional ammonia synthesis processes are mainly based on the Haber-Bosch process, which has made significant contributions to global food production and industrial development since its invention.

[0003] With advancements in technology and increasing demands for sustainable development, the limitations of traditional ammonia synthesis processes are becoming increasingly apparent. Specifically, these limitations manifest in the following ways: First, the reaction conditions for traditional ammonia synthesis are extremely demanding, requiring high temperatures (350℃-550℃) and high pressures (15MPa-30MPa). This places extremely high demands on equipment materials and manufacturing processes, and also results in significant resource consumption during production. Furthermore, the high operating temperatures and pressures necessitate the use of gas-phase methods, which face the significant challenge of extremely difficult mass transfer and a lack of technological breakthroughs. Second, the iron-based catalysts used in traditional processes have limited performance. Although this catalyst possesses a certain degree of stability and activity, its internal diffusion problem slows down the diffusion rate of gas within the catalyst particles, and the catalyst also has limitations in optimizing gas-gas reactions. These factors collectively restrict the improvement of reaction efficiency. Furthermore, traditional ammonia synthesis processes mainly employ a fixed-bed method, which involves complex separation and recovery processes and extremely high energy consumption. The fixed-bed method also presents numerous inconveniences when the catalyst needs to be replaced due to deactivation. Finally, due to the high energy consumption of traditional processes, a large amount of greenhouse gases are emitted during production, causing serious environmental impact.

[0004] In view of the above, this utility model is hereby proposed. Utility Model Content

[0005] The purpose of this invention is to provide a system for ammonia synthesis via liquid phase. This system uses a liquid phase method to synthesize ammonia and combines a cluster-matrix cocatalyst and a pneumatically enhanced mass transfer device to effectively reduce reaction temperature and pressure, reduce resource consumption, and improve reaction efficiency. In addition, the system simplifies the catalyst addition process by mixing the catalyst into the liquid ammonia before adding it to the reactor, and simplifies the catalyst separation process by setting up a buffer tank.

[0006] In order to achieve the above-mentioned objectives of this utility model, the following technical solution is adopted:

[0007] This invention provides a system for synthesizing ammonia using a liquid phase method, comprising: a hydrogen pipeline, a nitrogen pipeline, a liquid ammonia pipeline, a catalyst pipeline, a gas mixer, a solid-liquid mixer, a reactor, and a buffer tank;

[0008] Both the catalyst pipeline and the liquid ammonia pipeline are connected to the solid-liquid mixer. The cluster-matrix co-catalyst delivered by the catalyst pipeline and the liquid ammonia delivered by the liquid ammonia pipeline are mixed in the solid-liquid mixer and then fed into the reactor.

[0009] Both the hydrogen pipeline and the nitrogen pipeline are connected to the gas inlet of the gas mixer;

[0010] The reactor is equipped with two pneumatically enhanced mass transfer devices, which are located below the liquid surface and at the same height. The radial outlets of the two devices are staggered, while their tangential outlets face opposite directions. This allows the microbubbles emitted from the devices to drive the liquid within the reactor to flow in a predetermined direction, either clockwise or counterclockwise. The outlet of the gas mixer is connected to the pneumatically enhanced mass transfer devices.

[0011] The reactor outlet is connected to the buffer tank inlet, the buffer tank has a product outlet on its side wall, and a reflux port is provided at the bottom of the buffer tank. The reflux port is connected to the reactor to return the catalyst deposited at the bottom of the buffer tank to the reactor.

[0012] In the above scheme, by using a cluster-matrix co-catalyst to catalyze the synthesis of ammonia from hydrogen and nitrogen, the reaction temperature and pressure can be reduced, and the internal diffusion problem of traditional catalysts can be avoided. By using a pneumatically enhanced mass transfer device to disperse and break the reaction mixture (hydrogen + nitrogen) into micron-sized microbubbles, the mass transfer area is increased, and the reaction conditions are reduced. Using a liquid-phase ammonia synthesis method can improve reaction efficiency, reduce reaction difficulty, and increase reaction conversion rate at the mass transfer level. Adding the catalyst to the reactor after mixing it with liquid ammonia reduces the difficulty of catalyst addition, and the catalyst can be uniformly dispersed within the reactor, which helps improve the overall catalytic effect. By setting up a buffer tank, the product can be purified, preventing impurities from affecting product purity. To facilitate catalyst recovery and avoid catalyst waste, the two pneumatically enhanced mass transfer devices are staggered radially with opposite tangential outlets. This avoids collisions between the two radial airflow streams, preventing dead zones in the liquid. Furthermore, the microbubbles emitted from the two devices agitate the liquid within the reactor, promoting uniform microbubble distribution, preventing aggregation, increasing the mass transfer area and the contact area between the reactants (hydrogen and nitrogen) and the catalyst, thus improving reaction efficiency. Additionally, the agitation ensures uniform catalyst distribution, preventing deposition at the bottom of the reactor and maintaining catalytic effectiveness. This agitation also leads to a more uniform temperature distribution within the reactor. In summary, this system, combining liquid-phase method, cluster-matrix co-catalyst, and pneumatically enhanced mass transfer device, can reduce the reaction temperature and pressure of ammonia synthesis, minimizing resource consumption while improving mass transfer and reaction efficiency. This system aligns with green chemistry principles, featuring low energy consumption, environmental friendliness, and easy catalyst replacement and recovery, making it a promising candidate for widespread applications.

[0013] Preferably, the buffer tank is equipped with a baffle plate that divides the interior of the buffer tank into a buffer zone and a collection zone. The inlet of the buffer tank is located on the side wall of the buffer zone, and the outlet of the buffer tank is located at the bottom of the collection zone. The crude product entering the buffer tank settles and separates in the buffer zone, and the liquid ammonia in the crude product overflows through the top of the baffle plate to the collection zone. As the crude product enters the buffer tank, the ammonia in the crude product condenses and liquefies, while the catalyst settles at the bottom of the buffer tank. As the amount of crude product increases, the liquid level in the buffer tank rises, and the upper layer of liquid ammonia gradually rises to the top of the baffle plate, overflows from the top of the baffle plate to the collection zone, and is collected through the outlet of the buffer tank. The catalyst at the bottom flows back to the reactor to continue participating in the reaction. This scheme, by setting up a baffle plate, helps to avoid the catalyst affecting the purity of the product, thereby contributing to the obtaining of high-purity liquid ammonia.

[0014] Preferably, a baffle is provided at the inlet of the buffer tank, and the baffle is inclined upward; the bottom of the baffle is connected to the inner sidewall of the buffer tank, and the top height is lower than that of the isolation plate. The baffle can block the coarse product, preventing the kinetic energy of the coarse product when entering the buffer tank from impacting the liquid inside the buffer tank, thereby avoiding affecting the sedimentation and separation effect inside the buffer tank. Therefore, this solution is beneficial to further improve the purity of the product.

[0015] Preferably, the system further includes an annular agitator disposed inside the reactor; the annular agitator includes an annular tube and multiple nozzles arranged in an array below the annular tube along the target direction; the multiple nozzles are inclined downwards; the solid-liquid mixture input from the solid-liquid mixer enters the annular tube and then enters the reactor through the nozzles. The multiple nozzles of the annular agitator spray the solid-liquid mixture into the reactor, which can agitate and stir the liquid in the reactor. This is beneficial for rapidly mixing the solid-liquid mixture with the liquid, improving the uniformity of catalyst distribution; furthermore, it can capture unreacted feed gas by stirring, further increasing the mass transfer area of ​​the feed gas and improving the feed conversion rate; and still more importantly, this method can further improve the uniformity of temperature distribution in the liquid.

[0016] Preferably, the tilt angle of the nozzle in the horizontal direction is within the range of [15°, 45°]. This angle design can improve the stirring effect of the solid-liquid mixture sprayed by the nozzle on the liquid in the reactor.

[0017] Preferably, the target direction is the same as the preset direction. In this case, both the target direction and the preset direction are clockwise or counterclockwise. The annular agitator and the two oppositely arranged pneumatically enhanced mass transfer devices can agitate the liquid in the same direction at different liquid level heights. This helps to improve the agitation effect on the liquid, thereby further improving the uniformity of the distribution of the catalyst and the microbubbles ejected by the pneumatically enhanced mass transfer devices in the liquid, and thus further improving the reaction efficiency and raw material conversion rate.

[0018] Preferably, a circulation pipeline is provided on one side of the reactor, and a hydraulically enhanced mass transfer device is installed inside the reactor, located below the pneumatically enhanced mass transfer device. The inlet of the circulation pipeline is connected to the reactor and located above the pneumatically enhanced mass transfer device, while the outlet of the circulation pipeline is connected to the hydraulically enhanced mass transfer device. A circulation pump and a heat exchanger are installed on the circulation pipeline. In this design, the liquid in the upper part of the reactor can be continuously circulated to the hydraulically enhanced mass transfer device through the circulation pipeline. This helps to increase the residence time of hydrogen and nitrogen in the liquid and makes the temperature distribution of the liquid in the reactor more uniform. In addition, the heat exchanger on the circulation pipeline can improve the temperature stability inside the reactor, ensuring that the reaction always takes place at a suitable temperature, thereby further guaranteeing the reaction efficiency.

[0019] Preferably, the outlet of the hydraulically enhanced mass transfer device is connected to a diffuser tube, the upper end of which has multiple openings, and the upper end of the diffuser tube is located between the two pneumatically enhanced mass transfer devices. The gas-liquid emulsion obtained by the dispersion and breakup of the hydraulically enhanced mass transfer device is input into the space between the two pneumatically enhanced mass transfer devices via the diffuser tube. In this scheme, the gas-liquid emulsion obtained by the dispersion and breakup of the hydraulically enhanced mass transfer device can be directly transported between the two pneumatically enhanced mass transfer devices, and uniformly dispersed into the liquid under the action of microbubbles ejected from the two pneumatically enhanced mass transfer devices, which helps to further improve the mass transfer area and reaction efficiency.

[0020] Preferably, the reactor further includes a cooler and a gas-liquid separator; the cooler and the gas-liquid separator are connected in sequence to the top of the reactor; the gas outlet of the gas-liquid separator is connected to the pneumatically enhanced mass transfer device. The gas discharged from the top of the reactor can be separated by the cooler and the gas-liquid separator, wherein the cooled and liquefied gas is liquid ammonia, and the uncooled gas is a mixture of hydrogen and nitrogen. The mixture is returned to the reactor via the pneumatically enhanced mass transfer device to continue participating in the reaction.

[0021] Preferably, the system further includes a reflux pipeline, the inlet of which is connected to the reflux port, and the outlet of which is connected to the reactor. The outlet of the reflux pipeline is located vertically between the liquid surface of the reactor and the pneumatically enhanced mass transfer device. By positioning the reflux port above the pneumatically enhanced mass transfer device, the agitation effect of the microbubbles ejected from the two devices can be used to uniformly disperse the catalyst in the reflux material in the liquid, preventing catalyst aggregation and deposition at the bottom of the reactor. Furthermore, the outlet of the reflux pipeline can be located vertically between the annular agitator and the pneumatically enhanced mass transfer device, which can further improve the agitation and dispersion effect on the reflux material.

[0022] It will be understood by those skilled in the art that the pneumatic enhanced mass transfer device and the hydraulic enhanced mass transfer device used in this utility model have been reflected in the inventor's prior patents, such as patents with application numbers CN201610641119.6, CN201610641251.7, CN201710766435.0, CN106187660A, CN105903425A, CN205833127U and CN207581700U. The prior patent CN201610641119.6 details the specific product structure and working principle of a micron-sized bubble generator (i.e., a bubble breaker). This application document states that "the micron-sized bubble generator includes a main body and a secondary breaking component. The main body has a cavity, and an inlet communicating with the cavity is provided on the main body. The first and second ends of the cavity are both open, and the cross-sectional area of ​​the cavity decreases from the middle of the cavity towards the first and second ends. The secondary breaking component is located at at least one of the first and second ends of the cavity, with a portion of the secondary breaking component located within the cavity. A ring-shaped channel is formed between the secondary breaking component and the open through-holes at both ends of the cavity. The micron-sized bubble generator also includes an air inlet pipe and a liquid inlet pipe." From the specific structure disclosed in this application document, its specific working principle can be understood as follows: liquid enters the micron-sized bubble generator tangentially through the liquid inlet pipe, rotates at ultra-high speed, and cuts the gas, causing the gas bubbles to break into micron-sized microbubbles, thereby increasing the mass transfer area between the liquid and gas phases. Moreover, the micron-sized bubble generator in this patent is a pneumatic bubble breaker.

[0023] Furthermore, prior patent 201610641251.7 describes a primary bubble breaker with a circulating liquid inlet, a circulating gas inlet, and a gas-liquid mixture outlet, while a secondary bubble breaker connects the feed inlet to the gas-liquid mixture outlet. This indicates that both bubble breakers require a gas-liquid mixture to enter. Additionally, as shown in the accompanying drawings, the primary bubble breaker primarily utilizes the circulating liquid as its power source, thus classifying it as a hydraulically driven enhanced reactor. The secondary bubble breaker simultaneously introduces the gas-liquid mixture into an elliptical rotating sphere for rotation, thereby achieving bubble breakage during rotation. Therefore, the secondary bubble breaker is actually a gas-liquid linkage bubble breaker. In fact, both hydraulically driven and gas-liquid linkage bubble breakers are specific forms of bubble breakers. However, the enhanced mass transfer device used in this invention is not limited to these forms; the specific structure of the bubble breaker described in the prior patent is merely one possible form for this invention.

[0024] Furthermore, prior patent 201710766435.0 states that "the principle of the bubble breaker is to achieve mutual collision of gases by high-speed jetting"; and prior patent CN106187660 also describes the specific structure of the bubble breaker, as detailed in paragraphs

[0031] -

[0041] of the specification and the attached drawings. It elaborates on the specific working principle of the bubble breaker S-2. The top of the bubble breaker is the liquid phase inlet, and the side is the gas phase inlet. The liquid phase entering from the top provides the entrainment force, thereby achieving the effect of crushing into ultrafine bubbles. The attached drawings also show that the bubble breaker has a conical structure, with the upper diameter being larger than the lower diameter, which is also to allow the liquid phase to provide better entrainment force.

[0025] Because the bubble breaker was newly developed in the early stages of the prior patent application, it was initially named a micron bubble generator (CN201610641119.6), etc. With continuous technological improvements, it was later renamed a bubble breaker. The enhanced mass transfer device in this utility model is equivalent to the previous micron bubble generator, micro-interface generator, etc., only with different names. In summary, both the pneumatic enhanced mass transfer device and the hydraulic enhanced mass transfer device of this utility model belong to the prior art.

[0026] This invention also provides a method for synthesizing ammonia using a liquid phase method, which uses the system described in any of the above embodiments to synthesize ammonia.

[0027] Preferably, the reaction temperature of this method is in the range of [85℃, 115℃], and the reaction pressure is in the range of [3MPa, 8MPa].

[0028] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0029] 1. By using a cluster-matrix co-catalyst to catalyze the synthesis of ammonia from hydrogen and nitrogen, the reaction temperature and pressure can be reduced, and the internal diffusion problem caused by traditional catalysts can be avoided.

[0030] 2. By using a pneumatically enhanced mass transfer device to disperse and break the reaction mixture (hydrogen + nitrogen) into micron-sized microbubbles, the mass transfer area is increased and the reaction conditions are reduced.

[0031] 3. By using the liquid-phase method to synthesize ammonia, the reaction efficiency can be improved, the reaction difficulty reduced, and the reaction conversion rate increased at the mass transfer level;

[0032] 4. By mixing the catalyst with liquid ammonia before adding it to the reactor, the difficulty of adding the catalyst can be reduced, and the catalyst can be evenly dispersed in the reactor, which helps to improve the overall catalytic effect. By setting up a buffer tank, the product can be purified to avoid the catalyst mixed in affecting the purity of the product, and the catalyst can be easily recovered to avoid catalyst waste.

[0033] 5. By staggering the radial outlets of the two pneumatically enhanced mass transfer devices and having their tangential outlets facing opposite directions, the collision of the two radial airflows can be avoided, preventing liquid dead zones. Furthermore, the microbubbles ejected from the two pneumatically enhanced mass transfer devices can drive the liquid in the reactor to flow in a preset direction, thereby stirring the liquid in the reactor. This can ensure that the microbubbles are evenly distributed, preventing microbubble aggregation, increasing the mass transfer area and the contact area between the reactants (hydrogen and nitrogen) and the catalyst, thus improving the reaction efficiency. On the other hand, stirring the liquid can ensure that the catalyst is evenly distributed in the liquid, preventing the catalyst from depositing at the bottom of the reactor, thereby ensuring the catalytic effect of the catalyst. Moreover, this stirring method can make the temperature distribution of the liquid in the reactor more uniform.

[0034] 6. The system of this utility model combines liquid phase method, cluster-matrix co-catalyst and pneumatic enhanced mass transfer device, which can improve mass transfer effect and reaction efficiency while reducing the reaction temperature and reaction pressure of ammonia synthesis reaction and reducing resource consumption. The system has the characteristics of low energy consumption, greenness and easy replacement and recycling of catalyst, and has broad application prospects. Attached Figure Description

[0035] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0036] Figure 1 A schematic diagram of the system for synthesizing ammonia by liquid phase according to Embodiment 1 of this utility model is shown;

[0037] Figure 2 This diagram shows the structure of the reactor according to Embodiment 1 of the present invention;

[0038] Figure 3 This diagram illustrates the flow direction of microbubbles ejected from two pneumatically enhanced mass transfer devices in Embodiment 1 of this invention.

[0039] Figure 4 This diagram shows the structure of the pneumatic enhanced mass transfer device according to Embodiment 1 of the present invention.

[0040] Figure 5 This diagram shows a structural schematic of the annular disturbance according to Embodiment 1 of the present invention;

[0041] Figure 6 This diagram shows a schematic representation of the diffuser tube in Embodiment 1 of the present invention.

[0042] Figure 7A schematic diagram of the structure of a traditional ammonia synthesis process system in related technologies is shown.

[0043] In the diagram: 1. Catalyst pipeline; 2. Solid-liquid mixer; 3. Liquid ammonia pipeline; 4. Hydrogen storage tank; 5. Nitrogen storage tank; 6. Gas mixer; 7. Reactor; 8. Reflux pipeline; 9. Reflux pump; 10. Buffer tank; 1001. Isolation plate; 1002. Baffle; 11. Product storage tank; 12. Gas-liquid separator; 13. Cooler; 14. Annular agitator; 1401. Annular pipe; 1402. Nozzle; 15. Pneumatic enhanced mass transfer device; 1501. Radial outlet; 1502. Tangential outlet; 1503. Vertical outlet; 16. Diffuser; 1601. Opening; 17. Hydraulic enhanced mass transfer device; 18. Heat exchanger; 19. Circulation pump; 20. Circulation pipeline; 21. Hydrogen pipeline; 22. Nitrogen pipeline; 23. Fixed bed reaction tower. Detailed Implementation

[0044] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are only some embodiments of this utility model, not all embodiments, and are only used to illustrate this utility model, and should not be regarded as limiting the scope of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0045] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0047] To more clearly illustrate the technical solution of this utility model, the following description is provided in the form of specific embodiments.

[0048] Example 1

[0049] See also Figure 1-6 This embodiment provides a system for liquid-phase ammonia synthesis, comprising: a hydrogen pipeline 21, a nitrogen pipeline 22, a liquid ammonia pipeline 3, a catalyst pipeline 1, a gas mixer 6, a solid-liquid mixer 2, a reactor 7, and a buffer tank 10. Both the catalyst pipeline 1 and the liquid ammonia pipeline 3 are connected to the solid-liquid mixer 2. The cluster-matrix co-catalyst delivered by the catalyst pipeline 1 and the liquid ammonia delivered by the liquid ammonia pipeline 3 are mixed in the solid-liquid mixer 2 and then fed into the reactor 7. Both the hydrogen pipeline 21 and the nitrogen pipeline 22 are connected to the gas inlet of the gas mixer 6. The inlet of the hydrogen pipeline 21 is connected to a hydrogen storage tank 4, and the inlet of the nitrogen pipeline 22 is connected to a nitrogen storage tank 5.

[0050] Two pneumatically enhanced mass transfer devices 15 are installed inside reactor 7, located below the liquid surface. The two devices are installed at the same height. Their radial outlets 1501 are staggered, while their tangential outlets 1502 face opposite directions. This allows the microbubbles ejected from the devices to drive the liquid within reactor 7 to flow in a predetermined direction, either clockwise or counterclockwise. Figure 3 As shown, in this embodiment, the preset direction is counterclockwise. The microbubbles ejected by the two pneumatically enhanced mass transfer devices 15 can drive the liquid in the reactor 7 to flow counterclockwise.

[0051] The outlet of the gas mixer 6 is connected to the pneumatic enhanced mass transfer device 15; the outlet of the reactor 7 is connected to the inlet of the buffer tank 10. The side wall of the buffer tank 10 is provided with a product outlet, and the bottom of the buffer tank 10 is provided with a reflux port. The reflux port is connected to the reactor 7 to return the catalyst deposited at the bottom of the buffer tank 10 to the reactor 7.

[0052] like Figure 4As shown, the pneumatically enhanced mass transfer device 15 also includes a vertical outlet 1503. Microbubbles are ejected along the radial outlet 1501, tangential outlet 1502 and vertical outlet 1503 of the pneumatically enhanced mass transfer device 15, which helps to make the liquid in the reactor 7 more uniform.

[0053] Continue reading Figure 1 In this embodiment, the system also includes a product storage tank 11. The product outlet of the buffer tank 10 is connected to the product storage tank 11 to transport high-purity liquid ammonia to the product storage tank 11.

[0054] Continue reading Figure 1 In this embodiment, a baffle plate 1001 is provided inside the buffer tank 10. The baffle plate 1001 divides the interior of the buffer tank 10 into a buffer zone and a extraction zone. The inlet of the buffer tank 10 is located on the side wall of the buffer zone, and the outlet of the buffer tank 10 is located at the bottom of the extraction zone. The crude product entering the buffer tank 10 settles and separates in the buffer zone, and the liquid ammonia in the crude product overflows to the extraction zone through the top of the baffle plate 1001.

[0055] Continue reading Figure 1 In this embodiment, a baffle 1002 is provided at the inlet of the buffer tank 10. The baffle 1002 is inclined upward. The bottom of the baffle 1002 is connected to the inner side wall of the buffer tank 10, and the top height is lower than that of the isolation plate 1001.

[0056] See also Figure 1 , 5 In this embodiment, the system further includes an annular disturbance 14, which is disposed inside the reactor 7. The annular disturbance 14 includes an annular tube 1401 and a plurality of nozzles 1402 arranged in an array below the annular tube 1401 along the target direction (counterclockwise in this embodiment). The plurality of nozzles 1402 are inclined downward. The solid-liquid mixture input from the solid-liquid mixer 2 enters the annular tube 1401 and enters the reactor 7 through the nozzles 1402. The tilt angle of the nozzles 1402 in the horizontal direction can be within the range of [15°, 45°]. In this embodiment, the tilt angle of the nozzles 1402 in the horizontal direction is 30°. The target direction is the same as the preset direction.

[0057] Continue reading Figure 1 In this embodiment, a circulation pipeline 20 is provided on one side of the reactor 7, and a hydraulic enhanced mass transfer device 17 is provided inside the reactor 7. The hydraulic enhanced mass transfer device 17 is located below the pneumatic enhanced mass transfer device 15. The inlet of the circulation pipeline 20 is connected to the reactor 7 and is located above the pneumatic enhanced mass transfer device 15. The outlet of the circulation pipeline 20 is connected to the hydraulic enhanced mass transfer device 17. A circulation pump 19 and a heat exchanger 18 are provided on the circulation pipeline 20.

[0058] See also Figure 1 ,6 In this embodiment, the outlet of the hydraulic enhanced mass transfer device 17 is connected to a diffuser 16. The upper end of the diffuser 16 is provided with a plurality of openings 1601, and the upper end of the diffuser 16 is located between two pneumatic enhanced mass transfer devices 15. The gas-liquid emulsion obtained by the dispersion and crushing of the hydraulic enhanced mass transfer device 17 is input into the space between the two pneumatic enhanced mass transfer devices 15 through the diffuser 16.

[0059] See also Figure 1 , 6 In this embodiment, the system further includes a cooler 13 and a gas-liquid separator 12; the cooler 13 and the gas-liquid separator 12 are connected in sequence to the top of the reactor 7; the gas outlet of the gas-liquid separator 12 is connected to a pneumatically enhanced mass transfer device 15. The gas at the top of the reactor 7 is cooled by the cooler 13 and then enters the gas-liquid separator 12. The separated liquid is liquid ammonia, which can be directly input into the product storage tank 11 through the liquid outlet of the gas-liquid separator 12. The gas is a mixture of hydrogen and nitrogen, which can be returned to the reactor 7 via the pneumatically enhanced mass transfer device 15 to continue participating in the reaction.

[0060] Continue reading Figure 1 In this embodiment, the system further includes a reflux pipeline 8, with its inlet connected to a reflux port and its outlet connected to the reactor 7. The outlet of the reflux pipeline 8 is located vertically between the liquid surface of the reactor 7 and the pneumatically enhanced mass transfer device 15. Liquid ammonia containing a high concentration of catalyst at the bottom of the buffer tank 10 is refluxed back to the reactor 7 via the reflux port. In this embodiment, a reflux pump 9 is installed on the reflux pipeline 8 to drive the catalyst reflux.

[0061] It is understood that, in this embodiment, pumps can be installed on the pipelines to facilitate the flow of the medium in each pipeline, which will not be elaborated further.

[0062] The inventors discovered through research that existing researchers are using Buckyballs (C 60 Anchored to a non-ferrous transition metal, a highly efficient cluster-matrix co-catalyst for ammonia synthesis was prepared, significantly reducing the reaction temperature and pressure during the ammonia synthesis process. This catalyst is characterized by avoiding the internal diffusion problem inherent in traditional catalysts, and it can be readily processed into micro / nano-scale solid particles. In this embodiment, the cluster-matrix co-catalyst used is C2. 60 / Mo2M X The catalyst is prepared as follows:

[0063] Mo2M XSynthesis of Mo2Ga2C: Mo2Ga2C was prepared by etching with hydrofluoric acid. Approximately 2.0 g of Mo2Ga2C was mixed with 100 ml of a hydrofluoric acid solution with a concentration ≥48% in a sealed Teflon-lined autoclave and stirred continuously at 60°C for 4 days. After the reaction was complete, the resulting suspension was centrifuged, collected, washed, and then freeze-dried under vacuum for 12 h. Residual F anions were removed with an alkaline solution to finally obtain Mo2M. X powder.

[0064] C 60 / Mo2M X Preparation: The initial wet impregnation method was used. Approximately 5 wt.% (actual loading was 3.62 wt.%) of C was added. 60 Disperse in 15 ml of toluene and sonicate for 30 min to dissolve completely. Then, dissolve the C... 60 / Toluene solution impregnated with approximately 300 mg of Mo2M X Dry at 60°C for 12 hours, then reduce at 400°C for 2 hours in a 10% H2 / Ar atmosphere before each use.

[0065] This embodiment also provides a method for synthesizing ammonia using a liquid-phase method, which utilizes the aforementioned system. Specifically, the method includes the following steps:

[0066] First, catalyst C 60 / Mo2M X The catalyst solution is added to the solid-liquid mixer 2, and then liquid ammonia is added to the solid-liquid mixer 2. The liquid ammonia and catalyst are thoroughly mixed and evenly dispersed in the solid-liquid mixer 2, and then pumped into the reactor 7. The height of the pure catalyst solution in the reactor 7 is 1 / 5 of the reactor 7. Then, nitrogen and hydrogen are introduced into the gas mixer 6 at a nitrogen-to-hydrogen molar ratio of 1:3. After thorough mixing, the mixture is blown into the reactor 7 through the pneumatically enhanced mass transfer device 15, causing the nitrogen-hydrogen mixture to form micron-sized small bubbles in the catalyst solution. During this process, the nitrogen-hydrogen mixture reacts with the catalyst. During the reaction, the gas flowing out from the top of the reactor 7 is cooled by the cooler 13 and enters the gas-liquid separator 12. The separated liquid ammonia enters the product storage tank 11, while the gas is returned to the reactor 7 via the pneumatically enhanced mass transfer device 15 to continue participating in the reaction. The crude product at the bottom of the reactor 7 is fed into the buffer tank 10 and deposited there. The higher purity liquid ammonia at the top is separated by the isolation plate 1001 and fed into the product storage tank 11. The liquid ammonia at the bottom, containing a high concentration of catalyst, is refluxed back into reactor 7 to continue participating in the reaction.

[0067] The system using this embodiment was used in small-scale experiments under the following reaction conditions:

[0068] A. Reaction temperature 85℃, reaction pressure 3MPa;

[0069] B. Reaction temperature 85℃, reaction pressure 4MPa;

[0070] C. Reaction temperature 100℃, reaction pressure 5.5MPa;

[0071] D. Reaction temperature 115℃, reaction pressure 8MPa.

[0072] In this small-scale experiment, the flow rate of the mixed gas (hydrogen-ammonia molar ratio 3:1) was 200 ml / min, the amount of catalyst was 150 mg, and the circulating liquid ammonia flow rate was 3 L / min.

[0073] Four hours after the reaction, the yield of liquid ammonia in product storage tank 11 was measured. Under condition A, the yield was 1.4 kg with a purity of 99.5%; under condition B, the yield was 1.5 kg with a purity of 99.6%; under condition C, the yield was 1.6 kg with a purity of 99.5%; and under condition D, the yield was 1.8 kg with a purity of 99.7%. Simultaneously, the incompletely reacted nitrogen-hydrogen mixture (extracted from the gas outlet of the gas-liquid separator) after the reaction under conditions A, B, C, and D was analyzed. Its composition ratio remained stable, allowing for continued recycling, and the catalyst activity did not significantly decrease after multiple cycles. Monitoring also revealed that the system operated stably under these conditions without any abnormalities.

[0074] The system of this embodiment was used for a scale-up experiment (i.e., based on the small-scale experiment, the experimental setup was scaled up proportionally, using larger reaction equipment and auxiliary facilities to ensure that the equipment materials and structure met the process requirements). The reaction temperature was 95℃, the reaction pressure was 5MPa, the mixed gas flow rate was 10L / min, the catalyst dosage was 1.5g, and the circulating liquid ammonia flow rate was 8L / min. After 8 hours of reaction, the liquid ammonia yield in the product storage tank was measured to be 5.2kg, and the product purity reached over 99.5%, meeting industrial standards. During the reaction, the equipment operated stably without any abnormalities, proving the feasibility of the scale-up experiment.

[0075] Example 2

[0076] The difference between this embodiment and Embodiment 1 is that the preset direction is clockwise. In this case, the microbubbles ejected from the two pneumatically enhanced mass transfer devices 15 drive the liquid in the reactor 7 to flow counterclockwise. At this time, the preset direction is opposite to the target direction.

[0077] The system of this embodiment was used in a small-scale experiment under condition B of Example 1. After 4 hours of reaction, the yield of liquid ammonia in the product storage tank was measured to be 1.1 kg, with a purity of 99.3%. Analysis of the incompletely reacted nitrogen-hydrogen mixture (extracted from the gas outlet of the gas-liquid separator) showed that its composition ratio was stable and it could be recycled. Furthermore, the catalyst activity did not significantly decrease after multiple cycles. Monitoring also revealed that the system operated stably throughout the reaction process without any abnormalities.

[0078] Example 3

[0079] The difference between this embodiment and embodiment 1 is that the upper end of the diffuser tube 16 is located below the pneumatically enhanced mass transfer device 15 in the vertical direction.

[0080] The system of this embodiment was used in a small-scale experiment under condition B of Example 1. After 4 hours of reaction, the yield of liquid ammonia in the product storage tank was measured to be 1.3 kg, with a purity of 99.4%. Analysis of the incompletely reacted nitrogen-hydrogen mixture (extracted from the gas outlet of the gas-liquid separator) showed that its composition ratio was stable and it could be recycled. Furthermore, the catalyst activity did not significantly decrease after multiple cycles. Monitoring also revealed that the system operated stably throughout the reaction process without any abnormalities.

[0081] Example 4

[0082] The difference between this embodiment and embodiment 1 is that the outlet of the return pipeline 8 is located vertically below the pneumatic enhanced mass transfer device 15.

[0083] The system of this embodiment was used in a small-scale experiment under condition B of Example 1. After 4 hours of reaction, the yield of liquid ammonia in the product storage tank was measured to be 1.2 kg, with a purity of 99.4%. Analysis of the incompletely reacted nitrogen-hydrogen mixture (extracted from the gas outlet of the gas-liquid separator) showed that its composition ratio was stable and it could be recycled. Furthermore, the catalyst activity did not significantly decrease after multiple cycles. Monitoring also revealed that the system operated stably throughout the reaction process without any abnormalities.

[0084] Example 5

[0085] The difference between this embodiment and Embodiment 1 is that the nozzle 1402 is tilted at a horizontal angle of 15°.

[0086] The system of this embodiment was used in a small-scale experiment under condition B of Example 1. After 4 hours of reaction, the yield of liquid ammonia in the product storage tank was measured to be 1.4 kg, with a purity of 99.5%. Analysis of the incompletely reacted nitrogen-hydrogen mixture (extracted from the gas outlet of the gas-liquid separator) showed that its composition ratio was stable and it could be recycled. Furthermore, the catalyst activity did not significantly decrease after multiple cycles. Monitoring also revealed that the system operated stably throughout the reaction process without any abnormalities.

[0087] Example 6

[0088] The difference between this embodiment and Embodiment 1 is that the nozzle 1402 is tilted at a horizontal angle of 45°.

[0089] The system of this embodiment was used in a small-scale experiment under condition B of Example 1. After 4 hours of reaction, the yield of liquid ammonia in the product storage tank was measured to be 1.5 kg, with a purity of 99.5%. Analysis of the incompletely reacted nitrogen-hydrogen mixture (extracted from the gas outlet of the gas-liquid separator) showed that its composition ratio was stable and it could be recycled. Furthermore, the catalyst activity did not significantly decrease after multiple cycles. Monitoring also revealed that the system operated stably throughout the reaction process without any abnormalities.

[0090] Example 7

[0091] The difference between this embodiment and Embodiment 1 is that the nozzle 1402 is tilted at a horizontal angle of 90°.

[0092] The system of this embodiment was used in a small-scale experiment under condition B of Example 1. After 4 hours of reaction, the yield of liquid ammonia in the product storage tank was measured to be 1.2 kg, with a purity of 99.4%. Analysis of the incompletely reacted nitrogen-hydrogen mixture (extracted from the gas outlet of the gas-liquid separator) showed that its composition ratio was stable and it could be recycled. Furthermore, the catalyst activity did not significantly decrease after multiple cycles. Monitoring also revealed that the system operated stably throughout the reaction process without any abnormalities.

[0093] Example 8

[0094] The difference between this embodiment and Embodiment 1 is that the nozzle 1402 is tilted at a horizontal angle of 5°.

[0095] The system of this embodiment was used in a small-scale experiment under condition B of Example 1. After 4 hours of reaction, the yield of liquid ammonia in the product storage tank was measured to be 1.3 kg, with a purity of 99.4%. Analysis of the incompletely reacted nitrogen-hydrogen mixture (extracted from the gas outlet of the gas-liquid separator) showed that its composition ratio was stable and it could be recycled. Furthermore, the catalyst activity did not significantly decrease after multiple cycles. Monitoring also revealed that the system operated stably throughout the reaction process without any abnormalities.

[0096] Example 9

[0097] The difference between this embodiment and embodiment 1 is that the top height of the baffle 1002 is higher than that of the isolation plate 1001.

[0098] The system of this embodiment was used in a small-scale experiment under condition B of Example 1. After 4 hours of reaction, the yield of liquid ammonia in the product storage tank was measured to be 1.5 kg, with a purity of 99.1%. Analysis of the incompletely reacted nitrogen-hydrogen mixture (extracted from the gas outlet of the gas-liquid separator) showed that its composition ratio was stable and it could be recycled. Furthermore, the catalyst activity did not significantly decrease after multiple cycles. Monitoring also revealed that the system operated stably throughout the reaction process without any abnormalities.

[0099] Comparative Example 1

[0100] The difference between this example and Example 1 is that the radial outlets of the two pneumatic enhanced mass transfer devices 15 are arranged opposite each other.

[0101] Using this system, a small-scale experiment was conducted under conditions B of Example 1. After 4 hours of reaction, the yield of liquid ammonia in the product storage tank was measured to be 1.0 kg, with a purity of 99.0%. Analysis of the incompletely reacted nitrogen-hydrogen mixture (extracted from the gas outlet of the gas-liquid separator) showed that its composition ratio was stable and it could be recycled. Furthermore, the catalyst activity did not significantly decrease after multiple cycles. Monitoring also revealed that the system operated stably throughout the reaction process without any abnormalities.

[0102] Comparative Example 2

[0103] The difference between this example and Example 1 is that the tangential outlets of the two pneumatic enhanced mass transfer devices 15 have the same orientation.

[0104] Using this system, a small-scale experiment was conducted under conditions B of Example 1. After 4 hours of reaction, the yield of liquid ammonia in the product storage tank was measured to be 1.2 kg, with a purity of 99.3%. Analysis of the incompletely reacted nitrogen-hydrogen mixture (extracted from the gas outlet of the gas-liquid separator) showed that its composition ratio was stable and it could be recycled. Furthermore, the catalyst activity did not significantly decrease after multiple cycles. Monitoring also revealed that the system operated stably throughout the reaction process without any abnormalities.

[0105] Comparative Example 3

[0106] The system in this example is a traditional ammonia synthesis process system. For example... Figure 7As shown, the system includes a hydrogen storage tank 4, a nitrogen storage tank 5, a gas mixer 6, a fixed-bed reaction tower 23, a product storage tank 11, a cooler 13, and a gas-liquid separator 12. The hydrogen storage tank 4 and nitrogen storage tank 5 are connected to the gas mixer 6, which is connected to the fixed-bed reaction tower 23. The top outlet of the fixed-bed reaction tower 23 is sequentially connected to the cooler 13 and the gas-liquid separator 12. The gas phase outlet of the gas-liquid separator 12 is connected to the gas mixer 6, and the liquid phase outlet is connected to the product storage tank 11. During the reaction, nitrogen and hydrogen are mixed in the gas mixer 6 at a nitrogen-to-hydrogen molar ratio of 1:3 and then introduced into the fixed-bed reaction tower 23 for ammonia synthesis under conventional reaction conditions. The reacted gas is cooled by the cooler 13, and liquid ammonia is separated in the gas-liquid separator 12 and collected in the product storage tank 11.

[0107] A small-scale experiment was conducted using the system described in this example. The reaction temperature was 450℃, the reaction pressure was 20MPa, and after 4 hours of reaction, the liquid ammonia yield in the product storage tank was measured to be 0.8 kg with a purity of 99.1%. Simultaneously, monitoring revealed slight losses in the fixed-bed reaction tower of the system after the experiment.

[0108] A scale-up experiment was conducted using the system from this example, with a reaction temperature of 500℃ and a reaction pressure of 25MPa. After 8 hours of reaction, the yield of liquid ammonia in the product storage tank was measured to be 3kg, with a purity of 99.3%. Simultaneously, monitoring revealed some sealing problems during equipment operation and significant energy consumption.

[0109] As can be seen from the data in Examples 1-9, the system of this invention can stably and efficiently synthesize ammonia under relatively low temperature and pressure conditions. Furthermore, according to the experimental data in Example 1, the system of this invention can achieve good ammonia production efficiency within a reaction temperature range of 85℃-115℃ and a reaction pressure range of 3MPa-8MPa.

[0110] Comparing the experimental data of Example 1 and Example 2 under condition B, it can be seen that the product yield and purity of Example 1 are significantly better than those of Example 2. This may be because the preset direction in Example 2 is opposite to the target direction, which causes the stirring effect of the pneumatic enhanced mass transfer device and the annular disturbance device on the liquid in the reactor to a certain extent to cancel each other out. This results in poor uniformity of the catalyst and microbubbles in the reactor, affecting the catalytic effect and reaction efficiency of the catalyst.

[0111] Comparing the experimental data of Example 1 and Example 3 under condition B, it can be seen that the product yield and purity of Example 1 are both better than those of Example 3. This may be because the upper end of the diffuser in Example 1 is located vertically between the pneumatically enhanced mass transfer device and the annular disturbance device, allowing the output microbubbles to disperse more quickly and uniformly, resulting in better reaction efficiency.

[0112] Comparing the experimental data of Example 1 and Example 4 under condition B, it can be seen that the product yield and purity of Example 1 are both superior to those of Example 4. This may be because, on the one hand, compared to Example 4, the refluxed catalyst in Example 1 is farther from the bottom of the reactor, and the catalyst may settle to the bottom of the reactor more slowly; on the other hand, the refluxed catalyst in Example 1 is simultaneously stirred by the annular agitator and the pneumatically enhanced mass transfer device, which can quickly and uniformly disperse it into the reactor, thereby resulting in better catalytic effect and reaction efficiency in Example 1.

[0113] Comparing the experimental data of Example 1 and Examples 5-8 under condition B, it can be seen that the liquid ammonia yield and purity of Examples 1, 5, and 6 are better, while the liquid ammonia yield and purity of Examples 7 and 8 are relatively worse. This indicates that the annular agitator has a better stirring effect on the liquid in the reactor when the tilt angle of the nozzle in the horizontal direction is within the range of [15°, 45°].

[0114] Comparing the experimental data of Example 1 and Example 9 under condition B, it can be seen that the product purity of Example 1 is significantly better than that of Example 9. This may be because the baffle top height is relatively high in Example 9, causing some crude product to overflow into the collection area of ​​the buffer tank without settling, resulting in a large amount of catalyst mixed in the product and affecting the product purity.

[0115] Comparing the experimental data of Example 1 and Comparative Example 1 under condition B, it can be seen that the product yield and purity of Example 1 are significantly better than those of Comparative Example 1. This may be because the collision of microbubble flows in the two pneumatically enhanced mass transfer devices in Comparative Example 1 leads to dead zones in the liquid within the reactor, which in turn affects the uniform dispersion of the catalyst and microbubbles, reducing the catalytic effect and reaction efficiency.

[0116] Comparing the experimental data of Example 1 and Comparative Example 2 under condition B, it can be seen that the product yield and purity of Example 1 are significantly better than those of Comparative Example 2. This may be because the stirring effect is better when the tangential outlets of the two pneumatically enhanced mass transfer devices in Example 1 are oriented in opposite directions, resulting in a more uniform distribution of catalyst and microbubbles, thus leading to higher reaction efficiency and higher yield.

[0117] Comparing the experimental data of Example 1 and Comparative Example 3, it can be seen that the system of this invention can achieve a higher product yield under the premise that the reaction temperature and pressure are significantly lower than those of the traditional ammonia synthesis process, and the system stability is significantly better than that of the traditional ammonia synthesis process.

[0118] In summary, this invention combines a liquid-phase method, a cluster-matrix co-catalyst, and a pneumatically enhanced mass transfer device. This system can reduce the reaction temperature and pressure of ammonia synthesis, reduce resource consumption, and improve mass transfer and reaction efficiency. The system features low energy consumption, green operation, and easy catalyst replacement and recovery, and has broad application prospects.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model 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 this utility model.

Claims

1. A system for synthesizing ammonia via a liquid-phase method, characterized in that, include: Hydrogen pipelines, nitrogen pipelines, liquid ammonia pipelines, catalyst pipelines, gas mixers, solid-liquid mixers, reactors, and buffer tanks; Both the catalyst pipeline and the liquid ammonia pipeline are connected to the solid-liquid mixer. The cluster-matrix co-catalyst delivered by the catalyst pipeline and the liquid ammonia delivered by the liquid ammonia pipeline are mixed in the solid-liquid mixer and then fed into the reactor. Both the hydrogen pipeline and the nitrogen pipeline are connected to the gas inlet of the gas mixer; The reactor is equipped with two pneumatically enhanced mass transfer devices, which are located below the liquid surface and at the same height. The radial outlets of the two devices are staggered, while their tangential outlets face opposite directions. This allows the microbubbles emitted from the devices to drive the liquid within the reactor to flow in a predetermined direction, either clockwise or counterclockwise. The outlet of the gas mixer is connected to the pneumatically enhanced mass transfer devices. The reactor outlet is connected to the buffer tank inlet, the buffer tank has a product outlet on its side wall, and a reflux port is provided at the bottom of the buffer tank. The reflux port is connected to the reactor to return the catalyst deposited at the bottom of the buffer tank to the reactor.

2. The system for liquid-phase ammonia synthesis according to claim 1, characterized in that, The buffer tank is equipped with a partition plate that divides the interior of the buffer tank into a buffer zone and a production zone. The inlet of the buffer tank is located on the side wall of the buffer zone, and the outlet of the buffer tank is located at the bottom of the production zone. The crude product entering the buffer tank settles and separates in the buffer zone, and the liquid ammonia in the crude product overflows to the production zone through the top of the partition plate.

3. The system for ammonia synthesis via liquid phase according to claim 2, characterized in that, A baffle is provided at the inlet of the buffer tank, and the baffle is inclined upward; the bottom of the baffle is connected to the inner side wall of the buffer tank, and the top of the baffle is lower than the isolation plate.

4. The system for liquid-phase ammonia synthesis according to claim 1, characterized in that, It also includes an annular disturbance, which is disposed inside the reactor; the annular disturbance includes an annular tube and a plurality of nozzles arranged in an array below the annular tube along the target direction; The nozzles are arranged at an angle downwards; the solid-liquid mixture input from the solid-liquid mixer enters the annular tube and then enters the reactor through the nozzles.

5. The system for liquid-phase ammonia synthesis according to claim 4, characterized in that, The nozzle's tilt angle along the horizontal direction is within the range of [15°, 45°].

6. The system for liquid-phase ammonia synthesis according to claim 4, characterized in that, The target direction is the same as the preset direction.

7. The system for liquid-phase ammonia synthesis according to claim 1, characterized in that, A circulation pipeline is provided on one side of the reactor. A hydraulic enhanced mass transfer device is provided inside the reactor and is located below the pneumatic enhanced mass transfer device. The inlet of the circulation pipeline is connected to the reactor and is located above the pneumatic enhanced mass transfer device. The outlet of the circulation pipeline is connected to the hydraulic enhanced mass transfer device. A circulation pump and a heat exchanger are provided on the circulation pipeline.

8. The system for liquid-phase ammonia synthesis according to claim 7, characterized in that, The outlet of the hydraulic enhanced mass transfer device is connected to a diffusion tube, the upper end of which is provided with multiple openings, and the upper end of the diffusion tube is located between the two pneumatic enhanced mass transfer devices; the gas-liquid emulsion obtained by the dispersion and crushing of the hydraulic enhanced mass transfer device is input into the space between the two pneumatic enhanced mass transfer devices through the diffusion tube.

9. The system for liquid-phase ammonia synthesis according to claim 1, characterized in that, It also includes a cooler and a gas-liquid separator; the cooler and the gas-liquid separator are connected in sequence to the top of the reactor; the gas outlet of the gas-liquid separator is connected to the pneumatically enhanced mass transfer device.

10. The system for liquid-phase ammonia synthesis according to any one of claims 1-9, characterized in that, It also includes a reflux pipeline, the inlet of which is connected to the reflux port and the outlet of which is connected to the reactor; the outlet of the reflux pipeline is located vertically between the liquid surface of the reactor and the pneumatically enhanced mass transfer device.

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