Ammonia synthesis system

Abstract

The present disclosure relates to an ammonia synthesis system comprising: an ammonia synthesis reactor; two or more catalyst layers included in the ammonia synthesis reactor; a distribution plate disposed upstream of each of the catalyst layers; a backflow prevention plate disposed downstream of each of the catalyst layers other than the lowermost catalyst layer among the two or more catalyst layers, the backflow prevention plate preventing backflow of the mixed gas; a distribution device which is disposed upstream of each of the distribution plates and distributes the mixed gas to the distribution plates; and a mixed gas supply line arranged to supply a mixed gas to each of the distribution devices, the distribution plates having a plurality of openings formed independently of each other, and the opening ratio of the distribution plates gradually decreasing downward when the percentage of the total area of the openings with respect to the total area of each of the distribution plates is referred to as the opening ratio.

Description

Technical Field

[0001] The present disclosure relates to an ammonia synthesis system. Background Art

[0002] In order to achieve the goal of reducing greenhouse gas emissions in response to climate change and the depletion of oil resources, the need to use new renewable energy is increasing. However, the areas that meet the appropriate conditions for producing new renewable energy are limited, so it is necessary to find means for storage and transportation. For example, there is a problem that new renewable energy, which is abundant in the equatorial region and the southern hemisphere, needs to be transported to the northern hemisphere where the demand for new renewable energy is high.

[0003] In addition, new renewable energy sources have temporal variability, so they must be accompanied by power storage devices. In order to solve the problems caused by the regional bias and temporal variability of new renewable energy sources, ammonia has attracted much attention as an energy carrier. In particular, ammonia can be liquefied at 8.5 atmospheres at room temperature, so it has the advantage of being easier to store and transport than hydrogen. Therefore, as an alternative solution to the problems caused by the regional bias and temporal variability of new renewable energy sources, it is necessary to pay attention to the solution of using electricity produced from new renewable energy sources to produce hydrogen and nitrogen, and using the produced hydrogen and nitrogen as raw materials to synthesize ammonia.

[0004] Hydrogen, the main raw material in ammonia synthesis, can be produced in a water electrolyzer driven by new renewable energy such as solar energy or wind energy. New renewable energy such as solar energy or wind energy has time variability. For example, solar energy cannot be used at night. Therefore, the ammonia synthesis system cannot always operate at a fixed flow rate, and there is a problem that the flow rate fluctuations that occur during the production cycle must be predicted and handled.

[0005] In addition, when the flow rate of raw materials such as hydrogen fed into the ammonia synthesis system decreases, the unevenness of the flow distribution at the front end of the catalyst layer included in the ammonia synthesis reactor increases. In particular, when there are multiple catalytic layers, the raw materials cannot fully reach the catalyst layer at the bottom end, the reaction performance becomes low, and there is a problem of shortening the replacement cycle.

[0006] Furthermore, the conventional ammonia synthesis system has a problem that a temperature deviation occurs between the center and the edge of the catalyst layer, especially in the initial stage of operation, thereby reducing the ammonia synthesis yield.

[0007] To this end, it is necessary to develop an ammonia synthesis system that can cope with flow fluctuations that occur during the production cycle, while solving the problems of uneven flow distribution at the front end of the catalyst layer and temperature deviations between the center and edge of the catalyst layer during the initial operation, which lead to reduced ammonia synthesis yield. Summary of the invention

[0008] According to an aspect of the present disclosure, an ammonia synthesis system capable of coping with flow rate fluctuations occurring during a production cycle may be provided.

[0009] According to another aspect of the present disclosure, an ammonia synthesis system can be provided which can maintain a uniform flow distribution at the front end of the catalyst layer included in the ammonia synthesis reactor even if the flow rate of raw materials such as hydrogen is reduced, and make the supplied mixed gas pass through only a minimum number of catalyst layers, thereby improving the reaction performance of the catalyst layer.

[0010] According to another aspect of the present disclosure, an ammonia synthesis system can be provided in which the reaction performance of the catalyst layer is improved by allowing the supplied mixed gas to pass through two or more catalyst layers even when the flow rate of the introduced raw material such as hydrogen increases.

[0011] According to still another aspect of the present disclosure, an ammonia synthesis system can be provided that can make the temperature deviation between the center and the edge of the catalyst layer uniform in the initial stage of operation, thereby improving the ammonia synthesis yield.

[0012] According to one aspect of the present disclosure, an ammonia synthesis system can be provided that preheats a catalytic layer in an early stage of operation, thereby being able to improve the ammonia synthesis yield in the early stage of operation.

[0013] According to one aspect of the present disclosure, an ammonia synthesis system can be provided which optimizes the amount of energy required in the system during operation, thereby enabling energy saving.

[0014] According to an aspect of the present disclosure, an ammonia synthesis system can be provided which can uniformly use each catalytic layer during operation, thereby extending a replacement cycle of a catalyst.

[0015] The present disclosure provides an ammonia synthesis system, which includes: an ammonia synthesis reactor; more than two catalytic layers included in the ammonia synthesis reactor; a distribution plate, which is arranged upstream of each of the catalytic layers; an anti-backflow plate, which is arranged downstream of each of the catalytic layers other than the lowest catalytic layer among the more than two catalytic layers to prevent the mixed gas from backflowing; a distribution device, which is arranged upstream of each of the distribution plates to distribute the mixed gas to the distribution plates; and a mixed gas supply route, which is arranged to supply the mixed gas to each of the distribution devices, the distribution plates are independently formed with a plurality of openings, and when the percentage of the total area of ​​the openings relative to the total area of ​​each distribution plate is referred to as the opening rate, the distribution plate opening rate gradually decreases toward the lower part.

[0016] According to an embodiment of the present disclosure, when the uppermost distribution plate among the distribution plates is referred to as an upper distribution plate, the opening ratio A of the upper distribution plate is t More than 40%.

[0017] According to an embodiment of the present disclosure, when the lowest distribution plate among the distribution plates is referred to as the lower distribution plate, the opening ratio A of the lower distribution plate is b Less than 20%.

[0018] According to an embodiment of the present disclosure, when there are three distribution plates, when the distribution plate in the middle of the distribution plates is called the middle distribution plate, the opening ratio A of the middle distribution plate is m It is between 20 and 40%.

[0019] According to an embodiment of the present disclosure, the ammonia synthesis system may further include: a plurality of mixed gas flow pipes fixed to a lower surface of at least one of the distribution plates for the mixed gas to flow.

[0020] According to one embodiment of the present disclosure, the mixed gas flow tube may have a bottom surface and a side surface connecting the bottom surface and the distribution plate, a plurality of upper openings formed along the circumference are formed on the upper side surface of the mixed gas flow tube, a plurality of middle openings formed along the circumference are formed on the middle side surface of the mixed gas flow tube, a plurality of lower openings formed along the circumference are formed on the lower side surface of the mixed gas flow tube, and the mixed gas flow tube includes a covering member, which is formed to surround at least a portion of the side surface of the mixed gas flow tube to provide a space for guiding the fluid that passes through the upper openings and then flows out to the outside of the side surface of the mixed gas flow tube toward the middle opening side.

[0021] According to an embodiment of the present disclosure, the ammonia synthesis system may further include: a microwave heating device, which irradiates microwaves to the catalyst layer.

[0022] According to an embodiment of the present disclosure, the mixed gas supply routes may each include a flow regulating device.

[0023] According to an embodiment of the present disclosure, a plurality of openings may be formed on each of the anti-backflow plates, and an anti-backflow cover that is selectively opened according to a flow direction of the gas may be formed on the plurality of openings formed on each of the anti-backflow plates.

[0024] According to an embodiment of the present disclosure, the backflow prevention cover may be hingedly coupled to a position of a perimeter portion of a plurality of opening portions formed on each of the backflow prevention plates.

[0025] According to an embodiment of the present disclosure, a spring may be provided at the hinge joint portion of the hinge joint, so as to apply elastic force in a direction in which the anti-backflow cover approaches the distribution plate.

[0026] According to an embodiment of the present disclosure, the ammonia synthesis system may further include: a heat exchanger, which is arranged downstream of the catalyst layer and removes heat from the effluent of the catalyst layer.

[0027] According to an embodiment of the present disclosure, the distribution device may be in the shape of a circular plate or a ring.

[0028] According to an embodiment of the present disclosure, in the ammonia synthesis system, ammonia synthesis may be performed at 10 to 300 bar.

[0029] According to an embodiment of the present disclosure, in the ammonia synthesis system, ammonia synthesis may be performed at 200 to 700° C.

[0030] According to an embodiment of the present disclosure, the ammonia synthesis system can cope with flow rate fluctuations occurring during a production cycle.

[0031] According to an ammonia synthesis system of another embodiment of the present disclosure, even if the flow rate of raw materials such as hydrogen is reduced, a uniform flow distribution can be maintained at the front end of the catalyst layer included in the ammonia synthesis reactor, and the supplied mixed gas only passes through a minimum number of catalyst layers, thereby improving the reaction performance of the catalyst layer.

[0032] According to the ammonia synthesis system of another embodiment of the present disclosure, even if the flow rate of the added raw material such as hydrogen increases, the supplied mixed gas passes through two or more catalyst layers, thereby improving the reaction performance of the catalyst layers.

[0033] According to an ammonia synthesis system according to still another embodiment of the present disclosure, the temperature deviation between the center and the edge of the catalyst layer is made uniform at the initial stage of operation, thereby improving the ammonia synthesis yield.

[0034] According to an ammonia synthesis system according to an embodiment of the present disclosure, the catalyst layer is preheated at the initial stage of operation, thereby being able to improve the ammonia synthesis yield at the initial stage of operation.

[0035] According to an embodiment of the present disclosure, the ammonia synthesis system optimizes the amount of energy required in the system during operation, thereby saving energy.

[0036] According to an ammonia synthesis system according to an embodiment of the present disclosure, during operation, each catalyst layer is used evenly, and the reaction performance is improved, thereby being able to extend the catalyst replacement cycle.

[0037] According to an ammonia synthesis system according to an embodiment of the present disclosure, ammonia can be synthesized in an eco-friendly manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 1 is a schematic diagram showing an ammonia synthesis system according to an embodiment of the present disclosure.

[0039] Figure 2 is a schematic diagram showing an ammonia synthesis system according to another embodiment of the present disclosure.

[0040] Figure 3 is a perspective view showing a lower distribution plate and a mixed gas flow pipe according to an embodiment of the present disclosure.

[0041] Figure 4 is a perspective view showing the interior of a mixed gas flow pipe according to an embodiment of the present disclosure.

[0042] Figure 5 is a perspective view showing the interior of a mixed gas flow pipe according to another embodiment of the present disclosure.

[0043] Figure 6 1 is a diagram showing a state in which a backflow prevention cover is closed in a backflow prevention plate according to an embodiment of the present disclosure.

[0044] Figure 7 1 is a diagram showing a state in which a backflow prevention cover is opened in a backflow prevention plate according to an embodiment of the present disclosure.

[0045] Reference numerals: 1: ammonia synthesis system, 10: ammonia synthesis reactor, 20: catalyst layer, 30: upper distribution plate, 301: upper distribution plate opening, 302: lower surface of upper distribution plate, 31: upper distribution plate ( Figure 1 ) or the middle distribution board ( Figure 2 ), 311: Upper distribution plate opening ( Figure 1 ) or the middle distribution plate opening ( Figure 2 ), 312: Lower surface of upper distribution plate ( Figure 1 ) or the lower surface of the middle distribution plate ( Figure 2 ), 32: lower distribution plate, 321: lower distribution plate opening, 322: lower surface of lower distribution plate, 330: mixed gas flow tube, 332: side, 332a: upper part, 332b: middle part, 332c: lower part, 333: upper opening, 335: middle opening, 337: lower opening, 339: partition, 340: cover, 40, 41: anti-backflow plate, 401: anti-backflow plate, 402: opening, 403: anti-backflow cover, 404: hinge, 50, 51, 52: distribution device, 60, 61, 62: mixed gas supply route, 70, 71, 72: microwave heating device, 701, 702, 703: microwave guide. DETAILED DESCRIPTION

[0046] The advantages, features and methods of achieving the advantages and features of the present invention will become clear through the embodiments described in detail below. However, the present invention is not limited to the embodiments disclosed below, and can be implemented in a variety of different forms. The embodiments are only used to make the disclosure of the present invention complete and to fully inform the scope of the invention to those with common knowledge in the technical field to which the present invention belongs. The present invention is only defined by the scope of the claims.

[0047] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this specification have the same meanings as commonly understood by those skilled in the art in the technical field to which the present disclosure belongs.

[0048] Unless otherwise indicated in the context, a singular form used in this specification may also include a plural form.

[0049] The numerical range used in this specification includes all values ​​within the range including the lower limit and the upper limit, all values ​​logically derived from the form and span of the defined range, all values ​​of the double definition, and all possible combinations of the upper and lower limits within the numerical range defined in different forms. Unless otherwise defined in the specification of the present invention, values ​​that may exceed the numerical range due to experimental errors or rounding of numerical values ​​are also included in the defined numerical range.

[0050] The term "including" mentioned in this specification is an open description, which is equivalent to expressions such as "having", "containing", "having", "having characteristics", etc., and does not exclude factors, materials or processes that are not additionally listed.

[0051] Unless otherwise defined, the unit "%" used without particular reference in the present specification means "% by weight".

[0052] Unless otherwise defined, “A to B” in this specification means “A or more and B or less”.

[0053] In this specification, when referring to a layer, film, region, plate or the like being “on” or “over” other parts, it includes not only the case where they are “directly on” other parts, but also the case where there is another part in between.

[0054] In this specification, when referring to structures such as a layer, film, region, plate, component, etc. being on "one side" or "a side" of other structures, it not only includes the case where they are in direct contact with other structures, but also includes the case where there is another structure in between.

[0055] Hereinafter, the ammonia synthesis system of the present disclosure will be described in detail. However, this is only an example, and the present disclosure is not limited to the specific embodiments described in the examples.

[0056] The present disclosure provides an ammonia synthesis system, which includes: an ammonia synthesis reactor; more than two catalytic layers included in the ammonia synthesis reactor; a distribution plate, which is arranged upstream of each catalytic layer; an anti-backflow plate, which is arranged downstream of each catalytic layer other than the lowest catalytic layer among the more than two catalytic layers to prevent the backflow of mixed gas; a distribution device, which is arranged upstream of each distribution plate to distribute the mixed gas to the distribution plate; and a mixed gas supply route, which is arranged to supply the mixed gas to each distribution device.

[0057] In an ammonia synthesis system according to a specific embodiment, it is characterized in that a distribution plate is independently formed with a plurality of openings, and when the percentage of the total area of ​​the openings relative to the total area of ​​each distribution plate is referred to as the opening ratio, the distribution plate opening ratio gradually decreases toward the lower part.

[0058] refer to Figure 1 and Figure 2 According to one embodiment of the present disclosure, an ammonia synthesis system 1 can be provided, which includes: an ammonia synthesis reactor 10; catalyst layers 20, 21, 22, which are included in the ammonia synthesis reactor 10; distribution plates 30, 31, 32, which are arranged upstream of each catalyst layer; anti-backflow plates 40, 41, which are arranged downstream of each catalyst layer other than the lowest catalyst layer located among more than two catalyst layers 20, 21, 22 to prevent the mixed gas from flowing back; distribution devices 50, 51, 52, which are arranged upstream of each distribution plate 30, 31, 32 to distribute the mixed gas to the distribution plates 30, 31, 32; and mixed gas supply routes 60, 61, 62, which are arranged to supply the mixed gas to the distribution devices 50, 51, 52, and the distribution plates 30, 31, 32 are independently formed with multiple openings 301, 311, 321.

[0059] Hereinafter, as an example of the ammonia synthesis system 1 of the present disclosure, an ammonia synthesis system including two catalytic layers may be described. Of course, an ammonia synthesis system including two or more catalytic layers, such as three, four, five, seven or ten catalytic layers, is included in an embodiment of the present disclosure.

[0060] When the ammonia synthesis system includes two catalytic layers according to an embodiment of the present disclosure, Figure 1As shown, it is characterized by including: an upper catalytic layer 20 and a lower catalytic layer 21; an upper distribution plate 30 and a lower distribution plate 31 arranged upstream of each catalytic layer; an anti-backflow plate 40 for preventing the mixed gas from flowing back; distribution devices 50, 51 for distributing the mixed gas to the distribution plates 30, 31; and mixed gas supply routes 60, 61 arranged to supply the mixed gas to the distribution devices 50, 51. The distribution plates 30, 31 are independently formed with a plurality of openings 301, 311. When the percentage of the total area of ​​the openings relative to the total area of ​​each distribution plate is referred to as the opening rate, the opening rate of the upper distribution plate 30 is greater than the opening rate of the lower distribution plate 31.

[0061] According to an embodiment of the present disclosure, an ammonia synthesis system includes a mixed gas supply route to supply mixed gas to two or more catalyst layers respectively, so as to cope with flow changes occurring during the production cycle. For example, when the flow rate of the raw material to be fed is large, it can be fed through the mixed gas supply route 60 located at the upper end to pass through the catalyst layer 20 located at the uppermost end, and when the flow rate of the raw material to be fed is small, it can be fed through the mixed gas supply route 61 located at the lower end to pass through the catalyst layer 21 located at the lower end instead of the catalyst layer 20 located at the upper end, thereby operating. At this time, when the mixed gas is fed through the mixed gas supply route 61 located at the lower end to pass through the catalyst layer 21 located at the lower end, the mixed gas is prevented from backflowing to the upper catalyst layer 20 by the anti-backflow plate 30.

[0062] When an ammonia synthesis system including three catalytic layers according to another embodiment of the present disclosure is used, Figure 2 As shown, it is characterized by including: an upper catalytic layer 20, a middle catalytic layer 21 and a lower catalytic layer 22; an upper distribution plate 30, a middle distribution plate 31 and a lower distribution plate 32 arranged upstream of each catalytic layer; anti-backflow plates 40, 41 for preventing the mixed gas from flowing back; distribution devices 50, 51, 52 for distributing the mixed gas to the distribution plates 30, 31, 32; and mixed gas supply routes 60, 61, 62 arranged to supply the mixed gas to the distribution devices 50, 51, 52. The distribution plates 30, 31, 32 are independently formed with a plurality of openings 301, 311, 321. When the percentage of the total area of ​​the openings relative to the total area of ​​each distribution plate is referred to as the opening rate, the opening rate of the upper distribution plate 30 is greater than the opening rate of the middle distribution plate 31, and the opening rate of the middle distribution plate 31 is greater than the opening rate of the lower distribution plate 32.

[0063] According to an embodiment of the present disclosure, an ammonia synthesis system includes a mixed gas supply route to supply mixed gas to three or more catalyst layers respectively, so as to cope with flow rate changes occurring during the production cycle. For example, when the flow rate of the raw material to be fed is large, it can be fed through the mixed gas supply route 60 located at the upper end to start passing through the catalyst layer 20 located at the uppermost end, and when the flow rate of the raw material to be fed is small, it can be fed through the mixed gas supply route 62 located at the lower end to pass through the catalyst layer 22 located at the lower end instead of the catalyst layer 20 located at the upper end, thereby operating. At this time, when the mixed gas is fed through the mixed gas supply route 62 located at the lower end to pass through the catalyst layer 22 located at the lower end, the anti-backflow plate 31 prevents the mixed gas from flowing back to the middle catalyst layer 21.

[0064] At this time, for convenience, in this specification, the flow rate changes that occur during the production cycle are roughly divided into three types, as above, which can be divided into a small flow rate, a normal flow rate, and a large flow rate, which can be easily adjusted according to the common sense or judgment of ordinary technicians. It can be that the small flow rate refers to a situation where the annual average production flow rate (100%) is less than half (50%), the normal flow rate refers to a situation where the annual average production flow rate (100%) is more than half (50%) and less than 2 times (200%), and the large flow rate refers to a situation where the annual average production flow rate (100%) is more than 2 times (200%), but it is not limited to this.

[0065] On the one hand, when the flow rate is small as described above, the ammonia synthesis system can be operated by feeding the mixed gas through the mixed gas supply line 61 or 62 located at the lower end so as to pass through the catalyst layer 21 or 22 located at the lower end, so it is not necessary to maintain the temperature of the entire reactor. Therefore, during operation, the amount of energy required in the system can be optimized as needed, thereby saving energy.

[0066] In addition, when the ammonia synthesis system is in operation, each catalyst layer is used evenly, thereby being able to extend the catalyst replacement cycle. Generally, when the flow rate of the reaction fluid is small, the distribution performance at the upper part of the catalyst layer is reduced, resulting in differences in reaction performance not only between catalysts located at the same height, but also between the upper catalyst layer and the lower catalyst layer. When the distribution performance is reduced due to such a reduction in flow rate, resulting in lower reaction performance, there is a problem of shortened replacement cycle. However, as in the ammonia synthesis system according to the present disclosure, if the supplied mixed gas is passed through only a single catalyst layer when the flow rate of the raw material is reduced, and passes through multiple catalyst layers when the flow rate of the raw material is increased, and the raw material distribution performance between the catalyst layers is improved, the catalyst layers are used relatively evenly, thereby being able to improve the reaction performance of the catalyst layers, thereby being able to extend the catalyst replacement cycle.

[0067] In addition, according to an embodiment of the present disclosure, the ammonia synthesis system includes microwave heating devices 70, 71, and 72, which can make the temperature deviation between the center and the edge of the catalyst layer uniform at the initial stage of operation, thereby improving the ammonia synthesis yield. Specifically, the microwave heating device can make the temperature deviation between the center and the edge of the catalyst layer uniform by irradiating microwaves to the catalyst layer at the initial stage of operation. In addition, the microwave heating device preheats the catalyst layer that is not fully preheated at the initial stage of operation, thereby improving the ammonia synthesis yield at the initial stage of operation.

[0068] For example, when the flow rate of the raw material to be fed is small, it can be operated to pass through the catalyst layer 21 or 22 located at the lower end instead of the catalyst layer 20 located at the upper end. At this time, the mixed gas is not fed to the catalyst layer 20 located at the upper end, so the temperature of the catalyst layer 20 located at the upper end decreases over time. Then, when the catalyst layer 20 located at the upper end is used again, the ammonia synthesis efficiency may decrease because the catalyst layer 20 located at the upper end is in a cooled state. At this time, the microwave heating device is used to irradiate microwaves to the catalyst layer 20 located at the upper end in a cooled state for preheating, so that even if the catalyst layer is reused for operation, excellent ammonia synthesis efficiency can be achieved.

[0069] The number of microwave heating devices may be 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, or 8 or more, but not limited thereto, and the number of microwave heating devices may be increased according to the size of the reactor, and the location of the microwave heating devices may be adjusted for efficient microwave irradiation.

[0070] The ammonia synthesis system may further include microwave guides 701, 702, 703. The microwave guides enable the microwaves irradiated from the microwave heating device to reach the catalyst layer more effectively. Of course, the shape or setting position of the guides may be changed according to the microwave waveform.

[0071] In one embodiment according to the present disclosure, the number of catalyst layers may be more than 2, more than 3, more than 4, more than 5, more than 6, more than 7, more than 10, less than 20, less than 10, less than 8, less than 7, less than 6, less than 5, less than 4, less than 3, less than 2, or intervals of these values. The number of catalyst layers and the number of distribution plates and / or distribution devices may be the same.

[0072] In one embodiment according to the present disclosure, the number of distribution plates may be more than 2, more than 3, more than 4, more than 5, more than 6, more than 7, more than 10, less than 20, less than 10, less than 8, less than 7, less than 6, less than 5, less than 4, less than 3, or intervals of these values. The number of distribution plates and the number of distribution devices may be the same.

[0073] In one implementation example, Figure 1and Figure 3 As shown, the distribution plate may include an upper distribution plate 30 and a lower distribution plate 31 which are distinguished according to the configuration height. The upper distribution plate and the lower distribution plate are independently formed with a plurality of openings 301 and 311. When the percentage of the total area of ​​the openings relative to the total area of ​​each distribution plate is referred to as the opening ratio, the upper distribution plate and the lower distribution plate have different opening ratios. Specifically, the opening ratio A of the upper distribution plate is t and the opening ratio A of the lower distribution board b Satisfy A t >A b .

[0074] In another implementation example, Figure 2 and Figure 3 As shown, the distribution plate may include an upper distribution plate 30, a middle distribution plate 31 and a lower distribution plate 32 which are distinguished according to the configuration height, and the upper distribution plate, the middle distribution plate and the lower distribution plate are independently formed with a plurality of openings 301, 311, 321. When the percentage of the total area of ​​the openings relative to the total area of ​​each distribution plate is referred to as the opening ratio, the upper distribution plate, the middle distribution plate and the lower distribution plate have different opening ratios. Specifically, the opening ratio A of the upper distribution plate is t , the opening ratio of the middle distribution plate A m And the opening ratio A of the lower distribution plate b Satisfy A t >A m >A b .

[0075] In the ammonia synthesis system according to an embodiment of the present disclosure, the opening ratio of the distribution plates 30, 31, and 32 gradually decreases toward the bottom according to the configuration height, so as to cope with the flow rate changes during the production cycle. When the number of distribution plates is further greater than 2 or 3, the opening ratio can be gradually decreased toward the bottom according to the configuration height of the distribution plates.

[0076] When the uppermost distribution plate among the distribution plates is referred to as an upper distribution plate, the upper distribution plate 30 has a plurality of upper distribution plate openings 301, and the percentage of the total area of ​​the upper distribution plate openings 301 relative to the total area of ​​the upper distribution plate 30 is referred to as the upper distribution plate opening ratio A. t When the opening ratio A of the upper distribution plate is t It may be more than 40%, 45 to 60%, or 50 to 60%.

[0077] When the lowest distribution plate among the distribution plates is referred to as the lower distribution plate, the lower distribution plate 31 or 32 has a plurality of lower distribution plate openings 311 or 321, and the percentage of the total area of ​​the lower distribution plate openings 311 or 321 relative to the total area of ​​the lower distribution plate 31 or 32 is referred to as the upper distribution plate opening ratio A. b When the opening ratio of the lower distribution plate is A b It may be less than 20%, 5 to 20%, or 10 to 20%.

[0078] like Figure 2 As described in the figure, when there are three distribution plates, when the distribution plate located in the middle of the distribution plates is called the middle distribution plate, the middle distribution plate 31 has a plurality of middle distribution plate openings 311, and when the percentage of the total area of ​​the middle distribution plate openings 311 relative to the total area of ​​the middle distribution plate 31 is called the middle distribution plate opening ratio A m When the opening ratio of the middle distribution plate is m It may be 20 to 40%, 25 to 35% or 30 to 35%.

[0079] In addition, relative to the upper distribution plate opening ratio A t The middle part of the distribution board opening ratio A m The ratio may be less than 1, 0.3 to 0.8, or 0.4 to 0.7.

[0080] In addition, relative to the upper distribution plate opening ratio A t The lower distribution board opening ratio A b The ratio may be less than 1, 0.1 to 0.5, or 0.2 to 0.4.

[0081] In addition, the opening ratio A of the central distribution plate m The lower distribution board opening ratio A b The ratio may be less than 1, 0.1 to 0.8, or 0.4 to 0.7.

[0082] In an ammonia synthesis system according to an embodiment of the present disclosure, the diameter of the openings 301, 311, and 321 of the distribution plates gradually decreases downward according to the configuration height, so as to cope with flow changes occurring during the production cycle. When the number of distribution plates is further greater than 2 or 3, the diameter of the openings can be gradually reduced downward according to the configuration height of the distribution plates. The size of the diameter gradually decreases downward, so that it can help the mixed gas to flow easily from the top to the bottom. In addition, when the flow rate of the mixed gas is small, the uniformity of the flow distribution is improved at the front end of the catalyst layer, or when the flow rate is large, the gas is easily flowed from the top to the lower catalyst layer, and the raw material distribution performance between the catalyst layers is improved, so that the reaction performance of the catalyst layer can be improved.

[0083] According to one embodiment, when there are two catalyst layers and two distribution plates, the diameters of the upper distribution plate opening 301 and the lower distribution plate opening 311 may be the same or different. Specifically, the diameter of the upper distribution plate opening 301 is t and the diameter l of the lower distribution plate opening 311 b Can satisfy l t ≥l b or t > b .

[0084] According to another embodiment, when there are three catalyst layers and three distribution plates, the diameters of the upper distribution plate opening 301, the middle distribution plate opening 311, and the lower distribution plate opening 321 may be the same or different from each other. Specifically, the diameter of the upper distribution plate opening 301 is l t , the diameter l of the middle distribution plate opening 311 m and the diameter l of the lower distribution plate opening 321 b Can satisfy l t ≥l m ≥l b or t > m > b .

[0085] The ammonia synthesis system according to one embodiment of the present disclosure can cope with the flow rate changes of raw materials such as hydrogen during the production cycle. Specifically, the mixed gas supply route and distribution device can be changed according to the situation of low flow rate, average flow rate or high flow rate of the raw materials, thereby making it possible to make the number of catalyst layers and distribution plates through which the mixed gas passes different.

[0086] like Figure 1 As shown, in the case of an ammonia synthesis system according to an embodiment having two catalytic layers, when the flow rate of the raw materials is large, the mixed gas can be introduced through the mixed gas supply route 50 located at the uppermost end, so that the upper distribution plate 30 and the lower distribution plate 31 are used for all operations. Specifically, the mixed gas passes through the upper catalytic layer 20 in sequence from the upper distribution plate 30 located at the upper end, and then passes through the lower distribution plate 31 to reach the lower catalytic layer 21 located at the lowermost end, so that the mixed gas can be evenly distributed while passing through all catalytic layers, thereby improving the distribution performance of the mixed gas at the front end of the catalytic layer, allowing the mixed gas to pass through more than two catalytic layers, thereby significantly improving the reaction performance of the catalytic layer. Therefore, in the operation of the ammonia synthesis system according to an embodiment, each catalytic layer is evenly used, so that the replacement cycle of the catalytic layer can be effectively extended.

[0087] According to an embodiment of the ammonia synthesis system of the present disclosure, when the flow rate is small, the mixed gas can be supplied through the mixed gas supply route at the lowest end to operate so that the mixed gas only passes through the lower catalyst layer at the lower end, so there is no need to maintain the overall temperature of the reactor. Therefore, during operation, the amount of energy required in the system can be optimized as needed, thereby saving energy.

[0088] like Figure 1 As shown, when there are two catalytic layers, the ammonia synthesis system according to one embodiment can supply mixed gas through the lower mixed gas supply route 61 located at the lowest end when the flow rate is small, so that other distribution plates can be used without using other distribution plates, and only the lower distribution plate 31 with the smallest opening ratio can be used for operation. Specifically, the mixed gas can reach the lower catalytic layer 21 only through the lower distribution plate 31 located at the lowest end among the distribution plates.

[0089] like Figure 2 As shown, when there are three catalytic layers, the ammonia synthesis system according to one embodiment, when the flow rate is small, supplies the mixed gas through the lower mixed gas supply route 62 located at the lowest end, so that other distribution plates can be used without using other distribution plates, and only the lower distribution plate 32 with the smallest opening ratio can be used for operation. Specifically, the mixed gas can only pass through the lower distribution plate 32 located at the lowest end among the distribution plates to reach the lower catalytic layer 22.

[0090] like Figure 2 As shown, according to another embodiment of the present disclosure, the ammonia synthesis system, when the flow rate is averaged, supplies the mixed gas through the middle mixed gas supply route 61 located in the middle, so that the upper distribution plate 50 is not used, and only the middle distribution plate 31 and the lower distribution plate 32 are used for operation. Specifically, the mixed gas can sequentially pass through the middle catalyst layer 21 from the middle distribution plate 31 located in the middle, and then pass through the lower distribution plate 32 to reach the lower catalyst layer 22 located at the bottom.

[0091] In an embodiment according to the present disclosure, the mixed gas may include at least one selected from the group consisting of hydrogen and nitrogen.

[0092] Hydrogen can be produced in an installation powered by new renewable energy sources. Specifically, hydrogen can be produced in a water electrolyzer powered by new renewable energy sources.

[0093] The new renewable energy may include at least one selected from the group consisting of solar heat, sunlight, biomass, wind, hydropower, geothermal energy, ocean energy, and waste energy. The new renewable energy has temporal variability. For example, solar energy cannot be used at night. Therefore, when hydrogen is produced in a device driven by the new renewable energy, the ammonia synthesis system cannot always operate at a certain flow rate. That is, due to the temporal variability of the new renewable energy, an ammonia synthesis system that can cope with the flow rate changes that occur during the production cycle is required.

[0094] In addition, the mixed gas supplied in the mixed gas supply lines 60, 61, and 62 may be a mixed gas of low temperature. Therefore, the mixed gas supplied in the mixed gas supply lines 60, 61, and 62 plays a role in cooling the mixed gas, and may also function as a means for cooling the mixed gas flowing in the ammonia synthesis system. For example, the mixed gas of low temperature may be used as a cooling means for cooling the mixed gas supplied to the catalyst layer.

[0095] The ammonia synthesis system according to an embodiment of the present disclosure may further include: a plurality of mixed gas flow pipes 330, which are fixed to the lower surfaces 302, 312, 322 of the distribution plates 30, 31, 32, and are used for the mixed gas to flow. The ammonia synthesis system further includes the mixed gas flow pipes, so that even if the flow rate of raw materials such as hydrogen is reduced, a uniform flow distribution can be maintained at the front end of the catalyst layer included in the ammonia synthesis reactor. Figure 3 The diagram in the figure shows a schematic diagram of the upper distribution plate in the distribution plate. The schematic diagram is not limited to the upper distribution plate, and can be a schematic diagram of the middle distribution plate and / or the lower distribution plate.

[0096] refer to Figure 3 and Figure 4 The mixed gas flow pipe 330 may have a bottom surface and a side surface 332 connecting the bottom surface and the distribution plate.

[0097] A plurality of upper openings 333 formed at intervals along the circumference may be formed on the side of the upper portion 332a of the mixed gas flow pipe 330, a plurality of middle openings 335 formed at intervals along the circumference may be formed on the side of the middle portion 332b of the mixed gas flow pipe 330, and a plurality of lower openings 337 formed at intervals along the circumference may be formed on the side of the lower portion 332c of the mixed gas flow pipe 330. The mixed gas flows through the upper openings 333, the middle openings 335, and the lower openings 337. The mixed gas flow pipe 330 may include a cover 340 formed to surround at least a portion of the side of the mixed gas flow pipe 330 to provide a space for guiding the fluid that flows out to the outside of the side of the mixed gas flow pipe 330 after passing through the upper openings 333 to the side of the middle openings 335. The cover 340 may be formed to surround at least one of the group consisting of the upper portion and the middle portion of the side of the mixed gas flow pipe 330.

[0098] The cover 340 guides the fluid that has passed through the upper opening 333 and then flowed out to the outside of the side of the mixed gas flow pipe 330 to the middle opening 335. This forms a flow that moves to the outside of the side of the mixed gas flow pipe 330 and then moves to the inside of the side again. The flow formed in this way can more smoothly complete the mixing of the fluids.

[0099] refer to Figure 5 , the mixed gas flow tube 330 may further include a partition 339 configured to divide the upper portion and the middle portion of the mixed gas flow tube 330. The partition 339 completely separates the upper portion and the middle portion of the mixed gas flow tube 330 so that the fluid cannot move. Therefore, the fluid flowing into the upper portion of the mixed gas flow tube 330 does not directly drop to the middle portion due to the partition 339, but flows out to the space between the mixed gas flow tube 330 and the cover 340 through the upper opening portion 333. Thereafter, the fluid flows into the mixed gas flow tube through the middle opening portion 335 in the space, drops to the lower portion, and flows out to the outside of the mixed gas flow tube 330 through the lower opening portion 337. As described above, by forming a flow that flows out to the outside of the mixed gas flow tube 330, then flows into the inside again, and then flows out again, the mixing of the fluid can be completed more smoothly, and a uniform flow distribution can be maintained at the front end of the catalyst layer.

[0100] In one embodiment of the present disclosure, the mixed gas supply routes 60, 61, 62 and the distribution devices 50, 51, 52 may be arranged upstream of the respective distribution plates 30, 31, 32. Figure 1In the embodiment, the upper mixed gas supply line 60 and the upper distribution device 50 may be located upstream of the upper distribution plate 30, and the lower mixed gas supply line 61 and the upper distribution device 51 may be located downstream of the upper distribution plate 30 and upstream of the lower distribution plate 31, that is, between the upper distribution plate 30 and the lower distribution plate 31. In addition, as Figure 2 As shown, the upper mixed gas supply route 60 and the upper distribution device 50 can be located upstream of the upper distribution plate 30, the middle mixed gas supply route 61 and the middle distribution device 51 can be located downstream of the upper distribution plate 30 and upstream of the middle distribution plate 31, that is, between the upper distribution plate 30 and the middle distribution plate 31, and the lower mixed gas supply route 62 and the lower distribution device 52 can be located downstream of the middle distribution plate 31 and upstream of the lower distribution plate 32, that is, between the middle distribution plate 31 and the lower distribution plate 32.

[0101] In one embodiment of the present disclosure, each of the mixed gas supply routes 60, 61, and 62 may include a flow regulating device. The flow regulating device may independently control the flow rate of the mixed gas in each of the mixed gas supply routes. Specifically, the flow regulating device independently regulates the flow rate of the mixed gas flowing in each of the mixed gas supply routes, so that the flow rate of the mixed gas entering the distribution device is maintained within a desired flow rate range. The flow regulating device may be a flow regulating valve.

[0102] In one embodiment of the present disclosure, the mixed gas supply routes 60, 61, 62 may each be a route branching from a main supply route. In addition, the mixed gas supply routes 60, 61, 62 may each be supplied with at least one selected from the group consisting of nitrogen and hydrogen from a separate supply route.

[0103] In one embodiment according to the present disclosure, a plurality of openings 402 may be formed on each of the anti-backflow plates 40 and 41, and an anti-backflow cover 403 that is selectively opened according to the flow direction of the gas may be formed on the plurality of openings 402 formed on each of the anti-backflow plates 40 and 41. The ammonia synthesis system according to the present disclosure includes anti-backflow plates 40 and 41 formed with anti-backflow covers 403, so that even if the mixed gas is fed through the mixed gas supply route located at the lower end or the middle to pass through the catalyst layer located at the lower end or the middle, the mixed gas can be prevented from flowing back toward the upper end. In addition, as described above, by realizing a system capable of preventing the mixed gas from flowing back, the amount of energy required in the system can be optimized as needed during operation, thereby saving energy, and each catalyst layer can be used evenly, thereby extending the catalyst replacement cycle.

[0104] refer to Figure 6 and Figure 7The backflow prevention cover 403 can be coupled to a position of the perimeter of the plurality of openings 402 formed on each of the backflow prevention plates 40 , 41 via a hinge 404 . Figure 7 The backflow prevention cover 403 connected with the hinge 304 is shown in an open state. When the mixed gas flows from the upstream to the downstream of the backflow prevention plates 40 and 41, the backflow prevention cover 403 remains in an open state, so that the mixed gas flows normally. Figure 6 The backflow prevention cover 403 connected by the hinge 404 is shown in a closed state. When the mixed gas wants to flow from the downstream to the upstream of the backflow prevention plates 40 and 41, the backflow prevention cover 403 is closed due to the flow of the mixed gas flowing from the downstream to the upstream. Due to this principle, the backflow prevention plates 40 and 41 according to the present disclosure can prevent the mixed gas from flowing back.

[0105] In one embodiment of the present disclosure, a spring is provided at a hinge 404 joint portion where the hinge 404 is joined, so as to apply elastic force in a direction in which the anti-backflow cover 403 approaches the distribution plate.

[0106] In an embodiment according to the present disclosure, the distribution devices 50 , 51 , 52 may be in the shape of a circular plate or a toroidal ring, but are not limited thereto, and commonly used gas distribution devices may be used.

[0107] The ammonia synthesis system according to one embodiment of the present disclosure may further include microwave heating devices 70, 71, 72 for irradiating microwaves to the catalyst layer. By including the microwave heating devices 70, 71, 72, the temperature deviation between the center and the edge of the catalyst layer can be made uniform at the initial stage of operation, thereby improving the ammonia synthesis yield. Specifically, the microwave heating device can make the temperature deviation between the center and the edge of the catalyst layer uniform by irradiating microwaves to the catalyst layer at the initial stage of operation. In addition, the microwave heating device preheats the catalyst layer that has not been fully preheated at the initial stage of operation, thereby improving the ammonia synthesis yield at the initial stage of operation.

[0108] The number of microwave heating devices may be 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, or 8 or more, but is not limited thereto. The number of microwave heating devices may be increased according to the size of the reactor, and the installation position may be adjusted for efficient microwave irradiation.

[0109] The ammonia synthesis system may further include a microwave guide. The microwave guide enables the microwave irradiated from the microwave heating device to reach the catalyst layer more effectively. Of course, the shape or setting position of the guide may be changed according to the microwave waveform.

[0110] In the ammonia synthesis system according to an embodiment of the present disclosure, ammonia synthesis may be performed at 1 to 500 bar or 10 to 300 bar.

[0111] In addition, in the ammonia synthesis system according to an embodiment of the present disclosure, ammonia synthesis may be performed at 100 to 800°C or 200 to 700°C.

[0112] The ammonia synthesis system according to one embodiment of the present disclosure may further include: a heat exchanger, which is arranged downstream of each of the two or more catalyst layers to remove heat from the effluent of the catalyst layer. The heat exchanger can be arranged to surround the catalyst layer or its periphery. The ammonia synthesis system according to the present disclosure also includes a heat exchanger, so that an additional heat removal unit other than the supply cooling mixed gas can be provided. Thereby, the ammonia synthesis system can be flexibly operated.

[0113] The above-described contents are merely examples of applying the principles of the present disclosure, and other structures may also be included without departing from the scope of the present disclosure.

Claims

1. An ammonia synthesis system, comprising: Ammonia synthesis reactor; Two or more catalytic layers, which are included in the ammonia synthesis reactor; a distribution plate disposed upstream of each of the catalytic layers; an anti-backflow plate, which is arranged downstream of each of the catalyst layers other than the lowest catalyst layer among the two or more catalyst layers to prevent the mixed gas from backflowing; a distribution device, which is arranged upstream of each of the distribution plates and distributes the mixed gas to the distribution plates; and a mixed gas supply route arranged to supply the mixed gas to each of the distribution devices, The distribution plate is independently formed with a plurality of openings, and when the percentage of the total area of ​​the openings relative to the total area of ​​each distribution plate is referred to as an opening ratio, the distribution plate opening ratio gradually decreases toward the lower portion.

2. The ammonia synthesis system according to claim 1, wherein: When the uppermost distribution plate among the distribution plates is referred to as an upper distribution plate, the opening ratio (A t ) exceeds 40%.

3. The ammonia synthesis system according to claim 1, wherein: When the lowest distribution plate among the distribution plates is referred to as the lower distribution plate, the opening ratio (A b ) is less than 20%.

4. The ammonia synthesis system according to claim 1, wherein: When there are three distribution plates, when the distribution plate in the middle of the distribution plates is called the middle distribution plate, the opening ratio (A m ) is 20 to 40%.

5. The ammonia synthesis system according to claim 1, wherein: The ammonia synthesis system further includes: a plurality of mixed gas flow pipes fixed to a lower surface of at least one of the distribution plates for allowing the mixed gas to flow.

6. The ammonia synthesis system according to claim 5, wherein: The mixed gas flow pipe has a bottom surface and a side surface connecting the bottom surface and the distribution plate. A plurality of upper openings are formed on the upper side of the mixed gas flow pipe and are spaced apart along the circumference. A plurality of intermediate openings are formed on the intermediate side of the mixed gas flow pipe at intervals along the circumference. A plurality of lower openings are formed on the lower side of the mixed gas flow pipe and are spaced apart along the circumference. The mixed gas flow pipe includes a cover formed to surround at least a portion of a side surface of the mixed gas flow pipe to provide a space for guiding a fluid that flows out of the side surface of the mixed gas flow pipe after passing through the upper opening toward the middle opening.

7. The ammonia synthesis system according to claim 1, wherein: The ammonia synthesis system further includes a microwave heating device for irradiating microwaves to the catalyst layer.

8. The ammonia synthesis system according to claim 1, wherein: The mixed gas supply routes each include a flow regulating device.

9. The ammonia synthesis system according to claim 1, wherein: A plurality of openings are formed on each of the backflow prevention plates. A backflow prevention cover that is selectively opened according to a gas flow direction is formed at a plurality of openings formed on each of the backflow prevention plates.

10. The ammonia synthesis system according to claim 9, wherein: The backflow prevention cover is hingedly coupled to a position of a peripheral portion of a plurality of openings formed on each of the backflow prevention plates.

11. The ammonia synthesis system according to claim 10, wherein: A spring is provided at the hinge joint portion of the hinge joint, so as to apply elastic force to the direction in which the backflow prevention cover approaches the distribution plate.

12. The ammonia synthesis system according to claim 1, wherein: The ammonia synthesis system further includes a heat exchanger disposed downstream of the catalyst layer to remove heat from an outflow of the catalyst layer.

13. The ammonia synthesis system according to claim 1, wherein: The distribution device is in the shape of a circular plate or a ring.

14. The ammonia synthesis system according to claim 1, wherein: In the ammonia synthesis system, ammonia synthesis is performed at 10 to 300 bar.

15. The ammonia synthesis system according to claim 1, wherein: In the ammonia synthesis system, ammonia synthesis is performed at 200 to 700°C.

Images