Reactor and gas recovery device
By arranging honeycomb structures with facing end faces and protrusions on partition walls, the reactor enhances gas recovery efficiency by increasing contact with the functional material, addressing inefficiencies in existing designs.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- NGK CORP
- Filing Date
- 2023-03-30
- Publication Date
- 2026-07-30
AI Technical Summary
Existing reactors with honeycomb structures face inefficiencies in gas recovery due to inadequate gas flow disturbance, leading to insufficient contact between the gas and the adsorbent, which results in reduced capture efficiency.
The reactor design arranges multiple honeycomb structures such that their outflow and inflow end faces face each other, with coinciding central axes, and incorporates protrusions on partition walls to enhance gas turbulence, ensuring better contact with the functional material.
This configuration increases the amount of captured gas by improving the contact efficiency between the process gas and the functional material, enhancing the overall recovery performance.
Smart Images
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Abstract
Description
[Technical Field]
[0001] This invention relates to a reactor and a gas recovery apparatus. [Background technology]
[0002] As a measure against global warming, there is a growing demand for CO2 capture from combustion exhaust gases of CO2 emission sources such as factory exhaust gases and thermal power plants, as well as direct CO2 capture (DAC) and sequestering from the atmosphere, and effective utilization of captured CO2 through methanation.
[0003] The main methods for CO2 capture include adsorbing CO2 onto an adsorbent capable of adsorbing CO2, releasing the CO2 by varying the temperature, pressure, and humidity, and recovering it as high-concentration CO2 for use as a raw material in the chemical industry, or injecting it underground for immobilization. Adsorbents are used by supporting them on porous pellets, porous particles, fiber filters, honeycomb structures, etc. (for example, Non-Patent Document 1). [Prior art documents] [Non-patent literature]
[0004] [Non-Patent Document 1] "Cost and Evaluation of Direct Air Capture (DAC) Method for Carbon Dioxide (Vol. 2) - Adsorption Separation Process -", Japan Science and Technology Agency, Low Carbon Society Strategy Center, March 2021. [Overview of the project] [Problems that the invention aims to solve]
[0005] Non-patent document 1 describes a partition wall thickness of 0.15 mm and a cell density of 400 cells / inch. 2 (62 pieces / cm 2 A reactor is described in which an adsorbent is supported on the surface of the partition wall of a honeycomb structure made of mullite material, with an opening ratio of 75.0% (forming an adsorbent layer). However, simply supporting an adsorbent on the surface of the partition walls of a honeycomb structure may not sufficiently improve the amount of CO2 recovered. This is thought to be because when a gas containing CO2 is circulated through the honeycomb structure, the gas flow is not easily disturbed, and the gas containing CO2 does not come into sufficient contact with the adsorbent supported on the partition walls. In the above explanation, we used the example of a reactor where the target gas is CO2 and an adsorbent capable of adsorbing CO2 is used. However, the same problems may occur even if the target gas is a gas other than CO2 and a functional material other than an adsorbent capable of adsorbing CO2 is used in the reactor.
[0006] The present invention was made to solve the above-mentioned problems, and aims to provide a reactor and a gas recovery device that can increase the amount of captured gas recovered. [Means for solving the problem]
[0007] The inventors have diligently researched reactors equipped with multiple honeycomb structures and have found that the above problems can be solved by arranging multiple honeycomb structures such that the outflow end faces and inflow end faces of adjacent honeycomb structures face each other, and the central axes of the cells of adjacent honeycomb structures coincide, and by providing protrusions at predetermined positions on the partition walls that divide each cell. This has led to the completion of the present invention. That is, the present invention is illustrated as follows.
[0008] [1] A plurality of honeycomb structures comprising an outer perimeter wall and partition walls disposed inside the outer perimeter wall, which divide a plurality of cells extending from an inlet end face to an outlet end face through which a processing gas containing the gas to be captured can flow, The honeycomb structures are arranged such that the outflow end face and the inflow end face of adjacent honeycomb structures face each other, and the central axes of the cells of adjacent honeycomb structures coincide. The partition wall has at least one protrusion that projects into the cell and extends from the inlet end face to the outlet end face, A reactor in which the positions of the protrusions provided on the partition walls of adjacent honeycomb structures are different.
[0009] [2] The reactor according to [1], wherein the outflow end face and the inflow end face of adjacent honeycomb structures are in contact.
[0010] [3] The reactor according to [1] or [2], wherein the honeycomb structure is further arranged such that the outer peripheral walls parallel to the direction in which the cells extend face each other.
[0011] [4] The reactor according to [3], wherein the outer peripheral walls parallel to the direction in which the cell extends are in contact with each other.
[0012] [5] The reactor according to any one of [1] to [4], wherein the protrusions are provided in the partition wall that partitions the cells other than the outermost cell in the cross section of the honeycomb structure perpendicular to the direction in which the cells extend.
[0013] [6] The reactor according to any one of [1] to [5], wherein the shape of the honeycomb structure is a rectangular prism.
[0014] [7] The reactor according to any one of [1] to [6], wherein the shape of the cells in a cross-section of the honeycomb structure perpendicular to the direction in which the cells extend is square or hexagonal.
[0015] [8] The reactor according to any one of [1] to [7], wherein in a cross-section of the honeycomb structure perpendicular to the direction in which the cells extend, the partition wall forming a single cell has a structure in which sides having the protrusions and sides without the protrusions are alternately continuous.
[0016] [9] The reactor according to any one of [1] to [8], wherein in the cross section of the honeycomb structure perpendicular to the direction in which the cells extend, the width of the protrusion is 20 to 80% of the length of one side on which the protrusion is provided.
[0017]
[10] In the cross-section of the honeycomb structure perpendicular to the direction in which the cells extend, the height of the convex portion is 10 to 40% of the length of one side on which the convex portion is provided, the reactor according to any one of [1] to [9].
[0018]
[11] The length of the honeycomb structure in the direction in which the cells extend is 10 to 200 mm, the reactor according to any one of [1] to
[10] .
[0019]
[12] The honeycomb structure contains, as a main component, one or more selected from cordierite, mullite, alumina, silica, silicon carbide, and Si-bonded silicon carbide, the reactor according to any one of [1] to
[11] .
[0020]
[13] The thickness of the partition wall is 0.05 to 5 mm, the reactor according to any one of [1] to
[12] .
[0021]
[14] The porosity of the partition wall is 30% or more and less than 80%, the reactor according to any one of [1] to
[13] .
[0022]
[15] The average pore diameter of the partition wall is 10 to 300 μm, the reactor according to any one of [1] to
[14] .
[0023]
[16] Further comprising a functional material supported on the partition wall, the reactor according to any one of [1] to
[15] .
[0024]
[17] The functional material is an amine compound and / or a metal organic framework, the reactor according to
[16] .
[0025]
[18] Further comprising a cylindrical member that houses the honeycomb structure, the reactor according to any one of [1] to
[17] .
[0026]
[19] A gas recovery device for adsorbing and releasing a target gas contained in a process gas, [1] to
[18] any one of the reactors described in The reactor comprises a heating section capable of heating, A gas supply pipe capable of supplying the processing gas or purge gas to the inlet of the reactor, A gas discharge pipe capable of discharging the process gas or the purge gas from the outlet of the reactor, A gas recovery device equipped with the following features.
[0027]
[20] The gas supply piping has two branched gas supply branch pipes, the first gas supply branch pipe capable of supplying the processing gas and the second gas supply branch pipe capable of supplying the purge gas, The gas discharge piping has two branched gas discharge branch pipes, the first gas discharge branch pipe capable of discharging the processed gas and the second gas discharge branch pipe capable of discharging the purge gas. The gas recovery device according to
[19] further comprises a supply gas switching valve capable of shutting off the first gas supply branch pipe or the second gas supply branch pipe, and an exhaust gas switching valve capable of shutting off the first gas discharge branch pipe or the second gas discharge branch pipe. [Effects of the Invention]
[0028] According to the present invention, it is possible to provide a reactor and a gas recovery device that can increase the amount of captured gas recovered. [Brief explanation of the drawing]
[0029] [Figure 1A] This is a schematic diagram of a cross-section parallel to the direction in which the cells of a honeycomb structure constituting a reactor according to one embodiment of the present invention extend. [Figure 1B] This is a schematic diagram of the cross-section of the honeycomb structure shown in Figure 1A, along the line a-a'. [Figure 1C] This is a schematic diagram of the cross-section of the honeycomb structure along the line b-b' in Figure 1A. [Figure 2] This is an enlarged schematic diagram of a single cell in a cross-section of a honeycomb structure perpendicular to the direction in which the cells extend. [Figure 3]This is a schematic diagram of a cross-section parallel to the direction in which the cells of a honeycomb structure constituting a reactor according to another embodiment of the present invention extend. [Figure 4A] This is a schematic diagram of a cross-section parallel to the direction in which the cells of a honeycomb structure constituting a reactor according to another embodiment of the present invention extend. [Figure 4B] Figure 4A is a schematic diagram of the cross-section of the honeycomb structure along the line c-c'. [Figure 4C] Figure 4A is a schematic diagram of the cross-section of the honeycomb structure along the line d-d'. [Figure 5] This is a schematic diagram of a cross-section parallel to the direction in which the cells of a cylindrical member and honeycomb structure constituting a reactor according to another embodiment of the present invention extend. [Figure 6] This is a schematic diagram showing the configuration of a gas recovery device according to one embodiment of the present invention. [Modes for carrying out the invention]
[0030] The reactor of the present invention comprises a plurality of honeycomb structures, each having an outer periphery wall and partition walls disposed inside the outer periphery wall, which divide a plurality of cells extending from an inlet end face to an outlet end face through which a process gas containing the gas to be captured can flow. The honeycomb structures are arranged so that the outlet end face and inlet end face of adjacent honeycomb structures face each other, and the central axes of each cell in adjacent honeycomb structures coincide. The partition walls have at least one protrusion that projects into the cell and extends from the inlet end face to the outlet end face, and the positions of the protrusions on the partition walls of adjacent honeycomb structures are different. With this configuration, the reactor of the present invention is prone to turbulence in the flow of the process gas circulating within the cells of the honeycomb structures. As a result, when a functional material is supported on the honeycomb structure, the contact efficiency of the process gas with the functional material is improved, and the amount of gas to be captured recovered can be increased.
[0031] The gas recovery apparatus of the present invention is for adsorbing and releasing a target gas contained in a process gas, and comprises the above-mentioned reactor, a heating unit capable of heating the reactor, a gas supply pipe capable of supplying process gas or purge gas to the inlet of the reactor, and a gas discharge pipe capable of discharging process gas or purge gas from the outlet of the reactor. By having such a configuration, the gas recovery apparatus of the present invention uses a reactor capable of increasing the amount of target gas recovered, and therefore can improve gas recovery performance.
[0032] The embodiments of the present invention will be described in detail below with reference to the drawings. The present invention is not limited to the following embodiments, and it should be understood that modifications, improvements, etc., to the following embodiments, based on the ordinary knowledge of those skilled in the art, without departing from the spirit of the invention, also fall within the scope of the present invention.
[0033] <reactor> The reactor according to the embodiment of the present invention can be suitably used to recover target gases contained in the process gas. The process gas is not particularly limited, but examples include exhaust gases emitted from factories and power plants, and atmospheric air. The exhaust gas is not particularly limited, but examples include combustion exhaust gases generated when burning fossil fuels, coal gasification gases obtained by gasifying coal, and natural gas at thermal power plants and steel mills. The target gas is not particularly limited, but examples include carbon dioxide (CO2) and nitrogen oxides (NOx). x ), sulfur oxides (SO x Examples include acidic gases such as hydrogen sulfide (H2S). Among these, the reactor according to the embodiment of the present invention is particularly useful for recovering combustion exhaust gas and carbon dioxide (CO2) contained in the atmosphere.
[0034] Figure 1A is a schematic diagram of a cross-section parallel to the direction in which the cells of a honeycomb structure constituting a reactor according to one embodiment of the present invention extend. Figure 1B is a schematic diagram of a cross-section of the honeycomb structure in Figure 1A along the line a-a'. Figure 1C is a schematic diagram of a cross-section of the honeycomb structure in Figure 1A along the line b-b'. The reactor shown in Figures 1A-1C comprises two honeycomb structures 10 (10a, 10b). The two honeycomb structures 10 (10a, 10b) each have an outer perimeter wall 11 and partition walls 15 disposed inside the outer perimeter wall 11, which divide and form a plurality of cells 14 extending from the inlet end face 12 to the outlet end face 13. The cells 14 are through which a processed gas containing the gas to be captured can flow. The outflow end face 13 of adjacent honeycomb structure 10a and the inflow end face 12 of honeycomb structure 10b are positioned to face each other. In addition, the central axes C1 of each cell 14 of adjacent honeycomb structures 10a and 10b coincide. The partition wall 15 has at least one protrusion 16 that projects into the cell 14 and extends from the inlet end face 12 to the outlet end face 13. Furthermore, the positions of the protrusions 16 provided on the partition walls 15 of adjacent honeycomb structures 10a and 10b are different.
[0035] In a reactor with the above configuration, the flow of the process gas flowing in from the inlet end face 12 of the honeycomb structure 10a is disturbed by the protrusions 16 provided in the cell 14. Also, the process gas flowing out from the outlet end face 13 of the honeycomb structure 10a flows in from the inlet end face 12 of the honeycomb structure 10b. At this time, the flow of the process gas is disturbed because the positions of the protrusions 16 provided on the partition wall 15 of the adjacent honeycomb structures 10a and 10b are different. Furthermore, the flow of the process gas flowing in from the inlet end face 12 of the honeycomb structure 10b is disturbed by the protrusions 16 provided in the cell 14. Thus, in a reactor with the above configuration, turbulence of the process gas is likely to occur, so when a functional material is supported on the honeycomb structures 10a and 10b, the contact efficiency of the process gas with the functional material is improved, and the amount of captured gas recovered can be increased.
[0036] Figures 1A to 1C show an example of a reactor having two honeycomb structures 10, but the number of honeycomb structures 10 is not particularly limited as long as there are multiple (two or more). For example, if the reactor has three honeycomb structures 10, they can be arranged in series in the order of honeycomb structure 10a, honeycomb structure 10b, and honeycomb structure 10a with respect to the flow direction of the process gas. There is no particular upper limit to the number of honeycomb structures 10 arranged in series with respect to the flow direction of the process gas, and it can be adjusted as appropriate according to the processing amount of the process gas, etc.
[0037] In the reactor shown in Figures 1A to 1C, the outflow end face 13 of adjacent honeycomb structures 10a and the inflow end face 12 of honeycomb structure 10b are in contact. This configuration allows for a more compact reactor. However, the outflow end face 13 of adjacent honeycomb structures 10a and the inflow end face 12 of honeycomb structures 10b do not necessarily have to be in contact. For example, they may be indirectly in contact by placing a spacer 20 (see Figure 3, which will be explained below) between the outflow end face 13 of adjacent honeycomb structures 10a and the inflow end face 12 of honeycomb structures 10b.
[0038] The position of the protrusions 16 provided on the partition wall 15 is not particularly limited and can be appropriately determined according to the performance required of the reactor. In particular, as shown in Figures 1A to 1C, it is preferable that the protrusions 16 be provided on the partition wall 15 that partitions the cells 14 other than the outermost cell 14 in the cross section of the honeycomb structure 10 perpendicular to the direction in which the cells 14 extend (Figures 1B and 1C). By providing the protrusions 16 in such a position, the effect of disturbing the flow of the processed gas can be maximized while stably forming the protrusions 16 on the partition wall 15.
[0039] Here, Figure 2 shows an enlarged schematic diagram of one cell 14 in a cross-section of the honeycomb structure 10 perpendicular to the direction in which the cell 14 extends. As shown in Figure 2, it is preferable that the partition wall 15 that divides one cell 14 has a structure in which sides 15a and 15c with protrusions 16 and sides 15b and 15d without protrusions 16 are alternately continuous. By adopting such a structure, the effect of disturbing the flow of the processed gas can be maximized.
[0040] The width W of the protrusion 16 is not particularly limited, but is preferably 20-80% of the length L1 of the sides 15a, 15c on which the protrusion 16 is provided in the cross-section of the honeycomb structure 10 perpendicular to the direction in which the cell 14 extends, more preferably 25-75%, and even more preferably 30-70%. By providing a protrusion 16 having such a width W, it is possible to maximize the effect of disturbing the flow of the processed gas while suppressing pressure loss when the processed gas flows through the cell 14.
[0041] The height H of the protrusion 16 is not particularly limited, but is preferably 10 to 40% of the length L1 of the sides 15a, 15c on which the protrusion 16 is provided in the cross-section of the honeycomb structure 10 perpendicular to the direction in which the cell 14 extends, more preferably 15 to 35%, and even more preferably 20 to 30%. By providing a protrusion 16 having such a height H, it is possible to maximize the effect of disturbing the flow of the processed gas while suppressing pressure loss when the processed gas flows through the cell 14.
[0042] In the reactor, the honeycomb structure 10 may be further arranged so that the outer peripheral walls 11, which are parallel to the direction in which the cells 14 extend, face each other. Here, Figure 3 shows a schematic cross-section parallel to the direction in which the cells of the honeycomb structure constituting the reactor having the structure described above extend. As shown in Figure 3, this reactor has honeycomb structures 10a, 10b and honeycomb structures 10c, 10d arranged adjacent to each other in the direction in which cell 14 extends (the direction of flow of the processed gas). Furthermore, honeycomb structures 10a, 10b and honeycomb structures 10c, 10d are arranged adjacent to each other in a direction perpendicular to the direction in which cell 14 extends. By arranging the honeycomb structures 10a to 10d in this way, the amount of target gas to be captured contained in the processed gas can be increased when a functional material is supported on the honeycomb structures 10a to 10d.
[0043] It is preferable that the outer peripheral walls 11 parallel to the direction in which cell 14 extends are in contact between honeycomb structures 10a and 10c, and between honeycomb structures 10b and 10d, which are arranged adjacent to each other in a direction perpendicular to the direction in which cell 14 extends. By adopting such a configuration, the reactor can be made more compact. However, spacers 20 may be placed between honeycomb structures 10a and 10c, and between honeycomb structures 10b and 10d, similar to the spacers 20 placed between honeycomb structures 10a and 10b, and between honeycomb structures 10c and 10d. The shape and type of spacers 20 are not particularly limited and may be adjusted as appropriate depending on their placement.
[0044] Next, we will describe the details of the honeycomb structure 10 that constitutes the reactor.
[0045] The shape of the honeycomb structure 10 is not particularly limited as long as it has the characteristics described above. For example, the outer shape of the cross section perpendicular to the direction in which the cells 14 of the honeycomb structure 10 extend can be a polygon such as a triangle, square, hexagon, or octagon, or a round shape such as a circle, ellipse, oval, egg, oblong, or rounded square (a square composed of curves overall, where each side and each corner is composed of curves, and the radius of curvature of each side is greater than the radius of curvature of each corner). Among these, from the viewpoint of manufacturability, it is preferable that the outer shape of the cross section and end faces (inlet end face 12 and outlet end face 13) of the honeycomb structure 10 is square (i.e., the shape of the honeycomb structure 10 is a rectangular prism).
[0046] The length of one side of the inlet end face 12 and outlet end face 13 of a single honeycomb structure 10 is preferably 100 to 500 mm, and more preferably 200 to 400 mm. With a honeycomb structure 10 of this size, a sufficient amount of functional material can be secured in the cell 14, thus ensuring practicality as a reactor.
[0047] A single honeycomb structure 10 preferably has a length of 10 to 200 mm in the direction in which the cells 14 extend, more preferably 15 to 190 mm, and even more preferably 20 to 180 mm. With a honeycomb structure 10 of such length, a sufficient amount of functional material can be secured in the cells 14, thereby ensuring practicality as a reactor.
[0048] The shape of the cell 14 is not particularly limited, but in a cross-section perpendicular to the direction in which the cell 14 of the honeycomb structure 10 extends, it can be a polygon such as a triangle, square, hexagon, or octagon, or a round shape such as a circle, ellipse, oval, egg-shaped, or oblong. The shape of each cell may be single, or two or more types may be combined. Among these cell shapes, a square or hexagon is preferred. By providing cells of such shapes, the pressure loss when the processed gas flows can be reduced. The shape of each cell in the cross-section is the same as the shape of each cell at the end face.
[0049] The material of the honeycomb structure 10 (outer wall 11 and partition wall 15) is not particularly limited, but from the viewpoint of ensuring the strength of the honeycomb structure 10, it is preferable that one or more selected from cordierite, mullite, alumina, silica, silicon carbide, and Si-bonded silicon carbide be used as the main component. Herein, in this specification, "main component" means a component that accounts for more than 50% by mass of the total components.
[0050] The thickness of the partition wall 15 is not particularly limited, but from the viewpoint of ensuring the strength of the honeycomb structure 10 and reducing pressure loss when the processed gas passes through the cell 14, it is preferably 0.05 mm to 5 mm, more preferably 0.10 mm to 4.5 mm, and even more preferably 0.15 mm to 4 mm. In this specification, "thickness of partition wall 15" refers to the length of the line segment that crosses the partition wall 15 when the centroids of adjacent cells 14 are connected by a line segment in a cross section perpendicular to the direction in which the cells 14 of the honeycomb structure 10 extend. The thickness of partition wall 15 refers to the average value of the thickness of all partition walls 15.
[0051] The porosity of the partition wall 15 is not particularly limited, but from the viewpoint of ensuring the strength of the honeycomb structure 10 and reducing pressure loss when the processed gas passes through the cell 14, it is preferably 30% or more and less than 80%, more preferably 35% to 75%, and even more preferably 40% to 70%. In this specification, the "porosity of the partition wall 15" means the porosity of the partition wall 15 measured by the mercury intrusion method in accordance with JIS R1655:2003.
[0052] The average pore diameter of the partition wall 15 is not particularly limited, but from the viewpoints of ensuring the strength of the honeycomb structure 10 and reducing the pressure loss when the processing gas passes through the cell 14, it is preferably 10 μm to 300 μm, more preferably 15 μm to 280 μm, and still more preferably 20 μm to 260 μm. In this specification, the "average pore diameter of the partition wall 15" means the pore diameter of the partition wall 15 at 50% of the integrated value in the pore size distribution determined by the mercury intrusion method in accordance with JIS R1655:2003.
[0053] The thickness of the outer peripheral wall 11 is not particularly limited, but from the viewpoint of ensuring the strength of the honeycomb structure 10, etc., it is preferably 0.05 mm to 10 mm, more preferably 0.20 mm to 8 mm, and still more preferably 0.30 mm to 6 mm. In this specification, the thickness of the outer peripheral wall 11 refers to the length in the normal direction of the outer peripheral surface from the boundary between the outer peripheral wall 11 and the outermost peripheral cell 14 or partition wall 15 to the outer peripheral surface of the honeycomb structure 10 in a cross section orthogonal to the direction in which the cell 14 of the honeycomb structure 10 extends.
[0054] The cell density of the honeycomb structure 10 is not particularly limited, but from the viewpoints of ensuring the strength of the honeycomb structure 10 and increasing the loading amount of the functional material, etc., it is preferably 0.05 cells / cm 2 ~25 cells / cm 2 and more preferably 0.1 cells / cm 2 ~20 cells / cm 2 and still more preferably 0.5 cells / cm 2 ~15 cells / cm 2 is still more preferable. In this specification, the "cell density" is a value obtained by dividing the number of cells by the area of one end face of the honeycomb structure 10 (the total area of the partition wall 15 and the cell 14 excluding the outer peripheral wall 11).
[0055] The reactor may further include a functional material supported on the partition walls 15 of the honeycomb structure 10. The functional material can also be supported on the outer peripheral wall 11 facing the cell 14. By supporting the functional material, it becomes possible to recover (adsorb) and release (desorb) the target gas from the processed gas.
[0056] Here, Figure 4A shows a schematic cross-section parallel to the direction in which the cells of the honeycomb structure supporting the functional material extend. Furthermore, Figure 4B shows a schematic cross-section of the honeycomb structure of Figure 4A along the line c-c', and Figure 4C shows a schematic cross-section of the honeycomb structure of Figure 4A along the line d-d'. In the honeycomb structure 10 shown in Figures 4A to 4C, the functional material 30 is supported on the partition walls 15 (the parts where the protrusions 16 are formed are the protrusions 16) and the outer peripheral walls 11 facing the cells 14. The method for supporting the functional material 30 is not particularly limited, but the layer containing the functional material 30 may be formed on the outer peripheral wall 11 facing the partition walls 15 and cells 14 of the honeycomb structure 10. The functional material 30 is not particularly limited as long as it is capable of recovering the target gas contained in the processed gas; for example, an adsorbent for the target gas can be used. By using an adsorbent as the functional material 30, the target gas can be adsorbed and recovered, and the recovered target gas can be easily released by changing conditions such as temperature.
[0057] The adsorbent is not particularly limited and can be appropriately selected depending on the type of gas to be captured. Effective adsorbents for adsorbing gases such as carbon dioxide (CO2) include amine compounds, organometallic complexes, nanoporous ceramics or mesoporous silica supported with amine compounds and / or organometallic complexes. These can be used individually or in combination of two or more. Examples of amine compounds, though not particularly limited, include monoethanolamine (MEA) and N-methyldiethanolamine (MDEA). Examples of organometallic complexes are not particularly limited, but include porous organometallic structures (MOFs: Metal-organic Frameworks) that have a structure capable of adsorbing target gases in their pores. Among the various adsorbents mentioned above, amine compounds and / or metal-organic structures are preferred. By using these adsorbents, the amount of target gases such as carbon dioxide (CO2) adsorbed can be stably improved.
[0058] The thickness of the layer containing the functional material 30 can be determined according to the size of the cell 14 and is not particularly limited. For example, from the viewpoint of ensuring sufficient contact with air, the thickness of the layer containing the functional material 30 is preferably 20 μm or more, more preferably 25 μm or more, and even more preferably 30 μm or more. On the other hand, from the viewpoint of suppressing the peeling of the layer containing the functional material 30 from the partition wall 15 and the outer peripheral wall 11, the thickness of the layer containing the functional material 30 is preferably 400 μm or less, more preferably 380 μm or less, and even more preferably 350 μm or less.
[0059] The reactor can use the honeycomb structure 10 itself as the reactor, but it may also further include a cylindrical member that houses the honeycomb structure 10. Here, Figure 5 shows a schematic diagram of a cross-section parallel to the direction in which the cells of the honeycomb structure housed in the cylindrical member extend. As shown in Figure 5, this reactor comprises two honeycomb structures 10 (10a, 10b) and a cylindrical member 40 that houses the honeycomb structures 10. By housing the honeycomb structures 10 within the cylindrical member 40, the honeycomb structures 10 can be protected from external impacts and the like.
[0060] In Figure 5, the two honeycomb structures 10 (10a, 10b) and the cylindrical member 40 are in direct contact, but another material, such as an insulating material, may be placed between the honeycomb structures 10 and the cylindrical member 40. The cylindrical member 40 is not particularly limited, but from the viewpoint of manufacturability, it is preferably made of metal. Examples of materials that can be used for the cylindrical member 40 include stainless steel, titanium alloy, copper alloy, aluminum alloy, and brass. Among these, stainless steel is preferred due to its high durability, reliability, and low cost.
[0061] <Method for manufacturing a reactor> The method for manufacturing the reactor according to the embodiment of the present invention is not particularly limited as long as it can achieve the above-described structure. For example, a method for manufacturing a reactor according to an embodiment of the present invention includes a step of manufacturing a honeycomb structure 10 (step A) and a step of arranging the honeycomb structure 10 in a predetermined position (step B).
[0062] In step A, the method for manufacturing the honeycomb structure 10 is not particularly limited and can be carried out in accordance with methods known in the art. For example, the honeycomb structure 10 can be manufactured as follows. First, a clay mold containing ceramic powder is extruded into a desired shape to produce a honeycomb molded body. At this time, by selecting a die and jig of an appropriate shape, the shape and density of each cell, the shape and thickness of the partition walls 15 and the outer peripheral wall 11, and the shape of the protrusions 16 provided on the partition walls 15 can be controlled. As the ceramic powder, the aforementioned ceramic powder or raw material powder that becomes the aforementioned ceramic after firing (for example, cordierite-forming raw material) can be used. Cordierite-forming raw material is a raw material that becomes cordierite upon firing. The cordierite-forming raw material preferably has a chemical composition of alumina (Al2O3) (including the portion of aluminum hydroxide that is converted to alumina): 30-45% by mass, magnesia (MgO): 11-17% by mass, and silica (SiO2): 42-57% by mass. The clay mold may also contain a binder, pore-forming agent, dispersant, water, organic solvent, etc. Furthermore, the porosity and average pore size of the partition wall 15 can be controlled by appropriately selecting the type and amount of ceramic powder, binder, pore-forming agent, and dispersant used. Next, the honeycomb structure 10 can be obtained by drying and firing the honeycomb molded body obtained above. The drying method is not particularly limited, and conventional known drying methods such as hot air drying, microwave drying, dielectric drying, reduced pressure drying, vacuum drying, and freeze drying can be used. Among these, a drying method combining hot air drying with microwave drying or dielectric drying is preferred because it can dry the entire honeycomb molded body quickly and uniformly.
[0063] Next, in step B, the honeycomb structures 10 obtained above are placed in predetermined positions. Specifically, multiple honeycomb structures 10 are prepared and placed so that the outflow end faces 13 and inflow end faces 12 of adjacent honeycomb structures 10 face each other, and the central axes C1 of each cell 14 of adjacent honeycomb structures 10 coincide. At this time, spacers are placed between adjacent honeycomb structures 10 as needed.
[0064] In addition to the steps described above, the method for manufacturing a reactor according to an embodiment of the present invention may further include the step of supporting the functional material 30 on the partition walls 15 of the honeycomb structure 10. This step may be performed at any stage after step A. For example, this step may be performed between step A and step B, or after step B. The method for supporting the functional material 30 is not particularly limited, but for example, it can be formed by the following steps. The honeycomb structure 10 is immersed in a slurry containing the functional material 30, an organic binder, and a dispersion medium for a predetermined time, and excess slurry from the end faces and outer circumference of the honeycomb structure 10 is removed by blowing and wiping. The dispersion medium can be water, an organic solvent (e.g., toluene, xylene, ethanol, n-butanol, ethyl acetate, butyl acetate, terpineol, dihydroterpineol, texanol, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether), or a mixture thereof. After that, the functional material 30 can be supported on the surface of the partition wall 15 or the like by drying the slurry. Drying can be done by heating the honeycomb structure 10 to a temperature of, for example, 120 to 600°C. The series of steps—immersion, slurry removal, and drying—may be performed only once, but by repeating them multiple times, the desired amount of functional material 30 can be supported.
[0065] In addition to the steps described above, the method for manufacturing a reactor according to an embodiment of the present invention may further include the step of housing a plurality of honeycomb structures 10 in a cylindrical member 40. The method for housing multiple honeycomb structures 10 in a cylindrical member 40 is not particularly limited, and known methods can be used. For example, as such methods, fixing methods by fitting, such as crevice fitting, interference fit, and shrink fitting, as well as brazing, welding, and diffusion bonding can be used.
[0066] <Gas recovery device> The gas recovery apparatus according to the embodiment of the present invention can be suitably used to adsorb and release target gases contained in the processed gas. Figure 6 is a schematic diagram showing the configuration of a gas recovery device according to one embodiment of the present invention. As shown in Figure 6, the gas recovery device 100 comprises a reactor 110, a heating unit 120 capable of heating the reactor, a gas supply pipe 130 capable of supplying a process gas or purge gas to the inlet 111 of the reactor 110, and a gas discharge pipe 140 capable of discharging the process gas or purge gas from the outlet 112 of the reactor 110. The reactor 110 uses the above-described reactor, which allows the process gas containing the target gas to be captured to easily flow to the cells 14 in the outer peripheral region, thereby increasing the amount of the target gas to be captured and extending its lifespan. Therefore, the gas recovery device 100 can maintain good gas recovery performance over a long period of time. Furthermore, when the functional material 30 is supported on the above-described reactor, the amount of heating required when releasing (desorbing) the target gas can also be reduced, thus reducing the operating costs of the gas recovery device 100.
[0067] The gas supply piping 130 has two branched gas supply branch pipes. These branch pipes can be a first gas supply branch pipe 131 capable of supplying processing gas and a second gas supply branch pipe 132 capable of supplying purge gas. The gas discharge piping 140 has two branched gas discharge branch pipes. These branch pipes can be a first gas discharge branch pipe 141 capable of discharging processed gas and a second gas discharge branch pipe 142 capable of discharging purge gas. Furthermore, the gas recovery device 100 may further include a supply gas switching valve 150 capable of shutting off the first gas supply branch pipe 131 or the second gas supply branch pipe 132, and an exhaust gas switching valve 160 capable of shutting off the first gas discharge branch pipe 141 or the second gas discharge branch pipe 142.
[0068] In the gas recovery device 100 having the structure described above, when recovering the target gas contained in the process gas, the supply gas switching valve 150 is switched to shut off the second gas supply branch pipe 132 and open the first gas supply branch pipe 131, and the exhaust gas switching valve 160 is switched to shut off the second gas discharge branch pipe 142 and open the first gas discharge branch pipe 141. Next, the process gas containing the target gas is supplied from the first gas supply branch pipe 131 to the inlet 111 of the reactor 110 via the gas supply pipe 130. The process gas supplied to the reactor 110 recovers the target gas and is discharged from the outlet 112. The discharged process gas is then discharged from the first gas discharge branch pipe 141 via the gas discharge pipe 140.
[0069] Next, to release the target gas recovered in reactor 110, the supply gas switching valve 150 is switched to open the second gas supply branch pipe 132 and shut off the first gas supply branch pipe 131, and the exhaust gas switching valve 160 is switched to open the second gas discharge branch pipe 142 and shut off the first gas discharge branch pipe 141. Next, purge gas is supplied from the second gas supply branch pipe 132 to the inlet 111 of reactor 110 via the gas supply pipe 130. At this time, reactor 110 is heated by the heating section 120. The purge gas supplied to reactor 110 is discharged from the outlet 112 together with the target gas captured by the functional material 30 of reactor 110. The purge gas containing the target gas is discharged from the second gas discharge branch pipe 142 via the gas discharge pipe 140. Herein, in this specification, "purge gas" means a gas that can desorb the target gas trapped in the functional material 30 of the reactor 110 and discharge it from the reactor 110. The purge gas can be appropriately selected depending on the type of target gas, but for example, if the target gas is carbon dioxide, water vapor can be used. It is preferable that the water vapor is heated to 100°C or higher (for example, 120°C) in the reactor 110 by heating in the heating section 120. [Explanation of symbols]
[0070] 10, 10a, 10b, 10c, 10d Honeycomb structure 11 Peripheral wall 12 Inlet end face 13 Outflow end face 14 cells 15 Bulkhead 15a, 15b, 15c, 15d sides 16 Convex part 20 Spacers 30 Functional Materials 40 Cylindrical member 100 Gas recovery device 110 Reactor 111 Inlet 112 Outlet 120 Heating section 130 Gas supply piping 131 First gas supply branch piping 132 Second gas supply branch piping 140 Gas discharge piping 141 First gas discharge branch piping 142 Second gas discharge branch piping 150 Supply gas switching valve 160 Exhaust gas switching valve
Claims
1. The structure comprises multiple honeycomb structures, each having an outer perimeter wall and partition walls disposed inside the outer perimeter wall, which divide and form multiple cells extending from an inlet end face to an outlet end face, through which a processing gas containing the gas to be captured can flow. The honeycomb structures are arranged such that the outflow end face and the inflow end face of adjacent honeycomb structures face each other, and the central axes of the cells of adjacent honeycomb structures coincide. The partition wall has at least one protrusion that projects into the cell and extends from the inlet end face to the outlet end face, A reactor in which the positions of the protrusions provided on the partition walls of adjacent honeycomb structures are different.
2. The reactor according to claim 1, wherein the outflow end face and the inflow end face of adjacent honeycomb structures are in contact.
3. The reactor according to claim 1 or 2, wherein the honeycomb structure is further arranged such that the outer peripheral walls, which are parallel to the direction in which the cells extend, face each other.
4. The reactor according to claim 3, wherein the outer peripheral walls parallel to the direction in which the cells extend are in contact with each other.
5. The reactor according to claim 1 or 2, wherein in a cross-section of the honeycomb structure perpendicular to the direction in which the cells extend, the protrusions are provided on the partition wall that partitions the cells other than the outermost cell.
6. The reactor according to claim 1 or 2, wherein the shape of the honeycomb structure is a rectangular prism.
7. The reactor according to claim 1 or 2, wherein in a cross-section of the honeycomb structure perpendicular to the direction in which the cells extend, the shape of the cells is square or hexagonal.
8. The reactor according to claim 1 or 2, wherein in a cross-section of the honeycomb structure perpendicular to the direction in which the cells extend, the partition wall forming a single cell has a structure in which sides having the protrusions and sides without the protrusions are alternately continuous.
9. The reactor according to claim 1 or 2, wherein in a cross-section of the honeycomb structure perpendicular to the direction in which the cells extend, the width of the protrusion is 20 to 80% of the length of one side on which the protrusion is provided.
10. The reactor according to claim 1 or 2, wherein in a cross-section of the honeycomb structure perpendicular to the direction in which the cells extend, the height of the protrusion is 10 to 40% of the length of one side on which the protrusion is provided.
11. The reactor according to claim 1 or 2, wherein the length in the direction in which the cells of one of the honeycomb structures extend is 10 to 200 mm.
12. The reactor according to claim 1 or 2, wherein the honeycomb structure is mainly composed of one or more selected from cordierite, mullite, alumina, silica, silicon carbide, and Si-bonded silicon carbide.
13. The reactor according to claim 1 or 2, wherein the thickness of the partition wall is 0.05 to 5 mm.
14. The reactor according to claim 1 or 2, wherein the porosity of the partition wall is 30% or more and less than 80%.
15. The reactor according to claim 1 or 2, wherein the average pore size of the partition wall is 10 to 300 μm.
16. The reactor according to claim 1 or 2, further comprising a functional material supported on the partition wall.
17. The reactor according to claim 16, wherein the functional material is an amine compound and / or a metal-organic structure.
18. The reactor according to claim 1 or 2, further comprising a cylindrical member for housing the honeycomb structure.
19. A gas recovery device for adsorbing and releasing target gases contained in a processed gas, A reactor according to claim 1 or 2, The reactor comprises a heating section capable of heating, A gas supply pipe capable of supplying the processing gas or purge gas to the inlet of the reactor, A gas discharge pipe capable of discharging the process gas or the purge gas from the outlet of the reactor, A gas recovery device equipped with the following features.
20. The gas supply piping has two branched gas supply branch pipes, the first gas supply branch pipe capable of supplying the processing gas and the second gas supply branch pipe capable of supplying the purge gas. The gas discharge piping has two branched gas discharge branch pipes, the first gas discharge branch pipe capable of discharging the processed gas and the second gas discharge branch pipe capable of discharging the purge gas. The gas recovery device according to claim 19, further comprising a supply gas switching valve capable of shutting off the first gas supply branch pipe or the second gas supply branch pipe, and an exhaust gas switching valve capable of shutting off the first gas discharge branch pipe or the second gas discharge branch pipe.