Honeycomb structure and method for producing same, adsorption member, and gas recovery device

Abstract

This honeycomb structure comprises a partition wall 14 that demarcates a plurality of cells 13 extending from an inflow end face 11 to an outflow end face 12. The partition wall 14 is formed from a single sheet of paper 15 or laminated-structure paper obtained by laminating and bonding two or more sheets of paper 15 together. In a cross section orthogonal to the direction in which the cells 13 extend, there is a portion in which the number of sheets of paper 15 constituting the partition wall 14 in an outer peripheral region is fewer than the number of sheets of paper 15 constituting the partition wall 14 in a central region.

Description

Honeycomb structure, method for manufacturing the same, adsorption member, and gas recovery device

[0001] The present invention relates to a honeycomb structure, a method for manufacturing the same, an adsorption member, and a gas recovery device.

[0002] As a measure against global warming, demands are increasing for CO2 recovery from combustion exhaust gas of CO2 emission sources such as factory exhaust gas and thermal power plants, direct CO2 recovery from the atmosphere (Direct Air Capture: DAC) and fixation, and effective utilization of the recovered CO2 through methanation and the like.

[0003] As main methods for CO2 recovery, proposals have been made to adsorb CO2 to an adsorbent capable of adsorbing CO2, desorb the CO2 by varying temperature, pressure, humidity and the like, recover the CO2 as high-concentration CO2, and use it as a chemical industry raw material, or inject and fix it underground. The adsorbent is used by being supported on a base material such as porous pellets, porous particles, a fiber filter, or a honeycomb structure (Non-Patent Document 1). Among them, the honeycomb structure has the advantage of low pressure loss.

[0004] "Cost and Evaluation of Direct Air Capture (DAC) Method for Carbon Dioxide (Vol. 2) - Adsorption Separation Process -", Low Carbon Society Strategy Center, National Research and Development Agency Science and Technology Promotion Agency, March 3rd year of Reiwa

[0005] In a typical simple honeycomb structure, in a cross-section perpendicular to the direction in which the cells extend, gas containing CO2 flows more easily into the central region (i.e., the gas flow rate through the central region is higher), while it flows less easily into the outer region (i.e., the gas flow rate through the outer region is lower). Therefore, the adsorption rate and amount of CO2 adsorbed by the adsorbent supported on the partition walls that partition the outer region cells are lower than those adsorbed by the adsorbent supported on the partition walls that partition the central region cells. Furthermore, while adsorbents gradually degrade through repeated adsorption and desorption of CO2, the adsorbent supported on the partition walls that partition the central region cells degrades faster and has a shorter lifespan than the adsorbent supported on the partition walls that partition the outer region cells. Note that although the above explanation uses the case of an adsorbent capable of adsorbing CO2 as an example, similar problems may occur even when using adsorbents capable of adsorbing components other than CO2.

[0006] To solve the above problem, one possible method is to make the gas flow in the central region and the outer region roughly the same by making the thickness of the partition walls and the cell density in the central region greater than in the outer region. However, honeycomb structures used to support adsorbents are often made of ceramics. Therefore, in order to produce honeycomb structures with partially different partition wall thicknesses and cell densities, it is necessary to prepare a dedicated mold, which increases costs, and it is also necessary to adjust the manufacturing conditions in order to produce a structure without surface defects. Furthermore, if the structure of the honeycomb structure to be produced is different, the structure of the required mold will also be different, and the manufacturing conditions will also need to be adjusted, so it is not easy to increase the variations in the structure of the honeycomb structure.

[0007] The present invention was made to solve the above-mentioned problems, and aims to provide a honeycomb structure and a method for manufacturing the same that allows the processing gas containing the target component to flow easily to the cells in the outer peripheral region, and that can be manufactured easily and inexpensively. Furthermore, the present invention aims to provide an adsorption member and a gas recovery device that can increase the amount of target component recovered and extend the lifespan.

[0008] The inventors of the present invention have diligently researched honeycomb structures for supporting adsorbents and have found that the above problems can be solved by constructing the partitions of the honeycomb structure from a single sheet of paper or a laminated paper structure obtained by laminating and bonding two or more sheets of paper, and by having a portion where the number of sheets of paper constituting the partitions in the outer region is less than the number of sheets of paper constituting the partitions in the central region. This led to the completion of the present invention. That is, the present invention is illustrated as follows.

[0009] <1> A honeycomb structure comprising partition walls that divide a plurality of cells extending from an inlet end face to an outlet end face, wherein the partition walls are made of a single sheet of paper or a laminated structure paper made by laminating and bonding two or more sheets of paper, and in a cross section perpendicular to the direction in which the cells extend, the number of sheets of paper constituting the partition walls in the outer peripheral region is less than the number of sheets of paper constituting the partition walls in the central region.

[0010] <2> The honeycomb structure according to <1>, wherein the cell density of the central region is greater than the cell density of the outer peripheral region.

[0011] <3> The honeycomb structure according to <2>, wherein the ratio of the cell density of the central region to the cell density of the outer peripheral region is greater than 1.00 and less than 6.00.

[0012] <4> The honeycomb structure according to <1>, wherein the thickness of the partition wall in the outer peripheral region is smaller than the thickness of the partition wall in the central region.

[0013] <5> The honeycomb structure according to <4>, wherein the ratio of the cell density of the central region to the cell density of the outer peripheral region is 0.16 to 1.00, and the ratio of the thickness of the partition wall in the central region to the thickness of the partition wall in the outer peripheral region is greater than 1.00 and less than 6.00.

[0014] <6> A honeycomb structure according to any one of <1> to <5>, wherein the thickness of one sheet of the aforementioned paper is 20 to 500 μm.

[0015] <7> The honeycomb structure according to any one of <1> to <6>, wherein the shape of the cell in a cross section perpendicular to the direction in which the cell extends is triangular, quadrilateral, or hexagonal.

[0016] <8> The honeycomb structure according to any one of <1> to <7>, wherein the length in the direction in which the cells of the honeycomb structure extend is 10 to 200 mm.

[0017] <9> A method for manufacturing a honeycomb structure according to any one of <1> to <8>, comprising: a laminate manufacturing step of obtaining a laminate by bonding a plurality of papers together with an adhesive applied parallel to each other at predetermined intervals in a linear or strip-like manner; and a stretching step of stretching the laminate in the thickness direction, wherein, prior to the laminate manufacturing step, a laminated structure paper is manufactured by laminating and bonding one or more other papers to the paper in the portion located in the central region when the honeycomb structure is formed, and the laminated structure paper is used as part of the plurality of papers in the laminate manufacturing step.

[0018] <10> The method according to <9>, wherein in the laminate manufacturing step, the application position of the adhesive is offset by a 1 / 2 interval between adjacent sheets of paper.

[0019] <11> An adsorption member comprising a honeycomb structure described in any one of <1> to <8> and an adsorbent supported on the partition wall of the honeycomb structure.

[0020] <12> The adsorption member according to <11>, wherein the adsorbent is capable of adsorbing and desorbing components to be captured.

[0021] <13> The adsorbent member according to <11> or <12>, wherein the adsorbent is an amine compound and / or a metal-organic structure.

[0022] <14> A gas recovery device comprising an adsorption member described in any one of <11> to <13>.

[0023] According to the present invention, it is possible to provide a honeycomb structure and a method for manufacturing the same, which allows the processing gas containing the target component to flow easily to the cells in the outer peripheral region and can be manufactured easily and inexpensively. Furthermore, according to the present invention, it is possible to provide an adsorption member and a gas recovery device that can increase the amount of target component recovered and extend the lifespan.

[0024] This is a schematic diagram of a cross-section perpendicular to the direction in which the cells of a honeycomb structure according to an embodiment of the present invention extend. This is a schematic diagram of a cross-section along the line a-a' of the honeycomb structure in Figure 1A. This is a schematic diagram for explaining the partition walls of the outer peripheral region and the central region. This is a schematic diagram for explaining the partition walls of the outer peripheral region and the central region. This is a schematic diagram for explaining the partition walls of the outer peripheral region and the central region. This is a schematic diagram of a cross-section perpendicular to the direction in which the cells of a honeycomb structure according to another embodiment of the present invention extend. This is a schematic diagram for explaining the laminate manufacturing process and the stretching process in the manufacturing method of a honeycomb structure according to an embodiment of the present invention.

[0025] The honeycomb structure of the present invention comprises partition walls that divide a plurality of cells extending from the inlet end face to the outlet end face. The partition walls are made of a single sheet of paper or a laminated paper structure formed by laminating and bonding two or more sheets of paper. In a cross-section perpendicular to the direction in which the cells extend, the number of sheets of paper constituting the partition walls in the outer peripheral region is less than the number of sheets of paper constituting the partition walls in the central region. By having such a configuration, the honeycomb structure of the present invention allows the processing gas containing the target component to flow easily into the cells in the outer peripheral region, and can be manufactured easily and inexpensively.

[0026] In this specification, "processed gas" refers to various gases containing the components to be captured. Processed gases are not particularly limited, but include exhaust gases and atmospheric air emitted from factories and power plants. Exhaust gases are not particularly limited, but include combustion exhaust gases generated when burning fossil fuels, coal gas (calculated from coal), and natural gas at thermal power plants and steel mills. Components to be captured include carbon dioxide, moisture, and volatile components. Volatile components include, for example, volatile organic compounds (VOCs) and odor components other than VOCs. Specific examples of volatile components include carbon monoxide (CO) and nitrogen oxides (NOx). x ), sulfur oxides (SO xExamples include hydrogen sulfide (H2S), ammonia, acetic acid, isovaleric acid, nonenal, formaldehyde, toluene, xylene, paradichlorobenzene, ethylbenzene, styrene, chlorpyrifos, di-n-butyl phthalate, tetradecane, di-2-ethylhexyl phthalate, diazinon, acetaldehyde, and N-methylcarbamate-2-(1-methylpropyl)phenyl.

[0027] 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.

[0028] In this specification, unless otherwise specified, the "%" notation refers to a mass basis. In this specification, a numerical range expressed using "~" means a range that includes the numbers before and after "~" as the lower and upper limits, respectively, unless otherwise specified. In this specification, when a numerical range is preceded by "greater than" or "less than", it means a range that does not include the number as the lower or upper limit. In numerical ranges described in steps in this specification, the upper limit of one step may be replaced with the upper limit of another step described numerical range. In numerical ranges described in steps in this specification, the lower limit of one step may be replaced with the lower limit of another step described numerical range.

[0029] (1. Honeycomb Structure) Figure 1A is a schematic diagram of a cross-section perpendicular to the direction in which the cells of a honeycomb structure according to an embodiment of the present invention extend. Figure 1B is a schematic diagram of a cross-section along line a-a' (a cross-section parallel to the direction in which the cells extend) of the honeycomb structure in Figure 1A. As shown in Figures 1A and 1B, the honeycomb structure includes partition walls 14 that divide a plurality of cells 13 extending from an inlet end face 11 to an outlet end face 12. In Figure 1A, the partition walls 14 that divide a horizontal row of cells 13 are composed of a plurality of base materials (paper 15), and the spaces between the paper 15 (base materials) other than the parts facing the cells 13 are bonded together with adhesive 20. With such a structure, a processing gas containing the target component can be circulated into the cells 13. Therefore, when an adsorbent is supported on the honeycomb structure, the target component can be adsorbed and desorbed by circulating a processing gas containing the target component into the cells 13. The partition wall 14 is made of a single sheet of paper 15, or a laminated paper structure made by laminating and bonding two or more sheets of paper 15 together. By constructing the partition wall 14 from such paper 15, it can be manufactured more easily and inexpensively than in the case of a ceramic partition wall, and the honeycomb structure can be made lighter and have a lower heat capacity. The number of sheets of paper 15 in the laminated paper structure is not particularly limited as long as there are two or more sheets, but it is typically 2 to 5 sheets, preferably 2 to 4 sheets, and more preferably 2 to 3 sheets.

[0030] In a cross-section perpendicular to the direction in which the cells 13 extend (Figure 1A), the honeycomb structure has a portion where the number of paper sheets 15 constituting the partition walls 14 in the outer periphery is less than the number of paper sheets 15 constituting the partition walls 14 in the central region. This structure allows the processing gas to flow more easily to the cells 13 in the outer periphery, thereby reducing the difference in the amount of processing gas flowing (pressure loss) between the cells 13 in the central region and the cells 13 in the outer periphery. Here, in this specification, the partition walls 14 in the central region refer to a region in a cross-section perpendicular to the direction in which the cells 13 extend of the honeycomb structure that has a partition wall 14 that demarcates one cell 13 located at the center P1 of the honeycomb structure, or a region that has partition walls 14 that demarcate multiple cells 13 closest to the center of the honeycomb structure. The outer periphery refers to a region in the said cross-section other than the central region. For example, if the cross-section perpendicular to the direction in which the cells 13 extend has the structure shown in Figure 2A, the partition wall 14 that demarcates one cell 13 located at the center P1 of the honeycomb structure corresponds to the partition wall 14 in the central region C. Furthermore, if the cross-section perpendicular to the direction in which the cells 13 extend has the structure shown in Figure 2B, the partition wall 14 separating the two cells 13 closest to the center P1 of the honeycomb structure corresponds to the partition wall 14 of the central region C. Moreover, if the cross-section perpendicular to the direction in which the cells 13 extend has the structure shown in Figure 2C, the partition wall 14 separating the six cells 13 closest to the center P1 of the honeycomb structure corresponds to the partition wall 14 of the central region C. Note that in Figures 2A to 2C, cells 13 located in the central region are shown with diagonal lines, and partition walls 14 are shown with solid lines, and details such as the number of sheets of paper 15 constituting the partition wall 14 are omitted.

[0031] The honeycomb structure shown in Figures 1A and 1B has partition walls 14 in the outer region composed of a single sheet of paper 15, and partition walls 14 in the central region C composed of laminated paper made by laminating and bonding two sheets of paper 15. The laminated paper is made by bonding two sheets of paper 15 with adhesive 20. Therefore, the honeycomb structure shown in Figures 1A and 1B has a portion where the number of sheets of paper 15 constituting the partition walls 14 in the outer region is less than the number of sheets of paper 15 constituting the partition walls 14 in the central region C. On the other hand, the honeycomb structure may have a portion where the number of sheets of paper 15 constituting the partition walls 14 in the outer region is the same as the number of sheets of paper 15 constituting the partition walls 14 in the central region C, in addition to the portion where the number of sheets of paper 15 constituting the partition walls 14 in the outer region is less than the number of sheets of paper 15 constituting the partition walls 14 in the central region C. A schematic diagram of a cross-section perpendicular to the direction in which the cells 13 of such a honeycomb structure extend is shown in Figure 3. The honeycomb structure shown in Figure 3 has a portion of the outer peripheral region partition wall 14 made of a single sheet of paper 15 and a portion made of a laminated structure paper formed by laminating and bonding two sheets of paper 15 together, and the partition wall 14 in the central region C is made of a laminated structure paper formed by laminating and bonding two sheets of paper 15 together. Therefore, the honeycomb structure shown in Figure 3 has a portion in which the number of sheets of paper 15 making up the outer peripheral region partition wall 14 is less than the number of sheets of paper 15 making up the central region C partition wall 14, as well as a portion in which the number of sheets of paper 15 making up the outer peripheral region partition wall 14 is the same as the number of sheets of paper 15 making up the central region C partition wall 14. The portion in which the number of sheets of paper 15 making up the outer peripheral region partition wall 14 is the same as the number of sheets of paper 15 making up the central region C partition wall 14 is preferably located on the central region C side from the viewpoint of reducing the difference in the amount of processed gas flow (pressure loss) between the cells 13 in the central region C and the cells 13 in the outer peripheral region.

[0032] In one embodiment of the honeycomb structure of the present invention, the cell density of the central region C can be made greater than the cell density of the outer peripheral region. In this case, the ratio of the cell density of the central region C to the cell density of the outer peripheral region is preferably greater than 1.00 and less than 6.00, more preferably between 1.10 and 5.80, and even more preferably between 1.20 and 5.60. By controlling the cell density ratio within the above range, the processed gas can be more easily and stably flowed to the cells 13 in the outer peripheral region. Hereinafter, the cell density is the value obtained by dividing the number of cells by the area of ​​one end face of the honeycomb structure (inlet end face 11 or outlet end face 12) (total area of ​​partition wall 14 and cells 13).

[0033] In another embodiment of the present invention, the honeycomb structure may have a portion where the thickness of the partition walls 14 in the outer peripheral region is smaller than the thickness of the partition walls 14 in the central region C. In this case, the ratio of the thickness of the partition walls 14 in the central region C to the thickness of the partition walls 14 in the outer peripheral region is preferably greater than 1.00 and less than 6.00, more preferably between 1.10 and 5.80, and even more preferably between 1.20 and 5.60. By controlling the ratio of the thicknesses of the partition walls 14 within the above range, the processing gas can be more easily and stably supplied to the cells 13 in the outer peripheral region. Furthermore, by controlling the ratio of the thicknesses of the partition walls 14 within the above range, the processing gas can be more easily and stably supplied to the cells 13 in the outer peripheral region even when the ratio of the cell density in the central region C to the cell density in the outer peripheral region is between 0.16 and 1.00.

[0034] The thickness of a single sheet of paper 15 in the honeycomb structure is not particularly limited, but is preferably 20 to 500 μm, more preferably 25 to 450 μm, and even more preferably 30 to 400 μm. By using paper 15 of such thickness, sufficient strength of the honeycomb structure can be ensured. The thickness of a single sheet of paper 15 refers to the length that a line segment connecting the centroids of adjacent cells 13 in a cross section perpendicular to the direction in which the cells 13 of the honeycomb structure extend crosses a single sheet of paper 15 (partition wall 14). The thickness of a single sheet of paper 15 refers to the average value of the thicknesses of all the sheets of paper 15.

[0035] The paper 15 constituting the honeycomb structure contains pulp. Preferably, the paper 15 contains 30% by mass or more of recycled paper. Using paper 15 containing such a proportion of recycled paper is preferable from the standpoint of resource recycling and can also reduce costs. Furthermore, the paper 15 may contain fillers, various additives, and other materials in addition to pulp and recycled paper.

[0036] As pulp, chemical pulps such as bleached hardwood kraft pulp (LBKP), bleached softwood kraft pulp (NBKP), unbleached hardwood kraft pulp (LUKP), unbleached softwood kraft pulp (NUKP), and sulfite pulp can be used; mechanical pulps such as stone-ground pulp and thermomechanical pulp; wood fibers such as deinked pulp and recycled paper pulp; and non-wood fibers obtained from kenaf, bamboo, hemp, etc. Among these, chemical pulp and mechanical pulp are preferred, and chemical pulp is more preferred, because they are less likely to cause foreign matter contamination in the base paper and less likely to discolor over time when recycled using recycled paper as raw material. As fillers, known fillers such as white carbon, talc, kaolin, clay, heavy calcium carbonate, light calcium carbonate, titanium dioxide, zeolite, and synthetic resin fillers can be used. Furthermore, aluminum sulfate, various anionic, cationic, nonionic, or amphoteric yield enhancers, water drainage enhancers, paper strength enhancers, and internal sizing agents can be used as needed. In addition, dyes, fluorescent whitening agents, pH adjusters, defoamers, pitch control agents, and slime control agents can also be added as needed.

[0037] The paper 15 may have a coating layer formed on at least a portion of it, if necessary. Forming a coating layer can improve the properties of the paper 15, such as its strength and water resistance. The coating layer is not particularly limited, but examples include a resin coating layer and a silica coating layer.

[0038] The method for manufacturing (papermaking) the paper 15 is not particularly limited, and it can be manufactured by papermaking using known methods such as acidic papermaking, neutral papermaking, and alkaline papermaking using a known long-screen former, on-top hybrid former, or gap former machine. Furthermore, the surface of the paper 15 may be treated with various chemicals as needed. For example, a coating layer can be formed by immersing the paper 15 in a chemical for forming a coating layer or by applying the chemical to the paper 15. Examples of paper 15 obtained in the above manner include various known types such as fine paper, medium-grade paper, coated paper, glossy paper on one side, kraft paper, glossy kraft paper on one side, bleached kraft paper, glassine paper, cardboard, white cardboard, and liner. Since such paper 15 is commercially available, commercially available products may also be used.

[0039] The external shape of the honeycomb structure is not particularly limited and can be of various shapes. For example, the external shape of the cross section perpendicular to the direction in which the cells 13 of the honeycomb structure 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 entirely of curves, 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 external shape of the honeycomb structure is square in cross section and end faces (inlet end face 11 and outlet end face 12) (i.e., the shape of the honeycomb structure is a rectangular prism). When the external shape of the honeycomb structure is as described above, the honeycomb structure can be inserted into a frame of the above external shape made of paper 15 or the like and glued in place.

[0040] The shape of the cells 13 in the honeycomb structure is not particularly limited, but it is preferable that the cross-section perpendicular to the direction in which the cells 13 extend is triangular, quadrilateral, or hexagonal. By using cells 13 of such shape, the pressure loss when the processed gas flows can be reduced. The shape of each cell 13 in the said cross-section is the same as the shape of each cell 13 at the end face.

[0041] The honeycomb structure preferably has a length in the direction in which the cells 13 extend of 10 to 200 mm, more preferably 15 to 150 mm. With a honeycomb structure of such a length, a sufficient supported amount can be ensured when the adsorbent is supported on the partition walls 14 of the honeycomb structure. The diameters of the inflow end face 11 and the outflow end face 12 are not particularly limited, and may be, for example, 35 to 500 mm, preferably 100 to 400 mm. With a honeycomb structure of such a diameter, a sufficient supported amount can be ensured when the adsorbent is supported on the partition walls 14 of the honeycomb structure. The diameters of the inflow end face 11 and the outflow end face 12 are equivalent circle diameters.

[0042] The cell density in the honeycomb structure is not particularly limited, but from the viewpoints of ensuring strength and suppressing pressure loss, it is 4.65 to 186.00 cells / cm 2 preferably, and 5.00 to 180.00 cells / cm 2 more preferably, and 5.50 to 175.00 cells / cm 2 still more preferably. By controlling the cell density within such a range, a sufficient supported amount can be ensured when the adsorbent is supported on the partition walls 14 of the honeycomb structure.

[0043] (2. Method for manufacturing honeycomb structure) The method for manufacturing a honeycomb structure according to an embodiment of the present invention is a method for manufacturing the above-described honeycomb structure. The method for manufacturing a honeycomb structure according to an embodiment of the present invention is not particularly limited as long as it is a method capable of manufacturing the above-described honeycomb structure, and can be carried out according to a known method. Hereinafter, an example of the method for manufacturing a honeycomb structure according to an embodiment of the present invention will be described.

[0044] A method for manufacturing a honeycomb structure according to an embodiment of the present invention includes a laminate production step and a stretching step. The laminate production step and the stretching step can be performed in the same manner as known methods. Here, a schematic diagram for explaining the laminate production step and the stretching step is shown in Figure 4. The laminate production step is a step of obtaining a laminate in which a plurality of sheets of paper are bonded to each other by an adhesive applied linearly or in strips in parallel at predetermined intervals. Specifically, after preparing the base paper (Figure 4(a)), the adhesive is applied linearly or in strips in parallel at predetermined intervals to both sides of the paper (Figure 4(b)), and the bonding with another sheet of paper is repeated to produce a predetermined laminate (Figure 4(c)). The laminate may be cut to a predetermined length as necessary. In the laminate production step, the application positions of the adhesive are preferably shifted by half the interval between adjacent sheets of paper. By controlling the application positions of the adhesive in this manner, a honeycomb structure can be produced in which the cross-sectional shape of the cells in a cross section perpendicular to the extending direction of the cells is quadrangular or hexagonal.

[0045] The stretching step is a step of stretching the laminate in the thickness direction. Specifically, by expanding the laminate in the thickness direction, the portion composed of the sheets of paper not bonded by the adhesive becomes partition walls that define the cells (Figure 4(d)).

[0046] The method for manufacturing a honeycomb structure according to an embodiment of the present invention includes, before the laminate production step, producing a laminated structured paper by laminating and bonding one or more additional sheets of paper to the portion of the paper that will be located in the central region C when the honeycomb structure is formed, and using the laminated structured paper as a part of the plurality of sheets of paper in the laminate production step. Specifically, before the step of Figure 4(b), the adhesive is applied at least to the portion of the paper that will be located in the central region C to laminate another sheet of paper, and then the step of Figure 4(c) is performed. When applying the adhesive to the portion of the paper located in the central region C, the adhesive may be applied to the entire portion of the paper located in the central region C, but it may be applied in a direction perpendicular to the application direction of the adhesive in Figure 4(b). By applying the adhesive in this manner, peeling between the plurality of sheets of paper constituting the partition walls in the central region C can be suppressed.

[0047] In the embodiment of the present invention, a honeycomb structure can be manufactured by bonding paper 15 to the portion located in the central region C. Therefore, it is not necessary to prepare a mold as in conventional ceramic honeycomb structures, or to prepare paper 15 of different thicknesses as in conventional paper honeycomb structures, and it can be manufactured easily and inexpensively.

[0048] (3. Adsorption Member) The adsorption member according to the embodiment of the present invention comprises the above-described honeycomb structure and an adsorbent supported on the partition walls 14 of the honeycomb structure. The adsorbent is supported in the gaps and on the surface of the paper 15 that constitute the partition walls 14 of the honeycomb structure. In particular, the adsorbent supported on the surface of the paper 15 forms a coating layer. By supporting the adsorbent on the partition walls 14 of the honeycomb structure, when a processing gas containing the components to be captured is circulated in the cell 13, the components to be captured can be adsorbed and desorbed. In particular, since the adsorption member according to the embodiment of the present invention comprises the above-described honeycomb structure, it is possible to increase the amount of adsorbed (recovered) components to be captured and extend the lifespan.

[0049] The adsorbent is not particularly limited as long as it is capable of adsorbing and desorbing the target component, and can be appropriately selected according to the type of target component. For example, it is preferable that the adsorbent is capable of adsorbing one or more components selected from carbon dioxide, water, and volatile components.

[0050] When the target component is carbon dioxide, the adsorbent is preferably an amine compound and / or a metal-organic framework (MOF). Such an adsorbent can efficiently adsorb and desorb carbon dioxide. The metal-organic framework is a porous material having a structure that can adsorb the target component in its pores.

[0051] The amine compound is preferably a compound having one or more amino groups (-NH2, -NHR, -NRR' (where R and R' represent organic groups)), an ammonium group (-NH4), and one or more ammonium salts. Although the present invention is not intended to be limited by theory, it is thought that such compounds can adsorb carbon dioxide and the like by reacting with carbon dioxide and the like to produce carbamates or bicarbonates.

[0052] Examples of compounds having one or more selected from amino groups, ammonium groups, and ammonium salts include basic anion exchange resins having one or more selected from amino groups, ammonium groups, and ammonium salts. Such basic anion exchange resins are water-insoluble and have excellent water resistance, making it difficult for the adsorbent to leach out from the coating layer. Examples of basic anion exchange resins are not particularly limited, but include acrylic copolymers such as styrene-divinylbenzene copolymers and polyvinylbenzyl polymers. These can be used individually or in combination of two or more.

[0053] The exchange capacity of the basic anion exchange resin is preferably 0.6 meq / mL or more, more preferably 0.8 meq / mL or more, and even more preferably 1.1 meq / mL or more, from the viewpoint of adsorption performance of the target component. The exchange capacity of the basic anion exchange resin is measured by the tap method, after treating 10 mL of ion exchange resin with hydrochloric acid, washing off excess hydrochloric acid with ethanol, and measuring the amount of chloride ions that leach out when ammonia water is flushed through.

[0054] In addition to the adsorbents described above, organometallic complexes other than organometallic structures, or nanoporous ceramics or mesoporous silica on which organometallic complexes and / or the above-mentioned amine compounds are supported may also be used as adsorbents.

[0055] The adsorption member according to the embodiment of the present invention can be used for adsorption and desorption of components to be captured contained in a processing gas. Specifically, the adsorption member according to the embodiment of the present invention can adsorb components to be captured by the adsorbent by bringing the processing gas containing the components to be captured into contact with the adsorbent. Furthermore, by bringing a desorption gas into contact with the adsorbent on which the components to be captured have been adsorbed, the components to be captured adsorbed on the adsorbent can be desorbed into the desorption gas. Here, the desorption gas is not particularly limited as long as it is a gas capable of desorbing the components to be captured, but for example, water vapor can be used. The desorption gas, such as water vapor, is preferably at a high temperature of 80°C or higher. The desorption gas may be heated by a heater or by mixing it with a high-temperature gas.

[0056] The adsorbent member according to the embodiment of the present invention can be manufactured by supporting an adsorbent on a honeycomb structure. The method for supporting the adsorbent on the honeycomb structure is not particularly limited, but for example, it can be done using a suction coating method. Specifically, a slurry containing an adsorbent and a dispersion medium is supplied from the inlet end face 11 of the honeycomb structure and suctioned from the outlet end face 12 of the honeycomb structure. After suction, the slurry is dried to support the adsorbent on the partition walls 14 of the honeycomb structure. Drying can be done by heating the honeycomb structure to a temperature of, for example, room temperature (e.g., 25°C) to about 100°C. These operations may be performed multiple times until a coating layer formed on the surface of the partition walls 14 reaches the desired thickness. Furthermore, by reversing the direction of slurry input and suction, a coating layer of uniform thickness can be formed on the surface of the partition walls 14. Alternatively, the adsorbent can also be supported on the honeycomb structure by immersing the honeycomb structure in the slurry for a predetermined time and removing excess slurry from the end faces and outer circumference of the honeycomb structure by blowing and wiping. For example, water can be used as the dispersion medium.

[0057] (4. Gas Recovery Device) The gas recovery device according to the embodiment of the present invention is equipped with the above-described adsorption member. Because this gas recovery device is equipped with the above-described adsorption member, it is possible to increase the amount of captured components recovered and extend the lifespan.

[0058] A gas recovery device according to an embodiment of the present invention may further include a housing section for housing an adsorption member. Preferably, the housing section is connected to a pipe through which a processed gas containing the component to be captured and a desorbed gas can be supplied and discharged. With a gas recovery device having such a structure, the adsorption and desorption of the component to be captured can be easily achieved.

[0059] 11 Inlet end face 12 Outlet end face 13 Cell 14 Partition wall 15 Paper 20 Adhesive 30 Laminate

Claims

1. A honeycomb structure comprising partition walls that divide a plurality of cells extending from an inlet end face to an outlet end face, wherein the partition walls are composed of a single sheet of paper or a laminated structure paper formed by laminating and bonding two or more sheets of paper, and in a cross section perpendicular to the direction in which the cells extend, the number of sheets of paper constituting the partition walls in the outer peripheral region is less than the number of sheets of paper constituting the partition walls in the central region.

2. The honeycomb structure according to claim 1, wherein the cell density in the central region is greater than the cell density in the outer peripheral region.

3. The honeycomb structure according to claim 2, wherein the ratio of the cell density of the central region to the cell density of the outer peripheral region is greater than 1.00 and less than 6.

00.

4. The honeycomb structure according to claim 1, wherein the thickness of the partition wall in the outer peripheral region is smaller than the thickness of the partition wall in the central region.

5. The honeycomb structure according to claim 4, wherein the ratio of the cell density of the central region to the cell density of the outer peripheral region is 0.16 to 1.00, and the ratio of the thickness of the partition wall in the central region to the thickness of the partition wall in the outer peripheral region is greater than 1.00 and less than 6.

00.

6. The honeycomb structure according to any one of claims 1 to 5, wherein the thickness of one sheet of paper is 20 to 500 μm.

7. The honeycomb structure according to any one of claims 1 to 5, wherein the shape of the cell is triangular, quadrilateral, or hexagonal in a cross section perpendicular to the direction in which the cell extends.

8. The honeycomb structure according to any one of claims 1 to 5, wherein the length in the direction in which the cells of the honeycomb structure extend is 10 to 200 mm.

9. A method for manufacturing a honeycomb structure according to any one of claims 1 to 5, comprising: a laminate manufacturing step of obtaining a laminate by bonding a plurality of papers together with an adhesive applied parallel to each other at predetermined intervals in a linear or strip-like manner; and a stretching step of stretching the laminate in the thickness direction, wherein, prior to the laminate manufacturing step, a laminated structure paper is manufactured by laminating and bonding one or more other papers to the paper in the portion located in the central region when the honeycomb structure is formed, and the laminated structure paper is used as part of the plurality of papers in the laminate manufacturing step.

10. The method according to claim 9, wherein, in the laminate manufacturing step, the application position of the adhesive is offset by a 1 / 2 interval between adjacent sheets of paper.

11. An adsorption member comprising a honeycomb structure according to any one of claims 1 to 5, and an adsorbent supported on the partition wall of the honeycomb structure.

12. The adsorption member according to claim 11, wherein the adsorbent is capable of adsorbing and desorbing components to be captured.

13. The adsorbent member according to claim 11, wherein the adsorbent is an amine compound and / or a metal-organic structure.

14. A gas recovery device comprising the adsorption member described in claim 11.

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