Structure and carbon dioxide capture device equipped with said structure

Abstract

To provide a structure which is capable of efficiently adsorbing and absorbing carbon dioxide, and which also makes it possible to reduce costs for desorption and release of carbon dioxide.SOLUTION: A structure for carbon dioxide recovery is formed with alternate lamination of a reaction layer for carrying out adsorption and desorption of carbon dioxide and a heating layer for heating the reaction layer. The reaction layer is made up of a base, a carrier and an absorbent for carrying out adsorption and desorption of carbon dioxide carried in the carrier.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a structure and a carbon dioxide capture device including the structure. [Background technology]

[0002] It is widely known that carbon dioxide (CO2) concentrations show a strong correlation with global warming, which leads to rising atmospheric temperatures and increased chances of natural disasters such as typhoons and floods. Power plants, oil refineries, cement factories, steel production processes, and other industries emit large amounts of CO2 from their plants, and how to reduce these CO2 emissions has become a major issue.

[0003] As a method to solve the above problems, capturing and storing released CO2 has been studied and considered for some time. The above method is excellent in that it can substantially reduce CO2 emissions, and various methods that do not require major changes to the basic process are being considered.

[0004] One method used was to support amines as an absorbent on pellets to capture CO2, but it is difficult to make the contact area with CO2 large. Therefore, attempts have been made to increase the contact area in order to increase the amount of CO2 absorbed by the absorbent. In addition, in order to release the CO2 absorbed by the amines, it is necessary to heat the pellets to about 120°C, and the heat source is generally cheap steam discharged from power plants. However, when steam is used, moisture adheres to the absorbent, so it is necessary to dry the absorbent containing moisture, which requires equipment for drying and increases costs. To solve these problems, the following devices and methods have been proposed.

[0005] That is, Patent Document 1 discloses an apparatus for recovering carbon dioxide by immersing a honeycomb-shaped substrate (honeycomb structure) in a slurry containing a carrier to coat the substrate with the carrier, and further coating the carrier with an adsorbent using a slurry containing an adsorbent such as an amine.

[0006] Patent Document 2 discloses a carbon dioxide recovery and release device having an adsorption section in which adsorption units each having a breathable container containing pelletized zeolite and a heater installed around the breathable container are stacked in multiple stages.

[0007] Patent Document 3 discloses a method of using, as a substrate, a honeycomb structure having an adsorbent formed on the surface of partition walls and having thermally conductive filaments inside the partition walls.

[0008] Patent Document 4 discloses a honeycomb structure having a base made of activated carbon and an adsorbent formed on the surface thereof, in which a conductive dopant material is contained within the porous cell walls constituting the honeycomb structure, making the honeycomb structure electrically conductive and capable of generating heat. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Special Publication No. 2014-533195 [Patent Document 2] JP 2019-98220 A [Patent Document 3] Special Publication No. 2013-540573 [Patent Document 4] JP 2015-128771 A Summary of the Invention [Problem to be solved by the invention]

[0010] In the CO2 capture device described in Patent Document 1, nitrogen gas or water vapor is used as a means for heating the honeycomb structure, but when nitrogen gas is used, the nitrogen gas needs to be heated, which requires the installation of a nitrogen gas heating device, resulting in an increase in capture costs. When water vapor is used, the adsorbent containing moisture needs to be dried, as described above.

[0011] In addition, in the device described in Patent Document 2, the adsorbent is in the form of pellets, so when the gas containing CO2 is passed through the layer containing the pellets, there is a large pressure loss and it is necessary to apply a large pressure. In addition, there is a problem that the heat transfer efficiency from the heater is low, making the cost of desorbing CO2 high. Furthermore, the methods of Patent Documents 3 and 4 involve heating by passing electricity, which is not a cheap heating method, and there is still a problem in that the cost of desorbing CO2 is high.

[0012] The present invention has been made to solve the above problems, and has an object to provide a structure that can efficiently adsorb and absorb carbon dioxide and keep the cost of desorbing and releasing carbon dioxide low, and a carbon dioxide recovery device equipped with the above structure. [Means for solving the problem]

[0013] The structure of the present invention for achieving the above object is a structure for carbon dioxide capture in which a reaction layer for adsorbing and desorbing carbon dioxide and a heating layer for heating the reaction layer are alternately laminated, The reaction layer is characterized by comprising a substrate, a support, and an adsorbent supported on the support for adsorbing and desorbing carbon dioxide.

[0014] According to the structure of the present invention, a reaction layer that adsorbs and desorbs carbon dioxide and a heating layer for heating the reaction layer are alternately stacked, and since the reaction layer has a large contact area with the heating layer, the reaction layer can be efficiently heated by the heating layer. In addition, since the heating layer is provided separately from the reaction layer that adsorbs and desorbs carbon dioxide, the heat source and the adsorbent in the reaction layer do not come into direct contact with each other, and inexpensive water vapor can be used as the heat source for the heating layer, and there is no need to evaporate the water adsorbed in the reaction layer, so carbon dioxide can be efficiently adsorbed and desorbed at low cost. In this specification, the term "adsorption / desorption" is used to mean not only "adsorption" and "desorption" but also "absorption" and "release." Also, an adsorbent means a substance that adsorbs and absorbs carbon dioxide and desorbs and releases it at a predetermined temperature.

[0015] In the structure of the present invention, it is desirable that the substrate constituting the reaction layer is made of a honeycomb structure in which a plurality of through holes, which serve as flow paths for gas containing carbon dioxide, are arranged side by side in the direction in which the through holes extend, separated by partition walls.

[0016] In the structure of the present invention, when the substrate constituting the reaction layer is a honeycomb structure in which a plurality of through holes, which serve as flow paths for gas containing carbon dioxide, are arranged in parallel in the direction in which the through holes extend, separated by partition walls, the pressure loss in the flow paths is low, so there is no need to apply a large pressure to the reaction layer. Furthermore, compared to the case in which pellets or the like are used as the adsorbent, the surface area of ​​the layer containing the adsorbent on which the adsorbent is carried can be made large and heat transfer is also good, so that a large amount of carbon dioxide can be adsorbed and desorbed efficiently.

[0017] In the structure of the present invention, the honeycomb structure is preferably the substrate and the support. In the structure of the present invention, when the honeycomb structure is the base and the support, the adsorbent can be directly supported in the through holes of the honeycomb structure, heat transfer to the adsorbent is also improved, and carbon dioxide can be efficiently adsorbed and desorbed from the adsorbent.

[0018] In the structure of the present invention, it is desirable that the substrate is made of at least one material selected from the group consisting of carbon, metal and highly thermally conductive ceramic.

[0019] In the structure of the present invention, when the base is made of at least one material selected from the group consisting of carbon, metal and highly thermally conductive ceramic, the support has high thermal conductivity and can therefore efficiently receive heat from the heating layer, thereby enabling the carbon dioxide adsorbed in the adsorbent to be desorbed and released efficiently in a short period of time.

[0020] In the structure of the present invention, it is desirable that the heating layer is made of at least one material selected from the group consisting of carbon, metal and ceramic. In the structure of the present invention, when the heating layer is made of at least one selected from the group consisting of carbon, metal and ceramic, the heating layer has high thermal conductivity and can efficiently transfer heat from water vapor or the like to the base or support, and can efficiently desorb and release carbon dioxide adsorbed in the adsorbent in a short time. Furthermore, when water vapor is used as the heating fluid, being made of these materials improves corrosion resistance.

[0021] In the structure of the present invention, it is desirable that the heating layer is made of a plate-shaped heat transfer material or a heat transfer material having one or more through holes that serve as a flow path for the heating fluid, and is adhered to the reaction layer.

[0022] In the structure of the present invention, when the heating layer is made of a plate-shaped heat transfer material or a heat transfer material having one or more through holes that serve as a flow path for the heating fluid and is adhered to the reaction layer, heat from the heating layer can be efficiently transferred to the reaction layer via the adhesive layer. Furthermore, in the case of a heat transfer material having through holes, heat from steam or the like is transferred to the heating layer via the through holes having a large surface area, and the reaction layer can be heated efficiently.

[0023] In the structure of the present invention, it is desirable that the honeycomb structure and the heat transfer body are stacked so that the flow passages of the honeycomb structure constituting the reaction layer intersect with the flow passages of the heat transfer body constituting the heating layer.

[0024] In the structure of the present invention, when the honeycomb structure and the heat transfer body are laminated so that the flow passages of the honeycomb structure constituting the reaction layer and the flow passages of the heat transfer body constituting the heating layer cross each other, the fluids flowing through the reaction layer and the heating layer can flow in and out without being mixed, and therefore carbon dioxide can be adsorbed and desorbed efficiently and at low cost.

[0025] In the structure of the present invention, the heating fluid is preferably water vapor. In the structure of the present invention, when the heating fluid is steam, which is an inexpensive heat source, the reaction layer can be heated inexpensively via the heating layer.

[0026] Moreover, in the structure of the present invention, it is desirable that the adsorbed and absorbed carbon dioxide is desorbed and released at a temperature of 60 to 150°C. In the structure of the present invention, when the adsorbed / absorbed carbon dioxide is desorbed / released at 60 to 150° C., inexpensive water vapor can be used as a heating source, and adsorption / desorption of carbon dioxide can be performed at low cost.

[0027] The carbon dioxide capture device of the present invention is characterized by including the above-mentioned structure.

[0028] Since the carbon dioxide capture apparatus of the present invention includes the above-described structure, it is possible to provide a carbon dioxide capture apparatus capable of adsorbing and desorbing carbon dioxide efficiently and at low cost. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 is a perspective view that illustrates an example of a structure of the present invention. [Figure 2A]FIG. 2A is a cross-sectional view that typically shows a honeycomb formed body produced by the method for producing a structure of the present invention. [Figure 2B] FIG. 2B is a cross-sectional view of the honeycomb formed body shown in FIG. 2A taken along line AA. [Figure 3A] FIG. 3A is a cross-sectional view that typically illustrates one step of the method for producing a heat transfer material of the present invention. [Figure 3B] FIG. 3B is a cross-sectional view that typically shows a heat transfer body obtained by the method for producing a heat transfer body of the present invention. [Figure 4] FIG. 4 is an explanatory diagram that illustrates a carbon dioxide capture device equipped with the structure of the present invention.

[0030] Detailed Description of the Invention The structure of the present invention will now be described. The structure of the present invention is a structure for carbon dioxide capture in which a reaction layer for adsorbing and desorbing carbon dioxide and a heating layer for heating the reaction layer are alternately laminated, The reaction layer is characterized by comprising a substrate, a support, and an adsorbent supported on the support for adsorbing and desorbing carbon dioxide.

[0031] According to the structure of the present invention, a reaction layer that adsorbs and desorbs carbon dioxide and a heating layer for heating the reaction layer are alternately laminated, and since the reaction layer has a large contact area with the heating layer, the reaction layer can be efficiently heated by the heating layer. In addition, since the heating layer is provided separately from the reaction layer that adsorbs and desorbs carbon dioxide, the heat source and the adsorbent of the reaction layer do not come into direct contact with each other, and inexpensive water vapor can be used as the heat source for the heating layer, and there is no need to evaporate the water adsorbed in the reaction layer due to the water vapor, and carbon dioxide can be efficiently adsorbed and desorbed at low cost.

[0032] (Reaction layer) In the structure of the present invention, the reaction layer comprises a substrate, a support, and an adsorbent supported on the support for adsorbing and desorbing carbon dioxide.

[0033] The substrate is a base member constituting the reaction layer, and a support is coated on the portion of the substrate that comes into contact with the gas containing carbon dioxide, and the adsorbent is supported on the support. Alternatively, the substrate may also serve as a support, and the adsorbent may be supported on the substrate that also serves as a support. The material constituting the substrate is not particularly limited, but may be at least one selected from the group consisting of carbon, metal, and highly thermally conductive ceramic.

[0034] The structure of the substrate is not particularly limited, but may be a corrugated structure member in which multiple layers of flat and corrugated plates are stacked, the contact portions being glued or joined to form through holes, and a frame is placed on the side of the stack, or a member consisting of a honeycomb structure in which multiple through holes that serve as flow paths for gases including carbon dioxide are arranged side by side, separated by partitions, in the direction in which the through holes extend.

[0035] When the base body is made of a member having a corrugated structure, the flat or corrugated shape may be made of a metal plate, or may be made of fibers made of metal or highly thermally conductive ceramic woven into a flat or corrugated shape, or may be made of filaments woven into a mesh structure into a flat or corrugated shape. In this case, the metal plate used is preferably porous or has a surface area increased by etching or the like, and fibers or mesh structures made of metal or highly thermally conductive ceramics are also preferably porous or have a surface area increased by etching or the like.

[0036] When the corrugated structure member is made of metal, it is preferable to coat the surface of the metal in the form of a plate, fiber or thread with a carrier by washcoating or the like, and then load the adsorbent onto the carrier. Examples of the support include Al2O3, TiO2, SiO2, ZrO2, zeolite, carbon, etc. In practice, these can be made into supports made of the above materials by using a suspension in which the above oxides are dispersed in a dispersion medium such as an inorganic sol, an organic binder, or a mixture of these, and attaching the suspension to the surface of a substrate, followed by drying and firing.

[0037] When the corrugated structure member is made of a highly thermally conductive ceramic, a support may be coated on the fibrous or filamentous metal surface by washcoating or the like, and the adsorbent may be supported on this support, or the substrate may also serve as the support, and the adsorbent may be directly supported on the substrate.

[0038] Metals constituting the corrugated structure members include iron, aluminum, copper, nickel, cobalt, chromium, etc., and alloys of these metals.

[0039] Examples of highly thermally conductive ceramics that form the members of the corrugated structure include aluminum nitride, silicon carbide, silicon nitride, and alumina.

[0040] When the reaction layer is made of a honeycomb structure, the material of the honeycomb structure is not particularly limited, but is preferably metal, carbon or highly thermally conductive ceramic. Examples of highly thermally conductive ceramics that form the honeycomb structure include aluminum nitride, silicon carbide, silicon nitride, and alumina. The types of metals constituting the honeycomb structure include iron, aluminum, copper, nickel, cobalt, chromium, and alloys thereof. The honeycomb structure material may be a mixture of metal and ceramic.

[0041] When the material of the honeycomb structure is carbon, the surface of the partition walls separating the through holes of the honeycomb structure may be covered with a carrier and the adsorbent may be supported on this carrier. However, it is preferable that the partition walls separating the through holes of the honeycomb structure have a porous, high-specific surface area structure and that the adsorbent is supported directly on these porous, high-specific surface area partition walls without the intervention of a carrier.

[0042] The adsorbent supported in the reaction layer includes an amine compound. Specific examples of the amine compound include polyethyleneimine, monoethanolamine, diethanolamine, triethanolamine, tetraethyleneaminepentamine, methyldiethanolamine, dibutylamine, ethylenediamine, diethylenetriamine, triethylenetetramine, hexaethylenediamine, benzylamine, metaxylenediamine, polyethyleneimine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine.

[0043] The amine compound may be supported on the support by, for example, passing an aqueous solution of the amine compound through the through-holes of the honeycomb structure or immersing the honeycomb structure in an aqueous solution of the amine compound. Alternatively, an aqueous solution or alcohol solution of these amine compounds may be mixed with particles constituting the support, and after sufficient impregnation, the partition walls inside the reaction layer may be covered with the support containing the amine, and the water or alcohol may be removed. By the supporting step of impregnating the partition walls with an amine compound, the partition walls are provided with a carbon dioxide adsorbent having an amine-derived residue on their surfaces.

[0044] (heating layer) The heating layer is made of a plate-like heat transfer material or a heat transfer material having one or a plurality of through holes which serve as a flow path for a heating fluid, and is bonded to the reaction layer. The heating layer is desirably made of at least one material selected from the group consisting of carbon, metal and ceramic.

[0045] The type of metal constituting the heating layer is not particularly limited, but is preferably one having high thermal conductivity, such as aluminum, nickel, chromium, cobalt, tungsten, copper, iron, etc., and alloys thereof. Ceramics also preferably have high thermal conductivity, such as aluminum nitride, silicon carbide, silicon nitride, alumina, etc.

[0046] When using a metal, a plate-shaped heat transfer material without through holes may be used as is, and heat may be transferred to the reaction layer via the plate-shaped heat transfer material by contacting the plate with a heat transfer medium such as steam. However, it is preferable to use a metal heat transfer material having one or more through holes that serve as a flow path for the heating fluid.

[0047] The structure of such a metal heat transfer body having a plurality of through holes is not particularly limited, but it is desirable to have a structure in which a flat plate and a corrugated plate-shaped body or a plate-shaped body having a plurality of regularly-spaced grooves are laminated and joined together, or a honeycomb structure made of a mixture of ceramic or organic matter and metal as a filler.

[0048] When carbon or ceramic is used, a raw material composition obtained by mixing the raw material ceramic powder or carbon powder with a binder and a dispersion medium such as water can be extruded and then fired to obtain a heat transfer material having a plurality of through holes.

[0049] (adhesive layer) The adhesive constituting the adhesive layer that bonds the reaction layer and the heating layer is not particularly limited, but inorganic adhesives, heat-resistant organic synthetic adhesives, carbon-based adhesives, and metal adhesives such as solder can be used. Examples of inorganic adhesives include inorganic adhesives whose main components are silica alumina, silica, alumina, zirconia, etc. Examples of heat-resistant organic synthetic adhesives include silicone adhesives, phenolic resin adhesives, polyimide adhesives, polybenzimidazole adhesives, etc., and in order to increase thermal conductivity, those containing ceramic powders such as highly thermally conductive alumina, aluminum nitride, boron nitride, silicon nitride, etc., or metal powders such as aluminum, copper, nickel, etc., can be used.

[0050] The heating fluid for heating the heat transfer body is not particularly limited, and examples thereof include nitrogen, air, and steam, but steam used in power generation plants and other factories is preferable because it is an inexpensive heating source.

[0051] The structure of the present invention has a structure in which reaction layers and heating layers are alternately stacked, and although its external shape is not particularly limited, a rectangular prism shape is preferable, and the shapes of the reaction layers and heating layers are also preferably rectangular prism shapes (rectangular parallelepiped shapes).

[0052] Also, a structure in which a honeycomb structure and a heat transfer body are laminated so that the flow passages of the honeycomb structure constituting the reaction layer and the flow passages of the heat transfer body constituting the heating layer intersect is desirable.

[0053] FIG. 1 is a perspective view that illustrates an example of a structure of the present invention. As shown in Figure 1, the structure 100 of the present invention comprises a ceramic honeycomb structure (reaction layer) 20 in which a large number of through holes 21 serving as flow passages for gases including carbon dioxide are arranged in parallel in the longitudinal direction separated by partition walls 22, and a heat transfer body 10 in which a plurality of through holes 11 serving as flow passages for heat sources such as water vapor are arranged in parallel in the extension direction of the through holes 11 separated by partition walls 12, stacked so that the flow passages (through holes 21) of the honeycomb structure 20 intersect with the flow passages (through holes 11) of the heat transfer body 10.

[0054] In addition, an adhesive layer 30 is formed between the honeycomb structure 20 and the heat transfer body 10, and the honeycomb structure 20 and the heat transfer body 10 are bonded together by this adhesive layer 30.

[0055] In the structure 100 shown in FIG. 1, the honeycomb structure 20 has through holes 21 exposed on the left front side and right rear side, and the heat transfer body 10 has through holes 11 exposed on the right front side and left rear side. Therefore, in the honeycomb structure 20, gas containing carbon dioxide flows from the front left side to the rear right side or in the opposite direction, and in the heat transfer body 10, gas containing water vapor, etc. flows from the front right side to the rear left side or in the opposite direction. Since the two flow paths intersect at right angles, it is easy to circulate the two types of fluids (gases), and heat from the heat transfer body 10 can be efficiently transferred to the honeycomb structure 20.

[0056] In the structure 100 shown in FIG. 1, the honeycomb structure 20 constituting the structure 100 is composed of a single honeycomb structure 20, but a plurality of small honeycomb structures may be combined and bonded together to form a honeycomb structure, and the heat transfer body 10 may also be a plurality of small heat transfer bodies combined and bonded together to form a heat transfer body.

[0057] In the structure of the present invention, the width of the reaction layer between the two heating layers is desirably 20 to 100 cm, and the volume of the reaction layer is desirably 200 to 1000 (liters). Moreover, the volume ratio of the reaction layer to the total volume (volume of the reaction layer / (volume of the reaction layer+volume of the heating layer)) is preferably 0.6 to 0.9.

[0058] As described above, by setting the width and volume ratio of the reaction layer, the volume of the reaction layer can be made sufficient and the number of layers can be reduced, resulting in excellent cost performance and allowing the reaction layer to be heated efficiently by the heating layer.

[0059] 1, the end face of the honeycomb structure where the through-holes are exposed is rectangular, and in this case, the length of one side is preferably 20 to 100 cm. When the end face of the honeycomb structure is rectangular and the length of one side is 20 to 100 cm, the surface area inside the honeycomb structure becomes sufficiently large to support a large amount of adsorbent and facilitate the transfer of heat from the heating layer to the adsorbent.

[0060] In the structure of the present invention, the shape of the through holes constituting the honeycomb structure is preferably a square prism with rectangular end faces as a whole, but may also be a triangular prism or a hexagonal prism, as shown in Fig. 1. The shapes of the through holes may be different from one another, but it is preferable that they are all the same.

[0061] In the structure of the present invention, the partition walls of the honeycomb structure are desirably uniform in thickness. Specifically, the partition walls of the honeycomb structure are desirably 0.1 to 1.0 mm in thickness, and more desirably 0.2 to 0.5 mm in thickness. If the partition walls of the honeycomb structure are thin, the surface area is increased, and it becomes possible to support a larger amount of catalyst.

[0062] When the thickness of the partition walls of the honeycomb structure is set as described above, a larger amount of adsorbent can be supported, enabling a large amount of carbon dioxide to be adsorbed and absorbed, and a large amount of heat can be quickly supplied from the heating layer, enabling efficient adsorption and desorption of carbon dioxide.

[0063] In the structure of the present invention, the through hole density in a cross section perpendicular to the longitudinal direction of the honeycomb structure is 46.5 to 155 holes / cm. 2 (300~1000 pieces / inch 2 ) is preferable, and 62 to 124 pieces / cm 2 (400~800 pieces / inch 2 ) is more preferable because it has a larger surface area and can support a larger amount of adsorbent. The thermal conductivity of the honeycomb structure serving as the reaction layer is desirably 15 to 300 W / m·K.

[0064] In the structure of the present invention, it is preferable that 1 to 20 honeycomb structures serving as reaction layers are laminated, and the reaction layers are sandwiched between the heating layers. With the structure of the present invention configured as described above, a heat source such as steam is passed through the heating layer to heat the reaction layer, and the adsorbed and absorbed carbon dioxide can be efficiently desorbed and released through the reaction layer. In addition, since the heating layer is provided separately from the reaction layer that adsorbs and desorbs carbon dioxide, the heat source and the adsorbent in the reaction layer do not come into direct contact with each other, and inexpensive steam can be used as the heat source for the heating layer, and there is no need to evaporate the water adsorbed in the reaction layer due to this steam, so carbon dioxide can be efficiently adsorbed and desorbed at low cost.

[0065] The heating layer shown in Figure 1 is assumed to be made of metal, and is made by combining and bonding flat and corrugated sheets. The shape of the through holes on the end faces varies depending on the shape of the corrugated sheets, but a triangular prism shape or a shape consisting of a curved surface approximating a triangular prism as shown in Figure 1 is preferable. When the heating layer is made of carbon or ceramic, the shape of the through holes of the heating layer may be a square pillar, a triangular pillar, a hexagonal pillar or the like, similar to the shape of the through holes of the honeycomb structure.

[0066] The density of the through holes in the cross section perpendicular to the longitudinal direction of the heating layer is 0.005 to 77.5 pcs / cm 2 (0.03~500 pieces / inch 2 ) is preferable, and 0.15 to 46.5 pieces / cm 2 (1~300 pieces / inch 2 ) is more preferable because the heat capacity is small and the heat of water vapor or the like can be rapidly transferred to the honeycomb structure.

[0067] In the structure of the present invention, the width of the heating layer is preferably 2 to 20 cm, and the volume of the heating layer is preferably 20 to 200 L (liters). Also, the thermal conductivity of the heating layer is preferably 15 to 300 W / m·K.

[0068] [Method of manufacturing the structure] Next, a method for producing the above structure will be described. When manufacturing the above-mentioned structure, the steps described below are carried out to manufacture a structure in which the honeycomb structure and the heat transfer body are laminated. Below, we will explain the case where carbon is used as the material constituting the honeycomb structure and metal is used as the material constituting the heat transfer body. However, as mentioned above, the materials constituting the honeycomb structure and the heat transfer body are not limited to the above materials, and the manufacturing method thereof is not limited to the method described below.

[0069] When manufacturing the structure of the present invention, first, a honeycomb structure and a heat conductor are manufactured, and then the manufactured honeycomb structure and the heat conductor are bonded to each other. When manufacturing a honeycomb structure using carbon as a substrate or a substrate and a support, for example, first, particles of a carbon precursor that will become carbon, particles of a highly thermally conductive filler, a pore-forming material, a binder, a dispersion medium, etc. are mixed and kneaded to prepare a raw material composition.

[0070] FIG. 2A is a cross-sectional view that typically shows a honeycomb formed body produced by the manufacturing method for a structure of the present invention, and FIG. 2B is a cross-sectional view along the line AA of the honeycomb formed body shown in FIG. 2A. After the above steps, the raw material composition is extrusion molded to produce a honeycomb molded body 40 having a shape almost similar to that of a honeycomb structure having a large number of through holes 41 and partition walls 42 that separate the through holes 41, as shown in Figures 2A and 2B. Furthermore, the honeycomb molded body 40 is fired at a temperature of about 600 to 1000°C in an inert gas such as nitrogen to carbonize the carbon precursor.

[0071] Examples of carbon precursors include non-graphitizable carbons such as cellulose fibers and phenolic resins, graphitizable carbons such as mesophase pitch, coke, polyvinyl chloride, polyimide, and polyacrylonitrile (PAN), and mixtures thereof. These carbon precursors may be used alone or in combination of two or more. Among these, phenolic resins, PAN, coke, and the like are preferred.

[0072] Examples of the highly thermally conductive filler include aluminum, copper, natural graphite (scale-like), aluminum nitride, etc. By adding these in particulate (powder) form to the raw material composition as described above, the thermal conductivity of the honeycomb structure can be increased.

[0073] When manufacturing a honeycomb structure, a honeycomb formed body containing a carbon precursor is heated and carbonized as described above, and then an activation treatment is performed, thereby making it possible to manufacture a honeycomb structure having a higher specific surface area and to support a large amount of adsorbent on the honeycomb structure.

[0074] Examples of the activation method include gas activation and chemical activation. Gas activation is a method in which the carbonized material is heated to a predetermined temperature and then an activation gas is supplied to perform the activation. As the activation gas, water vapor, air, carbon dioxide, oxygen, combustion gas, and a mixture of these gases can be used. The activation may be performed by supplying the above-mentioned activation gas after the predetermined temperature is reached when the molded body is fired at a temperature of about 800 to 1000°C, or by supplying the activation gas when the molded body is fired at a temperature higher than 1000°C.

[0075] The chemical activation treatment is a method in which an activator is added to a raw material composition when preparing the raw material composition, and a honeycomb formed body is produced and then fired, thereby simultaneously carrying out carbonization treatment and activation treatment. In the present invention, it is preferable to use an alkali metal compound as the activator. The alkali metal compound is not particularly limited, but examples thereof include alkali metal hydroxides such as potassium hydroxide and sodium hydroxide, alkali metal carbonates such as potassium carbonate and sodium carbonate, and alkali metal sulfates such as potassium sulfate and sodium sulfate. Of these, potassium hydroxide and sodium hydroxide are preferable. The activator may contain other activators than the alkali metal compound, such as phosphoric acid, sulfuric acid, calcium chloride, zinc chloride, potassium sulfide, etc. The raw material composition may further contain a molding aid and the like.

[0076] The binder is not particularly limited, but examples thereof include pitch, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, polyethylene glycol, phenol resin, epoxy resin, etc., and two or more of these may be used in combination. Among these, pitch, which is easily converted to carbon when fired, is preferred.

[0077] The pore-forming agent is not particularly limited, but examples thereof include acrylic resins and starch. The pore-forming agent is a material used for introducing pores into the honeycomb structure when the honeycomb structure is manufactured.

[0078] The molding aid is not particularly limited, but examples thereof include ethylene glycol, dextrin, fatty acid, fatty acid soap, polyalcohol, etc., and two or more of these may be used in combination.

[0079] The dispersion medium is not particularly limited, but examples thereof include water, organic solvents such as benzene, and alcohols such as methanol, and two or more of these may be used in combination.

[0080] When preparing the raw material composition, it is desirable to mix and knead the ingredients. The ingredients may be mixed using a mixer, an attritor, or the like, or kneaded using a kneader, or the like.

[0081] Next, the honeycomb formed body is dried and then heated and fired to be carbonized, thereby manufacturing a honeycomb structure made of carbon (graphite). In the drying step, the honeycomb formed body is dried using a dryer such as a microwave dryer, a hot air dryer, a dielectric dryer, a reduced pressure dryer, a vacuum dryer, or a freeze dryer. After that, it is heated and sintered at 600 to 1000°C. The heating and calcination is usually carried out in a nitrogen or argon atmosphere, but as described above, activation can also be carried out at the same time by using water vapor, air, carbon dioxide gas, oxygen, combustion gas, or a mixture of these gases.

[0082] (Heat transfer material manufacturing) The method for producing the metal heat transfer body having a plurality of through holes is not particularly limited, but the following method is conceivable. FIG. 3A is a cross-sectional view that typically shows one step of the method for producing the heat transfer body, and FIG. 3B is a cross-sectional view that typically shows the heat transfer body obtained by the method for producing the heat transfer body. First, a flat steel plate 51 and a corrugated steel plate 52 made of stainless steel or the like are prepared and stacked together (see FIG. 3A). Next, the flat steel plate 51 and the corrugated steel plate 52, whose stacked state is fixed with a fixture (not shown), are placed in a vacuum furnace or the like, and the contact parts are joined by applying a predetermined pressure with a diffusion bonding jig and heating. Thereafter, a flat plate is joined to the side surface to obtain a heat transfer body 10 having through holes 11 and partition walls 12 as shown in FIG. 3B.

[0083] Also, a flat metal plate made of stainless steel or the like is etched using a masking member placed on one side thereof, with the masking member as a mask to obtain a flat metal plate having grooves formed therein that serve as fluid passages (through holes). Next, the flat metal plate having the grooves and a flat metal plate having no grooves are stacked together, and placed in a vacuum furnace or the like in the same manner as above. A predetermined pressure is applied by a diffusion bonding jig while heating is performed, and the contact portions are bonded to obtain a heat transfer body having through holes and partition walls.

[0084] (Adhesion process between heat transfer body and honeycomb structure) The manufactured heat transfer body and honeycomb structure are alternately bonded using the above-mentioned highly thermally conductive inorganic adhesive, organic synthetic adhesive, carbon-based adhesive, or metal-based adhesive so that the flow passages of the honeycomb structure constituting the reaction layer intersect with the flow passages of the heat transfer body constituting the heating layer, thereby producing a structure 100 as shown in Figure 1.

[0085] (Carbon dioxide capture equipment) The carbon dioxide capture device of the present invention is characterized by including the above-mentioned structure. FIG. 4 is an explanatory diagram that illustrates a carbon dioxide capture device equipped with the structure of the present invention. The carbon dioxide capture device 200 of the present invention includes two structures, a first structure 211 and a second structure 212. The carbon dioxide capture device 200 may include three or more structures, but here, the system will be described as an apparatus including two structures. Although not shown, the first structure 211 and the second structure 212 provided in the carbon dioxide capture device 200 are stacked such that a plurality of reaction layers and heating layers intersect with each other in their flow paths.

[0086] The carbon dioxide (CO2)-containing gas 210 generated from a generator or the like passes through a denitration device, a dust collector, a desulfurization device, a precooler, and the like (not shown), and is then introduced into the reaction layer of the first structure 211 or the second structure 212. The pipe through which the carbon dioxide (CO2)-containing gas 210 passes is equipped with switching valves 240, 241, 250, and 251, and the carbon dioxide (CO2)-containing gas 210 is selectively introduced into either structure by switching the switching valves 240, 241, 250, and 251. After leaving the reaction layer of the first structure 211 or the second structure 212, the carbon dioxide (CO2)-containing gas 210 passes through a chimney 213 and is discharged as exhaust gas 214.

[0087] On the other hand, the pipe through which the water vapor gas 230 containing water vapor as a heat source passes is equipped with switching valves 244, 245, 247, and 248, and the water vapor gas 230 is introduced into the heating layer of either the first structure 211 or the second structure 212, passes through a heat exchanger 231, and is discharged as an exhaust gas 232. A gas 233 consisting of air or the like is introduced into the heat exchanger 231, and the gas 233 warmed by the water vapor gas 230 leaving the heating layer is used as a water vapor residual heat gas 234, and preheats the water vapor through a heat exchanger not shown. This gas may be used for other purposes such as heating a predetermined facility or the like.

[0088] The first structure 211 or the second structure 212 is also adapted to introduce carbon dioxide (CO2) capture gas 220. The piping for the carbon dioxide (CO2) capture gas 220 is equipped with switching valves 246, 249, 242, and 243, and carbon dioxide desorbed and released in any of the reaction layers is passed through a pump 221 and stored as carbon dioxide (CO2) 222 by various methods.

[0089] When the carbon dioxide capture device of the present invention is operated, first, a carbon dioxide (CO2)-containing gas 210 is introduced into the reaction layer of the first structure 211, and after the carbon dioxide is adsorbed and absorbed, the gas is discharged through the chimney 213. When the reaction layer of the first structure 211 becomes saturated, the switching valves 240, 241, 250, and 251 are operated, and the carbon dioxide (CO2)-containing gas 210 is introduced into the reaction layer of the second structure 212, and after the carbon dioxide is similarly adsorbed and absorbed, the gas is discharged through the chimney 213.

[0090] While the carbon dioxide (CO2)-containing gas 210 is being introduced into the second structure 212, steam gas 230 is introduced into the heating layer of the first structure 211, which has sufficiently adsorbed and absorbed carbon dioxide, and the reaction layer of the first structure 211, heated by the heating layer, desorbs and releases carbon dioxide. The desorbed and released carbon dioxide is introduced into a pump 221 together with a carbon dioxide capture gas 220, and after leaving the pump 221, is stored as carbon dioxide (CO2) 222, and carbon dioxide generated by a generator or the like is captured.

[0091] While the above-mentioned carbon dioxide recovery operation is being performed in the first structure 211, carbon dioxide is sufficiently adsorbed and absorbed in the reaction layer of the second structure 212. Therefore, by operating the switching valves 240, 241, 250, and 251, the carbon dioxide (CO2)-containing gas 210 is introduced again into the first structure 211. Meanwhile, in the second structure 212, the carbon dioxide recovery operation is performed in the same manner as in the case of the first structure 211 described above. By alternately repeating the above-mentioned operations of adsorption / absorption and desorption / release of carbon dioxide between the first structure 211 and the second structure 212, carbon dioxide can be efficiently captured.

[0092] (Example) EXAMPLES Hereinafter, examples will be given that more specifically disclose the embodiments of the present invention, however, the present invention is not limited to these examples.

[0093] Example 1

[0094] (Manufacturing of honeycomb structures) A raw material composition was prepared by mixing 25.5 parts by weight of polyacrylonitrile (PAN), 4.1 parts by weight of an organic binder (methyl cellulose), 55.2 parts by weight of aluminum metal (average particle size 10 μm), 1.4 parts by weight of a lubricant (UNILUBE, manufactured by NOF Corporation), and 13.8 parts by weight of water.

[0095] Next, the raw material composition was extrusion molded using a die for manufacturing a honeycomb structure to prepare a honeycomb formed body having the same structure as the honeycomb structure.

[0096] Next, the honeycomb molded body was dried using a microwave dryer, and then was carried into a heating furnace, where it was fired and carbonized under heating conditions of 1000° C. for 1 hour in a nitrogen atmosphere.

[0097] Next, the obtained honeycomb structure member was heated at 900°C in water vapor for activation treatment to increase the surface area.

[0098] Thereafter, an aqueous solution of an amine compound containing monoethanolamine was prepared, and the honeycomb structure that had been subjected to the carbonization step was immersed in the aqueous solution of the amine compound, thereby supporting 30 g / L of the amine compound on the partition walls of the honeycomb structure.

[0099] The honeycomb structure carrying the obtained amine compound had a shape of an end surface where the through holes were exposed, with a length (width) in the lamination direction of 8.9 cm, a length of the bonding surface of 10 cm, a length in the through hole direction of 10 cm, and a through hole density of 155 pieces / cm. 2 (1000 cpsi), and the thickness of the partition wall was 0.2 mm. The length of the honeycomb structure in the lamination direction corresponds to the width of the reaction layer.

[0100] The honeycomb structure thus obtained contains 43% by weight of aluminum and has a density of 2.3 g / cm 3 The thermal conductivity was 20 W / m K.

[0101] (Heat transfer material manufacturing) A flat stainless steel plate with a thickness of 0.5 mm and a corrugated stainless steel plate with a thickness of 0.5 mm, a wave pitch of 2 mm, and a valley depth / peak height of 2 mm were prepared, and the two were stacked alternately. The plates were then placed in a vacuum furnace or the like, and pressure was applied using a diffusion bonding tool while heating was applied to bond the contact parts. A plate-shaped body was then bonded to the side surface, thereby producing a heat transfer body 10 having a through hole 11 and a partition wall 12 as shown in Figure 3B. The shape of the end face where the through holes were exposed in the heat transfer body was: width in the stacking direction (vertical): 0.55 cm, length of the adhesive surface (horizontal): 10 cm, length in the through hole direction: 10 cm. The thermal conductivity of the heat transfer material was 16.3 W / m·K.

[0102] (Lamination, adhesion process) An inorganic adhesive made of silica alumina was applied to the bonding surfaces of one honeycomb structure 20 and two heat transfer bodies 10 produced by the above process, and the structures were stacked and bonded together with the heat transfer bodies 10 positioned on the outside of both. The adhesive was hardened by heating to 150°C, completing the production of the laminate of the present invention.

[0103] (Carbon dioxide adsorption / desorption test) A pipe for circulating a gas containing carbon dioxide was connected to the end surface where the through holes of the honeycomb structure constituting the manufactured structure were exposed, and a pipe for circulating a heat source containing water vapor was connected to the end surface where the through holes of the heat transfer material were exposed.

[0104] Next, a gas containing 5% by volume of carbon dioxide at 40°C was introduced into the through holes of the honeycomb structure at SV (space velocity) = 5000 / hr until the adsorbent in the structure was saturated. The state of adsorption and absorption was analyzed by a gas analyzer for the gas that had passed through the honeycomb structure, and it was determined that saturation had been reached when the carbon dioxide concentration, which had decreased due to adsorption and absorption by the adsorbent, returned to the initial concentration. The time required to reach saturation was 248 seconds.

[0105] After this, a gas containing water vapor at 120°C was introduced into the through-holes of the heat transfer body, and nitrogen gas was introduced into the through-holes of the honeycomb structure at SV (space velocity) = 1000 / hr to desorb and release carbon dioxide. At this time, the amount of carbon dioxide desorbed and released was measured with a gas analyzer, and when the carbon dioxide concentration became 0.1% by volume or less, it was determined that the desorption and release was complete. As a result, the desorption / release time was 307 seconds, and the amount of carbon dioxide released was 0.20 L under standard conditions, indicating that a large amount of carbon dioxide can be adsorbed and desorbed in a short period of time. In this embodiment, a structure was evaluated in which two heat transfer bodies 10 were bonded to both sides of one honeycomb structure 20. However, similar results can be expected even if multiple honeycomb structures 20 and heat transfer bodies 10 are stacked alternately, since this is the same structure. [Explanation of symbols]

[0106] 10 Heat Transfer Material 11 Through hole 12 Bulkhead 20 Honeycomb structure 21 Through hole 22 Bulkhead 30 Adhesive layer 40 Honeycomb molded body 41 Through hole 42 Bulkhead 51 Flat steel plate 52 Corrugated steel sheet 100 structures 200 Carbon dioxide capture device 210 Carbon dioxide (CO2)-containing gases 211 First structure 212 Second structure 213 Chimney 214, 232 Exhaust gas 220 Carbon dioxide (CO2) capture gas 221 Pump 222 Carbon Dioxide (CO2) 230 Water Vapor Gas 231 Heat exchanger 233 Gas 234 Steam residual heat gas 240, 241, 242, 243, 244, 245 Switching valves 246, 247, 248, 249, 250, 251 Switching valve

Claims

1. A structure for carbon dioxide capture in which a reaction layer for adsorbing and desorbing carbon dioxide and a heating layer for heating the reaction layer are alternately laminated, the reaction layer comprises a substrate, a carrier, and an adsorbent that is supported on the carrier and that adsorbs and desorbs carbon dioxide, the substrate constituting the reaction layer is made of a honeycomb structure in which a plurality of through holes serving as flow paths for a gas containing carbon dioxide are arranged in parallel in the extension direction of the through holes with partition walls therebetween, the substrate is made of at least one material selected from the group consisting of carbon, metal, and highly thermally conductive ceramic; The support is Al ２ O ３ , TiO ２ , SiO ２ , ZrO ２ and zeolite, the heating layer is made of a plate-shaped heat transfer material or a heat transfer material having one or more through holes serving as a flow path for a heating fluid, and is bonded to the reaction layer; The structure, wherein the heating layer is made of at least one material selected from the group consisting of carbon, metal, and highly thermally conductive ceramic.

2. 2. The structure according to claim 1, wherein the highly thermally conductive ceramic contained in the substrate is at least one selected from the group consisting of aluminum nitride, silicon carbide, and silicon nitride.

3. 2. The structure according to claim 1, wherein the highly thermally conductive ceramic contained in the heating layer is at least one selected from the group consisting of aluminum nitride, silicon carbide, and silicon nitride.

4. The structure according to any one of claims 1 to 3, wherein the honeycomb structure and the heat transfer body are laminated so that the flow passages of the honeycomb structure constituting the reaction layer and the flow passages of the heat transfer body constituting the heating layer intersect.

5. The structure according to any one of claims 1 to 4, wherein the heating fluid is water vapor.

6. The structure according to any one of claims 1 to 5, wherein the adsorbent is an amine compound.

7. A carbon dioxide recovery device comprising the structure according to any one of claims 1 to 6.

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