Exhaust gas stabilization device, exhaust gas adsorption system, and exhaust gas adsorption method

Abstract

The flow rate and composition of exhaust gases emitted from factories and other sources can fluctuate. Therefore, in devices that adsorb specific components, fluctuations in the concentration of specific components in the exhaust gas, more specifically, fluctuations in the concentration of specific components from high to low concentrations, can cause the adsorbed specific components to desorb, thereby reducing the amount of adsorbed specific components. The present invention aims to provide an exhaust gas stabilization device that can suppress fluctuations in the concentration of specific components in exhaust gas. [Solution] An exhaust gas stabilization device having an exhaust gas inlet passage, an exhaust gas storage section, a grid-like structure, and an exhaust gas outlet passage, wherein exhaust gas flowing in from the exhaust gas inlet passage flows into the exhaust gas storage section and then flows out through the grid-like structure from the exhaust gas outlet passage.

Description

[Technical Field]

[0001] The present invention relates to an exhaust gas stabilization device, an exhaust gas adsorption system, and an exhaust gas adsorption method. [Background technology]

[0002] From an environmental protection perspective, there is a growing need to recover specific components contained in exhaust gases from factories and other sources that pose environmental risks, such as volatile organic compounds (VOCs) and carbon dioxide (CO2). One method for recovering these specific components from exhaust gases is to use adsorption, and the following devices and methods focusing on the exhaust gas flowing into the adsorption equipment are known.

[0003] For example, Patent Document 1 discloses an activated carbon filter device having a filter device body through which exhaust gas discharged from a predetermined zone where volatile organic compounds are generated passes, and the filter device body is equipped with an activated carbon cartridge that adsorbs and retains a portion of the volatile compounds contained in the exhaust gas discharged from the predetermined zone, and releases a portion of the adsorbed and retained volatile compounds when the concentration of volatile compounds contained in the exhaust gas is low. According to the activated carbon filter device of Patent Document 1, it is possible to stabilize the concentration of VOCs contained in the exhaust gas supplied to the adsorption and concentration device.

[0004] Patent Document 2 discloses a CO2 recovery method for recovering CO2 from a raw material gas using an adsorption tower equipped with an adsorbent, comprising: an adsorption step of introducing a raw material gas into the adsorption tower and adsorbing the CO2 contained in the raw material gas onto the adsorbent; a cleaning step of introducing a cleaning gas into the adsorption tower and removing gases other than CO2 from the adsorbent; and a recovery step of removing CO2 from the adsorbent and releasing it from the adsorption tower, wherein the off-gas released from the adsorption tower in the cleaning step is stored in an off-gas storage section, and the CO2 concentration of the raw material gas introduced into the adsorption tower is adjusted by mixing the off-gas stored in the off-gas storage section. According to the CO2 recovery method of Patent Document 2, the CO2 concentration of the raw material gas can be adjusted by utilizing the off-gas with a high CO2 concentration released in the cleaning step, thereby adjusting the partial pressure of CO2 in the adsorption tower, allowing CO2 to be suitably adsorbed onto the adsorbent, and improving the CO2 recovery efficiency.

[0005] Patent Document 3 discloses a gas concentration control method characterized by comprising: an adsorption step in which a gas to be treated containing volatile organic compounds is passed from the upstream side to the downstream side of an adsorbent layer to adsorb volatile organic compounds onto the adsorbent layer; a bypass step in which the adsorption step is terminated and the gas to be treated bypasses the adsorbent layer when the concentration of volatile organic compounds in the gas to be treated decreases over time and the gas concentration of the gas to be treated falls below a predetermined concentration; and a concentration adjustment step in which the gas concentration is adjusted to a certain range by mixing the detached gas obtained by releasing the volatile organic compounds from the adsorbent layer with the gas to be treated that bypassed in the bypass step. According to the gas concentration control method of Patent Document 3, the gas concentration (concentration of volatile organic compounds) of the gas to be treated decreases over time due to aeration of the raw gas to be treated, and when it falls below a predetermined concentration, the gas to be treated bypasses the adsorbent layer, and the detached gas obtained by detaching the volatile organic compounds from the adsorbent layer is mixed in, thereby gradually increasing the gas concentration of the gas to be treated whose concentration has decreased, and controlling it to a concentration within a certain range.

[0006] Patent Document 4 describes a carbon dioxide separator in which the internal space is divided by a separation membrane that selectively permeates carbon dioxide into a first space through which carbon dioxide-containing gas flows in from a carbon dioxide-containing gas channel and non-permeable gas that does not permeate the separation membrane flows out into a non-permeable gas channel, and a second space through which permeable gas that has permeated the separation membrane flows out into a permeable gas channel; a depressurizing pump provided in the middle of the permeable gas channel to depressurize the second space so that carbon dioxide contained in the carbon dioxide-containing gas permeates the separation membrane and the permeable gas flows out into the permeable gas channel; a carbon dioxide concentration detector that detects the concentration of carbon dioxide contained in either the carbon dioxide-containing gas flowing through the carbon dioxide-containing gas channel or the non-permeable gas flowing through the non-permeable gas channel; a permeable gas flow rate adjustment means for adjusting the flow rate of the permeable gas; and a plurality of adsorbents filled with an adsorbent that adsorbs carbon dioxide and connected to the downstream side of the non-permeable gas channel, wherein at least one of the adsorbents contains carbon dioxide contained in the non-permeable gas. Disclosed is a carbon dioxide separation device comprising: an adsorption device configured such that at least one of the remaining adsorbents is in a regeneration process in which carbon dioxide is depermeated from the adsorbent while carbon dioxide is being adsorbed onto the adsorbent; an exhaust gas flow path connected downstream of the plurality of adsorbents so that the non-permeable gas that was not adsorbed onto the adsorbent in the adsorption process is exhausted to the outside from the adsorbent in the adsorption process; a de-emission gas discharge flow path connected to the plurality of adsorbents so that the de-emission gas de-emissioned from the adsorbent in the regeneration process is recovered from the adsorbent in the regeneration process; a suction pump provided in the middle of the de-emission gas discharge flow path to reduce the pressure inside the adsorbent in the regeneration process to de-emission carbon dioxide from the adsorbent and discharge the de-emission gas into the de-emission gas discharge flow path; and a controller that controls the permeate gas amount adjustment means so that the concentration of carbon dioxide contained in the non-permeable gas flowing into the adsorbent in the adsorption process is within a predetermined range, based on the concentration detected by the carbon dioxide concentration detector. According to the carbon dioxide separation apparatus described in Patent Document 4, when the carbon dioxide concentration in the carbon dioxide-containing gas flowing into the adsorbent changes, the amount of carbon dioxide that permeates through the separation membrane can be changed, making it possible to control the carbon dioxide concentration in the carbon dioxide-containing gas flowing into the adsorbent within a predetermined range. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2010-051935 [Patent Document 2] Japanese Patent Publication No. 2008-174407 [Patent Document 3] Japanese Patent Publication No. 2008-200606 [Patent Document 4] Japanese Patent Publication No. 2022-127004 [Overview of the project] [Problems that the invention aims to solve]

[0008] Generally, when adsorbing specific components in exhaust gas, a higher concentration of the component results in greater adsorption, while a lower concentration results in less adsorption. Therefore, when the concentration of the component decreases, the adsorbed component may desorb. Similarly, a lower exhaust gas temperature results in greater adsorption, while a higher exhaust gas temperature results in less adsorption. Therefore, when the exhaust gas temperature increases, the adsorbed component may desorb. In addition, when the exhaust gas flow rate is high, the contact time between the adsorbent and the exhaust gas decreases, which can reduce the adsorption efficiency.

[0009] The composition, temperature, flow rate, and other conditions of exhaust gases emitted from factories and other facilities can fluctuate. Therefore, in devices that adsorb specific components, fluctuations in the exhaust gas conditions, for example, causing a change in the concentration of a specific component from high to low, can lead to the desorption of the adsorbed component, resulting in a decrease in the amount of the specific component adsorbed.

[0010] Therefore, the present invention aims to provide an exhaust gas stabilization device that can suppress fluctuations in the state of exhaust gas. [Means for solving the problem]

[0011] The present invention achieves the above object by the following means.

[0012] <Aspect 1> An exhaust gas inflow passage, An exhaust gas storage section, A lattice structure, and An exhaust gas outflow passage, having, and the exhaust gas flowing in from the exhaust gas inflow passage flows into the exhaust gas storage section, and then flows out from the exhaust gas outflow passage through the lattice structure, An exhaust gas stabilizer. <Aspect 2> The exhaust gas stabilizer according to Aspect 1, wherein the lattice structure is composed of at least one metal material selected from copper, aluminum, brass, nickel, iron, and stainless steel. <Aspect 3> The exhaust gas stabilizer according to Aspect 1 or 2, wherein the lattice structure is a metal honeycomb. <Aspect 4> The exhaust gas stabilizer according to any one of Aspects 1 to 3, wherein the direction of the exhaust gas flowing into the exhaust gas storage section from the exhaust gas inflow passage is different from the direction of the exhaust gas flowing out from the exhaust gas storage section to the exhaust gas outflow passage. <Aspect 5> The exhaust gas stabilizer according to any one of Aspects 1 to 3, wherein the direction of the exhaust gas flowing into the exhaust gas storage section from the exhaust gas inflow passage is the same as the direction of the exhaust gas flowing out from the exhaust gas storage section to the exhaust gas outflow passage. <Aspect 6> The exhaust gas stabilizer according to any one of Aspects 1 to 5, wherein the exhaust gas inflow passage and / or the exhaust gas outflow passage is bent within the exhaust gas storage section. <Aspect 7> The exhaust gas stabilizer according to any one of Aspects 1 to 6, wherein a barrier is disposed between the inflow end of the exhaust gas inflow passage and the lattice structure. <Aspect 8> An exhaust gas stabilization device for exhaust gas whose inflow rate fluctuates periodically, wherein the exhaust gas storage section has a capacity equal to or greater than the inflow rate for one cycle of the exhaust gas whose inflow rate fluctuates periodically, the exhaust gas stabilization device according to any one of Aspects 1 to 7. <Aspect 9> An exhaust gas adsorption system comprising an exhaust gas stabilization device according to any one of Aspects 1 to 8, and an exhaust gas adsorption device arranged downstream of the exhaust gas stabilization device to adsorb a specific component in the exhaust gas. <Aspect 10> An exhaust gas adsorption method including flowing exhaust gas through the exhaust gas adsorption system according to Aspect 9 to adsorb the specific component of the exhaust gas.

Advantages of the Invention

[0013] According to the exhaust gas stabilization device of the present invention, fluctuations in the state of the exhaust gas can be suppressed.

Brief Description of the Drawings

[0014] [Figure 1] FIG. 1 is an adsorption isotherm for CO2 concentration in activated carbon. [Figure 2] FIG. 2 is a schematic diagram for explaining the exhaust gas stabilization device of the present invention. [Figure 3] FIG. 3 is a schematic diagram for explaining another aspect of the exhaust gas stabilization device of the present invention. [Figure 4] FIGS. 4(A), 4(B), and 4(C) are schematic diagrams for explaining another aspect of the exhaust gas stabilization device of the present invention, respectively. [Figure 5] FIGS. 5(A) and 5(B) are schematic diagrams for explaining another aspect of the exhaust gas stabilization device of the present invention, respectively. [Figure 6] FIG. 6 is an adsorption isotherm for pressure in activated carbon at 27°C, 45°C, 60°C, and 140°C. [Figure 7] FIG. 7 is a schematic diagram for explaining the exhaust gas adsorption system of the present invention. [Figure 8]Figure 8 is a graph showing the fluctuations in exhaust gas in Example 1 and Comparative Example 1 (Figure 8(A): gas flow rate, Figure 8(B): CO2 concentration). [Figure 9] Figure 9 is a graph showing the cumulative exhaust gas volume in Example 1 and Comparative Example 1. [Modes for carrying out the invention]

[0015] The embodiments of the present invention will be described in detail below. However, the present invention is not limited to the embodiments described below, and can be implemented with various modifications within the scope of the gist of the invention. Furthermore, in the description of the drawings, the same elements are denoted by the same reference numerals, and redundant explanations are omitted.

[0016] Exhaust gas stabilization device The exhaust gas stabilization device of the present invention is Exhaust gas inflow path, Exhaust gas storage section, Grid-like structure, and Exhaust gas outflow path, It has and The exhaust gas flowing in from the exhaust gas inflow channel flows into the exhaust gas storage section and then flows out through the grid-like structure from the exhaust gas outflow channel.

[0017] According to the exhaust gas stabilization device of the present invention, fluctuations in the state of exhaust gas can be suppressed.

[0018] Figure 1 shows the adsorption isotherm with respect to CO2 concentration when CO2 is adsorbed onto activated carbon as a specific component. In the adsorption isotherm shown in Figure 1, the amount of CO2 adsorbed increases as the CO2 concentration increases. For example, when the CO2 concentration in the exhaust gas changes from 10% to 0%, the amount of CO2 adsorbed decreases, so it is predicted that the adsorbed CO2 will be desorbed. Since the exhaust gas stabilization device of the present invention can suppress fluctuations in the state of the exhaust gas, if the exhaust gas adsorption device is located downstream of the exhaust gas stabilization device, the desorption of adsorbed material can be suppressed, and the decrease in the amount of adsorption can be suppressed.

[0019] Although not limited to theory, exhaust gas flowing in from the exhaust gas inlet channel flows into the exhaust gas storage section and then flows out from the exhaust gas outlet channel through the grid-like structure. In particular, the passage of exhaust gas through the grid-like structure promotes gas diffusion of the exhaust gas in the exhaust gas storage section, thereby suppressing fluctuations in the state of the exhaust gas.

[0020] Figure 2 is a schematic diagram showing one embodiment of the exhaust gas stabilization device of the present invention, but is not limited to this case.

[0021] The exhaust gas stabilization device 100 shown in Figure 2 has an exhaust gas inlet passage 110, an exhaust gas storage section 120, a grid-like structure 130, and an exhaust gas outlet passage 140. The grid-like structure 130 is uniformly arranged at a predetermined position in the exhaust gas storage section 120, parallel to the bottom surface of the exhaust gas storage section 120, and the exhaust gas inlet passage 110 and the exhaust gas outlet passage 140 are inserted from the top of the exhaust gas storage section 120. More specifically, the grid-like structure 130, the exhaust gas inlet passage 110, and the exhaust gas outlet passage 140 are arranged such that exhaust gas flows into the exhaust gas storage section 120 from a position lower than the grid-like structure 130 via the exhaust gas inlet passage 110, and exhaust gas flows out from the exhaust gas outlet passage 140, which is at a position higher than the grid-like structure 130. In the exhaust gas stabilization device 100 shown in Figure 1, exhaust gas flows in from the exhaust gas inlet passage 110, flows into the exhaust gas storage section 120, and then flows out through the grid-like structure 130 via the exhaust gas outlet passage 140. As the exhaust gas passes through the grid-like structure, gas diffusion of the exhaust gas in the exhaust gas storage section is promoted, thereby suppressing fluctuations in the state of the exhaust gas. The exhaust gas stabilization device 100 is not particularly limited, but the exhaust gas inlet passage 110 and / or the exhaust gas outlet passage 140 may be equipped with measuring instruments capable of measuring concentration, gas temperature, pressure, etc. Such measuring instruments can be used to confirm that fluctuations in the state of the exhaust gas that has flowed through the exhaust gas stabilization device 100 are being suppressed.

[0022] In the exhaust gas stabilization device of the present invention, the direction of the exhaust gas flowing from the exhaust gas inflow channel to the exhaust gas storage section and the direction of the exhaust gas flowing from the exhaust gas storage section to the exhaust gas outflow channel may be different directions or the same direction, but from the viewpoint of gas diffusion, different directions are preferred.

[0023] Figures 3 and 4(A) are schematic diagrams showing other embodiments of the exhaust gas stabilization device of the present invention, but are not limited to these cases.

[0024] In the exhaust gas stabilization device 100 shown in Figure 3, the grid-like structure 130 is uniformly arranged at a predetermined position in the exhaust gas storage section 120, perpendicular to the bottom surface of the exhaust gas storage section 120, and the exhaust gas inlet passage 110 and the exhaust gas outlet passage 140 are inserted from the top of the exhaust gas stabilization device 100. More specifically, the exhaust gas storage section 120 is divided into two spaces by the grid-like structure 130, and the grid-like structure 130, the exhaust gas inlet passage 110, and the exhaust gas outlet passage 140 are arranged so that exhaust gas flows into one space of the exhaust gas storage section 120 from the exhaust gas inlet passage 110, and exhaust gas flows out from the exhaust gas outlet passage 140 located in the other space of the exhaust gas storage section 120. In the exhaust gas stabilization device 100 shown in Figure 3, exhaust gas flows downward from the exhaust gas inlet passage 110 into the exhaust gas storage section 120, and exhaust gas flows upward from the exhaust gas storage section 120 into the exhaust gas outlet passage 140. The direction of the exhaust gas flowing from the exhaust gas inlet passage 110 into the exhaust gas storage section 120 and the direction of the exhaust gas flowing from the exhaust gas storage section 120 into the exhaust gas outlet passage 140 are different. In the exhaust gas stabilization device 100 shown in Figure 3, exhaust gas flows in from the exhaust gas inlet passage 110 into the exhaust gas storage section 120, and then flows out through the grid-like structure 130 into the exhaust gas outlet passage 140.

[0025] Furthermore, in the exhaust gas stabilization device 100 shown in Figure 4(A), the exhaust gas inlet passage 110 is inserted from one side of the exhaust gas storage section 120, and the exhaust gas outlet passage 140 is inserted from the side of the exhaust gas storage section 120 opposite to the side into which the exhaust gas inlet passage 110 is inserted. In the exhaust gas stabilization device 100 shown in Figure 4, exhaust gas flows from the exhaust gas inlet passage 110 to the exhaust gas storage section 120 in a rightward direction, and exhaust gas flows from the exhaust gas storage section 120 to the exhaust gas outlet passage 140 in a rightward direction. The direction of the exhaust gas flowing from the exhaust gas inlet passage 110 to the exhaust gas storage section 120 and the direction of the exhaust gas flowing from the exhaust gas storage section 120 to the exhaust gas outlet passage 140 are the same. In the exhaust gas stabilization device 100 shown in Figure 4(A), exhaust gas flows in from the exhaust gas inlet passage 110, flows into the exhaust gas storage section 120, and then flows out through the grid-like structure 130 from the exhaust gas outlet passage 140.

[0026] In the exhaust gas stabilization device of the present invention, from the viewpoint of improving gas diffusion, the exhaust gas inlet passage and / or exhaust gas outlet passage may be bent within the exhaust gas storage section.

[0027] Figure 4(B) is a schematic diagram showing another embodiment of the exhaust gas stabilization device of the present invention, but is not limited to this case.

[0028] In the exhaust gas stabilization device 100 shown in Figure 4(B), the exhaust gas inflow passage 110 is bent towards the upper part of the exhaust gas storage section 120 within the exhaust gas storage section 120. By bending the exhaust gas inflow passage 110, the incoming exhaust gas flows along the wall surface of the exhaust gas storage section 120, improving the gas diffusion properties of the exhaust gas in the exhaust gas storage section 120, thereby further suppressing fluctuations in the state of the exhaust gas.

[0029] In the exhaust gas stabilization device of the present invention, a barrier may be placed between the inlet end of the exhaust gas inlet passage and the grid-like structure from the viewpoint of improving gas diffusion.

[0030] Figure 4(C) is a schematic diagram showing another embodiment of the exhaust gas stabilization device of the present invention, but is not limited to this case.

[0031] In the exhaust gas stabilization device 100 shown in Figure 4(C), a barrier 150 is provided between the inlet end of the exhaust gas inlet passage 110 and the grid-like structure 130. By providing the barrier 150 at the inlet end of the exhaust gas inlet passage 110, the incoming exhaust gas collides with the barrier 150 and diffuses into the exhaust gas storage section 120. This improves the gas diffusion properties of the exhaust gas in the exhaust gas storage section 120, thereby further suppressing fluctuations in the state of the exhaust gas.

[0032] The exhaust gas stabilization device of the present invention may have a plurality of exhaust gas storage sections, and each exhaust gas storage section may be connected to one another via a grid-like structure, from the viewpoint of improving the capacity of the stored exhaust gas.

[0033] Figure 5(A) is a schematic diagram showing another embodiment of the exhaust gas stabilization device of the present invention, but is not limited to this case.

[0034] The exhaust gas stabilization device 100 shown in Figure 5(A) has two exhaust gas storage units 120, which are connected to each other via a grid-like structure 130. Although the exhaust gas stabilization device 100 shown in Figure 5(A) has two exhaust gas storage units 120, it may have three or more exhaust gas storage units 120. By having multiple exhaust gas storage units in this way, the capacity of the exhaust gas storage units can be increased, thereby improving the capacity of the stored exhaust gas. As a result, even when the inflow rate for one cycle is large, as will be explained in detail later, fluctuations in the concentration and inflow rate of the exhaust gas can be suppressed.

[0035] From the viewpoint of improving gas diffusion, the exhaust gas stabilization device of the present invention may have an exhaust gas storage section that includes a frustoconical expansion section, a cylindrical section, and a frustoconical contraction section, and a grid-like structure is arranged in the cylindrical section, so that the exhaust gas that flows into the expansion section flows into the contraction section through the grid-like structure and then flows out from the contraction section.

[0036] Figure 5(B) is a schematic diagram showing another embodiment of the exhaust gas stabilization device of the present invention, but is not limited to this case.

[0037] The exhaust gas storage section 120 of the exhaust gas stabilization device 100 shown in Figure 5(B) has a frustoconical expansion section, a cylindrical section, and a frustoconical contraction section, and a grid-like structure 130 is arranged in the cylindrical section. With this structure, exhaust gas flowing into the expansion section flows through the grid-like structure into the contraction section and then flows out from the contraction section. Because the exhaust gas storage section 120 of the exhaust gas stabilization device 100 has this structure, the exhaust gas flowing in from the exhaust gas inflow passage 110 collides with the wall surface of the exhaust gas storage section 120, improving the gas diffusion of the exhaust gas within the exhaust gas storage section 120, thereby further suppressing fluctuations in the state of the exhaust gas.

[0038] Exhaust gas stabilization device; components The following describes the various components of the exhaust gas stabilization system.

[0039] <Lattice structure> The exhaust gas stabilization device of the present invention has a grid-like structure. The grid-like structure is not particularly limited, but from the viewpoint of heat uniformity, it is preferably made of a material having high thermal conductivity, and specifically, it may be made of at least one metallic material selected from copper, aluminum, brass, nickel, iron, and stainless steel. When the grid-like structure is made of a material having high thermal conductivity, the exchange of thermal energy becomes possible, and heat diffusion is promoted. As a result, not only fluctuations in the concentration of specific components but also fluctuations in temperature can be suppressed.

[0040] The thermal conductivity of the grid structure is not particularly limited, but may be 5 W / m·K or higher, 10 W / m·K or higher, 100 W / m·K or higher, or 200 W / m·K or higher, or it may be 400 W / m·K or lower, 300 W / m·K or lower, or 250 W / m·K or lower. The thermal conductivity of the grid structure is determined by processing the grid structure to a predetermined size (Φ10 mm × thickness 1 mm) and using the flash method.

[0041] Figure 6 shows the adsorption isotherms with respect to pressure when CO2, a specific component, is adsorbed onto activated carbon at 27°C, 60°C, 45°C, and 140°C. The adsorption isotherms shown in Figure 6 show that the amount of CO2 adsorbed increases as the pressure increases, and also increases as the temperature decreases. For example, when adsorbing CO2 contained in exhaust gas, when the temperature changes from 27°C to 60°C, the amount of CO2 adsorbed decreases, so it is expected that the adsorbed CO2 will be desorbed. By circulating exhaust gas through an exhaust gas stabilization device having a lattice structure made of a material with high thermal conductivity, not only fluctuations in the concentration of specific components but also temperature fluctuations can be suppressed. Therefore, if the exhaust gas adsorption device is located downstream of the exhaust gas stabilization device, the desorption of adsorbed substances due to concentration and temperature fluctuations can be suppressed, and the decrease in the amount of adsorption can be suppressed.

[0042] In the exhaust gas stabilization device of the present invention, the lattice structure is not particularly limited, but may be a metal honeycomb, specifically a metal honeycomb formed by overlapping and winding metal corrugated sheets and flat sheets. By using a metal honeycomb for the lattice structure, not only can gas diffusion be promoted, but because the metal honeycomb has high thermal conductivity and a certain heat capacity, fluctuations in exhaust gas concentration and temperature can be further suppressed.

[0043] (Corrugated sheets and flat sheets) The corrugated sheets and flat sheets are not particularly limited, but they may or may not have openings. From the viewpoint of improving gas diffusion, it is preferable that the metal corrugated sheets and flat sheets constituting the metal honeycomb have openings.

[0044] The openings in the corrugated and flat sheets are not particularly limited, and all of them may be the same size or of different sizes. From the viewpoint of improving the exhaust gas purification efficiency, it is preferable that the openings in the metal flat sheets be larger than those in the metal corrugated sheets.

[0045] The openings in the corrugated sheet may be entirely or partially circular, or non-circular, such as polygonal. The equivalent diameter of the openings in the corrugated sheet may be 2.0 mm or more, 2.5 mm or more, 3.0 mm or more, 4.0 mm or more, 5.0 mm or more, or 7.0 mm or more, and may be 20 mm or less, 15 mm or less, 10 mm or less, 7.0 mm or less, 5.0 mm or less, or 4.0 mm or less. The equivalent diameter refers to the diameter of a perfect circle having an outer circumference equal to the outer circumference of the surface.

[0046] The openings in the plate may be entirely or partially circular or elliptical, or non-circular, such as polygonal. The equivalent diameter of the openings in the plate may be 3.0 mm or more, 3.5 mm or more, 5.0 mm or more, 8.0 mm or more, 10 mm or more, or 12 mm or more, and may be 25 mm or less, 20 mm or less, 15 mm or less, 10 mm or less, 7.0 mm or less, or 5.0 mm or less.

[0047] The pitch (distance between the centers of adjacent openings) of adjacent openings in the axial direction of a cylindrical honeycomb structure may be 5.0 mm or more, 6.0 mm or more, 8.0 mm or more, 10 mm or more, 12 mm or more, or 15 mm or more for corrugated and flat sheets, respectively, and may also be 25 mm or less, 20 mm or less, 15 mm or less, 10 mm or less, 7.0 mm or less, or 5.0 mm or less. In this case, the opening pitch for corrugated sheets refers to the pitch when the corrugated sheet is stretched flat.

[0048] The pitch of adjacent openings in the circumferential direction of the cylindrical honeycomb body may be 5.0 mm or more, 6.0 mm or more, 8.0 mm or more, 10 mm or more, 12 mm or more, or 15 mm or more for the openings of the corrugated sheet and the flat sheet, respectively, or it may be 35 mm or less, 25 mm or less, 20 mm or less, 15 mm or less, 10 mm or less, 7.0 mm or less, or 5.0 mm or less. In this case, the opening pitch of the corrugated sheet refers to the pitch when the corrugated sheet is stretched flat.

[0049] The perforation ratio of the corrugated sheet and the flat sheet may be 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, or 60% or more, respectively, and may also be 80% or less, 70% or less, 60% or less, 50% or less, 40% or less, or 30% or less.

[0050] The openings in the corrugated and flat sheets may be evenly distributed throughout the entire circumferential and axial direction of the tubular honeycomb body, or they may be concentrated in certain locations. For example, the openings in the corrugated and flat sheets may not be present at their ends.

[0051] The openings in corrugated and flat sheets are not particularly limited, but can be created by punching metal foil to achieve a desired porosity using a punching machine or the like. The shape of the openings is not particularly limited.

[0052] The shape of the corrugated sheet is not particularly limited, but it may be formed in a wave shape, or it may be formed in an omega wave shape or a zigzag shape.

[0053] The thickness of the corrugated sheet and the flat sheet is not particularly limited, but may be 20 μm or more, 40 μm or more, 80 μm or more, or 100 μm or more, respectively, or 500 μm or less, 300 μm or less, 200 μm or less, 100 μm or less, or 80 μm or less.

[0054] <Exhaust gas storage section> The exhaust gas stabilization device of the present invention has an exhaust gas storage section.

[0055] The shape of the exhaust gas storage section is not particularly limited and may be cylindrical or a column with a polygonal base. If the shape of the exhaust gas storage section is cylindrical or a column with a polygonal base, the height of the exhaust gas storage section may be 0.2 times or more, 0.5 times or more, 1.0 times or more, 2.0 times or more, or 5.0 times or more, and may be 10.0 times or less, 8.0 times or less, 6.0 times or less, 4.0 times or less, 2.0 times or less, or 1.0 times or less, relative to the equivalent diameter of the base of the exhaust gas storage section. The equivalent diameter refers to the diameter of a perfect circle having an outer circumference equal to the outer circumference of that surface.

[0056] The capacity of the exhaust gas storage section is not particularly limited. When stabilizing exhaust gas with periodically fluctuating inflow rates, it is preferable that the exhaust gas storage section has a capacity equal to or greater than the inflow rate of one cycle of the exhaust gas. By having a capacity equal to or greater than the inflow rate of one cycle of the exhaust gas, fluctuations can be leveled within the exhaust gas storage section, thereby suppressing fluctuations in the concentration and inflow rate of the exhaust gas.

[0057] <Exhaust gas inflow path and exhaust gas outflow path> The exhaust gas stabilization device of the present invention has an exhaust gas inlet passage and an exhaust gas outlet passage. The shape of the exhaust gas inlet passage and the exhaust gas outlet passage is not particularly limited and may be a straight pipe or a curved pipe having a bend.

[0058] <Exhaust gas> Exhaust gases are not particularly limited, but examples include exhaust gases emitted from factories, exhaust gases emitted from combustion such as burners, and exhaust gases emitted from paint booths, but are not limited to these cases.

[0059] The exhaust gas is not particularly limited, but may be a mixed gas containing two or more components. The exhaust gas may contain, for example, oxygen, nitrogen, argon, carbon dioxide, carbon monoxide, hydrogen, alkanes, alkenes, alkynes, volatile organic compounds (VOCs), etc.

[0060] Exhaust gas adsorption system The exhaust gas adsorption system of the present invention is The system includes the exhaust gas stabilization device described above, and an exhaust gas adsorption device located downstream of the exhaust gas stabilization device to adsorb specific components in the exhaust gas.

[0061] According to the exhaust gas adsorption system of the present invention, it is possible to suppress the decrease in the amount of specific components adsorbed in the exhaust gas.

[0062] Figure 7 is a schematic diagram showing one embodiment of the exhaust gas adsorption system of the present invention, but is not limited to this case.

[0063] The exhaust gas adsorption system 300 includes an exhaust gas stabilization device 100 and an exhaust gas adsorption device 200 located downstream of the exhaust gas stabilization device. As described above, since fluctuations in the state of the exhaust gas that has passed through the exhaust gas stabilization device 100 are suppressed, the desorption of specific adsorbed components due to fluctuations in the state of the exhaust gas is suppressed in the exhaust gas adsorption device 200, thereby suppressing a decrease in the amount of specific components adsorbed. The exhaust gas adsorption system is not particularly limited, but the exhaust gas stabilization device 100 and the exhaust gas adsorption device 200 may be directly connected, or another device may be included between the exhaust gas stabilization device 100 and the exhaust gas adsorption device 200.

[0064] <Exhaust gas adsorption device> The exhaust gas adsorption device is not particularly limited and may be an exhaust gas adsorption device having a solid adsorbent. The solid adsorbent may be, for example, a material having a porous structure, and specifically, examples include activated carbon and zeolite, but is not limited to this case.

[0065] Exhaust gas adsorption devices can be applied to the adsorption of various specific components contained in exhaust gas. Examples of specific components adsorbed by exhaust gas adsorption devices include, but are not limited to, oxygen, nitrogen, argon, carbon dioxide, carbon monoxide, hydrogen, alkanes, alkenes, and alkynes.

[0066] Exhaust gas adsorption method The exhaust gas adsorption method of the present invention is, This includes passing exhaust gas through the exhaust gas adsorption system described above to adsorb the specific components of the exhaust gas.

[0067] According to the exhaust gas adsorption method of the present invention, specific components in exhaust gas can be efficiently adsorbed.

[0068] The exhaust gas adsorption method of the present invention is not particularly limited, but may further include recovering specific adsorbed components. When recovering specific components, the adsorbed components can be recovered by controlling pressure, temperature, humidity, etc.

[0069] The exhaust gas adsorption method can be used for any application. For example, one method may involve passing exhaust gas emitted from a factory through an exhaust gas adsorption system to adsorb specific components from the exhaust gas. Alternatively, one method may involve passing exhaust gas emitted from an internal combustion engine through an exhaust gas adsorption system to adsorb specific components from the exhaust gas. Here, the internal combustion engine is not particularly limited, but any known internal combustion engine can be used as appropriate. Examples include gasoline engines, motorcycle engines, diesel engines, and lean-burn engines with low fuel consumption. [Examples]

[0070] The present invention will be described in more detail with reference to the following embodiments, but the scope of the present invention is not limited to these embodiments. In this embodiment, the invention was verified using an exhaust gas stabilization device having the structure shown in Figure 2.

[0071] Example 1: When an exhaust gas stabilization device is provided. A test was conducted to adsorb CO2 as a specific component in exhaust gas using an exhaust gas adsorption system equipped with an exhaust gas stabilization device and an exhaust gas adsorption device containing activated carbon as an exhaust gas adsorbent, as shown in Figure 2. Here, the capacity of the exhaust gas storage section of the exhaust gas stabilization device is 4 m³. 3As shown in Figures 8(A) and 8(B), the exhaust gas flow rate and carbon dioxide (CO2) concentration fluctuated periodically. Specifically, the exhaust gas flow rate varied depending on the opening and the input flow rate variation (0.5 m 3 / min~2.5m 3 Considering the gas flow rate ( / min), the total gas flow rate over 120 seconds is approximately 4m 3 The spatial velocity was set to 2 m. 3 The value was set to / min. From the exhaust gas cumulative volume in Figure 9, the amount of exhaust gas flowing in for one cycle in this test was 4 m 3 That was the case.

[0072] Table 1 shows the CO2 adsorption and desorption amounts at CO2 concentrations (a), (b), and (c) in Figures 8(A) and 8(B), respectively. Here, the CO2 adsorption amount was estimated from the adsorption isotherm shown in Figure 1, and the CO2 desorption amount was defined as the difference between the adsorption amount at the highest CO2 concentration in the exhaust gas passing through the exhaust gas adsorption device and the adsorption amount at the CO2 concentration at that time. In this test, since an exhaust gas stabilization device was in place, the fluctuations in CO2 concentration were leveled out as described later, and there were no fluctuations in CO2 concentration, so the desorption amount was 0 g / g.

[0073] [Table 1]

[0074] The exhaust gas stabilization device has a grid-like structure, and the exhaust gas flowing in from the exhaust gas inlet channel flows into the exhaust gas storage section and then flows out from the exhaust gas outlet channel via the grid-like structure, thereby suppressing fluctuations in the concentration of specific components in the exhaust gas. Furthermore, the capacity of the exhaust gas storage section of the exhaust gas stabilization device is 4 m³ 3 Therefore, the inflow rate for one cycle of periodically fluctuating exhaust gas exceeds the capacity of the exhaust gas storage unit, further suppressing fluctuations in CO2 concentration and gas inflow rate. As a result, the CO2 concentration flowing into the exhaust gas adsorption device is leveled out, and the average concentration becomes 6.9%. Consequently, a constant amount of CO2 can be adsorbed without desorption, thereby improving the adsorption efficiency of CO2 as a specific component.

[0075] 《Comparative Example 1: Case without Exhaust Gas Stabilization Device》 A test was conducted to adsorb CO2 as a specific component in exhaust gas using only an exhaust gas adsorption device containing activated carbon as an exhaust gas adsorbent, that is, without using an exhaust gas stabilization device. Here, as in Example 1, the inflow rate and the carbon dioxide (CO2) concentration of the exhaust gas fluctuated periodically as shown in FIGS. 8(A) and 8(B). Specifically, the exhaust gas flow rate was considered in terms of the opening degree and the input flow rate variation (0.5 m 3 / min to 2.5 m 3 / min), and the total gas flow rate for 120 seconds was set to approximately 4 m 3 . The space velocity was 2 m 3 / min. As shown in FIG. 9, from the integrated amount of the exhaust gas, the inflow amount of the exhaust gas for one cycle in this test was 4 m 3 .

[0076] Table 2 shows the CO2 adsorption amount and desorption amount at (a), (b), and (c) in FIGS. 8(A) and 8(B). Here, the CO2 adsorption amount was estimated from the adsorption isotherm shown in FIG. 1, and the CO2 desorption amount was defined as the difference between the adsorption amount at the highest CO2 concentration among the exhaust gases passing through the exhaust gas adsorption device and the adsorption amount at that time point of the CO2 concentration.

[0077]

Table 2

[0078] In the case of (a) in FIGS. 8(A) and 8(B), since the CO2 concentration was high, the CO2 adsorption amount was high. However, in the cases of (b) and (c), since the CO2 concentration was low, the CO2 adsorption amount also became low, and furthermore, the CO2 adsorbed in (a) was desorbed. As a result, the adsorption efficiency of CO2 as a specific component decreased.

[0079] Although the preferred embodiments of the exhaust gas stabilization device, exhaust gas adsorption system, and exhaust gas adsorption method of the present invention have been described, those skilled in the art understand that changes can be made without departing from the scope of the claims.

Explanation of Signs

[0080] 100 Exhaust gas stabilization device 110 Exhaust gas inflow path 120 Exhaust gas storage section 130 Lattice structure 140 Exhaust gas outflow path 150 barriers 200 Exhaust gas adsorption device 300 Exhaust Gas Adsorption System

Claims

1. Exhaust gas inflow path, Exhaust gas storage section, Grid-like structure, and Exhaust gas outflow path, It has and The exhaust gas flowing in from the exhaust gas inflow channel flows into the exhaust gas storage section and then flows out through the grid-like structure from the exhaust gas outflow channel. Exhaust gas stabilization device.

2. The exhaust gas stabilization device according to claim 1, wherein the lattice structure is made of at least one metallic material selected from copper, aluminum, brass, nickel, iron, and stainless steel.

3. The exhaust gas stabilization device according to claim 1, wherein the lattice structure is a metal honeycomb.

4. The exhaust gas stabilization device according to claim 1, wherein the direction of exhaust gas flowing from the exhaust gas inflow channel to the exhaust gas storage section and the direction of exhaust gas flowing from the exhaust gas storage section to the exhaust gas outflow channel are different.

5. The exhaust gas stabilization device according to claim 1, wherein the direction of exhaust gas flowing from the exhaust gas inflow channel to the exhaust gas storage section and the direction of exhaust gas flowing from the exhaust gas storage section to the exhaust gas outflow channel are the same.

6. The exhaust gas stabilization device according to claim 1, wherein the exhaust gas inflow channel and / or the exhaust gas outflow channel are bent within the exhaust gas storage section.

7. The exhaust gas stabilization device according to claim 5, wherein a barrier is provided between the inlet end of the exhaust gas inlet passage and the grid-like structure.

8. An exhaust gas stabilization device for exhaust gas whose inflow rate fluctuates periodically, wherein the exhaust gas storage unit has a capacity equal to or greater than the inflow rate of one cycle of the exhaust gas whose inflow rate fluctuates periodically, according to claim 1.

9. An exhaust gas adsorption system comprising an exhaust gas stabilization device according to any one of claims 1 to 8, and an exhaust gas adsorption device disposed downstream of the exhaust gas stabilization device for adsorbing specific components in the exhaust gas.

10. An exhaust gas adsorption method comprising passing exhaust gas through the exhaust gas adsorption system described in claim 9 and adsorbing the specific components of the exhaust gas.

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