JP2021187717A - Honeycomb structure and gas recovery device - Google Patents

Abstract

To keep proper strength of a honeycomb structure while properly increasing an amount of gas adsorption.SOLUTION: The present invention discloses a honeycomb structure 10 for gas adsorption having a wall part including a plurality of ceramic particles. The ceramic particles contain at least one of zeolite, silica, and cerium oxide as a component. The content of the ceramic particles in the wall part is 70 vol.% or more. The wall part contains a carbonaceous component of 0.5 mass% or more.SELECTED DRAWING: Figure 1

Description

The present invention relates to a honeycomb structure and a gas recovery device including the honeycomb structure.

Patent Document 1 describes a specific gas by adsorbing a specific gas by a gas separation technique such as pressure swing adsorption (hereinafter, also referred to as “PSA”) or temperature swing adsorption (hereinafter, also referred to as “TSA”). The gas recovery device that separates and recovers the gas is described. The gas recovery device uses a self-supporting structure having an active material, and a honeycomb-shaped monolith substrate is exemplified as the self-supporting structure.

International Publication No. 2018/118360

In the gas recovery device of Patent Document 1 and the like, further performance of the gas recovery device by increasing the amount of gas adsorbed while appropriately maintaining the strength of the honeycomb-shaped monolith substrate (hereinafter, also referred to as “honeycomb structure”). Improvement is required. The present invention has been made in view of these circumstances, and an object of the present invention is to provide a honeycomb structure capable of suitably increasing the amount of gas adsorbed while appropriately maintaining the strength of the honeycomb structure.

The honeycomb structure of the present invention for solving the above-mentioned problems is a honeycomb structure for gas adsorption including a wall portion containing a plurality of ceramic particles, and the ceramic particles are zeolite, silica, and cerium oxidation. It is said that at least one of the substances is contained in the constituent components, the content of the ceramic particles in the wall portion is 70% by volume or more, and the wall portion contains 0.5% by mass or more of the carbonaceous component. It is a summary.

According to the above configuration, since zeolite, silica, and cerium oxide are materials having a relatively large surface area, it becomes easy to increase the amount of gas adsorbed. Further, when the content of the ceramic particles is 70% by volume or more, the proportion of the ceramic particles contributing to the adsorption in the wall portion becomes large, so that it becomes easy to increase the gas adsorption amount and the wall portion. The strength can be improved. Furthermore, since the carbonaceous component has a relatively large surface area, it can also be used as a gas adsorbent. Therefore, it is possible to suitably increase the amount of gas adsorbed while appropriately maintaining the strength of the honeycomb structure.

Regarding the honeycomb structure of the present invention, it is preferable that the wall portion contains 1% by mass or more of the carbonaceous component. According to this configuration, the strength of the wall portion is further improved, and it can be utilized as a gas adsorbent.

With respect to the honeycomb structure of the present invention, it is preferable that the carbonaceous component is a residue of an organic component heated in the manufacturing process of the honeycomb structure. According to this configuration, the organic component contained in the organic binder used as the binder and the dispersion medium can be utilized as the carbonaceous component. In addition, the carbonaceous component can be more uniformly dispersed throughout the honeycomb structure.

In the honeycomb structure of the present invention, it is preferable that the plurality of ceramic particles are bonded to each other via the carbonaceous component. According to this configuration, the strength of the honeycomb structure can be improved.

It is preferable that the gas recovery device includes the honeycomb structure. According to this configuration, it is possible to obtain a gas recovery device that exhibits the effect of the honeycomb structure.

According to the honeycomb structure and the gas recovery device of the present invention, it is possible to suitably increase the amount of gas adsorbed while appropriately maintaining the strength of the honeycomb structure.

Perspective view of the honeycomb structure. Schematic diagram of the gas recovery device.

An embodiment of the honeycomb structure will be described.
As shown in FIG. 1, the honeycomb structure 10 of the present embodiment has a cylindrical peripheral wall 11 and a honeycomb-shaped partition wall 12 having a cross section that divides the inside of the peripheral wall 11 into a plurality of cells S extending in the axial direction of the peripheral wall 11. And have. The peripheral wall 11 and the partition wall 12 form a wall portion of the honeycomb structure 10. The wall portion of the honeycomb structure 10 contains a plurality of ceramic particles.

The cell structure of the honeycomb structure 10 is not particularly limited, but for example, the wall thickness of the partition wall 12 is 0.2 to 0.5 mm, and the cell density is 93 to 248 cells (600 to 1600 cpsi) per ^{1 cm 2.} ) Can be a cell structure. In addition, cpsi means the number of cells per square inch.

The geometric surface area per unit volume of the honeycomb structure 10 (hereinafter, also referred to as “GSA”) is not particularly limited, but is preferably ^{20 to} 45 cm 2 / cm ^3. GSA is more preferably 25~45cm ² / cm ^3, further preferably 30~45cm ² / cm ^3. Here, GSA means a value obtained by dividing the total surface area of the partition wall 12 of the honeycomb structure 10 on the appearance by the volume of the honeycomb structure 10.

The aperture ratio of the honeycomb structure 10 is not particularly limited, but is preferably 30 to 45%. The aperture ratio of the honeycomb structure 10 is more preferably 35 to 45%. Here, the aperture ratio of the honeycomb structure 10 is the ratio of the area of the space derived from the plurality of cells S to the cross-sectional area of the honeycomb structure 10 in the cross section orthogonal to the axial direction of the honeycomb structure 10. It shall mean.

The GSA and aperture ratio of the honeycomb structure 10 can be adjusted by changing the cell structure of the honeycomb structure 10.
The BET specific surface area of the wall portion of the honeycomb structure 10 is not particularly limited, ^{but is preferably 100 m 2} / g or more. BET specific surface area of the wall portion of the honeycomb structure 10, more preferably from 100~1000m ² / g, more preferably from 150~600m ² / g. Here, the BET specific surface area means the surface area per unit mass of the wall portion measured by _{N 2 adsorption by the BET method.}

Pore may be formed between ceramic particles on the wall portion of the honeycomb structure 10. The porosity of the wall portion is not particularly limited, but is preferably 50% or less, and more preferably 45% or less. The porosity of the wall portion is preferably 30% or more, more preferably 35% or more. The porosity of the wall portion can be measured by a mercury intrusion method (according to JISR1655: 2003). As the conditions of the mercury intrusion method, a Micromeritics automatic porosimeter Autopore III9405 manufactured by Shimadzu Corporation is used, and the measurement range is 0.006 to 500 μm. At 100 to 500 μm, it is measured at every pressure of 0.1 psia, and at 0.006 to 100 μm, it is measured at every pressure of 0.25 psia. At that time, the contact angle is 130 ° and the surface tension is 485 mN / m.

The BET specific surface area and porosity of the honeycomb structure 10 can be adjusted by changing the type and composition of materials such as ceramic particles constituting the wall portion of the honeycomb structure 10.

The ceramic particles contained in the wall portion of the honeycomb structure 10 contain at least one of zeolite, silica, and cerium oxide as a constituent component. Since zeolite, silica, and cerium oxide are materials having a relatively large surface area, the amount of gas adsorbed can be increased.

Here, the fact that at least one of zeolite, silica, and cerium oxide is contained in the constituents means that the wall portion of the honeycomb structure 10 is a material of any one of zeolite, silica, and cerium oxide. It shall be meant to include particles composed of. Further, among the primary particles of zeolite, silica, and cerium oxide, secondary particles in which two or more kinds are aggregated may be contained.

Further, as the zeolite, DDR type, CHA type, LTA type and AFI type are preferable.
The average particle size of the ceramic particles is not particularly limited, but is preferably 0.1 to 50 μm, more preferably 0.5 to 30 μm.

The average particle size of the ceramic particles can be measured by observing the wall portion of the honeycomb structure 10 using a known electron microscope. Further, in the raw material stage, it can be measured by a laser diffraction type particle size distribution meter.

The content of the ceramic particles in the wall portion is 70% by volume or more. The content of the ceramic particles is preferably 75% by volume or more. The content of the ceramic particles is preferably 95% by volume or less, more preferably 90% by volume or less.

Here, the content of the ceramic particles is assumed to mean the ratio (volume%) of the ceramic particles to the base material portion excluding the pores in the wall portion.
The wall portion of the honeycomb structure 10 contains a carbonaceous component as a constituent component thereof. Further, it may contain other components other than the ceramic particles and the carbonaceous component. Examples of other components include inorganic binders and inorganic fibers.

Examples of the inorganic binder include alumina sol, silica sol, titania sol, water glass, sepiolite, attapulsite, bentonite, and boehmite. These may be used alone or in combination of two or more.

The content of the inorganic binder in the wall portion is not particularly limited, but is preferably 1% by volume or more, and more preferably 3% by volume or more, for example. The content of the inorganic binder is preferably 25% by volume or less, more preferably 20% by volume or less.

Examples of the inorganic fiber include silica-alumina fiber, mullite fiber, silica fiber, alumina fiber, zirconia fiber, glass fiber and the like. These may be used alone or in combination of two or more.

The content of the inorganic fiber in the wall portion is not particularly limited, but is preferably 1% by volume or more, and more preferably 3% by volume or more, for example. The content of the inorganic fiber is preferably 25% by volume or less, more preferably 20% by volume or less.

Examples of the carbonaceous component include a residue of a heated organic component in the manufacturing process of the honeycomb structure 10 described later. The organic component is contained in the organic binder and the dispersion medium used as the binder. Here, the carbonaceous component means a material containing 50% by mass or more of carbon as a main component. Since the carbonaceous component has a relatively large surface area, the carbonaceous component can also be used as a gas adsorbent.

The content of the carbonaceous component in the wall portion is not particularly limited, but is preferably 1% by mass or more, and more preferably 3% by mass or more, for example. The content of the carbonaceous component is preferably 25% by mass or less, more preferably 20% by mass or less.

The content of the carbonaceous component is determined by crushing a part of the honeycomb structure into a powdery sample and measuring the weight of the powdery sample in the range of 300 ° C. to 600 ° C. by thermogravimetric analysis (TG). It can be calculated from the carbonaceous component). When obtaining a powdery sample, prepare from the inside (inside 50% diameter with respect to diameter) and outside (outside 50% diameter with respect to diameter) of the honeycomb structure, respectively, and reduce the weight in each measurement. It is preferable to average the minutes (= carbonaceous component).

In the wall portion of the honeycomb structure 10, the ceramic particles may be configured to maintain the shapes of the peripheral wall 11 and the partition wall 12 by the binder existing between the particles. In other words, a plurality of ceramic particles may be bonded to each other via a binder. Since the plurality of ceramic particles are bonded to each other via a binder, the strength of the honeycomb structure 10 can be improved. Further, the inorganic fiber functions as a reinforcing material for the peripheral wall 11 and the partition wall 12 of the honeycomb structure, and the carbonaceous component functions as a filler in the peripheral wall 11 and the partition wall 12, respectively, thereby improving the strength of the honeycomb structure 10. can.

Next, an example of the method for manufacturing the honeycomb structure 10 will be described.
The honeycomb structure 10 is manufactured by going through the molding step, the drying step, and the firing step described below in this order.

(Molding process)
The molding step is a step of molding a mixture containing ceramic particles and a dispersion medium containing water as a main component to obtain a molded product.

First, a mixture containing ceramic particles and a dispersion medium containing water as a main component is prepared. The dispersion medium containing water as a main component is a dispersion medium consisting only of water or a dispersion medium consisting of 50% by volume or more of water and an organic solvent. Examples of the organic solvent include alcohols such as benzene and methanol. Further, the dispersion medium may contain only one of the above-mentioned organic solvents, or may contain two or more of them.

The content of the dispersion medium in the mixture is preferably in the range of 10 to 50% by mass.
Further, the mixture may contain other components. Examples of other components include inorganic binders, inorganic fibers, organic binders, molding aids, plasticizers, dispersants, and lubricants. The inorganic binder and the inorganic fiber are the same as those described in the description of the honeycomb structure 10.

Examples of the organic binder include methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, polyethylene glycol, phenol resin, and epoxy resin. These may be used alone or in combination of two or more.

Examples of the molding aid include ethylene glycol, dextrin, fatty acid, fatty acid soap, and polyalcohol.
Examples of the plasticizer include polyoxyalkylene compounds such as polyoxyethylene alkyl ether and polyoxypropylene alkyl ether.

Examples of the dispersant include sorbitan fatty acid ester.
Examples of the lubricant include glycerin.
Next, using the mixture having the above composition, a molded body having the same shape as the honeycomb structure 10 shown in FIG. 1, that is, a tubular peripheral wall 11, and a plurality of cells S extending inside the peripheral wall 11 in the axial direction of the peripheral wall 11. A molded body having a shape including the honeycomb-shaped partition wall 12 having a cross-section divided into the above is molded. The molded body can be molded by, for example, extrusion molding.

(Drying process)
The drying step is a step of obtaining a dried body from which the dispersion medium has been removed by drying the molded body obtained by the molding step using a dryer. As the dryer, for example, a known electric dryer or microwave dryer can be used.

(Baking process)
The firing step is a step of firing the dried body obtained by the drying step to obtain the honeycomb structure 10. The firing temperature in the firing step is preferably in the range of, for example, 300 to 600 ° C, more preferably in the range of 300 to 500 ° C. The firing atmosphere in the firing step is not particularly limited, and may be an atmospheric atmosphere or a reducing atmosphere. The reducing atmosphere may be a nitrogen atmosphere or an argon atmosphere.

The honeycomb structure 10 is obtained by going through the above-mentioned molding step, drying step, and firing step.
The honeycomb structure 10 is used as an adsorbent used in a gas recovery device.

Hereinafter, a pressure swing adsorption device (hereinafter, also referred to as “PSA device”) as a gas recovery device will be described.
As shown in FIG. 2, the PSA device 20 includes a pressure applying device 21, a gas adsorption tank 22, and a gas recovery tank 23. Two gas adsorption tanks 22 are provided. The honeycomb structure 10 of the present embodiment is arranged inside each gas adsorption tank 22. The pressure applying device 21, each gas adsorption tank 22, and the gas recovery tank 23 are connected by a pipe 24.

When recovering the gas using the PSA device 20, first, the gas whose pressure has been increased by the pressure applying device 21 is also referred to as one of the two gas adsorption tanks 22 (hereinafter, also referred to as “first gas adsorption tank 22a”). ), And a specific gas is adsorbed on the honeycomb structure 10 in the first gas adsorption tank 22a. When the honeycomb structure 10 in the first gas adsorption tank 22a reaches a predetermined gas adsorption amount, the pressure of the first gas adsorption tank 22a is lowered to desorb the gas adsorbed on the honeycomb structure 10 and recover the gas. Collect in tank 23. At that time, the gas whose pressure has been increased by the pressure applying device 21 is supplied to the other of the two gas adsorption tanks 22 (hereinafter, also referred to as “second gas adsorption tank 22b”), and is contained in the second gas adsorption tank 22b. A specific gas is adsorbed on the honeycomb structure 10. When the honeycomb structure 10 in the second gas adsorption tank 22b reaches a predetermined gas adsorption amount, the pressure of the second gas adsorption tank 22b is lowered to desorb the gas adsorbed on the honeycomb structure 10 to recover the gas. Collect in tank 23.

The supply of gas from the pressure applying device 21 to each gas adsorption tank 22 and the recovery of gas from each gas adsorption tank 22 to the gas recovery tank 23 are performed by using an on-off valve (not shown) provided in the pipe 24. , The flow path of the pipe 24 is switched.

By repeating the above operation, the predetermined gas can be recovered in the gas recovery tank 23. The gas to be recovered in the gas recovery tank 23 is not particularly limited, and examples thereof include oxygen, nitrogen, carbon dioxide, and water. The gas recovered in the gas recovery tank 23 may be a gas adsorbed on the honeycomb structure 10, or when a specific gas is adsorbed on the honeycomb structure 10, the gas is not adsorbed on the honeycomb structure 10. It may be a gas that has passed through.

In the case of the TSA device, the pressure applying device 21 in the PSA device is replaced with a blower, a heater is attached around the gas adsorption tank 22 in the PSA device, and the honeycomb structure arranged in the gas adsorption tank 22 is heated by the heater. By raising the temperature, the gas adsorbed on the honeycomb structure is desorbed and recovered in the gas recovery tank 23.

The operation and effect of this embodiment will be described.
(1) A honeycomb structure for gas adsorption including a wall portion containing a plurality of ceramic particles, wherein the ceramic particles contain at least one of zeolite, silica, and cerium oxide as a constituent, and the wall portion. The content of the ceramic particles in the above is 70% by volume or more, and the wall portion contains 0.5% by mass or more of a carbonaceous component.

Since zeolite, silica, and cerium oxide are materials having a relatively large surface area, it becomes easy to increase the amount of gas adsorbed. Further, when the content of the ceramic particles is 70% by volume or more, the proportion of the ceramic particles contributing to the adsorption in the wall portion becomes large, so that it becomes easy to increase the gas adsorption amount and the strength of the wall portion. Can be improved. Furthermore, since the carbonaceous component has a relatively large surface area, it can also be used as a gas adsorbent. Therefore, it is possible to suitably increase the amount of gas adsorbed while appropriately maintaining the strength of the honeycomb structure.

(2) The wall portion contains 1% by mass or more of a carbonaceous component. Therefore, the strength of the wall portion is further improved, and it can be utilized as a gas adsorbent.
(3) The carbonaceous component is an organic residue heated in the manufacturing process of the honeycomb structure. The organic content contained in the organic binder or dispersion medium used as the binder can be utilized as the carbonaceous component. In addition, the carbonaceous component can be more uniformly dispersed throughout the honeycomb structure.

(4) A plurality of ceramic particles are bonded to each other via a carbonaceous component. Therefore, the strength of the honeycomb structure can be improved.
(5) A honeycomb structure for gas adsorption having a wall portion containing a plurality of ceramic particles, having a geometric surface area (GSA) of 20 to 45 ^{cm 2} / cm 3 per unit volume and an aperture ratio of ^{20 to 45 cm 2 / cm 3.} When it is 30 to 45%, the area of the wall portion required for gas adsorption can be relatively increased, and the volume of the wall portion can be appropriately secured to maintain the strength of the honeycomb structure. Further, when the BET specific surface area of the wall portion is 100 m ² / g or more, the gas adsorption rate can be improved and the gas adsorption amount can be improved. Therefore, it is possible to suitably increase the amount of gas adsorbed while appropriately maintaining the strength of the honeycomb structure.

(6) The porosity of the wall portion is 50% or less. The proportion of pores in the wall can be made relatively small, and the proportion of ceramic particles in the wall that contribute to adsorption can be made relatively large. Therefore, it becomes easy to increase the amount of gas adsorbed. Further, the strength of the wall portion can be improved. Therefore, it becomes easy to maintain the strength of the honeycomb structure.

This embodiment can be modified and implemented as follows. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
-In the present embodiment, the honeycomb structure has a cylindrical peripheral wall, but the present invention is not limited to this embodiment. The peripheral wall of the honeycomb structure may have a square cylinder shape, and the cross section may have an elliptical shape, an oval shape, or the like.

-In the present embodiment, the wall portion of the honeycomb structure is composed of a peripheral wall and a partition wall, but the present invention is not limited to this embodiment. The wall portion of the honeycomb structure is composed of only the partition wall, and the peripheral wall may be composed of a material different from that of the partition wall.

-In the present embodiment, the carbonaceous component contained in the wall portion is derived from the organic residue heated in the manufacturing process of the honeycomb structure, but the present invention is not limited to this embodiment. The carbonaceous component may be, for example, particles such as graphite and activated carbon, which may be contained in the mixture used in the molding step.

Hereinafter, examples in which the above embodiment is further embodied will be described.
(Example 1)
First, the following raw material compositions were mixed to prepare a mixture.

Zeolite particles (LTA type) (ceramic particles) with an average particle diameter of 5 μm: 46.8% by mass
Boehmite (inorganic binder): 9.6% by mass
Glass fiber (inorganic fiber): 6.1% by mass
Methyl cellulose (organic binder): 5.7% by mass
Sorbitan fatty acid ester (dispersant): 1.6% by mass
Water (dispersion medium): 30.2% by mass
Using this mixture, a columnar molded body was molded by an extrusion molding machine. This molded body was cut to a predetermined length to produce a honeycomb molded body. The honeycomb molded product was dried at a pressure of 6.7 kPa and 25 ° C. for 5 minutes using a known vacuum microwave dryer. Further, the honeycomb structure was produced by heating the honeycomb molded body at 450 ° C. for 2 hours and firing it.

In the obtained honeycomb structure, the plurality of ceramic particles constituting the wall portion were bonded to each other via a binder containing a carbonaceous component.
The wall thickness of the honeycomb structure was 0.25 mm, the cell density was 171 cells / cm ² , the GSA was 34.9 ^{cm 2} / cm ³ , the opening ratio was 44.7%, and the porosity of the wall was 41%. The outer shape of the honeycomb structure had a cross section of 35 mm × 35 mm and a length of 76.2 mm. The content of the ceramic particles in the wall portion was 79.4% by volume, and the content of the carbonaceous component was 0.7% by mass.

The content of the carbonaceous component is determined by crushing a part of the honeycomb structure into a powdery sample and measuring the weight of the powdery sample in the range of 300 ° C. to 600 ° C. by thermogravimetric analysis (TG). Calculated from (= carbonaceous component).

(Example 2)
A honeycomb structure was produced in the same manner as in Example 1 except that the honeycomb molded body was fired at 470 ° C. for 2 hours, and this was used as the honeycomb structure of Example 2.

The content of the ceramic particles in the wall portion of the honeycomb structure of Example 2 was 79.6% by volume, and the content of the carbonaceous component was 0.5% by mass. The porosity of the wall was 41%.
(Example 3)
A honeycomb structure was produced in the same manner as in Example 1 except that the composition of the raw material was as follows, and this was used as the honeycomb structure of Example 3.

Zeolite particles (ceramic particles) with an average particle diameter of 5 μm: 49.5% by mass
Boehmite (inorganic binder): 9.8% by mass
Glass fiber (inorganic fiber): 2.5% by mass
Methyl cellulose (organic binder): 5.8% by mass
Sorbitan fatty acid ester (dispersant): 1.7% by mass
Water (dispersion medium): 30.7% by mass
The content of the ceramic particles in the wall portion of the honeycomb structure of Example 3 was 82.4% by volume, and the content of the carbonaceous component was 0.7% by mass. The porosity of the wall was 41%.

(Example 4)
A honeycomb structure was produced in the same manner as in Example 1 except that the raw material composition was blended as follows and the honeycomb molded body was heated at 300 ° C. for 2 hours, and the honeycomb structure was prepared in the same manner as in Example 1. It was made into a structure.

Zeolite particles (ceramic particles) with an average particle diameter of 5 μm: 40.3% by mass
Boehmite (inorganic binder): 8.3% by mass
Glass fiber (inorganic fiber): 5.2% by mass
Methyl cellulose (organic binder): 9.0% by mass
Sorbitan fatty acid ester (dispersant): 1.4% by mass
Water (dispersion medium): 35.8% by mass
The content of the ceramic particles in the wall portion of the honeycomb structure of Example 4 was 70.5% by volume, and the content of the carbonaceous component was 12.0% by mass. The porosity of the wall was 36%.

(Example 5)
A honeycomb structure was produced in the same manner as in Example 1 except that the composition of the raw material was as follows, and this was used as the honeycomb structure of Example 5.

Zeolite particles (ceramic particles) with an average particle diameter of 5 μm: 44.3% by mass
Boehmite (inorganic binder): 9.1% by mass
Glass fiber (inorganic fiber): 5.7% by mass
Activated carbon: 4.0% by mass
Methyl cellulose (organic binder): 5.6% by mass
Sorbitan fatty acid ester (dispersant): 1.6% by mass
Water (dispersion medium): 29.7% by mass
The content of the ceramic particles in the wall portion of the honeycomb structure of Example 5 was 74.5% by volume, and the content of the carbonaceous component was 7.0% by mass. The porosity of the wall was 38%.

(Comparative Example 1)
A honeycomb structure was produced in the same manner as in Example 1 except that the honeycomb molded body was fired at 500 ° C. for 2 hours, and this was used as the honeycomb structure of Comparative Example 1.

The content of the ceramic particles in the wall portion of the honeycomb structure of Comparative Example 1 was 79.7% by volume, and the content of the carbonaceous component was 0.3% by mass. The porosity of the wall was 36%.
(Comparative Example 2)
A honeycomb structure was produced in the same manner as in Example 1 except that the composition of the raw material was as follows, and this was used as the honeycomb structure of Comparative Example 2.

Zeolite particles (ceramic particles) with an average particle diameter of 5 μm: 36.9% by mass
Boehmite (inorganic binder): 16.3% by mass
Glass fiber (inorganic fiber): 10.3% by mass
Methyl cellulose (organic binder): 5.5% by mass
Sorbitan fatty acid ester (dispersant): 1.6% by mass
Water (dispersion medium): 29.4% by mass
The content of the ceramic particles in the wall portion of the honeycomb structure of Comparative Example 2 was 64.5% by volume, and the content of the carbonaceous component was 0.7% by mass. The porosity of the wall was 41%.

(Evaluation of gas adsorption amount)
The gas adsorption amount of the honeycomb structure was evaluated by the following test.
First, the honeycomb structure is placed in the pipe. Evaluation gas is supplied from the upstream side of the honeycomb structure to circulate inside the honeycomb structure. On the downstream side of the honeycomb structure, the components of the gas flowing inside the honeycomb structure are measured.

As the components of the evaluation gas, carbon dioxide 1%, oxygen 20%, and nitrogen 79% were used. The temperature of the gas was about 40 ° C., and the flow rate of the gas was 15.6 L / min.
At the stage when the supply of the evaluation gas is started, for example, the carbon dioxide in the evaluation gas is adsorbed on the honeycomb structure, so that the concentration of carbon dioxide on the downstream side of the honeycomb structure becomes substantially zero. When a certain period of time has passed from the start of supply of the evaluation gas and the amount of carbon dioxide adsorbed on the honeycomb structure reaches the upper limit, carbon dioxide is not adsorbed any more, so that carbon dioxide is distilled off on the downstream side of the honeycomb structure. The concentration of carbon increases. The time from the start of supply of the evaluation gas until the concentration of carbon dioxide on the downstream side of the honeycomb structure reaches the predetermined threshold of 0.05% is measured, and the carbon dioxide adsorbed on the honeycomb structure is measured. The amount of adsorption was relatively evaluated.

As a result of the above test, in Comparative Examples 1 and 2, the time required for the carbon dioxide concentration to reach 0.05% was 304 seconds and 272 seconds, respectively, whereas in Examples 1, 2, 3 and 4, In No. 5, it was 334 seconds, 320 seconds, 393 seconds, 352 seconds, and 371 seconds, respectively, and it was confirmed that the amount of carbon dioxide adsorbed was increased. In particular, with respect to the honeycomb structure of Comparative Example 2, the honeycomb structures of Examples 1 to 5 showed an increase in the amount of carbon dioxide adsorbed by 20% or more.

(Measurement of mechanical strength)
As the mechanical strength of the honeycomb filter, the bending strength was measured by the following method.
First, from the honeycomb structures obtained in Examples 1 to 5 and Comparative Examples 1 and 2, 10 members having a cross section of 5 mm × 5 mm and a length of 40 mm were prepared as samples for measuring the bending strength at three points. A load was applied in a direction perpendicular to the main surface of the sample for measuring the three-point bending strength (the wider surface of the outer peripheral surface of the sample), and the fracture load (the load at which the sample was fractured) was measured. The breaking load was measured for 10 samples for measuring the bending strength at three points, and the average value was taken as the bending strength of the honeycomb structure obtained in Examples and Comparative Examples, respectively. The three-point bending strength test was carried out using an Instron 5582 with reference to JIS R1601 at a distance between spans of 30 mm and a speed of 0.5 mm / min.

The honeycomb structures of Comparative Examples 1 and 2 have wall strengths of 0.9 MPa and 1.6 MPa, respectively, and in Examples 1, 2, 3, 4, and 5, 1.6 MPa, 1.4 MPa, and 1 respectively. It was .1 MPa, 1.8 MPa, and 1.3 MPa. From this, it was confirmed that the honeycomb structures of Examples 1 to 5 had improved mechanical strength as compared with the honeycomb structure of Comparative Example 1.

10 ... Honeycomb structure, 11 ... Circumferential wall, 12 ... Division wall, S ... Cell.

Claims (5)

A honeycomb structure for gas adsorption having a wall portion containing a plurality of ceramic particles.
The ceramic particles contain at least one of zeolite, silica, and cerium oxide as a constituent.
The content of the ceramic particles in the wall portion is 70% by volume or more, and the content is 70% by volume or more.
The wall portion is a honeycomb structure characterized by containing 0.5% by mass or more of a carbonaceous component. The honeycomb structure according to claim 1, wherein the wall portion contains 1% by mass or more of the carbonaceous component. The honeycomb structure according to claim 1 or 2, wherein the carbonaceous component is a residue of an organic component heated in the manufacturing process of the honeycomb structure. The honeycomb structure according to any one of claims 1 to 3, wherein the plurality of ceramic particles are bonded to each other via the carbonaceous component. A gas recovery device comprising the honeycomb structure according to any one of claims 1 to 4.

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