JP2011143359A - Compound gas adsorbent, compound gas adsorbent composition and adsorption filter using the adsorbent or composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compound gas adsorbent having excellent performance of adsorbing a compound gas containing an aldehyde and butane. <P>SOLUTION: The compound gas adsorbent includes activated charcoal added with an aromatic amino sulfonic acid and an organic acid. The compound gas adsorbent has a BET specific surface area of activated charcoal of 700-1,300 m<SP>2</SP>/g, and the organic acid is a 2-6C organic acid being soluble in water and solid at 25°C. The addition ratio of the aromatic amino sulfonic acid is 2-12 pts.mass to 100 pts.mass of activated charcoal, with a combined addition ratio of the aromatic amino sulfonic acid and the organic acid of 3-20 pts.mass. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a composite gas adsorbent and an adsorption filter using the same.

  There are various odor components (such as aldehydes (such as acetaldehyde), lower hydrocarbons (such as butane), amines (such as trimethylamine)) in the interiors of houses and automobiles. Higher concentrations may cause discomfort. In order to remove such odor components, activated carbon is generally used.

  However, it cannot be said that the adsorptive power to the odor component of activated carbon is sufficient. Moreover, activated carbon has selectivity of the odor component to adsorb | suck, for example, it is hard to adsorb | suck acetaldehyde etc. Furthermore, the activated carbon has a problem that the adsorbed components are easily separated again. Therefore, activated carbon is effective in selectively removing a single odor component, but is not effective in removing a plurality of odor components.

  As an adsorbing material (deodorizing material) capable of removing a plurality of odor components, an adsorbing material obtained by attaching aminobenzenesulfonic acid to activated carbon (Patent Document 1), and a deodorizing material obtained by attaching aminobenzenesulfonic acid and a weak acid to activated carbon. (Patent Document 2) is disclosed. These adsorbents (deodorizing materials) are intended to remove aldehydes and ammonia.

  In recent years, adsorbents capable of removing lower hydrocarbons such as butane in addition to aldehydes have been desired. However, the adsorbents (deodorizing materials) in Patent Documents 1 and 2 are intended to remove aldehydes and ammonia.

  Lower hydrocarbons such as butane having a small molecular size are well adsorbed in the micropores of the activated carbon. However, lower aldehydes such as formaldehyde and acetaldehyde are less likely to be adsorbed in the micropores of the activated carbon even though the molecular size is small like butane. Therefore, the aldehyde adsorption performance of the activated carbon can be enhanced by attaching the agent that reacts with the aldehyde such as aminobenzenesulfonic acid to the activated carbon.

  In particular, in order to enhance the aldehyde adsorption performance, it is preferable to add not only as much and as uniformly a drug that reacts with the aldehyde but also to micropores and mesopores having a physical adsorption function by capillary condensation. However, when the drug is attached to the micropores, the pores to which butane is adsorbed are blocked by the drug, which causes a problem that the performance of adsorbing lower hydrocarbons such as butane in addition to aldehyde is reduced.

JP-A-7-136502 JP 2001-522 A

  An object of the present invention is to provide a composite gas adsorbent excellent in the adsorption performance of a composite gas containing aldehyde and butane.

  Among the mesopores and micropores of activated carbon, the present inventors uniformly distributed aromatic aminosulfonic acid and a specific organic material in the mesopore region to such an extent that the micropores, which are butane-adsorbing pores, are not blocked by the drug. It has been found that by adding an acid, a composite gas adsorbent capable of efficiently adsorbing a composite gas containing aldehyde and butane can be obtained, and the present invention has been completed.

The present invention provides a composite gas adsorbent in which an aromatic aminosulfonic acid and an organic acid are impregnated into activated carbon, and the composite gas adsorbent has a BET specific surface area of the activated carbon of 700 to 1300 m ² / g. The organic acid is a water-soluble organic acid having 2 to 6 carbon atoms that is solid at 25 ° C., and the proportion of the aromatic aminosulfonic acid is 2 to 12 parts by mass with respect to 100 parts by mass of the activated carbon. And the aromatic aminosulfonic acid and the organic acid are added in a ratio of 3 to 20 parts by mass in total.

  In one embodiment, the organic acid has a melting point of 90 ° C. or higher.

  In another embodiment, the molar equivalent ratio of the aromatic aminosulfonic acid to the carboxyl group of the organic acid is 1: 0.75 to 1: 2.

Furthermore, the present invention provides a method for producing a composite gas adsorbent, the method comprising solubilizing an aromatic aminosulfonic acid and attaching it to activated carbon; and after the addition of the aromatic aminosulfonic acid, 1 A step of impregnating the activated carbon with the organic acid within minutes to 24 hours, wherein the activated carbon has a BET specific surface area of 700 to 1300 m ² / g, and the organic acid is water-soluble and solid carbon at 25 ° C. 2 to 6 organic acids, and the aromatic aminosulfonic acid is added in an amount of 2 to 12 parts by mass with respect to 100 parts by mass of the activated carbon, and the aromatic aminosulfonic acid and the organic acid Are added at a ratio of 3 to 20 parts by mass in total.

  In one embodiment, the organic acid has a melting point of 90 ° C. or higher.

  In another embodiment, the molar equivalent ratio of the aromatic aminosulfonic acid to the carboxyl group of the organic acid is 1: 0.75 to 1: 2.

  In another embodiment, the pH of the composite gas adsorbent is adjusted to 2-8.

  Furthermore, the present invention provides a composite gas adsorbent composition comprising the composite gas adsorbent and another adsorbent.

  In one embodiment, the other adsorbent is activated carbon.

  The present invention also provides an adsorption filter comprising at least one selected from the group consisting of the composite gas adsorbent and the composite gas adsorbent composition.

  ADVANTAGE OF THE INVENTION According to this invention, the composite gas adsorption material excellent in the adsorption | suction performance of the composite gas containing an aldehyde and butane can be provided.

  In the composite gas adsorbent of the present invention, an aromatic aminosulfonic acid and a specific organic acid are attached to activated carbon.

The BET specific surface area of the activated carbon used in the present invention is measured by a nitrogen adsorption method. The BET specific surface area of the activated carbon used in the present invention is 700 to 1300 m ² / g, preferably 800 to 1200 m ² / g, more preferably 850 to 1100 m ² / g.

  Activated carbon has micropores having a pore diameter of 2 nm or less, mesopores having a pore diameter of 2 to 50 nm, and macropores having a pore diameter of 50 nm or more. Since lower hydrocarbons such as butane having a small molecular size are well adsorbed in the micropores, it is preferable that the volume of the micropores is large.

When the BET specific surface area is less than 700 m ² / g, since the activation is insufficient, the micropore volume is small and the butane adsorption performance is lowered. Moreover, since the specific surface area is small, the amount of aromatic aminobenzenesulfonic acid and the specific organic acid added is also not preferable. On the other hand, when the activation is advanced to increase the micropore volume and the BET specific surface area exceeds 1300 m ² / g, the pores expand, and the ratio of the micropore volume of the activated carbon relatively decreases. Moreover, the decrease in the density of activated carbon due to the increase in mesopores and macropores reduces the butane adsorption performance per volume. Therefore, the range BET specific surface area of 700m ² / g~1300m ² / g, micropore volume is preferably 0.25 mL / g or more, more preferably composite gas adsorbent having the above 0.35 mL / g, volume It is preferable because of its excellent butane adsorption performance.

  Examples of the carbonaceous material of activated carbon used in the present invention include plant-based materials such as fruit shells (coconut shells, walnut shells, etc.), wood, sawdust, charcoal, fruit seeds, pulp production by-products, lignin, and molasses. Mineral materials such as peat, grass charcoal, lignite, lignite, lignite, anthracite, coke, coal tar, coal pitch, petroleum distillation residue; synthetic materials such as phenol resin, saran resin, acrylic resin; regenerated fiber (rayon) Etc.). Among these, coconut shell activated carbon is more preferable because the ratio of micropores is high.

  The condition for carbonizing the carbonaceous material is not particularly limited. For example, in the case of a granular carbonaceous material, a condition of processing at a temperature of 300 ° C. or higher while flowing a small amount of inert gas through a batch rotary kiln, etc. It is done.

  The method for producing activated carbon is not particularly limited. Usually, the activated carbon used in the present invention is obtained by sufficiently carbonizing a carbonaceous material and then activating by a method such as gas activation or drug activation. Examples of the gas used in the gas activation method include water vapor, carbon dioxide, oxygen, LPG combustion exhaust gas, or a mixed gas thereof. In consideration of safety and reactivity, a water vapor-containing gas (a gas containing 10 to 50% by volume of water vapor) is preferable.

  The activation temperature is usually 700 ° C to 1100 ° C, preferably 800 ° C to 1000 ° C. However, the activation temperature, time, and heating rate are not particularly limited, and vary depending on the type, shape, size, etc. of the carbonaceous material to be selected. Activated carbon obtained by activation can be used as it is as a material for the composite gas adsorbent, but it is possible to use activated carbon from which inorganic components such as metal oxide components in the activated carbon have been removed by acid washing, water washing or the like. preferable.

  The shape of the activated carbon is not particularly limited, and examples thereof include powder, granule, and fiber. When the composite gas adsorbent of the present invention is used as an air purification filter, it is sometimes required to satisfy both dynamic adsorption characteristics and appropriate air permeability, and 35 μm to 2.8 mm (350 mesh to 7 mesh). Preferred is activated carbon having an average particle size of

  The aromatic aminosulfonic acid used in the present invention is not particularly limited, and examples thereof include p-aminobenzenesulfonic acid, m-aminobenzenesulfonic acid, o-aminobenzenesulfonic acid, polycyclic aromatic aminosulfonic acid ( For example, 2-amino-1-naphthalenesulfonic acid, 4-amino-1-naphthalenesulfonic acid, and the like). Among these, it is preferable to use at least one kind of p-aminobenzenesulfonic acid in terms of easy handling, low cost, and excellent reactivity with aldehyde.

  The specific organic acid used in the present invention is a water-soluble organic acid having 2 to 6 carbon atoms that is solid at 25 ° C. In the present specification, “water-soluble” means that the solubility in water at 25 ° C. is 3% by mass or more, preferably 5% by mass or more, more preferably 8% by mass or more. When the solubility in water at 25 ° C. is less than 3% by mass, a large amount of an organic acid aqueous solution is required to precipitate the aromatic aminosulfonic acid, which is complicated.

  Examples of the organic acid having a water solubility (that is, a solubility in water at 25 ° C. of 3% by mass or more) and a solid having 2 to 6 carbon atoms at 25 ° C. include monocarboxylic acids such as hydroxyacetic acid and lactic acid; oxalic acid, Examples include dicarboxylic acids such as malonic acid, succinic acid, maleic acid, malic acid, and tartaric acid; polyvalent carboxylic acids such as aconitic acid and citric acid; and ascorbic acid. Among these, an organic acid having a melting point of 60 ° C. or higher is preferable, and an organic acid having a melting point of 90 ° C. or higher is preferable in order to prevent excess organic acid from melting and clogging the micropores of the activated carbon in the heating step such as drying. Organic acids are more preferred.

  Aromatic aminosulfonic acid generally has low solubility in water, and is solubilized under alkaline conditions using, for example, sodium hydroxide.

  The composite gas adsorbent of the present invention can be obtained by attaching an aromatic aminosulfonic acid and a specific organic acid to activated carbon. The method of attaching the aromatic aminosulfonic acid and the specific organic acid to the activated carbon is not particularly limited as long as the aromatic aminosulfonic acid and the specific organic acid can be uniformly attached to the activated carbon. However, in order to prevent the micropores from being clogged with each component, it is important to uniformly add the aromatic aminosulfonic acid and the specific organic acid to the mesopore region. It is preferable to attach each component of a sulfonic acid and a specific organic acid for each individual component. Thereby, the aromatic aminosulfonic acid has a reduced solubility in the mesopore region of the activated carbon, and is easily precipitated.

  Specifically, for example, it is desirable to start the addition of the liquid in which the organic acid is dissolved after the completion of the addition of the liquid in which the aromatic aminosulfonic acid is solubilized in the activated carbon. In this case, it is preferable to start the addition of the organic acid within 1 minute to 24 hours after completion of the addition of the liquid in which the aromatic aminosulfonic acid is dissolved, more preferably within 2 minutes to 12 hours, and most preferably 5 minutes. Within minutes to 1 hour. When the time is less than 1 minute, the aromatic aminosulfonic acid and the specific organic acid may not be uniformly applied in the mesopore region. On the other hand, when it exceeds 24 hours, the liquid solubilized with the aromatic aminosulfonic acid may block the micropores.

  To add aromatic aminosulfonic acid and specific organic acid to activated carbon, solubilize aromatic aminosulfonic acid by immersing activated carbon in a solution in which aromatic aminosulfonic acid is solubilized or in a specific organic acid solution. For example, the activated carbon and the specific organic acid solution are sprayed onto activated carbon.

  Although the cause of obtaining a composite gas adsorbent with excellent adsorption performance of both aldehyde and butane by adopting the above-mentioned impregnation method has not been confirmed, it has been identified as aromatic aminosulfonic acid in the mesopore region of activated carbon This is presumed to be due to the phenomenon that the organic acid is uniformly attached and the micropore region is extremely closed.

  The aromatic aminosulfonic acid is added in an amount of 2 to 12 parts by mass, preferably 4 to 10 parts by mass, more preferably 6 to 9 parts by mass with respect to 100 parts by mass of the activated carbon. The organic acid is added in a proportion of 3 to 20 parts by mass in total, preferably 5 to 18 parts by mass, more preferably 6 to 16 parts by mass. When the total is less than 3 parts by mass, the aldehyde adsorption performance of the obtained composite gas adsorbent is lowered. On the other hand, when the amount is more than 20 parts by mass, the micropores are blocked and the butane adsorption performance is lowered.

  The aromatic aminosulfonic acid and the specific organic acid preferably have a molar equivalent ratio of the aromatic aminosulfonic acid to the carboxyl group of the specific organic acid of 1: 0.75 to 1: 2, more preferably 1: 0. .9 to 1: 1.5 so as to be attached to the activated carbon. When the molar equivalent ratio exceeds 1: 2, the unreacted organic acid may block the pores. On the other hand, when the molar equivalent ratio is less than 1: 0.75, the aromatic aminosulfonic acid is not sufficiently precipitated, and the micropores may be blocked.

  The aromatic aminosulfonic acid and the specific organic acid are preferably attached so that the pH of the composite gas adsorbent satisfies 2 to 8, and more preferably attached so that the pH satisfies 3 to 7. preferable. When the pH is less than 2, the apparatus may corrode due to contact with the composite gas adsorbent. On the other hand, when pH exceeds 8, not only aldehyde adsorption | suction performance falls, but aromatic aminosulfonic acid becomes difficult to precipitate and there exists a possibility of plugging a micropore.

  The use form of the composite gas adsorbent thus obtained is not particularly limited, and is used for an air cleaner filter, a ceiling material, an industrial filter, and the like, and particularly preferably used for a cabin filter for an automobile.

  The composite gas adsorbent of the present invention efficiently adsorbs aldehyde and butane alone, but may be used as a composite gas adsorbent composition in combination with another adsorbent (such as a deodorizing material). For example, butane can be more efficiently adsorbed by using it in combination with activated carbon that has not been subjected to an impregnation treatment.

  When the composite gas adsorbent of the present invention is used in combination with another adsorbent, the composite gas adsorbent of the present invention and the other adsorbent are preferably in a mass ratio of 1: 0.5 to 1:30, More preferably, they are combined at a mass ratio of 1: 2 to 1:20.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated concretely, this invention is not limited to these Examples.

(Activated carbon)
Activated carbon having a particle size of 30 to 60 mesh obtained from carbide of coconut shell was used.

(Acid cleaning method for activated carbon)
The activated carbon was immersed in a 0.5N hydrochloric acid solution (95 ° C.) for 20 minutes. Next, washing with water was repeated until the pH of the washing solution reached 6-7. The activated carbon thus treated was dried until the water content was 3% by mass or less.

(Measurement method of BET specific surface area)
Measurement of nitrogen adsorption isotherm at 77K by the constant volume method was performed using Bell Soap 28SA (Nippon Bell Co., Ltd.). The BET specific surface area was calculated from the obtained results.

(Measurement method of pH)
10 mL of distilled water was added to 1 g of activated carbon or composite gas adsorbent. The pH of the supernatant after 60 minutes was measured using a pH meter (Horiba, Ltd .: F-52).

(Pre-measurement of composite gas adsorbent)
20 g of composite gas adsorbent was placed in a 50 mL beaker. The beaker containing the composite gas adsorbent was heat-treated for 16 days in a dryer (90 ° C.), and then an adsorption test for each gas was performed.

(Measurement method of acetaldehyde adsorption amount)
1 g of the composite gas adsorbent subjected to the measurement pretreatment was placed in an about 4 L glass sealed container and sealed. An appropriate amount of acetaldehyde was injected into this glass sealed container with a syringe. Then, this glass closed container was left still in a 25 degreeC thermostat for 24 hours. After 24 hours, an acetaldehyde adsorption isotherm was obtained by measuring the acetaldehyde concentration in the gas phase portion in the glass sealed container using a gas detector tube (manufactured by Gastec Co., Ltd .: No. 92L acetaldehyde). The acetaldehyde equilibrium adsorption amount at 10 ppm was calculated from the obtained acetaldehyde adsorption isotherm.

(Measurement method of butane adsorption amount)
2.23 g of the composite gas adsorbent pre-measured was placed in a sample holder (60 mm × 60 mm). Next, air mixed with n-butane (n-butane 80 ppm, relative humidity 50%) was allowed to flow into the sample holder under the condition of a linear velocity (LV) of 31 cm / sec. The concentration of n-butane in the sample holder was measured using Thermo Electron Co., Ltd. product: MIRAN SapphlRe). The n-butane concentration on the sample holder inlet side was C1, and the n-butane concentration on the outlet side was C2, and measurement was performed until C2 / C1 × 100 = 95 (%). The adsorption amount of n-butane was calculated by the following formula.

  n-butane adsorption amount (% by mass) = [C2 / C1 × 100 = 95 (%)] n-butane amount adsorbed on the composite gas adsorbent / composite gas adsorbent amount × 100

Example 1
Acid-washed activated carbon having a BET specific surface area of 1050 m ² / g and a p-aminobenzenesulfonic acid aqueous solution having a concentration of 18% by mass (containing 0.95 mol of sodium hydroxide per 1 mol of p-aminobenzenesulfonic acid) ) And sprayed with p-aminobenzenesulfonic acid. After 30 minutes, an aqueous solution of citric acid having a concentration of 46% by mass (melting point: 153 ° C., solubility: 59.2% by mass) was sprayed on the activated carbon to add citric acid. After 60 minutes from the addition of citric acid, the activated carbon was dried in a dryer (90 ° C.) for 24 hours. In this way, a composite gas adsorbent in which 8 parts by mass of p-aminobenzenesulfonic acid and 4.4 parts by mass of citric acid were added to 100 parts by mass of activated carbon was obtained.

  Next, the obtained composite gas adsorbent was subjected to the above-described measurement pretreatment, and then the adsorption amounts of acetaldehyde and butane were measured by the above method. The results are shown in Table 1.

(Example 2)
A composite gas adsorbent was obtained by the same procedure as in Example 1 except that activated carbon having a BET specific surface area of 890 m ² / g that had been subjected to acid cleaning was used. Adsorption of acetaldehyde and butane by the same procedure as in Example 1 The amount was measured. The results are shown in Table 1.

(Example 3)
A composite gas adsorbent was obtained by the same procedure as in Example 1 except that activated carbon having a BET specific surface area of 1150 m ² / g subjected to acid cleaning was used. Adsorption of acetaldehyde and butane by the same procedure as in Example 1 The amount was measured. The results are shown in Table 1.

Example 4
A composite gas adsorbent was obtained in the same procedure as in Example 1 except that activated carbon having a BET specific surface area of 1000 m ² / g without acid cleaning was used and 8.9 parts by mass of citric acid was added. The adsorption amount of acetaldehyde and butane was measured in the same procedure as in Example 1. The results are shown in Table 1.

(Example 5)
A composite gas adsorbent was obtained by the same procedure as in Example 1 except that 3 parts by mass of citric acid was added, and the amounts of acetaldehyde and butane adsorbed were measured by the same procedure as in Example 1. The results are shown in Table 1.

(Example 6)
Aside from adding 4.4 parts by mass of hydroxyacetic acid using an aqueous solution of hydroxyacetic acid (melting point: 80 ° C., solubility: 100% by mass) having a concentration of 9% by mass instead of the citric acid aqueous solution having a concentration of 46% by mass. The composite gas adsorbent was obtained in the same procedure as in Example 1, and the adsorption amounts of acetaldehyde and butane were measured in the same procedure as in Example 1. The results are shown in Table 1.

(Example 7)
The composite gas was prepared in the same procedure as in Example 1 except that the composite gas adsorbent was placed in a sealed container and heated at 60 ° C. for 72 hours between the p-aminobenzenesulfonic acid and citric acid. An adsorbent was obtained, and the adsorption amount of acetaldehyde and butane was measured in the same procedure as in Example 1. The results are shown in Table 1.

(Example 8)
A composite gas adsorbent was obtained in the same procedure as in Example 1 except that 6 parts by mass of p-aminobenzenesulfonic acid and 3.3 parts by mass of citric acid were added. The amount of butane adsorbed was measured. The results are shown in Table 1.

Example 9
A composite gas adsorbent was obtained in the same procedure as in Example 3 except that 9 parts by mass of p-aminobenzenesulfonic acid and 6.7 parts by mass of citric acid were added. The amount of butane adsorbed was measured. The results are shown in Table 1.

(Example 10)
The same as in Example 1 except that activated carbon having a BET specific surface area of 1050 m ² / g without acid washing was used and 8 parts by mass of p-aminobenzenesulfonic acid and 1.5 parts by mass of citric acid were added. The composite gas adsorbent was obtained by the procedure, and the adsorption amounts of acetaldehyde and butane were measured by the same procedure as in Example 1. The results are shown in Table 1.

(Example 11)
Instead of an aqueous citric acid solution having a concentration of 46% by mass, an aqueous solution of oxalic acid having a concentration of 8% by mass (melting point: 190 ° C., solubility: 8.34% by mass) was added with 2.1 parts by mass of oxalic acid. Except for the above, a composite gas adsorbent was obtained in the same procedure as in Example 1, and the adsorption amounts of acetaldehyde and butane were measured in the same procedure as in Example 1. The results are shown in Table 1.

(Example 12)
Instead of the citric acid aqueous solution with a concentration of 46% by mass, malic acid (melting point: 132 ° C., solubility: 55.8% by mass) aqueous solution with a concentration of 35% by mass was added with 4.6 parts by mass of malic acid. Except for the above, a composite gas adsorbent was obtained in the same procedure as in Example 1, and the adsorption amounts of acetaldehyde and butane were measured in the same procedure as in Example 1. The results are shown in Table 1.

(Example 13)
A composite gas adsorbent was obtained in the same procedure as in Example 2 except that 3 parts by mass of p-aminobenzenesulfonic acid and 1.7 parts by mass of citric acid were added. The amount of butane adsorbed was measured. The results are shown in Table 1.

(Comparative Example 1)
A composite gas adsorbent was obtained in the same procedure as in Example 1 except that activated carbon having a BET specific surface area of 1050 m ² / g without acid cleaning was used and no citric acid aqueous solution was used. The adsorption amount of acetaldehyde and butane was measured by the procedure described above. The results are shown in Table 1.

(Comparative Example 2)
The same procedure as in Example 1 except that activated carbon having a BET specific surface area of 600 m ² / g subjected to acid cleaning was used and 4 parts by mass of p-aminobenzenesulfonic acid and 2.2 parts by mass of citric acid were added. Then, a composite gas adsorbent was obtained, and the adsorption amounts of acetaldehyde and butane were measured in the same procedure as in Example 1. The results are shown in Table 1.

(Comparative Example 3)
A composite gas adsorbent was obtained by the same procedure as in Example 1 except that activated carbon having a BET specific surface area of 1400 m ² / g subjected to acid cleaning was used. Adsorption of acetaldehyde and butane by the same procedure as in Example 1 The amount was measured. The results are shown in Table 1.

(Comparative Example 4)
Example, except that instead of the 46% by mass citric acid aqueous solution, a sulfuric acid (melting point: 10 ° C., soluble in water) aqueous solution having a concentration of 45% by mass was used, and 3.4 parts by mass of sulfuric acid was added. The composite gas adsorbent was obtained by the same procedure as in Example 1, and the adsorption amounts of acetaldehyde and butane were measured by the same procedure as in Example 1. The results are shown in Table 1.

(Comparative Example 5)
A composite gas adsorbent was obtained in the same procedure as in Example 2 except that 16 parts by mass of p-aminobenzenesulfonic acid and 8.9 parts by mass of citric acid were added. The amount of butane adsorbed was measured. The results are shown in Table 1.

(Comparative Example 6)
A formic acid (melting point: 8.4 ° C., soluble in water) aqueous solution having a concentration of 45 mass% was used instead of the 46 mass% citric acid aqueous solution, and 3.2 parts by mass of formic acid was added. A composite gas adsorbent was obtained in the same procedure as in Example 1, and the amounts of acetaldehyde and butane adsorbed were measured in the same procedure as in Example 1. The results are shown in Table 1.

  As shown in Table 1, it can be seen that the composite gas adsorbents (Examples 1 to 13) of the present invention have larger amounts of adsorption of acetaldehyde and butane than the composite gas adsorbents of Comparative Examples 1 to 6.

On the other hand, the composite gas adsorbent of Comparative Example 1 is alkaline because it is water-soluble and not impregnated with a solid organic acid having 2 to 6 carbon atoms at 25 ° C., and has a very small amount of acetaldehyde adsorption. Recognize. The composite gas adsorbent of Comparative Example 2 has a small BET specific surface area of activated carbon (700 m ² / g or less) and insufficient activation, so that the amount of butane adsorbed is small, and p-aminobenzenesulfonic acid and citric acid are sufficiently sufficient. It can be seen that since the acid cannot be impregnated, the amount of acetaldehyde adsorbed is small. In the composite gas adsorbent of Comparative Example 3, the activated carbon has a large BET specific surface area (1300 m ² / g or more) and the activation becomes excessive, so that the proportion of micropores is relatively reduced and the amount of butane adsorbed is small. I understand. The composite gas adsorbent of Comparative Example 4 is considered to have a small amount of adsorption of acetaldehyde and butane because liquid sulfuric acid has entered the micropores. In the composite gas adsorbent of Comparative Example 5, the amount of p-aminobenzenesulfonic acid and citric acid added is excessive (20 parts by mass or more in total), so that the micropores are blocked and the butane adsorption amount is very small. I understand. The composite gas adsorbent of Comparative Example 6 was difficult to produce because the liquid formic acid entered the micropores, so that the amount of butane adsorbed was small, and the formic acid evaporated when dried at 90 ° C.

(Example 14: Preparation of composite gas adsorbent composition)
The composite gas adsorbent obtained in Example 1 and the activated carbon having a BET specific surface area of 1000 m ² / g were mixed at a mass ratio of 3: 7 to obtain a composite gas adsorbent composition. Using this composite gas adsorbent composition, the adsorption amounts of acetaldehyde and butane were measured in the same procedure as in Example 1. The aldehyde adsorption amount was 1.6% by mass, and the butane adsorption amount was 3.2% by mass.

  ADVANTAGE OF THE INVENTION According to this invention, the composite gas adsorption material excellent in the adsorption | suction performance of the composite gas containing an aldehyde and butane can be provided. Therefore, the composite gas adsorbing material of the present invention is used for an air cleaner filter, a ceiling material, an industrial filter, and the like, and particularly used for a cabin filter for an automobile.

Claims (10)

A composite gas adsorbent in which an aromatic aminosulfonic acid and an organic acid are attached to activated carbon,
The activated carbon has a BET specific surface area of 700 to 1300 m ² / g;
The organic acid is a water-soluble organic acid having 2 to 6 carbon atoms that is solid at 25 ° C., and the aromatic aminosulfonic acid is in a ratio of 2 to 12 parts by mass with respect to 100 parts by mass of the activated carbon. A composite gas adsorbent which is attached and the aromatic aminosulfonic acid and the organic acid are attached in a ratio of 3 to 20 parts by mass in total.   The composite gas adsorbent according to claim 1, wherein the organic acid has a melting point of 90 ° C. or higher.   The composite gas adsorbent according to claim 1 or 2, wherein a molar equivalent ratio between the aromatic aminosulfonic acid and the carboxyl group of the organic acid is 1: 0.75 to 1: 2. A method for producing a composite gas adsorbent, comprising:
Solubilizing and attaching aromatic aminosulfonic acid to activated carbon; and attaching organic acid to the activated carbon within 1 minute to 24 hours after addition of the aromatic aminosulfonic acid;
The activated carbon has a BET specific surface area of 700 to 1300 m ² / g;
The organic acid is a water-soluble organic acid having 2 to 6 carbon atoms that is solid at 25 ° C., and the aromatic aminosulfonic acid is added in an amount of 2 to 12 parts by mass with respect to 100 parts by mass of the activated carbon. A method in which the aromatic aminosulfonic acid and the organic acid are added at a ratio of 3 to 20 parts by mass in total.   The method of claim 4, wherein the organic acid has a melting point of 90 ° C. or higher.   The method according to claim 4 or 5, wherein a molar equivalent ratio between the aromatic aminosulfonic acid and the carboxyl group of the organic acid is 1: 0.75 to 1: 2.   The method according to any one of claims 4 to 6, wherein the pH of the composite gas adsorbent is adjusted to 2 to 8.   A composite gas adsorbent composition comprising the composite gas adsorbent according to any one of claims 1 to 3 and another adsorbent.   The composite gas adsorbent composition according to claim 8, wherein the other adsorbent is activated carbon.   An adsorption filter comprising at least one selected from the group consisting of the composite gas adsorbent according to any one of claims 1 to 3 and the composite gas adsorbent composition according to claim 8 or 9.