JP4794875B2 - Production method of adsorbent - Google Patents

Description

  The present invention relates to a method for producing an adsorbent capable of efficiently removing impurities such as sulfur and nitrogen components contained in fuel gas.

In recent years, fuel cells have attracted attention as power generation systems that use clean hydrogen as an energy source and do not generate greenhouse gases such as CO _{2 with} no pollution. Such fuel cells have been fully developed and researched for use in fixed facilities such as homes and offices, and mobile facilities such as automobiles.

Examples of the fuel used in the fuel cell include hydrocarbon fuels such as natural gas, LP gas, city gas, alcohol, gasoline, kerosene, light oil, and other biomass.
Such hydrocarbon fuel is first converted into hydrogen gas and CO gas by reactions such as steam reforming and partial oxidation, and the hydrogen gas is removed by poisoning the anode described later to remove the CO gas that lowers the power generation performance. Get. This hydrogen is supplied to the anode, dissociated into hydrogen ions and electrons by the metal catalyst of the anode, the electrons flow to the cathode while working through an external circuit, and the hydrogen ions diffuse to the cathode and flow to the cathode. The electrons, hydrogen ions, and oxygen supplied to the cathode are converted into water and diffused into the electrolyte membrane. That is, it is a mechanism for taking out an electric current in the process of supplying water with oxygen and hydrogen derived from fuel gas.

  However, noble metals such as Ru, Pt, Ni, and Fe or metal catalysts are usually used in the CO gas removal step. However, if sulfur components are present even in ppm order in fuel gas or fuel oil, the CO removal catalyst is poisoned. There is a problem that the activity is lowered and the performance of the fuel cell is lowered.

Therefore, it has been desired to remove such sulfur components in the fuel gas.
Conventionally, porous, high specific surface area inorganic oxides and inorganic composite oxides such as zeolite (crystalline aluminosilicate), silica, alumina, silica / alumina, and silica / zirconia have been used as adsorbents.

  In addition, the applicant of the present application proposes the use of an adsorbent in which the metal component is supported on the inorganic oxide or activated carbon as an efficient removal method when the sulfur component in the consumer fuel oil is at a low concentration. (Japanese Patent Laid-Open No. 2002-249787, Patent Document 1).

Japanese Patent Laid-Open No. 2002-66313 (Patent Document 2) discloses a material in which silver is supported on Na-Y zeolite by ion exchange. Furthermore, Japanese Patent No. 2969634 (Patent Document 3) discloses that a metal ion-exchanged zeolite other than Ag such as Mn, Fe and Co efficiently adsorbs odorous sulfur compounds such as mercaptans. .
JP 2002-249787 A JP 2002-66313 A Japanese Patent No. 2969634

  However, if the adsorbent has a metal component supported on an inorganic oxide or activated carbon, the distribution of the metal component is increased on the outer surface of the particle, resulting in uneven distribution and sufficient adsorption to form large metal particles. Performance may not be obtained.

Adsorbents with metal components supported on zeolites have poor heat resistance when zeolites with a low SiO ₂ / Al ₂ O ₃ molar ratio are used. Adsorption performance such that water is adsorbed during use and breakthrough time is shortened. May be insufficient. On the other hand, zeolite having a high SiO ₂ / Al ₂ O ₃ molar ratio cannot support a large amount of metal components, so that the adsorption performance may be insufficient.

  Further, the conventional adsorbents cannot obtain sufficient strength when used as a molded body, and are pulverized when the adsorbent is filled in or taken out from the adsorber and block the adsorber line. was there.

As a result of intensive investigations to solve the above problems, the present inventors have determined that the metal component functioning as a catalyst is an ammine complex in advance when preparing the composite oxide colloidal particles constituting the adsorbent. It has been found that if it is contained in the particles, the metal component can be contained in an arbitrarily large amount as compared with the prior art, and a molded article excellent in strength can be obtained.

(1) To alkaline aqueous solution or alkaline seed particle dispersion,
(i) an aqueous silicate solution and / or an acidic silicate solution;
(ii) Aluminic acid, 4 boric acid, antimonic acid, stannic acid, aluminosilicic acid, vanadic acid, molybdic acid, zirconic acid, tungstic acid, selenic acid, antimonic acid, bismuth acid, titanic acid, niobic acid, cerium oxysulfate, oxy An alkali metal salt or ammonium salt aqueous solution of at least one oxo acid selected from the group consisting of zirconium carbonate and phosphoric acid;
(iii) an ammine complex aqueous solution of at least one metal selected from Cu, Ag, Zn, Ni, Co, and Zr,
Mix to prepare composite compound fine particles,
A method for producing an adsorbent, comprising molding and firing the obtained fine particles.

(2) The amount of (iii) ammine complex to be mixed is in the range of 0.1 to 40% by weight in terms of the amount of metal supported in the adsorbent.
(3) (iii) The ammine complex is a complex of Cu and / or Ag.

(4) The composite compound fine particles have an average particle size in the range of 2 to 500 nm.
(5) expressed by (i) Symbol silicate and / or the number of moles of the acidic silicic acid solution as SiO ₂ (M _S), an alkali metal salt or ammonium salt of (ii) O Kiso acid, constitutes an oxo acid Addition of (i) and (ii) to the molar ratio (M _S ) / (M _NS ) in the range of 0.5 to 20 when expressed in moles (M _NS ) of metal element in terms of oxide To do.
(6) (ii) The oxoacid salt is an aluminate.

According to the present invention, when preparing the composite oxide colloidal particles constituting the adsorbent, the metal component that functions as a catalyst is uniformly included in the particles in advance as an ammine complex. While being dispersed in, the metal content can be arbitrarily controlled and increased. For this reason, the adsorbent excellent in adsorption | suction performance can be obtained. Furthermore, the obtained adsorbent has high strength and can obtain a molded product with excellent strength, and also has high heat resistance, and since the metal is uniformly dispersed, water is adsorbed during use. You can increase the breakthrough time. Furthermore, since the strength is high, it is easy to fill, there is no pulverization, and the line of the adsorption device is not blocked.

Hereinafter, the production method of the adsorbent according to the present invention will be specifically described.
In the present invention, an alkaline aqueous solution or an alkaline seed particle dispersion includes (i) an aqueous silicate solution and / or an acidic silicic acid solution, (ii) an aqueous alkali metal salt or ammonium salt solution of a specific oxo acid, and (iii) an ammine. The complex aqueous solution is mixed to prepare complex compound fine particles.

(i) Silicate aqueous solution As the silicate used in the present invention, an alkali metal silicate such as sodium silicate or potassium silicate, or an ammonium or organic base silicate can be used. Examples of the organic base include quaternary ammonium salts such as tetraethylammonium salt, and amines such as monoethanolamine, diethanolamine, and triethanolamine. An ammonium silicate or an organic base silicate includes an acidic silicate solution. Also included are alkaline aqueous solutions to which ammonia, quaternary ammonium hydroxide, amine compounds and the like are added.

The acidic silicic acid solution is obtained by dealkalizing from an alkali metal silicate with an ion exchange resin or the like.
The concentration of the silicate (including the acidic silicate solution) in the aqueous solution is preferably 0.1 to 10% by weight, more preferably 0.5 to 5% by weight as an oxide (SiO ₂ ). When the concentration is lower than the lower limit, the concentration is too thin and the production efficiency is remarkably lowered.

  If the concentration of the aqueous solution used as the silica source exceeds 10% by weight as an oxide, the resulting composite compound fine particles may gel or aggregate, and the fine particles in the colloidal region may not be obtained.

  (ii) oxo acid alkali metal salt or ammonium salt oxo acid includes aluminate, 4-boric acid, antimonic acid, stannic acid, aluminosilicic acid, vanadic acid, molybdic acid, zirconyl acid, tungstic acid, selenic acid, antimonic acid, Examples include at least one oxo acid selected from the group consisting of bismuth acid, titanic acid, niobic acid, cerium oxysulfate, zirconium oxycarbonate, and phosphoric acid. Examples of the alkali metal include sodium, potassium, lithium and the like, and the ammonium salt is not particularly limited as long as it is a quaternary ammonium.

  Examples of such oxo acids include sodium aluminate, sodium tetraborate, ammonium zirconium carbonate, potassium antimonate, potassium stannate, sodium aluminosilicate, sodium molybdate, cerium ammonium nitrate, ammonium zirconium carbonate, sodium phosphate and the like. It is done.

  Of these, aluminates are easily combined with the silica component, and sodium aluminate, potassium aluminate and the like are particularly preferable because they have high solubility and easily react with the silica source to form a complex.

The concentration of the aqueous oxoacid salt solution is preferably in the range of 0.1 to 10% by weight, more preferably 0.5 to 5% by weight in terms of oxide.
If the concentration is low, the production efficiency may be significantly reduced. Even if the concentration is too high, the reaction between the silica source and the inorganic oxide source other than silica becomes non-uniform, the distribution of components other than silica in the resulting composite compound fine particles becomes non-uniform, and the distribution of metal components is also non-uniform The adsorption performance may be insufficient.

(iii) Ammine complex aqueous solution As the metal of the metal ammine complex, a metal capable of forming an ammine complex such as Cu, Ag, Zn, Ni, Co, Zr and the like can be used. Specifically, as the ammine complex , [ Cu (NH ₃ ) ₄ ] ²⁺ , [Ag (NH ₃ ) ₂ ] ⁺ , [Zn (NH ₃ ) ₄ ] ²⁺ , [Co (NH ₃ ) ₆ ] ²⁺ , [Ni (NH ₃ ) ₆ ] Further examples include ammonium, such as ²⁺ and (NH ₄ ) ₂ ZrO (CO ₃ ) ₂ (provided that (a) does not use ammonium zirconium carbonate). The counter ion is not particularly limited, and usually includes OH, CO ₃ , Cl, NO ₃ , SO ₄ , CH ₃ COO, etc., but is not limited thereto. As the metal ammine complex , a solution obtained by dissolving the metal or metal oxide in aqueous ammonia can also be used.

The metal of the metal ammine complex is particularly preferably Cu and / or Ag. Cu and / or Ag can be preferably used because they have excellent adsorption performance for sulfur compounds such as mercaptans, thiophenes, and sulfides that are also odor components.

The concentration of the metal ammine complex aqueous solution is preferably 0.1 to 10% by weight, more preferably 0.5 to 5% by weight in terms of metal. If the concentration of the ammine complex aqueous solution is low, the content of the metal component in the resulting composite compound fine particles may be insufficient, or the production efficiency may be significantly reduced. On the other hand, if the concentration of the ammine complex aqueous solution is too high, the produced metal aggregates, and it becomes difficult to uniformly disperse in the composite oxide fine particles, and the adsorption performance may be insufficient.

In the present invention, (i) an aqueous solution of silicate and / or an acidic silicate solution, (ii) an oxoacid salt aqueous solution, and (iii) an ammine complex aqueous solution, an alkaline aqueous solution or an alkaline seed particle dispersion. Add with stirring. The pH of the aqueous alkali solution or alkaline seed particle dispersion at this time is preferably 10 or more. As the addition method, (i) to (iii) may be added simultaneously, or a mixed aqueous solution of (i) and (ii) prepared in advance and (iii) may be added simultaneously.

Usually, when mixed, a composite oxide of silica and an oxide (such as alumina) of an element constituting oxo acid is precipitated (it is usually a hydroxide because it is precipitated in a solution).
(i) Silicate aqueous solution and (ii) Oxo salt aqueous solution are usually alkaline and have a pH of 10 or more. If necessary, an alkaline aqueous solution may be added so that the pH is 10 or more during mixing. Good.

The mixing ratio of (i) silicate aqueous solution and (ii) oxoacid aqueous solution is determined by the number of silica (M _s ) in the obtained inorganic composite oxide compound particles and inorganic oxidation other than silica derived from oxo acid. number of moles of the object (M _NS) and the molar ratio of _{(M S) / (M NS} ), 0.5~20, more to be in the range of 1 to 10, it is preferred to mix. Within this range, the composite effect of the composite compound obtained is high, the specific surface area of the fine particles is high, sufficient adsorption performance is achieved, and the metal content can be increased.

When the molar ratio (M _S ) / (M _NS ) ratio is small, the generated fine particles are unstable and the specific surface area is high, but stable inorganic oxide fine particles cannot be obtained, and the molar ratio (M _S ) / ( If M _NS ) is too large, the properties are close to those of silica particles only, and the specific surface area of the resulting composite compound fine particles is low, so that sufficient adsorption performance may not be obtained. Moreover, since the amount of the metal derived from the ammine complex is reduced, the adsorption performance tends to be insufficient.

(iii) The metal ammine complex aqueous solution is preferably added so that the metal content in the finally obtained composite compound fine particles is 0.1 to 40% by weight, more preferably 1 to 30% by weight. . If the amount of the metal ammine complex aqueous solution added is small, the amount of the active component metal is reduced, and the sufficient adsorption performance is lowered. On the other hand, if the amount of the metal ammine complex aqueous solution added is excessive, It may be difficult to incorporate, or the distribution in the composite compound fine particles may be uneven, and sufficient adsorption performance may not be obtained.

Although the pH of the mixed solution changes simultaneously with the addition of each aqueous solution, it is not necessary to control the pH within a predetermined range in the present invention.
In the production method according to the present invention, when a seed particle dispersion is used, the seed particles serve as nuclei and promote particle growth. When composite compound fine particles are prepared using seed particles as nuclei, particles having a uniform particle size distribution of the composite compound fine particles can be obtained and the particle size can be easily controlled. As seed particles, fine particles of inorganic oxides such as SiO ₂ , Al ₂ O ₃ , TiO ₂ or ZrO ₂ , or composite oxides thereof are used, and these sols can be usually used. Moreover, the composite compound fine particles obtained by the production method of the present invention can also be used as seed particles.

Each of the aqueous solutions described above has high solubility on the alkali side. However, when each aqueous solution is mixed in this highly soluble alkaline region, the solubility of silicate ions and oxo acid ions decreases, and these composites precipitate to form fine particles. At this time, the metal ammine complex present around It is considered that the composite compound particles taking in the particles are precipitated and further grown to obtain composite compound fine particles. In addition, when seed particles are present, it is considered that composite compounds are deposited on the seed particles and the particles grow to obtain composite compound fine particles.

The composite compound fine particles thus obtained are a kind of colloidal particles, but are different from conventional colloidal particles and are porous and have a large specific surface area.
The average particle size of the obtained composite compound fine particles is usually in the range of 2 to 500 nm, more preferably 5 to 300 nm. In the present invention, the amount of each raw material added is controlled so that the average particle diameter falls within the above range. It is difficult to obtain a composite compound fine particle having an average particle size of less than 2 nm. Even if it is obtained, gelation or aggregation is likely to occur, and the moldability and the like when used as a molded product to be described later are lowered. If the average particle size of the composite compound fine particles exceeds 500 nm, the specific surface area of the adsorbent finally obtained becomes small, and sufficient adsorption performance may not be obtained. The average particle size of the composite compound fine particles of the present invention can be determined by a dynamic scattering method.

The specific surface area of the obtained composite compound fine particles is usually in the range of 400 to 1300 m ² / g, and more preferably in the range of 500 to 1200 m ² / g. In the present invention, the amount of each raw material added is controlled so that the specific surface area falls within the above range.

The specific surface area of the composite compound fine particles can be measured based on a titration method [Analytical Chemistry Vol. 28, No. 12 (1956)].
Next, the obtained composite compound fine particle dispersion may be washed if necessary. As a cleaning method, a method using an ion exchange resin, an ultrafiltration membrane method, or the like can be employed.

  Next, the obtained fine particles are molded. The fine particles can be taken out from the composite compound fine particle dispersion at the time of molding, dried, and molded by a known dry molding method. It is desirable to concentrate and dilute the dispersion liquid as necessary, and to mold the dispersion as it is without drying.

As a molding method, a conventionally known extrusion molding method is generally used, and pellets are obtained by extrusion molding.
When molding, the water content of the composite oxide particle dispersion (including paste and semi-dry and semi-moist dispersion) may be adjusted to 5 to 40% by weight, further 10 to 30% by weight. desirable.

  Examples of the moisture adjustment method include concentration by an ultrafiltration membrane method or a rotary evaporator method. Further, as a method for adjusting the moisture, there are methods such as spray drying, a kneader with a steam jacket, a rotary evaporator, and a constant temperature dryer.

  If the water content is less than the above range, molding becomes difficult, and even if it can be molded, it may be easily pulverized. Even if the water content is too high, pellets obtained by extrusion molding may adhere to each other to form an aggregate.

  A molding aid can be added to the dispersion during molding. Examples of the molding aid include crystalline cellulose, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, starch, and lignin.

When such a molding aid is added, the optimum moisture width at the time of molding is widened, moisture adjustment becomes easy, and moldability is excellent.
The amount of the molding aid added is preferably in the range of 0.5 to 15% by weight, more preferably 1 to 10% by weight of the total solid content. If the amount of the molding aid is too small, the effect of adding the molding aid described above cannot be obtained sufficiently, and if it is too much, it will be pulverized during granulation, and the strength and wear resistance of the resulting molded product will be reduced. There is a tendency.

  The size of the pellet to be molded is not particularly limited, and is appropriately selected according to the application, the size of the filling container, the use conditions, and the like. Usually, the diameter is approximately 0.3 to 5 mm, more preferably 0.5 to 4 mm, and the length is 0.3 to 20 mm, further 0.5 to 10 mm. Other than this range, molding is possible, but when the diameter and pellet length are small, the molding efficiency is poor, and even if the diameter is increased, the packing density is finally reduced when used as an adsorbent. May decrease and the adsorption performance may be insufficient. Even if the length of the pellet is increased, the pellet may be easily broken when used as an adsorbent, or the packing density may be lowered, resulting in insufficient adsorption performance.

  Prior to drying, the formed pellets may be spheroidized by a rotary granulator so that at least the corners of the pellets are rounded. It is preferable to use a pellet having a diameter and a length close to each other when spheroidizing.

The pellet is then dried. As a drying method, a conventionally known method can be adopted, and it is usually dried at 80 to 150 ° C. for about 0.5 to 12 hours.
After drying, firing is performed, but the firing temperature is preferably in the range of 300 to 800 ° C, more preferably 400 to 700 ° C. By this firing, the hydroxide in the composite oxide fine particles constituting the compact becomes an oxide, and at least a part of the metal ammine complex is reduced to become a metal.

  If the firing temperature is low, the strength and wear resistance of the resulting molded product may be insufficient. In addition, a large amount of water molecules may remain in the adsorbed state, and the adsorption performance of sulfur compounds and the like may be insufficient.

  If the calcination temperature is too high, the specific surface area of the adsorbent obtained by sintering the composite oxide will decrease, the metal components will aggregate, and it will be substantially an oxide. Performance may not be obtained.

The adsorbent obtained by the production method according to the present invention as described above is composed of inorganic oxide fine particles comprising silica, an inorganic oxide other than silica, and a metal derived from a metal ammine complex . The metal derived from the metal ammine complex may be in an ionic state (ionic bond) or a metal.

The molar ratio of the moles of silica inorganic oxide particles constituting the adsorbent (M _S) and the number of moles of inorganic oxides other than silica _{(M NS) (M S)} / (M NS) is generally (I) silicate aqueous solution and
(ii) Corresponds to the molar ratio with the oxoacid salt aqueous solution. The content of the metal derived from the metal ammine complexes corresponds to charging amount of (iii) a metal ammine complex.

Therefore, (M _S ) / (M _NS ) is in the range of 0.5 to 20, more preferably in the range of 1 to 10, with high composite effect, high specific surface area of fine particles, and sufficient adsorption performance. Since the metal content is also high, it is suitable as an adsorbent.

The specific surface area of the adsorbent obtained in the present invention, but are not particularly limited, 200~1000m ² / g, more preferably in the range of 300~800m ² / g. Within this range, the adsorption performance is high and the strength is also excellent. The surface area of the adsorbent substantially corresponds to the specific surface area of the composite oxide particles.

[Example]
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited by these Examples.

[Example 1]
Preparation of inorganic oxide fine particle (1) dispersion A mixture of 14 g of silica sol (pH 10.5) having an average particle diameter of 5 nm and a SiO ₂ concentration of 20 wt% and 266 g of pure water was heated to 80 ° C. with stirring. To this, 840 g of 3 wt% sodium silicate aqueous solution as SiO ₂ , 317 g of 3 wt% sodium aluminate aqueous solution as Al ₂ O ₃ , and 1 wt% ammine complex ([Ag (NH ₃ ) ₂ ] OH) as Ag 1250 g of aqueous solution was added simultaneously over 3 hours (pH after addition was 12.3).

During this time, the temperature was maintained at 80 ° C. After completion of the addition, the reaction solution is cooled to room temperature, then washed by an ultrafiltration membrane method and concentrated to form inorganic oxide fine particles (1) composed of SiO ₂ · Al ₂ O ₃ · Ag having a solid content concentration of 10 wt%. A dispersion was prepared.
Table 1 shows the metal content, average particle diameter, and specific surface area of the inorganic oxide fine particles (1).

Preparation of Adsorbent (1) 2% by weight of crystalline cellulose was added to the dispersion of inorganic oxide fine particles (1), and the mixture was placed in a kneader with a steam jacket and concentrated while stirring until the water content was 28% by weight. A pellet having a diameter of 2 mm and a length of about 6 mm was formed using an extrusion molding machine.

  The obtained pellets were dried at 130 ° C. for 16 hours and fired at 550 ° C. to obtain an adsorbent (1). The diameter and length of the adsorbent (1) are shown in Table 1.

Performance evaluation (1)
A stainless steel reaction tube having an inner diameter of 28.4 mm was filled with 20 g of the adsorbent (1).
Subsequently, methyl mercaptan gas (concentration 6.6 ppm) was supplied as an adsorption gas so that the space velocity (SV) was 32,000 h ⁻¹ . At this time, the pressure was maintained at normal pressure and the temperature was maintained at 25 ± 3 ° C.

The amount of methyl mercaptan adsorbed was determined as follows.
First, the concentration of methyl mercaptan in the outlet gas was analyzed by gas chromatography, and the supply of methyl mercaptan was stopped when the concentration of methyl mercaptan reached 0.5 ppm. The adsorption amounts up to this time are integrated, and the results are shown in Table 1 as weight percent with respect to the adsorbent (1). Table 1 shows the results with the time until the concentration of methyl mercaptan at the outlet becomes 0.5 ppm as the breakthrough time.

Performance evaluation (2)
In the performance evaluation (1), the same procedure was performed except that a gas adjusted by adding water so that the relative humidity (RH) of the methyl mercaptan gas (concentration 6.6 ppm) was 50% was used as the adsorption gas. The results are shown in Table 2.

Performance evaluation (3)
In the performance evaluation (1), the same procedure was performed except that the gas adjusted by adding water so that the relative humidity (RH) of the methyl mercaptan gas (concentration 6.6 ppm) was 90% was used as the adsorption gas. The results are shown in Table 1.

[Example 2]
Preparation of inorganic oxide fine particle (2) dispersion A mixture of 8 g of silica sol 1 (pH 10.5) having an average particle size of 5 nm and a SiO ₂ concentration of 20 wt% and 342 g of pure water was heated to 80 ° C. with stirring. To this, 648 g of 5 wt% sodium silicate aqueous solution as SiO ₂ , 500 g of 1 wt% sodium aluminate aqueous solution as Al ₂ O ₃ , and 900 g of 1 wt% ammine complex aqueous solution as Ag were simultaneously added over 3 hours. (The pH after the addition was 12.25). During this time, the temperature of the reaction solution was maintained at 80 ° C.

After completion of the addition, the reaction solution is cooled to room temperature, then washed by an ultrafiltration membrane method and concentrated to form inorganic oxide fine particles (2) composed of SiO ₂ · Al ₂ O ₃ · Ag having a solid content concentration of 10% by weight. A dispersion was prepared.
Table 1 shows the metal content, average particle diameter, and specific surface area of the inorganic oxide fine particles (2).

Preparation of adsorbent (2) 2% by weight of crystalline cellulose was added to the inorganic oxide fine particle (2) dispersion, and the mixture was placed in a kneader with a steam jacket and concentrated until the water content became 29% by weight. A pellet having a diameter of 2 mm and a length of about 6 mm was formed using an extrusion molding machine.

The obtained pellets were dried at 130 ° C. for 16 hours and fired at 550 ° C. to obtain an adsorbent (2). Table 1 shows the diameter and length of the adsorbent (2).
Performance evaluations (1), (2) and (3) were performed on the resulting adsorbent (2), and the results are shown in Table 1.

[Example 3]
Preparation of inorganic oxide fine particle (3) dispersion A mixture of 17 g of silica sol (pH 10.5) having an average particle size of 5 nm and a SiO ₂ concentration of 20% by weight and 318 g of pure water was heated to 80 ° C. with stirring. 3% by weight as SiO ₂
1005 g of an aqueous solution of sodium silicate, 1150 g of an aqueous solution of sodium aluminate having a concentration of 1% by weight as Al ₂ O ₃ and 500 g of an aqueous solution of ammine complex having a concentration of 1% by weight as Cu were simultaneously added over 4 hours (the pH after addition was 12.3). ) During this time, the temperature of the reaction solution was maintained at 80 ° C.

After completion of the addition, the reaction solution is cooled to room temperature, then washed by an ultrafiltration membrane method, concentrated and inorganic oxide fine particles composed of SiO ₂ · Al ₂ O ₃ · Cu having a solid content concentration of 10% by weight (3) A dispersion was prepared.
Table 1 shows the metal content, average particle diameter, and specific surface area of the inorganic oxide fine particles (3).

Preparation of adsorbent (3) Add 1% by weight of methyl cellulose and crystalline cellulose to the dispersion of inorganic oxide fine particles (3), respectively, and concentrate in a kneader with a steam jacket until the water content reaches 28% by weight. did. A pellet having a diameter of 2 mm and a length of about 6 mm was formed using an extrusion molding machine.

The obtained pellets were dried at 130 ° C. for 16 hours and fired at 550 ° C. to obtain an adsorbent (3). Table 1 shows the diameter and length of the adsorbent (3).
Performance evaluations (1), (2) and (3) were performed on the resulting adsorbent (3), and the results are shown in Table 1.

[Example 4]
Preparation of adsorbent (4) The inorganic oxide fine particle (1) dispersion prepared in the same manner as in Example 1 was spray-dried using a spray dryer. The water content of the obtained dry powder was 14% by weight. Water was added while stirring and mixing this to obtain a powder having a water content of 26% by weight. This powder was added to a granulator (manufactured by Fuji Powder Co., Ltd .: Malmerizer), and spherical particles having a diameter of about 2 mm were formed while rotating at 400 rpm.

The obtained spherical particles were dried at 110 ° C. for 16 hours and calcined at 550 ° C. to obtain an adsorbent (4). The diameter of the adsorbent (4) is shown in Table 1.
Performance evaluation (1), (2) and (3) was performed on the resulting adsorbent (4), and the results are shown in Table 1.

[Example 5]
Preparation of Inorganic Oxide Fine Particle (4) Dispersion A mixture of 16 g of silica sol (pH 10.5) having an average particle diameter of 5 nm and a SiO ₂ concentration of 20% by weight and 309 g of pure water was heated to 80 ° C. with stirring. To this was added 975 g of a 3 wt% sodium silicate aqueous solution as SiO ₂ , 750 g of a 1 wt% sodium tetraborate aqueous solution as B ₂ O ₃ , and 1000 g of an ammine complex aqueous solution of 1 wt% concentration as Ag over 3 hours. .

During this time, the temperature of the reaction solution was maintained at 80 ° C. After completion of the addition, the reaction solution is cooled to room temperature, then washed by an ultrafiltration membrane method and concentrated to form inorganic oxide fine particles (4) composed of SiO ₂ .B ₂ O ₃ .Ag having a solid content concentration of 10% by weight. A dispersion was prepared.
Table 1 shows the metal content, average particle diameter, and specific surface area of the inorganic oxide fine particles (4).

Preparation of adsorbent (5) 2% by weight of crystalline cellulose was added to the dispersion of inorganic oxide fine particles (4), and the mixture was placed in a kneader with a steam jacket and stirred until the water content was 28% by weight. A pellet having a diameter of 2 mm and a length of about 6 mm was formed using an extrusion molding machine.

The obtained pellets were dried at 130 ° C. for 16 hours and fired at 550 ° C. to obtain an adsorbent (5). The diameter and length of the adsorbent (5) are shown in Table 1.
Performance evaluations (1), (2) and (3) were performed on the obtained adsorbent (5), and the results are shown in Table 1.

[Comparative Example 1]
Preparation of adsorbent (R1) NaY zeolite powder (manufactured by Catalyst Chemical Industry Co., Ltd., SiO ₂ / Al ₂ O ₃ = 5.1, moisture 1
(7 wt%) 120 g was suspended in 1 L of pure water, 39.4 g of silver nitrate was added, and the pH was adjusted to 6.5 with nitric acid having a concentration of 10 wt%. Then, ion exchange was performed by stirring at 50 ° C. for 1 hour. This was filtered and washed, dried at 130 ° C. for 16 hours, crushed in a mortar, and silver-ion exchanged zeolite (AgY) powder was obtained. The Ag content in the powder was 20% by weight.

To the obtained AgY zeolite powder, an alumina sol (catalyst conversion industry Co., Ltd. product: AP-1, Al ₂ O ₃ concentration 70 so that the content of Al ₂ O ₃ as a binder in the total solid content is 20% by weight. % By weight), water was added so that the water content was 41% by weight, and kneaded sufficiently, and this was molded into a pellet having a diameter of 2 mm and a length of about 5.5 mm by an extruder.

The obtained pellets were dried at 130 ° C. for 16 hours and calcined at 550 ° C. to obtain an adsorbent (R1). The diameter and length of the adsorbent (R1) are shown in Table 1.
Performance evaluations (1), (2) and (3) were performed on the obtained adsorbent (R1), and the results are shown in Table 1.

[Comparative Example 2]
Preparation of adsorbent (R2) 104 g of β zeolite powder (SiO ₂ / Al ₂ O ₃ = 27, moisture 4 wt%) was suspended in 1 L of pure water. To this was added 39.4 g of silver nitrate, and the pH was adjusted to 6.5 with nitric acid having a concentration of 10% by weight. Thereafter, the mixture is stirred and mixed at 50 ° C. for 1 hour. This was filtered and washed, dried at 130 ° C. for 16 hours, crushed in a mortar to obtain zeolite (Agβ) powder in which silver was ion-exchanged. The Ag concentration in the powder was 5% by weight.

To the obtained Agβ zeolite powder, an alumina sol (manufactured by Catalyst Kasei Kogyo Co., Ltd .: AP-1, Al ₂ O ₃ concentration 70 so that the content of Al ₂ O ₃ as a binder in the total solid content is 20% by weight. % By weight), water was added so that the water content was 41% by weight, and kneaded sufficiently, and this was molded into a pellet having a diameter of 2 mm and a length of about 5.5 mm by an extruder.

The obtained pellets were dried at 130 ° C. for 16 hours and calcined at 550 ° C. to obtain an adsorbent (R2). The diameter and length of the adsorbent (R2) are shown in Table 1.
Performance evaluation (1), (2) and (3) was performed on the obtained adsorbent (R2), and the results are shown in Table 1.

Claims (6)

In alkaline aqueous solution or alkaline seed particle dispersion,
(i) an aqueous silicate solution and / or an acidic silicate solution;
(ii) Aluminic acid, 4 boric acid, antimonic acid, stannic acid, aluminosilicic acid, vanadic acid, molybdic acid, zirconic acid, tungstic acid, selenic acid, antimonic acid, bismuth acid, titanic acid, niobic acid, cerium oxysulfate, oxy An alkali metal salt or ammonium salt aqueous solution of at least one oxo acid selected from the group consisting of zirconium carbonate and phosphoric acid;
(iii) Mixing an aqueous solution of an ammine complex of at least one metal selected from Cu, Ag, Zn, Ni, Co, and Zr to prepare composite compound fine particles,
A method for producing an adsorbent, comprising molding and firing the obtained fine particles. The method for producing an adsorbent according to claim 1, wherein the amount of (iii) ammine complex to be mixed is in the range of 0.1 to 40% by weight in terms of the amount of metal supported in the adsorbent. . (iii) The method for producing an adsorbent according to any one of claims 1 to 2, wherein the ammine complex is a complex of Cu and / or Ag.   The method for producing an adsorbent according to any one of claims 1 to 3, wherein the composite compound fine particles have an average particle diameter in the range of 2 to 500 nm. (i) The silicate and / or acidic silicate liquid is expressed in terms of moles (M _S ) as SiO ₂ , and (ii) an alkali metal salt or ammonium salt of oxo acid is an oxide of a metal element constituting the oxo acid (I) and (ii) are added so that the molar ratio (M _S ) / (M _NS ) is in the range of 0.5 to 20 when expressed in terms of the number of moles (M _NS ) when converted. The manufacturing method of the adsorption agent in any one of Claims 1-4.   (ii) The method for producing an adsorbent according to any one of claims 1 to 5, wherein the oxoacid salt is an aluminate.