JP2820484B2 - Adsorbent manufacturing method - Google Patents

Description

The present invention relates to a method for producing an adsorbent used for a dehumidifier, a deodorant and the like.

[Conventional technology]

Conventionally, many things have been used as adsorbents,
Particularly, silica gel, activated carbon and the like are frequently used.

[Problems to be solved by the invention]

Silica gel has a large specific surface area and excellent adsorption performance, but easily breaks when molded as an adsorbent,
In addition, there is a problem that reproduction is difficult because of the hydrophilicity.

Activated carbon has the advantage of being hydrophobic and easy to regenerate.However, wood, lignite, and peat are treated with zinc chloride, phosphoric acid, etc., and then carbonized, or charcoal is heated with steam. It has a problem that not only is there a problem in mass production as a resource because wood and the like are used as a raw material, but also the adsorption performance is not so high. In addition, there is another problem that activated carbon cannot be used in a clean room purification device such as a diode factory where carbon must be avoided as much as possible.

The present invention has been made in view of the above technical level, and has as its object to provide a method for producing an adsorbent having an advantage of the hydrophobicity of activated carbon (ease of regeneration) and having an adsorption performance 2 to 4 times that of activated carbon. is there.

[Means for solving the problem]

The first adsorbent targeted by the present invention is an adsorbent obtained by firing a mixed molded product of ultrafine amorphous silica and a small amount of a binder, and having a specific surface area of 70 m ² / g or more. The first adsorbent is formed by burning the fuel and oxygen in a combustion furnace, as described below, which is the first invention of the present invention.
In a high-temperature field of 2300 ° C. or higher, a powdered raw material containing silicon oxide is charged to generate gaseous silica, and a combustion gas containing the gaseous silica is guided outside the furnace, and a cooling gas is blown into this. To produce ultrafine amorphous silica, which is collected, added with a binder, molded, and then calcined to produce an adsorbent.

The second adsorbent aimed at by the present invention is obtained by firing a mixed molded product of aluminum oxide or iron oxide, an alkali metal oxide, ultrafine amorphous silica and a small amount of a binder, and has a specific surface area of a 70m ² / g or more in which the adsorbent, the second adsorbent second invention following preparation method which is of the present invention, i.e., formed by the fuel and oxygen are combusted in the combustion furnace 23
A powder material containing aluminum oxide or iron oxide, an alkali metal oxide and a silicon oxide is simultaneously charged into a high temperature field of 00 ° C. or more to generate the metal oxide and silica in a gaseous phase, A combustion gas containing an oxide and silica is introduced outside the furnace, and a cooling gas is blown into the furnace to generate and collect an amorphous compound composed of ultrafine metal oxide and silica, and a binder is added thereto. It is manufactured by a method of manufacturing an adsorbent that is molded and fired.

That is, the present invention can be summarized as follows. According to the present invention, silica (SiO ₂ ) is once vaporized and then quenched to obtain amorphous ultrafine particles (0.08) microns or less: average particle size of about 0.04 microns. ) To produce an adsorbent containing amorphous ultrafine silica as a main component.

 Hereinafter, the first invention of the present invention will be described.

Since silica does not vaporize unless it is at a high temperature, it is necessary to burn a fuel and oxygen in a combustion furnace to form a high-temperature field of 2300 ° C. or higher, and to supply a powder material containing silicon oxide to this high-temperature field.

Combustion gas containing silica vaporized in a high-temperature field is led outside the furnace, and a cooling gas is blown into it to rapidly cool (1000 ° C or lower,
When the temperature is as low as possible), the silica is collected as amorphous and ultrafine powder. At this time, the particle size of the powder becomes smaller as the temperature is lowered.

A binder and, if necessary, a pore-forming agent such as cellulose are added to the collected ultrafine amorphous silica, mixed and molded, and the mixture is calcined to obtain an adsorbent. At this time, the mixing ratio of the ultrafine amorphous silica and the binder (kaolin, silica sol, alumina sol, attapulgite, etc.) is 75
It is preferable that the content be in the range of about 95% by weight and the latter in the range of 3 to 23% by weight (the remaining 2% by weight of cellulose). The firing temperature after molding is not particularly limited, but is generally 450 to 800 ° C. In this way, an adsorbent having a specific surface area of at least 70 m ² / g is obtained.

The second invention of the present invention is the first invention except that aluminum oxide or iron oxide and an alkali metal oxide are added together with silicon oxide as a powder raw material to be charged into a high temperature field in the description of the first invention. This is exactly the same method.

[Action]

Since the adsorbents produced in the first and second inventions are inherently hydrophobic, they have properties that can be easily regenerated after being used as adsorbents, and are 2 to 4 times smaller than commercially available activated carbon.
It has twice the adsorptivity and has the property that a molded article as an adsorbent is hard to break.

In the method for producing an adsorbent according to the first and second aspects of the present invention, the raw material oxide in a gas phase is quenched, so that the raw material oxide is collected in an amorphous and ultrafine state. Adsorbents that can be used for various purposes can be produced.

Hereinafter, one embodiment of the method for producing the adsorbent according to the first and second aspects of the present invention will be described with reference to FIG.

In FIG. 1, reference numeral 1 denotes a combustion furnace having a cooling structure;
(G ₁ ) is a high temperature combustion flame in the furnace, 3 is a molten slag containing silica, 4 is a molten slag receiving chamber, 5 is a burner, and burner 5 blows combustion F, powdered silica S and oxygen O ₂ 1
The figure shows the figure. Further, 6 is ultrafine silica in solid phase contained in the combustion gas, 7 is a gas duct, 8 is a collecting device,
9 is an ultrafine amorphous silica granulator, and 10 is a firing device.

Also, a is the cooling gas, G ₂ is the clean gas, P ₁ is the collected ultra-fine amorphous SiO _2, P ₂ is granulated pellets adding silica binder, P ₃ is calcined product adsorbent Is shown.

M represents an added metal oxide powder such as an aluminum oxide or an iron oxide and an alkali metal oxide.

Example 1 In FIG. 1, fuel F and oxygen charged into a combustion furnace 1 were used.
A high-temperature flame of 2,500 to 3,000 ° C. is formed by O _2, and a part of the powdered silica S (boiling point of 2,230 ° C.) is evaporated and vaporized at the same time, becomes gas-phase silica, and is exhausted to the outside of the furnace together with the combustion gas. This exhaust gas is quenched by a cooling gas a such as air or nitrogen (for example, a gas at 2500 to 3000 ° C is 1000 ° C or less).
As a result, the gas phase silica becomes solid amorphous ultrafine silica. The generated ultrafine amorphous silica is guided to a collecting device 8 by a gas duct 7 and collected. After that, a granulating device 9 is used to mix the ultrafine amorphous silica with 80 wt%, a silica binder as a silica sol of 18 wt%, and pores. Cellulose, a drug
After adding 2 wt% and adding 15 wt% of water and kneading, extruded granules to form cylindrical pellets with a diameter of 1.5 mm and a length of 2 to 3 mm, and further dried at 110 ° C for 6 hours to form granulated pellets. It was P _2.

The granulating pellets P ₂ a baking apparatus 10 and baked for one hour to 500 to 800 ° C. to produce a product adsorbent P _3.

The powdered silica S that does not evaporate and evaporate in the combustion furnace 1 becomes molten slag 3 and is collected in the molten slag receiving chamber 4 outside the combustion furnace 1 system, and is reused as raw silica.

As described above, the points of the manufacturing process according to the present invention are as follows.

In order to increase the activated surface area, which is a requirement of the adsorbent,
By evaporating the powdered silica S, the specific surface area becomes 10
The reason is that 0 to 300 m ² / g of amorphous ultrafine silica 9 was obtained, and further, dry collection was performed so as not to impair the activity.

When the additive metal oxide powder M is used in combination, the additive metal oxide powder M may be added from a powder silica supply line as shown in FIG.

The adsorption performance of the adsorbent produced by the production method of the present invention was confirmed by the adsorption of moisture in gas.

FIG. 2 shows a test device for evaluating the adsorption performance, 20 is an adsorbent storage container, 11 is an adsorbent, 12, 13, 14 are automatic switching valves, 15
Is an exhaust fan.

Test, the water content level _{CH 2 O, 0 (mg /} ) of the gas G _o (Nl /
Cycle) to the adsorbent amount W (g), and G ₁ in the exhaust gas.
Moisture content level CH ₂ O of (Nl / cycle) in, 1 (mg /) was measured, adsorption rate from moisture concentration ratio C ₁ / C _o between the outlet and inlet openings of the adsorbent 11 Was evaluated by.

In the test, the adsorbent according to the present invention and commercial activated carbons A and B were compared and evaluated, and the gas amount per adsorbent G ₁ / W ([/ g / cycle] / m ² / g) for comparative evaluation ) Is the same value. Furthermore, the adsorption / desorption cycle is 1 minute, the adsorption pressure is 1 atm,
The desorption pressure is 0.2 atm. The test results are shown in FIG.

FIG. 3 shows that the adsorption speed of each sample is set to 1.0, the adsorption speed of the adsorbent (denoted as the adsorbent of the present invention) by the method of the present invention is 1.0,
It is expressed as an adsorption speed ratio.

As is clear from FIG. 3, the adsorbent according to the present invention was found to have 2 to 4 times the adsorption performance as compared with commercial activated carbons A and B.

The Example 2 ultrafine particles of aluminum oxide of the second silica methods in specific surface area 150 meters ² / g of the invention ultrafine particles and a specific surface area of 150 meters ² / g of the present invention were mixed 1: Preparation 1, kaolin 10 wt% , 1,000-10
A cellulosic pore piercing agent that forms ⁴ mm macropores was added, granulated, and heat-treated to produce 1.6 mmφ pellets (third invention).

This pellet is used as an adsorbent and packed in a two-tower pressure swing device, and wet air containing 4% by volume of water is adsorbed under pressure.
After flowing at 1.05 atm., Ultra-dry air dehumidified to a dew point of −50 ° C. was obtained from the outlet at SV = 500 (based on the inlet).

Since the dew point began to rise after aeration for about 10 minutes, the column was switched to a vacuum pump, and the pressure was reduced to an ultimate pressure of 0.05 atm.

At that time, it is not enough to just attach and remove the vacuum pump.
After reaching the vacuum of atm., while maintaining the vacuum, flow about 1/20 of the dry air countercurrently to the adsorption tower to significantly reduce the water partial pressure in the tower, strengthen the regeneration level, and perform desorption. Was.

The performance of the obtained adsorbent was almost the same as that of the adsorbent using the ultrafine silica particles of Example 1.

Ultrafine particles of Example 3 second method specific surface area 150m of the invention ² / g of silica ultrafine particles and the specific surface area of 150m ² / g of Fe ₂ O ₃ of the present invention were mixed 1: Preparation 1, kaolin 10 wt%, to prepare a 1,000～10 ⁴ by adding cellulosic pore pirates agent that forms macropores of Å and granule thermally treated 1.6mmφ pellets (third invention).

This pellet was used as an adsorbent and packed in a two-tower type pressure device, and moist air containing 4 vol% of water was adsorbed at an adsorption pressure of 1.05 atm.
Then, ultra dry air dehumidified to a dew point of −50 ° C. was obtained from the outlet at SV = 500 (based on the inlet).

Since the dew point began to rise after aeration for about 10 minutes, the column was switched to a vacuum pump, and the pressure was reduced to an ultimate pressure of 0.05 atm.

At that time, it is not enough to just attach and remove the vacuum pump.
After reaching the vacuum of atm., while maintaining the vacuum, downflow about 1/20 of the dry air in the countercurrent to the adsorption tower to significantly reduce the water partial pressure in the tower, strengthen the regeneration level, and perform desorption. Was.

The performance of the obtained adsorbent was almost the same as that of the adsorbent using the ultrafine silica particles of Example 1.

The Example 4 ultrafine particles aluminosilicate of the second silica methods in specific surface area 150 meters ² / g of the invention ultrafine particles and a specific surface area of 150 meters ² / g of the present invention were mixed 1: Preparation 1, kaolin 10 wt% , 1,000〜1
0 ⁴ added cellulosic pore pirates agent that forms macropores of Å and granule heat treated to produce pellets of 1.6mmφ to.

This pellet is used as an adsorbent and packed in a two-tower pressure swing device, and wet air containing 4% by volume of water is adsorbed under pressure.
After flowing at 1.05 atm., Ultra-dry air dehumidified to a dew point of −50 ° C. was obtained from the outlet at SV = 500 (based on the inlet).

Since the dew point began to rise after aeration for about 10 minutes, the column was switched to a vacuum pump, and the pressure was reduced to an ultimate pressure of 0.05 atm.

At that time, it is not enough to just attach and remove the vacuum pump.
After reaching the vacuum of atm., while maintaining the vacuum, flow about 1/20 of the dry air countercurrently to the adsorption tower to significantly reduce the water partial pressure in the tower, strengthen the regeneration level, and perform desorption. Was.

The performance of the obtained adsorbent was almost the same as that of the adsorbent using the ultrafine silica particles of Example 1.

Example 5 Na ₂ O / Al having a specific surface area of 150 m ² / g by the method of the second invention of the present invention
₂ O ₃ ratio of 0.5, to prepare a ultrafine particles aluminosilicate containing sodium SiO ₂ / Al ₂ O ₃ ratio of 4, kaolin 10wt
%, A cellulosic pore-forming agent that forms macropores of 1,000 to 10 ⁴ Å was added, granulated and heat-treated to produce 1.6 mmφ pellets.

This pellet is used as an adsorbent and packed in a two-tower pressure swing device, and wet air containing 4% by volume of water is adsorbed under pressure.
After flowing at 1.05 atm., Ultra-dry air dehumidified to a dew point of −50 ° C. was obtained from the outlet at SV = 500 (based on the inlet).

Since the dew point began to rise after aeration for about 10 minutes, the column was switched to a vacuum pump, and the pressure was reduced to an ultimate pressure of 0.05 atm.

At that time, it is not enough to just attach and remove the vacuum pump.
After reaching the vacuum of atm., while maintaining the vacuum, flow about 1/20 of the dry air countercurrently to the adsorption tower to significantly reduce the water partial pressure in the tower, strengthen the regeneration level, and perform desorption. Was.

The performance of the obtained adsorbent was almost the same as that of the adsorbent using the ultrafine silica particles of Example 1.

Example 6 Na ₂ O / Fe having a specific surface area of 150 m ² / g by the method of the second invention of the present invention
Ultrafine particles of iron silicate containing sodium having a ₂ O ₃ ratio of 0.5 and a SiO ₂ / Fe ₂ O ₃ ratio of 4 were prepared, and kaolin 10 wt%, 1,000 wt.
A cellulosic pore-forming agent that forms macropores of up to 10 ⁴ mm was added, granulated, and heat-treated to produce 1.6 mmφ pellets.

This pellet is used as an adsorbent and packed in a two-tower pressure swing device, and wet air containing 4% by volume of water is adsorbed under pressure.
After flowing at 1.05 atm., Ultra-dry air dehumidified to a dew point of −50 ° C. was obtained from the outlet at SV = 500 (based on the inlet).

Since the dew point began to rise after aeration for about 10 minutes, the column was switched to a vacuum pump, and the pressure was reduced to an ultimate pressure of 0.05 atm.

At that time, it is not enough to just attach and remove the vacuum pump.
After reaching the vacuum of atm., while maintaining the vacuum, downflow about 1/20 of the dry air in the countercurrent to the adsorption tower to significantly reduce the water partial pressure in the tower, strengthen the regeneration level, and perform desorption. Was.

The performance of the obtained adsorbent was almost the same as that of the adsorbent using the ultrafine silica particles of Example 1.

〔The invention's effect〕

According to the present invention, there is provided a hydrophobic adsorbent mainly composed of ultrafine amorphous wet silica, and therefore, an adsorbent having better adsorption performance than activated carbon and easy to regenerate is 1/1 / active carbon production cost.
It can be manufactured in 2 to 1/3.

The adsorbent provided in the present invention can be used not only for absorbing moisture, but also for adsorbing CO ₂ , O ₂ , and N ₂ .

[Brief description of the drawings]

FIG. 1 is a process diagram showing one embodiment of the method for producing the adsorbent of the present invention, FIG. 2 is a system diagram of a test apparatus for evaluating the performance of the adsorbent, and FIG. 3 is an adsorbent obtained by the method of the present invention. 5 is a table for verifying the effect of the above.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Akinori Yasutake 1-1, Akunouramachi, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries, Ltd. Nagasaki Research Laboratory (56) References JP-A-53-48091 (JP, A) JP-A-53-67258 (JP, A) JP-A-61-251551 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B01J 20/00-20/34 A61L 9/01

Claims (2)

(57) [Claims] 1. A powdery raw material containing silicon oxide is charged into a high-temperature field of 2300 ° C. or higher formed by burning fuel and oxygen in a combustion furnace to generate gaseous silica. To the outside of the furnace, blowing a cooling gas into the furnace and quenching it to produce ultrafine amorphous silica, collect it, add a binder to it, mold it, and then bake it. Characteristic method for producing adsorbents. 2. A powder material containing aluminum oxide or iron oxide, an alkali metal oxide and silicon oxide is simultaneously charged into a high-temperature field of 2300 ° C. or higher formed by burning fuel and oxygen in a combustion furnace, and The phase-forming metal oxide and silica are generated, and a combustion gas containing the gas-phase metal oxide and silica is guided to the outside of the furnace. A method for producing an adsorbent, which comprises producing and collecting an amorphous compound as described above, adding a binder to the mixture, forming the mixture, and firing the resultant.