JP2000233916A - Spherical-granular active carbon and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce high purity spherical-granular active carbon from which fine-powdery active carbon is hardly formed and which has excellent fluidity and has such specified small granule size as to be suitable for use in a gas phase as well as a liquid phase by carbonizing a spherical-granular phenolic resin while applying an oil to the spherical granular resin or fluidizing/vibrating the resin to prevent blocking of the spherical-granular resin from being caused and thereafter activating the carbonized spherical-granular material. SOLUTION: This production process comprises carbonizing a spherical-granular phenolic resin having a 50-300 μm average granule size while preventing blocking of the resin from being caused, by heating the resin to about 500-700 deg.C, and then activating the spherical- granular carbonized material by heating the carbonized material in e.g. air to an about 900 deg.C high temperature, wherein: as the blocking prevention method, a method that comprises fluidizing/vibrating the spherical-granular phenolic resin or applying an oil such as mineral oil to the surface of the spherical-granular resin, is preferred; and as the oil to be used, oil that is not decomposed at a temperature at which the spherical-granular phenolic resin are completely hardened, and also completely decomposed at a temperature at which the spherical-granular carbonized material is activated, is preferred. Thus, the objective high purity spherical-granular active carbon which has a 20-200 μm average granule size and excellent fluidity, can easily be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a spherical activated carbon, particularly to a spherical activated carbon suitable for a fluidized bed and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, activated carbon has been used as an adsorbent, a catalyst or its carrier for deodorization, decolorization, removal of impurities, and the like. In addition, as a usage form, there are a fixed bed, a fluidized bed (also referred to as a fluidized bed), a moving bed type device, and the like. In particular, activated carbon used in fluidized bed deodorizers or adsorbers to remove exhaust gas or recover solvents from organic solvent vapors is a catalyst that has good contact with the fluid and has high adsorption performance of activated carbon or supports it. In order to obtain a high catalytic action, a granular material is used. Conventionally, as such granular activated carbon, those made of crushed carbon and those obtained by granulating powdered activated carbon are mainly used.

However, in the case of the above-mentioned crushed coal, it is difficult to completely remove fine powder generated during crushing from the crushed coal surface.
Not only the production efficiency is poor, but also because the surface of the crushed coal is angular, the crushed coal rubs against each other during use in a fluidized bed, and the corners are shaved, and fine powder is easily generated. As a result, there is a problem that the performance of the activated carbon is deteriorated, and the adsorption device and the like are adversely affected due to troubles due to contamination and blockage in the piping of the device. Further, in a fluidized bed apparatus or the like, the higher the fluidity of the activated carbon, the higher the adsorption performance or the action of the supported catalyst. The fluidity is affected by the shape and particle size distribution of the particles, and a spherical shape has better fluidity than an angular shape. However, those made of crushed coal have poor fluidity due to the angular shape of the surface, and thus have a problem that it is difficult to exhibit excellent adsorption performance and catalytic action.

The particle size of activated carbon used in a fluidized bed apparatus or the like is not so limited when activated carbon is used in a liquid phase, and can be used up to about 2 mm. May have a mean particle size of 100 μm or less. However, since the yield of the crushed coal decreases as the particle diameter decreases, the average particle diameter is at least 150 μm at the minimum when mass-producing efficiently, and the yield of the crushed coal decreases when the particle diameter is further reduced. Extremely low. Therefore, it was not realistic to obtain a crushed coal having a small average particle diameter as required in the gas phase.

On the other hand, in the case of a molded product of the above-mentioned powdered activated carbon, the powdered activated carbon is bound in a granular form with a binder. There is a problem that the adsorption performance is hindered.

[0006] Further, conventionally, since natural materials such as sawdust, coconut shell, and coal are used in molded products of crushed carbon and powdered activated carbon, the carbon purity is low and the carbon purity is high in fields where high purity is required. Was not preferred.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been proposed in view of the above-mentioned problems, and is intended to provide a powder having a small average particle size which is hard to generate fine powder, has excellent fluidity, and is suitable for a gas phase. And to provide a method for producing the high-purity spherical activated carbon.

[0008]

[Means for Solving the Problems]

The invention of claim 1 comprises spherical activated carbon having an average particle diameter of 20 to 200 μm obtained by carbonizing and activating a spherical phenol resin. The invention of claim 2 relates to a spherical activated carbon having an average particle diameter of 20 to 200 μm, which is obtained by carbonizing a spherical phenol resin while preventing blocking, and then activating the carbonized carbon.

[0010] The invention of claims 3 to 8 relates to a method for producing spherical activated carbon. First, the invention of claim 3 is characterized in that the spherical phenol resin is activated after carbonization while preventing blocking.

[0011] The invention of claim 4 is characterized in that the spherical phenol resin is activated while being carbonized while flowing or vibrating. The invention of claim 5 is characterized in that after the oil is attached to the spherical phenol resin, the spherical phenol resin is activated. Carbonized phenolic resin,
The invention according to claim 6 is characterized in that the oil is adhered to the spherical phenolic resin, and the spherical phenolic resin after the oil adhesion is carbonized while flowing or vibrating, and then activated, whereby the blocking prevention effect is obtained. The invention of claim 7 is characterized in that an oil which does not decompose at the temperature at the time of complete curing of the spherical phenolic resin but decomposes at the temperature at the time of activation is used as the oil.

The invention of claim 8 is the invention of claim 3 to claim 7, wherein the spherical phenolic resin has an average particle diameter of 50.
~ 300μm, average particle size of spherical activated carbon is 20 ~ 200μ
m.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The spherical activated carbon of the present invention is obtained by carbonizing and activating a phenol resin to form a sphere, preferably by carbonizing the spherical phenol resin while preventing blocking as described below, and then activating the catalyst. It is particularly suitable for a fluidized bed type apparatus. The average particle size of the spherical activated carbon is preferably 20 to 200 μm so as to be suitable for the gas phase in a fluidized bed apparatus. In this specification, the average particle size refers to a volume cumulative distribution average particle size, which is measured by a particle size distribution measuring device or the like.

The phenol resin used is preferably a spherical phenol resin. Spherical phenolic resin is a phenolic resin whose surface is molded into a spherical shape and has an aromatic structure, so that the carbonization rate can be increased and activated carbon with a large surface area can be obtained by activation. The adsorption performance of the spherical activated carbon of the present invention produced from this spherical phenol resin is excellent.

Further, since the spherical phenolic resin is formed into a spherical shape, unlike crushed charcoal, the spherical activated carbon of the present invention obtained by its carbonization and activation has no angular portions on the surface. When used in a fluidized bed apparatus as well as during transportation, etc., there is no danger that the corners of the activated carbon particles will be rubbed and fine powder will be generated. The micropores on the surface are not broken, and the adsorption performance and the like do not decrease.

As the spherical phenol resin, known ones can be used, but those having an average particle diameter of 50 to 300 μm are preferably used. By using an average particle diameter in this range, the spherical activated carbon of the present invention having an average particle diameter of 20 to 200 μm suitable for the gas phase can be obtained. Needless to say, the spherical phenolic resin is appropriately selected from the range of the average particle diameter of the phenolic resin of 50 to 300 μm according to the desired average particle diameter of the spherical activated carbon. As an example of a known spherical phenol resin having an average particle diameter in the above range, PR-FSD (trade name, manufactured by Sumitomo Duyres Co., Ltd.)
And AH-3a (manufactured by Gunei Chemical Industry Co., Ltd.).

Next, a method for producing the spherical activated carbon will be described. The production of the spherical active substance is carried out by carbonizing the spherical phenol resin while preventing blocking, and then activating the carbonized phenol resin. At that time, as the spherical phenolic resin, the one having an average particle diameter of 50 to 300 μm as described above is used, and the obtained spherical activated carbon is suitable for a fluidized bed apparatus.
It is preferable that the average particle diameter is 20 to 200 μm.

The carbonization of the spherical phenol resin is carried out by placing the spherical phenol resin in a heating furnace or the like and heating the phenol resin at a temperature at which the phenol resin carbonizes for a required time. The temperature at that time depends on the heating time and the like, but is usually set to 500 to 700 ° C. when the heating time is about 1 to 3 hours. In order to efficiently perform the carbonization, it is preferable to dry the spherical phenol resin at a temperature lower than the carbonization temperature before the carbonization operation. Generally, an uncured portion generally remains in the spherical phenol resin, and the uncured portion is carbonized after being completely cured by heating in the carbonizing step.

Further, if the spherical phenolic resins are bonded to each other during carbonization and remain as they are after activation to form a non-sized granulated activated carbon (this is called blocking), the fluidity is impaired during use. Become so. Therefore, in the present invention, blocking is prevented by using the following two blocking prevention methods alone or preferably in combination.

In the first blocking prevention method, if the spherical phenol resin is left standing in the heating furnace in the carbonization step, blocking tends to occur. Therefore, gas is blown into the heating furnace from below or the heating furnace device itself is rotated. Alternatively, the spherical phenol resin is heated while being flown or vibrated by vibrating or the like, and carbonized to prevent blocking. More preferably, in the activation step after carbonization, heating is performed while the spherical phenol resin is flowed or vibrated.

In the second method for preventing blocking, if an uncured portion remains on the surface of the spherical phenolic resin, the spherical phenolic resins are completely cured by being brought into contact with each other and heated in the carbonization step. In order to cause blocking, oil is adhered to the spherical phenol resin, and the surface of the spherical phenol resin is coated with the oil so that the surfaces of the spherical phenol resins do not directly contact each other.

The oil used in the second method covers the surface of the spherical phenol resin until the uncured portion of the spherical phenol resin is completely cured during the carbonization step, and furthermore, the surface of the spherical activated carbon after the activation step is completed. Is preferably not remaining. As such an oil, those having a decomposition temperature of the oil higher than the temperature at the time of complete curing of the spherical phenol resin and lower than the temperature at the time of the activation step are suitable. If the oil has a decomposition temperature in this range, the oil is present on the surface of the spherical phenolic resin without being decomposed until the uncured portion of the phenolic resin is completely cured, and the surfaces of the spherical phenolic resins are in direct contact with each other. This can prevent the occurrence of blocking, and can prevent the occurrence of blocking. Further, in the activation step, it is decomposed and burnt and disappears, so that there is no need to subsequently perform an oil removal treatment. Incidentally, since the complete curing temperature of the spherical phenolic resin is lower than the maximum temperature in the carbonization step, for convenience, an oil whose decomposition temperature is higher than the maximum temperature in the carbonization step and is equal to or lower than the temperature in the activation step is used. May be used. As the type of oil, an appropriate one is used, and examples thereof include mineral oil (particularly heavy oil having a high boiling point), animal and vegetable oil, and synthetic lubricating oil.

Activation is a treatment method in which the surface of the spherical phenolic resin is increased after carbonization of the spherical phenolic resin to increase the surface area, and various methods are known. For example, there are a method of heating the object to be activated in a gas atmosphere mainly containing carbon dioxide gas and oxygen for several minutes to several hours, a method of treating with an alkali metal hydroxide, and the like. In the present invention, an activation method of heating at a high temperature in the air is simple and suitable.

[0024]

Next, Examples 1 to 7 of the present invention and Comparative Example 1 will be described. Further, in Examples 6 and 7, the change in the blocking ratio depending on the manufacturing conditions was also examined. Blocking rate, from the particle size distribution of the spherical phenolic resin used,
A diameter that allows 90% of the spherical phenolic resin particles to pass through (hereinafter referred to as a 90% passage diameter) is determined, and is a JIS standard having an opening that is equal to or larger than the 90% passage diameter and closest to the 90% passage diameter. The object to be measured was sieved using the sieve described above, the weight fraction of the substance remaining on the sieve relative to the object to be measured was calculated, and the calculated value was defined as the blocking ratio. Also,
For Examples and Comparative Examples, average particle size, iodine adsorption performance,
The abrasion resistance, fine powder value, water absorption and ignition residue were measured. The results and the blocking ratio are shown in Tables 1 and 2. In addition,
The measuring method is as follows.

Average particle size: Measured using a laser type particle size distribution analyzer (PRO-7000 manufactured by Seishin Enterprise).・ Iodine adsorption performance and ignition residue: JIS K147
4 Measured by the activated carbon test method. The larger the value of the iodine adsorption performance, the higher the adsorption performance, and the larger the value of the residue on ignition, the more impurities. Abrasion resistance (hardness of generation of fine powder): Approximately 0.2 g of a sample (activated carbon) was circulated by a pump using a laser type particle size distribution analyzer (PRO-7000 manufactured by Seishin Enterprise), and 10 μm after 60 minutes. The abrasion resistance was measured from the following increase in particles. 100% indicated in the numerical values in the table indicates that the amount of increase of the particles of 10 μm or less is 0, and indicates that as the numerical value decreases, the particles of 10 μm or less increase. Fine powder value: 5.0 g of the sample (activated carbon) was added to a 200 ml beaker containing 100 ml of a 5.0% aqueous ethanol solution, and the mixture was shaken vigorously for 30 minutes using a shaker. Within 5 minutes thereafter, use a spectrophotometer at 650 nm, 10 mm
The absorbance was measured in the cell, and the measured value of the absorbance was directly used as the fine powder value. The greater the value of this fine powder, the more fine powder. Water absorption: 5.0 g of a sample (activated carbon) was slowly dropped with a pipette and stirred, and the amount of water dropped by the time immediately before the activated carbon started to stick was measured, and the amount of the dropped water ( g) to determine the water absorption per 1 g of activated carbon. At the time of dropping, the measurement was performed while cooling the activated carbon so that water did not evaporate due to the heat of absorption. -Blocking ratio: 500 (sample of spherical phenol resin alone or mixture of spherical phenol resin and oil)
After carbonization at 3 ° C. for 3 hours, the carbide is sieved for 10 minutes using a test sieve defined by the above-mentioned blocking ratio. After sieving, the weight fraction of the carbide remaining on the sieve was determined, and the value was expressed as a blocking rate (%).

(Example 1) Oil (trade name: SF / CC SA) was added to 100 g of a spherical phenol resin (trade name: PR-FSD-1, manufactured by Sumitomo Durez Co., Ltd.) having an average particle size of 150 μm.
E 10W-30, manufactured by Castrol Co., Ltd., 10 g, and then mixed with a metal retort container (content 13 liter)
After drying at 120 ° C for 1 hour in a heating furnace,
While rotating the container at 15 rpm in the same heating furnace, 5
It was heated at 00 ° C. for 1 hour and carbonized. After the carbonization, the container was activated by heating at 900 ° C. for 1 hour while rotating the container at 1 rpm in the same heating furnace to obtain a spherical activated carbon. The obtained spherical activated carbon has a spherical shape with an average particle size of 110 μm, and has an iodine adsorption performance of 102 as measured as activated carbon characteristics.
It was 0 mg / g. The measurement result of the wear resistance is 10
It was found that there was no increase in the fine particles of μm or less, and the wear resistance was excellent.

Example 2 100 g of the same spherical phenol resin as in Example 1 was mixed with 10 g of oil in the same manner as in Example 1, dried, carbonized while rotating the container at 15 rpm, and then the container was cooled at 1 rpm. 900 ° C while rotating,
Activated by heating for 2 hours to obtain spherical activated carbon. The obtained spherical activated carbon was spherical with an average particle diameter of 100 μm, and had an iodine adsorption performance of 1180 mg / g. Also,
The same results as in Example 1 were obtained and the abrasion resistance was excellent.

Example 3 10 g of oil in the same manner as in Example 1 for 100 g of a spherical phenol resin (trade name: PR-FSD, manufactured by Sumitomo Durez) having an average particle diameter of 130 μm
And mixed in a retort container,
After drying at ℃ for 1 hour, the container was kept at 15 rpm in the heating furnace.
While being rotated at 500 ° C. for 1 hour to carbonize.
After carbonization, the container was activated by heating at 900 ° C. for 3 hours while rotating the container at 1 rpm in the same heating furnace to obtain a spherical activated carbon. The obtained spherical activated carbon was spherical with an average particle diameter of 80 μm, and had an iodine adsorption performance of 1280 mg / g.
Further, the abrasion resistance was excellent because the same results as in Examples 1 and 2 were obtained.

Example 4 The same spherical phenol resin as in Example 3 was carbonized in the same manner as in Example 3, and activated by heating at 900 ° C. for 4 hours while rotating the vessel at 1 rpm in a heating furnace. Then, spherical activated carbon was obtained. The obtained spherical activated carbon was spherical with an average particle size of 70 μm, and had an iodine adsorption performance of 1350 mg / g. The measured value of the wear resistance was 99.9%, indicating excellent wear resistance.

Example 5 10 g of oil was mixed with 100 g of a spherical phenol resin (trade name: PR-FSD, manufactured by Sumitomo Durez Co., Ltd.) having an average particle diameter of 300 μm and put in a retort container in the same manner as in Example 1. After drying in a heating furnace at 120 ° C. for 1 hour, the container was heated at 500 ° C. for 1 hour in the same heating furnace while rotating at 15 rpm to carbonize. After carbonization, 900 ° C while rotating the vessel at 1 rpm in the same heating furnace.
Activated by heating for 2 hours, average particle size 200μ
m of spherical activated carbon was obtained. The same measurement was performed on the spherical activated carbon. The results are shown in Examples 1 to 3 for the wear resistance.
Examples 4 to 5 were equivalent to Example 4, but the fine powder value was large.
Was inferior.

Example 6 Oil (trade name: SF / CC SAE) was added to 100 g of a spherical phenol resin (trade name: PR-FSD, manufactured by Sumitomo Durez Co., Ltd.) having an average particle size of 80 μm.
10W-30, manufactured by Castrol Co., Ltd.) were mixed in the proportions shown in Table 2, placed in the same retort container as in Example 1, dried in a heating furnace at 120 ° C. for 1 hour, and then statically heated in the same heating furnace. The mixture was heated at 500 ° C. for 3 hours and carbonized. The obtained carbide was spherical with an average particle size of 70 μm. The blocking ratio was 3.0% when the oil addition amount was 5% by weight, and was clearly lower than the blocking ratio 20.0% when the oil addition ratio was 0%. The blocking rate was 1.1% at 25% by weight, which is the limit of the amount of oil added.

The carbide obtained in Example 6 was activated by heating at 900 ° C. for 2 hours while rotating the vessel at 1 rpm in the same heating furnace as in the carbonization.
A spherical activated carbon was obtained. The obtained spherical activated carbon has an average particle size of 70.
It was spherical with a diameter of μm and had an iodine adsorption performance of 1190 mg / g. When the abrasion resistance of the obtained spherical activated carbon was measured in the same manner as in Example 1, there was no increase in fine particles of 10 μm or less, and it was excellent.

(Example 7) The same spherical phenol resin as in Example 6, which was subjected to the oil mixing and drying steps in the same manner as in Example 6, was heated at 500 ° C while rotating the vessel at 15 rpm in the same heating furnace. Heated for 3 hours and carbonized. The blocking ratio of the carbide was measured. Example 7
Comparing the blocking rates of Example 6 and Example 6, it is clear that the carbide of Example 7 has a lower blocking rate. This is because in Example 7, the occurrence of blocking can be effectively prevented by both the effect of the oil and the flow (rotation) effect of the spherical phenol resin, whereby the blocking rate can be suppressed to 1% or less. It has become possible.

Comparative Example 1 Activated carbon having an average particle size of 110 μm was produced from crushed coal made from coconut shell as a raw material by sieving. The same measurement as in Example 1 was performed on this activated carbon,
Various performances were compared. As a result, the abrasion resistance and the fine powder value were worse than those of Examples 1 to 7 of the product of the present invention, and the residue on ignition showed an extremely large value as compared with Examples 1 to 7 of the product of the present invention. .

[0035]

[Table 1]

[0036]

[Table 2] (Use an 83 mesh sieve to measure the blocking ratio)

[0037]

As described above, according to the present invention, the spherical phenol resin is carbonized and activated while preventing the spherical phenol resin from blocking, thereby forming a spherical activated carbon. Therefore, the shape can be made spherical. Therefore, when the spherical activated carbon of the present invention is used as an adsorbent or a catalyst of a fluidized bed type device and a carrier thereof, the spherical activated carbon exerts a high adsorptivity to odors and chemical substances due to the excellent fluidity of the spherical activated carbon, The catalyst reaction and the operation stability of the apparatus can be sufficiently exhibited. Further, since the activated carbon has a spherical shape, there is no problem that the corner of the surface is shaved and fine powder is generated as in the case of crushed carbon when used in a fluidized bed, and the fine powder has an adverse effect on the apparatus (contamination of pipes and blockage) and There is no risk of performance degradation of activated carbon. In addition, unlike the spherical activated carbon of the present invention in which the powdered active substance is bound with a binder, the surface is not covered with the binder, so that the activated carbon content is increased, and the adsorption performance and catalyst performance are not hindered.

In the present invention, since spherical activated carbon is produced from a phenolic resin having an aromatic structure, the carbonization rate of activated carbon is higher than activated carbon made of natural raw materials such as coconut shells and sawdust powder. The effect of improving the adsorption performance and the catalyst performance can be obtained. Furthermore, in the present invention, the spherical activated carbon has an average particle size of 20 to 200 μm, so that it can be suitably used not only for the liquid phase but also for the gas phase.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Nao Inada 2-262 Mimoncho, Minokamo-shi, Gifu Pref. Nimura Chemical Industry Co., Ltd. Gifu Plant (72) Inventor Tsukasa Takasaka 2 Mimoncho, Minokamo-shi, Gifu -2-62 Nimura Chemical Industry Co., Ltd. Gifu Factory (72) Inventor Hirofumi Ito 2-3-1 Minatomirai, Nishi-ku, Yokohama-shi, Kanagawa Prefecture JGC Corporation F-term (reference) 4G046 HA03 HB02 HB05 HC14 HC21 4G066 AA05B AC25A BA09 BA20 BA35 BA36 BA38 CA31 FA18 FA21 FA23 4G069 AA01 AA08 BA08A BA08B BA22A BA22B BA22C DA08 EA02X EA02Y ED03

Claims (8)

[Claims] 1. A spherical activated carbon having an average particle diameter of 20 to 200 μm obtained by carbonizing and activating a spherical phenol resin. 2. An average particle diameter of 20 to 2 obtained by carbonizing the spherical phenol resin while preventing blocking, and then activating.
00 μm spherical activated carbon. 3. A method for producing a spherical activated carbon, wherein a spherical phenol resin is carbonized while preventing blocking, and then activated. 4. A method for producing a spherical activated carbon, characterized in that a spherical phenol resin is carbonized while flowing or vibrating, and then activated. 5. A method for producing a spherical activated carbon, comprising: adhering an oil to a spherical phenol resin; and carbonizing and activating the spherical phenol resin. 6. A method for producing a spherical activated carbon, comprising: adhering oil to a spherical phenol resin; carbonizing the spherical phenol resin after the oil adhesion while flowing or vibrating; and activating the activated carbon. 7. The method for producing spherical activated carbon according to claim 5, wherein an oil which does not decompose at the temperature at the time of complete curing of the spherical phenolic resin and decomposes at the temperature at the time of activation is used. 8. The spherical phenolic resin having an average particle size of 50 to 50.
300 μm, average particle size of spherical activated carbon is 20-200 μm
The method for producing a spherical activated carbon according to any one of claims 3 to 7, wherein