KR100912203B1 - Method for stabilizing particles containing carbon, activated carbon and method for preparing the same - Google Patents

Abstract

A method for stabilizing particles containing carbon, activated carbon and a method for preparing the same are provided to improve compression fracture load, a specific surface area, and sphericity etc, and to offer high yield of a final gaining material. A method for manufacturing activated carbon includes the following steps of: stabilizing particles containing carbon after impregnation of the particles containing carbon; oxidizing the stabilized particles in the oxygen atmosphere; reducing the oxidized particles before activation; and activating the oxidized particles in activation gas. An oxidation process is progressed at a temperature of 200‹C -400‹C for 5 minutes - 1 hour.

Description

Stabilization method of carbon-containing particles, activated carbon and manufacturing method thereof {METHOD FOR STABILIZING PARTICLES CONTAINING CARBON, ACTIVATED CARBON AND METHOD FOR PREPARING THE SAME}

The present invention relates to a method for stabilizing carbon-containing particles, activated carbon, and a method for producing the same. More particularly, the present invention relates to active carbon having high yield, excellent compressive fracture load, and specific surface area by impregnating and stabilizing carbon-containing particles in a specific solution. It relates to a method for stabilizing carbon-containing particles that can be produced, activated carbon using the same and a method for producing the same.

Porous activated carbon is used in many fields. Activated carbon is used, for example, as an electrode for capacitors, column fillers for water treatment, molecular sieve carbon, deodorants, decolorants, and the like. Activated carbon is also used as an oral adsorbent that can treat kidney or liver dysfunction.

In general, activated carbon is manufactured in powder form through carbonization and activation treatment of carbon precursors such as petroleum pitch. However, it has been pointed out that activated carbon in powder causes secondary pollution problems. Accordingly, the production of activated carbon having a certain shape, for example, a spherical shape, has been attempted.

For example, Japanese Unexamined Patent Publication No. 2002-308785 (Previous Document 1) discloses a spherical activated carbon having a diameter of 0.01 to 1 mm using a petroleum pitch as a carbon precursor as an adsorbent for oral administration. In addition, Korean Patent Laid-Open Publication No. 10-2007-0001211 (Previous Document 2) discloses a method for producing spherical activated carbon prepared by oxidizing and activating a heat-melting resin sphere.

Prior art 2 refers to "incompatibility treatment". Specifically, if the insoluble treatment is not subjected to the inactivation treatment before the activation treatment, the heat-melting resin spherical body is mentioned that melting and decomposition occurs as the temperature rises, so that the spherical body cannot be maintained. It is described as oxidizing at 150 ° C to 400 ° C under an atmosphere. The incompatibility treatment (oxidation treatment) suppresses softening and can suppress deformation into non-spherical shapes or fusion of spherical bodies.

However, the prior art including the prior arts have a problem in that the yield (production rate) of the activated carbon, which is the final product, is lowered, the compressive fracture load (compressive strength) is lowered, and durability, and the starting material (carbon precursor) is limited. It is also pointed out that the problem of not having satisfactory characteristics also in specific surface area and sphericity.

Therefore, the present invention is to solve the problems as described above, by impregnating and stabilizing the carbon precursor (carbon-containing particles) in a specific solution, the yield of the final product is high and the compressive fracture load (compressive strength), specific surface area, sphericity It is an object of the present invention to provide a method for stabilizing carbon-containing particles, an activated carbon using the same, and a method for producing the same.

In order to achieve the above object, the present invention provides a method for stabilizing carbon-containing particles comprising the step of impregnating the carbon-containing particles in the acid solution, and then heat treatment.

The method for stabilizing carbon-containing particles according to the present invention preferably further includes a step of oxidizing the impregnated and heat-treated resin particles.

In addition, the present invention comprises the steps of stabilizing the carbon-containing particles by the stabilization treatment method; And it provides a method for producing activated carbon comprising the step of activating the stabilized carbon-containing particles.

In addition, the present invention, the step of stabilizing carbon-containing particles by the stabilization treatment method; Reducing the stabilized carbon-containing particles; And it provides a method for producing activated carbon comprising the step of activating the reduction-treated carbon-containing particles.

In addition, the present invention provides spherical activated carbon having an average diameter of 50 µm to 10 mm and a compressive fracture load of 2 N or more per unit particle. The spherical activated carbon preferably has a compressive fracture load of 3 N or more.

According to the present invention, due to the impregnation stabilization process through the acid solution has a high yield of the final product (active carbon) and has an effect of improving the compressive fracture load (compressive strength), specific surface area, sphericity.

Hereinafter, the present invention will be described in more detail.

The method for stabilizing carbon-containing particles according to the present invention includes at least a first step of impregnating the carbon-containing particles in an acid solution and then heat-treating them. Preferably, the method further includes a second step of oxidizing the carbon-containing particles impregnated and heat-treated through the first step.

According to the present invention, the carbon-containing particles stabilized through at least the first step, preferably the first step and the second step, have improved thermal properties while finally maintaining their shape after undergoing any post-treatment step. And the yield and compressive fracture load (compressive strength) of the final product are increased.

For example, in the production of spherical activated carbon, the spherical carbon precursor (carbon-containing particles), which is a starting material, is spherical even after a subsequent process (oxidation, reduction, carbonization, activation) when stabilized by the above process. Keep the shape as it is. In addition, productivity is increased due to high yield, and compression failure load is increased to improve durability. In addition, the prepared activated carbon has an increased specific surface area.

In the present invention, the carbon-containing particles used as the starting raw material are at least carbon-containing particulate matter, and may contain elements such as hydrogen, oxygen, and nitrogen in addition to carbon. For example, the carbon-containing particles may be used as starting materials for activated carbon. For example, the carbon-containing particles can be used as long as they are particulates having a certain shape as petroleum pitch, high molecular compound or the like. The carbon-containing particles are, for example, spherical and the like, but are not particularly limited and may have a size of 50 μm to 10 mm in average diameter.

In addition, the carbon-containing particles are a high molecular compound, and include natural and synthetic polymers. In this case, the polymer compound may be selected from, for example, a heat meltable resin. In the present invention, the heat-melt resin may be selected from thermoplastic resins to be melted or decomposed without incompatibilization. The thermoplastic resin is not particularly limited, and examples thereof include crosslinked vinyl resins and ion exchange resins. In addition, in the present invention, even if the thermosetting resin is melted or decomposed as the temperature rises without the incompatibility treatment, even if the thermosetting resin, the thermosetting resin also includes a thermosetting resin if it can be made of activated carbon after the stabilization treatment through the process. .

The carbon-containing particles used as starting materials in the present invention include the above materials, for example, any material as long as it can be produced with activated carbon. Hereinafter, the stabilization treatment method according to the present invention will be described for each step.

1st process

The first step proceeds by impregnating the carbon-containing particles into the acid solution and then heat treatment. (Impregnation stabilization treatment)

In this case, the acid solution may be, for example, an inorganic acid solution, and more specifically, for example, one or more selected from the group consisting of nitric acid solution, sulfuric acid solution, and phosphoric acid solution may be used. In this case, when the nitric acid solution is used as the acid solution, although not particularly limited, an aqueous nitric acid solution having a nitric acid concentration of 10 to 60% by weight (wt)% may be used. The carbon-containing particles are heat treated after being impregnated with the above acid solution, wherein the heat treatment may be performed by heating while being impregnated with the acid solution.

According to the present invention, by performing the first step (impregnation stabilization treatment), functional groups are introduced and / or changed inside the carbon-containing particles as starting materials, and the introduced and / or changed functional groups are dehydrated during the oxidation process. It is discharged as water through dehydration. In addition, the degree of crosslinking is increased by the substitution reaction. For example, when the nitric acid solution is used as the acid solution, nitrogen (N) is substituted to perform a cross linking role. Specifically, the nitric acid impregnation stabilization treatment using nitric acid solution provides a basis for crosslinking of hydrocarbon compounds and nitrogen (N) through the introduction of functional groups, for example, the process for producing activated carbon (oxidation, reduction) , Carbonization, activity, etc.) to increase the fixed carbon content and to maintain the spherical shape. In addition, despite the well-developed micropores have a thermal stability that can be converted to a carbon-based porous material (active carbon) having a predetermined compressive strength or more (compression failure load of 2N or more). In addition, for example, in the case of using a sulfuric acid solution as the acid solution, sulfur (S) is substituted to perform a cross-linking role, to have the same effect as above.

In addition, the suitability of the nitric acid impregnation stabilization treatment through the nitric acid solution, for example, may vary depending on the starting material, but can be determined by the nitrogen content of the carbon-containing particles (for example, spherical polymer compounds). The carbon-containing particles may be, for example, 1 to 10% by weight of the nitrogen content according to element analysis after the impregnation stabilization treatment, and more specifically 3 to 5% by weight. Specifically, the nitric acid impregnation stabilization treatment through the nitric acid solution can be such that the nitrogen content after the treatment is, for example, 1 to 10% by weight, more specifically, 3 to 5% by weight. At this time, when the nitrogen content after the nitrate impregnation stabilization treatment is less than 1% by weight, the crosslinking degree may be inferior to the desired effect (increasing yield and compressive fracture load, etc.) in the present invention, when the carbon content exceeds 10% by weight The content may be small and not useful as activated carbon. The nitrogen content can be controlled through the concentration of the nitric acid solution, the heat treatment temperature and time.

In addition, the heat treatment may vary depending on the type of acid solution and starting material (carbon-containing particles), for example, at a temperature of 50 to 200 ° C., for 5 minutes to 72 hours. At this time, if the heat treatment temperature is less than 50 ℃ or the heat treatment time is less than 5 minutes, it may vary depending on the type of acid solution, but the reactivity (functional group introduction and change) is poor, the effect (increase in yield and compression load, etc.) ) May be insignificant. And when the heat treatment temperature exceeds 200 ℃ may vary depending on the type of acid solution, the acid solution may boil explosive. The heat treatment time may vary depending on the starting material. For example, in the case of the polymer compound, the synergistic effect due to the overtreatment may not be so great even if it exceeds 72 hours. When using nitric acid solution as the acid solution, the heat treatment may be performed for 10 minutes to 12 hours, for example at a temperature of 80 to 180 ℃. More specifically, it may proceed for 20 minutes to 6 hours at a temperature of 120 to 160 ℃. In this temperature and time range the nitric acid solution effectively works in the present invention.

In addition, the carbon-containing particles impregnated and stabilized through the first process may be selectively subjected to a neutralization process and / or a drying process depending on the intended use thereof. When used as a source of activated carbon it can be neutralized and dried. For example, it may be washed several times (eg 3 to 5 times) with distilled water to neutralize the pH to be neutral and then dried at a temperature of at least 100 ° C.

In addition, the carbon-containing particles impregnated and heat treated through the first process may have a weight increase rate of 3 to 20% than before impregnation and heat treatment. Specifically, the carbon-containing particles may be increased by 3 to 20% than before impregnation and heat treatment by controlling the concentration of the acid solution and the heat treatment conditions in the first step.

2nd process

The second step is a step of oxidizing the carbon-containing particles impregnated and heat-treated through the first step. This second process proceeds by heat treatment in an oxygen atmosphere. In the stabilization treatment method according to the present invention, the second step is an optional step carried out as necessary, and if the carbon-containing particles are used as a source of activated carbon, it is preferable to proceed. In the case of carrying out the second step, higher yields, compressive failure loads, and shape retention (spherization) can be expected.

The second process may be similar to the oxidation treatment in the production of conventional activated carbon, but according to the present invention, the first process is preceded and the second process has the following effects.

Carbon-containing particles, such as spherical polymer compounds, having a weak binding force may soften or melt or decompose upon high temperature oxidation treatment. However, according to the present invention, by introducing a functional group through the first step, during the oxidation treatment according to the second step, the introduced functional group leads to a dehydration reaction, inhibits the combustion reaction to prevent melting or fusion of the spherical body prevent. In addition, for example, in the case of using a nitric acid solution as the acid solution, the dehydration reaction to induce a nitrogen-substituted reaction with the hydrocarbon material inside the spherical polymer compound, thereby improving the internal crosslinking degree. 1 is a molecular model illustrating that a carbon atom in a spherical polymer compound is introduced into a functional group by an impregnation stabilization treatment (first step), and then forms a crosslink with nitrogen (N) atoms through a dehydration reaction (second step). It is.

Therefore, when the first step and the second step are continuously performed, the degree of crosslinking is improved compared to the case where only the first step is performed, and thus have a high yield and a compressive fracture load. In addition, form retention (spherical retention) is excellent due to the increase in internal bonding force. In other words, the spherical polymer compound, which has been excluded from use as a starting material due to its low binding strength, also provides a condition for producing activated carbon, which is the final target, due to the increase in internal binding strength. Therefore, according to the present invention, the kind of starting raw material (carbon-containing particles) is not limited than before. In addition, the second step also serves to remove excess nitrogen components not involved in nitrogen replacement by dehydration reaction of the nitrogen components introduced excessively during the nitric acid impregnation stabilization treatment of the first step. In addition, by performing the second process, it is possible to generate and control mesopore in the formation of the specific surface area of the activated carbon as a final product.

The second process may be performed by heat treatment under an oxygen atmosphere, for example, at a temperature of 200 ° C. to 400 ° C., and more specifically, at a temperature of 220 ° C. to 280 ° C. At this time, if the temperature is less than 200 ℃, the effect (oxidation reaction, dehydration reaction, etc.) according to the oxidation treatment of the second process is insignificant, and if it exceeds 400 ℃ may vary depending on the type of starting material (carbon-containing particles). In the case of a low melting polymer compound, there is a possibility of softening. In addition, the second process may be performed, for example, for 5 minutes to 1 hour in the above temperature range. In this case, if the oxidation treatment time is too short, the effect of the oxidation treatment may be insignificant, and if the treatment time is too long, it may not be preferable in terms of productivity.

After performing the second process, the appropriate nitrogen content of the carbon-containing particles may be, for example, 0.1 to 5.0% by weight, more specifically, 0.2 to 2.0% by weight, and more specific examples of 0.5. To 1.5% by weight. In addition, after performing the second process, the oxygen content may be, for example, 2 to 25% by weight, more specifically, 5 to 20% by weight. Through this oxygen content, it can be judged whether it was performed as an appropriate oxidation treatment condition.

In addition, as the impregnation stabilization treatment time of the first process increases, the compressive fracture load after the second process (oxidation treatment) may increase, but a large increase in yield cannot be expected, which is proportional to the polymer in proportion to the impregnation stabilization treatment time. The introduction of functional groups into the compound is increased, so that the dehydration reaction during the oxidation process can be seen as an increased result. Therefore, as the impregnation stabilization treatment time increases, the compressive fracture load increases, but considering the manufacturing time and yield according to the excessive treatment time, as described above, the impregnation stabilization treatment time (first step) may be 5 minutes to 72 hours. Can be. In particular, the nitric acid impregnation stabilization treatment with nitric acid solution may be 10 minutes to 12 hours, more specifically 20 minutes to 6 hours.

Therefore, according to the stabilization treatment method according to the present invention described above, it is possible to increase the yield and compressive failure load of the final product (eg, activated carbon), it can have excellent shape retention (spherical). And it is possible to produce activated carbon with an increased specific surface area.

On the other hand, the method for producing activated carbon according to the present invention, while following a conventional general activated carbon manufacturing process, at least includes the impregnation stabilization treatment process of the present invention. That is, the impregnation stabilization process of the present invention is preceded before the activation process. Figure 2 shows a process diagram of the manufacturing method according to the present invention.

Specifically, the method for producing activated carbon according to the present invention comprises the steps of stabilizing carbon-containing particles by the impregnation stabilization treatment method of the present invention (stabilization treatment process); And oxidizing the stabilized carbon-containing particles (oxidation treatment process). And activating the oxidized carbon-containing particles (activation treatment step).

In addition, the production method according to the present invention may be further performed between the oxidation treatment step and the activation treatment step, and may further include a step (reduction treatment step) of reducing the oxidation-containing carbon-containing particles as necessary.

Specifically, the method for producing activated carbon according to the present invention includes stabilizing carbon-containing particles by the impregnation stabilization treatment method of the present invention (stabilization treatment process) according to another embodiment; And oxidizing the stabilized carbon-containing particles (oxidation treatment process). Reducing the oxidation-treated carbon-containing particles (reduction treatment process); And activating the reduced treated carbon-containing particles (activation treatment step).

At this time, as described above, the stabilization treatment includes at least the first step (impregnation, heat treatment). In the manufacturing method, the oxidation treatment step is the same as the above-described second step (oxidation treatment).

In addition, the reduction treatment process (hereinafter referred to as "third process") is performed before the activation treatment of the oxidized carbon-containing particles. This third process is a process for forming and controlling micropores in the formation of specific surface area of activated carbon as opposed to the oxidation treatment (second process). It is a process. Through this third process, the oxygen content can be reduced, which can be selectively performed according to the purpose and use of activated carbon. When the activated carbon is used orally for the third step, the third step is preferably performed because the removal of the oxygen functional group and the formation of fine pores are possible.

The third process is not particularly limited, but may be performed by heat treatment at a temperature of 350 ° C. to 600 ° C. for 2 minutes to 10 hours under a reducing atmosphere. At this time, if the heat treatment temperature is too low or the heat treatment time is too short, the efficiency according to the reduction treatment may be insignificant. If the heat treatment temperature is too high, softening of the carbon-containing particles may occur, and if the heat treatment time is long, it may not be preferable in terms of productivity. In addition, the third process may be carried out in a reducing atmosphere such as nitrogen, argon, helium.

In addition, the activation process (hereinafter referred to as "fourth process") may be performed by a conventional method. Specifically, the fourth process may be performed by activating in the presence of an activating gas, for example, at a temperature of 650 ° C to 1,000 ° C, more specifically at a temperature of 750 ° C to 900 ° C. In this case, the activating gas includes at least one gas reactive to carbon (one or more selected from steam and carbon dioxide gas). The activating gas may further contain an inert gas such as nitrogen, argon, helium, etc. in addition to the reactive gas. At this time, the reactive gas (water vapor or carbon dioxide gas, etc.) and the inert gas are adjusted in volume ratio, for example, 0.3 to 0.5: 0.5 to 0.7 (reactive gas: inert gas = 0.3 to 0.5: 0.5 to 0.7) to be activated. And, as a more specific example it can be activated by adjusting the volume ratio of 0.75: 0.25. In addition, the fourth process may be performed by heat treatment for 5 minutes to 10 hours in the temperature range.

In addition, the fourth process is a rotary kiln or an upflow method is suitable, in particular a flow method using a rotary kiln is suitable. In addition, the inert gas may be selected from helium, nitrogen, argon or a mixture thereof.

The activated carbon produced through the above process may have a specific surface area (BET method) of 500 m ² / g or more, specifically 500 m ² / g to 3,000m ² / g. The activated carbon may have a micropore, a mesopore, an atmospheric pore, or a combination thereof, depending on the purpose of use, and the activated carbon according to the present invention prepared through the above process may be fine. The pores are developed to have a specific surface area of 700 m ² / g or more (eg, 700 to 3,000 m ² / g), specifically, a specific surface area of 1,000 m ² / g or more (eg, 1,000 to 3,000 m ² / g), more specifically It may have a specific surface area (eg, 1,500 to 3,000 m ² / g) of 1,500 m ² / g or more.

In addition, the activated carbon may include pores having a diameter of 5.0 to 15,000 nm, for example, may have a pore volume of 0.25 mL / g or less. As a more specific example, the activated carbon may include pores having a diameter of 7.0 to 10,000 nm, and may have a pore volume of 0.2 mL / g or less. In addition, the activated carbon, the nitrogen content according to the elemental analysis may be, for example, 0.1 to 5.0% by weight, more specifically 0.2 to 2.0% by weight, even more specifically 0.5 to 1.5% by weight. have.

In addition, the activated carbon may have, for example, a spherical shape, an average diameter of 50 μm to 10 mm, and specifically, an average diameter of 0.01 to 1.0 mm. In particular, the activated carbon according to the present invention has a higher compressive fracture load of 2 N or higher than the conventional one, despite having such a high specific surface area and pore diameter. The activated carbon according to the present invention may preferably have a compressive fracture load of 3 N or more. At this time, the higher the compressive fracture load, the better, but is not particularly limited, but may have a maximum of 50N.

In the present invention, the compressive breaking load (N) means the maximum load (breaking strength) that is broken when a load (N: Newton) is applied to a unit particle (grain) of spherical activated carbon. This compression failure load can be measured using, for example, AIKOH Model-AFK-500TE, DTG-1 (conditions: Capacity 10N, Resolution 0.001N, Test speed 10mm / min).

According to the present invention, since activated carbon has a high compressive fracture load (2N or more) as described above, durability is increased, and thus it is usefully applied to various fields. In particular, it can be usefully applied as an environmental and oral adsorbent requiring durability.

Hereinafter, the Example and comparative example of this invention are illustrated. The following examples are merely provided to aid the understanding of the present invention, whereby the technical scope of the present invention is not limited.

<Stabilization treatment of spherical polymer compound>

Example 1

Immersion of 35 wt% nitric acid (Wako, 60-61 wt%, first grade reagent) solution with a thermomelting spherical polymer compound (Soocheong, SQCL80, 80% crosslinking product) having an average diameter of 350 μm Then, heat treatment was performed at 140 ° C. for 30 minutes (impregnation stabilization treatment). After that, the mixture was washed several times with distilled water 10 times the volume of the spherical polymer compound to neutralize the filtrate, and then heated to 120 ° C. (ISUZU SSVD-). 13S, ISUZUSEISAKUSHO.Co. Ltd.) for 24 hours.

The dried spherical polymer compound specimen was subjected to thermogravimetric analysis (TGA, SII nanotechnology EXTRA 6000) according to temperature change, and the results are shown in FIG. 3. At this time, the thermogravimetric analysis was measured while continuously heating the temperature up to 900 ℃ under inert conditions.

In addition, for the dried spherical polymer compound specimens, the functional group change was measured through an FT-IR spectrometer, and the results are shown in FIG. 4.

Example 2

After impregnating 35 wt% nitric acid (Wako, purity 60-61 wt%, first-class reagent) solution with 35 wt% of a hot melt spherical polymer compound (SQCL80) having an average diameter of 350 μm, the mixture was heated at 140 ° C. for 30 minutes. Heat treatment (impregnation stabilization treatment), and then washed several times with distilled water 10 times the volume of the spherical polymer compound to neutralize the filtrate pH, and then the thermostatic bath (ISUZU SSVD-13S, ISUZUSEISAKUSHO. Co. Ltd.) ) For 24 hours. Next, the dried specimens were heated at a temperature increase rate of 5 ° C./min in an air atmosphere, heat-treated at a temperature of 270 ° C. for 30 minutes, and then naturally cooled. (Oxidized at 270 ° C. for 30 minutes). That is, the specimen according to the present embodiment was further subjected to the oxidation treatment in comparison with the first embodiment.

For the specimen according to the present embodiment, thermogravimetric analysis and functional group change were measured in the same manner as in Example 1. The thermogravimetric analysis results are shown in FIG. 3, and the functional group change results are shown in FIG. 4.

Comparative Example 1

In comparison with Example 1, it was set as a specimen according to this Comparative Example that the impregnation stabilization treatment was not performed in the nitric acid solution. That is, a spherical polymer compound (Socheong Co., SQCL80), which was not subjected to the impregnation stabilization treatment, was used as a specimen of this comparative example.

For the specimen according to this comparative example, thermogravimetric analysis and functional group change were measured in the same manner as in Example 1, and the results are shown in FIGS. 3 and 4, respectively.

[Examples 3 to 6]

After impregnating a heat-soluble spherical polymer compound having an average diameter of 350 μm (Socheong, SQCL45, crosslinking degree 45%) in a solution of 35% by weight of nitric acid (Wako, purity 60-61%, primary reagent), Heat treatment was carried out at 140 ° C. for 30 minutes (impregnation stabilization treatment). After washing several times with distilled water of 10 times the volume of the spherical polymer compound to neutralize the filtrate, the thermostat was heated at 120 ° C. (ISUZU SSVD-13S, Dried at ISUZUSEISAKUSHO.Co. Ltd) for 24 hours. That is, it carried out in the same manner as in Example 1 except that the diameter was different as the spherical polymer compound. At this time, to find out the effect according to the impregnation stabilization treatment time, 30 minutes (Example 3), 1 hour (Example 4), 2 hours (Example 5) and 4 hours (Example 6) under the same temperature conditions of 140 ℃ ) Was carried out with different heat treatment times.

For the specimens according to each of the examples (3 to 6), thermogravimetric analysis and functional group change were measured in the same manner as in Example 1. The thermogravimetric analysis results are shown in FIG. 5, and the functional group change results are shown in FIG. 6.

Comparative Example 2

In comparison with Example 3, the specimen was not subjected to the impregnation stabilization treatment in the nitric acid solution according to this comparative example. That is, a spherical polymer compound (Socheong Co., SQCL45), which was not subjected to the impregnation stabilization treatment, was used as a specimen of this comparative example.

For the specimen according to the comparative example, thermogravimetric analysis and functional group change were measured in the same manner as in Example 1, and the results are shown in FIGS. 5 and 6, respectively.

[Examples 7 to 10]

After impregnating 35 wt% nitric acid (Wako, purity 60-61 wt%, first-class reagent) solution with 35 wt% of a hot melt spherical polymer compound having an average diameter of 350 μm, the solution was heated at 140 ° C. for 30 minutes. After the impregnation stabilization treatment, the pH of the filtrate was neutralized by washing several times with distilled water 10 times the volume of the spherical polymer compound, followed by a constant temperature bath (ISUZU SSVD-13S, ISUZUSEISAKUSHO. Co. Ltd.). ) For 24 hours. Next, the dried specimens were heated at a temperature increase rate of 5 ° C./min in an air atmosphere, heat-treated at a temperature of 270 ° C. for 30 minutes, and then naturally cooled. (Oxidized at 270 ° C. for 30 minutes). That is, the specimen according to the present examples was further subjected to the oxidation treatment in comparison with the third embodiment. At this time, to determine the effect according to the impregnation stabilization treatment time, 30 minutes (Example 7), 1 hour (Example 8), 2 hours (Example 9) and 4 hours (Example 10) under the same temperature conditions of 140 ℃ ) Was carried out with different heat treatment times.

For the specimens according to each of the examples (7 to 10), thermogravimetric analysis was performed in the same manner as in Example 1, and the results are shown in FIG. 7.

Comparative Example 3

Compared to Example 7, except that the impregnation stabilization treatment was not performed in the nitric acid solution was carried out in the same manner. In other words, the spherical polymer compound (Socheong Co., SQCL45), which was not subjected to the impregnation stabilization treatment, was subjected to heat treatment (oxidation treatment) for 30 minutes at a temperature of 270 ° C as a specimen according to the comparative example.

For the specimen according to this comparative example, thermogravimetric analysis was performed in the same manner as in Example 1, and the results are shown in FIG. 7.

First, as shown in Figures 3, 5 and 7 showing the results of thermogravimetric analysis, it can be seen that the case of the impregnation stabilization according to the present invention is superior to the thermal properties than the comparative example. In addition, it can be seen from the results of FIG. 3 that the thermal characteristics are better when the oxidation treatment is performed, and the thermal characteristics are improved as the impregnation stabilization treatment time (heat treatment time) is increased from the results of FIGS. 5 and 7. have.

In addition, the functional groups introduced and changed through the impregnation stabilization process were observed. First, as can be seen from the spectra results shown in FIG. 6, the raw material (spherical polymer compound, Socheong Co., Ltd., SQCL45) was applied to The change of the functional group introduced with the degree (time) can be observed. At this time, the amine group (NH group) and the hydroxyl group (hydroxyl group (-OH)) are in the wavelength range of 3,000 to 3,500 cm ^-1 ), aldehyde group (aldehyde group, R-CHO), carboxyl group (carboxylic group, COOH). ) And ester groups (ester, COOR) are observed in the wavelength range of 1,000 ~ 1,300 cm ^-1 , and another amine group (CN) is observed in the wavelength range of 1,000 ~ 1,350 cm ^-1 , all perform an impregnation stabilization treatment As can be seen, the range and intensity of the peaks are expanded.

In addition, as shown in Figure 4, it can be seen that after the introduction of the functional group dehydration reaction and the degree of crosslinking is formed. By nitrate impregnation stabilization (heat treatment in 35% nitric acid solution for 30 minutes) of the raw material (spherical polymer compound, Socheong Co., Ltd., SQCL80), it can be confirmed that the functional group is introduced as shown in FIG. When the spherical polymer compound is subjected to oxidation treatment (30 minutes at 270 ° C.), hydroxyl (-OH) functional group among the introduced functional groups is reacted with oxygen introduced during the oxidation process to be removed by dehydration reaction, which is a wavelength range of 3,000 to 3,500. It can be seen that a wide range of peaks of cm ⁻¹ is reduced. In addition, the degree of cross ^- linking due to nitrogen (N) is developed, the wavelength range of the amine group (amine group, CN, NH) (a sharp portion of the peak of 1,000 ~ 1,350 cm ^-1 , 3,000 ~ 3,500cm ^-1 ) can be confirmed that the development have.

On the other hand, [Table 1] below, for the specimens according to the above Examples and Comparative Examples, evaluating the yield (%) according to nitric acid impregnation stabilization treatment (140 ℃ heat treatment), oxidation treatment (270 ℃ heat treatment), 900 ℃ high temperature heat treatment One result. In Table 1 below, each yield (%) is a value calculated by the following equation.

[Equation 1]

% Yield = (weight of specimen after heat treatment / weight of specimen before heat treatment) x 100

[Equation 2]

Overall yield (%) = (weight of specimen after heat treatment / weight of starting material (spherical polymer compound)) x 100

[Equation 3]

Yield increase = total yield (%)-total yield of corresponding comparative example (%)

At this time, the yield (%) in the following step [Table 1] is based on the weight of the continuous before and after process (for example), for example, the yield "25.62%" after 900 ℃ heat treatment in Example 1, 900 ℃ heat treatment It is a percentage obtained by dividing the weight of the post-treatment by the weight after the nitric acid stabilization treatment (pre-process). In addition, the yield increase in Table 1 below is, for example, "15.21" in Example 1 is the total yield "28.95" of Example 1 minus the total yield "13.74" of Comparative Example 1.

As shown in Table 1, it can be seen that in the case of the impregnated stabilization example according to the present invention, the overall yield is superior to the comparative example. In addition, as shown in Table 1, it can be seen from the results of Examples 1 and 2 that the yield is better when the oxidation treatment is further performed (Example 2).

<Spherical Activated carbon  Manufacture

Example 11

After impregnating 35 wt% nitric acid (Wako, purity 60-61 wt%, first-class reagent) solution with 35 wt% of a hot melt spherical polymer compound (SQCL80) having an average diameter of 350 μm, the mixture was heated at 140 ° C. for 30 minutes. Heat treatment (impregnation stabilization treatment), and then washed several times with distilled water 10 times the volume of the spherical polymer compound to neutralize the filtrate pH, and then the thermostatic bath (ISUZU SSVD-13S, ISUZUSEISAKUSHO. Co. Ltd.) ) For 24 hours. Next, the dried specimens were heated at a temperature increase rate of 5 ° C./min in an air atmosphere, heat-treated at a temperature of 270 ° C. for 30 minutes, and then naturally cooled. (Oxidized at 270 ° C. for 30 minutes).

The spherical polymer compound impregnated and stabilized and oxidized as described above was heated at a heating rate of 10 ° C./min under an argon (Ar) gas atmosphere, heat-treated at 500 ° C. for 30 minutes, and then naturally cooled. (Reduction treatment) Next, reduction The treated spherical polymer compound was heated in a nitrogen gas having a water content of 75% by weight at a heating rate of 5 ° C./min and subjected to heat treatment at 850 ° C. for 60 minutes. (Activation treatment) That is, oxidation treatment in comparison with Example 1 above. Further, a reduction treatment and an activation treatment were performed to prepare spherical activated carbon specimens according to the present example.

For the spherical activated carbon specimens prepared above, the physical properties were evaluated and the results are shown in the following [Table 2].

Example 12

In contrast to Example 11, except that the reduction was not carried out in the same manner as in Example 11 to prepare a spherical activated carbon specimen. And for the prepared specimens, the physical properties were evaluated and the results are shown in the following [Table 2].

[Comparative Example 4]

In contrast to Example 11, except that the impregnation stabilization was not carried out in the same manner as in Example 11 to prepare a spherical activated carbon specimen. And for the prepared specimens, the physical properties were evaluated and the results are shown in the following [Table 2].

[Comparative Example 5]

In contrast to Example 11, the spherical activated carbon specimens were prepared in the same manner as in Example 11 except that the impregnation stabilization treatment and the reduction treatment were not performed. And for the prepared specimens, the physical properties were evaluated and the results are shown in the following [Table 2].

As shown in Table 2, the activated carbon according to the embodiment prepared by impregnation stabilization according to the present invention is excellent in all physical properties such as specific surface area, compressive fracture load (compressive strength), final yield and sphericity. It can be seen. In particular, in the case of the embodiment of the present invention it can be seen that the compression failure load is very superior to the comparative example over 6 N / grain. In addition, in the yield increase fraction, it can be seen that in Example 11, 6.46% compared to Comparative Example 4, and in Example 12, 5.53% increased compared to Comparative Example 5. This means that much increase in productivity.

On the other hand, Table 3 below shows the results of analyzing the element content of the step-by-step specimens according to the embodiment of the present invention. At this time, the increase of the nitrogen content due to the impregnation stabilization treatment using the nitric acid solution was observed, and whether the increase in yield due to the impregnation stabilization treatment is due to the increase in the content of the simple nitrogen component.

The yield increase after the impregnation stabilization treatment using nitric acid solution (Example 1) was about 10% (see Table 1), but the content of nitrogen after activation (Examples 11 and 12) as shown in [Table 3] In view of the fact that silver is less than 1%, the increased yield due to nitric acid impregnation stabilization treatment is because the internal crosslinking degree is improved rather than the nitrogen component. This can be confirmed in the following experimental section.

Example 13

In contrast to Example 11, except that 35% by weight of sulfuric acid (Wako, 95% by weight, first-class reagent) solution was used as the acid solution in performing the impregnation stabilization treatment. A spherical activated carbon specimen was prepared. And for the spherical activated carbon specimens prepared, the physical properties were evaluated and the results are shown in the following [Table 4].

Example 14

In contrast to Example 11, the impregnation stabilization treatment was carried out except that 35% by weight of sulfuric acid (Wako, purity 95% by weight, primary reagent) solution was used as the acid solution, except that the reduction treatment was not performed. Spherical activated carbon specimens were prepared in the same manner as in step 11. And for the spherical activated carbon specimens prepared, the physical properties were evaluated and the results are shown in the following [Table 4].

In addition, Table 4 shows the physical property evaluation results of the spherical activated carbon specimens according to Comparative Examples 4 and 5.

As shown in [Table 4], even when sulfuric acid solution was used as the acid solution, the activated carbon prepared by impregnation stabilization treatment had a specific surface area, compressive fracture load (compressive strength), final yield and sphericity in comparison with the comparative example. It can be seen that it is excellent in all physical properties such as.

From the above results, it can be seen that the increase in physical properties such as yield and compressive fracture load (compressive strength, etc.) is due to the improvement in internal crosslinking degree rather than due to an increase in the content of nitrogen or sulfur components.

As described above, according to the present invention, a relatively simple impregnation stabilization treatment process is newly inserted, thereby preparing activated carbon having a high specific surface area and sphericity as well as a high yield and a compressive fracture load. At this time, the excellent compressive fracture load means increased durability. Accordingly, it can be usefully applied as an environmental adsorbent for which durability is required. In addition, due to the high compressive fracture load (durability) can be applied more safely in the body when applied for oral or medicinal use.

FIG. 1 illustrates a molecular model in which carbon atoms in a spherical polymer compound form crosslinks with nitrogen (N) atoms through introduction and dehydration of functional groups through impregnation stabilization.

Figure 2 schematically shows a process chart of activated carbon production according to the present invention.

Figure 3 is a graph showing the results of measuring the thermogravimetric analysis (TGA) of the weight change of the spherical polymer compound according to an embodiment of the present invention.

Figure 4 is a graph showing the spectra of the results measured by the FT-IR spectroscopy (FT-IR) to examine the functional group changes of the spherical polymer compound according to the embodiment of the present invention.

5 is a graph showing a result of measuring the thermogravimetric analysis (TGA) of the weight change according to the impregnation stabilization treatment time of the spherical polymer compound according to an embodiment of the present invention.

6 is a graph showing spectra of the results measured by FT-IR spectroscopy to examine the functional group change according to the impregnation stabilization treatment time of the spherical polymer compound according to the embodiment of the present invention.

Figure 7 is a graph showing the results of measuring the thermogravimetric analysis (TGA) of the weight change according to the impregnation stabilization treatment time of the spherical polymer compound according to another embodiment of the present invention.

Claims (17)

Impregnating the carbon-containing particles into the acid solution and then heat-treating; And And a process for oxidizing the impregnated and heat treated carbon-containing particles. The method of claim 1, The acid solution is a method for stabilizing carbon-containing particles, characterized in that at least one selected from the group consisting of nitric acid solution, sulfuric acid solution and phosphoric acid solution. The method of claim 1, Nitrogen content of the carbon containing particle | grains after impregnation and heat processing is 1 to 10 weight%, The stabilizing treatment method of carbon containing particle | grains characterized by the above-mentioned. The method of claim 1, Heat treatment is a stabilization treatment method of the carbon-containing particles, characterized in that for 5 minutes to 72 hours at a temperature of 50 to 200 ℃. The method of claim 1, The acid solution comprises a nitric acid solution, the heat treatment is a stabilization treatment method for carbon-containing particles, characterized in that for 10 minutes to 12 hours at a temperature of 80 to 180 ℃. The method of claim 1, The acid solution comprises a nitric acid solution, the heat treatment is a stabilization treatment method for carbon-containing particles, characterized in that for 20 minutes to 6 hours at a temperature of 120 to 160 ℃. The method of claim 1, The weight of the carbon-containing particles after impregnation and heat treatment is increased by 3 to 20% than before impregnation and heat treatment. delete The method of claim 1, Oxidation treatment is a stabilization treatment method for carbon-containing particles, characterized in that for 5 minutes to 1 hour at 200 ℃ to 400 ℃ under an oxygen atmosphere. The method of claim 1, Nitrogen content of the carbon containing particle | grains after an oxidation process is 0.1-5.0 weight%, The stabilizing treatment method of carbon containing particle | grains characterized by the above-mentioned. Impregnating the carbon-containing particles into an acid solution, followed by heat treatment to stabilize the carbon-containing particles; Oxidizing the stabilized carbon-containing particles under an oxygen atmosphere; And Activated carbon production method comprising the step of activating the oxidation-treated carbon-containing particles in the presence of an activation gas. The method of claim 11, The method for producing activated carbon, further comprising the step of reducing the oxidized carbon-containing particles under a reducing atmosphere prior to activation treatment. The method of claim 11, Oxidation treatment is a method for producing activated carbon, characterized in that for 5 minutes to 1 hour at a temperature of 200 ℃ to 400 ℃. The method of claim 11, The nitrogen content of the carbon containing particle | grains after an oxidation process is 0.1-5.0 weight%, The manufacturing method of the activated carbon characterized by the above-mentioned. The method of claim 12, Reduction treatment is a method for producing activated carbon, characterized in that for 2 minutes to 10 hours at a temperature of 350 ℃ to 600 ℃. The method of claim 11, Activation process is a method for producing activated carbon, characterized in that for 5 minutes to 10 hours at a temperature of 650 ℃ to 1,000 ℃. A spherical activated carbon prepared according to any one of claims 11 to 16, having an average diameter of 50 µm to 10 mm and a compressive fracture load per unit particle of 2 N or more.

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