KR102023064B1 - Method for manufacturing porous pelletized activated carbon from wood pellet and porous pelletized activated carbon manufactured therefrom - Google Patents

Abstract

The present invention relates to a method for producing porous granular activated carbon using wood moldings and granulated activated carbon which is a porous carbon material produced therefrom. Method for producing a porous granulated activated carbon of the present invention comprises the steps of (1) carbonizing the wood compact in an inert atmosphere; (2) impregnating the carbonized wood compact into the impregnating agent; (3) re-carbonizing the carbonized molded body impregnated with the carbonized impregnating agent; And (4) activating the carbonized, impregnated and re-carbonized wood compacts.

Description

Method for producing porous granular activated carbon based on wood moldings and porous granular activated carbon produced therefrom

The present invention relates to a method for producing porous granular activated carbon using wood moldings and granulated activated carbon which is a porous carbon material produced therefrom.

The types of activated carbon are generally divided into crushed activated carbon and granulated (pelleted) activated carbon, which is more expensive than crushed activated carbon. In particular, cylindrical pelletized granular activated carbon has a consistent shape and high hardness, which is superior to the pulverized activated carbon, and has excellent air permeability in the packed layer of activated carbon and generates less dust during handling and operation. It is used for various purposes such as separation.

However, the conventional method for producing granulated activated carbon is prepared by mixing activated carbon powder and a binder and then molding in a granulation molding machine and reactivating the granulated activated carbon. Since the hardness of carbon is relatively higher than that of raw materials before carbonization, the nozzle part must be continuously replaced after a certain time of use, and a complicated molding device necessary for the function of heating of binder, etc. must be used. Etc.

On the other hand, wood moldings such as wood pellets are made to a certain size by crushing and compression molding by-products collected from waste wood or sawmill, and are generally used as fuel or bedding for pets.

The present invention has been made to solve the problems of the prior art granulated activated carbon manufacturing method as described above, a method of manufacturing a porous carbon activated carbon in the form of a molded body using a wooden molding as a raw material without undergoing a granulation molding process and It provides a porous granulated activated carbon produced by this method.

In the present invention to achieve the above object,

(1) carbonizing the wood compact in an inert atmosphere;

(2) impregnating the carbonized wood compact into the impregnating agent;

(3) re-carbonizing the carbonized molded body impregnated with the carbonized impregnating agent; And

(4) activating the carbonized, impregnated and re-carbonized wood compacts,

It provides a method for producing a porous granulated activated carbon comprising a.

Preferably, the step of carbonizing the wood molded product of the step (1) in an inert atmosphere, may include heat treatment of the wood molded product at a temperature of 500 ℃ to 1200 ℃ in an inert atmosphere for 1 minute to 12 hours.

According to a preferred embodiment, the step of impregnating the impregnating agent of step (2) may include using a pitch or a thermosetting resin as the impregnating agent.

According to a preferred embodiment, the re-carbonization of step (3) may include heat treatment for 1 minute to 5 hours at a temperature of 500 ℃ to 1000 ℃ in an inert atmosphere.

According to a preferred embodiment, the activating step (4) may include heat treatment for 1 minute to 5 hours at a temperature of 500 ℃ to 1200 ℃ under an atmosphere selected from water vapor, carbon dioxide and air.

The present invention also provides a porous granular activated carbon prepared by the above method, the hardness of the porous granular activated carbon thus prepared is preferably 85% or more as measured by the KS 1802 method.

In the present invention, the wood molded body is generally manufactured in pellet form, and can be used regardless of the type of raw wood used for the production of the wood molded body. The specific surface area, pore volume, pore distribution, etc. of the activated carbon produced by the method of the present invention may vary depending on the type of raw wood, and for a specific purpose, a more suitable wood molded body may be selected. In addition, the raw material is not limited because it can be used for water purification or wastewater treatment used for general purposes.

In the present invention, a pitch or a thermosetting resin may be used as the impregnation agent used for impregnation. In the case of using pitch, both coal tar pitch and petroleum pitch may be used, and a softening point of 50 ° C. or higher and 300 ° C. or lower may be used. If the softening point is less than 50 ℃, the fixed carbon content of the pitch is low, so the effect of the impregnation is not preferable. If the temperature exceeds 300 ℃, the impregnation temperature should also exceed 300 ℃, the process cost increases and the viscosity during impregnation The impregnating effect is lowered because the pitch is not so well impregnated into the interior of the carbonized wood molded body, which is undesirable. Preferably, when using the impregnation pitch used in the production of artificial graphite, the impregnation effect is good because the carbonization yield is high and the penetration into the interior is easy.

When the thermosetting resin is used for impregnation, it must be able to be kept in a liquid state so that it can be used in the impregnation process. Resol type phenol resin, furfuryl alcohol resin, epoxy resin, etc. can be used. In the case of a solid Novolac phenol resin, it can be dissolved in an appropriate organic solvent. All of the thermosetting resins which can be impregnated after being liquefied by directly or in a solvent or the like can be used and are not limited separately.

According to a preferred embodiment of the present invention, the manufacturing process of the present invention may more specifically include the following steps. (See Figure 1)

end. wood Molded object  Carbonization step

In the present invention, the wood molded body is carbonized by heat treatment in an inert atmosphere. The carbonization temperature is suitable for 1 minute or more and 12 hours or less at 500 ° C or more and 1200 ° C or less, and sufficient volatiles are not removed even after heat treatment for longer than 12 hours at a temperature below 500 ° C. It is not preferable because effective activation is difficult and it is not preferable in case of heat treatment at temperature exceeding 1200 ℃, even though short term heat treatment of 1 minute or less, the structure of the structure proceeds to crystallization and it is difficult to develop effective pores in the later activation process. not.

I. Carbonized wood Molded object In impregnation Impregnated  step

The carbonized wood compacts are immersed in the impregnation agent. When pitch is used as the impregnant, the pitch is heated to a temperature above the softening point to liquefy. In the case of a liquid, it may be used directly or after appropriately adjusting the concentration and viscosity by the solvent to facilitate the impregnation. The impregnation procedure may be a method of immersing the carbonized wood molded body so that the impregnating agent penetrates into the pores therein. Alternatively, the carbonized wood molded body may be charged into the impregnation apparatus and injected into the liquid impregnating agent. In this case, the carbonized wood molded product may be impregnated more effectively by depressurizing the container loaded with carbon and then injecting the impregnant. After the impregnation is completed, the pressure may be increased to increase the pressure. You can also use methods that make penetration more effective.

All. Impregnation Molded object  Re-carbonization step

In the previous step, the molded body of the impregnation step is carbonized in an inert atmosphere. The carbonization process can be produced according to the carbonization method and conditions in the manufacturing process of the conventional granulated activated carbon. As a preferable example, heat treatment may be performed for 1 minute to 5 hours at a temperature of 500 ° C. to 1000 ° C. in an inert atmosphere. In the next step of activation, the raw material formed by direct activation may not be properly fused to each other. Devices designed to be able to process the carbonization step may be omitted.

la. Step to activate

The step of activating the carbonized molded body in the previous step can be prepared according to the conventional methods and conditions for producing activated carbon. As a preferred example, the heat treatment may be performed for 1 minute to 5 hours at a temperature of 500 ° C. to 1200 ° C. in an atmosphere such as steam, carbon dioxide, or air.

According to the present invention, it is possible to manufacture granulated activated carbon which is a porous carbon material of high hardness without the granulation process of activated carbon. According to the present invention, carbonized wood shaped bodies, such as pellets, are carbonized and re-carbonized after reinforcement by impregnating voids generated within the tissue due to decomposition of volatiles during carbonization into impregnants such as pitches and thermosetting resins. By activating, it has the same shape and hardness as the granulated activated carbon prepared in the prior art, and can be easily manufactured at a much lower cost, thereby replacing the existing expensive granulated activated carbon.

1 is a process chart of the manufacturing method according to the present invention.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be embodied in various different forms, and the present embodiments merely make the disclosure of the present invention complete, and are common in the art to which the present invention pertains. It is provided to fully inform those skilled in the art of the scope of the invention, which is to be defined only by the scope of the claims.

Hereinafter, a method of manufacturing porous granular activated carbon according to a preferred embodiment of the present invention will be described.

<Examples 1 to 4 according to the present invention>

Wood pellets made of pine were carbonized by heat treatment at 700 ° C. for 30 minutes in a nitrogen atmosphere to produce carbide char in pellet form. As the impregnating agent, the coal tar pitch having a softening point of 70 ° C. was heated to 100 ° C. or more, and the above carbide was added to impregnate. The impregnated wood pellets were carbonized at 700 ° C. for 30 minutes in an inert atmosphere and activated at 850 ° C. for 30 minutes, 1 hour, and 1 hour 30 minutes in a steam atmosphere to prepare granulated activated carbon as a porous carbon material. (Examples 1 to 3, respectively)

As a result, the specific surface area measured by nitrogen isotherm adsorption and calculated by the BET equation showed 603 m ² / g, 800 m ² / g, 1101m ² / g. The highest practical hardness is shown. (Measured by KS 1802 method) In addition, in Example 4, the impregnation step was impregnated with Resol-type phenolic resin instead of coal tar, and carbonized at 700 ° C. for 30 minutes in an inert atmosphere and at 850 ° C. under steam atmosphere for 1 hour. Activated during As a result, granulated activated carbon, which is a porous carbon material having a very high hardness of specific surface area of 982 m ² / g, was prepared.

<Comparative Examples 1 to 2>

Bedding wood pellets made of pine were carbonized by heat treatment at 700 ° C. for 30 minutes in a nitrogen atmosphere, and activated by heat treatment at 800 ° C. and 850 ° C. for 60 minutes in a steam atmosphere.

As a result, the specific surface area measured by nitrogen isotherm adsorption and calculated by BET equation showed 459m ² / g and 1262m ² / g, respectively. It was so low that it easily crumbled and showed inadequate results for use as activated carbon.

The above results are summarized as follows.

Impregnants used for impregnation Activation
Temperature Activation
time Specific surface area Hardness Example 1 Koltar Pitch 850 ℃ 0.5 hour 603 m ² / g 99% Example 2 Koltar Pitch 850 ℃ 1 hours 800 m ² / g 98% Example 3 Koltar Pitch 850 ℃ 1.5 hours 1101 m ² / g 94% Example 4 Resol resin 850 ℃ 1 hours 982 m ² / g 93% Comparative Example 1 Untreated 800 ℃ 1 hours 459 m ² / g 81% Comparative Example 2 Untreated 850 ℃ 1 hours 1262 m ² / g 67%

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that.

Claims (6)

(1) carbonizing the wood compact in an inert atmosphere;
(2) impregnating the carbonized wood compact into the impregnating agent;
(3) re-carbonizing the carbonized molded body impregnated with the carbonized impregnating agent; And
(4) activating the carbonized wood impregnated and impregnated and re-carbonized wood compacts;
Impregnating the impregnating agent of the step (2) is to enhance the hardness by reinforcing the voids generated in the wood molded body tissue due to decomposition of volatiles during carbonization, the method of producing porous granulated activated carbon. The method of claim 1,
Carbonizing the wood molded product of the step (1) in an inert atmosphere, the porous granular activated carbon production, characterized in that it comprises a heat treatment for 1 minute to 12 hours at a temperature of 500 ℃ to 1200 ℃ in an inert atmosphere Way. The method of claim 1,
Impregnating the impregnating agent of step (2), the method of producing porous granular activated carbon, characterized in that it comprises using a pitch or a thermosetting resin as the impregnating agent. The method of claim 1,
Re-carbonization of step (3), the method of producing a porous granulated activated carbon, characterized in that the heat treatment for 1 minute to 5 hours at a temperature of 500 ℃ to 1000 ℃ in an inert atmosphere. The method of claim 1,
The activating step of the step (4), the method of producing porous granulated activated carbon, characterized in that it comprises a heat treatment for 1 minute to 5 hours at a temperature of 500 ℃ to 1200 ℃ under an atmosphere selected from water vapor, carbon dioxide and air. Porous granulated activated carbon produced by the method according to any one of claims 1 to 5.

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