KR102082155B1 - Preparation of porous carbon materials by kenaf and manufacturing methode - Google Patents

Abstract

The present invention relates to a porous carbon material using Kenaf and a method for manufacturing the same, according to the present invention, by making Kenaf activated by a high temperature furnace after impregnation with phosphoric acid to prepare a porous carbon material, a commercially available porous carbon material It is possible to implement a higher porosity characteristic than the manufacturing method, and to provide a porous carbon material using Kenaf having a higher porosity characteristic than a conventional water vapor and chemical activator and a manufacturing method thereof.

Description

Preparation of porous carbon materials by kenaf and manufacturing methode}

The present invention relates to a method for manufacturing a porous carbon material using kenaf, and more specifically, to activate the kenaf in a high temperature furnace to produce a porous carbon material, which is superior to a porous carbon material using conventional coconut shell and coal. It relates to a porous carbon material using a Kenaf to implement the pore characteristics and a method for manufacturing the same.

Recently, interest in environmental pollution has increased, and environmental regulations have been strengthened. Porous carbon material is a material that is mainly applied to air and water environment purification due to its unique high specific surface area and pore characteristics such as pore volume.

The existing porous carbon material is produced by using coconut water vapor palm, coal-based porous carbon material.

However, the porous carbon material produced by using water vapor is a structure in which micropores make up most of the pores and has disadvantageous pore characteristics for adsorbing various pollutants, and in particular, many VOCs have adsorption capacity determined by the medium pores.

In addition, the porous carbon material produced by the existing water vapor has a very difficult property to form a medium pore, and there is a limit that can be applied only to a precursor having a high fixed carbon ratio.

Accordingly, there is an urgent need to develop new technologies capable of manufacturing porous carbon materials inexpensively with high yields as well as excellent quality due to excellent pore characteristics with well-developed mesopores.

In order to solve the above problems, the present invention activates Kenaf in a high-temperature furnace to prepare a porous carbon material, thereby improving not only excellent pore characteristics and medium pore development, but also a high yield of porous carbon material. It is to provide a porous carbon material using a kenaf that can be prepared and a method for manufacturing the same.

In order to solve the above problems, a method of manufacturing a porous carbon material using kenaf according to an embodiment of the present invention includes the steps of: (a) impregnating phosphorus with kenaf; (b) charging the kenaf impregnated with phosphoric acid to a high temperature furnace; (c) activating the Kenaf impregnated with phosphoric acid to produce a porous carbon material; It is possible to provide a method of manufacturing a porous carbon material using Kenaf, which includes (d) cooling the resulting porous carbon material and (e) washing and neutralizing the cooled porous carbon material.

In addition, the step (a) is characterized in that the phosphorus is impregnated at 15 to 200 ℃ to the kenaf.

In addition, the step (a) is characterized in that the phosphorus is impregnated in the weight ratio of 1: 0.5 to 1:10 to the kenaf.

In addition, the high-temperature furnace is maintained in a nitrogen atmosphere at 400 to 900 ° C. for 30 to 120 minutes to activate Kenaf impregnated with phosphoric acid.

In addition, the porous carbon material using the kenaf according to the embodiment of the present invention can provide a porous carbon material using the kenaf, characterized in that it is prepared by activating the kenaf immersed in phosphoric acid.

The porous carbon material using Kenaf according to an embodiment of the present invention and its manufacturing method can realize higher yield and porosity characteristics than the conventional commercially available porous carbon material manufacturing method. Can be manufactured.

In addition, since it is possible to realize higher porosity characteristics than the conventional commercially available porous carbon material, it can be usefully used as an energy storage and environmental purification material such as adsorbents for water purification, canisters for automobiles, filters for air purification, and active materials for supercapacitors. Is expected.

1 is a flowchart sequentially showing a method of manufacturing a porous carbon material using kenaf according to an embodiment of the present invention.
2 is a conceptual diagram schematically showing a manufacturing apparatus for producing a porous carbon material using a kenaf prepared by activating a kenaf impregnated with phosphoric acid according to an embodiment of the present invention.
3 is an X-ray diffraction curve of a porous carbon material using Kenaf according to Example 9 of the present invention.

Hereinafter, the description of the present invention with reference to the drawings is not limited to a specific embodiment, and various conversions may be applied and various embodiments may be provided. In addition, it should be understood that the contents described below include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention.

In the following description, terms such as first and second are terms used to describe various components, and are not limited in meaning to themselves, and are used only to distinguish one component from other components.

The same reference numerals used throughout this specification denote the same components.

The singular expression used in the present invention includes the plural expression unless the context clearly indicates otherwise. In addition, the terms "include", "have" or "have" described below are intended to designate the existence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification. It should be interpreted and understood to not preclude the existence or addition possibility of one or more other features, numbers, steps, actions, components, parts or combinations thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 3.

1 is a flowchart sequentially showing a method of manufacturing a porous carbon material using a kenaf according to an embodiment of the present invention, and FIG. 2 is a keen prepared by activating a kenaf impregnated with phosphoric acid according to an embodiment of the present invention. It is a conceptual diagram schematically showing a manufacturing apparatus for manufacturing a porous carbon material using a naphtha.

Hereinafter, a method of manufacturing a Kenaf-based porous carbon material activated with phosphoric acid will be described with reference to FIGS. 1 and 2.

1 and 2, the method of manufacturing a porous carbon material using a kenaf according to an embodiment of the present invention is a step of impregnating phosphoric acid in the kenaf (S100), and a kenaf impregnated with phosphoric acid in a high temperature furnace. Charging (S200), activating the Kenaf impregnated with phosphoric acid to generate a porous carbon material (S300), cooling the resulting porous carbon material (S400), and washing and neutralizing the cooled porous carbon material It may include a step (S500).

First, in the step of attaching phosphoric acid to the kenaf (S100), phosphoric acid may be impregnated into the kenaf by placing phosphoric acid in a heatable container, supporting and heating the kenaf.

In this case, the kenaf used may be one whose moisture content is controlled to 1% or less.

Here, when the water content of Kenaf exceeds 1%, it is difficult to control the concentration of phosphoric acid during the impregnation process of phosphoric acid, and control of activation conditions may be difficult.

In addition, phosphoric acid may be used having a concentration of 0.1 to 100%, most preferably 10 to 100% concentration. The concentration of phosphoric acid is intended to control the reaction of kenaf and phosphoric acid and to facilitate the adhesion of phosphoric acid to kenaf.

That is, when the concentration of phosphoric acid is less than 0.1%, the time required for the impregnation process is prolonged, and the yield and porosity characteristics of the porous carbon material may be reduced due to insufficient decomposition of hemicellulose and lignin of Kenaf.

In this step S100, phosphoric acid is impregnated to the kenaf to elicit the activation reaction of kenaf, and phosphoric acid attacks the hemicellulose and lignin of the kenaf at low temperatures to form a phosphorus compound and crosslinks the polymer chain with cellulose to yield. Improve it.

In addition, phosphoric acid can expand the structure of Kenaf, helping to form pores.

In addition, in order to easily attach phosphoric acid to the kenaf in step S100, it is preferable that the kenaf is completely contained in the phosphoric acid in the container, so the step S100 in the weight ratio of phosphate 1: 0.5 to 1:10. It is desirable to impregnate.

At this time, if the proportion of phosphoric acid in the impregnation ratio of impregnating phosphate to kenaf is less than 0.5, the concentration of phosphoric acid is lowered to fully support kenaf in phosphoric acid, whereby decomposition of hemicellulose and lignin in kenaf is sufficiently achieved. The yield and porosity characteristics may decrease due to lack of support, and as the proportion of phosphoric acid increases, the phosphoric acid and kenaf react sufficiently to increase the yield and porosity characteristics.

However, when the proportion of phosphoric acid exceeds 10, it can be changed into a powder form by decomposition of hemicellulose and lignin of Kenaf, which may not be easy to apply to an activation process and a washing process.

In addition, in step S100, phosphoric acid is added to the container and the kenaf is supported, followed by impregnation at 15 to 200 ° C. for 1 to 12 hours.

At this time, when the impregnation temperature is less than 15 ° C, the reaction rate of kenaf and phosphoric acid decreases, and the time of the impregnation process increases, and when it exceeds 200 ° C, it changes into a powder form due to the rapid reaction rate of kenaf and phosphoric acid, thereby activating. It may not be easy to apply to the process and washing process.

In addition, the impregnation time is inversely proportional to the impregnation temperature, and if the impregnation time is less than 1 hour, kenaf and phosphoric acid fail to react sufficiently, and thus the yield and porosity characteristics of the porous carbon material may decrease. It may turn into a powder form due to excessive reaction of naphth, so it may not be easy to apply to an activation process and a washing process.

In addition, a wet / dry / vibration / heat treatment step may be additionally performed before and after the S100 step to increase the impregnation efficiency so that phosphoric acid is easily impregnated.

In addition, after the phosphoric acid is supported on the kenaf, the step (S200) of loading the vessel containing the phosphoric acid and the kenaf into a high temperature furnace is carried out, thereby leading to the reaction of phosphoric acid and kenaf in step S300 to simplify the process. That is, the activation process is simultaneously performed while reacting kenaf with phosphoric acid.

In the step (S200) of loading the Kenaf impregnated with phosphoric acid in the high temperature furnace, the Kenaf 20 impregnated with phosphoric acid may be charged in the high temperature furnace 10.

That is, referring to FIG. 2, the kenaf 20 impregnated with phosphoric acid may be charged into the high temperature furnace 10 using the tube tube 30.

Subsequently, by heating and activating the Kenaf 20 impregnated with phosphoric acid loaded in the high temperature furnace 10 in a nitrogen atmosphere, activating the Kenaf 20 impregnated with phosphoric acid to produce a porous carbon material (S300). ).

In step S300, a porous carbon material may be manufactured using the manufacturing apparatus illustrated in FIG. 2.

Here, the high-temperature furnace 10 of the manufacturing apparatus of Figure 2 is formed to be rotatable on the outer shell of the tube tube 30, it is preferably formed to be closed.

In addition, the manufacturing apparatus is formed to allow the introduction of nitrogen into the tube tube 30.

For example, as shown in FIG. 2, a nitrogen injection pipe 40 is formed at one end of the tube tube 30 to penetrate therein.

At this time, the tube tube 30 inserted into the high temperature furnace 10 can be formed of various materials such as iron (including stainless steel), alumina, aluminum, quartz, but the durability of the tube tube 30 when rotated at a high temperature In order to solve the problem, it is most preferable that the material is formed of iron.

In addition, when generating a porous carbon material by heating and activating the Kenaf 20 impregnated with phosphoric acid charged in the high temperature furnace 10 in a nitrogen atmosphere, the overall activation conditions are performed at a high temperature of 400 to 900 ° C. It is preferable that a SiC heating element suitable for this is formed on the upper and lower sides of the tube tube 30.

At this time, it is preferable that the manufacturing apparatus removes all of the air inside the tube tube 30 in order to manufacture the porous carbon material.

To this end, by filling the nitrogen (N2) gas of 99.99% or more from the input pipe 40 to the inside of the pipe tube 30 for at least 30 minutes, the pipe tube 30 of the high temperature furnace 10 is made into a nitrogen atmosphere and heated up. ) It can stabilize the inside before.

However, the atmosphere gas is not limited to nitrogen, and any method capable of weakening the oxidizing atmosphere may be included. This is the same in the cooling process.

In addition, the step S300 may be activated by heating the kenaf 20 impregnated with phosphoric acid in the high temperature furnace 10 of the nitrogen atmosphere for 30 minutes to 120 minutes at 400 to 900 ° C.

At this time, if the temperature is less than 400 ℃, the activation process is not activated well, the pore characteristics are weakened, and if it exceeds 900 ° C, the yield may be reduced due to excessive activation reaction and the pore properties may also be lowered.

Cooling the resulting porous carbon material (S400) may be activated in step S300 to cool the resulting porous carbon material in a high temperature furnace, which is a nitrogen atmosphere.

At this time, by cooling the porous carbon material in a nitrogen atmosphere to room temperature (25 ℃) it is possible to obtain a porous carbon material that is a final product excellent in physical properties such as pore characteristics.

In addition, the cooled porous carbon material may be pulverized to 10 to 1500 mesh to suit the intended use, or processed into a pellet (2 to 6 mm) form.

Finally, in the step S500 of washing and neutralizing the cooled porous carbon material, the cooled porous carbon material in step S400 may be neutralized to pH 7.

The porous carbon material using Kenaf prepared by the above-described manufacturing method may have a specific surface area of 800 to 2,400 m 2 / g, and a ratio of medium pores to 20 to 80%.

As described above, the porous carbon material using Kenaf according to the embodiment of the present invention and a method for manufacturing the same can have higher yield and porosity characteristics than the conventional commercially available porous carbon material, and are environmentally friendly as well as manufacturing cost This can be cheap.

In addition, since it can have a higher porosity characteristic than the conventional commercially available porous carbon material, it can be usefully applied as an energy storage and environmental purification material such as an adsorbent for water purification, an automotive canister, an air purification filter, and an active material for a supercapacitor.

Hereinafter, the present invention made as described above can be better understood by the following examples, examples are only for illustrative purposes of the present invention and the present invention is not limited by these examples.

The following description describes the examples produced through the above-described manufacturing method, an experimental example in which the prepared porous carbon material is analyzed, and an example of using the porous carbon material for a canister made of the porous carbon material manufactured through the above-described manufacturing method. I will do it.

< Example >

<Example 1>

10 g of Kenaf was supported in phosphoric acid at a weight ratio of 1: 4, placed in a furnace, heated to 150 ° C., and maintained for 6 hours to prepare Kenaf impregnated with phosphoric acid.

After inserting the Kenaf impregnated with phosphoric acid into a high temperature furnace at room temperature, nitrogen was introduced to a nitrogen atmosphere, and then the temperature of the high temperature furnace was increased to 400 ° C. to activate for 30 minutes to obtain a porous carbon material. Subsequently, nitrogen was introduced into the high-temperature furnace to make a nitrogen atmosphere, and then the porous carbon material was cooled to 25 ° C, washed with distilled water, and neutralized to pH 7 to produce 5 g of the final product, the porous carbon material.

<Example 2>

Compared to Example 1, the activation temperature was changed at 500 ° C. instead of 400 ° C., but the rest of the processes were the same.

<Example 3>

Compared to Example 1, the only difference was that the activation temperature was activated at 600 ° C instead of 400 ° C, and the rest of the process was the same.

<Example 4>

Compared to Example 1, the activation temperature was changed at 700 ° C. instead of 400 ° C., but the rest of the processes were the same.

<Example 5>

Compared to Example 1, the only difference was that the activation temperature was activated at 800 ° C instead of 400 ° C, and the rest of the process was the same.

<Example 6>

Compared to Example 1, the activation temperature was changed at 900 ° C. instead of 400 ° C., but the rest of the processes were the same.

<Example 7>

Compared to Example 1, the activation time was only 60 minutes instead of 30 minutes, and the rest of the steps were the same.

<Example 8>

Compared to Example 7, only the difference in activation temperature at 500 ° C instead of 400 ° C was different, and the rest of the process was the same.

<Example 9>

Compared to Example 7, only the difference in activation temperature was 600 ° C instead of 400 ° C, and the rest of the processes were the same.

<Example 10>

Compared to Example 7, the only difference was that the activation temperature was activated at 700 ° C instead of 400 ° C, and the rest of the process was the same.

<Example 11>

Compared to Example 7, only the difference in activation temperature at 800 ° C instead of 400 ° C was the same as the rest of the process.

<Example 12>

Compared to Example 7, only the difference in activation temperature at 900 ° C instead of 400 ° C was the same as the rest of the process.

<Example 13>

Compared to Example 1, the activation time was only 120 minutes instead of 30 minutes, and the rest of the steps were the same.

<Example 14>

Compared to Example 13, the activation temperature was changed at 500 ° C instead of 400 ° C, but the rest of the steps were the same.

<Example 15>

Compared to Example 13, the only difference was that the activation temperature was activated at 600 ° C instead of 400 ° C, and the rest of the process was the same.

<Example 16>

Compared to Example 13, the only difference was that the activation temperature was activated at 700 ° C instead of 400 ° C, and the rest of the process was the same.

<Example 17>

Compared to Example 13, the only difference was that the activation temperature was activated at 800 ° C instead of 400 ° C, and the rest of the process was the same.

<Example 18>

Compared to Example 13, the activation temperature was changed at 900 ° C instead of 400 ° C, but the rest of the process was the same.

<Example 19>

Compared to Example 9, only the point where the proportion of phosphoric acid was impregnated with 0.5 instead of 4 was different, and the rest of the steps were the same.

<Example 20>

Compared to Example 9, only the point where the proportion of phosphoric acid was impregnated with 2 instead of 4 was different, and the rest of the steps were the same.

<Example 21>

Compared to Example 9, the only difference was that the ratio of phosphoric acid was impregnated with 6 instead of 4, and the rest of the process was the same.

<Example 22>

Compared to Example 9, only the point where the proportion of phosphoric acid was impregnated with 10 instead of 4 was different, and the rest of the steps were the same.

<Example 23>

Compared to Example 9, the temperature of the impregnation process was changed only at 15 ° C instead of 150 ° C, and the rest of the processes were the same.

<Example 24>

Compared to Example 9, the temperature of the impregnation process was changed only at the point of impregnation at 100 ° C instead of 150 ° C, and the rest of the processes were the same.

<Example 25>

Compared to Example 9, the temperature of the impregnation process differed only in that the impregnation was different at 200 ° C instead of 150 ° C.

<Comparative Example 1>

A palm-based porous carbon material activated by water vapor (Woosung Tech) was used.

<Comparative Example 2>

Coal-based commercial porous carbon materials (natural science industry) were used.

<Comparative Example 3>

A wood-based commercially available porous carbon material (WV-A 1100, Ingevity) activated with phosphoric acid was used.

The following tests were performed on the porous carbon materials prepared in Examples 1 to 18 and Comparative Examples 1 to 3.

< Test example  1> Analysis of yield and pore characteristics of porous carbon materials

The yields after activation of the porous carbon materials prepared in Examples 1 to 25 are shown in Table 1 below.

In addition, in order to analyze the pore characteristics of the porous carbon materials prepared in Examples 1 to 18 and Comparative Examples 1 to 3, each sample isothermally adsorbed after degassing for 6 hours while maintaining a residual pressure of 10-3 torr or less at 573K. Using a device (BELSORP-max, BEL JAPAN, Japan), measure the adsorption amount of nitrogen (N2) gas according to relative pressure (P / P0) at 77K to measure the specific surface area, total pore volume, and micropore volume of the porous carbon material. , The pore volume and the pore ratio were calculated, and the results are shown in [Table 2].

 [Table 2] is a table comparing the pore characteristics of the porous carbon materials according to Examples 1 to 18.

As can be seen from Tables 1 and 2, it was confirmed that the porous carbon materials prepared in Examples 1 to 25 exhibited high yield characteristics, and also showed a high numerical value of the medium pore ratio.

In addition, as can be seen from [Table 2], the porous carbon materials prepared in Examples 8, 9, 10, 11, 15, 16 and 19 to 25 have a specific surface area than the porous carbon materials of Comparative Examples 1 to 3. It was found that the porosity was very good because the ratio of the high and medium pores was 50% or more.

In addition, the porous carbon materials prepared in Examples 1 to 25 were confirmed to have excellent porosity characteristics compared to Comparative Example 3, and in addition, it was found that both the micropore and medium pore volumes were superior to Comparative Example 3.

Therefore, the porous carbon material using Kenaf according to the embodiment of the present invention and a method of manufacturing the same can provide a porous carbon material having superior porosity characteristics than the existing porous carbon material.

3 is an X-ray diffraction curve of a porous carbon material using Kenaf according to Example 9 of the present invention.

Referring to FIG. 3, 022 and 101 peaks of the porous carbon material were observed in the diffraction curve, and the peaks were clearly observed, indicating that the crystal structure of the porous carbon material was well developed due to the good crosslinking by phosphoric acid. .

As described above, since a specific part of the contents of the present invention has been described in detail, for those skilled in the art, this specific technology is only a preferred embodiment, and the scope of the present invention is not limited thereby. It will be obvious. Accordingly, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

10: high temperature furnace
20: Kenaf impregnated with phosphoric acid
30: tube tube
40: nitrogen input tube

Claims (5)

(a) impregnating phosphoric acid in Kenaf;
(b) charging the kenaf impregnated with phosphoric acid to a high temperature furnace;
(c) activating the Kenaf impregnated with phosphoric acid to produce a porous carbon material;
(d) cooling the resulting porous carbon material and
(e) washing and neutralizing the cooled porous carbon material,
The Kenaf,
The moisture content is controlled to 1% or less,
Step (d) is,
The porous carbon material is cooled to room temperature in a nitrogen atmosphere of a high temperature furnace,
Step (a) is,
Phosphoric acid is added to the kenaf at a weight ratio of 1: 0.5 to 1:10 and then impregnated at 15 to 200 ° C for 1 to 12 hours,
Step (c) is,
Maintaining the high temperature furnace in a nitrogen atmosphere at 500 to 900 ° C. for 30 to 120 minutes to activate Kenaf impregnated with phosphoric acid,
In step (c),
A method of manufacturing a porous carbon material using Kenaf, characterized in that the inside of the high-temperature furnace is filled with nitrogen gas of at least 99.99% for at least 30 minutes before being heated to remove all of the internal air.
delete delete delete In the porous carbon material using a kenaf prepared by the method of claim 1,
Manufactured by activating Kenaf, where phosphoric acid is immersed,
Porous carbon material using Kenaf, characterized in that the specific surface area is 1520 ~ 2,400㎡ / g, and the proportion of the medium pores in the total pores is 43 ~ 80% by volume.

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