KR101683006B1 - Preparation of steam-activated carbon by polyolefine and manufacuring methode - Google Patents

Abstract

After polyolefin is cross-linked by using sulfuric acid, carbonized in a high temperature furnace, and activated by steam, activated carbon is manufactured. According to a method of the present invention, activated carbon can realize higher porous and electrochemical properties than an existing commercialized method for manufacturing activated carbon; and is eco-frinedly and can be manufactured at low costs by not using chemicals such as an existing drug activating agent.

Description

[0001] The present invention relates to a process for producing activated carbon from polyolefins,

The present invention relates to a polyolefin-based activated carbon activated by water vapor and a process for producing the activated carbon. More particularly, the present invention relates to a process for producing polyolefins, which comprises crosslinking polyolefins, carbonizing them at high temperature, activating them with water vapor to produce activated carbon, thereby realizing excellent pore characteristics and electrochemical characteristics than conventional coconut shells, coke and phenol- Activated carbon and a method for producing the same.

Recently, due to high oil prices and popular use of smart portable devices, interest in renewable energy and energy storage devices is increasing. Activated carbon is a material mainly applied to environmental purification and energy storage because of its peculiar pore characteristics. These conventional activated carbons are produced by using coconut shells based on water vapor, activated carbon based on coke, and phenol based activated carbon using potassium hydroxide. However, a large amount of ash is present in the coconut shell and the coke, which may cause side reactions to the use as an electrode or an adsorbent, and the conventional phenol-based activated carbon using potassium hydroxide has a disadvantage of high production cost due to the use of an activator.

As a conventional technique relating to the production of activated carbon, Japanese Patent Application Laid-Open No. 10-0476713 discloses a method in which a polystyrene-based anion exchange resin or an acrylic-based anion exchange resin as a porous polyolefin material is impregnated with an acidic aqueous solution of a chemical activator, , &Quot; a method for producing activated carbon, " However, the use of the chemical activator has the problem that the pollution and the specific surface area of the activated carbon, which is a product, are not so large, resulting in poor product quality.

Therefore, it is inevitable to develop a new technology that not only has excellent pore characteristics and electrochemical characteristics using an environmentally friendly activation method, but also is excellent in quality and can be produced at a low cost.

DISCLOSURE OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a polyolefin-activated polyolefin which is not only excellent in pore characteristics and electrochemical characteristics by producing environmentally friendly activated carbon using polyolefin, Based activated carbon and a method for producing the same.

In order to achieve the above object, the present invention provides a method for producing a polyolefin comprising: (a) crosslinking a polyolefin using sulfuric acid; (b) carbonizing the crosslinked polyolefin by heating in a nitrogen atmosphere to produce amorphous carbon; (c) heating the amorphous carbon in a nitrogen atmosphere and then activating the amorphous carbon in a steam atmosphere to produce activated carbon; And (d) cooling the generated activated carbon in a nitrogen atmosphere to produce activated carbon. The present invention can provide a method for producing activated carbon based on polyolefins based on water vapor.

In the step (a), the crosslinking method of the polyolefin may be heated at a temperature of 150 to 180 ° C for 1 to 2 hours.

The activated polyolefin-based activated carbon may be heated in the step (b) at a temperature of 800 to 1,000 ° C for 1 to 2 hours.

In the step (c), the activation may be carried out in a steam atmosphere for 20 to 40 minutes after the temperature is maintained at 900 DEG C in a nitrogen atmosphere.

In the step (c), the activation may be carried out in a steam atmosphere for 20 to 30 minutes after the temperature is maintained at 1,000 DEG C in a nitrogen atmosphere.

The step (d) may be cooled to room temperature in a nitrogen atmosphere.

The present invention also provides an activated carbon according to at least one of the above methods for producing activated carbon, which has a specific surface area of 950 to 2,430 m 2 / g.

The polyolefin-based activated carbon activated by water vapor according to an embodiment of the present invention and its manufacturing method can realize higher pore characteristics and electrochemical characteristics than conventional commercial activated carbon production methods, Since no chemicals are used, it is not only environmentally friendly, but also can produce inexpensive activated carbon.

Also, the polyolefin-based activated carbon activated by water vapor according to the embodiment of the present invention and the manufacturing method thereof can realize higher pore characteristics and electrochemical characteristics than conventional commercialized activated carbon. Therefore, the electrode material for electrochemical capacitors, Electrode material, carbon dioxide storage material, and the like, which are useful for energy storage and environmental purification.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart illustrating a method of manufacturing a polyolefin-based activated carbon activated with water vapor according to an embodiment of the present invention; FIG.
2 is a conceptual view schematically showing a production apparatus for producing activated carbon based on polyolefins activated with water vapor.
3 is a scanning electron microscope (SEM) photograph of activated carbon produced by the activated carbon production method of the present invention.
4 is an X-ray diffraction curve of activated carbon produced by the production method 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 transformations can be applied and various embodiments can be made. It is to be understood that the following description covers all changes, equivalents, and alternatives falling within the spirit and scope of the present invention.

In the following description, the terms first, second, and the like are used to describe various components and are not limited to their own meaning, and are used only for the purpose of distinguishing one component from another component.

Like reference numerals used throughout the specification denote like elements.

As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. It is also to be understood that the terms " comprising, "" comprising, "or" having ", and the like are intended to designate the presence of stated features, integers, And should not be construed to preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 4 attached hereto.

FIG. 1 is a flowchart illustrating a method for producing activated polyolefin-based activated carbon according to an embodiment of the present invention. FIG. 2 schematically illustrates a manufacturing apparatus for producing activated carbon of FIG. Hereinafter, a method for producing a polyolefin-based activated carbon activated by water vapor will be described with reference to FIGS. 1 and 2. FIG.

Referring to FIGS. 1 and 2, a method of manufacturing activated carbon for polyolefin activated with water vapor according to an embodiment of the present invention includes: supporting polyolefin in a heatable container together with sulfuric acid (S100); heating the supported polyolefin (S300) washing the crosslinked polyolefin (S300), charging the crosslinked polyolefin having been cleaned into the high temperature furnace (S400), heating the crosslinked polyolefin in the high temperature furnace in a nitrogen atmosphere to carbonize A step of forming amorphous carbon (S500), a step of heating the amorphous carbon to activate activated carbon in a steam atmosphere to generate activated carbon (S600), and a step of cooling activated carbon to produce activated carbon (S700) have.

First, sulfuric acid is added to the heatable container and the polyolefin is carried thereon (S100).

Subsequently, the container is heated to crosslink the polyolefin (S200). In the present invention, sulfuric acid is used to crosslink the polyolefin. In order to induce the crosslinking reaction, the sulfuric acid is heated. When the temperature of the sulfuric acid increases, the dehydrogenation reaction is caused to cause the polyolefin fibers to cyclize and to use the sulfuric acid in order to smooth the crosslinking reaction of the sulfuric acid. In order to easily carry the polyolefin in the sulfuric acid and to easily put it into the furnace, for example, polyolefin is completely supported on the sulfuric acid in the crucible.

At this time, in order to crosslink the polyolefin, it is supported on sulfuric acid and then crosslinked at 150 to 180 ° C for 1 to 2 hours. When the heating temperature for heating the container is lower than 150 ° C, the crosslinking reaction hardly occurs and the yield is greatly reduced during the carbonization process. Since the crosslinking reaction is completed at 180 ° C, the crosslinking reaction is not performed even if the temperature is raised above 180 ° C The production cost will rise.

The crosslinked polyolefin is then washed (S300).

After washing, the crosslinked polyolefin is charged into the high temperature furnace 10 using the tube tube 30 of FIG. 2 (S400).

Subsequently, the crosslinked polyolefin charged in the high-temperature furnace 10 is carbonized by heating in a nitrogen atmosphere to produce amorphous carbon (S500). At this time, the manufacturing apparatus of Fig. 2 is used.

2, it is preferable that the high temperature furnace 10 is formed to be rotatable on the outer periphery of the tube tube 30 and is formed to be hermetically closed. In addition, nitrogen and water vapor can be introduced 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 so as to pass therethrough. Further, a heating tube 50 connected to the heating furnace 70 connected to the water tank 80 for supplying water vapor and heating the supplied water is penetrated into the tube tube 30. Here, a flow controller 60 may be provided between the water tank and the heating furnace to regulate the amount of steam supplied into the tube tube 30. At this time, as the tube tube 30 inserted into the high temperature furnace 10, various materials such as iron (including stainless steel), alumina and aluminum can be used. However, in order to solve the durability problem of the tube tube 30 when rotating at high temperature It is preferable that the material is made of iron. Any device can be used as long as it raises the temperature by heating the water.

When the crosslinked polyolefin charged in the high temperature furnace 10 is carbonized by heating in a nitrogen atmosphere to produce amorphous carbon, the overall carbonization and activation conditions are carried out at a high temperature of 800 to 1000 ° C, It is preferable that the upper and lower portions are located on the upper and lower sides of the base 30, respectively. At this time, the manufacturing apparatus must remove all the air inside the tube tube 30 in order to produce the amorphous carbon 20 and activated carbon. For this, nitrogen gas (N2) of 99.99% or more is charged into the tube tube 30 from the charging tube 40 for 30 minutes or more to stabilize the inside of the tube tube before the temperature increase.

The crosslinked polyolefin is carbonized at 800 to 1000 ° C for 1 to 2 hours in a nitrogen atmosphere of the tube tube (30). If the temperature is lower than 800 ° C., carbonization is not completely performed, activation is not performed well in the activation process, and pore characteristics are weakened. When the temperature exceeds 1000 ° C., most of the constituents remain only carbon, A problem occurs in that it becomes low.

Next, the amorphous carbon is heated and activated with water vapor to produce activated carbon (S600). At this time, when the temperature of the tube tube 30 charged with nitrogen is maintained at 900 ° C to 1000 ° C and the temperature of the high temperature furnace 10 is raised to the activation temperature, the introduction of nitrogen is stopped and then steam is supplied to the tube tube 30 The amorphous carbon is activated for 10 to 40 minutes after being charged and converted to a steam atmosphere. This is to control the activation reaction of hard carbon by water vapor over time. When the activation temperature is lower than 900 ° C., the activation reaction of hard carbon is not performed well due to the low temperature. When the activation temperature exceeds 1000 ° C., the yield is very low due to the excessive activation reaction.

Next, the generated activated carbon is cooled to produce activated carbon (S700). Activated carbon activated by water vapor is cooled in a nitrogen atmosphere to produce activated carbon. At this time, the supply of water vapor is stopped with the tube tube 30, the inside of the tube tube 30 is stabilized by filling nitrogen and switching to nitrogen atmosphere. Subsequently, by cooling the activated carbon to room temperature in a nitrogen atmosphere, activated carbon, which is a final product having excellent physical properties such as pore characteristics, can be obtained. The activated carbon may be pulverized to 10 to 1500 mesh according to the intended use.

FIG. 3 is a scanning electron microscope (SEM) photograph of the activated carbon produced by the method for producing activated carbon, showing that activated carbon having excellent pore characteristics was produced. Further, a graph of 2? Measured by x-ray diffraction can be obtained in Fig. The wavelength of the CuKa line was 0.15406 mm. At this time, the measurement range was 5 ° to 80 ° and the measurement speed was 2 ° / min. As a result of the measurement, it can be confirmed that amorphous activated carbon having a wide peak width was produced as in the 002 region.

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

The following description will be directed to embodiments produced through the above-described production method, an experimental example in which the activated carbon produced is analyzed, and an application example of the electrode and the battery made of the activated carbon produced through the above-described manufacturing method.

≪ Example 1 >

The polyolefin was supported on sulfuric acid and placed in a furnace, and the temperature was raised to 170 ° C to induce the cyclization reaction. The temperature was maintained for 30 minutes to prepare a cyclized polyolefin.

 10 g of the crosslinked polyolefin was put into a high temperature furnace at room temperature, and then nitrogen was introduced into the furnace to raise the temperature of the furnace to 900 ° C. and carbonization for 120 minutes to obtain 5 g of amorphous carbon. Subsequently, while the temperature of the high-temperature furnace was kept at 900 ° C, steam was introduced into the high-temperature furnace to convert it into a steam atmosphere, and the amorphous carbon was activated at 900 ° C for 10 minutes to obtain activated carbon. Subsequently, nitrogen was introduced into the high temperature furnace to set the atmosphere to nitrogen, and then the activated carbon was cooled to room temperature to obtain 3.5 g of activated carbon as the final product.

≪ Example 2 >

     The remaining processes were the same except that the steam activation time was activated for 20 minutes instead of 10 minutes as compared with Example 1.

≪ Example 3 >

     The remaining steps were the same except that the steam activation time was activated for 30 minutes instead of 10 minutes as compared with Example 1.

<Example 4>

     The remaining steps were the same except that the steam activation time was activated for 40 minutes instead of 10 minutes as compared with Example 1.

&Lt; Example 5 >

     Compared to Example 1, the remaining steps were the same except that the steam activation temperature was activated at 1000 占 폚 instead of 900 占 폚.

&Lt; Example 6 >

     The remaining steps were the same except that the steam activation time was activated for 20 minutes instead of 10 minutes as compared with Example 5.

&Lt; Example 7 >

     The remaining steps were the same except that the steam activation time was activated for 30 minutes instead of 10 minutes as compared with Example 5.

<Comparative Example>

Commercial activated carbon (YP-50F) of kuraray, which is commonly used for electrochemical capacitors, was used.

The following tests were conducted on the activated carbon prepared in Examples 1 to 7 and Comparative Examples.

<Test Example 1> Analysis of pore characteristics of activated carbon

For the analysis of the pore characteristics of the activated carbon prepared in Examples 1 to 7 and Comparative Examples, each sample was deaerated at 573 K for 6 hours while keeping the residual pressure at 10 -3 torr or less. Thereafter, an isothermal adsorption device (BELSORP-max, BEL The specific surface area of activated carbon was calculated by measuring the adsorption amount of nitrogen (N ₂ ) gas according to the relative pressure (P / P ₀ ) at 77 K using JAPAN, Japan. The results are shown in Table 1.

Preparation Example 1 Preparation of electrode for electrochemical capacitor using activated carbon

(SBR) and carboxymethyl cellulose (CMC) were used as a binder in a ratio of 1: 2, Super-P of Timcal Co. was used as a conductive material, and activated carbon prepared in Examples 1 to 7 and Comparative Example Are mixed at a weight ratio of 10: 5: 85 using a three-dimensional mixer. After mixing, the mixture was coated on an aluminum foil with a thickness of 0.125 mm, followed by compression using a roll press at 150 ° C., followed by drying in a vacuum oven at 150 ° C. for 12 hours to prepare an electrode for an electrochemical capacitor.

Preparation Example 2 Coin cell type electrochemical capacitor production

The electrode prepared in Preparation Example 1 was drilled to a diameter of 12 mm and processed into a coin cell type electrode. The separator was made by drilling cellulose of NKK Co., Ltd., Japan, with a diameter of 18 mm. A coin unit product having a diameter of? 27 mm and a height of 12 mm was used for the preparation of the cell. The electrolytic solution was 1 M tetraethylammonium tetrafluoroborate (TEABF4) and the solvent was propylene carbonate. Electrochemical capacitors were manufactured.

<Test Example 2> Electrochemical characterization of activated carbon

The charging and discharging tests were carried out by using a charge / discharge device (MACCOR 4300K DESKTOP) manufactured by MACCOR, USA and measuring the charge / discharge with a current of 2 mA / cm ² . ). The capacitances of the Coin cells prepared as described above are shown in Table 1.

Precursor Yield after carbonization (%) Activation
Temperature (℃) Activation
Time (min) After activation
yield(%) Specific surface area of activated carbon (m ² / g) Activated carbon
Capacitance Capacity (F / g) Example 1 Polyolefin 50 900 10 70 950 10.9 Example 2 " 900 20 49 1520 21.3 Example 3 " 900 30 35 1870 23.2 Example 4 " 900 40 29 2080 22.9 Example 5 " 1000 10 40 1740 19.5 Example 6 " 1000 20 28 2050 21.3 Example 7 " 1000 30 15 2430 20.4 Comparative Example Palm angle - - - 1620 20.5

Table 1 is a table comparing pore and electrochemical characteristics of activated carbon according to Examples 1 to 7.

As can be seen from the above Table 1, the activated carbon prepared in Examples 3, 4, 6, and 7 had a larger specific surface area of activated carbon than that of the activated carbon of the comparative example, and the electrochemical capacity .

 In addition, the activated carbon according to the production method of the present invention can remove the side reaction in the adsorption or the use of the electrode because there is no ash which is a disadvantage of the existing coconut angle based activated carbon, and since the environmentally friendly activation method is used by using the steam activation, The manufacturing cost is low because no chemicals are used, and the porosity is also excellent in comparison with the expensive phenol-based activated carbon using an activator such as KOH.

Further, when the electrode using the activated carbon according to the present invention was applied to an electrochemical capacitor, it was confirmed that the electrochemical performance was excellent.

Having described specific portions of the present invention in detail, those skilled in the art will appreciate that these specific descriptions are only for the preferred embodiment and that the scope of the present invention is not limited thereby. It will be obvious. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

10: high temperature furnace 20: amorphous carbon
30: tube tube 40: nitrogen inlet tube
50: heating tube 60: flow regulator
70: Heating furnace 80: Water tank

Claims (7)

(a) crosslinking the polyolefin with sulfuric acid;
(b) carbonizing the crosslinked polyolefin by heating in a nitrogen atmosphere to produce amorphous carbon;
(c) heating the amorphous carbon in a nitrogen atmosphere and then activating the amorphous carbon in a steam atmosphere to produce activated carbon; And
(d) cooling the generated activated carbon in a nitrogen atmosphere to produce activated carbon,
The step (a)
Wherein the crosslinking temperature of the polyolefin is 150 to 180 ° C.
delete The method of claim 1, wherein
In the step (b)
Wherein the heating is carried out at a temperature of 800 to 1,000 DEG C for 1 to 2 hours.
The method of claim 1, wherein
In the step (c)
Wherein the activation is performed at a temperature of 900 ° C in a nitrogen atmosphere and then in a steam atmosphere for 20 to 40 minutes.
The method of claim 1, wherein
In the step (c)
Wherein the activation is carried out in a steam atmosphere for 20 to 30 minutes after being maintained at 1,000 DEG C in a nitrogen atmosphere.
The method according to claim 1,
The step (d)
Wherein the polyolefin-based activated carbon is cooled in a nitrogen atmosphere at a normal temperature.
delete

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