KR101305454B1 - Carbon adsorbent codoped nitrogen, oxygen, fluorine for carbon dioxide adsorption and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A carbon absorbent for adsorbing carbon dioxide and a manufacturing method thereof improve the ionic attraction between the carbon absorbent and carbon dioxide to enhance the carbon dioxide adsorption ability, and nitrogen, oxygen and fluorine are introduced to carbon materials of the carbon absorbent by using a weather-liquid simultaneous reaction, presenting excellent economic feasibility and efficiency. CONSTITUTION: A manufacturing method of a carbon absorbent for adsorbing carbon dioxide comprises the steps of: dissolving a compound containing nitrogen and oxygen in a solvent to produce a solution; inserting the solution of the previous step and carbon materials in a reactor; and injecting fluorine gas or gas mixture of fluorine gas and inert gas in a bubble injection way to introduce nitrogen, oxygen and fluorine to the carbon materials at the same time. [Reference numerals] (AA) Example 1; (B1) Comparative example 1; (B2) Comparative example 2; (B3) Comparative example 3

Description

Carbon adsorbent codoped nitrogen, oxygen, fluorine for Carbon dioxide adsorption and manufacturing method

The present invention relates to a carbon adsorbent for carbon dioxide adsorption and a method for manufacturing the same, and more particularly, carbon adsorbent for carbon dioxide adsorption which improves the carbon dioxide adsorption capacity of carbon materials by introducing nitrogen, oxygen, and fluorine into the carbon material in a gas-liquid phase reaction. And to a method for producing the same.

Various methods of capturing carbon dioxide are currently being studied in view of solving the global warming problem caused by carbon dioxide and the efficient use of renewable energy, especially bio-mass.

The carbon dioxide capture technology known to date includes carbon dioxide absorption using an amine-based absorbent, carbon dioxide recovery using a solid adsorbent such as activated carbon, zeolite, alkali metal or alkali metal oxide, and carbon dioxide separation using a carbon dioxide separator. How to do it.

Carbon dioxide absorption using the amine-based absorbent requires a large amount of energy in the separation process, and the purification process of the amine used is essential. Therefore, the process is very complicated, there is a problem that the equipment cost is the highest among known methods of separation of carbon dioxide.

The method of using a solid adsorbent has the advantage of directly obtaining a high concentration of carbon dioxide in a separation process of carbon dioxide and a solid adsorbent, but has a disadvantage in that loss due to wear of the solid adsorbent is large.

In the case of the carbon dioxide separator, the price of the separator currently manufactured and sold is very high, a pretreatment device for purifying combustion gas is required, and the replacement cost due to contamination of the separator is very high.

Recently, many studies on carbon adsorbents having excellent thermal and chemical stability have been conducted, but the carbon dioxide adsorption amount of carbon adsorbents known to date is still insufficient in commercialization standards. In addition, the current method, which is performed to increase the carbon dioxide adsorption amount of the carbon material, is still mainly limited to the pore characteristics and simple surface treatment methods, which are traditional methods, and the method is also very complicated and expensive.

The present invention has been made to solve the above problems, while maintaining the inherent properties of the carbon material having micro and meso pores, by introducing nitrogen, oxygen and fluorine on the surface of the carbon adsorbent by the simultaneous reaction of the gas phase and liquid phase to improve the carbon dioxide adsorption capacity An object of the present invention is to provide an improved carbon adsorbent for carbon dioxide adsorption and a method of manufacturing the same.

In order to achieve the above object, the present invention provides a method for producing a carbon adsorbent for carbon dioxide adsorption, the method for producing a carbon adsorbent for carbon dioxide adsorption according to an example of the present invention,

(1) a first step of preparing a solution by dissolving a compound containing nitrogen and oxygen in a solvent;

(2) a second step of injecting the solution and carbon material obtained in the first step into the reactor; And

(3) a third step of introducing nitrogen, oxygen, and fluorine simultaneously into the carbon material by injecting fluorine gas or a mixed gas of fluorine gas and inert gas into the reactor by bubble injection.

Compounds containing nitrogen and oxygen of the first step are nitric acid (HNO ₃ ), sodium nitrate (NaNO ₃ ), potassium nitrate (KNO ₃ ), ammonium nitrate (NH ₄ NO ₃ ), calcium nitrate (Ca (NO ₃ ) ₂ ), barium nitrate (Ba (NO ₃ ) ₂ ) and mixtures thereof.

The concentration of the solution obtained through the process of the first step is preferably 0.5 to 5M.

Preferably, the ratio of the solution and the carbon material introduced into the reactor in the second step is 5 to 30 parts by weight of the carbon material based on 100 parts by weight of the solution.

In the third step, the fluorine gas injected into the reactor by bubble injection is fluorine (F ₂ ), nitrogen trifluoride (NF ₃ ), carbon tetrafluoride (CF ₄ ), carbon trifluoride (CHF ₃ ), trifluorooctafluorocarbon (C ₃₎ F ₈ ), tetrafluorocarbons (C ₄ F ₈ ) and mixtures thereof.

In the third step, the fluorine gas injected into the reactor by bubble injection is preferably injected in a volume of 1 to 100 per minute based on the volume of the solution and the carbon material in the reactor.

The third step is preferably made for 0.2 to 2 hours at a temperature of 40 to 100 ℃.

In another aspect, the present invention provides a carbon adsorbent for carbon dioxide adsorption produced by the above-described manufacturing method.

According to the present invention as described above, due to the introduction of nitrogen, oxygen and fluorine in the carbon material, the ionic attraction between the carbon dioxide and the carbon adsorbent is improved to improve the carbon dioxide adsorption capacity.

In addition, the present invention can improve the carbon dioxide adsorption capacity of the carbon adsorbent by introducing nitrogen, oxygen and fluorine to the carbon material by using the simultaneous reaction of the gas phase-liquid phase compared to the complicated process and costly conventional, economical and efficiency Very good in terms of

1 is an XPS analysis result of the carbon adsorbent prepared according to the Examples and Comparative Examples of the present invention.
Figure 2 is a graph showing the measurement of the carbon dioxide adsorption amount of the carbon adsorbent prepared by Examples and Comparative Examples of the present invention.

Hereinafter, the present invention will be described in detail.

First, the present invention provides a method for preparing a carbon adsorbent for carbon dioxide adsorption, the method for preparing a carbon adsorbent for carbon dioxide adsorption according to an example of the present invention,

(1) a first step of preparing a solution by dissolving a compound containing nitrogen and oxygen in a solvent;

(2) a second step of injecting the solution and carbon material obtained in the first step into the reactor; And

(3) a third step of introducing nitrogen, oxygen, and fluorine simultaneously into the carbon material by injecting fluorine gas or a mixed gas of fluorine gas and inert gas into the reactor by bubble injection.

The compound containing nitrogen and oxygen may be used as long as it contains nitrogen and oxygen. For example, nitric acid (HNO ₃ ), sodium nitrate (NaNO ₃ ), potassium nitrate (KNO ₃ ), and nitric acid It may be selected from the group consisting of ammonium (NH ₄ NO ₃ ), calcium nitrate (Ca (NO ₃ ) ₂ ), barium nitrate (Ba (NO ₃ ) ₂ ) and mixtures thereof, but is not limited thereto.

The solvent may be used as long as it can dissolve a compound containing nitrogen and fluorine. Examples thereof include organic solvents such as dimethylformamide, chloroform and N-methylpyrrolidone tetrahydrofuran. , Acid / base solvents, distilled water and mixtures thereof.

It is preferable that the concentration of the solution obtained through the process of the first step is 0.5 to 5M. When the concentration of the solution is less than the lower limit, the reaction rate is slowed, and nitrogen and oxygen may not be sufficiently introduced into the carbon material. If the concentration exceeds the upper limit, the reaction may occur violently and the carbon material may be excessively modified, and the pore structure of the carbon material may collapse, which may lower the carbon adsorption capacity of the carbon adsorbent.

The carbon material introduced into the reactor in the second step may use any known material that can be used as a carbon adsorbent. Moreover, you may use what kind of form, such as spherical form, fibrous form, powder form, and pellet form.

In another aspect, the present invention may further comprise the step of removing the intrinsic moisture of the carbon material introduced into the reactor through the second step before the second step. Removal of the intrinsic moisture can be carried out for 1 to 10 hours at a temperature of 100 to 200 ° C, for example.

The ratio of the solution and the carbon material introduced into the reactor in the second step is preferably 5 to 30 parts by weight of the carbon material based on 100 parts by weight of the solution, when the carbon material is a lower limit when the mixing ratio of the carbon material is less than the lower limit. There is no difference, and only waste of solution and energy. If the mixing ratio of the carbon material exceeds the upper limit, the carbon material may not be sufficiently in contact with the solution during the reaction, which is not preferable.

In the second step, the reactor into which the solution and the carbonaceous material are introduced may be a reactor capable of gas-liquid reaction, for example, a bubble reactor. The bubble (bubble) reactor is to receive a liquid inside the reactor, and injects gas through the inlet to form a bubble (bubble) in contact with the liquid in the reactor as the reactor itself is a known technique, so its detailed description is omitted.

In the third step, the gas injected into the reactor by the bubble injection method may use fluorine gas alone or a mixed gas of fluorine gas and inert gas. The fluorine gas is fluorine (F ₂ ), nitrogen trifluoride (NF ₃ ), carbon tetrafluoride (CF ₄ ), carbon trifluoride (CHF ₃ ), trifluorofluorocarbons (C ₃ F ₈ ), tetrafluorocarbons (C ₄ F ₈ ) and mixtures thereof, but is not necessarily limited thereto.

In the third step, the fluorine gas injected into the reactor by bubble injection is preferably injected in a volume of 1 to 100 per minute based on the volume of the solution and the carbon material in the reactor. If the fluorine gas is injected below the lower limit, the reaction efficiency may be lowered, that is, nitrogen, oxygen, and fluorine may not be sufficiently introduced into the carbon material, which is not preferable. When the fluorine gas is injected above the upper limit, excessive fluorine is introduced. The reaction is violent due to the injection of gas, and the carbon material may be excessively modified, and the pore structure of the carbon material may collapse, which may lower the carbon dioxide adsorption capacity of the carbon adsorbent. In the case where a mixed gas of fluorine gas and inert gas is used, the proportion of fluorine gas to be injected is preferably as described above.

In addition, the third step is preferably performed for 0.2 to 2 hours at a temperature condition of 40 to 100 ℃, when the reaction temperature and the reaction time is less than the lower limit there is a fear that the desired amount of nitrogen, oxygen and fluorine is not introduced. If the reaction time exceeds the upper limit, there is no difference between the upper limit and no profit. If the reaction temperature exceeds the upper limit, nitrogen, oxygen, and fluorine quickly escape from the solution together with the evaporated water. Therefore, nitrogen, oxygen and fluorine may not be sufficiently introduced into the carbon material, which is not preferable.

In another aspect, the present invention provides a carbon adsorbent for carbon dioxide adsorption produced by the above-described manufacturing method.

Hereinafter, the present invention will be described in more detail with reference to Examples and Test Examples.

Example  : Preparation of Carbon Adsorbent for Adsorbing Carbon Dioxide Adopted Nitrogen, Oxygen and Fluorine Simultaneously

Activated carbon (CMS FB610, Carbo Tech AC GmbH, Germany) as a carbon material, nitric acid (HNO ₃ ) as a compound containing nitrogen and oxygen, and distilled water as a solvent were selected.

First, 1M nitric acid solution was prepared using distilled water as a solvent.

Next, 1000 ml of the solution and 150 g of activated carbon were put into a bubble reactor capable of injecting gas, and fluorine (F ₂ ) was supplied to generate bubbles at a rate of 100 cc / min. The reaction temperature was maintained at 50 ℃, the reaction was carried out for 30 minutes.

Finally, the activated carbon was separated to prepare a carbon adsorbent for adsorption of carbon dioxide into which nitrogen, oxygen and fluorine were simultaneously introduced.

Comparative example

A comparative example was selected for comparison with the above example.

Activated carbon (CMS FB610, Carbo Tech AC GmbH, Germany) without any treatment itself as Comparative Example 1, except for the reaction with a fluorine gas carbon adsorbent prepared through the same process as in Example 2, except that distilled water was used instead of nitric acid solution, the carbon adsorbent prepared through the same process as in Example was selected as Comparative Example 3.

Furtherance

Photoelectron spectroscopy (X-ray Photoelectron Spectroscopy, XPS, MultiLab 2000 spectrometer, Thermo electron corporation, England) to confirm the chemical composition and bonding structure of the carbon adsorbent prepared through the above Examples and Comparative Examples 1, 2, 3 It was analyzed using, the results are shown in Table 1 and FIG.

As can be seen from the results of Table 1 and FIG. 1, it was confirmed that nitrogen, oxygen, and fluorine were introduced into the carbon material in the carbon adsorbent according to the embodiment of the present invention. On the other hand, in the case of Comparative Example 1, which did not undergo any treatment, the peaks of nitrogen and fluorine did not appear, and in the case of Comparative Example 2, the peaks of nitrogen did not appear in the case of Comparative Example 3.

Carbon dioxide adsorption amount evaluation

In order to evaluate the carbon dioxide adsorption capacity of the carbon adsorbent for carbon dioxide adsorption prepared by the above Examples and Comparative Examples 1, 2, and 3, the carbon dioxide adsorption capacity was evaluated at room temperature (25 ° C.) using a specific surface area meter (ASAP2020, Micromeritics). It carried out, and the results are shown in Figure 2 and Table 2 below.

As can be seen from the results of Table 2 and Figure 2, the carbon dioxide adsorption capacity was found to be excellent in the order of Examples Comparative Example 2, Comparative Example 3, Comparative Example 1.

That is, the carbon adsorbent for carbon dioxide adsorption prepared according to the embodiment of the present invention was found to have sufficient nitrogen, oxygen, and fluorine introduced to improve the ionic attraction between carbon dioxide and the carbon adsorbent, thereby improving carbon dioxide adsorption capacity. This result was also confirmed from the improved carbon dioxide adsorption capacity of Comparative Example 2 and Comparative Example 3 in which nitrogen and fluorine were partially introduced compared to Comparative Example 1 in which nitrogen and fluorine were not introduced.

Although the present invention has been described with reference to the above-described embodiments, different embodiments may be configured within the spirit and scope of the present invention. Therefore, the scope of the present invention is defined by the appended claims and equivalents thereof, and is not limited by the specific embodiments described herein.

Claims (8)

(1) a first step of preparing a solution by dissolving a compound containing nitrogen and oxygen in a solvent;
(2) a second step of injecting the solution and carbon material obtained in the first step into the reactor; And
(3) a carbon adsorbent for carbon dioxide adsorption comprising a third step of introducing nitrogen, oxygen, and fluorine simultaneously into a carbon material by injecting fluorine gas or a mixed gas of fluorine gas and an inert gas into the reactor by bubble injection; Manufacturing method.
The method of claim 1,
Compounds containing nitrogen and oxygen of the first step are nitric acid (HNO ₃ ), sodium nitrate (NaNO ₃ ), potassium nitrate (KNO ₃ ), ammonium nitrate (NH ₄ NO ₃ ), calcium nitrate (Ca (NO ₃ ) ₂ ), barium nitrate (Ba (NO ₃ ) ₂ ) and a method for producing a carbon adsorbent for carbon dioxide adsorption, characterized in that it is selected from the group consisting of these.
The method of claim 1,
Method for producing a carbon adsorbent for carbon dioxide adsorption, characterized in that the concentration of the solution obtained through the process of the first step is 0.5 to 5M.
The method of claim 1,
The ratio of the solution and the carbon material introduced into the reactor in the second step is a carbon adsorbent for carbon dioxide adsorption, characterized in that 5 to 30 parts by weight of the carbon material based on 100 parts by weight of the solution.
The method of claim 1,
In the third step, the fluorine gas injected into the reactor by bubble injection is fluorine (F ₂ ), nitrogen trifluoride (NF ₃ ), carbon tetrafluoride (CF ₄ ), carbon trifluoride (CHF ₃ ), trifluorooctafluorocarbon (C ₃₎ F ₈ ), carbon tetrafluorocarbon (C ₄ F ₈ ) and a mixture thereof, the method for producing a carbon adsorbent for carbon dioxide adsorption.
The method of claim 1,
The fluorine gas injected into the reactor by the bubble injection in the third step is a carbon adsorbent for carbon dioxide adsorption, characterized in that the injection of a volume of 1 to 100 per minute based on the volume 100 of the solution and the carbon material in the reactor.
The method of claim 1, wherein
The third step is a method for producing a carbon adsorbent for carbon dioxide adsorption, characterized in that made for 0.2 to 2 hours at a temperature condition of 40 to 100 ℃.
Carbon adsorbent for carbon dioxide adsorption, characterized in that produced by the method of any one selected from claims 1 to 7.

Images