WO2014088148A1

WO2014088148A1 - Method for reducing carbon dioxide, and apparatus for reducing carbon dioxide using same

Info

Publication number: WO2014088148A1
Application number: PCT/KR2012/011443
Authority: WO
Inventors: 김태오; 임광진; 김찬수; 송동근
Original assignee: 금오공과대학교 산학협력단
Priority date: 2012-12-05
Filing date: 2012-12-26
Publication date: 2014-06-12
Also published as: KR101451630B1; KR20140073007A

Abstract

The present invention relates to a method and apparatus for reducing carbon dioxide. More particularly, the present invention relates to a method and apparatus for reducing carbon dioxide, in which the method and apparatus electrochemically reduces the carbon dioxide so as to produce new renewable energy such as alkane and hydrogen.

Description

CO2 Reduction Method and CO2 Reduction Device Using the Same

The present invention relates to a method and apparatus for reducing carbon dioxide to alkanes and hydrogen gas. More particularly, carbon dioxide dissolved in an electrolyte converts and produces alkanes and hydrogen, which are renewable energy, by electrochemical decomposition. The present invention relates to a device that can significantly reduce and reduce. In addition, the conventional carbon dioxide reduction method requires a large overvoltage because the reduction reaction of carbon dioxide does not easily occur, and there is a problem that an efficient catalyst with improved selectivity is required. Renewable energy can be produced at less cost than the method.

In recent years, carbon dioxide emitted to the atmosphere by rapid industrialization and economic activity increases the greenhouse effect, raising the temperature of the surface or the lower atmosphere, causing global warming and climate change. Technical fields for separating and recovering carbon dioxide include physicochemical absorption, adsorption, and membrane separation, which can be stored underground or in the ocean. In addition, carbon dioxide is the most abundant carbon compound on the planet, so it can be effectively activated to convert carbon dioxide into useful organic materials to be used as a source of carbon for energy or organic synthesis. Catalysis, electrochemistry, biological conversion, photochemistry Has been converted to the same form as renewable energy.

Since the conversion of carbon dioxide to useful compounds is a technique of converting the most stable carbon dioxide among other carbon compounds into other useful compounds, input of energy is essential and establishment of related reaction conditions is essential for effective conversion. Available energy sources include chemical energy such as hydrogen and methane, solar energy, and electrical energy.

Among them, a carbon dioxide resource recycling method using electrochemical reduction converts carbon dioxide saturated in an electrolyte solution into a metal electrode and converts it into methane, ethane, alcohol, and the like, causing electrolysis and hydrogenation. In particular, the device and the simple operation and the produced compounds can be used as a general gas fuel, liquid fuel, chemical products. However, the reduction of carbon dioxide does not occur easily and requires a large overvoltage. Hydrogen generation at the positive electrode and reduction at the negative electrode compete with each other and react at a relatively large negative potential. Therefore, the development of efficient catalysts with improved selectivity as well as increased efficiency of voltage and potential is very important for the reduction of carbon dioxide.

However, prior arts for solving the above problems are aimed at reducing carbon dioxide only, and the treatment processes disclosed in some prior documents are not suitable for effectively treating a large amount of carbon dioxide, and in particular, only remove carbon dioxide generated during biogas purification. There is a disadvantage to aiming at.

In addition, the existing method and apparatus for reducing carbon dioxide did not lead to the production of alkanes and hydrogen gas by reducing carbon dioxide, and the reduction reaction of carbon dioxide did not occur easily, so that overvoltage was required, and there was a lot of cost and risk. In order to reduce, a reduction catalyst capable of selectively reducing only carbon dioxide was needed. However, these reduction catalysts are difficult to commercialize because of their high cost, and there are problems that it is difficult to obtain useful renewable energy from the reduced carbon dioxide.

The present invention has been made to solve the above-mentioned problems, the problem to be solved of the present invention to solve the problem of carbon dioxide treatment and at the same time to obtain a large amount of renewable energy, carbon dioxide is electrochemically without the use of a reduction catalyst Provided are an apparatus and a method for reducing and converting renewable energy such as alkanes and hydrogen.

The present invention includes the steps of: (1) injecting an electrolyte containing carbon dioxide and a precipitation aid in a reactor comprising an anode, a cathode and an ion permeable diaphragm dividing them; And (2) electrolyzing carbon dioxide dissolved in the electrolyte by applying a current to the reactor.

According to a preferred embodiment of the present invention, the precipitation aid is lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), rubidium hydroxide (RbOH), cesium hydroxide (CsOH), francium hydroxide (FrOH) One or more selected from the group consisting of, more preferably two or more selected from the group, and more preferably potassium hydroxide and sodium hydroxide.

According to another preferred embodiment of the present invention, the alcohol may be one or more selected from C ₁ ~ C ₅ alcohol, more preferably methanol.

According to another preferred embodiment of the present invention, the cathode may be a copper (Cu) or mercury (Hg) electrode.

According to another preferred embodiment of the present invention, the positive electrode may be one or more selected from the group consisting of platinum (Pt), stainless steel, gold (Au) and silver (Ag).

In addition, the present invention includes a reactor including an alcohol and a precipitation aid and a carbon dioxide dissolved electrolyte; An anode provided in the reactor and partially or fully immersed in the electrolyte; A negative electrode provided in the reactor to face the positive electrode and partially or fully immersed in the electrolyte; And it provides a carbon dioxide reduction device comprising an ion permeable diaphragm that divides them between the anode and the cathode.

According to a preferred embodiment of the present invention, it may further include a power supply unit for applying a current to the positive electrode and the negative electrode.

According to another preferred embodiment of the present invention, the precipitation aid is lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), rubidium hydroxide (RbOH), cesium hydroxide (CsOH), francium hydroxide (FrOH) One or more selected from the group consisting of, more preferably two or more selected from the group, more preferably potassium hydroxide and sodium hydroxide can be used.

According to another preferred embodiment of the present invention, the precipitation aid may be a mixture of potassium hydroxide and sodium hydroxide 100 to 300 parts by weight of sodium hydroxide compared to 100 parts by weight of potassium hydroxide.

According to another preferred embodiment of the present invention, the precipitation aid may comprise 0.1 to 0.6 mol per 1L of electrolyte.

According to another preferred embodiment of the present invention, the alcohol is one or more selected from C ₁ ~ C ₅ alcohol, more preferably methanol can be used.

According to another preferred embodiment of the present invention, the cathode may be a metal electrode, more preferably a copper (Cu) or mercury (Hg) electrode.

According to another preferred embodiment of the present invention, the anode is one or more selected from the group consisting of platinum (Pt), stainless steel, gold (Au) and silver (Ag), more preferably platinum (Pt) Stainless steel can be used.

According to another preferred embodiment of the present invention, the carbon dioxide reduction device may be produced by alkanes and hydrogen.

According to another preferred embodiment of the present invention, it is possible to provide a carbon dioxide reduction device further comprising a reference electrode.

In addition, the present invention includes an alcohol and a precipitation aid, and provides a carbon dioxide reduction electrolyte in which carbon dioxide is dissolved.

Hereinafter, the terms used in the present specification will be briefly described.

The term "precipitation aid" of the present invention is a preparation for maximizing the amount of reduced alkanes and hydrogen, and may also play a role of a conduction aid when the precipitation aid is added in the present invention.

The term "conductive aid" of the present invention means a substance which is added to all alcohols which are non-electrolytes and participates in the generation and flow of electric current.

The carbon dioxide reduction apparatus of the present invention can produce renewable energy such as alkanes and hydrogen by electrochemically reducing carbon dioxide and can provide an excellent carbon dioxide reduction method that can significantly reduce carbon dioxide. In addition, since the overvoltage required in the existing method and apparatus for reducing carbon dioxide is not required, renewable energy may be produced by reducing carbon dioxide without much cost and risk required for overvoltage. In addition, it is possible to produce renewable energy by reducing carbon dioxide without the efficient catalyst with improved selectivity required in the existing reduction method, which can reduce the cost of the reduction catalyst. Therefore, it is possible to mass produce renewable energy at a significantly lower cost than the conventional reduction method. Can be.

1 is a cross-sectional view of a carbon dioxide reduction apparatus according to a preferred embodiment of the present invention.

2 is a cross-sectional view of a carbon dioxide reduction apparatus according to another preferred embodiment of the present invention.

3 is a graph showing a concentration change over time of alkanes produced by performing Example 1. FIG.

4 is a graph of concentration change with time of hydrogen produced by performing Example 1. FIG.

5 is a graph of concentration change with time of alkanes produced by performing Examples 2 to 5.

6 is a graph of concentration change with time of hydrogen generated by performing Examples 2 to 5. FIG.

Hereinafter, with reference to the accompanying drawings will be described the present invention in more detail.

As described above, the conventional carbon dioxide reduction method does not easily occur in the reduction reaction of carbon dioxide, so there is a lot of cost and risks due to overvoltage, and there is a problem in that an efficient catalyst development with improved selectivity is required.

Accordingly, the present invention includes an alcohol and a precipitation aid, a reactor including an electrolyte in which carbon dioxide is dissolved, a positive electrode provided in the reactor and partially or fully immersed in the electrolyte, provided in the reactor to face the positive electrode, and partially or fully immersed in the electrolyte. The above-mentioned problem has been sought by providing a carbon dioxide reduction apparatus and a method for reducing the same, including a negative electrode and an ion permeable diaphragm which divides them between the positive electrode and the negative electrode. In addition, the carbon dioxide reduction apparatus of the present invention can produce new renewable energy such as alkanes and hydrogen by electrochemically reducing carbon dioxide and can provide an excellent carbon dioxide reduction method that can significantly reduce carbon dioxide. In addition, since the overvoltage required in the existing method and apparatus for reducing carbon dioxide is not required, renewable energy may be produced by reducing carbon dioxide without much cost and risk required for overvoltage. In addition, it is possible to produce renewable energy by reducing carbon dioxide without the efficient catalyst with improved selectivity required in the existing reduction method, which can reduce the cost of the reduction catalyst. Therefore, it is possible to mass produce renewable energy at a significantly lower cost than the conventional reduction method. Can be.

Specifically, Figure 1 is a cross-sectional view of the carbon dioxide reduction apparatus 100 according to an embodiment of the present invention. The carbon dioxide reduction apparatus 100 includes an alcohol and a precipitation aid, includes an electrolyte 110 in which carbon dioxide is dissolved, and is provided in the reactor 160 and is provided in the anode 120 partially or fully immersed in the electrolyte and the anode. Opposed to and includes a cathode 130 partially or fully immersed in the electrolyte. It also includes an ion permeable diaphragm 140 to divide them between the anode and the cathode and a power supply unit 150 for applying a voltage to the anode and the cathode.

First, the reactor 160 will be described. The reactor is not particularly limited as long as it is commonly used, but preferably, the material of the reactor is pyrex to acryl to polyvinyl chloride (PVC; PolyVinyl Chloride), and the size of the reactor may be 0.1 m ³ to 100.0 m ³ . However, it is not limited thereto.

Next, the electrolyte 110 included in the reactor 160 will be described. Electrolyte dissolves carbon dioxide and flows a current so that carbon dioxide is reduced to play a role of converting renewable energy such as alkanes and hydrogen. In the electrolyte of the present invention, a solution containing carbon dioxide and an alcohol and a precipitation aid may be used. In addition, the alcohol, precipitation aid and carbon dioxide contained in the electrolyte can be used to dissolve sequentially or all at once, and in particular, carbon dioxide can be dissolved by supplying the electrolyte to the reducing device after supplying or dissolving it before supplying the reducing device. Is also included in the scope of the present invention.

Next, the alcohol contained in the electrolyte 110 will be described. Alcohol may serve to absorb and dissolve carbon dioxide. Alcohol of the present invention is not particularly limited as long as it is alcohol, but more preferably at least one selected from C ₁ ~ C ₅ alcohol, more preferably using methanol is very advantageous to maximize the reduction efficiency of carbon dioxide ( Table 1, Figures 5 and 6).

In addition, the content of the alcohol contained in the electrolyte 110 may be included in the weight of 50 to 100% by weight of the total electrolyte. If the alcohol content is less than 50% by weight, a large amount of unreacted carbon dioxide may be generated, which may cause a problem in that the purity of the generated gas is reduced.

The precipitation aid included in the electrolyte 110 can be used without limitation as long as it can electrolyze carbon dioxide that is thermodynamically stable, ie, combine with electrons in carbon dioxide to radicalize carbon dioxide, and preferably use an alkali hydroxide. More preferably, at least one selected from the group consisting of lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), rubidium hydroxide (RbOH), cesium hydroxide (CsOH), and francium hydroxide (FrOH) can be used. have. Meanwhile, most preferably, a mixture of potassium hydroxide and sodium hydroxide is most advantageous for maximizing renewable energy production efficiency such as alkanes and hydrogen (see Table 1 and FIGS. 5 to 6). In addition, when the precipitation aid is not added to the electrolyte, carbon dioxide may not be smoothly reduced, and thus it may be difficult to reduce carbon dioxide to renewable energy such as alkanes and hydrogen.

In addition, when using potassium hydroxide and sodium hydroxide as a precipitation aid, the mixing ratio of potassium hydroxide and sodium hydroxide may be used by mixing 100 to 300 parts by weight of sodium hydroxide compared to 100 parts by weight of sodium hydroxide, but is not limited thereto. In addition, 0.1 to 0.3 mol of potassium hydroxide and sodium hydroxide dissolved in 1 L of the electrolyte may be used, but is not limited thereto. If the concentration of potassium hydroxide and / or sodium hydroxide is less than 0.1 mol, the amount of methane and hydrogen is lowered and unreacted carbon dioxide may be emitted. If the concentration is higher than 0.6 mol, a large amount of carbonate may occur. have.

The electrolyte 110 including the alcohol and the precipitation aid and dissolving carbon dioxide may include the precipitation aid in a concentration of 0.1 to 0.6 mol per liter of the electrolyte. If the concentration is less than 0.1 mol / L there is a problem of low purity of renewable energy, such as alkanes and hydrogen, there may be a problem that a large amount of carbonate occurs when more than 0.6 mol / L.

Carbon dioxide dissolved in the electrolyte 110 is not particularly limited as long as it is usually generated during the industrial process, the concentration of carbon dioxide in the electrolyte may be used in the 0.05 ~ 99%, but is not limited thereto.

In addition, the electrolyte may further include materials generally used in the electrolyte of the electrochemical reduction method, preferably distilled water, neon gas, argon gas, nitric acid, carbon dioxide, NaCl, HCl, HNO ₃ , KOH, KCl, CH ₃ COOH, CuSO ₄ and HgCl ₂ may be further included.

Next, the cathode 130 partially or fully immersed in the electrolyte 110 will be described. The negative electrode may be used without limitation as long as it is commonly used as a negative electrode material of the electrochemical reduction apparatus, preferably a metal electrode, and more preferably a copper (Cu) or mercury (Hg) electrode. Copper electrode has an excellent efficiency for hydrocarbon gas, and excellent adsorption power for carbon dioxide generated during the electrolysis process is most preferred for use as a cathode of the present invention, but is not limited thereto.

The following describes the anode 120 which is partially or wholly immersed in the electrolyte 110 and is opposed to the cathode 130. The positive electrode may be used without limitation as long as it is commonly used as a positive electrode material of an electrochemical reduction apparatus, and preferably may be durable to oxides, more preferably platinum (Pt), stainless steel, gold (Au), and the like. One or more selected from the group consisting of silver (Ag), more preferably platinum or stainless steel may be used, but is not limited thereto.

Next, the ion-permeable diaphragm 140 dividing them between the anode 120 and the cathode 130 may be used without limitation as long as it is generally used as an ion-permeable diaphragm of an electrochemical reduction apparatus, and preferably, ion exchange. The resin may be molded in a film shape, more preferably, a perfluorinated sulfonic acid polymer material, and more preferably, one selected from the group consisting of Nafion 112, Nafion 115, and Nafion 117 of DuPont The above can be used, but it is not limited to this. When the ion-permeable diaphragm is immersed in an electrolyte and an electric current is applied to the electrolyte, the ion-permeable diaphragm exhibits a resistance close to 100% for the passage of cations but anion passage.

The power supply unit 150 for applying a voltage to the positive electrode 120 and the negative electrode 130 may be connected to both the positive electrode and the negative electrode or only one, and the carbon dioxide reduction apparatus of the present invention may include one or more power supply units.

The voltage applied by the power supply unit 150 is not particularly limited, but more preferably 10 volts or more may be used, and more preferably 10 to 100 volts may be applied. In the conventional carbon dioxide reduction method, a voltage of at least 60 volts is applied, but in the present invention, a reduction reaction of carbon dioxide may occur even with a voltage of at least 10 volts. When the voltage is applied below 10 volts, current exchange is not smooth due to the resistance of the ion permeable diaphragm, and there may be a problem in that the purity of alkanes and hydrogen gas is low. In this case, alkanes and hydrogen gas can be obtained in proportion to the voltage.

In addition, the carbon dioxide reduction apparatus of the present invention may provide a carbon dioxide reduction apparatus 100 further comprising a reference electrode 170, as shown in FIG. The reference electrode is not particularly limited as long as it is a conventional electrode that can be used as a reference because a single pole potential used when measuring electromotive force or electrode potential of a chemical cell is more preferable. More preferably, silver chloride electrode, calomel electrode, and sulfuric acid are used. Mercury (I) can be used. In addition, the reference electrode may be positioned on either the cathode or the anode.

In addition, the carbon dioxide reduction apparatus of the present invention may include a renewable energy collection unit (not shown). The renewable energy collection unit serves to capture renewable energy such as alkanes and hydrogen produced by the carbon dioxide reduction device.

Alkanes produced by the carbon dioxide reduction apparatus of the present invention may be methane, ethane, propane.

In addition, describing the carbon dioxide reduction method according to an embodiment of the present invention, (1) injecting an electrolyte containing carbon dioxide and a precipitation aid and carbon dioxide dissolved in a reactor including an anode, a cathode and an ion permeable diaphragm that divides them ; And (2) applying a voltage to the reactor to electrolyze carbon dioxide dissolved in the electrolyte; It provides a carbon dioxide reduction method comprising a.

In the step (1), the electrolyte is injected before or after the negative electrode and the positive electrode are installed in the reactor, so that the ion-permeable diaphragm may be installed after the electrolyte is injected.

In addition, the alcohol, precipitation aid and carbon dioxide contained in the electrolyte in step (1) may be used by sequentially dissolving or dissolving all at once, in particular, carbon dioxide is supplied by dissolving the electrolyte after feeding the electrolyte into the reducing device or inputting the reducing device. Dissolution by feeding before is also included in the scope of the present invention.

The alcohol of step (1) is not particularly limited as long as it is alcohol, but more preferably at least one selected from C ₁ to C ₅ alcohols, and more preferably methanol.

In addition, the precipitation aid is not particularly limited as long as it is a hydroxide consisting of an alkali element, more preferably lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), rubidium hydroxide (RbOH), cesium hydroxide (CsOH) ), May be used one or more selected from the group consisting of francium hydroxide (FrOH), more preferably two or more selected from the group. In addition, when using potassium hydroxide and sodium hydroxide as a precipitation aid, it is most preferred for the production of renewable energy, such as alkanes and hydrogen, but is not limited thereto.

In the step (1), the electrolyte containing the alcohol and the precipitation aid, and the carbon dioxide dissolved electrolyte may be used in the concentration of 0.1 ~ 0.6 mol per 1L electrolyte. If the concentration is less than 0.1 mol / L there is a problem of low purity of renewable energy, such as alkanes and hydrogen, there may be a problem that a large amount of carbonate occurs when more than 0.6 mol / L.

In addition, carbon dioxide dissolved in the electrolyte is not particularly limited as long as it is usually generated during industrial processes, it may reduce the risk of explosion if carbon dioxide and inert gas is included.

The negative electrode included in the reactor in the step (2) is not particularly limited as long as it uses a conventional metal electrode, more preferably a copper (Cu) or mercury (Hg) electrode can be used. The copper electrode is most preferable for use as a cathode of the present invention because it has excellent efficiency for hydrocarbon gas and excellent adsorption power for carbon dioxide generated during electrolysis.

In addition, the anode included in the reactor in step (2) is not particularly limited as long as the oxide is durable, more preferably a group consisting of platinum (Pt), stainless steel, gold (Au) and silver (Ag). At least one selected from, more preferably platinum or stainless steel may be used.

The ion permeable diaphragm dividing the positive electrode and the negative electrode of step (2) is not particularly limited as long as the ion-exchange resin is molded into a membrane shape.

In addition, the voltage applied to the cathode and the anode is not particularly limited, but preferably a voltage of 10 to 100 V may be applied. Therefore, using a lower voltage than the conventional reduction method can reduce the cost of carbon dioxide reduction method.

Hereinafter, the carbon dioxide conversion device of the present invention through the operation example will be described in more detail. However, the following working examples are not intended to limit the scope of the present invention, which should be construed as to help the understanding of the present invention.

First, an alcohol and a precipitation aid are mixed to prepare an electrolyte, and carbon dioxide is injected and dissolved in the electrolyte, and then the electrolyte is placed in a reactor as shown in FIG. 2 to install a cathode, an anode, and an ion permeable membrane. Then, when a voltage is applied to the cathode and the anode, carbon dioxide is reduced at the cathode to generate an alkane gas, and at the anode, alcohol is reduced to generate hydrogen gas. At this time, alkanes and hydrogen gas may be collected in separate renewable energy collectors to measure concentration and purity.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are not intended to limit the scope of the present invention, which will be construed as to help the understanding of the present invention.

[실시예]EXAMPLE

실시예 1. Example 1.

0.2 M potassium hydroxide and 0.2 M sodium hydroxide were dissolved in 200 ml of methanol by stirring for 30 minutes. 200 ml of the stirred solution was transferred to an electrochemical apparatus, and the positive electrode and the negative electrode were connected. Then, carbon dioxide was supplied at 20 ml / min to dissolve for 30 minutes, and then the negative electrode and the positive electrode were separated by an ion permeable membrane to perform electrolysis. . The concentration of alkanes and hydrogen generated during the electrolysis was measured for each reaction time and is shown in FIGS. 3 and 4.

As can be seen in Figure 3, it was confirmed that methane, ethane, propane and hydrogen are detected. In addition, as can be seen in Figure 4, hydrogen was detected at a concentration of 3% or more.

실시예2. Example 2.

The same procedure as in Example 1 was carried out except that 0.1 M potassium hydroxide and 0.1 M sodium hydroxide were mixed in 200 ml of methanol.

실시예3. Example 3.

The same process as in Example 1 was carried out except that 0.15 M potassium hydroxide and 0.15 M sodium hydroxide were mixed in methanol.

실시예4. Example 4.

The same procedure as in Example 1 was carried out except that 0.25 M potassium hydroxide and 0.25 M sodium hydroxide were mixed in 200 ml of methanol.

실시예5. Example 5.

The same procedure as in Example 1 was carried out except that 0.3 M potassium hydroxide and 0.3 M sodium hydroxide were mixed with 200 ml of methanol.

실시예 6.Example 6.

It carried out similarly to Example 1 except having used ethanol instead of the methanol used in Example 1. The combustible gases such as alkanes or hydrogen produced at this time were not measured.

실시예 7.Example 7.

It carried out similarly to Example 1 except having used butanol instead of the methanol used in Example 1. The combustible gases such as alkanes or hydrogen produced at this time were not measured.

실시예 8.Example 8.

It carried out similarly to Example 1 except having used isopropyl alcohol instead of the methanol used in Example 1. The combustible gases such as alkanes or hydrogen produced at this time were not measured.

실시예 9.Example 9.

The concentration of alkanes and hydrogen produced was measured in the same manner as in Example 1 except that only 0.2 M sodium hydroxide was mixed with 200 ml of methanol, but the measured concentrations of flammable gases such as alkanes or hydrogen were insufficient. Methane, ethane and propane were not measured and hydrogen was measured at 0.5% or less.

실시예 10.Example 10.

The concentration of alkanes and hydrogen produced was measured in the same manner as in Example 1 except that only 0.2 M potassium hydroxide was mixed in 200 ml of methanol, but the measured concentrations of flammable gases such as alkanes or hydrogen were insufficient. Methane, ethane and propane were not measured and hydrogen was measured at 1% or less.

실험예 1.Experimental Example 1.

The concentrations of methane and hydrogen produced through the carbon dioxide reduction apparatuses manufactured in Examples 1 to 5 were measured and shown in FIGS. 5 and 6.

As confirmed in FIG. 5, the measured concentration of methane was the highest in Example 1 using 0.2 M sodium hydroxide and 0.2 M potassium hydroxide. In addition, as confirmed in FIG. 6, the measured concentration of hydrogen was also highest in Example 1 using 0.2 M sodium hydroxide and 0.2 M potassium hydroxide.

비교예 1. Comparative Example 1.

Except not dissolving carbon dioxide in 200 ml of the stirred solution in Example 1, the concentration of alkanes and hydrogen produced was measured in the same manner as in Example 1, but a flammable gas such as alkanes or hydrogen was not measured.

비교예 2. Comparative Example 2.

The concentration of alkanes and hydrogen produced was measured in the same manner as in Example 1 except that the precipitation aid was not added to 200 ml of methanol, but the measured concentration of the flammable gas such as alkanes or hydrogen was not measured.

비교예 3.Comparative Example 3.

Except for using distilled water instead of methanol in Example 1 was carried out in the same manner as in Example 1 to measure the concentration of alkanes and hydrogen produced, but the measured concentration of the alkanes or hydrogen and flammable gas is inadequate. Methane, ethane and propane were not measured and hydrogen was measured at 1.5% or less.

비교예 4.Comparative Example 4.

Except for using distilled water instead of methanol and dissolving carbon dioxide in Example 1 was carried out in the same manner as in Example 1 to measure the concentration of alkanes and hydrogen produced, but the measured concentration of alkane or hydrogen and flammable gas was not enough. Methane, ethane and propane were not measured and hydrogen was measured at 1.5% or less.

비교예 5.Comparative Example 5.

Except for using distilled water instead of methanol and mixing only 0.2M sodium hydroxide as a precipitation aid in Example 1 was measured in the same manner as in Example 1 but the concentration of alkanes and hydrogen was measured The concentration was inadequate. Methane, ethane and propane were not measured and hydrogen was measured at 1% or less.

비교예 6.Comparative Example 6.

Except for using distilled water instead of methanol and mixing only 0.2M potassium hydroxide as a precipitation aid in Example 1 was measured in the same manner as in Example 1 but the measurement of alkanes and hydrogen and flammable gas The concentration was inadequate. Methane, ethane and propane were not measured and hydrogen was measured at 1% or less.

실험예 2.Experimental Example 2.

The concentrations of alkanes and hydrogen gas obtained by treating Examples 1 to 10 and Comparative Examples 1 to 6 for 5 hours are shown in Table 1 below.

Table 1

division	Generated Methane Gas Concentration (ppm)	Produced ethane gas concentration (ppm)	Generated Propane Gas Concentration (ppm)	Generated hydrogen gas concentration (ppm)
Example 1	967.85	247.52	311.91	4.95
Example 2	355.43	116.41	189.32	3.15
Example 3	377.60	154.71	249.66	3.30
Example 4	527.10	200.54	275.83	4.20
Example 5	278.20	34.50	68.10	3.05
Example 6	Not detected	Not detected	Not detected	Not detected
Example 7	Not detected	Not detected	Not detected	Not detected
Example 8	Not detected	Not detected	Not detected	Not detected
Example 9	Not detected	Not detected	Not detected	0.5% or less
Example 10	Not detected	Not detected	Not detected	1% less than
Comparative Example 1	Not detected	Not detected	Not detected	Not detected
Comparative Example 2	Not detected	Not detected	Not detected	Not detected
Comparative Example 3	Not detected	Not detected	Not detected	1.5% or less
Comparative Example 4	Not detected	Not detected	Not detected	1.5% or less
Comparative Example 5	Not detected	Not detected	Not detected	1% less than
Comparative Example 6	Not detected	Not detected	Not detected	1% less than

As can be seen in Table 1, electrolysis of carbon dioxide using an electrolyte containing carbon dioxide and potassium hydroxide and sodium hydroxide as a precipitation aid and dissolving carbon dioxide can produce alkanes, methane, ethane and propane, Hydrogen could be produced. In addition, when the concentrations of potassium hydroxide and sodium hydroxide were less than 0.15M, the purity of alkanes and hydrogen generated was low, and when the concentrations of potassium hydroxide and sodium hydroxide exceed 0.25M, a large amount of carbonate is generated to hinder the reduction of carbon dioxide. It was confirmed that.

Claims

(1) injecting an electrolyte containing carbon dioxide and a precipitation aid and dissolving carbon dioxide into a reactor including an anode, a cathode, and an ion permeable diaphragm dividing the same; And

(2) applying a voltage to the reactor to electrolyze carbon dioxide dissolved in the electrolyte;

Carbon dioxide reduction method comprising a.
According to claim 1, wherein the precipitation aid is selected from the group consisting of lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), rubidium hydroxide (RbOH), cesium hydroxide (CsOH), francium hydroxide (FrOH) Carbon dioxide reduction method, characterized in that at least one.
The method of claim 2, wherein the precipitation aid is a carbon dioxide reduction method, characterized in that the mixture of potassium hydroxide and sodium hydroxide.
The method of reducing carbon dioxide according to claim 1, wherein the alcohol is at least one selected from C 1 to C 5 alcohols.
The method of reducing carbon dioxide according to claim 4, wherein the alcohol is methanol.
The method of claim 1, wherein the anode is at least one selected from the group consisting of platinum (Pt), stainless steel, gold (Au) and silver (Ag), and the cathode is a copper (Cu) or mercury (Hg) electrode. Reduction of carbon dioxide, characterized in that.
The method of reducing carbon dioxide according to claim 1, wherein the voltage applied to the reactor is 10 to 100 volts.
A reactor including an alcohol and a precipitation aid and comprising an electrolyte in which carbon dioxide is dissolved;

An anode provided in the reactor and partially or fully immersed in the electrolyte;

A negative electrode provided in the reactor to face the positive electrode and partially or fully immersed in the electrolyte; And

A carbon dioxide reduction device comprising an ion permeable membrane for dividing them between the anode and the cathode.
9. The carbon dioxide reduction apparatus according to claim 8, further comprising a power supply unit for applying current to the anode and the cathode.
The method of claim 8, wherein the precipitation aid is selected from the group consisting of lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), rubidium hydroxide (RbOH), cesium hydroxide (CsOH), francium hydroxide (FrOH) Carbon dioxide reduction device, characterized in that at least one.
The method of claim 8, wherein the precipitation aid is selected from the group consisting of lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), rubidium hydroxide (RbOH), cesium hydroxide (CsOH), francium hydroxide (FrOH) Carbon dioxide reduction device, characterized in that two or more kinds.
The carbon dioxide reduction apparatus according to claim 11, wherein the precipitation aid is potassium hydroxide and sodium hydroxide.
13. The carbon dioxide reduction apparatus according to claim 12, wherein the precipitation aid is a mixture of potassium hydroxide and sodium hydroxide in an amount of 100 to 300 parts by weight based on 100 parts by weight of potassium hydroxide.
The carbon dioxide reduction device according to claim 8, wherein the alcohol is at least one selected from C 1 to C 5 alcohols.
The carbon dioxide reduction apparatus according to claim 8, wherein the alcohol is methanol.
The method of claim 8, wherein the cathode is a copper (Cu) or mercury (Hg) electrode, the anode is one or more selected from the group consisting of platinum (Pt), stainless steel, gold (Au) and silver (Ag). Carbon dioxide reduction device, characterized in that.
The carbon dioxide reduction apparatus according to claim 8, further comprising a reference electrode for voltage measurement.
18. The carbon dioxide reduction apparatus according to any one of claims 8 to 17, wherein the precipitation aid comprises 0.1 to 0.6 mol per liter of the electrolyte.
18. The carbon dioxide reduction apparatus according to any one of claims 8 to 17, wherein alkane and hydrogen are produced.
Carbon dioxide reduction electrolyte containing alcohol and precipitation aid, carbon dioxide dissolved.
The method of claim 20, wherein the precipitation aid is selected from the group consisting of lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), rubidium hydroxide (RbOH), cesium hydroxide (CsOH), francium hydroxide (FrOH) Carbon dioxide reduction electrolyte, characterized in that two or more.
The electrolyte for reducing carbon dioxide according to claim 21, wherein the precipitation aid is potassium hydroxide and sodium hydroxide.
The electrolyte for reducing carbon dioxide according to claim 22, wherein the precipitation aid mixes potassium hydroxide and sodium hydroxide in an amount of 100 to 300 parts by weight based on 100 parts by weight of potassium hydroxide.
The method of claim 20, wherein the alcohol is carbon dioxide reducing electrolyte, characterized in that at least one selected from C 1 ~ C 5 alcohol.
The electrolyte for reducing carbon dioxide according to claim 24, wherein the alcohol is methanol.