KR101451630B1 - Method for reducing carbon dioxide and reductor of carbon dioxide using the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reducing carbon dioxide and a reducing apparatus, and more particularly, to a carbon dioxide reducing method and a carbon dioxide reducing apparatus which are characterized in that carbon dioxide is electrochemically reduced to produce renewable energy such as alkane and hydrogen .

Description

TECHNICAL FIELD The present invention relates to a carbon dioxide reducing method and a carbon dioxide reducing apparatus using the same,

More particularly, the present invention relates to a method and apparatus for reducing carbon dioxide into alkane and hydrogen gas, and more particularly, to a method and apparatus for converting carbon dioxide dissolved in an electrolyte into an alkane and hydrogen, The present invention relates to an apparatus and a method capable of dramatically reducing and reducing the amount of waste.

Carbon dioxide, which is released into the atmosphere by rapid industrialization and economic activity in recent years, increases the greenhouse effect, raising the temperature of the surface and lower atmosphere, causing global warming and climate change. Technological fields for separating and recovering such carbon dioxide include physicochemical absorption, adsorption, membrane separation, etc., which can be stored in the earth or in the ocean. In addition, since carbon dioxide is the most abundant carbon compound on the planet, carbon dioxide is effectively activated and converted into a useful organic material to be used as a source of carbon necessary for energy source or organic synthesis. In order to utilize carbon dioxide as a source of carbon necessary for catalysis, electrochemical, biological conversion, Have been transformed into renewable energy.

Since the technology for converting carbon dioxide to useful compounds is a technique for converting the most stable carbon dioxide among carbon compounds into other useful compounds, it is essential to establish the relevant reaction conditions for the conversion of energy into the necessary and effective conversion. Energy sources include hydrogen, methane and other chemical energy, solar energy, and electrical energy.

Among these, the carbon dioxide recycling method by the electrochemical reduction converts the carbon dioxide saturated in the electrolyte solution into a methane, ethane, alcohol or the like by causing an electrochemical reaction with the metal electrode, thereby causing the hydrogenation reaction at the same time as the electrolysis. In particular, the devices and their operation are simple, and the produced compounds can be used as general gas fuels, liquid fuels, chemicals, and the like. However, the reduction reaction of carbon dioxide does not take place easily but requires a large overvoltage. The hydrogen generation at the anode and the reduction at the cathode compete with each other, so that they react at a relatively large negative potential. Therefore, the development of an efficient catalyst with improved selectivity as well as an increase in the efficiency of voltage and potential is very important in the reduction of carbon dioxide.

However, the prior arts for solving the above problems are aimed only at the reduction of carbon dioxide, and the treatment processes disclosed in some prior art documents are not suitable for effectively treating a large amount of carbon dioxide. In particular, the removal of carbon dioxide .

In addition, the conventional method and apparatus for reducing carbon dioxide did not lead to production of alkane and hydrogen gas by reducing carbon dioxide, and since the reduction reaction of carbon dioxide was not easily performed, overvoltage was required, which was costly and dangerous. A reduction catalyst capable of selectively reducing only carbon dioxide was required for reduction. However, such a reduction catalyst is not only difficult to commercialize because of its high cost, but also has a problem that it is difficult to obtain useful renewable energy from the reduced carbon dioxide.

DISCLOSURE Technical Problem The present invention has been conceived to solve the above-mentioned problems, and an object of the present invention is to solve the problem of carbon dioxide treatment and to obtain a large amount of new and renewable energy. And reducing and converting it into renewable energy such as alkane and hydrogen.

(1) injecting an electrolyte containing an alcohol and a precipitation auxiliary agent into a reactor including an anode, a cathode and an ion-permeable diaphragm for dividing the anode and the cathode, the electrolyte containing dissolved carbon dioxide; And

(2) electrolyzing the carbon dioxide dissolved in the electrolyte by applying an electric current to the reactor.

According to a preferred embodiment of the present invention, the precipitation auxiliary agent is selected from the group consisting of lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), rubidium hydroxide (RbOH), cesium hydroxide (CsOH) And one or more selected from the group consisting of potassium hydroxide and sodium hydroxide, more preferably potassium hydroxide and sodium hydroxide.

According to another preferred embodiment of the present invention, the alcohol may be at least one selected from C ₁ to C ₅ alcohols, 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 anode may be at least one selected from the group consisting of platinum (Pt), stainless steel, gold (Au), and silver (Ag)

The present invention also relates to a reactor comprising an alcohol and an electrolytic solution containing carbon dioxide dissolved in an auxiliary agent for precipitation;

A cathode provided in the reactor and partially or completely immersed in the electrolyte;

A negative electrode disposed in the reactor and facing the positive electrode, the negative electrode partially or wholly immersed in the electrolyte; And

And an ion-permeable diaphragm that divides them between the positive electrode and the negative electrode.

According to a preferred embodiment of the present invention, the apparatus 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 auxiliary agent is selected from the group consisting of lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), rubidium hydroxide (RbOH), cesium hydroxide (CsOH) , More preferably at least two selected from the group mentioned above, more preferably potassium hydroxide and sodium hydroxide can be used.

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

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

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

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 at least one selected from the group consisting of platinum (Pt), stainless steel, gold (Au) and silver (Ag) , Stainless steel can be used.

According to another preferred embodiment of the present invention, the carbon dioxide reducing apparatus can produce alkane and hydrogen.

According to another preferred embodiment of the present invention, it is possible to provide a carbon dioxide reducing apparatus further including a reference electrode.

In addition, the present invention provides an electrolyte for carbon dioxide reduction, comprising an alcohol and a precipitation auxiliary agent, in which carbon dioxide is dissolved.

According to another preferred embodiment of the present invention, 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) , More preferably at least two selected from the group mentioned above, more preferably potassium hydroxide and sodium hydroxide can be used.

According to another preferred embodiment of the present invention, potassium hydroxide and sodium hydroxide may be mixed with sodium hydroxide in an amount of 100 to 300 parts by weight relative to 100 parts by weight of potassium hydroxide.

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

Hereinafter, terms used in this specification will be briefly described.

The "precipitation auxiliary" of the present invention is a preparation for maximizing the precipitation amount of alkane and hydrogen to be reduced, and can also serve as a conduction auxiliary agent when the precipitation auxiliary agent is added in the present invention.

&Quot; Conducting auxiliary " of the present invention means a substance which is injected into all non-electrolytic alcohols and participates in the generation and flow of electric current.

The carbon dioxide reducing apparatus of the present invention can provide an excellent carbon dioxide reducing method capable of producing carbon dioxide by electrochemically reducing it to produce renewable energy such as alkane and hydrogen and reducing carbon dioxide dramatically. In addition, since the conventional method of reducing carbon dioxide and the overvoltage required in the apparatus are not necessary, it is possible to produce new and renewable energy by reducing the amount of carbon dioxide without much risk and cost required for the overvoltage. In addition, it is possible to produce new and renewable energy by reducing carbon dioxide even without an efficient catalyst, which is required for the conventional reduction method, and thus it is possible to reduce the cost of the reduction catalyst, thereby massively producing new and renewable energy at a significantly lower cost than the conventional reduction method .

1 is a cross-sectional view of a carbon dioxide reducing apparatus according to a preferred embodiment of the present invention.
2 is a cross-sectional view of a carbon dioxide reducing apparatus according to another preferred embodiment of the present invention.
FIG. 3 is a graph showing a change in concentration of an alkane produced in Example 1 over time. FIG.
FIG. 4 is a graph showing a change in concentration of hydrogen produced in Example 1 over time. FIG.
FIG. 5 is a graph showing a change in concentration of an alkane produced in Examples 1 to 5 over time. FIG.
FIG. 6 is a graph of concentration change with time of hydrogen produced in Examples 1 to 5. FIG.

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

As described above, the conventional carbon dioxide reduction method has a problem that the reduction reaction of carbon dioxide does not easily take place, and thus, there is a large cost and a risk due to the necessity of an overvoltage, and there is a need to develop an efficient catalyst with improved selectivity.

Accordingly, the present invention provides a process for producing a polymer electrolyte membrane, comprising: a reactor including an alcohol and a precipitation auxiliary agent and containing an electrolyte in which carbon dioxide is dissolved; a cathode provided in the reactor and partially or completely immersed in an electrolyte; And an ion-permeable diaphragm for separating the anode and the cathode from each other, and a method for reducing the carbon dioxide, thereby solving the above-mentioned problem. In addition, the carbon dioxide reducing apparatus of the present invention can provide an excellent carbon dioxide reducing method which can reduce carbon dioxide dramatically, by electrochemically reducing carbon dioxide to produce renewable energy such as alkane and hydrogen. In addition, since the conventional method of reducing carbon dioxide and the overvoltage required in the apparatus are not necessary, it is possible to produce new and renewable energy by reducing the amount of carbon dioxide without much risk and cost required for the overvoltage. In addition, it is possible to produce new and renewable energy by reducing carbon dioxide even without an efficient catalyst, which is required for the conventional reduction method, and thus it is possible to reduce the cost of the reduction catalyst, thereby massively producing new and renewable energy at a significantly lower cost than the conventional reduction method .

1 is a cross-sectional view of a carbon dioxide reduction apparatus 100 according to an embodiment of the present invention. The carbon dioxide reducing apparatus 100 includes an anode 110 including an electrolyte 110 in which alcohol and a precipitation aid are dissolved and carbon dioxide is dissolved and which is provided in the reactor 160 and partially or wholly immersed in an electrolyte, And a cathode 130 that is partially or fully immersed in the electrolyte. And an ion permeable diaphragm 140 for dividing them between the positive and negative electrodes and a power supply unit 150 for applying a voltage to the positive and negative electrodes.

First, the reactor 160 will be described. The reactor is not particularly limited as long as it is generally used, but preferably the material of the reactor is pyrex to acrylic or polyvinyl chloride (PVC), and the size of the reactor is 0.1 m ³ to 100.0 m ³ . But is not limited thereto.

Next, the electrolyte 110 included in the reactor 160 will be described. The electrolyte dissolves carbon dioxide, and by flowing current, the carbon dioxide is reduced, and it can play a role of converting renewable energy such as alkane and hydrogen. The electrolyte of the present invention can use a solution in which carbon dioxide is dissolved and which contains an alcohol and a precipitation auxiliary agent. In addition, the alcohol, the precipitation auxiliary agent and the carbon dioxide contained in the electrolyte can be sequentially dissolved or completely dissolved, and in particular, the carbon dioxide can be supplied to the reduction apparatus after the electrolyte is supplied and then dissolved or supplied before the reduction apparatus is introduced Are also included in the scope of the present invention.

Next, the alcohol included in the electrolyte 110 will be described. Alcohol can absorb and dissolve carbon dioxide. The alcohol of the present invention is not particularly limited as long as it is an alcohol, but more preferably one selected from among C ₁ to C ₅ alcohols, more preferably methanol, is very advantageous for maximizing the reduction efficiency of carbon dioxide See Table 1, Fig. 5 and Fig. 6).

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

The precipitation auxiliary agent included in the electrolyte 110 can be used without limitation as long as thermodynamically stable carbon dioxide can be oxidized by electrolysis, that is, by coupling with electrons in carbon dioxide to radicalize carbon dioxide. Preferably, an alkali group hydroxide can be used. 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) have. On the other hand, mixing potassium hydroxide and sodium hydroxide is most advantageous for maximizing the efficiency of producing renewable energy such as alkane and hydrogen. Further, when the precipitation auxiliary agent is not added to the electrolyte, reduction of carbon dioxide is not smooth and it may be difficult to reduce carbon dioxide to renewable energy such as alkane and hydrogen.

When potassium hydroxide and sodium hydroxide are used as the precipitation auxiliary agent, the mixing ratio of potassium hydroxide and sodium hydroxide may be 100-300 parts by weight of sodium hydroxide per 100 parts by weight of sodium hydroxide, but not limited thereto. In addition, 0.1 to 0.3 moles of potassium hydroxide may be dissolved in 1 liter of the electrolyte, and 0.1 to 0.3 moles of sodium hydroxide may be dissolved in 1 liter of the electrolyte. However, the present invention is not limited thereto. If the concentration of potassium hydroxide or sodium hydroxide is less than 0.1 mol, the precipitation amount of methane and hydrogen may be lowered and the unreacted carbon dioxide may be discharged. If the concentration exceeds 0.3 mol, a large amount of carbonate may occur.

The electrolyte 110 in which the alcohol and the precipitation auxiliary agent are dissolved and the carbon dioxide is dissolved may contain the precipitation auxiliary agent in a concentration of 0.1 to 0.6 mol per 1 L of the electrolyte. When the concentration is less than 0.1 mol / L, the purity of renewable energy such as alkane and hydrogen is low. When the concentration is more than 0.6 mol / L, carbonate may be generated in a large amount.

The concentration of carbon dioxide dissolved in the electrolyte 110 is not particularly limited as long as it occurs in an industrial process. The concentration of carbon dioxide in the electrolyte may be 0.05 to 99%, but the present invention is not limited thereto.

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

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

Next, the anode 120 facing the cathode 130 and partially or wholly immersed in the electrolyte 110 will be described. The anode can be used without limitation as long as it is usually used as an anode material of an electrochemical reduction apparatus. The anode may preferably be an oxide-resistant one, more preferably platinum (Pt), stainless steel, gold Silver (Ag), and more preferably platinum or stainless steel. However, the present invention is not limited thereto.

Next, the ion-permeable diaphragm 140, which divides them between the anode 120 and the cathode 130, can be used without limitation as long as it is generally used as an ion-permeable diaphragm of an electrochemical reduction apparatus, The resin may be formed into a film shape, more preferably a perfluorosulfonic acid polymer material, and more preferably, one selected from the group consisting of Nafion 112, Nafion 115, and Nafion 117 of DuPont But the present invention is not limited thereto. When an ion-permeable diaphragm is immersed in an electrolyte and an electric current is applied to the electrolyte, the ion-permeable diaphragm passes positive ions but exhibits resistance close to 100% for passage of anions.

The power supply unit 150 for applying a voltage to the anode 120 and the cathode 130 may be connected to the anode or the cathode or may be connected to only one of the anode and the cathode 130. The carbon dioxide reducing 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 it is more preferably 10 volts or more, and more preferably 10 to 100 volts. 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 with a voltage of at least 10 volts. When a voltage of 10 volts or less is applied, the current exchange is not smooth due to the resistance of the ion-permeable diaphragm, and the purity of the alkane and the hydrogen gas may be low, and a voltage of 10 volts or more and 100 volts or less may be applied , Alkane and hydrogen gas can be obtained in proportion to the voltage.

In addition, the carbon dioxide reducing apparatus of the present invention can provide the carbon dioxide reducing apparatus 100 further including the reference electrode 170, as shown in FIG. The reference electrode is not particularly limited as long as it is a standard electrode that can be used as a standard since the single-electrode potential used for measuring the electromotive force or the electrode potential of the chemical cell is a standard. More preferably, the reference electrode is a silver chloride electrode, Mercury (I) can be used. Further, it may be located on either the reference electrode cathode or the anode.

In addition, the carbon dioxide reducing apparatus of the present invention may include a renewable energy collecting unit (not shown). The renewable energy collecting part collects renewable energy such as alkane and hydrogen produced by the carbon dioxide reducing device.

The alkane gas produced by the carbon dioxide reducing apparatus of the present invention may be methane, ethane, or propane.

The method for reducing carbon dioxide according to an embodiment of the present invention includes the steps of: (1) injecting an electrolyte containing an alcohol and a precipitation auxiliary agent into a reactor including an anode, a cathode, and an ion permeable diaphragm for dividing them, ; And (2) electrolyzing dissolved carbon dioxide in the electrolyte by applying a voltage to the reactor; And a method for reducing carbon dioxide.

In the step (1), the electrolyte may be injected before or after the cathode and the anode are installed in the reactor, and the ion-permeable diaphragm may be provided after the electrolyte is injected into the reactor.

In addition, the alcohol, the precipitation auxiliary agent and the carbon dioxide contained in the electrolyte in the step (1) may be sequentially dissolved or completely dissolved, and in particular, the carbon dioxide may be supplied to the reduction apparatus after the electrolyte is supplied, It is also within the scope of the present invention to supply and dissolve beforehand.

The alcohol in the step (1) is not particularly limited as long as it is an alcohol, but more preferably one selected from among C ₁ to C ₅ alcohols, more preferably methanol.

The precipitation aid is not particularly limited as long as it is a hydroxide of an alkaline group element, but more preferably, it is a hydroxide of lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), rubidium hydroxide (RbOH) ), And fridic acid hydroxide (FrOH), and more preferably at least two kinds selected from the above-mentioned group can be used. In addition, when potassium hydroxide and sodium hydroxide are used as the precipitation auxiliary, they are most preferable for producing renewable energy such as alkane and hydrogen, but are not limited thereto.

In the step (1), the electrolyte containing the alcohol and the precipitation auxiliary agent and dissolved in the carbon dioxide may be used at a concentration of 0.1 to 0.6 mol per liter of the electrolyte. When the concentration is less than 0.1 mol / L, the purity of renewable energy such as alkane and hydrogen is low. When the concentration is more than 0.6 mol / L, carbonate may be generated in a large amount.

In addition, the carbon dioxide dissolved in the electrolyte is not particularly limited as long as it occurs in industrial processes. However, when carbon dioxide and inert gas are contained, the risk of explosion can be reduced.

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

The positive electrode included in the reactor in the step (2) is not particularly limited as long as it is resistant to oxides, but is more preferably composed of platinum (Pt), stainless steel, gold (Au) , More preferably platinum or stainless steel may be used.

The ion-permeable diaphragm for dividing the positive electrode and the negative electrode in the step (2) is not particularly limited as long as the ion-exchange resin is formed into a film shape.

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

In addition, the present invention provides an electrolyte for carbon dioxide reduction, comprising an alcohol and a precipitation auxiliary agent, in which carbon dioxide is dissolved.

Hereinafter, the carbon dioxide conversion device of the present invention will be described in more detail through an operation example. However, the following working examples do not limit the scope of the present invention, but should be construed to facilitate understanding of the present invention.

First, an electrolyte is prepared by mixing alcohol and a precipitation auxiliary agent, and then carbon dioxide is injected and dissolved in the electrolyte. Then, the electrolyte is put into a reactor as shown in FIG. 2, and a cathode, a cathode and an ion permeable diaphragm are installed. Then, when a voltage is applied to the cathode and the anode, carbon dioxide is reduced in the cathode to produce alkane gas, and in the anode, alcohol is reduced to generate hydrogen gas. At this time, alkane and hydrogen gas are collected in a separate renewable energy collector and concentration and purity can be measured.

Hereinafter, the present invention will be described more specifically by way of examples. However, the following examples should not be construed as limiting the scope of the present invention, but should be construed to facilitate understanding of the present invention.

[ Example ]

Example  One.

To 200 ml of methanol, 0.2 M potassium hydroxide and 0.2 M sodium hydroxide were dissolved by stirring for 30 minutes. 200 ml of the stirred solution was transferred to an electrochemical apparatus to connect the positive electrode and the negative electrode. Then, carbon dioxide was supplied at a rate of 20 ml / min and dissolved for 30 minutes. Then, the negative electrode and the positive electrode were divided and electrolyzed by ion- . The concentration of alkane and hydrogen produced in the electrolysis is measured according to the reaction time and is shown in FIG. 3 and FIG. 4, respectively.

As can be seen in FIG. 3, methane, ethane and propane were detected. Also, as can be seen from Fig. 4, hydrogen was detected at a concentration of 3% or more.

Example 2 .

The procedure of Example 1 was repeated except that 200 ml of methanol was mixed with 0.1 M potassium hydroxide and 0.1 M sodium hydroxide.

Example 3 .

The procedure of Example 1 was repeated except that 0.15M potassium hydroxide and 0.15M sodium hydroxide were mixed in methanol.

Example 4 .

Except that 0.25M potassium hydroxide and 0.25M sodium hydroxide were mixed in 200 ml of methanol.

Example 5 .

The procedure of Example 1 was repeated except that 200 ml of methanol was mixed with 0.3 M potassium hydroxide and 0.3 M sodium hydroxide.

Example  6.

The procedure of Example 1 was repeated except that ethanol was used in place of the methanol used in Example 1. No flammable gas such as alkane or hydrogen was produced at this time.

Example  7.

The procedure of Example 1 was repeated except that butanol was used instead of the methanol used in Example 1. No flammable gas such as alkane or hydrogen was produced at this time.

Example  8.

The procedure of Example 1 was repeated except that isopropyl alcohol was used instead of methanol used in Example 1. No flammable gas such as alkane or hydrogen was produced at this time.

Example  9.

The concentration of alkane and hydrogen produced was measured in the same manner as in Example 1 except that only 0.2M sodium hydroxide was mixed with 200 mL of methanol, but the measurement concentration of combustible gas such as alkane or hydrogen was insufficient. Methane, ethane and propane were not measured and hydrogen was measured to be below 0.5%.

Example  10.

The concentration of alkane and hydrogen produced was measured in the same manner as in Example 1 except that only 0.2M potassium hydroxide was mixed with 200 mL of methanol, but the measurement concentration of combustible gas such as alkane or hydrogen was insufficient. Methane, ethane and propane were not measured, and hydrogen was measured to be less than 1%.

Experimental Example  One.

The concentrations of methane and hydrogen produced through the carbon dioxide reduction apparatus manufactured in Examples 1 to 5 were measured and are shown in FIG. 5 and FIG. 6, respectively.

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

Comparative Example  One.

The concentration of alkane and hydrogen produced was measured in the same manner as in Example 1 except that the carbon dioxide was not dissolved in 200 ml of the solution stirred in Example 1, but a combustible gas such as alkane or hydrogen was not measured.

Comparative Example  2.

The concentration of alkane and hydrogen produced was measured in the same manner as in Example 1 except that no precipitation auxiliary agent was added to 200 ml of methanol, but the measured concentration of combustible gas such as alkane or hydrogen was not measured.

Comparative Example  3.

The concentration of alkane and hydrogen produced in Example 1 was measured in the same manner as in Example 1, except that distilled water was used instead of methanol. However, the measurement concentration of alkane or hydrogen and combustible gas was insufficient. Methane, ethane and propane were not measured, and hydrogen was measured at 1.5% or less.

Comparative Example  4.

The concentration of alkane and hydrogen produced in Example 1 was measured in the same manner as in Example 1 except that distilled water was used instead of methanol and carbon dioxide was not dissolved, but the measured concentration of alkane or hydrogen and combustible gas was insufficient. Methane, ethane and propane were not measured, and hydrogen was measured at 1.5% or less.

Comparative Example  5.

The concentration of alkane and hydrogen produced in Example 1 was measured in the same manner as in Example 1 except that distilled water was used instead of methanol and 0.2 M sodium hydroxide was mixed as a precipitation aid. However, measurement of alkane or hydrogen and combustible gas The concentration was insufficient. Methane, ethane and propane were not measured, and hydrogen was measured to be less than 1%.

Comparative Example  6.

The concentration of alkane and hydrogen produced in Example 1 was measured in the same manner as in Example 1, except that distilled water was used instead of methanol, and only 0.2 M potassium hydroxide was mixed as a precipitation aid. However, measurement of alkane or hydrogen and combustible gas The concentration was insufficient. Methane, ethane and propane were not measured, and hydrogen was measured to be less than 1%.

Experimental Example  2.

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

division The produced methane gas concentration (ppm) The concentration of produced ethane gas (ppm) Concentration of produced propane gas (ppm) The generated hydrogen gas concentration (%) 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 Less than 1% 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 Less than 1.5% Comparative Example 4 Not detected Not detected Not detected Less than 1.5% Comparative Example 5 Not detected Not detected Not detected Less than 1% Comparative Example 6 Not detected Not detected Not detected Less than 1%

As shown in Table 1, electrolysis of carbon dioxide using methanol and electrolytic solution containing potassium hydroxide and sodium hydroxide as precipitation aids, dissolved in carbon dioxide, can produce alkane, methane, ethane and propane, Hydrogen could be generated. In addition, when the concentration of potassium hydroxide and sodium hydroxide is less than 0.15M, the purity of alkane and hydrogen generated is low, and when the concentration of potassium hydroxide and sodium hydroxide is more than 0.25M, a large amount of carbonate is generated to prevent the reduction of carbon dioxide .

Claims (25)

(1) injecting an electrolyte containing methanol and a precipitation auxiliary agent in a reactor including an anode, a cathode and an ion-permeable diaphragm for dividing the anode and the cathode, and dissolving carbon dioxide therein; And
(2) electrolyzing the carbon dioxide dissolved in the electrolyte by applying a voltage of 10 to 55 V to the reactor,
The precipitation auxiliary agent includes potassium hydroxide and sodium hydroxide,
Wherein said electrolyte comprises 0.35-0.5 mol per liter of a precipitation aid. delete delete delete delete The positive electrode according to claim 1, wherein the positive electrode is at least one selected from the group consisting of platinum (Pt), stainless steel, gold (Au), and silver (Ag) ≪ / RTI > delete A reactor containing an precipitation auxiliary agent containing potassium hydroxide and sodium hydroxide and an electrolyte containing methanol and containing carbon dioxide dissolved therein;
A cathode provided in the reactor and partially or completely immersed in the electrolyte;
A negative electrode disposed in the reactor and facing the positive electrode, the negative electrode partially or wholly immersed in the electrolyte; And
And an ion-permeable diaphragm that divides them between the positive electrode and the negative electrode,
The precipitation auxiliary agent includes 100 to 300 parts by weight of sodium hydroxide based on 100 parts by weight of potassium hydroxide,
Wherein the electrolyte comprises 0.35-0.5 mol per liter of a carbon dioxide reducing agent. The apparatus according to claim 8, further comprising a power supply unit for applying a current to the positive electrode and the negative electrode. delete delete delete delete delete delete The positive electrode according to claim 8, wherein the negative electrode is a copper (Cu) or mercury (Hg) electrode, and the positive electrode is at least one selected from the group consisting of platinum (Pt), stainless steel, gold (Au) Wherein the carbon dioxide reduction device comprises: 9. The apparatus of claim 8, further comprising a reference electrode for voltage measurement. delete 18. A carbon dioxide reducing apparatus according to any one of claims 8, 9 and 16 to 17, wherein an alkane and hydrogen are produced. Precipitation aids containing potassium hydroxide and sodium hydroxide; Methanol; And carbon dioxide,
The precipitation auxiliary agent includes 100 to 300 parts by weight of sodium hydroxide based on 100 parts by weight of potassium hydroxide,
Wherein the electrolytic solution contains 0.35 to 0.5 mol of an auxiliary precipitation agent per liter of the electrolyte. delete delete delete delete delete

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