KR101696599B1 - Electrochemical system by using ionic solution for the effective treatment of water-insoluble organic compound - Google Patents

Abstract

According to the present invention, an electrolysis system for removing aromatic compounds comprises the following steps of: a) preparing a solution containing an electric activated catalyst containing transition metal halides by injecting and dissolving a precursor of the electric activated catalyst containing transition metal halides in an ionic solution; b) activating the electric activated catalyst by injecting the solution obtained from step a) to a reactor, and applying an electric current; and c) removing the aromatic compound by injecting an aromatic compound in the reactor.

Description

TECHNICAL FIELD [0001] The present invention relates to an electrolytic system using an ionic solution as an efficient treatment method of a water-insoluble organic compound,

The present invention relates to an electrolytic system which effectively removes non-water-soluble organic compounds using an electrolytic cell including an ionic solution, and more particularly to an electrolytic system which is environmentally friendly, has high moisture resistance, To the removal of aromatic compounds.

Air pollutants emitted from various sources are classified into various types such as volatile organic compounds (VOCs), odorous substances, and SOx and NOx. The continuous emission of these air pollutants is not limited to direct environmental pollution such as acid rain Desertification of meteorology and grassland and depletion of water resources are causing serious social problems that directly or indirectly threaten the survival of humankind.

In order to treat such pollutants, various methods such as a dry method such as adsorption, thermal incineration, catalytic reaction, a wet method such as absorption, and a biological treatment method have been proposed variously.

Problems of currently used treatment technologies are that high-temperature processes are used to generate large amounts of carbon emissions, secondary pollutants such as dioxins, and a large amount of oxidizing agents and absorbents continuously required, resulting in wastewater and slurry, And waste catalysts such as waste catalysts generate a vicious circle of environmental pollution.

In order to cut off the vicious cycle of environmental pollution and lead the global low carbon green growth, it is necessary to reduce the secondary pollutants such as a large amount of waste oxidizing agent, wastewater, waste catalyst, And carbon emissions should be drastically reduced.

In order to realize this, it is possible to operate with supply of current only at normal temperature and atmospheric pressure without the need of additional supply of chemicals and without generation of wastes and wastewater, (MEO: Mediated Electrochemical Oxidation) process is suitable.

The electrochemical mediated oxidation process is an aqueous process in which an electrocatalyst is oxidized at the anode of an electrolytic cell and the oxidized medium is oxidized and decomposed in the bulk of the electrolyte. This process almost destroys the organic matter, and ultimately converts the carbon and hydrogen in the organic matter into carbon dioxide and water, which is mostly mineralized. At this time, the reduced medium is again used by being oxidized at the surface of the electrode to be regenerated and reacted with the organic material continuously (Korean Patent Publication No. 2006-0105969, Korean Patent Publication No. 2004-0012770, Japanese Patent Laid- Publication No. 1998-500900).

However, in the above intermediate oxidation process, it has been found that the electrolyte is mainly used after a strong acid is added to an aqueous solution, so that the aqueous process can be performed smoothly. However, such an aqueous process has difficulties in decomposing or removing non-aqueous organic compounds such as aromatic hydrocarbons.

Accordingly, a process that uses an ionic solution as an electrolyte may be used as a substitute for the water-soluble process. The ionic solution may be defined as a salt present in a liquid state at room temperature, and is known to be composed of a cation and an anion.

These ionic liquids are characterized by their ability to dissolve various organic and inorganic substances and gases, have very low vapor pressure, are environmentally stable, are thermally stable up to about 300 ° C and are only suitable for specific application purposes with a combination of cation and anion It is widely used in various chemical industry fields.

However, the commercialized ionic solution has a high unit price to be used as an electrolyte, and an electrolytic system utilizing an ionic solution can present various problems since it is an initial stage in which full-scale research has not been conducted yet. For example, when performing the mediated oxidation reaction using the ionic solution together with the above-mentioned electroactive catalyst, stability problems that the ionic solution can be continuously driven after contact (or reaction) with contaminants, that is, (Air or air), and an electrolytic system including the development of an electrolytic cell (or a diaphragm cell) and a process development using the electrolytic cell .

Korean Patent Publication No. 2006-0105969 (October 12, 2006) Korean Patent Publication No. 2004-0012770 (Feb. Japanese Laid-Open Patent Publication No. 1998-500900 (1998.01.27)

The present invention provides an electrolytic system capable of improving the removal efficiency of a non-aqueous aromatic compound, having excellent durability and moisture resistance, and capable of continuous operation by using an electrolytic system utilizing an ionic solution.

The present invention also provides an apparatus for removing aromatic compounds using the electrolysis system of the present invention.

According to an aspect of the present invention,

A diaphragm cell including an anode portion, a cathode portion, and a separator separating the anode portion and the cathode portion; A tank for containing the ionic solution; And an electric power supply unit,

a) introducing and dissolving a precursor of an electroactive catalyst comprising a transition metal halide into an ionic solution to produce a solution containing said electroactive catalyst; b) activating the electrocatalyst by applying the solution prepared in step a) to the anode chamber of the anode section and the cathode chamber of the cathode section, respectively, and then applying current by the power supply section; And c) introducing an aromatic compound into the anode chamber containing the electroactive catalyst of step b), thereby removing the aromatic compound.

The ionic solution is not particularly limited, but it is preferable for the purpose of the present invention that the melting point is 0 DEG C or less.

In the electrolytic system according to an embodiment of the present invention, the ionic solution may have an electrical conductivity of 1 × 10 ^-4 to 9 × 10 ^-2 S / cm, but the present invention is not limited thereto.

Also, in the electrolytic system according to an embodiment of the present invention, the aromatic compound is treated by the anode half reaction, and the oxidation potential of the anode half reaction may be 0.5 to 3 V, but the present invention is not limited thereto.

The removal temperature of the aromatic compound may be 0 to 100 ° C, but the present invention is not limited thereto.

In the electrolytic system according to an embodiment of the present invention, the precursor of the electroactive catalyst is not limited but may be a transition metal halide including at least one of cobalt and nickel. More specifically, the precursor of the electroactive catalyst may be a chloride containing cobalt, but is not necessarily limited thereto.

In the electrolytic system according to an embodiment of the present invention, the ionic solution includes a pyrrolidinium-based cation for achieving the object of the present invention, but the present invention is not limited thereto.

In the electrolytic system according to an embodiment of the present invention, the reactor may use a diaphragm cell, and the diaphragm cell includes an anode portion, a cathode portion, and a separator for controlling the movement of the proton, An anode chamber, and a cathode tab, wherein the cathode section has a cathode, a cathode chamber, and a cathode tab, wherein the anode chamber and the cathode chamber are each filled with the solution prepared in the step a) But is not necessarily limited thereto.

In addition, the separation membrane may have a plate-like shape including a front surface and a rear surface opposite to the front surface, and the front surface of the separation membrane may be opposed to the anode, but is not limited thereto. Further, the anode is made of platinum, and the cathode is made of silver, but is not limited thereto.

In the electrolytic system according to an embodiment of the present invention, the current density in step b) may be 1 to 100 mA / cm ² , but is not limited thereto. In addition, it is more preferable to apply the electric current to the reactor in the step b) and to apply the ultrasonic wave to achieve the object of the present invention.

In addition, in the step b), the activation of the electrocatalyst is advantageous in that the transition metal of the electrocatalyst is oxidized by the anode half reaction or reduced by the cathode half reaction, but the present invention is not limited thereto It does not.

In the step c), it is preferable to apply ultrasonic waves to the anode chamber to achieve the object of the present invention, but the present invention is not limited thereto.

In the electrolytic system according to an embodiment of the present invention, the aromatic compound is not limited to a great extent, but may be an aromatic hydrocarbon containing at least one or more of benzene, toluene, and xylene.

In the present invention, it is preferable to apply ultrasonic waves to the anode chamber of step b), and the solution obtained in step c) may be introduced into the anode chamber of step b). This is not limited, but is suitable for the continuous removal of the aromatic compound according to the present invention.

Further, the present invention can also disclose an intermediate oxidation apparatus and article used for removing aromatic compounds using the above-described electrolytic system.

The electrolytic system for removing aromatic compounds according to the present invention improves the removal efficiency of aromatic compounds and the durability and moisture resistance of the ionic solution by using a precursor and an ionic solution of an electrocatalyst including a transition metal halide .

In addition, the reactor according to the present invention uses a diaphragm cell in which two or more solutions can be continuously reacted, and two or more aromatic compounds can be continuously removed.

In addition, the present invention provides a device and system using the electrolytic system of the present invention to reduce greenhouse gas emissions by using sustainable green technology capable of overcoming the problems of existing environmental technologies, that is, using clean energy at low temperature and atmospheric pressure No additional supply of oxidizers or chemicals is required, which can provide guidelines for the development of zero emission technology without the emission of secondary pollutants.

1 is a process diagram of an electrolytic system for removing aromatic compounds according to an embodiment of the present invention,
2 is a schematic diagram showing an apparatus for performing a conventional intermediate oxidation process,
3 is a schematic diagram showing an apparatus of an electrolytic system for removing aromatic compounds according to Example 1 of the present invention,
4 is a schematic diagram showing a diaphragm cell according to Embodiment 1 of the present invention,
FIG. 5 is a graph showing cyclic-current voltage characteristics of an electrocatalyst according to an embodiment of the present invention,
FIG. 6 is a graph showing another cyclic-current voltage characteristic of an electrocatalyst according to an embodiment of the present invention,
FIG. 7 is a graph showing another cyclic-current voltage characteristic of an electrocatalyst according to an embodiment of the present invention,
FIG. 8 is a graph showing another cyclic-current voltage characteristic of an electrocatalyst according to an embodiment of the present invention,
9 is a graph showing removal characteristics of aromatic compounds according to Example 1 of the present invention and Comparative Examples,
10 is a graph showing the removal characteristics of aromatic compounds according to Example 2 of the present invention and Comparative Examples,
11 is a graph showing removal characteristics of aromatic compounds according to Example 3 of the present invention and Comparative Examples.

Hereinafter, the electrolytic system of the present invention will be described in detail. The following embodiments and drawings are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. In addition, unless otherwise defined in the technical and scientific terms used herein, unless otherwise defined, the meaning of what is commonly understood by one of ordinary skill in the art to which this invention belongs is as follows, A description of known functions and configurations that may unnecessarily obscure the gist of the present invention will be omitted. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. It is noted that the terms "comprises" and / or "comprising" used in the specification are intended to be inclusive in a manner similar to the components, steps, operations, and / Or additions. The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by terms. Terms are used only for the purpose of distinguishing one component from another. Hereinafter, the same member numbers are used for the same members in order to facilitate understanding. In the present specification, the term " connected "includes not only a direct connection but also a connection via another member in the middle.

In describing the present invention, the term "diaphragm cell" may refer to an electrochemical cell having a diaphragm or separator provided between an anode and a cathode, and may refer to a two-electrode system including an anode and a cathode.

In describing the present invention, the term " intermediate oxidation reaction (MEO) "may mean intermolecular exchange of electrons around the anode. As a specific example, an intermediate oxidation reaction may mean a transition of a metal ion of a mediator to a high oxidation potential by losing electrons around the anode.

In describing the present invention, the term " intermediate reduction reaction (MER) "may mean intermolecular electron exchange around the cathode. As a specific example, an intermediate reduction reaction may mean a reaction in which a metal ion of an electrocatalyst receives electrons around a cathode to cause a transition to a low oxidation state.

In describing the present invention, the term "mediator" may refer to a substance capable of directly receiving electrons (oxidation or reduction) around the anode or cathode and participating in an electrochemical reaction. Specific, an example non-limiting days, the medium is ^{[M x + (HA)]} y (z) - can be represented as such ^{-, [M (x-1} ) + (HA)] y (z + 1) . Wherein x means a natural number of 1 to 6, y means a natural number of 1 to 10, and z means a natural number of 1 to 10.

In the above formula, M may be a transition metal, M ^{(x-1) +} may be a reduced metal ion or metal, and M ^{(x) +} means an oxidized metal ion . Further, HA means a halogen material.

In describing the present invention, the term "moisture resistance " refers to a performance that can be used to withstand moisture, and refers to a case where there is performance that can be used in an environment with high humidity in an electric device, an electrolytic system and the like. As a non-limiting, specific example, an ionic solution with moisture resistance may resist wetting or penetration by one or more types of moisture, or that it is impermeable or substantially impermeable to moisture of one or more types can do.

In describing the present invention, the term "air" is not limited to atmospheric air, but may include a combination of gases containing oxygen, or pure oxygen gas.

2, the conventional electrolytic system for removing contaminants includes a diaphragm cell 10 including an anode portion, a cathode portion, and a separator, a power supply portion 50 for supplying power to the diaphragm cell, A positive electrode tank 60 for supplying an anolyte to the diaphragm cell, and a negative electrode tank 70 for supplying a catholyte to the diaphragm cell.

Referring to the electrolysis system of FIG. 2, the electrolysis system of the present invention differs from the electrolysis system using the diaphragm cell in that the prior art consists only of an intermediate oxidation process (MEO), in which the electrolyte used in the intermediate oxidation process is based on an aqueous solution Is used. This water-based oxidation process is difficult to remove non-water-soluble organic compounds, and energy applied to the intermediate oxidation process contributes greatly to water decomposition, rather than removal of contaminants by mediated oxidation.

The inventor of the present invention has developed an ionic solution which can be applied to the above process after several years of efforts to perform an intermediate oxidation process (MEO) which can solve the above problems in an electrolytic system using diaphragm cells, An electroactive catalyst which is dissolved in the liquid and which is very stable in the process has been developed and the orientations of the separator and the types of electrodes capable of maximizing the removal efficiency of the pollutants have been developed and applied.

An electrolytic system according to the present invention is an electrolytic system that uses an intermediate oxidation reaction (MEO) to remove an aromatic compound and improve its removal efficiency,

Wherein the electrolytic system comprises: a diaphragm cell including an anode portion, a cathode portion, and a separator separating the anode portion and the cathode portion; A tank for containing the ionic solution; And a power supply unit, the electrolytic system comprising:

a) introducing and dissolving a precursor of an electroactive catalyst comprising a transition metal halide into an ionic solution to produce a solution containing said electroactive catalyst; b) activating the electroactive catalyst by applying the solution prepared in step a) to the anode chamber of the anode section and the cathode chamber of the cathode section, respectively, and then applying current by the power supply section; And c) introducing an aromatic compound into the anode chamber containing the electroactive catalyst of step b), thereby removing the aromatic compound.

The ionic solution is not particularly limited, but it is preferable for the purpose of the present invention that the melting point is 0 DEG C or less. Specifically, the melting point of the ionic solution may be -30 ° C to 0 ° C, and more preferably -25 ° C to 10 ° C, but is not limited thereto.

Further, the aromatic compound is treated by the reaction of the anode half reaction, and the oxidation potential of the anode half reaction may be 0.5 to 3 V, but the present invention is not limited thereto.

In addition, the ionic solution is not limited to a specific one, but may include a pyrrolidinium-based cation. This is preferable in terms of improving stability with air and moisture resistance.

The diaphragm cell may include an anode, a cathode, and a separator for controlling the movement of the proton, and the anode includes an anode, an anode chamber, and a cathode tab, The cathode portion includes a cathode, a cathode chamber, and a cathode tab, wherein the cathode chamber can be filled with the solution prepared in the step a).

In addition, the separation membrane may have a plate-like shape including a front surface and a rear surface opposite to the front surface, and the front surface of the separation membrane may be opposed to the anode, but is not limited thereto. Further, the anode is made of platinum, and the cathode is made of silver, but is not limited thereto. Which is good for activating the electroactive catalyst of the present invention.

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

1 is a process diagram of an electrolytic system for removing aromatic compounds according to the present invention. As shown in FIG. 1, the electrolytic system according to the present invention includes a step (S10) of selecting a precursor and an ionic solution of an electroactive catalyst, a step (S20) of mixing a precursor and an ionic solution, a step (S30) An application step S40, and an aromatic compound injection and removal step S50.

In the electrolytic system according to an embodiment of the present invention, the precursor of the electrocatalyst of the step (S10) is dissolved in the ionic solution according to the present invention, and in the continuous operation of the electrolytic system according to the present invention, A substance is enough. In one example, the precursor of the electroactive catalyst may comprise a material comprising a transition metal halide.

In a specific, non-limiting example, the transition metal halide can be a transition metal fluoride, a transition metal chloride, a transition metal bromide, a transition metal iodide, or a combination thereof.

More specifically, the transition metal halide is selected from the group consisting of MnF ₃ , MnF ₄ , MnCl ₂ , MnCl ₃ , MnBr ₂ , MnI ₂ , FeF ₂ , FeF ₃ , FeCl ₃ , FeCl ₂ , FeBr ₂ , FeBr ₃ , FeI ₂ , _{FeI 3, CoF 2, CoF 3} , CoF 4, CoCl 2, CoCl 3, CoBr 2, CoI 2, NiF 2, NiCl 2, NiI 2, CrF 2, CrF 3, CrF 4, CrF 5, CrF 6, CrCl 2 , CrCl ₃ , CrCl ₄ , CrBr ₂ , CrBr ₃ , CrBr ₄ , CrI ₂ , CrI ₃ , CrI ₄ , VF ₂ , VF ₃ , VF ₄ , VF ₅ , VCl ₂ , VCl ₃ , VCl ₄ , VBr ₂ , VBr ₃ , VBr ₄ , VI ₂ , VI ₃ , VI ₄ , CuF, CuF ₂ , CuCl, CuCl ₂ , CuBr ₂ , CuI, or mixtures thereof, but the present invention is not limited thereto.

For example, when the metal salt is selected as at least one transition metal halide selected from cobalt and nickel, the electrocatalyst according to the present invention has improved oxidizing power and can prevent electrodeposition of metal during the mediated oxidation reaction.

Further, in the electrolytic system according to the present invention, the ionic solution in the step (S10) may be a substance that has high stability to air and does not easily change its physical properties, and is preferably a substance having high moisture resistance.

In addition, the ionic solution may be defined as a salt present in a liquid state at room temperature, and may be composed of a cation and an anion. More specifically, if the melting point of the ionic solution is 0 캜 or lower, it is preferable to achieve the object of the present invention, but the present invention is not limited thereto.

In addition, the electrical conductivity of the ionic solution is not particularly limited, but may be 1 x 10 ^-4 to 9 x 10 ^-2 S / cm. By using an ionic solution within the above range, it is good for stable operation of the electrolytic system according to the present invention.

As a specific and non-limiting example, the ion conductivity of the ionic solution may be measured by a four-terminal method (or a 4-wire method) at room temperature, and a conventionally known electric conductivity measurement method may be used.

In addition, in the electrolytic system according to an embodiment of the present invention, the ionic solution may include a pyrrolidinium-based cation, but the present invention is not limited thereto.

In a more specific example, the ionic solution is selected from the group consisting of butyl methylpyrrolidinium bis (trifluorosulfonyl) imide (BMPyrTFSI), propylmethylpiperidinium bis (trifluorosulfonyl) imide (PMPipTFSI) ([EMPyrr] [EHPO ₃ ]), butyl ethyl (methyl) pyrrolidinium methyl phosphate ([MPyrr] [MHPO ₃ ]), ethyl methyl pyrrolidinium ethyl phosphate pyrrolidin pyridinium ethyl phosphate _{([BEPyrr] [EHPO 3]} ), dibutyl-pyrrolidin pyridinium butyl phosphate _{([DBPyrr] [BHPO 3]} ), hexyl silpi Raleigh pyridinium hexyl phosphate _{([HxPyrr] [HxHPO 3]} ), octanoic tilpi Raleigh pyridinium octyl phosphate _{(OcPyrr] [OcHPO 3])} , butyl methylpyrrolidin pyridinium butyl phosphate _{([BMPyrr] [BHPO 3]} ) , but may alone or in combination of two or more selected from, the present invention is not limited to this.

In the electrolytic system according to an embodiment of the present invention, the step (S20) of mixing the precursor and the ion solution includes a step of dropping the precursor of the electrocatalyst and the ionic solution into a container such as a tank . Thus, a solution containing a homogeneous electroactive catalyst can be prepared.

The mixing method can be carried out by a method known to a person skilled in the art and the detailed mixing method can be changed according to the kind and concentration of the precursor and the kind and concentration of the ion solution. Do.

In the electrolytic system according to an embodiment of the present invention, the step of injecting (S30) into the reactor may include the step of injecting the solution containing the electroactive catalyst into the reactor. The reactor is not particularly limited, but may mean an anode chamber, a cathode chamber, a diaphragm cell, or the like, which will be described later. The method of injecting the solution into the reactor can be carried out by a method known to those skilled in the art, and a specific example can be supplied at a predetermined flow rate from the above-described vessel using a peristaltic pump.

In the electrolytic system according to an embodiment of the present invention, the current application (S40) may include applying a current to a reactor containing a solution containing the electroactive catalyst. That is, by applying an electric current to the reactor, the electroactive catalyst can be activated.

The activation of the electrocatalyst is not critical, but it means that the transition metal ion of the above-mentioned electrocatalyst can be prepared by oxidation by the anion half reaction. This can be expressed by the following equations 1 and 2, but the material of the electroactive catalyst is not limited to cobalt and chlorine.

[Formula 1]

The formula (1) may be a reaction formula in which an electroactive catalyst is activated by oxidation of cobalt ions by an anode half reaction.

In the electrolysis system according to an embodiment of the present invention, in the current application step (S40), the applied current density may be 1 to 100 mA / cm < ² > to about 50 mA / cm ^2, more preferably from 20 to 40 mA / cm ² Lt; / RTI > It is preferable in terms of the reaction rate, the reaction rate, etc. of the medium when operated within the above range.

As a result, the transition metal of the electroactive catalyst according to the present invention can be oxidized by an anode half reaction.

In addition, the activation of the electrocatalyst according to the present invention can be performed not only by the anode half reaction but also by the cathode half reaction. In other words, activation of the electrocatalyst may be performed by oxidizing the transition metal of the electrocatalyst by the anion half reaction, and at the same time, reducing the transition metal of the other species by the anion half reaction.

Specifically, the transition metal of the other species may mean a transition metal that is oxidized by the reaction of the anode halide and a transition metal of another kind. For example, if the transition metal oxidized by the reaction of the anode halide is Co, The transition metal to be reduced may be Ni, but the present invention is not limited thereto.

In the electrolytic system according to an embodiment of the present invention, the introduction and removal of the aromatic compound (S50) may be performed by injecting an aromatic compound into a reactor containing a solution containing the electroactive catalyst activated in the step (S40) And removing the aromatic compound.

The amount of the aromatic compound to be injected is not particularly limited, but may be 1 to 500 rpm per minute.

In addition, the aromatic compound is injected in an amount of 0.1 to 0.8 moles per mole of the transition metal halide described above to achieve the object of the present invention, but the present invention is not limited thereto.

The reactor may further include a solution prepared by receiving a solution prepared by oxidizing transition metal ions of an electrocatalyst by an anode half reaction and independently reducing the transition metal ions of the electrocatalyst by a cathode half reaction, It can be accommodated separately. Thereby simultaneously removing two or more same or different kinds of aromatic compounds.

As a specific and non-limiting example, the reaction formula in which the aromatic compound is removed can be represented by the following formula 2, but the aromatic compound is not necessarily limited to the following benzene, and the metal ion of the electrocatalyst is necessarily limited to cobalt no.

When an aromatic compound is injected as described above and an electric current is applied to the reaction product having the reaction as shown in Formula 2, the reduced electroactive catalyst can be returned to the activated electroactive catalyst in the initial state. This can be expressed by the following equation (3).

In addition, the removal characteristics of the aromatic compound can be measured using spectroscopy using infrared rays or the like. As a specific, non-limiting example, the removal characteristic can be confirmed by a peak of -C = O stretching vibration, as shown in FIG. Thus, the removal rate of benzene according to the electrolytic system of the present invention may be 90% or more.

In addition, the step of injecting and removing contaminants (S50) may apply ultrasonic waves to the reactor in which the aromatic compound is injected. This can improve the removal rate and the reaction rate of the air pollutant according to the above-described formula (2) when the activated electrocatalyst is removed by contacting with the aromatic compound.

In addition, the aromatic compound may be injected and removed in a state where current is continuously applied to the reactor in the step of injecting and removing the contaminants (S50), but the present invention is not limited thereto.

In addition, the solution obtained in step (S50) (or after step S50) may be introduced into the reactor of step b). This can be used by reactivating the oxidized electroactive catalyst and the reduced electroactive catalyst, and the removal of the aromatics of the electrolysis system according to the present invention can be carried out continuously.

In addition, when the aromatic compound is continuously removed, ultrasonic waves may be applied while the current of the step b) is applied. This can improve the reaction rate at which the aromatic compound is activated, and can be effective in preventing electrodeposition of the electrode. In addition, the electrolytic system for removing the aromatic compounds according to the present invention can be further continuously operated.

For example, the ultrasonic wave may have a frequency (20 kHz) higher than that of the audible frequency region, and the frequency of the ultrasonic wave applied in the ultrasonic wave applying process of the present invention may be more than 20 kHz and less than several hundred kHz. In addition, the removal rate of the aromatic compound of the present invention can be independently increased by 10 to 50% by the ultrasonic wave application process.

In the electrolytic system according to an embodiment of the present invention, the precursor of the electroactive catalyst in the above-described step (S10) may be a transition metal halide including at least one of cobalt, silver, nickel and copper.

As a specific, non-limiting example, the oxidation potential of an electrocatalyst comprising a transition metal is shown in Table 1 below.

[Table 1]

For example, the cobalt-containing metal salt or metal compound, that is, the cobalt metal salt may have better oxidizing power than the metal salt containing other metals. As shown in Table 1, the oxidation potential of Co ^{3 +} represents the 1.83 V, Ag ^{2 +} is 1.98 V, Ce ^{4 +} is 1.61 V, Mn ^{3 +} represents the 1.54 V, respectively. In addition, SHE can refer to a standard hydrogen electrode.

However, since Ag ^{2 +} has a higher oxidizing power than Co ^{3 +} , it may be good in terms of reactivity, but it can migrate to the cathode via the separation membrane during the mediated oxidation reaction. Therefore, Ag ^{2 +} may be transferred from the cathode or the cathode to cause electrodeposition of the metal, deterioration of the electrode, and durability of the chemical cell.

In addition, Ag ^{2 +} is relatively expensive compared to Co ^{3 +} and exhibits irreversibility in the oxidation and reduction reaction, so that it may not be advantageous to apply the electrolysis system according to the present invention.

Further, in achieving the object of the present invention, the metal salt containing cobalt is very stable because it is stable in the ionic solution described above and the reaction in the anode half can be reversibly repeated.

Referring to FIG. 4, the reactor may include a diaphragm cell 1000. The diaphragm cell 1000 includes an anode portion 200, a cathode portion 300, and a separator 100 that separates the anode portion and the cathode portion and controls the movement of protons, And may be formed in a plate-like shape including the opposite rear surface.

Although the kind of the separation membrane 100 is not limited to achieve the object of the present invention, a substance capable of transferring hydrogen ions is sufficient, and it is more preferable that the substance is stable in the ion solution. As a specific and non-limiting example, the separation membrane 100 may be a Nafion polymer membrane including at least one ionic functional group selected from the group consisting of sulfonate, carboxylate, and phosphate.

In an anode chamber (not shown) of the anode part 200, a cobalt metal salt dissolved ion solution may be contained. In the cathode chamber 320 of the cathode part 300, a cobalt metal salt May include a dissolved ionic solution. Also, the ionic solution contained in the anode chamber may mean an anolyte solution, and the ion solution included in the cathode chamber may mean a catholyte solution, but the present invention is not limited thereto.

In addition, the front surface of the separation membrane 100 may have a positive polarity and a rear surface thereof may have a negative polarity. At this time, when the front surface of the separation membrane is opposed to the anode 210, the movement of the hydrogen ions (H ⁺ ), H ₃ O ^+, etc. generated in the solution in the anode chamber to the cathode (or cathode chamber) . During which the activation of the mediators of step b) according to the present invention, it is possible to increase the production rate of Co ^{+ 3.} Specifically, when the entire surface of the separation membrane is opposed to the anode, the production rate of Co ^{3 +} can be improved by 10 to 50% compared with the case where the separation membrane is not opposed to the anode.

In addition, the production rate of the Co ^{3 +} can be calculated using the following equation (4).

In the formula 4, C may mean the concentration of cobalt ions.

Also, in the electrolytic system according to the present invention, after the solution of step a) is put into the reactor, the cathode 310 is made of silver and the anode 210 ) May be made of platinum.

The present invention may also include a mediated oxidizing device used for the removal of aromatic compounds using the above-described electrolysis system. 3, the intermediate oxidation / reduction apparatus includes a diaphragm cell 1000, an anode tank 600 communicating with the anode chamber of the diaphragm cell for injecting / discharging an ionic solution, and a cathode chamber of the diaphragm cell And a negative electrode tank 700 for injecting / discharging an ionic solution.

The apparatus may further include a power supply unit 500 electrically connected to the diaphragm cell. The current density supplied from the power supply device may be 1 to 200 mA / cm ² , but the present invention is not limited thereto.

Specifically, in order to prepare mediators having different oxidation numbers (or intermediates having different properties), the solution prepared in step (S20) of FIG. 1 is injected into the anode chamber and the cathode chamber connected to the power supply unit respectively, is from 10 to 100 mA / cm ² to the solution i.e., the anolyte Co ^{2 +} is oxidation by Co ^{3 +,} the catholyte Co ^{2 +} is a reduction reaction by Co ^{1 +,} oxidation number other parameters metal Ions can be produced.

In the electrolytic system according to an embodiment of the present invention, the production rate of Co ^{3 +} is changed in the half-anion reaction according to the magnitude of the current density, and the production rate of Co ^{1 +} is changed in the half-cathode reaction.

As a specific and non-limiting example, it can be seen that the production concentration of Co ^{3 +} is increased about 300% compared to the current density 10 mA / cm ² at a current density of 30 mA. In addition, the generated concentration of Co ^{+ 1} is not substantially generated in a current density of 10 mA / cm ^2, can identify improved considerably at a current density of 30 mA / cm ^2.

In addition, the present invention may include an injection tube and a discharge tube for allowing the anode tank 600 of FIG. 3 to communicate with the electrochemical cell and the cathode tank 700 to communicate with the electrochemical cell. A pump may be attached to the injection tube to control the flow rates of the catholyte and catholyte. Further, the anolyte and the catholyte are similar or identical to the ionic solution containing the above-mentioned electrocatalyst. Thus, the electrolytic system according to the present invention can circulate the solution continuously.

The flow rate of the catholyte injected from the anode tank 600 may be 10 to 500 ml / min, and the flow rate of the catholyte injected from the cathode tank 700 may be similar to or the same as the flow rate of the anolyte , But the present invention is not limited thereto.

In addition, the positive electrode tank 600 and the negative electrode tank 700 may have discharge ports through which gas is discharged to the upper end portion independently of each other. The outlet may be operated in a manner of opening and closing under pressure. This can prevent leakage of sulfuric acid gas, chlorine gas and the like, which may occur during the intermediate oxidation and the intermediate reduction reaction, . Also, the precursor of the electroactive catalyst and the injection port into which the ionic solution is injected may be provided at the same time.

The positive electrode tank 600 and the negative electrode tank 700 may further include at least one electro-scrubber (not shown) having an outlet at an upper end independently of each other and communicating with the outlet. This configuration is based on the fact that chlorine or the like is discharged together with the gas discharged by the above-described intermediate oxidation reaction. For example, by providing the electrostatic scrubber at the rear end of the negative electrode tank 700, .

In addition, the electro-scrubber used in the present invention may be a scrubber used in a chemical process. If necessary, the electro-scrubber may be provided with a plurality of scrubbers to sequentially scrub different gases, can do.

Referring to FIG. 5, the activation characteristics of the electrocatalyst in the step b) according to the present invention may be improved depending on the type and concentration of the metal salt, the type and concentration of the ionic solution, the reaction time, and the like. .

That is, as a non-limiting and specific example, the metal salt is cobalt chloride, the content of cobalt chloride is 0.01 to 0.1 M, and the ionic solution is N-butyl-N-methylpyrrolidinium bis ([Bmpyr] [TFSI]), the activation from Co (II) to Co (III) is more conspicuous.

5 (a) shows a continuous cyclic current-voltage graph driven by only an ionic solution when the precursor of the electrocatalyst according to the present invention is not included, and FIG. 5 (a) As shown, it can be confirmed that no oxidation or reduction peak appears.

On the other hand, referring to FIG. 5 (b), FIG. 5 (b) shows a continuous circulating current-voltage graph when driven by an ionic solution containing a precursor of the electroactive catalyst according to the present invention. As shown in Fig. 5 (b), the oxidation peak from Co (II) to Co (III) by the anodic half reaction at about 1.68 V and the oxidation peak from Co (III) to Co And the reduction peak are remarkably exhibited respectively.

In addition, in the electrolytic system according to the present invention, in the case of producing an electrocatalyst comprising a precursor of an electrocatalyst including a transition metal halide and the above-mentioned ionic solution, as shown in FIG. 5, The potential window of the transition metal ion can be further expanded to improve the reactivity of the mediated oxidation reaction.

In addition, depending on the ratio of the size (Ia) of the activation peak from Co (II) to Co (III) and the size (Ib) of the restored peak from Co (III) to Co ) Activation of the electroactive catalyst can be improved. The ratio is expressed by Ia / Ib, and the rate may be 0.5 to 2 at a scan rate of 50 mV, but the present invention is not limited thereto.

Further, in the present invention, Co (I) is ^{1 +} Co, Co (II) is Co ^{2 +,} Co (III) may refer to Co ^{+ 3,} other metal ions may also be applicable to this.

Referring to FIG. 6, the electrolytic system according to the present invention shows that cyclic current-voltage characteristics may vary depending on the refresh rate. As shown in FIG. 6, the oxidation peak from Co (II) to Co (III) and the reduction peak from Co (III) to Co (II) .

As a specific, non-limiting example, the diffusion coefficient from Co (II) to Co (III) using the results of FIG. 6 may be 0.1 × 10 ^-7 to 9 × 10 ^-7 cm ² / s. The diffusion coefficient can be measured by the Randles-Sevcik formula, but is not limited thereto.

Referring to FIG. 7, the electrolysis system according to the present invention shows that cycling current-voltage characteristics may vary depending on the presence or absence of an electroactive catalyst. 7 (a) shows the removal characteristics of toluene in an electrolytic system using an ionic solution to which an electroactive catalyst is not added, and Fig. 7 (b) It may be a removal characteristic of toluene in an electrolytic system using an ionic solution. The ionic solution may also be N-butyl-N-methylpyrrolidinium bis (trifluoromethylsulfonyl) imide ([bmpyr] [TFSI]).

In detail, as described above in Fig. 5, a reduction peak at about 0.74 V shown in Fig. 7, an oxidation peak at about 1.68 V, respectively, and an oxidation peak of toluene at about 2.0 V can be confirmed.

In addition, it can be seen that the intensity of the oxidation peak of toluene is improved about 10 times as compared with the case where the electrocatalyst of FIG. 7 (a) is not added. This is because the electrolytic system containing the ionic solution of the present invention includes toluene It can be maximized in the removal of aromatic compounds.

In the electrolytic system according to an embodiment of the present invention, the removal temperature of the aromatic compound may be 0 to 100 ° C. Referring to FIG. 8, the electrolysis system according to the present invention shows that the characteristics of the circulating current-voltage may differ depending on the removal temperature of the aromatic compound.

As a specific, non-limiting example, the intensity of the oxidation peak of toluene (about 2.0 V) at about 80 ° C is 1.5 to 3 times higher than the intensity of the oxidation peak of toluene (about 2.0 V) have.

Hereinafter, the present invention will be described in detail with reference to the following examples. However, the present invention is not limited to the following examples.

Example 1

The solution containing the electroactive catalyst was prepared by adding 0.2 L of N-butyl-N-methylpyrrolidinium bis (trifluoromethylsulfonyl) imide ([bmpyr] [TFSI]) to the positive electrode tank 600, and the cathode tank 700, respectively, and 0.05 mmol of anhydrous CoCl ₂ was injected into the anode tank inlet 610 and the cathode tank inlet 710, respectively, and mixed.

The solution prepared in the anode tank 600 was introduced into the anode chamber of the diaphragm cell shown in FIG. 4, and the solution prepared in the cathode tank 700 was introduced into the cathode chamber 320. At this time, the diaphragm cell was a plate-shaped, Pt-coated mesh-type anode, a Ti cathode, and a Nafion® 324 separator. The surface areas of the cathode and anode were 4 cm ² . In addition, the distance between the electrode plates was maintained at 5 mm, and at least two Viton rubber gaskets were provided inside the cells, and the thickness thereof was 2 mm. The separation membrane is plate-shaped and divided into a front surface and a rear surface. The orientation of the separator, that is, the entire surface of the separator, was controlled to face the anode.

The two solutions were continuously circulated at a flow rate of 70 ml / min using a peristaltic pump (Masterflex-L / S, Cole Parmer Instrument Company). The current density was applied at 30 mA / cm ² using a power supply (Korea Switching Instruments), where the medium was activated. Specifically, activation of the mediator was activated from Co (II) to Co (III) in the anode chamber and from Co (II) to Co (I) in the cathode chamber 320.

Then, 0.015 mmol of benzene was injected into the circulating anode tank inlet 610, and the electrolysis system of the present invention was operated for 1 hour to confirm the removal characteristics of the benzene.

Example 2

The procedure of Example 1 was repeated except that toluene was injected into the anode tank inlet (610).

Example 3

The same procedure as in Example 1 was carried out except that xylene was injected into the anode tank inlet (610).

Comparative Example 1

The procedure of Example 1 was repeated except that no anhydrous CoCl _{2 was} injected and no current was applied.

Comparative Example 2

The procedure of Example 1 was repeated except that no anhydrous CoCl _{2 was} injected.

Comparative Example 3

The procedure of Example 2 was repeated except that no anhydrous CoCl _{2 was} injected and no current was applied.

Comparative Example 4

The procedure of Example 2 was repeated except that no anhydrous CoCl _{2 was} injected.

Comparative Example 5

The procedure of Example 3 was repeated except that no anhydrous CoCl _{2 was} injected and no current was applied.

Comparative Example 6

The procedure of Example 3 was repeated except that no anhydrous CoCl _{2 was} injected.

The removal of benzene is shown in Fig. 9, the removal of toluene is shown in Fig. 10, and the removal of the xylene is shown in Fig. 11 by infrared absorption spectrum in Examples 1 to 3 and Comparative Examples 1 to 6 . The spectrum was measured in liquid phase using FTIR (Nicolet-Is10 FT-IR, Thermo scientific).

Referring to FIG. 9, FIG. 9 is a spectrum showing the removal characteristics of benzene according to the present invention. FIG. 9 (a) is an FTIR spectrum of Comparative Example 1, FIG. 9 (b) is an FTIR spectrum of Comparative Example 2, and FIG. 9 (c) is an FTIR spectrum of Example 1. The removal characteristics of benzene were confirmed by the presence or absence of -C = O stretching vibration at about 1710 cm ^-1 or by the intensity of this peak. The peak appearing at about 1710 cm ^-1 is attributed to the keto group of the α, β-unsaturated carbonyl compound, and it is confirmed that the peak appears when the benzene is decomposed or removed by the electrolysis system according to the present invention .

Referring to FIG. 10, FIG. 10 is a spectrum showing the removal characteristics of toluene according to the present invention. 10 (a) is an FTIR spectrum according to Comparative Example 3, FIG. 10 (b) is an FTIR spectrum according to Example 2, and FIG. 10 (c) is an FTIR spectrum according to Comparative Example 4. The removal characteristics of toluene were confirmed by the presence or absence of -C = O stretching vibration at about 1710 cm ^-1 or by the intensity of this peak. The peak appearing at about 1710 cm ^-1 is due to the keto group of the α, β-unsaturated carbonyl compound, and it is confirmed that the peak appears when the toluene is decomposed or removed by the electrolysis system according to the present invention .

Referring to FIG. 11, FIG. 11 is a spectrum showing the removal characteristics of xylene according to the present invention. 11 (a) is an FTIR spectrum according to Comparative Example 5, FIG. 11 (b) is an FTIR spectrum according to Comparative Example 6, and FIG. 11 (c) is an FTIR spectrum according to Embodiment 3. The removal characteristic of xylene was confirmed by the presence or absence of -C = O stretching vibration at about 1710 cm ^-1 or by the intensity of this peak. The peak appearing at about 1710 cm ^-1 is due to the keto group of the α, β-unsaturated carbonyl compound, and it is confirmed that the peak appears when the xylene is decomposed or removed by the electrolytic system according to the present invention Respectively.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Those skilled in the art will recognize that many modifications and variations are possible in light of the above teachings.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

100: membrane
200: anode portion, 210: positive electrode, 211: positive electrode tab
300: cathode part, 310: cathode, 311: negative electrode tab, 320: cathode chamber (reactor)
410, 420: case, 411, 412: inlet port, 421, 422:
500: Power supply
600: anode tank, 610: anode tank inlet, 620: anode tank outlet
700: cathode tank, 710: cathode tank inlet, 720: cathode tank outlet

Claims (14)

A diaphragm cell including an anode portion, a cathode portion, and a separator separating the anode portion and the cathode portion; A tank for containing the ionic solution; And an electric power supply unit,
a) introducing and dissolving a precursor of an electroactive catalyst comprising a transition metal halide into an ionic solution to produce a solution containing said electroactive catalyst;
b) activating the electroactive catalyst by applying the solution prepared in the step a) to the anode chamber of the anode part and the cathode chamber of the cathode part, respectively, and then applying current by the power supply part; And
c) introducing a non-aqueous aromatic compound into the anode chamber containing the electroactive catalyst of step b), thereby removing the non-aqueous aromatic compound,
Wherein the melting point of the ionic solution is 0 占 폚 or lower. The method according to claim 1,
Wherein the ionic solution has an electric conductivity of 1 x 10 ^-4 to 9 x 10 ^-2 S / cm. The method according to claim 1,
The aromatic compound is treated by an anode half reaction,
Wherein the oxidation potential of the anode half reaction is 0.5 to 3 V. The method according to claim 1,
Wherein the removal temperature of the water-insoluble aromatic compound is 0 to 100 ° C. The method according to claim 1,
Wherein the precursor of the electroactive catalyst is a transition metal halide comprising at least one of cobalt and nickel. The method according to claim 1,
Wherein the ionic solution comprises a pyrrolidinium-based cation. The method according to claim 1,
Wherein the anode portion includes a cathode, an anode chamber, and a cathode tab,
The cathode section includes a cathode, a cathode chamber, and a cathode tab,
Wherein the separation membrane has a plate-like shape including a front surface and a rear surface opposite to the front surface,
Wherein the surface of the separator is opposed to the anode. 8. The method of claim 7,
Wherein the anode is made of platinum, and the cathode is made of silver. The method according to claim 1,
Wherein the activation of the electrocatalyst in step b) is such that the transition metal of the electrocatalyst is oxidized by the anode half reaction or reduced by the cathode half reaction. The method according to claim 1,
Wherein the current density of step (b) ranges from 1 to 100 mA / cm < ² >. The method according to claim 1,
Wherein in step (c), ultrasonic waves are applied to the anode chamber. The method according to claim 1,
Wherein the water-insoluble aromatic compound is an aromatic hydrocarbon containing at least one of benzene, toluene and xylene. The method according to claim 1,
In the step b), ultrasonic waves are applied to the anode chamber,
Wherein the solution obtained in step c) is introduced into the anode chamber of step b). delete

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