JP2000229218A - Treatment of gas by hydrothermal electrolysis and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently decompose various reducing materials by supplying DC current to a reactor filled with a water medium containing a halide ionic material while supplying a gas containing a reducing material under a condition of a temp. equal to or below the critical temp. of the water medium and a pressure necessary for keeping the water medium to a liquid phase. SOLUTION: After the reactor 10 containing the water medium is heated by a heating device 30 to reach a prescribed temp., the gas to be treated which contains the reducing material is introduced from a nozzle 125 while applying current between an anode 22 and the reactor body 12 of the reactor 10 acting as a cathode from a DC power source 24. At this time, the gas to be treated is made bubbles by pressurizing the inside of the reactor and the bubbles are micronized by utilizing the shearing force accompanying the revolution of an impeller 39 driven by a motor 52. The water medium, in which the reducing material and oxygen are dissolved, ascends together with bubbles in a space between an inserting electrode 22 and the inside wall 12s of the reactor and the reducing material dissolved in water is passed through a space between the inserting electrode 22 of the anode and the inside wall 22s of the reactor to be electrolyzed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for treating a gas containing a reducing substance such as an odor and a pollutant by performing a hydrothermal reaction and an electrolysis reaction. In this specification, performing a hydrothermal reaction and electrolysis simultaneously is called hydrothermal electrolysis. As a gas to be treated by the method of the present invention (a gas to be treated), a reducing substance such as a low molecular weight organic substance, a volatile organic halogen compound, ammonia, hydrogen sulfide, and cyan gas is composed of a balance of nitrogen, argon, air, and oxygen. Gas bodies. The present invention uses a reducing substance contained in the gas to be treated as described above, harmless carbon dioxide gas,
The present invention relates to a method and an apparatus for converting nitrogen gas, sulfide ions, chloride ions, and the like.

[0002]

2. Description of the Related Art Conventionally, a gas containing a reducing substance has been treated by gas phase catalytic oxidation, activated carbon adsorption, ultraviolet oxidation or the like. In the gas phase catalytic oxidation method, a gas containing a reducing substance is mixed with an oxidizing agent such as air and brought into contact with the catalyst under the condition of approximately normal pressure and 160 to 300 ° C. to remove malodorous components from carbon dioxide gas and nitrogen. And oxidative decomposition into water, and can treat various malodorous components such as ammonia, low molecular weight amines, mercaptans, and aldehydes. However, in this gas phase catalytic oxidation method, when the gas contains a large amount of reducing substances,
The phenomenon that local high temperature is generated inside the catalyst layer due to self-combustion is often observed. When such a local high temperature is generated, if the non-process gas contains a nitrogen compound (ammonia, amines, or the like), a high-concentration combustion NOx gas is generated. If the gas contains a reducing substance containing sulfur in the molecule, SOx may be generated. Further, when an organic halogen compound is contained in the gas to be treated, halogen acid is generated in the catalyst layer. Once halogen acid is generated, there is a problem that the catalyst is easily poisoned. When dust components such as a phosphorus compound, a sulfur compound, and silica are contained in the gas to be treated in addition to the halogen acid, the catalyst is often poisoned in many cases. Such poisoning is remarkable especially when a noble metal catalyst is used. Even when a reducing substance containing no hetero atom, for example, a low molecular weight hydrocarbon is treated by gas phase catalytic oxidation, incomplete combustion products such as CO gas may be generated depending on the treatment conditions. Strict temperature control of the catalyst layer is required for the complete oxidative decomposition to proceed by the catalytic oxidation method. If the temperature is too high, problems such as catalyst deterioration and NOx generation occur. Conversely, if the temperature is too low, the reducing substance remains in the processing gas without being decomposed. Therefore, depending on the type and concentration of the reducing substance contained in the gas to be treated, it may be very difficult to perform the treatment by catalytic oxidation.

[0003] The activated carbon adsorption method is a method in which a reducing substance is physically or chemically adsorbed and held in pores of activated carbon. Activated carbon adsorption is usually performed at normal temperature and normal pressure. Needless to say, any reducing substance adsorbed on the activated carbon must be disposed of by another method such as a combustion method. If the size of the reducing substance molecule does not match the pore size of the activated carbon, or if the reducing substance does not have a functional group suitable for being adsorbed, the adsorption effect is not exhibited and the gas treatment proceeds smoothly. May not be. Furthermore, if the gas contains moisture, dust, or the like, the adsorption capacity may be significantly reduced. Further, when processing the gas to be treated containing a high-concentration reducing substance, a large amount of activated carbon is required, and there is a problem that the cost of regeneration or treatment of the large amount of activated carbon increases.

The ultraviolet oxidation method is a method of mixing a gas containing a reducing substance with air and irradiating ultraviolet rays to promote a chain reaction of radicals, thereby mineralizing the reducing substance into carbon dioxide gas or the like. When a bond that absorbs a specific ultraviolet wavelength is present in the reducing substance molecule, a radical reaction is likely to be chained, and is efficiently decomposed by ultraviolet oxidation.
Ultraviolet oxidation may be effective, especially when the gas contains components such as trichlorethylene. But,
In this ultraviolet oxidation, since the reaction proceeds by a chain reaction of radicals, it is necessary to contain a relatively high concentration of a reducing substance in the gas to be treated in order to promote the chain reaction. In addition, since the radical reaction is the main decomposition reaction, it is necessary to pay particular attention to dioxin by-products when treating an organic chlorine compound. In addition, even if the target reducing substance is effectively decomposed, the reaction does not always proceed to harmless inorganic components such as carbon dioxide gas, and when a high concentration of carbon monoxide is generated as a by-product. There is also.

As described above, in the prior art, there is still a problem in a method of treating a gas containing various reducing substances.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems and find a method capable of efficiently decomposing a gas containing various reducing substances. The inventors have found that various reducing substances can be efficiently decomposed by treating a gas by a thermoelectrolysis method, and have completed the present invention.

[0007] The present inventors previously conducted a hydrothermal reaction and an electrolysis reaction under a predetermined condition on an aqueous medium containing a reducing substance simultaneously (hydrothermal electrolysis reaction) to obtain hydrogen. They found that reducing substances can be decomposed efficiently while suppressing generation of gas and oxygen gas, and filed a patent application (International Patent Application PCT / JP98 / 0354).
No. 4). The present inventors have found that as a result of further research, this hydrothermal electrolysis reaction method can be applied to the treatment of a gas containing a reducing substance to decompose and remove the reducing substance in the gas, The present invention has been completed.

That is, according to one aspect of the present invention, in a reactor filled with an aqueous medium containing halide ions, the aqueous medium is in a liquid phase at a temperature of 100 ° C. or more and below the critical temperature of the aqueous medium. A method for treating a gas containing a reducing substance by hydrothermal electrolysis, wherein a direct current is supplied into the reactor while supplying a gas containing the reducing substance under a pressure that maintains the pressure. Is provided.

The present invention further provides an apparatus for performing the above method, that is, an apparatus for treating a gas containing a reducing substance by hydrothermal electrolysis, wherein A reactor capable of withstanding the pressure of the hydrothermal reaction, which comprises an inlet for discharging the treated gas and a treated gas outlet for discharging the treated gas, and a pair for performing electrolysis inside the reactor. An electrode is provided.

In the present invention, an aqueous medium containing a halide ion such as a chloride ion and a gas containing a reducing substance are mixed, and an electrolysis reaction is carried out under a predetermined high temperature and high pressure. Oxidatively decomposes toxic substances. In the electrolysis, an oxidation reaction proceeds at an anode, and a halogen-based oxidizing agent such as oxygen gas and hypohalous acid is generated. Further, when an oxidizing agent such as oxygen gas coexists under the high temperature and high pressure of the hydrothermal reaction, the oxidation reaction easily proceeds in the first place. And
In the present invention, by simultaneously performing the hydrothermal reaction and the electrolysis, it is possible to effectively oxidatively decompose a reducing substance such as an organic substance or ammonia.

The electrode reactions that can proceed in the hydrothermal electrolysis of the present invention are described below. At the anode, the following reaction (1),
It is thought that (2) and (3) proceed.

[0012]

Embedded image

(Wherein, X is a chlorine atom, a bromine atom, an iodine atom or any combination thereof.)

[0014]

Embedded image

[0015]

Embedded image

In the formula (1), halide ions are oxidized to generate halogen molecules. For example, when X is a chlorine atom, chlorine gas is generated. In the equation (2), water is electrolyzed to generate oxygen gas. In equation (3),
Organic matter is oxidized directly at the anode. The reaction of the formula (1) and the reaction of the formula (2) compete with each other, and which reaction proceeds favorably depends on the type of the anode, the halide ion concentration in the aqueous medium, and the like. In the case where a chlorine generating electrode is used, when the halide ion concentration is equal to or higher than a predetermined concentration, the reaction of the formula (1) proceeds preferentially.

According to the formula (1), the halogen molecules generated at the interface between the anode and the electrolyte react with water in the vicinity thereof to generate hypohalous acid and hydrogen halide.

[0018]

Embedded image

(In the formula, X has the above-mentioned meaning.) Then, hypohalous acid is an excellent oxidizing agent and can oxidatively decompose a reducing substance contained in the gas to be treated. For example, when the reducing substance is an organic substance, it is considered that the organic substance is oxidized by the following reaction.

[0020]

Embedded image

(In the formula, X has the above-mentioned meaning.) When the reducing substance is ammonia, it is considered that ammonia is oxidized by the following reaction.

[0022]

Embedded image

Hypohalous acid is particularly excellent as an oxidizing agent in an acidic solution. In the vicinity of the anode where hypohalous acid is generated, the following formulas (2), (3) and (4) are used. Since hydrogen ions are generated, they tend to be acidic. Therefore, it appears that hypohalous acid is particularly likely to act as an oxidizing agent near the anode.

When X is a chlorine atom, the oxidation reaction with hypohalous acid seems to be particularly involved in the decomposition of the reducing substance. On the other hand, when X is a bromine atom or an iodine atom, the halogenate ion may be involved in the decomposition of the reducing substance. Hypohalite ions disproportionate in a basic solution to produce halide ions and halide ions.

[0025]

Embedded image

For example, when hypohalous acid moves to the vicinity of the cathode by diffusion or the like, it is considered that the reaction of the formula (7) may occur. This is because, in the vicinity of the cathode, hydroxide ions are generated by the cathodic reaction, so that the hydroxide easily becomes basic. The rate of the disproportionation reaction of the formula (7) is chlorine,
The order of bromine and iodine increases, and halogenate ions can be obtained quantitatively with bromine and iodine (FA Cotton, G. Wilkinson, PL Gauss, "Basic Inorganic Chemistry" Baifukan, 1991) , 2nd edition, 379
page). Halogen acids are strong acids and powerful oxidants.

In the formula (2), oxygen gas is generated by electrolysis of water. Here, it is considered that oxygen atoms are first generated at the interface between the anode and the electrolyte. Such an oxygen atom has higher activity as an oxidizing agent than an oxygen molecule, and can oxidize a reducing substance efficiently. In addition, even when oxygen molecules are generated, by hydrothermal oxidation reaction,
Reducing substances can be oxidized.

When the reducing substance is an organic substance, the oxidation reaction with oxygen proceeds according to the following equation.

[0029]

Embedded image

Further, as shown in the formula (3), reducing substances such as organic substances and ammonia are directly
May be oxidized at the anode. For example, when the reducing substance is ammonia, the reaction of the following formula can proceed.

[0031]

Embedded image

Thus, in the hydrothermal electrolysis of the present invention,
There are many reaction mechanisms at or near the anode where the reducing substance is efficiently oxidatively decomposed. On the other hand, the following reactions can be considered as possible reactions at the cathode.

Water generates hydrogen at the cathode by electrolysis.

[0034]

Embedded image

By using the reactor as a cathode, so-called cathodic protection can be achieved. It is further believed that the reaction in which the oxidant is reduced at the cathode may also proceed. Here, the oxidizing agent includes an oxidizing agent such as hypohalous acid generated at the anode and, if necessary, an oxidizing agent input from the outside. An example of the reaction is represented by the following formula (11):
(12) and (13).

The hypohalous acid is reduced at the cathode.

[0037]

Embedded image

Further, oxygen dissolved in the aqueous medium (in the following formula, represented by O _{2 (aq.)) Is} also reduced.

[0039]

Embedded image

If hydrogen peroxide is present, it is reduced at the cathode.

[0041]

Embedded image

At the cathode, the formula (1) in which the oxidant is reduced
The reactions of 1), (12) and (13) compete with the reaction for generating hydrogen of formula (10). According to our experiments,
In the hydrothermal electrolysis, the reactions represented by the formulas (11), (12), and (13) in which the oxidizing agent is reduced proceed preferentially over the reaction that generates hydrogen. Along with this, in the hydrothermal electrolysis, the generation of hydrogen is suppressed, the possibility that oxygen gas and hydrogen gas coexist in the reactor at the same time is reduced, and the danger of explosion is reduced. Further, since the oxidizing agent such as hypohalous acid is decomposed at the cathode, a secondary treatment for detoxifying the oxidizing agent in the discharged water becomes unnecessary. For example, in electrolysis at room temperature, hypohalite ions are generated at a high concentration. On the other hand, in the electrolysis at a high temperature, generation of hypohalite ions was hardly detected.

Regardless of the reaction mechanism, according to the present invention, reducing substances such as organic substances and ammonia are oxidatively decomposed, and the generation of hydrogen gas or oxygen gas can be suppressed. Reducing substances that can be decomposed by the present invention include methane, ethane, propane, butane, methyl mercaptan, low molecular weight organic substances such as acetaldehyde, trichloroethane, trichloroethylene, chloroform, volatile organic halogen compounds such as various fluorocarbons, Ammonia, hydrogen sulfide, cyan gas and the like can be mentioned.

In the present invention, it is considered that the reducing substance in the gas to be treated is basically dissolved in the aqueous medium and then electrolyzed in the aqueous medium. In the present invention, 10
At a temperature between 0 ° C. and the critical temperature of the aqueous medium, the hydrothermal reaction is performed under a pressure at which the aqueous medium maintains a liquid phase. 1
If the temperature is lower than 00 ° C., the rate of the hydrothermal reaction decreases, and the reaction time becomes longer. On the other hand, at temperatures higher than the critical temperature, the physical properties of the aqueous medium change significantly,
Naturally, the knowledge of the present invention cannot be applied, and a separate experiment is required. For example, in the supercritical state, the solubility of halide ions and the like as the electrolyte is significantly reduced, and the electric conductivity is reduced.

In the present invention, the hydrothermal electrolysis reaction temperature is 1
The temperature is preferably from 20 ° C to 370 ° C,
More preferably, the temperature is 140 ° C. or more and 370 ° C. or less.

In the present invention, the aqueous medium preferably contains a halide ion. The halide ions act as a catalyst in the hydrothermal electrolysis reaction, and the decomposition reaction proceeds more effectively. Note that the same catalytic effect can be obtained when a halogenated organic substance is contained in the gas to be treated.

Examples of such a halide ion include chloride ion (Cl ⁻ , bromide ion (Br ⁻ ), iodide ion (I ⁻ ), and any combination thereof. Chloride ion or bromide ion is preferred. Particularly preferred are ions, which may be dissolved in an aqueous medium, and salts which form halide ions, and acids such as hydrogen chloride (HCl), hydrogen bromide (HBr), and hydrogen iodide (HI). May be included.

The salt for generating a halide ion may be an inorganic salt or an organic salt. For example, hydrogen chloride (HCl), hydrogen bromide (HBr), hydrogen iodide (H
A salt comprising an acid such as I) and a base is preferably used. Examples of the inorganic salt include alkali metal halides such as sodium chloride and potassium chloride; alkaline earth metal halides such as calcium chloride; ammonium halides such as ammonium chloride; tris (ethylenediamine)
Complex salts such as cobalt (III) chloride and tris (2,2′-bipyridine) iron (II) bromide are exemplified. Also,
The organic salt may be a tetraalkylammonium halide such as tetraethylammonium chloride.
Further, addition salts of amines and hydrogen halide (for example,
An addition salt such as aniline / hydrogen chloride) may be used. In addition, the exhaust gas from the groundwater treatment equipment or the like often contains an organic halide such as trichloroethylene.

Preferably, the aqueous medium contains not less than 0.05 mmol / l of halide ions,
More preferably, it contains 0.5 mmol / l or more of halide ions, and even more preferably, 5 mmol / l or more of halide ions. This is because, by the electrolysis of the aqueous medium, the halide ions generate hypohalous acid and oxidize the reducing substance in the aqueous medium.

The aqueous medium preferably contains not less than 0.05 mmol / l of chloride ion (Cl ⁻ ), more preferably not less than 0.5 mmol / l of chloride ion. It is even more preferred to contain more than mmol / l of chloride ions.

Further, when an oxidizing agent is included in the reaction system, active oxygen and the like are generated even at the cathode, and the decomposition reaction proceeds more quickly, which is more preferable. As the oxidant source, oxygen contained in the gas to be treated can be used,
In the case of a shortage, the generation of hydrogen is suppressed by adding an oxidizing agent from the outside, and the formation of an explosive mixed gas is avoided. As the oxidizing agent that can be added from the outside for such a purpose, oxygen gas, ozone gas, hydrogen peroxide, and hypohalous acid are preferable, and oxygen gas is more preferable. As the oxygen gas, a gas containing an oxygen gas may be used. For example, air is preferably used.

In the case where the oxidizing agent is added from the outside in the present invention, the amount of the oxidizing agent to be added is set to a value which is equal to the amount required to completely oxidize the reducing substance contained in the gas to be treated.
It is preferably in the range of a chemical equivalent of 01 to 100 times. When the added amount of the oxidizing agent is less than 0.01 chemical equivalent, it is necessary to generate all the oxidizing agent electrically, which is not preferable because the electricity cost is large. On the other hand, when the added amount of the oxidizing agent is more than 100 equivalents, useless energy is consumed to pressurize the oxidizing agent more than necessary, which is not preferable.

When the gas to be treated is acidic, an alkali is added to the aqueous medium,
The reducing substance can be dissolved by the aqueous medium in the reaction chamber, and the reducing substance is effectively decomposed by hydrothermal electrolysis. Conversely, when the gas to be treated is basic, the reducing substance can be dissolved in the aqueous medium by adding an acid to the aqueous medium, and the reducing substance is effectively hydrothermally electrolyzed. Decomposed. In this specification, the term “acid” or “basic” refers to the term “acid” or “basic”. These are referred to as "acidic" gases.

Further, when the reducing substance in the liquid medium is concentrated and transferred to a gas by a method such as aeration, distillation, or stripping, the reducing substance can be treated by the present method even if it is not contained in the gas in advance. Thereby, the liquid medium containing the reducing substance can be treated using the method according to the present invention. Since the specific heat of a gas is much lower than the specific heat of water, heating a gas to hydrothermal reaction conditions is usually more energetically advantageous than heating a liquid. Therefore, rather than treating a liquid medium containing a reducing substance by hydrothermal electrolysis as it is, if the reducing substance is once transferred to a gas by the above-described method and then treated by hydrothermal electrolysis, the cost is reduced. May be advantageous in some cases. This is particularly the case for low molecular weight reducing substances and volatile reducing substances, for example, when the substance can be easily transferred from the aqueous solution to the gas phase. In the case of a reducing substance that cannot be easily transferred to the gas phase, such as a high molecular weight substance, enormous energy is required to transfer to the gas phase.

According to a second aspect of the present invention, there is provided an apparatus for smoothly performing a method for treating gas by hydrothermal electrolysis.

[0056]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The hydrothermal electrolysis reaction of the present invention will be described with reference to FIG. FIG. 1 is a schematic diagram of a hydrothermal electrolysis reaction apparatus for performing a hydrothermal electrolysis reaction according to the present invention.

The hydrothermal electrolysis reactor has a reactor 10 capable of withstanding the pressure of the hydrothermal reaction.
Has a body 12 and a lid 14 that can hold an aqueous medium 47. A flange 13 is provided on an upper portion of the main body 12. The flange 13 of the main body 12 and the end of the lid 14 can be fixed by fasteners not shown, for example, bolts and nuts. As the reactor 10, for example, an autoclave can be used. Reactor 10
Can withstand the pressure of the hydrothermal reaction and form a closed space.

The inside of the reactor 10 is provided with a pair of electrodes for electrolysis. Main body 1 of reactor 10
2 has a metal inner wall 12s, which can act as a cathode. For example, as shown in FIG.
The entire body 12 may be made of metal. In this case,
Corrosion of the inner wall 12s of the main body 12 can be prevented.
When a cathode is provided separately from the main body 12, the inner wall 12s of the main body 12 is susceptible to corrosion by halide ions, for example, chloride ions under high temperature and high pressure of hydrothermal reaction.

As the main body 12, for example, Hastelloy,
Nickel-based alloys such as Inconel and Incoloy; titanium-based alloys; steels such as carbon steel and stainless steel can be used. However, the inner wall 12s of the main body 12 may be coated with a coating layer made of a metal such as platinum, and the coating layer may function as a cathode.

Further, an anode 22 is provided inside the main body 12 of the reactor 10. The shape of the anode, in principle,
No restrictions. In the present invention, the distance between the anode and the cathode is preferably equal. This is because, if the distance varies, an excessively large current flows locally in a portion where the distance is short, and deterioration of the anode in that portion is promoted. In the present invention, it is preferable that the inner wall 12s of the main body 12 has a cylindrical shape. Further, it is preferable that the outer surface 22 s of the anode 22 also has a cylindrical shape, and the central axis of the anode 22 substantially coincides with the central axis of the inner wall 12 of the main body 12.

The anode 22 may have a mesh or net formed in a cylindrical shape, or may have a plate formed in a cylindrical shape. It is preferable that the electrode capable of acting as an anode has a surface, and this surface contains ruthenium, iridium, platinum, palladium, rhodium, tin, or an oxide or ferrite thereof. For example, the electrodes themselves may be made of these substances. Alternatively, the surface of the electrode substrate may be coated with these substances.

Ruthenium, iridium, platinum, palladium, rhodium and tin may be metal elements themselves or oxides. Also, alloys of these metals are suitably used. Examples of the alloy include platinum-iridium, ruthenium-tin, ruthenium-titanium and the like. The above metals and the like are excellent in corrosion resistance,
When used as an anode, it exhibits excellent insolubility and has a high generation efficiency of halogen molecules such as chlorine gas. As the electrode for generating chlorine, an electrode mainly composed of palladium, ruthenium, or an alloy of platinum and iridium is particularly preferable.

The positive terminal 26 and the negative terminal 27 of the DC power source 24 are connected to the anode 2 via lines 28 and 29, respectively.
2 and the cathode 12s. A line 28 for supplying electricity to the anode passes through the reactor 10, and the line 28 is insulated from the reactor 10 by the insulating member 16. Body 12
And if the lid 14 is made of metal, the line 29 is
2 or lid 14 only needs to be connected. Note that, as a DC power supply, for example, a full-wave rectifier including a diode, a capacitor, a resistor, and the like may be used to convert an AC current into a DC current.

Inside the reactor 10, preferably at the bottom,
A mixing nozzle 125 is arranged through which the gas to be treated and (in a preferred embodiment) oxidant air are introduced into the reactor.

The reactor 10 is heated by the heating device 30. The heating device may be, for example, an electric heater. Further, a bath of silicone oil or the like may be used. When the reactor is a tower, the outside of the reactor may be heated by a burner or the like.

The hydrothermal electrolyzer preferably has a thermocouple 32 for measuring the temperature of the aqueous medium 47. As the thermocouple, for example, a chromel-alumel alloy or a platinum alloy can be used. In FIG. 1, an insulating member 18 is provided on the lid 14 of the reactor 10, and a thermocouple 32 penetrates the insulating member 18. Note that the thermocouple 32 may directly penetrate the lid 14 without providing the insulating member 18.
Further, a temperature control mechanism for controlling the heating device 32 based on the value of the thermocouple 32 may be provided.

The aqueous medium 47 is preferably stirred by a stirring device, for example, an impeller 39. Impeller 39
May have, for example, a rotation axis coinciding with the central axis of the reactor 10.

The hydrothermal electrolysis reactor 10 has a discharge line for the treated gas. The discharge line has a lid 14
The inside of the reactor 10 is communicated with the through hole 14a formed in the reactor 10.

Next, a hydrothermal electrolysis method using the hydrothermal electrolysis apparatus shown in FIG. 1 will be described. Reactor 10 containing aqueous medium
Is heated to a predetermined temperature by the heating device 30. At this time, it is preferable to monitor the internal temperature of the reactor 10 using the thermocouple 32. After reaching a predetermined temperature, the DC power supply 24 causes the reactor 1 to act as the anode 22 and the cathode.
Through the nozzle 125 while energizing the main body 12
A gas to be treated containing a reducing substance is introduced. At this time, the inside of the reactor 10 is maintained in a pressurized state. Further, it is preferable to introduce oxidant air together with the gas to be treated.

Since the inside of the reactor 10 is kept in a pressurized state, the gas to be treated and the air discharged from the nozzle 125 are fine bubbles of several millimeters to several tens of micrometers. Is further refined and mixed and stirred by the shearing force of The shape of the impeller may be a centrifugal pump. It is preferable that the rotation speed of the impeller is set in a range of 50 rpm to 10,000 rpm. If the rotation speed is 50 rpm or less, the fineness of the bubbles and the mixing of gas and air do not proceed smoothly. On the other hand, if the rotation speed is 10,000 rpm or more, problems such as generation of vortex, abrasion of the rotating part, frictional heat of the bearing, and the like occur, and the hardware becomes unreasonable. In the present invention, the impeller may be rotated by a direct drive for the rotation of the impeller. However, considering the sealing problem of high temperature and high pressure, as shown in FIG.
The magnet drive system driven by 2 is more preferable. This impeller also has a function of pushing out gas between the insertion electrode 22 and the reactor by centrifugal force, in addition to miniaturization of bubbles and mixing and stirring. From the micronized gas bubbles,
The reducing substance contained in the gas is easily transferred to the aqueous medium, and the solubility of malodorous components and the like is increased. When the gas is acidic, the reducing substance such as the malodorous component is further dissolved in the aqueous medium by keeping the pH of the aqueous medium alkaline. Conversely, when the gas is alkaline, it is preferable to make the aqueous medium acidic. By making air bubbles finer, oxygen is easily dissolved in the aqueous medium. The aqueous medium in which these reducing substances and oxygen are dissolved rises between the insertion electrode 22 and the inner wall 12s of the reactor together with the bubbles. The reducing substance dissolved in water passes between the insertion electrode 22 as the anode and the inner wall 22s of the reactor as the cathode, and is electrolyzed. At the anode, halide ions and the like are electrochemically generated in a nascent state, and mineralize the reducing substance dissolved in the aqueous medium. On the other hand, on the cathode side, dissolved oxygen is converted into active oxygen or the like, and this active oxygen mineralizes the reducing substance. Even if the reducing substances are not completely dissolved in the aqueous medium, some of the reducing substances in the bubbles react directly with these electrically generated oxidizing agents, and oxidative decomposition proceeds in the bubbles. It is possible. In any case, the finer the bubbles, the more effectively the decomposition reaction proceeds.

The treated gas is supplied to the outlet 14 together with air.
is discharged through a. The DC power supply 24 preferably has a constant current rather than a constant voltage. As the electrolysis of the aqueous medium proceeds, the resistance of the aqueous medium changes due to various factors. This is because the control of the amount of generated gas and the like is easier when the current is constant. Also, by monitoring the voltage required to supply a constant current, it is possible to grasp the adhesion of the scale inside the reactor.

In the method of the present invention, the current density at the anode is
It is preferably from 0.1 mA / dm ^{2 to} 500 A / dm ² . If the current density is higher than 500 A / dm ² ,
The surface of the anode may peel off or elute easily.
On the other hand, if the current density is lower than 0.1 mA / dm ² , it is necessary to increase the area of the anode, and the device becomes larger. The current density is 10 mA / dm ^{2 to} 100 A / dm ²
And more preferably 100 mA / dm ² to 50
Even more preferably, it is A / dm ² . When a new material for the anode is developed, the current density of the anode can be further increased.

Next, a method for performing the hydrothermal electrolysis of the present invention under automatic control will be described. FIG. 2 shows an apparatus capable of performing the hydrothermal electrolysis of the present invention under automatic control.
The apparatus shown in FIG. 2 is particularly effective when the amount of gas to be treated is small. As a guide for effective throughput, 5
It is 0 L / min or less. As described below, in the present invention, 50 L / m
If it is not less than in, it is preferable to use the apparatus of the form shown in FIG.

In the present invention, the aqueous medium serving as the reaction medium is adjusted in advance in the adjusting tank 167. Adjustment tank 1
Water, an added halide, or an acid or alkali for adjusting pH, which is used as necessary, are introduced into the line 67 through lines 160, 161, and 162. The water quality of the aqueous medium is not particularly limited, and city water, industrial water, hydrothermal electrolyzed water, or the like may be used. Preferably, the aqueous medium is first adjusted so that the halogen ion concentration is in the range of 5 mg / L to 20 wt%. Furthermore, the properties of the gas to be treated should be grasped in advance, and p
It is preferable that the H adjustment be performed in the tank 167. When the gas to be treated is an acidic gas, it is preferable to adjust the pH of the aqueous medium in the adjusting tank 167 to a range of 7.5 to 13 by adding an alkali.
When the gas to be treated is alkaline, it is preferable to adjust the pH of the aqueous medium in the adjustment tank 167 to a range of 1 to 6.5 by adding an acid. The adjusted aqueous medium is sucked into the high-pressure pump 171 via the channel 170. The aqueous medium is pressurized by the high-pressure pump 171 to a pressure approximately 3 MPa higher than the reaction pressure. This pressure adjustment is performed by the pressure regulator 176. That is, when the pressure becomes equal to or higher than the reaction pressure +3 MPa due to the pressurization of the high-pressure pump 171, the valve 178 shifts to the opening direction, and acts to reduce the pressure. In this way, the pressure on the discharge side of the pump is always kept constant. Since the high-pressure pump 171 pressurizes the liquid, by providing an accumulator 174 filled with a gas, it is possible to absorb the pressure fluctuation of the pump, and the valve 178 enables smooth pressure control. The reason why the discharge side of the pump needs to be kept at a constant pressure is that the flow controller 180 operates smoothly. In the present invention, as the sensor of the flow controller, any one of an orifice type and a heat conduction type used in a mass flow controller can be used. If not maintained, incorrect values may be shown. The flow controller 180 operates the flow control valve 181 to flow the aqueous medium through the flow path 182 at a predetermined flow rate. Note that the pressure in the flow path 182 is a reaction pressure. The aqueous medium is inserted at the top of the reactor,
It is mixed with the aqueous medium in the reactor.

On the other hand, the gas containing the reducing substance is
00 to the present invention. The gas is pressurized to a pressure higher than the reaction pressure in the compressor 103 and temporarily stored in the accumulator 105. The accumulator 105 is equipped with a pressure sensor, and it is preferable to control the compressor 103 to operate when the pressure in the accumulator becomes equal to or less than the reaction pressure +1 Mpa, and to stop when the pressure in the accumulator becomes the reaction pressure +3 Mpa. It is preferable to automatically control the pressure of the accumulator 105 so that it is always in the range of the reaction pressure + 1 MPa to the reaction pressure + 3 MPa. The gas is further supplied to the valve 1 through the flow path 107.
At 08, the pressure is reduced to about 0.5 Mpa as the reaction pressure. This pressure reducing valve 108 is a secondary pressure adjusting valve.
The secondary pressure adjusting valve may be a spring type or an air operation control valve type provided with a pressure sensor 110 as shown in FIG. Either way, the valve 112
It is preferable that the primary side is always at a constant pressure. A predetermined amount of gas maintained at a constant pressure in the flow path 109 is inserted into the flow reactor by operating the flow control valve 112. The sensor of the flow controller 111 may be an orifice type or a mass flow controller. In the present invention, the flow control method is not particularly limited, but it is preferable to perform control so that a constant predetermined flow is inserted into the reactor. If not inserted into the reactor at a constant flow rate, the amount of reductant inserted into the reactor fluctuates and unresolved reductant may be discharged from the reactor. The gas flowing through the flow control valve is the heat exchanger 1
Preheated at 14 and inserted into mixing nozzle 125.

In the mixing nozzle 125, the air is mixed with air containing an oxidizing agent and inserted into the reactor 40. Air used as an oxidant is taken in from the channel 130. Then, it is pressurized by the compressor 131 to a pressure approximately 3 MPa higher than the reaction pressure. The pressurized air is temporarily stored in an accumulator 133 equipped with a pressure controller 134. The accumulator 133 is equipped with a pressure sensor, and when the pressure in the accumulator becomes about reaction pressure +1 Mpa or less,
It is preferable to control the compressor 131 to operate and stop when the reaction pressure reaches +3 MPa. It is preferable that the pressure of the accumulator 133 is always automatically controlled so as to be in the range of the reaction pressure +1 MPa to the reaction pressure +3 MPa. The pressurized air is further reduced in the valve 135 to a reaction pressure of about +0.5 Mpa. The pressure reducing valve 135 is a secondary pressure adjusting valve. The secondary pressure adjusting valve may be a spring type or an air operation control valve type provided with a pressure sensor 137 as shown in FIG. In any case, it is preferable that the primary side of the valve 139 is always kept at a constant pressure. Channel 135
The gas maintained at a constant pressure is inserted into the predetermined flow rate reactor by the operation of the flow rate control valve 139. The sensor of the flow controller 138 may be an orifice type or a mass flow controller. In the present invention, the flow control method is not particularly limited, but it is preferable to perform control such that a constant predetermined air flow is inserted into the reactor. If it is not inserted into the reactor at a certain flow rate,
In some cases, the oxidizing agent may be insufficient, and unresolved reducing substances may be discharged from the reactor. Further, when the oxidizing agent is insufficient in the hydrothermal electrolysis reactor, generation of hydrogen is activated from the inner wall of the reactor body serving as a cathode, which may cause a problem of formation of explosive gas. Thus, it is important to insert a controlled flow rate of the oxidant air into the reactor. In order to measure this flow rate, it is important to always keep the pressure in the flow path 136 in which the flow controller 138 is installed constant. The gas flowing through the flow control valve is preheated by the heat exchanger 141 and inserted into the mixing nozzle 125.

The flow and reaction of gas, air and aqueous medium in the hydrothermal electrolysis reactor are the same as those described above with reference to FIG. In the apparatus of the embodiment shown in FIG. 2, if the gas flow rate is 50 NL / min or more, the porosity between the electrodes increases, and as a result, the electrical resistance between the electrodes increases, and a predetermined current is applied. However, there is a problem that the voltage is significantly increased. Therefore, in the apparatus of the embodiment shown in FIG. 2, the flow rate of the gas to be processed is 50 NL / min.
It is economical if: The aqueous medium is a reaction medium,
Since the halide ions act as a catalyst, the substantial consumption of the aqueous medium is very low. Either way, water and carbon dioxide gas are generated by the oxidation reaction of the reducing substance, so that water tends to increase in the reactor. In addition, since the pH of the aqueous medium changes as the reducing substance is dissolved or the electrolytic reaction progresses, a small amount is extracted,
Preferably, a fresh aqueous medium is supplied to the reactor. The extraction of the aqueous medium is performed from a flow path 241 provided at the lower part of the reactor. The flow rate of this extraction is performed by the liquid level control 216.
That is, when the liquid level in the reactor rises, the liquid level controller operates in a direction to open the valve 243 and draws an appropriate amount of the aqueous medium from the reactor. Note that if a high-temperature aqueous medium directly contacts the valve 243, there is a problem of heat resistance of the seal portion of the valve, and leakage may occur. Therefore, the cooler 242 shown in FIG. preferable.
In addition, since the flow rate withdrawn is small, air cooling of the cooler 242 is sufficient. The aqueous medium to be replenished is inserted into the upper part of the reactor and mixes with the insertion electrode and the aqueous medium that has risen up the reactor wall and travels downstream through the inside 41 of the insertion electrode. For this reason, the shape of the insertion electrode is preferably cylindrical. Therefore,
As a flow of the aqueous medium in the reactor, a flow is formed that rises outside the electrode and sinks inside the electrode. It is also effective to attach a wing to the stirring rod 41 to further activate this flow. It is also effective to devise the impeller 39 to accelerate the sedimentation velocity in the electrode.

The treated gas is supplied to the flow path 220 together with air.
Taken out of Since the processing gas has a high temperature, it is cooled by the heat exchangers 114 and 141. The cooled processing gas is then inserted into the gas-liquid separator through the pressure reducing valve 224. The reaction pressure is up to the primary side of the pressure reducing valve 224. The pressure reducing valve 224 is a pressure controller 223
Is controlled by A pressure controller 223 determines the reaction pressure. Usually, 0.01 to 5 Mp from the saturated vapor pressure at the reaction temperature.
It is preferable to set the pressure controller 223 at a higher pressure value. When the pressure is 0.01 MPa or less, when a small pressure fluctuation occurs in the reaction system, the aqueous medium in the reactor 40 evaporates, a large amount of steam enters the flow path 220, and a phenomenon such as cooking from the reactor occurs. When the cooking phenomenon occurs, the attachment of reducing substances, the attachment of salts, the occurrence of scaling, etc., occur in the reactor, electrodes, etc., thereby hindering stable continuous operation. In addition, if the operation is performed at 5 MPa or more than the saturated vapor pressure, a device design for maintaining the pressure more than necessary is required, and there is a problem that the cost of manufacturing the device is increased.

The gas inserted into the gas-liquid separator passes through the demister and is discharged to the atmosphere via the pressure control valve 231. Since the processing gas discharged from the flow path 220 contains a small amount of water vapor that becomes parallel to the reaction temperature, it is preferable that the processing gas pass through a demister to reduce moisture. In addition, it is preferable that the pressure of the gas-liquid separator is adjusted to a range higher than the normal pressure by 0.001 MPa to 1 MPa by using the pressure regulator 230. Extraction of the condensed water or the aqueous medium extracted from the flow path 241 from the gas-liquid separation is performed by liquid level control, and is extracted from the valve 228. Since the valve 228 causes some pressure loss, it is possible to smoothly extract the aqueous medium if the gas-liquid separator is slightly pressurized. The processing gas passing through the valve 231 is supplied to the oxygen concentration controller 232.
, The oxygen concentration is read, and the set value of the air flow controller 138 is controlled. Here, the oxygen concentration controller has an oxygen concentration of 0.
It is preferable to set so as to be 01 vol% or more. When the oxygen concentration in the processing gas is low, the generation of hydrogen in the hydrothermal electrolysis reactor is significantly increased. That is, the hydrothermal electrolysis reaction promotes the oxidative decomposition reaction using oxygen atoms of water when the oxidizing agent inserted from the outside is not substantially present. Therefore, excess hydrogen atoms in water are generated as hydrogen gas. In order to suppress the generation of hydrogen gas, it is necessary to sufficiently supply oxygen to the hydrothermal electrolysis reaction field. Since it is difficult to measure the oxygen concentration of the hydrothermal electrolysis reactor at high temperature and high pressure, the oxygen concentration of the decompressed and cooled treated gas is monitored as in the present invention, and the hydrothermal electrolysis is performed. It is useful to determine the amount of oxidant to supply to the reactor. Needless to say, when an oxidizing agent such as oxygen is already contained in the gas to oxidatively decompose the reducing substance, the air flow controller 138 automatically moves in the direction of blocking the injection of air. Move.

As described above, in the present invention, a gas containing a reducing substance is stably and continuously processed by a device utilizing a high degree of automation. Another embodiment of the present invention will be described with reference to FIG. The apparatus shown in FIG. 3 is particularly effective when the amount of gas to be treated is large. As a guide, it is particularly effective when processing a gas flow rate of 50 L / min or more.

The press-in mechanism and control of the aqueous medium, air and gas are the same as in the embodiment of FIG. The differences are the mechanism for heating the gas and air to be injected and the mechanism in the hydrothermal electrolysis reactor. That is, when treating a large amount of gas, the heat exchanger alone is not sufficient to heat the gas and air. In particular, if only the reactor heater 206 is used during startup, it takes a long time to reach the reaction temperature. Therefore, in the apparatus of the embodiment shown in FIG.
After passing through the heat exchangers 114 and 141 and being heated, respectively, they are heated by the heating devices 117 and 143. In addition, between the heating devices, it is preferable to increase the heating efficiency by forming the pipes into coils (115, 142). It is desirable to control the heating by measuring the temperature in the heating device and the temperature of the unheated body at the heating device outlet by the temperature sensors 120/121 and 147/148. The gas to be treated and the oxidizing air are desirably heated to a predetermined reaction temperature in a hydrothermal electrolysis reactor. In the present invention, the heating device is not limited to the electric heater system, and an existing fluid heating system such as an oil burner heating system or a heating medium heating system may be used.

Next, the behavior of the aqueous medium, gas, and air in the reactor and the progress of the decomposition reaction step will be described. First, the gas and the air are inserted into the reactor 202 through the mixing nozzle 125 in a heated state. Although the shape of the mixing nozzle is not particularly limited in the present invention, a shape that promotes a mixed state of air and gas as much as possible and generates fine bubbles is preferable. The gas and air bubbles inserted from the nozzle 125 rise in the aqueous medium 47 inside the reactor 202 through the inside of the insertion electrode 204 by buoyancy.
In this embodiment, the insertion electrode 204 has a cylindrical shape. During this ascent process, the reducing substance contained in the gas is absorbed from the gas into the aqueous medium. As an absorption mechanism of the aqueous medium, an increase in the solubility of the reducing substance in a hydrothermal atmosphere can be cited. The dielectric constant of high-temperature high-pressure water decreases with increasing temperature. That is, even a substance having low solubility in water at normal temperature and normal pressure partially dissolves. In addition, if the gas is acidic, the absorption will be further increased if the aqueous medium is made basic. Conversely, if the gas is basic, the absorption will be increased if the aqueous medium is acidified. Thus, in the reactor shown in FIG. 3, it is an important step to transfer the reducing substance contained in the gas to the aqueous medium. Further, in order to increase the absorption, it is effective to insert a filler 205 of an insulating material inside the cylindrical insertion electrode 204 in order to promote the contact between gas and air and the aqueous medium. As the filler of the insulating substance, ceramic materials (silica, silica alumina, zirconia, alumina, single crystal alumina, titania) and the like can be used. As the shape, a shape such as a sphere, a cylinder, and a lash ring can be used. Thereby, the contact efficiency between the aqueous medium and the gas or air is improved, and the dissolving of the reducing substance in the gas or air into the aqueous medium is enhanced. The reducing substance in the gas absorbed in the aqueous medium rises inside the insertion electrode, and then sinks outside the insertion electrode by the flow of the aqueous medium. Part of the gas and air from which the reducing substance has been removed rises directly by buoyancy and is discharged from the reactor via the flow path 220. On the other hand, the reducing substances contained in the aqueous medium are mineralized into harmless components by hydrothermal electrolytic oxidation that proceeds between the inner wall of the reactor 202, which is a cathode, and the insertion electrode 204 during the sedimentation process. Is done. In the reaction field where the electrochemical reaction proceeds, basically no bubbles are present, and the voltage applied between the electrodes can be kept low.

Further, in the present invention, a strong acid ion can be used instead of or in combination with the halide ion contained in the aqueous medium. That is, in another embodiment of the present invention, in a reactor filled with an aqueous medium containing strong acid ions, the pressure at which the aqueous medium maintains a liquid phase at a temperature equal to or higher than 100 ° C. and equal to or lower than the critical temperature of the aqueous medium. A method for treating a gas containing a reducing substance by hydrothermal electrolysis, wherein a direct current is supplied into the reactor while supplying a gas containing the reducing substance. .

The strong acid ions used for this purpose are 25
It is preferably an ion corresponding to a strong acid having a dissociation constant (pK) at 3.5 ° C. of 3.5 or less, and more preferably an ion corresponding to a strong acid having a dissociation constant at 25 ° C. of 2.5 or less. It is also preferred that the acid corresponding to the strong acid ion is protic.

The strong acid ion may be an inorganic acid ion or an organic acid ion. However, the strong acid is preferably an inorganic acid ion. Organic acid ions are
This is because, as the hydrothermal electrolysis proceeds, it may be decomposed.

Examples of the strong inorganic acid ions include halide ions, sulfate ions (SO ₄ ^{2 −} ), nitrate ions (NO ₃ ⁻ ), and phosphate ions (PO ₄ ³⁻ ).
Examples of the organic strong acid ion include trifluoroacetate ion (CF ₃ COO ⁻ ).

The strong acid ion may be present as an acid or as a salt. In the case of a salt, a salt may be formed together with an inorganic cation such as an alkali metal ion or an alkaline earth metal ion, or an organic cation.

[0088]

EXAMPLE 1 A mixed gas of 50 ppm of hydrogen sulfide and 50 ppm of methyl mercaptan (nitrogen balance) was treated in the hydrothermal electrolysis reactor shown in FIG. The flow rate of the mixed gas is 0.5 L / min, and the flow rate of the oxidant air is also 0.5 L / min.
/ Min. 0.5 wt% NaC as aqueous medium
1 aqueous solution was used. The pH of the aqueous medium was adjusted to pH 10 by adding NaOH. The amount of aqueous medium inserted is 1 mL /
min. The reactor temperature was set at 250 ° C,
The reaction pressure was set at 7 MPa. After the reaction temperature and reaction pressure reached the predetermined temperatures, a DC power supply of 12 A was supplied to the reactor and the insertion electrode. The reactor body was a cathode and the insertion electrode was an anode. When the concentrations of hydrogen sulfide and methyl mercaptan in the processing gas at the time of the steady state were examined with a calibration tube, both were 1 ppm or less and were odorless.

[Brief description of the drawings]

FIG. 1 is a view showing the concept of a hydrothermal electrolysis reactor according to the present invention.

FIG. 2 is an outline of a hydrothermal electrolysis reactor according to one embodiment of the present invention, which can be automatically controlled, and an instrumentation diagram thereof.

FIG. 3 is an outline of an automatically controlled hydrothermal electrolysis apparatus according to an embodiment of the present invention, which is suitable for treating a gas having a relatively large discharge amount, and an instrumentation diagram thereof.

[Explanation of symbols]

PA Pressure indicator PC Pressure controller FC Flow controller TC Temperature controller LC Liquid level controller O ₂ C Oxygen concentration controller EcC Electrical conductivity controller pHC pH controller 10 Hydrothermal electrolysis reactor 22 Electrode 30 Heating device Reference Signs List 39 Stirring impeller 40 Reactor body 41 Insertion electrode 42 Insertion electrode conduction part 43 Anode conduction part 44 Cathode conduction part 45 DC power supply 46 Stirring rod 47 Aqueous medium 48 Reactor gas phase part 49 Liquid level 50 Reactor lid 51 Magnet 52 Motor for rotating magnet 53 Electric heater 55 Thermocouple 100 Gas flow passage to be processed 103 High pressure compressor 105 Gas accumulator 106 Pressure controller 107 Gas flow passage 108 Gas secondary pressure control valve 109 Gas secondary pressure flow passage 110 2 Secondary pressure controller 111 Flow controller 112 Flow control valve 14 Heat Exchanger 115 Spiral Heater 117 Thyristor Controller 120 Heater Furnace Temperature Controller 121 Heater Gas Temperature Controller 124 Air Flow Path 125 Gas Insertion Nozzle 130 Air Intake Flow Path 131 High Pressure Compressor 132 Air Flow Path 133 Air Accumulator 134 Pressure Controller 135 Secondary pressure control valve 136 Secondary pressure flow path 137 Secondary pressure controller 138 Flow controller 139 Flow control valve 140 Air flow path 141 Heat exchanger 142 Spiral heater 143 Thyristor Regerator 147 Furnace temperature controller 148 Air temperature controller 160 halide ion medium supply channel 161 acid or alkali aqueous solution supply channel 162 water source supply channel 167 aqueous medium control tank 170 high-pressure pump suction channel 171 high-pressure pump 174 accumulator 17 6 Pressure Controller 178 Aqueous Medium Release Valve 179 Aqueous Medium Return Channel 180 Aqueous Medium Flow Controller 181 Aqueous Medium Flow Control Valve 182 Aqueous Medium Flow Channel 201 Reactor Lower Lid 202 Reactor Body 203 Reactor Upper Lid 204 Insertion electrode 205 Filler in insertion electrode 206 Electric heater 207 Thyristor regulator 208 Reactor furnace temperature controller 209 Reactor internal temperature controller 210 Thermocouple 212 Insulating agent 213 Insertion electrode conduction part 214 Anode conduction part 215 DC power supply 216 Reactor liquid level controller 217 Upper part of impulse line for liquid level control 218 Lower part of impulse line for liquid level control 220 Process gas reactor outlet 223 Reactor pressure regulator 224 Reactor pressure control valve 226 Gas-liquid separator 227 Demister 228 Liquid level Control valve 229 Liquid level controller 230 Gas-liquid separator pressure control Total 231 Gas-liquid separator pressure control valve 232 Oxygen concentration controller 233 pH controller 234 Process water medium flow path 235 Process water medium storage tank 240 Vent 241 Water medium take-out flow path 242 Water medium cooling unit 243 Liquid level control valve 244 Water Medium flow path

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor, Kei Izumi, 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Works Co., Ltd. (72) Inventor, Masahiro Isaka 4-2-1 Motofujisawa, Fujisawa-shi, Kanagawa Prefecture F term in EBARA Research Institute, Ltd. (reference) 4D002 AA03 AA06 AA13 AA15 AA17 AA21 AA40 AB02 BA02 BA08 BA12 BA20 DA17 DA35 DA70 GA01 GA03 GB09 GB11 GB20

Claims (19)

[Claims] In a reactor filled with an aqueous medium containing halide ions, at a temperature not lower than 100 ° C. and lower than the critical temperature of the aqueous medium, the aqueous medium is reduced under a pressure that maintains a liquid phase. A method for treating a gas containing a reducing substance by hydrothermal electrolysis, wherein a direct current is supplied into the reactor while supplying a gas to be treated containing the substance. 2. The method according to claim 1, wherein the gas to be treated contains a halogenated organic substance. 3. The method according to claim 1, further comprising the step of including an oxidizing agent in the aqueous medium. 4. The method according to claim 3, wherein oxygen in the gas to be treated is used as the oxidizing agent. 5. The method according to claim 3, wherein air is added to the reaction system as the oxidizing agent. 6. The method according to claim 1, wherein the gas to be treated containing the reducing substance is acidic, and further comprising a step of adding an alkali to the aqueous medium. 7. The method according to claim 1, wherein the gas to be treated containing the reducing substance is basic, and further comprising a step of adding an acid to the aqueous medium. 8. In a reactor filled with an aqueous medium containing strong acid ions, at a temperature of 100 ° C. or more and below the critical temperature of the aqueous medium, the reducing substance is placed under a pressure at which the aqueous medium maintains a liquid phase. A method for treating a gas containing a reducing substance by hydrothermal electrolysis, wherein a direct current is supplied into the reactor while supplying a gas to be treated containing: 9. The method according to claim 1, wherein the reducing substance contained in the liquid medium is transferred to a gas and supplied as a gas to be treated.
A method for treating a reducing substance contained in a liquid medium, characterized in that the treatment is carried out by the method according to any one of claims 1 to 8. 10. An apparatus for treating a gas containing a reducing substance by hydrothermal electrolysis, comprising an inlet for a gas containing a reducing substance and a treated gas for discharging the treated gas. An apparatus comprising: a reactor capable of withstanding the pressure of a hydrothermal reaction having an outlet; and a pair of electrodes for performing electrolysis inside the reactor. 11. The apparatus according to claim 10, further comprising a heating device for heating the reactor. 12. The apparatus according to claim 10, further comprising an inlet for introducing an aqueous medium, and an outlet for discharging used aqueous medium. 13. The apparatus according to claim 10, further comprising a means for introducing an oxidizing agent into the reactor. 14. The apparatus according to claim 13, wherein the means for introducing the oxidizing agent is a nozzle for mixing with the gas to be treated. 15. A heating means for heating the gas to be treated before introducing it into the reactor.
5. The apparatus according to any one of 4. 16. The apparatus according to claim 12, further comprising heating means for heating the oxidizing agent before introducing it into the reactor. 17. The electrode according to claim 10, wherein the electrode has a cylindrical shape.
The apparatus according to any one of claims 16 to 16. 18. The device according to claim 17, wherein a filler is filled inside the cylindrical electrode. 19. The apparatus of claim 18, wherein said filler is a ceramic material in the form of a sphere, a cylinder, a lashing.