JP3219706B2 - Method and apparatus for decomposing hardly decomposable substances - Google Patents

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 decomposing hardly decomposable substances such as environmental pollutants, and more particularly to fluorocarbon, polyethylene, plastic, wood, organic compounds having a benzene nucleus, and other industrial waste. The present invention relates to a processing method and an apparatus for decomposing by thermal decomposition, hydrolysis, reduction reaction, oxidation reaction and a combination thereof by reacting environmental pollutants such as substances in an atmosphere of a solvent superheated steam. .

[0002]

2. Description of the Related Art It has been pointed out that chlorofluorocarbon and halon gas used as a refrigerant and a spray agent are environmental pollutants, and the detoxification of these substances protects the global environment. From a viewpoint, it has become a global concern, and various countermeasures have been proposed. For example, as a method for treating CFCs, a hydrothermal reaction method, an incineration method, an explosion reaction decomposition method, a microbial decomposition method, an ultrasonic decomposition method, a plasma reaction method, and the like have been proposed.

[0003] Among these treatment methods, the hydrothermal reaction method is not limited to chlorofluorocarbon gas and the like, but is applicable to all decomposed substances mainly composed of industrial solvents such as organic solvents such as trichlene, waste oil, dioxin, PCB, and manure. On the other hand, it is attracting attention as a versatile processing method. In this hydrothermal reaction method, for example, fluorocarbon gas can be decomposed into a safe substance such as sodium chloride and carbon dioxide.

[0004] Regarding the apparatus for realizing the hydrothermal reaction method, a processing experiment using an autoclave in a laboratory, for example, a mixing ratio of caustic soda solution, ethanol and fluorocarbon solution, a set value of temperature, a set value of pressure and a reaction value Experiments have been conducted on the set time, but usually the hydrothermal reaction is 3
It is performed while maintaining the high temperature and high pressure conditions of 100 to 250 (kg / cm ² ) at 00 to 450 ° C.

The applicant of the present application has previously filed Japanese Patent Application No. 6-204519.
Proposed a method and apparatus for treating environmental pollutants by hydrothermal treatment. The contents will be briefly described with reference to the flow chart of the chlorofluorocarbon treatment system shown in FIG. 13. A tank 1 contains a mixed liquid of chlorofluorocarbon, caustic soda, and ethanol, which is heated from a pipe 4 through a pump 2 and a flowmeter 3. After being sent to the exchanger 5 and reacted in the hydrothermal reactor 6, it is sent again to the cooler 7 via the heat exchanger 5 and sent from the cooler 7 to the separator 9 via the pressure regulating valve 8 for controlling the flow rate. ,
The water is separated into clean water and clean material by a separator 9. The tank 1a, the pump 2a, and the flow meter 3a shown in FIG. 1 are gasified at room temperature depending on the type of chlorofluorocarbon gas.

As the pumps 2 and 2a, ordinary slurry pumps are used. As this slurry pump, it is necessary that the suction is vacuum, the pumping force is high, and the volume efficiency is good. A high-concentration slurry pumping cylinder such as a high-concentration slurry, a powder mixed slurry, an acid or an alkaline slurry is employed.

As shown in FIG. 14, the hydrothermal reactor 6 allows the mixture passed through the heat exchanger 5 to be discharged from the inlet 11 through the pipe 12 around which the band heater 13 is wound, and from the outlet 14. It is configured to meander. A required number of band heaters 13 are arranged at appropriate intervals in the longitudinal direction of the pipe 12 and are controlled so that the temperature inside the pipe 12 becomes constant. Further, as the cooler 7, a normal cooling device having a cooling water passage formed around a reaction tube is employed.

On the other hand, Japanese Patent Publication No. 58-56396 discloses that superheated steam obtained by a superheated steam generator is injected into a cracking furnace to separate waste tires into cracked gas, carbon and other residues and beat wires. A pyrolysis device intended for reuse is disclosed. Further, JP-A-3-12220 discloses a method of hydrolyzing a chloroalkane (fluorocarbon) to a harmless compound by bringing the fluorinated alkane (fluorocarbon) into contact with a catalyst comprising activated carbon carrying iron oxide in the presence of steam. I have.

[0009]

As described above, since the hydrothermal reactor 6 must maintain high-temperature and high-pressure conditions,
The structure of the pressure regulating valve 8 is complicated and expensive, and furthermore, it is difficult to design to withstand mechanical strength such as tensile stress or thermal stress because it is used at high temperature and high pressure, and the material used is limited. There are difficulties. In addition, the mechanism for feeding and discharging the solid-liquid mixture under high temperature and high pressure is complicated, and it is necessary to change the structure depending on the type of the substance to be decomposed, and there is a problem that it is difficult to control the operation. In addition, the pipe 4 may be damaged during operation due to the high pressure, and there is still a difficulty from the viewpoint of ensuring safety.

Although the above-mentioned hydrothermal reaction method is a closed system, the rotary kiln method or the incineration method, which is an open type apparatus, has a problem in that measures against dioxin and the like generated in the residue are problematic. It is difficult to change the reaction process depending on the decomposed substance, and a dedicated device is required. Therefore, running costs and initial costs are high, and these devices have a drawback that they have little versatility.

In the pyrolysis apparatus described in Japanese Patent Publication No. 58-56396, waste tires can be separated into residues such as cracked gas and carbon. No mention is made of the efficient decomposition of these materials, and the decomposition of these substances cannot be carried out. Further, in the means described in JP-A-3-12220 for hydrolyzing chlorofluorocarbon by bringing it into contact with a catalyst in the presence of water vapor, decomposition of substances other than chlorofluorocarbon, such as organic compounds having a benzene nucleus and other industrial wastes, is performed. In addition to the above, it is not possible to use it, and depending on the type of chlorofluorocarbon, it is not possible to obtain a sufficient effect in terms of decomposition efficiency, and the catalyst used lacks durability. There is a drawback that it cannot be done.

The present invention solves the above-mentioned problems in a system for decomposing environmentally polluting substances such as chlorofluorocarbon, polyethylene, plastic, wood, organic compounds having a benzene nucleus, and other hardly decomposable substances such as industrial waste. It can be decomposed at normal pressure without high pressure, and there is no damage to piping and discharge valves due to high temperature and high pressure. Selected from iron, carbon and carbon steel for one or both of the heater and the reactor.
It is an object of the present invention to provide a method and an apparatus for decomposing a hardly decomposable substance, in which one or more substances are arranged, and decomposition is promoted by a reduction reaction with hydrogen generated in a heater or a reactor. is there.

[0013]

According to the present invention, as a method for decomposing a hardly decomposable substance, a mixture of a substance to be decomposed and a solvent is heated to a predetermined temperature using a heater. In the method of decomposing a substance to be decomposed by passing the superheated vapor through a normal pressure reactor heated to a predetermined temperature after a predetermined reaction time, water is used as a solvent. Use iron and carbon or carbon steel in one or both of the heater and the reactor.
A method of disposing one or more substances selected from the group consisting of a reduction reaction with hydrogen generated in a heater or a reactor and a hydrolysis reaction with superheated steam to decompose hardly decomposable substances, and heating the solvent with a heater The superheated steam is heated to a predetermined temperature by using a superheated steam, and the superheated steam is continuously supplied into a reactor at a normal pressure heated to a predetermined temperature, and is then covered in a reactor in an atmosphere of the superheated steam. In a method of decomposing a decomposition target by supplying the decomposition treatment product and passing it after a predetermined reaction time has elapsed, water is used as a solvent, and at least one of a heater and a reactor is used. ,
One or more substances selected from iron, carbon, and carbon steel are arranged, and a hardly decomposable substance is generated in the reactor by a reduction reaction with hydrogen generated in the heater or the reactor and a hydrolysis reaction with superheated steam. Is provided on the basis of a method for disassembling. Also, when the substance to be decomposed is Freon,
Provided is a method in which the temperature of air is set at 500 ° C. to 750 ° C.

[0014]

[0015] Further, as an apparatus for decomposing hardly decomposable substances,
A heater that generates a superheated steam by heating a mixture of the substance to be decomposed and the solvent to a predetermined temperature and is maintained at a predetermined temperature at which the obtained superheated steam is decomposed by a predetermined reaction time. Atmospheric pressure reactor and iron, carbon, or carbon steel placed in one or both of the heater and reactor
A heater configured to heat the solvent to a predetermined temperature to generate a superheated vapor, and a heater for heating the solvent to a predetermined temperature and generating a superheated vapor of the obtained solvent and a substance to be decomposed for a predetermined reaction time. A reactor at normal pressure maintained at a predetermined temperature for decomposition treatment over time, and iron, carbon, or carbon steel selected from one or both of the heater and the reactor.
The present invention is provided on the basis of a configuration comprising one or more substances.

[0016] Also, the passage of superheated steam is opened, centered portion,
Two types of iron plates, an iron plate with an opening through which an internal heater is inserted in the peripheral portion and an iron plate with an opening through which the internal heater is inserted in the peripheral portion and a passage for superheated steam, are placed inside the reactor. The superheated steam introduced into the reactor alternately juxtaposed,
Providing <br/> configuration which is adapted to pass while flowing periphrastic the passage of the superheated steam.

According to the method and the apparatus for the decomposition treatment, the non-decomposable substances such as CFCs, organic compounds having a benzene nucleus, and other industrial wastes become superheated steam together with the solvent.
Alternatively, it is supplied into the reactor in an atmosphere of superheated steam, becomes superheated steam together with the solvent, is further heated in the reactor, and the temperature of the superheated steam increases only at normal pressure. Ri by the passing through, iron, carbon, and produce hydrogen by reacting carbon steel with superheated steam, a reduction with hydrogen, the hardly decomposable substance is decomposed by hydrolysis with superheated steam. Thereafter, the superheated steam after the decomposition is cooled and liquefied and discharged.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of a method and apparatus for decomposing hardly decomposable substances according to the present invention will be described below with reference to the drawings. In view of the above-mentioned problems in the hydrothermal reaction treatment, the inventor of the present application has conducted various improvement experiments, and as a result, water to be decomposed such as chlorofluorocarbon as a solvent, and superheated steam using hydrogen peroxide water, If the predetermined reaction time is maintained in the state of the superheated steam, the reactor is not brought into a high pressure state, but is kept at a normal pressure, that is, even if the reactor is at a normal pressure with the discharge port opened. By raising the temperature alone and maintaining the atmosphere of superheated steam, we obtained the knowledge that the decomposition target in superheated steam can be decomposed by thermal decomposition, hydrolysis, reduction reaction, oxidation reaction, and a combination of these. Was.

Further , by contacting the superheated steam with iron, carbon, or carbon steel heated to substantially the same temperature, hydrogen is generated in the reaction vessel. It was decomposed, and at the same time, it was found that the substance to be decomposed could be decomposed by hydrolysis with superheated steam. Hereinafter, specific embodiments will be described.

The present invention decomposes hard-to-decompose substances such as environmental pollutants such as chlorofluorocarbon gas under normal pressure. The hard-to-decompose substances to be treated are organic compounds that are stable. There is no limitation, it covers all kinds of organic solvents such as chlorofluorocarbon, trichlene, waste oil, dioxin, PCB, manure, wood, paper, rubber, etc. Absent. It is mainly useful as an organic compound, but is difficult to treat after use or harmful, for example, chlorobenzene, chlorofluorocarbon (halogen carbon compound), dioxin in question, and the like. But very stable and not harmful but difficult to process,
For example, PE, plastic, rubber and the like.

Since these are often made from petroleum and can be almost oilified when decomposed, they are intended to be used as fuel or to be decomposed so that they can be recycled. Further, in the case of rubber, it is another object of the present invention to detoxify the organic compound or to decompose the organic compound so that it can be recycled.
Further, the decomposition of paper, wood, and the like is for decomposing cellulose to glucose, and aims to convert those having little utility value to useful ones.

The solvent used in the present invention may be any solvent as long as it produces steam or hydrogen by heating, but the most suitable solvent is water, and hydrogen peroxide can also be used. If hydrogen peroxide solution is used as a solvent, the amount of oxygen increases and wet oxidation can be performed.

Further, according to the present invention, it is possible to open the benzene ring, and the benzene to be decomposed in the present invention is a basic compound of an aromatic hydrocarbon, and is represented by C ₆ H _6. And monochlorobenzene is represented by C ₆ H ₅ Cl. Examples of the organic compound having a benzene nucleus include phenols. These phenols are a general term for organic compounds in which an OH group is bonded to a benzene nucleus, and are represented by C ₆ H ₅ OH. Further, according to the present invention, dioxins and PCBs having a benzene ring as a skeleton structure can be decomposed and made harmless.

FIG. 1 is a system diagram schematically showing an embodiment of the present invention. In the figure, reference numeral 21 denotes a tank for decomposed substances such as chlorofluorocarbon, 22 denotes a pump for decomposed substances, 23 denotes a water tank as a solvent, and 24 denotes a water tank as a solvent. Is a water pump, 25 is a heater, and an internal heater 26 and an external heater 27 are arranged in the heater 25,
Further, a plurality of iron plates 28, 28 are arranged in the heater 25 as a substance that reacts with the superheated steam to generate hydrogen. A pump capable of pumping an object to be decomposed according to the object to be decomposed is selected as the object to be decomposed pump 22. A slurry pump having a high pumping force capable of pumping a high-concentration slurry, a powder mixed slurry, etc., and having a good volumetric efficiency It is appropriate to use

Numeral 29 denotes a reactor for decomposing the substance to be decomposed, the superheated vapor of the solvent and hydrogen for a predetermined time while maintaining a predetermined temperature. This reactor 29
Are provided with internal heaters 30 and 30 and external heaters 31 and 31, and iron plates 28 and 28 are also disposed in the reactor 29. Note that, as will be described in detail later, carbon, carbon steel, or the like can be used as a substance that reacts with superheated steam to generate hydrogen instead of the iron plate 28.

The inside of the reactor 29 is not pressurized, and the outlet is open to the normal pressure. That is, the pressure of the pipe on the inlet side has a pressure gradient of only the pressure loss due to the pipe. As described above, one of the features of the present invention is that, unlike the conventional high-pressure hydrothermal reactor, the reactor 29 can decompose the substance to be decomposed by using the open-type reactor 29 that does not forcibly pressurize. It is. In the reactor 29, a slight pressure is spontaneously generated by the superheated steam, and a pressure gradient is formed to transfer the decomposition products. In the present invention, the normal pressure indicates a state in which the discharge port is opened without forcibly increasing the pressure as in the conventional hydrothermal reactor.

Numeral 32 denotes a cooler, in which a pipe 33 communicating with a pipe led out of the reactor 29 is arranged. 34 is an inlet of cooling water, and 35 is an outlet of cooling water. 36 is a gas-liquid separator, 37 is a neutralization device, and the other end of a pipe 38 led out of the cooler 32 is inserted into the gas-liquid separator 36 and is led out of the gas-liquid separator 36. The other end of the pipe 39 is inserted into the neutralization device 37. Reference numeral 40 denotes a processing liquid discharge port.

The operation of this embodiment will be described.
Taking the case of decomposing fluorocarbon gas, which is an environmental pollutant, as an example, chlorofluorocarbon is charged into the decomposed substance tank 21 and the decomposed substance pump 22 and the water pump 24 are activated, so that the fluorocarbon and water as a solvent are removed. It is sent to the heater 25 through the pipe and mixed at an appropriate ratio.

The internal heater 2 previously disposed in the heater 25
6 and the external heater 27 are operated to make the inside of the heater 25 5
Superheated steam is generated by heating to 00C to 750C. Since the temperature of the superheated steam required for the decomposition treatment varies depending on the decomposition target, each temperature is set according to the decomposition target. For example, in the case of Freon gas, 50
It is appropriate to use a superheated steam of 0 ° C. to 750 ° C. and about 400 ° C. for polyethylene, but heating above the above may be used.

When the iron plates 28, 28 are heated to substantially the same temperature in the heater 25, the superheated steam contacts the iron plate 28 to generate magnetite and hydrogen by the following reaction formula. 3Fe + 4H ₂ O → Fe ₃ O ₄ + 4H ₂ (1)

The hydrogen generated here has a very strong reducing power, and combines with many substances to decompose the substance to be decomposed. On the other hand, the inside of the reactor 29 is also heated and held in advance so as to maintain the temperature of the superheated steam by driving the internal heaters 30, 30 and the external heaters 31, 31, and the iron plates 28, 28
The reaction of the above formula (1) is proceeding due to the presence of Since superheated steam also exists in the same atmosphere in the reactor 29, hydrolysis also occurs at the same time, and a complex decomposition reaction proceeds. As a result, the decomposition rate of the decomposition target material is increased, and the decomposition rate is also improved.

Depending on the substance to be decomposed, a superheated steam of about 300 ° C. may be used, and the temperature is set to an individually suitable temperature according to the substance to be decomposed. There is no limitation on the set temperature. When the substance to be decomposed is Freon gas, the temperature of the heater 25 is 500 to 750.
Suitably, it is heated to about ° C. to form superheated steam, which is transferred to the reactor 29 by a pressure gradient.

It is appropriate to heat the inside of the reactor 29 to substantially the same temperature as the inside of the heater 25. A predetermined reaction time elapses while the superheated steam passes through the inside of the reactor 29, the decomposition target material in the superheated steam is decomposed, and the next cooler 32
Sent inside.

In the cooling device 32, the cooling water is supplied from an inlet 34 of the cooling water and discharged from the outlet 35,
The gas of the decomposition product decomposed in the pipe 33 communicating with the reactor 29 is cooled and liquefied. The temperature inside the cooler 32 may be any temperature at which the gas of the decomposed product can be liquefied. By liquefying in this way, the generation of by-products is prevented, and there is no fear of secondary pollution due to release in the gaseous state and scattering into the atmosphere.

The discharged liquid enters a gas-liquid separator 36 through a pipe 38, where the gas-liquid is separated, and the liquid material flows into a neutralization device 37. And stored in a drain tank (not shown). The cooler 32
It is also possible to incorporate a heat exchanger into the heat exchanger, recover the heat cooled by the heat exchanger, and reuse the recovered heat to generate superheated steam.

In the above description, only water as a solvent is turned into superheated steam by the heater 25 and is continuously supplied to the reactor 29.
The substance to be decomposed may be supplied into the inside of the chamber to allow a predetermined reaction time to elapse. This configuration is suitable for decomposing solid substances to be decomposed other than fluid or gaseous substances, for example, PE, plastic, rubber, wood, paper, etc. It is preferable to supply the substance to the reactor 29 and to provide a means for transferring the substance to be decomposed such as a feeder in the reactor 29.

When chlorofluorocarbon gas was used as the material to be decomposed, the following products were confirmed. First, the gas is CO ₂ ,
H ₂ , HCl, HF, CO (trace amount), liquid is HC
1, HF and Fe ³ +. Solids are Fe ₂ O ₄ , C (graphite), FeF ₂ , FeF ₂ .4H ₂ O, FeCl ₂ , F
eCl ₂ .4H ₂ O. As the measuring method, the gas is GC-MC method, H ₂ and CO is GC-TCD method, HCl and HF is ion chromatography, CO ₂ is a detector tube method, metals ICP spectrometry, solid X-ray diffraction Method was used.

The decomposition reaction of CFC-12 is as follows. [When water is used as a solvent] CCl ₂ F ₂ + 2H ₂ → + 2HCl + 2HF + C (2) CCl ₂ F ₂ + 2H ₂ O → 2HCl + 2HF + CO ₂ (3) 2CCl ₂ F ₂ + 3H ₂ O → 2HCl + 2HF + CO ₂ + CO + H ₂ … (4)

The equation (2) represents the decomposition of the reduction reaction with hydrogen,
The equations (3) and (4) are hydrolysis by water, and the reaction of the equation (3) is mainly performed in view of the amount of CO. As a whole, the reactions of the equations (2) and (3) are 95% or more. , (4) is about 5%.

Further, the hydrochloric acid gas and the hydrofluoric acid gas of the products act on iron to cause the following reaction. Fe + 2HCl → FeCl ₂ + H ₂ (5) Fe + 2HF → FeF ₂ + H ₂ (6)

When this is cooled by the cooler 32, it absorbs the moisture in the air and receives FeCl ₂ .4H ₂ O and FeF _2.
Changes to 4H ₂ O.

Next, a reaction formula when carbon or carbon steel is used in place of the iron plate 28 will be described. That is, when superheated steam of water as a solvent acts on carbon, C + H ₂ O → CO + H ₂ (7) is obtained, and a water gas as a mixed gas of CO and H ₂ is generated. The obtained hydrogen causes the reactions of the above formulas (1) to (6) to decompose the fluorocarbon gas. However, when carbon is used, the amount of generated hydrogen is slightly lower than when iron or carbon steel is used, and it takes about 10 seconds to achieve a decomposition rate of 99.99. Slightly lower.

In the formula (1), the magnetite (Fe
₃ O ₄ ) is a passivation having high corrosion resistance to acid, and adheres to the surface of a container or the like to form a protective film. The magnetite adhering to the iron plate 28 reacts with the carbon to become Fe ₃ O ₄ + 2C → 3Fe + 2CO ₂ (8) and also reacts with CO to become Fe ₃ O ₄ + 4CO → 3Fe + 4CO ₂ (9) The iron required for the reaction of the formula (1) is recycled. However, in many cases, expansion and contraction due to heat progress, magnetite peels off, a new iron surface is exposed, and the reaction continues.

When water is used as the solvent for the chlorofluorocarbon, the mixture becomes strongly acidic due to the action of hydrochloric acid and hydrofluoric acid generated by the reaction of the above formula (2), and the pipes and tubes become severely corroded. May be shortened. Therefore, as shown in the following equation (10), caustic soda NaOH is added according to the concentration of chlorofluorocarbon to convert carbon dioxide into sodium bicarbonate NaHCO _3, and as shown in equation (11), sodium chloride is produced by the reaction of caustic soda and hydrochloric acid. And then (1
In some cases, sodium fluoride NaF is generated by the reaction of caustic soda and hydrofluoric acid as shown in equation 2). NaOH + CO ₂ → NaHCO ₃ (10) NaOH + HCl → NaCl + H ₂ O (11) NaOH + HF → NaF + H ₂ O (12)

[When Hydrogen Peroxide Solution is Used as Solvent] Hydrogen peroxide solution is thermally decomposed to produce water and oxygen. 2H ₂ O ₂ → 2H ₂ O + O ₂ (13) Therefore, in addition to hydrolysis by H ₂ O and O ₂ , the following reaction occurs simultaneously by oxygen and hydrogen. CCl ₂ F ₂ + O ₂ → CO ₂ + 2HCl + 2HF (14) CCl ₂ F ₂ + O ₂ = CO ₂ + Cl ₂ + F ₂ (15) Equation (14) is a combustion reaction, and equation (15) is It is an oxidation reaction. Cl ₂ and F ₂ obtained by the oxidation reaction are converted into HCl and HF as follows: Cl ₂ + H ₂ → 2HCl (16) F ₂ + H ₂ → 2HF (17)

When hydrogen peroxide solution is used as a solvent as described above, in addition to the above-mentioned hydrolysis and reduction reactions,
Since the above-described combustion reaction and oxidation reaction proceed simultaneously, the decomposition rate is high, and the decomposition target material changes into a stable substance from an early stage, so that no extra by-product is generated.

This embodiment is for decomposing a fluid or gaseous substance to be decomposed, and decomposes a liquid substance of a halogenated carbon compound such as chlorobenzene and trichloroethane as an environmental pollutant, in addition to chlorofluorocarbon and trichloroethane. Although it is possible, the temperature in the superheater 25 and the reactor 29 was set to 650 ° C., and the temperature of the pipe 33 in the cooler 32 was set to 18 ° C. as the experimental conditions in the case of CFC gas. In addition, the solvent (water or hydrogen peroxide solution) was selected to be in excess in molar ratio. That is, Freon gas: water (or hydrogen peroxide solution) = 1:
It was set to 3. At this time, the decomposition rate was such that no CFCs were detected by gas chromatography, in other words, 99.99.
% Was obtained.

FIG. 10 shows that the superheated steam temperature of chlorofluorocarbon gas was 650 ° C. using water as a solvent, (a) an iron plate 28 was juxtaposed in the reactor 29, (b) carbon was put in the reactor 29, 3C is a graph showing the relationship between the decomposition rate and time when nothing is put in the reactor 29. The time when the decomposition rate reaches 100% is the shortest when the iron plates 28 in (A) are juxtaposed. However, even if carbon is used, it is sufficiently practical.

FIG. 2 is a plan view of the heater 25, FIG. 3 is a side view of the same, and FIG. 4 is a front view as viewed from the left side of FIG. On the upper surface of a container 41 constituting the heater 25, water inlets 42, 42 as a solvent and a Freon inlet 4 as a substance to be decomposed are provided.
A plurality of fan-shaped iron plates 28 and 28 are arranged inside the container 41 so as to face each other with a space in the center for allowing superheated steam to flow. 27 is an external heater, 44 is a pressure gauge, 45 is a pipe derived from the heater 25,
This pipe 45 is connected to the next-stage reactor 29.

FIG. 5 is a plan view showing another configuration (used in FIG. 1) of the iron plate 28, and FIG. 6 is a side sectional view showing the assembling structure. The iron plate 28 is formed in a disk shape. A heater tube 48 is fitted and fixed in a hole 47 opened at the center, and a heater 49 is inserted into the inside thereof. 50 is an electrode for a heater. Further, a plurality of holes 51 and 5 for allowing gas to flow are provided at appropriate positions on the peripheral surface of the iron plate 28.
1 is open.

FIG. 7 is a side sectional view of the reactor 29.
A gas inlet 57 is provided on one side of a container 55 constituting the reactor 29 with a flange 56 interposed therebetween, and a gas outlet 58 and a flange 59 are provided on the other side. Inside the container 55, two types of iron plates 28a, 28b are alternately arranged. An internal heater 30 is arranged to penetrate these iron plates 28a and 28b. 60 is a thermometer.

FIG. 8 is a front sectional view of the iron plate 28a. In this example, the hole 6 through which the internal heater 30 is inserted is provided at the periphery.
2, 62 and passages 61, 61 for superheated steam are opened. FIG. 9 is a front cross-sectional view of the iron plate 28b. In this example, a passage 61 for superheated steam is opened at the center of the disk-shaped iron plate 28b, and a hole 6 through which the internal heater 30 is inserted at the peripheral edge.
2, 62 are open. Therefore, since the superheated steam introduced into the reactor 29 passes while bypassing the superheated steam passages 61, 61, there is an effect that the reaction efficiency is enhanced.

According to the configuration of the heater 25, the container 4
When water as a solvent is injected from the water injection ports 42 provided in 1 and at the same time fluorocarbon gas as a substance to be decomposed is injected from the fluorocarbon injection port 43, the heater 49 and the external The mixed gas is generated by being heated and evaporated by the heater 27 (FIG. 1), and becomes a superheated steam, flows through the holes 51 opened in the iron plates 28, 28, and flows into the reactor 29 in the next stage.

The superheated steam introduced from the gas inlet 57 of the reactor 29 is alternately arranged with the iron plates 28a, 28
b is heated by the internal heater 30 and the external heater 31 (FIG. 1) while passing through the passages 61, 61 of the superheated steam opened in b, and by the action of hydrogen generated by the presence of the iron plate 28, CFCs are decomposed by the decomposition reactions shown in the above equations (1) to (6) and flow into the cooler 32 of the next stage from the gas outlet 58 of the reactor 29. While passing through the cooler 32, the cooling water inlet 34 and outlet 35
The liquid is cooled and liquefied by the cooling water circulated therein, and flows into the gas-liquid separator 36 from the pipe 38.

Next, the decomposition reaction of trichloroethane (CH ₃ · CCl ₃ ) and chlorobenzene (C ₆ H ₅ Cl) which is an organic substance having a benzene nucleus according to the present embodiment will be described.
The reaction temperature was 650 ° C.

First, trichloroethane (CH ₃ · CCl ₃ )
Is decomposed, the reaction proceeds as follows.

[When water is used as a solvent] When water is used as a solvent, the hydrolysis proceeds as follows: CH ₃ · CCl ₃ + H ₂ O → 3HCl + CO + C + H ₂ (18) CH ₃ · CCl ₃ + 2H ₂ O → 3HCl + CO ₂ + C + 2H ₂ (19) Meanwhile, the (1) decomposition by hydrogen superheated steam is generated in contact with the iron plate 28 as shown in expression decomposition during the gas qualitative analysis, first, the decomposition reaction of the product, CH ₃ · CCl ₃ + 3H ₂ → CH ₃ .CH ₃ + 3HCl (20) A substitution reaction with hydrogen was observed, and further, CH ₃ .CH ₃ + H ₂ → 2CH ₄ (21) decomposition proceeded, and then CH ₄ → C + 2H ₂ (22) Therefore, in this decomposition reaction, CO ₂ , C
Decomposed into O, H ₂ , C, HCl.

[When Hydrogen Peroxide Water is Used as Solvent] When hydrogen peroxide water is used as a solvent, CH ₃ .CCl ₃ + 2O ₂ → 2CO ₂ + 3HCl is used in addition to the above-mentioned hydrolysis and decomposition by hydrogen. 23) A decomposition reaction by oxidation takes place, and CH ₄ generated in the equation (21) is also partially oxidized, and CH ₄ + 2O ₂ → CO ₂ +2
H ₂ O (24), hydrolysis, decomposition of the reduction reaction by hydrogen, and oxidative decomposition occur in parallel, and the decomposition efficiency is further improved.

FIG. 11 shows trichloroethane (CH ₃ CC)
l ₃ ) The temperature of the superheated steam was set at 650 ° C. using water and hydrogen peroxide as a solvent, and the iron plate 28 was placed in the reactor 29.
7 is a graph showing the relationship between the decomposition rate and time when juxtaposed. As shown in the graph, the decomposition efficiency is better when hydrogen peroxide solution is used as a solvent, but there is no significant difference. This is because trichloroethane (CH ₃ · CCl ₃ ) is an organic compound having no benzene ring.

Next, when chlorobenzene (C ₆ H ₅ Cl) is decomposed, the reaction proceeds as follows.

[When water is used as the solvent] When water is used as the solvent, the hydrolysis is performed as follows: C ₆ H ₅ Cl + H ₂ O → C ₆ H ₅ OH + HCl (25) As shown in the equation (1), the decomposition by hydrogen generated by the contact of the superheated steam with the iron plate 28 is as follows.
The gas in the middle of decomposition is qualitatively analyzed, and the decomposition reaction is first performed on the product by replacing Cl with H, resulting in C ₆ H ₅ Cl + H ₂ → C ₆ H ₆ + HCl (26). Hydrochloric acid is generated, and H is further added to form C ₆ H ₆ + 3H ₂ → C ₆ H ₁₂ (27), cyclohexane (C ₆ H ₁₂ ) is generated, and the ring is further opened to form methane. Is decomposed into ethane and the like. C ₆ H ₁₂ + 6H ₂ → 6CH ₄ (28) This methane becomes CH ₄ → C + 2H ₂ (29) and is decomposed into C (graphite), hydrochloric acid and hydrogen.

[0062] [If using hydrogen peroxide as a _{solvent] C 6 H 5 Cl + 6O} 2 → 6CO 2 + HCl + 2H 2 ......... other degradation by hydrolysis and hydrogen described above and using aqueous hydrogen peroxide in a solvent ( 30) Oxidation reaction occurs simultaneously.

FIG. 12 shows that chlorobenzene (C ₆ H ₅ Cl) was heated to a superheated steam temperature of 6 using water and hydrogen peroxide as a solvent.
5 is a graph showing the relationship between decomposition rate and time when an iron plate 28 is juxtaposed in a reactor 29 at 50 ° C. As shown in the graph, decomposition is sufficient even if water is used as the solvent,
The use of aqueous hydrogen peroxide further stabilizes the decomposition and increases the decomposition rate. In other words, when hydrogen peroxide solution is used as a solvent, the time required to reach 99.99% of decomposition can be decomposed in approximately half the time when water is used as a solvent.

[0064]

As described in detail above, according to the present invention, a mixture of a substance to be decomposed and a solvent is used by using a heater.
To obtain superheated steam or heat the solvent using a heater in advance.
Continuously into the reactor as superheated steam
Method and apparatus for supplying a substance to be decomposed and reacting in a reactor
, One or both of a heater and a reactor
One or more materials selected from iron, carbon and carbon steel
Due to the arrangement of the materials, the hardly decomposable substances such as CFC gas, organic compounds and other industrial wastes become superheated steam together with the solvent, and are further heated in the reactor to become superheated steam whose temperature only rises at normal pressure . Alternatively , when passing through the reactor for a predetermined reaction time, it reacts with iron, carbon, carbon steel, etc. to generate hydrogen, which is a hardly decomposable substance by a reduction reaction with this hydrogen and a hydrolysis reaction with superheated steam. Can be decomposed. Thereafter, the superheated steam having undergone decomposition is cooled to be liquefied and discharged. In particular, heating under normal pressure is the main process,
There is no need for a high-pressure pump, and there is no fear that the discharge valve or piping will be damaged. Since the reaction is a closed system in which all reactions take place in the reactor, the effect of no secondary contamination is obtained.

The degree of decomposition can be controlled by arbitrarily setting the reaction time and temperature of the above-mentioned heater and reactor. The degree of decomposition of polyethylene is changed, and the rubber is converted into rubber again. Cellulose in waste wood can be processed under conditions that can be recycled as useful glucose.

In particular, in the case of the conventionally known catalyst method, there is a problem that the catalyst is deteriorated by oxidation or the like, whereas in the case of the present invention, the above-mentioned problem is caused because the catalyst is not used. There is no point, and it can be applied not only to CFCs but also to other industrial wastes and organic substances having a benzene nucleus.

Further, according to the present invention, since the process proceeds at a low pressure, the material can be arbitrarily selected as long as it can withstand a predetermined high temperature, and can withstand mechanical strength and tensile stress or thermal stress. Therefore, there is an advantage that no design is required, and measures against breakage of various devices are easy and automation of the device itself is also easy. Since the reaction is performed in the state of superheated steam, even if there is a breakage in a pipe or the like, the generation of superheated steam is stopped as soon as the liquid supply is stopped, so that there is an effect that the safety is high.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a basic embodiment of the present invention.

FIG. 2 is a plan view of a heater used in the embodiment.

FIG. 3 is a side view of FIG. 2;

FIG. 4 is a front view of FIG. 2;

FIG. 5 is a front view of an iron plate used in the embodiment.

FIG. 6 is a side sectional view showing an assembly structure of an iron plate used in the embodiment.

FIG. 7 is a side sectional view of a reactor used in the present embodiment.

FIG. 8 is a front sectional view showing the structure of the iron plate used in the embodiment.

FIG. 9 is a front sectional view showing the structure of another iron plate used in the embodiment.

FIG. 10 is a graph showing the relationship between the decomposition rate of chlorofluorocarbon and the time depending on the difference in the substance generating hydrogen.

FIG. 11 is a graph showing the relationship between the decomposition rate of trichloroethane and time.

FIG. 12 is a graph showing the relationship between the decomposition rate of chlorobenzene and time.

FIG. 13 is a flowchart of a CFC processing system according to the prior application.

FIG. 14 is a schematic diagram of a hydrothermal reactor in the system flow diagram of FIG.

[Explanation of symbols]

 21: Decomposed substance tank 22: Decomposed substance pump 23 ... Water tank 24 ... Water pump 25 ... Heater 26, 30 ... Internal heater 27, 31 ... External heater 28, 28a, 28b ... Iron plate 29 ... Reactor 32 ... Cooling Vessel 36 ... Gas-liquid separator 37 ... Neutralizer 41, 55 ... Container 42 ... Water inlet 43 ... Freon inlet 44 ... Pressure gauge 48 ... Heater tube 49 ... Heater 70 ... Electrode 57 ... Gas inlet 58 ... Gas Outlet 60 ... thermometer

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takehiko Moriya 7-2-1, Nakayama, Aoba-ku, Sendai, Miyagi Prefecture Tohoku Electric Power Company R & D Center (72) Inventor Masazumi Kanazawa 5033-21, Nagahama, Kochi City, Kochi Prefecture (56) References JP-A-3-12220 (JP, A) JP-A-7-242883 (JP, A) JP-A-4-63133 (JP, A) JP-A-4- 325170 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01J 19/00-19/32 A62D 3/00 B01D 53/34-53/96 B09B 3/00 C07B 35/06 C07B 37/06

Claims (6)

(57) [Claims] 1. A mixture of a substance to be decomposed and a solvent is heated to a predetermined temperature using a heater to form superheated steam, and the superheated steam is heated in a normal pressure reactor heated to a predetermined temperature. In a method of decomposing a substance to be decomposed by passing through a predetermined reaction time, water is used as a solvent, and iron, carbon, carbon steel is added to one or both of a heater and a reactor. Selected from
One or more of the above-mentioned substances are disposed, and a decomposition reaction of the hard-to-decompose substance characterized by a reduction reaction by hydrogen generated in a heater or a reactor and a hydrolysis reaction by superheated steam is used to decompose the hard-to-decompose substance. Disassembly processing method. 2. A solvent is heated to a predetermined temperature by using a heater to form superheated steam, and the superheated steam is continuously supplied to a normal pressure reactor heated to a predetermined temperature. In the method of decomposing the decomposition target by supplying the decomposition target to the reactor in the atmosphere of the above and passing it after a predetermined reaction time, water is used as a solvent, a heater and Select one or both of the reactors from iron, carbon and carbon steel.
One or more substances are arranged, and the hardly decomposable substances are decomposed in the reactor by a reduction reaction with hydrogen generated in the heater or the reactor and a hydrolysis reaction with superheated steam. Decomposition method for hardly decomposable substances. 3. A cracking process of hardly decomposable substance according to claim 1 or 2, wherein the decomposition material was 500 ° C. to 750 ° C. The temperature of the superheated steam when a chlorofluorocarbon. 4. A heater for heating a mixture of an object to be decomposed and a solvent to a predetermined temperature to generate superheated steam, and a predetermined heater for decomposing the obtained superheated steam after a predetermined reaction time has elapsed. A normal pressure reactor maintained at a temperature, iron disposed in one or both of the heater and the reactor ,
An apparatus for decomposing hardly decomposable substances, comprising one or more substances selected from carbon and carbon steel . 5. A heater for heating a solvent to a predetermined temperature to generate superheated steam, and a predetermined temperature for decomposing the obtained superheated steam of the solvent and a substance to be decomposed after a predetermined reaction time has elapsed. Maintained normal pressure reactor and iron, carbon, charcoal placed in one or both of the heater and reactor
An apparatus for decomposing hardly decomposable substances, comprising one or more substances selected from raw steel . 6. An iron plate having a superheated steam passage opened in the center and an opening through which an internal heater is inserted in a peripheral portion,
Two types of iron plates, a hole through which an internal heater is inserted in the peripheral portion and an iron plate having a passage for the superheated steam, are alternately juxtaposed inside the reactor, and the superheated steam introduced into the reactor is overheated. claim was to pass while flowing periphrastic the passage of the steam 4
Or an apparatus for decomposing hardly decomposable substances according to 5 .