JP2718884B2 - Apparatus and method for decomposing and recycling fluorocarbons by ultraviolet light - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a specific fluorocarbon (hereinafter referred to as CF).
I may say C. ) And Halon, alternative Freon (H
Decomposition of CFCs, HFCs) or CFC-like substances such as halogen-containing organic solvents (hereinafter, such substances including specific CFCs may be referred to as CFCs or CFC-based substances ).
More particularly, the present invention relates to a system for efficiently decomposing fluorocarbons or the like using ultraviolet light and performing resource recycling.

[0002]

2. Description of the Related Art Refrigerators, refrigerators, air conditioners, aerosols,
It is said that CFCs used in electronic components and cleaning agents for dry cleaning are released into the atmosphere and rise to the stratosphere, where they are photodegraded by sunlight and liberated chlorine atoms destroy the ozone layer. . In addition, research reports that the infrared absorption cross section per molecule of CFC is nearly two orders of magnitude larger than that of CO ₂ molecule, and the global warming effect of CFC is estimated to be 10,000 to 20,000 times that of CO ₂ per molecule. There is also. Therefore, the necessity of reducing the amount of CFC used has been called out, but current measures to reduce CFC include a method of suppressing emission to the atmosphere and a method of substituting CFC. Among them, methods to control release to the atmosphere are divided into (a) recovery and reuse methods and (b) decomposition methods. Degrading used CFCs is a practical measure. Decomposition methods are being studied, but have not yet been put to practical use.

[0003] At the 1992 Conference of the Parties to the Montreal Protocol, a treaty on the regulation of ozone-depleting substances,
By 2020, FC production has been decided to be totally abolished. Although HFCs do not destroy the ozone layer, they do affect global warming and are expected to have some restrictions in the future. In particular, the problem of the detoxification of HCFC22, which has been used for household room coolers for nearly 20 years and is currently produced more than 30,000 tons annually in Japan, is a problem of CF.
This is the second most important issue after C. Therefore, if detoxification treatment can be performed on these chlorofluorocarbon substitutes for HCFC and HFC, it can further contribute to global environmental protection. The present inventors previously radiated ultraviolet rays having a specific wavelength to achieve the highest decomposition rate to continuously supplied gaseous fluorocarbons to decompose the fluorocarbons, and separated the reaction product and unreacted fluorocarbon into a separation membrane. A method and an apparatus for continuous decomposition and separation of CFCs, which are continuously separated by the method, were developed and a patent application was filed (Japanese Patent Application No. 3-3062).
No. 97, Japanese Patent Application No. 4-137311).

[0004]

The invention of the present patent application relates to a method and an apparatus for continuously decomposing and separating CFCs without a chemical treatment. The CFCs used in various applications are disclosed. No decomposition / recycling treatment system for chlorofluorocarbons or the like has been established, including recovering the chlorofluorocarbons and supplying them to the continuous decomposition and separation treatment, and collecting decomposition products such as chlorofluorocarbons. Therefore, an object of the present invention is to
The purpose is to establish a system for processing and decomposing resources such as chlorofluorocarbons by ultraviolet light, and to commercialize the system.

[0005]

The above object of the present invention is achieved by the following constitution. In other words, the pressure of the specified CFC, alternative CFC, halon or halogen-containing organic solvent in a pressurized state
Contains at least one type of CFC-based material, lubricating oil, and moisture
The fluorocarbon material-containing mixture is photolyzed by ultraviolet light, in the degradation and recycling processing method fluorocarbon material-containing mixture by ultraviolet light rendered harmless by separating the solid product and the halogen products, in a pressurized state After the mixture containing the chlorofluorocarbon-based substance is brought to normal temperature and normal pressure , the lubricating oil is separated and removed, and the air is accelerated in the mixture containing the chlorofluorocarbon-based substance after the separation of the lubricating oil.
Was added as a substance, after almost completely water separated and removed from the resulting mixture, subjected to photolysis by ultraviolet light, Freon-based material containing continuously fed by separation and recovery of halogen compounds from the product A method for decomposing and recycling a mixture containing a chlorofluorocarbon-based substance by ultraviolet light, characterized by treating the mixture , or

A specific CFC in a pressurized state , an alternative CFC,
Composed of one or more halons or halogen-containing organic solvent
Contains Freon-based substances including Freon-based substances, lubricating oil and water
The mixture was photolyzed by ultraviolet light, fluorocarbon mixture by ultraviolet light rendered harmless by separating the solid product and the halogen product
In decomposing and recycling apparatus of the quality-containing mixture, pressurizing flatly
Room temperature the Freon material-containing mixture was introduced lubricating oil in the state, the gas-liquid separator separated off at normal pressure, the gas-liquid separation
It separated gas to the supply device of the air to be added as a photolysis reaction promoting agent, the water content separation you separated off fluorocarbon material-containing mixture and al water content Toka air supplied from the two devices from the release device A photo-decomposition reaction device comprising: an apparatus; and an ultraviolet light irradiation unit for introducing a mixture of a fluorocarbon-based substance-containing mixture and air from which water has been separated by the water separation apparatus.
A halogen compound separation device for separating gaseous or liquid halogen compounds generated by photolysis in a decomposition reaction device ,
A halogen capture and storage device for collecting the halogen compound separation device separated halogen compound, the off continuously supplied to the respective devices sequentially connected in fluid flow path
An apparatus for decomposing and recycling a mixture containing a chlorofluorocarbon-based substance by ultraviolet light, comprising treating the mixture containing a chlorofluorocarbon-based substance .

[0007] The optimal wavelength for the decomposition of a specific CFC is 190 nm.
It was reported in the above-mentioned patent application invention of the present inventors that the low-pressure mercury lamp used at that time had a performance of 1 or less.
It was impossible to output a wavelength of 85 nm or less. Therefore, the wavelength at which the fluorocarbon and the like of the present invention can be most efficiently decomposed may be 185 nm or less. As an example of the specific CFC (CFC) decomposed in the present invention, CFC11 (CFC)
Cl ₃ F), CFC 12 (CCl ₂ F ₂ ), CFC 113
_{(CCl 2 F-CClF 2)} , CFC114 (CClF 2
-CClF ₂ ) and CFC115 (CCIF ₂ -CF ₃ ).
1: CF ₂ ClBr, 1301: CF ₃ Br, 2402:
CF ₂ BrCF ₂ Br), alternative chlorofluorocarbon HCFC (22: C
HF ₂ Cl, 123: CHCl ₂ CF ₃ , 141b: CH ₃
CCl ₂ F), alternative chlorofluorocarbon HFC (134a: CH ₂ FC)
F ₃ ), halogen-containing organic solvent (carbon tetrachloride, 1,1,1)
-Trichloroethane, trichloroethylene) and the like.
Note that it is necessary to use an HFC having a different wavelength from that of the ultraviolet lamp used for the HFC.

[0008]

According to the present invention, lubricating oil which may generate harmful substances upon irradiation with ultraviolet rays is separated and removed from the collected chlorofluorocarbon and the like at normal temperature and normal pressure. Then, a photolysis reaction is performed. At this time, oxygen in the air is used as a photolysis reaction promoting substance. By using air as an oxygen source, a low-cost reaction promoting substance can be obtained. Further, if water is mixed in the photolysis reaction device, hydrogen fluoride harmful to the human body is generated during the photolysis reaction, and it is necessary to introduce Freon and air from which water has been completely removed. Chlorine (in the case of freon, 1,1,1-trichloroethane) and bromine (in the case of specific halon) generated by the photolysis reaction are easily removed by a separation device such as a gas separation membrane and stored in the recovery and storage device. Can be Further, since the fluorine-based powder produced by the photolysis reaction is a solid, it is separated from the photolysis reaction device and collected by the recovery device.

The principle of this treatment method is to efficiently carry out the photodissociation reaction of halogen atoms such as chlorofluorocarbons by ultraviolet rays occurring in the ozone layer in a reaction vessel on the ground. Therefore, all ozone-depleting substances can be detoxified by this method. (Decomposition and prediction of decomposition reaction of fluorocarbon and the like by ultraviolet light by molecular orbital method) In the above-mentioned earlier application of the present inventors, C
The decomposition reaction analysis of FC by ultraviolet light was calculated by molecular orbital method (PM3) using a personal computer, and the following was predicted.

(I) Five kinds of CFCs and C-
Calculating the strength of Cl, CF, CC bond, CFC
Regardless of the difference between the five types and the CFC radical (chlorine dissociation radical), C-Cl bonds of about 10 eV, C-F bonds of about 14.5 eV, and C-C bonds of about 12 eV are obtained, limiting the wavelength of ultraviolet light. Then C- with the smallest binding energy
It is highly likely that only Cl bonds are photodissociated (see Table 1). (Ii) From the potential curve of the photodecomposition reaction (Cl dissociation) of the five CFCs and the CFC radical, CFC and the CFC radical intersect the chlorine dissociation curve near the minimum point of each excited state, and dissociate chlorine atoms by specific UV. Is shown.

[0011] In the present invention, as in the above-mentioned patent application, HCFC can be photodecomposed at substantially the same wavelength as CFC and the main product gas is chlorine. / 386 (Ver6.
0 compatible version, manufactured by Toray System Center) and MOPA
C Ver6.01 (Japan Chemical Program Exchange Organization JC
(PE PROGRAM P015, for a large computer) using molecular orbital method (PM3).

The following conclusions were obtained from the reaction analysis and reaction prediction using ultraviolet light. (I) Ozone depleting substances undergo a common photolysis reaction. Photodegradation reactions were examined for ozone layer depleting substances other than specific freon, such as specific halon, HCFC alternative freon, and halogen-containing organic solvents shown in Table 2 (HFC134a and 1,1,1-trichloroethylene are the ozone depleting substances. No, but was considered for comparison). As a result, it was inferred that the ozone depleting substances including the specific chlorofluorocarbons perform a common photolysis reaction.

A) The optimum wavelengths of the photolysis reaction take values close to each other (see Tables 1 and 2).

[Table 1]

[0014]

[Table 2]

(B) Bromine atoms and specific freons in the specific halon, and chlorine atoms in the organic solvent as a substitute for HCFC. c, photodissociation is S ₁ - cross the T ₁ (lowest excited triplet state) near the minimum point of the (lowest excited triplet state) halogen atom dissociation potential curve, dissociating halogen atom. d, HFC134a was conducted for comparison was found to be photolysis by ultraviolet light, the photodissociation reaction occurs C-C bond dissociation reaction, dissociate directly from S _1. Further, since the optimum resolution wavelength is on the short wavelength side of about 1/2 of the ozone depleting substance, it is necessary to select a light source different from other substances. e, The photodissociation reaction of trichlorethylene carried out for comparison is the dissociation of a CＣC bond. Further, the optimum decomposition wavelength is on the shorter wavelength side than the ozone depleting substance.

(Ii) Specified halon and chlorofluorocarbon alternative HCFC undergo a specific atom abstraction reaction due to oxygen radicals or the like. Using a calculation model shown in FIG. 2, specific atom abstraction reactions by oxygen atom radicals and chlorine atom radicals were examined for specific halon and HCFC alternative chlorofluorocarbon. As a result, it was found that the specific halon and the HCFC-substituted fluorocarbon receive abstraction of chlorine atoms and hydrogen atoms in the molecule from oxygen atom radicals, chlorine atom radicals, and bromine atom radicals, similarly to the specific freon. From the results of the above (i) and (ii), the method of the present invention is a detoxification / recycling treatment method (using oxygen as a reaction promoting gas) not only for specific CFCs but also for ultraviolet light, but other ozone It has been found that by selecting an appropriate gas separation membrane for a layer-destructing substance, a detoxifying and recycling process (using oxygen as a reaction promoting gas) by ultraviolet light is possible.

[0017]

An embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the recovery of Freon and its decomposition / recycling treatment will be described on behalf of Freon and Freon-like substances unless otherwise specified. FIG. 1 shows a schematic configuration diagram of a fluorocarbon decomposition / resource processing system using ultraviolet light according to the present embodiment. First, the lubricating oil is separated and removed from the collected freon by the separating device 1 for freon and lubricating oil. Next, in order to almost completely separate water, which is a factor inhibiting decomposition of CFCs by ultraviolet light,
Freon is passed through moisture removal device 2. Air promote the reaction gas is introduced from the air supply device 3, excluding the water through moisture removal device 2. Thus, in the photolysis reactor 4,
(Bromine liquids For halons (bromine boiling point 58.8 ° C.) so, the gas can be easily separated and recovered.) Chlorine gas produced performs decomposition of Freon gas gases whose main component separation membrane 5 (In the case of bromine, a separation membrane is unnecessary), the chlorine (or bromine) is recovered by the halogen recovery / storage device 6, and unreacted separated by the gas separation membrane (gas-liquid separation in the case of halon). (Halon) is recovered in the photolysis reaction device 4 and reacted again by photolysis. Further, the fluorine-based powder generated by the photolysis reaction is collected in the fluorine-based powder separation and recovery device 7.

[0018] (1) separation apparatus 1 car cooler or an electric refrigerator of the refrigerant with Flon and the lubricating oil in the refrigerant, and CFC12 and lubricating oil from about 1 weight ratio: is composed at a ratio of 1. The lubricating oil used is a mineral oil-based oil containing an aromatic hydrocarbon. (Reaction analysis and reaction prediction of lubricating oil by molecular orbital method) Lubricating oil for compressors of electric refrigerators and car coolers is composed of naphthenic, paraffinic and aromatic. Therefore, prior to the experiment, the photolysis characteristics of each component of the naphthenic, paraffinic and aromatic lubricating oils were calculated by the molecular orbital method (PM3) using the large computer and personal computer, and the following conclusions were obtained. Was.

A, The photoexcitation energy (dissociation of C—H bond) of the naphthenic or paraffinic lubricating oil is at least twice as long as the shortest ultraviolet (185 nm) wavelength of a low-pressure mercury lamp (ultraviolet having a short wavelength of 1/2 or less). is required. Therefore, photodissociation does not occur with a low-pressure mercury lamp. b 、 Aromatic system is low pressure mercury lamp at 185nm, C-H
The bond can be photodissociated. Further, when an aromatic radical is combined with a chlorine radical generated by photodissociation of a specific chlorofluorocarbon, there is a risk that a highly toxic compound is generated. Therefore, the lubricating oil must be almost completely removed before being introduced into the photolysis reactor 4. Of the aromatic hydrocarbons,
Depending on the chemical structure, the wavelength of the low pressure mercury lamp or C
Photochemical reaction is caused by ultraviolet rays having the optimal photolysis wavelength of FC12 (benzene: 122.94 kcal / mol, toluene: 122.45 kcal / mol, isobutylbenzene: 121.45 kcal / mol, naphthalene: 10)
3.80 kcal / mol, β-isobutylnaphthalene: 104.62 kcal / mol). Also CFC12
When a chemical reaction occurs between the aromatic hydrocarbon and oxygen atoms generated by the photolysis of chlorine radicals and oxygen (a reaction-promoting gas) generated by the photolysis of water, there is a possibility that many types of compounds may be formed. large. Especially dioxin and PCB
It is feared that chlorine-based harmful substances such as will be generated. Therefore, the lubricating oil and the CFC 12 are almost completely separated, and the CFC 12
Only need to be introduced into the reactor.

(Structure of separation device 1 for chlorofluorocarbon and lubricating oil)
The mixture of CFC12 and lubricating oil has a boiling point difference (CFC12: -29.79 ° C., lubricating oil 2) at normal temperature and normal pressure.
50C or more), only CFC12 can be taken out in gaseous state,
It has been found that pure CFC 12 can be detoxified and introduced into the photolysis reactor 4. However, when only the gaseous CFC 12 is taken out at normal temperature, about 5% of the CFC 12 remains in the lubricating oil. CFC12 in the lubricating oil is not chemically bonded to the lubricating oil, but is only physically bonded. Therefore, when the CFC12 is placed at a temperature of 100 ° C to 200 ° C for about 2 hours, only the CFC12 is taken out from its boiling point difference. Can be.

Therefore, in order to make a practical separation device,
As shown in FIG. 3, the separation device 1 for chlorofluorocarbon and lubricating oil has a configuration in which separators 10 are arranged in multiple stages. The inlet of each separator 10 is connected to a duct 11 for introducing a refrigerant for a car air conditioner or an electric refrigerator collected by a CFC recovery machine or the like.
From the CFC 12 in the separator 10 at normal temperature and normal pressure.
And the lubricating oil are separated. The separated chlorofluorocarbon is led from the outlet of the separator 10 to the inlet of the next stage of the separator 10 through the duct 11. A felt-like filter 12 is provided in the separator 10 near the outlet to prevent mist-like lubricating oil from coming out of the outlet along with Freon. The separated liquid lubricating oil is stored in a lubricating oil reservoir 13 provided at the bottom of the separator 10. At this time, separation from Freon
In order to make the mixture almost complete, a baffle plate 15 is provided at a position opposite to the direction in which the mixture of chlorofluorocarbon and lubricating oil is blown from the inlet into the separator 10, and the mixed flow introduced into the baffle plate 15 is sprayed to scatter the lubricating oil. Prevention can also be achieved. In this way, by passing the mixture of Freon and lubricating oil through the multi-stage separator 10, the lubricating oil can be almost completely separated from the collected Freon.

(2) Decomposition of Freon by Ultraviolet Light Using Air as a Reaction Accelerating Gas In decomposing Freon by ultraviolet light, oxygen is used as a reaction accelerating gas. Oxygen molecules are photolyzed into oxygen atoms by the 185 nm ultraviolet light of the mercury lamp as in the following formula (1). O ₂ → 2O · (1) As shown in the reaction formulas (2) and (3),
It was found from the molecular orbital method, which is a computational chemistry, and experimental results that a chlorine atom abstraction reaction of chlorofluorocarbons is caused to accelerate the decomposition of chlorofluorocarbons.

[0023]

Embedded image If the outside air can be used as it is as the supply source of the oxygen molecules, the apparatus of this embodiment becomes simple and compact. For example, oxygen cylinder or PSA
(Pressure swing adsorption) It is not necessary to incorporate the apparatus into the processing apparatus. Experiments have confirmed that there is no difference in the promotion of CFC decomposition between pure oxygen and air.

(Nitrogen Oxide Generation Experiment Using Ultraviolet Light in the Coexistence of Air and Freon) Ultraviolet light of 185 nm from a low-pressure mercury lamp photolyzes oxygen molecules to generate oxygen atoms. When air is used as a source of oxygen, the oxygen atoms react with nitrogen molecules, and nitrogen oxides harmful to the human body according to the reaction formula (4) .
It is feared to generate. N ₂ + O.fwdarw.N ₂ O (4) Then, generation of nitrogen oxides was considered from experiments and computational chemistry. As a result, the reactions of formulas (2), (3) and (4) occur in the form of a competitive reaction in the reaction vessel, but the reactions of formulas (2) and (3) predominantly occur. It was found that the generation of nitrogen oxides was very small. After mixing air and chlorofluorocarbon into a UV reactor and irradiating them with ultraviolet light from two low-pressure mercury lamps 32W (cold cathode type: manufactured by Riko Kagaku Co., Ltd.), the amount of nitrogen oxides (NOx) generated Was measured with a nitrogen oxide meter. Table 3 shows the results.

[0025]

[Table 3] As described above, NOx is 0.2 ppm at the maximum, and in the reaction with ultraviolet light by mixing air and chlorofluorocarbon, in particular, N
Ox generation proved to be no problem.

[0026] (3) When introducing moisture removal device 2 refrigerant photolytic reactor 4, water mixed in the refrigerant is also always fall. Also, when using outside air as the reaction promoting gas, moisture is mixed with the air. If these moistures are not almost completely removed by the dehydrator before the introduction into the reactor 4, the excess and harmful reactions of the following formulas (5) to (7) occur due to the moisture mixed in the reactor. The reaction of _{H 2 O → H · + OH} · (5) H 2 O + O · → 2OH · (6) CCl 2 F 2 + H · → CCl 2 F · + HF (7) , especially the formula (7), Hydrogen fluoride (H
F). Further, this HF is a dangerous chemical substance that becomes hydrofluoric acid in the presence of moisture and corrodes the glass on the wall surface of the photolysis reaction device 4. Equation (5)
The photodecomposition reaction of water molecules by ultraviolet light is a hydrogen radical generation reaction that causes hydrogen fluoride to be generated. Further, the reaction of the formula (6) is a wasteful reaction that consumes an oxygen atom which is a chemical substance for accelerating the decomposition of chlorofluorocarbon.

The moisture removal device 2 of this embodiment powerful hygroscopic device filled with hygroscopic material on the front and air flow paths immediately before introduction into the photolytic reactor 4 (not shown) is used many stages It has a structure having a good moisture absorbing effect. As the hygroscopic material, zeolite, calcium chloride, or the like, which has a large hygroscopic effect, is harmless to the human body, and is easy to handle, is used. Thus, the fluorocarbon separated from the lubricating oil and the water contained in the air used as the reaction promoting gas are almost completely removed.

(4) Photolysis Reaction Device 4 by Ultraviolet Light When the photochemical reaction device 4 is made of a glass container,
Ultraviolet rays emitted from an ultraviolet ray generator provided at the center of the container pass through the glass and reach the outside. When the photolysis reaction device 4 is made of a container made of a metal, a polymer, a ceramic material, or the like, the container absorbs ultraviolet rays. In any of the above cases, this is one of the causes of lowering the energy efficiency in the photochemical reaction. Further, the ultraviolet light transmitted from the glass container photodecomposes oxygen in the air as shown in the following formulas (1) and (8) to generate oxygen atoms and ozone harmful to the human body. O ₂ → 2O. (1) O ₂ + O. → O ₃ (8) Further, there is a danger that the ultraviolet light transmitted through the glass may have an adverse effect on vision.

Therefore, the photodecomposition reactor 4 of this embodiment is manufactured in a glass reaction vessel 20 as shown in FIG. The outer peripheral portion is covered with an ultraviolet reflective film 22, and the ultraviolet light 23 emitted from the ultraviolet lamp 21 is reflected by the outer peripheral portion of the glass reaction vessel 20, thereby increasing the energy efficiency in the photochemical reaction, preventing the generation of harmful gas, and preventing the visual perception. Provide protection.

The ultraviolet reflective film 22 may be coated on the inside or outside of the outer periphery of the glass reaction vessel 20. In particular, a vacuum deposited film of aluminum has excellent reflectance in the ultraviolet region (91.nm at a wavelength of 220 nm). 5%)
It is a preferred reflective film material. Further, the ultraviolet reflective film 22 and the glass reaction vessel 2 on which the reflective film 22 is coated
It is necessary to make close contact with the 0 wall. This is because, when coating the ultraviolet reflective film 22 on the outer wall surface of the glass reaction container 20, if there is a space between the reflective film 22 and the wall surface of the glass reaction container 20, a photochemical reaction of oxygen in the air occurs, and the ultraviolet light is This is because they are consumed and generate oxygen atoms and ozone that are harmful to the human body. When the ultraviolet reflective film 22 is coated on the inner wall of the glass reaction vessel 20, oxides or chlorides are formed on the metal surface of the reflective film 22 by oxygen atoms and chlorine radicals of the reaction products, and the reflectance is reduced. Further, even when the material of the photolysis reaction device 4 is synthetic quartz, which has low ultraviolet absorption among the glass, ultraviolet absorption in the glass on the outer periphery occurs to a considerable extent, resulting in loss of ultraviolet. Therefore, it is desirable to use a material made of LiF, CoF ₂ , fused quartz or the like which has almost no absorption.

The chlorofluorocarbon decomposition / treatment method of this embodiment is a chlorofluorocarbon detoxification treatment method using a gas phase photochemical reaction. When a cold cathode type low-pressure mercury lamp (for example, UVL-32LP manufactured by Riko Kagaku Co., Ltd.) is used as a light source in the glass reaction vessel 20, several tens of 100 W-class lamps having a maximum wattage are required. Become. Also, since the life of mercury lamps varies, it is necessary to gradually replace them with new lamps. Therefore, a replacement / detachment system for the ultraviolet lamp 21 that satisfies the following two conditions is required. The photolysis reaction vessel 20 is divided into a light source section having an ultraviolet lamp 21 and a reaction vessel having no ultraviolet lamp 21 and supplying and discharging a mixed gas of chlorofluorocarbon and air. The light source unit and the reaction vessel are independent of each other, and the replacement and detachment of the ultraviolet lamp 21 of the light source unit can be performed without stopping the reaction even during operation. The replacement and detachment of the ultraviolet lamp 21 is facilitated.

Therefore, in this embodiment, the photolysis reaction device 4
As shown in FIG. 5, the light source unit 20a and the reaction vessel 20
b have independent mechanisms, and the light source unit 20a and the reaction vessel 20b are connected by an optical fiber cable 25 (FIG. 5).
(A), (b)) or the high reflection mirror 26 (FIG. 5)
(C) The connection type in ()) is adopted. The light source section is filled with nitrogen gas or the like that does not absorb light from the low-pressure mercury lamp. In addition, a condenser lens 24 is disposed near the ultraviolet light outlet of the light source unit 20a, and the ultraviolet light is efficiently supplied to the reaction container 20b. FIG. 5A is a schematic diagram of the entire device 4 showing a light source unit 20 in which an ultraviolet lamp 21 is housed.
An example is shown in which a is connected to the reaction vessel 20b by an optical fiber cable 25. Further, as shown in the enlarged views of the connection portion between the light source section 20a and the reaction vessel 20b in FIGS. 5B and 5C, the light source section 20a and the reaction vessel 20 are both made of synthetic quartz glass.
The outer wall of b is coated with a highly reflective film 22 of aluminum, and the ultraviolet rays from the light source section 20a are effectively irradiated to the reaction vessel 20b, and the ultraviolet rays are uniformly reflected from the outer wall section of the reaction vessel 20b. The chlorofluorocarbon decomposition reaction conditions inside the container 20b are made uniform. FIG. 5C is an enlarged view of the connection portion when the light source unit 20a and the reaction container 20b are connected using the high reflection mirror 26. Light source unit 20
The ultraviolet light from a is connected to the reaction vessel 2 through a high reflection mirror 26 through a connection pipe 27 made of a material that does not absorb the light of a low-pressure mercury lamp such as a metal filled with nitrogen gas or a fluororesin.
0b.

The replacement of the reaction vessel 20b is performed as shown in FIG.
(A) is a top view, and FIG. 6 (b) is a partial cross-sectional side view: a connection portion between the light source unit and the reaction vessel 20b is not shown). The two reaction vessels 20b provided in the
Rotate again to change the arrangement of the reaction container 20b in which the ultraviolet lamp 21 is to be replaced and the spare reaction container 20b, remove the ultraviolet lamp 21 from the reaction system, open the holding lid 31, take out the used ultraviolet lamp 21 and remove the new lamp 21 Replace with The fixing of each ultraviolet lamp 21 in the reaction vessel 20b is not shown, but is a combination of a spring and a screw.
The lamp 21 can be replaced with one touch. In this manner, the exchange / removal of the ultraviolet lamp 21 can be performed without stopping the reaction even during the operation of the photolysis reaction device 4. In the mechanism without the spare reaction vessel 20b (see FIG. 4), the fluorocarbon is not photodecomposed during the replacement of the ultraviolet lamp, but the unreacted fluorocarbon is continuously fed back to the photolysis reactor 4 by the gas separation membrane 5. You. Therefore, also in this case, the lamp can be replaced without stopping the operation.

The cooling of the ultraviolet lamp in a conventional open-type reaction vessel (not shown) is performed by air cooling.
The air cooling method is an open type reaction vessel in which air is forced to flow through a cavity between a plurality of ultraviolet lamps of the reaction vessel, an outer peripheral wall surface of the reaction vessel, and a gap between the ultraviolet lamps. Therefore, the ultraviolet rays are absorbed by air (oxygen) for air cooling, and the ultraviolet rays to be sent to the reaction vessel are consumed here. Oxygen that has absorbed ultraviolet rays undergoes a photolysis reaction, and is partially converted into oxygen atoms and ozone. The air for air cooling containing oxygen atoms and ozone is released to the outside as it is, but the oxygen atoms and ozone contained therein are harmful to the human body even in trace amounts (the working environment of ozone for 8 hours is 0.1 ppm. Below). However, oxygen atoms and ozone are valuable chemicals that promote the decomposition of chlorofluorocarbon in the reaction vessel.

Therefore, instead of the conventional open-type reaction vessel,
In the case of the photolysis reaction device 4 of the type in which the ultraviolet lamp 21 is housed in the reaction vessel 20 as shown in FIG. 4, the reaction vessel 20 is used as a closed reaction vessel 20 as shown in FIG. Without providing a cavity, the ultraviolet lamp 21 is cooled by the chlorofluorocarbon used for the reaction and the reaction air from which water has been removed. This has the following advantages. That is, oxygen atoms and ozone that are harmful to the human body are not released to the outside air even in small amounts. Oxygen atoms and ozone generated by cooling are used for the CFC treatment without waste.

In the case of the photolysis reaction device 4 in which the light source section 20a and the reaction vessel 20b are connected by the optical fiber 25 or the high reflection mirror 26 as shown in FIG. 5, the light source section 20a is connected to the light source section 20a as shown in FIG. A cock 33 is provided in the flow path of the mixed gas of air and Freon connecting the reaction vessel 20b, and when the ultraviolet lamp 21 of the light source section 20a is replaced, the cock 3
3, the gas flow path 34 is closed, the gas in the light source unit 20a is temporarily stored in a gas reservoir 36 attached to the light source unit 20a, and the light source unit 20a is removed from the lamp 21 used outside the photoreaction system. Then, when returning to the photoreaction system again, the cock 33 of the gas flow path 34 and the cock 37 of the gas reservoir are opened again to resume the continuous reaction.

(6) Gas Separation Membrane 5 As described in detail in the previous patent application invention (Japanese Patent Application No. Hei 4-137311) , the gas separation membrane 5 of the present embodiment comprises: (i) silicone Hollow fiber membrane (M-6, manufactured by Nagayanagi Industry Co., Ltd.)
0, M-80) (ii) Polyimide hollow fiber membrane (UM-A manufactured by Ube Industries, Ltd.)
1) Use one of In the continuous method of this example, the polyimide hollow fiber membrane had a higher chlorine gas separation ability than the silicone hollow fiber membrane. Also, about 1 hollow polyimide fiber membrane
When the temperature is raised to 50 ° C., the degree of separation shows a high value. Therefore, it is preferable to use the polyimide hollow fiber membrane in a state where the separation membrane is heated.

(7) Halogen recovery / storage device 6 The main product of the method for decomposing and recycling CFCs using ultraviolet light is chlorine gas or bromine. Although chlorine gas is industrially beneficial, it is toxic to the human body. (The 8-hour working environment of chlorine gas is regulated by law to be less than 0.5 ppm.)
Is ). Therefore, a device for safely and reliably collecting and storing the chlorine gas separated from the unreacted chlorofluorocarbon by the gas separation membrane 5 is required. Halogen recovery and storage device 6 of this embodiment
Is for collecting and storing chlorine gas permeated through the gas separation membrane 5 and separated from unreacted Freon, based on the same principle as a Freon recovery machine of a car cooler. That is, chlorine gas is compressed by a compressor to produce a high-temperature and high-pressure gas, and the compressed halogen gas is allowed to cool by a condenser to form liquid chlorine, which is recovered and stored in a cylinder in a liquid state. As described above, the principle of the CFC recovery machine for the car cooler (in some cases, the recovery machine itself) can be applied because the boiling point of CFC12, which is the refrigerant of the car cooler, and the boiling point of chlorine are considerably close. .

(8) Fluorine-based powder separation and recovery device 7 Fluorine-based powder produced by polymerization of the reaction intermediate is
It travels with the gas fluid in the device. Therefore, a felt-like filter and a reservoir of the fluorine-based powder falling from the filter (fluorine-based powder separation device 7) are provided in front of the gas separation membrane 5, and the fluorine-based powder is separated and recovered from the gas fluid. In addition, a reservoir (not shown) of the fluorine-based powder which falls under the reaction vessel 20 is provided to perform recovery.

(9) Equipment for Decomposing and Recycling CFCs in Foaming Materials The annual amount of CFC used for foaming is about 40,000 tons, which accounts for 25% of the total amount of CFCs used in Japan. Approximately 25,000 tons of CFC11, CFC1
2 is used for about 12,000 tons per year (actual in 1988). Freon in these used foam materials is crushed (
To destroy by pressing. ), Etc., release into the atmosphere. Also, when left or landfilled, the foam material gradually deteriorates, and accordingly, CFCs are released into the atmosphere. Therefore, about the Freon in the used foam material,
It is necessary to perform detoxification processing. Since a small amount of the used foamed material is individually collected, it is reasonable to perform a detoxification treatment at a collection establishment. The CFCs in the foamed material are compressed by a compression force only at a temperature close to room temperature using an electric hydraulic pressure or the like using an electric hydraulic pressure or the like to discharge the CFCs, and the CFC collection device collects the CFCs in the container. The collected Freon is directly introduced into a device for decomposing and recycling Freon using ultraviolet light, and is rendered harmless. There is also an advantage that the compression of the foam material reduces the volume of the base material itself of the foam material.

As described above, according to the present embodiment, a small amount of individual refrigerant filled in an electric refrigerator, a car cooler, a home cooler, and the like is recovered, and fluorocarbons and the like are easily decomposed to make them harmless, and the resources are recycled. can do. The system of this embodiment does not have a chemical treatment step, can perform processing under processing conditions close to normal temperature and normal pressure, and has good operability because it is a fully automatic continuous processing apparatus. Further, the device of this embodiment can be provided as a portable and simple device.

[0042]

According to the present invention, a practical and continuous decomposition / recycling treatment system for chlorofluorocarbons and chlorofluorocarbons can be established. Further, the system of the present invention has no chemical treatment step, can be processed under processing conditions close to normal temperature and normal pressure, and is a simple system with good operability since it is a continuous processing apparatus.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a CFC decomposition / recycling processing system according to an embodiment of the present invention.

FIG. 2 is a reaction calculation model of an atom abstraction reaction.

3 is a diagram of the separation apparatus of Freon and lubricant embodiment of the present invention.

FIG. 4 is a diagram showing a photolysis reaction device according to an example of the present invention.

FIG. 5 is a diagram showing a photolysis reaction device according to an example of the present invention.

FIG. 6 is a view showing a photolysis reaction apparatus according to an example of the present invention.

[Description of Reference Numerals] 1 ... separator with Flon and the lubricating oil, 2 ... water content separation device,
DESCRIPTION OF SYMBOLS 3 ... Air supply apparatus, 4 ... Photolysis reaction apparatus, 5 ... Gas separation membrane, 6 ... Halogen gas recovery / storage apparatus, 7 ... Fluorine-based powder separation and recovery apparatus, 10 ... Separator, 11 ... Refrigerant introduction duct, 12 ... felt-like filter, 13 ... lubricating oil reservoir,
Reference numeral 15: baffle plate, 20: glass reaction vessel, 20a: light source section, 20b: reaction vessel, 21: ultraviolet lamp, 22: ultraviolet reflection film, 23: ultraviolet ray, 24: condenser lens, 25 ...
Optical fiber cable, 26: high reflection mirror, 27: connecting pipe, 30: rotating shaft, 34: gas flow path

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Zhao Xingzheng 17 Kyoto Research Park Kansai New Technology Research Institute, Kyoto, Shimogyo-ku, Kyoto, Kyoto Prefecture (72) Inventor Shigeru Morikawa Terani-cho 17 Kyoto Research Park Kansai New Technology Research Institute Co., Ltd. A) JP-A-1-300969 (JP, A) JP-A-5-277359 (JP, A) JP-A-5-277205 (JP, A) JP-B-61-59779 (JP, B2)

Claims (2)

(57) [Claims] 1. A CFCs in the pressurized state, HCFCs, from one or more of Halon or halogen-containing organic solvent
Substance containing chlorofluorocarbon, lubricating oil and water
The containing mixture was photolyzed by ultraviolet light, CFCs by ultraviolet light rendered harmless by separating the solid product and the halogen product
In the method for decomposing and recycling a mixture containing a system-based substance, after the mixture containing a CFC-based substance in a pressurized state is brought to normal temperature and normal pressure , the lubricating oil is separated and removed, and the flow after lubricating oil separation is performed.
Air as a photodecomposition reaction promoting substance
Almost completely separates and removes water from the resulting mixture
After that, a photodecomposition reaction is performed by ultraviolet light, and a fluorocarbon-based substance-containing mixture that is continuously supplied by separating and recovering a halogen compound from a product is treated . Decomposition and recycling methods. 2. A CFCs in the pressurized state, HCFCs, from one or more of Halon or halogen-containing organic solvent
Substance containing chlorofluorocarbon, lubricating oil and water
The containing mixture was photolyzed by ultraviolet light, CFCs by ultraviolet light rendered harmless by separating the solid product and the halogen product
In decomposing and recycling apparatus of the system material-containing mixture, ambient temperature the Freon material-containing mixture was introduced lubricating oil in the pressurized state, the gas-liquid separator you separated off at normal pressure, the
A supply device for air to be added to the separated gas from the gas-liquid separator as photolysis reaction promoting agent, separated off fluorocarbon material-containing mixture and al water content Toka air supplied from the two devices Water And a mixture of air and a mixture containing the CFC-based substance from which water has been separated by the water separator.
A photodecomposition reaction device provided with an ultraviolet light irradiation unit for introducing a compound, a halogen compound separation device for separating gaseous or liquid halogen compounds generated by photolysis in the photodecomposition reaction device , and a halogen compound separation device. With a halogen recovery and storage device that recovers the separated halogen compounds,
An apparatus for decomposing and recycling a mixture containing a chlorofluorocarbon-based substance by ultraviolet light, wherein the apparatuses are sequentially connected by a fluid flow path to treat the mixture containing a chlorofluorocarbon-based substance supplied continuously.