FR3108040A1 - Process for dechlorination of one or more aromatic organochlorine compound(s) contained in an oil or constituting said oil - installation and associated electrical/electronic apparatus - Google Patents

Abstract

The present invention relates to a process for the dechlorination of one or more aromatic organochlorine compound (s) contained in an oil or constituting said oil, the said organochlorine compound (s) (s) aromatic (s) being chosen, in particular, from molecules comprising two or three benzene rings and of which at least one benzene ring or all of the benzene rings are substituted by at least one chlorine atom, in particular the polychlorinated biphenyls and polychlorinated terphenyls, according to which said oil is irradiated with radiation having wavelengths equal to or greater than 300 nm, in particular with radiation having wavelengths equal to or greater than 320 nm and in particular with radiation having wavelengths equal to or greater than 320 nm and equal to or less than 390nm, while maintaining the temperature of said oil at a value less than or equal to a given threshold value. The present invention also relates to an installation and an associated electrical / electronic device. Fig. 1

Description

Process for bleaching one or more aromatic organochlorine compound(s) contained in an oil or constituting said oil - associated installation and electrical/electronic apparatus

The present invention relates to a method of one or more organic organochlorine compound(s) contained or constituting an oil and chosen, in particular, from molecules comprising two or three benzene rings and of which at least one benzene ring or all the benzene rings are substituted by at least one chlorine atom, in particular the polychlorobiphenyls and the polychloroterphenyls. The present invention also relates to an installation and an electrical/electronic apparatus for implementing the method of the invention.

Prior Art

Polychlorinated biphenyls (PCB) and polychlorinated terphenyls (PCT) compounds are compounds that have been widely used for their electrical insulation properties, their excellent dielectric characteristics, their resistance to high temperatures and their good thermal conduction. They have thus been widely used in electrical devices, such as transformers, capacitors and even oil-filled heaters.

All these aromatic organochlorine compounds, in particular PCBs and PCTs, are very hydrophobic, highly lipophilic and poorly soluble in water. A large part of PCBs and PCTs are POPs (persistent organic pollutants).

PCBs and PCTs are sometimes used alone or in a mixture as a heat transfer fluid/electrical insulator in electrical devices.

The treatment of these toxic molecules present in transformers (as a mixture in a hydrocarbon oil or siloxanes, for example) is currently carried out by the implementation of various techniques. The main technique used on an industrial scale is high temperature incineration under strictly controlled conditions because the incineration of PCBs and PCTs produces highly toxic dioxins and furans.

Incineration is not an ecological process and remains dangerous due to the production of the aforementioned toxic compounds. So there have been attempts to develop other more environmentally friendly methods. In particular, some methods have focused on the dechlorination of PCBs. Indeed, the toxicity of PCBs and PCTs depends on the number and position of the chlorine atoms substituting the benzene rings.

The publication entitled “Ionizing Radiation Induced Degradation of Tetrachlorobiphenyl in Transformer Oil” by Mahnaz Chaychian, Joseph Silverman and Mohamad Al-Sheikhly, published in the journal “Environ. Science. Technol,” vol. 33, page 2461-2464 in 1999, indicates that it is possible to degrade tetrachlorobiphenyls, by means of ionizing radiation of the electron beam type. This method degrades the oil, which can no longer be used and therefore becomes waste.

The publication entitled “Photodegradation of 4-Chlorobiphenyl in Hexane by UV Irradiation” by Qin Hai-Feng, Bao Hua-Ying, Liu An-Dong Hou and Xing-Gang and published in “Chinese Journal of Chemistry”, vol 24, page 355-359, in 2006 indicates that 4-chlorobiphenyl can be dechlorinated in hexane by means of UV radiation with a maximum wavelength equal to 254 nm. The radiation forms diphenyl free radicals, which capture a hydrogen atom from hexane to form diphenyl. The diphenyl is then broken down into lower molar mass hydrocarbons. This method remains a laboratory method and requires the organochlorine aromatic compound to be mixed with hexane.

The publication entitled “Dechlorination of polychlorinated biphenyls in industrial transformer oil by radiolytic and photolytic methods” by Cynthia G. Jones, Joseph Silverman and Mohamad Al-Sheikhly, published in the journal “Environ. Science. Technol”, vol 37, pages 5773-5777 in 2003, indicates that it is possible to dechlorinate transformer oil contaminated with PCBs and containing more than 800,000 µg/g of various PCBs. This oil is diluted with 2-propanol and triethylamine (v/v/v, 1/79/20). This mixture is introduced into a sealed quartz reactor and placed under a nitrogen atmosphere then irradiated with radiation produced by a xenon lamp. The xenon lamp emits in particular at wavelengths below 300 nm. After 120 hours of irradiation, the PCBs are completely transformed into diphenyl. It seems that the reaction involves the transfer of an electron from the triethanolamine to a chlorinated or unchlorinated benzene ring which thus becomes an activated radical. This is a method that requires the prior dilution of the contaminated oil and is therefore difficult to implement on an industrial scale, as a transformer can contain thousands of liters of contaminated oil. Moreover, this method cannot be used to treat a transformer on site and even less a transformer in operation.

The publication entitled “Dechlorination of polychlorinated biphenyls in transformer oil using UV and visible light” by Jiansong Kong, Gopal Achari, Cooper H. Langford et al published in the journal “Journal of Environmental Science and Health”, Part A:Toxic/Hazardous Substances and Environmental Engineering, vol. 48, pages 92-98 in 2013, indicates that it is possible to dechlorinate PCB No. 138, either by using UV radiation or radiation in the wavelengths of visible light.

PCB No. 138 is dissolved in 2-propanol so as to form solutions containing from 0.06% by mass to 92.1% by mass of PCB No. 138. The solutions are mixed with soda until a 0.1N soda solution is obtained. They are then introduced into sealed quartz tubes. For UV irradiation, 8 lamps emitting radiation with a maximum wavelength of 254nm are used; the solutions remain at a temperature of 35°C during the irradiation. For irradiation in the visible light spectrum, solutions of PCB No. 138 in 2-propanol are used, to which methylene blue and triethylamine are added. The solutions are placed in Pyrex tubes and irradiated with a lamp emitting in the visible at a power of 14.8 Watt. Prior to irradiation, a stream of nitrogen is bubbled through the solutions for 10 minutes to remove all the oxygen. The dechlorination of the PCBs contained in a mixture of PCBs called Aroclor 1254 is also obtained with visible light radiation, in the presence of methylene blue, which acts as a catalyst, and of triethylamine.

These methods which require the addition of solvent(s) and/or other compounds are difficult to implement industrially. In addition, the addition of solvent or other affects the chemical and physical properties of the oils, which remain waste (since they cannot be reused due to the alteration of their physico-chemical properties), even if they are less dangerous waste than oil. initial contaminated oil. Moreover, these methods cannot be used on a transformer in operation because the latter can only operate with an oil possibly containing PCB/PCT but not with an oil mixed with a solvent, methylene blue and triethylamine, For example ; these methods therefore require stopping the transformer and rinsing it with new oil in order to extract all the organochlorine compounds contained in the transformer, in particular in the cellulose it contains. The flushing oil which is then contaminated must then be treated. New oil must be injected into the transformer which can then be put back into operation. These methods therefore generate large quantities of waste and only ensure a dilution of the initial PCB level in the transformer.

An object of the present invention is therefore to provide a method for dechlorinating one or more aromatic organochlorine compound(s) contained in an oil or constituting said oil, which overcomes one or more drawbacks of the methods of prior art.

Another object of the present invention is to provide a process which makes it possible to dechlorinate aromatic organochlorine compounds, in particular PCBs and PCTs, so as to obtain aromatic compounds which are not chlorinated or contain 1, 2, 3 or 4 chlorine atoms.

According to a first aspect, the present invention relates to a process for dechlorinating one or more aromatic organochlorine compound(s) contained in an oil or constituting said oil and chosen, in particular, among the molecules comprising two or three benzene rings and of which at least one benzene ring or all the benzene rings are substituted by at least one chlorine atom, in particular the polychlorinated biphenyls and the polychloroterphenyls, according to which said oil is irradiated with radiation having lengths wavelengths equal to or greater than 300 nm, in particular with radiation having wavelengths equal to or greater than 320 nm and in particular with radiation having wavelengths equal to or greater than 320 nm and equal to or less than 390nm, while maintaining the temperature of said oil at a value less than or equal to a given threshold value.

The inventors have in fact demonstrated that an oil as mentioned above is not degraded (neither chemically - apart from the organochlorine aromatic compounds which are dechlorinated - nor physically) by the radiation used in the process according to the invention. In other words, the inventors have demonstrated that the radiation used in the process of the invention does not react with an oil containing one or more organochlorine aromatic compound(s) as defined above, but only with the (s) organochlorine contaminants in the oil, in particular PCBs and PCTs, in such a way as to break the C-Cl bond(s) present on the benzene cycles of the PCBs and PCTs. It is therefore the Applicant's merit to have demonstrated that the oil containing PCB/PCT can be treated without dilution and without adding catalyst or other, by means of radiation of wavelengths such as mentioned above. , which allow the removal of C-Cl bonds, thus dechlorinating organochlorine aromatic compounds, in particular, PCBs/PCTs. This dechlorination reaction takes place despite the high viscosity of the oil, which is unexpected, and without the use of a catalyst, contrary to what is known from the prior art; moreover, the wavelengths used according to the method of the invention make it possible to use robust and inexpensive equipment, thus making the method of the invention economically interesting. In addition, the wavelengths used correspond mostly to UVA and visible; this radiation, in the event of leakage, is not harmful to the organisms subjected to it. The method of the invention can therefore be implemented in complete safety.

Furthermore, the inventors have also demonstrated that the heat provided by the irradiation chemically degrades the oil containing one or more organochlorine aromatic compound(s) chosen, in particular, from the molecules comprising two or three benzene rings and of which at least one benzene ring or all the benzene rings are substituted by at least one chlorine atom, in particular polychlorobiphenyls and polychloroterphenyls. Thus, the threshold value given above is determined experimentally and depends on the oil to be treated. It corresponds to a temperature lower than the temperature at which the oil begins to degrade under the effect of heat input (thermal degradation corresponding to the breaking of the carbon or silica chains of the components of the oil: the molecules of oil are broken down into smaller molecules, which changes the electrical and thermal conductivity properties of the oil). This threshold value can be determined experimentally, for example, by thermogravimetric analysis.

The inventors have therefore demonstrated that, surprisingly, the process of the invention makes it possible to obtain the breaking of C-Cl bonds on organochlorine compounds, in particular the benzene rings of PCBs/PCTs contaminating an oil, without using solvent, catalyst or electron donors. They also demonstrated that the process of the invention does not degrade the oil either chemically or physically: the radiation does not cause any thermal degradation of the oil, since the irradiation (and the entire process of the invention ) takes place below the threshold temperature which corresponds to the thermal degradation temperature of the oil; only PCBs/PCTs are therefore dechlorinated.

According to a particular mode of implementation, the method of the invention makes it possible to dechlorinate organochlorine aromatic compounds until aromatic compounds no longer comprising any chlorine atoms or comprising 1, 2, 3 or 4 chlorine atoms are obtained. chlorine and in particular, compounds which are not taken into account by the legislation because considered as not harmful. These compounds are less toxic than those containing more than 4 chlorine atoms. The irradiation conditions of the process of the invention (time of irradiation intensity, oil flow rate, etc.) make it possible to dechlorinate more or less the organochlorine aromatic compounds.

The intensity of the radiation is not limited according to the invention. The duration t of the irradiation which makes it possible to obtain the dechlorination of all the PCB/PCT contaminants or at least to obtain a concentration of PCB/PCT (other than PCB N°0) equal to or less than 50ppm depends, in particular the intensity of the radiation, the temperature of the oil during the irradiation and its flow rate as well as its PCB/PCT concentration. A person skilled in the art is therefore able to determine, in particular experimentally, the duration t of the irradiation of the oil according to the temperature of the oil during the irradiation, the power and the intensity of the radiation, of the PCB/PCT concentration for a final PCB/PCT concentration after treatment equal to or less than 50 ppm.

The method of the invention can also be implemented with radiation corresponding to the visible spectrum, which makes it particularly harmless for the environment and personnel.

Advantageously, said oil is subjected to said radiation while maintaining said oil at a threshold temperature equal to or lower by 1, 2, 5 or 10 degrees than the value of the thermal degradation temperature determined experimentally. The inventors have also demonstrated that the higher the oil temperature during irradiation by the aforementioned radiation, the higher the rate of dechlorination of organochlorine compounds, in particular PCBs/PCTs.

A threshold value determined for a naphthenic mineral oil containing PCB/PCT is 70° C. or 73° C., for example.

The method of the invention is not limited with regard to the step of maintaining the temperature of the oil during the irradiation. It is thus possible, according to the process of the invention, to cool the oil, by means of a heat exchanger or by a stream of air (external to the reactor) or nitrogen, for example. Advantageously, during irradiation, the temperature of said oil is maintained at a value less than or equal to said given threshold value by varying the distance traveled by said radiation to reach said oil. In other words, the distance between the oil and the radiation source is changed. This solution is simple to implement and inexpensive.

According to the process of the invention, the oil to be treated can be an oil stored for the purpose of its treatment; it is then extracted from the electrical/electronic device, stored and then treated according to the process of the invention, without prior modification of its chemical composition, in particular without addition of methylene blue and/or triethylamine. After treatment according to the process of the invention, the oil can be stored before its reuse, for example.

According to a particularly advantageous embodiment, said oil is a fraction withdrawn, optionally continuously, from the oil contained in a dielectric fluid tank or in an electrical/electronic device, the remaining fraction of said oil optionally being in circulation in said apparatus, said fraction of said oil withdrawn outside of said apparatus is irradiated and said oil fraction is reinjected, optionally continuously after irradiation, into said apparatus, optionally without stopping the circulation of said oil in said device.

The method of the invention can therefore be implemented continuously, a fraction for example of 1% to 5% of the oil contained in the electrical device, in particular a transformer, is extracted from the device and irradiated at the outside of the latter then reinjected. The fraction withdrawn is low enough not to interfere with the operation of the device. A quantity of oil can be sampled (withdrawn) at once, irradiated then reinjected (batch operation). It is also possible to draw off a flow of oil and to irradiate it continuously according to the method of the invention and to reinject it continuously (continuous operation).

The process of the invention requiring neither the dissolution of the oil nor the addition of a reagent/catalyst or other, it can also be easily implemented directly at the outlet of an electrical/electronic device without having to store the contaminated oil. This saves time and avoids the problems of storage and transport of contaminated oils (leaks during storage, accidents during transport, for example), which remain dangerous for the environment. It is thus possible to continuously treat the oil contained in an electrical/electronic device while the latter is operating or not, by treating a fraction of the oil it contains, the other fraction being used for the operation of the device. , for example or by continuously treating a flow of oil coming from the electrical appliance, the latter being in operation

The oil or other dielectric fluids which it is possible to treat according to the method of the invention are not limited. The oil is in particular chosen from oils consisting of an aromatic organochlorine compound, in liquid form, and comprising two or three benzene rings, of which at least one benzene ring or all the benzene rings are substituted by at least one chlorine atom , in particular polychlorobiphenyls and polychloroterphenyls, oils consisting of liquid mixtures of said organochlorine compounds, in particular mixtures of polychlorinated biphenyls and/or polychloroterphenyls, oils consisting of a mixture of an oil chosen from mineral oils, naphthenic oils, paraffinic oils, intermediate oils, silicone oils and synthetic ester oils and of one or more aromatic organochlorine compound(s) chosen, in particular, from molecules comprising two or three rings benzene and of which at least one benzene ring or all the benzene rings are substituted by at least one chlorine atom, in particular polychlorobiphenyls and polychloroterphenyls and mixtures of at least two of these oils.

The oil to be treated is therefore notably free of methylene blue and/or triethylamine.

An intermediate oil is defined as an oil that contains 50% to 56% by mass (50% and 56% inclusive) of alkanes. This percentage can be determined by infrared spectroscopy. Advantageously, the oil is a naphthenic oil containing at least one PCB and/or PCT.

The oil capable of being dechlorinated according to the process of the invention has, for example, a kinematic viscosity measured at 40° C. of less than 16.5 mm ² /s, in particular less than 11.0 mm ² /s and more particularly less than 3.5 mm ² /s. The breakdown voltage of the contaminated oil before treatment is, for example, greater than 30 kV (measured at 50 Hz); it increases after the treatment according to the invention, to become greater than 50 kV when it was less than 30 kV. It is also possible, according to the process of the invention, to treat oils or dielectric fluids of higher viscosity.

The inventors have also demonstrated that an oil which has stayed in an electrical/electronic device for a long time and has been used for a long time can also be treated according to the method of the invention. Such oil becomes dark and opaque due to non-thermal deterioration of the oil in the device. The inventors have demonstrated that it was even possible to treat black and opaque oil - which therefore absorbs the wavelengths of the visible - according to the process of the invention and to successfully dechlorinate the organochlorine aromatic compounds that it contains, in particular, PCBs and PCTs. The color influences the kinetics of the reaction but does not prevent the reaction.

The PCB/PCT concentration of the oil to be treated according to the process of the invention is not limited. Legislation indicates that an oil said to be contaminated with PCBs/PCTs and which therefore needs to be treated, contains a total content of PCBs (and/or PCTs) equal to or greater than 50ppm. Thus, according to the invention, the contaminated oil to be treated by the method of the invention may contain a total PCB/PCT concentration greater than or equal to 50ppm, in particular equal to or greater than 100ppm and more particularly equal to or greater than 200ppm. or greater than or equal to 500ppm or greater than or equal to 2000ppm. The oil can even be a PCB, a PCT or a mixture of PCB and/or PCT.

The oil which it is possible to treat according to the process of the invention may contain any one of the 209 congeners of the PCB family and/or any one of the congeners of the PCT family. It may also contain a mixture of PCBs, a mixture of PCTs or a mixture of PCBs (one or more) and PCTs (one or more). For example, it may be an oil containing at least one PCB compound chosen from: i: 2-Chlorobiphenyl (PCB No. 1), 3-Chlorobiphenyl (PCB No. 2), 4-Chlorobiphenyl PCB No. 3, 2,2'-Dichlorobiphenyl (PCB No. 4), 2,3-Dichlorobiphenyl (PCB No. 5), 2,3'-Dichlorobiphenyl (PCB No. 6), 2,4- Dichlorobiphenyl (PCB No. 7), 2,4'-Dichlorobiphenyl (PCB No. 8), 2,5-Dichlorobiphenyl (PCB No. 9), 2,6-Dichlorobiphenyl (PCB No. 10), 3 ,3'-Dichlorobiphenyl (PCB No. 11), 3,4-Dichlorobiphenyl (PCB No. 12), 3,4'-Dichlorobiphenyl (PCB No. 13), 3,5-Dichlorobiphenyl (PCB No. 14 ), 4,4'-Dichlorobiphenyl (PCB No. 15), 2,2',3-Trichlorobiphenyl (PCB No. 16), 2,2',4-Trichlorobiphenyl (PCB No. 17), 2 ,2',5-Trichlorobiphenyl (PCB No. 18), 2,2',6-Trichlorobiphenyl (PCB No. 19), 2,3,3'-Trichlorobiphenyl (PCB No. 20), 2,3 ,4-Trichlorobiphenyl (PCB No. 21), 2,3,4'-Trichlorobiphenyl (PCB No. 22), 2,3,5-Trichlorobiphenyl (PCB No. 23), 2,3,6-Trichlorobiphenyl (PCB No. 24), 2,3',4-Trichlorobiphenyl (PCB No. 25), 2,3',5-Trichlorobiphenyl (PCB No. 26), 2,3',6-Trichlorobiphenyl, ( PCB No. 27), 2,4,4'-Trichlorobiphenyl (PCB No. 28), 2,4,5-Trichlorobiphenyl, (PCB No. 29), 2,4,6-Trichlorobiphenyl (PCB No. 30), 2,4',5-trichlorobiphenyl (PCB No. 31), 2,4',6-trichlorobiphenyl (PCB No. 32), 2,3',4'-trichlorobiphenyl (PCB No. 33), 2,3',5'-trichlorobiphenyl (PCB No. 34), 3,3',4-trichlorobiphenyl (PCB No. 35), 3,3',5-trichlorobiphenyl (PCB No. 36 ), 3,4,4'-trichlorobiphenyl (PCB No. 37), 3,4,5-trichlorobiphenyl (PCB No. 38), 3,4',5-trichlorobiphenyl (PCB No. 39), 2,2',3,3'-tetrachlorobiphenyl (PCB No. 40), 2,2',3,4-tetrachlorobiphenyl (PCB No. 41) 2,2',3,4'-tetrachlorobiphenyl (PCB No. °42), 2,2',3,5-tetrachlorobiphenyl (PCB No. 43), 2,2',3,5'-tetrachlorobiphenyl

(PCB No. 44), 2,2',3,6-tetrachlorobiphenyl (PCB No. 45), 2,2',3,6'-tetrachlorobiphenyl (PCB No. 46), 2,2', 4,4'-tetrachlorobiphenyl (PCB No. 47), 2,2',4,5-tetrachlorobiphenyl (PCB No. 48), 2,2',4,5'-tetrachlorobiphenyl (PCB No. 49), 2,2',4,6-tetrachlorobiphenyl (PCB No. 50), 2,2',4,6'-tetrachlorobiphenyl (PCB No. 51), 2,2',5,5'-tetrachlorobiphenyl ( PCB No. 52), 2,2',5,6'-tetrachlorobiphenyl (PCB No. 53), 2,2',6,6'-tetrachlorobiphenyl (PCB No. 54), 2,3,3 ',4-tetrachlorobiphenyl (PCB No. 55), 2,3,3',4'-tetrachlorobiphenyl (PCB No. 56), 2,3,3',5-tetrachlorobiphenyl (PCB No. 57), 2,3,3',5'-tetrachlorobiphenyl (PCB No. 58), 2,3,3',6-tetrachlorobiphenyl (PCB No. 59), 2,3,4,4'-tetrachlorobiphenyl (PCB No. °60), 2,3,4,5-tetrachlorobiphenyl (PCB No. 61), 2,3,4,6-tetrachlorobiphenyl (PCB No. 62), 2,3,4',5-tetrachlorobiphenyl ( PCB No. 63), 2,3,4',6-tetrachlorobiphenyl (PCB No. 64), 2,3,5,6-Tetrachlorobiphenyl

(PCB No. 65), 2,3',4,4'-tetrachlorobiphenyl (PCB No. 66), 2,3',4,5 tetrachlorobiphenyl (PCB No. 67), 2,3',4 ,5'-tetrachlorobiphenyl (PCB No. 68), 2,3',4,6-tetrachlorobiphenyl (PCB No. 69), 2,3',4',5-tetrachlorobiphenyl (PCB No. 70), 2,3',4',6-tetrachlorobiphenyl (PCB No. 71), 2,3',5,5'-tetrachlorobiphenyl (PCB No. 72), 2,3',5',6-Tetrachlorobiphenyl ( PCB No. 73), 2,4,4',5-Tetrachlorobiphenyl (PCB No. 74), 2,4,4',6-tetrachlorobiphenyl (PCB No. 75), 2,3',4' ,5'-tetrachlorobiphenyl (PCB No. 76), 3,3',4,4' tetrachlorobiphenyl (PCB No. 77), 3,3',4,5-tetrachlorobiphenyl (PCB No. 78), 3 ,3',4,5'-tetrachlorobiphenyl (PCB No. 79), 3,3',5,5'-tetrachlorobiphenyl (PCB No. 80), 3,4,4',5-tetrachlorobiphenyl (PCB No. °81), 2,2',3,3',4-pentachlorobiphenyl (PCB No. 82), 2,2',3,3',5-pentachlorobiphenyl (PCB No. 83), 2,2 ',3,3',6-pentachlorobiphenyl (PCB No. 84), 2,2',3,4,4'-pentachlorobiphenyl (PCB No. 85), 2,2',3,4,5- Pentachlorobiphenyl (PCB No. 86), 2,2',3,4,5'-Pentachlorobiphenyl (PCB No. 87), 2,2',3,4,6-Pentachlorobiphenyl (PCB No. 88), 2,2',3,4,6'-Pentachlorobiphenyl (PCB No. 89), 2,2',3,4',5-Pentachlorobiphenyl (PCB No. 90), 2,2',3,4 ',6-Pentachlorobiphenyl (PCB No. 91), 2,2',3,5,5'-pentachlorobiphenyl (PCB No. 92), 2,2',3,5,6-Pentachlorobiphenyl (PCB No. 93), 2,2',3,5,6'-pentachlorobiphenyl (PCB No. 94), 2,2',3,5',6-pentachlorobiphenyl (PCB No. 95), 2,2' ,3,6,6'-Pentachlorobiphenyl (PCB No. 96), 2,2',3,4',5'-pentachlorobiphenyl (PCB No. 97), 2,2',3,4',6 '-Pentachlorobiphenyl (PCB No. 98), 2,2',4,4',5-pentachlorobiphenyl (PCB No. 99), 2,2',4,4',6-Pentachlorobiphenyl (PCB No. 100 ), 2,2',4,5,5'-Pentachlorobiphenyl (PCB No. 101), 2,2',4,5,6'-pentachlorobiphenyl (PCB No. 102), 2,2', 4,5',6-Pentachlorobiphenyl (PCB No. 103), 2,2',4,6,6'-pentachlorobiphenyl (PCB No. 104), 2,3,3',4,4'-pentachlorobiphenyl (PCB No. 105), 2,3,3',4,5-pentachlorobiphenyl (PCB No. 106), 2,3,3',4',5-pentachlorobiphenyl (PCB No. 107), 2 ,3,3',4,5'-pentachlorobiphenyl (PCB No. 108), 2,3,3',4,6-pentachlorobiphenyl (PCB No. 109), 2,3,3',4', 6-pentachlorobiphenyl (PCB No. 110), 2,3,3',5,5'-pentachlorobiphenyl (PCB No. 111), 2,3,3',5,6-pentachlorobiphenyl (PCB No. 112) , 2,3,3,5',6-pentachlorobiphenyl (PCB No. 113), 2,3,4,4',5-pentachlorobiphenyl (PCB No. 114), 2,3,4,4 ',6-Pentachlorobiphenyl (PCB No. 115), 2,3,4,5,6-Pentachlorobiphenyl (PCB No. 116), 2,3,4',5,6-pentachlorobiphenyl (PCB No. 117) , 2,3',4,4',5-Pentachlorobiphenyl (PCB No. 118), 2,3',4,4',6-pentachlorobiphenyl (PCB No. 119), 2,3',4 ,5,5'-Pentachlorobiphenyl (PCB No. 120), 2,3',4,5',6-pentachlorobiphenyl (PCB No. 121), 2,3,3,3',4',5'-pentachlorobiphenyl (PCB No. 122), 2,3',4,4',5'-Pentachlorobiphenyl (PCB No. 123), 2,3',4',5,5'-pentachlorobiphenyl (PCB No. 124) , 2,3',4',5',6-pentachlorobiphenyl (PCB No. 125), 3,3',4,4',5-pentachlorobiphenyl (PCB No. 126), 3,3', 4,5,5'-pentachlorobiphenyl (PCB No. 127), 2,2',3,3',4,4'-hexachlorobiphenyl (PCB No. 128), 2,2',3,3', 4,5- hexachlorobiphenyl (PCB No. 129), 2,2',3,3',4,5'-hexachlorobiphenyl (PCB No. 130), 2,2',3,3',4,6 -hexachlorobiphenyl (PCB No. 131), 2,2',3,3',4,6'-hexachlorobiphenyl (PCB No. 132), 2,2',3,3',5,5'-hexachlorobiphenyl (PCB No. 133), 2,2',3,3',5,6-hexachlorobiphenyl (PCB No. 134), 2,2',3,3',5,6'-hexachlorobiphenyl (PCB No. °135), 2,2',3,3',6,6'-hexachlorobiphenyl (PCB No. 136), 2,2',3,4,4',5-hexachlorobiphenyl (PCB No. 137) , 2,2',3,4,4',5'-hexachlorobiphenyl (PCB No. 138), 2,2',3,4,4',6-hexachlorobiphenyl (PCB No. 139), 2 ,2',3,4,4',6'-hexachlorobiphenyl (PCB No. 140), 2,2',3,4,5,5'-hexachlorobiphenyl (PCB No. 141), 2,2' ,3,4,5,6-hexachlorobiphenyl (PCB No. 142), 2,2',3,4,5,6'-hexachlorobiphenyl (PCB No. 143), 2,2',3,4, 5',6-hexachlorobiphenyl (PCB No. 144), 2,2',3,4,6,6'-hexachlorobiphenyl (PCB No. 145), 2,2',3,4',5,5 '-hexachlorobiphenyl (PCB No. 146), 2,2',3,4',5,6-hexachlorobiphenyl (PCB No. 147), 2,2',3,4',5,6'-hexachlorobiphenyl (PCB No. 148), 2,2',3,4',5',6-hexachlorobiphenyl (PCB No. 149), 2,2',3,4',6,6'-hexachlorobiphenyl (PCB No. 150), 2,2',3,5,5',6-hexachlorobiphenyl (PCB No. 151), 2,2',3,5,6,6'-hexachlorobiphenyl (PCB No. 152) , 2,2',4,4',5,5'-hexachlorobiphenyl (PCB No. 153), 2,2',4,4',5,6'-hexachlorobiphenyl (PCB No. 154), 2,2',4,4',6,6'-Hexachlorobiphenyl (PCB No. 155), 2,3,3',4,4',5-hexachlorobiphenyl (PCB No. 156), 2,3 ,3',4,4',5'-hexachlorobiphenyl (PCB No. 157), 2,3,3',4,4',6-Hexachlorobiphenyl (PCB No. 158), 2,3,3' ,4,5,5'-hexachlorobiphenyl (PCB No. 159), 2,3,3',4,5,6-hexachlorobiphenyl (PCB No. 160), 2,3,3',4,5' ,6-Hexachlorobiphenyl (PCB No. 161), 2,3,3',4',5,5'-Hexachlorobiphenyl (PCB No. 162), 2,3,3',4',5,6- hexachlorobiphenyl (PCB No. 163), 2,3,3',4',5',6-hexachlorobiphenyl (PCB No. 164), 2,3,3,3',5,5',6-hexachlorobiphenyl (PCB No. 165), 2,3,4,4',5,6-hexachlorobiphenyl (PCB No. 166), 2,3',4,4',5,5'-Hexachlorobiphenyl (PCB No. 167), 2,3',4,4',5',6-Hexachlorobiphenyl (PCB No. 168), 3,3',4,4',5,5'-hexachlorobiphenyl (PCB No. 169), 2 ,2',3,3',4,4',5-Heptachlorobiphenyl (PCB No. 170), 2,2',3,3',4,4',6-heptachlorobiphenyl (PCB No. 171), 2,2',3,3',4,5,5'-heptachlorobiphenyl (PCB No. 172), 2,2',3,3',4,5,6-heptachlorobiphenyl (PCB No. 173) , 2,2',3,3',4,5,6'-heptachlorobiphenyl (PCB No. 174), 2,2',3,3',4,5',6-heptachlorobiphenyl (PCB No. 175), 2,2',3,3',4,6,6'-heptachlorobiphenyl (PCB No. 176), 2,2',3,3',4,5',6'-heptachlorobiphenyl ( PCB No. 177), 2,2',3,3',5,5',6-heptachlorobiphenyl (PCB No. 178), 2,2',3,3',5,6,6'- heptachlorobiphenyl (PCB No. 179), 2,2',3,4,4',5,5'-Heptachlorobiphenyl (PCB No. 180), 2,2',3,4,4',5,6 -heptachlorobiphenyl (PCB No. 181), 2,2',3,4,4',5,6'-heptachlorobiphenyl (PCB No. 182), 2,2',3,4,4',5' ,6-Heptachlorobiphenyl (PCB No. 183), 2,2',3,4,4',6,6'-heptachlorobiphenyl (PCB No. 184), 2,2',3,4,5,5 ',6-Heptachlorobiphenyl (PCB No. 185), 2,2',3,4,5,6,6'-Heptachlorobiphenyl (PCB No. 186), 2,2',3,4',5, 5',6-Heptachlorobiphenyl (PCB No. 187), 2,2',3,4',5,6,6'-Heptachlorobiphenyl (PCB No. 188), 2,3,3',4,4 ',5,5'-Heptachlorobiphenyl (PCB No. 189), 2,3,3',4,4',5,6-Heptachlorobiphenyl (PCB No. 190), 2,3,3',4, 4',5',6-Heptachlorobiphenyl (PCB No. 191), 2,3,3',4,5,5',6-Heptachlorobiphenyl (PCB No. 192), 2,3,3',4 ',5,5',6-Heptachlorobiphenyl (PCB No. 193), 2,2',3,3',4,4',5,5'-Octachlorobiphenyl (PCB No. 194), 2,2 ',3,3',4,4',5,6-Octachlorobiphenyl (PCB No. 195), 2,2',3,3',4,4',5,6'-Octachlorobiphenyl (PCB No. 196), 2,2',3,3',4,4',6,6'-Octachlorobiphenyl (PCB No. 197), 2,2',3,3',4,5,5', 6-Octachlorobiphenyl (PCB No. 198), 2,2',3,3',4,5,5',6'-Octachlorobiphenyl (PCB No. 199), 2,2',3,3', 4,5,6,6'-Octachlorobiphenyl (PCB No. 200), 2,2',3,3',4,5',6,6'-Octachlorobiphenyl (PCB No. 201), 2,2 ',3,3',5,5',6,6'-Octachlorobiphenyl (PCB No. 202), 2,2',3,4,4',5,5',6-Octachlorobiphenyl (PCB No. 203), 2,2',3,4,4',5,6,6'-Octachlorobiphenyl (PCB No. 204), 2,3,3',4,4',5,5',6 -octachlorobiphenyl (PCB No. 205), 2,2',3,3',4,4',5,5',6-nonachlorobiphenyl (PCB No. 206), 2,2',3,3' ,4,4',5,6,6'-nonachlorobiphenyl (PCB No. 207), 2,2',3,3',4,5,5',6,6'-nonachlorobiphenyl (PCB No. 208 ) and decachlorobiphenyl (PCB No. 209).

PCB No. 0 corresponds to diphenyl; it is not chlorinated and is designated by extension as being a PCB. This compound is not toxic.

In particular, the oil to be treated may contain the following PCBs, alone or in a mixture: PCB No. 209, PCB No. 1, PBC No. 2, PCB No. 7, PCB No. 18, PCB No. 31, PCB No. No. 52, PCB No. 70, PCB No. 101, PCB No. 153 and PCB No. 180.

Advantageously, the oil coming from the transformer or other electrical/electronic device is also filtered so as to remove the suspended solids coming, for example, from the degradation of the cardboard contained in the transformers; it has also been subjected to degassing, for example, by placing it under vacuum with a vacuum pump to remove the water mixed with the oil; advantageously, any trace of acid and/or base has been eliminated, by passing the oil to be treated over a column of Fuller's earth or another type of support, in particular clay capable of retaining acids and/or the basics. These operations are carried out continuously in a maintenance unit (or first module) located outside the transformer and implemented before the implementation of the method of the invention. The oil which can be treated by the method of the invention is therefore filtered and free of acid(s), base(s) and water (in addition to being free of methylene blue and triethylamine) . The filtration step is not mandatory but preferred.

The present invention also relates to an installation, possibly mobile, which allows the implementation of the method of the invention and which comprises:

• a reactor comprising an inlet opening and an outlet opening capable of being connected in a sealed manner with the interior of an electrical/electronic device, which contains an oil containing or consisting of one or more organochlorine compound(s) s), the said organochlorine compound(s) being chosen in particular from molecules comprising two or three benzene rings and of which at least one benzene ring or all the benzene rings are substituted by at least one chlorine atom, in particular polychlorobiphenyls and polychloroterphenyls;
• at least one pump arranged so as to set said oil in motion in the circuit formed by said reactor and said electrical/electronic apparatus, when the latter is connected to said reactor;
• a radiation source capable of emitting radiation having wavelengths equal to or greater than 300 nm and in particular equal to or greater than 320 nm and more particularly equal to or greater than 320 nm and equal to or less than 390 nm, said source being arranged so as to irradiate said oil contained in said reactor; And
• means for regulating the temperature of the oil contained in said reactor.

The means for regulating the temperature of the oil are not limited according to the invention. They are shaped to maintain the temperature of the oil at a value equal to or lower than said threshold value. These may be, for example, cooling means such as fans. According to one embodiment, said means for regulating the temperature of the oil contained in said reactor comprise at least one support on which said radiation source and/or said reactor is/are mounted and said support makes it possible to vary the distance between said radiation source and said reactor. The support(s) can be mobile, i.e. capable of being moved away from or closer to the reactor/source. The support can also comprise a part whose length is adjustable which makes it possible, without moving the support, to bring the source of radiation closer to or further away from the reactor. The support can thus comprise telescopic sliding tubes and/or deformable parallelograms, which support the radiation source and make it possible to modify the distance between the latter and the reactor. The reactor can also be mounted on a support of this type, the source being fixed or not.

The reactor can be at least partially transparent or not. It can also be opaque to the radiation used for oil irradiation and at least partially or completely contain the radiation source. The installation is thus particularly safe. Advantageously, the emitting part of the radiation source is located in said reactor.

The installation may also include an analysis unit, for example of the gas phase chromatography type, which takes a fraction of the oil leaving the reactor and determines the PCB/PCT concentration of the oil during treatment. The analysis unit can include an NMR spectrometer, an X-ray fluorescence spectrometer, a Maldi/Tof mass spectrometer. Advantageously, it comprises a gas phase chromatograph coupled to a mass spectrometer and/or an X-ray fluorescence spectrometer. This analysis unit is mounted at the outlet of the reactor, for example.

The residence time of the oil in the reactor depends on the concentration of PCB/PCT in the oil, the intensity of the radiation emitted by the source, the temperature of the oil and the power of the radiation source. radiation and the flow of oil to be treated. By way of example, said installation can be dimensioned so that the residence time of said contaminated oil in said reactor is equal to or greater than 4 hours and less than 15 hours and in particular equal to 8 hours.

The reactor is not limited according to the invention. It may, for example, comprise a plurality of parallel tubes. These tubes make it possible to divide the flow of oil entering the reactor into several low-flow flows that are easy to treat because they are easily crossed by radiation. The tubes can be transparent to the radiation used for the irradiation of the oil according to the process of the invention or be opaque to this radiation if the radiation source is placed in these tubes.

The present invention also relates to an installation which, characteristically according to the invention, comprises a tank for collecting dielectric fluids and/or at least one electrical/electronic device, in particular an electrical transformer, said tank and said device containing an oil containing or consisting of one or more organochlorine aromatic compound(s), the said compound(s) being chosen, in particular, from molecules comprising two or three benzene rings and of which at least one benzene ring or all of the benzene rings are substituted by at least one chlorine atom, in particular polychlorobiphenyls and polychloroterphenyls, said inlet opening and said outlet opening of said reactor are respectively connected to an opening of inlet and to an outlet opening provided in said collection tank and/or said at least one device and which allow said oil contained in said tank and/or said at least one device to circulate in said reactor, said reactor comprises, in further, a recirculation loop, which connects the outlet opening of said reactor to the inlet opening of said reactor and a pump capable of moving said oil in said recirculation loop.

The recirculation loop allows the oil to pass several times through the reactor where it is irradiated. It is thus possible to continuously treat a large volume of oil in several passes without using a large volume reactor. The transformer remains in operation with the remaining fraction of oil. It is also possible to simultaneously process a continuous flow coming from the transformer and a flow circulating in the recirculation loop.

The installation thus makes it possible to centrally treat several electrical devices (in particular transformers) and/or to treat the dielectric fluids of several devices after they have been extracted from the device and stored in the collection tank.

Advantageously, the installation comprises a unit for holding said oil contained in said collection tank and/or in said at least one device, said holding unit is connected to the outlet opening of said collection tank and/or of said at least one device and includes:

• a pump for moving said oil leaving said tank and/or said at least one device;
• means for filtering said oil; And
• means for extracting water and any acids and bases contained in said oil;

and said inlet opening of said reactor is connected downstream of said holding unit, said outlet opening of said reactor being connected to said inlet opening of said vessel and/or of said at least one electrical/electronic device.

This holding unit comprises filtration means capable of retaining the particles in suspension in the oil (in particular originating from the degradation of the cardboard contained in a transformer, when the device is a transformer), means for degassing the oil (in order to remove any water contained in the oil; this may be a vacuum pump) and a column filled with a substrate capable of retaining acids and/or bases without retaining organochlorine compounds; it can be a column of clay, for example, in particular, Fuller's earth. In this case, the oil to be treated according to the method of the invention is taken downstream of this maintenance unit and the installation of the invention is connected not directly to the transformer but to the output of the maintenance unit. . The treated oil is also reinjected downstream of this maintenance unit, directly into the transformer or other electrical/electronic device.

The radiation source is not limited according to the invention. It can have, for example, a power of 400 W.

Definitions

The terms "oil" and "oil to be treated" within the meaning of the present invention include dielectric fluids consisting of an aromatic organochlorine compound, in liquid form, and comprising two or three benzene rings, including at least one benzene ring or all the benzene rings are substituted by at least one chlorine atom, in particular polychlorobiphenyls and polychloroterphenyls, dielectric fluids consisting of liquid mixtures of said aromatic organochlorine compounds, in particular mixtures of polychlorobiphenyls and/or polychloroterphenyls, dielectric fluids consisting of a mixture of an oil chosen from mineral oils, naphthenic oils, paraffinic oils, intermediate oils, silicone oils and synthetic ester oils and one or more organochlorine aromatic compound(s) chosen( s), in particular, among the molecules comprising two or three benzene rings and of which at least one benzene ring or all the benzene rings are substituted by at least one chlorine atom, in particular polychlorobiphenyls and polychloroterphenyls and mixtures of at least two of these oils.

A synthetic ester oil is, for example, pentaerythritol ester oil.

The term "contaminated oil" designates the mixture consisting of an oil and one or more organochlorine aromatic compound(s) chosen, in particular, from molecules comprising two or three benzene rings and of which at least one benzene ring or all the benzene rings are substituted by at least one chlorine atom, in particular the polychlorobiphenyls and the polychloroterphenyls.

The term “electrical/electronic device” is not limited according to the invention. It designates more particularly electronic components and electrical appliances containing an oil as mentioned above. Mention may be made, in particular, of capacitors and transformers.

The term “transformer” within the meaning of the present invention designates electrical power and distribution transformers, impedance transformers, measurement transformers, phase-shifting transformers, test transformers, high-frequency transformers, transformers pulse generators and three-phase transformers.

The term "pure oil" refers to an oil that contains no PCBs and no PCTs except PCB No. 0.

The terms "UV-visible" refer to radiation having wavelengths equal to or greater than 300nm and in particular to radiation having wavelengths equal to or greater than 320nm and more particularly to radiation having wavelengths equal to or greater than 320nm or greater than 320 nm and less than or equal to 390 nm.

Brief description of figures

- There represents an example of an installation making it possible to implement the method of the invention;

- There shows a diagram of an installation according to the invention, the reactor being provided with a recirculation loop;

- There depicts a close-up of the aromatic region of an 1H-NMR spectrum of fraction 6 of an unirradiated contaminated mineral oil;

- There shows a close-up of the aromatic region of an H-NMR spectrum of fraction 6 of a contaminated mineral oil after irradiation for 8h;

- There represents the GC gas phase chromatograms of fraction 6 of oil B, a) before irradiation, b) after irradiation for 4 hours, c) after irradiation for 8 hours;

- there represents the mass spectra of the model mixture of 12 PCBs at 200 ppm shown in Table 7;

- there represents the mass spectra of fraction 6 of the model system (mineral oil/12 PCB at 200 ppm) after irradiation for 4 hours (mass from 51 to 145 m/z);

- there represents the mass spectra of fraction 6 of the model system (mineral oil/12 PCBs at 200 ppm) after irradiation for 4 hours (mass from 51 to 163 m/z);

- there represents the mass spectra of fraction 6 of the model system (mineral oil/12 PCBs at 200 ppm) after 8 hours of irradiation (mass from 51 to 188 m/z);

- there represents the mass spectra of fraction 6 of the model system (mineral oil/12 PCBs at 200 ppm) after 8 hours of irradiation (mass from 51 to 536 m/z);

- there represents the mass spectra of fraction 6 of oil B (real system) before irradiation (mass from 51 to 145 m/z);

- there represents the mass spectra of fraction 6 of oil B (actual system) not irradiated (from 52 to 246 m/z);

- there represents the mass spectra of fraction 6 of oil B (real system) after 4 hours of irradiation (from 53 to 212 m/z);

- there represents the mass spectra of fraction 6 of oil B (real system) after 4 hours of irradiation (from 53 to 238 m/z);

- there represents the mass spectra of fraction 6 of oil B (real system) after 4 hours of irradiation (from 53 to 227 m/z);

- there represents the mass spectra of fraction 6 of oil B (real system) after 8 hours of irradiation (from 51 to 211 m/z);

- there represents the mass spectra of fraction 6 of oil B (real system) after 8 hours of irradiation (from 51 to 240 m/z);

- there represents the mass spectra of fraction 6 of oil B (real system) after 8 hours of irradiation (from 51 to 273 m/z); And

- there represents the variation of the PCB concentration in the contaminated mineral oil as a function of the irradiation time.

EXAMPLES

With reference to FIG. 1, an example of an installation allowing the implementation of the method according to the invention will now be described. The installation comprises a lamp 1 emitting in the wavelengths corresponding to the method of the invention and powered by an electrical power supply 3. Under the lamp 1 is the radiation zone on which the reactor 5 is placed. temperature, not shown, makes it possible to measure the temperature of the oil in the reactor by means of a thermometer 6. The lamp is mounted on a frame 4 whose height is adjustable. The distance between the lamp 1 and the reactor 5 can thus be modified. Control means not shown are coupled to the thermometer 6 and to the armature 4 which is provided with a motor. The control means are configured to modify the distance between the lamp 1 (its radiation-emitting part) and the reactor 5 placed under the lamp 1, according to the temperature measured by the thermometer 6. If the measured temperature is greater than a set value, the armature 4 lengthens so as to move the lamp 1 away from the reactor 5. If the temperature is below a set value, the armature shortens so as to bring the lamp 1 closer to the reactor 5. armature 4 can for example comprise deformable parallelograms equipped with motors or sliding tubes, equipped with motors.

With reference to FIG. 2, an example of an apparatus according to the invention will now be described. The device 11 is for example a power transformer. It contains PCB/PCT contaminated oil. It comprises a first circulation loop 13, which comprises a pump 30 which moves the oil coming from the transformer 11 in the loop 13 and reinjects it into the transformer 11. The first loop 13 passes through the reactor 5. The reactor 5 is irradiated by a radiation source not shown. The reactor 5 is equipped with a second loop 55, called recirculation. This recirculation loop 55 comprises a pump 70 which makes it possible to circulate the oil in the reactor 5 and in the loop 55. The contaminated oil can thus circulate several times in the recirculation mouth 55 and pass several times in the reactor 5, without being injected into the transformer 11. The first loop 13 can be placed in communication with the recirculation loop 55 by means of two valves 8 and 81, arranged respectively upstream and downstream of the reactor 5.

The operation of transformer 11 is as follows. The transformer 11 being in operation, that is to say delivering electricity, a fraction of the contaminated oil contained in the transformer 11 is removed by means of the opening of a valve not shown. of contaminated oil circulates in the first loop 13, thanks to the pump 30. When the oil passes through the reactor 5, it is irradiated according to the method of the invention in the reactor 5. It is also possible, depending in particular the rate of contamination of the oil, to take a fraction of the oil circulating in the first loop 13 by opening the valve 8. The opening of the valve 8 causes the contaminated oil to enter the recirculation loop 55, the valve 81 being closed. The fraction withdrawn and circulating in the recirculation loop 55 can pass several times into the reactor 5 to be treated there according to the process of the invention, without re-entering the transformer 11. When the fraction of oil circulating in the recirculation loop 55 is decontaminated, the valve 81 is opened and the treated fraction thus enters the first loop 13 and joins the transformer 11. A valve, not shown, mounted on the first loop 13 downstream of the valve 8 makes it possible to close the first loop 13 and to circulate the contaminated oil only in the recirculation loop 55. This valve is nevertheless not necessary, the contaminated oil also being able, according to the invention, to circulate simultaneously in the two loops 13 and 55 to cross the reactor 5.

Tests on different oils: determination of the effectiveness of the process according to the invention

Mineral transformer oils containing different types of polychlorinated biphenyls (PCBs) were subjected to the deactivation process according to the invention. MALDI-TOF spectra corresponding to pure transformer oils supplied by manufacturers (mineral oil, silicone oil, synthetic oil) were recorded. The maximum molar masses detected for the three oils (mineral, silicone, synthetic) exceed 1000 g/mol (see the appended figures), which does not allow their direct analysis in a gas phase chromatograph coupled with a mass spectrometer ( the molecules do not evaporate, making it impossible to analyze them in the gas phase). A separation of the oils on a standard silica column about 33 cm long and 3 cm in diameter, with as mobile phase a mixture of solvent (99% petroleum ether – 1% Acetone) was carried out. This separation was monitored by thin layer chromatographic analysis in the form of thin silica plates. These separation processes were employed with the aim of distinguishing PCB molecules from other molecules in the contaminated oil. The TLC results showed that the latter comprises six fractions, three of which correspond to pure oil. After obtaining six fractions of the contaminated oil, a vacuum distillation was implemented. This physical process consists in separating the eluent and the oil fraction by heat and under vacuum, the various elements constituting the liquid mixture are collected in gas form at the top of the column; this vaporization is followed by liquefaction by cooling (liquefaction and recovery of the eluent). The fractions obtained were analyzed by H-NMR after drying in a vacuum oven at 70°C. This analysis makes it possible, among other things, to detect the signals of protons bound to aromatic molecules located between 7.30 and 8.5 ppm. The appearance of peaks in this area confirms the presence of PCB molecules in fraction six.

For the radiative tests, a Dymax 5000-EC type UV-visible source with a power of 400 W was used. The dose of irradiation varies according to the time of exposure to the radiation. The oil tested (sample) is spread evenly between two plates of a closed quartz tank. The volume between the walls of the tank has a thickness of 1 mm. The distance between the UV-visible source and the sample is modulated according to the temperature of the oil so that the latter remains at 70°C (temperature slightly lower by -5°C or -10°C than the temperature of thermal degradation of the oil tested). The 5000-EC Series UV-Visible source provides concentrated light in the 320-390 nm wavelength range, to achieve UV penetration depths that allow the breaking of chlorine-aromatic bonds at a given source-sample distance and greater than or equal to the distance separating the tank from the source.

During the irradiation treatment according to the process of the invention, samples were taken in order to follow the evolution of the deactivation of the chlorinated derivatives qualitatively and quantitatively before and after treatment. The main analytical techniques used are thin layer chromatography (TLC), nuclear magnetic resonance (H-NMR) and gas chromatography coupled with mass spectroscopy (GC-MS).

EXAMPLE 1: Thin layer chromatography (TLC) of pure and PCB-contaminated mineral oils (Model systems/Real systems)

The TLC of the oils was carried out on an aluminum support on which was spread a uniform layer of silica gel as the stationary phase. The thickness of this layer is of the order of 0.2 mm (200 μm). The TLC plate was placed in a tank containing the eluent, which is a mixture of solvents (Petroleum ether 95/5 Acetone). The latter diffuses along the silica support allowing the separation of the non-irradiated and irradiated mineral oil/PCB mixtures for 4h and 8h, respectively.

The spots of the fractions migrate on the sheet more or less quickly according to electrostatic-type interactions between the mobile phase (eluent+oil/PCB) and the stationary phase (standard silica). The visualization of the different spots consists of placing the plate under a UV lamp at the wavelength of 254 nm. The plaque appears fluorescent green and the products that absorb the radiation appear as dark spots. This qualitative detection method is used as a priority because it does not damage the oil or the TLC plate and can be transposed onto a silica column.

The chromatographic results (not shown) show that the contaminated oils have six fractions, three of which belong to the pure oil.

The following samples were treated with the method of the invention in the installation already described above, with reference to FIG. 1.

Samples processed:

• Pure mineral oil (Real System).
• The mineral oil / PCB N°0 mixture at a concentration of 200 ppm (Model system).
• The mineral oil / PCB N°209 mixture at a concentration of 200 ppm (Model system).
• Contaminated mineral oil (Real System).

All the systems cited were irradiated under the same conditions at a temperature set at 70°C. Table 1 below summarizes the experimental conditions and results of the TLC analyses.

Samples


Settings System s model s
H mineral oil/PCB Real system
H contaminated mineral oil Pure mineral oil / PCB N°0 Pure mineral oil / PCB No. 209 Pure mineral oil Contaminated mineral oil Type of UV-visible source Dymax 5000-EC/400W Dymax 5000-EC/400W Dymax 5000-EC/400W Dymax 5000-EC/400W Percentage relative to the maximum light intensity of the source
100%
Constant
100%
Constant
100%
Constant
100%
Constant Light source-sample distance Variable
So that T=70°C Variable
So that T=70°C
Variable
So that T=70°C
Variable
So that T=70°C
Exposure time to UV-visible radiation
8am
8am
8am
4h
8am Number of fractions before irradiation
4
4
3
6
6 Number of fractions after irradiation 4
(The 4^th fraction corresponds to PCB n°209) 4
(The ^{4th fraction} corresponds to PCB n°0) 3
(no effects on pure oil fractions)
5
4

It can be seen from the results of Table 1, that the radiative effect on pure mineral oil is zero, the same for the mineral oil/PCB No. 0 system, that is to say that in l Absence of chlorinated PCBs, UV-Visible irradiation has no influence on the oil. On the other hand, the effect is considerable when the PCBs are increasingly chlorinated, for example the mineral oil/PCB model system No. 209 or the real system (mineral oil contaminated with PCBs). In these latter cases, we also observe the disappearance of certain undesirable spots after irradiation for 4 hours and the virtual disappearance of the spots belonging to the PCBs after 8 hours.

EXAMPLE 2: Effects of UV-visible irradiation on pure mineral oil containing PCB N°0 in H-NMR (proton NMR)

The H-NMR analysis of the oils was carried out following a well-defined preparation protocol, starting with the grinding of a few milligrams of the external standard (acetamide) in the form of a crystalline powder. Then, 1 to 5 mg of the selected substance is weighed by a high-sensitivity balance. The weighed quantity was solubilized with 0.6 mL of chloroform-d (CDCl ₃ , 99.8%) in a tube 5 mm in diameter. Finally, a 10 min treatment is applied by sonication of the NMR tubes in an ultrasonic bath after addition of the desired quantity of the oils to be analyzed. In order to verify the qualitative and quantitative reproducibility of the standard signal, the integrals of the single peak of acetamide, the chemical shift of which is 2 ppm, were calculated, taking the TMS as a reference at 0 ppm.

It is observed, in view of the H-NMR spectra of the pure mineral oil, the presence of two signals corresponding to the C—CH _{3 ,} C—CH ₂ groups. These govern the composition of the mineral oil, thus inducing a considerable loss of sensitivity. It is therefore necessary to employ a zoom on the aromatic part in order to quantitatively exploit the characteristic signals of PCBs located between 7.30 and 8.5 ppm in model systems, first, and subsequently in real systems. The sample of mineral oil containing PCB No. 1 was treated for 4 hours and 8 hours with the method of the invention in the installation described above.

Samples processed:

• The mineral oil / PCB N°0 mixture at a concentration of 200 ppm (model system).

Table 2 below summarizes the conditions and experimental results of a first series of treatments.

Samples



Settings
Oil mineral pure
Oil pure mineral/PCB N°0
200ppm Type of UV-visible source Dymax 5000-EC/400W Non-irradiated samples Dymax 5000-EC/400W Percentage relative to the maximum light intensity of the source 100%
Constant Non-irradiated sample 100%
Constant Light source-sample distance Variable
So that T=70°C Non-irradiated sample Variable
So that T=70°C Exposure time to UV-visible radiation
8am Non-irradiated sample
8am Integration of the signal on the aromatic zone (PCB)
No signal
0.4
0.4 Integrations report
(Acetamide) / (PCB)
Report not defined
1 / 0.4 = 2.5
1 / 0.4 = 2.5

The proton NMR spectra are followed mainly at the level of the characteristic peaks of PCBs (7.35 ppm – 8.5 ppm).

It is found that UV-visible irradiation has no effect on pure mineral oil, since there is no change observed in the proton NMR spectrum of pure mineral oil irradiated during 8 a.m. It is also noted that the radiative effect on the model system (pure mineral oil/PCB No. 0 at 200 ppm) is almost zero through the equality of the integration ratios (Acetamide) / (PCB), indicating the non-change of the intensities of the aromatic peaks and the stability of the PCB N°0 molecule.

EXAMPLE 3: Effects of UV-visible irradiation on pure mineral oil containing decachlorobiphenyl (PCB No. 209) in proton NMR

The sample of mineral oil containing PCB No. 209 was treated for 4 and 8 hours with the process of the invention in the installation described above.

Sample treated:

• Mineral oil containing 200 ppm of PCB No. 209.

All the samples of the mineral oil containing were treated under the same conditions and with the same way for 4h and 8h.

Table 3 below summarizes the conditions and experimental results of a first series of tests.

Samples


Settings

I' oil pure mineral/PCB N°209 ( 200ppm )


Type of UV-visible source Non-irradiated samples Dymax 5000-EC/400W Dymax 5000-EC/400W Percentage relative to the maximum light intensity of the source Non-irradiated samples 100%
Constant 100%
Constant Light source-sample distance Non-irradiated samples Non-irradiated samples Variable
So that T=70°C Exposure time to UV-visible radiation
Non-irradiated sample
4h
8am Integration of the signal on the aromatic zone (PCB)
No signal
0.26
0.36 Integrations report
(Acetamide) / (PCB)
Report not defined
1/0.2=5
1 / 0.36=2.77

-Before irradiation, the aromatic part of the proton NMR spectrum of PCB No. 209 shows no band or peak, since this molecule is saturated with chlorine and shows no proton grouping (H NMR spectrum not reproduced).

After the irradiation, a considerable effect of the irradiation of the process of the invention is observed on the PCB No. 209, contained in the mineral oil. We note, in fact, the photo-degradation of PCB N°209 with the increase of the aromatic peaks between 7.3 ppm and 8.5 ppm thus forming diphenyl (PCB N°0) at 65% and at 85%, respectively after irradiation for 4 hours and 8 hours, which confirms the substitution of the chlorine atoms of PCB No. 209 with protons which come from hydrocarbon mineral oil.

EXAMPLE 4: Effects of UV-visible irradiation on contaminated mineral oil (Real system) in proton NMR

The sample of contaminated mineral oil (real system) was treated for 4 and 8 hours with the process of the invention in the installation described above.

Sample treated:

• Contaminated mineral oil (actual system).

All the samples of the contaminated mineral oil containing PCBs were treated under the same conditions and with the same way for 4 and 8 hours.

Table 4 below summarizes the conditions and experimental results of a first series of tests.

Samples



Settings

Contaminated mineral oil
(System r el)

Type of UV-visible source Non-irradiated samples Dymax 5000-EC/400W Dymax 5000-EC/400W Percentage relative to the maximum light intensity of the source Non-irradiated samples 100%
Constant 100%
Constant Light source-sample distance Non-irradiated samples Variable
So that T=70°C Variable
So that T=70°C Exposure time to UV-visible radiation
Non-irradiated sample
4h
8am Integration of the signal on the aromatic zone (PCB)
Non-irradiated sample
0.23
0.5 Integrations report
(Acetamide) / (PCB)
Non-irradiated samples
1/0.23= 4.35
1/0.5= 2 Percent conversion to diphenyl (%)
0
49
86.1

The proton NMR spectra are followed mainly at the level of the characteristic aromatic zone of PCBs (7.30ppm-8.50ppm)

After irradiation for 4 h, a significant increase in the aromatic signals (spectra not reproduced) is observed. It is also observed that the radiative effect is greater after 8 hours. This observed phenomenon is due to the aromatic substitution of the chlorine atoms of the PCB mixture contained in the mineral oil by the H atoms taken from the same medium, thus forming diphenyl at 49% and 86.1%, after irradiation for 4 hours and 8 a.m., respectively. In particular, a very slight decrease in the C—CH ₂ , C—CH ₃ groups belonging to the pure mineral oil is observed, which confirms that the radiative effect on the pure oil remains very weak.

EXAMPLE 5: Effects of UV-visible irradiation on pure mineral oil containing PCB No. 0 in GC-MS (gas phase chromatography coupled with mass spectrometry)

The chromatograms as well as their associated spectra of mineral oils were carried out with a GC/MS apparatus (Clarus, 680/Clarus 600T Perkin Elmer, United States), equipped with a capillary column in fused silica grafted with 95% polysiloxanes and 5% diphenyl (Elite-5 30 m length × 0.53 mm thickness). The identification of PCB molecules was carried out using a mass spectrometer equipped with an EI (electron impact) ionization source and a quadrupole filter (ion separator) at a direct voltage (U ) and alternative (V), set by the device.

The thermal oven conditions that were applied for all GC examples are as follows:

The column was maintained at a temperature of 70°C initially for 4 min, then a rate ramp of 20°C/min up to 120°C is applied. It is then brought to 250° C. at a rate of 30° C./min. The oven remains isothermal at this temperature for 20 min, then the temperature is increased to 300°C with a heating rate of 20°C/min, which is maintained for an additional 20 min.

The injector and transfer line temperatures were 300°C. The identification of the products was carried out by their retention times and their mass spectra thereafter. The carrier gas used in our analyzes is Helium (He).

- The mass spectroscopy (MS) analytical conditions listed below were applied to all model and real systems:

The detection and identification of PCB molecules is done in relation to a reference standard which is FC-43 (Heptacosa). The masses shown by the MS are limited to the range 30 - 1166 m/z due to the type of electron ionization source, which is the most capable of fragmenting molecules with high masses. The ionization source temperature was set at 280°C. The voltage applied by the filament is 430 V. In order to meet the needs of detection, identification and quantification, systems containing a single PCB compound have been developed.

The sample of mineral oil mixed with PCB No. 0 (model system) was treated for 4 and 8 hours with the process of the invention in the installation described above.

Samples treated: Mineral oil + PCB N°0 (model system).

The chromatograms of the diphenyl molecule (PCB No. 0) at 200 ppm non-irradiated and irradiated for 8 hours are not reproduced. However, it is also observed that the characteristic signal at PCB No. 0 appears at the retention time of 7.66 min.

It is confirmed that the UV-Visible irradiation effect is nil on the PCB N°0 molecule, which does not react despite the significant duration of exposure to the radiation.

Table 5 below summarizes the conditions and experimental results of the 8 hour irradiation of PCB No. 0.

Samples

Settings
Pure mineral oil/PCB N°0 To 200ppm
Type of UV-visible source Non-irradiated samples Dymax 5000-EC/400W Percentage relative to the maximum light intensity of the source Non-irradiated samples 100%
Constant Light source-sample distance Non-irradiated samples Variable
So that T=70°C Exposure time to UV-visible radiation Non-irradiated sample
8am Concentration before treatment (ppm)
200
200 Concentration after treatment (ppm)
200
200

EXAMPLE 6: Effects of UV-visible irradiation on pure mineral oil containing Decachlorobiphenyl (PCB No. 209) in GC-MS

The sample of mineral oil mixed with PCB No. 0 (model system) was treated for 4 and 8 hours with the process of the invention in the installation described above:

Sample treated: Mineral oil + PCB N°209 (model system).

It is observed, at first sight, a signal detection sensitivity despite the low concentrations indicated above of the molecule PCB No. 209, but also that the peak characteristic of PCB No. 209 appears at the retention time of 34.5 min.

After irradiation for 4 hours, then 8 hours, respectively, the peak corresponding to the target molecule has completely disappeared. We also observe new peaks attributed to the by-products generated by this irradiated molecule.

By-products from the photo-degradation of PCB No. 209 are identified by mass spectroscopy (spectra not shown)

It is observed, after treatment for 8 hours, that the initial concentration of PCB No. 209 has gone from 200 ppm to about 30 ppm.

The photo-degradation of PCB N°209 produced PCB N°0, which is found in high concentration and other PCBs including 1 and 2 chlorines. These molecules are not toxic and are not addressed by legislation knowing that the toxicity of PCBs starts from molecules with 4 or more chlorines.

Table 6 summarizes below the conditions and experimental results of the 4h and 8h irradiation of PCB No. 209.

Samples


Settings

Pure mineral oil/PCB N°0 To 209ppm

Type of UV-visible source Non-irradiated samples Dymax 5000-EC/400W Dymax 5000-EC/400W Percentage relative to the maximum light intensity of the source Non-irradiated samples 100%
Constant 100%
Constant Light source-sample distance Non-irradiated samples Variable
So that T=70°C Variable
So that T=70°C Exposure time to UV-visible radiation Non-irradiated samples
4h
8am Concentration before treatment (ppm)
200
200
200 Concentration after treatment (ppm)
200
75
30

EXAMPLE 7: Effects of UV-visible irradiation on pure mineral oil containing 12 PCB molecules in GC-MS

The mineral oil sample mixed with 12 PCB-type molecules (model system) was treated for 4 and 8 hours with the process of the invention in the installation described above.

Sample treated: Mineral oil + 12 PCB (model system).

The spectra have not been reproduced for simplicity.

In view of the results in Table 7, it can be seen that after irradiation for 4 h and 8 h, respectively, a significant reduction in the peaks corresponding to the PCB molecules is observed, and new peaks attributed to the by-products generated are also observed. The photo-products of the 12 PCB system irradiated for 4h and 8h were analyzed in detail by mass spectroscopy (MS). Biphenyl (tr=7.40 min) and other molecules

PCBs were detected at low concentrations, even after treatment (see Table 8, and Table 9) and other aliphatic compounds were observed, but these are not affected by the legislation.

After irradiating the model mixture of PCBs at 200 ppm for 4 h and 8 h, their initial concentration decreased to 55 and 40 ppm, respectively.

Table 7 presents the 12 PCB molecules mixed with mineral oil as well as their retention times (before irradiation).

Kind of PCBs
you _R (Mins) Percentage of probability in MS %
(1) PCB #0
7.61
100
(2) PCB #1
9.8
100
(3) PCB #2
11.8
100
(4) PCB #7
15.85
100
(5) PCB #18
24.8
100
(6) PCB #31
28.01
100
(7) PCB #52
29.00
100
(8) PCB #70
30.00
100
(9) PCB #101
30.45
100
(10) PCB #153
31.44
100
(11) PCB #180
32.36
100
(12) PCB #209
34.56
100

Table 8 presents the photo-products of the model system with 12 PCB molecules mixed with mineral oil, as well as their retention times (after 4 hours of irradiation).

Table 9 presents the photo-products of the model system with 12 PCB molecules mixed with mineral oil as well as their retention times (after 8 hours of irradiation).

s we -products after 8 hours of treatment
you time retention (min)
p percentage of probability in MS % PCB No. 0 7 , 61 100 PCB #1 9 , 8 100 PCB No. 15 24 , 56 100

EXAMPLE 8: Effects of UV-visible irradiation on contaminated mineral oil (Real system) in GC-MS

The sample of contaminated mineral oil (real system) was treated for 4 and 8 hours with the process of the invention in the installation described above.

Processed sample: Contaminated mineral oil (actual system).

Laboratory studies on contaminated mineral oil exposed to UV-visible radiation for 4 and 8 hours have shown the effectiveness of the proposed treatment.

Indeed, at the end of the photo degradation reactions of the PCBs in the oil followed by the GC, we obtained less toxic by-products in 8 hours such as diphenyl, monochlorinated diphenyls, dichorinated or aliphatic hydrocarbons. notably. These were detected and subsequently identified with mass spectroscopy.

Table 10 below summarizes the conditions and experimental results of the 4h and 8h irradiation of the contaminated mineral oil.

Samples

Settings

h contaminated mineral oil (actual system)

Type of UV-visible source Non-irradiated samples Dymax 5000-EC/400W Dymax 5000-EC/400W Percentage relative to the maximum light intensity of the source Non-irradiated samples 100%
Constant 100%
Constant Light source-sample distance Non-irradiated samples Variable
So that T=70°C Variable
So that T=70°C Exposure time to UV-visible radiation Non-irradiated sample
4h
8am Concentration before treatment (ppm)
337.5
337.5
337.5 Concentration after treatment (ppm)
Non-irradiated sample

86
42

After treatment for 4 hours, then 8 hours, the chlorine was mainly observed in the form of acids, inorganic salts or even PCBs with one or two chlorines (see figures above).

It can be seen that the least chlorinated PCBs PCB N°1, PCB N°2, PCB N°15 and diphenyl are present in irradiated contaminated mineral oil, which proves the dechlorination of the most chlorinated PCBs and their sensitivity to -live the proposed treatment.

Table 11 presents the PCBs present in the contaminated mineral oil as well as their respective retention times.

PCBs present in contaminated mineral oil before irradiation

you _R (Mins)
p percentage of probability in MS %
(1) PCB #0
7.61
100 PCB No. 15 24 , 56 100
(6) PCB #31
28.01
98
(9) PCB #101
30.45
86
(10) PCB #153
31.44
75

Table 12 presents the photo-products of contaminated mineral oil exposed to UV-visible radiation for 4 hours as well as their retention times.

By-products after 4 h treatment of contaminated mineral oil
Retention time (min)
Probability percentage in MS % PCB No. 0 7 , 61 100 PCB #1 9 , 8 100 PCB No. 15 24 , 56 70 PCB No. 52 29 75 PCB No. 101 30 , 45 50 Dichloroacetic acid , _ _ _ _
2-pentadecyl ester 31 , 41 45 Acid d ichloro - In this ic , heptadecyl e star 33 , 14 35

Table 13 presents the photo-products of contaminated mineral oil exposed to UV-visible radiation for 8 hours as well as their retention times.

By-products after 8 hours of treatment contaminated mineral oil
Retention time (min)
p percentage of probability in MS % PCB No. 0 7 , 61 100 PCB #1 9 , 8 100 PCB No. 15 24 , 56 70 Dichloroacetic acid , _ _ _ _
2-pentadecyl ester 31 , 41 62 Acid d ichlor oh - In this ic , heptadecyl e star 33 , 14 45

All of the above examples demonstrate that the process according to the invention makes it possible to effectively deactivate the polychlorinated biphenyls contained in mineral oils. The average percentages of elimination of organochlorine aromatic compounds were calculated by the following formula:

With for its definition:

PEM: mean elimination percentage

PE _mi : percentage of elimination for a molecule i

X _0i : initial molar fraction of molecule i

The results obtained for the real system containing 9 PCBs are presented in Table 14.

Type of pcb
T _R (mins) (retention time) vs oh ncentration before irradiation (ppm) vs concentration after irradiation (ppm)
% elimination
PCB No. 180
32.36
27.9 0
No peaks
100
PCB No. 153
31.44
14.0 0
No peaks
100
PCB No. 52
29.0
24.6 0
No peaks
100
PCB No. 31
28.01
52.4
9.8
81.3
PCB No. 18
24.8
1.3 0
No peaks
100
PCB No. 15
24.56
14.2
12.2
14
PCB No. 7
15.85
61.4 0
No peaks
100
PCB No. 2
11.8
70.5
10.3
85.4
PCB #1
9.9
85.4
22.8
73.2
PCB No. 0
7.6
91.8
200 Increase
from the peak Elimination average
PCBs in a real oil system
87%

The products resulting from the radiation are present in very small quantities and therefore do not risk damaging the electrical and dielectric properties of the oils. Finally, the inexpensive radiation treatment of contaminated oil limits the production of toxic waste and will save considerable time and money.

The kinetic study of the photo-degradation of PCBs by UV-Visible radiation in used mineral oils was followed by GC-MS.

It is observed that the concentration of PCBs in mineral oil gradually decreases with increasing exposure time. We also note that after 8 hours of irradiation, the objective set by the legislation in force which imposes PCB concentrations of less than 50 ppm is achieved with an elimination percentage of 87%.

The kinetics of PCB photodegradation follows the first-order model in view of the optimal correlation coefficient of the linear regression line with respect to the other models.

The equation of the kinetic model followed is the following:

Where we have:

k , the rate constant

[PCBs] ₀ , the initial concentration at timeyou=0h

[PCBs] _you , the concentration at time t

Equation (1) is that of a straight line which can be written:

y = ax ( 2)

The PCB photodegradation rate constant was determined by superimposing equation (1) and the linear regression curve (2) plotted with Origin version 8.1 where k=a is the slope. (See Table 15)

t (h) [PCB] average (ppm) Ln ([PCB] ₀ / [PCBs] _you ) k
(Mol ^-1 L s ^-1 ) R ² 0 353.2±0.5 0


0.253


0.996 1 291.0± 0.5 0.150 2 207.0± 0.5 0.493 4 111.0± 0.5 1,112 6 75.0± 0.5 1,507 8 44.0±0.5 2,033

Claims (10)

Process for dechlorinating one or more aromatic organochlorine compound(s) contained in an oil or constituting said oil, said aromatic organochlorine compound(s) s) being chosen, in particular, from molecules comprising two or three benzene rings and of which at least one benzene ring or all the benzene rings are substituted by at least one chlorine atom, in particular polychlorobiphenyls and polychloroterphenyls, whereinsaid oil is irradiated with radiation having wavelengths equal to or greater than 300 nm, in particular with radiation having wavelengths equal to or greater than 320 nm and in particular with radiation having wavelengths equal to or greater than 320 nm and equal to or less than 390 nm, while maintaining the temperature of said oil at a value less than or equal to a given threshold value. Method according to Claim 1, characterized in that the temperature of the said oil is maintained at a value lower than or equal to the said given threshold value by varying the distance traveled by the said rays to reach the said oil. Process according to Claim 1 or 2, characterized in that the said oil is a fraction withdrawn, optionally continuously, from an oil contained in a tank of dielectric fluid or in an electrical/electronic device, the remaining fraction of the said oil being optionally in circulation in said apparatus, in that said fraction of oil withdrawn outside of said apparatus is irradiated and in that said fraction of oil is reinjected, optionally continuously, after irradiation into said apparatus, optionally without stopping the circulation of said oil in said apparatus. Process according to any one of the preceding claims, characterized in that the said oil is chosen from oils consisting of an organochlorine aromatic compound, in liquid form, and comprising two or three benzene rings, including at least one benzene ring or all the benzene rings are substituted by at least one chlorine atom, in particular polychlorobiphenyls and polychloroterphenyls, oils consisting of liquid mixtures of said organochlorine compounds, in particular mixtures of polychlorinated biphenyls and/or polychloroterphenyls, oils consisting of the mixture of an oil selected from mineral oils, naphthenic oils, paraffinic oils, intermediate oils, silicone oils and synthetic ester oils and one or more selected aromatic organochlorine compound(s), in particular, among the molecules comprising two or three benzene rings and of which at least one benzene ring or all the benzene rings are substituted by at least one chlorine atom, in particular polychlorobiphenyls and polychloroterphenyls and mixtures of at least two of these oils. Process according to any one of the preceding claims, characterized in that the said oil contains at least one PCB compound chosen from: 2-Chlorobiphenyl (PCB No. 1), 3-Chlorobiphenyl (PCB No. 2), 4- Chlorobiphenyl PCB No. 3, 2,2'-Dichlorobiphenyl (PCB No. 4), 2,3-Dichlorobiphenyl (PCB No. 5), 2,3'-Dichlorobiphenyl (PCB No. 6), 2, 4-Dichlorobiphenyl (PCB No. 7), 2,4'-Dichlorobiphenyl (PCB No. 8), 2,5-Dichlorobiphenyl (PCB No. 9), 2,6-Dichlorobiphenyl (PCB No. 10), 3,3'-Dichlorobiphenyl (PCB No. 11), 3,4-Dichlorobiphenyl (PCB No. 12), 3,4'-Dichlorobiphenyl (PCB No. 13), 3,5-Dichlorobiphenyl (PCB No. 14), 4,4'-Dichlorobiphenyl (PCB No. 15), 2,2',3-Trichlorobiphenyl (PCB No. 16), 2,2',4-Trichlorobiphenyl (PCB No. 17), 2,2',5-Trichlorobiphenyl (PCB No. 18), 2,2',6-Trichlorobiphenyl (PCB No. 19), 2,3,3'-Trichlorobiphenyl (PCB No. 20), 2 ,3,4-Trichlorobiphenyl (PCB No. 21), 2,3,4'-Trichlorobiphenyl (PCB No. 22), 2,3,5-Trichlorobiphenyl (PCB No. 23), 2,3,6 -Trichlorobiphenyl (PCB No. 24), 2,3',4-Trichlorobiphenyl (PCB No. 25), 2,3',5-Trichlorobiphenyl (PCB No. 26), 2,3',6-Trichlorobiphenyl , (PCB No. 27), 2,4,4'-Trichlorobiphenyl (PCB No. 28), 2,4,5-Trichlorobiphenyl, (PCB No. 29), 2,4,6-Trichlorobiphenyl (PCB No. 30), 2,4',5-Trichlorobiphenyl, (PCB No. 31), 2,4',6-Trichlorobiphenyl (PCB No. 32), 2,3',4'-Trichlorobiphenyl (PCB No. 33), 2,3',5'-Trichlorobiphenyl (PCB No. 34), 3,3',4-Trichlorobiphenyl (PCB No. 35), 3,3',5-Trichlorobiphenyl (PCB No. 36), 3,4,4'-Trichlorobiphenyl (PCB No. 37), 3,4,5-Trichlorobiphenyl (PCB No. 38), 3,4',5-Trichlorobiphenyl, (PCB No. 39 ), 2,2',3,3'-Tetrachlorobiphenyl (PCB No. 40), 2,2',3,4-Tetrachlorobiphenyl (PCB No. 41) 2,2',3,4'-Tetrachlorobiphenyl (PCB No. 42), 2,2',3,5-Tetrachlorobiphenyl (PCB No. 43), 2,2',3,5'-Tetrachlorobiphenyl (PCB No. 44), 2,2', 3,6-Tetrachlorobiphenyl (PCB No. 45), 2,2',3,6'-Tetrachlorobiphenyl (PCB No. 46), 2,2',4,4'-Tetrachlorobiphenyl (PCB No. 47), 2,2',4,5-Tetrachlorobiphenyl (PCB No. 48), 2,2',4,5'-Tetrachlorobiphenyl (PCB No. 49), 2,2',4,6-Tetrachlorobiphenyl (PCB No. 50), 2,2',4,6'-Tetrachlorobiphenyl (PCB No. 51), 2,2',5,5'-Tetrachlorobiphenyl (PCB No. 52), 2,2',5 ,6'-Tetrachlorobiphenyl (PCB No. 53), 2,2',6,6'-Tetrachlorobiphenyl (PCB No. 54), 2,3,3',4-Tetrachlorobiphenyl (PCB No. 55), 2,3,3',4'-Tetrachlorobiphenyl (PCB No. 56), 2,3,3',5-Tetrachlorobiphenyl (PCB No. 57), 2,3,3',5'-Tetrachlorobiphenyl (PCB No. 58), 2,3,3',6-Tetrachlorobiphenyl (PCB No. 59), 2,3,4,4'-Tetrachlorobiphenyl (PCB No. 60), 2,3,4,5- Tetrachlorobiphenyl (PCB No. 61), 2,3,4,6-Tetrachlorobiphenyl (PCB No. 62), 2,3,4',5-Tetrachlorobiphenyl (PCB No. 63), 2,3,4' ,6-Tetrachlorobiphenyl (PCB No. 64), 2,3,5,6-Tetrachlorobiphenyl (PCB No. 65), 2,3',4,4'-Tetrachlorobiphenyl (PCB No. 66), 2, 3',4,5 Tetrachlorobiphenyl (PCB No. 67), 2,3',4,5'-Tetrachlorobiphenyl (PCB No. 68), 2,3',4,6-Tetrachlorobiphenyl (PCB No. 69) , 2,3',4',5-Tetrachlorobiphenyl (PCB No. 70), 2,3',4',6-Tetrachlorobiphenyl (PCB No. 71), 2,3',5,5'- Tetrachlorobiphenyl (PCB No. 72), 2,3',5',6-Tetrachlorobiphenyl (PCB No. 73), 2,4,4',5-Tetrachlorobiphenyl (PCB No. 74), 2,4, 4',6-Tetrachlorobiphenyl (PCB No. 75), 2,3',4',5'-Tetrachlorobiphenyl (PCB No. 76), 3,3',4,4' Tetrachlorobiphenyl (PCB No. 77) , 3,3',4,5-Tetrachlorobiphenyl (PCB No. 78), 3,3',4,5'-Tetrachlorobiphenyl (PCB No. 79), 3,3',5,5'-Tetrachlorobiphenyl (PCB No. 80), 3,4,4',5-Tetrachlorobiphenyl (PCB No. 81), 2,2',3,3',4-Pentachlorobiphenyl (PCB No. 82), 2,2 ',3,3',5-Pentachlorobiphenyl (PCB No. 83), 2,2',3,3',6-Pentachlorobiphenyl (PCB No. 84), 2,2',3,4,4' -Pentachlorobiphenyl (PCB No. 85), 2,2',3,4,5-Pentachlorobiphenyl (PCB No. 86), 2,2',3,4,5'-Pentachlorobiphenyl (PCB No. 87), 2,2',3,4,6-Pentachlorobiphenyl (PCB No. 88), 2,2',3,4,6'-Pentachlorobiphenyl (PCB No. 89), 2,2',3,4 ',5-Pentachlorobiphenyl (PCB No. 90), 2,2',3,4',6-Pentachlorobiphenyl (PCB No. 91), 2,2',3,5,5'-Pentachlorobiphenyl (PCB No. °92), 2,2',3,5,6-Pentachlorobiphenyl (PCB No. 93), 2,2',3,5,6'-Pentachlorobiphenyl (PCB No.94), 2,2' ,3,5',6-Pentachlorobiphenyl (PCB No. 95), 2,2',3,6,6'-Pentachlorobiphenyl (PCB No. 96), 2,2',3,4',5' pentachlorobiphenyl (PCB No. 97), 2,2',3,4',6'-Pentachlorobiphenyl (PCB No. 98), 2,2',4,4',5-pentachlorobiphenyl (PCB No. 99) , 2,2',4,4',6-Pentachlorobiphenyl (PCB No. 100), 2,2',4,5,5'-Pentachlorobiphenyl (PCB No. 101), 2,2',4 ,5,6'-Pentachlorobiphenyl (PCB No. 102), 2,2',4,5',6-Pentachlorobiphenyl (PCB No. 103), 2,2',4,6,6'-Pentachlorobiphenyl ( PCB No. 104), 2,3,3,3',4,4'-Pentachlorobiphenyl (PCB No. 105), 2,3,3,4,5-Pentachlorobiphenyl (PCB No. 106), 2, 3,3',4',5-Pentachlorobiphenyl (PCB No. 107), 2,3,3',4,5'-Pentachlorobiphenyl (PCB No. 108), 2,3,3',4,6 -Pentachlorobiphenyl (PCB No. 109), 2,3,3',4',6-Pentachlorobiphenyl (PCB No. 110), 2,3,3,5,5'-Pentachlorobiphenyl (PCB No. 111) , 2,3,3,5,6-Pentachlorobiphenyl (PCB No. 112), 2,3,3,5',6-Pentachlorobiphenyl (PCB No. 113), 2,3,4,4 ',5-Pentachlorobiphenyl (PCB No. 114), 2,3,4,4',6-Pentachlorobiphenyl (PCB No. 115), 2,3,4,5,6-Pentachlorobiphenyl (PCB No. 116) , 2,3,4',5,6-Pentachlorobiphenyl (PCB No. 117), 2,3',4,4',5-Pentachlorobiphenyl (PCB No. 118), 2,3',4, 4',6-Pentachlorobiphenyl (PCB No. 119), 2,3',4,5,5'-Pentachlorobiphenyl (PCB No. 120), 2,3',4,5',6-Pentachlorobiphenyl (PCB No. 121), 2,3,3,3',4',5'-Pentachlorobiphenyl (PCB No. 122), 2,3',4,4',5'-Pentachlorobiphenyl (PCB No. 123), 2,3',4',5,5'-Pentachlorobiphenyl (PCB No. 124), 2,3',4',5',6-Pentachlorobiphenyl (PCB No. 125), 3,3',4 ,4',5-Pentachlorobiphenyl (PCB No. 126), 3,3',4,5,5'-Pentachlorobiphenyl (PCB No. 127), 2,2',3,3',4,4' -Hexachlorobiphenyl (PCB No. 128), 2,2',3,3',4,5-hexachlorobiphenyl (PCB No. 129), 2,2',3,3',4,5'-hexachlorobiphenyl ( PCB No. 130), 2,2',3,3',4,6-hexachlorobiphenyl (PCB No. 131), 2,2',3,3',4,6'-hexachlorobiphenyl (PCB No. 132), 2,2',3,3',5,5'-hexachlorobiphenyl (PCB No. 133), 2,2',3,3',5,6-hexachlorobiphenyl (PCB No. 134), 2,2',3,3',5,6'-hexachlorobiphenyl (PCB No. 135), 2,2',3,3',6,6'-hexachlorobiphenyl (PCB No. 136), 2 ,2',3,4,4',5-hexachlorobiphenyl (PCB No. 137), 2,2',3,4,4',5'-hexachlorobiphenyl (PCB No. 138), 2,2' ,3,4,4',6-hexachlorobiphenyl (PCB No. 139), 2,2',3,4,4',6'-hexachlorobiphenyl (PCB No. 140), 2,2',3, 4,5,5'-hexachlorobiphenyl (PCB No. 141), 2,2',3,4,5,6-hexachlorobiphenyl (PCB No. 142), 2,2',3,4,5,6 '-Hexachlorobiphenyl (PCB No. 143), 2,2',3,4,5',6-hexachlorobiphenyl (PCB No. 144), 2,2',3,4,6,6'-Hexachlorobiphenyl ( PCB No. 145), 2,2',3,4',5,5'-hexachlorobiphenyl (PCB No. 146), 2,2',3,4',5,6-hexachlorobiphenyl (PCB No. 147), 2,2',3,4',5,6'-hexachlorobiphenyl (PCB No. 148), 2,2',3,4',5',6-Hexachlorobiphenyl (PCB No. 149) , 2,2',3,4',6,6'-hexachlorobiphenyl (PCB No. 150), 2,2',3,5,5',6-hexachlorobiphenyl (PCB No. 151), 2 ,2',3,5,6,6'-Hexachlorobiphenyl (PCB No. 152), 2,2',4,4',5,5'-hexachlorobiphenyl (PCB No. 153), 2,2' ,4,4',5,6'-Hexachlorobiphenyl (PCB No. 154), 2,2',4,4',6,6'-hexachlorobiphenyl (PCB No. 155), 2,3,3' ,4,4',5-hexachlorobiphenyl (PCB No. 156), 2,3,3',4,4',5'-hexachlorobiphenyl (PCB No. 157), 2,3,3',4, 4',6-hexachlorobiphenyl (PCB No. 158), 2,3,3',4,5,5'-hexachlorobiphenyl (PCB No. 159), 2,3,3',4,5,6- hexachlorobiphenyl (PCB No. 160), 2,3,3,3',4,5',6-hexachlorobiphenyl (PCB No. 161), 2,3,3,3',4',5,5'-hexachlorobiphenyl (PCB No. 162), 2,3,3,3',4',5,6-hexachlorobiphenyl (PCB No. 163), 2,3,3,3',4',5',6-hexachlorobiphenyl (PCB No. 164 ), 2,3,3,3',5,5',6-hexachlorobiphenyl (PCB No. 165), 2,3,4,4',5,6-hexachlorobiphenyl (PCB No. 166), 2,3 ',4,4',5,5'-hexachlorobiphenyl (PCB No. 167), 2,3',4,4',5',6-hexachlorobiphenyl (PCB No. 168), 3,3', 4,4',5,5'-hexachlorobiphenyl (PCB No. 169), 2,2',3,3',4,4',5-heptachlorobiphenyl (PCB No. 170), 2,2', 3,3',4,4',6-heptachlorobiphenyl (PCB No. 171), 2,2',3,3',4,5,5'-heptachlorobiphenyl (PCB No. 172), 2,2 ',3,3',4,5,6-heptachlorobiphenyl (PCB No. 173), 2,2',3,3',4,5,6'-heptachlorobiphenyl (PCB No. 174), the 2, 2',3,3',4,5',6-heptachlorobiphenyl (PCB No. 175), 2,2',3,3',4,6,6'-heptachlorobiphenyl (PCB No. 176), 2,2',3,3',4,5',6'-heptachlorobiphenyl (PCB No. 177), 2,2',3,3',5,5',6-heptachlorobiphenyl (PCB No. 178 ), 2,2',3,3',5,6,6'-heptachlorobiphenyl (PCB N°179), 2,2',3,4,4',5,5'-heptachlorobiphenyl (PCB N °180), 2,2',3,4,4',5,6-heptachlorobiphenyl (PCB No. 181), 2,2',3,4,4',5,6'-heptachlorobiphenyl (PCB No. 182), 2,2',3,4,4',5',6-heptachlorobiphenyl (PCB No. 183), 2,2',3,4,4',6,6'-heptachlorobiphenyl (PCB No. 184), 2,2',3,4,5,5',6-heptachlorobiphenyl (PCB No. 185), 2,2',3,4,5,6,6'-heptachlorobiphenyl (PCB No. 186), 2,2',3,4',5,5',6-heptachlorobiphenyl (PCB No. 187), 2,2',3,4',5,6,6' -Heptachlorobiphenyl (PCB No. 188), 2,3,3',4,4',5,5'-heptachlorobiphenyl (PCB No. 189), 2,3,3',4,4',5, 6-Heptachlorobiphenyl (PCB No. 190), 2,3,3',4,4',5',6-Heptachlorobiphenyl (PCB No. 191), 2,3,3',4,5,5' ,6-heptachlorobiphenyl (PCB No. 192), 2,3,3',4',5,5',6-Heptachlorobiphenyl (PCB No. 193), 2,2',3,3',4, 4',5,5'-octachlorobiphenyl (PCB No. 194), 2,2',3,3',4,4',5,6-octachlorobiphenyl (PCB No. 195), 2,2', 3,3',4,4',5,6'-Octachlorobiphenyl (PCB No. 196), 2,2',3,3',4,4',6,6'-Octachlorobiphenyl (PCB No. 197 ), 2,2',3,3',4,5,5',6-Octachlorobiphenyl (PCB No. 198), 2,2',3,3',4,5,5',6' -Octachlorobiphenyl (PCB No. 199), 2,2',3,3',4,5,6,6'-Octachlorobiphenyl (PCB No. 200), 2,2',3,3',4, 5',6,6'-Octachlorobiphenyl (PCB No. 201), 2,2',3,3',5,5',6,6'-Octachlorobiphenyl (PCB No. 202), 2,2' ,3,4,4',5,5',6-Octachlorobiphenyl (PCB No. 203), 2,2',3,4,4',5,6,6'-Octachlorobiphenyl (PCB No. 204) , 2,3,3',4,4',5,5',6-Octachlorobiphenyl (PCB No. 205), 2,2',3,3',4,4',5,5', 6-Nonachlorobiphenyl (PCB No. 206), 2,2',3,3',4,4',5,6,6'-Nonachlorobiphenyl (PCB No. 207), 2,2',3,3 ',4,5,5',6,6'-Nonachlorobiphenyl (PCB No. 208) and Decachlorobiphenyl (PCB No. 209). Installation, possibly mobile, allowing the implementation of the method according to any one of Claims 1 to 5, characterized in that it comprises:

• a reactor comprising an inlet opening and an outlet opening capable of being connected in a sealed manner with the interior of an electrical/electronic device, which contains an oil containing or consisting of one or more organochlorine compound(s) s) aromatic(s), the said organochlorine compound(s) being chosen in particular from molecules comprising two or three benzene rings and of which at least one benzene ring or all the rings benzenes are substituted by at least one chlorine atom, in particular polychlorobiphenyls and polychloroterphenyls;
• at least one pump arranged so as to set said oil in motion in the circuit formed by said reactor and said electrical/electronic apparatus, when the latter is connected to said reactor;
• a radiation source capable of emitting radiation having wavelengths equal to or greater than 300 nm and in particular equal to or greater than 320 nm and more particularly equal to or greater than 320 nm and equal to or less than 390 nm, said source being arranged so as to irradiate said oil contained in said reactor; And
• means for regulating the temperature of the oil contained in said reactor.

Installation according to Claim 6, characterized in that the said means for regulating the temperature of the oil contained in the said reactor comprise at least one support on which the said radiation source and/or the said reactor is/are mounted. ) and in that said support makes it possible to vary the distance between said radiation source and said reactor. Installation according to Claim 6 or 7, characterized in that the said radiation source is disposed at least partially in the said reactor. Installation according to any one of claims 6 to 8, characterized in that it comprises a tank for collecting dielectric fluids and/or at least one electric/electronic device, in particular an electric transformer, said tank and said device containing an oil containing or consisting of one or more aromatic organochlorine compound(s), the said compound(s) being chosen, in particular, from molecules comprising two or three rings benzene rings and of which at least one benzene ring or all the benzene rings are substituted by at least one chlorine atom, in particular the polychlorobiphenyls and the polychloroterphenyls, in that the said inlet opening and the said outlet opening of the said reactor are respectively connected to an inlet opening and an outlet opening provided in said tank and/or said device and which allow said oil contained in said tank and/or said device to circulate in said reactor and in that said reactor further comprises , a recirculation loop, which connects the outlet opening of said reactor to the inlet opening of said reactor and a pump capable of moving said oil in said recirculation loop. Installation according to claim 9, characterized in that it comprises a unit for holding said oil contained in said collection tank and/or in said at least one device, in that said holding unit is connected to the opening of outlet from said tank and/or said at least one device and comprises:

• a pump for moving said oil leaving said apparatus;
• means for filtering said oil; And
• means for extracting water and any acids and bases contained in said oil;

and in that said inlet opening of said reactor is connected downstream of said holding unit, said outlet opening of said reactor being connected to said inlet opening of said collection vessel or of said at least one electrical/electronic device.