WO1995028993A1

WO1995028993A1 - Method of decomposing halogenated aromatic compound with alkaline substance

Info

Publication number: WO1995028993A1
Application number: PCT/JP1995/000785
Authority: WO
Inventors: Fumio Tanimoto; Kiyohiko Tsukumo; Atsuhiko Nakamura; Tsuneo Yano; Nobuhiro Suzuki; Toshinori Toma; Koichi Furuhashi; Nobuyuki Nakayama
Original assignee: Research Institute For Production Development; Mitsui & Co., Ltd.; Neos Co., Ltd.
Priority date: 1994-04-22
Filing date: 1995-04-20
Publication date: 1995-11-02
Also published as: EP0711580A1; JP3247543B2; AU2267295A; EP0711580A4; TW288009B; JPH07289656A

Abstract

A method of decomposing a halogenated aromatic compound with an alkaline substance safely without fail, which comprises bringing the aromatic compound into contact with the alkaline substance in an aprotic polar solvent at a temperature ranging from about 150 to about 300 °C for about one to about ten hours, the alkaline substance being present in an amount of about 5,000 mg per kilogram of the reaction mixture as a whole in starting the reaction.

Description

Description Method for decomposing halogenated aromatic compounds with alkaline substances [Technical field]

The present invention relates to a method for safely decomposing a halogenated aromatic compound such as polychlorinated biphenyl (hereinafter abbreviated as PCB) by using an alkaline substance in a polar solvent.

! 0 [Background Art]

Since halogenated aromatic compounds such as PCB are extremely difficult to treat, much effort has been made for the removal or decomposition of halogenated aromatic compounds for more than 20 years. Some examples are given below.- The reaction in the presence of alkali is described in U.S. Pat. No. 2,951,80.

No. 54 discloses the alumina-alkaline method. U.S. Pat. No. 4,532,028 also discloses that in a mixture of an alkyl or alkylene sulfoxide and a polyol, an alkali and a PCB having a concentration of 50,000 ppm or less are used. A method is described in which the reaction is carried out at 0 ° C or less to obtain a few ppm. In addition, Canadian Patent Nos. 1, 1 using sodium melts

The method disclosed in US Pat. No. 2,081,770 and the method disclosed in Italian Patent Nos. 1, 206, 508 using an alkaline earth metal to which polyethylene glycol is adsorbed are exemplified. Are known.

Each of these conventional techniques has excellent features, but it further removes halogenated aromatic compounds from low-concentration levels of samples, and consequently contains substantially ₂₅ halogenated aromatic compounds. At present, it has not been reduced to such an extent that it is less than 1 ppm. Removal to the bottom has not yet been realized. In addition, when the solvent used in the conventional method is heated to a high temperature of 150 ° C or more in the presence of an alkaline substance or an alkaline metal, the solvent loses chemical stability. As a result, decomposition and polymerization proceed, so that there is a problem that it cannot be carried out industrially.

Recently, a reduction method using paraffin as a hydrogen source has also been studied. However, even this method has a drawback that about 1 ppm of PCB remains and the reaction temperature is high.

[Disclosure of the Invention]

The inventors of the present invention have made various studies to solve the above-mentioned problems, and as a result, have a high boiling point polar solvent and have excellent stability against alcohol even at high temperatures. Select a non-proton polar solvent, and in this non-proton polar solvent, heat a halogenated aromatic compound and an amount of an alkali substance that significantly exceeds the amount dissolved in the non-proton polar solvent at a high temperature. It has been found that the contacting method below is very effective in decomposing the halogenated aromatic compound.

Accordingly, the present invention provides a method for decomposing a halogenated aromatic compound by bringing the halogenated aromatic compound into contact with the alkali substance in a non-proton polar solvent. The contact temperature ranges from about 150 ° C to about 300 ° C, and the contact time ranges from 1 hour to 10 hours. A special feature is that the mixing ratio at the start is 5,000 mg Z kg or more.

In particular, it is preferable that the mixing ratio of the alkali substance to the whole reaction system at the start of the reaction is 7, OOOOmgZkg or more.

Here, typical halogenated aromatic compounds to be decomposed A halogenated aromatic compound selected from the group consisting of polychlorinated biphenyls, polychlorinated terphenyls, polybrominated biphenyls, and analogs thereof, or two or more halogens selected from this group There are mixtures of fluorinated aromatic compounds.

5 Regarding the method according to the present invention, at this stage, it has not been possible to scientifically explain as what kind of chemical reaction the halogenated aromatic compound is decomposed as an essential reaction mechanism. As a result of repeatedly examining the decomposition method according to the present invention, it was confirmed that the halogenated aromatic compound was decomposed to an undetectable concentration level. Here, the chemical reaction is completed.

In order to form a bond, a method of adding an inexpensive chemical in excess of the reacting chemicals is generally used, but in the present invention, the amount of the non-proton polar solvent as a solvent is reduced. Set the amount of alkaline substance corresponding to. That is, in the present invention, rather than excess of the alkali substance with respect to the halogenated aromatic compound, excess of the alkali substance with respect to the non-proton polar solvent is used.

It should be noted that IS enhances the action of non-proton polar solvents.

In the present invention, in each of the case where the starting material is one in which the halogenated aromatic compound is 100% and the case where the starting material is one in which the halogenated aromatic compound is diluted to several ppm, Halogenated

It was confirmed that the 20 aromatic compounds were decomposed to undetectable concentration levels. Therefore, in the present invention, the content of the halogenated aromatic compound is not limited to 100%, and for example, the content of the halogenated aromatic compound may be reduced from 2 ppm by a hydrocarbon oil whose main component is a non-aromatic hydrocarbon. Those diluted to a concentration range of up to 80% can also be treated.

25 In the present invention, sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca (OH) ) 2), and magnesium hydroxide (Mg (OH) 2), or a mixture of two or more alkaline substances selected from this group. Incidentally, calcium hydroxide (Ca (OH) 2) and the like may be added to the reaction system in the form of calcium oxide (Ca0) and an oxide.

In the present invention, there is a slight difference in the effect of decomposing the halogenated aromatic compound depending on the type of the non-proton polar solvent, and the effective non-proton polar solvent is 1, 3 under any conditions. — Dimethyl 2 — imidazolidinone, tetramethylene sulfone, or 1,3 — Dimethyl 2 — imidazolidinone and a mixture of tetramethylen sulfone. These non-proton polar solvents are readily available because they are commercially available because they are used relatively industrially. Of particular note is that these non-proton polar solvents, in addition to being less toxic and less dangerous, also better dissolve halogenated aromatics. Furthermore, in the conventional method, when the amount of the halogenated aromatic compound is reduced to a small amount, for example, to the order of ppm, the reaction rate between the halogenated aromatic compound and the alkali substance may be significantly reduced. Although it was obvious, when the non-proton polar solvent was used, the halogenated aromatic compound was decomposed from a concentration of several ppm to a value lower than the detection limit (less than 0.5 ppb). However, it was confirmed that they were substantially eliminated.

Also, non-proton polar solvents include 1,3-dimethyl-2-imidazolidinone (hereinafter abbreviated as DMI), tetramethylethylene sulfone, and 1.3— Dimethyl-1 2—Imidazolidinone and tetramethylene sulfonate, the main component of which is a solvent selected from the group consisting of a mixture of dimethyl sulfoxide, N-methylpyrrolidone, Is it possible to use methyl urea, methyl blend liquor, and polyethylene glycol dimethyl ether? The halogenated aromatic compound can be effectively decomposed even when one polar solvent selected from the above or a mixture containing two or more polar solvents selected from this group at a concentration of 35% or less is used.

[Best mode for carrying out the invention]

Table 1 shows the processing conditions and the amount of residual PCB after the processing for the examples and comparative examples of the present invention. In Table 1, when the amount of residual PCB is below the detection limit, the column of residual PCB is indicated as ND.

Example 1

As shown in Table 1, 50 g of insulating oil containing about 80 ppm of PCB (hydrocarbon oil mainly containing non-aromatic hydrocarbons), 100 g of DMI, and 2 g of After mixing the powdered NaOH with the flask, keep them at a temperature of 200 for about 6 hours with good stirring. Next, after cooling to room temperature, the lower DMI layer is removed. After that, the PCB in the oil layer was analyzed using a gas chromatography-duffy mass spectrometer (GC-MS), which showed that it was below the detection limit of GC-MS. kg). Under these conditions, the initial combination ratio of the alkaline substance to the whole reaction system is equivalent to 13, OOOmgZkg. Under these conditions, the molar ratio of the chlorine in the PCB to the amount of chlorine (the number of moles of the zinc and the number of moles of chlorine) is equivalent to 800 in molar ratio.

In addition, it was confirmed that the concentration of PCB in the oil layer was reduced to 70 ppb even when the treatment was performed for about 2 hours under the same conditions.

Example 2

As shown in Table 1, 5 Og of insulating oil containing about 8 Oppm of PCB, 01 ^ 1 of 50 ^ :, and 2.5 g of powdered KOH were mixed in a flask. After combining, as in Example 1, they are kept at a temperature of 200 ° C. for about 6 hours with good stirring. Next, after cooling to room temperature, the lower DMI layer is removed. After that, the PCB in the oil layer was analyzed by GC-MS, and it was confirmed that the PCB had decreased to below the detection limit of GC-MS. Under these conditions, the initial compounding ratio of the alkali substance to the whole reaction system is equivalent to 25,000 mg Z kg, and the alcohol ratio to the chlorine amount in the PCB is equivalent to 720 in molar ratio. . In addition, it was confirmed that the PCB concentration in the oil layer was reduced to 90 ppb even if the treatment was performed for about 2 hours under the same conditions.

Example 3

As shown in Table 1, 50 g of insulating oil containing about 8 O ppm of PCB, 100 g of DM I, 1.5 g of powdered NaOH, and 1.O g of powder After mixing with the CaO in a flask, the mixture is kept at a temperature of 210 ° C. for about 6 hours while thoroughly stirring them as in Example 1. C a0 also acts as an alkaline substance. Next, after cooling to room temperature, the lower DMI layer is removed. Thereafter, the PCB of the oil reservoir was analyzed by GC_MS, and it was confirmed that the PCB was reduced to below the detection limit of GC-MS. Under these conditions, the initial compounding ratio of the alkaline substance to the entire reaction system is equivalent to 17,000 mg / kg, and the alkaline ratio to the chlorine amount in PCB is equivalent to 90 molar ratio. In addition, it was confirmed that the PCB concentration in the oil reservoir was reduced to 80 ppb even if the treatment was performed for about 2 hours under the same conditions.

Example 4

As shown in Table 1, 50 g of insulating oil containing about 800 ppm of PCB, 150 g of DMI, and 2.5 g of powdered KOH were mixed in a flask. Later, as in Example 1, while stirring them well, Hold at a temperature of 210 ° C for about 4 hours. Next, after cooling to room temperature, the lower DMI layer is removed. Thereafter, the PCB in the oil layer was analyzed by GC-MS, and as a result, it was confirmed that it was reduced to below the detection limit of GC-MS. Under these conditions, the initial blending ratio of alkaline substance to the entire reaction system is 12.500 mg / kg, and the alkaline ratio to the chlorine amount in the PCB is 7 in molar ratio. . In addition, it was confirmed that the PCB concentration in the oil layer was reduced to 50 ppb even if the treatment was performed for about 2 hours under the same conditions.

Example 5

As shown in Table 1, 50 g of insulating oil containing PCB of about 8, OOO ppm, 50 g of DMI, 2.8 g of powdered CaO, and 2. Og of powdered After mixing in a flask with NaOH, as in Example 1. Keep them at a temperature of 190 ° C. for about 5 hours with good stirring. Next, after cooling to room temperature, the lower DMI layer is removed. Thereafter, the PCB of the oil layer was analyzed by GC-MS, and as a result, it was confirmed that the PCB was reduced to below the detection limit of GC-MS. Under these conditions, the initial compounding ratio of the alkaline substance to the entire reaction system is equivalent to 48,000 mg / kg, and the alkaline ratio to the chlorine amount in the PCB is equivalent to 16 in molar ratio. . In addition, it was confirmed that the PCB concentration in the oil reservoir was reduced to 40 ppb even after the treatment was performed for about 3 hours under the same conditions.

Example 6 ―

As shown in Table 1, 50 g of insulating oil containing about 8 ppm of PCB, 0 ^ 11 of 1502, and 3.8 g of NaOH powder were mixed in a flask. After that, as in Example 1, they are kept at a temperature of 210 ° C. for about 5 hours with good stirring. Next, after cooling to room temperature, the lower DMI layer is removed. After that, analyze the PCB of the oil layer by GC-MS As a result, it was confirmed that the amount decreased to below the detection limit of GC-MS. Under these conditions, the initial combination ratio of alkali substances to the entire reaction system was 19,000 mg / kg, and the alkali ratio to the chlorine amount in the PCB was 150,000 in molar ratio. I do. In addition, it was confirmed that the PCB concentration in the oil layer was reduced to 30 ppb even when the treatment was performed for about 2 hours under the same conditions.

Example 7

As shown in Table 1, 50 g of insulating oil containing about 8000 ppm PCB, 150 g of DMI, and 5.5 g of powdered KOH were mixed in a flask. After combining, as in Example 1, they are kept at a temperature of 200 ° C. for about 3 hours with good stirring. Next, after cooling to room temperature, the lower DMI layer is removed. Thereafter, the PCB of the oil reservoir was analyzed by GC-MS, and it was confirmed that the PCB was reduced to below the detection limit of GC-MS. Under these conditions, the initial blending ratio of alkaline substances to the whole reaction system is equivalent to 27,500 mg / kg, and the alkaline ratio to the chlorine amount in the PCB is equivalent to 16 by molar ratio. I do. In addition, it was confirmed that the PCB concentration in the oil reservoir was reduced to 20 ppb even after the treatment was performed for about 2 hours under the same conditions.

Comparative Example 1

In contrast, the following study was performed as Comparative Example 1 with respect to Examples 1 to 7. First, as shown in Table 1, 50 g of insulating oil containing about 80 ppm of PCB, 100 g of DMI, and 0.3 g of powdered NaOH were mixed in a flask. After the combination, as in Example 1, they are kept at a temperature of 210 ° C. for about 6 hours while stirring them well. Next, after cooling to room temperature, the lower DMI layer is removed. After that, the PCB in the oil layer was analyzed by GC-MS. Existed. Also, when the treatment was performed for about 4 hours under the same conditions, 500 O ppb of the PCB remained.

As described above, the alkali ratio to the chlorine amount in the PCB is 120 in molar ratio, which is higher than or equal to that of Examples 1 to 7, but high concentration of PCB remains. The reason is that, unlike in Examples 1 to 7, the initial compounding ratio of the alkaline substance to the whole reaction system was 2, 000 mg / day despite the excess of NaOH relative to the PCB. kg.

Example 8

In Examples 1 to 7, the case where 50 g of insulating oil containing PCB was added to the reaction system was explained.In Examples 8 to 10, the insulating oil containing PCB was added to the reaction system. The case where a very small amount is added to the above is described. In this case, since the amount of insulating oil is small, the insulating oil itself dissolves into the DMI layer. After the reaction, the PCB concentration in the DMI layer is analyzed by GC-MS.

First, as shown in Table 1, 3 g of insulating oil containing PCB, 90 g of DMl, and 13 g of powdered NaOH were mixed in a flask. As in Example 1. Keep them at a temperature of 200 ° C for about 5 hours, stirring them well. Next, after cooling to room temperature, the PCB of the DMI layer is analyzed by GC-MS. As a result, it was confirmed that the concentration of PCB, which was initially 70, OOO ppm in the entire reaction system, decreased to below the detection limit of GC-MS. Under these conditions, the initial blending ratio of the alkaline substance is equivalent to 130,000 mg / kg, and the alkaline ratio to the chlorine amount in the PCB is equivalent to 3 in molar ratio. In addition, it was confirmed that the PCB was reduced to 70 ppb even when the treatment was performed for about 2 hours under the same conditions. Example 9

As shown in Table 1, 3 g of insulating oil containing PCB, 90 £ of 011, and 16 g of powdered KOH were mixed in a flask, and then mixed as in Example 8. Maintain the temperature at 200 ° C for about 4 hours while stirring well. After cooling to room temperature, analyze the PCB of the DMI layer by GC-MS. As a result, it was confirmed that the concentration of PCB, which was initially 70,000 ppm in the entire reaction system, was reduced to below the detection limit of GC-MS. Under these conditions, the initial compounding ratio of the alkaline substance is equivalent to 160,000 Omg / kg, and the alkaline ratio to the chlorine amount in PCB is equivalent to 2.6 in molar ratio. In addition, it was confirmed that PCB was reduced to 25 ppb even if the treatment was performed for about 2 hours under the same conditions.

Example 10

As shown in Table 1, 0.3 g of insulating oil containing PCB, 99 g of DMI, 1.5 g of powdered KOH, and 1.0 g of powdered CaO in a flask After mixing in the same manner as in Example 8, they are kept at a temperature of 210 ° C. for about 5 hours while stirring them well. Next, after cooling to room temperature, the PCB of the DMI layer is analyzed by GC-MS. As a result, it was confirmed that PCB, which initially had a concentration of 7,000 ppm in the entire reaction system, was reduced to below the detection limit of GC-MS. Under these conditions, the initial blending ratio of the alkaline substance is equivalent to 25,000 mg / kg, and the alkaline ratio to the chlorine amount in PCB is equivalent to 4 in molar ratio. In addition, it was confirmed that PCB was reduced to 60 ppb even when the treatment was performed for about 2 hours under the same conditions.

Example 1 1

In Examples 1 to 10, the insulating oil containing PCB was used in the reaction system. Example 11 to Example 14 described the case where insulating oil was not added instead of adding PCB directly to the reaction system. In these cases, too, after the reaction, the concentration of the PCB in the DMI layer is analyzed by GC-MS.

First, as shown in Table 1, 0 ^ 11 of 1002, 1.9 g of powdery NaOH, and an amount of PCB with a concentration of 100,000 ppm in total reaction system After mixing them in a flask, they are kept at a temperature of 200 for about 5 hours, with good stirring, as in Example 8. Next, after cooling to room temperature, the PCB of the DMI layer is analyzed by GC-MS. As a result, it was confirmed that PCB decreased to below the detection limit of GC-MS. Under these conditions, the initial blending ratio of the alkaline substance is 19, OOOmgZkg, and the alkaline ratio to the chlorine amount in PCB is 3 in molar ratio. In addition, it was confirmed that PCB was reduced to 35 ppb even when the treatment was performed for about 2 hours under the same conditions, Example 12

As shown in Table 1, 01 ^ 1 of 1002, 2.6 g of powdered KOH, and an amount of PCB of 100,000 ppm in total concentration in the reaction system were placed in a flask. After mixing, as in Example 8, they are kept at a temperature of 200 ° C. for about 4 hours with good stirring. Next, after cooling to room temperature, the PCB of the DMI layer is analyzed by GC-MS. As a result, it was confirmed that the PCB was reduced to below the detection limit of GC-MS. Under these conditions, the initial compounding ratio of the alkaline substance is equivalent to 26,000 mg / Zkg, and the alkaline ratio to the chlorine amount in the PCB is equivalent to 3 in molar ratio. In addition, it was confirmed that the PCB power was reduced to 30 ppb even if the treatment was performed for about 2 hours under the same conditions. As shown in Table 1, 100 g of DM I, 1.0 Og of powdered NaOH, 1.0 g of powdered Ca0, and a concentration of 10, After mixing in a flask with the amount of PCB which becomes 0.000 ppm, as in Example 8, they are kept at a temperature of 200 ° C. for about 65 hours while stirring them well. Next, after cooling to room temperature, Step 8 — Analyze by MS. As a result, it was confirmed that the PCB was reduced to below the detection limit of GC-MS. Under these conditions, the initial compounding ratio of the alkali substance is equivalent to 20, OOO mggZkg, and the alkali ratio to the chlorine amount in the PCB is equivalent to 2.8 in molar ratio. In addition, it was confirmed that the PCB was reduced to 40 ppb even if the treatment was performed for about 2 hours under the same condition> 0 cases.

Example 14

As shown in Table 1, 0¾11 of 1002, 39 g of KOH in powder form, and PCB with an amount of 10

After mixing 15 and 15 in a flask, as in Example 8, they are kept at a temperature of 200 ° C. for about 3 hours with good stirring. Next, after cooling to room temperature, the PCB of the DMI layer is analyzed by GC-MS. As a result, it was confirmed that PCB was reduced to below the detection limit of GC-MS. Under these conditions, the initial compounding ratio of the alkaline substances is 390, 000

This corresponds to 20 mg Z kg, and the alkali ratio to the chlorine amount in PCB is equivalent to 4.5 in molar ratio. In addition, it was confirmed that PCB was reduced to 100 ppb even when the treatment was performed for about 1 hour under the same conditions.

Comparative Example 2

2 = On the other hand, the following study was performed as Comparative Example 2 with respect to Examples 8 to 14. First, as shown in Table 1, 100 £ 01 \ 1 And 0.4 g of powdered Na0H in a flask with a PCB amount of 100,000 ppm in total concentration in the reaction system, and then the same as in Example 8. Keep them at a temperature of 200 ° C for about 6 hours, stirring them well. Next, after cooling to room temperature, the PCB of the DMI layer was analyzed by GC-MS, and as a result, 2,000 ppm of the PCB remained. It should be noted that PCBs remained at 8,000 PPb after only about 2 hours of treatment under the same conditions.

The reason why such a high concentration of PCB remained was that the reaction system was different from Examples 8 to 14, rather than the fact that the molar ratio of chlorine to the amount of chlorine in the PCB was as small as 0.6. This is because the initial compounding ratio of the alkaline substance to the whole is as low as 4, OOO mg gZ kg.

Effects of the embodiment

As described above, in Comparative Examples 1 and 2, the PCB did not decrease to 1 ppm or less, whereas in Examples 1 to 14, the PCB force was less than 1 ppm. It was confirmed that it was decomposed.

Other embodiments

The conditions for decomposing the PCB by bringing the PCB and the alkaline substance into contact with each other in a non-proton polar solvent are, in addition to the above examples, the amount of the alkaline substance added at the start of the reaction, The study was conducted by changing the contact temperature with the alkaline substance and the contact time. As a result, the contact temperature between the PCB and the alkaline substance is set in a range from about 150 ° C to about 300 ° C, and the contact time is set in a range from about 1 hour to about 10 hours. In addition, it was confirmed that if the mixing ratio of the alkaline substance to the entire reaction system at the start of the reaction was 5,000 mg / kg or more, the PCB could be reliably decomposed to below the detection limit. Also, the mixing ratio of the alkaline substance to the entire reaction system at the start of the reaction was set to 7.0000 mg kg or more. By doing so, it was confirmed that the PCB could be more reliably decomposed to below the detection limit.

Instead of PCB, other halogenated aromatic compounds can be decomposed in the same manner. For example, polychlorinated terphenyls,

5 Biphenyl bromide or related compounds can be decomposed to below the detection limit.

In the present invention, in addition to NaOH, KOH, CaOH, and CaO, NaO, Mg (OH) _{2, and the} like can be used as the alkaline substance.

, ο In the above embodiment, an example was described in which DMI was used as the non-proton polar solvent. However, other examples include tetramethylbenzene sulfonate, or DMI and tetramethyl. Mixtures with lensulfone can be used <

, 5 A mixture with lenglycol dimethyl ether may be used. In this case, dimethyl sulfoxide, N-methylpyrrolidone, and tetramethyl are preferred from the viewpoint of alkali resistance at high temperatures. It is preferable that the blending ratio of tyl urea, polyethylene glycol, or polyethylene glycol dimethyl ether is 35% or less.

Table 1 (Part 1)

PCB-containing non-proton Aluminium re-treatment Treatment Insulation oil amount under remaining conditions Polar soluble matter amount [g] vs. temperature control PCB

[g] agent. C hourly volume () in () () in () is between oils [ppb] Insulating oil is solvent Total concentration Power [Hr] PCB concentration amount [mg / kg] Ratio

LPPm] [g] molar ratio

1 50 DMI NaOH 800 200 2 70 (80) (100) 2.0

(13.000) 6 N.D.

2 50 DMI KOH 720 200 2 90 (80) (50) 2.0

(25,000) 6 N.D.

3 50 DMI NaOH 2 80 Application (800) (100) 1.5 90 210

CaO

1.0 6 N.D.

(17, 000)

An example

4 50 DMI KOH 2 50

(8,000) (150) 2.5 7 210

(12, 500) 4 N.D.

5 50 DMI CaO 3 40

(8,000) (50) 2.8 16 190

NaOH

2.0 5 N.D.

(48,000)

6 50 DMI NaOH 2 30 (80) (150) β g 1500 210

(19: 000) 5 N.D.

7 50 DMI KOH 2 20

(8,000) (150) 5, 5 16 200

(27, 500) 3 N.D.Comparative Example 50 DMI NaOH 120 210 4 5,000

1 (80) (100) 0.3

(2,000) 64,000 Table 1 (Part 2)

Insulation oil amount under residual conditions PB containing non-p-ton D ton temperature R

Eg] agent. C hourly volume () is in () is in () is in the space [ppb] is the solvent in the entire system is the total concentration power [Hr] The amount of PCB concentration [mg / kg] ratio

[ppm] [g] molar ratio

8 3 DMI NaOH 3 200 2 70

(70, 000) (90) 13

(130,000) 5 N.D.

9 3 DMI KOH 2.6 200 2 25

(70,000) (90) 16

Al (160,000) 4 N.D.

10 0.3 DMI KOH 2 60 cases (7,000) (99) 1.5 4 210

CaO

1.0 5 N.D.

(25,000)

Table 1 (Part 3) Non-pton tonality treatment for the entire system Residual conditions Polar solvent content [g] vs. temperature PCB

Addition of PCB in ° C hours Addition concentration () In () is between Al [ppb] Lopm] is the total concentration of solvent [Hr]

Amount [mg / kg] ratio

[g] molar ratio

11 10.000 DMI NaOH 3 200 2 35

(100) 1.9

(19 000) 5 K D

12 10,000 DMI KOH 3 200 0 o yj

(100) 2.6

(9fi 000 A H I.

13 10,000 DMI NaOH 2 40 cases (100) 1.0 2.8 200

CaO

1.0 6 N.D.

(20, 000)

14 100,000 DMI KOH 4.5 200 1 100

(100)

(390.000) 3 N.D.Comparative Example 10,000 DMI NaOH 0.6 200 2 8,000

2 (100) 0.4

(4,000) 62,000

[Industrial applicability]

As described above, in the present invention, the halogenated aromatic compound and the alkali substance are mixed in a non-proton polar solvent at a temperature of about 150 ° C. to about 300 ° C. for about 1 hour. It is characterized in that it is brought into contact for about 10 hours and the mixing ratio of the alkaline substance to the whole reaction system at the start of the reaction is set to 5,000 mg / kg or more. Therefore, according to the present invention, even small amounts of halogenated aromatic compounds such as PCBs that directly harm the human body can be reliably and safely removed to a substantially harmless state. It is. Therefore, it is possible to treat hydrocarbon oil containing PCB to a substantially harmless state.

Claims

The scope of the claims

1. In the method of decomposing a halogenated aromatic compound by contacting the halogenated aromatic compound with an alkali substance in a non-proton polar solvent, the contact temperature between the halogenated aromatic compound and the alkali substance is about The contact time is in the range of from about 1 hour to about 10 hours, and the mixing time at the start of the reaction of the alkali substance with respect to the entire reaction system is from 150 to about 300 ° C. A method for decomposing a halogenated aromatic compound with an alkali substance, wherein the ratio is 5,000 m / kg or more.

2. The halogenated aromatic compound according to claim 1, wherein the compounding ratio of the alkaline compound to the whole reaction system at the start of the reaction is 7,000 mg or more. Decomposition by alkaline substances.

3. In claim 1, wherein the halogenated aromatic compound is selected from the group consisting of polychlorinated biphenyls, polychlorinated terphenyls, polybrominated biphenyls, and analogs thereof. A method of decomposing a halogenated aromatic compound, which is characterized by being one halogenated aromatic compound or a mixture of two or more halogenated aromatic compounds selected from this group, with an alkali substance. 2. The halogenated aromatic compound according to claim 1, wherein the halogenated aromatic compound is diluted with a hydrocarbon oil whose main component is a non-aromatic hydrocarbon to a concentration range of 2 ppm to 80%. Non-proton polarity A method of decomposing a halogenated aromatic compound, which is specially added to a solvent, with an alkaline substance.

5. In any one of Claims 1 to 4, the alkaline material may be sodium hydroxide, sodium hydroxide, calcium hydroxide, or magnesium hydroxide. A method for decomposing a halogenated aromatic compound with an alkali substance, wherein the halogenated aromatic compound is a single alkali substance selected from the group or a mixture of two or more alkali substances selected from the group.

6. In any one of claims 1 to 4, the non-proton polar solvent may be 1,3-dimethyl-2-imidazolidinone-tetramethylethylenesulfonic acid. , And a solvent selected from the group consisting of a mixture of 1,3-dimethyl-2, -imidazolidinone and tetramethylethylene sulfonate Is decomposed by alkaline substances.

7. In any one of claims 1 to 4, the non-proton polar solvent may be 1,3-dimethyl-2-imidazolidinone tetramethyle. 1,3-dimethyl 2-, a solvent selected from the group consisting of a mixture of imidazolidinone and tetramethylene sulfonic acid, and dimethyl sulfoxide, N — A polar solvent selected from methyl pyrrolidone, tetramethyl urea, diethyl glycol, and polyethylene glycol dimethyl ether, or two or more polar solvents selected from this group. % Of halogenated aromatic compounds, which is a mixture blended at a concentration of less than How to decompose more.