KR100733571B1 - Destruction and removal of pcbs in hydrocarbon oil by chemical treatment technology - Google Patents

Abstract

A method for destruction and removal of PCBs(polychlorinated biphenyls) in hydrocarbon oil, which can improve destruction and removal efficiencies of the PCBs, is easily operated, and can reduce the operating cost, is provided. A method for destruction and removal of PCBs in hydrocarbon oil comprises the steps of: adding 1 to 25 wt.% of an alkaline solvent, 0.3 to 7.5 wt.% of an alkaline material and 0.2 to 0.5 wt.% of aluminum to 67 to 98.5 wt.% of hydrocarbon oil comprising PCBs(polychlorinated biphenyls) to prepare a hydrocarbon oil mixture; and heating the mixture to a temperature of 25 to 250 deg.C for 10 minutes to 24 hours to destruct and remove the PCBs. The alkaline solvent is at least one selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, lower alkylether of polyethylene glycol, trimethylene glycol, butylene glycol, lower alkylether of butylene glycol, and 1,3-dimethyl-2-imidazolidinone. The alkaline material is at least one selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium alcoholate, potassium alcoholate, and calcium hydroxide.

Description

Destruction and removal of PCBs in hydrocarbon oil by chemical treatment technology

1 is a schematic diagram of a batch reactor used in a method of destroying and removing PCBs in accordance with one embodiment of the present invention.

Figure 2 is a flow chart for the analysis of PCBs in hydrocarbon oil used in the PCBs destruction and removal method according to an embodiment of the present invention.

3 is a diagram illustrating a GC / ECD chromatogram of a PCB mixture for calibration before chemical treatment as a reference example of the present invention.

4 is a diagram illustrating a GC / ECD chromatogram of a PCB mixture in hydrocarbon oil chemically treated by a PCBs destruction and removal method according to an embodiment of the present invention.

FIG. 5 illustrates a GC / ECD chromatogram of a PCB mixture in hydrocarbon oil chemically treated by the PCBs destruction and removal method according to another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: batch reactor 101: agitator

102: reactor 103: temperature controller

104: hot wire 105: nitrogen storage container

The present invention relates to a method for destroying and removing polychlorinated biphenyls (PCBs) in hydrocarbon oils by chemical treatment, and more particularly, to the destruction and removal efficiency of PCBs in hydrocarbon oils that can be easily handled and reduced in operating costs. A method of destruction and removal.

PCBs collectively refer to substances in which one or more hydrogen atoms in biphenyl are substituted with chlorine, as shown in Formula 1 below, and 209 called PCB congeners depending on the number and position of substituted chlorine atoms. It consists of a compound. PCBs were first synthesized in 1881 by Schmidt and Schulz, which are chemically stable, heat-saveable, and electrically resistant. Therefore, since 1929, these PCBs have been widely used in various countries such as USA, Japan, and France under the trade names Aroclor, Phenoclor and Kaneclor for commercial purposes for use in insulating oils in transformers and capacitors, as well as lubricants, plasticizers, paints, inks and copy papers. Has been produced.

[Formula 1]

  Wherein x is an integer of 0 ≦ x ≦ 5 and y is an integer of 0 ≦ y ≦ 5.

PCBs were selected for regulatory and controlled substances by the entry into force of the Stockholm Convention (2004) for the reduction and elimination of dioxin (PCDDs / PCDFs) emissions from incineration or industrial facilities. As a result, the issue of regulation, control and disposal of PCB-containing products and wastes manufactured and used in the past has been highlighted. In addition, the Convention requires States to report the identification and removal of devices using PCBs by 2025 and to establish a management system for PCBs by no later than 2028. In order to achieve this goal, the movement began to investigate the status of PCB-containing products and waste and safety management plan in Korea two or three years ago. Prevention measures are being established, and various ways are being sought for environmentally friendly disposal of PCBs-containing waste.

Currently, high temperature incineration is the mainstream method for treating PCBs. Degradation efficiency of PCBs by high temperature incineration usually shows 99.9999%, but in case of instability during processing, for example, when incineration temperature is less than 1,100 ℃, contact time is less than 2 seconds, surplus oxygen is less than 6%, Toxic substances, such as dioxins, may be generated and discharged from sewage and solid residues. In addition, the high temperature incineration requires high cost due to the use of auxiliary fuel for high temperature, the installation of a prevention facility for toxic substances, the treatment cost of secondary generated by-products, and the possibility of recycling because it decomposes all insulating oils in addition to the PCBs. There is a problem that the loss of resources is uneconomical.

Although there are no accurate statistics on the total amount of waste transformers and waste oil in Korea, there are 50,000 to 70,000 waste transformers per year and 2,000 to 3,000 ㎘ of waste insulation oil managed by KEPCO. It is estimated that about 300,000 units of waste insulating oil exist. The laws and regulations related to the disposal of domestic waste transformer oil and waste insulating oil are as follows. In other words, waste transformer containing insulation oil with PCBs concentration of 2ppm or more is managed by designated waste to be incinerated or melted at high temperature by waste management law.In case of incineration treatment, however, domestic treatment is caused by complaints such as dioxin generation. 21 tons incineration from 1994 to 1994) ceased. Therefore, as of 2006, KEPCO and other electric power companies are discharging their wastes by discharging them only to high-density terrestrial transformers, but this is also difficult to deal with in a timely manner, such as requiring the consent of transit countries under the Basel Convention. It is true.

Therefore, the introduction and development of effective and environmentally friendly waste transformer oil and waste insulating oil treatment method is very necessary.

An object of the present invention is to provide a method for destroying and removing PCBs in hydrocarbon oil, which can improve the destruction and removal efficiency of PCBs.

Still another object of the present invention is to provide a method of destroying and removing PCBs in hydrocarbon oil, which is easy to handle and can reduce operating costs.

According to the invention,

Preparing a hydrocarbon oil mixture by adding an alkaline solvent, an alkaline substance, and aluminum to a hydrocarbon oil including polychlorinated biphenyls (PCBs); And

A method of destroying and removing PCBs in a hydrocarbon oil is provided, comprising: heating the mixture to a predetermined temperature for a predetermined time to destroy and remove the PCBs.

According to one embodiment of the invention, the alkaline solvent is ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, lower alkyl ether of polyethylene glycol, trimethylene glycol, butylene glycol, lower alkyl ether of butylene glycol, And 1,3-dimethyl-2-imidazolidinone.

According to another embodiment of the present invention, the hydrocarbon oil, the alkaline solvent, the alkaline material, and the aluminum is 67 to 98.5% by weight, 1 to 25% by weight, 0.3 to 7.5% by weight, respectively, based on the total weight of the mixture, 0.2 to 0.5% by weight.

According to another embodiment of the present invention, the alkaline substance is at least one selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium alcoholate, potassium alcoholate, and calcium hydroxide.

According to another embodiment of the invention, the heating temperature is 25 to 250 ℃.

According to another embodiment of the invention, the heating time is 10 minutes to 24 hours.

According to another embodiment of the invention, the aluminum is in powder form.

According to another embodiment of the invention, the hydrocarbon oil is a waste transformer oil.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram of a batch reactor used in a method of destroying and removing PCBs in accordance with one embodiment of the present invention.

Referring to FIG. 1, the batch reactor 100 used in the PCBs destruction and removal method according to the present embodiment includes a stirrer 101, a reaction vessel 102, a temperature controller 103, and a nitrogen storage vessel 105. Equipped.

The stirrer 101 serves to uniformly mix the hydrocarbon oil mixture including the PCBs in the reactor 102. Here, the stirrer 101 is preferably a magnetic stirrer, but the present invention is not limited thereto. In addition, the hydrocarbon oil may include a waste transformer oil.

The reactor 102 is a place where a hydrocarbon oil mixture is accommodated and a chemical reaction takes place.

The material of the reactor 102 is not particularly limited, but glass, stainless steel, or the like, such as pyrex, is preferable. The reactor 102 is made of a double jacket, so that the transformer oil inside is maintained and the temperature is maintained outside. Silicone oil is filled. However, the present invention is not limited thereto. The heating tape 104 was wound around the outside of the reactor 102 to control the temperature inside the reactor 102 using a temperature controller 103 during chemical treatment. In addition, by maintaining the reactor 102 in a nitrogen atmosphere during chemical treatment of the hydrocarbon oil mixture, the hydrocarbon oil oil is prevented from contacting with oxygen in the air and oxidized. Here, nitrogen (N ₂ ) is supplied from the nitrogen storage vessel 105 in high purity of 99.99% by volume or more.

As described above, the method of destroying and removing PCBs in a hydrocarbon oil of the present invention comprises the steps of preparing an hydrocarbon oil mixture by adding an alkaline solvent, an alkaline substance, and aluminum to a hydrocarbon oil comprising PCBs, and Heating to temperature for a predetermined time to destroy and remove the PCBs.

In preparing the hydrocarbon oil mixture, the hydrocarbon oil may include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol (PEG), lower alkyl ether of polyethylene glycol, trimethylene glycol, butylene glycol, lower alkyl ether of butylene glycol, And an alkaline solvent composed of at least one of 1,3-dimethyl-2-imidazolidinone, an alkaline substance composed of at least one of sodium hydroxide, potassium hydroxide, sodium alcoholate, potassium alcoholate, and calcium hydroxide, and aluminum. . Here, in the case of preparing a hydrocarbon oil mixture, the order of adding the alkaline solvent, the alkaline substance, and aluminum to the hydrocarbon oil and the timing of the addition may be variously changed.

The content of the alkaline solvent is preferably 1 to 25% by weight based on 100% by weight of the total mixture. If the content of the solvent is less than 1% by weight, the dechlorination reaction hardly occurs, and it is not preferable. Specifically, the hydrocarbon oil including the PCBs, the alkaline solvent, the alkaline substance, and the aluminum are 67 to 98.5% by weight, 1 to 25% by weight, 0.3 to 7.5% by weight based on 100% by weight of the mixture as a whole. %, 0.2-0.5 wt%.

Alkaline substances are used to make chemical reaction conditions basic.

Aluminum (Al) is used as a dechlorination accelerator to increase the reaction rate during chemical treatment of PCBs in hydrocarbon oils, such as waste transformer oil, and is preferably used in powder form. At least one type of aluminum powder may be used, such as spherical or plate-shaped, and the average particle size of the spherical aluminum powder is between several microns and several hundred microns, and the size of the plate-shaped aluminum powder has a mean length, width and thickness of several microns, respectively. Between hundreds of microns. Aluminum is chemically stable against substances containing active hydrogens such as water and alcohols, so it is easy to handle. Therefore, it is possible to lower operating costs in the chemical treatment of hydrocarbon oils including PCBs, such as waste transformer oil.

In the step of reacting the hydrocarbon oil mixture, the mixture is heated to a predetermined temperature and reacted for a predetermined time.

The heating temperature may be selected at least one temperature in the range of 25 to 250 ℃. If the heating temperature is less than 25 ° C, dechlorination hardly occurs, and if the heating temperature is higher than 250 ° C, hydrocarbon oil, that is, waste transformer oil, is heat-modified, which is not preferable. Specifically, the heating temperature is preferably between 80 and 200 ° C, more preferably between 100 and 150 ° C.

The heating time can be selected between 10 minutes and 24 hours. If the heating time is less than 10 minutes, the dechlorination reaction hardly occurs, which is not preferable. If the heating time is more than 24 hours, it is uneconomical and not preferable. Specifically, the heating time is preferably 2 to 10 hours, more preferably 4 to 8 hours.

Hereinafter, the present invention will be described with reference to the following examples, but the present invention is not limited only to the following examples.

Example

Used reagents

In order to process PCBs in waste transformer oil, Samchun Pure Chemical Co. PEG 600 [H (OCH ₂ CH ₂ ) _n OH, each purchased from Ltd., Korea; polyethylene glycol # 600], potassium hydroxide (potassium hydroxide, pellet), aluminum (aluminum powder, 200 mesh), and anhydrous sodium sulfate (anhydrous sodium sulfate) was used.

Waste transformer oil was obtained from one nuclear power plant and used as a sample of this example. Prior to analysis of PCBs in a sample, the organic solvents for HPLC, n-hexane, acetone, iso-octane, MTBE, for sample pretreatment such as alkali degradation, extraction, and clean-up. , Dichloromethane (Malinckrodt Baker, Inc., USA) was used. PCB mixtures such as Aroclor 1242, 1254, 1260, etc., used in this example were purchased from AccuStandard, Inc., USA in solid phase with a purity of at least 99.9%. The number of chlorine substituents in these PCB mixtures is 3-4 for Aroclor 1242, 5-6 for Aroclor 1254, and 6-7 for Aroclor 1260.

Hydrocarbon Oil Mixture Preparation

The PCBs contained in the transformer oil were obtained from waste transformer oil from a nuclear power plant and analyzed according to the experimental procedure according to the PCB analysis guideline proposed by the National Institute of Environmental Research as shown in FIG. 2.

Referring to Figure 2, the experimental procedure goes through the following process. First, a predetermined amount (0.1-1.0 mL) of insulating oil is prepared and placed in a predetermined container, and 50 mL of 1M KOH / EtOH is added to this insulating oil to decompose. Next, a reflux condenser is attached to the vessel containing the insulating oil subjected to the alkali decomposition process and the vessel is heated on an aqueous solution to boil the insulating oil for 1 hour. The vessel is then left to cool to 50 ° C. Thereafter, 50 mL of n-hexane, 20 mL of hexane / ethanol (v / v, 1: 1) mixed solution, and 25 mL of water were added to the vessel, and then allowed to stand. Then, 100 mL of distilled water per mixture was mixed to separate the solvent layer three times. Next, if the organic material is not effectively removed during the alkali decomposition process, the resultant is treated with sulfuric acid. Subsequently, if the oil is present in the hexane layer after alkali decomposition, the resultant is passed through a Florisil column. Here, the filling amount of florisil is 5 g, and 250 mL of a 15 vol% ethyl ether-85 vol% hexane mixed solution is used as the mobile phase solvent. Next, the resultant is passed through a silica gel column. Here, the silica gel filling amount is 4 g, and 200 mL of hexane is used as the mobile phase solvent. The resultant exiting the silica gel column is analyzed by GC analysis. Here, Florisil (Florisil, 600-800, JT Baker, Mallinckrodt Baker, Inc., USA) and silica gel (Silica gel 60, Merck, Germany) are activated for 18 hours in a 130 ^° C. oven beforehand.

Here, the peak pattern method, which is a quantitative method, was specifically used for the GC analysis, the final concentration was 1.0 mL, and the effective measurement concentration was 0.05 mg / L. In this embodiment, waste transformer oil is used as the insulating oil.

As a result of analysis according to the above procedure, since no PCBs are contained in the waste transformer oil, in this embodiment, a predetermined amount of Aroclor 1242, 1254, and 1260 is added to the waste transformer oil to make a final concentration of 100 ppm, which is hydrocarbon oil. The mixture was used as a sample.

Destruction and Removal of PCBs in Hydrocarbon Oils

Chemical treatment methods for the destruction and removal of the PCB mixture (Aroclor 1242, 1254, and 1260) artificially injected into the waste transformer oil used as hydrocarbon oil were as follows. First, in order to find out the optimum conditions for treating each PCBs added to the waste transformer oil, the transformer oil and its relative PEG 600 and KOH amounts (wt / wt%), and PCBs according to heating temperature and heating time I checked the degree of removal. Samples of hydrocarbon oil and reagents were placed in a reactor to produce a hydrocarbon oil mixture, that is, a waste transformer oil, and then treated with increasing temperature from room temperature up to 150 ° C. with gentle stirring using an agitator. The heating time was 0 min, 30 min, 1 hr, 2 hr and the like and samples were taken for each time period. In addition, it was examined how the reaction rate is different depending on the presence or absence of aluminum (Al) powder acting as a dechlorination reaction promoter.

(Reference example)

The waste transformer oil prepared by the above procedure was not subjected to chemical treatment for destruction and removal of PCBs.

(Example 1)

With the heating time fixed at 120 minutes, only the heating temperature was changed to 25, 50, and 100 ° C, and chemical treatment for destruction and removal of PCBs was performed on the waste transformer oil prepared by the above procedure.

(Example 2)

Chemical treatment for destruction and removal of PCBs was performed on the waste transformer oil prepared by the above procedure while changing the heating time only to 30, 60, 120, and 240 minutes while the heating temperature was fixed at 150 ° C. .

PCBs Analysis

PCBs contained in waste transformer oil were analyzed using gas chromatograph / electron capture detector (GC / ECD, Trace 2000, Italy). Separation of each PCB analog was carried out using a 30 m length x 0.25 mm fused silica column (DB 5, Sulelco Inc., USA). GC went through a two-step temperature rise through a temperature program. That is, first, the GC temperature was raised from 80 ^o C to 180 ^o C at a rate of 10 ^o C / min, and then to 260 ^o C at a rate of 3 ^o C / min. As a carrier gas, a mixed gas containing 90% by volume and 10% by volume of methane (CH ₄ ) in argon (Ar) was used. Chromatogram peaks of PCB analogs were confirmed by the relative retention time of the internal standard PCBz (pentachlorobenzene). Quantification of each isolated analog was determined by comparing the calibrated curve with the relative peak area.

Experiment result

(Reference example)

A reference example is the result of analyzing the mixture without chemical treatment of the waste transformer oil.

Waste transformer oil, used as a hydrocarbon oil mixture, can be added to the same amount of Aroclor 1242, 1254, and 1260 in a PCB-free waste transformer oil sample prior to chemical treatment. The final PCBs concentration was set to 100 ppm.

3 is a GC / ECD chromatogram analyzed by 2 × dilution of the hydrocarbon oil mixture sample. As shown in FIG. 3, a mixture of commercial Aroclor 1242, 1254, 1260 out of a total of 209 PCB analogs theoretically possible consists of a total of 126 PCB analogs. However, multiple PCB analogs ((PCB nos. 15, 17, 18), (PCB nos. 28, 31), (PCB nos. 66, 95), (PCB nos. 118, 123, 149), (PCB) nos. 105, 132, 153, etc.) are not completely separated from each other in the column and thus exist as a cluster.

Further, PCB nos. 77, 118, 105, 123, and 169 have a coplanar or monoortho coplanar structure, resulting in common receptor mediated responses (stereoselective ligand receptors such as dioxins (PCDDs / PCDFs)). Reactions and the corresponding structural activity relationships) and similar biological or toxic effects are called dioxin-like PCBs.

(Example 1)

Example 1 is a result of analyzing the results of each case after performing the chemical treatment of the waste transformer oil while changing only the heating temperature in a fixed heating time.

4 is a diagram illustrating a GC / ECD chromatogram of a PCB mixture in hydrocarbon oil chemically treated by the PCBs destruction and removal method according to another embodiment of the present invention. In Fig. 4, a tank having a heating time of 120 minutes is mixed with reagents such as PEG 600 / KOH / Al powder (10% by weight, 3% by weight, and 2% by weight with respect to 100% by weight of the transformer oil). Under dry conditions, the GC / ECD chromatogram of the PCB mixture is shown as a change in heating temperature only (25, 50, and 100 ^° C.). Each of the peaks shown in the chromatogram represents PCB analogs that remain in the waste transformer oil without being removed after chemical treatment by the experimental conditions.

The peak heights or peak patterns of the PCB analogs were nearly similar to each other at 25 ^o C and 50 ^o C (FIGS. 4A and 4B). However, in Fig. 3, PCB no. You can see that the existence of 169 has grown significantly. PCB no. 169 has a coplanar structure similar to dioxin and is composed of 3, 3 ', 4, 4', 5, 5'-hexachlorinated biphenyl (CB) with 6 chlorine substituted biphenyls. . The chemical treatment according to the present embodiment is a reaction in which chlorine in biphenyl is continuously desorbed. The result is that chlorine desorbed from PCB analogs during chemical treatment of PCBs at low temperature is replaced by adjacent biphenyls 3, 3 ', 4, 4', 5, 5'- means that it can be in the form of hexachlorinated biphenyl (hexachlorinated biphenyl). However, when the temperature was raised to 100 ^o C (Fig. 4C), PCB no. 169 was completely removed and no longer detected.

At the heating temperature of 100 ^o C, the peak height of each PCB analog was significantly reduced, unlike at 25 ^o C and 50 ^o C. This results in 25 ^o C and 50 when chemically treating PCBs in waste transformer oil. ^o It was found that PCBs were effectively removed at relatively high temperatures rather than at somewhat lower temperatures such as C. In addition, when comparing the chromatograms at the heating temperature of 100 ^o C with the chromatograms of 25 ^o C and 50 ^o C, the peaks with a longer retention time disappeared than the peaks with short retention time. I could confirm it. Among the peaks with long residence times, the last PCB analog was PCB no. 183, 2, 2 ', 3, 4, 4', 5 ', 6-heptaCB (heptachlorinated biphenyl) with 7 chlorine in biphenyl. As a result, the PCB no. Under conditions of PEG 600 / KOH / Al powder / heating time 120 minutes / heating temperature 100 ^o C. PCB analogs with a longer residence time than 183, namely PCB analogs of hepta, octa, and nonna-CB, PCB nos. It has been found that 128, 185, 174, (156, 171, 202), 180 and the like are almost or completely destroyed and removed by chemical treatment.

Before and after chemical treatment, that is, the quantitative results of Reference Example and Example 1 shown in the experimental conditions are shown in Table 1 in detail. The destruction and removal efficiencies of the PCB analogs shown in Table 1 were selected from the PCB mixtures (Aroclor 1242, 1254, and 1260) shown in the chromatogram of FIG. 3 by selecting only those PCB analogs having a detection limit of 0.05 ppm or more. Obtained using the relative difference in peak area of each PCB analog before and after chemical treatment, as shown in 3 and 4.

Ie destruction and removal efficiencies (% DRE )

= [Initial amount of PCBs (reference example)-remaining amount of PCBs (example 1)] / initial amount of PCBs (reference example) ㅧ 100.

As shown in Table 1, when the PCB mixture in the waste transformer oil was chemically treated, the average destruction and removal efficiency of the overall PCB mixture was very low at 25 ^o C and 50 ^o C heating temperatures. Were 28.91% and 29.67%, respectively. Therefore, it has been found that such low heating temperatures are not fundamentally suitable when chemically treating PCBs in waste transformer oil. However, when the heating temperature was increased to 100 ^o C, the average destruction and removal efficiency of PCBs increased steeply, reaching 77.94%, an increase of almost 50% at lower temperatures. However, this level of efficiency is still far below the 99.9999% decomposition efficiency of PCBs during chemical treatment proposed by the Korean Ministry of Environment.

In addition, the PCB nos. 77, 118, 123 and 105 showed similar or somewhat lower levels of breakdown and removal efficiencies at various temperatures selected in this example compared to the average values of breakdown and removal efficiencies of the entire PCBs. In addition, PCB no. In the case of 169, the peak area was increased by 6,000 to 7,000 times, rather than being slightly removed like the dioxins-analog described above. However, PCB no. 169 was almost completely destroyed and removed at this temperature because it was not identified above the detection limit when chemically treated at a heating temperature of 100 ^° C. In addition, PCB no. PCB analogs with residence times longer than 183 were also completely removed at a heating temperature of 100 ^° C.

Table 1. Dechlorination of PCB mixtures (Aroclor 1242, 1254, and 1260) in waste transformer oil as treated with chemical reagents (PEG 600, KOH, Al) for 2 hours at different heating temperatures

PCB mixtures (Aroclor 1242, 1254, 1260) Before chemical treatment After chemical treatment IUPAC No. ^a Chemical structure Peak area 25 ^o C peak area (DRE ^b %) 50 ^o C peak area (% DRE) 100 ^o C peak area (% DRE) 8 5 2,4 '2,3 3421 2252 (34.17) 2260 (33.94) 556 (83.75) 18 17 15 2,2 ', 5 2,2', 4 4,4 ' 4231 1899 (55.17) 1876 (55.66) 518 (87.76) 16 32 2,2 ', 3 2,4', 6 4847 2108 (56.51) 2176 (55.11) 627 (87.06) 26 2,3 ', 5 2009 1073 (46.59) 1084 (46.04) 174 (91.34) 31 28 2,4 ', 5 2,4,4' 12031 10124 (15.85) 11584 (3.72) 10829 (14.48) 20 33 53 2,3,3 '2', 3,4 2,2'5,6 '  7005 4989 (28.78) 4703 (32.86) 3577 (48.94) 51 22 2,2 ', 4,6' 2,3,4 ' 4964 3740 (24.66) 3569 (28.10) 3108 (37.39) 45 2,2 ', 3,6 1081 534 (50.60) 573 (46.99) nd ^e 52 2,2 ',, 5,5' 11168 7623 (31.74) 5077 (54.54) 8755 (21.61) 49 2,2 ', 4,5 5077 3324 (34.53) 2561 (49.56) 579 (88.60) 47 48 75 2,2 ', 4,4' 2,2'4,5 2,4,4'6 2144 466 (78.26) 488 (77.24) n.d. 35 3,3 ', 4 2009 231 (88.50) 162 (91.94) n.d. 44 2,2 ', 3,5' 8590 5245 (38.94) 5077 (40.90) 4975 (42.08) 37 59 42 3,4,4 '2,3,3', 6 2,2 ', 3,4' 5203 2176 (58.18) 2084 (59.95) 161 (96.91) 41 64 2,2 ', 3,4 2,3,4', 6 9442 7013 (25.73) 7529 (20.26) 4529 (52.03) 40 2,2 ', 3,3' 1574 619 (60.67) 679 (56.86) 160 (89.83) 74 2,4,4 ', 5 9221 6910 (25.06) 6886 (25.32) 3303 (64.18) 70 2,3 ', 4', 5 22869 18018 (21.21) 19586 (14.36) 16748 (26.77) 66 95 2,3,4,4 '2,2', 3,5 ', 6 34697 24119 (30.49) 25186 (27.41) 21420 (38.27) 91 2,2 ', 3,4', 6 2964 1062 (64.17) 1091 (63.20) 152 (94.88) 60 56 2,3,4,4 '2,3,3', 4 9950 6881 (30.84) 6739 (32.27) 4332 (56.46) 84 2,2 ', 3,3'6 15284 11145 (27.08) 12632 (17.35) 4523 (70.41) 90 101 2,2 ', 3,4', 5 2,2 ', 4,5,5' 49039 39657 (19.13) 43650 (10.99) 26001 (46.98) 99 2,2 ', 4,4', 5 13989 11481 (17.93) 11678 (16.52) 3840 (72.55) 83 2,2 ', 3,3'5 1572 496 (68.45) 515 (67.24) n.d. 97 2,2 ', 3', 4,5 10033 7461 (25.64) 7028 (29.95) 2581 (74.27) 87 115 2,2 ', 3,4,5' 2,3,4,4'6 23369 16542 (29.21) 17401 (25.54) 3994 (82.91) 85 2,2 ', 3,4,4' 7229 3217 (55.50) 3199 (55.75) 236 (96.74)  136 2,2 ', 3,3', 6,6 ' 6955 2658 (61.78) 2576 (62.96) 198 (97.15) 77 ^c 110 3,3 ', 4,4' 2,3,3 ', 4', 6 47165 30366 (35.62) 33688 (28.57) 17299 (63.32) 82 151 2,2 ', 3,3', 4 2,2 ', 3,5,5', 6 27065 20280 (25.07) 18629 (31.17) 1234 (95.44) 135 2,2 ', 3,3', 5,6 ' 9943 6176 (37.89) 4469 (55.05) 157 (98.42)

^a IUPAC No. In K. Ballschmiter and M. Zell, Analytical Chemistry, 302, 1980; ^b DRE: destruction and removal efficiency; ^c 77 and 169: coplanar PCB analogs; ^d 123, 118, 105 and 169: monoortho coplanar PCB analogs; ^e nd: Not detected above concentration level of 0.05 ppm.

(Example 2)

Example 2 is a result of analyzing the results of each case after performing the chemical treatment of the waste transformer oil while changing only the heating time in a fixed heating temperature.

FIG. 5 illustrates the addition of PEG 600 / KOH / Al powder to the waste transformer oil in the same amount to form a hydrocarbon oil mixture, that is, the waste transformer oil and chemically reacting the mixture by changing only the heating time at a heating temperature of 150 ^° C. FIG. This is followed by GC / ECD analysis of each PCB analog remaining in the transformer oil to show the chromatogram obtained from this analysis. Comparing the chromatograms of FIG. 4C and FIG. 5A with each other, it can be seen that the heights of the peaks of FIG. 5A are significantly reduced compared to the case of FIG. 4C. Unlike qualitative analysis, the number of peaks detected is also different from PCB nos. A total of 12 (5, 8), (5, 17, 18), and (16, 32) were identified. This shows that such test results that are more worthy than 150 ^o C 100 ^o C as the heating temperature when manage processing of the PCBs waste transformer oil chemically. And, other experimental conditions were the same as above and when the heating time was gradually increased to 240 minutes, as shown in FIGS. 5B, 5C, and 5D, the number of peaks shown in each chromatogram, that is, the number of PCB analogs Showed a tendency to gradually decrease and finally only one peak, PCB no. Only (5, 8) was confirmed. Verified PCB no. The structure of (5, 8) is (2, 3-diCB 2, 4'-diCB), in which only two chlorine substituents are present on biphenyl, and accordingly, in the chemical dechlorination reaction PCB analogs with more than two chlorine substituents all showed dechlorination.

The quantitative values of the destruction and removal efficiency of the PCBs in the waste transformer oil before and after the chemical treatment in the experimental conditions are shown in Table 2 below. When the heating time was 30 minutes under PEG 600 / KOH / Al powder / heating temperature of 150 ^o C, the average destruction and removal efficiency of PCBs was 99.46%. However, by gradually increasing the heating time to 60 minutes and 120 minutes under the above conditions, the destruction and removal efficiency of PCBs was also slightly increased to 99.73% and 99.93%, and when the heating time was 240 minutes, the efficiency was 99.98. Reached% In particular, PCB no. In the case of (5, 8), the destruction and removal efficiency was 93.60%, which was lower than the average, but the PCB no. PCB analogs other than (5, 8) were almost completely destroyed and removed. Although the results of this experiment are PCB no. Although the average destruction and removal efficiencies due to (5, 8) are slightly below 99.9999%, in practice most of the PCB mixtures used in the past transformers used Aroclor 1254 and 1260. (5, 8) are not present in the lung transformer. Therefore, the PCB destruction and removal efficiency in the waste transformer is almost 99.9999% under the reaction conditions of PEG 600 / KOH / Al / heating temperature 150 ^o C / heating time 240 minutes set in this example. .

Table 2. Dechlorination of PCB mixtures (Aroclor 1242, 1254, and 1260) in waste transformer oil as treated with chemical reagents (PEG 600, KOH, Al) at various heating times at 150 ° C

PCB mixtures (Aroclor 1242, 1254, 1260) Before chemical treatment After chemical treatment IUPAC NO. ^a Chemical structure Peak area 30 min peak area (DRE ^b %) 60 min peak area (DRE%) 120 min peak area (DRE%) 240 min peak area (DRE%) 8 5 2,4 '2,3 3421 324 (90.53) 295 (91.38) 252 (92.63) 219 (93.60) 18 17 15 2,2 ', 5 2,2', 4 4,4 ' 4231 369 (91.28) 297 (92.98) 266 (93.71) nd ^e 16 32 2,2 ', 3 2,4', 6 4847 337 (93.05) 213 (95.61) n.d. n.d. 26 2,3 ', 5 2009 n.d. n.d. n.d. n.d. 31 28 2,4 ', 5 2,4,4' 12031 752 (93.75) 577 (95.20) 205 (98.30) n.d. 20 33 53 2,3,3 '2', 3,4 2,2'5,6 ' 7005 378 (94.60) n.d. n.d. n.d. 51 22 2,2 ', 4,6' 2,3,4 ' 4964 299 (93.98) n.d. n.d. n.d. 45 2,2 ', 3,6 1081 n.d. n.d. n.d. n.d. 52 2,2 ',, 5,5' 11168 817 (92.68) 612 (94.52) n.d. n.d. 49 2,2 ', 4,5 5077 294 (94.21) 154 (96.97) n.d. n.d. 47 48 75 2,2 ', 4,4' 2,2'4,5 2,4,4'6 2144 n.d. n.d. n.d. n.d. 35 3,3 ', 4 2009 n.d. n.d. n.d. n.d. 44 2,2 ', 3,5' 8590 396 (95.39) 242 (97.18) n.d. n.d. 37 59 42 3,4,4 '2,3,3', 6 2,2 ', 3,4' 5203 n.d. n.d. n.d. n.d. 41 64 2,2 ', 3,4 2,3,4', 6 9442 258 (97.57) n.d. n.d. n.d. 40 2,2 ', 3,3' 1574 n.d. n.d. n.d. n.d. 74 2,4,4 ', 5 9221 n.d. n.d. n.d. n.d. 70 2,3 ', 4', 5 22869 n.d. n.d. n.d. n.d. 66 95 2,3,4,4 '2,2', 3,5 ', 6 34697 842 (97.57) 265 (99.24) n.d. n.d. 91 2,2 ', 3,4', 6 2964 n.d. n.d. n.d. n.d. 60 56 2,3,4,4 '2,3,3', 4 9950 n.d. n.d. n.d. n.d. 84 2,2 ', 3,3'6 15284 n.d. n.d. n.d. n.d. 90 101 2,2 ', 3,4', 5 2,2 ', 4,5,5' 49039 269 (99.45) n.d. n.d. n.d. 99 2,2 ', 4,4', 5 13989 n.d. n.d. n.d. n.d. 83 2,2 ', 3,3'5 1572 n.d. n.d. n.d. n.d. 97 2,2 ', 3', 4,5 10033 n.d. n.d. n.d. n.d. 87 115 2,2 ', 3,4,5' 2,3,4,4'6 23369 n.d. n.d. n.d. n.d. 85 2,2 ', 3,4,4' 7229 n.d. n.d. n.d. n.d.  136 2,2 ', 3,3', 6,6 ' 6955 n.d. n.d. n.d. n.d. 77 ^c 110 3,3 ', 4,4' 2,3,3 ', 4', 6 47165 n.d. n.d. n.d. n.d. 82 151 2,2 ', 3,3', 4 2,2 ', 3,5,5', 6 27065 n.d. n.d. n.d. n.d. 135 2,2 ', 3,3', 5,6 ' 9943 n.d. n.d. n.d. n.d.

^a IUPAC No. In K. Ballschmiter and M. Zell, Analytical Chemistry, 302, 1980; ^b DRE: destruction and removal efficiency; ^c 77: coplanar PCB analog; ^d 123, 118, 105 and 169: monoortho coplanar PCB analogs; ^e nd: Not detected above concentration level of 0.05 ppm.

As described above, the experiments on the removal of PCBs in the oil of the waste transformer by chemical treatment techniques were carried out. The chemical efficiency of the PCB mixture in the waste transformer oil in this experiment was 99.98% destruction and removal efficiency of PCB analogs under the reaction conditions of PEG 600 / KOH / Al powder / heating temperature 150 ^o C / heating time 240 minutes. PCB no. Having two chlorine substituents on biphenyl under the above conditions. Of the three or more PCB analogues except (5, 8) and in particular the 209 PCB analogues theoretically possible, the PCB analogues (PCB no. 77, 118, 123, and 105) with dioxin-like toxicity are almost completely It decomposed and showed more than 99.9999% of destruction and removal efficiency.

The method of destroying and removing PCBs in hydrocarbon oils according to the present invention can be adopted as an evaluation method of chemical treatment technology of PCBs which is not defined in the current national laws and regulations. In addition, the present invention can reduce the processing cost of the overseas outflow treatment of domestic PCBs by presenting a technology that can be maintained in the decomposition efficiency is more than 99.9999% and its concentration is less than 2ppm when chemically treating the PCBs in the waste transformer. Can be. In addition, the aluminum used as the dechlorination accelerator in the present invention is chemically stable in a water-soluble solvent and the like and easy to handle, thereby reducing the operating cost during chemical treatment of the waste transformer oil.

Although the preferred embodiment according to the present invention has been described above, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the protection scope of the present invention should be defined by the appended claims.

According to the present invention, a method for destroying and removing polychlorinated biphenyls (PCBs) in a hydrocarbon oil may be provided in which destruction and removal efficiency of polychlorinated biphenyls (PCBs) may be improved.

In addition, according to the present invention, there can be provided a method for destroying and removing polychlorinated biphenyls (PCBs) in hydrocarbon oil which can be easily handled and reduce operating costs.

Claims (8)

Preparing a hydrocarbon oil mixture by adding an alkaline solvent, an alkaline substance, and aluminum to a hydrocarbon oil including polychlorinated biphenyls (PCBs); And And heating the mixture to a predetermined temperature for a predetermined time to break through the PCBs to remove the PCBs in the hydrocarbon oil. The method of claim 1, The alkaline solvent is ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, lower alkyl ethers of polyethylene glycol, trimethylene glycol, lower alkyl ethers of butylene glycol, butylene glycol, and 1,3-dimethyl-2- Method for destroying and removing PCBs in hydrocarbon oil, characterized in that at least one selected from the group consisting of imidazolidinone. The method of claim 1, The hydrocarbon oil, the alkaline solvent, the alkaline material, and the aluminum are 67 to 98.5% by weight, 1 to 25% by weight, 0.3 to 7.5% by weight, 0.2 to 0.5% by weight based on the total weight of the mixture, respectively. Method of destruction and removal of PCBs in hydrocarbon oils The method of claim 1, And said alkaline substance comprises at least one selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium alcoholate, potassium alcoholate, and calcium hydroxide. The method of claim 1, The heating temperature is a destruction and removal method of PCBs in hydrocarbon oil, characterized in that 25 to 250 ℃. The method of claim 1, The heating time is 10 minutes to 24 hours, characterized in that destruction and removal of PCBs (Polychlorinated biphenyls) in hydrocarbon oil. The method of claim 1, The method of destroying and removing PCBs in a hydrocarbon oil, characterized in that the aluminum in powder form. The method of claim 1, The hydrocarbon oil is a waste transformer oil, characterized in that the destruction of PCBs in hydrocarbon oil.

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