JP5383582B2

JP5383582B2 - Detoxification method for PCB mixed insulating oil

Info

Publication number: JP5383582B2
Application number: JP2010091009A
Authority: JP
Inventors: 賢治徳政
Original assignee: Chugoku Electric Power Co Inc
Current assignee: Chugoku Electric Power Co Inc
Priority date: 2010-04-11
Filing date: 2010-04-11
Publication date: 2014-01-08
Anticipated expiration: 2030-04-11
Also published as: JP2011217982A

Description

本発明は、金属ナトリウムを用い絶縁油に混入するＰＣＢを脱塩素化し無害化するＰＣＢ混入絶縁油の無害化処理方法に関する。 The present invention relates to the detoxification how the PCB contamination insulating oil to harmless dechlorination of PCB to be mixed in the insulating oil using sodium metal.

ＰＣＢ（ポリ塩化ビフェニル）は、不燃性で化学安定性及び電気絶縁性に優れるため、従来、電気機器の絶縁油などとして使用されていたが、その有害性から現在では使用が禁止され、保管されているＰＣＢ及びＰＣＢを含有する廃油などについても、平成１３年に制定された「ＰＣＢ廃棄物処理特別法」により、平成２８年７月までに処理を完了することが義務付けられている。 PCB (polychlorinated biphenyl) is nonflammable and excellent in chemical stability and electrical insulation, so it was conventionally used as an insulating oil for electrical equipment, but its use is now prohibited and stored due to its harmfulness. PCBs and waste oils containing PCBs are also required to complete treatment by July 2016 under the “PCB Waste Disposal Law” enacted in 2001.

ＰＣＢの脱塩素化技術は、これまでに多くの方法が提案されており、幾つかの方法は実用化されている。金属ナトリウムとＰＣＢとを反応させＰＣＢを脱塩素化させる方法は、ＰＣＢ混入絶縁油の無害化処理に使用され、処理プラントも稼働中である。金属ナトリウムとＰＣＢとを反応させるとＰＣＢが脱塩素化され、ビフェニル、塩化ナトリウム、ビフェニルが重合したビフェニル重合物、水酸化ナトリウムが生成するが、この生成物に関しては幾つかの問題が指摘され、これに対する対策案が提案されている。 Many methods have been proposed for PCB dechlorination techniques, and several methods have been put to practical use. The method of dechlorinating PCB by reacting sodium metal with PCB is used for detoxification treatment of PCB mixed insulating oil, and the processing plant is also in operation. When metal sodium and PCB are reacted, PCB is dechlorinated to produce biphenyl, sodium chloride, a biphenyl polymer obtained by polymerizing biphenyl, and sodium hydroxide. Several problems have been pointed out regarding this product, A countermeasure plan for this has been proposed.

例えば、従来の反応槽では、反応槽内に析出するビフェニル重合物、塩化ナトリウム及び水酸化ナトリウムの固形分が反応槽の底部に設けられた排出管を閉塞させるとし、反応槽の底面と面一又は突出する状態で排出口を閉止する底栓弁を備える反応槽が提案されている（例えば特許文献１参照）。また、ＰＣＢを脱塩素化した後の固形のＰＣＢ残渣には、高分子化したポリビフェニルに食塩、絶縁油が含まれるため有効利用できないとして、固形のＰＣＢ残渣からポリビフェニル、食塩、絶縁油をそれぞれ分離する方法が提案されている（例えば特許文献２参照）。 For example, in a conventional reaction vessel, the solid content of biphenyl polymer, sodium chloride, and sodium hydroxide that precipitates in the reaction vessel closes the discharge pipe provided at the bottom of the reaction vessel, and is flush with the bottom of the reaction vessel. Or the reaction tank provided with the bottom plug valve which closes a discharge port in the state which protrudes is proposed (for example, refer patent document 1). In addition, solid PCB residues after dechlorination of PCB cannot be effectively used because polymerized polybiphenyl contains salt and insulating oil, so polybiphenyl, salt and insulating oil are removed from solid PCB residue. A method of separating them has been proposed (see, for example, Patent Document 2).

特開２００５−３１９４１５号公報JP 2005-319415 A 特開２００６−２０５１０６号公報JP 2006-205106 A

本発明者の経験では、ＰＣＢ微量混入絶縁油を処理する場合には、特許文献１に記載の問題点は特に発生していない。またＰＣＢ微量混入絶縁油を処理するとき反応槽内に析出するビフェニル、ビフェニル重合物は、イソプロピルアルコールで洗浄可能なことも経験済みである。本発明者の経験によれば、金属ナトリウムを用いてＰＣＢ微量混入絶縁油を無害化処理するとき、被処理油がＰＣＢ微量混入絶縁油のみである場合には、特に問題となるような事象は発生しないが、他の物質が混入したＰＣＢ微量混入絶縁油を処理するときには、ＰＣＢ微量混入絶縁油のみを処理するときには全く見られない問題が発生した。 According to the inventor's experience, the problem described in Patent Document 1 does not occur particularly when the PCB trace amount insulating oil is processed. In addition, it has been experienced that biphenyl and biphenyl polymers deposited in the reaction tank when treating PCB trace insulating oil can be washed with isopropyl alcohol. According to the experience of the present inventor, when detoxifying the PCB trace-mixed insulating oil using metallic sodium, when the oil to be treated is only PCB trace-mixed insulating oil, an event that is particularly problematic is Although not generated, when processing a PCB trace mixed insulating oil mixed with other substances, there is a problem that cannot be seen at all when processing only a PCB trace mixed insulating oil.

例えばＰＣＢ微量混入絶縁油を抜き出した後に柱上変圧器を破砕しこれを真空加熱し回収される留出液とＰＣＢ微量混入絶縁油とを混合し、これを金属ナトリウムを用いて処理すると、スケールが反応槽の壁面、攪拌翼の表面、攪拌軸の表面（以下、反応槽の壁面、攪拌翼の表面、攪拌軸の表面を合わせて反応槽内壁面と言う）に付着する。このスケールは運転を重ねる毎に成長し、スケールが反応槽から剥離し排出口を閉塞させる事象が発生した。排出口がスケールで閉塞されると復旧作業に多大の時間と労力を必要とすることは改めて言うまでもない。また反応槽壁面にスケールが付着すると熱伝達も阻害される。我々の知る限りこれまでにスケールが反応槽内壁面に付着するとの指摘、報告はされていない。反応槽内壁面に付着するスケールを洗浄することができれば、反応槽を定期的に洗浄することで対処できるが、このスケールは、ビフェニル、ビフェニル重合物とは異なり、イソプロピルアルコールを含め有機溶剤には殆ど溶解せず、従来の洗浄方法は効果がない。ＰＣＢ混入絶縁油の無害化処理に当たり、不純物を含むＰＣＢ混入絶縁油の処理は避けて通ることができず、反応槽内壁面に付着するスケール対策が急務となっている。 For example, after extracting a PCB trace amount insulating oil, a pole transformer is crushed, and this is heated in a vacuum and the recovered distillate and PCB trace amount mix insulating oil are mixed and treated with metallic sodium. Adheres to the wall surface of the reaction tank, the surface of the stirring blade, and the surface of the stirring shaft (hereinafter, the wall surface of the reaction tank, the surface of the stirring blade, and the surface of the stirring shaft are collectively referred to as the inner wall surface of the reaction tank). This scale grew with each operation, and an event occurred in which the scale was detached from the reaction tank and the outlet was blocked. It goes without saying that if the discharge port is blocked by the scale, a great deal of time and labor is required for the restoration work. Also, heat transfer is hindered when scale adheres to the reaction vessel wall. As far as we know, there has been no indication or report that the scale adheres to the inner wall of the reactor. If the scale adhering to the inner wall of the reaction vessel can be washed, it can be dealt with by periodically washing the reaction vessel, but this scale is different from biphenyl and biphenyl polymer in organic solvents including isopropyl alcohol. It hardly dissolves and the conventional cleaning method is ineffective. In detoxifying the PCB-mixed insulating oil, treatment of PCB-mixed insulating oil containing impurities cannot be avoided and measures against scale adhering to the inner wall surface of the reaction tank are urgently needed.

本発明の目的は、金属ナトリウムを用い絶縁油に混入するＰＣＢを脱塩素化し無害化するとき反応槽内壁面へスケールが付着することを防止できるＰＣＢ混入絶縁油の無害化処理方法を提供することである。 An object of the present invention provides a detoxification how the PCB contamination insulating oil can prevent the scale to the reaction vessel inner wall is attached when the harmless dechlorination of PCB to be mixed in the insulating oil using sodium metal That is.

本発明者は、鋭意研究を重ねた結果、金属ナトリウムを用い絶縁油に混入するＰＣＢを脱塩素化し無害化するとき反応槽内壁面へ付着するスケールは、絶縁油に混入するＣ＝Ｏ結合及びＣ−Ｏ結合を含む油酸化変質物が金属ナトリウム、又は前記油酸化変質物が金属ナトリウム、反応促進剤と反応し生成した反応生成物である鹸化物、炭酸塩、有機酸塩が反応槽内壁面へ付着し、析出したものであること、これら鹸化物、炭酸塩、有機酸塩は極性が強いため金属面に付着しやすく油に不溶であることを見出し、本発明を完成するに至った。 As a result of intensive research, the present inventor, as a result of dechlorination and detoxification of PCB mixed in insulating oil using metallic sodium, the scale adhering to the inner wall surface of the reaction tank has C═O bonds mixed in insulating oil and Oil oxidation alteration containing C—O bond is metallic sodium, or said oil oxidation alteration is metallic sodium, reaction product produced by reaction with reaction accelerator, saponification product, carbonate, organic acid salt in reaction tank It was found that the saponified product, carbonate, and organic acid salt adhered to the wall surface, and these saponified products, carbonates, and organic acid salts were strong in polarity, so that they easily adhered to the metal surface and were insoluble in oil. .

すなわち本発明は、金属ナトリウムを用い絶縁油に混入するＰＣＢを脱塩素化し無害化するＰＣＢ混入絶縁油の無害化処理方法において、被処理油は、油酸化変質物を含むＰＣＢ混入絶縁油であり、前記被処理油を無害化するとき生成する反応生成物が反応槽内壁面に付着することを防止する付着防止剤を反応槽に添加し、金属ナトリウムとＰＣＢとを反応させ被処理油を無害化することを特徴とするＰＣＢ混入絶縁油の無害化処理方法である。 That is, the present invention is a detoxification treatment method for PCB-mixed insulation oil that dechlorinates PCBs mixed with insulation oil using metallic sodium, and the treated oil is a PCB-mixed insulation oil containing oil-oxidized denatured substances. In addition, an anti-adhesive agent that prevents the reaction product produced when detoxifying the oil to be treated from adhering to the inner wall surface of the reaction tank is added to the reaction tank, and the sodium to be reacted with PCB to harm the oil to be treated. This is a detoxifying treatment method for insulating oil mixed with PCB.

また本発明において、前記付着防止剤は、前記反応生成物と同一の物質を含む種晶であることを特徴とする。 In the present invention, the adhesion preventing agent is a seed crystal containing the same substance as the reaction product.

また本発明において、前記付着防止剤は、前記反応生成物を吸着する粉粒状の吸着剤であり、さらに該吸着剤は、反応槽内壁面に付着する反応生成物、スケールを掻き取ることを特徴とする。 In the present invention, the adhesion inhibitor is a granular adsorbent that adsorbs the reaction product, and the adsorbent scrapes off the reaction product and scale adhering to the inner wall surface of the reaction tank. And

また本発明において、前記被処理油を金属ナトリウムで無害化した後の前記反応生成物を含む処理済油を反応槽に返送し、該反応生成物を前記種晶とすることを特徴とする。 In the present invention, the processed oil before Symbol comprising the reaction product after treated oil was detoxified with metallic sodium returned to the reaction vessel, characterized in that the reaction product and the seed crystal .

また本発明において、前記種晶は、前記被処理油を金属ナトリウムで無害化した後の処理済油から回収された汚泥を乾燥させた乾燥汚泥であることを特徴とする。 Moreover, in this invention, the said seed crystal is the dry sludge which dried the sludge collect | recovered from the processed oil after detoxifying the said to-be-processed oil with metallic sodium, It is characterized by the above-mentioned.

また本発明において、前記油酸化変質物は、Ｃ＝Ｏ結合及びＣ−Ｏ結合を含むことを特徴とする。 In the present invention, the oil-oxidized modified product includes a C═O bond and a C—O bond.

また本発明において、前記油酸化変質物は、ＰＣＢ混入絶縁油を抜き取った後の柱上変圧器を破砕し、該破砕物を真空加熱し回収される紙木類乾留物を含む留出液に含まれることを特徴とする。 Further, in the present invention, the oil-oxidized denatured product is obtained by crushing the pole transformer after extracting the PCB-containing insulating oil, and heating the crushed material in a vacuum to recover a distillate containing paper-wood dry distillate. It is included.

また本発明において、前記反応槽は撹拌槽であり、反応槽の内壁、攪拌翼及び攪拌軸の表面がフッ素樹脂加工されていることを特徴とする。 In the present invention, the reaction tank is a stirring tank, and the inner wall of the reaction tank, the stirring blade, and the surface of the stirring shaft are processed with a fluororesin .

本発明に係るＰＣＢ混入絶縁油の無害化処理方法は、反応生成物が反応槽内壁面に付着することを防止する付着防止剤を反応槽に添加し、金属ナトリウムとＰＣＢとを反応させＰＣＢを脱塩素化させるので、ＰＣＢ混入絶縁油に油酸化変質物が含まれ、反応生成物が生成してもこの反応生成物は反応槽内壁面に付着することはない。また本発明に係るＰＣＢ混入絶縁油の無害化処理方法では、反応槽にフッ素樹脂加工された反応槽を使用するので、ＰＣＢ混入絶縁油に油酸化変質物が含まれ反応生成物が生成してもこの反応生成物は反応槽内壁面に付着することはない。これらにより反応生成物は処理済油と一緒に反応槽から排出され、反応槽内に蓄積しないので、反応槽内壁面にスケールは形成されず、従来見られたスケールによるトラブルの発生を回避し、ＰＣＢ混入絶縁油の無害化処理を安定的に行うことができる。 In the method for detoxifying PCB-containing insulating oil according to the present invention, an adhesion inhibitor that prevents reaction products from adhering to the inner wall surface of the reaction vessel is added to the reaction vessel, and the PCB is made to react with metallic sodium and PCB. Since dechlorination is performed, the PCB-mixed insulating oil contains oil-oxidized denatured substances, and even if a reaction product is generated, the reaction product does not adhere to the inner wall surface of the reaction tank. In the detoxification process of PCB contaminated insulating oil according to the present invention, because it uses the reaction vessel which is fluorine resin processed into the reaction vessel, contains an oil oxide alteration was to PCB contaminated insulating oil is the reaction product was purified However, this reaction product does not adhere to the inner wall surface of the reaction vessel. As a result, the reaction product is discharged from the reaction tank together with the treated oil and does not accumulate in the reaction tank, so no scale is formed on the inner wall surface of the reaction tank, avoiding the occurrence of troubles due to the scale that has been seen in the past, It is possible to stably perform the detoxification treatment of the PCB mixed insulating oil.

本発明の第１実施形態としてのＰＣＢ混入絶縁油の無害化処理方法を適用するＰＣＢ混入絶縁油無害化処理装置１のプロセスフロー図である。It is a process flow figure of PCB mixed insulation oil detoxification processing apparatus 1 which applies a detoxification process method of PCB mixed insulation oil as a 1st embodiment of the present invention. 紙木類乾留物を含む絶縁油と紙木類乾留物を含まない絶縁油をフーリエ変換赤外分析法ＦＴＩＲで分析した結果を示す図である。It is a figure which shows the result of having analyzed the insulating oil containing a paper-wood dry product and the insulating oil which does not contain a paper-wood dry product by the Fourier-transform infrared analysis FTIR. 本発明の第２実施形態としてのＰＣＢ混入絶縁油の無害化処理方法を適用するＰＣＢ混入絶縁油無害化処理装置２のプロセスフロー図である。It is a process flow figure of the PCB mixing insulation oil detoxification processing apparatus 2 to which the PCB mixing insulation oil detoxification processing method as 2nd Embodiment of this invention is applied. 本発明の第３実施形態としてのＰＣＢ混入絶縁油の無害化処理方法を適用するＰＣＢ混入絶縁油無害化処理装置３のプロセスフロー図である。It is a process flow figure of the PCB mixing insulation oil detoxification processing apparatus 3 which applies the detoxification processing method of the PCB mixing insulation oil as 3rd Embodiment of this invention. 本発明の第４実施形態としてのＰＣＢ混入絶縁油の無害化処理方法を適用するＰＣＢ混入絶縁油無害化処理装置４のプロセスフロー図である。It is a process flow figure of the PCB mixing insulation oil detoxification processing apparatus 4 which applies the detoxification processing method of the PCB mixing insulation oil as 4th Embodiment of this invention.

図１は本発明の第１実施形態としてのＰＣＢ混入絶縁油の無害化処理方法を適用するＰＣＢ混入絶縁油無害化処理装置１のプロセスフロー図である。ＰＣＢ混入絶縁油無害化処理装置１は、ＳＰプロセス（soduim pulverulent dispersion）法を用いてＰＣＢ混入絶縁油を無害化する装置であり、金属ナトリウムとＰＣＢとを反応させＰＣＢを脱塩素化する。 FIG. 1 is a process flow diagram of a PCB-mixed insulating oil detoxification processing apparatus 1 to which the PCB-mixed insulating oil detoxification processing method according to the first embodiment of the present invention is applied. The PCB-mixed insulating oil detoxification treatment apparatus 1 is a device that detoxifies PCB-mixed insulating oil using an SP process (soduim pulverulent dispersion) method, and reacts metallic sodium with PCB to dechlorinate PCB.

ＰＣＢ混入絶縁油無害化処理装置１は、被処理油を貯留する貯留タンク１３、被処理油に含まれる水を除去する減圧蒸留槽１５、ＰＣＢを金属ナトリウムと反応させ脱塩素化する反応槽１７、ＰＣＢの脱塩素化を確認するための分解確認槽１９、処理済油に含まれる残存金属ナトリウムを水和させ、さらに中和する抽出中和槽２１、処理済油と水とを分離する油水分離槽２３、水を回収する洗浄水再生設備２５を備える。 The PCB-mixed insulating oil detoxification treatment apparatus 1 includes a storage tank 13 for storing the oil to be treated, a vacuum distillation tank 15 for removing water contained in the oil to be treated, and a reaction tank 17 for reacting the PCB with metal sodium to dechlorinate. Decomposition confirmation tank 19 for confirming dechlorination of PCB, extraction neutralization tank 21 for hydrating and neutralizing residual metallic sodium contained in the treated oil, oil water for separating the treated oil and water A separation tank 23 and a washing water recycling facility 25 for collecting water are provided.

被処理油は、柱上変圧器から抜き出されたＰＣＢ微量混入絶縁油と、ＰＣＢ微量混入絶縁油を抜き出した後の柱上変圧器を破砕しこれを真空加熱し回収される留出液との混合物であり、これらは貯留タンク１３に貯留された後、減圧蒸留槽１５に送られる。 The oil to be treated consists of the PCB trace mixed insulating oil extracted from the pole transformer, and the distillate recovered by crushing the column transformer after extracting the PCB trace mixed insulating oil and heating it in vacuum. These are stored in the storage tank 13 and then sent to the vacuum distillation tank 15.

減圧蒸留槽１５は、ジャケット付き攪拌槽であり、ジャケットに加熱した熱媒を供給することで被処理油を加熱する。また減圧蒸留槽１５は、槽内を減圧し被処理油に含まれる水を蒸発させ凝縮し回収する減圧装置（図示を省略）を備え、貯留タンク１３から送られた被処理油は、ここで９０℃程度に加熱、０．０１４２Ｍｐａ程度に減圧され、被処理油に含まれる水が除去される。減圧蒸留槽１５で水分が除去された被処理油は反応槽１７に送られる。 The vacuum distillation tank 15 is a stirring tank with a jacket, and heats the oil to be treated by supplying a heated heat medium to the jacket. The vacuum distillation tank 15 includes a decompression device (not shown) that depressurizes the inside of the tank to evaporate, condense, and recover the water contained in the oil to be treated, and the oil to be treated sent from the storage tank 13 is here. It is heated to about 90 ° C. and depressurized to about 0.0142 Mpa to remove water contained in the oil to be treated. The treated oil from which moisture has been removed in the vacuum distillation tank 15 is sent to the reaction tank 17.

反応槽１７は、ジャケット付き攪拌槽であり、ここで減圧蒸留槽１５で水分が除去された被処理油に金属ナトリウムが添加される。金属ナトリウムは、絶縁油中に金属ナトリウムの微粒子を分散させた金属ナトリウム分散体（ＳＤ：soduim dispersion）として反応槽１７に添加される。被処理油と金属ナトリウムとは、攪拌されながらジャケットに供給される加熱した熱媒により９０℃程度まで加熱され、ＰＣＢは金属ナトリウムと反応し脱塩素化し、被処理油は無害化される。なお、金属ナトリウム分散体を添加し所定の時間経過後に、反応促進剤として所定量の水が添加される。反応槽１７の気相部には窒素ガスが供給されている。ＰＣＢ微量混入絶縁油を抜き出した後の柱上変圧器を破砕しこれを真空加熱し回収される留出液が含まれるＰＣＢ微量混入絶縁油を処理すると反応生成物が生成する。この反応生成物は金属面に付着しやすいため、反応槽１７内、攪拌翼２７及び攪拌軸２９の表面はテフロン（登録商標）加工され、反応生成物の反応槽内壁面への付着を防止している。また反応槽１７には、反応に伴い生成する反応生成物が反応槽内壁面に付着することを防止するための種晶が添加される。この点については、後述する。 The reaction tank 17 is a jacketed stirring tank, in which metal sodium is added to the oil to be treated from which water has been removed in the vacuum distillation tank 15. Metal sodium is added to the reaction tank 17 as a metal sodium dispersion (SD: soduim dispersion) in which fine particles of metal sodium are dispersed in insulating oil. The oil to be treated and the metal sodium are heated to about 90 ° C. by a heated heating medium supplied to the jacket while being stirred, and the PCB reacts with the metal sodium to dechlorinate, so that the oil to be treated is rendered harmless. A predetermined amount of water is added as a reaction accelerator after the metal sodium dispersion is added and a predetermined time elapses. Nitrogen gas is supplied to the gas phase portion of the reaction tank 17. When the pole transformer after the PCB trace contamination insulating oil is extracted is crushed and vacuum-heated to treat the PCB trace contamination insulation oil containing the distillate collected, a reaction product is generated. Since this reaction product tends to adhere to the metal surface, the surfaces of the reaction vessel 17, the stirring blade 27 and the stirring shaft 29 are processed with Teflon (registered trademark) to prevent the reaction product from adhering to the inner wall of the reaction vessel. ing. The reaction tank 17 is added with a seed crystal for preventing a reaction product produced by the reaction from adhering to the inner wall surface of the reaction tank. This point will be described later.

反応槽１７でＰＣＢが脱塩素化された被処理油（処理済油）は、分解確認槽１９に送られ、サンプリングライン２０を介してサンプリングされ、処理済油中のＰＣＢ濃度が所定の濃度以下になっているか確認される。ここでＰＣＢが所定濃度以下に達していないことが確認されると、処理済液を反応槽１７に返送し再度、ＰＣＢの脱塩素化を行う。処理済油は、ＰＣＢ濃度が所定の濃度以下であることが確認されると冷却され、その後に抽出中和槽２１に送られる。 The treated oil (treated oil) from which PCB has been dechlorinated in the reaction tank 17 is sent to the decomposition confirmation tank 19 and sampled via the sampling line 20, and the PCB concentration in the treated oil is below a predetermined concentration. Is confirmed. Here, when it is confirmed that the PCB does not reach the predetermined concentration or less, the treated liquid is returned to the reaction tank 17 and the PCB is dechlorinated again. The treated oil is cooled when it is confirmed that the PCB concentration is equal to or lower than a predetermined concentration, and then sent to the extraction neutralization tank 21.

分解確認槽１９から送られる処理済油は、抽出中和槽２１で多量の水と混合され、処理油済中に残存する金属ナトリウムが水和される。さらに金属ナトリウムが水和され生成した水酸化ナトリウムを中和させるための炭酸ガスが吹き込まれ所定のｐＨに調整された後、油水分離槽２３に送られる。 The treated oil sent from the decomposition confirmation tank 19 is mixed with a large amount of water in the extraction neutralization tank 21 to hydrate the metallic sodium remaining in the treated oil. Further, carbon dioxide gas for neutralizing sodium hydroxide produced by hydration of metallic sodium is blown and adjusted to a predetermined pH, and then sent to the oil / water separation tank 23.

油水分離槽２３に送られる多量の水を含む処理済油は、油水分離槽２３で静置され比重差により油相３１と水相３３とに分離される。上層の油相３１は、処理済油タンク３５に送られ貯留される。一方、下層の水相３３は、水を回収する洗浄水再生設備２５に送られる。 The treated oil containing a large amount of water sent to the oil / water separation tank 23 is left in the oil / water separation tank 23 and separated into the oil phase 31 and the water phase 33 due to the difference in specific gravity. The upper oil phase 31 is sent to the treated oil tank 35 and stored. On the other hand, the lower aqueous phase 33 is sent to the washing water recycling facility 25 for recovering water.

洗浄水再生設備２５は、乾燥機３７を備え、水を蒸発させ回収すると共に水に含まれる塩化ナトリウム等を蒸発乾固させる。油水分離槽２３から送られる水は静置分離水受槽３９に一度、貯留された後、乾燥機３７に送られ加熱される。蒸発した水は、凝縮器４１で凝縮し凝縮水槽４３に貯留される。この水は抽出中和槽２１に送られ、金属ナトリウムを水和させるための水として使用される。一方、水に溶解していた塩化ナトリウム等は乾燥汚泥として回収される。このようにＰＣＢ混入絶縁油無害化処理装置１は、水を系外に排出しないクローズドシステムとなっている。 The washing water regeneration facility 25 includes a dryer 37, which evaporates and collects water and evaporates and drys sodium chloride and the like contained in the water. The water sent from the oil / water separation tank 23 is once stored in the stationary separated water receiving tank 39 and then sent to the dryer 37 and heated. The evaporated water is condensed by the condenser 41 and stored in the condensed water tank 43. This water is sent to the extraction neutralization tank 21 and used as water for hydrating metallic sodium. On the other hand, sodium chloride or the like dissolved in water is recovered as dry sludge. As described above, the PCB-mixed insulating oil detoxification treatment apparatus 1 is a closed system that does not discharge water out of the system.

ＰＣＢ微量混入絶縁油を抜き出した後の柱上変圧器を破砕しこれを真空加熱し回収される留出液が含まれるＰＣＢ微量混入絶縁油を被処理油とする場合、被処理油には、Ｃ＝Ｏ結合及びＣ−Ｏ結合を含む油酸化変質物が含まれる。Ｃ＝Ｏ結合及びＣ−Ｏ結合を含む油酸化変質物が含まれる理由は、次の通りである。絶縁油を抜き出した後の柱上変圧器には、ＰＣＢ微量混入絶縁油が付着しているためこれを回収する目的で絶縁油を抜き出した後の柱上変圧器は、破砕機で破砕され真空加熱炉で真空加熱される。このとき柱上変圧器には、紙、木が含まれているため、これら乾留物が留出液に含まれる。図２は、紙木類乾留物を含む絶縁油と紙木類乾留物を含まない絶縁油をフーリエ変換赤外分析法ＦＴＩＲで分析した結果を示す図である。紙木類乾留物を含む絶縁油にはＣ＝Ｏのピーク１７５０ｃｍ^−１が強く表れている。Ｃ＝Ｏ結合を含む油酸化変質物としては、カルボン酸、エステル、アルデヒド、ケトンがある。 When the PCB trace mixed insulating oil containing the distillate collected by crushing the column transformer after extracting the PCB trace mixed insulating oil and vacuum heating it is used as the oil to be treated, Oil oxidation alteration products containing C═O bonds and C—O bonds are included. The reason why the oil-oxidized alteration product containing C═O bond and C—O bond is contained is as follows. Since the PCB transformer after the insulation oil is extracted has a small amount of PCB-containing insulation oil, it is crushed by a crusher and vacuumed. It is heated in vacuum in a heating furnace. At this time, since the pole transformer includes paper and wood, these distillates are contained in the distillate. FIG. 2 is a diagram showing the results of analysis by Fourier transform infrared analysis FTIR of insulating oil containing paper-wood dry matter and insulating oil not containing paper-wood dry matter. A peak of 1750 cm ^{−1 of} C═O appears strongly in the insulating oil containing the paper tree dry matter. Examples of the oil-oxidized alteration product containing a C═O bond include carboxylic acid, ester, aldehyde, and ketone.

油酸化変質物を含むＰＣＢ微量混入絶縁油と金属ナトリウム、反応促進剤である水との代表的な反応は、次式で示される。

A typical reaction between a PCB trace insulating oil containing an oxidized product of oil, metallic sodium, and water as a reaction accelerator is represented by the following formula.

油酸化変質物と金属ナトリウム又は油酸化変質物と金属ナトリウム、反応促進剤とが反応し生成する鹸化物、炭酸塩、有機酸塩等は、絶縁油には溶解せずかつ極性が強いため金属面に付着し易い。従来の反応槽は、鹸化物、炭酸塩、有機酸塩等の反応生成物が反応槽内壁面に付着することを防止する対策が講じられていなかったので、鹸化物、炭酸塩、有機酸塩等の反応生成物が壁面に付着、成長しスケールとなることで種々のトラブルが発生していた。これに対して本実施形態に示す反応槽１７は、反応槽１７の内面のみならず攪拌翼２７、攪拌軸２９の表面がテフロン（登録商標）加工されているため鹸化物、炭酸塩、有機酸塩等の反応生成物は反応槽内壁面に付着することはない。 Saponified products, carbonates, organic acid salts, etc. produced by the reaction of oil-oxidized denatured products with sodium metal or oil-oxidized denatured products with sodium metal, reaction accelerators are not soluble in insulating oil and are highly polar. Easy to adhere to the surface. Conventional reaction tanks have not been provided with measures to prevent reaction products such as saponified products, carbonates, and organic acid salts from adhering to the inner wall of the reaction tank. Various troubles have occurred due to the reaction products such as adhering to the wall surface and growing and becoming a scale. On the other hand, the reaction tank 17 shown in this embodiment has not only the inner surface of the reaction tank 17 but also the surfaces of the stirring blade 27 and the stirring shaft 29 processed with Teflon (registered trademark), so that the saponified product, carbonate, organic acid Reaction products such as salt do not adhere to the inner wall of the reaction vessel.

さらに本実施形態では、反応槽１７に金属ナトリウム、反応促進剤の他、種晶が添加されるので、油酸化変質物と金属ナトリウム又は油酸化変質物と金属ナトリウム、反応促進剤とが反応し生成する鹸化物、炭酸塩、有機酸塩等の反応生成物は種晶に付着し種晶を核として成長する。これにより反応生成物が反応槽内壁面に付着することをより確実に防止することができる。種晶に付着する鹸化物、炭酸塩、有機酸塩等の反応生成物は不溶性固形分となり、処理済油中に懸濁し、処理済油と共に分解確認槽１９を経由して抽出中和槽２１へ送られる。抽出中和槽２１には多量の水が加えられるので、鹸化物、炭酸塩、有機酸塩等は水に溶解し、最終的には、塩化ナトリウムなどと一緒に乾燥汚泥として回収される。 Furthermore, in this embodiment, since seed crystals are added to the reaction tank 17 in addition to metallic sodium and a reaction accelerator, the oil oxidation modified product and metal sodium or the oil oxidation modified product and metal sodium and the reaction accelerator react. Reaction products such as saponified products, carbonates, and organic acid salts are attached to the seed crystals and grow using the seed crystals as nuclei. Thereby, it can prevent more reliably that the reaction product adheres to the reaction tank inner wall surface. Reaction products such as saponified substances, carbonates, and organic acid salts adhering to the seed crystals become insoluble solids, suspended in the treated oil, and together with the treated oil, the extraction neutralization tank 21 via the decomposition confirmation tank 19. Sent to. Since a large amount of water is added to the extraction neutralization tank 21, saponified products, carbonates, organic acid salts and the like are dissolved in water, and finally recovered as dry sludge together with sodium chloride and the like.

種晶は、鹸化物、炭酸塩、有機酸塩等の反応生成物が付着しやすいものが好ましく、種晶として金属石鹸、炭酸塩が例示される。 The seed crystals are preferably those to which reaction products such as saponified products, carbonates, and organic acid salts easily adhere, and examples of the seed crystals include metal soaps and carbonates.

図３は、本発明の第２実施形態としてのＰＣＢ混入絶縁油の無害化処理方法を適用するＰＣＢ混入絶縁油無害化処理装置２のプロセスフロー図である。図１に示すＰＣＢ混入絶縁油無害化処理装置１と同一の構成部材には同一の符号を付して説明を省略する。 FIG. 3 is a process flow diagram of the PCB-mixed insulating oil detoxification processing apparatus 2 to which the PCB-mixed insulating oil detoxification processing method according to the second embodiment of the present invention is applied. The same components as those in the PCB-mixed insulating oil detoxification treatment apparatus 1 shown in FIG.

第２実施形態では、反応槽１７へ添加する種晶として、処理済油中に懸濁する、油酸化変質物と金属ナトリウム又は油酸化変質物と金属ナトリウム、反応促進剤とが反応し生成した鹸化物、炭酸塩、有機酸塩等の不溶性固形分を利用する。具体的には金属ナトリウムとＰＣＢとを反応させるとき、分解確認槽１９から反応槽１７へ処理済油の２０〜３０％程度を返送する。これにより種晶をわざわざ用意する必要がなく便利である。分解確認槽１９は元々、処理済油中のＰＣＢ濃度が所定の濃度まで低下していないとき処理済油を反応槽１７へ返送するラインを備えているので、分解確認槽１９から反応槽１７へ処理済油の一部返送は簡単に行うことができる。 In the second embodiment, as a seed crystal to be added to the reaction tank 17, an oil oxidation modified product and metal sodium or an oil oxidation modified product and metal sodium, which are suspended in the treated oil, are reacted and generated. Insoluble solids such as saponified products, carbonates and organic acid salts are used. Specifically, when metal sodium and PCB are reacted, about 20 to 30% of the treated oil is returned from the decomposition confirmation tank 19 to the reaction tank 17. This is convenient because there is no need to prepare seed crystals. Since the decomposition confirmation tank 19 originally has a line for returning the treated oil to the reaction tank 17 when the PCB concentration in the treated oil has not decreased to a predetermined concentration, the decomposition confirmation tank 19 is transferred from the decomposition confirmation tank 19 to the reaction tank 17. Part of the treated oil can be returned easily.

図４は、本発明の第３実施形態としてのＰＣＢ混入絶縁油の無害化処理方法を適用するＰＣＢ混入絶縁油無害化処理装置３のプロセスフロー図である。図１に示すＰＣＢ混入絶縁油無害化処理装置１と同一の構成部材には同一の符号を付して説明を省略する。 FIG. 4 is a process flow diagram of the PCB-mixed insulating oil detoxification processing apparatus 3 to which the PCB-mixed insulating oil detoxification processing method according to the third embodiment of the present invention is applied. The same components as those in the PCB-mixed insulating oil detoxification treatment apparatus 1 shown in FIG.

第３実施形態では、反応槽１７へ添加する種晶として、油水分離後の水を乾燥機３７で蒸発させ得られる水側の乾燥汚泥を使用する。油酸化変質物と金属ナトリウム又は油酸化変質物と金属ナトリウム、反応促進剤とが反応し生成する金属石鹸、炭酸塩等は、水に溶解するため、油水分離後の水を乾燥機３７で蒸発させ得られる乾燥汚泥には、油酸化変質物と金属ナトリウム又は油酸化変質物と金属ナトリウム、反応促進剤とが反応し生成する鹸化物、炭酸塩、有機酸塩等が含まれている。これにより種晶をわざわざ用意する必要がなく便利である。 In the third embodiment, water-side dry sludge obtained by evaporating water after oil-water separation with a dryer 37 is used as a seed crystal to be added to the reaction tank 17. Oil soap and carbonate produced by the reaction of oil oxidation alteration with metal sodium or oil oxidation alteration with metal sodium and reaction accelerator dissolves in water, so the water after oil-water separation is evaporated in dryer 37 The resulting dried sludge contains saponified products, carbonates, organic acid salts, and the like that are produced by the reaction of oil oxidation-modified products with metallic sodium or oil oxidation-modified products with metallic sodium, and reaction accelerators. This is convenient because there is no need to prepare seed crystals.

図５は、本発明の第４実施形態としてのＰＣＢ混入絶縁油の無害化処理方法を適用するＰＣＢ混入絶縁油無害化処理装置４のプロセスフロー図である。図１に示すＰＣＢ混入絶縁油無害化処理装置１と同一の構成部材には同一の符号を付して説明を省略する。 FIG. 5 is a process flow diagram of the PCB-mixed insulating oil detoxification processing apparatus 4 to which the PCB-mixed insulating oil detoxification processing method according to the fourth embodiment of the present invention is applied. The same components as those in the PCB-mixed insulating oil detoxification treatment apparatus 1 shown in FIG.

第４実施形態では、第１〜第３実施形態とは異なり反応槽１７へ種晶の代わりに粒状の吸着剤を添加する。この吸着剤に油酸化変質物と金属ナトリウム又は油酸化変質物と金属ナトリウム、反応促進剤水とが反応し生成する鹸化物、炭酸塩、有機酸塩等を吸着させることで、反応生成物の反応槽内壁面への付着を防止する。さらに粒状の吸着剤を使用することで、吸着剤は反応槽内壁面に付着した反応生成物、スケールを掻き取る効果も奏する。ここで使用可能な吸着剤は、油酸化変質物と金属ナトリウム又は油酸化変質物と金属ナトリウム、反応促進剤とが反応し生成する鹸化物、炭酸塩、有機酸塩等を吸着可能であれば特に限定されず、ケイ砂、ゼオライト、アルミナ等のセラミックス粒子が例示される。粒子の大きさは、砂粒くらいの大きさが好ましい。 In the fourth embodiment, unlike the first to third embodiments, a granular adsorbent is added to the reaction tank 17 instead of a seed crystal. The adsorbent adsorbs saponified products, carbonates, organic acid salts, etc. produced by the reaction of oil-oxidized denatured product with sodium metal or oil-oxidized denatured product with metal sodium, reaction accelerator water, and so on. Prevents adhesion to the inner wall of the reaction tank. Furthermore, by using a granular adsorbent, the adsorbent also has an effect of scraping off the reaction product and scale adhering to the inner wall surface of the reaction tank. The adsorbent usable here can adsorb saponified products, carbonates, organic acid salts, etc. produced by the reaction of oil oxidation-modified products with metallic sodium or oil oxidation-modified products with metallic sodium and reaction accelerators. There is no particular limitation, and ceramic particles such as silica sand, zeolite, and alumina are exemplified. The size of the particles is preferably about the size of sand particles.

油酸化変質物と金属ナトリウム又は油酸化変質物と金属ナトリウム、反応促進剤とが反応し生成する鹸化物、炭酸塩、有機酸塩等は、ヘキサン、石油エーテルなど極性の弱い有機溶剤には殆ど不溶であり、極性の強い有機溶媒には多少溶解するが溶解度が低く完全溶解には多量の溶剤と非常に長い時間が必要である。これに比較し本発明に係るＰＣＢ混入絶縁油の無害化処理方法及び無害化処理装置は、簡単な方法で反応生成物の反応槽内壁面への付着を防止することができるので、従来見られたスケールによるトラブルの発生を回避し、ＰＣＢ混入絶縁油の無害化処理を安定的に行うことができ、コストメリットも大きい。なおビフェニルは、プラスチックゆえ壁面には付着しにくい。 Saponifications, carbonates, organic acid salts, etc. produced by the reaction of oil oxidation alteration products with metallic sodium or oil oxidation alteration products with metal sodium, reaction accelerators are rarely used in organic solvents with weak polarity such as hexane and petroleum ether. It is insoluble and slightly soluble in highly polar organic solvents, but has low solubility and requires a large amount of solvent and a very long time for complete dissolution. Compared to this, the detoxification treatment method and the detoxification treatment apparatus for PCB-mixed insulating oil according to the present invention can prevent the reaction product from adhering to the inner wall surface of the reaction tank by a simple method, and thus have been conventionally seen. Therefore, it is possible to avoid the trouble caused by the scale and to stably perform the detoxification process of the PCB mixed insulating oil, and the cost merit is great. Biphenyl is difficult to adhere to the wall surface because it is plastic.

１ＰＣＢ混入絶縁油無害化処理装置
２ＰＣＢ混入絶縁油無害化処理装置
３ＰＣＢ混入絶縁油無害化処理装置
４ＰＣＢ混入絶縁油無害化処理装置
１３貯留タンク
１５減圧蒸留槽
１７反応槽
１９分解確認槽
２０サンプリングライン
２１抽出中和槽
２３油水分離槽
２５洗浄水再生設備
２７攪拌翼
２９攪拌軸
３１油相
３３水相
３５処理済油タンク
３７乾燥機
３９静置分離水受槽
４１凝縮器
４３凝縮水槽 DESCRIPTION OF SYMBOLS 1 PCB mixing insulating oil detoxification processing apparatus 2 PCB mixing insulating oil detoxification processing apparatus 3 PCB mixing insulating oil detoxification processing apparatus 4 PCB mixing insulating oil detoxification processing apparatus 13 Storage tank 15 Vacuum distillation tank 17 Reaction tank 19 Decomposition confirmation tank 20 Sampling Line 21 Extraction Neutralization Tank 23 Oil Water Separation Tank 25 Washing Water Regeneration Equipment 27 Stirring Blade 29 Stirrer Shaft 31 Oil Phase 33 Water Phase 35 Treated Oil Tank 37 Dryer 39 Static Separation Water Receiving Tank 41 Condenser 43 Condensation Water

Claims

金属ナトリウムを用い絶縁油に混入するＰＣＢを脱塩素化し無害化するＰＣＢ混入絶縁油の無害化処理方法において、
被処理油は、油酸化変質物を含むＰＣＢ混入絶縁油であり、
前記被処理油を無害化するとき生成する反応生成物が反応槽内壁面に付着することを防止する付着防止剤を反応槽に添加し、金属ナトリウムとＰＣＢとを反応させ被処理油を無害化することを特徴とするＰＣＢ混入絶縁油の無害化処理方法。 In the detoxifying treatment method for PCB-containing insulating oil that dechlorinates PCBs mixed into insulating oil using metallic sodium,
The oil to be treated is insulating oil mixed with PCB containing oil-oxidized denatured material,
An anti-adhesive agent that prevents the reaction product generated when detoxifying the oil to be treated from adhering to the inner wall of the reaction tank is added to the reaction tank, and the sodium is reacted with PCB to detoxify the oil to be treated. A detoxifying treatment method for insulating oil mixed with PCB.

前記付着防止剤は、前記反応生成物と同一の物質を含む種晶であることを特徴とする請求項１に記載のＰＣＢ混入絶縁油の無害化処理方法。 The method for detoxifying PCB-containing insulating oil according to claim 1, wherein the adhesion preventing agent is a seed crystal containing the same substance as the reaction product.

前記付着防止剤は、前記反応生成物を吸着する粉粒状の吸着剤であり、さらに該吸着剤は、反応槽内壁面に付着する反応生成物、スケールを掻き取ることを特徴とする請求項１に記載のＰＣＢ混入絶縁油の無害化処理方法。 2. The adhesion preventive agent is a granular adsorbent that adsorbs the reaction product, and the adsorbent scrapes off the reaction product and scale adhering to the inner wall surface of the reaction tank. The method for detoxifying PCB-containing insulating oil according to claim 1.

前記被処理油を金属ナトリウムで無害化した後の前記反応生成物を含む処理済油を反応槽に返送し、該反応生成物を前記種晶とすることを特徴とする請求項２に記載のＰＣＢ混入絶縁油の無害化処理方法。 Returns the processed oil containing pre Symbol treated oil the reaction product after detoxification with metallic sodium in the reaction vessel, wherein the reaction product to claim 2, characterized in that the said seed crystal Detoxification treatment method for insulating oil mixed with PCB.

前記種晶は、前記被処理油を金属ナトリウムで無害化した後の処理済油から回収された汚泥を乾燥させた乾燥汚泥であることを特徴とする請求項２に記載のＰＣＢ混入絶縁油の無害化処理方法。 The said seed crystal is the dry sludge which dried the sludge collect | recovered from the processed oil after detoxifying the said to-be-processed oil with metallic sodium, The PCB mixing insulating oil of Claim 2 characterized by the above-mentioned. Detoxification treatment method.

前記油酸化変質物は、Ｃ＝Ｏ結合及びＣ−Ｏ結合を含むことを特徴とする請求項１から５のいずれか１に記載のＰＣＢ混入絶縁油の無害化処理方法。 The method for detoxifying PCB-containing insulating oil according to any one of claims 1 to 5, wherein the oil-oxidized denatured material includes a C = O bond and a C-O bond.

前記油酸化変質物は、ＰＣＢ混入絶縁油を抜き取った後の柱上変圧器を破砕し、該破砕物を真空加熱し回収される紙木類乾留物を含む留出液に含まれることを特徴とする請求項１から６のいずれか１に記載のＰＣＢ混入絶縁油の無害化処理方法。 The oil-oxidized denatured material is contained in a distillate containing a paper-wood dry distillate recovered by crushing the pole transformer after extracting the PCB-containing insulating oil and vacuum-heating the crushed material. The method for detoxifying PCB-containing insulating oil according to any one of claims 1 to 6.

前記反応槽は撹拌槽であり、反応槽の内壁、攪拌翼及び攪拌軸の表面がフッ素樹脂加工されていることを特徴とする請求項１から７のいずれか１に記載のＰＣＢ混入絶縁油の無害化処理方法。 The reactor is a stirred tank, the inner wall of the reaction vessel, P CB contamination insulating oil according to any one of claims 1 to 7, the surface of the stirring blade and the stirring shaft, characterized in that it is fluoropolymer processing Detoxification treatment method.