JP4490544B2 - Decomposition treatment method and apparatus for organochlorine compounds - Google Patents

Description

【００１９】
結果、繰り返し反応で６回目の反応でも初回とトランス油中のＰＣＢの分解率は大差なく（初回分解率９９．７８％、６回目分解率９９．７７％）、反応処理後の処理薬剤の分解等で減量した分のみ新しい処理薬剤を追加すれば、廃液を出さずに継続処理できる。反応処理後の処理薬剤の再利用には蟻酸ソーダ、炭酸ソーダ等の析出物を分離し、副生水分の発生分を無水芒硝の脱水吸着処理にて除去してやれば十分再利用できることを確認できた。これは廃液、廃棄物をできるだけ出さない方向性から処理薬剤のリサイクルができることは大きなメリットと考えられる。
【００２０】
以上本発明の代表的と思われるトランス油（絶縁油ＪＩＳ第１種２号）中のＰＣＢの難分解性有機塩素化合物の実施例について説明したが、本発明は必ずしもこれらの実施例構造のみに限定されるものではなく、本発明にいう前記の構成要件を備え、かつ、本発明にいう目的を達成し、以下にいう効果を有する範囲内において適宜改変して実施することができるものである。また難分解物質が気体、液体、混合物であっても本発明の分解処理装置を組合わせることにより具体化することができる。
【００２１】
【発明の効果】
以上の説明から既に明らかなように、本発明にいうところの有機塩素化合物の分解処理法は有機塩素化合物と処理薬剤として、苛性ソーダ液とメタノール液を混合したアルカリ−メタノール液とを混合し、この混合液を圧力反応行程中に供給し、加熱して反応処理後、スラリー分離器にて気体の一酸化炭素、水素ガスと結晶析出物の蟻酸ソーダ、炭酸ソーダと反応処理後の処理薬剤とに分離して、この分離した反応処理後の処理薬剤を無水芒硝による脱水処理した後に処理薬剤として循環する構成とし、また有機塩素化合物の分解処理装置はタンクからの有機塩素化合物と処理薬剤槽からの苛性ソーダ液とメタノール液を混合したアルカリ−メタノール液とを混合し、この混合した被処理液を予備加熱する予熱器と、この予熱器から配管を通し予熱した被処理液を圧力下、加温しつつ反応する反応器と、この反応器で反応した処理液を冷却する冷却器と、この冷却された処理液が圧力調整バルブを経て常圧で蟻酸ソーダ、炭酸ソーダの結晶析出物と一酸化炭素、水素ガスの気体と反応処理後の処理薬剤とに分離するスラリー分離器と、このスラリー分離器からの反応処理後の処理薬剤を配管を通し無水芒硝にて脱水する脱水槽と、脱水槽にて脱水されたアルカリ−メタノール液を処理薬剤槽へ循環する配管とを備えてなる構成としたものであるから、反応後のアルカリ−メタノール液をリサイクルして新しい処理薬剤と混合して用い、反応後に廃液、排水を出さない効率的な操作をして、ランニングコストの低廉をはかるという顕著な効果を期待することが出来るに至ったのである。
【図面の簡単な説明】
【図１】本発明の分解処理装置の一例を示す説明図。
【符号の説明】
１ タンク
３ 処理薬剤槽
１１ 予熱器
２０ 反応器
２２ スラリー分離器
２４ 圧力調整バルブ
２５ 冷却器
２８ 配管
２９ 分離槽
３１ 脱水槽
３２ 配管[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a decomposition method and apparatus for decomposing an organic chlorine compound containing PCB, dioxin, chlorofluorocarbon, trichrene and the like by an alkali-methanol solvent (chemical) reaction.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a decomposition treatment apparatus using a chemical treatment reaction of an organic chlorine compound containing PCB, dioxin, chlorofluorocarbon, trichrene or the like with a solvent (chemical) or the like has been proposed and attracted attention. For example, in the case of chlorofluorocarbon treatment, a decomposition treatment apparatus for chemical treatment reaction of this solvent (drug) or the like first mixes a solvent (drug) in an alkali-methanol solution with a substance to be decomposed in a tank, and pumps this mixture with a pump. To the heat exchanger, the processed material from this heat exchanger is reacted in the solvent (chemical) reactor, then further sent to the cooler via the heat exchanger, and the gas-liquid is sent from the cooler through the pressure adjustment valve. It was sent to a separator and separated by this gas-liquid separator.
[0003]
[Problems to be solved by the invention]
However, in the decomposition treatment apparatus for the solvent (chemical) reaction of the substance to be decomposed, the alkali-methanol solution of the treatment chemical remains largely after the reaction, and there is a problem that the running cost becomes expensive if the waste liquid is used as it is. The decomposition processing apparatus could not be operated efficiently.
[0004]
Therefore, the present invention solves the problems of such a conventional decomposition treatment apparatus, and recycles the alkali-methanol liquid after the reaction and mixes it with a new treatment chemical, and uses the waste liquid after the reaction. Another object of the present invention is to provide an organic chlorine compound decomposition treatment method and apparatus for the purpose of reducing the running cost by performing an efficient operation without discharging drainage.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the organic chlorine compound decomposition treatment method of the present invention comprises an alkali- methanol solution in which caustic soda solution and methanol solution are mixed as an organic chlorine compound containing PCB, dioxin, chlorofluorocarbon, trichrene and the like and a treatment agent. It was mixed, and supplies the mixture in a pressure reaction process, after heating to reaction treatment, gas carbon monoxide in the slurry separator, sodium formate hydrogen gas and crystalline precipitates after reaction treatment with sodium carbonate and separated into a processing agent, it has a configuration for circulating a processing agent processing agent after the separation reaction process after dehydration with anhydrous sodium sulfate. In addition, the organic chlorine compound decomposition treatment apparatus mixes an organic chlorine compound containing PCB, dioxin, chlorofluorocarbon, trichlene, etc. from the tank 1 with an alkali- methanol liquid obtained by mixing a caustic soda liquid and a methanol liquid from the treatment chemical tank 3, The preheater 11 that preheats the mixed liquid to be processed, the reactor 20 that reacts while preheating the liquid to be preheated through the pipe from the preheater 11 while reacting under pressure, and the reactor 20 reacted. A cooler 25 that cools the treatment liquid, and the cooled treatment liquid passes through the pressure adjustment valve 24 and is treated with sodium formate, sodium carbonate crystal precipitates, carbon monoxide, and hydrogen gas at normal pressure and after the reaction treatment. slurry separator 22 for separating the drug, and dehydrating tub 31 to dehydrated over anhydrous sodium sulfate processing agent after the reaction process through a pipe 28 from the slurry separator 22, the dewatering tank 31 Alkali dehydrated Te - is obtained by a composed and a pipe 32 for circulating a methanol solution to the processing chemical tank 3 configuration.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
In the figure, FIG. 1 is an explanatory view showing an example of the decomposition processing apparatus of the present invention.
The present invention treats industrial degradable organic chlorine substances such as PCB, dioxin, chlorofluorocarbon, and trichrene, and organic chlorinated solvents (dichloromethane, chloroform, carbon tetrachloride, etc.). The hard-to-decompose organochlorine substance of PCB in transformer oil (insulating oil JIS type 1 No. 2) is treated.
[0007]
Reference numeral 1 denotes a tank that stores a substance to be decomposed made of an organic chlorine compound of transformer oil (insulating oil JIS type 1 No. 2) containing PCB. 4 is sent to the suction side. Reference numeral 3 denotes a processing chemical tank. In the processing chemical tank 3, an alkali-methanol liquid obtained by mixing caustic soda and methanol liquid is stored as a processing chemical .
[0008]
2 is a metering pump, which temporarily heats the processing chemical in the processing chemical tank 3 through the pipe 6 by using the heat of the cooler 25 at the lower part of the reactor which will be described later. Together with the processed material, it is led to the mixer 7 of the pressure reaction process by high-pressure determination. The material to be decomposed from the tank 1 and the processing chemical from the processing chemical tank 3 are sufficiently stirred and mixed in the mixer 7. The object to be processed in which the object to be decomposed and the processing chemical are mixed is guided to the preheater 11 through the pipe 10.
[0009]
The heat of the preheater 11 is guided to the preheater 11 through the pipe 12 using the remaining heat of the heating medium of the reactor 20 described later. In the preheater 11, the object to be processed is heated to about 250 ° C to 300 ° C. The preheater 11 may be high frequency heating, or may be gradually heated rather than heated at once.
[0010]
The object to be processed heated by the preheater 11 is guided to the reactor 20 through the pipe 13. This reactor 20 is provided with a heating medium on its peripheral surface, and the object to be treated is kept warm and held at about 300 ° C. to 350 ° C. with this heating medium. A cooler 25 is provided at the bottom of the reactor 20. In this reactor 20, the pressure is set to a set pressure of about 200 kg / cm ² or less to decompose the object to be treated.
[0011]
Although this reactor 20 is performed in a batch system, it is not particularly limited to this batch system, and there is no problem even if it is a continuous reaction process. The processed product decomposed by the reaction in the reactor 20 is cooled in the cooler 25. The heat generated during cooling in the cooler 25 is preliminarily warmed with the alkali-methanol solution of the treatment chemical guided through the pipe 6 described above. Reference numeral 14 denotes a heating medium suction side pipe for heating the reactor 20, and 15 denotes a level detector.
[0012]
The cooler 25 cools the processed material and makes it liquefiable. The processed product that can be liquefied is reduced in pressure by the pressure adjusting valve 24 through the pipe 21 and led to the slurry separator 22. Treated sent from the cooler 25 is separated into a slurry separator 22 in sodium formate, crystalline precipitate sodium carbonate and carbon monoxide, the process agent after the reaction process, including the gas and transformer oil of hydrogen gas . Crystalline precipitates of sodium formate and sodium carbonate are discharged from the lower portion of the slurry separator 22 through a valve 27, and carbon monoxide and hydrogen gas gases are discharged from a pipe 17 at the upper end of the slurry separator 22.
[0013]
The processing chemical after the reaction treatment including the transformer oil in the slurry separator 22 is guided into the separation tank 29 through the pipe 28. In the separation tank 29, the oil layer is separated into the upper layer and the alkali-methanol agent layer is separated into the lower layer. The lower layer in the separation tank 29 is guided to the dehydration tank 31 through the pipe 28a. The upper layer in the separation tank 29 is reused as transformer oil.
[0014]
The separation tank 29 is provided in the embodiment because the object to be treated is made of the hardly-decomposable organic chlorine substance of PCB in the transformer oil, and the present invention is not particularly limited to the separation tank 29. When an organic chlorinated solvent such as chlorofluorocarbon or trichlene is used as an object to be treated, a separation tank is not required, and is directly led to the dehydration tank 31 through the pipe 28 and the pipe 28a from the slurry separator 22.
[0015]
Anhydrous mirabilite is put into the dehydration tank 31, the alkali-methanol agent layer is stirred, and a small amount of water produced as a by-product is dehydrated by the anhydrous mirabilite. The liquid dehydrated in the dehydration tank 31 becomes an alkali-methanol liquid, and is circulated to the treatment chemical tank 3 as a treatment chemical through the pipe 32 via the metering pump 18. Reference numeral 19 denotes a filter. The dehydration tank 31 is a batch type, but is not particularly limited to a batch type, and may be a dehydration tower using anhydrous sodium sulfate as a continuous treatment.
[0016]
[Experiment 1]
Transformer oil (manufactured by Matsumura Oil, insulating oil JIS type 1 No. 2, average molecular weight 270, average boiling point 280 ° C., component Aromatic 20.6%, Naphthene 18.2%, Parafin 61.2%) and KC400 (Kanechlor 400) at 1000PPM A diluted sample was prepared as a sample of an organic chlorine compound. As the alkali-methanol solution for the treatment agent, caustic soda and methyl alcohol and sodium methoxide special grade made by Wako Pure Chemical as reaction auxiliary were used. The reactor of this experimental example was batch-type using a micro autoclave. The autoclave used was a TVS-N2 type manufactured by pressure-resistant glass industry, an internal volume of 120 ml, and made of SUS316.
[0017]
Put the sample and stirring Teflon (registered trademark) rotor in this micro autoclave container, fill and replace with nitrogen to prevent oxidation reaction, heat with a band heater from the outside, and heat to a predetermined temperature (300 ° C) Reacted. After the reaction product is naturally cooled by a wind blower, the precipitates such as sodium formate and sodium carbonate are taken out, and then the alkali-methanol liquid after the reaction treatment separated from the transformer oil is subjected to dehydration adsorption treatment with anhydrous sodium sulfate. Then, the alkali-methanol solution was recovered, and a new alkali-methanol solution was added to the recovered alkali-methanol solution to carry out the reaction operation repeatedly. The operating conditions and progress are shown in Table 1 below.
[0018]
[Table 1]

[0019]
As a result, the decomposition rate of PCB in the first and trans oils was not much different even in the 6th reaction in the repetitive reaction (initial decomposition rate 99.78%, 6th decomposition rate 99.77%), and decomposition of the treatment chemical after the reaction treatment If new treatment chemicals are added only for the reduced amount, etc., continuous processing can be performed without producing waste liquid. It was confirmed that for the reuse of the treatment chemical after the reaction treatment, precipitates such as sodium formate and sodium carbonate were separated and the generated by-product water was removed by dehydration adsorption treatment of anhydrous sodium sulfate. . This is considered to be a great merit that processing chemicals can be recycled from the direction of not generating waste liquid and waste as much as possible.
[0020]
As mentioned above, the examples of the hardly-decomposable organochlorine compounds of PCB in the transformer oil (insulating oil JIS type 1 No. 2) considered to be representative of the present invention have been described. However, the present invention is not limited to these example structures. The present invention is not limited, and includes the above-described constituent requirements according to the present invention, achieves the object according to the present invention, and can be implemented with appropriate modifications within the scope of the following effects. . Even if the hardly decomposable substance is gas, liquid or mixture, it can be embodied by combining the decomposition treatment apparatus of the present invention.
[0021]
【The invention's effect】
As is apparent from the above description, the organic chlorine compound decomposition treatment method referred to in the present invention is a mixture of an organic chlorine compound and an alkali- methanol solution obtained by mixing a sodium hydroxide solution and a methanol solution as a treatment agent. The mixed liquid is supplied during the pressure reaction process, heated and reacted, and then in a slurry separator, gas monoxide, hydrogen gas, crystal precipitate sodium formate, sodium carbonate, and the treated chemical after the reaction treatment. The separated processing chemical after the reaction treatment is dehydrated with anhydrous sodium sulfate and then circulated as a processing chemical, and the organochlorine compound decomposition treatment device is supplied from the organic chlorine compound from the tank and from the processing chemical tank. alkali were mixed sodium hydroxide and methanol solution - of methanol was mixed, through a preheater, a pipe from the preheater to preheat the liquid to be treated and this mixture A reactor that reacts while preheating the liquid to be treated is heated under pressure, a cooler that cools the reaction liquid that has reacted in the reactor, and the cooled treatment liquid passes through a pressure adjustment valve at normal pressure and formic acid. soda, anhydrous through crystallization of sodium carbonate and carbon monoxide, and a slurry separator for separating and processing the drug after the gas reaction process of hydrogen gas, the pipe processing agent after the reaction process from the slurry separator Recycles the alkali-methanol solution after the reaction because it has a dehydration tank that dehydrates with sodium sulfate and a pipe that circulates the alkali-methanol liquid dehydrated in the dehydration tank to the treatment chemical tank. It was possible to expect a remarkable effect of reducing the running cost by using it mixed with new treatment chemicals, performing efficient operation without discharging waste liquid and waste water after the reaction.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an example of a decomposition processing apparatus according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tank 3 Treatment chemical tank 11 Preheater 20 Reactor 22 Slurry separator 24 Pressure adjustment valve 25 Cooler 28 Pipe 29 Separation tank 31 Dehydration tank 32 Piping

Claims (2)

An organochlorine compound and an alkali- methanol solution obtained by mixing a caustic soda solution and a methanol solution are mixed as a treatment agent , and the mixture solution is supplied during a pressure reaction process, heated, reacted, and then gasified in a slurry separator. Carbon monoxide, hydrogen gas, crystal precipitate sodium formate, sodium carbonate and the treatment chemical after the reaction treatment are separated, and the separated treatment chemical is dehydrated with anhydrous sodium sulfate as a treatment chemical. An organic chlorine compound decomposition process characterized by circulation. A preheater (11) for preliminarily heating the mixed liquid to be treated by mixing an organochlorine compound from the tank (1) and an alkali- methanol liquid obtained by mixing a caustic soda liquid and a methanol liquid from the treatment chemical tank (3). And a reactor (20) that reacts while preheating the liquid to be treated that has been preheated through a pipe from the preheater (11) under pressure, and a cooler that cools the reaction liquid reacted in the reactor (20) (25), and the cooled treatment liquid is converted into sodium formate, sodium carbonate crystal precipitates, carbon monoxide, hydrogen gas, and a treatment agent after the reaction treatment at normal pressure through a pressure regulating valve (24). A slurry separator (22) to be separated, a dehydration tank (31) for dehydrating the treated chemical after the reaction treatment from the slurry separator (22) with anhydrous sodium sulfate through a pipe (28), and a dehydration tank (31) And a pipe (32) for circulating the alkali-methanol liquid dehydrated in step (3) to the treatment chemical tank (3). Cracking facility of the machine chlorine compounds.

Images