JP3081176B2 - Hazardous chlorine compound removal method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for detoxifying harmful chlorine substances such as dioxin.

[0002]

2. Description of the Related Art Although many studies have been made on detoxification of harmful chlorine substances typified by dioxin, no practical and effective method has been developed at present. For example, transformer oil containing PCB is replaced with NaOH or CaO.
It is known to treat at high temperature with alkalis such as, or to heat to high temperature using dangerous sodium, but in any case, the operation is not easy and the recovery of organic compounds is impossible. . There was a time when the incineration method was considered as a way to remove PCBs, but it is new to remember that the occurrence of dioxin was recognized as a major social problem. In addition, the necessity of reuse is becoming increasingly important from the viewpoint of effective use of resources.

[0003]

SUMMARY OF THE INVENTION The present invention is directed to the development of a method for removing a chlorine atom from PCB, chlorinated dibenzofuran and dioxin by an easy operation and recovering the respective base compounds biphenyl, dibenzofuran and dibenzodioxane. With the goal.

[0004]

In order to achieve the above object, the present invention is characterized in that a Raney Ni-Al alloy is added to and mixed with a mixture of an aromatic chlorine compound and an aqueous alkali solution under ultrasonic irradiation. It is constructed by the method of removing harmful chlorine compounds.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Raney Ni-A
The method of adding the alloy 1 has a reducing power and can remove chlorine atoms from the aromatic chlorine compound reductively. However, they do not have a sufficient reducing power for reductive dechlorination of the above-mentioned PCB, chlorinated dibenzofuran and dioxin compounds. Therefore, by performing ultrasonic irradiation during the above reaction to accelerate the reaction, the detoxification reaction of these harmful chlorine compounds proceeds smoothly. In addition, as a feature not in the conventional dechlorination method, there is no need to heat to a high temperature, and the reaction proceeds at a temperature of about 60 ° C. There is the generation of hydrogen, which can be used as a heat source, in which case only water is generated, so there is no danger.

The reaction is represented by the following chemical formula. ArX + 10% NaOH + Ni-Al = ArH + NaX
+ H ₂ + [Ni, Al (OH) ₃ ] Ar: aromatic compound, X: halogen (chlorine), Ni-A
l: Raney alloy

[0007]

EXAMPLES 4-Chlorodiphenyl (1 mmol, 18
8 mg), dioxane (2 ml), and 10% NaOH
Was added little by little to 60 g of a Raney alloy (commercially available Ni-Al alloy) under ultrasonic irradiation while stirring. After stirring this mixture at 60 ° C. for 10 hours under ultrasonic irradiation, insolubles were filtered off, and the organic layer was washed with water and extracted with dichloromethane. The extract was dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure.
10 mg (71%) of diphenyl were obtained. The gas chromatogram showed that the yield of diphenyl was almost quantitative. In this reaction, the use of dioxane is not always necessary. Without ultrasonic irradiation, the reaction requires a slightly higher reaction temperature (90 ° C.) and a longer time, and furthermore, when the alloy is added, the operation becomes difficult due to a large amount of heat generation and remarkable foaming. In some cases (when the chlorine content is low), it is not always necessary to use dioxane as a solvent.

[0008]

It can be confirmed that the method of the present invention is economical, easy to operate, and extremely effective in treating transformer oil and condenser containing PCB and untreated PCB. It is also expected to be effective in detoxifying dioxins contained in fly ash related to the generation of dioxins associated with waste incineration. In addition, since the above-mentioned mother compound can be recovered almost quantitatively, it can contribute to the reuse of resources. Furthermore, Ni and Al generated in the course of this reaction
The mixture of (OH) ₃ becomes Ni—Al ₂ O ₃ by heating and can be used as a catalyst, and hydrogen is used as a fuel and a reducing agent as described above. Thus, the method of the present invention is expected to be economical and make a great contribution to social life.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Liu Binbin 1-1-1, Chikushi-oka, Minami-ku, Fukuoka City School Corporation Fukuda Gakuen Towa University Central Science Research Institute (56) References JP-A-7-265461 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B01J 19/00 A62D 3/00

Claims (1)

(57) [Claims] 1. A method for removing harmful chlorine compounds, comprising adding and mixing a Raney Ni-Al alloy to a mixture of an aromatic chlorine compound and an aqueous alkali solution under ultrasonic irradiation.