JPH1078210A - Regeneration and treatment method for harmful gas contained-waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make harmless dioxin contained in flying ashes economically and regenerate the flying ashes as a useful substance. SOLUTION: Flying ashes produced in an incineration process of waste are collected and are irradiated with a multi-arc, thereby melting the collected flying ashes. A multi-arc is irradiated at the gas produced in a process which melts the flying ashes. The molten substance of the flying ashes is solidified and turned into a ceramic. The molten metal is sorted according to each type based on a differential specific weight so as to produce an useful material. The combustible wastes are gasified, thereby producing a combustible gas. The combustible gas is employed for the power generation of a boiler, thereby providing electric power for the generation of multi-arc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for regenerating toxic gas-containing waste, which detoxifies harmful gas-containing waste such as fly ash generated by incineration of the waste and collectively regenerates the valuable waste.

[0002]

2. Description of the Related Art In the incineration of waste, laws and regulations have been amended so that black smoke is not emitted from the chimney. Fly ash containing dioxin has become a serious problem as a result of the ash being accumulated in the incineration plant.

[0003] Dioxin is said to be the most toxic among the substances created by mankind, and poses a serious problem because it damages DNA in thin slices. The source of this dioxin is a chlorine-based organic compound such as PCB. Vinyl in urban garbage is a major source of dioxin.

It is said that the mechanism of the generation of dioxin in a garbage incinerator is the synthesis between chemical substances, the combustion process, the catalytic action of incinerated ash, and the like. In preventing the generation of dioxins, complete combustion, residence time, etc. are important from the viewpoint of high-temperature decomposition, and from the viewpoint of complete combustion,
Secondary combustion is employed in incinerators.

[0005]

However, organic substances, including dioxins, are not decomposed only at high temperatures. That is, according to Boyle-Charles law, it is practically impossible to exceed the binding energy of an organic substance by heat. It is considered that the decomposition of the organic matter by combustion or the like is caused by the catalytic effect of the coexisting substance and the photochemical action mainly by ultraviolet rays.

[0006] Therefore, in complete combustion aimed at high temperature decomposition, the decomposition efficiency of dioxin is low. In addition, since a large amount of exhaust gas is generated in this method, it is difficult to completely detoxify a large amount of exhaust gas even if a large-sized exhaust gas treatment facility is used, because the size of exhaust gas treatment equipment is increased.

[0007] In addition, dioxin has the property of being regenerated in the process of decreasing the temperature from 800 ° C (around 300 ° C). That is, even if dioxin is once rendered harmless by high-temperature decomposition, dioxin appears again in the cooling process. It is considered that a metal oxide such as copper oxide acts as a catalyst for such dioxin regeneration. It is also said that regenerated dioxin is more toxic than the original dioxin, and rapid cooling has been adopted as a preventive measure, but it is not perfect.

As a secondary treatment for detoxifying dioxins in fly ash, melting and decomposition by plasma are employed. However, the irradiation range of general plasma is narrow and the cost is increased.

As described above, the treatment of fly ash containing dioxin has not been abandoned in Japan because there is no good measure for detoxifying the dioxin. The fact is that they are struggling with ash handling.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is a method for regenerating harmful gas-containing waste which can completely detoxify harmful gas-containing waste such as fly ash containing dioxin at low cost. The aim is to provide a method.

[0011]

According to the present invention, there is provided a method for regenerating harmful gas-containing waste, comprising collecting harmful gas-containing waste such as fly ash generated by incineration of the waste, and irradiating the collected arc with a multi-arc. Melting harmful gas-containing waste to detoxify the harmful gas in the waste and irradiating the exhaust gas generated in the process of melting with a multi-arc to detoxify the harmful gas in the exhaust gas It is.

The multi-arc is a self-sustained type ultra-high temperature arc developed by the present applicant. Normally, this multi-arc is generated without a counter electrode from a plurality of electrode rods by applying a voltage having a different phase to a plurality of electrode rods arranged symmetrically around the center line with the tips approaching each other. . This multi-arc has a high temperature of 4000 ° C. or more and reaches 10,000 ° C. in the center. In addition to the high temperature, it is accompanied by strong electromagnetic vibration, a rotating magnetic field, and wave energy such as ultraviolet rays.

By irradiating the fly ash with this multi-arc, for example, the fly ash is melted, and the dioxin in the fly ash is rendered harmless. Further, the fly ash becomes a ceramic or the like having a large utility value by melting. Since the multi-arc does not supply air unlike a normal incinerator, fly ash can be treated in a non-oxidizing atmosphere. Therefore, gas generation is small. The generated gas is also irradiated with the multi-arc, so that the regeneration and secondary generation of dioxin can be prevented. Thus, the fly ash is rendered harmless and can be used as a useful material.

In the multi-arc, by injecting water vapor into the center of the plasma flame, the water is decomposed into hydrogen gas and oxygen gas, and becomes a fuel, thereby emitting an incandescent flame. As a result, heat calories are greatly increased. By injecting an auxiliary fuel gas such as methane gas together with or instead of steam, heat calories are increased and electricity costs are significantly reduced.

As a power source for generating a multi-arc, it is preferable to supply power by boiler power generation using combustible gas collected from combustible waste. When extracting combustible gas from combustible waste, it is desirable to heat the combustible waste with a multi-arc or the like without burning (without supplying air). When burned, a large amount of exhaust gas is generated, and not only is a useful combustible gas not obtained, but also dioxin is generated in this process.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining a facility arrangement suitable for carrying out the method for regenerating harmful gas-containing waste according to the present invention.

The regenerating facility comprises a power generating facility A also serving as a waste incineration facility, and a facility B for treating fly ash generated by incineration of the waste.

In the power generation facility A, petroleum, waste oil and the like are introduced into the facility as an energy source (G1). In some cases, reclaimed oil is also placed in the facility. Recycled oil is oil collected by a plastic oiling device and is rarely used, so it is also used as an energy source.
Emulsified water or oil can also be used.

A catalytic substance having a catalytic effect effective for converting organic matter into harmless fuel gas is introduced into the equipment (G2).
At this time, select from municipal waste and municipal waste,
It is better to cover the processing costs. A catalyst that enhances the thermal reaction and is easily gasified, or an industrial waste that enhances the reactivity can be used as the catalyst substance.

These materials are transferred to the heating chamber (G
3). In the heating room, the organic matter in the room is heated by a burner without supplying air (G4). The organic material is vaporized by this heating and becomes a fuel gas (G5). Fuel gas is stored in the tank, and the boiler is operated to generate power (G7). On the other hand, some fuel gas is used as fuel for the burner (G8). On the other hand, steam is produced by preheating the heating chamber. The soot and activated carbon generated in this process are collected and commercialized.

The residue remaining after gasification is melted by multi-arc irradiation (G11). The melt is separated and collected in the crucible according to the specific gravity difference. The additional material is added to the material taken out of the crucible and kneaded, and soil fertilizer, gravel raw material,
It is used in various fields as a mold or the like (G12 to G16).

Here, the power generation system is a normal steam power generation system. However, a hollow multiple good circulation system developed by the present applicant may be used. This power generation system using partially underwater MHD power generation has twice the efficiency of the conventional one and is clean.

In parallel with the power generation in the power generation facility A and the incineration of waste, in the fly ash treatment facility B, the fly ash is charged into a charging tank and transported to the heating chamber [(1) (2) (4) )]. In the heating chamber, the fly ash is heated without supplying air. At this time, aluminum powder of industrial waste that generates an exothermic reaction and other materials that promote melting by a catalytic effect are added as a catalyst [(3) (5)].
The heating may be burner heating, but electric heating is more desirable from the viewpoint of suppressing gas generation.

The heated fly ash is melted by multi-arc irradiation [(6)]. As a result, the dioxin contained in the fly ash is decomposed by the ultra-high temperature of the multi-arc and strong wave energy. The gas generated here is rendered harmless by the irradiation of the multi-arc in the cooling process [(7) (9)]. The harmless gas is released through a filter in water [(11)-(1
3)].

In heating and melting, the generated gas hardly comes into contact with air. Even during cooling, the amount of air contact is usually 1 /
Extremely small, 100 to 1/500, and cooling time is 1/1
0 or less. Therefore, secondary generation of dioxin is small, and even if it is generated, it is rendered harmless by irradiation with the multi-arc.

The melt generated by the multi-arc irradiation is stored in the crucible [(8)]. By the multi-arc irradiation, the fly ash melts and becomes a beautiful ceramic. Take the melt out of the crucible and pour it into a mold to commercialize it
[(10) (14)-(19)]. Further, metals can be separately collected in the crucible according to the difference in specific gravity. Each metal can also be made into a product by pouring it into a mold [(20) to (24)].

In the work area adjacent to the fly ash processing equipment B,
Using the obtained materials, processed products such as pots, dishes, pots, containers, flowerpots, etc. are made [(25)].

In the above embodiment, fly ash containing dioxin has been described as an example. However, waste containing chlorine gas, PCB, and other harmful gases (including those in containers) is similarly detoxified and regenerated. It is possible.

[0029]

As described above, according to the method for regenerating harmful gas-containing waste according to the present invention, fly ash which cannot be disposed of because it contains dioxin is rendered harmless. In addition, the fly ash is effectively used and does not even need to be disposed of, and its economic effect is great. Further, there is no danger of producing dioxin in the process of detoxifying incineration ash, and the treatment itself is very safe.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a facility arrangement suitable for carrying out a method for regenerating and processing harmful gas-containing waste according to the present invention.

Claims (4)

[Claims] 1. Collecting harmful gas-containing wastes such as fly ash generated by incineration of the wastes and irradiating them with a multi-arc to melt the harmful gas-containing wastes, thereby reducing harmful gases in the wastes. A method for reclaiming harmful gas-containing waste, wherein the harmful gas in the exhaust gas is rendered harmless by irradiating the exhaust gas generated during the melting process with a multi-arc. 2. Combustible waste is heated and vaporized without supplying air, boiler power generation is performed using the combustible gas generated here as a raw material, and the multi-arc is generated by the electricity. The method for reclaiming harmful gas-containing waste according to claim 1. 3. The method according to claim 2, wherein the combustible waste is heated directly or indirectly by a gas burner, and a combustible gas generated by heating the combustible waste is used as the fuel. The method for reclaiming harmful gas-containing waste described in the above. 4. The method for reclaiming harmful gas-containing waste according to claim 1, wherein the melt produced by the irradiation of the multi-arc is used as a commercial product.