JPH11197627A - Waste processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste processing system which produces supercritical water efficiently, supplies the supercritical water appropriately, and can treat produced ash and dust. SOLUTION: In a waste processing system equipped with an incinerator 2 for incinerating supplied waste 1 are provided a water supply tank 18 for supplying water, a booster pump 29 for pressurizing water supplied from the tank 18, supercritical water generators 13a, 13b which receive pressurized water from the booster pump 29 and produce supercritical water using exhaust gas 4 from the incinerator 2 as a heat source, and decomposition apparatuses 27, 28 which receive burned ash 5 of the incinerator 2 or dust in the exhaust gas 4 and the produced supercritical water and decompose dioxin in the burned ash 5 or the dust.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste treatment system, and more particularly to a waste treatment system having a function of decomposing organic chlorine compounds in ash or dust generated by an incinerator or the like using supercritical water. About.

[0002]

2. Description of the Related Art Recently, landfill sites have begun to tighten due to the increasing amount of waste. For this reason, incineration is performed as a volume reduction treatment, but dioxin, which is a harmful substance, is generated due to the organic chlorine-based waste contained in the waste. At present, harmful substances are contained in flue gas, dust collected in dust removal equipment and ash discharged from incinerators, and must be detoxified.

[0003] For example, Japanese Patent Application Laid-Open No. 9-19671 discloses that ash generated by incineration of waste is supplied with supercritical water and a predetermined treatment liquid to produce heavy metals, sodium chloride, potassium chloride, and the like. Separation of salts is described.

[0004]

However, when treating ash using supercritical water, heat is supplied efficiently to generate supercritical water while suppressing a decrease in plant efficiency, and the supercritical water is appropriately treated. It is required that ash processing operation can be performed by supplying critical water.

[0005] Japanese Patent Application Laid-Open No. 9-19671 does not describe or suggest the above, and can efficiently generate supercritical water and appropriately treat the ash and dust generated by supplying the supercritical water. There is no specific description or suggestion about the waste treatment system.

Accordingly, it is an object of the present invention to provide a waste treatment system capable of efficiently generating supercritical water and appropriately supplying supercritical water to treat ash and dust generated.

[0007]

SUMMARY OF THE INVENTION The present invention reduces the temperature of exhaust gas discharged from an incinerator of exhaust gas and generates supercritical water using the heat of the exhaust gas to reduce dust and soot generated from the incinerator. Removes harmful components such as ash dioxin.

Specifically, the present invention relates to a waste water treatment system provided with an incinerator where waste is supplied and incinerated, and a water supply tank for supplying water and a pressure of water supplied from the water supply tank. A booster pump, a supercritical water generator that is supplied with pressurized water supplied by the booster pump and generates supercritical water using exhaust gas generated from the incinerator as a heat source, and incineration ash from the incinerator or dust in the exhaust gas. And a decomposer for supplying the generated supercritical water and decomposing the dioxin in the incinerated ash or dust.

As the incinerator, a stoker furnace, a fluidized bed furnace, an incineration melting furnace or the like can be used.

As a result, the temperature of the exhaust gas discharged from the incinerator is reduced, and dioxin in ash and dust is decomposed with supercritical water by effectively utilizing the heat generated from the incinerator. As a result, the present invention can efficiently generate supercritical water and appropriately supply supercritical water to treat ash and dust generated.

Alternatively, the present invention specifically provides a waste treatment system provided with an incinerator in which waste is supplied and incinerated, comprising a water supply device, and a booster pump for increasing the pressure of water supplied from the water supply device. A supercritical water generating apparatus for generating supercritical water using the exhaust gas generated from the incinerator supplied with the supply water pressurized by the pressurizing pump, and a storage for supplying the supercritical water generated by the generating apparatus; A tank and a decomposer for supplying dust in the incinerator ash or the exhaust gas and supplying supercritical water from the storage tank to decompose the dioxin in the incineration ash or dust. And

[0012] Thus, smooth operation can be performed regardless of temperature and flow rate fluctuations. Further, supercritical water can be smoothly supplied to the decomposer while efficiently reducing the temperature of the exhaust gas passing through the supercritical water generator.

According to another aspect of the present invention, there is provided a waste treatment system provided with an incinerator in which waste is supplied and incinerated, and a water supply device, and a booster pump for increasing the pressure of water supplied from the water supply device. And a supercritical water generator that supplies supercharged water supplied by the booster pump and generates supercritical water using exhaust gas generated from the incinerator as a heat source, and incineration ash from the incinerator or dust in the exhaust gas is supplied. And the generated supercritical water is supplied, and a decomposer for decomposing the dioxin in the incineration ash or dust is installed on a path from the supercritical water generator to the decomposer, and the generated supercritical water is provided. It is characterized by comprising a discharge device for guiding water out of the system, and a control device for controlling the amount of the generated supercritical water to be supplied to the decomposition device and the discharge device.

[0014] Even when the supercritical water is supplied to the decomposing device in a batch, the temperature of the exhaust gas passing through the supercritical water generating device can be suppressed by continuously supplying the supercritical water generating device.

According to another aspect of the present invention, there is provided a waste treatment system including an incinerator in which waste is supplied and incinerated, and a water supply device, and a booster pump for increasing the pressure of water supplied from the water supply device. And a supercritical water generator that supplies supercharged water supplied by the booster pump and generates supercritical water using exhaust gas generated from the incinerator as a heat source, and incineration ash from the incinerator or dust in the exhaust gas is supplied. And the generated supercritical water is supplied, and a plurality of decomposition devices for decomposing the dioxin in the incineration ash or dust, and when supplying the supercritical water to one separation device, the supercritical water is supplied to another separation device. A controller that stops the supply and controls the supply of the supercritical water to the other separation device when the supply of the supercritical water to the one separation device is stopped. In this way, continuous treatment can be performed, so that supercritical water is not wasted, the treatment amount can be treated in a nearly continuous state, the operation can be performed efficiently, and the pressurized water supply to the supercritical water generator can be stably performed. To reduce the heat temperature of the exhaust gas and stably suppress the dioxin regeneration of the exhaust gas.

Alternatively, the present invention specifically provides an incinerator to which waste is supplied and incinerated, and a combustion apparatus to which exhaust gas discharged from the incinerator is supplied and fuel is supplied and burned. A wastewater treatment system provided with a water supply tank, a booster pump for increasing the pressure of water supplied from the water supply tank, and a pump provided at a downstream side of the combustion device. A supercritical water generating apparatus that generates supercritical water using exhaust gas generated from the apparatus as a heat source, and incineration ash of an incinerator or dust in the exhaust gas is supplied and the generated supercritical water is supplied, and the incineration ash is supplied. Alternatively, a decomposition device for decomposing dioxin in dust is provided.

Thus, the concentration of harmful components such as dioxin in the exhaust gas discharged from the incinerator and the reduction of harmful components such as dioxin in dust or ash can be efficiently reduced.

The supercritical water is 22.5 MPa
It is preferable to use high-temperature, high-pressure water in a supercritical state at a temperature of 374.1 ° C. or higher at the above pressure. It is preferable to set the pressure to 50 MPa or lower and 600 ° C. or lower in view of the strength of the generating apparatus. Note that, depending on the device, the temperature can be further increased.

However, in the present invention, among the high-temperature and high-pressure water, even if the water is not supercritical water in the above-mentioned range, the performance such as reactivity is lowered as compared with the supercritical water, and the desired harmful component such as dioxin can be reduced. To the extent that degradability can be obtained,
It is assumed that high-temperature and high-pressure water having a desired temperature and pressure can be used as the supercritical water.

Therefore, a desired high-temperature and high-pressure water in a state that does not reach the supercritical state, that is, in a so-called subcritical state, may be used by imitating the supercritical water.

As an example, high-temperature and high-pressure water having a pressure of 22.5 MPa or more and a temperature of 250 ° C. or more is used. The pressure is 10 MPa or more, and high-temperature high-pressure water having a temperature of 374.1 ° C. or more is used. High-temperature, high-pressure water with a pressure of 10 MPa or more and a temperature of 250 ° C. or more is used.

Of these, the use of high-temperature high-pressure water is preferred in terms of performance, but high-temperature high-pressure water may be selected from the viewpoint of easy production. Alternatively, high-temperature and high-pressure water may be used in order to most easily generate the water.

The following embodiment shows an example in which supercritical water is produced.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

The first embodiment will be described with reference to FIG.

The system comprises: An incinerator 2 for incinerating the waste 1 (a fluidized bed furnace and a stoker furnace are not limited, but the figure is represented by a stoker furnace), and a combustion exhaust gas 4 from the incinerator 2 is supplied to remove dust in the exhaust gas. A dust collector (dust removing device) 6 is provided. The exhaust gas that has passed through the dust collector 6 is discharged out of the system. It has a water supply tank 18 that supplies water for generating desired supercritical water, and a high-pressure pump 29 that pressurizes water supplied from the water supply tank 18. The pressurized water is supplied by the high-pressure pump 29, and the heat exchanger 13 is provided in the incinerator 2, which is a supercritical water generation device that heats water supplied from the high-pressure pump 29 to generate supercritical water.
The supercritical water generated by the heat exchanger 13 is introduced, and the dust 16 collected by the dust collector 6 is supplied to decompose harmful substances in the dust. And an ash reaction vessel 28 that introduces supercritical water and supplies ash 5 discharged from the bottom of the incinerator 2 to decompose harmful substances in the ash. Dust reaction container 27 and ash reaction container 28
Is provided with a discharge device that discharges a reaction product after the supercritical water reacts with dust or ash.

[0027] Waste (waste) 1 is put into the incinerator 2
Burned in. The combustion exhaust gas 4 containing dust by this combustion
And incineration ash 5 are generated. For example, the inside of the furnace is 700
The temperature is between about 1200 ° C. and 1200 ° C. As a result of this combustion, for example, a combustion exhaust gas of usually 700 ° C. or more is generated.

The generated fuel exhaust gas (for example, 800 ° C.) is cooled by exchanging heat in the heat exchanger 13 (for example, 150 ° C.).
° C), the dust is supplied to the dust collector 6, where the dust is removed, and the exhausted gas is discharged out of the system. On the other hand, water (for example, 30 MPa) supplied from the water supply tank 18 (for example, normal temperature, 15 ° C.) and pressurized by the high-pressure pump 29 is heated in the heat exchanger 13 which is a supercritical water generator using heat of exhaust gas. Then, supercritical water is generated (for example, at 400 ° C.) and supplied to the dust reaction container 27 or the ash reaction container 28 to which the collected dust and incinerated ash are supplied.

In the reaction vessel (27 or 28), harmful substances such as dioxin adhering to the incineration ash 5 and the dust 16 are decomposed and converted into harmless gases. Compared to treating dust and ash by heat treatment, etc., it can contact the inside with supercritical water in a short time using the high permeability of supercritical water,
Dust or ash can be easily purified in a short time.

As described above, by installing the heat exchanger 13 in the exhaust gas passage, the temperature of the exhaust gas can be reduced by using water for generating supercritical water. Preferably, the flue gas is
By lowering the temperature to 0 ° C. or lower, the resynthesis of dioxin can be suppressed, and the dioxin concentration in exhaust gas can be further reduced.

Thus, the temperature of the exhaust gas is reduced to suppress the resynthesis of dioxin in the exhaust gas to reduce the concentration of dioxin in the exhaust gas, and the heat generated from the incinerator is effectively used to efficiently use the supercritical water. Produced and appropriately generated supercritical water can be supplied to ash and dust to decompose dioxin in the ash and dust.

Further, it is preferable that the generated exhaust gas is cooled by the heat exchanger 13 and supplied to the dust collector 6. By cooling the exhaust gas to make dioxin easily adhere to the dust surface and lowering it to a temperature not lower than the dew point temperature (for example, 150 ° C. to 250 ° C., more preferably around 150 ° C.), harmful substances such as dioxin are removed. Dust collected by the dust collector 6 can collect more dust and dust, thereby further reducing the emission of harmful substances.

The heat exchanger 13 is provided downstream of the exhaust gas flow path and is supplied with water pressurized by the high-pressure pump 29. The heat exchanger 13 is provided upstream of the heat exchanger 13b for heat exchange. It is preferable to dispose a heat exchanger 13a to which water heated by the vessel 13b is supplied.

For example, it is heated by the heat exchanger 13b (35
(0 ° C.) and further heat (400 ° C.) in the heat exchanger 13a to generate supercritical water.

The supercritical water supplied through the heat exchanger 13a is supplied to the dust reactor 27 or the ash reactor 28.

At this time, in the heat exchanger 13a in the in-furnace combustion part, the upper limit temperature of the regenerating region of dioxin is about 600 ° C. so as not to hinder the decomposition of dioxin by combustion.
It is preferred not to lower it. The flue gas generated in the combustion section is cooled to a desired temperature of 600 ° C. or higher (for example, 600 ° C. to 700 ° C.). It is preferable to rapidly cool from a desired temperature of 600 ° C. or higher to about 150 ° C. in the heat exchanger 13b downstream of the in-furnace combustion section (for example, 150 ° C. to 250 ° C.). Thereby, 600 ° C. to 2
The dioxin can be prevented from being regenerated by passing the dioxin regenerating region at about 50 ° C. in a short time.

After being heated in the heat exchanger 13b, the pressure may be further increased by a pressure pump and supplied to the heat exchanger 13a.

In this case, in the high-pressure pump 29, the pressure is once increased to a pressure lower than the pressure in the supercritical state, heated in the heat exchanger 13a to a temperature lower than the temperature in the supercritical state, and Pressure to the heat exchanger 1
Heat at 3b to produce supercritical water.

As described above, according to this embodiment, it is possible to comprehensively decompose harmful substances into water, carbon dioxide and inorganic substances, and to provide an environmentally friendly and low-cost simple waste disposal system.

A second embodiment will be described with reference to FIGS.

The second embodiment can basically have the same structure as the structure shown in FIG. The branch to the pipe 30 and the pipes 21 and 20 is configured as shown in FIG. Supercritical water is passed from heat exchanger 13 via line 30 to lines 21 and 20.
A storage tank 25 for temporarily storing the supercritical water supplied from the pipeline 30 is provided near a branch point where the supercritical water is branched into the dust reaction vessel 27 or the ash reaction vessel 28. In addition, pressure reducing valve 26
It is preferable to provide Supercritical water is supplied from a storage tank 25 to a dust reaction vessel 27 or an ash reaction vessel 28.

Even if the temperature of the supercritical water generated due to the change in the calorific value of the waste 1 fluctuates, the temperature of the supercritical water is supplied to the storage tank 25 and averaged. 27 or an ash reaction vessel 28. As described above, since the device operates as a supercritical water temperature fluctuation suppressing device, it is possible to suppress a change in reactivity due to a temperature fluctuation of the supercritical water and a change in a reaction path of a reaction component in dust and ash, thereby achieving a desired reaction. It is easier to obtain the product. Therefore,
Storage tank 2 against fluctuations in the amount of waste and heat generation in incinerator 2
5, the fluctuation can be absorbed and the supercritical water can be stably supplied. Further, since it is not necessary to raise the supercritical water generation temperature in consideration of the fluctuation, it is possible to generate a larger amount of low-temperature supercritical water.

Even when supercritical water is intermittently supplied to the dust reaction vessel 27 or the ash reaction vessel 28, water is continuously supplied from the high-pressure pump 29 to generate supercritical water. Supply of supercritical water to the dust reactor 27 or the ash reactor 28
The pressure fluctuation of the supercritical water in the pipe due to the switching of the stop is suppressed from directly affecting the heat exchanger 13 and the like. In this way, the intermittent use of the supercritical water in the dust container 27 and the ash reaction container 28 is buffered so that the heat exchangers 13a and 13b are not subjected to fluctuations in the temperature and the flow rate, and a smooth operation is performed. Can drive.

The pressure in the storage tank 25 is measured, and when the pressure exceeds a predetermined pressure, the pressure reducing valve 26 is opened to discharge the supercritical water out of the system. If the flow rate and temperature fluctuation exceed certain limits, the pressure can be reduced through the pressure reducing valve 26 so that the surplus can be released without adversely affecting the outside, thereby protecting the supercritical water production and supply system. When the supercritical water is supplied to the dust reaction vessel 27 or the ash reaction vessel 28, the pressure reducing valve 26 is closed, and when the supercritical water is not supplied to the dust reaction vessel 27 or the ash reaction vessel 28, the pressure reducing valve 26 is opened and the supercritical water is opened. It can be operated to discharge water out of the system.

As a result, a smooth operation can be performed irrespective of temperature and flow rate fluctuations. Further, the supercritical water can be smoothly supplied to the dust reaction vessel 27 or the ash reaction vessel 28 while efficiently reducing the exhaust gas temperature in the heat exchanger 13 which is a supercritical water generation device.

The configuration shown in FIG. 2 is not limited to the configuration shown in FIG. 1, and the storage tank 25 or the pressure reducing valve 26 shown in FIG. Can be installed.

A third embodiment will be described with reference to FIGS.

The second embodiment can basically have the same structure as the structure shown in FIG. The dust reaction container 27 or the ash reaction container 28 is configured as shown in FIG. A plurality of dust reaction containers 27 or ash reaction containers 28 are arranged in parallel. In this figure, the dust reaction container 27 is shown as a representative.
Although the description is omitted, the same configuration can be adopted for the ash reaction container 28.

When the production of supercritical water is performed continuously, it is possible to suppress the occurrence of a discrepancy at the interface with the dust reaction vessel 27 or the ash reaction vessel 28, thereby reducing the efficiency.
By operating a plurality of dust reaction containers 27 in parallel and shifting the phases, the operation can be made close to continuous operation and the efficiency can be maintained.

A plurality of the dust reaction vessels 27 are arranged in parallel. The lower house road, which supplies dust and supercritical water to each reactor, is in communication. Each of the dust reaction containers has a dust supply switching valve 1 for controlling the supply of the dust 16.
9, a supercritical water switching valve 22 for controlling the supply of supercritical water, a gas discharge valve 23 for discharging gas and steam after decomposition, and a discharge valve 24 for discharging solid and liquid after decomposition. FIG. 3 shows a case in which three containers 27 are arranged in parallel, and they are designated as 27a, 27b, and 27c, respectively. In the dust reaction vessel, the process of introducing dust to close dust 22 and 24 and open dust 19 and 23 to introduce dust 16 and then to dust 19, 23 and 24
Has a step of closing and opening the 22 and introducing the supercritical water 21, and then a step of closing 19 and 22 and opening 23 and 24 to discharge the decomposition products. In the process of introducing supercritical water, the valve 22 is gradually opened. The ratio between water and dust is adjusted according to the processing capacity of the equipment (for example, the volume of supercritical water: dust is set to about 10: 1). The above three steps are sequentially repeated for three containers (27a, 27b, 27c). When there are more than three dust reaction containers and the like, for example, a plurality of containers perform one of the above steps. For example,
The process of introducing dust at 27a, the process of introducing supercritical water at 27b, the process of discharging at 27c are performed, and then the process of supplying supercritical water at 27a, the process of discharging at 27b, 27
The steps of introducing the next dust at c are sequentially performed.

In this way, since the treatment can be performed continuously, the supercritical water is not wasted, the treatment amount can be treated in a nearly continuous state, the operation can be performed efficiently, and the pressurized water supply to the supercritical water generator can be performed. Can be stably supplied, the exhaust gas can be cooled stably, and the dioxin regeneration of the exhaust gas can be stably suppressed.

The configuration shown in FIG. 3 is not limited to the configuration shown in FIG. 1. A plurality of the dust reaction vessels 27 shown in FIG. Can be installed.

A fourth embodiment will be described with reference to FIG.

Basically, it is the same as FIG. 1, but in FIG. 4, the heat exchanger 14 which is supplied with water pressurized by the high pressure pump 29 and generates supercritical water is connected between the incinerator 2 and the dust collector 6. It was installed in the exhaust gas channel between the two.

In this figure, the water heated by the heat exchanger 14 is further supplied to the heat exchanger 13 (the heat exchanger 13b to which water is supplied from the heat exchanger 14 and the water heated by the heat exchanger 13b. Heat exchanger 13a), and generates supercritical water in the heat exchanger 13 (heat exchanger 13a).
Through the pipe 21 or the pipe 20 to the dust reaction vessel 27
Alternatively, it is supplied to the ash reaction container 28. In addition, heat exchanger 1
A bypass path connecting the water supplied to the heat exchanger 4 and the water supplied to the heat exchanger 13b and a bypass valve 60 for controlling a bypass flow rate are set. Water supply tank 18 (for example, room temperature 15
° C) and water (for example, 30 MPa) pressurized by the high-pressure pump 29 is supplied from the heat exchanger 14 to the heat exchanger 13b, where it is heated (for example, 350 ° C).
The superheated water can be supplied to the heat exchanger 13a and heated (for example, 400 ° C.) to generate supercritical water. In this case, the water pressurized by the high-pressure pump is heated once in the heat exchanger 14, further heated in the heat exchanger 13b, supplied to the heat exchanger 13a and heated to generate supercritical water. Adjust the heating temperature in each heat exchanger.

However, if necessary, supercritical water is generated in the heat exchanger 14, the generated supercritical water is directly supplied to the pipe 30, and the dust reaction vessel 27 or You may comprise so that it may supply to the ash reaction container 28. In such a case, the heat exchanger 14 heats pressurized water supplied from the high-pressure pump 29 to generate supercritical water. The generated supercritical water is supplied to the pipe 30 and the pipe 2
The gas is supplied to the dust reaction vessel 27 or the ash reaction vessel 28 through the pipe 1 or the pipe 20. If the heat exchanger 14 does not sufficiently cool the exhaust gas temperature, a heat recovery boiler may be installed at the same position to supply water to generate steam and supply the steam to the steam-using equipment.

As described above, the heat exchanger 1 is provided downstream of the incinerator 2.
4, the temperature of the exhaust gas can be reduced by using water that generates supercritical water. Preferably, the combustion exhaust gas is lowered to 250 ° C. or less, and the resynthesis of dioxin is suppressed to further reduce the dioxin concentration in the exhaust gas.

As a result, the temperature of the exhaust gas is reduced, the resynthesis of dioxin in the exhaust gas is suppressed, the concentration of dioxin in the exhaust gas is reduced, and the supercritical water is efficiently used by effectively utilizing the heat generated from the incinerator. Produced and appropriately generated supercritical water can be supplied to ash and dust to decompose dioxin in the ash and dust.

It is preferable that the generated exhaust gas is cooled by the heat exchanger 14 and supplied to the dust collector 6 installed downstream. By cooling the exhaust gas to make the dioxin easily adhere to the dust surface and lowering it to a temperature not lower than the dew point temperature (for example, 150 ° C. to 250 ° C.,
More preferably, around 150 ° C.), the dust to which a large amount of harmful substances such as dioxin is attached is collected by the dust collector 6, and the amount of harmful substances discharged can be further reduced.

Further, as in the present embodiment, the heat exchanger 14 is installed outside the furnace to facilitate maintenance and the like.

When the heat exchanger 13 is further provided, for example, the temperature of the exhaust gas supplied to the heat exchanger 14 by the heat exchanger 13b is lowered to 300 ° C. or less, preferably about 250 ° C. By reducing the reactivity of the reactive component, the influence of corrosion of the heat exchanger 14 and the like can be suppressed.

Further, the temperature of the exhaust gas after the heat exchangers 13a and 13b is set at about 250 ° C., and the temperature of the exhaust gas 4 after the heat exchanger 14 is set at about 150 ° C., so that the dioxin regeneration temperature and the dust collector inlet temperature become water. Even when the amount of heat and the amount of heat generated by the bypass valve 60 change and the temperature of each part changes, the temperature can be adjusted by changing the bypass amount passing through the valve 60.
Dioxin in exhaust gas can be made more harmless.

A fifth embodiment will be described with reference to FIG.

Basically, it is the same as FIG. 1, but in FIG. 5, a heat exchanger 14 which is supplied with water pressurized by a high-pressure pump 29 and generates supercritical water is connected to an exhaust gas passage downstream of the dust collector 6. It was installed in.

The heat exchanger 14 is a heat exchanger 13 of the incinerator 2
(From the heat exchanger 14 to the heat exchanger 13b,
The heat exchanger 13b is connected to the heat exchanger 13a), the heat exchanger 1
3 (heat exchanger 13a) to the line 30 and the line 21
Alternatively, it is connected to the dust reaction container 27 or the ash reaction container 28 via the pipe line 20.

The water (eg, 30 ° C.) supplied from the water supply tank 18 (eg, normal temperature 15 ° C.) and pressurized by the high pressure pump 29
MPa) is heated in the heat exchanger 14 (for example, 90 ° C.)
Supercritical water (for example, 400 ° C.) is generated in the heat exchanger 13 to which the heated water is supplied (for example, water from the heat exchanger 14 is heated by the heat exchanger 13b (for example, 350 ° C.), and heat exchange is performed). Is supplied from the heat exchanger 13b to the heat exchanger 13a to generate supercritical water). The generated supercritical water is supplied to the pipes 30 and 21.
Reaction vessel 27 or ash reaction vessel 2
8 is supplied. In this drawing, the heat exchanger 14 communicates with the heat exchanger 13, but communicates with another heating device to connect the line 3.
0 may be contacted. Further, if supercritical water can be generated by the heat exchanger 14, the supercritical water may be directly connected to the pipeline 30.

By installing the heat exchanger 14 downstream of the dust collector 6, exhaust gas from which corrosive components have been removed by the dust collector is supplied to the heat exchanger 14, so that corrosion of the heat exchanger 14 is suppressed and the soundness of the equipment is improved. While maintaining the properties, it is possible to efficiently generate supercritical water to remove components such as dust and dioxin in ash.

In addition, if the temperature of the exhaust gas discharged from the dust collector 6 is adjusted so that the temperature of the exhaust gas falls below the dew point, the moisture in the exhaust gas can be condensed and the water-soluble components in the exhaust gas can be collected and removed. This can prevent the formation of white smoke due to the generation of condensed water droplets when exhaust gas is discharged from the chimney.

A sixth embodiment will be described with reference to FIG.

FIG. 6 includes an incinerator 2 and a combustor 11 for supplying exhaust gas and fuel generated in the incinerator 2.

Specifically, an incinerator 2 for incinerating the waste 1, a dust collector 6 for removing dust in the exhaust gas 4 from the incinerator 2, a fuel 7 such as oil or LNG, a reformed steam 32, air and the like. A reformer 9 to which an oxidizing agent 8 is supplied to reform the fuel 7 into a fuel containing hydrogen, a combustor to which a reformed gas 10 is supplied from the reformer 9 and an exhaust gas 17 from the dust collector 6 is supplied and burned. 1
1, a heat exchanger (exhaust heat recovery device) 15 for lowering the temperature of the combustion exhaust gas 12 of the combustor 11 is provided. The exhaust gas that has passed through the heat exchanger 15 is then discharged out of the system. A water supply tank 18 for supplying water, a high-pressure pump 29 for increasing the pressure of water supplied from the water supply tank 18, and a heat exchanger 15 for supplying water heated by the high-pressure pump 29 and heating it to generate supercritical water
Having. The supercritical water generated by the heat exchanger 15 is introduced, and the dust 16 collected from the dust collector 6 is introduced to introduce the dust 1
6. A dust reaction vessel 27 for decomposing harmful substances in 6 and supercritical water generated in the heat exchanger 15 are introduced, and ash 5 recovered from the incinerator 2 is introduced to decompose harmful substances in ash. It has a container 28.

In this embodiment, an example is shown in which the reformer 9 for producing the fuel (reformed gas 10) to be supplied to the combustor 11 is installed. However, the apparatus is simplified, and the exhaust gas 17 is supplied. The oxidizer such as fuel and air may be supplied to the combustor 11.

The waste 1 is burned in the incinerator 2 to generate combustion exhaust gas 4 containing dust and incineration ash 5. The combustion exhaust gas 4 containing dust enters the dust collector 6, and then enters the combustor 11 after the dust is removed. At least 700 ° C. or higher with fuel in the combustor 11 to which the exhaust gas 17 is supplied
(For example, 700 to 1200 ° C .; for example, 850 ° C.), and the flue gas 12 is heat-exchanged in the heat exchanger 15 to be cooled (for example, 200 ° C.) and discharged outside the system. On the other hand, water supplied from the water supply tank 18 (for example, at room temperature
℃) is increased by a high pressure pump 29 (for example, 30MP
a) It is supplied to the heat exchanger 15 which is a supercritical water generator and is heated (for example, 400 ° C.) to generate supercritical water. The supercritical water generated by the heat exchanger 15 is supplied to the dust reaction vessel 27 or the ash reaction vessel 28 from the pipe 21 or the pipe 20 via the pipe 30 to decompose and purify dioxins and the like in the dust or ash. .

As described above, in the combustor 11, the exhaust gas from the incinerator 2 is burned at a high temperature (for example, 850 ° C.), and harmful substances in the exhaust gas such as dioxin are decomposed and made harmless.
It is possible to efficiently decompose components such as dioxin in dust and ash while easily decomposing components such as dioxin in exhaust gas with a simple configuration.

At this time, by providing the reformer 9, the fuel 7 is reformed into the fuel 10 containing hydrogen by the reforming steam 32 and the oxidant 8 by the reformer 9 and supplied. Then
By using easily available fuel, it is possible to easily combust the exhaust gas 17 having a low oxygen concentration, which is difficult to burn, and to suppress generation of nitrogen oxides generated by high-temperature combustion.

Further, by installing the combustor 11 or the heat exchanger 15 downstream of the dust collector 6, the exhaust gas from which the corrosive components in the exhaust gas have been removed can be discharged from the combustor 11 or the heat exchanger 15.
Therefore, the degree of freedom in setting the temperature in the combustor 11 or the heat exchanger 15 can be increased. In the combustor 11, it is possible to burn to a high temperature of 700 ° C. or more while ensuring the soundness of the constituent members. In addition, heat exchanger 1
In No. 5, it is possible to set so that the temperature of the supplied exhaust gas is increased and high heat recovery is performed while maintaining the soundness of the constituent members. Therefore, highly efficient operation can be performed while maintaining the soundness of the plant.

As described above, the temperature of the exhaust gas can be reduced by using the water that generates the supercritical water. Preferably, the combustion exhaust gas is lowered to 250 ° C. or less, and the resynthesis of dioxin is suppressed to further reduce the dioxin concentration in the exhaust gas.

As a result, the temperature of the exhaust gas is reduced, the resynthesis of dioxin in the exhaust gas is suppressed, the concentration of dioxin in the exhaust gas is reduced, and the supercritical water is efficiently used by effectively utilizing the heat generated from the incinerator. Produced and appropriately generated supercritical water can be supplied to ash and dust to decompose dioxin in the ash and dust. Therefore, the harmful substances in the ash, dust and gas from the incinerator can be efficiently decomposed by heat and water, so that an environmentally friendly waste treatment system can be provided.

The heat exchanger 15 may be provided with an exhaust heat recovery boiler. Water is supplied to the exhaust heat recovery boiler to generate steam, and the generated steam is supplied to a steam-using device such as a steam turbine. This makes it possible to provide a highly efficient system for the entire plant.

A seventh embodiment will be described with reference to FIG.

FIG. 7 is basically the same as FIG. 6, except that water pressurized by the high-pressure pump 29 is supplied to the heat exchanger 1
4 was installed in the exhaust gas channel between the incinerator 2 and the dust collector 6.

In this figure, the water heated by the heat exchanger 14 is further cooled by the heat exchanger 13 (the heat exchanger 13b supplied with water from the heat exchanger 14 and the water heated by the heat exchanger 13b (for example, 350 mm). C) is supplied to the heat exchanger 13a), and supercritical water (for example, 400 ° C.) is generated in the heat exchanger 13 (heat exchanger 13a).
1 or the pipe 20 is supplied to the dust reaction vessel 27 or the ash reaction vessel 28. Further, a bypass path connecting the water supplied to the heat exchanger 14 and the water supplied to the heat exchanger 13b and a bypass valve 60 for controlling a bypass flow rate are set. The exhaust gas is cooled through the heat exchanger 13 (for example, 3
(00 ° C. or 250 ° C.), supplied to the heat exchanger 14 and further cooled (for example, 150 ° C.), introduced into the dust collector 6 to purify the exhaust gas, and then guided to the combustor 11.

However, if necessary, supercritical water is generated in the heat exchanger 14, the generated supercritical water is directly supplied to the pipe 30, and the dust reaction vessel 27 or You may comprise so that it may supply to the ash reaction container 28.

Thus, the same effect as in the sixth embodiment can be obtained.

Incidentally, an exhaust heat recovery boiler may also be installed in the exhaust gas flow path downstream of the combustor 11. Water is supplied to the exhaust heat recovery boiler to generate steam, and the generated steam is supplied to a steam-using device such as a steam turbine. This makes it possible to provide a highly efficient system for the entire plant.

In this embodiment, an example is shown in which the reformer 9 for producing the fuel (reformed gas 10) to be supplied to the combustor 11 is installed. It may be configured to supply the oxidant such as fuel and air to the supplied combustor 11. An eighth embodiment will be described with reference to FIG. In FIG. 8, a combustion melting furnace or a gasification melting furnace is used.

The waste 1 is supplied and pyrolyzed (for example, at 450 ° C.) in a state where the oxygen concentration is low, and a pyrolyzer 50 for generating solids, liquids and gases, and a solid from the pyrolyzer 50 are supplied and carbonized. And a classifier 52 that separates the gas and the liquid, a fluid from the pyrolysis device 50 is supplied, and a gas-liquid separator 51 that separates into gas and liquid, and carbon from the classifier 52 and fluid from the gas-liquid separator 51 are supplied. Then, the air 57 is used as an oxidizing agent and burned, and the temperature is raised (for example, 1300 ° C.). The combustion smelting furnace 55 that melts the dust contained in the supply fluid and generated by combustion is recovered. Exhaust gas from the cooling water tank 58 and the combustion and melting furnace 55 to be stored is supplied, and the heat thereof is used to heat a heating medium such as air that heats the pyrolysis device 50 and the high-temperature heat exchanger 54 and the incineration and melting furnace 55. Exit The heat exchanger 56 and the heat exchanger 54 are located between the heat exchanger 56 and recover heat from the exhaust gas of the melting furnace 55 to lower the temperature of the exhaust gas and heat the feed water from the high-pressure pump 26 to supercritical water. The exhaust gas that has passed through the dust collector 6 that collects dust in the exhaust gas is discharged to the outside of the system. The high-pressure pump 29 that heats the water supplied from the water supply tank 18, and the water pressurized by the high-pressure pump 29 is guided to the heat exchanger 56, where the supercritical water is generated. A dust reaction container 27 is provided to which the supercritical water generated by the heat exchanger 56 is supplied via the pipe 30 and to which the dust 7 collected from the dust collector 6 is supplied.

The waste 1 is supplied to the thermal decomposition apparatus 50, and heat is exchanged by the high-temperature heat exchanger 54 using the temperature of the exhaust gas of the melting furnace 55 of about 1300 ° C., and the heated air is led to the thermal decomposition. Heat the device 50 from the outside and 450 ° C inside
As described above, the waste is decomposed to obtain a solid and a fluid. The solid is guided to a classifier 52 and separated into incombustibles and carbon. The fluid is guided to the gas-liquid separator 51 and is separated into gas and fluid. Excluding incombustibles, the mixture is supplied to the melting furnace 55 and burned at a high temperature of 1300 ° C. or more to burn and melt refuse to decompose dioxin and obtain slag and exhaust gas. The heat of the exhaust gas is recovered by the heat exchanger 56 and recovered and cooled by the high-temperature heat exchanger 54 (for example, the exhaust gas is cooled to 850 ° C. at the outlet of the heat exchanger 56 and to 150 ° C. at the outlet of the high-temperature heat exchanger 54). The dust in the exhaust gas is removed by the dust collector 6 and discharged. If necessary, an exhaust heat recovery boiler that generates steam using exhaust gas as a heat source may be installed, and the generated steam may be supplied and used for a steam engine such as a steam turbine. This collected dust 16
Is supplied to the dust reaction container 27.

On the other hand, water (for example, normal temperature 15 ° C.) supplied from the water supply tank 18 is pressurized by a high-pressure pump 29,
The pressurized water is supplied to the heat exchanger 56 and heated (for example, 400 ° C.) to produce supercritical water. This supercritical water is introduced into the dust reaction container 27. In the dust reaction container 27, harmful substances in the dust are decomposed by the high-speed decomposability of supercritical water. Thereby, supercritical water can be economically produced, and the temperature and cost of the high-temperature heat exchanger can be reduced.

At this time, since the heat exchanger 56 is installed on the upstream side of the high-temperature heat exchanger 54, the temperature of the exhaust gas supplied to the high-temperature heat exchanger 54 is adjusted by using water for generating supercritical water. Can be reduced. For example, in a liquid / gas heat exchanger for producing supercritical water, the heat exchanger 56 heats 1300 ° C. to 85 ° C.
The temperature is lowered to about 0 ° C., so that it enters the high-temperature heat exchanger 54 at about 850 ° C. Therefore, the burden on the material structure of the high-temperature heat exchanger 54, which is a gas-gas heat exchanger, can be reduced.
In addition, the temperature can be reduced to 850 ° C. or less, which is the limit that can be made with a normal steel plate, and cost reduction can be achieved.

The ninth embodiment will be described with reference to FIG.

9 is basically the same as FIG. 8, except that water pressurized by the high-pressure pump 29 is supplied in FIG.
6 was set in an exhaust gas passage while the exhaust gas discharged from the incineration melting furnace 55 reached the dust collector 6.

The heat exchanger 56 pressurized by the high-pressure pump 29
Supercritical water generated in step 2 is supplied with dust.
And the components such as dioxin in the dust are decomposed.

As described above, the heat exchanger 56 is installed downstream of the incineration melting furnace 55 (downstream of the high-temperature heat exchanger 54 if it is provided), and water for generating supercritical water is used. The temperature of the exhaust gas. Preferably, the combustion exhaust gas is lowered to 250 ° C. or less, and the resynthesis of dioxin is suppressed to further reduce the dioxin concentration in the exhaust gas.

For example, the exhaust gas at 1300 ° C. is cooled to 900 ° C. through the high-temperature heat exchanger 54,
To about 150 ° C.

As a result, the temperature of the exhaust gas is reduced to suppress the resynthesis of dioxin in the exhaust gas, thereby reducing the concentration of dioxin in the exhaust gas, and efficiently utilizing the heat generated from the incinerator to efficiently use the supercritical water. Produced and appropriately generated supercritical water can be supplied to ash and dust to decompose dioxin in the ash and dust.

It is preferable that the generated exhaust gas is cooled by the heat exchanger 56 and then supplied to the dust collector 6. By cooling the exhaust gas to make dioxin easy to adhere to the dust surface and lowering it to a temperature not lower than the dew point temperature (for example, 150 ° C. to 250 ° C., more preferably around 150 ° C.), harmful substances such as dioxin are removed. Dust collected by the dust collector 6 can collect more dust and dust, thereby further reducing the emission of harmful substances.

Further, installation and maintenance can be facilitated by installing the apparatus outside the melting furnace 55. This has the effect of being applicable to existing furnaces. Further, an exhaust heat recovery boiler that generates steam by using exhaust gas as a heat source can be further provided at the heat exchanger 56.

The tenth embodiment will be described with reference to FIG.

Basically, it is the same as FIG.
In the first embodiment, a heat exchanger 61 for supplying water pressurized by a high-pressure pump 29 to generate supercritical water is provided in an exhaust gas flow path downstream of the dust collector 6.

The heat exchanger 61 is provided between the incineration melting furnace 55 (high-temperature heat exchanger 54) and the dust collector 6.
0, the heat exchanger 160 communicates with the pipe 30, and the pipe 21 communicates with the dust reaction vessel 27. The water pressurized by the high-pressure pump 29 is heated by the heat exchanger 60, and supercritical water is generated by the heat exchanger 61 to which the heated water is supplied. The generated supercritical water is supplied to the dust reaction container 27 via the pipes 30 and 21.

For example, the exhaust gas at 1300 ° C. is cooled to 900 ° C. by the high-temperature heat exchanger 54, cooled to 150 ° C. by the heat exchanger 60, and discharged out of the system at 79 ° C. by the heat exchanger 61 through the dust collector 6. I do. On the other hand, the supply water at normal temperature (15 ° C.) is pressurized, heated in the heat exchanger 61, and further heated in the heat exchanger 60 to become supercritical water (400 ° C.).
To supply.

In this figure, the heat exchanger 61 is connected to the heat exchanger 60
, But may be communicated to the conduit 30 by communicating with another heating device. Further, if supercritical water can be generated by the heat exchanger 61, the supercritical water may be directly connected to the pipeline 30.

By installing the heat exchanger 61 on the downstream side of the dust collector 6, the exhaust gas from which the corrosive components have been removed by the dust collector is supplied to the heat exchanger 61, so that the corrosion of the heat exchanger 61 is suppressed, and the soundness of the equipment is reduced. While maintaining the properties, it is possible to efficiently generate supercritical water to remove components such as dust and dioxin in ash.

In addition, if the temperature of the exhaust gas discharged from the dust collector 6 is adjusted to a temperature lower than the dew point, the moisture in the exhaust gas can be condensed and the water-soluble components in the exhaust gas can be collected and removed. This can prevent the formation of white smoke due to the generation of condensed water droplets when exhaust gas is discharged from the chimney.
In addition, since it is outside the melting furnace 55, it can be easily attached and maintenance is easy. Furthermore, it can be applied to existing furnaces, and can effectively utilize heat.

An eleventh embodiment will be described with reference to FIG.

Basically, it is the same as FIG.
Uses a simple pyrolysis furnace. Waste input 1
62, a classifier 52 for classifying the crushed waste into incombustibles and fuel, and an incineration and melting where the classified fuel, fuel 63 such as coke, and oxidant 57 such as air are supplied. It has a furnace 65. A heat exchanger 5 for heat-exchanging and cooling the exhaust gas (for example, 1300 ° C.) from the incineration melting furnace 65.
6, the exhaust gas cooled by the heat exchanger 56 (for example, 150
Exhaust gas that has passed through the dust collector 6 and the dust collector 6 is discharged out of the system. The heat exchanger 56 is provided in a path where the exhaust gas discharged from the incineration melting furnace 65 reaches the dust collector. The supercritical water (400 ° C.) pressurized by the high-pressure pump 29 and generated by the heat exchanger 56 is supplied to the dust reaction container 27 to which the dust is supplied, and components such as dioxin in the dust are decomposed.

As a result, basically the same effects as in the embodiment of FIG. 10 can be obtained. Further, since the heat supplied to the high-temperature heat exchanger 54 is unnecessary, the heat of the exhaust gas from the incineration melting furnace 65 can be sufficiently recovered, and a large amount of supercritical water can be generated. On the other hand, an exhaust heat recovery boiler that generates steam using the exhaust gas as a heat source can also be installed in the heat exchanger 56. By configuring so that the steam generated in the exhaust heat recovery boiler is supplied to a steam utilization device such as a steam turbine, a highly efficient operation can be performed as a whole.

[0109]

According to the present invention, it is possible to provide a waste treatment system capable of efficiently producing supercritical water and appropriately treating the ash and dust generated by supplying the supercritical water.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing one embodiment of the present invention.

FIG. 2 is a schematic diagram showing one embodiment of the present invention.

FIG. 3 is a schematic diagram showing one embodiment of the present invention.

FIG. 4 is a schematic diagram showing one embodiment of the present invention.

FIG. 5 is a schematic diagram showing one embodiment of the present invention.

FIG. 6 is a schematic diagram showing one embodiment of the present invention.

FIG. 7 is a schematic diagram showing one embodiment of the present invention.

FIG. 8 is a schematic diagram showing one embodiment of the present invention.

FIG. 9 is a schematic diagram showing one embodiment of the present invention.

FIG. 10 is a schematic diagram showing one embodiment of the present invention.

FIG. 11 is a schematic diagram showing one embodiment of the present invention.

[Explanation of symbols]

1 ... waste, 2 ... incinerator, 3 ... heater, 4 ... exhaust gas, 5
... ash, 6 ... dust remover, 7 ... fuel, 8 ... oxidizer, 9 ... reformer, 10 ... reformed fuel, 11 ... combustor, 12,17 ... exhaust gas, 13,14 ... heat exchanger, 15 ... Exhaust heat recovery unit, 16
... dust, 18 ... water tank, 20, 21, 30 ... pipeline,
27: dust reaction container, 28: ash reaction container, 29: high pressure pump.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F23J 15/00 B09B 3/00 303L F23J 15/00 Z (72) Inventor, etc. Ishimaru, etc. 3-1-1 Sachicho, Hitachi-shi, Ibaraki No. Hitachi, Ltd. Hitachi Plant (72) Inventor Yukio Ishigaki 3-1-1, Sachimachi, Hitachi City, Ibaraki Prefecture Inside Hitachi, Ltd. Hitachi Plant

Claims (10)

[Claims] 1. A waste treatment system provided with an incinerator for supplying and incinerating waste, a water supply tank for supplying water, a booster pump for increasing the pressure of water supplied from the water supply tank, and the booster pump. A supercritical water generator for supplying supercharged water and generating supercritical water using exhaust gas generated from the incinerator as a heat source, and supplying incineration ash of the incinerator or dust in the exhaust gas to generate the supercritical water. A decomposing device to which supercritical water is supplied and decomposes dioxin in the incinerated ash or dust. 2. A waste treatment system provided with an incinerator for supplying and incinerating waste, comprising: a water supply device; a booster pump for increasing the pressure of water supplied from the water supply device; A supercritical water generator that generates supercritical water using supplied exhaust water generated from the incinerator as a heat source, a storage tank to which the supercritical water generated by the generator is supplied, and incineration ash of the incinerator Alternatively, a waste treatment system comprising: a decomposer that supplies the dust in the exhaust gas and supercritical water from the storage tank to decompose the incinerated ash or dioxin in the dust. 3. A waste treatment system comprising an incinerator for supplying and incinerating waste having a mechanism for discharging supercritical water to the outside of the system in response to operation of the separation device, comprising: a water supply device; and the water supply device. Pump for increasing the pressure of water supplied from an incinerator, a supercritical water generator for supplying supercharged water by the booster pump and generating supercritical water using exhaust gas generated from the incinerator as a heat source, and incineration of the incinerator Ash or dust in the exhaust gas is supplied and the generated supercritical water is supplied, and a decomposer for decomposing dioxin in the incinerated ash or dust; and from the supercritical water generator to the decomposer. A discharge device installed in a path, for guiding the generated supercritical water out of the system; and a control device for controlling an amount of the generated supercritical water to be supplied to the decomposition device and the discharge device. Waste processing system to be. 4. A waste treatment system provided with an incinerator for supplying and incinerating waste, comprising: a water supply device; a booster pump for increasing pressure of water supplied from the water supply device; A supercritical water generating apparatus for generating supercritical water by using feed gas supplied from the exhaust gas generated from the incinerator as a heat source, and supplying incinerator ash from the incinerator or dust in the exhaust gas and generating the supercritical water. A plurality of decomposing devices for decomposing the dioxin in the incinerated ash or dust, and when supplying supercritical water to one separation device, stopping the supply of supercritical water to another separation device; A wastewater treatment system, comprising: a control device that controls supply of supercritical water to another separation device when supply of supercritical water to the device is stopped. 5. The waste treatment system according to claim 1, wherein said supercritical water generator is installed in said incinerator. 6. The waste treatment system according to claim 1, further comprising a dust collecting device for collecting dust in exhaust gas discharged from the incinerator, wherein the supercritical water generating device is connected to the incinerator and the dust collecting device. A waste treatment system which is installed between the apparatus and the apparatus. 7. A waste treatment system comprising: an incinerator to which waste is supplied and incinerated; and a combustion device to which exhaust gas discharged from the incinerator is supplied and fuel is supplied and burned. A water supply tank for supplying water, a booster pump for increasing the supply water supplied from the water supply tank, and a booster pump installed between the incinerator and the combustion device, wherein the supply water pressurized by the pressure increase pump is supplied to the combustion device. A supercritical water generator that generates supercritical water using exhaust gas generated from the heat source, and incineration ash of an incinerator or dust in the exhaust gas is supplied and the generated supercritical water is supplied, and the incineration ash or A waste treatment system, comprising: a decomposition device that decomposes dioxin in dust. 8. A waste treatment system comprising: an incinerator to which waste is supplied and incinerated; and a combustion device to which exhaust gas discharged from the incinerator is supplied and fuel is supplied and burned. A tank, a booster pump that boosts the feedwater supplied from the feedwater tank, and a booster pump that is installed downstream of the combustion device, and is supplied with the feedwater pressurized by the booster pump and uses exhaust gas generated from the combustion device as a heat source. A supercritical water generating apparatus for generating supercritical water, and a decomposing unit for supplying incineration ash from an incinerator or dust in the exhaust gas and supplying the generated supercritical water to decompose dioxin in the incineration ash or dust. And a device. 9. A combustion-melting furnace to which waste is supplied and burnt and melted, an air heater for heating air using exhaust gas discharged from the combustion-melting furnace as a heat source, and an air heater heated by the air heater. A waste water treatment system comprising: a water supply tank; a pressure pump for increasing the pressure of water supplied from the water supply tank; A supercritical water generator installed between a high-temperature heater and supplied water pressurized by the booster pump to generate supercritical water using exhaust gas generated from the combustion device as a heat source; and incineration ash of an incinerator or A decomposer for supplying the dust in the exhaust gas and supplying the generated supercritical water to decompose the incinerated ash or dioxin in the dust. Beam. 10. A waste treatment system provided with a combustion melting furnace in which waste is supplied and burned and melted, wherein a dust collecting device for collecting dust in exhaust gas discharged from the combustion melting furnace, and a water supply are supplied. A water supply tank, a booster pump for increasing the pressure of water supplied from the water supply tank, and an exhaust gas discharged from the combustion and melting furnace are installed while reaching the dust collector, and the water supply pressurized by the booster pump is supplied. And a supercritical water generator that generates supercritical water using exhaust gas generated from the combustion device as a heat source, and incinerator ash of an incinerator or dust in the exhaust gas is supplied and the generated supercritical water is supplied. A decomposition apparatus for decomposing the incineration ash or dioxin in the dust.