JPH11114362A - Treatment of discharged gas and soot and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease the cost of facilities, to make operation and maintenance easy and to obtain an excellent removing effect for carcinogenic harmful substances such as dioxin, etc., by bringing a discharged gas or soot produced by combustion into contact with an oxidation-reduction water to decompose and remove a harmful component. SOLUTION: Only an oxidation-reduction water produced from water 11 and a treating agent such as ozone 12 in a generating and supply part 1 is supplied to a contact part 2 and brought into contact with a discharged gas or soot introduced from a generating source. The discharged gas or soot and the oxidation-reduction water are sent to a reaction mixing part 3 to sufficiently decompose the harmful substances such as NOx, SOx and dioxin, etc. The dispersed nitrogen gas, oxygen gas or hydrocarbon gas as the finish gas component 31 is separated and emitted through a filter to the air. The used water 32 of the oxidation-reduction water is mixed in a recovering part 4 with incineration ash from an incineration furnace, and the sludge 41 is separated. The used water 42 is circulated to a water tank 11 and reused. Thus, harmful substances in a discharged gas and soot can be effectively decomposed and removed with the small cost of facilities and easy operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The invention of this application relates to exhaust gas
The present invention relates to a method for treating soot and a treatment apparatus therefor. More specifically, the invention of this application treats exhaust gas and soot generated from garbage and waste incinerators or equipment such as factories, and decomposes and removes harmful substances such as NO _x , SO _x , and dioxin. The present invention relates to a new method for treating exhaust gas and soot and a device therefor which are useful for environmental support.

[0002]

BACKGROUND OF and THE INVENTION Conventionally, in combustion facilities and incineration equipment in a factory or the like, NO _x, and the various means for suppressing the dissipation into the air of toxic substances such as SO _x have been implemented Also, in the incineration facilities of refuse and industrial waste, various means for decomposing and removing harmful substances in exhaust gas and soot and smoke have been tried.

[0003] These means are used to decompose harmful substances contained in exhaust gas and fumes. 1) Decomposition by heating to an extremely high temperature, irradiation of actinic rays such as ultraviolet rays, and generation of excited species by plasma. Activating by physical means to decompose harmful substances, such as generating and decomposing; 2) Decomposing harmful substances by applying chemical reaction means such as ozone and other oxidizing agents; Are roughly divided into

However, in the conventional method, N
The effect of removing harmful substances such as O _x and SO _x is not always sufficient, and in particular, there is a problem that it is not very effective in removing carcinogenic harmful substances such as dioxin, which has been a problem in recent years. . In improving each of the above-mentioned means, there is a problem that the physical means of 1) imposes a heavy burden on capital investment, and the operation and maintenance of special means are not easy. Further, in the chemical means of the above 2), it is not always easy to set processing conditions and the like, and there is a problem to be solved above all in terms of how to improve the reaction efficiency.

Therefore, the invention of this application solves the problems of the conventional method and the apparatus therefor as described above, and has a relatively small capital investment burden, easy operation and maintenance,
Moreover, it is an object of the present invention to provide a new method for treating exhaust gas and soot and an apparatus therefor which are excellent in removing carcinogenic harmful substances such as dioxin.

[0006]

Means for Solving the Problems The object of the present invention is to solve the above-mentioned problem by contacting exhaust gas or soot generated by combustion with redox water to decompose and remove harmful components. The present invention provides a method for treating exhaust gas and soot (claim 1). In this invention, the oxidation-reduction water is a treatment method (claim 2) in which the oxidation-reduction water is oxidation water or reduction water or a mixture of both,
A treatment method in which an oxidizing agent or a reducing agent or both are added to water (claim 3), and a treatment method in which redox water is generated by electrolysis of water (claim 4). The contact treatment with redox water also provides aspects such as a method for treating exhaust gas and soot (claim 5), which is performed by flushing, showering, or liquid level contact of redox water.

Further, the present invention provides a processing apparatus for the above-mentioned processing method, comprising: (a) a generation and supply section of redox water; (b) a contact section between redox water and exhaust gas or soot; and (c) a mixing reaction. A treatment device for treating exhaust gas and soot (Claim 6), characterized by comprising a unit, and a treatment device in which the contact unit is provided with a means for flushing redox water (Claim 7). ), And a processing apparatus (Claim 8) in which the mixing reaction section is provided with a flow channel reaction section.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention of this application is characterized by the configuration as described above, and will be further described as follows. First, the source of the exhaust gas and the soot and smoke generated by the combustion targeted by the method and the apparatus of the present invention is not particularly limited. Exhaust gas and soot from various sources such as garbage and waste incineration facilities, boilers and other combustion facilities in factories, etc. are targeted. Of these, exhaust gases and soot containing harmful substances such as SO _x and NO _x , organic substances, and carcinogenic harmful substances such as dioxin are the targets.

[0009] The oxidation-reduction water for treating these exhaust gas and soot is used in the present invention as a comprehensive concept, and the meaning is oxidized water or reduced water. Or a mixture of both at an appropriate ratio. The “redox water” is generally considered as activated water in which neutral water is deflected to an acidic side or an alkaline side as a pH value. In the case of mixed water, it can be considered as a mixture of these deflected waters. For such redox water, an oxidizing agent or a reducing agent is added to normal water (neutral) to deflect pH, or water generated by electrolysis, or May be used.

Either oxidized water, reduced water, or a mixture thereof is used depending on the status of harmful substances contained in exhaust gas and smoke. NO _x, when a high content of the inorganic harmful substances SO _x, if when a high content of organic harmful substances, or gas that may have been contaminated by bacteria, the content of harmful substances such as dioxin high It will be used accordingly.

For the production of redox water, for example, ozone can be used. In this case, it is considered as water generated by adding and mixing ozone, active oxygen, and the like obtained by ozone generation into water. More practically, ozone (O ₃ ) generated in an ozonizer (ozone generator), free radical species as various kinds of active oxygen, for example, HO, HO ₂ , etc., and H ₂ O ₂
(Hydrogen peroxide) is considered as redox water in a state of being dissolved in water.

The presence as ozone is, for example, 5000
It will be considered as high-concentration ozone-containing water of ppm or more. Use of hydrogen peroxide is considered, and use of a solid oxidizing agent or reducing agent is also considered. In the case of electrolysis, oxidized water or reduced water generated by a diaphragm decomposition method is used, and furthermore, water that has the above-mentioned ozone or active oxygen added thereto may be characterized.

The present invention will be further described with reference to the drawings. For example, each of the processing apparatuses illustrated in FIG. 1 realizes a processing method using redox water generated by adding ozone and active oxygen to water. Showing things. In this treatment device, a redox water generation / supply unit (1) for mixing water supplied from a water tank (11) with ozone and active oxygen generated in an ozonizer (12) is provided. A first reaction tank and a second reaction tank as a contact part (2) with soot and smoke, a third reaction tank as a reaction mixing part (3), and a fourth reaction tank as a part for recovering redox water (4) And

In the production and supply section (1) of the oxidation-reduction water, a treatment agent such as ozone (12) is introduced together with the water (11) as required. Only the desired redox water (13) is supplied to the contact (2). In the contact part (2), exhaust gas or soot (21) from various sources is introduced and brought into contact with the redox water (13). The contact at this time may be such that exhaust gas / smoke (21) is blown into the supplied redox water (13), or redox water / smoke (21) may be supplied to the supplied exhaust gas / smoke (21). A flash method in which (13) is sprayed may be used. Alternatively, the oxidation-reduction water (13) may be brought into contact with the plate using a plate-flow method or a thin-film flow method. Of these, the flash method is preferred.

The device for the contact will be determined according to these methods. Exhaust gas and soot from the source have a temperature of, for example, about 500 to 800 ° C., but at the contact portion (2), the temperature is 120 ° C. or less, and further 60 ° C.
It is preferable that the temperature is cooled to about 10 ° C. or less. This cooling may be performed by providing the device of the contact portion (2) with a cooling means. In particular, the cooling is preferably performed at 50 ° C. or lower when ozone or active oxygen is contained.

After the contact, the exhaust gas and the soot and the redox water are transferred to the reaction mixing section (3). In the reaction mixing section (3), harmful substances such as NO _x , SO _x and dioxin are sufficiently decomposed. Therefore, for example, in the example of FIG. 1, it is also preferable to separately supply the oxidation-reduction water from the oxidation-reduction water generation / supply unit (10) provided separately from the above.

The reaction mixing section (3) is for further increasing the mutual diffusion contact between the exhaust gas, the soot and the redox properties, and it is practical to provide a baffle plate or a perforated plate, for example. preferable. In the reaction mixing section (3), the dispersed nitrogen gas, oxygen gas, or hydrocarbon gas is separated as a final gas component (31) and is released into the atmosphere through purifying means such as a filter provided as necessary. Will be. These final gas components (31) do not contain any harmful substances except for trace components below the environmental safety standard value.

On the other hand, the agent water (32) of the oxidation-reduction water is
It is led to the recovery section (4) and mixed with the incineration ash from the incinerator to treat it. The sludge (41) is separated from the separator, and the spent water (42) is reused. The water is circulated to the water tank (11). Actual results of processing by the method and apparatus of the present invention will be described below.

The oxidation-reduction water was treated for 3 hours by using oxidation-reduction water of about pH 7 (containing 5000 ppm of ozone) which was generated by charging ozone and active oxygen from an ozone generator into water. The average content of harmful substances in exhaust gas is
Before the treatment, the NO was about 150 ppm and the SO _{2 was} about 50 ppm, but after the treatment, it was confirmed that it was decomposed and removed to about 5 ppm of NO and about ₂ ppm of SO _{2 on} average over the treatment time.

In addition, regarding the decomposition and removal of dioxins, the following calculation method is used. Dioxins in waste treatment Standard measurement and analysis manual (February 1997) As a result of the continuous operation for 4 hours, the concentrations of dioxins in the exhaust gas shown in Table 1 and the exhaust gas shown in Table 1 were extremely remarkably reduced to the exhaust gas concentration shown in Table 2, and the spent redox water ( It was confirmed that the concentration of dioxins in the washing water) was also extremely low as shown in Table 3.

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

[Table 3]

[0024]

As described above in detail, according to the invention of the present application, decomposition and removal of harmful substances in exhaust gas and soot and smoke can be performed very effectively. In addition, the equipment burden is small, the driving operation is easy, and long-term operation can be stably performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of an apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Production supply part 2 Contact part 3 Reaction mixing part 4 Recovery part

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B01D 53/70

Claims (8)

[Claims] 1. A method for treating exhaust gas or soot, comprising subjecting exhaust gas or soot generated by combustion to contact treatment with redox water to decompose and remove harmful components. 2. The method according to claim 1, wherein the redox water is oxidized water, reduced water, or a mixture of both. 3. The treatment method according to claim 1, wherein the oxidation-reduction water is generated by charging the oxidizing agent or the reducing agent or both into water. 4. The treatment method according to claim 1, wherein the oxidation-reduction water is generated by electrolysis of water. 5. A method for treating exhaust gas and soot, wherein the contact treatment with redox water according to any one of claims 1 to 5 is performed by flushing, showering, or liquid level contact of redox water. 6. A processing apparatus for the processing method according to any one of claims 1 to 5, wherein: (a) a generation and supply section of redox water; (b) a contact section between redox water and exhaust gas or soot; and (c) mixing. An exhaust gas and soot treatment device characterized by having a reaction section. 7. The processing apparatus according to claim 6, wherein said contact portion is provided with a means for flushing redox water. 8. The processing apparatus according to claim 6, wherein the mixing reaction section includes a flow pipe reaction section.