JP2002115820A - Method for waste combustion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effect perfect decomposition of a benzene ring, which is believed to constitute recombination of dioxin at the time of waste combustion. SOLUTION: Waste is burned by using water-added fuel obtained by mixing oil with water in a ratio 1 to (2-5). In producing the water-added fuel, waste (waste oil, PCB, etc.), is dissolved or suspended in oil, and the obtained water- added fuel is used in waste combustion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for safely burning waste.

[0002]

2. Description of the Related Art It is important to prevent the generation of dioxins when burning waste. Chemical Engineering 19
According to the April 1998 issue, dioxin is decomposed if it stays at a temperature of 850 ° C. or more for 2 seconds or more in a normal combustion furnace, but in order to prevent re-generation of dioxin when cooling the waste gas, quenching of the waste gas, Cleaning and activated carbon adsorption are required. However, the regulation value of dioxin is becoming stricter year by year, and recently, use of mini-blast furnaces, melting of ash, oxidative decomposition with supercritical water, and the like have been developed. However, if the furnace is heated to a high temperature, the generation of dioxin can be suppressed, but NOX
Increasing costs and increasing costs have become problems.

[0003]

Dioxin is 850.
Decomposes above ℃, but it is problematic to regenerate when the waste gas is cooled. This is because the benzene ring is difficult to burn when burning waste, and it is said that if a little benzene ring remains, dioxin is regenerated by adsorbing a small amount of chlorine in the air. Therefore, if the benzene ring is completely decomposed during combustion, there is no regeneration of dioxin during cooling, and the subject of the present invention is complete decomposition and combustion of the benzene ring.

[0004]

The means of the present invention are as follows. (1) Oil 1: A waste combustion method characterized in that waste is burned using a water-based fuel of 2 to 5 water. (2) Oil 1: A waste combustion method characterized by burning a water-soluble fuel in which a waste is dissolved or suspended in oil when producing a water-fuel with 2 to 5 water.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the case of burning waste, the presence of a benzene ring and chlorine tends to generate dioxins. In recent years, regulations have become stricter, and the problem of 0.1 ng / m ³ or less has become a problem. Even if the waste does not contain chlorine, the presence of a benzene ring will react with chlorine in the air to generate dioxin. Have been. In order to decompose the benzene ring, simply raising the temperature and oxidizing does not result in any decomposition. Decomposition of dioxin requires heating to a temperature of at least 1.100 ° C if at least 850 ° C is possible, but this is a separation of benzene ring and chlorine, which may recombine upon cooling.
The safest way to prevent recombination is to open and oxidize the benzene ring.

Conventionally, a method of adding 5 to 30% of water to petroleum to prevent seizure of carbon and increase combustion efficiency has been used. However, dioxin trace amounts of 1M ³ per 0.1ng (nanograms) The following is a problem, 5-30%
Addition of water is not sufficient. In the present invention, two to two oils are used.
This is an invention utilizing a method of burning a hydrofuel with five times the amount of water. Generally, when 50% or more of water is added to 1 oil, the amount of heat for evaporating the water is extra, and the temperature generally does not rise and gradually disappears.

[0007] However, the inventors have filed Japanese Patent Application No. 11-3744.
0, Japanese Patent Application No. 11-1903032, Japanese Patent Application 2000-284
Using the method of 840, the temperature of the combustion furnace whose outlet is slightly narrowed is heated to 600 ° C. or more by another burner, and water is added to oil 1 to 2 to 5 times and emulsified water spray is sprayed. The energy of the shock wave due to the steam explosion is stored in the combustion furnace, and H ₂ O is decomposed into 2H + O, and is ejected and burned with oil outside the combustion furnace. At this time, the gas ejected is oil + 2H +
Although it becomes O + air, the oil is considered to be in an ultrafine state when the emulsion undergoes steam explosion, decomposed and partially oxidized.

[0008] The gas mixture ejected to the outside of the combustion furnace is oxidized and eventually becomes CO ₂ and H ₂ O. As shown in the analysis values in Table 1, the complete combustion of carbon and the CO ₂ The characteristic is that CO becomes zero. (Hydrofuel has good flammability)

[Table 1] Comparison of heavy fuel oil A and hydrofuel waste gas

The present invention is characterized in that wastes (such as waste oil PCBs) are added to this oil, mixed and emulsified with 2 to 5 times the amount of water and completely burned. 600 ° C to 1.200
Spray emulsified waste (such as waste oil PCB) with 2 to 5 times water in a combustion furnace heated to ° C. This is compared with a conventional fuel oil in which 5 to 30% of water is added (the oil was used as kerosene and the ratio of H ₂ O / C was calculated assuming C ₁₂ H ₂₆ ). 1: water _{5~30% = 0.05~0.3) H 2 O} / C = 0.04~0.24 present invention (oil 1: 2 to 5 times water) H ₂ O / C = 1.57 in ~3.94 H ₂ O / If C comparing the present invention is the amount of H ₂ O in comparison with the conventional method on average 10 times more, H ₂ O whereas C atoms 1.5
Up to 4 times. It is known that carbon and water react at a temperature of 700 ° C. or higher (water gas reaction) to form C + H ₂ O → CO + H ₂ .

When there is a double bond in the fuel, -C = C-
And H ₂ O cause a water-gas-like reaction to destroy the double bond.

Embedded image Reaction of carbon double bond with water When waste (waste oil, PCB, etc.) is mixed in the fuel, the benzene ring contained therein has three double bonds, and if one of them reacts with H ₂ O, the benzene ring opens. Rings and turns into aliphatic.

Embedded image Reaction of benzene ring with water

When H ₂ O acts on all the double bonds, it is converted to acetaldehyde and easily oxidized. Combustion of the hydrofuel is performed by preparing an emulsion of oil 1: water 2 to 5 in advance of 600 to
1. Spray the outlet heated to a temperature of 200 ° C. into a narrowed combustion furnace. The water in the sprayed water is from normal temperature to 60
Rapidly heated to 0 to 1.200 ° C, causing steam explosion. The energy of the steam explosion collides with the wall of the combustion furnace as a shock wave, but since the exit of the combustion furnace is narrow, the energy of this steam explosion is confined in the furnace and the echo of the generated explosion sound is also affected. The steam explosion energy is collected in the gaseous H ₂ O by working, and is decomposed into H ₂ O → 2H + O.

Decomposed 2H + O and oil (partly waste oil or PC
B) is ejected from the narrowed outlet while being gasified, and oxidizes and burns. At this time, if the outlet is widened, the energy of the steam explosion will be dissipated, and the decomposition of H ₂ O → 2H + O will be insufficient, and the fuel will not burn. The gas ejected from the outlet is 2H + O + waste oil or a partially oxidized oil containing PCB + air, which burns outside the outlet of the combustion furnace. H ₂ O → 2H + O →
In this method, the difference between the decomposition energy and the binding energy of H ₂ O is extracted as heat.

According to the laws of thermodynamics, the decomposition energy and the binding energy of water are exactly the same, so that the difference between these energies is zero. However, the combustion furnace whose outlet was narrowed was heated to 600 to 1.200 ° C in advance,
When the fuel is sprayed therein, the energy of the steam explosion is trapped in a combustion furnace having a narrowed outlet, and H ₂ O
The decomposition temperature of water is usually required to be 4.000 ° C. or higher.
Since it decomposes at 200 ° C., there is a difference between the decomposition energy and the binding energy of water.

The present invention is a method of mixing waste oil (waste oil or PCB) with the oil of the hydrofuel and burning it. The benzene ring in the waste undergoes a reaction in the form of H ₂ O → 2H + O → H ₂ O while receiving the energy of steam explosion. . That is, the benzene ring is not just water vapor reaction, other H ⁺ hydrogen atom, an oxygen atom, O ^-, not OH radicals and the like is notwithstanding et plasma reaction undergone explosive energy, destruction of the benzene ring proceeds rapidly.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Waste dissolved in oil (waste oil, PCB, etc.) is oil 1: water 2
Mixed with oil during the production of the hydrofuel. The mixing ratio is usually 20 to 80%, but the ratio is small in the case of non-flammable and may be 100% in the case of combustible waste oil. A surfactant and water are added to the oil to form an emulsion. 1
Is heated to 600 to 1.200 ° C in advance, and spraying the waste-containing hydrofuel causes a steam explosion, causing a shock wave, and the energy is confined because the outlet is narrowed. With the decomposition of H ₂ O → 2H + O, the waste also becomes fine particles in the aftermath of the explosion, and partial oxidation proceeds.

The gas ejected from the outlet of the furnace is 2H + O + fine particles of waste and oil + air, which is a combustion fuel combustion flame 8
Then, it burns in the rotary furnace 6. Since 2H + O is a self-combustible gas, the amount of air may be sufficient to burn waste and oil sufficiently, and may be 1/3 to 1/5 of that of normal oil combustion.
At this time, the temperature of the rotary furnace 6 is 700 to 900 ° C., and the mixture is further introduced into the rotary furnace 9 to complete the reaction. The rotary furnace 9 is a distributor 3 of the secondary water-fuel combustion device 2.
The mixture is sufficiently stirred with the waste gas with the fuel flame 11 dispersed in the above, and the temperature is set to 1.000 to 1.200 ° C. to proceed the reaction. This hydrofuel is oil 1: water 2 to 5, but the rotary furnace 9 is heated without putting waste into the secondary hydrofuel. At this time, the waste that has not been sufficiently burned in the rotary furnace 6 further contains 2H + O → H ₂ O
Decomposes in combustion. In particular, a benzene ring which is not easily burned is decomposed and oxidized in the rotary furnaces 6 and 9 in a water gas-like reaction in an overwhelmingly large amount of H ₂ O.

In this case, not only water vapor but also H ₂ O
The reaction proceeds in an activated form with water in the process of → 2H + O → H ₂ O, so that the decomposition of the benzene ring proceeds. At this time, the solidified ash is discharged from the water-sealed ash discharge port 14. The waste gas is further mixed and oxidized and decomposed in the ceramic packed bed 16 by the tertiary water-fuel combustion device 2a to achieve zero dioxin and zero residual benzene. The waste gas 17 is released through processes such as heat recovery and water washing.

In the case of solid waste, the fuel-burning combustion device 1
, The rotary furnace 6 is preliminarily heated, and the crushed waste is continuously charged from the charging port 4. Although 95 to 99% of dioxins are removed in the rotary furnace 6, the dioxin is further cooled to 1,000 to 1.200 ° C. in the rotary furnace 9 by the secondary flame fuel burner 2 and the combustion flame 11 dispersed by the distributor 3. Heat to completely decompose dioxin. The ash from which dioxin has been removed is carried out through a water-sealed ash outlet 14. Dioxin content is 1 when dioxin contaminated soil is treated
/ 3,000-1 / 10,000. Further, if waste water which is difficult to treat is used as water for adding fuel and the fuel is burned, waste water treatment and calorific value can be obtained at the same time, and cyan waste water, polishing waste water, print substrate manufacturing waste water and the like can be easily treated. Also, if the cooling and washing water of this apparatus is also used as water for the hydrofuel, a closed system is obtained.

[0019]

Industrial Applicability The present invention relates to a method for efficiently removing dioxins and PCBs which has caused pollution. Conventionally, dioxins and PCBs require equipment costs such as a method of decomposing at an extremely high temperature such as a mini blast furnace and an ash melting furnace, and a method of using supercritical water. In the case of a high temperature, another pollution such as NOX is also a problem. Least amount of oil 1 / 2-1 / 3 because it uses hydro fuel in the present invention, also blowing amount of air also becomes still 1 / 2-1 / 3 the oil is small, N ₂ is Since it is small, the amount of NOX also decreases. Further, since the method of the present invention uses H ₂ O for combustion, the benzene ring which has been hardly decomposed by conventional heat and easily decomposes does not have the danger of regenerating dioxin during cooling.

Although this method can be applied to large furnaces, it is suitable for medium and small furnaces, and it is possible to install a water-fuel combustion apparatus in an existing furnace, which is very economical even from the national viewpoint. Invention. Next, the advantages of the present invention will be listed. (1) Dioxin and PCB can be completely separated and burned. (2) The amount of oil used is ２〜 to １ ／, which is a resource saving type. (3) Decompose and burn benzene rings that have been difficult to decompose. (4) NOX, SOX, CO 2 respectively 1 / 2-1 / 3. (5) Existing furnaces can be modified. (6) Contaminated soil can be treated continuously.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of a waste combustion method according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 fueled fuel combustion device 2 secondary fueled fuel combustion device 2a tertiary fueled fuel combustion device 3 distributor 3a distributor 4 waste input port 5 waste 6 rotary furnace 7 refractory material 8 hydrofuel combustion flame 9 rotary furnace 10 refractory material Reference Signs List 11 combustion flame 12 ash 13 water for sealing water 14 ash outlet 15 combustion flame 16 ceramic packed bed 17 waste gas, heat recovery, exit to washing process

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F23G 7/04 603 F23G 7/04 603A

Claims (4)

[Claims] 1. A method for burning waste, comprising burning waste using oil-to-water fuel of 2 to 5 oils. 2. A method for burning waste, characterized in that when producing a water-to-fuel fuel of oil 1: water 2 to 5, water-soluble fuel in which waste is dissolved or suspended in oil is burned. 3. A method for burning waste, characterized in that a hydrofuel using wastewater instead of water is burned when producing a hydrofuel of oil 1 to water 2-5. 4. The method for burning waste according to claim 1, wherein the fuel is additionally combusted secondary or tertiary as needed with an oil 1: water 2 to 5 hydrofuel.