JPH05180423A - Incinerating method for waste - Google Patents

Abstract

PURPOSE:To cleanly burn waste, to prevent the corrosion of a boiler and so on, and to collect highly effective energy by resonably conducting the additional treatment of CaO in each process and conducting the treatment of physicochemical reaction, in the title method wherein the waste such as municipal refuse is thrown into an incinerator through each of the processes and is incinerated. CONSTITUTION:When waste G is incinerated in an incinerator 7 through a crusher 1, a waste-receiving reservoir 3, a secondary crusher 9 as necessary, and a feeder 5, alkaline earth metal oxide most suitable therefor, such as CaO, is added into the crusher 1 and/or the waste-receiving reservoir 3 and is mixed with the waste, and thus the treatment of physicochemical reaction is done. When thrown into the incinerator 7, the waste is cleanly burnt in the incinerator 7 and highly effective energy is recovered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a waste disposal method in which waste such as combustibles discharged from ordinary households or offices is put into an incinerator through a crusher or a waste receiving storage tank to incinerate the waste. Regarding the method of incinerating things.

[0002]

2. Description of the Related Art So-called combustible municipal solid waste (waste), which has been conventionally disposed of in municipal solid waste incineration facilities, has been mixed with various chemical substances in recent years. In the process of disposing of incinerated ash, a secondary environmental pollution problem has occurred, and it has become extremely difficult to deal with it. In particular, against the background of global-scale environmental problems, it is an urgent and important task to develop technology that suppresses the emission of environmental pollutants from exhaust gas from municipal solid waste incinerators and uses combustion energy with high efficiency. Is coming. As the solution, the following two methods have been taken so far.

[0003] First, the pollution control equipment such as an exhaust gas treatment facility provided in an incinerator for municipal solid waste is sophisticated, and the residual heat from the incinerator is recovered by a waste heat boiler, which is effectively used for power generation and steam / hot water. Is the way to do it.

Second, there are various manufacturing methods (referred to as RDF) aiming at converting municipal waste into fuel and replacing it with fossil fuel resources.

[0005]

By the way, of the above-mentioned prior arts, the former has a severe limit in increasing the cost of treating municipal solid waste and effectively utilizing the energy generated from the municipal solid waste. I know that. First, in the combustion of municipal waste, hydrogen chloride (HCL) is produced at a higher concentration than in the case of fossil fuels, which causes corrosion of the boiler and the like, so high-temperature and high-pressure steam is generated,
There is a problem that energy cannot be used with high efficiency.

Next, there is a method in which powder such as calcium hydroxide (Ca (OH) ₂ ) is blown into exhaust gas cooled by a boiler to absorb and remove hydrogen chloride.
There is a problem that the contact between the exhaust gas and the powder is poor and an excessive amount must be blown.

Further, although nitrogen oxide has been suppressed by adjusting combustion conditions such as combustion temperature and oxygen concentration, this method alone is not sufficient.
It has become necessary to add a more aggressive denitration step.

[0008] Further, the latter has been attracting attention as a method capable of solving the problems of the above-mentioned municipal solid waste incinerator, but it is still in the development stage, and it is not possible to fully commercialize it. Not.

The object of the present invention is to improve the above-mentioned problems in an incinerator for municipal solid wastes, by using alkaline earth metal oxides, or viscous minerals having adsorptivity with alkaline metal oxides in wastes such as municipal wastes. By adding a certain amount of it, performing physicochemical treatment to carry out a denitrification reaction, and sending ammonia into the incinerator, a cleaner combustion and a more efficient energy recovery of the waste It is to provide an incineration method.

[0010]

In order to achieve the above object, the first invention is to put waste such as municipal solid waste into a crusher for crushing treatment, and then once to a waste receiving storage tank. When the waste is stored and then put into an incinerator to incinerate the waste, the crusher and / or the waste receiving storage tank contains an alkaline earth metal oxide or a clay mineral having an adsorptivity with the alkaline earth metal oxide. Is added to perform a physicochemical reaction treatment reasonably, and ammonia generated as a result of the reaction in the waste receiving and storing tank is sent to the incinerator. ..

The second aspect of the invention is to throw waste such as municipal waste into the first waste receiving and storing tank, then through the crusher into the second waste receiving and storing tank, and then into the incinerator. And then incinerate the waste, in the first waste receiving storage tank and / or the crusher, alkaline earth metal oxides,
Alternatively, an alkaline earth metal oxide and a viscous mineral having adsorptivity are added to rationally perform a physicochemical reaction treatment, and at least ammonia generated as a result of the reaction in the second waste receiving storage tank is added to the incinerator. It is a method of incinerating waste, characterized in that it is sent to.

[0012]

By adopting the waste incineration method of the present invention, the crusher and / or the waste receiving storage tank before incinerating the waste in the incinerator, or the first waste receiving storage tank, and Alternatively, a physicochemical reaction treatment is reasonably carried out by adding a necessary amount of alkaline earth metal oxide or a clay mineral having an adsorptivity to the alkaline earth metal oxide to the crusher. Ammonia generated as a result of the reaction is sent to an incinerator for denitrification, and the reformed waste is put into the incinerator for more clean combustion, as well as for boilers using acid gas. Corrosion is suppressed and highly efficient energy recovery is performed.

[0013]

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

With reference to FIG. 1, for example, waste G such as dust removed from general households or offices includes combustible materials such as paper, cardboard and fibers, and iron, aluminum, glass, earth, stones, etc. The non-combustible material and the water content contained in the non-combustible material are carried by a carrier such as a truck or a packer truck and put into the crusher 1.

This crusher 1 is, for example, a low-speed rotation type shearing coarse crusher, and since its specific structure is known, a detailed description thereof will be omitted, but it has two or three axes with different rotation speeds. A plurality of blades are provided on the outer circumference of each shaft.

[0016] Then, the thrown waste G is gripped by two or three-axis rotary shearing blades having different rotational speeds, torn and coarsely crushed slowly by shearing, and discharged from the discharge port at the bottom of the main body. ..

First waste G1 crushed by this crusher 1
Is once put into a waste receiving storage tank 3 such as a pit. In the waste receiving and storing tank 3, the first waste G1 is temporarily stored, and the stored second waste G2 is passed through the feeder 5 at the required time and in the required amount, and then the incinerator 7 is provided.
Be thrown into.

As the incinerator 7, a well-known fluidized bed type incinerator, a stalker type incinerator, or the like is used, and the second waste G2 is incinerated under necessary conditions and integrated with the incinerator 7. Combustion gas is cooled by the installed boiler and steam is recovered.

Before the second waste G2 is charged from the waste receiving storage tank 3 through the feeder 5 into the incinerator 7,
For example, it may be thrown into a second crusher 9 such as a hammer mill for further crushing.

The waste receiving and storing tank 3 is provided in a closed chamber, and an air suction port 11 is arranged above it. One end of a pipe 13 is connected to the air suction port 11, and the other end of the pipe 13 is connected to the incinerator 7. A blower 15 is provided in the middle of the pipe 13.

With the above structure, when the blower 15 is driven, the first storage unit for storing the waste in the waste receiving storage tank 3
Incinerator 7 sucking in gas and air generated from waste G1
The gas and air are used as combustion air in the incinerator 7 by being supplied to.

When the above-mentioned waste G is charged into the crusher 1 and then the waste receiving and storing tank 3 and, if necessary, the second crusher 9 is introduced into the incinerator 7 via the feeder 5 for incineration, In the crusher 1 and / or the waste receiving storage tank 3, for example, C as an alkaline earth metal oxide is used.
For the purpose of deodorizing and suppressing spoilage fermentation, aO is added to the waste G (G1) to carry out a physicochemical reaction treatment. In this case, the amount of CaO added is waste G
About 2 to 5% is preferable with respect to the amount of (G1). 5%
Even if it exceeds, it will not be very effective.

That is, by actually introducing CaO into the crusher 1 and / or the waste receiving and storing tank 3, the acceptance of the municipal waste which must be overcome in common by the facilities of this type up to now. It is possible to prevent the generation of offensive odors from the storage facility. And calcium oxide CaO
Has the effect of suppressing spoilage / fermentation and insect development.

In particular, before the waste G is directly charged into the waste receiving storage tank 3, the waste G is charged into the crusher 1 and CaO is crushed so that the waste G can be converted into the waste G.
With sufficient stirring, CaO is dispersed in the waste G, and contact with the waste G causes a physicochemical reaction. Further, once the reaction-treated waste G1 is stored in the waste receiving storage tank 3, the physicochemical reaction is enhanced.

Moreover, in the waste receiving storage tank 3, Ca
By the action of O, for example, the protein contained in the waste G is hydrolyzed and ammonia NH ₃ is generated. The generated NH ₃ is supplied to the incinerator 7 from the air suction port 11 through the pipe 13 by the drive of the blower 15 and is intentionally denitrified from the waste G. In the incinerator 7, the nitrogen oxide NOx generated by combustion reacts with the NOx as shown in the following formula to reduce NOx.

6NO + 4NH ₃ → 5N ₂ + H ₂ O 6NO ₂ + 8NH ₃ → 8N ₂ + 12H ₂ O Therefore, in the incinerator 7, the exhaust gas NOx after incineration can be reduced.

In addition, the activity of microorganisms is suppressed by alkali such as CaO and Ca (OH) _2, and the deterioration of odor is markedly reduced because the malodorous substances such as H ₂ S and methyl mercaptan are neutralized as well as the progress of decay. ..

Further, the heat generated by the reaction of CaO and water causes the water to be evaporated, so that the water content of the waste G ₂ is lowered.
Further, since the waste G ₂ is roughly crushed, it can be stably and quantitatively supplied, so that the combustion can be stabilized. This stabilization of combustion and reduction by NH ₃ can reduce NOx in the exhaust gas, and absorption of CaO or Ca (OH) ₂ can reduce HCL and SOx in the exhaust gas. Thus, it is possible to perform cleaner combustion and also possible to recover energy with higher efficiency.

FIG. 2 shows another embodiment as an alternative to FIG. In FIG. 2, an auxiliary waste receiving storage tank 17 is arranged in front of the crusher 1 in FIG. 1, and the waste G is put into this auxiliary waste receiving storage tank 17. An air intake port 19 is arranged above the auxiliary waste receiving storage tank 17, and one end of a pipe 21 is connected to the air intake port 19 and the other end of the pipe 21 is connected to the pipe 13. Connected on the way. Other than that, the configuration is the same as in FIG. In this case, the auxiliary waste receiving storage tank 17 and the waste receiving storage tank 3 become the first and second waste receiving storage tanks, respectively.

In the above structure, CaO as an alkaline earth metal oxide is added to the auxiliary waste receiving storage tank 17 and the crusher 1, for example, from 2 to the amount of the waste G.
By adding about 5%, the same operation and effect as those of the above-described embodiment are obtained, and therefore detailed description will be omitted.

The present invention is not limited to the above-described embodiments, but can be implemented in other modes by making appropriate changes. For example, although CaO is described as an example of the alkaline earth metal oxide in the present embodiment, CaO may be mixed with MgO, or CaO may be mixed with adsorbent viscous minerals such as bentonite. It is possible.

[0032]

As can be understood from the above description of the embodiments, according to the present invention, since the constitution is as described in the claims, an alkaline earth metal oxide or an alkaline earth metal is used. By adding an appropriate amount of clay minerals with adsorptive properties to physico-chemical reaction treatments, the ammonia generated as a result of the reaction is sent to the incinerator to consciously remove nitrogen from waste. Can be denitrified. In addition, the reformed waste is put into an incinerator and is incinerated to perform clean combustion,
A small amount of clean exhaust gas such as NOx, SOx, and HCL can be obtained, and corrosion due to chlorine can be prevented, so that steam conditions of the boiler can be increased and highly efficient energy recovery can be performed.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment for carrying out the present invention, which is a diagram showing a conceptual process of incinerating collected waste through each treatment process in an incinerator.

FIG. 2 is a diagram showing another embodiment instead of FIG.

[Explanation of symbols]

1 crusher 3 waste receiving storage tank (first waste receiving storage tank) 5 feeder 7 incinerator 9 crusher 11 air intake port 15 blower 17 auxiliary waste receiving storage tank (second waste receiving storage tank) G waste object

Claims (2)

[Claims] 1. When waste such as municipal waste is put into a crusher for crushing treatment and then stored in a waste receiving storage tank and then put into an incinerator to incinerate the waste.
In addition to the alkaline earth metal oxide or the alkaline earth metal oxide and a clay mineral having adsorptivity to the crusher and / or the waste storage tank, the physicochemical reaction treatment can be reasonably performed. A method for incinerating waste, comprising feeding ammonia generated as a result of the reaction in the waste receiving storage tank to the incinerator. 2. The waste such as municipal waste is put into the first waste receiving storage tank, then put into the second waste receiving storage tank through the crusher, and then put into the incinerator to incinerate the waste. In doing so, an alkaline earth metal oxide or a clay mineral having an adsorbing property with an alkaline earth metal oxide is added to the first waste receiving storage tank and / or the crusher to reasonably perform a physicochemical reaction treatment. And at least ammonia generated as a result of the reaction in the second waste receiving storage tank is sent to the incinerator.