JP2001137806A - Waster treatment method and recycled goods - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste treatment method which can rapidly treat wastes at a low cost without producing hazardous materials, such as dioxins, and allows the recycling thereof and can provide recycled goods. SOLUTION: The wastes 1 are pressurized and heated to 10 atm and 183 deg.C by a steam kettle, such as an autoclave, in a pressurizing and heating stage. The generation of the dioxins is prevented by maintaining the heating temperature at <=200 deg.C. The treated materials 2 with which the pressurizing and heating stage ends are taken out of the steam kettle and are classified to the garbage treated materials 31 formed from garbage 11 and the other treated materials 32 formed from the wastes exclusive of the garbage 12. The garbage treated materials 31 are brittle solids and the other treated materials 32 are pliable resin-like solids and therefore the garbage treated materials 31 and the other treated materials 32 may be easily separated and classified. The classified garbage treated materials 31 are recyclable as compost 41 and the other treated materials 32 are recyclable as solid fuel 42.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating waste, and more particularly, to a method for treating waste including garbage discarded from homes and business establishments, and to a recycled product.

[0002]

2. Description of the Related Art A large amount of garbage is discarded from homes and business establishments, and their disposal has become a major social problem. That is, garbage disposal is an important issue in future social life. 2. Description of the Related Art Conventionally, as a method of treating garbage, the use of incineration has been dominant, and a compost system that decomposes and composts with bacteria or bacteria has been partially used.

[0003]

However, incineration, which accounts for most of the garbage disposal, has been pointed out by dioxin in recent years. Therefore, in order to incinerate garbage in the future, in order to promote the separation of garbage from organic chlorine compounds that may generate dioxin and garbage, or to prevent the generation of dioxin, the incineration temperature of garbage should be, for example, 800 ° C. Need to be raised. However, there is a problem that it is difficult to mechanize the separation of garbage and a large number of humans are required, thereby increasing the cost.
In addition, even if the incineration temperature rises, capital investment will be required to make equipment that can withstand higher temperatures than the current equipment,
There is still a problem that the cost rises.

On the other hand, even in the use of a compost system, bacteria and bacteria cannot disassemble a bag made of resin such as polyethylene, so that it is necessary to separate garbage from bags packed with garbage. . As a result, as described above, there is a problem that humans are required and the cost is increased. In addition, there is a problem that, because of treatment with bacteria or bacteria, it is not possible to treat a large amount of garbage or to treat in a short period of time, resulting in low treatment efficiency.

Accordingly, the present invention provides a waste disposal method and a reusable product which can be treated at low cost and in a short time without generating harmful substances such as dioxin, and which can be reused. It is in.

[0006]

According to a first aspect of the present invention, there is provided a method for treating waste, comprising the steps of pressurizing and heating waste with a steam kettle. A steam pot blows steam into the pot and pressurizes and heats the inside of the pot with the steam. When the waste is pressurized and heated in this steam pot, for example, after introducing waste containing garbage into the steam pot, steam is blown into the pot,
The waste is pressurized and heated with the moisture contained in the waste.

[0007] By pressurizing and heating in a steam pot, the waste is carbonized, and the volume of the waste to be treated is reduced. Therefore, the amount of waste can be reduced at low cost. Further, for example, no harmful substances are generated as in the case of incineration of waste, and the treatment does not require a long time as in the case of treating waste by a compost system.

According to the waste treatment method of the second aspect of the present invention, since the heating temperature is set at 150 ° C. to 200 ° C., it is possible to prevent the generation of dioxin which is likely to occur at 300 ° C. or higher. it can. Further, the waste can be treated in a short time by heating under pressure in a steam pot.

According to the recycle product of the third aspect of the present invention, the waste treated by the waste disposal method of the first aspect can be reused. For example, a processed material obtained by treating garbage can be reused as compost.

[0010] According to the recycled product of the fourth aspect of the present invention, the processed food waste can be safely reused as compost. According to the recycled product according to the fifth aspect of the present invention, since other processed materials are separated from the processed garbage generated from the garbage, incineration at a high temperature is possible. Therefore, by burning at a temperature of, for example, 800 ° C. or more, generation of dioxin can be prevented.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; As shown in FIG. 2, the waste treatment method according to one embodiment of the present invention includes a pressure heating step and a separation step.

As shown in FIG. 1, wastes 1 to be treated by the waste treatment method according to the present embodiment are mainly foods discarded from homes or offices or other so-called garbage 11 discarded in daily life. Contains. The waste 1 also includes non-garbage 12, such as containers for the garbage 11, so-called plastic bags such as polyethylene, polypropylene and polyvinyl chloride, and other resin products such as polyvinylidene chloride used for wraps. In addition, the garbage 11 may include natural products such as paper and wood.

Pressure Heating Step (S 201) In the pressure heating step shown in FIG. 2, the waste 1 is heated under pressure by a steam pot such as an autoclave. When the waste 1 containing the garbage 11 is put into the steam pot and steam is blown into the steam pot, the pressure and temperature inside the pot rise. As the temperature of the kettle rises, the moisture contained in the garbage 11 evaporates and becomes steam, so that the garbage 11
Is dehydrated and carbonized.

The pressurizing pressure in the pressurizing and heating step is 3.8 to 15.0 atm, and the heating temperature is 150 to 200 ° C. In this embodiment, the pressure is set to 10 atm and 183 ° C. In the pressurization and heating by the steam pot, the pressure and the temperature are not set as independent conditions, but when the pressure or the temperature is set, the temperature or the pressure according to the pressure or the temperature is determined. Further, by setting the heating temperature to 200 ° C. or lower, it is possible to prevent the generation of dioxin which is concerned at 300 ° C. to 800 ° C.

In the heating step under pressure, the waste 1 containing the garbage 11 is put into a steam pot. Then, the pressure is raised and the temperature is raised over 1 hour so that the above-mentioned predetermined pressure and temperature are 10 atm and 183 ° C. When 10 atmospheres and 183 ° C. are reached, the pressure and temperature are maintained for 3 hours. And
After maintaining at 10 atmospheres and 183 ° C. for 3 hours, the pressure is reduced to atmospheric pressure and room temperature over 1 hour, and the temperature is decreased. The time required for increasing the pressure and raising the temperature and maintaining the pressure at 10 atm and 183 ° C., and the time required for decreasing the pressure and decreasing the temperature can be set according to the performance of the steam tank, not limited to the above-described time.

Separation step (S 202) The waste 1 that has completed the pressure heating step shown in FIG.
And the processed material 2 is taken out of the steam pot and separated. The processed material 2 includes a processed garbage 31 generated from the garbage 11 and another processed material 32 generated from waste other than the garbage 12.

The garbage processed material 31 is a compost-like carbonized processed material obtained by heating and pressing the garbage 11 in a steam pot. The garbage processed material 31 is formed into a solid state that is easily broken and easily carbonized by removing moisture contained in the garbage 11 by heating under pressure. Further, the processed food 31 includes not only the food waste originating from the food waste 11 but also waste originating from natural products such as paper. On the other hand, the other processed product 32 is a resin-like solid which is softened and hardly collapsed again after a plastic resin such as a plastic bag mainly contained therein is melted by heating under pressure and then solidified again.

By heating and heating the treated material 2, the volume of the waste 1 is reduced to about 1/15 of that before heating under pressure.
It contributes to the reduction of waste 1. The above-mentioned food waste 31
Since the other processed materials 32 are fragile and soft resinous, the raw garbage processed materials 31 removed from the steam pot and the other processed materials 32 can be easily separated and separated.
For example, by using a sieve or the like, the processed garbage 31 is brittle and easily passes through the sieve, whereas the other processed materials 32 are not easily broken and do not pass through the sieve. By the operation as described above, the processed material 2 that has been pressurized and heated is replaced with the garbage processed material 31 and the other processed materials 32.
It is possible to separate them.

Next, a description will be given of a recycle product including the raw garbage processed material 31 obtained by the above-described waste processing method and other processed materials 32.

(Green Garbage) The raw garbage 31 is in the form of fragile compost carbonized as described above. Since the raw garbage 31 is an organic substance originating from animal or vegetable natural products, it can be reused as the compost 41.
Table 1 below shows the results of component analysis of the compost 41 composed of the processed food waste 31.

[0021]

[Table 1]

As shown in Table 1, harmful metals such as cadmium, lead, arsenic, mercury, and chromium, and their compounds, which were measured, are equivalent to the values normally contained in the garbage 11 from which they were derived. It is not a value that affects the human body. That is, it is equivalent to the value normally contained in natural animals or plants, and indicates that no harmful substances are generated by heating under pressure in a steam pot. Further, it contains a sufficient amount of components essential for plant growth, such as nitrogen, phosphorus, ammonium ions, and potassium. Therefore, it is possible to reuse the processed garbage 31 as the compost 41.

On the other hand, the amount of dioxin contained in the processed garbage 31 is almost zero, and when used as the compost 41, it does not affect the human body. Further, the numerical value of dioxin indicates that dioxin is not generated even if the waste 1 containing the garbage 11 is heated under pressure in a steam pot. As described above, the reusable product including the garbage disposal material 31 obtained by treating the waste 1 can be reused as the compost 41.

(Other Processed Products) Other processed products 32 mainly made of a plastic resin such as a plastic bag may be made of dioxin depending on the material of the origin, for example, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride and the like. It is feared that this will occur. The waste 1 treated according to the present embodiment is stored in a steam kettle at 150 ° C. to 20 ° C.
Dioxin is not generated because the treatment is performed at 0 ° C.

However, there is a possibility that dioxin may be generated by subjecting the above-mentioned other processed material 32 to, for example, incineration. As described above, dioxin is said to be generated at a combustion temperature in the range of 300 ° C to 800 ° C,
For example, dioxin is thermally decomposed by incineration in a combustion pot in which the temperature of the combustion chamber is set to 800 ° C. or higher, and the generation thereof can be prevented. Therefore, the generation of dioxin can be prevented by incinerating the other treated materials 32 as solid fuel 42 in a combustion chamber having a high temperature of 800 ° C. or higher in the combustion chamber as described above. In particular,
In the present embodiment, since the garbage 11 that leads to the lowering of the combustion temperature is completely separated, the other processed materials 32 are removed by 800.
It is easy to burn at a high temperature of ℃ or more.

Table 2 below shows a comparison between the calorific value of the solid fuel 42 and the calorific value of garbage that has not been treated.

[0027]

[Table 2]

As shown in Table 2, the solid fuel 42, which is a recycle product including the other processed materials 32, generates a large amount of heat as compared with untreated garbage. This is considered to be because the moisture in the garbage is reduced by the treatment in the steam pot, and the incineration at a high temperature is easy. Therefore, generation of dioxin due to incineration of the solid fuel 42 can be prevented. As described above, the reused product including the other processed materials 32 can be reused as the solid fuel 42. By operating the steam pot using the heat generated by burning the solid fuel 42, it is possible to effectively use energy.

As described above, according to the waste treatment method of the present embodiment, the volume of the treated material 2 is reduced to about 1/15 of that before the pressure heating by heating the waste 1 under pressure. The object 1 can be reduced in weight. When the heating temperature is 1
Since the temperature is set at 50 ° C to 200 ° C, generation of harmful substances such as dioxin can be prevented. further,
Since it is only necessary to heat the waste 1 under pressure in a steam pot, the treatment can be performed in a short time, at low cost, and easily.

The recycled product containing the processed garbage 31 of the present embodiment does not contain harmful substances such as harmful metals and dioxins, while it contains sufficient compost components such as nitrogen, phosphorus and potassium. It can be reused as compost 41. The recycled product including the other processed material 32 of the present embodiment can be incinerated at a high temperature because it is separated from the garbage 11. Therefore, other processed materials 3
By burning 2 at a high temperature of 800 ° C. or higher as the solid fuel 42, generation of dioxin and the like can be prevented.

As described above, the waste disposal method and the reused product of the present invention can prevent the generation of harmful substances such as dioxin, which is a problem in the conventional waste disposal.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining a waste disposal method according to one embodiment of the present invention.

FIG. 2 is a flowchart showing a waste disposal method according to one embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 waste 2 processed material 11 garbage 31 garbage processed material 32 other processed material 41 compost 42 solid fuel

Claims (5)

[Claims] 1. A waste treatment method for treating waste containing garbage, the method comprising pressurizing and heating the waste with a steam pot. 2. The waste containing garbage is removed in a steam kettle at 3.8 to 15.0 atm and 150 to 200 ° C.
A pressurized heating step of pressurizing and heating, and a treated material generated from the waste material pressurized and heated in the pressurized heating step, a treated garbage produced from the garbage, and a material other than the treated garbage. A separation step of separating the waste into other processed materials. 3. A reusable product comprising a processed material processed by the waste processing method according to claim 1. 4. A recycled product comprising the garbage processed material processed by the waste processing method according to claim 2. 5. A reusable product comprising the other processed material processed by the waste processing method according to claim 2.