JPH1110108A - Method for solidification of material to be treated and solidified material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute solidification which does not generate chlorine gas even though burnt by a method wherein various kinds of waste and material not to be treated with desalination are mixed with a dechlorination agent of potassium material of carbonate series reacting with chlorine gas, treated by heating, and the generated product is formed by pressurizing to be solidified in a pellet form. SOLUTION: In the case a pellet 7 is manufactured from a waste of municipal refuse or the like being a material to be treated in which a material containing a great amount of a chlorine component is mixed, at first the material is charged into a material supply part 1, a dechlorination agent is contained in a dechlorination agent supply part 3, and they are supplied to a mixer 2 by a specific ratio. In the mixer 2, the material to be treated and the dechlorination agent are treated by heating with a heating means 4 mixing them. The heating treatment is treated by heating for 10 min under a state wherein the open air is shielded at a temperature of, for example, 200 deg.C or under, preferably 100 deg.C to 150 deg.C. Then, an opening and closing door 2b of the mixer 2 is opened, a mixture is supplied to a granulator 5, the mixture is formed by compression with a press means heating the mixture at the same temperature condition, and the pellet 7 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for heating and treating solidified products such as wastes, and a solidified product formed by this method. The present invention relates to a solidification method and a solidification method.

[0002]

2. Description of the Related Art The amount of processed waste such as municipal garbage increases year by year, and its disposal has become a problem. In general, municipal garbage is mainly discharged from general households or offices as flammable waste. Recently, it has been considered that this flammable treated material is not simply incinerated, but is effectively used as a resource, and the treated material is once solidified and reused as fuel. However, some of the processed materials contain a large amount of chlorine components in recent years, such as a wide variety of chemical substances, for example, plastics containing a large amount of vinyl chloride resin and chlorine bleach for paper used in offices. Due to the inclusion of substances, simply solidifying will generate harmful chlorine-based gas when used and burned as fuel, and if released directly into the atmosphere, it will cause air pollution and have undesirable environmental consequences . Therefore, there is a problem in reusing as a high-efficiency and clean energy resource, and development of a technology corresponding to this problem has become an important issue.

[0003]

A problem that arises when heat-treating a treated product is the treatment of chlorine components contained in the treated product, and the chlorine-based gas (hydrogen chloride, chlorine chloride) gasified in the incineration process. Gas) is subjected to an adsorption treatment with a filter or the like so that chlorine-based gas is not discharged into the atmosphere.

[0004] On the other hand, chlorine components that have not been gasified during the heating process are combined with the treated ash, resulting in treated ash containing a high concentration of chlorine components.

[0005] If the treated ash contains a chlorine component as described above, it is difficult to reuse the treated ash as a fuel resource, and the ash is treated only by burying it in the ground.

Therefore, when reusing the treated ash,
Processed materials are separated in advance, only processed materials that generate less chlorine-based gas are selected and incinerated, and the processed ash (residue) is solidified as fuel or in a block or the like and reused.

[0007] However, since the separation of the treated material is inefficient and the resource recovery rate is low, it is desired to establish a technique for effectively removing the chlorine component.

[0008] Further, it is also practiced to solidify the processed material (garbage) and use it as a fuel. However, at present, the flammable processed material is simply compressed and solidified. Can be achieved, but when used as a fuel, harmful chlorine-based gas is generated in the same manner as described above, and countermeasures are required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to solidify a treated material which does not generate chlorine-based gas (hydrogen chloride, chlorine gas) even when burned, and a method for solidifying the treated material. To provide.

[0010]

As a result of numerous experimental investigations, the inventors of the present application have found that a proper amount of a chlorine component and a carbonate-based potassium substance contained in the treated product is mixed into the treated product as a dechlorinating agent, When the heat treatment is performed at a temperature of, the chlorine component is decomposed at a predetermined temperature to generate harmful chlorine-based gas, and the harmful chlorine-based gas reacts with the dechlorinating agent to generate harmless chloride, and the gas is removed. It was also found that no harmful chlorine-based gas components remained in the residue.

Attention is also paid to the fact that a dechlorinating agent is added during the heat treatment to perform a treatment aimed at the dechlorination effect. In addition, we focused on manufacturing by mixing a dechlorinating agent.

[0012] The inventors first searched for a substance having a dechlorination effect, and investigated the effect of mixing the substance into pellets and burning it.

The present invention has been made based on these experimental investigations, in which a treated product is solidified by mixing a dechlorinating agent,
When this is incinerated as a fuel, a solidified fuel that does not generate harmful chlorine-based gas can be obtained.

In the present invention, the treatment method for solidifying the treated material includes a general RDF, which is a non-desalted treatment, in addition to general various wastes, and a carbonate-based material which reacts with chlorine-based gas. Heat treatment by mixing with a potassium substance dechlorination agent
It is characterized in that the produced product is pressure-formed and solidified into pellets.

At this time, the temperature at the time of the heat treatment is set to be equal to or lower than the temperature (200 to 300 ° C.) at which the precipitation of the chlorine-based gas starts.

The heat treatment is performed in a low oxygen atmosphere.

Then, the product is compression-molded by a granulator to form a solidified product (pellet). Alternatively, a dechlorinating agent is further added to the product to form pellets.

The dechlorinating agent used in the present invention includes:
(1) A substance selected from a mixture of two or more simple substances of a carbonate-based potassium substance.

(2) A simple substance selected from potassium carbonate and potassium hydrogen carbonate and a mixture of two or more simple substances are appropriately selected and used.

The shape of the dechlorinating agent is a powder (powder,
(Granules), a solution or a suspension.

The amount of addition is equivalent to the processed material to be treated or equivalent to 5 or
To 30% by weight, or 0.5 to the generated chlorine-based gas
Add ~ 1.5 mol.

The pressing force for producing a solid material is 10 to 1000 kg / kg for the reason that solidification is difficult if the pressing force is small, and the equipment becomes large if the pressing force is large.
cm ² is preferred.

Under the above conditions, when a dechlorinating agent is added to the treated product and the solidified product solidified by the heat treatment at a temperature lower than the temperature at which the chlorine-based gas precipitates is incinerated, the chlorine-based gas precipitates. Because of the presence of a dechlorinating agent, for example, when potassium hydrogen carbonate (KHCO ₃ ) is added, it reacts with hydrogen chloride (HCl) to give the following.

(KHCO ₃ ) + (HCl) → (KCl)
+ (H ₂ O) + (CO ₂ ) As described above, hydrogen chloride reacts with sodium hydroxide to form potassium chloride (KCl), which is a part of the residue, and water (H ₂ O).
O) and carbon dioxide (CO ₂ ) and do not generate chlorine-hydrogen gas, which is a cause of dioxin, and can make the exhaust gas and the residue harmless.

In addition, harmless chloride KCl in the residue
(Potassium chloride) can be easily removed by washing with a solution such as water, and naturally, no harmful chlorine-based gas component is present in the carbide after the chloride removal.

Therefore, even if the carbide extracted from the residue is used as a fuel, the resulting air pollution does not occur, and effective utilization becomes possible.

[0027]

FIG. 1 is a block diagram showing an embodiment of the present invention.
It will be explained by.

FIG. 1 is a conceptual diagram of an embodiment of the present invention.
Denotes a processing material supply unit, 2 denotes a mixer, and 3 denotes a dechlorinating agent supply unit. Reference numeral 4 denotes a heating means for heating the processed material in the mixer 2.
This heating means 4 includes gas heating, electric heating or combustion heating,
Any heating means such as microwave heating and induction heating may be used.

Numeral 5 denotes a granulator having a heating means 6 on the outside and a press means comprising a pressure roller and the like inside.
Reference numeral 7 denotes a solid (pellet) formed by the granulator 5.

The procedure for manufacturing the pellets is as follows. First, the processed material is charged into the processed material supply unit 1, the dechlorinating agent is stored in the dechlorinating agent supply unit 3, and these are supplied to the mixer 2 at a predetermined ratio. I do. In the mixing machine 2, while mixing the processed material and the dechlorinating agent,
The heating (dry distillation) treatment is performed by the heating means 4. (The heat treatment may be performed in a granulator).

The heat treatment is performed at a temperature of 200 ° C. or less, preferably 1 ° C.
A heat treatment (dry distillation) is performed for 10 minutes at a temperature of 00 ° C. to 150 ° C. with the outside air shut off.

Next, the opening / closing door 2b of the mixer 2 is opened, the mixture is supplied to the granulator 5, and the mixture is compression-molded by press means while the mixture is heated under the same temperature conditions as described above. Then, a pellet 7 is formed. The crushing function may be added to the mixer 2.

If plastics are mixed in the processed material in the above process, the plastics are mixed with the processed material in a softened state and are molded, so that the plastics as an adhesive (binder) between the processed materials is used. Acting, the pallets produced maintain a stable solid form.

The pressing means includes, for example, a feed rotary roller for feeding the mixture and a squeezing rotary roller (which may be a heating roller) for compression molding, and adjusts the interval between the feed rotary rollers to adjust the pressing force to 100 to 1000 kg. / C
to adjust to the m ^2. If the pressure is small, solidification is difficult, and if it is too large, the equipment becomes large.

By performing the compression molding in this manner, the volume ratio of the pellet is reduced as follows.

[0036]

[Table 1]

FIG. 2 shows another embodiment of the present invention, in which a screw feeder 10 is provided between the mixer 2 and the granulator 5. The screw feeder 10 includes a heating unit 11
And provided to further promote the mixing of the treated product and the dechlorinating agent.

Since the screw feeder 10 is also heated in a dry distillation state, it is configured to be shielded from outside air. Accordingly, the inlet side and each have a door 10d ₁ and 10d ₂ on the outlet side, rotary driven screw 10b is provided in the cylindrical member 10a, transported while mixing the treated product and the dechlorinated agent.

The heating may be performed in either the crusher / mixer 2 or the screw feeder 10, or may be performed in both.

Using the processed material solidified by the above-described processing method as a fuel, the chlorine component contained in the processed material to be burned is determined to be harmless by the following experiment. Chloride was generated, and it was found that the exhaust gas and the residue did not contain harmful chlorine-based gas components.

That is, the following experimental investigation revealed that the carbonate-based potassium substance reacts with the harmful chloride-based gas in the gas to generate harmless chloride. The experiment is
Put the sample in a closed container with an exhaust pipe and a door,
Heat in an electric furnace to create a low oxygen atmosphere, hold at 250 ° C to 600 ° C at 50 ° C intervals at each temperature for 5 minutes, and raise and keep the hydrogen chloride gas (HCl) concentration (pp
m) is measured.

The gas concentration was measured using a detector tube specified in JIS-K0804.

Table 1 shows the measurement results. In Table 1, the hydrogen chloride gas concentration is a measured value in 10 experiments, and Examples 1 and 2 show the highest values, and Comparative Examples 1 to 3 show the lowest values.

Note that "ND" represents "not detected" and 1
It shows that none was detected in 0 experiments.

[0045]

[Table 2]

In the experiment, first, a preliminary experiment was performed using only polyvinylidene chloride containing a large amount of a chlorine component as a treated material. Comparative Example 1 in Table 1 was a sample for a preliminary experiment in which no dechlorinating agent was added to 4 g of polyvinylidene chloride.

Comparative Example 2 is a sample obtained by adding 20 g of slaked lime powder as a conventional dechlorinating agent to 4 g of the same treated product. Comparative Example 3
Was a sample obtained by adding calcium carbonate as a dechlorinating agent to 4 g of the same treated product.

Next, as an example of the dechlorination treatment according to the present invention, a sample obtained by adding 10 g of ground potassium hydrogen carbonate as a dechlorinating agent to 4 g of polyvinylidene chloride as a processed material was used as an example 1, and 40 g of standard waste was removed. Example 2 A sample to which 10 g of ground potassium hydrogen carbonate as a chlorine agent was added was used.
And Powder having an average particle size of 100 μm was used as a dechlorinating agent.

The standard garbage was prepared by simulating the following standard municipal garbage and used.

・ Standard garbage 20% by weight ・ Plastic (PE, PP, PS, PVDC) 50% by weight ・ Paper (tissue, newspaper, wrapping paper, box, drink pack) 20% by weight ・ Cloth (eg, waste cloth) 10% by weight -Kitchen garbage The following is considered from the experimental results shown in Table 1.

First, a preliminary test was conducted using only polyvinylidene chloride containing a large amount of a chlorine component. As a result, as shown in Comparative Example 1, a large amount of hydrogen chloride was generated by the heat treatment.

Next, in Comparative Examples 2 and 3 to which slaked lime and calcium carbonate, which are conventional dechlorinating agents, were added, although the generation of hydrogen chloride was considerably suppressed as compared with Comparative Example 1,
Not yet enough.

On the other hand, in Examples 1 and 2 in which potassium hydrogen carbonate, which is a potassium carbonate substance, was added as a dechlorinating agent to the above treated material, the temperature in Example 2 was 350 ° C.
Although slight generation of hydrogen chloride gas was observed when the temperature was raised to 400 ° C. and when the temperature was kept for 5 minutes, hydrogen chloride gas was not detected over the entire temperature range, and very good results were obtained.
Therefore, according to this example, very good results were obtained as compared with Comparative Examples 1 to 3.

In the case of potassium hydrogen carbonate (KHCO ₃ ), the temperature at which hydrogen chloride (HCl) decomposes and precipitates (250 ° C.)
Above) Decompose at the following temperature to separate CO _3, and the atmosphere condition is such that the reaction between the remaining KH and generated HCl can be smoothly performed as follows.

KH + CO ₃ + HCl → KCl + H ₂ O + CO ₂ Therefore, the decomposed HCl and KH react quickly to newly produce harmless chloride (KCl).

On the other hand, calcium carbonate (CaCO ₃ ) and slaked lime (Ca (OH) ₂ ) similarly produce harmless chloride (CaCl), but the reaction is not as smooth as that of potassium. Seem.

The same effect was obtained at a temperature of 600 ° C. or more and 1000 ° C.

When potassium hydrogen carbonate reacts with a chlorine-based gas, the gas and the residue can be rendered harmless because the harmful chloride-based gas is replaced with a harmless chloride as follows.

Here, when potassium hydrogen carbonate (KHCO ₃ ) is used as a dechlorinating agent and added to the processed product, potassium hydrogen carbonate is converted to hydrogen chloride (HC) as described above.
The following reaction formula proceeds with 1).

(KHCO ₃ ) + (HCl) → (KCl)
+ (H ₂ O) + (CO ₂ ) Thus, potassium hydrogen carbonate reacts with hydrogen chloride to produce harmless potassium chloride, water and carbon dioxide gas.

When potassium carbonate (K ₂ CO ₃ ) is used, the reaction formula is (K ₂ CO ₃ ) + (2HCl) → (2KCl) + (H
_{As 2} O) + (CO ₂ ), potassium carbonate reacts with hydrogen chloride to form harmless potassium chloride, water and carbon dioxide.

When the obtained residue was analyzed, no harmful chlorine-based gas was detected, and potassium chloride (KCl), which was a harmless chloride, was detected. Further, by washing the residue with water while stirring for 10 minutes, potassium chloride was dissolved in the water, and a carbide remained, but no chlorine-based gas component was detected in the carbide.

Therefore, if a carbonate-based potassium substance which reacts with a chlorine component to form harmless chloride in the dechlorinating agent is present, it becomes a part of the residue as potassium chloride, which is one of the causes of the generation of dioxin. Hydrogen chloride is not generated, and these residues and exhaust gas can be made harmless.

From the above, the following substances showing the same reaction as described above can be used as the dechlorinating agent.

(1) A substance selected from a mixture of a simple substance of a carbonate-based potassium substance and two or more kinds of simple substances.

(2) A simple substance selected from potassium carbonate and potassium hydrogen carbonate and a substance selected from a mixture of two or more simple substances.

On the other hand, KCl is produced by the reaction,
The generated KCl is a harmless chloride, and can be effectively removed by a washing treatment with a solution such as water, and after washing, a reusable carbonized substance remains.

FIG. 3 is an explanatory view for cleaning the treated ash. The treated ash is put into a water tank, and stirred for a predetermined time (about 30 minutes) to dissolve potassium chloride (KCl) in water and remove it from the treated ash. Then, it is dehydrated and dried to be solidified.
After cleaning, valuable carbonized material remains.

Therefore, depending on the characteristics of the residue, the residue can be separated into various substances by a separation means or the like, and the separated substance can be dried and solidified to be used as fuel or other effectively.

Since the treatment liquid after washing contains almost no harmful substances, it can be discharged to rivers or oceans as it is.

As a result of measuring the residual chlorine component in the residue by ion chromatography, what was conventionally 1000 ppm was not confirmed in the present invention, and harmless chloride (KC
l) was confirmed.

The concentration of hydrogen chloride in the residue not washed with water was measured.
As described above, it was not detected in the present invention.

[0073]

As described above, according to the present invention, the treatment product is mixed with a dechlorinating agent for a carbonate-based potassium substance, heated at a temperature lower than a temperature at which a chlorine-based gas is deposited, and pressurized. Since the solidified material (pellet) is formed, (1) a safe pellet free of generation of chlorine-based gas (hydrogen chloride, chlorine gas) when burning the solidified material is obtained.

(2) Since the harmful chlorine gas in the gas generated during the combustion of the pellets reacts with the dechlorinating agent to form harmless chloride, the harmful chlorine material in the exhaust gas is effectively eliminated. Even if the exhaust gas is released to the atmosphere as it is, the generation of Diokin is prevented.

(3) For the above reasons, it can be effectively reused as a solidified fuel which is convenient to handle.

The following effects are obtained.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an embodiment of the present invention.

FIG. 2 is a conceptual diagram of another embodiment of the present invention.

FIG. 3 is an explanatory diagram of the processing of the processing ash.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Process supply part 2 ... Mixer 3 ... Dechlorination agent supply part 4, 6, 11 ... Heating means 5 ... Granulator 7 ... Pellet 10 ... Screw feeder.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI B09B 3/00 304H

Claims (11)

[Claims] 1. A process wherein a treated product and a dechlorinating agent for a potassium carbonate substance that reacts with a chlorine-based gas are mixed and heat-treated, and the produced product is solidified into pellets. A method for solidifying the processed material. 2. The method according to claim 1, wherein the temperature range of the heat treatment is lower than a temperature at which precipitation of chlorine-based gas starts. 3. The method according to claim 1, wherein the heat treatment is performed in a low oxygen atmosphere. 4. The method according to claim 1, wherein the heat treatment is dry distillation. 5. The method according to claim 1, wherein the dechlorinating agent is selected from a mixture of two or more of potassium carbonate substances alone. 6. The method according to claim 1, wherein the dechlorinating agent is selected from a simple substance selected from potassium carbonate and potassium hydrogen carbonate and a mixture of two or more simple substances. 7. The process according to claim 1, wherein the dechlorinating agent is formed in the form of a powder, a solution, or a suspension. Processing method. 8. The method according to claim 1, wherein the amount of the dechlorinating agent added is 5 to 30% by weight of the treated material.
The solidification treatment method for a treated product according to any one of claims 5, 6, and 7. 9. The method according to claim 1, wherein the amount of the dechlorinating agent is 0.5 to 1.5 mol based on the amount of the generated chlorine component. The solidification treatment method for a treated product according to claim 1. 10. The pressure for pressure molding is 100 to 1000.
^{2. The} method for solidifying a treated product according to claim 1, wherein the solid content is set to kg / cm ² . 11. A mixture of the treated product and a dechlorinating agent for a carbonate-based potassium substance that reacts with a chlorine-based gas and heat-treated.
A solid product obtained by press-molding the produced product and solidifying it into a pellet.