JPH10235310A - Solidification treatment of object to be treated and solidified matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent evolution of chlorine-containing gases even in the case that an object to be treated is burned by mixing a proper amount of a carbonic acid-type alkaline substance as a dechlorination agent with the object to be treated which contains chlorine and heating the resultant mixture at a prescribed temperature. SOLUTION: An object to be treated is thrown to a supply part 1 for the object to be treated, a dechlorination agent is stored in a dechlorination agent supply part 3, and the object to be treated and the agent in a prescribed ratio are supplied to a mixing apparatus 2. The dechlorination agent to be used is selected from carbonic acid type alkaline simple substances, two or more types of simple substances, and mixtures of two or more types of simple substances. While being mutually mixed by the mixing apparatus 2, the object to be treated and the dechlorination agent are heated (dry distilled) by a heating means 4. The heating treatment is carried out at least two stages with different heating temperature regions and the temperature in the posterior stage is made higher than that in the prior stage. The heating treatment (dry distillation) is carried out at a prescribed temperature for a prescribed time in the state that the outer air is shut. Then, heating treatment is carried out at higher temperature than the temperature in the prior stage to precipitate chlorine- containing gases and react the gases with the added dechlorination agent to produce harmless chlorides.

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 method of performing a chemical conversion treatment and a solidified product.

[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 office paper. 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 its object is to produce a chlorine-based gas (hydrogen chloride,
A solidification treatment method for a treated material that does not generate chlorine gas);
It is to provide the solidified product.

[0010]

As a result of numerous experimental investigations, the inventors of the present application have found that a chlorine component contained in a treated product and a carbonate-based alkaline substance are mixed in a proper amount as a dechlorinating agent into the treated product, and a predetermined amount is mixed. 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 was incinerated as a fuel, a solidified fuel that did not generate harmful chlorine-based gas could be obtained.

[0014] In the present invention, the processing method for solidifying the processed product is a process in which the processed product is mixed with a dechlorinating agent for a carbonate-based alkali substance that reacts with a chlorine-based gas, and heat-treated in a plurality of temperature ranges. The resulting product is pressure-formed and solidified into pellets.

At this time, the temperature at the time of the heat treatment is not more than the temperature (200 to 300 ° C.) at which the precipitation of the chlorine-based gas starts, and then the chlorine-based gas is precipitated at 300 to 500 ° C. Reacts to produce harmless chloride.

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.

As the dechlorinating agent used in the present invention, a simple substance of a carbonate-based alkaline substance, two or more simple substances,
Select from a mixture of two or more simple substances.

In particular, a simple substance of a carbonate-based sodium substance,
A mixture of at least one kind of simple substance and two or more kinds of simple substance is selected.

Specifically, it is selected from a simple substance selected from sodium bicarbonate, sodium carbonate, sodium sesquicarbonate and natural soda, a mixture of two or more simple substances, and a mixture of two or more simple substances.

The amount of addition is equivalent to the treated material to be treated or 5 equivalents.
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.

When a dechlorinating agent is added to the treated product under the above-mentioned conditions and heat treatment is performed, for example, when sodium hydrogen carbonate (NaHCO ₃ ) is added, hydrogen chloride (HC) is added.
l) reacts with:

(NaHCO ₃ ) + (HCl) → (NaC
l) + (H ₂ O) + (CO ₂ ) From this, if there are Na and CO components, the chlorine component becomes
It becomes NaCl, water (H ₂ O), and gaseous CO ₂ , which are a part of the residue, and does not generate a chlorine-based gas that contributes to dioxin, thereby making the gas and the residue harmless.

Further, NaC which is a harmless chloride in the residue is used.
l (sodium chloride) can be easily washed and removed with a solution such as water, and naturally, no harmful chlorine-based gas component exists in the carbide after the removal of chloride.

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

[0026]

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

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.
The 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 solidified product (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 in at least two or more stages having different heating temperature ranges. The temperature range of the latter stage is made higher than that of the former stage.

As shown in FIG.
A heat treatment (dry distillation) is performed at a temperature of 00 ° C. or less, preferably 150 ° C. to 250 ° C., with the outside air shut off for 10 minutes. Next, a heat treatment is performed at 300 to 600 ° C. (preferably 400 to 500 ° C.), which is higher than that in the previous step, to precipitate a chlorine-based gas from the processed product, and to react with the added dechlorinating agent to produce harmless chloride. Let it.

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 heating the mixture under the same temperature conditions as described above. Then, a pellet 7 is formed. The crushing function may be added to the mixer 2.

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

The pressing means includes, for example, a feed rotary roller for feeding out the mixture and a squeezing rotary roller (which may be a heating roller) for compression molding. / 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 compression molding in this manner, the volume ratio of the pellets is reduced as follows.

[0035]

[Table 1]

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 carbonic acid-based alkali substance reacts with the harmful chlorine-based gas in the gas to generate harmless chloride.

In the experiment, first, a sample shown in Table 2 was prepared using polyvinylidene chloride containing a large amount of a chlorine component.
When 4 g of polyvinylidene chloride was added with 20 g of sodium bicarbonate powder as a dechlorinating agent (Example 1),
When no dechlorinating agent was added (Comparative Example 1), when 20 g of slaked lime powder was used as the dechlorinating agent (Comparative Example 2), and when 20 g of calcium carbonate was used as the dechlorinating agent (Comparative Example 3) A comparative experiment was performed.

[0039]

[Table 2]

As a result of the experiment, as shown in Table 4, good results were obtained when sodium hydrogen carbonate was added.

Therefore, a simulated garbage simulating the following standard municipal garbage was prepared, and polyvinylidene chloride was added to create a more severe situation, and the amount thereof was changed, and the amount of the dechlorinating agent was changed. Experiments (additional tests) for practical use of Example 2, Example 3, Example 4, and Example 5 were conducted. In addition, the influence of moisture was also examined.

As the dechlorinating agent, a powder having an average particle diameter of 100 μm was used.

-Simulated garbage 20% by weight-Plastic (PE, PP, PS, PVDC) 50% by weight-Paper (tissue, newspaper, wrapping paper, box, drink pack) 20% by weight-Cloth (waste, etc.) 10% by weight・ Crushed garbage

[0044]

[Table 3]

In the experiment, the sample was placed in a closed vessel equipped with an exhaust pipe, heated in an electric furnace, and heated from 250 ° C. to 600 ° C.
The temperature was maintained at each temperature for 5 minutes at intervals of ° C, and the concentration (ppm) of hydrogen chloride gas (HCl) was measured at the time of temperature rise and at the time of keeping.

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

Table 4 shows the measurement results. The hydrogen chloride gas concentration is a value measured in 10 experiments and is shown in Examples 1 to 5.
Indicates the highest value, and Comparative Examples 1 to 3 indicate the lowest values.

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

[0049]

[Table 4]

In the experiment, first, a preliminary experiment was performed using only polyvinylidene chloride containing a large amount of a chlorine component.
The results are shown in Comparative Example 1 of Table 4.

Next, an experiment was conducted by adding a conventionally known powder of slaked lime and calcium carbonate as a dechlorinating agent.
The results are shown in Comparative Examples 2 and 3.

Next, an experiment was conducted by selecting the sodium hydrogencarbonate of the present invention. The results are shown in Example 1.

Subsequently, an experiment was conducted using simulated garbage simulating the above-mentioned standard municipal garbage and changing the amounts of polyvinylidene chloride and sodium hydrogen carbonate. The results are shown in Examples 2, 3, and 4.

Further, water was added to the simulated garbage, and the effect of the water was examined. The results are shown in Example 5.

From the results shown in Table 4, the following is considered. First, when polyvinylidene chloride containing a large amount of chlorine component was treated, Comparative Example 1 in which no dechlorinating agent was added
In this case, a large amount of hydrogen chloride gas is generated over each temperature for the heat treatment. In Comparative Example 2 in which slaked lime as a conventional dechlorinating agent was added to this treated product, and in Comparative Example 3 in which calcium carbonate was added as a dechlorinating agent, generation of hydrogen chloride gas was considerably suppressed as compared with Comparative Example 1. But not yet enough.

On the other hand, in Example 1 in which sodium hydrogencarbonate was added as a dechlorinating agent to the above treated product, hydrogen chloride gas was not detected over the entire temperature range, and very good results were obtained. Furthermore, in the cases of Examples 2, 3, and 4 in which the amount of sodium hydrogencarbonate added as a dechlorinating agent was changed for the treated product obtained by adding polyvinylidene chloride to simulated garbage, over the entire temperature range, Hydrogen chloride gas was not detected.

Further, in the case of Example 5 in which sodium bicarbonate was added to a processed product obtained by adding moisture to simulated garbage, the temperature was raised and kept at 450 ° C., and the temperature was raised at 500 ° C. Although a slight generation of hydrogen chloride gas was observed, generally, even if water was present, it was hardly affected, and a very good result was obtained as compared with Comparative Example 2 using slaked lime as a dechlorinating agent. Obtained.

According to the above experimental investigation, when a substance containing a chlorine component is dechlorinated by thermal treatment, a carbonate-based alkali substance (particularly, a sodium-based substance) reacting with harmful chlorine-based gas is dechlorinated. It was confirmed that harmless treatment can be achieved by adding and treating.

Although the same effect was obtained at a temperature of 600 ° C. or higher, the maximum temperature is preferably 1000 ° C. in consideration of the fact that the equipment becomes large at high temperatures.

When a carbonic acid-based alkali substance, in particular, a sodium-based substance reacts with a chlorine-based gas, the detoxification of the gas and the residue can be realized as follows. It is due to being generated by substitution in the product.

(1) In the case of sodium hydrogen carbonate When sodium hydrogen carbonate (NaHCO ₃ ) is added, it reacts with aqueous chloride (HCl) to give the following.

(NaHCO ₃ ) + (HCl) → (NaC
l) + (H ₂ 0) + (CO ₂ ) When water is present (NaHCO ₃ ) + (H ₂ O) → (NaOH) + (H ₂ C)
O ₃ ) (NaOH) + (H ₂ CO ₃ ) + (HCl) → (NaC
1) + (H ₂ O) + (CO ₂ ).

(2) In the case of sodium carbonate When sodium carbonate (Na ₂ CO ₃ ) is added, it reacts with hydrogen chloride (HCl) to give the following.

(Na ₂ CO ₃ ) + (2HCl) → (2Na
Cl) + (H ₂ O) + (CO ₂ ) (3) In the case of sodium sexquicarbonate represented by the chemical formula Na ₂ CO ₃ .NaHCO ₃ .2H ₂ O, the same reaction as in the above (1) and (2) Then, harmful hydrogen chloride (HCl) is replaced with harmless chloride (NaCl) to generate.

Accordingly, the chlorine-based gas becomes NaCl, which is a part of the residue, water (H ₂ O) and gaseous CO ₂ , and does not generate hydrogen chloride which is a cause of dioxin. In addition, detoxification of the residue can be realized.

On the other hand, NaCl produced by the reaction is a harmless chloride, and this NaCl can be effectively removed by washing with a solution such as water.

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

Further, since the treatment liquid after washing contains almost no harmful substances, it can be discharged by a simple treatment.

From the above, it is clear that similar results can be obtained if there is a component that reacts with the chlorine component (Cl) to form harmless and stable chlorides. The following substances can be used:

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

(2) Carbonic acid-based sodium substance (3) A substance selected from a simple substance selected from sodium bicarbonate, sodium carbonate, sodium sesquicarbonate and natural soda, a mixture of two or more simple substances, and a mixture of two or more simple substances .

Note that sodium hydrogen carbonate (NaHC)
O ₃ ) is also referred to as (a) sodium acid carbonate (b) sodium bicarbonate (c) sodium bicarbonate, and is also commonly referred to as baking soda.

[0073] Sodium carbonate (Na ₂ CO ₃ ) is also referred to as sodium carbonate or simply soda as another name. Further, anhydrous salt is also referred to as soda ash, and decahydrate is also referred to as washing soda or crystal soda. .

Sodium sesquicarbonate (Na ₂ CO ₃ .Na
HCO ₃ .2H ₂ O) is also referred to as (a) sodium monocarbonate bicarbonate (b) sodium bicarbonate (c) sodium sesquicarbonate, and is naturally produced as trona (natural soda).

On the other hand, NaCl is produced by the reaction, and the produced NaCl is a harmless chloride as described above. This NaCl can be effectively removed by a washing treatment with a solution such as water. Reusable carbonized material remains, so if this is formed into pellets by a granulator,
It can be used effectively as fuel.

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.

[0077]

As described above, according to the present invention, a treated product is mixed with a dechlorinating agent, first heat-treated at a low temperature below the temperature at which chlorine-based gas is precipitated, and then heat-treated at a high temperature. Since the solidified material (pellet) is formed by pressurizing, (1) a safe pellet free of generation of chlorine-based gas (hydrogen chloride, chlorine gas) when burning the solidified material is obtained.

(2) Even in the process of producing pellets, the harmful chlorine-based gas in the exhaust gas is generated because the harmful chlorine-based gas in the generated gas reacts with the dechlorinating agent to form harmless chloride. Can be effectively removed, and the generation of Diokin is prevented even if the exhaust gas is directly discharged into the atmosphere.

(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 an explanatory diagram of a processing method 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 ... Dechlorinating agent supply part 4, 6 ... Heating means 5 ... Granulator 7 ... Pellets

Claims (14)

[Claims] Claims: 1. A mixture of a treated product and a dechlorinating agent for a carbonic acid-based alkali substance that reacts with a chlorine-based gas, and heat-treated in a plurality of temperature ranges to solidify the resulting product into pellets. A method for solidifying a treated product, characterized by the following. 2. The heat treatment temperature range is set higher in a temperature range in a latter stage than in a former stage, and the temperature range in a former stage is a temperature at which chlorine-based gas starts to be deposited, and the temperature is maintained for a predetermined time. Item 6. A method for solidifying a treated product according to Item 1. 3. The temperature range before the heat treatment is 200 ° C.
The method according to claim 1, wherein the temperature is set to 300 ° C. 4. 4. The heat treatment temperature range is set higher in the latter stage than in the former stage, and the latter temperature range is set to a temperature at which the deposited chlorine-based gas is fixed to the dechlorinating agent, and the temperature is maintained for a predetermined time. The method for solidifying a treated product according to claim 1, wherein: 5. The temperature range of the latter stage of the heat treatment is 300 ° C.
The method for solidifying a treated product according to claim 1 or 4, wherein the temperature is set to 500C. 6. The method according to claim 1, wherein the heat treatment is performed in a low oxygen atmosphere. 7. The solidification treatment of a treated product according to claim 1, wherein the dechlorinating agent is selected from a simple substance of a carbonate-based alkali substance, two or more simple substances, and a mixture of two or more simple substances. Method. 8. The method according to claim 1, wherein the dechlorinating agent is a carbonate-based sodium substance. 9. The dechlorinating agent is selected from a simple substance selected from sodium hydrogen chloride, sodium carbonate, sodium sesquicarbonate and natural soda, a mixture of two or more simple substances, and a mixture of two or more simple substances. A method for solidifying a treated product according to claim 1. 10. The dechlorinating agent according to claim 1, wherein the dechlorinating agent is formed in any one of a lump, a plate, a porous shape, a powder, a solution, and a suspension. 4. The method for solidifying a treated product according to claim 1. 11. The method according to claim 1, wherein the amount of the dechlorinating agent added is 5 to 30% by weight of the treated material.
11. The method for solidifying a treated product according to any one of 7 to 10. 12. The method according to claim 1, wherein the dechlorinating agent is added in an amount of 0.5 to 1.5 mol based on the amount of the generated chlorine component. Solidification treatment method of the treated product. 13. 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 . 14. A mixture of a treated product and a dechlorinating agent for a carbonic acid-based alkali substance that reacts with a chlorine-based gas, and heat-treated in a plurality of temperature ranges. A solidified processed product characterized by being solidified.