KR100579427B1 - A method for incinerating trash - Google Patents

Abstract

The present invention suppresses abnormal heat generation inside the incinerator to prevent damage of the refractory constituents of the furnace, while suppressing the generation of harmful exhaust gases such as dioxins generated during incineration, and adsorbing heavy metal ions in the incineration residue. The present invention relates to a method for incineration of waste, which is excellent for environmental protection, by fixing it to prevent leakage and leakage.

Description

A method for incinerating trash}

The present invention relates to a waste incineration method using an incinerator. Specifically, it is possible to prevent abnormal heat generation inside the incinerator to prevent damage of the refractory constituents of the furnace, to suppress the generation of harmful emissions such as dioxins generated during incineration, and to remove heavy metal ions in the incineration residue. The present invention relates to a waste incineration method that is excellent for environmental protection by preventing adsorption and leakage by leaking.

As the Yosai lifestyle changes and the income level improves, the amount of household waste and commercial waste increases. In addition, there is a change in the type of waste and the increase of petroleum-related goods is increasing the waste of combustible resin products. Typically, these wastes are recovered from various valuable components in terms of resource saving, resource recycling, and environmental protection, and then classified into non-combustible waste and combustible waste, and landfilled or incinerated.

By the way, the combustible waste discharged from the general household contains a large amount of combustible resin, the following problems occur in the current waste incineration process.

In other words, ① The combustible resin contained in a large amount of waste has a large amount of heat generated when incinerated, the temperature inside the incinerator rises abnormally, and the incinerator is severely damaged. ② Vinyl chloride, vinylidene chloride (wrap for food packaging) When chlorine-containing resins, such as), are burned, harmful hydrogen chloride gas and dioxins derived therefrom are generated, and they may be released into the atmosphere. In the case of the treatment, heavy metal ions may be dissolved in rain water and leaked.

As a method to cope with such a problem, for example, by spraying water on the incinerator in the furnace with respect to the temperature rise in the incinerator and suppressing the temperature rise in the furnace, raw materials such as garbage bags or the like are filled with calcium carbonate The method of reducing the heat of combustion of itself using resin is mentioned. On the other hand, there are two ways to deal with the discharge of dioxins into the atmosphere: from the direction of reducing dioxin itself and from adsorbing and recovering dioxins. The method of suppressing generation | occurrence | production of the precursor substance of dioxins by completely burning a combusted product according to operation control of a furnace, introduction of a new furnace, etc. which were described in the guideline of this is mentioned. As the latter adsorption recovery measure, for example, a method of injecting activated carbon or the like into a part of a bag filter of a dust collector is mentioned. As a method for preventing the leakage of harmful substances at the time of landfill, for example, a method of insolubilizing the contained hazardous substances and then solidifying them with cement or the like may be used to dispose of landfills.

However, all of these methods take individual measures for each purpose, such as protection of furnace refractory materials, prevention of dioxin scattering due to new construction and modification, and leakage of heavy metal ions from incineration residues. Since enormous processing costs are required to carry out, there is a need for a method that is both inexpensive and capable of solving all problems simultaneously.

An object of the present invention is to prevent an incinerator from rising in temperature, suppressing the damage of the furnace, preventing the emission of harmful emissions such as dioxins, and leaking harmful substances such as heavy metal ions contained in the incineration residue from the landfill. It is to provide a waste incineration method that can be prevented.

In view of these circumstances, the present inventors have diligently studied to achieve the above object, and as a result, when the incinerator is incinerated, a very simple method of coexisting aluminum hydroxide and / or activated alumina (transition alumina) in the waste being incinerated is disclosed. All of the above problems are solved at the same time, and the present invention is found to satisfy all of these objects.

That is, the present invention provides a method for incineration of waste, characterized in that when incinerating waste in the incinerator, the waste is burned in the presence of activated alumina (transition alumina) having an aluminum hydroxide and / or BET specific surface area of 30 m ² / g or more. do.

Hereinafter, the present invention will be described in detail again.

The greatest feature of the present invention is that when burning the waste inside the incinerator, the presence of aluminum hydroxide and / or activated alumina (transition alumina) with a BET specific surface area of at least 30 m ² / g. When the aluminum hydroxide is incinerated with the waste, crystal water is released due to the heat of combustion generated when the waste is incinerated inside the incinerator. Since the release of the crystalline water is an endothermic reaction, the temperature inside the furnace is lowered. In the case of incineration at a specific temperature, the aluminum hydroxide crystallizes and transitions to activated alumina (transition alumina) having a very high gas adsorption capacity or a heavy metal ion adsorption capacity and a large BET specific surface area. In the present invention, when incinerating waste in an incinerator, aluminum hydroxide and / or activated alumina (transition alumina) having a BET specific surface area of 30 m ² / g or more are present in the waste, and the waste is incinerated at a specific temperature, whereby aluminum hydroxide is present. In the case of the presence of activated alumina (transition alumina) having a BET specific surface area of 30 m ² / g or more, and it is transferred to activated alumina (transition alumina), hydrogen chloride gas generated upon incineration in its own form, or Adsorption of dioxin and the like to prevent them from being discharged, and also to adsorb heavy metal ions contained in the residual ash when the residual ash is embedded, prevents it from leaking.

The type of aluminum hydroxide used in the present invention generally has crystal water such as gibbsite, vialite, boehmite, norstrandite and the like. Among these, gibbsite is produced in large quantities as a raw material of alumina and aluminum using Bayer process, and thus can be obtained at an easy and low price, and is suitably used.

In addition, the aluminum hydroxide used by this invention may be aluminum hydroxide etc. which were collect | recovered from the alkaline solution used for aluminum surface treatment, such as sludge containing aluminum hydroxide used for wastewater treatment, and aluminum sash.

In the present invention, the active alumina (transition alumina) having a BET specific surface area of 30 cm ² / g or more may be a known one, and is a kind of aluminum oxide of the formula Al ₂ O ₃ , and its crystalline form is γ-alumina, δ-alumina, κ Aluminum oxide mainly comprising alumina, η-alumina, θ-alumina, σ-alumina, χ-alumina, ι-alumina, ρ-alumina, amorphous alumina and the like. In the present invention, the BET specific surface area is a specific surface area based on the adsorption method (Braunauer-Emmerit-Teller method), and is measured according to the flow specific surface area measurement. The BET surface area of (transition alumina) is at least 30 m ² / g, preferably from about 30 m ² / g to about 500 m ² / g, more preferably from about 50 m ² / g to about 300 m ² / g.

In addition, in the present invention, the method of having aluminum hydroxide present in the furnace is not particularly limited, and the following method is usually used. For example, a method of pre-mixing the waste provided for incineration with activated alumina (transition alumina) having an aluminum hydroxide and / or BET specific surface area of 30 m ² / g or more, separately controlling aluminum hydroxide while controlling the temperature inside the incinerator during waste incineration, / Or direct addition of activated alumina (transition alumina) having a BET specific surface area of at least 30 m ² / g into the furnace, containing aluminum hydroxide and / or active alumina (transition alumina) having a BET specific surface area of at least 30 m ² / g in the resin In the form of the molded resin molded product (for example, a bag for shopping of goods such as a supermarket and a bag for collecting garbage), it is applied to the inside of an incinerator and combusted with other wastes, and solid fuel (RDF) manufactured by compression molding flammable waste. Activated alumina (transition alumina) with aluminum hydroxide and / or BET specific surface area of 30 m ² / g or more in the solid fuel The amount is 0.001% to 40% by weight of aluminum hydroxide, preferably 0.01% to 30% by weight, and 0.001% to 30% by weight of active alumina (transition alumina) having a BET specific surface area of 30 m ² / g or more, Preferably from 0.01% to 20% by weight of activated alumina (transition alumina) with aluminum hydroxide and / or BET specific surface area of at least 30 m 2 / g in the form of the solid fuel is added to the incinerator, together with other waste. And a method of burning.

The amount of aluminum hydroxide present in the waste is preferably about 0.001% to about 40% by weight, more preferably 0.01% to about 30% by weight. The amount of activated alumina (transition alumina) having a BET specific surface area of 30 m 2 / g or more is preferably about 0.001% to about 30% by weight, more preferably about 0.01% to about 20% by weight relative to the waste. When the amount of activated alumina (transition alumina) having an aluminum hydroxide and / or BET specific surface area of 30 m 2 / g or more at incineration is less than about 0.001% by weight, the effect of temperature suppression, adsorption of exhaust gas and adsorption of heavy metal ions On the other hand, when the amount of the abundant exceeds the above-mentioned range, the temperature suppressing effect, the adsorption effect of the exhaust gas, and the adsorption effect of heavy metal ions are large, but since the incineration residue is increased, the upper limit of the amount of aluminum hydroxide is incinerated The amount of residual ash is determined by the increase in balance between achieving the objective.

It does not specifically limit about the kind of incinerator used by this invention, For example, a stocker type incinerator, a fluidized bed type incinerator, a rotary kiln, etc. which are generally used are mentioned.

In the embodiment of the present invention, the incineration conditions are not unique depending on the incinerator used, the incineration temperature, the incineration time, the amount of waste put into the incinerator, and the type of waste, but the temperature of the incinerator is preferably about 500 ° C to about 1100. ° C, more preferably about 500 ° C to about 1000 ° C, most preferably about 600 ° C to about 900 ° C. If the temperature inside the incinerator is lower than about 500 ° C, the combustion speed is slow inside the furnace and it is not practical because the incineration of waste requires more time than in normal operation. In addition, if it exceeds about 1100 ° C, there is a risk of damaging the furnace, and when aluminum hydroxide is present, the activity of the activated alumina (transition alumina) crystallized therefrom is lowered, and the BET specific surface area is 30 m ^2. When the presence of activated alumina (transition alumina) of / g or more exceeds about 1100 ° C, the crystal transition is caused by α-alumina, and the specific surface area is small, so that the ability to adsorb exhaust gas or adsorb heavy metal ions in any case There is a possibility that the ability to do so is reduced.

Incineration time is especially when aluminum hydroxide is present, in which aluminum hydroxide after incineration is a crystalline form of χ-alumina, γ-alumina, θ-alumina, η-alumina, δ-alumina, κ-alumina, σ-alumina, ι-alumina , ρ-alumina, amorphous alumina and the like, having a BET specific surface area of at least about 30 m ² / g, preferably from about 30 m ² / g to about 500 m ² / g, more preferably from about 50 m ² / g to about 300 m ² / It is preferred that the time is sufficient to transfer to active alumina (transition alumina), which is g.

In the present invention, the aluminum hydroxide present in the incinerator is crystallized from aluminum hydroxide to activated alumina (transition alumina) due to waste incineration heat, and has an effect of absorbing and adsorbing gas. In general, when incinerating waste on a commercial base, incineration residues always remain in the furnace in either case of continuous incineration or intermittent incineration in the waste incinerator, so once aluminum hydroxide is added to the incinerator, the activity derived from aluminum hydroxide Alumina (transition alumina) is always present inside the furnace, thereby fully exhibiting the effects of the present invention, such as removing harmful components such as exhaust gas generated. On the other hand, when incineration is resumed after the incineration residue is completely removed from the furnace, activated alumina (transition alumina) is added therein as necessary, and aluminum hydroxide which is present at the time of incineration of wastes as an effect complement is activated alumina. It can be used until it is transferred to (transition alumina). Further, in the present invention, activated alumina (transition alumina) can be mixed with aluminum hydroxide from the beginning.

As described above, according to the present invention, an abnormal temperature rise inside an incinerator is a very simple way to present activated alumina (transition alumina) having aluminum hydroxide and / or BET specific surface area of at least 30 m ² / g upon waste incineration. While adsorbing harmful emissions such as dioxins due to hydrogen chloride gas and the like, and suppressing their discharge, while adsorbing harmful substances such as heavy metal ions contained in incineration residues, they leak from landfills It can be prevented so that it is very valuable in terms of environmental hygiene and industrial use.

Example

Next, although an Example demonstrates this invention in detail, this invention is not limited to these. In addition, the center particle diameter which concerns on this invention means the central cumulative value of the particle size distribution map obtained by the laser diffraction particle size distribution measurement.

Example 1

100 parts by weight of a high density polyethylene film containing 30% by weight of aluminum hydroxide powder (center particle diameter 8 占 퐉, manufactured by Sumitomo Chemical Co., Ltd.) and 100 parts by weight of a high density polyethylene film containing no aluminum hydroxide powder were burned. The calorific value is measured using a bomb calorimeter. As a result, the heat of combustion of the high density polyethylene film containing aluminum hydroxide powder is 7791 cal / g, and the thing which does not contain is 11200 cal / g. The results show that the heat of combustion decreases in the presence of aluminum hydroxide.

Example 2

Aluminum hydroxide powder (C-31 from Sumitomo Chemical Co., Ltd.) was burned in an electric furnace together with polyethylene film, wood chips and cardboard to obtain an incineration residue. This incineration residue is substantially activated alumina and its BET specific surface area is 101 m ² / g.

1.5 mg of the above incineration residue ash, 1.5 mg of aluminum hydroxide (C-31) and 10 mg of vinyl chloride powder were put into a plastic combustion tester PCT (manufactured by Sugiyamagen Iriki), and the combustion temperature was 750 ° C., and the air flow amount was 0.5 l / min. And a burn time of 10 minutes. The generated hydrogen chloride gas is absorbed with 20 mM sodium carbonate in accordance with Japanese Industrial Standard JIS-K 7217, and then nitrate is quantified by titration method. As a result, the detection amount of hydrogen chloride gas is 4.3 mg. On the other hand, when only 10 mg of vinyl chloride powder was burned in the same manner, the detection amount of hydrogen chloride gas was 5.1 mg. The results show that the hydrogen chloride gas generated when burning vinyl chloride in the presence of aluminum hydroxide is adsorbed and its discharge is suppressed.

Example 3

A high density polyethylene film containing 30% by weight of aluminum hydroxide powder (manufactured by Sumitomo Chemical Co., Ltd.) having a central particle diameter of 3 µm is burned in an electric furnace together with wood chips and corrugated cardboard to obtain an incineration residue. This incineration residue is substantially activated alumina and its BET specific surface area is 114 m ² / g.

A glass column for gas chromatography (outer diameter 5 mm, inner diameter 3 mm, length 50 cm) is charged with 0.5 g of the above incineration residue. The glass column was fixed to gas chromatography, maintained at 200 ° C. to flow carrier gas (nitrogen), and 0.2 ml of a 4.8 μg / ml dioxin / n-hexane solution was divided into 4 times with a 50 μl syringe for 2 minutes. Inject. The dioxin / n-hexane solution used is 1,3,6,8-tetrachlorodibenzodioxin, 1,2,4,7,8-pentachlorodibenzodioxin, 1,2,6,7-tetra N-hexane solution containing 1.2 µg / ml of chlorodibenzofuran and 1,3,4,7,8-pentachlorodibenzofuran, respectively. After injecting the dioxin / n-hexane solution, the carrier gas continues to flow for 5 minutes, then the heater and carrier gas are stopped and the apparatus is quenched. After cooling, the incineration residue (active alumina) in the column is taken out, and the amount of dioxins contained in the incineration residue (active alumina) is analyzed. The analysis uses the method based on the "Dioxin standard measurement analysis manual (February 9, 2017)" prepared by the Ministry of Environment, Health and Welfare Department, Ministry of Water, Environment and Environment, Ministry of Water, Environment and Environment. The results are shown in Table 1.

Example 4

In place of the incineration residues used in Example 3, adsorption tests of dioxins are carried out in accordance with Example 3, except that commercially available activated alumina having a BET specific surface area of 170 m ² / g is used. The results are shown in Table 1.

Comparative Example 1

The adsorption test of dioxins is performed based on Example 3 except having used the incineration residual material prepared in the following procedure instead of the incineration residual material (active alumina) used in Example 3.

A high density polyethylene film containing 30% by weight of calcium carbonate is burned in an electric furnace together with wood chips and corrugated cardboard to obtain incineration residue. The main component of this incineration residue is calcium carbonate, and its BET specific surface area is 4 m ² / g. The results are shown in Table 1.

Comparative Example 2

A dioxin adsorption test was carried out in accordance with Example 3, except that activated carbon having a BET specific surface area of 1200 m ² / g was used in place of the incineration residual ash (activated alumina) used in Example 3. The results are shown in Table 1.

TABLE 1

The results of Table 1 show that the aluminum hydroxide or activated alumina present at the time of incineration exhibits the effect of adsorbing dioxins and suppressing their release. In addition, it can be seen that the effect is superior to calcium carbonate and activated carbon.

Example 5

25 tons of household waste using a 40 tons / day mechanical batch furnace (type: Ebara type B dust incinerator, Evaline Filco Co., Ltd.), an incineration plant equipped with a gas cooling chamber and multi-cyclone And 250 kg of aluminum hydroxide are put in an incinerator so as to be uniformly dispersed in the waste of aluminum hydroxide and burned for about 7 hours. After the end of combustion, 70 g of the recovered fly ash was filled into a glass column having an inner diameter of 25 mm and a length of 600 mm having a gate valve attached to the bottom portion, and 200 ml of deionized water was introduced therefrom. After leaving for 24 hours, the gate valve was opened, and deionized water was taken out as an extract from the bottom portion over 12 hours, and the concentration of heavy metal ions in the extract was measured with an atomic absorption spectrophotometer. On the other hand, the heavy metal ion concentration in a fly ash is computed from the result of fluorescence X-ray analysis. The following formula is used to calculate the extraction rate from the fly ash of various metal ions to the extract from the heavy metal ion concentration in the fly ash and the heavy metal ion concentration in the extract. The results are shown in Table 2.

% Extraction = (weight of deionized water used x heavy metal ion concentration in extract) ÷

     (Weight of fly ash used X concentration of heavy metal ion in fly ash) X 100

Comparative Example 3

The waste was burned in the same manner as in Example 5 except that aluminum hydroxide was not added, and the extraction experiment of heavy metal ions from the fly ash was carried out in the same manner as in Example 6 using the recovered fly ash. The results are shown in Table 2.

In addition, the concentration of the aluminum component in the fly ash used in Example 5 and Comparative Example 3 was measured by fluorescence X-ray analysis, and the concentration of the aluminum component in the fly ash of Example 5 was compared with that of the comparative example 3. Value of 5% by weight.

TABLE 2

From the results in Table 2, it can be seen that in the incineration of waste, by adding aluminum hydroxide, ions such as Cu, Pb, and Zn are adsorbed, and its discharge is suppressed.

Example 6

Instead of using deionized water in the extraction experiment of Example 5, the extraction experiment was carried out in the same manner as in Example 5 except that 200 ml of hydrochloric acid at pH 4 was used. The results are shown in Table 3.

Comparative Example 4

Instead of using deionized water in the extraction experiment of Comparative Example 3, an extraction experiment was conducted in the same manner as in Comparative Example 3 except that 200 ml of hydrochloric acid having a pH of 4 was used. The results are shown in Table 3.

TABLE 3

From the results in Table 3, it can be seen that in the waste incineration, by adding aluminum hydroxide, ions such as Cu, Pb, and Zn are adsorbed and the discharge of these ions is suppressed.

The waste incineration method of the present invention prevents an incinerator's abnormal temperature rise and suppresses damage to the furnace while suppressing the emission of harmful exhaust gases such as dioxins, and also burying harmful substances such as heavy metal ions contained in the incineration residue. Leakage can be prevented.

Claims (8)

In the waste incineration method, the waste is combusted in the presence of aluminum hydroxide, activated alumina (transition alumina) having a BET specific surface area of at least 30 m ² / g, or both, wherein the amount of aluminum hydroxide in the waste A method for incineration of rubbish, characterized in that the amount of active alumina (transition alumina) having a BET specific surface area of 30 m 2 / g or more is 0.001% to 30% by weight based on 0.001% by weight to 40% by weight. In the waste incineration method, aluminum hydroxide, activated alumina (transition alumina) having a BET specific surface area of 30 m ² / g or more, or both are added to combust the waste, and the amount of aluminum hydroxide for the waste is 0.001. A waste incineration method, characterized in that the amount of activated alumina (transition alumina) having a BET specific surface area of 30 m ² / g or more is 0.001% to 30% by weight. According to claim 1, Incineration method of the waste, characterized in that the incineration temperature of the waste 500 ℃ to 1100 ℃. The waste incineration method according to claim 1, wherein the aluminum hydroxide turns into activated alumina (transition alumina) after incineration. The activated alumina (transition alumina) of claim 1, wherein the aluminum hydroxide, BET specific surface area is 30 m ² / g or more, or both, the active alumina (transition alumina), or both of aluminum hydroxide, BET specific surface area is 30 m ² / g or more A waste incineration method, characterized in that it is in the form of a resin molded product contained in a different resin. According to claim 2, Incineration method of the waste, characterized in that the incineration temperature of the waste 500 ℃ to 1100 ℃. The waste incineration method according to claim 2, wherein the aluminum hydroxide turns into activated alumina (transition alumina) after incineration. The method of claim 2, wherein the aluminum hydroxide, active alumina (transition alumina), a BET specific surface area of more than 30m ² / g, or both, the aluminum hydroxide, active alumina (transition alumina), a BET specific surface area of more than 30m ² / g, or both, The waste incineration method, characterized in that the form of a resin molded body containing in the resin.