JP2003170042A - Harmful substance removal material and harmful substance removal method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a harmful substance removal material capable of economically and highly efficiently removing a variety of harmful substances such as dioxins contained in a flue gas emitted out of a carbonization furnace and an incinerator and a harmful substance removal method using the harmful substance removal material. <P>SOLUTION: The harmful substance removal material is made of sedimentary rock containing at least silicon dioxide, aluminum oxide, iron oxide, calcium oxide, magnesium oxide, sodium oxide, and potassium oxide. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toxic substance removing material and a toxic substance removing method, and its purpose is to reduce various toxic substances such as dioxins contained in flue gas generated from a carbonization furnace or an incinerator at low cost. Another object of the present invention is to provide a harmful substance removing material that can be removed at a high removal rate and a harmful substance removing method using this harmful substance removing material.

[0002]

2. Description of the Related Art Dioxins are three kinds of dichlorinated dibenzoparadioxane (hereinafter referred to as PCDDs), dichlorinated dibenzofuran (hereinafter referred to as PCDFs), and coplanar polychlorinated biphenyl (hereinafter referred to as Co-PCBs). It is a general term for a group of compounds. In each compound group, many isomers exist (75 types in PCDDs and 135 types in PCDFs) depending on the chlorine substitution position and the number thereof. Dioxins are extremely stable compounds, and it takes more than half a year to decompose half of them in soil.

Since dioxins are hardly soluble in water and easily soluble in oil, when they are taken up by living organisms, they are hardly dissolved in lipids in the body and are hardly discharged. Therefore, dioxins released into the environment may undergo bioconcentration and accumulate in high concentrations in the human body located at the top of the food chain.

Dioxins are extremely toxic and at low concentrations, they are teratogenic, lethal, reproductive toxicity, immune / hematopoietic dysfunction, growth suppression, atopic dermatitis, endocrine disruption,
It is suspected to have various effects such as carcinogenicity. The most toxic dioxins are 2,
It is 3,7,8-tetrachlorodibenzoparadioxane and is the most toxic of the artificial substances.

The sources of dioxins are dust and
Industrial waste / medical waste incineration facilities, steel mills, non-ferrous mills, paper mills, ceramic mills, automobiles, cleaning plants, tobacco, etc. are considered, but most of them are generated from incineration facilities, especially municipal waste incineration facilities. It is estimated that In particular, Japan has a small land area and a large amount of waste, so the rate of incineration of general waste is higher than in Europe and the United States. Therefore, Japan is considered to be a country with a large amount of dioxins generated in the world.

[0006] It is considered that the mechanism of producing dioxins by incineration of waste is due to incomplete combustion and due to de novo synthesis. Regarding the mechanism of generating dioxins by incomplete combustion, polynuclear aromatic compounds, polychlorobenzene, etc. are generated when an organic compound containing chlorine is incompletely burned. It is believed that dioxins are formed when these are cooled in the range of about 450 to 200 ° C. The mechanism of dioxin formation by de novo synthesis is considered to be that dioxin is produced by the reaction of air, moisture, inorganic chlorine, etc. on the surface of unburned carbon particles (soot) at a temperature of about 250 to 350 ° C. Has been.
At this time, copper, cobalt, etc. contained in the ash act as a catalyst for promoting the reaction.

[0007]

On the other hand, in recent years, attention has been paid to its excellent deodorizing property and humidity control property, or charcoal and bamboo charcoal have attracted attention as high-quality fuels. Charcoal and bamboo charcoal are generally manufactured using a charcoal-burning furnace. Such a carbonization furnace is small in scale, and only wood and bamboo materials are burned in the carbonization furnace, and dust that produces harmful substances is burned like general incinerators. Therefore, there is no particular restriction on smoke emitted from the carbonization furnace. However,
Since flue gas is also generated in a carbonization furnace that burns only wood, it is considered that harmful substances such as dioxins are generated in a very small amount compared to general incinerators. Therefore, it is desired to remove harmful substances in flue gas even in a relatively small furnace such as a carbonization furnace.

As a technique for removing dioxins in flue gas, for example, Japanese Patent Application Laid-Open No. 10-99677 discloses an Fe content of 1500 pp, which has a low dioxin production catalytic ability.
An adsorbent made of activated carbon having a Cu content of 40 ppm or less and a m or less is disclosed. In addition, JP-A-10-151342
The publication describes an adsorbent containing one or more inorganic porous substances selected from silicic acid, aluminum silicate, magnesium silicate, aluminum hydroxide, and amorphous aluminum hydroxide whose surfaces are hydrophilic. Japanese Patent Laid-Open No. 10-15
1343 describes an adsorbent containing one or more inorganic porous substances selected from silicic acid, aluminum silicate, magnesium silicate, aluminum hydroxide, and amorphous aluminum hydroxide having a hydrophobic surface. JP-A-11
JP-A-226397 describes an adsorbent composed of activated carbon carrying a metal or a metal oxide having an oxidative decomposition ability.

The above-mentioned adsorbent can adsorb and remove dioxins and the like, but it is impossible to use an expensive adsorbent in a small-scale carbonization furnace in terms of cost. It was The present invention is capable of removing various harmful substances such as dioxins contained in flue gas generated from a carbonization furnace, an incinerator, etc. at a low cost with a high removal rate, and a relatively small-scale carbonization furnace or incinerator. The present invention aims to provide a hazardous substance removing material that can be easily applied in the above and a method for removing a harmful substance using the hazardous substance removing material.

[0010]

That is, the invention according to claim 1 is characterized by comprising sedimentary rock containing at least silicon dioxide, aluminum oxide, iron oxide, calcium oxide, magnesium oxide, sodium oxide, and potassium oxide. Related to the harmful substance removing material. The invention according to claim 2 is composed of sedimentary rock containing at least silicon dioxide, aluminum oxide, iron oxide, calcium oxide, magnesium oxide, sodium oxide, and potassium oxide, and a phytocarbide, and is a harmful substance removing material. Regarding The invention according to claim 3 relates to a harmful substance removing material, characterized in that the sedimentary rock is molded into a required shape, and the plant charcoal-based material is molded into a required shape. The invention according to claim 4 relates to a harmful substance removing material comprising a molded body obtained by firing a kneaded material of sedimentary rock powder and water at a temperature of 600 ° C. or higher, and a vegetable carbon. The invention according to claim 5 relates to a harmful substance removing material, characterized by comprising a molded body obtained by firing a kneaded product of sedimentary rock powder grains, vegetable carbide powder grains and water at a temperature of 600 ° C. or higher. The invention according to claim 6 relates to the harmful substance removing material according to any one of claims 1 to 5, wherein the sedimentary rock is mudstone. According to a seventh aspect of the present invention, the harmful substance removing material according to any one of the first to sixth aspects is filled in a flue such as a carbonization furnace or an incinerator to remove the harmful substance contained in the flue gas. Relates to a method for removing harmful substances.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The harmful substance removing material according to the present invention will be described below. The harmful substance removing material according to the present invention,
It consists of sedimentary rocks. Sedimentary rock is rock formed by depositing a medium such as air or water on the surface of the earth's surface under normal temperature and pressure conditions. Particularly in the present invention, gravel,
It is preferable to use clastic rock formed by calcification of debris such as sand and mud, and it is more preferable to use mudstone among clastic rocks. The reason for this is that mudstone has a smaller grain size than debris and sandstone (1/16 mm for mudstone).
Because of the following), the surface area of clastic rock is increased, and harmful substances such as dioxins can be efficiently removed. In addition, the mudstone contains components such as silicon dioxide, aluminum oxide, iron oxide, calcium oxide, magnesium oxide, sodium oxide, and potassium oxide, and the adsorption performance is far superior to other sedimentary rocks. Examples of mudstone that can be preferably used include mudstone from Gojome-cho, Minami-Akita-gun, Akita Prefecture.

The form of the sedimentary rock is not particularly limited, and examples thereof include blocks, pellets, and powder particles.
The size of the block is not particularly limited, but it is preferably a cube or a rectangular parallelepiped having a size of 5 to 15 cm. When it is made into powder, its particle size is not particularly limited, but is 5 to 200 μm, preferably 10 to 4
It is set to 0 μm.

As described above, the sedimentary rock can be used in the form of block, pellet, powder or the like.
Finely crushed sedimentary rock is kneaded with water and molded into 6 pieces.
It can also be used as a molded product obtained by firing at a temperature of 00 ° C or higher, preferably 700 ° C or higher. The form of the molded product is not particularly limited, and examples thereof include block form, pellet form, and powder form. By doing so, the sedimentary rock can be easily formed into an arbitrary shape.

Furthermore, in the present invention, in addition to the above-mentioned sedimentary rock, vegetable carbide can be used together. By using vegetable carbon, it is possible to remove heavy metals such as mercury, zinc, lead, cadmium, and arsenic in addition to dioxins contained in flue gas. The vegetable charcoal is charcoal or bamboo charcoal, and raw wood is 750-10.
White charcoal and raw wood obtained by baking at 00 ° C and carbonizing at 350 to 520 ° C are baked at 350 to 750 ° C, and 25
Any of the black charcoal obtained by carbonizing at 0-450 degreeC can be used preferably. Logs include Quercus acutissima and Quercus serrta
Thunb), black pine (Pinus thunbergii), red pine (Pinus densiflora), cypress (Chamaecyparis obtus)
a), Japanese cedar (Cryptomeria japonica), Uva Mekashi (Qu
ercus phllyraeoides), bamboo and the like.

When using the plant charcoal, the amount of sedimentary rock and the plant charcoal to be used is not particularly limited.
Sedimentary rock: vegetable carbide = 10:90 to 90:10, preferably 30:70 to 70:30, and more preferably approximately equal amounts of sedimentary rock and vegetable carbide. The reason for this is that if the amount of sedimentary rock used is less than 10% by weight of the total amount of harmful substance removing material, the effect of removing harmful substances such as dioxins may not be obtained, and if the amount exceeds 90% by weight. Then, the effect of adding the vegetable charcoal is not obtained, which is not preferable in any case.

When using a vegetable carbonized material, its form is not particularly limited, but examples thereof include block form, powder form, pellet form and the like. When making a block,
The size thereof is not particularly limited, but it is preferably a cubic shape or a rectangular parallelepiped shape having a size of 5 to 15 cm. When it is made into powder, its particle size is not particularly limited, but is 5 to 2
The thickness is 00 μm, preferably 10 to 40 μm.

Further, when using the plant-based charcoal, it can be used in any form such as a block, a pellet or a powder as described above. However, finely crushed sedimentary rock and finely crushed plant-based charcoal, It can also be used as a molded product obtained by kneading with water and molding, and calcining this at a temperature of 600 ° C. or higher, preferably 700 ° C. or higher. The form of the molded product is not particularly limited, and examples thereof include block form, pellet form, and powder form. By doing so, it can be molded into an arbitrary shape.

Preferred forms of the sedimentary rock and the plant charcoal are a block-shaped sedimentary rock and a block-shaped plant charcoal-based material, a pelletized or granular granulated product of the sedimentary rock, and a charcoal block. Examples thereof include a mixed form in which a molded body made of sedimentary rock and vegetable carbide is used.

In order to remove harmful substances by using the harmful substance removing material according to the present invention described above, it is sufficient to fill the flue of an incinerator or a carbonization furnace with the harmful substance removing material. By doing so, harmful substances such as dioxins contained in the flue gas generated from the incinerator and the carbonization furnace can be adsorbed and removed. Further, the harmful substance removal according to the present invention prepared in the form of powder may be directly blown into the exhaust gas passage.

The toxic substance removing material according to the present invention can remove toxic substances such as dioxins generated from carbonization furnaces, incinerators of various wastes such as municipal waste, industrial wastes, clothing wastes, RDF combustion furnaces and the like. Effective for removal. Particularly, it can be preferably used in a relatively small furnace such as a carbonization furnace.

[0021]

EXAMPLES The present invention will be described below based on examples.
The invention is in no way limited to these examples. The blending amount is% by weight. <Preparation of sample> High quality refined coarse grain (5 to 15) produced by using oak as raw wood at a carbonization temperature of 1200 ° C or higher.
cm) of white charcoal (hardness: 15 °) was put in a hemp bag (180 kg) to prepare a removing material of Example 1. DKS5 (trade name, manufactured by Kagaya Wood Co., Ltd.) mudstone (natural mudstone after mining 10
~ 15% dry mudstone) is molded into a cube with 10 to 15 cm on each side, and 180 kg is put in a hemp bag.
The removal material of Example 2 was prepared. <Test Example 1; Analysis of Mudstone> The above mudstone (DKS5) was analyzed for its components. Moreover, the surface area per 1 g was measured. As a result, silicon dioxide, aluminum oxide, iron oxide, calcium oxide, magnesium oxide, sodium oxide, potassium oxide and the like were detected as constituent components. The surface area was 47 m ² / g. <Test Example 2; Removal Test of Toxic Substances in Exhaust Gas> A carbonization furnace (manufactured by Kagaya Wood Co., Ltd.) was used to test the effect of removing harmful substances from the exhaust gas generated when carbonizing wood. FIG. 1 is a block diagram showing an outline of a carbonization furnace (1). (2) is a carbonization chamber, and (3) is a flue. In the test, the midpoint (33) of the flue (3) was filled with the adsorbents of Example 1 (180 kg) and Example 2 (180 kg) prepared above. Downstream part (31) and upstream part (3) of the sample-filled part (33)
The flue gas was collected in 2), and the concentration of dioxins contained in the flue gas was examined.

The measurement of dioxins is carried out by the "method specified in Article 2-1 of the Enforcement Regulations of the Act on Special Measures Against Dioxins" (December 1999) and "JIS K0311 (199).
9) ”. Tables 1 to 3 show detailed analysis conditions of dioxins. Table 1 shows 4-6 of PCDDs and PCDFs.
Chloride analysis conditions are shown in Table 2. PCDDs and PCDF
It is an analysis condition of 7,8 chloride of s. Table 3 shows Co-PC
Bs analysis conditions. Table 4 shows the analysis results of dioxins. As the toxicity equivalent coefficient, the coefficient specified in "Article 3 of the Enforcement Regulations of the Act on Special Measures Against Dioxins (Prime Minister's Ordinance No. 67 of 2001)" was used. In addition, "N in the table
"D" indicates that the value is below the detection limit value. Moreover, the carbon monoxide concentration and the oxygen concentration were measured. The carbon monoxide concentration was measured in accordance with "JIS K0098: 1998 7.2 (non-dispersion infrared absorption densitometer)". The oxygen concentration was measured according to "JIS K0301: 1998 6".
The results are shown in Table 5.

[0023]

[Table 1]

[0024]

[Table 2]

[0025]

[Table 3]

[0026]

[Table 4]

[0027]

[Table 5]

As shown in the results of Table 4, 0.93n was present in the flue gas before treatment by the harmful substance removing material according to the present invention.
Dioxins of g / m ³ N (0.00084 ng TEQ) were contained, but 0.037 in flue gas after treatment.
Dioxins of ng / m ³ N (0 ng TEQ) were contained. It has been confirmed that the harmful substance removing material according to the present invention removes harmful substances such as dioxins.

[0029]

As described above in detail, the harmful substance removing material and the harmful substance removing method according to the present invention can remove various harmful substances such as dioxins contained in the flue gas generated from the carbonization furnace, the incinerator, etc. It has an excellent effect that it can be removed at a low cost with a high removal rate.

[Brief description of drawings]

FIG. 1 is a block diagram schematically showing a carbonization furnace used for measuring the concentration of dioxins.

[Explanation of symbols]

1 carbonization furnace 2 carbonization chamber 3 flue 31 Downstream location 32 upstream 33 Place filled with toxic substance adsorbent

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F27D 17/00 ZAB B01D 53/34 134E

Claims (7)

[Claims] 1. A harmful substance removing material comprising a sedimentary rock containing at least silicon dioxide, aluminum oxide, iron oxide, calcium oxide, magnesium oxide, sodium oxide, and potassium oxide. 2. A harmful substance removing material comprising sedimentary rock containing at least silicon dioxide, aluminum oxide, iron oxide, calcium oxide, magnesium oxide, sodium oxide, and potassium oxide, and vegetable carbide. 3. A harmful substance removing material comprising a sedimentary rock formed into a required shape and a vegetable carbonized material formed into a required shape. 4. A harmful substance removing material comprising a molded body obtained by firing a kneaded product of sedimentary rock powder particles and water at a temperature of 600 ° C. or higher, and a vegetable carbon. 5. A harmful substance removing material comprising a molded body obtained by firing a kneaded product of sedimentary rock powder grains, vegetable carbide powder grains and water at a temperature of 600 ° C. or higher. 6. The harmful substance removing material according to claim 1, wherein the sedimentary rock is mudstone. 7. A flue, such as a carbonization furnace or an incinerator, is filled with the harmful substance removing material according to any one of claims 1 to 6 to remove the harmful substances contained in the flue gas. Method of removing harmful substances.