JP2003201189A - Compact for cleaning and production method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact for cleaning which can be compacted into a desired shape without forcing out the adsorption and reduction functions of charcoal, and to provide a production method therefor. <P>SOLUTION: By weight, 5 to 95% charcoal powder carbonized at a carbonization temperature of 400 to 2,200°C, and 95 to 5% powder of diatomaceous shale are stirred and mixed to prepare a mixed composition as an aggregate of granular bodies of ≤1,000 μm. This mixed composition is filled into a compacting die, and is solidified. The solidified compact is fired at ≥600°C in a reducing atmosphere to obtain a compact for cleaning. Instead of diatomaceous shale, kaolinite and peat can be used. It is preferable that the prepared mixed composition is charged to the inside of water to be made into a slurried suspension, and is scooped up with a sheet making die, and is dried and solidified so as to be made into a compact. In particular, NOX and NO<SB>2</SB>as harmful substances in a vapor phase are converted into harmless N<SB>2</SB>. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

The present invention relates to relates to moldings and a manufacturing method thereof for purifying used to detoxify mainly nitrogen oxide (NO _X) and vapor phase contaminants such as carbon fine particles under gas phase environment .

[0002]

2. Description of the Related Art Sources of NO _X are divided into fixed sources of exhaust gas from power plants and the like, and mobile sources of exhaust gas from automobiles and the like. The concentration of NO _X by mobile sources in large cities and highways wayside become increasing tendency, environmental standards also many places that have not been achieved for nitrogen dioxide (NO ₂₎ According to the environmental white paper. Moreover, environmental pollution due to NO _X from the above-mentioned mobile generation sources has become more serious as urban highways become more complex and tunneled.

As a measure for purifying or reducing such NO _X , a combination of adsorption using silica gel or zeolite and selective catalytic reduction using ammonia is known for the fixed source, and the above-mentioned mobile source is used. On the other hand, removal using a three-way catalyst composed of a combination of a noble metal and a rare earth is known. However, the former has a problem that it requires a huge amount of operating energy for the operation of the ultra-large-sized treatment equipment and the treatment equipment and causes a rise in the purification treatment cost, while the latter has a problem under severe conditions such as high temperature thermal shock. There is a problem in maintaining the purification function of the above, and there are problems such as high cost of raw materials.

In recent years, there has been proposed a system intended to reduce NOX and collect fine carbon particles by a multi-layer filter using activated carbon or activated carbon fiber, but it has a contact / catalyst function and an adsorption / condensation function. However, it has not been widely used because it is difficult to secure the stability of each function.

On the other hand, it has been clarified by studies by the present inventors and other studies that charcoal obtained by carbonizing wood exhibits remarkable adsorption characteristics depending on the carbonization temperature.

As a natural material having a porous structure similar to that of silica gel, zeolite, etc., for example, diatom shale produced in large quantities in Hokkaido is known, and this diatom shale is used for humidity control. Attempts have been made to develop applications for application as a part of building materials and interior materials for houses.

[0007]

By the way, regarding the above charcoal, the present inventor controls the pores generated in the wood cell wall pore wall and the distribution thereof by controlling the carbonization temperature among various carbonization conditions. The charcoal obtained by carbonizing at a specific temperature exerts not only an adsorbing action but also a reducing action, and the reducing action is as high as 8 to 15 times higher than carbon materials such as coke and activated carbon. I found out that it would exert. Then, the present inventor uses charcoal, which has an adsorbing action due to continuous porosity, a catalytic condensing action, a filtering action, and the like in addition to such a strong reducing action, to convert NO _X into harmless N ₂ to render it harmless. Confirmed to get (eg,
"Materials", Vol. 48, No. 5, pp. 473-482, especially p. 478, May 1999, Material Society of Japan).

However, in order to render NO _X harmless, it is difficult to apply the charcoal material alone to an actual road environment, a residential environment, etc., and it is preferable to mold it into a predetermined shape adapted to each environment.

However, a wood carbonized material such as charcoal is fragile in strength and has a poor bonding function (adhesive function) between the individual materials, and it is extremely difficult to form a desired shape by itself. There is. In addition, the above-mentioned carbonized wood material has poor wettability, which makes molding with an adhesive difficult. Even if some kind of adhesive can be mixed with the above-mentioned carbonized wood material, if the adhesive closes the pore structure on the surface of the carbonized wood material, the above-mentioned excellent functions and actions of the carbonized wood material will be obtained. Can not be exerted.

The present invention has been made in view of the above circumstances, and an object thereof is to mold it into a desired shape without blocking the excellent function and action of the carbonized wood material. It is intended to provide a molded article for purification and a method for producing the same.

[0011]

[Means for Solving the Problem and Its Effect] In order to achieve the above object, the present inventor focused on natural porous inorganic materials such as diatom shale as a material for binding a wood carbonized material, It has been found that by bonding (adhering) carbonized materials to each other through interposition of a natural porous inorganic material, it is possible to form into a predetermined shape while ensuring the function and action of the wood carbonized material itself. The present invention has been completed as a result of various examinations of compounding conditions and heat treatment conditions for the compounding of different materials such as a compound of a carbonized wood material and a natural porous inorganic material. .

[0012] Specifically, in the invention relating to a purification molded body, a mixed composition containing a powdery, granular or flaky wood carbonized material and a powdery natural porous inorganic material is molded in a mold of a predetermined shape. It was made to be integrally compounded by heating at a high temperature in a state of being filled in (1).

Further, in the invention relating to the above-mentioned method for producing a purification molded body, a step of preparing a mixed composition containing a powdery, granular or flaky carbonized wood material and a powdery natural porous inorganic material And a step of filling the prepared mixed composition in a mold having a predetermined shape and a step of heating the filled composition at a high temperature to integrally form a composite (claim 3).

Here, as the "natural porous inorganic material", diatom shale or diatomaceous earth is preferably used (claims 2 and 4), and kaolinite, peat or the like can also be used. . In addition, in order to "integrately combine by heating at high temperature", baking at a temperature of 600 ° C or higher (Bakig) in a reducing atmosphere, 800 ° C to 3
Heat treatment (Heat-Treatment) or sintering (Sintering) at 000 ° C. or higher may be performed. Further, the above-mentioned "predetermined shape" includes a rectangular or spherical block shape such as brick, a pillar shape, a board shape, a tile shape, a sheet shape, and the like, and more specific applications include soundproof and sound insulation walls for highways. A shape suitable for a board for a tunnel exhaust port, a surface sheet or a filter, an inner wall constituent material of an exhaust gas chimney of a power plant, various interior and exterior materials for a house, etc. is preferably adopted.

Production of the above-mentioned purification molding or the purification molding
According to the purification molding obtained by the manufacturing method, wood carbonization
Material and natural porous inorganic material such as diatom shale were combined
Therefore, their pore structure and chemical structure (chemical
Based on the reactivity, the catalytic function by the reducing action, contact and coagulation
It exerts an adsorption function by shrinkage and molecular sieving action. to this
Therefore, the following effects are exhibited. That is, wood carbonization
NO based on the strong reducing action of materials_XTo N_TwoTo
Detoxification conversion [2N_Two→ (2NO + O_Two) → (N _Two+20
_Two)], A wood cell wall pore wall of the above carbonized wood material
Contact and condensation caused by nano-order pores (nanospace)
Detoxification based on each action of shrinkage and molecular sieving, and further Zeo
SiO like light_TwoAnd alumina as the main component 0.2
~ Diatomite Shale Powder with Pore Diameter of Several nm and Chemical Structure
Gas phase contamination due to adsorption function and catalyst function brought by
NO among the substances_XAnd carbon fine particles are made harmless
It

Particularly, a wood carbonized material carbonized at a carbonization temperature of 600 ° C. or higher has, for example, 100 ppm NO.
₂ is sufficient as a detoxifying function, and a mixed composition containing at least 5% of such a wood carbonized material exhibits the above-mentioned sufficient detoxifying function (claim 5). At least 5% natural porous inorganic material such as diatom shale
By heat treatment with the mixed composition containing them, they can be combined with each other so as to form an integral composite with the carbonized wood material, and thus exhibit high shape retention (claim 5).

On the other hand, the wood carbonized material is procured by utilizing unused waste wood, and the diatom shale as a natural porous inorganic material is a rock almost inexhaustible as a resource. You can in addition,
The wood carbonized material can be reused as a resource. Further, the wood carbonized material constituting the purification molded body is a wood resource, and the natural porous inorganic material such as diatom shale is a fossil of diatomaceous phytoplankton, that is, a plant resource, so it is discarded after use. Also, it has no environmental burden and can be returned to the natural world as soil, and can be recycled or diverted as another functional material by crushing and re-baking. In addition, high-temperature heating (firing, etc.) when molding (compositing) into a purification molded body is achieved by utilizing the wood carbonized material itself as a raw material or by utilizing the self-heating reaction heat of wood or biomass before carbonization. , Very low energy consumption with minimal use of new energy, and thus can be combined at low cost.

Further, even when it is applied in a high temperature environment such as a stack for exhaust gas, it can exhibit heat resistance, oxidation resistance, thermal shock resistance, high dimensional stability against heat, flame retardancy and the like.

In the method for producing the purification molded body according to any one of claims 3 to 5, various concrete production methods as described below can be adopted depending on the shape of the object to be molded and the object to be applied. That is, firstly, as the preparation of the mixed composition,
Finely powdered natural porous inorganic material is adhered to each surface of powdered or granular wood carbonized material to give 0.1 μm to 5 μm.
It can be an aggregate of granules of 00 μm (claim 6). In this case, regardless of the shape of the mold, it is possible to easily and surely fill the mold, and it is possible to prepare a versatile mixed composition.

Secondly, as the preparation of the mixed composition, the natural porous inorganic material is smoked by exposing the smoke generated during the carbonization treatment of the wood-based material to the smoke, and the thermal decomposition product contained in the smoke is used as the natural mixture. It can also be carried out by adhering to the surface of the porous inorganic material or by introducing it into the material (claim 7). That is, the natural porous inorganic material is made to function as a carbon carrier, and the carbon carrier is supported in the gas phase.

Thirdly, as the preparation of the mixed composition, the natural porous inorganic material is immersed in the liquid pyrolysis product generated during the carbonization treatment of the wood-based material, and the pyrolysis product is mixed with the natural porous inorganic material. It can also be carried out by attaching it to the surface of or by introducing it into the material (claim 8). That is, the natural porous inorganic material is made to function as a carbon support, and the carbon support is carried in the liquid phase.

Fourthly, in order to prepare the mixed composition and fill it in a predetermined mold, a powdery wood carbonized material and a powdery natural porous inorganic material are dispersed / suspended in water to form a slurry. Alternatively, the mixed composition may be prepared, and then the slurry-like suspension may be scooped up by a papermaking mold having a predetermined shape and dried and solidified to fill the predetermined mold (claim 9). It is preferably used when a sheet-shaped or film-shaped molded body for purification is used, and even such a molded body of a thin product can be reliably molded.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below.

<First Embodiment> The wood carbonized material is carbonized by using waste wood, wood waste (biomass) or the like as a raw material, and particularly carbonized at a carbonization temperature of 600 ° C. or higher. The upper limit of the carbonization temperature is the upper limit temperature of the heating capacity of the carbonization furnace, but it is usually up to 3000 ° C. Preferably 600 ° C-1500 ° C, 600 ° C-
It is 800 ° C. In addition, if it is 400 degreeC or more, the detoxification function of this invention can be exhibited. In addition, energy saving can be achieved by utilizing the self-generated heat of reaction of the raw material during the carbonization treatment. Then, the obtained wood carbonized material is made into powder having a diameter of 0.1 μm to 500 μm.

On the other hand, a diatom shale is used as a natural porous inorganic material, and this diatom shale has a diameter of 0.1 μm as described above.
˜500 μm powder.

Then, by mixing both powders of 5% by weight to 95% by weight of a wood carbonized material and 95% by weight to 5% by weight of diatom shale, an aggregate of granules having a diameter of 0.5 μm to 1000 μm is obtained. A mixed composition is prepared. For the preparation by the above mixing, for example, 20 rpm
It is sufficient to stir and mix at 500 rpm.

Next, the mixed composition, which is an aggregate of the above-mentioned granules, is filled in a molding die corresponding to the intended shape, and is preheated to cure and demold. This preheating may be carried out while applying pressure, and in the case of a material having a considerably low specific gravity, it may be hardened while being compressed by blowing hot air from one side while being filled in the mold. In addition,
If vacuum wrought molding is used as the above-mentioned molding die, the filling operation can be facilitated and the filling can be ensured.

Then, the above-mentioned molded product is put into a heating furnace and heated at a predetermined temperature in a reducing atmosphere to integrally form a composite. This heating may be determined from the following depending on the size of the target shape and the strength required for the object to which the target shape is applied. That is, firing at a temperature of 600 ° C. or higher, 800 ° C.
The heat treatment or sintering may be performed at ˜3000 ° C. or higher. In the case of sintering, the spark sintering method (Spark
Plasma Sintering) may be adopted.

In the preparation of the above-mentioned mixed composition, 5 powders of both the above-mentioned carbonized carbonaceous material and diatom shale powder were added.
After adding 30% by weight of the thermosetting resin, the above-mentioned granules may be obtained by performing the above-mentioned mixing and stirring. Examples of the thermosetting resin include, for example, a B-stage phenol formaldehyde resin which is not completely cured (synthesized by a conventional method with a formaldehyde / phenol molar ratio of 2 to 4) and a resorcinol resin. , Or one or more selected from furan resins and the like. In this case, the above-mentioned stirring and mixing will give granules of the above diameter in a state where the wood carbonized material and the diatom shale are attached in layers on the surface of the thermosetting resin, and the preheating causes heat treatment. It is possible to obtain a molded product that is in a more rigidly cured state than when no cured resin is added, and the handling during heat treatment such as firing becomes easier.

Alternatively, the above-mentioned mixed composition may be attached to a base having the same function as that of the molding die and molded without filling the molding die. As the base in this case, for example, a non-combustible non-woven fabric formed of carbon fiber, slag wool, glass wool, or the like is used, and the above-mentioned mixed composition is affixed / laminated to this non-combustible non-woven fabric and mixed on the surface of the non-combustible non-woven fabric Form a thin film of the composition. This allows
A molded article whose shape is retained by the noncombustible non-woven fabric as a base can be obtained without preheating. Then, this molded product may be heated in the same manner as described above to integrate it with the non-combustible non-woven fabric and to integrally integrate the mixed composition itself.

<Second Embodiment> In the second embodiment, a manufacturing method for obtaining a thin sheet-shaped or film-shaped purification molded body will be described.

First, the carbonized wood material and the diatom shale are crushed into powders having a diameter such that they pass through a 10-mesh sieve and are retained on a 100-mesh sieve.
The mixing ratio is the same as that of the embodiment.

Then, the mixed powder is dispersed / suspended in water to prepare a mixed composition as a slurry, and thereafter, the slurry-like suspension is scooped up by a papermaking mold having a predetermined shape and dried and solidified. . By baking, heat-treating or sintering the dried and solidified molded product as in the first embodiment, a thin sheet-shaped or film-shaped purification molded product can be obtained.

<Third Embodiment> In the third embodiment, a diatom shale powder is used as a carbon carrier, and a wood carbonized material is supported on the diatom shale powder to prepare a mixed composition. explain. In addition, regarding the mixed composition after being prepared, the steps until the molded article for purification is obtained using the mixed composition are the same as those in the first embodiment or the second embodiment.
It can be applied to any of the embodiments.

First, a manufacturing method in which the above-mentioned loading is carried out in the gas phase will be described. That is, the powder of the diatom shale is exposed to smoke generated during the carbonization treatment of the wood-based raw material in the carbonization furnace to smoke. Thereby, the thermal decomposition product contained in the smoke is attached to the powder surface of the diatom shale or introduced into the powder, and the mixed composition can be prepared.

On the other hand, the above-mentioned loading can be carried out in the liquid phase as follows. First, a liquid thermal decomposition product (liquid tar, wood vinegar solution, generated during carbonization of the wood-based raw material,
Bamboo vinegar etc.) is collected and dissolved in an organic solvent such as acetone or alcohol. Then, diatom shale powder is immersed in this solution. Thereby, the above-mentioned thermal decomposition product is attached to the powder surface of the diatom shale or introduced into the powder, and the mixed composition can be prepared.

<Other Embodiments> In addition to the detoxification of NO _x , the purification molded body of the present invention can be used for removing harmful substances as follows. That is, volatile organochlorine compounds such as endocrine disrupting chemicals (environmental hormones) (V
Since it can be made harmless by selective adsorption / decomposition even with respect to OC), it can be naturally applied to the purpose of gas phase purification in a closed space such as interior materials for houses, interior materials for vehicles, interior materials for ships. it can. Furthermore, it can be used for the purposes of CFC recovery / removal, heavy metal adsorption / recovery, odor removal, and water purification.

[0038]

EXAMPLE A purification compact A according to the second embodiment (specific gravity 0.4) and a purification compact B using a kaolinite powder instead of the diatom shale in the second embodiment (specific gravity 0.
5) and the purification molding C in which the zeolite powder (SZM-5) was used instead of the diatom shale in the second embodiment, and a comparative test was performed on the reduction rate of NO ₂ . For each of the purification moldings A, B, and C, the carbonization temperature (° C.) of the wood carbonized material is 400, 600, 800, 1000, 140.
0, 1800, 2200, 7 kinds of diatom shale powder, kaolinite powder, and zeolite powder are contained (mixing ratio; unit weight%) as 0, 10, 2
Six test pieces of 5, 50, 75, and 90 were used to fabricate 7 × 6 = 42 kinds of test pieces, and the following test was performed for each of 42 kinds. In addition, cedar wood was used as the raw material of the wood carbonized material, and cedar charcoal powder that passed through a 30-mesh sieve was used as the wood carbonized material.

The test method is as follows. 0.5 g of one type of test piece was placed in a closed system (in a glass tube), and He gas containing 98 ppm of NO ₂ was passed through this test piece at a flow rate of 100 ml / min. The reduction rate of NO ₂ concentration was measured. The reduction rate of NO ₂ concentration means that NO ₂ was converted to N ₂ and rendered harmless,
For example, 100% means that all of NO ₂ was converted to N ₂ and completely detoxified.

FIG. 1 shows the test results of the molded product A for purification.
2 shows the test results for the purification molded body B, and FIG. 3 shows the test results for the purification molded body C.
In addition, another test was carried out in the case where the peat powder was used instead of the kaolinite powder in the purification molding B, and the result was almost the same as that of the purification molding B in FIG.

According to the test results shown in FIGS. 1 to 3, the purification molding A has the best NO ₂ detoxification function, followed by the purification molding B and the purification molding C in this order. That is, the purification moldings A and B using the natural porous inorganic material diatom shale, kaolinite, or peat are more harmless than the purification molding C using the artificial porous inorganic material zeolite. As was excellent.

[Brief description of drawings]

FIG. 1 is a table showing the test results for the NO ₂ reduction rate using the purification molding A of the present invention.

FIG. 2 is a table showing the test results for the NO ₂ reduction rate using the purification molding B of the present invention.

FIG. 3 is a table showing the test results for the NO ₂ reduction rate using the purification molded body C of Comparative Example.

Claims (9)

[Claims] 1. A woody carbonized material in the form of powder, granules or flakes,
A purification molded article, characterized in that it is integrally compounded by heating a mixed composition containing a powdery natural porous inorganic material in a mold of a predetermined shape at a high temperature. 2. The purification molding according to claim 1, wherein the natural porous inorganic material is diatom shale or diatomaceous earth. 3. A powdery, granular or flaky wood carbonized material,
A step of preparing a mixed composition containing a powdered natural porous inorganic material, a step of filling the prepared mixed composition in a mold of a predetermined shape, and a high temperature heating in the filled state to integrally combine them. The method for producing a purification molded body, comprising: 4. The method for producing a purification molded article according to claim 3, wherein diatom shale or diatomaceous earth is used as the natural porous inorganic material. 5. The method for producing a molded article for purification according to claim 3 or 4, wherein at least 5% by weight of a wood carbonized material as a mixed composition and at least 5% by weight of a natural porous inorganic material. A method for producing a purification molded article, which comprises: 6. The method for producing the purification molded body according to claim 3, wherein the powdered or granular wood carbonized material is provided on each surface of the carbonized material as a preparation of the mixed composition. A method for producing a purification molded body, which comprises adhering a finely powdered natural porous inorganic material to form an aggregate of granules of 0.1 μm to 500 μm. 7. The method for producing a purification molded body according to claim 3, wherein the smoke produced during carbonization of the wood-based material is used as a mixed composition for the preparation of a natural porous material. A method for producing a molded article for purification, which is carried out by exposing a fine inorganic material to smoking, and by adhering or introducing a thermal decomposition product contained in the smoke to the surface of the natural porous inorganic material. 8. A method for producing a purification molded article according to claim 3, wherein a liquid pyrolysis product generated during carbonization of a wood-based material is used as a mixed composition. A method for producing a purification molded body, comprising immersing a natural porous inorganic material in a product, and impregnating or introducing the above-mentioned thermal decomposition product onto the surface of the natural porous inorganic material. 9. A method for producing a purification molded body according to claim 3, wherein a powdered wood carbonized material is used for preparing a mixed composition and filling a predetermined mold. A powdery natural porous inorganic material is dispersed and suspended in water to prepare a mixed composition in the form of a slurry, and then the slurry-like suspension is scooped up by a paper-making mold of a predetermined shape. A method for producing a purification molded body, which comprises filling into a predetermined mold by drying and solidifying.