WO2006030651A1

WO2006030651A1 - Carbon dioxide gas fixation material obtained by thermolysis of chrysotile asbestos and/or serpentinite containing chrysotile asbestos

Info

Publication number: WO2006030651A1
Application number: PCT/JP2005/016122
Authority: WO
Inventors: Kiyotsugu Yamashita; Tetsuya Shimamura
Original assignee: Nozawa Corporation
Priority date: 2004-09-02
Filing date: 2005-09-02
Publication date: 2006-03-23
Also published as: JP2008019099A

Abstract

[PROBLEMS] To attain effective utilization of chrysotile asbestos or serpentinite containing chrysotile asbestos as a carbon dioxide fixation material useful for reduction of carbon dioxide gas (carbon dioxide) contained in the atmosphere by converting the chrysotile structure of asbestos to the forsterite structure. [MEANS FOR SOLVING PROBLEMS] Forsterite excelling in carbon dioxide gas fixation potency produced by firing chrysotile asbestos and/or serpentinite containing chrysotile asbestos at 660˚ to 800˚C and characterized by exhibiting a crystallization degree, as expressed by a peak area of X-ray analysis, of 7 to 80. There is provided a carbon dioxide gas fixation material characterized by containing the forsterite produced by firing chrysotile asbestos and/or serpentinite containing chrysotile asbestos at 660˚ to 800˚C so as to exhibit a crystallization degree, as expressed by a peak area of X-ray analysis, of 7 to 80.

Description

Specification

Carbon dioxide fixing material obtained by thermal decomposition of warm asbestos and Z or serpentine containing warm asbestos

Technical field

[0001] The present invention relates to forsterite (also referred to as “forsterite”), which is effective as a measure against global warming, and has excellent performance of diacid-carbon fixation. It is related to forsterite, which is excellent in carbon dioxide fixation performance obtained from Iwaoka.

[0002] Hot asbestos and serpentinite containing Z or hot asbestos, and hot asbestos recovered from products containing hot asbestos, etc. are thermally decomposed to become non-asbestos, eliminating harmful biological effects and fixing carbon dioxide Recycled as a material with excellent ability.

Background art

[0003] The use of warm asbestos is completely prohibited by 2008 due to the risk of carcinogenesis after a long latent period by inhalation. The stock of industrial products including warm asbestos (clinotile), which is the largest amount of warm asbestos in both production and use, is enormous. . It has been pointed out that the capacity of industrial waste disposal sites is steadily decreasing, that there is an inherent danger in underground burial, and that the melting process for detoxification requires significant costs. Handling! / Is a problem.

[0004] In particular, until recently, warm asbestos has been widely used as a building material for cement products such as fireproof coating material slate. However, the use of hot asbestos is becoming a problem and its use is regulated, and the use of hot asbestos products is also prohibited. In the future, when the useful life of buildings using these warm asbestos has passed and the dismantling time has come, it will be necessary to treat them due to the disposal of building materials containing warm asbestos, which is effective as a building material. It is assumed that a recital is required. From these points, the rapid development of a useful use of recycled warm asbestos is awaited.

[0005] In addition, hot asbestos is a force that uses serpentine as the host rock. Is also a natural resource. Serpentinite has a warm asbestos content depending on its place of production, but it can be said that there is nothing at all. There is an enormous amount of these materials containing warm asbestos even if the use of warm asbestos is prohibited, so it is extremely important as an environmental measure to give safety and make it reusable. It is.

[0006] On the other hand, with respect to carbon dioxide, which is the main cause of global warming, various measures and measures have been studied by the entry into force of the Kyoto Protocol, and various methods have been developed for technologies for fixing carbon dioxide. However, it is difficult to say that the methods and materials that have no concern for economic efficiency and environmental impact have been established.

[0007] In particular, due to carbon dioxide (carbon dioxide) generated by the use of fossil fuels, environmental destruction such as global warming has become a global problem. In connection with the global warming phenomenon, technology for reducing carbon dioxide and carbon dioxide in the atmosphere and technology for reusing it are required, and carbon dioxide immobilization is one of them. Conventionally, carbon dioxide can be fixed by an electric energy method, a method of fixing to various substances, a method of fixing to the ground, a method of using marine organisms, or a method of absorbing it in seawater.

[0008] Further, there is a method of using forsterite as one of the methods of carbonate formation using natural minerals, but it is not used much industrially. The following technologies are available for carbon dioxide fixation.

[0009] a) Method using electric energy: Patent Document 1, Patent Document 2

b) Immobilization method in substance: Patent Document 3

c) Immobilization method in the ground: Patent Document 4

d) Immobilization to the deep sea: Patent Literature 5

Patent Document 1: Japanese Patent Application Laid-Open No. 2004-73978

Patent Document 2: Japanese Patent Laid-Open No. 2001-97894

Patent Document 3: Japanese Patent No. 3105953

Patent Document 4: JP-A-6-71161

Patent Document 5: Japanese Patent No. 3004393

Disclosure of the invention

Problems to be solved by the invention [0010] As long as the electric power generation method relies on the current thermal power generation method, the electric power generation method is meaningless because it generates carbon dioxide in the direction of thermal power generation. As a method for immobilizing the substance in a substance, there is a method using a crystalline silicate, but it is disadvantageous in terms of cost because it cannot be immobilized by a crystalline silicate alone. In addition, there are problems such as environmental safety in the method of using underground, deep sea, and marine organisms.

[ooii] By converting warm asbestos and Z or serpentinite containing warm asbestos into a forsterite structure, it is effective in reducing carbon dioxide (diacid-carbon) in the atmosphere. The purpose is to make effective use as an acid-carbon-fixing material.

Means for solving the problem

[0012] Thermal asbestos and serpentinite generally lose water of crystallization at 500 to 700 ° C, and the crystal structure is destroyed and becomes amorphous. However, when it exceeds 800 ° C, it reverts to forsterite. Crystallizes and further enstatite crystals form in the temperature range around 1000 ° C.

[0013] The present inventors have performed heat treatment in a temperature range in which warm asbestos and serpentinite become amorphous and crystallization into forsterite is suppressed as much as possible. In comparison with pure substance of forsterite, we found that the value of crystallinity in terms of peak area by X-ray analysis decreased, and the reactivity with carbon dioxide gas increased dramatically.

[0014] That is, when heated asbestos and Z or serpentinite containing warm asbestos are heated and fired, the chrysotile structure constituting the asbestos fibers is modified to a forsterite structure, and the generated forsterite is 660 ° C. It was discovered that it was fired at ˜800 ° C. and was excellent in performance for fixing carbon dioxide gas. Based on this knowledge, the present invention was completed.

[0015] That is, the present invention has solved the above-described problems by the following configuration.

(1) Hot asbestos and / or serpentinite containing hot asbestos is fired at 660 ° C to 800 ° C, and the crystallinity is 7 to 80 in terms of peak area by X-ray analysis. Forsterite with excellent carbon dioxide fixing performance.

(2) Hot asbestos and / or serpentinite containing hot asbestos is fired at 660 ° C to 800 ° C, and the crystallinity is 7 to 80 in terms of peak area by X-ray analysis. Carbon dioxide fixed material characterized by containing stellite.

[0016] In the present invention, the false obtained by firing warm asbestos and / or serpentine containing warm asbestos Carbon dioxide is fixed by using terlite. In the present invention, forsterite that immobilizes carbon dioxide is obtained by the following treatment. Forsterite with excellent carbon dioxide fixation performance is obtained by calcining warm asbestos and serpentinite containing Z or warm asbestos at 660 ° C to 800 ° C. The atmosphere during heating and firing may be in the air. By this treatment, the material structure of warm asbestos is modified into forsterite such as chrysotile mosquito. By controlling the degree of crystallinity depending on the firing temperature and using a high specific surface area, forsterite with excellent carbon dioxide immobilization performance can be obtained. When processing waste warm asbestos and building materials containing warm asbestos, it is desirable to crush and / or use the separated materials as raw materials.

[0017] The carbon dioxide fixing material obtained by thermally decomposing the warm asbestos according to the present invention is obtained by calcining warm asbestos and Z or serpentinite containing warm asbestos at a low temperature of 660 ° C to 800 ° C to obtain a crystallinity. By setting the value represented by the peak area by X-ray analysis to 7 to 80, it has excellent carbon dioxide fixation performance.

[0018] Here, the crystallinity is the peak area (peak height) of the first peak of forsterite (36.5 °) in the X-ray diffraction diagram of the carbon dioxide fixed material after pyrolysis. X half-value width) is calculated, and the comparison value is shown when the peak area of pure forsterite is 100 as a comparison. Therefore, the comparative value is high but the crystallinity is high, and the lower the comparative value is, the lower the crystallinity is.

The invention's effect

[0019] The carbon dioxide-fixed soot material obtained by thermally decomposing warm asbestos according to the present invention can be easily obtained by heat-treating warm asbestos-containing serpentine widely existing in Japan as a natural resource. Further, the carbon dioxide fixing material obtained by thermally decomposing the warm asbestos of the present invention is obtained by calcining warm asbestos and Z or serpentinite containing warm asbestos at 660 ° C to 800 ° C and analyzing the crystallinity by X-ray analysis. Those with a peak area value of 7 to 80 are excellent in carbon dioxide fixation performance and have higher diacid / carbon fixation performance than natural mineral forsterite. This makes it possible to effectively fix carbon dioxide, the main cause of global warming.

[0020] Further, warm asbestos, which is harmful to the respiratory tract by inhalation, is heated at a relatively low temperature, thereby providing safety and enabling recycling.

[0021] Further, it is separated from corrugated warm asbestos slate and warm asbestos slate board, which are building materials containing warm asbestos. Since the same material can be obtained using the separated waste warm asbestos, it can be used as an effective treatment and recycling method for waste building materials containing warm asbestos.

[0022] The energy required for non-asbestos formation can be reduced by lowering the heat treatment temperature and lowering the crystallinity.

BEST MODE FOR CARRYING OUT THE INVENTION

[0023] When warm asbestos and Z or serpentine containing warm asbestos are heated and baked, the chrysotile structural force constituting the asbestos fibers is modified to S forsterite structure. However, the higher the firing temperature, the more the crystallization is promoted and the crystallinity increases. The structure of chrysotile collapses when fired and becomes amorphous, creating a forsterite structure. By using forsterite close to this amorphous phase, a large amount of carbon dioxide can be adsorbed. In the amorphous state, the molecules are regularly arranged to form a crystal structure, so that they easily react with other substances. In the present invention, forsterite in this state is used.

[0024] The forsterite produced at this time was calcined at 660 ° C to 800 ° C, and the crystallinity was expressed as a peak area by X-ray analysis of 7 to 80.匕 Although it has excellent performance, specifically, we conducted a differential thermal analysis on the target warm asbestos and serpentinite, and exceeded the temperature showing an endothermic peak in the temperature range of 500 ° C or higher, generating heat. The purpose can be achieved by performing heat treatment in the temperature range below the peak temperature and decomposing the warm asbestos. That is, the firing temperature can be set by measuring the endothermic peak temperature in the differential thermal analysis.

[0025] The differential thermal analysis shows the peak of crystallization water withdrawal and the peak temperature of recrystallization into forsterite. Therefore, it is necessary to perform heating in this temperature range. In general, this temperature range may vary slightly depending on the location of the force temperature asbestos and serpentinite corresponding to 660 ° C to 800 ° C, so it is desirable to confirm this by differential thermal analysis.

[0026] The heating and holding time requires that the asbestos is completely decomposed to become non-asbestos. This makes it possible to completely eliminate harmful biological effects. Generally, the heat treatment is completed in about 0.5 to 3 hours. Note that the closer the temperature is to the upper limit, the shorter the processing time, the higher the recrystallization rate of forsterite, and the higher the crystallinity expressed by the peak area by X-ray analysis. On the other hand, the closer to the minimum temperature, the forsterite crystals The treatment time required for the decomposition of warm asbestos is long.

[0027] The heat treatment conditions are preferably a temperature of 700 to 750 ° C and a heating time of 1 to 1.5 hours in order to keep the economic efficiency of heating and the specific surface area of the processed material high. is there.

[0028] There are no particular restrictions on the equipment used for heating. Any heating furnace used as an industrial furnace can be used, but an externally heated rotary furnace or a roller hearth kiln that can easily maintain heating at 660 ° C to 800 ° C is suitable.

[0029] The target material of the present invention is warm asbestos, serpentinite containing warm asbestos, and warm asbestos recovered through processing such as pulverization and classification from industrial products such as building materials containing warm asbestos. Can also be applied.

[0030] The material treated as described above can be fixed with carbon dioxide at normal pressure. In order to shorten the reaction time, carbon dioxide gas may be immobilized under supercritical conditions.

[0031] In the carbon dioxide gas fixation reaction, effective fixation can be achieved by applying the conditions described below.

(1) Use a material with a large specific surface area. (25m ² Zg or more is desirable)

In order to increase the specific surface area, it is effective to lower the heat treatment temperature (700 to 750 ° C.) and to grind after heating.

[0032] The specific surface area of the obtained carbon dioxide fixed material is influenced by the length of the chrysotile fiber. Forsterite with a high specific surface area can be obtained by heating and firing long fiber products. This is because a long fiber has a large area for adsorbing carbon dioxide, so that the amount of fixed fiber increases. The fiber length also affects the crystallization during firing. When fired at the same temperature, those with long fiber lengths are forsterite with low crystallinity and those with short fiber length. Those with a long fiber length pass 30% on a 15 O / zm sieve, and those with a short fiber length pass all on a 150 m sieve. Even if the degree of crystallinity is low, the fixed amount is small when the specific surface area is small. Therefore, in order to fix efficiently, the crystallinity should be low and the specific surface area should be large. (2) Disperse moderate moisture uniformly in the material. (It is desirable that the water content is 30 to 60%.) No water content! In the soot state, the carbon dioxide immobilization reaction does not proceed at all.

(3) Under normal pressure, the immobilization reaction temperature is preferably near room temperature, and as the temperature increases, the immobilization efficiency decreases. (20-40 ° C is desirable.)

Also, the reaction time is 20 to 24 hours, and the fixed amount reaches saturation.

(4) Under supercritical conditions, the higher the reaction temperature, the more the fixation is progressed, and there is almost no difference due to pressure, but the lower one has a slightly higher immobilization efficiency and the reaction time is 1 hour, and the amount of fixation is Nearly saturated. (It is preferable to treat at 100 ° C and 8 MPa for about 1 hour.) Furthermore, under supercritical conditions, the temperature of the fixed liquid rises by stirring the fixed liquid material before the reaction.

[0033] In the present invention, hot asbestos and / or hot asbestos-containing serpentinite can be used as a raw material, but pulverized from corrugated hot asbestos slate and hot asbestos slate board, which are waste materials containing hot asbestos. Separated recycled asbestos can also be used. When processing waste building materials containing warm asbestos, it is desirable to grind and screen with a 450 μm mesh, and then use the net residue (including long fibers) as the raw material. This is because it is possible to separate hot asbestos on the net from the others by sieving 450 m, and long! This is because fibers can be taken.

Example 1

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

Examples and Comparative Examples

Wet Asbestos, serpentine and their treated products were compared under the following conditions.

1. Comparison of heat treatment conditions and carbon dioxide fixation rate of warm asbestos and serpentine

2. Carbon dioxide fixation conditions and fixation rate

(CO2 fixation test)

0.5 g of each forsterite obtained above and 0.15 ml of water were kneaded, and carbon dioxide was adsorbed in a supercritical apparatus, and the change in weight was measured. The adsorption treatment conditions were a reaction time of 48 hours, a pressure of 8 MPa, and a temperature of 100 ° C.

(1) Test procedure

Place forsterite (0.5 g) and water (0.15 ml) in a glass tube. [0035] Place the glass tube in a reactor (autoclave) and add dry ice (1.4 g).

[0036] The reactor is placed in an oil bath (100 ° C) (theoretical pressure: 8. OMPa) and allowed to react for 48 hours.

[0037] The product is vacuum dried at 60 ° C for 10 hours.

(2) Specific surface area measurement method

The specific surface area was measured by the BET 3-point method using a BET specific surface area measuring device.

[0038] The measurement results are shown in the following table.

(3) Immobilization amount measurement

The weight gain is also estimated by the amount of fixed carbon dioxide. The measurement results are shown in the following table. (Each test and test result)

1. Heat treatment conditions and carbon dioxide fixation rate of warm asbestos and serpentine

(Test sample)

Wet asbestos; Canadian 4-class chrysotile · Serpentine; Hokkaido Furano Pass

(Carbon dioxide fixation conditions);

* D Moisture content 30% Supercritical reaction (100 ° C · 8MPa · 48 hours)

* 2 Water content 30% Supercritical reaction (100 ° C · 13MPa · 48 hours)

Carbon dioxide fixation rate = Increased weight due to fixation Z Weight before fixation

(Test results)

The results are shown in Table 1.

[0039] [Table 1]

Table 1 Heat treatment conditions and carbon dioxide fixation rate of warm asbestos and serpentinite

Table 1 Heat treatment conditions and carbon dioxide fixation rate of hot asbestos and serpentinite (continued)

Carbon dioxide immobilization conditions and immobilization rate

(1) Specific surface area of fixed material and fixed ratio (Test sample)

Hot asbestos; Canadian 4 class chrysotile · · Grinding; Ball milling 1 hour (test conditions)

Carbon dioxide fixation conditions;

* D Moisture content 30% Supercritical reaction (100 ° C '8MPa' 48 hours)

*? Water content 30% Normal pressure reaction (20 ° C '24 hours)

(Test results)

The results are shown in Table 2.

[Table 2] Table 2 Specific surface area and immobilization rate of immobilization materials

[0042] (2) Moisture content and immobilization rate of immobilization material

(Test sample)

Immobilization material: Canadian 4 class chrysotile 740 ° C · 1 hour fired product (Test conditions)

Carbon dioxide fixation conditions; supercritical reaction (100 ° C · 8MPa · 48 hours) (test result)

The results are shown in Table 3.

[0043] [Table 3] Table 3 Moisture content and immobilization rate of immobilization materials

[0044] (3) Reaction temperature and reaction time under normal pressure

a) Reaction temperature

(Test sample)

Immobilization material: Canadian 4 class chrysotile 740 ° C · Crushed after firing for 1 hour (test conditions)

Carbon dioxide immobilization conditions: normal pressure reaction (water content 30% · 24 hours) (test result)

The results are shown in Table 4.

[0045] [Table 4] Table 4 Reaction temperature under normal pressure

[0046] b) Reaction time

(Test sample)

Carbon dioxide fixation conditions: normal pressure reaction (water content 30% · 24 hours)

(Test results)

The results are shown in Table 5. [0047] [Table 5] Table 5 Reaction time under normal pressure

[0048] (4) Supercritical reaction temperature, reaction time, and pressure

a) Reaction temperature and reaction time

(Test sample)

Carbon dioxide fixation conditions; supercritical reaction (water content 30% · 8 MPa) (test result)

The results are shown in Table 6.

[0049] [Table 6] Table 6 Reaction temperature and reaction time under supercritical conditions

b) Pressure

(Test sample)

Immobilization material: Canadian 4 class chrysotile 740 ° C (Test conditions)

Carbon dioxide fixation conditions; supercritical reaction (water content 30% · 100 ° C · 48 hours)

(Test results)

The results are shown in Table 7.

[0051] [Table 7] Table 7 Pressure under supercriticality

[0052] c) Stirring conditions

(Test sample)

Fixed candy material: Canadian 4 class chrysotile 740 ° 1 hour fired and ground product (test conditions)

However, during the test, the case where the immobilization material was agitated and the case where it was absent were used.

(Test results)

The results are shown in Table 8.

[0053] [Table 8] Comparison with and without immobilization of immobilization material before reaction

[0054] 3. Heat treatment conditions and biological effects of warm asbestos

The influence on the living body at the firing temperature was confirmed. About the baked product of the present invention The effect was confirmed.

(Test sample)

Hot asbestos; Canadian 4-class chrysotile

(contents of the test)

(Cytotoxicity test); Test using cultured mammalian cells (Colony formation method)

In both Examples 2-1 and 2-2, the cytotoxicity is the same level as that of the inorganic fiber wollastonite, which has been confirmed to be safe.

(Rat tracheal instillation test); dose; lmgZ rat 180 days

In Examples 2-1 and 2-2, it was confirmed that fibrosis, which is related to carcinogenesis, did not occur.

(Test results)

The results are shown in Table 9.

[0055] [Table 9] Heat treatment conditions and biological effects of hot asbestos

Industrial applicability

[0056] The forsterite having excellent carbon dioxide fixation performance according to the present invention renders warm asbestos in cement product waste such as fire-resistant coating material slate as a construction material particularly problematic in terms of pollution, and recycles it. It provides a useful application of recycled warm asbestos in building materials that need to be recycled.

Claims

The scope of the claims

[1] Hot asbestos and serpentinite containing Z or hot asbestos are baked at 660 ° C to 800 ° C, and the crystallinity is 7 to 80 in terms of peak area by X-ray analysis. This is a forsterite with excellent carbon dioxide gas fixing performance.

[2] Hot asbestos and / or serpentinite containing hot asbestos are fired at 660 ° C to 800 ° C, and the crystallinity is 7 to 80 in terms of peak area by X-ray analysis. Carbon dioxide fixed material characterized by containing stellite.