JPH0321595B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a low-cost carbonaceous solid/water slurry composition that has good fluidity, excellent stability, and can be directly combusted. [Prior Art] In recent years, due to the instability of petroleum supply, the development of technology for effectively utilizing carbonaceous solids such as coal, oil coke, and petroleum-based pitch has been progressing. For example, various techniques for effectively utilizing these carbonaceous solids include pyrolysis, gasification, combustion, alternative fuels for blast furnace-injected heavy oil in the steel industry, and alternative fuels for heavy oil in cement kilns. However, in these various utilization technologies, carbonaceous solids are difficult to handle because they are solid at room temperature, and there is a risk of pollution due to dust scattering and dust explosions, making it difficult to use carbonaceous solids. It's summery. Therefore, it is desirable to convert these carbonaceous solids into a fluid to facilitate handling and prevent pollution and danger. On the other hand, in order to reduce the cost of transporting carbonaceous solids, it is effective to transport them in the form of a fluid. For the above purposes, it is effective to make a slurry as a method of fluidizing carbonaceous solids, but this slurry can be pyrolyzed, gasified, combusted, blown into a blast furnace, or used as fuel for a cement kiln. In order to use the slurry, it is necessary to make the slurry highly concentrated and to prevent solid particles suspended in the slurry from settling and solid-liquid separation. Conventionally, as a stable coal/water slurry composition,
Slurry composition comprising particle size-adjusted coal, thickener, surfactant, and water; Slurry composition comprising coal, alkali metal salt of a specific anion, surfactant, and water; JP-A-59-100191 As shown in Japanese Patent Application Laid-Open No. 59-4691, a slurry composition consisting of a solid fuel, an alkali metal salt of lignin sulfonic acid, an alkali metal salt of carboxymethylcellulose (CMC), and water, Slurry compositions consisting of carbonaceous material, naphthalene sulfonate, karaya gum and water are known. [Problems to be solved by the invention] However, the coal/water slurry produced by the above-mentioned prior art does not have satisfactory stability in practical use, the cost of the dispersant is high, and the amount of stabilizer added is too high. Since there are many, there is a problem in that the cost increases. In view of the above points, the present inventors have
As a result of intensive research on water slurry compositions, we found that a combination of one or more stabilizers selected from the group consisting of alkali metal salts of carboxymethyl cellulose, hydroxyethyl cellulose, or sodium polyacrylate and a dispersant,
It was discovered that the stabilizing effect was remarkable and that the addition rate of the stabilizer was reduced, and based on this, the patent application
60-183340, patent application No. 183341, patent application No. 60-18334, patent application No. 1983-
A patent application was filed as No. 2660. However, as a result of subsequent research, it was found that depending on the type of carbonaceous solid, especially the type of coal, stabilization may occur due to inorganic metal salts eluted from the coal or changes in the PH of the slurry caused by these. It was found that the effect decreased. Therefore, as a result of conducting research on combinations of dispersants and stabilizers that are effective for these types of coal, we found that the following combination can provide a stabilizing effect relatively regardless of the difference in coal type. I found out. That is, as a dispersant, a compound having the general formula _CH2 =C( _CH3 )COO(-XO) _-oY (wherein, X is an alkylene group having 2 to 4 carbon atoms, and n is an average of 1
-100, and Y represents hydrogen, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or an alkylphenyl group having 1 to 3 alkyl groups having 1 to 9 carbon atoms as substituents. ) A polyalkylene glycol monomethacrylate monomer () represented by
General formula _CH2 =C( _CH3 ) _COOZSO3M (wherein Z is an alkylene group having 1 to 4 carbon atoms, M is hydrogen,
Indicates an alkali metal, alkaline earth metal, ammonium group or amine base. ) is an essential component, and the molar ratio of the monomer () to the monomer () is in the range of 1:5 to 1:500, and A dispersant (hereinafter referred to as a dispersant N
-1), a clay mineral, especially bentonite or palygorskite of the montmorillonite group, or a polysaccharide, especially xanthan gum, a microbial polysaccharide, is used as a stabilizer, and the above-mentioned dispersant and stabilizer are combined. Then,
It was found that the stabilizing effect was remarkable, and that the stabilizing effect was not significantly affected by the type of eluted inorganic salt, the concentration difference, or the PH difference due to the difference in the type of coal. The present invention was made based on the above findings, and aims to provide a carbonaceous solid/water slurry composition that is inexpensive and has good fluidity and stability. [Means and effects for solving the problems] The carbonaceous solid/water slurry composition of the present invention contains the following four components (a) to (d): (a) coal, oil coke, petroleum-based Carbonaceous solid powder such as pitch, (b) General formula CH ₂ = C (CH ₃ ) COO (-XO) - _o Y (However, in the formula, X is an alkylene group having 2 to 4 carbon atoms, and n is an average of 1 ~100, Y is hydrogen,
It represents an alkyl group having 1 to 5 carbon atoms, a phenyl group, or an alkylphenyl group having 1 to 3 alkyl groups having 1 to 9 carbon atoms as substituents. ) A polyalkylene glycol monomethacrylate monomer () represented by the general formula CH ₂ =C(CH ₃ )COOZSO ₃ M (wherein Z is an alkylene group having 1 to 4 carbon atoms, M is hydrogen, An essential component is a sulfoalkyl methacrylate monomer () represented by alkali metal, alkaline earth metal, ammonium group or amine base. Molar ratio is 1:5 to 1:500
A dispersant made of a water-soluble copolymer obtained from raw material monomers that are in the range of and the total of the monomer () and the monomer () is 50 mol% or more based on the total monomers, (c) one or more stabilizers selected from the group consisting of clay minerals or polysaccharides; and (d) water. Further, the proportion of each composition of the carbonaceous solid/water slurry composition of the present invention is as follows: (a) carbonaceous solid powder such as coal, oil coke, petroleum pitch: 40 to 90% by weight, preferably 65% by weight;
~75% by weight (b) Dispersant: 0.01~5% by weight, preferably 0.2~
1.0% by weight (c) Stabilizer: 0.0001-2.0% by weight, preferably
0.001-0.5% by weight (d) Water: 10-60% by weight, preferably 25-35% by weight. A water-soluble copolymer effective as a dispersant has monomer () and monomer () as essential components, and the molar ratio of monomer () to monomer () is 1:5 to 1: 500, more preferably in the range of 1:20 to 1:200, and the total of monomer () and monomer () is 50 mol% or more of the total monomers. things are used. The monomer () is represented by the above general formula and can be obtained by a known method. Examples of monomers () include polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, polybutylene glycol monomethacrylate, methoxypolyethylene glycol monomethacrylate, methoxypolypropylene glycol monomethacrylate, methoxypolybutylene glycol monomethacrylate, ethoxypolyethylene glycol monomethacrylate , ethoxypolypropylene glycol monomethacrylate, methoxypolybutylene glycol monomethacrylate, methoxypolyethylene glycol
Examples include polypropylene glycol monomethacrylate, and one or more of these can be used. Further, the monomer () is similarly represented by the above general formula, and can also be obtained by a known method. Examples of the monomer () include 2-sulfoethyl methacrylate, 3-sulfopropyl methacrylate, 2-sulfopropyl methacrylate, 1-sulfopropan-2-yl methacrylate, 4-sulfobutyl methacrylate, and their sodium and potassium. alkali metal salts of
Examples include alkaline earth metal salts such as magnesium and calcium, ammonium salts, and organic amine salts, and one or more of these may be used. The molar ratio of monomer () to monomer () is in the range of 1:5 to 1:500, and if the ratio is outside this range, the copolymer with excellent dispersion performance will result. Can't get union. In addition to these monomers () and monomers (), monomers () copolymerizable with these monomers can be used within a range of less than 50 mol% of the total monomers. . Examples of this monomer () are acrylic acid, methacrylic acid, crotonic acid, itaconic acid,
Maleic acid, fumaric acid, monovalent metal salts, divalent metal salts, ammonium salts, organic amine salts of these acids, and methyl (meth)acrylate, (meth)acrylic acid 2 obtained from these acids and alcohols. -Esters such as hydroxyethyl:
Various sulfonic acids other than monomers () such as vinyl sulfonic acid, styrene sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, 2-acrylamide 2-methylpropanesulfonic acid, and 2-sulfoethyl acrylate, and their monovalent metals Salts, divalent metal salts, ammonium salts and organic amine salts:
(meth)acrylamide, N-methylol (meth)
Various (meth)acrylamides such as acrylamide: Aromatic vinyl compounds such as styrene and p-methylstyrene: Vinyl acetate, propenyl acetate, vinyl chloride, etc., and one or more of these can be used. . The amount of these monomers () and monomers () that can be copolymerized with monomers () is within the range of less than 50 mol% of the total monomers, and if used in large amounts exceeding this range, The dispersion performance of the resulting copolymer deteriorates. In addition, the molecular weight of the copolymer can be used in a wide range, but considering its performance as a dispersant for coal/water slurry, it is in the range of 1,000 to 500,000, especially 5,000,000 to 500,000.
A range of ~300,000 is preferred. Also suitable as stabilizers are clay minerals, especially
montmorillonite family or/and polysaccharides,
In particular, it is desirable to use xanthan gum. However, as clay minerals, that is, hydrated alumina silicates, in addition to the montmorillonite group, the kaolin group,
It is also possible to use the illite group, and as the polysaccharide, it is also possible to use glycosaminoglycans, mannans, etc. in addition to microbial polysaccharides. [Example] Examples and comparative examples will be described below. Comparative Example 1 After coarsely pulverizing coal with the properties shown in Table 1 to 2 mm or less, various dispersants shown in Table 2 were applied per unit of coal.
This aqueous solution and coarsely ground coal are continuously fed to a wet mill to grind and mix to obtain a coal concentration of 70% by weight and a particle size of 200mesh pass.
(74 μm or less) 80±2% by weight slurry was produced. After putting this slurry into the static tank 1 shown in the drawing, the upper, middle, and lower layer sampling ports 2,
From 3 and 4, take small samples periodically.
Concentration analysis was performed to investigate the status of sedimentation separation. 5 is a coal/water slurry. The unit of numerical value is mm. The test results are shown in a part of Table 4 (the part where the stabilizer addition rate is 0). As a result of the static tank test, the period during which the difference in the concentration analysis values of the slurry samples taken out from the upper layer and the lower layer was within 2% by weight was defined as the stable period.

【table】

[Table] Example 1 A slurry produced in the same manner as in Comparative Example 1 (to which a dispersant was added in the same way) was placed in a stirring tank,
To this, various stabilizers shown in Table 3 are added per coal.
0.005% by weight, 0.01% by weight, 0.02% by weight, 0.05% by weight, 0.1% by weight, 0.3% by weight were added and mixed, and the stabilized slurry was put into the static tank 1 shown in the drawing,
The situation of sedimentation separation was investigated. The test results are shown in Table 4.

【table】

【table】

[Table] Example 2 After coarsely pulverizing coal having the properties shown in Table 5 to a particle size of 90% of 3 mm or less, 0.5% by weight of a methacrylate-based anionic dispersant (Table 2 No.D-
1) is fed to a wet mill, pulverized and mixed 67
A weight percent slurry was produced. Furthermore, after adding and mixing palygorskite in an amount of 0.2% by weight based on coal to this slurry, physical properties were measured and stability was evaluated using the static tank 1 shown in the drawing. The results are shown in Table 6.

【table】

[Table] Example 3 A 67% by weight slurry was produced in the same manner as in Example 2 using 0.5% by weight of a methacrylate anionic dispersant (No. D-2 in Table 2) based on coal. The results are shown in Table 6. Example 4 A 67% by weight slurry was produced in the same manner as in Example 2 using 0.5% by weight of a methacrylate anionic dispersant (No. D-3 in Table 2) based on coal. The results are shown in Table 6. Comparative Example 2 After coarsely pulverizing coal having the properties shown in Table 5 to a particle size of 90% of 3 mm or less, a 66% by weight slurry was produced using an aqueous solution of sodium ligninsulfonate of 0.8% by weight based on the coal, and further powdered with palygorskite. After adding and mixing 0.2% by weight based on coal, physical properties were measured and stability was evaluated using the standing tank 1 shown in the drawing. The results are shown in Table 6.

[Table] Example 5 Coal having the properties shown in Table 7 was coarsely pulverized in advance to a particle size of 2 mm or less, 90%, and then fed to a wet ball mill with water to give a slurry concentration of 45% by weight, resulting in a particle size of 200 mesh or less, 84%. Grind it so that it becomes
Particles larger than 200 μm were removed with a vibrating sieve. Next, this slurry was dehydrated using a belt filter to reduce the total water content to 25%, and then 0.5% by weight of a methacrylate-based anionic dispersant (see Table 2)
No. D-3) was mixed with a kneader while adding 0.02% by weight of xanthan gum based on coal and water in an amount to make the slurry concentration 67% by weight to produce a highly concentrated slurry. Table 8 shows the results of measuring the physical properties of the product slurry and evaluating the stability using the standing tank 1 shown in the drawing.

[Table] Comparative Example 3 Coal having the properties shown in Table 7 was coarsely pulverized in advance to a particle size of 2 mm or less, 90%, and then fed to a wet ball mill with water so that the slurry concentration was 45% by weight, and the particle size was 83% of 200 mesh or less. Grind it so that
Particles larger than 200 μm were removed with a vibrating sieve. Next, this slurry was dehydrated using a belt filter to reduce the total water content to 25%, and then 0.5% by weight of sodium ligninsulfonate (Table 2 No.D
-4) and 0.02% by weight of xanthan gum based on coal and water in an amount to make the slurry concentration 65% by weight were mixed in a kneader to produce a highly concentrated slurry. Table 8 shows the results of measuring the physical properties of the product slurry and evaluating the stability using the standing tank 1 shown in the drawing.

【table】

〔Effect of the invention〕

As explained above, according to the present invention, the amount of stabilizer added can be reduced, and even if the types of carbonaceous solids are different, stable effects can be obtained for a long period of time, and costs can be reduced. The excellent effect of being able to achieve this can be achieved.

[Brief explanation of drawings]

The drawing is an explanatory diagram of a stationary tank used in Examples and Comparative Examples. 1...Stationing tank, 2, 3, 4...Sampling outlet, 5...Coal/slurry.

Claims (1)

[Claims] 1. The following four components (a) to (d): (a) Carbonaceous solid powder such as coal, oil course, petroleum pitch, etc.; (b) General formula CH ₂ =C ( CH ₃ )COO(-XO)- _o Y (wherein, X is an alkylene group having 2 to 4 carbon atoms, n is an average number of 1 to 100, and Y is hydrogen,
It represents an alkyl group having 1 to 5 carbon atoms, a phenyl group, or an alkylphenyl group having 1 to 3 alkyl groups having 1 to 9 carbon atoms as substituents. ) A polyalkylene glycol monomethacrylate monomer () represented by the general formula CH ₂ =C(CH ₃ )COOZSO ₃ M (wherein Z is an alkylene group having 1 to 4 carbon atoms, M is hydrogen, An essential component is a sulfoalkyl methacrylate monomer () represented by alkali metal, alkaline earth metal, ammonium group or amine base. Molar ratio is 1:5 to 1:500
A dispersant made of a water-soluble copolymer obtained from raw material monomers that are in the range of and the total of the monomer () and the monomer () is 50 mol% or more based on the total monomers, (c) one or more stabilizers selected from the group consisting of clay minerals or polysaccharides; and (d) water. A carbonaceous solid/water slurry composition characterized by comprising as main components: