JPH0321596B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention is a low-cost, high-concentration carbonaceous solid that has good fluidity, excellent stability, and can be directly combusted.
The present invention relates to a water slurry composition. [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, carboxymethyl cellulose and karaya gum used to increase the stability of the slurry may increase the viscosity of the slurry and lower the slurry concentration. It was found that this method was necessary and could not be applied to all types of coal. Therefore,
As a result of conducting research on additives that are effective for these types of coal, we discovered that the stability of slurry can be increased by adjusting the zeta potential on the solid surface of slurry in combination with a dispersant. That is, it has been found that stability can be improved by using dispersants with different zeta potentials and optimizing the zeta potential on the solid surface by adjusting the blending ratio of the dispersants. That is, the inventors have the general formula CH ₂ =C(R)
COO(-XO) _l -Y (wherein, R is hydrogen or methyl group, X is alkylene group having 2 to 4 carbon atoms, _l is 1 to 100 on average
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 mono(meth)acrylate monomer () represented by
General formula _CH2 =C(R) _COOZSO3M (wherein, R is hydrogen or a methyl group, Z is an alkylene group having 1 to 4 carbon atoms, M is hydrogen, an alkali metal, an alkaline earth metal, an ammonium group, or sulfoalkyl (meth)acrylate monomer () represented by amine base) is an essential component, and the molar ratio of the monomer () to the monomer () is from 1:5 to 1. :500, and the total of the monomer () and the monomer () is 50 mol% or more of the total monomers. Agent (b) and the general formula (In the formula, n is 5 to 250, m is 1 to 250) When combined with a dispersant (c) selected from polystyrene sulfonate or styrene-styrene sulfonate copolymer, the viscosity of the slurry It is possible to have a stabilizing effect without increasing the carbon content, and the stabilizing effect can be obtained without being significantly affected by the type of eluted inorganic salt, the difference in concentration, or the difference in PH due to the difference in the type of coal. I found out that. 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(R)COO(-XO) _l -Y (wherein, R is hydrogen or a methyl group, and X is an alkylene group having 2 to 4 carbon atoms) , _l is 1 to 100 on average
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 mono(meth)acrylate monomer () represented by
General formula CH ₂ = C (R) COOZSO ₃ M (wherein,
R represents hydrogen or a methyl group, Z represents an alkylene group having 1 to 4 carbon atoms, and M represents hydrogen, an alkali metal, an alkaline earth metal, an ammonium group, or an amine base. ) is an essential component, and the molar ratio of the monomer () to the monomer () is 1:5.
to 1:500, and the monomer ()
and a dispersant (b) consisting of a water-soluble copolymer obtained from raw material monomers in which the sum of said monomers () is 50 mol% or more based on the total monomers, (c) General formula (wherein n is 5 to 250, m is 1 to 250) as a dispersant selected from polystyrene sulfonate or styrene-styrene sulfonate copolymer; and (d) water. It is characterized by being an ingredient. 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 (b): 0.01-5% by weight, preferably 0.02
~1.0% by weight (c) Dispersant (c): 0.01-5% by weight, preferably 0.02
-1.0% by weight (d) Water: 10-60% by weight, preferably 25-35% by weight. Further, it is preferable that the dispersant (b) and the dispersant (c) be in the following mixing ratio. Dispersant (b): 1 to 99% by weight Dispersant (c): 1 to 99% by weight A water-soluble copolymer effective as a dispersant (b) must contain monomer () and monomer (). component, the molar ratio of monomer () to monomer () is in the range of 1:5 to 1:500, more preferably 1:20 to 1:200, and A monomer obtained from raw material monomers in which the total amount of monomers () is 50 mol % or more based on the total monomers is 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, ethoxypolybutylene glycol monomethacrylate, methoxypolyethylene glycol polypropylene glycol monomethacrylate, etc., 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 esters obtained from these acids and alcohols, such as methyl (meth)acrylate: vinylsulfonic acid , styrene sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, 2-acrylamide 2-methylpropanesulfonic acid, and other sulfonic acids other than monomers (), as well as their monovalent metal salts, divalent metal salts, and ammonium salts. and organic amine salt: (meth)acrylamide, N
- Various (meth)acrylamides such as methylol (meth)acrylamide: Aromatic vinyl compounds such as styrene and p-methylstyrene: Vinyl acetate, propenyl acetate, vinyl chloride, etc., 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. Water-soluble polymers useful as dispersants (c) are obtained by polymerization of styrene sulfonate monomers and copolymerization of styrene and styrene sulfonate. It can also be obtained by subjecting polystyrene to a sulfonation reaction by a known method. As the salt of the sulfonic acid group, alkali metal or ammonium salts are preferable, but some hydrogen may remain, and alkaline earth metal salts and amino salts may also be used. Further, the molecular weight is preferably 1,000 or more, more preferably in the range of 2,000 to 50,000. By combining dispersants, the zeta potential of the solid surface used in the slurry can be adjusted, so the same type of dispersant can be used for more types of carbonaceous solids than ever before. [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 (b) shown in Tables 2 and 3,
(c) in an amount of 0.5% by weight based on coal;
This aqueous solution and coarsely pulverized coal are continuously fed to a wet mill to grind and mix, resulting in a slurry with a viscosity of 10±
1Poise, particle size is 200mesh pass (74μm or less) 85±
A 2% by weight slurry was produced. After putting this slurry into the static tank 1 shown in the drawing, a small amount of sample is periodically taken out from the sampling outlets 2, 3, and 4 in the upper, middle, and lower layers, and the concentration is analyzed and the status of sedimentation separation is investigated. Ta. 5 is a coal/water slurry. The unit of numerical value is mm. The test results are shown in a part of Table 6 (the part without the addition rate of dispersants (b) and (c)). Furthermore, as a result of the static tank test,
The period during which the difference between 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.

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[Table] Example 1 Both dispersants (b) and (c) shown in Tables 2 and 3 were
A slurry was produced in the same manner as in Comparative Example 1 except that a total amount of 0.5% by weight based on coal was added. The obtained slurry was put into the standing tank 1 shown in the drawing, and the status of sedimentation and separation was examined. The test results are shown in Table 6. Example 2 After coarsely pulverizing coal having the properties shown in Table 4 to a particle size of 90% of 3 mm or less, both of the various dispersants (b) and (c) shown in Tables 2 and 3 were applied to the coal. Supply it to a wet mill with an amount of 0.6% by weight, and grind and mix to make a slurry with a viscosity of 10±1Poise and a particle size of 200mesh pass.
(74 μm or less) 85±2% by weight slurry was produced. Furthermore, the physical properties of this slurry were measured and its stability was evaluated using a standing tank 1 shown in the drawings. The results are shown in Table 6.

[Table] Comparative Example 2 Slurry was prepared in the same manner as in Example 2 except that 0.6% by weight of the dispersant (b) shown in Table 2 or the dispersant (c) shown in Table 3 was added to the coal. manufacture,
A stabilization test was conducted. The results were as shown in Table 6. Example 3 Coal having the properties shown in Table 5 was coarsely ground in advance to a particle size of 90% of 2 mm or less, and then fed to a wet ball mill with water so that the slurry concentration was 45% by weight, and the particle size was 85% of 200 mesh or less. and further
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 various dispersants (b) and (c) shown in Tables 2 and 3 were added to it at 0.6% by weight based on the coal. A high concentration slurry was produced by mixing with a kneader while adding water in an amount such that the slurry viscosity was 10±1 Poise. Table 6 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 Only the dispersant (b) shown in Table 2 or the dispersant (c) shown in Table 3 was added at 0.6% by weight based on the coal, and other than that, slurry was prepared in the same manner as in Example 3. manufacture,
A stabilization test was conducted. The results were as shown in Table 6.

〔Effect of the invention〕

As explained above, according to the present invention, by combining dispersants with different zeta potentials, the fluidity of the coal/water slurry is not impaired.
Not only can long-term stability be achieved, but excellent effects can be achieved that can be applied to more carbonaceous solids.

[Brief explanation of the drawing]

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

Claims (1)

[Claims] 1. The following four components (a) to (d): (a) Carbonaceous solid powder such as coal, oil coke, petroleum pitch, etc.; (b) General formula CH ₂ =C ( R) COO(-XO) _l -Y (wherein, R is hydrogen or a methyl group,
is an alkylene group having 2 to 4 carbon atoms, and _l is 1 to 4 on average.
The number is 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. ) and a polyalkylene glycol mono(meth)acrylate monomer () represented by the general formula CH ₂ =C(R)
COOZSO ₃ M (wherein, R is hydrogen or methyl group, Z
represents an alkylene group having 1 to 4 carbon atoms, and M represents hydrogen, an alkali metal, an alkaline earth metal, an ammonium group or an amine base. ) is an essential component, and the molar ratio of the monomer () to the monomer () is from 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) polystyrene sulfonate or styrene-
A carbonaceous solid/water slurry composition comprising as main components: a dispersant selected from styrene sulfonate copolymers, and (d) water.