JPS63207897A - Dispersant for coal-water slurry - Google Patents

Abstract

PURPOSE:To obtain a dispersant providing coal-water slurry having fluidity even at high coal concentration, dispersing coal powder into water, comprising a specific water-soluble copolymer (neutralized material thereof). CONSTITUTION:The dispersant for aimed coal-water slurry comprising a water- soluble copolymer derived from (A) 0.2-5mol% vinyl monomer shown by formu la I (A<1>-A<3> are H, methyl, etc.; R<1> is -CO-, etc.; R<2> is 2-4C alkylene; n is 1-100; R<3> is 1-30C alkyl, etc.; X is H, etc.), (B) 50-94.8mol% unsaturated carboxylic acid monomer shown by formula II (R<4>-R<6> are H, methyl, etc.; M is H, etc.), (C) 5-45mol% sulfoalkyl (meth)acrylate monomer shown by formula III (R<7> is H, methyl, etc.; Z is 1-4C alkylene; Y is H, etc.) and (D) 0-20mol% another monomer copolymerizable with the components A-C and/or a water-soluble copolymer obtained by further neutralizing the copolymer with a basic substance.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a dispersant for coal-water slurry. More specifically, the present invention relates to a dispersant that disperses coal powder in water and provides a fluidized coal-water slurry even with a high concentration of coal.

(Problems to be solved by conventional techniques and inventions) Petroleum, which has been widely used as an energy source,
Its price has increased significantly and there are concerns that it will run out.

Therefore, the challenge is to develop other energy sources that can provide a stable supply, and coal is once again becoming widely available.

However, the biggest problem in using coal is transportation problems due to the fact that coal is solid.

BACKGROUND ART Conventionally, mined coal is pulverized into powder, and this is made into a coal-water slurry, which is fluidized and transported through a vibrine line.

On the other hand, COM (Coal-
0il-Mixture) has entered the practical stage, but since it uses oil, there are problems in terms of stable supply and price, and high-concentration coal-water slurry is promising as a coal utilization technology in the future. being watched.

This technology for slurrying coal into water is about to be used in an extremely wide range of coal uses, including direct combustion of coal and gasification, in addition to the aforementioned coal pipeline ring.
This has become an important issue in the use of coal. This coal-
It is preferable for the water slurry to be a high-concentration slurry with little water content from the economic and pollution prevention viewpoints. In particular, in the case of direct combustion of coal-water slurry, which can eliminate wastewater treatment and pollution problems, the coal-water slurry is passed through a cyclone or turbulent burner without dehydration, drying, etc. Since it is charged and burned directly in the furnace, it is necessary to reduce the moisture content as much as possible.

However, when attempts are made to increase the concentration of coal powder using known techniques, the slurry becomes significantly thickened and loses fluidity. On the other hand, if the concentration of coal powder in the slurry is lowered, transportation efficiency, combustion efficiency, etc. will decrease, and if the coal-water slurry is used after dehydration, the dehydration and drying processes may also be costly. There are problems such as causing pollution problems.

Conventionally, various dispersants for coal-water slurries have been proposed to solve such problems. For example, surfactants such as sodium oleate, sodium dodecylbenzenesulfonate, alkylarylsulfonate, polyoxyethylene alkylphenyl ether, and stearylamine hydrochloride, polyethylene glycol, polyacrylamide, celluloses, sodium polyacrylate, and ligninsulfonic acid. Examples include water-soluble polymers such as soda and sodium naphthalene sulfonate/formalin condensate. However, both have insufficient fluidity and lack practicality.

The present inventors continued intensive research to solve the above-mentioned problems in dispersants for coal-water slurries, and found that a certain water-soluble copolymer has excellent effects as a dispersant for coal-water slurries. The present invention was completed based on the discovery that the present invention has the following properties.

That is, the present invention provides a dispersant for easily producing a coal-water slurry that has fluidity even at high concentrations.

(Means and Effects for Solving the Problems) The present invention is based on the general formula (wherein A and A2 each independently represent hydrogen, a methyl group, or -coox, and A1 and A
cannot be -coox at the same time, A represents hydrogen, methyl group, -coox or -CH2C00X,
and when A is -COoX or 10H2C00X, A1 and A2 are each independently hydrogen or a methyl group, R1 is -CO- or 10H2Co-,
R2 is an alkylene group having 2 to 4 carbon atoms, n is a number of 1 to 100 on average, and R3 is an alkyl group having 1 to 30 carbon atoms, an alkenyl group, an aryl group, an aralkyl group, a cyclic alkyl group, It is a monovalent organic group derived from a cyclic alkenyl group or a heterocyclic compound, and X represents hydrogen, an alkali metal, an alkaline earth metal, an ammonium group, or an organic amine group. ) and one or more vinyl monomers (I) represented by the general formula (wherein R4 and R5 each independently represent hydrogen, a methyl group, or 1000M, and R and R5 are never 1000M at the same time, R6 represents hydrogen, methyl group, -000M or -CH2000M8,
When R6 is -CoOM or 10)-12C00M, R4 and R5 each represent hydrogen or a methyl group, and M represents hydrogen, an alkali metal, an alkaline earth metal, an ammonium group or an organic amine group. ) and one or more unsaturated carboxylic acid monomers (II) represented by the general formula % formula % (wherein R7 is hydrogen or a methyl group, and Z is a carbon number 1
In the alkylene group of ~4, Y represents hydrogen, an alkali metal, an alkaline earth metal, an ammonium group, or an organic amine group. 0.2 to 5 mol% of the sulfoalkyl (meth)acrylate spinning wheel matrix (Ill) represented by III) is 5 to 45 mol%, and the monolayer (IV) is 0
~20 mol% (however, monomers (I), (II), (I
The sum of [[) and (IV) is 100 mol%. )
The present invention relates to a dispersant for a coal-water slurry comprising a water-soluble copolymer derived by using a ratio of 1 and/or a water-soluble copolymer derived by further neutralizing the copolymer with a basic substance.

The coal used for the coal-water slurry is, for example, anthracite,
ill! Although any type of coal such as blue coal, sub-bituminous coal, lignite, etc. can be used regardless of its type and production area, as well as its moisture content and chemical composition, the dispersant of the present invention has an ash content of 4% by weight or less ( It exhibits particularly excellent dispersion ability for low ash coal (anhydrous base) or deashing valves. Such coal is
By wet or dry grinding using conventional methods,
200 mesh pass 50% by weight or more, preferably 70~
90ffi% is a guideline for use. Further, the slurry concentration is 60 to 90% by weight on a dry basis of pulverized coal, and if it is less than 60% by weight, it is not practical from the viewpoints of economy, transportation efficiency, combustion efficiency, etc.

The water-soluble copolymer effective as a dispersant for coal-water slurry of the present invention comprises the monomers (I), (I), (II) and (rV) in which the monomer (I) has 0 .2 to 5 mol%,
The molecule (ff) exceeds 50 and is 94.8 mol% or less,
The monomer (I) is 5 to 45 mol%, and the monomer (IV) is 0 to 20 mol% (however, monomers (I), (II), (
The sum of 1) and (IV) is 100 mol%. ) and/or a water-soluble copolymer derived by further neutralizing the copolymer with a basic substance.

The monomer (I> is represented by the above general formula,
It can be obtained by a known method. Examples of monomer (I) include methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, and methoxypolybutylene glycol (meth)acrylate.
Acrylate, Ethoxypolyethylene glycol (meth)acrylate, Ethoxypolypropylene glycol (
In addition to meth)acrylate, ethoxypolybutylene glycol (meth)acrylate, methoxypolyethylene glycol, polypropylene glycol (meth)acrylate, etc., alkoxypolyethylene glycol (meth)acrylates alkoxylated with organic groups having up to 30 carbon atoms; carbon Alkenoxypolyethylene glycol (meth)acrylates alkenoxylated with up to 30 alkenyl groups; phenoxypolyethylene glycol (meth)acrylate, nonylphenoxypolyethylene glycol (meth)acrylate, naphthoxypolyethylene glycol (meth)acrylate, phenoxypolypropylene Aryloxypolyalkylene glycol (meth)acrylates such as glycol (meth)acrylate, naphthoxypolyethylene glycol/polypropylene glycol (meth)acrylate, p-methylphenoxypolyethylene glycol (meth)acrylate; benzyloxypolyethylene glycol (meth)acrylate, etc. Alkyloxypolyalkylene glycol (meth)
Acrylates Cyclic alkoxypolyalkylene glycol (meth)acrylates such as dichlorohexoxypolyethylene glycol (meth)acrylate; Cyclic alkenoxypolyalkylene glycol (meth)acrylates such as cyclopentenoxypolyethylene glycol (meth)acrylate; Heterocyclic ethers of polyalkylene glycol mono(meth)acrylates such as pyrisiloxypolyethylene glycol (meth)acrylate and chenyloxypolyethylene glycol (meth)acrylate; methoxypolypropylene glycol monomaleate;
Phenoxypolyethylene glycol mono, maleate,
Examples include unsaturated polycarboxylic acid monoesters of monoetherified polyalkylene gelcol such as naphthoxypolypropylene glycol monoitaconate and phenoxypolyethylene glycol monoitaconate, and one or more of these may be used. Can be done.

Monomer (II) is also represented by the above general formula, and can also be obtained by a known method. Examples of the monomer (If) include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid and alkali metal aS, alkaline earth metal salts, ammonium salts, organic Examples include amine salts, and one or more of these can be used.

Monomer (III) is also represented by the above general formula, and can also be obtained by a known method. Examples of monomer (III) include 2-sulfoethyl (meth)
Acrylate, 3-sulfopropyl (meth)acrylate, 2-sulfopropyl (meth)acrylate, 1-sulfopropan-2-yl (meth)acrylate, 4-sulfobutyl (meth)acrylate and their alkali metals such as sodium and potassium Examples include alkaline earth metal salts such as magnesium and calcium salts, ammonium salts, and organic amine salts, and one or more of these may be used.

It can be used as necessary as long as the effect is not impaired. Examples of the monomer (IV) include esters such as methyl (meth)acrylate; vinylsulfonic acid, styrenesulfonic acid, allylsulfonic acid, methallylsulfonic acid,
2-acrylamide Various sulfonic acids other than monomer (III) such as 2-methylpropanesulfonic acid and their -valent metal salts, divalent metal salts, ammonium salts and organic amine salts; hydroxyethyl (meth)acrylate, polyethylene Hydroxyl group-containing monomers such as glycol mono(meth)acrylate: various (meth)acrylamides such as (meth)acrylamide and N-methylol(meth)acrylamide; aromatic vinyl compounds such as styrene and p-methylstyrene: vinyl acetate, Examples include propenyl acetate and vinyl chloride, and one or more of these can be used.

These monolayers (I), (U), (III) and (I
If V) is used outside the above blending ratio range, the dispersion performance of the resulting copolymer will deteriorate.

In the present invention, in order to produce a water-soluble copolymer, the monomer components may be copolymerized using a polymerization initiator.

Copolymerization can be carried out by methods such as polymerization in a solvent or bulk polymerization.

Polymerization in a solvent can be carried out either batchwise or continuously, and the solvents used include: water, lower alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol, benzene, toluene, xylene, cyclohexane, n - Aromatic, aliphatic or heterocyclic aliphatic hydrocarbons such as hexane and dioxane; Ketone compounds such as ethyl acetate: acetone and methyl ethyl ketone. In view of the solubility of the raw material monomer and the resulting copolymer, and the convenience of using the copolymer, at least one selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms should be used. is preferred. Among the lower alcohols having 1 to 4 carbon atoms, methyl alcohol, ethyl alcohol, and isopropyl alcohol are particularly effective.

When polymerization is carried out in an aqueous medium, a water-soluble polymerization initiator such as ammonium or alkali metal persulfate or hydrogen peroxide is used as the polymerization initiator. At this time, an accelerator such as sodium hydrogen sulfite can also be used in combination. In addition, lower alcohols, aromatic hydrocarbons, aliphatic hydrocarbons,
For polymerization using ethyl acetate or a ketone compound as a solvent, peroxides such as benzoyl peroxide and lauroyl peroxide; hydroperoxides such as cumene hydroperoxide; and aliphatic azo compounds such as azobisisobutyronitrile are used to initiate polymerization. used as an agent. At this time, a promoter such as an amine compound can also be used in combination. Furthermore, when a water-lower alcohol mixed solvent is used, it can be appropriately selected from among the various polymerization initiators or combinations of polymerization initiators and accelerators mentioned above. The polymerization temperature is appropriately adjusted depending on the solvent and polymerization initiator used, but it is usually carried out within the range of 0 to 120'C.

Bulk polymerization uses peroxides such as benzoyl peroxide and lauroyl peroxide; hydroperoxides such as cumene hydroperoxide; and aliphatic azo compounds such as azobisisobutyronitrile as polymerization initiators.
It is carried out within a temperature range of 50-150°C.

Although a wide range of molecular weights can be used for the water-soluble copolymer, a range of 1,000 to 500,000, particularly a range of 5,000 to 300,000 is preferred in consideration of performance as a dispersant for coal-water slurry.

In addition, the water-soluble copolymer obtained by copolymerization in this way can be used as a dispersant for coal-water slurry as it is, but if necessary, it can be further neutralized with a basic substance before being used as a dispersant. May be used.

Examples of the basic substance used in this case include hydroxides, oxides, and carbonates of alkali metals or alkaline earth metals, ammonia, and organic amines.

The dispersant for coal-water slurry of the present invention is used in pulverized coal-water slurry, but its addition area is not particularly limited and is effective in a wide range of additive groups. 0.05 of ff1ffi (dry base)
It is used in a proportion of ~2% by weight, preferably 0.1-1% by weight.

In order to use the dispersant for coal-water slurry of the present invention, the dispersant may be mixed with coal in advance to form a slurry, or the dispersant may be dissolved in water in advance. May be used. Of course, a predetermined amount of the dispersant may be mixed at once in Kanayama, or may be used batchwise.

Furthermore, due to the nature of the dispersant, any device for slurrying coal in water may be used as the slurry device.

The scope of the present invention is not limited by these addition methods and slurry-forming methods.

In addition, the dispersant for coal-water slurry of the present invention may optionally contain various polymers having dispersion ability, surfactants, rust preventives,
A pH 11 adjuster, an anticorrosive agent, an antioxidant, an antifoaming agent, an antistatic agent, a solubilizer, and the like can be added.

(Effects of the Invention) The dispersant for coal-water slurry of the present invention has excellent dispersibility of coal in water, and provides highly fluid and highly concentrated coal-water slurry with the addition of a small amount of dispersant. It is possible.

By applying the highly concentrated coal-water slurry obtained using the dispersant for coal-water slurry of the present invention, it becomes possible to economically transport coal by pipeline, and it is possible to transport solid coal by combustion. The above problems can be resolved.

Therefore, the dispersant for coal-water slurry of the present invention can greatly contribute to the spread of coal utilization technologies such as direct combustion of coal and coal gasification.

(Example) Next, the dispersant for coal-water slurry of the present invention will be described in more detail with reference to comparative examples and examples, but the present invention is of course not limited thereto.

In the examples, unless otherwise specified, parts are by weight.

Example 1 100 parts of water was charged into a polymerization container equipped with a thermometer, a stirrer, two dropping funnels, a gas introduction tube, and a reflux cooler.The inside of the polymerization container was replaced with nitrogen while stirring, and the mixture was heated in a nitrogen atmosphere. Heated to 95°C. Thereafter, the temperature was maintained at the same temperature, and methoxypolyethylene glycol methacrylate (1) was used as the monomer (1).
containing on average 15 ethylene oxide units per molecule, average molecule 11760) 7.6 parts, sodium methacrylate as monomer (I) (molecule ji 708) 39.
A monomer mixed solution consisting of 4 parts, 27.0 parts of monomer (sodium salt of 2-sulfoethyl methacrylate (molecule! 216 as I[[)) and 100 parts of water was added dropwise over 120 minutes, and at the same time From one dropping funnel, add 14 parts of an aqueous solution consisting of 1.2 parts of ammonium persulfate and 20 parts of water.
It was added dropwise over 0 minutes. After dropping, continue to heat at the same temperature for 60 minutes.
After continuing polymerization for a minute, the mixture was cooled to obtain an aqueous solution of copolymer (1) having an average molecular weight of 40,000.

Examples 2 to 9 and Comparative Examples 1 to 5 Monomer (1), monomer (I[), monomer (Ill) and, if necessary, monomer (IV) shown in Table 1 were Copolymers (2) to (9) and comparative copolymers (1) to (5) were obtained by polymerizing according to the method of Example 1 using the monopolymer compositions (mol%) shown in Table 1. ) was obtained.

Example 10 A 200-mesh sieve was added to a 78% aqueous solution containing the copolymers (1) to (9) obtained in Examples 1 to 9 in the amounts shown in Table 2. Pass-pulverized blue coal (ash content 1.5%, anhydrous basis) was added little by little at room temperature with stirring. After adding the entire amount to give the coal concentration shown in Table 2, the mixture was stirred for 3 minutes at 5000 PPM using a homomixer (manufactured by Tokushu Kikako) to prepare a coal-water slurry.

The viscosity of the obtained coal-water slurry was measured at 25°C,
Fluidity was evaluated. The results are shown in Table 2. Low viscosity indicates good fluidity.

For comparison, comparative copolymers (1) to (5) obtained in Comparative Examples 1 to 5, sodium polyacrylate (average molecular weight 60,000) or polyethylene glycol (average molecular weight f
Table 2 also shows the results when F121500) was used as a dispersant and when no dispersant was used at all as comparative examples.

Table 2 ×: Bad

Claims (1)

[Claims] 1. General formula▲ Numerical formula, chemical formula, table, etc.▼ (However, in the formula, A^1 and A^2 each independently represent hydrogen, a methyl group, or -COOX, and A^1 and A^2 cannot be -COOX at the same time, and A^3
is hydrogen, methyl group, -COOX or -CH_2COO
represents X, and A^3 is -COOX or -CH_2
In the case of COOX, A^1 and A^2 are each independently hydrogen or a methyl group, R^1 is -CO- or -CH_2CO-, and R^2 is an alkylene group having 2 to 4 carbon atoms. , n is a number from 1 to 100 on average, and R
^3 is a monovalent organic group derived from an alkyl group, alkenyl group, aryl group, aralkyl group, cyclic alkyl group, cyclic alkenyl group, or heterocyclic compound having 1 to 30 carbon atoms, and X is hydrogen, Indicates an alkali metal, alkaline earth metal, ammonium group or organic amine group. ) and one or more vinyl monomers (I) represented by the general formula ▲ mathematical formula, chemical formula, table, etc. ▼ (However, in the formula, R^4 and R^5 each independently represents hydrogen, a methyl group or -COOM, and R^4 and R^5 cannot be -COOM at the same time, R^6 represents hydrogen, a methyl group, -COOM or -CH_2COOM, and R^6 -COO
R^4 and R for M or -CH_2COOM
^5 are each hydrogen or methyl group, M is hydrogen,
Indicates an alkali metal, alkaline earth metal, ammonium group or organic amine group. ) and one or more unsaturated carboxylic acid monomers (II) represented by the general formula ▲ mathematical formula, chemical formula, table, etc. ▼ (However, in the formula, R^7 is hydrogen or methyl. group, Z is an alkylene group having 1 to 4 carbon atoms, Y is hydrogen, alkali metal, alkaline earth metal, ammonium group, or organic amine group). ) and another monomer (IV) copolymerizable with these monomers,
The monomer (I) is 0.2 to 5 mol%, the monomer (II) is
is more than 50 and 94.8 mol% or less, the monomer (III)
is 5 to 45 mol%, and the monomer (IV) is 0 to 20 mol% (
However, monomers (I), (II), (III) and (IV)
The total amount is 100 mol%. ) and/or a water-soluble copolymer obtained by further neutralizing the copolymer with a basic substance, a dispersant for a coal-water slurry.