JPS63113098A - Dispersing agent for coal-water slurry - Google Patents

Abstract

PURPOSE:To provide a dispersing agent composed of a water-soluble copolymer containing a specific vinyl monomer and a specific unsaturated carboxylic acid monomer as essential constituent components, effective in dispersing coal powder in water and giving a coal-water slurry keeping high fluidity even at a high concentration. CONSTITUTION:The objective dispersing agent is composed of a water-soluble copolymer containing (A) one or more vinyl monomers of formula I (A<1>-A<3> are H, methyl, etc.; R<1> is -CO- or -CH2CO-; R<2> is 2-4C alkylene; n is 1-100 on an average; R<3> is 1-30C alkyl, alkenyl, etc.) and (B) one or more unsaturated carboxylic acid monomers of formula II [R<4> is H or methyl; M is H, alkali metal, alkaline earth metal, etc.] as essential components. The weight ratio of A/B is 0.5:99.5-7:93 and the sum of the components A and B is >=60wt% of the total monomers.

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 high-grade 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-former xture) has entered the practical stage, but since it uses oil, there are problems in terms of stable supply and price, and in the future, high-concentration coal-water slurry is considered as one of the coal utilization technologies. It is seen as promising.

This technology for slurrying coal into water is about to be used in an extremely wide range of coal uses, including the above-mentioned vibrine transportation of coal, direct combustion of coal, gasification, etc.
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, if an attempt is made to increase the y:J degree of coal powder using known techniques, the slurry will significantly thicken and lose fluidity. Conversely, if the concentration of coal powder in the slurry is lowered, the transport efficiency,
Combustion efficiency is reduced, and when the coal-water slurry is used after being dehydrated, the dehydration and drying steps also have problems such as extra costs and pollution problems.

Conventionally, various dispersants for coal-water slurries have been proposed to solve such problems. For example, surfactants such as sodium oleate, sodium dodecylbenpine sulfonate, alkylaryl sulfone, polyoxyethylene alkylphenyl ether, and stearylamine hydrochloride, polyethylene glycol, polyacrylamide, cellulose, and sodium polyacrylate. ,
There are water-soluble polymers such as sodium lignin sulfonate, sodium naphthalene sulfonate/formalin condensate, etc.
Additionally, a combination of a nonionic surfactant and a water-soluble polymer has also been used. However, both have insufficient fluidity and lack practicality, and when surfactants are used,
Bubbles tend to form, and the obtained coal-water slurry thickens over time, resulting in problems in terms of physical properties as a slurry.

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 A1 and A each independently represent hydrogen, a methyl group, or -coox, and A1 and A2
cannot be -coox at the same time, A represents hydrogen, a methyl group, -COOX or 1082 C00X, and A is -coox or 7. :l;t-CH2C00
In the case of X, A1 and A are each independently hydrogen or a methyl group, and R1 is 100- or 1082 G
o-, R is an alkylene group having 2 to 4 carbon atoms,
n is a number from 1 to 100 on average, and R is a number from 1 to 30 carbon atoms.
is a monovalent organic group derived from an alkyl group, an alkenyl group, an aryl group, an aralkyl group, a cyclic alkyl group, a cyclic alkenyl group, or a heterocyclic compound, and X is hydrogen, an alkali metal, an alkaline earth metal, Indicates an ammonium group or an alkylamine group. ) and one or more vinyl monomers (I) represented by the general formula % (wherein R4 is hydrogen or a methyl group, and M is hydrogen, an alkali metal, an alkaline earth metal, ammonium group or alkylamine group), and H11f
f1 body (I),! :The 1iffi body (ff),! :
(7) Weight jt lfi 0゜5:99.5 to 7=
93, and the monomer (I) and the monomer (I
The present invention relates to a dispersant for coal-water slurry comprising a water-soluble copolymer obtained from raw material monomers in which the total amount of I) is 60% by weight or more based on all monomers.

The coal used in the coal-water slurry is, for example, anthracite,
F1 blue coal, sub-F! Any type of coal, such as blue coal or lignite, can be used regardless of its type or origin, moisture content, or chemical composition, but especially low ash content of less than 3% ash (on an anhydrous basis). Effective for charcoal. Such coal is wet- or dry-pulverized by a conventional method to obtain a 200 mesh pass of 50% by weight or more, preferably 70 to 90% by weight. Also,
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 that is effective as a dispersant for coal-water slurry of the present invention contains a mono-ω-isomer (I) and a monomer (II) as essential components. [) is in the range of 0.5:99.5 to 7=93, and the total of monomer (I) and qjri:1 body (II) is 60% by weight or more in the entire vehicle m body. Obtained from a certain raw material monomer.

Monomer (I) is represented by the above general formula,
It can be obtained by a known method. Examples of monomer (1) include methoxypolyethylene glycol mono(meth)acrylate, methoxypolypropylene glycol mono(
meth)acrylate, methoxypolybutylene glycol mono(meth)acrylate, ethoxypolyethylene glycol mono(meth)acrylate, ethoxypolypropylene glycol mono(meth)acrylate, ethoxypolybutylene glycol mono(meth)acrylate, methoxypolyethylene glycol polypropylene glycol mono(meth)acrylate In addition to meth)acrylates, alkoxypolyalkylene glycol mono(meth)acrylates alkoxylated with an alkyl group having up to 30 carbon atoms: 3 carbon atoms
Alkenoxypolyalkylene glycol mono(meth)acrylates alkenoxylated with up to 0 alkenyl groups; phenoxypolyethylene glycol mono(meth)
Acrylate, naphthoxypolyethylene glycol mono(meth)acrylate, phenoxypolypropylene glycol mono(meth)acrylate, naphthoxypolyethylene glycol polypropylene glycol mono(meth)acrylate, p-methylphenoxypolyethylene glycol mono(meth)acrylate, etc. Roxypolyalkylene glycol mono(meth)acrylates;
Aralkyloxypolyalkylene glycol mono(meth)acrylates such as benzyloxypolyethylene glycol mono(meth)acrylate; Cyclic alkoxypolyalkylene glycol mono(meth)acrylates such as cyclohexoxypolyethylene glycol mono(meth)acrylate: Cyclopentynoki Cyclic alkenoxypolyalkylene glycol mono(meth)acrylates such as siboriethylene glycol mono(meth)acrylate; polyalkylene glycol monos such as pyrisiloxypolyethylene glycol mono(meth)acrylate and chenyloxypolyethylene glycol mono(meth)acrylate (
Heterocyclic ethers of meth)acrylates: unsaturated polyesters of monoetherified polyalkylene glycols such as methoxypolypropylene glycol monomaleate, phenoxypolyethylene glycol monomaleate, naphthoxypolypropylene glycol monoitaconate, phenoxypolyethylene glycol monoitaconate, etc. Examples include carboxylic acid monoesters, and one or more of these can be used.

Further, the monomer (It) is also represented by the above general formula, and can also be obtained by a known method.

Examples of the monomer (■) include acrylic acid or methacrylic acid, their alkali metal salts such as sodium and potassium, alkaline earth metal salts such as magnesium and calcium, ammonium salts, and alkylamine salts. , one or more of these can be used.

The ratio of monomer (I) and monomer (II) used is in the range of 0.5:99.5 to 7:93 by weight, and if the ratio is outside this range, dispersion will occur. A copolymer with excellent performance cannot be obtained.

In addition, in addition to these monomers (I) and monomers (If), a monomer (III) copolymerizable with these monomers is used within a range of 4Oflffi% in the total monomer. be able to. Examples include crotonic acid, itaconic acid, maleic acid, fumaric acid, monovalent metal salts, divalent metal salts, ammonium salts, alkylamine salts of these acids, and alcohols with these acids or (meth)acrylic acid. Resulting esters such as methyl (meth)acrylate; vinyl sulfonic acid, styrene sulfonic acid, allyl sulfonic acid,
Various unsaturated sulfonic acids such as methallylsulfonic acid, 2-acrylamide and 2-methylpropanesulfonic acid, and their -valent metal salts, divalent metal salts, ammonium salts and alkylamine salts: (meth)acrylamide, N-methylol ( Various types of (meth)acrylamides such as meth)acrylamides: aromatic vinyl compounds such as styrene and p-methylstyrene; examples include vinyl acetate, propenyl acetate, and vinyl chloride; one or more of these may be used. be able to.

The amount of 1lffi compound (I [[) that can be copolymerized with these monomers <I> and monomer (II) is within the range of less than 40% by weight in the total amount of monomers <I> and monomer (II), and in large amounts beyond this range. If used, the dispersion performance of the resulting copolymer will deteriorate.

In the present invention, the water-soluble copolymer can be produced by copolymerizing the monomer components 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; ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone; and the like. Single raw material and resulting copolymer −
In view of the solubility of the copolymer and the convenience of using the copolymer, it is preferable to use at least one selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms. Carbon number 1
Among the lower alcohols 4 to 4, 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 M salt 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 humidity is adjusted appropriately 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 the humidity range of 50-150°C.

In addition, a wide range of molecular groups can be used for the copolymer, but considering its performance as a dispersant for coal-water slurry, it is in the range of 1,000 to 500,000, particularly 5,000 to 300,000. Preferably.

The dispersant for coal-water slurry of the present invention is used for pulverized coal-water slurry, but its addition m is not particularly limited and is effective over a wide range of addition ω. It is used in a proportion of 0.05 to 2% by weight (dry basis), preferably 0.1 to 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 in its entirety, or it 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 i.

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

Further, an antisettling agent, a rust preventive agent, an anticorrosive agent, an antioxidant, an antifoaming agent, an antistatic agent, a solubilizer, etc. may be added to the dispersant for coal-water slurry of the present invention as necessary. Can be done.

(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 addition, unless otherwise specified, parts in the examples represent heavy ω parts.

Examples 1 to 9 The monomers (■), the monomers (n) and, if necessary, the monomers (III) shown in Table 1 were added to the monomers shown in Table 1 (wt% ) to carry out polymerization to produce copolymers (1) to
An aqueous solution of (9) was obtained.

Example 10 The copolymers (1) to (9) obtained in Examples 1 to 9 were
The additions indicated in the table are in an aqueous solution prepared to contain:
J: 75% of the coal passed through a 200 mesh sieve: sea urchin pulverized coal (properties shown in Table 3) was added little by little while stirring at room temperature. Total m with coal concentration shown in Table 2
After adding, the mixture was stirred for 3 minutes at 5000 RPM 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 not shown in Table 2. Low viscosity indicates good fluidity.

For comparison, 1 with the monomer composition shown in Table 1.
7 comparative copolymers (1) to (2), cases where sodium polyacrylate (average molecule ω 60,000) or polyethylene glycol (average molecule ff 121,500) was used as a dispersant, and cases where no dispersant was used at all. The results of the comparative example are also listed in Table 2.

Table 2 (Note) Q: Good ×: Bad Table 3

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 are -COOX at the same time
, A^3 represents hydrogen, a methyl group, -COOX or -CH_2COOX, and when A^3 is -COOX or -CH_2COOX, A^1 and A^2 each independently represent hydrogen. or a methyl group, R^1 is -CO- or -CH_2CO-, 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 an alkyl group, alkenyl group, aryl group, aralkyl group, cyclic alkyl group, cyclic alkenyl group, or a monovalent organic group derived from a heterocyclic compound having 1 to 30 carbon atoms, and X is hydrogen, an alkali metal , alkaline earth metal, ammonium group or alkylamine group. ) and one or more vinyl monomers (I) represented by the general formula ▲ Numerical formula, chemical formula, table, etc. represents hydrogen, an alkali metal, an alkaline earth metal, an ammonium group or an alkylamine group. The weight ratio of monomer (I) and monomer (II) is in the range of 0.5:99.5 to 7:93, and ) A dispersant for a coal-water slurry comprising a water-soluble copolymer obtained from raw material monomers having a total of 60% by weight or more of the total monomers.