JPS6264894A - Dispersant for coal-water slurry - Google Patents

Abstract

PURPOSE:To obtain a dispersant capable of providing a coal-water slurry having high flowability even when the concn. of the slurry is high, by copolymerizing a polyalkylene glycol monomethacrylate monomer with a particular monomer and, if necessary, a monomer copolymerizable with these monomers. CONSTITUTION:A polyalkylene glycol monomethacrylate monomer of formula I (wherein X is a 2-4 alkylene; n is 1-100 on the average; and Y is H, a 1-5 alkyl, phenyl, or alkylphenyl contg. 1-3 alkyl having a 1-9C) is mixed with at least one monomer selected from dialkylaminoalkyl methacrylate of formula II (wherein Z is a 1-4 alkylene; and R1-R2 are each a 1-5C alkyl) and a quaternary ammonium chloride methacrylate of formula III (wherein R3 is R1, R2 or benzyl; m is 1 or 2; and M is an anion) in a molar ratio of 1:2-500. 50mol% or more of the mixture is copolymerized with 50mol% or less of a monomer copolymerizable with the above monomers, e.g., methyl (meth)acrylate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dispersant for coal-water slurries. 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.

Petroleum, which has traditionally 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, which is made into a coal-water slurry to be fluidized and transported by pipeline.

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 of slurrying coal into water is used in an extremely wide range of coal uses, such as direct coal combustion and gasification, in addition to the above-mentioned coal pipeline transportation, and is an important issue in coal use. It becomes. It is preferable for this coal-water slurry to be a high-81 degree slurry with a low moisture content from the economic and pollution prevention viewpoints. especially,
υ1 In the case of direct combustion of coal-water slurry, which can eliminate water treatment and pollution problems, dehydration of coal-water slurry,
In order to charge the coal-water slurry into a cyclone or turbulent burner and burn it directly in the furnace without performing any treatment such as drying, 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 extremely thick and loses fluidity. On the other hand, if the concentration of coal powder in water is lowered, transportation efficiency and combustion efficiency will decrease, and if the coal-water slurry is dehydrated and used, additional costs may be incurred for dewatering and drying the culm. 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.

51 The present inventors have solved the above-mentioned problems in dispersants for coal-water slurries (as a result of intensive research, they have found that a certain water-soluble copolymer is excellent as a dispersant for Ishikawa-water slurries). The present invention was completed based on the discovery that the present invention has the following effects.

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

The present invention is based on the general formula % formula % (wherein, X is an alkylene group having 2 to 4 carbon atoms, n is a number of 1 to 100 on average, and Y is hydrogen,
represents an alkyl group, 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 (I) represented by the general formula (wherein 7 represents I; A represents an alkylene group having 1 to 4 prime numbers, and R1 and R2 represent an alkylene group having 1 to 5 carbon atoms. Indicates an alkyl group.

) dialkylaminoalkyl methacrylate-1 represented by
- and the general formula (wherein 7 represents an alkylene group having 1 to 4 carbon atoms, R1 and R2 represent hydrogen or an alkyl group having 1 to 5 carbon atoms, and R3 represents hydrogen or an alkyl group having 1 to 5 carbon atoms) at least one monomer selected from the group consisting of quaternary ammonium chloride methacrylate represented by ) is an essential component, and the molar ratio of the monomer (1) to the monomer (IT) is from 1:2 to 1:500. A water-soluble copolymer obtained from raw material monomers having a monomer composition of 50 mol % or more in total of the monomer (1) and the monomer (■) in the total 11-mers. This invention relates to a dispersant for coal-water slurry.

The coal used in the coal-water slurry is, for example, anthracite,
Bituminous coal, ail! Any type of coal, such as blue coal, 'l1lJ coal, etc., irrespective of type or origin, moisture content or chemical composition, can be used. Such coal may be wet or dry pulverized by conventional methods. Therefore, the standard for use is 200 mesh pass 50% by weight or more, preferably 70-80!If%.Also, the slurry concentration is 60-90% by weight on a dry base of pulverized coal, and less than 60% by weight. In this case, it is not practical in terms of economy, transportation efficiency, combustion efficiency, etc.

The water-soluble copolymer effective as a dispersant for Ishizuka-water slurry of the present invention has monomer (I> and monomer (I) as essential components, *m-isomer (J) and monomer ( ■) molar ratio is 1=
2 to 1:500, more preferably 1:10 to 1:20
0, and monomer (I) and 111 body (II)
It is obtained from raw material monomers having a total of 50 mol % or more of the total monomers.

Monomer (1) is represented by the above general formula,
It can be obtained by a known method. Examples of monomer (I) include polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate-1-, polybutylene glycol monomethacrylate, methoxypolyethylene glycol monomethacrylate, methoxypolyethylene glycol monomethacrylate, methoxypolyethylene glycol monomethacrylate, ethoxy Examples include polyethylene glycol monomethacrylate, ■toxypolypropylene glycol monomethacrylate, ■toxypolybutylene glycol monomethacrylate, methoxypolyethylene glycol polypropylene glycol monomethacrylate, and one or more of these can be used. .

Further, the monomer (IT) is at least one of dialkylaminoalkyl methacrylate and quaternary ammonium chloride methacrylate represented by the above general formula, and this can also be done by a known method, for example, transesterification of methyl methacrylate and dialkylamino alcohol. A method of converting dialkylaminoalkyl methacrylate into dialkylaminoalkyl methacrylate by reaction, or converting dialkylaminoalkyl methacrylate into alkyl halide,
It can be obtained by using a quaternizing agent such as benzyl halide, dialkyl sulfuric acid, or hydrochloric acid to form quaternary ammonium chloride methacrylate. Examples of monomers (■) are:
Dimethylaminoalkyl methacrylates such as dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, dimethylaminopropyl methacrylate, diethylaminopropyl methacrylate, methyl chloride quaternized product of dimethylaminoethyl methacrylate (β-methacryloxyethyltrimethylammonium chloride), dimethylaminoethyl methacrylate Quaternary ammonium chloride methacrylate-1, such as benzyl chloride quaternized product, dimethyl sulfate quaternized product of dimethylaminoethyl methacrylate, salt M quaternized product of dimethylaminoethyl methacrylate, and methyl chloride quaternized product of diethylaminoethyl methacrylate. One or more of these can be used.

The ratio of monomer (I) and monomer (JT) used is in the range of 1=2 to 1:500 in terms of molar ratio, and when used in a ratio outside this range, excellent dispersion performance can be obtained. Copolymer cannot be obtained.

In addition, in addition to these monomers (I) and monomer (II), a monomer (III) copolymerizable with these monomers is used in an amount of less than 50 mol% of the total monomers. be able to. Examples of this include acrylic acid, methacrylic acid, crotonic acid,
Various esters such as methyl (meth)acrylate and 2-hydroxyethyl acrylate obtained from unsaturated carboxylic acids such as itaconic acid, maleic acid, and fumaric acid and alcohol; (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., and one or more of these may be used. can be used.

The proportion of these intermediates (I) and monomers (IIT) that can be copolymerized with monomer (I) is less than 50 mol% of the total intermediates, and there are many proportions exceeding this range. If used for this purpose, 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 or aliphatic hydrocarbons such as hexane; 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 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 temperature 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.

Further, the molecular weight of the copolymer can be used in a wide range, but in consideration of its performance as a dispersant for coal-water slurry, a range of 1,000 to 500,000, particularly a range of 5,000 to 300,000 is preferable.

The water-soluble copolymer thus obtained can be used as it is as a dispersant for the stone-water slurry of the present invention, but if necessary, it may be further converted into a quaternary ammonium salt using a known quaternizing agent. good. Preferred examples of such quaternizing agents include alkyl halides such as methyl chloride, benzyl halides such as Pencil [1-lide], and dialkyl sulfates such as dimethyl sulfur M.

The dispersant for coal-water slurry of the present invention is used in fine powder M-water slurry, but the amount added is not particularly limited. From 0.05 to pulverized coal weight (dry base)
It is used in a proportion of 2% by weight, preferably from 0.1 to 1% by weight.

In order to use the dispersant for coal-water slurry of the present invention, it is possible to mix the dispersant with coal in advance and form a slurry, or to dissolve the dispersant in water in advance. You may also use Of course, a predetermined amount of the dispersant may be mixed all at once, or may be used in batches.

Furthermore, due to the nature of the dispersant, the slurry-forming device may be one that is used to slurry coal in water.

By these addition methods and slurry-forming methods, -15- The scope of the present invention is not limited.

Moreover, a rust preventive agent, a corrosion preventive agent, an antioxidant, an antifoaming agent, an antistatic agent, a solubilizer, and the like can be added to the dispersant for coal-water slurry of the present invention as required.

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 to these.

In addition, unless otherwise specified in steel, parts represent parts by weight.

Example 1 200 parts of water was charged into a polymerization container equipped with a temperature chamber, a stirrer, two dropping funnels, a gas introduction pipe, and a reflux condenser, and the inside of the polymerization container was replaced with nitrogen while stirring, and the temperature was reduced to 95% in a nitrogen atmosphere. heated to ℃. Thereafter, 8 parts of methoxypolyethylene glycol monomethacrylate (containing an average of 20 ethylene oxide ψ positions per molecule) as the IP body (1), and 4 parts of methyl chloride of dimedylaminoethyl methacrylate as the monomer (U) A solution of 92 parts of graded product and 150 parts of water was added dropwise for 60 minutes to the other dropping row I.
A solution of 0.4 parts of ammonium peroxide and 50 parts of water was added dropwise over 70 minutes. After dropping, continue at the same temperature for 6
After continuing polymerization for 0 minutes, the mixture was cooled to obtain an aqueous solution of copolymer (1) having an average molecular weight of 100,000.

Examples 2 to 8 Monomers (■), monomers (If), and optionally monomers (III) shown in Table 1 were added to monomer compositions shown in Table 1 (mol% ), polymerization was carried out according to the method used in Example 1 to obtain aqueous solutions of copolymers (2) to (8).

= 17- Example 9 200 parts of water was charged into a polymerization container equipped with a temperature reducer, a stirrer, two dropping funnels, a gas introduction pipe, and a reflux cooler, and while stirring, the inside of the polymerization container was replaced with nitrogen. 95℃ in nitrogen atmosphere
heated to. Thereafter, methoxypolyethylene glycol monomethacrylate-1 (containing an average of 20 ethylene oxide units per molecule) 8 as monomer (1)
A solution of 69.6 parts of dimethylaminoethyl methacrylate and 150 parts of water as ψmer (IT) was added dropwise over 60 minutes, and 0.4 parts of ammonium persulfate and 50 parts of water were added from the other dropping funnel. solution was added dropwise over 70 minutes. After the dropwise addition was completed, polymerization was further continued for 60 minutes at the same temperature and then cooled to obtain an aqueous solution of a copolymer with an average molecular weight of 100,000.

156 parts of dimethyl sulfur M was added to the aqueous solution of the copolymer obtained.
The dropwise addition took 20 minutes, and after the completion of the dropwise addition, the reaction temperature was 50°C.
After reacting for 00 minutes, an aqueous solution of the quaternized copolymer (9) was obtained.

Comparative Example 1 A comparative polymer with an average molecular weight of 100,000 (
An aqueous solution of 1) was obtained.

Example 10 A 200-mesh sieve was added to a 74% aqueous solution containing the copolymers (1) to (9) obtained in Examples 1 to 9 in the amounts shown in Table 2. Pulverized coal (bitumen) was added little by little at room temperature with stirring. After adding the entire amount to achieve the coal concentration shown in Table 2, use a homomixer (manufactured by Tokushu Kikako) to produce 5000 PPM.
, and stirred for 3 minutes 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.

In addition, for comparison, the comparative polymer obtained in Comparative Example 1 (
1) Sodium polyacrylate (average molecular weight 60,000) or poly(dithylene glycol) (average molecular ω21500)
Table 2 shows the results of comparative examples in which 411 were used as a dispersant and in which no dispersant was used at all.

Table 2 ×: Bad Manual correction correction @ (spontaneous) October 25, 1985

Claims (1)

[Claims] 1. General formula CH_2-C(CH_3)COO-(XO)-_nY(
However, in the formula, X is an alkylene group having 2 to 4 carbon atoms, n is a number on average from 1 to 100, and Y is hydrogen, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or an alkyl group having 1 to 9 carbon atoms. It shows an alkylphenyl group having 1 to 3 groups as substituents. ) Polyalkylene glycol monomethacrylate monomer (I) represented by the general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (However, in the formula, Z represents an alkylene group having 1 to 4 carbon atoms, R_1, (R_2 represents an alkyl group having 1 to 5 carbon atoms.) Dialkylaminoalkyl methacrylate represented by the general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (However, in the formula, Z represents an alkylene group having 1 to 4 carbon atoms.) R_1 and R_2 are hydrogen or carbon number 1
~5 alkyl group, R_3 represents hydrogen, an alkyl group having 1 to 5 carbon atoms, or a benzyl group, m is an integer of 1 or 2, and M represents an anion. ) at least one monomer (II) selected from the group consisting of quaternary ammonium chloride methacrylates represented by The ratio is in the range of 1:2 to 1:500, and the total of the monomer (I) and the monomer (II) is 50% of the total monomers.
A dispersant for coal-water slurry comprising a water-soluble copolymer obtained from raw material monomers having a mole % or more.