JPH0576995B2 - - Google Patents

Description

[Detailed description of the invention]

[Field of Application of the Invention] The present invention relates to a dispersion stabilizer used in the production of a highly concentrated coal-water slurry having a high coal concentration in the slurry, low viscosity, good fluidity, and excellent storage stability. [Prior Art] In recent years, the energy-related industry has been actively considering a change from the conventional dependence on oil to the effective use of coal as a fuel energy source. The use of coal has various advantages such as its reserves are estimated to be 5 to 10 times that of oil, it is easy to extract, it can be supplied stably, and it is cheap. When using coal as a fuel, the technology to convert coal into a liquid fuel is a method that can be transported in the same way as oil, and also allows equipment that used oil as fuel to be used as is. It is being considered. As such technology, coal has been used for about 10 years.
Research is being carried out on the practical application of coal-oil-mixture (COM), which is pulverized to about 200 mesh particles and dispersed in petroleum using a small amount of surfactant, but this is a liquid fuel. This method is unsatisfactory as a measure to effectively utilize coal for the purpose of resource conservation, as it requires approximately 50% heavy oil as a conversion medium.
Later, we focused on this point and aimed at the advanced utilization of coal.We created a dispersion fuel that does not contain any oil, unlike the COM mentioned above, in other words, by dispersing finely powdered coal in water using a surfactant and creating a slurry. Highly concentrated coal-water slurry (Coal-
The practical application of water-slury (hereinafter referred to as CWS) is being considered. In order for CWS to be a viable alternative fuel to conventional petroleum, it must have stability as a fluid fuel, i.e. fluid transport, pumpable viscosity, storage stability, and high coal concentration to reduce energy loss. For example, coal concentration 70% or more), etc.
It must satisfy various conditions. A dispersion stabilizer is added to produce a CWS that meets these conditions as described above. The physical properties of the CWS obtained vary greatly depending on the type of dispersion stabilizer added. Various dispersion stabilizers used in CWS have been studied and reported, but among them, polymers with sulfonic acid groups are said to be relatively effective. salts of copolymers of acrylic acid or methacrylic acid and vinyl sulfonic acid (JP 59-86694), salts of copolymers of acrylic acid or methacrylic acid, α-olefins, and vinyl sulfonic acid, etc. Salt (Japanese Unexamined Patent Publication No. 59-120234) is known. [Problems to be Solved by the Invention] However, with these dispersion stabilizers, it is difficult to increase the coal concentration in the slurry to a high concentration of 70% or more, and even if it is 70% or more, The slurry viscosity is abnormally high (approximately 3,000 centipoise or more), which causes significant problems in storage stability after CWS production (more than 2 months), pipeline transportation as a fluid fuel, pumping up, and nozzle injection during combustion. causing obstacles and practical
Its dispersion stabilization effect is still not sufficient to obtain CWS. The present invention was developed with attention to the above points, and it is possible to increase the coal concentration in the slurry to a high concentration of 70% or more, and the obtained slurry has low viscosity, so it has excellent fluidity. Excellent storage stability
The purpose of the present invention is to provide a dispersion stabilizer for highly concentrated coal-water slurry that can obtain CWS. [Means for Solving the Problems] As a result of intensive research to solve the above problems, the present inventors discovered that styrene sulfonic acid, styrene, and acrylic esters of polyoxyalkylene ether derivatives such as polyoxyalkylene alkyl ethers It was discovered that a coal-water slurry with a high coal concentration in the slurry, low viscosity, good fluidity, and excellent storage stability can be obtained by using a salt of a copolymer of I was able to complete it. That is, the present invention relates to (A) an alkali metal or amine salt of styrene sulfonic acid, (B) styrene, and (C) polyoxyalkylene alkyl ether, polyoxyalkylene phenyl ether, polyoxyalkylene alkyl phenyl ether (hereinafter referred to as these). (collectively referred to as "polyoxyalkylene ether derivatives"), and the molar ratio is A:B:C=1:0.2 to 1.5:0.02.
This is a dispersion stabilizer for high concentration coal-water slurry containing a copolymer of ~0.85. In the present invention, the component (A) constituting the copolymer is an alkali metal salt or amine salt of styrene sulfonic acid. Examples of the alkali metal that forms the salt include lithium, sodium, potassium, etc., and examples of the amine include ammonium, monoethanolamine,
Examples include diethanolamine, triethanolamine, diethylamine, triethylamine, n-propylamine, morpholine, ethylenediamine, and the like. In the present invention, the component (B) constituting the copolymer includes styrene. In the present invention, the component (C) constituting the copolymer is an acrylic ester or methacrylic ester of a polyoxyalkylene ether derivative, and the esterification reaction between the polyoxyalkylene ether derivative and acrylic acid or methacrylic acid, or the polyoxyalkylene ether derivative It is obtained by a transesterification reaction between an ether derivative and a lower alkyl ester of acrylic acid or methacrylic acid. The polyoxyalkylene ether derivative constituting the ester has 1 to 1 carbon atoms.
It is obtained by adding a lower alkylene oxide to a monohydric alcohol and phenol or alkylphenol having 18 alkyl groups. Carbon number 1-18
Examples of monohydric alcohols having an alkyl group include methanol, ethanol, n-propanol, n-
Butanol, n-hexanol, n-octanol, n-decyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol,
Straight chain alcohols such as stearyl alcohol, isopropyl alcohol, isobutyl alcohol, isooctyl alcohol, isodecyl alcohol,
Examples include side chain alcohols such as isostearyl alcohol. Furthermore, examples of phenols and alkylphenols include octylphenol and nonylphenol. Examples of the lower alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, and styrene oxide. The number of moles of lower alkylene oxide added is preferably 2 to 50. The copolymer used in the present invention has the above-mentioned components A, B, and C in a molar ratio of A:B:C=1:0.2 to
1.5:0.02 to 0.85, or by copolymerizing styrene sulfonic acid with component B and component C, and then neutralizing the sulfonic acid group in the copolymer with an alkali metal hydroxide or amine. It will be done. The mole ratio of each component constituting the copolymer is preferably within the above range; if the amount of component B is less than 0.5 mole per mole of component A, the dispersion stability of the resulting slurry will be poor and coal particles will settle over time, resulting in 1.5 moles of component B. Above this amount, the slurry becomes extremely viscous. Furthermore, if the C component is less than 0.02 mol, the viscosity of the slurry will increase significantly over time, and if it is more than 0.85 mol, the dispersion stability will be poor. The molecular weight of the copolymer is preferably 3,000 to 100,000, more preferably 10,000 to 50,000. If the molecular weight is 100,000 or more, the viscosity of the slurry will be high, and if it is less than 3,000, the dispersibility of the coal particles will be poor. Examples of copolymerization reaction methods include emulsion polymerization, suspension polymerization, bulk polymerization, and solution polymerization, with emulsion polymerization being particularly preferred. The dispersion stabilizer for high concentration coal-water slurry of the present invention contains one or more of the above copolymers as an active ingredient, and contains 5 to 50% by weight of the above copolymer.
It is used as an aqueous solution containing Furthermore, a rust preventive agent, a preservative, etc. may be added in addition to the above-mentioned copolymer. The dispersion stabilizer for high concentration coal-water slurry of the present invention can be used to increase the concentration of coal in coal-water slurry,
Used to prevent coal agglomeration and reduce slurry viscosity. Examples of the coal used in the slurry include brown coal, bituminous coal, subbituminous coal, and anthracite coal. In addition, it is preferable that the state is in the form of fine powder and the particle size is uniform. For example, if coal containing 70% by weight or more of particles with a particle size of 74μ or less is used, the effect of the dispersion stabilizer for high concentration coal-water slurry of the present invention is more exhibited. be done. As a method for producing a coal-water slurry using the dispersion stabilizer for a high-concentration coal-water slurry of the present invention, for example, after pulverizing coal, this and the dispersion stabilizer for a high-concentration coal-water slurry of the present invention may be used. Examples include a dry production method in which the agent is mixed with water, or a wet pulverization production method in which coal is pulverized in water to which a dispersion stabilizer for high-concentration coal-water slurry has been added. Not limited. The amount of the dispersion stabilizer for high concentration coal-water slurry of the present invention added is preferably 0.02 to 2% by weight as a copolymer component in the dispersion stabilizer, based on the coal in the slurry, and if it is less than 0.02% by weight, the dispersibility is poor. not enough,
A slurry with good performance can be obtained at 0.02 to 2% by weight, and even if more is added, no greater effect can be expected and it is not economical. The present invention will be explained below with reference to Examples. [Example] Example 1 896 parts by weight of deionized water and dodecylbenzenesulfonic acid as an emulsifier were placed in a polymerization vessel equipped with a stirrer, a thermometer, an inert gas introduction tube, and a dropping funnel.
14 parts by weight of Na and 0.003 parts by weight of ferrous sulfate as a reducing agent were added, and the mixture was purged with nitrogen for 1 hour while maintaining the temperature at 60°C. Separately, 206 parts by weight (1.0 mol) of sodium styrene sulfonate and a 15 mol ethylene oxide adduct of hexanol (hereinafter referred to as polyoxyethylene (n=15))
274 parts by weight (0.33 mol) of methacrylic acid ester (expressed as hexyl ether) was dissolved in 952 parts by weight of distilled water, the pH was adjusted to 3 with sulfuric acid, and 8.8 parts by weight of sodium metabisulfite was dissolved therein as a reducing agent. An aqueous solution was prepared, and it was added dropwise to the solution together with 34.3 parts by weight (0.33 mol) of styrene and 407 parts by weight of a 2% potassium persulfate aqueous solution over a period of about 1 hour while stirring.
It was aged at 60°C for 1 hour. After the reaction was completed, the reaction product was adjusted to pH 7 with caustic soda and filtered through a 400 mesh strainer to obtain 2780 parts by weight of a white translucent copolymer latex. The solid content concentration of this latex was 19.2% by weight, and the average molecular weight of the copolymer was 32,000. Table 2 shows the copolymerization molar ratio of the copolymer latex. The obtained copolymer was used as a dispersion stabilizer for coal-water slurry, a coal-water slurry was prepared, and its performance was evaluated by measuring the fluidity and static dispersion stability of the slurry. The results are shown in Table-3. The coal-water slurry was prepared as follows. Add the above dispersion stabilizer (solid content 19.2
% content) 10.6 parts by weight (based on coal in the slurry,
(equivalent to 0.4% by weight in terms of solid content) and 178.4 parts by weight of water were prepared and a homogeneous aqueous solution was prepared at room temperature using an ordinary blade stirrer. Add 511 parts by weight of pulverized coal (corresponding to 73% by weight of the total slurry) to this aqueous solution for about 1000 r.
After making a slurry by adding it for about 10 minutes at a stirring speed of pm, this slurry was further added to Tokushu Kika Kogyo Co., Ltd.
Coal-water-slurry composition 700 was mixed for 5 minutes at 6000 rpm at room temperature using a M-type homomixer manufactured by Kogyo Co., Ltd.
Parts by weight were prepared. Incidentally, the actual value of the coal concentration in the slurry was 72.0% by weight. Table 1 shows the properties of the pulverized coal used.

[Slurry performance test method]

Fluidity of slurry: The slurry immediately after preparation was placed in a 300 ml glass sample bottle, and the viscosity (centipoise) at 25°C was measured using a B-type rotational viscometer (manufactured by Tokyo Keiki Seisakusho). Further, this slurry was allowed to stand at a constant temperature of 25° C. in the same sample bottle, and the viscosity of the slurry was measured after 20 and 40 days to evaluate fluidity. Static dispersion stability of slurry (rod penetration test method): 200ml graduated cylinder (inner diameter 36mm, height 262mm)
Pour 200 ml of the slurry just prepared above into a
A glass rod (penetrating rod) with a diameter of 7 mm, a length of 300 mm, and a weight of 32 g is vertically dropped vertically from the center of the slurry liquid surface at ℃. The time it took to reach this point (in seconds) was measured. Further, the slurry was left to stand at a constant temperature of 25°C, and a rod penetration test was performed on the slurry after 20 and 40 days. The shorter the penetration time, the better the dispersion stability, and non-penetration indicates that the glass rod did not reach the bottom of the measuring cylinder and the coal separated and settled. Comparative Examples 1 to 4 Formalin condensate of β-naphthalene sulfonate Na Comparative Example 1, Polymer Comparative Example 2 of styrene sulfonate Na, Styrene sulfonate Na-Acrylic acid Na
Copolymer Comparative Example 3 and sodium styrene sulfonate-styrene-sodium acrylate copolymer Comparative Example 4 were synthesized and used as a dispersion stabilizer to prepare a coal-water slurry, and the fluidity of the slurry and the stability of the slurry were evaluated. The performance was evaluated by measuring the dispersion stability. The manufacturing conditions of the polymer or copolymer are shown in Table 2, and the fluidity and static dispersion stability of the coal-water slurry are shown in Table 2.
Shown in 3. Examples 2 to 10, Reference Examples 1 to 4 A copolymer using component A, component B, and component C shown in Table 2, with a ratio of 0.27 to 1.2 mole of component B and 0.05 to 0.7 mole of component C per 1 mole of component A. This was used as the dispersion stabilizer for high concentration coal-water slurry of the present invention (dispersion stabilizer No. 2 to 9), and using this, a coal-water slurry was prepared, and the fluidity of the slurry and the The dispersion stability was measured and its performance was evaluated. These are shown in Table 3 as Examples 2 to 10. In addition, a copolymer having a ratio of components A, B, and C outside the range of the present invention was synthesized, and this was used as a dispersion stabilizer (dispersion stabilizer No. 10 to 13) to prepare a coal-water slurry. The performance was evaluated by measuring the fluidity and static dispersion stability. These are shown in Table 3 as Reference Examples 1 to 4. Table 2 shows the composition and molecular weight of each copolymer, and the fluidity and static dispersion stability of the coal-water slurry are shown in Table 2.
Shown in 3.

【table】

〔Effect of the invention〕

As explained above, the present invention is a dispersion stabilizer for coal-water slurry containing a salt of a copolymer of styrene sulfonic acid, styrene, and acrylic acid or methacrylic acid of a polyoxyalkylene ether derivative in a specific molar ratio. According to the present invention, a coal-water slurry with a high coal concentration in the slurry, low viscosity, good fluidity, and excellent storage stability can be produced, and coal can be treated as a fluid. , transportation, pumping, combustion equipment, and other conventional equipment can be used effectively.

Claims (1)

[Claims] 1 (A) an alkali metal salt or amine salt of styrene sulfonic acid, (B) styrene and (C) an acrylic ester of polyoxyalkylene alkyl ether, polyoxyalkylene phenyl ether, or polyoxyalkylene alkyl phenyl ether Or methacrylic acid ester is used as a constituent unit, and the molar ratio is A:B:C=1:0.2~1.5:0.02~
A dispersion stabilizer for high concentration coal-water slurry, characterized by containing a copolymer of 0.85%.