JPS5849794A - Dispersant for highly concentrated coal-water slurry - Google Patents

Abstract

PURPOSE:The titled dispersant capable of dispersing coal powder in water in high concentration, transporting it by a pipe line, and burning it directly, containing a nonionic surface active agent consisting of a polyoxyethylene ether of a monohydric alcohol. CONSTITUTION:The desired dispersant containing a nonionic surface active agent consisting of a polyoxyethylene ether (A-POEE) (addition mol number of ethylene oxide of >=130) of a monohydric alcohol such as 3-30C aliphatic, alicyclic or aromatic monohydric alcohol. 0.01-5.0wt% of the dispersant is added to coal- water slurry having a concentration of usaully >=50wt%. The amount of the polyoxyethylene group in the A-POEE is usually >=95wt%, and the molecular weight of the A-POEE is usually 6,000-100,000.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dispersant for high concentration coal-water nuraries. More specifically, the present invention relates to a dispersant for high-concentration coal-water slurry that disperses coal powder in water at a high concentration so that it can be transported by pipeline and directly combusted.

In order to improve the fluidity of a coal-water slurry with a higher concentration than before, sulfonate salts (Japanese Patent Application Laid-Open No. 56-21686) and sulfuric acid ester salts (Japanese Patent Application Laid-open No. 56-20090) have been used.
, the combination of a polymer substance and a low-molecular surfactant (JP-A-54-88808), a copolymer substance (JP-A-56-88808),
57889), but sulfonates and sulfate ester salts contain sulfur molecules and metal ions, and have the disadvantage of generating sulfur oxides and metal oxides when burned. Further, even in a water slurry with a coal concentration of 60% by weight, there is a drawback that the viscosity decreases only to 1200 cp. Furthermore, when a polymer substance and a low-molecular surfactant are used in combination, the initial sedimentation rate is high, and coal settles in pipelines and pumps, which is a drawback. In addition, the viscosity of the copolymer-added slurry only decreased to 1700 cp even in a water slurry with a coal concentration of 60% by weight, and the viscosity increased in a highly concentrated coal-water slurry with a coal concentration of 70% by weight or more for practical use. It has drawbacks such as not being able to hold up.

The present inventors have found that there is no above drawback and the coal a degree is 50% by weight.
or more (preferably 60% by weight or more), the viscosity is sufficiently low, the fluidity is good enough to efficiently transport coal through pipelines, and the dispersant for high-concentration coal-water slurry is capable of direct combustion. As a result of intensive studies to find out the above object, it was discovered that the above object could be achieved by using a specific dispersant, and the present invention was achieved.

That is, the present invention provides a dispersant for highly concentrated coal-water slurry, which is characterized by containing a nonionic surfactant consisting of polyoxyethylene ether of a monohydric alcohol (the ether has 180 or more oxyethylene units). It is.

The monohydric alcohol in the polyoxyethylene ether used in the present invention includes aliphatic alcohol,
Alicyclic alcohol and aromatic a/l, ml-al are
included. These negative alcohols include those represented by the following general formula (1) + (2) or (3).
Can be used: R-OH (1) [In the formula, R usually has 8 to 80 carbon atoms, preferably 6 to 2 carbon atoms]
0 linear and/or branched saturated or unsaturated alkyl groups. ] (R'4. RC-OH (2) [In the formula, R' is a linear and/or branched saturated or unsaturated alkyl group having usually 1 to 27 carbon atoms, preferably 1 to 10 carbon atoms. The group nl is usually 0 or an integer of 1 to 3, preferably 0 or 1, and the group is usually an alicyclic group having 8 to 30 carbon atoms, preferably 5 to 10 carbon atoms.

(R"%Ar-R"'-OH(3) [in the formula, the number of carbon atoms is usually 1 to 23, preferably 1 to IO, straight chain and/or
or a branched saturated or unsaturated alkyl group, n2 is usually 0 or an integer of 1 to 8, preferably 0, 1 or 2 r
Ar is an aromatic nucleus, preferably a benzene nucleus, or a naphthalene nucleus, and ``'' is an alkylene group or alkenylene group usually having 1 to 24 carbon atoms, preferably 1 to 5 carbon atoms. ] The carbon number of the alcohol (total) is usually 80 or less, preferably 6 to 20.

The aliphatic alcohol represented by the above general formula (1) includes 1. A second or eighth saturated or unsaturated alcohol is included. Examples of the primary alcohol include hexyl alcohol and 2-ethylhexyl alcohol.

Lauryl alcohol, stearyl alcohol, Olay/
l/ Flucol, oxo alcohol (carbon number 11-1
7, side chain ratio of 50 or more).

Examples of the secondary alcohol include 2-hexanol, 2-octatool, and methylisobutylcarbinol.

Manufactured by Union Carbide (Tajitor SJ, etc.). Examples of the tertiary alcohol include augtyl alcohol. Two or more of these aliphatic alcohols may be used in combination, for example, a primary alcohol (lauryl alcohol, oxo alcohol, etc.) and a secondary alcohol (Union Carbide [Tajitor S, J, etc.)]
It is also possible to use a mixture with.

Examples of the alicyclic alcohol represented by the above general formula (2) include cyclopentanol and cyclohexanol.

cyclononanol, 1-methyl-1-cyclohexanol, 2-. Examples include 8- or 4-ethyl-1-cyclohexano- and nonylcyclohexanol.

Two or more of these alicyclic alcohols may be used in combination; for example, a mixture of cyclohexanol and 2-ethyl-1-cyclohexanol can also be used.

Furthermore, as the aromatic alcohol represented by the general formula (3), benzyl alcohol, methylphenyl carbinol, β-phenylethyl alcohol, 8-phenyl-1-
Examples thereof include propatool, tolylmethanol, p-nonylphenethylal;-ruacinnamyl alcohol, and 8-(1-naphthyl)-1-propatol. Two or more of these aromatic alcohols may be used in combination; for example, a mixture of benzyl alcohol and tolylmethanol may be used.

Among these, preferred are aliphatic alcohols and aromatic alcohols. Among the aliphatic alcohols, the first alcohol is particularly preferred. A secondary alcohol, a primary alcohol with a benzene nucleus among aromatic alcohols.

Two or more of these -hydric alcohols may be used in combination, such as aliphatic alcohols (lauryl alcohol, secondary alcohols with a carbon number of 12.14, aromatic alcohols (p-nonylphenethyl alcohol, benzyl It is also possible to use mixtures of alcohols.

The polyoxyethylene ether used in the present invention can be produced by a known method, in which ethylene oxide is added to the -hydric alcohol in the presence of a catalyst (a basic catalyst such as caustic potash, trimethylamine, or an acidic catalyst such as boron fluoride). It can be manufactured by

The number of oxyethylene units (the number of moles of ethylene oxide added) in the polyoxyethylene ether of the -hydric alcohol used in the present invention is usually 130 moles or more, preferably 180 to 1,600 moles. When the number of oxyethylene units is less than 180 moles, the dispersibility of coal becomes poor,
The viscosity does not decrease, which is not preferable.

The amount of holoxyethylene groups in the polyoxyethylene ether of the alcohol used in the present invention is usually 95% by weight or more, preferably 96 to 99.8% by weight. 9
When it is less than 5% by weight, the dispersibility of the coal becomes poor and the viscosity does not decrease, which is not preferable.

The molecular weight of the above-mentioned polyoxyethylene ether of the alcohol used in the present invention is usually 6,000 to 100,000.

Preferably it is 8,000 to 70,000. molecular weight is 10
If the viscosity of the coal-water slurry does not decrease sufficiently, and if it becomes smaller than 6000, the coal will not be sufficiently dispersed in water, and the viscosity will be 200% when the coal concentration is 70% by weight.
It is undesirable that the temperature does not drop below 0 cp (20° C.).

The dispersant of the present invention is generally 0.01 to 5.0%, preferably 0.01% to 5.0%, preferably 0.01% to 5.0%, based on the weight of coal in the coal-water slurry.
By adding 05 to 2-0'lNm', coal particles can be dispersed in water at a high concentration (for example, 50% by weight or more). Generally, it depends on the type and particle size of coal powder, but if no dispersant is added, the coal concentration will be 3.
If it exceeds 0% by weight, fluidity will be lost, but dispersants other than those of the present invention, such as dihydric alcohols,
Addition of alkylene-Oquinde adducts such as ethylene diamine and ester-linked metals (e.g. castor oil, sorbitan mono- or tri-fatty acid esters)
If the coal concentration exceeds 60% by weight, there will be no flow chamber, making it impractical. On the other hand, when a predetermined amount of the dispersant of the present invention is added,
Coal particles are dispersed in water, reducing viscosity and improving fluidity. If the coal concentration of the coal-water slurry is too low, the transportation efficiency will be poor, the dehydration process will be expensive, and direct combustion will not be possible, making it meaningless. Also,
If it is too large, the viscosity will become too high and it will not form into a slurry, so it varies depending on the type of coal and particle size, but it is usually 50%.
or more (especially 50-95%), preferably 60-90%
%.

The dispersant of the present invention may be mixed with the polyoxyalkylene ether of polyhydric alcohol described in Patent Application (1) dated September 7, 1982 in various ratios, for example, from 100:θ to 1:10.
Can be used together with 0.

The dispersant of the present invention is preferably used alone or in combination with the polyoxyalkylene ether of the polyhydric alcohol, but other dispersants may be used in combination if necessary. Other dispersants include JP-A-56-21686, JP-A-56-20090, JP-A-54-88.
Dispersants described in JP-A No. 808, JP-A-56-57889, JP-A-56-57890, JP-A-56-57891, and the like can be mentioned. The dispersant of the present invention (
and optionally polyoxyalkylene ether of the polyhydric alcohol) and other dispersants (weight ratio) is usually 10/90 to 10010, preferably 20/80 to 10.
010, particularly preferably 50150 to Zoo10.

A method for producing a coal-water slurry using the dispersant of the present invention may be a conventional method.Coal 2 Dispersant.

The water may be mixed in any order. For example, the dispersant can be dissolved or dispersed in water, and then the coal can be added and adjusted using a suitable mixing device or crushing device.

The viscosity of the coal-water slurry produced using the dispersant of the present invention is usually 50 QOcp or less (20°C), especially 50 to 2000 cp in a water slurry with a coal concentration of 80% or more (80-95cm). It is. However, for example, in a water slurry with a coal concentration of 60 cm, it is usually less than 1000 cp (20
°C), especially between 20 and 30 °C. Furthermore, in a water slurry with a coal concentration of 70%, it is usually 2000 cp or less (at 20°C), particularly 50 to 1400 cp.

The coal referred to in the present invention includes anthracite coal, bituminous coal, subbituminous coal, brown coal, and the like. The particle size of coal is usually 8111.
It is 1 or less, preferably 0.5 or less.

The coal-water slurry produced using the same dispersant can be transported by conventional pipelines. The delivered coal-water slurry can be directly burned as fuel in a conventional pulverized coal boiler. It can also be dehydrated or directly used for various purposes such as gasification, liquefaction, or coke production.

The coal-water slurry produced using the dispersant of the present invention can be prepared using a conventional dispersant (for example, JP-A-56-21686
JP-A-56-20090.

JP-A-54-88808, JP-A-56-5788
No. 9, JP-A-56-57890, JP-A-56-1989
The viscosity is extremely low (
Conventionally, coal concentration was 60 cm, coal average particle diameter was 0.07411
Viscosity of 1200 cp or more at 1+l+, trouble 2 to 9 of the present invention
00 cp), therefore, the coal concentration can be increased to improve transport efficiency (for example, coal concentration 70-95 cp). In addition, when the coal concentration is relatively low (for example, 80% or more and less than 60%), a homogeneous coal-water slurry with extremely low viscosity can be obtained, and the energy required for transporting the coal-water slurry can be reduced. can.

The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto.

In the following, EO and PO represent ethylene oxide and propylene oxide, respectively, and m represents the number of moles of EO added. MW indicates the average molecular weight, and EO% indicates the weight distribution of the polyoxyethylene groups in the polyoxyethylene ether molecule. Moreover, the ratio (fraction) indicates a weight ratio.

Examples 1 to 15 and Comparative Examples 1 to 9 Dispersants of the present invention having the following compositions (Examples 1 to 1)
5) and conventional dispersants (Comparative Examples 1 to 9),
A coal-water slurry IJ-J4 was prepared by the method described below and its performance was evaluated.

Practical Example 1 Nilauryl Alcohol EO Adduct 1 m2 Approximately 90
0. MW=about 40000. EQ%=99.5chi.

Example 2 Nilauryl alcohol EO+t710 1 m2 about 200M, W-about 9000. EO Qi 98 Chin Example 8: Mixture 1- with carbon numbers 10.12 and 14.16
Alcohol (straight chain, absolute) EO adduct 1m - approx. 1590
°MW - about 70000, EO chini 99.7%.

Example 4: Mixed primary alcohol (linear, saturated) EO adduct with carbon numbers of 10.12 and 14.16 9m - approx. 190°M
W=about 8500. EOchi = 98%.

Example 5: Calorie with stearyl alcohol EO.

m - about 220. MW: Approximately 10000. EO%=97%.

Example 6: Stearyl alcohol EO adduct.

m - about 1500. MW - about 65000, EO% = 9
9.6% Example 7: Oleyl alcohol EO adduct 2m
2 about 200. MW=about 9000. EO Chi 97%.

Example 8 Nioleyl alcohol EO adduct 2m2 approx. 50
0. MW - about 22500. EO%=99%.

Example 9: Oxoal:l-EO adduct with carbon number 12S-15 and side chain ratio 66-9m-about 190. MW - about 85
00.

EO%=98%.

Example 10: Secondary alcohol EO adduct with 12.14 carbon atoms 9m - about 180. MW=about 8000. EO%=98
%.

Example 11: Secondary alcohol EO adduct with 12.14 carbon atoms 2m - about 500. MW-about 28000. EO%=
99%.

Example m, 12: β-phenylethyl alcohol EO adduct + m” approx. 840. MW = approx. 15000, EO%
=99.2q6゜Example 18: β-phenylethyl alcohol EO adduct r m=about 1000. MW=about 48500. EO%=9
9.7chi.

Example 14: Benzyl alcohol EO adduct.

m2 approx. 1020. MW=about 45000. EO%=995
゜Example 15: Benzyl alcohol EO adduct.

m - about 500. MW2 about 22000, EO%-99ch.

Comparative Example 1: 2m of secondary alcohol EO adduct having 12.14 carbon atoms - about 80. MW=about 1400. EO% = 87 section.

Comparative Example 2: Polyoxyethylene (about 100 mol) nonylphenyl ether, MW=about 4600. EO%: 95
%.

Comparative Example 3: Block copolymer of polyoxyethylene polyoxypropylene glycol I MW: 1100.

MW of polyoxypropylene glycol: 1750° Comparative Example 4: PO, EO block adduct of ethylenediamine, MW: 2700. EO%: 30° Comparative Example 5: E030 mole adduct of castor oil.

Comparative Example 6: E0 of lauric acid monoester of sorbitan
20 molar adduct.

Comparative example 7: Na salt of maleic anhydride/diisobutylene=1/1 copolymer, MW: 15000° Comparative example 8: Methyl methacrylate/styrene-6/4 1-
Na salt of polymer hydrolyzate, MW: 10000
Comparative Example 9 Niacrylic acid/maleic e = 1/1 Na salt of copolymer, MW: 6000° 1) Preparation of coal-water slurry and evaluation of fluidity A dispersant was prepared using the active ingredient 1. When the t5yc coal concentration is 60% by weight, -1,
5p) and add water to make a total of 150f (coal concentration 6).
Dissolve or disperse the dispersant in water, and add 200 mesh 80q6 to this aqueous solution.
Minamitaiyu ■ Zhang No. 1 coal 55 oy crushed to pass (When the coal concentration is 60% by weight, a
oog) was added portionwise at room temperature. After adding the entire amount, stir at 500 rpm for 5 minutes using a 6-blade radial blade turbine, and then mix using a homomixer (manufactured by Tokushu Kikako) for 8 minutes.
000 rpm for 10 minutes to prepare a coal-water slurry.1. The viscosity was measured using yv (3) and the fluidity was evaluated. The results are shown in Table 1. The lower the viscosity, the better the fluidity.

(Note) ■Minamichi Yubari No. 1 coal (Japanese bituminous coal, Hokkaido dust) Calorific value 88
90 (Kcal/Q), inherent moisture 1.1%, ash 51%, volatile content 36.2%, fixed carbon 57.6% Elemental analysis values: C62.8%, H4.5%, 04.7%.

N1.2chi, SO,2chi Table 1 Table 1 (continued) (Note) *1: 1% by weight of coal.

*2: 2% by weight of the entire system.

*3: Viscosity at 20℃, centipoise (cpχ*
4: From these results, the dispersant of the present invention can be used even if the coal concentration is high (for example, 60% by weight or more, especially 70% by weight or more).
It is clear that it has excellent effects such as sufficiently low viscosity and fluidity suitable for pipeline transportation.

Claims (1)

[Claims] 1. A highly concentrated coal characterized by containing a nonionic surfactant consisting of a polyoxyethylene ether of a -hydric alcohol (provided that the ether has 130 or more oxyethylene units). Dispersant for water slurry. 2. The dispersant according to claim 1, wherein the 2-hydric alcohol is an aliphatic, alicyclic or aromatic alcohol having 8 to 30 carbon atoms. 3. The dispersant according to claim 1 or 2, wherein the polyoxyethylene ether has at least 95% by weight of polyoxyethylene groups in its molecule. 4. The polyoxyethylene ether is 600 to 1000
A dispersant according to claim 1, 2 or 3 having a molecular weight of 0.00.