JPS5845729A - Dispersant for high concn. coal-water slurry - Google Patents

Abstract

PURPOSE:To obtain a flowable coal-water slurry with low viscosity, as the dispersant for the high concn. coal-water slurry, by incorporating a nonionic surfactant comprising polyoxyalkylene ether of monohydric alcohol. CONSTITUTION:As a dispersant for dispersing coal powder in water at high concn., a substance containing a nonionic surfactant comprising polyoxyalkylene ether of monohydric alcohol (wherein this polyoxyalkylene ether has an oxyethylene group and 3C or more oxyalkylene group) is used. A coal-water slurry obtained by using this dispersant is sufficiently low in viscosity even at high coal concn. and has good flowability enabling transportation of coal by a pipeline in good efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dispersant for highly concentrated coal-water slurries. 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 recent years, due to the rise in the price of petroleum-based liquid fuels, coal, which is cheap and available in large quantities throughout the world, has been reconsidered.

Coal-water slurry, which is used to handle large amounts of coal, has attracted attention in recent years as a low-processing and inexpensive product, and a slurry with a coal concentration of 40 to 50% by weight has been put into practical use for pipeline transportation. ing. However, in this case, 50 to 60% by weight of water is transported, resulting in poor transport efficiency and the dehydration process is expensive.

In order to improve the fluidity of a coal-water slurry with a higher concentration than before, sulfonate salts (JP-A-56-21636) and sulfate ester salts (JP-A-56-20090%) are used.
, the combination of polymeric substances and low-molecular surfactants (JP-A-54-33803), and copolymer substances (JP-A-56-1989).
57889), but sulfonates and sulfur ester salts contain sulfur molecules and metal ions, and have the disadvantage of generating sulfur oxides and metal oxides when burned. Furthermore, there is a drawback that even a water slurry with a coal concentration of 60% by weight has a viscosity that decreases only to 1200 cp. In addition, when a polymer substance and a low molecular surfactant are used in combination, the initial sedimentation rate is high, and there is a drawback that coal settles in pipelines and pumps. In addition, the viscosity of the copolymer-added slurry decreased only to 1,700 cp even in a water slurry with a coal concentration of 60% by weight, and the viscosity was not high in a highly concentrated coal-water slurry with a coal concentration of 70% by weight or more. It has drawbacks such as not being able to hold up.

The present inventors have found that the coal concentration is 50% by weight without the above-mentioned drawbacks.
To find a dispersant for high-concentration coal-water slurry that has sufficiently low viscosity even when the content is above (preferably 60% by weight or above), has good fluidity to enable efficient pipeline transportation of coal, and is capable of direct combustion. As a result of intensive study, 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 -hydric alcohol polyoxia/l
/ Kylene ether tv (However, the polyokine alkylene ether has an oxyethylene group and an oxyaflekylene group having a carbon number north of 3). This is a dispersant for slurry.

The extreme alcohols in the polyoxyalkylene ether 7 used in the present invention include aliphatic alcohols, alicyclic alcohols, and aromatic alcohols. As the polar alcohol of Cholera, those represented by the following general formula (1), (2) or (3) can be used: R-OH (1) [In the formula, R usually has 3 to 30 carbon atoms, Preferably 6-2o
is a straight-chain and/or branched saturated or unsaturated alkyl group. ] (R1 dimension R6-OH■ [In the formula, R1 is a linear and/or branched saturated or unsaturated alkyl group having usually 1 to 27 carbon atoms, preferably 1 to 10 carbon atoms, and nl is O or 1 or more.

An integer preferably 0 or 1. Ro usually has 3 to 3 carbon atoms.
30, preferably an alicyclic group having 5 to 10 carbon atoms. ] (R2+TrrA r-R' -OH(3) [in the formula R2
usually has 1 to 23 carbon atoms, preferably 1 to 10 carbon atoms, and is a linear and/or branched saturated or unsaturated alexical μ group +
n2 is 0 or an integer greater than or equal to 1, preferably 0, 1 or 2. Ar is an aromatic nucleus, preferably a benzene nucleus or a naphthalene nucleus, and R' usually has 1 to 24 carbon atoms, preferably 1 to 24 carbon atoms.
5 is an alkylene or alkenylene group. ] These -valent alcohols μ usually have 3 to 30 carbon atoms, preferably 6 to 20 carbon atoms.

The aliphatic alcohol μ represented by the above general formula (1) includes the following: 1. A second or third saturated or unsaturated alcohol is included. The first A I record is a hexyl A.
First call, 2nd half call.

Laurirualcolle, star
Lilua 7th call, ov eel alcohol, okiso a! Shiko −
(Carbon 'Jkn~17. Side chain ratio 50% or more). Examples include 27th alcohol tano-μ, methylisobutyl 7-recarbinol on carbide "Tercit-)vS", and the like. Examples of the tertiary alcohol include t-butyl alcohol. Two or more of these aliphatic alcohols may be used in combination, for example, primary alcohol
(Lauri Rua 7 Years Old Cole, Okina 7 Record 7 Shi, etc.) and 2nd Apkor/Shiku Union Carbide "Arge")-/L/Sj, etc.) should be used. You can also do it. (c) Cyclopentanol, cyclohexanol as the alicyclic alcohol represented by the general formula (2) in (1).

Cyclononano μ, l-methy/L/-1-cyclohexanol s 2”- s 3”’ t or 4-ethy/L
Examples include /-1-cyclohexano-μ, nony-μ-cyclohexanol, and the like. These alicyclic alcohols are
Two or more extensions may be used together; for example, a mixture of cyclohexanol and 2-ethy)v-1-cyclohexanol may be used.

Further, as aromatic alcohol represented by the general formula (3), benzyl alcohol, methylphenyl carbinol, β-phenylethyl alcohol, 3-phenyl 1V-1
-Propanol μ, tolyl methanol alcohol, '3
-(1-nafti/l/)-1-propatool, etc. Two or more of these aromatic alcohols may be used in combination; for example, a mixture of benzyl aphreco-p and totanol may be used.

Among these, preferred are aliphatic alcohols and aromatic alcohols. Particularly preferred are primary and secondary alcohols among aliphatic alcohols, and primary alcohols having a benzene nucleus among aromatic after-recording alcohols.

Two or more of these -hydric alcohols may be used in combination, for example, an aliphatic alcohol (lauryl alcohol, a secondary alcohol in a mixture with 12.14 carbon atoms, etc.) and an aromatic alcohol (p -) 2 l refenetiμ7/l
/coal, benzyl alcohol mixtures can also be used.

The polyoxia 7 used in the present invention! / Oxia that composes Kiren Ether! Examples of the lekylene unit include oxyethylene groups and oxyalkylene groups having 3 or more carbon atoms [oxypropylene groups, oxybutylene groups, oxy(phenyl)ethylene groups, oxy(halo)ethylene groups, etc. A combination system of two or more of these is mentioned. Among these, preferred is a combination system with a mixture of oxyethylene group, toxypropylene group, oxybutylene group, or oxypropylene group and toxybutylene group.

The above-mentioned polyoxyalkylene ether can be produced by a known method f, in which alkylene oxide (ethylene oxide and propylene oxide, 1, 2-, 2-, 3-
-, 1,3-,1,4-butylene oxide.

It can be produced by adding styrene oxide, epichlorohydrin, etc.) in the presence of a catalyst (basic catalyst such as caustic potash, trimethylamine, or acidic catalyst such as boron fluoride). Addition of alkylene oxide can be carried out by mixing two or more types (random addition), sequential addition (block addition) 7 or a combination of random addition and block addition. A combination of these is preferred.

Block addition (or a combination of this with random addition)
The type polyoxyalkylene ether has the following formula (4
) to (7) are listed.

A-0. - Q - E - H
f41A-0-E-Q-H (
5) A-0-E, 7Q-E'-H f61A-0-
Q-E-Q'-H (8 out of 71 formulas are -hydric alcohol residues [general formula (↑).

(2) or (R-, ■ RC-, (R+F)
A, -R'-], and Q and -Q' are hydrophobic polyoxyalkylene groups.

E and E' represent hydrophilic polyoxyalkylene groups.

Hydrophobic polyoxyalkylene group Q, Q'Kfd polyoxypropylene group - (C3H60) - and mixed polyoxyaflekylene group with an oxygen/carbon atom ratio of α43 or less (especially one mainly composed of oxypropylene group) , hydrophilic polyoxyalkylene ME,E';:L.

It is a mixed polyoxy containing a polyoxyethylene group -(C2H,0)□- and an oxygen/carbon atom ratio larger than α43 and at least an oxyethylene group 7) V kylene group (
In particular, it includes poly(oxyethylene-oxypropylene) groups, which are mainly composed of oxyethylene groups.

Among formulas (4) to (7), formulas 14) and 16) are preferred.

Hydrophilic polyoxyalkylene iE, E' and hydrophobic polyoxyalkylene group Q in the block addition type polyoxyalkylene ether represented by AI'i~(7),
The ratio with Q' (total weight ratio) is usually 1:1 to 1.
The ratio is 9:1, preferably 3:1 to 19:1.

The polyoxyalkylene group in the polyoxyalkylene ether used in the present invention is usually song = %
Above, preferably 90 to 918% by weight. If the polyoxyalkylene group is less than 80% by weight, the dispersibility of the coal will deteriorate and the viscosity will not decrease, which is not preferable.

The content of the polyoxyalkyreso group in the polyoxyalkylene ether 1 is 5.
0-95% by weight, particularly preferably 75-95% by weight, 5
If it is less than 0 weight l5, the dispersion force for dispersing coal in water will be small, and it will not be possible to form a coal-water slurry, which is not preferable.
If it exceeds 95% by weight, the dispersion force decreases, which is undesirable (particularly when the molecular weight is less than 6,000).The oxygen/carbon atom ratio of all polyoxyalkylene groups is preferably α4 or more.

The molecular weight of the above-mentioned polyoxyalkylene ether of the -valent alcohol μ used in the present invention is 6, usually 2,000 to 100,000.
Preferably 3,000 to 70,000, particularly preferably 60
00-70000. If the molecular weight is greater than 100 OQO, the viscosity of the coal-water slurry will not be sufficiently reduced, and if it is less than 2,000, the coal will not be sufficiently dispersed in water and cannot be formed into a slurry, which is undesirable.

The dispersant of the present invention is usually 001 to 50%, preferably 005 to 2%, based on the weight of coal in the coal-water slurry.
．． By adding 0%, high concentration (for example, 5
0% by weight or more):,) of coal particles can be dispersed.

Generally speaking, this varies depending on the type and particle size of the coal powder, but if a dispersant is not added, if the amount of coal powder exceeds 30% by weight, not only will flow and mobility be lost, but dispersion other than that of the present invention will occur. Even with the addition of alkylene oxide adducts such as dihydric alcohol bond-containing agents (e.g. castor oil, SOI levitan mono or tri-fatty acid esters), the coal will flow if the coal concentration exceeds 60% by weight. It lacks functionality and is impractical.

On the other hand, when a predetermined amount of the dispersant of the present invention is added, coal particles are dispersed in water, the viscosity is reduced, and fluidity is improved.

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 be too high and it will not form into a slurry.
Although it varies depending on the type and particle size of coal, it is usually 50% or more (particularly 50'-95%), preferably 60-90%.

The dispersant of the present invention optionally contains a polyoxyalkylene ether of a polyhydric alcohol as described in the patent application dated September 7, 1980 (1, title of the invention "Dispersant for high concentration coal-water slurry"), Various ratios, e.g. 1:0 to 1: by weight
10 (especially 20=1 to 1:20) can be used together.

The dispersant of the present invention is preferably used alone or in combination with a polyoxyalkylene ether having a valence of 7 alexole, but other dispersants may be used in combination if necessary. Other dispersants include JP-A-56-21636, JP-A-56-2QO9 [Co., Ltd.], and JP-A-54-3.
Dispersants described in JP-A No. 3803, JP-A-56-5788, JP-A-56-5789, JP-A-56-57891, and the like can be mentioned. The ratio (weight ratio) of the dispersant of the present invention (and optionally the above-mentioned polyoxyalkylene ether of polyhydric alcohol-μ/I/) to other dispersants is usually 10/90 to 10010, preferably 2
0/3 0 to 10010, particularly preferably 50150 to
It is 10010.

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

The water can be mixed in any order. For example, it can be prepared by dissolving or dispersing a dispersant in water, adding coal, and using a suitable mixing or grinding device.

Coal-water slurry produced using the dispersant of the present invention
The viscosity of water slurry with a coal concentration of 80% or higher (80-95%) is usually less than 5000 cp (at 20°C), especially 50
~2000 cp. In addition, for example, in a water slurry with a coal concentration of 60%, it is usually less than 1000 cp (2
0°C), especially from 20 to 900 cp. Furthermore, in a water slurry with a coal concentration of 70%, it is usually less than 2000 cp (20
℃), especially 50 to 1400 cp. Furthermore, the viscosity of the coal-water slurry produced using the dispersant of the present invention with a molecular weight of 6,000 to 70,000 is usually 500 cp or less (at 20°C) in a water slurry with a coal concentration of 70%.
Especially 50-400 cp.

Coal referred to in the present invention includes anthracite and bituminous coal.

These include subbituminous coal and brown coal. The particle size of the coal is usually 3 mm or less, preferably α5 mm or less.

Coal-water slurries made using the dispersants of the present invention 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 conventional dispersants (for example, JP-A-56-21636
JP-A-56-20090, JP-A-54-
33803, JP 56-57889, JP 56-57890, JP 56-57891
The viscosity is extremely low compared to the coal-water slurry produced using the dispersant described in the above publication (conventionally, the viscosity was 1200c at a coal concentration of 60% and a coal average particle diameter of α074).
p or more, the present invention contains 2O-900cp. Therefore, the coal concentration is increased to improve transportation efficiency (for example, when the coal concentration is 70
~95%), the coal concentration is relatively low (~95%).
For example, if the viscosity is 30% or more and less than 60%), a homogeneous coal-water slurry with extremely low viscosity is obtained, and the coal-water slurry is
It is possible to reduce the transportation energy of water slurry by 7 regs.

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

In the following, EO, PO, BO are respectively h1no,
7 oxide, propylene oxide, butylene oxide, also POE, POP, POB, 8f
POA represents a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, and a mixed polyoxyalkylene group, respectively, and the ratio (fraction) represents a weight ratio.

However, O/C is the oxygen/carbon atomic ratio in the polyoxyalkylene group, 6Mw is the average molecular weight, and 80% is the oxyethylene group contained in the polyoxyalkylene group of the polyoxyalkylene ether. % by weight.

Examples 1 to 1> and Comparative Examples 1 to 9 Dispersants of the present invention having the following compositions (Examples 1 to 1)
2) and conventional dispersants (Comparative Examples 1 to 9), coal-water slurries were prepared by the method described below and their performance was evaluated.

Practical example 1: Formula [41, A nilauryl alcohol-1
residue, Q: POP, E: POE, MW
:3000.80%:9Q.

Example 2: In formula t61, A nilauryl alcohol group,
E: POE, Q: POP, E': POE,
E/Q/E'= 1/1/18.

hfW: 50000, Fi: target: 9 Hoji Example 3: Formula (
4) Inside, A: stearyl alcohol residue, Q: PO
P, E: POE, MW: 5500, 80%
:80.

Example 4: In formula (4), A: stearyl alcohol residue, Q: POP, E: POE, MW: 6200
0, EO% near 7.

Example 5: In formula (6), A nioyl alcohol residue.

E: POE, Q: The page consisting of PO and 1.2-BO is α324 11, IPOA, E': POE, E
/Q/E'=L4/1/10, kite: 4000.

EO%=92.

Example 6: In formula (4), A nioleyl alcohol residue,
Q: 0/C consisting of PO and 1, 2=BO is (132
4) MPOA.

E:POE, MW:50000, 80%:95
.

Example 7: In formula (4), A: Oki'/7/l/m with 12 to 15 carbon atoms and 66% side chain ratio; residue, Q: POP
, E:POE, MW:20000, 80%:
85.

Example 8: In the formula (6), A: oxoalcohol residue with 12 to 15 carbon atoms and 66% side chain ratio, E: MPOA with a VC of α481 consisting of EO and PO, Q: POP,
E': POE, E/Q/E'= 1o/9/81
, MW: 20000, 80% 'JO.

Example 9: In formula (6), A: 2nd alcohol residue having 12.14 carbon atoms, E: POE, Q:
POP, E': POE, E/Q/
E”1/3/26, MW:4000, 80%:
90.

Example 10: In formula (6), -A: second aμcol residue having 12 and 14 carbon atoms, E: POE, Q: POP,
E': POE, E/Q/E'=115/19
, MW: 19000, EO%=80.

Example 11: In formula (4), A: β-phenylethyl a!
Call residue, Q:POP, E:P
OE, MW: 3500, EO%93.

Example 12: In formula (6), A: benzyl alcohol residue, E: POE, Q: a group consisting of PO and 1,2-BO; 0.324(7) MPOA, E
': POE, E/Q/E'= 115/44,
hlW:30000.

80%:90.

Comparative Example 1: Formalin condensate of naphthalene sulfonic acid Na salt, degree of condensation: about 4.

Comparative Example 2: Polyoxyethylene (approximately 100 moles/L/) noniμphenyleneμ ether, MW: 460°C.

Comparative Example 3: Block copolymer of polyoxyethylene polyoxyfuropylene glycol μ, MW: 310
0.

MW of polyoxypropylene glycol: 1750° Comparative example 4: PO, EO block adduct of ethylenediamine, λ4'W: 2700, EO% = 300 Comparative example 5:
E030 mole adduct of castor oil.

Comparative Example 6: EO 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/L//Na salt of hydrolyzate of styrene-6/4 copolymer, MW: 10000° Comparative Example 9 Na salt of copolymer of acrylic acid/maleic acid = 1/1, MW: 6000゜1) Preparation of coal-water slurry and evaluation of fluidity Weigh out 175f (L5# when coal concentration is 60% by weight) of the dispersant as an active ingredient and add water to make a total of 150t (coal concentration 60%). 2QO for weight%
f? ), dissolve or disperse a dispersant in water, and add 3 soii (300# when the coal concentration is 60% by weight) crushed to 200 meths = 80% to this aqueous solution at room temperature. was added little by little. After adding the entire amount, put 6 radial plate blades into a root turbine at 500 rpm.
lTk Stir for 5 minutes, then use a homomixer (special 1
(manufactured by Ikikako) at 300 rpm.

A coal-water slurry was prepared by stirring for 10 minutes, and the viscosity was measured at 20°C to evaluate the fluidity.

The results are shown in Table 1, showing that those with lower viscosity have better fluidity.

(Note) ■ Seiki Yubari 1sa coal (Japanese bituminous coal, produced in Hokkaido) Calorific value 83
90 (kcat/kg), inherent moisture 1.1%, ash content ih
1%, volatile content 3a2%, fixed carbon 576%.

Elemental analysis value: C62.8%, H4.5%, 04.7
%, N1.2%.

Sα2%.

Table 1 (Sho) Zl: 1% by weight of coal, 2% by weight of the entire system of 5 and 52, 4:3. : Viscosity at 20°C, centivoise (cp
).

*4:

Claims (1)

[Claims] L-hydric alcohol polyoxyalkylene ether/1
/ (However, the polyoxyalkylene ether has an oxyethylene group and an oxyethylene group having 3 or more carbon atoms). Dispersant for slurry. 2 the polyoxy 7/I/kylene ether is at least 8
A dispersant according to claim 1, which contains 0% by weight of polyoxyalkylene groups. a. The dispersant according to claim 1 or 2, wherein the polyoxyalkylene ether contains 50 to 95% by weight of oxyethylene groups in the polyoxyalkylene groups. 4. The dispersant according to any one of claims 1 to 3, wherein the 4-hydric alcohol is an aliphatic, alicyclic or aromatic alcohol having 3 to 30 carbon atoms. 5 The polyoxyalkylene ether tV Ka2ooo~1
The dispersant according to any one of claims 1 to 4, having a molecular weight of 0,000 (f).