JPS5938288A - Dispersion stabilizer for aqueous coal powder slurry - Google Patents

Abstract

PURPOSE:A dispersion stabilizer with excellent standing stability and fluidity, prepd. by incorporating a specified polyether compd., and an aliph. alcohol, fatty acid sorbitan ester or silicone compd. CONSTITUTION:A dispersion stabilizer contg. as an effective component (a) a polyether compd. of MW 2,000-100,000 which is prepd. by adding ethylene oxide to an active hydrogen-contg. compd. and in which the total wt. of the polyoxyethylene chain portion amounts to 40-95wt% based on molecular wt. or its derivative and (b) at least one compd. selected from among an aliph. alcohol, fatty acid sorbitan ester and silicone compd. Said polyether compd. (a) is easily prepd. by adding an alkylene oxide including ethylene oxide to a compd. contg. at least one active hydrogen atom. In the dispersion stabilizer, the component (b) is used in an amt. of not more than 30wt%, pref. 15-5wt%, based on the component (a).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dispersion stabilizer for a water slurry of coal powder. In more detail, the present invention relates to a dispersion stabilizer for dispersing coal powder in water and stabilizing the dispersion in a state suitable for pipeline transportation.

In recent years, petroleum has been the most commonly used energy source, but due to its limited reserves and the accompanying price hike, diversifying energy sources and securing a stable supply have become important issues. It has become. For this reason, reserves n. The effective use of coal, which exists in large quantities and is not unevenly distributed, is being reconsidered. However, unlike petroleum, coal is a solid, so it cannot be transported by vibrine, making it extremely difficult to handle. Furthermore, coal generally contains more ash than petroleum, which causes problems such as lower calorific value and fly ash disposal. For this reason, in order to improve the handling disadvantages, various methods have been investigated in which coal is pulverized and dispersed in water to form a slurry.
．． I'm here. However, in this case too, if the coal concentration is increased, the viscosity increases significantly and fluidity is lost, and if the coal concentration is decreased, the transportation efficiency decreases and the dewatering process also becomes expensive, making it impractical. . This is because the coal particles in the coal-water slurry aggregate in water, causing an increase in viscosity and a decrease in fluidity. The smaller the coal particles in the water slurry, the better the dispersion stability, but the cost of pulverization increases as the degree of pulverization increases.

Currently, 200 pulverized coals are being burned in thermal power plants.
Since the particle size is approximately 80 microns, that is, about 74 microns, it is expected that this particle will be used as a guideline for the particle size of pulverized coal. Coal-pine rally,
When a surfactant, which is a dispersant, is added, the surfactant is adsorbed to the interface between the coal particles and water7, causing an action that loosens the coal particles and prevents the coal particles from coagulating with each other. It is expected that a good dispersion state will be created.

The inventors of this invention have already developed a dispersant having such an effect (see Japanese Patent Application No. 1974-94M73).

However, although such a dispersant improves fluidity, when left to stand still, the sediment becomes compacted and forms a hard cake, making it difficult for practical use. As a result of intensive research aimed at improving static stability and improving fluidity, which are the drawbacks of conventional coal-water slurries, we have discovered a dispersion stabilizer that has excellent effects on static stability and fluidity. The invention has been completed.

That is, the present invention a) adds an alkylene oxide that essentially contains ethylene oxide to a compound having active hydrogen,
and the total weight of the polyoxyethylene chain portion is 40 to 95 times the total molecular weight, and the molecular weight is 2.0
00 to 100.000, or 8% of 4 polyether compounds thereof, and b) one or more of aliphatic alcohol, sorbitan fatty acid ester, or silicone compound as active ingredients. 1PrI coal powder This is a dispersion stabilizer for water slurry.

In the present invention, the polyether compound of component (3) is abbreviated as ethylene oxide C or less (KO) by a conventional method to a compound containing one or more active hydrogen atoms. ) can be easily produced by adding an alkylene oxide containing The addition of alkylene oxide is preferably a block or partially block addition of ethylene oxide and other alkylene oxides, and the addition order may be in any order, but the addition of EO and propylene oxide (hereinafter abbreviated as Pot) is preferable. In the case of adducts, those in which PO'5C is first added and then 1!io is added exhibits good dispersion stability.

Compounds having active hydrogen that can be used in the present invention include hydroxyl groups and amino groups, respectively.

These include hydroxy compounds, amino compounds, mercapto compounds, etc., each having a mercapto group.

Specifically, hydroxy compounds and 1. So, methanol,
Lower-hydric alcohols such as ethanol, carastearyl alcohol, high WI-hydric alcohols such as oleyl alcohol, monohydric alcohols with side chains such as 2-ethylhexanol, ethylene glycol, propylene glycol,
Examples include polyhydric alcohols such as 1,4-butanediol, hexanediol, diethylene glycol, triethylene glycol, polytetrapyrene glycol, glycerin, sorbitol, polyglycerin, or partial esterified products thereof, phenols such as nonylphenol, and amines. Examples include monoamines such as octylamine, tallow amine, and methylstearylamine; polyamine compounds such as ethylenediamine, diethyltriamine, triethylenetetramine, N-alkylethylenediamine, and polyethyleneimine having 6 to 50 nitrogen atoms; and mercapto compounds. Examples of and 1- include lauryl mercaptan and the like.

In addition, alkanolamines such as mono-, di- or triethanolamine, ade compounds such as stearic acid amide,
Amino acids such as glycine may also be used.

As an alkylene oxide, ethylene oxide is essential, and a total of 1 polyoxyethylene chain accounts for 40% of the total amount.
-95%, preferably 60-90%. In addition to EO, propylene oxide.

Butylene oxide and the like may be used, but 110 and p
The block polymer of o shows good dispersion stability.

The molecular weight of polyether is 2,000 to 100,000, and the molecular weight is 4,000 to 50,000. As the polyneedle compound fatty conductor, the terminal hydroxyl group of the polyether compound is sulfated, a phosphorus oxide obtained by reaction with phosphorus pentoxide, a carboxyalkylated product, an esterified product with a polybasic acid, or a salt thereof, etc. Sialgyl sulfate, alkyl halides, and benzyl halides when anionic compounds and ε compounds are used as starting materials.
Examples include cJ-nyl quaternized products and cationized products obtained by neutralization with acetic acid, alkylbenzenesulfonic acid, and the like.

Furthermore, among the components b) used in the dispersion stabilizer of the present invention, the aliphatic alcohol is specifically an aliphatic alcohol having 6 to 12 carbon atoms, such as octyl alcohol, 2-ethylhexyl alcohol, etc. , lauryl alcohol, and the like. Sorbitan fatty acid esters include sorbitan monolaurate and sorbitan monopalmitate. Examples include sorbitan monooleate, sorbitan monostearate, and the like. The same (b+ component includes silicone compounds such as polydimethylsiloxane,
Dimethyl silicone oil.

Examples include fluorosilicone oil.

The dispersion stabilizer of the present invention has a concentration of 0.0% with respect to the water slurry.
01 to 5.0% by weight, preferably 0.05 to 2.0% by weight 11
: Coal particles can be dispersed in water by adding steamed rice. The aliphatic alcohol, sorbitan fatty acid ester, or silicone compound as component (b) in the dispersion stabilizer of the present invention is contained in an amount of 30% by weight or less, preferably 15 to 5% by weight, based on the polyether compound, and is added to the coal slurry together with the polyether compound. It may be added to the coal slurry or it may be added separately to the coal slurry.

The fluidity of a coal-water slurry generally varies depending on the type and particle size of the coal powder, but when no dispersion stabilizer is added, the viscosity increases rapidly when the coal concentration exceeds 30% by IJ%. On the other hand, when a predetermined amount of the dispersion stabilizer of the present invention is added, coal particles are dispersed, fluidity is improved, and a highly concentrated slurry can be obtained. If the concentration of coal constituting the coal-water slurry is too small, the shafting efficiency will be poor, and the dewatering process will be costly and meaningless. Also, if it is too large, the viscosity will become too high, so the type of coal,
Although the viscosity varies, it is generally 30 to 85. Preferably it is 50 to 75% by weight.

Various coal types such as coal Vi, anthracite, bituminous coal, sub-bituminous coal, and lignite are used in the present invention, and these are pulverized and used. Furthermore, the dispersion stabilizer of the present invention is effective even when these coals have undergone a coal cleaning process (deashing process) using a flotation method or the like.

The particle size of this coal powder may be any particle size that allows direct combustion in the boiler, but the typical particle size currently used in thermal power plants for this purpose is 200 mesh with a pass rate of 70 to 90%. particle size.

Coal 1 Dispersion stabilizer, water situation and 1- Any order may be used, but the dispersion stabilizer is dissolved or dispersed in water, coal is added thereto, and gl and l are mixed using an appropriate mixing device or crushing device.
Just make it.

The dispersion stabilizer of the present invention can be used in combination with other anionic surfactants or nonionic surfactants. For example, the present inventors have already invented a dispersion stabilizer for water slurry of coal powder of the present invention and are currently applying for a patent application (Patent Application No. 54-9517).
If used in combination with a nonionic surfactant such as naphthalene sulfonic acid formalin condensate or polyoxyethylene sorbitan fatty acid ester, which is a dispersant for coal powder water slurry described in Specification 1 of No. Dispersion ability can be obtained.

Further, in the coal water slurry using the dispersion stabilizer of the present invention, fatty acids such as oleic acid, cyamyl amine compounds, amide compounds such as stearylamide, phosphate esters such as tributyl phosphate, aluminum stearate, etc. By adding metal soap, etc., it is possible to create a stable slurry with less air bubbles.

The coal-water slurry to which the dispersion stabilizer of the present invention has been added is a third liquid that is immiscible with water as a dispersion medium in order to separate and recover the coal from the slurry when its use as a means of transportation is finished. A method in which coal powder is granulated by adding hydrocarbon oil or the like and then separated and recovered from water is attracting attention (for example, Japanese Patent Laid-Open No. 52-37901). For this purpose, hydrocarbon oil may be added in advance to MIW production of coal-water slurry, but the dispersion stabilizer of the present invention may lose its dispersion effect even in systems where such hydrocarbon oil coexists. It shows excellent performance without any problems.

The water slurry of coal powder obtained by adding the dispersion stabilizer of the present invention has good fluidity with little increase in viscosity even at high concentrations, and has good dispersion stability without forming hard cakes even after long-term storage. Pipeline transportation, tank storage, and boiler direct combustion are possible. In addition, the water slurry of coal powder obtained using the dispersion stabilizer of the present invention has few bubbles during production, little increase in volume of the slurry, and prevents thickening due to air bubbles, resulting in good properties. can.

EXAMPLES The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 1) Preparation and fluidity of water slurry 1.8F of the melon 1 compound in Table 1 and 0.182F of the melon 1 compound in Table 2 were dispersed in 1112 of water, and this warm mixture was ground to 200 mesh and 80 chips. Plea sole, F13187
1 little by little at room temperature. Nine minutes after adding the entire amount,
At 5000 rpm with a homomixer (manufactured by Tokushu Kikako),
A coal-water slurry was prepared by pressing TFF for 5 minutes.

When the viscosity was measured at 25°C, it was 560 centivoise, indicating good fluidity. The results are shown in Tables 3 and 4, including other Examples and Comparative Examples similarly conducted at Tohoku.

L2 shows that the lower the viscosity, the better the fluidity.

*1 Preasol charcoal heat generation jl 6720 Kce, l//kp +, T
Engineering 8 M88141 Ash content 7.1 Ch
(J Engineering 8 MQ8121 Moisture 7.0%
(M88111 fixed carbon from J 59.7
% fJI day M [1F11212) Stability of water slurry Stability of slurry is determined at 30 days and 60 days after producing the slurry.
After cooling for a few days, a stainless steel rod with a diameter of 5 mm (!: fi5
0f') was gently put into the slurry and its sedimentation state was observed. The slurry prepared in 1) has good stability and 6
There was almost no compaction even after 0 days had passed. The results, including other Examples and Comparative Examples, are shown in Tables 3 and 4.

Table 1 a + acid component Note) *1 Middle 2 showing the order of addition to the starting material
3 in Weight Ratio Regarding anionization, the ratio of the modified functional group of the terminal hydroxyl group is shown, and regarding cationization, the ratio to the contained nitrogen atom is shown.

Table 2 BL component

Claims (1)

[Scope of Claims] 1.a) An alkylene oxide that is essentially included in ethylene oxide is added to a compound having active hydrogen, and the total weight of the polyoxyethylene chain portion is 40 to 95 weight percent of the total molecular weight, Furthermore, the molecular weight is 2,000~
100,000 polyether compound or its derivative, and one or more of BL aliphatic alcohol, sorbitan fatty acid ester, or silicone compound as active ingredients. . 2. The dispersion stabilizer for a water slurry of coal powder according to claim 1, wherein the polyneedle compound or its derivative is a block-like or partially block-like adduct of ethylene oxide and an alkylene oxide other than ethylene oxide. 3. A dispersion stabilizer for a water slurry of coal powder according to claim 1 or 2, wherein the alkylene oxides in the polyether compound are ethylene oxide and propylene oxide. 4. Stable dispersion of coal powder for water slurry according to claim 1, 2 or 3, wherein the polyether compound derivative is a sulfate, phosphoric oxide, carboxyalkylated polyether compound, or a filler thereof. agent.