JPS5980320A - Dispersing stabilizer for aqueous coal powder slurry - Google Patents

Abstract

PURPOSE:To obtain the titled stabilizer having excellent effect, by adding a polyether compound obtained by adding alkylene oxide containing styrene oxide and ethylene oxide as essential components to a compound having active hydrogen. CONSTITUTION:A polyether compound or the derivative thereof which is obtained by adding alkylene oxide containing ethylene oxide as an essential component and styrene oxide to a compound having active hydrogen (e.g., glycerine) and has 1-20n (wherein n is the number of active hydrogen a toms in a molecule) of styrene oxide groups in its molecule and of which the total wt. of the polyoxyethylene chain is 40-95wt% of the total M.W. and the molecular wt. of 500-200,000 is contained as an effective component. An aqueous coal powder slurry obtained by adding the dispersing stabilizer having this constitution is low in the rising of viscosity even at a high concn., good in flowability, generates no hard cake even after long-term preservation and holds good dispersion stability.

Description

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

In recent years, petroleum, which has been the most commonly used energy source, has reached the limit of its reserves and its price has soared, making it important to diversify energy sources and secure a stable supply. It has become. Under these circumstances, the effective use of coal, which has large reserves and is not unevenly distributed around the world, is being reconsidered. However, unlike petroleum, coal is a solid, so it cannot be transported across pipelines, making it extremely disadvantageous in terms of handling. Furthermore, coal generally contains a larger amount of ash than petroleum, and there are also problems such as a decrease in heat generating capacity and processing of fly ash.

In order to overcome this problem, various methods have been studied in which coal is pulverized and dispersed in water to form a slurry.1 However, in this case, If you reduce the coal density, it will thicken and lose fluidity, and if you reduce the coal concentration, the transport efficiency will decrease.
Furthermore, the dehydration step is also expensive, making it impractical. This is because coal particles from 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. The amount of pulverized coal being burned at the current pressure and thermal power source d≦ is 200 mesh.

Since the particle size is about 80 yen passes, that is, about 74 microns, it is expected that this particle will be used as one of the particle sizes of pulverized coal. When a surfactant, which is a dispersant, is added to the coal-water slurry, the surfactant adheres to the interface between the coal particles and water, and has the effect of loosening the coal particles.

t154 has the effect of preventing coal particles from aggregating with each other.
It is expected that it will create a good limb condition.

The present inventors have already investigated a dispersant having such an effect (see Japanese Patent Application No. 54-95173).

However, although such a dispersant improves fluidity, it is not necessarily satisfactory in practice because the sediment is compacted and a hard cake is formed when the dispersant is allowed to stand still.

The present inventors conducted intensive research to improve static stability, vrt, and dynamic properties, which are the drawbacks of conventional coal-water slurries, and found that the slurry has excellent effects on static stability and fluidity. They discovered a dispersion stabilizer and completed the present invention.

That is, the present invention is a compound having active hydrogen to which alkylene oxide and styrene oxide containing ethylene oxide as an essential component are added, and the styrene oxide group is present in the molecule in the range of -1 to 20 ri (n is 1 to 20 ri in the molecule). (representing the number of active hydrogens), the total weight of the polyoxyethylene chain portion is 40 to 95 percent of the total molecular weight, and the molecular weight is s, ooo to 200,000. or derivatives thereof alone or together with one or more compounds selected from the group consisting of aliphatic alcohols, sorbitan fatty acid esters, and silicone compounds; It is a splitting stabilizer. The dispersion stabilizer of the present invention is a dispersion stabilizer for water slurry of coal powder, which is effective even for coal deashed by flotation method or underwater granulation method.

In the present invention, the polyether compound can be easily produced by adding an alkylene oxide which essentially contains styrene oxide and ethylene oxide to a compound containing one or more active hydrogens by a conventional method. Among these, a block or partially block adduct of styrene oxide and an alkylene oxide that essentially contains ethylene oxide is particularly preferable, and the order of addition may be in the form of falling first; In the case of the adduct (hereinafter abbreviated as (ll1O)), the one in which 80 is first added and then 20 is added exhibits good tailing properties.

Compounds having active hydrogen that can be used in the present invention include hydroxy compounds, amine compounds, mercapto compounds, carboxylic acids, etc. each having a hydroxyl group, an amino group, a mercapto group, a carboxyl group, etc.

Specifically, the hydroxy compounds include lower alcohols such as methanol and ethanol, higher alcohols such as la stearyl alcohol and oleyl alcohol,
- One-part alcohols with side chains such as ethylhexanol, ethylene glycol, glopylene glycol, 1.4
- Polyhydric alcohols such as butanediol, hexanediol, diethylene glycol, triethylene glycol, polypropylene glycol, glycerin, sorbitol, polyglycerin or partially esterified compounds thereof, and phenols such as nonylphenol are exemplified, and amine compounds include octyl Amine, tallow amine, monoamine such as methylstearylamine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, N-alkylethylenediamine, N
Examples of the mercapto compound include lauryl mercaptan and the like.

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

Carvone m class °C is caprylic acid, lauryl jW
%11 carboxylic acids such as oleic acid and stearic acid,
Examples include dicarboxylic acids such as oxalic acid, malonic acid, and maleic acid, and in the present invention, the polyether compound has 1 to 20n styrene oxide groups in the molecule (n is the aforementioned υ), The total weight of the polyoxyethylene chain portions is 40 to 95 parts by weight, preferably 60 to 95 parts by weight of the total molecular weight. In addition to styrene oxide and ethylene oxide, propylene oxide (hereinafter abbreviated as FrPOJ), butylene oxide, etc. may be used.

and po block polymers or EiO and BO block polymers exhibit good fractional stability.

The molecular weight of polyether compounds is 5000 to 200,000.
0, preferably 10,000 to 150,000.

Examples of the polyether compound derivatives include sulfates obtained by chain-oxidizing the terminal hydroxyl groups of revoliether compounds, phosphorus oxides obtained by reaction with phosphorus pentoxide, carboxyalkylated products, esterified products with polybasic acids, or salts thereof. Examples include anionized products and quaternized products using dialkyl sulfates, alkyl halides, benzyl halides, etc. when an amino compound is used as a starting material, and cationized products obtained by neutralization with acetic acid, alkylbenzenesulfone, shun, etc.

Further, as the aliphatic alcohol of the component (b) which is the second component of the dispersion stabilizer of the present invention, specifically, an aliphatic alcohol having 6 to 12 carbon atoms is used, such as octyl alcohol,
Examples include 2-ethylhexyl alcohol and lauryl alcohol.

Examples include sorbitan monolaurate, nlupitan monopalmitate, sorbitan monooleate-1, sorbitan monolaurate, and the like. Also, the same <(b) component adhesive silicone compound'. Examples of the snout include polydimethylsiloxane, dimethylsilicone oil, norolosilicone oil, and the like.

The dispersion stabilizer of the present invention has a weight ratio of 0.01 to 5.0% by weight, preferably t0.
By adding ,05~2,07t+t%'jl+5, coal particles can be dissolved in water.

The aliphatic alcohol, sorbitan fatty acid ester, or silicone compound as component (b) of the dispersion stabilizer of this invention has a molecular weight of 50) k' or less, preferably 15 to 5 k', relative to the polyether compound. Unfortunately, it may be added to the coal slurry together with the polyether compound, 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 if no dispersion stabilizer is added, the viscosity will increase rapidly when the coal vN degree exceeds 30% by weight. On the other hand, when a prescribed amount of the dispersion stabilizer of the present invention is added, coal particles are dispersed, fluidity is significantly improved, and a highly concentrated slurry can be obtained.At the same time, if left for a long time, it will settle and form a node cake. The storage stability of the slurry is questionable. If the coal di constituting the coal-water slurry is too small, the flow efficiency will be poor, and the dewatering process will be expensive, making it meaningless.

Also, if it is too large, the viscosity will become too high, so it is generally 50 to 85, preferably 50 to 78, depending on the type and viscosity of the coal.

Hitherto, yuzu compounds have been proposed as dispersion stabilizers for coal water slurry, and as compounds similar to the present invention, polyamides containing alkylene oxides such as ethylene oxide and propylene oxide are added to compounds having active hydrogen. Ether compounds have been proposed (Japanese Unexamined Patent Publication No. 102-1983)
No. 994, Japanese Unexamined Patent Publication No. 147595/1982). However, with these conventional dispersion stabilizers, it is necessary to add a relatively large amount in order to obtain a satisfactory effect, and it is greatly influenced by the particle size distribution of coal and adjustment conditions, When added at the time of pulverization, the flow axis property deteriorates as the pulverization progresses, so it is necessary to increase the required amount as the surface area increases.

The dispersion stabilizer of the present invention has a styrene oxide group.

By containing an ethyl oxide group, a relatively small amount of addition can produce a vague effect, and the particle size distribution and I! (10
S (has revolutionary performance that is unaffected by conditions, etc.) By incorporating a styrene oxide group with an aromatic ring into the molecule, it has good affinity with the 4g water portion of the coal surface. It is thought that this is because the adsorption of the coal surface -\ is dramatically improved.

By further adding a specific compound shown as component (11) to the dispersion-stable firmness of the present invention, it is possible to obtain an even lower viscosity and better fluidity due to their additive effects.

Coal utilized in the present invention is anthracite coal, 1-rekicho coal, lignite coal,
Free-flowing coal types such as lignite are used, which are pulverized and used. The particle size of this coal powder may be any particle size that allows direct combustion in the boiler, but the general particle size currently used at thermal power stations for this purpose is 2013.
The particle size has a mesh pass rate of 70 to 90 mm.

Any mixture of coal, dispersion stabilizer, and water + 1g may be used, but it may be prepared by dispersing the dispersion stabilizer in water in a bath or dispersing it, adding coal thereto, and using a suitable mixing device or crushing device. .

The dispersion stabilizer of the present invention can be used in combination with an anionic surfactant or a nonionic surfactant. For example, the present inventors have already invented the dispersion stabilizer for water slurry of coal powder of the present invention and are currently applying for a patent (Japanese Patent Application No. 54-951).
No. 73), a nonionic surfactant such as a naphthalene sulfone-formalin condensate or a polyoxyethylene sorbitan fatty acid ester, which is used as a separation agent for water slurry of coal powder, is used. , a more ambiguous dispersion H is obtained.

Historically, in the coal water slurry using the dispersion stabilizer of the present invention, oleic acid such as oleic acid, amine compound such as cyamylamine, amide compound such as stearylamide, phosphorus forged stellate such as tributyl phosphate, or aluminum stearate has been added. By adding metal stones such as H, etc., it is possible to make a stable slurry with less air bubbles.

Currently, consideration is being given to removing the ash from coal using various methods and burning it as a deashed coal-water slurry in a heavy oil-fired boiler. Coal deashing methods at this time include a method that applies the principles of the flotation method and uses Pudong agent and FfM agent to retain the ash in water and suck up the coal into foam and recover it;
An underwater granulation method, etc. (1+1, Japanese Patent No. 52-57901), in which oil or emulsion is added to J- and stirred to selectively recover coal by granulation, is attracting attention. The dispersion stabilizer of the present invention exhibits extremely good fractional stability even in coal slurry deashed by such a method. In addition, in this case, it is possible that hydrocarbon oil (for example, diesel oil, A heavy oil, B heavy oil, 0 heavy oil, etc.) may be mixed into the coal slurry, but the dispersion stabilizer of the present invention is suitable for systems where such hydrocarbon oil coexists. However, it shows excellent performance without losing its dispersion effect.

The water slurry of coal powder obtained by adding the dispersion stabilizer of the present invention for 65 seconds has good fluidity with little increase in viscosity even at high concentrations, and has good fractional stability without forming hard cakes even after long-term storage. Pipeline transport, tank storage, and boiler direct combustion are required to maintain the 1f capacity. In addition, the aqueous slurry of coal powder obtained using the dispersion stabilizer of the present invention has fewer bubbles during production, less increase in volume of the slurry, and can be made to have good properties by preventing thickening due to air bubbles. .

The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these X Mli examples.

(1) Preparation method of deashed coal 1) Manufacturing method of deashed coal by underwater granulation method Preasol charcoal with the following composition of 200 mesh 80911 pass 415 F (containing moisture of 3 and 25 sections) Coal and water slurry is obtained by dispersing it in water at room temperature and stirring at 400 F >' as a pure fraction of coal/rice.To this mixture, add 20% of Ay oil, and add the coal and water slurry at room temperature.
The mixture was deashed and granulated by stirring for 50 minutes at 100 Orpm in a trap (manufactured by % Shoki Kaf Kogyo Co., Ltd.). Thus obtained fc, rM
Place the S mixture on an 8-mesh sieve to remove the ash and 105
Deashed and dehydrated granules (deashed charcoal A and B) were obtained by drying at ℃. The residual ash content of this product is 4.8
It was wt96 (coal standard).

11) Method for producing deashed coal by flotation method (2) 1
), 413f of Preasol charcoal was dispersed in water at room temperature and placed in a F-W type flotation vessel together with 0.5f of pine oil to carry out the entire flotation process. Then, the deashed coal slurry collected together with the foam is dehydrated under reduced pressure to obtain deashed coal B.

The residual ash content of this product is 4. Owt% (based on coal).

1 Firesol charcoal heat generation 43 6720 Kcal / 7 (M from J
8814) Ash content 7.1 section (JI
SM8812) Moisture 7.0
(JIS M13811) Fixed carbon section 59.7
(JIS M8812) Table 1 Y8 production and fluidity evaluation table 2 of feed coal-nine water slurry. 1.8 t of A1 compound was divided into 97.7 F water for 14 minutes.
To this mixture, Pleiasol charcoal 587f, sample charcoal A1 in Table 1, was added in small portions at room temperature. After adding all-M, mix with a homo mixer (manufactured by Special 4N4 Kajogyo Co., Ltd.) for 500 min.
A coal water slurry was prepared by stirring at rpm for 5 minutes.

When the viscosity was measured at 25°C, it was 1900 cm, indicating good fluidity. Under the same conditions, various combinations of the test coal shown in Table 1, the polyether compound or its induced cuff body (component a) shown in Table 2, and the component (1) shown in Table 3 were carried out. The results are shown in Tables 4 and 5, including 110 examples and specific benefits. A low v3If value indicates good liquidity.

(5) Evaluation of stability of water slurry The stability of the slurry was evaluated at 30 days and 60 days after producing the slurry.
After allowing it to stand still for a day, a stainless steel pellet with a diameter of 5 mm (the weight is s
OF) was gently put into the slurry and its sedimentation state was observed. The slurry prepared in (2) had good stability and showed almost no compaction even after 60 days. The results are shown in Tables 4 and 5, including other examples and ratio V examples.

Claims (1)

[Scope of Claims] 1. A compound containing active hydrogen with an alkylene oxide and styrene oxide containing ethylene oxide as an essential component, and containing 1-20 n styrene oxide groups (n indicates the number of active hydrogens in one molecule.) The sum of the polyoxyethylene chain parts is 40 to 95 weight proportions of 1 degree of the entire molecule, and 1 degree of the molecule is s, ooo ~ A dispersion stabilizer for a water slurry of coal powder, characterized in that it contains a polyether compound or a derivative thereof having a molecular weight of 200,000 as an active ingredient. 2. Stable dispersion of coal powder for water slurry according to claim 1, wherein the polyether compound or its derivative is a block-like or partially block-like adduct of styrene oxide and alkylene oxide that essentially contains ethylene oxide. agent. 3. Stable dispersion of coal powder for water slurry according to claim 1 or 2, characterized in that the polyether compound or its derivative is an adduct of styrene oxide, ethylene oxide and propylene oxide. agent. 4. The dispersion stabilizer for a water slurry of coal powder according to claim 1 or 2, wherein the polyether compound or its derivative is an adduct of styrene oxide and ethylene oxide. 5. The coal powder according to claim 1, 2, 5, or 4, wherein the polyether compound derivative is a sulfate, phosphoric oxide, carboxyalkylated product, or a salt thereof of a polyether compound. Dispersion fixative for water slurry. 6. Claims 1 and 2, characterized in that the coal powder is deashed coal powder. The dispersion stabilizer for water slurry of coal powder according to item 3, item 4, or item 5. 7. The coal powder according to claim 6, characterized in that the coal powder is demineralized coal powder obtained by a flotation method or an underwater granulation method in which granulation is performed by adding oil in water. Dispersion stabilizer for water slurry. 8(a) A compound having an active water system to which an alkylene oxide and styrene oxide containing 1 ethylene oxide as an essential component is added, and the styrene oxide group is 1 to 20n in the molecule (n is the activity in one molecule). ), the total number of polyoxyethylene chain parts is 40 to 95% by weight of the total molecular weight, and the molecular weight is s, uoo to 200,000, or A dispersion stabilizer for an aqueous slurry of coal powder, characterized in that it contains as an active ingredient one or more compounds selected from the group consisting of a derivative thereof, and (b) an aliphatic alcohol, a sorbitan fatty acid ester, silica, and a corn compound. .