JPH0357956B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a coal-alcohol dispersion fuel that has excellent flow characteristics for pipeline transportation and combustion. In recent years, much research has been conducted on the handling of coal in order to use it as fuel. For example, powdered coal has been dispersed in fuel oil or water to form a slurry, and this has been transported by pipeline. However, all of them have problems such as low coal content of 20 to 40% by weight and a decrease in calorific value during combustion, so they have not been able to solve the problem of cost reduction. A mixed fuel of powdered coal and alcohol is attracting attention as a way to overcome the above-mentioned deficiencies.
However, simply mixing powdered coal and alcohol does not provide a satisfactory mixed fuel because the powdered coal settles and separates due to the difference in specific gravity, condenses, and loses fluidity. Therefore, finding additives that improve stability is one of the important issues.
An example of this can be seen in -149391, but even when 1% by weight or more of additives are used, the vibration stability required for ship transportation etc. is poor and it is difficult to put it into practical use. Furthermore, JP-A No. 53-55304 discloses that a combustible shudder and thixotropic suspension can be obtained by dispersing pulverized coal in which most of the coal particles are 100 mesh or less in methanol.
The suspension can be maintained in a suspended state with only mild agitation during storage, will not separate when pumped through pipelines, has sheer thinning rheology, and is static. It has the property of being able to be transported by pump with an apparent viscosity lower than the viscosity during storage. However, if the stirring is stopped, a portion of the suspended pulverized coal will settle at the bottom of the storage vessel, forming a hard coal layer, a so-called consolidation layer. The fluidity of this consolidated layer can be recovered by strong stirring, but in some cases it is difficult to recover completely, so the suspension must be transported from the place of manufacture to the place of consumption. When considering storage and storage, it becomes a big problem technically and economically, and it cannot be said to be practical. On the other hand, in the case of a colloidal suspension in which the coal particles are small and kept in a suspended state, sedimentation and separation are difficult to occur and the stability is good, but the grinding cost is high and the viscosity is extremely high. However, it is difficult to pump, and a satisfactory powdered coal-alcohol suspension cannot be obtained. Furthermore, a suspension obtained by simply mixing powdered coal and alcohol becomes significantly thicker when the coal concentration is increased.
The lack of fluidity makes pipeline transportation and spray combustion difficult, and lowering the coal concentration reduces transportation efficiency, which poses major technical and economical problems and is impractical. The inventors of the present invention have made extensive studies to overcome the above-mentioned defects in fuels whose main components are mixtures of powdered coal and alcohol, and have found that by using additives with a specific structure, they can lower the viscosity and The present invention was achieved by discovering that excellent effects can be obtained on the flow characteristics of line transportation and combustion. That is, the present invention provides a coal-alcohol dispersion fuel mainly composed of a mixture of powdered coal and alcohol, with a degree of sulfonation (phenylpropane units) of 0.25 obtained by desulfonating ligninsulfonic acid and salts thereof. The present invention is a coal-alcohol dispersion fuel characterized by containing an acid consisting of partially desulfonated lignin sulfonic acid and one or more salts thereof in an amount of 0.005 to 5% by weight or less. According to the present invention, by using the above-mentioned specific additive, the viscosity is reduced and the fluidity characteristics for pipeline transportation and combustion are excellent, and furthermore, the difference in ash content between the upper and lower layers of the slurry left still is large, and the slurry is removed. A coal-alcohol fuel with excellent ash properties can be obtained. The above-mentioned lignin sulfonic acids and their salts include, for example, the cooking waste liquid obtained by steaming in a sulfite-hydrochlorine-sulfite solution when pulp is produced from wood chips of softwood or hardwood, or other materials containing lignin. β-naphthylamine hydrochloride, acriflavine, thioflavin,
Lignosulfonic acids and their salts are useful after separating and purifying monosaccharides such as hexoses and pentoses, sugar modifications, inorganic substances, etc. by precipitation methods using precipitating agents such as lime, salting out methods, dialysis methods, extraction methods, etc. However, it is sufficient that the main component is lignin sulfonic acid and/or a salt thereof, and is not limited by the lignin raw material, the content of sugar and other components, the chemical treatment method, etc. The acids and salts thereof consisting of partially desulfonated ligninsulfonic acid used in the present invention include the above-mentioned ligninsulfonic acids and/or
or a compound obtained by desulfonating a salt thereof, the degree of sulfonation of the compound is from 0.06 to 0.25 equivalent of phenylpropane unit, preferably from 0.06 to 0.25 equivalent.
It is 0.2 equivalent or less. For example, acids and salts thereof consisting of compounds obtained by high-temperature oxidation and desulfonation of sulfite pulp cooking waste liquid or ligninsulfonic acid and/or salts thereof separated and purified therefrom, as well as sugar modifications contained therein; Compounds obtained by separating and purifying inorganic substances are useful. These partially desulfonated lignin sulfonic acid acids and their salts have a higher content of carboxyl groups and phenolic hydroxyl groups than untreated ones, but have a lower content of sulfonic groups and alcoholic hydroxyl groups, and have a lower molecular weight. is extremely small, less than 30,000. These partially desulfonated lignin sulfonic acids and their salts, especially those with a degree of sulfonation (phenylpropane units) of 0.25 equivalent or less, are alcohol compatible and have a low viscosity effect on coal-alcohol slurries. It has extremely good chemical and physical properties that are completely different from ligninsulfonic acid and its salts. The specific additive used in the coal-alcohol dispersion fuel of the present invention is an acid consisting of the above-mentioned partially desulfonated lignin sulfonic acid and/or a salt thereof, preferably a monovalent, divalent or trivalent metal. salt, ammonium salt or amine salt. In these salts, either the acid or the base may be in excess, and the salt may be used after being prepared, or the acid and the base to be paired may be used separately. Metals that form salts include lithium, sodium, potassium, magnesium, calcium, bad lead, cadmium, barium, aluminum, lead,
Useful materials include tin, copper, chromium, manganese, iron, cobalt, nickel, and the like. Examples of amines that form salts include aliphatic amines, alicyclic amines, aromatic amines, alkanolamines, pyridine and its derivatives, and compounds having quaternized N, such as methylamine, ethylamine, butylamine, Octylamine, laurylamine, stearylamine, oleylamine, dimethylamine, N-methyl-laurylamine, dilaurylamine, trimethylamine, N,
N-dimethyl laurylamine, ethylenediamine, hexamethylenediamine, diethylenetriamine, tallow alkylamine, cyclohexylamine, cyclohexyldiamine, triethylenediamine, morpholine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanol Amine, aniline, P
-Toluidine, m-toluidine, nitroaniline, benzylamine, pyridine, phenylenediamine, benzidine, and the like are useful. The partially desulfonated lignin sulfonic acid and salts thereof are known compounds,
It can be produced by a known method, and sulfite pulp cooking waste liquid or separated and purified ligninsulfonic acid and its salts are mixed in the presence of an alkali such as caustic soda at an initial pH of 9 or higher and at a temperature of 100 to 300°C.
Preferably at 150 to 250°C, air or oxygen is injected and high temperature oxidation is performed to effect desulfonation, and in some cases, reaction by-products such as sugar modifications of reducing sugars and inorganic substances are separated and removed. Further, it can be obtained by a salt-forming reaction, but is not limited thereto, and it may also be obtained by heat treatment at a lower pH and desulfonation. Specific examples of the additive according to the present invention include the following synthesis examples and products, but these are just examples and are not limited thereto. Partially desulfonated sodium lignin sulfonate salt (product name “Vanirex HW” manufactured by Sanyo Kokusaku Pulp Co., Ltd.) Partially desulfonated sodium lignin sulfonate salt (product name “Vanirex RN” manufactured by Sanyo Kokusaku Pulp Co., Ltd.) Sulfonated lignin sulfonic acid sodium salt (product name: "Marasperse CB" manufactured by Marathon) The amount of the specific additive used in the liquid-solid dispersion fuel of the present invention varies depending on the type of coal, particle size distribution, etc. , generally in a proportion ranging from 0.005 to 5% by weight, preferably from 0.01 to 2% by weight, based on the total weight of the dispersed fuel. If the amount added is less than 0.005% by weight, it is difficult to obtain a sufficient effect of improving fluidity, so it is not suitable, and if it exceeds 5% by weight, it is not only economically disadvantageous but also impairs the fluidity of the present invention. This is not preferred because the excellent physical properties of the coal-alcohol dispersion fuel cannot be obtained. This additive may also be used with other thinning agents, such as salts consisting of mono or copolymers of unsaturated acids such as acrylic acid,
Fatty acid salts such as citric acid, sulfonates of polymers made of unsaturated aromatic compounds, anionic surfactants such as salts of formalin condensates of naphthalene sulfonic acid and petroleum sulfonic acids, amines, condensed phosphates, Ionic compounds such as silicates and carbonates, etc.
Stabilizers such as carboxylic acids, alcohols, amines,
An alkylene oxide adduct starting from a compound having at least one active hydrogen in the molecule, such as polypropylene glycol or a compound having a phenolic hydroxyl group, with an ethylene oxide content of 80% by weight or more in the molecule and a number average molecular weight of 1000 to 1000. Ten
Nonionic surfactants such as 10,000 compounds, as well as sulfuric acid esters, phosphoric acid esters, N,
It may be used in combination with amphoteric surfactants such as N,N-distearyl methylammonium and betaine, and inorganic substances such as ultrafine silica, carbon black and bentonite. The additive of the present invention may be used alone, but in order to function effectively, it is preferable to dissolve it in advance in a solvent such as water, lower alcohol, acetone, toluene, or a mixture thereof. . The addition method may be, for example, during wet pulverization of a mixture of coal and alcohol, or during coal pulverization, or during or after mixing of pre-pulverized coal and alcohol. The effects of the present invention can also be achieved by. The powdered coal used in the coal-alcohol dispersion fuel of the present invention includes anthracite coal, bituminous coal, subbituminous coal,
It is a product made by pulverizing at least one type of coal selected from lignite, regardless of the type or origin of the coal, or regardless of its chemical composition or moisture content.
Anything can be used. Regarding the size of coal particles, the use of the excellent additive of the present invention shows an excellent effect on the flow characteristics of pipeline transportation and combustion by lowering the viscosity regardless of the particle size. In order to achieve the object of the present invention, it is particularly preferable that the particles have a size of 4 meshes or less, and most of these particles have a size of 16 meshes or less. The amount of powdered coal mixed is preferably 30 to 80% by weight based on the final liquid-solid dispersion fuel, and if more than 80% by weight of powdered coal is mixed with alcohol, the viscosity will increase significantly. This is not suitable because of loss of fluidity, and if less than 30% by weight is mixed, not only will the economic efficiency of the coal-alcohol dispersion fuel decrease, but also the excellent physical properties of the coal-alcohol dispersion fuel of the present invention will not be obtained. I don't like it because I can't do it. Therefore, it is usually in the range of 30 to 80% by weight, more preferably 40 to 70% by weight. Moreover, the coal-alcohol dispersion fuel of the present invention includes:
Water can be included in an amount of up to 30% by weight of the final coal-alcohol dispersion fuel. If the amount of water exceeds 30% by weight, transportation costs, storage costs, and other general administrative costs for the coal-alcohol dispersion fuel will increase, and furthermore, heat loss due to heat of evaporation of water during combustion will increase. unable to achieve the goal. The amount of water in the coal-alcohol dispersed fuel can be optimized depending on the purpose, but for example, _NO
In order to reduce the amount of soot and dust, it is preferable that the water content be 5 to 10% by weight. Moisture is usually provided by the moisture in the coal, but it can be added separately or selected as appropriate by the operator. The alcohol used in the coal-alcohol dispersion fuel of the present invention consists of at least one type of lower aliphatic alcohol having 1 to 4 carbon atoms,
For example, methyl alcohol, ethyl alcohol,
These include n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, tert-butyl alcohol, ethylene glycol, propylene glycol, etc. Methyl alcohol is particularly preferred from the viewpoint of economic efficiency and physical properties. Compounds contained during production, solvents, organic compounds such as water, and inorganic compounds may be included. The coal-alcohol dispersion fuel according to the present invention has a low viscosity and excellent flow characteristics, and can be easily transported by pipeline and spray-combusted. Furthermore, in the coal-alcohol dispersed fuel of the present invention, the difference in the ash content in the coal between the upper and lower layers after standing is significant, making it possible to separate the ash content from the coal-alcohol. This is because the additives used in the dispersed fuel are adsorbed onto the coal particles in the slurry, and
This is thought to be due to the fact that the coal particles are dispersed in the slurry by being charged, while the ash in the coal particles coagulates and settles. Next, the present invention will be explained in detail with reference to synthesis examples and examples. Synthesis Example 1 Sodium ligninsulfonate solution [Product name: “Sun Extract 252” manufactured by Sanyo Kokusaku Pulp Co., Ltd., concentration 43
Weight %, degree of sulfonation (per phenylpropane unit) of the sodium lignin sulfonate 0.46 equivalent] 232.6 g and 50.0 g of caustic soda added to 170 ~
After oxidation treatment at 200° C. for 1.5 hours by introducing oxygen under pressure, sulfuric acid was added to adjust the pH to 2.5 to precipitate desulfonated ligninsulfonic acid to obtain partially desulfonated ligninsulfonic acid (A-1). Degree of sulfonation (per phenylpropane unit) of this product (JISK3362-
1978 and barium sulfate gravimetric method)
It was 0.06 equivalent. This partially desulfonated ligninsulfonic acid (A-1) was neutralized to pH 7.5 with caustic soda to obtain partially desulfonated sodium ligninsulfonate (A-2) with a purity of 92%. Synthesis Example 2 Sodium ligninsulfonate solution [Product name: “Sun Extract 252” manufactured by Sanyo Kokusaku Pulp Co., Ltd., concentration 43
% by weight, degree of sulfonation (per phenylpropane unit) of 0.46 equivalents] of the sodium ligninsulfonate] was adjusted to pH 12 by adding 40% caustic soda solution,
Oxidation treatment was performed at 150 to 180°C for 60 minutes by pressurizing air. Sulfuric acid was added to the mixture to adjust the pH to 2.5, and desulfonated ligninsulfonic acid was precipitated to obtain partially desulfonated ligninsulfonic acid (A-3). The degree of sulfonation (per phenylpropane unit) of this product (measured by JISK3362-1978 and barium sulfate gravimetry) was 0.23 equivalent. This partially desulfonated ligninsulfonic acid (A-3) was adjusted to pH 9 with caustic soda to obtain partially desulfonated sodium ligninsulfonate (A-4) with a purity of 95%. Synthesis Example 3 Sodium ligninsulfonate solution [Product name: “Sun Extract 252” manufactured by Sanyo Kokusaku Pulp Co., Ltd., concentration 43
% by weight, degree of sulfonation (per phenylpropane unit) of 0.46 equivalents] of the sodium ligninsulfonate] was adjusted to pH 12 by adding 40% caustic soda solution,
Oxidation treatment was performed at 150 to 180°C for 30 minutes by pressurizing air. Sulfuric acid was added to the mixture to adjust the pH to 2.5, and desulfonated ligninsulfonic acid was precipitated to obtain partially desulfonated ligninsulfonic acid (A-5). The degree of sulfonation (per phenylpropane unit) of this product (measured by JISK3362-1978 and barium sulfate gravimetry) was 0.32 equivalent. This partially desulfonated ligninsulfonic acid (A-5) was adjusted to pH 8 with caustic soda to obtain partially desulfonated sodium ligninsulfonate (A-6) with a purity of 92%. Example 1 3.0 g of partially desulfonated sodium ligninsulfonate (A-2) obtained from Synthesis Example 1, 207 g of methyl alcohol, and 30 g of water were placed in a 1000 ml beaker, and heated at 1000 rpm at room temperature using a homomixer.
The mixture was stirred and mixed for 10 minutes under these conditions. Next, powdered subbituminous coal (97.5% by weight after 100 meshes, 75.2% by weight after 200 meshes, 53.6% by weight after 350 meshes,
Add 360g (moisture 5.0% by weight, ash content 14.8% by weight),
The mixture was stirred at 1000 rpm for 20 minutes to obtain 600 g of coal-alcohol slurry. The viscosity (*1) of this product was 1400 cp.
Next, as a result of a demineralization (ash content) test (*2), the ash content in the coal was 9.8% by weight in the upper layer and 11.2% in the middle layer.
The difference in ash content in the coal between the upper and lower layer samples was extremely large. This coal-alcohol dispersion fuel, which is mainly composed of a mixture of coal and alcohol, has low viscosity and excellent fluidity.
Easy to transport by pipeline and spray combustion;
Furthermore, the demineralization property was good. (*1) Viscosity measurement Double cylindrical viscometer (manufactured by Haake, rotor
MV) at a liquid temperature of 20°C and a rotation speed of 5 rpm. The lower the viscosity of the dispersed fuel, the better the fluidity. (*2) Deashing property (ash content) test Pour 500 ml of the above coal-alcohol dispersion fuel into a 500 ml measuring cylinder (inner diameter 50 m/m) and let it stand at room temperature for 3 days. After standing for a while, the upper 170ml of the dispersed fuel in this cylinder
Take out the remaining 330 ml and use it as the upper layer sample, then use the upper 170 ml of the remaining 330 ml as the middle layer sample and the lower 160 ml as the lower layer sample. The amount of ash in the coal in these samples is
Measured according to JISM8812. The larger the difference in the ash content in the coal between layers, the better the deashing performance. Example 2 Using the partially desulfonated lignin sulfonic acids and their salts obtained in Synthesis Examples 1 to 3, and the products containing partially desulfonated lignin sulfonates as main components, the same method as in Example 1 was carried out. A liquid whose main component is a mixture of coal and alcohol by changing the ratio of coal/added water/alcohol and the type and amount of additives.
Adjusted solid fuel. The viscosity and demineralization properties of these are shown in Table 1. Furthermore, cases in which no additives were used and cases in which additives other than the additives of the present invention were used are also listed in Table 1 as comparative examples. Table 2 shows the properties of the coal used in the Examples and Comparative Examples. As shown in Table 1, by using specific additives, the liquid-solid dispersion fuel of the present invention can reduce the viscosity regardless of coal type or alcohol, and has excellent fluidity characteristics for pipeline transportation and combustion. It was found to be effective and to have good demineralization properties. On the other hand, the lignin sulfonate shown in the comparative example that was not partially desulfonated had a significantly high viscosity, which significantly impaired the fluidity characteristics for pipeline transportation and combustion. Furthermore, the deashing properties were also poor, making it impossible to obtain a good dispersed fuel. Furthermore, as shown in Reference Examples 1 and 2, the relationship between the degree of sulfonation and the thinning effect in partially sulfonated lignin sulfonate is that the degree of sulfonation is around 0.25 equivalent (phenylpropane unit), and there is no difference in the thinning effect. It can be seen that this is occurring. Further, Reference Example 3 shows the effect of lignin sulfonate in a coal slurry system. In other words, ``lignin sulfonate'' has a very thinning effect on coal-water slurry and has excellent deashing properties, whereas coal-alcohol slurry has almost no thinning effect. That is, it was found that the interfacial state, slurry properties, etc. are completely different when the dispersion medium is water and alcohol.

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Claims (1)

[Claims] 1. Degree of sulfonation (phenylpropane units) obtained by desulfonating lignin sulfonic acid and salts thereof in a coal-alcohol dispersion fuel containing a mixture of powdered coal and alcohol as the main component. It contains 0.06 to 0.25 equivalents of an acid consisting of partially desulfonated lignin sulfonic acid and one or more of their salts in a range of 0.005 to 5% by weight, and in a standing state, the upper layer is larger than the lower layer. A coal-alcohol dispersion fuel that forms a slurry with a low ash content compared to the above, and has excellent fluidity with a low ash content obtained by collecting the upper layer. 2. The coal-alcohol dispersion fuel according to claim 1, wherein the counter ion forming the salt is a monovalent, divalent or trivalent metal, ammonium or amine.