JPH0369390B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a solid fuel slurry composition containing a specific dispersant and having excellent storage stability. [Conventional technology] Traditionally, energy has been based on petroleum, but in recent years, due to the depletion of petroleum resources, solid fuels such as coal, petroleum coke, and pituti have been reconfirmed, and their uses have become diverse. It is being considered. However, unlike liquid fuels such as petroleum, these solid fuels are solid and therefore difficult to transport by ordinary pipelines, tank trucks, and the like. For this reason, various techniques have been proposed in which solid fuel such as coal is pulverized, dispersed in water, and treated as a slurry in the same way as a liquid. In this case, it is possible to create a slurry with a low viscosity by lowering the solid fuel concentration and using a large amount of water, but this is not a good idea in terms of fuel efficiency. In addition, the slurry thus obtained has the disadvantage that the solid fuel settles when left standing. As a method of increasing the solid fuel concentration, a method has been proposed in which various dispersants are added to the slurry to improve the dispersibility of the solid fuel in water. It has been reported that the fluidity of solid fuel slurries to which such various dispersants are added is significantly improved compared to when no such dispersants are added, and that the use of dispersants makes it possible to produce highly concentrated solid fuel slurries. There is. [Problems to be solved by the invention] Since the solid fuel slurry produced in this way is generally transported, stored, and used as a fuel, it is necessary that the slurry has good static stability over a long period of time. has been done. However, the current situation is that long-term stability has not yet reached a fully satisfactory level. The present invention was made against the background of the above-mentioned problems of the prior art, and is capable of imparting high fluidity to highly concentrated solid fuel slurry and maintaining high fluidity even after being left for a long time. An object of the present invention is to provide a solid fuel slurry composition. [Means for Solving the Problems] As a result of intensive studies to solve the above-mentioned conventional technical problems, the present inventors found that when a specific new dispersant and a nonionic surfactant are used in combination, solid fuel It was discovered that a slurry with extremely excellent fluidity and stability could be obtained, and the present invention was achieved. That is, the present invention provides (a) a (co)polymer having a weight average molecular weight of 1,000 to 100,000 obtained by (co)polymerizing a sulfonated product of dicyclopentadiene, and (b) an added mole number of alkylene oxide of 4 to 800. and contains a nonionic surfactant whose main component is a polyether polyol compound whose polyoxyethylene group content in the polyether chain is 20% by weight or more, (c) solid fuel, and (d) water. Moreover, the present invention provides a solid fuel slurry composition characterized in that the weight ratio of component (a)/component (b) is from 95/5 to 55/45. The dispersant used in the present invention is a (co)polymer having a weight average molecular weight of 1,000 to 100,000 obtained by (co)polymerizing a sulfonated dicyclopentadiene. Dicyclopentadiene used as a starting material for the dispersant is represented by general formula (A). (In the formula, R ¹ and R ² represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.) Dicyclopentadiene (and its derivatives) represented by the general formula (A) is a compound such as cyclopentadiene. It is obtained by the Diels-Alder reaction between a diene component and a dienophile component, the thermal decomposition of naphtha, etc. Examples of the dienes used as the dienophile component include 1,2-pentadiene, 1,
Examples include 3-pentadiene, 2,3-pentadiene, cyclopentadiene, and branched dienes thereof. Methods for producing these sulfonated products of dicyclopentadiene (and its derivatives) and their (co)polymers are described in JP-A-61-19608 and JP-A-61-1961.
-Details are described in Publication No. 19609. By the way, to give an overview, dicyclopetadiene and/or its derivatives (hereinafter referred to as
Various methods can be considered to produce sulfonated products of these derivatives (sometimes simply referred to as "derivatives"). A sulfonated derivative containing one double bond in the molecule can be obtained by preferentially adding sulfites to double bonds with a high . As the sulfonating agent in this case, acidic sulfites, metasulfites, or sulfites of alkali metals are usually used alone or as a mixture. The amount of sulfonating agent per mole of derivative is:
Usually 0.1 to 2.0 mol, preferably 0.5 to 1.5 mol,
More preferably, it is 1 to 1.5 mol. If it is less than 0.1 mol, the reaction yield will be low, while if it exceeds 2.0 mol, a large amount of disulfonated product will be produced. When the amount of the sulfonating agent is less than 1 mole per mole of the derivative, a mixture of the sulfonated derivative and the non-sulfonated derivative is formed. Only the sulfonated derivative (used) or distillation may be removed from the mixture, or a mixture of the sulfonated derivative and the non-sulfonated derivative may be directly polymerized by the method described below. In that case as well, the sulfonated polymer can be separated from the non-sulfonated polymer by extraction (using e.g. n-hexane as a solvent) or distillation. In the sulfonation reaction, the use of a catalyst is not necessarily required, but the use of a catalyst such as an inorganic oxidizing agent usually improves the yield and shortens the reaction time, but is expensive. Examples of the inorganic oxidizing agent include nitrates, nitrites, chlorates, etc., and nitrates are particularly effective. The amount of the inorganic oxidizing agent is not particularly limited, but an effective amount is 0.02 to 0.15 mol, preferably 0.05 to 0.1 mol, per 1 mol of the derivative. Furthermore, it is preferable to use an appropriate solvent in order to allow the reaction to proceed uniformly and smoothly. Examples of solvents that can be advantageously used include water, lower alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, and tertiary butyl alcohol, lower glycols, ketones,
Examples include ethers and esters. Two or more of these solvents can be used in combination as appropriate. Among these, a mixed solvent of lower alcohol and water, especially a mixed solvent of methyl alcohol and water, is recommended as an excellent solvent. The reaction temperature is usually 50 to 200°C, preferably 70°C.
It is carried out at a temperature of -150°C, more preferably 90 - 130°C, and can be carried out either at normal pressure or under increased pressure. In order to suppress the progress of side reactions and reduce the production of inorganic salts, the pH of the reaction system is usually maintained at 2 to 9, preferably 5 to 7. The cationic species of the sulfonated product is not particularly limited, but in order to make it water-soluble, hydrogen, alkali metals, alkaline earth metals, ammonium, amines and the like are preferred. The alkali metals include sodium, potassium, etc., and the amines include methylamine, ethylamine, propylamine, dimethylamine, diethylamine, triethylamine, butylamine,
Examples of the alkaline earth metals include alkylamines such as dibutylamine and tributylamine, polyamines such as ethylenediamine, diethylenetriamine, and triethylenetetramine, morpholine, and piperidine, and calcium and magnesium as the alkaline earth metals. Additionally, these cationic species can be interchanged with other cationic species by various ion exchange techniques. Next, the polymer of the sulfonated derivatives used as component (a) of the present invention refers to a polymer obtained by polymerizing at least one of the sulfonated derivatives, or a polymer obtained by polymerizing at least one of the sulfonated derivatives. It represents a polymer obtained by copolymerizing a sulfonated product with a polymerizable monomer (hereinafter referred to as a "comonomer"). The method for producing this polymer is as follows. For example, a sulfonated product of the above derivative or a copolymer thereof is reacted in the presence of an acidic compound catalyst at a reaction temperature of usually -20 to 300°C, preferably 80°C.
A polymer can be produced by carrying out a polymerization reaction at ~180°C for several hours to several tens of hours. In the polymerization reaction, a solvent for the polymerization reaction can be used in order to carry out the reaction smoothly, and the solvent for the polymerization reaction may include polar solvents such as water, hydrocarbons, halogens, etc., as long as it does not hinder the polymerization reaction. Any material such as carbonized hydrocarbons can be used. The acidic compound catalyst includes sulfuric acid, phosphoric acid,
Examples include Lewis acids such as hydrogen fluoride, boron trifluoride and complexes thereof, aluminum chloride, aluminum bromide, tin tetrachloride, zinc chloride, and titanium trichloride, and organic protonic acids. Among them, sulfuric acid can be cited as a typical example. Comonomers include aliphatic, alicyclic, and aromatic hydrocarbons having olefinic double bonds, unsaturated amides, unsaturated alcohols, unsaturated esters, unsaturated nitriles, unsaturated carboxylic acids, and their like. Ester, unsaturated sulfonic acid and its ester, etc., aliphatic, alicyclic, aromatic alcohol or phenol, or alcohol or diol having an amino group, ester group, nitrile group, carboxylic acid group, sulfonic acid group, etc. 1 More than one species can be used in any proportion. By changing the type of comonomer used, the surface active properties of the polymer can be changed. When a polymer is produced from the sulfonated product of the present invention and a copolymer monomer and used as a dispersant for solid fuel, the sulfonated product/polymer of the present invention (by weight) is used to suppress foaming. %) is at least 50% by weight, preferably at least 70% by weight. The molecular weight of the polymer and copolymer obtained by the present invention can be changed as appropriate depending on the reaction conditions, especially the type and amount of the acidic compound catalyst, the type and amount of the solvent, or the reaction temperature and reaction time. be able to. When using the polymers and copolymers obtained in this way as the dispersant of the present invention, the characteristics cannot be determined unambiguously because they vary depending on the type of solid fuel, particle size, etc., but usually , the weight average molecular weight is 1000 to 100000. Furthermore, the sulfonated polymers and copolymers can be mutually exchanged into acid forms or salts of alkali metals, alkaline earth metals, ammonium, amines, etc. by ion exchange methods or neutralization reactions. Next, component (b) of the present invention is a nonionic surfactant containing a polyether polyol compound as a main component. The polyether polyol compound is produced by addition reaction of ethylene oxide and/or propylene oxide to a compound having one or more active hydrogen per molecule under pressure in the presence of an acid or alkali catalyst by a conventional method. It can be obtained by Examples of compounds having one or more active hydrogens in one molecule include monohydric alcohols such as lauryl alcohol, stearyl alcohol, phenol, octylphenol, and nonylphenol; ethylene glycol, propylene glycol, butanediol, glycerin, and trimethylolpropane. , polyhydric alcohols such as pentaerythritol, sorbitan, and sorbitol; amino compounds having one or more hydroxyl groups such as catechol, resorcinol, pyrogallol, nonylphenol formalin condensate, and phenol formalin condensate. Also included are compounds obtained by cationizing these amino compounds with alkyl halides, diethyl sulfate, and the like. Further, polyvinyl alcohol, a partially saponified product of polyvinyl acetate, and a polymer containing a monomer having a hydroxyl group as a component may also be used. These polyether polyol compounds are obtained by adding ethylene oxide and/or propylene oxide, which are alkylene oxides, to the above-mentioned compound having one or more active hydrogens in one molecule. In addition, in order to impart adsorption properties to solid fuel particles such as coal, it is necessary to add 4 moles or more on average. Approximately 4
When the amount is less than mol, the dispersion stabilizing effect of the slurry composition is significantly reduced. In addition, there is no particular upper limit to the number of moles added, but if it is too large, the viscosity is too high, it is difficult to handle, and there are many problems in production, so it is desirable that the number is 800 moles or less on average, and more preferably 20 to 600 moles, Particularly preferably 50 to 300 moles. Either ethylene oxide or propylene oxide is essential, but butylene oxide may also be added to the extent that the effects of the present invention are not impaired. It is also effective to add alkylene oxide to an amino compound and then cationize it with an alkyl halide, diethyl sulfate, or the like. The slurry dispersion stabilizing effect of these polyether polyol compounds is better when ethylene oxide and propylene oxide are added in block form. %
or more, preferably 20 to 100% by weight, more preferably 50 to 100% by weight, particularly preferably 75 to 100% by weight
It is 100% by weight. These polyether polyol compounds can be used even if the hydroxyl group is esterified, phosphorylated, sulfated, or carboxyalkylated. Esterification with a carboxylic acid can be obtained by esterifying the polyether polyol compound with a monovalent carboxylic acid such as acetic acid, lauric acid, or stearic acid, or an anhydride or acid halide thereof, using a conventional method. can. Phosphorylation, sulfation, carboxyalkylation are
By reacting the polyether polyol compound as described above with a phosphorylating agent such as phosphorus pentoxide, a sulfating agent such as sulfur trioxide, chlorosulfuric acid or sulfamic acid, or a carboxyalkylating agent such as monochloroacetic acid in a conventional manner. The salt can be obtained by further carrying out a salt-forming reaction. Compounds obtained by crosslinking polyether polyols are also effective. Examples of crosslinking agents include polyvalent isocyanates such as hexamethylene diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate, polyvalent epoxides such as diglycidyl bisphenol A and diglycidyl ethylene glycol, maleic anhydride, adipic acid, dimer acid, and trimeric anhydride. Polyhydric carboxylic acids such as acids can be mentioned. The proportion of the crosslinking agent used in the reaction is generally 0.05 to 2 equivalents, preferably 0.1 to 1 equivalent relative to the hydroxyl group. Also effective are compounds obtained by reacting polyether polyol with epihalohydrin. This compound can be obtained by reacting the above polyether polyol with an epihalohydrin such as epichlorohydrin or epibromohydrin in a conventional manner, generally in the presence of an alkali or metal catalyst such as tin. Furthermore, a compound having an isocyanate group at the end obtained by reacting a polyether polyol with a polyvalent isocyanate is also effective. This compound can be obtained by reacting the polyether polyol with a polyvalent isocyanate, but conditions must be selected so that the crosslinking reaction does not proceed. This compound has a highly reactive isocyanate group at the end, so it tends to lack storage stability.
A compound that protects the isocyanate group with ε-caprolactam, acidic sodium sulfite, etc. and regenerates the isocyanate group during the process may also be used. In addition to these, component (b) also includes water-soluble polyvinyl alcohol, polyvinyl acetate, or saponified products of all or part of these, polyethylene glycol or esterified products of part or all of these, polysaccharides such as saccharide, etc. can be used. Compounds that have a large effect on slurry stability cannot be specified because they vary depending on the type of solid fuel, but in general, compounds with an HLB value of 5 to 20 are effective, and compounds with an HLB value of 7 to 15 are effective. is even more preferable. Next, the solid fuel (c) used in the present invention is coal, petroleum coke, pitch, and charcoal. The coal may be lignite, sub-bituminous coal, bituminous coal, anthracite, etc., or may be coal obtained by cleaning these coals, without any particular limitation. Petroleum coke is residual coke produced by distilling asphalt, pitch, etc., which are obtained as heavy residues from distillation during petroleum refining, at higher temperatures to distill cracked oil, and is generally used for coal containing minerals. In comparison, it is extremely difficult to get wet with water. Pituchi is a heavy residue obtained by distilling petroleum distillation and tar obtained by coal carbonization, leaving an oil content, and its softening point is preferably 50 to 180 °C, but lower than 50 °C. and is difficult to crush. Pitch contains almost no ash and moisture compared to coal, and can be made into a slurry fuel with a high calorific value. The viscosity of these solid fuels can be any particle size as long as they are powder, but the pulverized coal currently burned in thermal power plants is 70% by weight or more for 200 mesh passes. The particle size is a rough guideline. However, the dispersant used in the present invention is not affected by the viscosity or type of solid fuel, and exhibits excellent effects on any solid fuel powder. The dispersant, which is the component (a) of the present invention, can be used in combination with one or more kinds of anionic surfactants, additives, etc. to be described later, if necessary, and can be used at a concentration of 50%, although not particularly limited.
~85% by weight is added to the solid fuel slurry. As the viscosity of the slurry increases as the amount of component (a), which is a dispersant, increases, the amount added can be selected according to the desired viscosity, and is usually 0.01 to 10% by weight based on the total amount of the slurry composition. However, from the viewpoint of workability and economic efficiency, 0.05 to 1% by weight is preferable. Examples of the anionic surfactant include dodecylbenzene sulfonate, oleate, alkylbenzene sulfonate, dialkyl sulfosuccinate, lignin sulfonate, alcohol ethoxysulfate, secondary alkanesulfonate, and α-olefin sulfonate. , naphthalene sulfonic acid formalin condensate, tamol, polystyrene sulfonate, etc., and commercially available products such as carboxylic acid type, sulfuric acid ester type, sulfonic acid type, phosphoric acid ester type, and alkylaryl sulfonate type containing these are dispersed. It can be used as an agent or wetting agent. Examples of additives include chelating agents for trapping polyvalent metals contained in ash in solid fuels, potassium tetrapolyphosphate, sodium citrate, sodium gluconate, sodium polyacrylate, and polycarboxylic acids. Moreover, an antifoaming agent can also be added to suppress foaming. As the antifoaming agent, for example, silicone emulsion is used. Freezing point depressants can also be added to prevent freezing in winter. As the freezing point depressant, for example, a lower alcohol such as ethylene glycol or a polyhydric alcohol is used. The amount of nonionic surfactant (b) used in the present invention is not particularly limited as long as it is within an effective range, but is usually 0.001 to
2% by weight, particularly 0.01 to 1% by weight, is preferred from the viewpoint of effectiveness and economy. In addition, component (b) is more easily adsorbed to coal particles than component (a), and by combining component (a) and component (b), component (b) is preferentially adsorbed to coal particles. This has the effect of making coal particles aggregate into a weak structure. For this reason, formulations that can maintain a high degree of stability without adversely affecting flowability are usually
Component (b) is preferably in a weight ratio of 95/5 to 55/45.
90/10 to 60/40, more preferably 85/15 to 70/
It is 30. The method for producing the slurry composition of the present invention is not particularly limited, and consists of mixing solid fuel, water, and the dispersant used in the present invention in a desired manner. For example, solid fuel is dry-pulverized in advance and then mixed into an aqueous solution containing a dispersant, a slurry is produced and then the dispersant is added, or the solid fuel, water, and dispersant are added in a mill. Any method can be used, such as a method of mixing the fuel while pulverizing it. Furthermore, it goes without saying that components (a) and (b) may be added at the same time or may be added separately. [Function] When the dispersant of the present invention is present in the solid fuel slurry composition, the dispersant is adsorbed onto the surface of the fuel particles, and the resulting electrostatic force and the relatively large steric hindrance of the dispersant itself prevent the particles from approaching each other. As a result, the viscosity of the composition is reduced and stable dispersibility is obtained. [Example] Hereinafter, the present invention will be described in further detail with reference to Examples. Note that % in the examples is based on weight. First, the synthesis method for component (a) of the present invention will be shown below as a reference example. Note that the component (a) of the present invention is not limited to the following reference examples. Reference Examples a-1 to a-6 4 moles of dicyclopentadiene and 4 moles of sodium hydrogen sulfite (416
g), 0.8 mol (40 g) of potassium nitrate, 1000 ml of methyl alcohol, and 500 g of distilled water were charged, and the mixture was sealed and reacted at a temperature of 130° C. for 5 hours while mixing under strong stirring. After that, the reaction mixture was left to cool to room temperature, and 200 ml of distilled water and n
-Add 600ml of hexane, mix thoroughly and disperse
-The residue except the hexane layer and the precipitate was concentrated and evaporated to dryness to obtain a pale yellow solid. This solid was extracted with n-hexane for 1 hour using a Soxhlet extractor to remove unreacted substances, and the remaining liquid was dried and then dissolved in 1000 ml of glacial acetic acid, and acetic acid insoluble components such as inorganic salts were filtered off. The obtained acetic acid soluble portion was condensed to dryness to obtain a white-yellow solid. Then, this solid was washed with ethanol and further dried to obtain 678 g of the sodium salt of the sulfonate shown in Table 1. Next, the following polymerization reaction was carried out using the sulfonated product. In a three-necked flask with an inner volume of 1 and equipped with a stirrer and a thermometer, charge 135 g of the above sulfonated product and the compounds shown in Table 1, and 58 g of distilled water, and after dissolving, add 135 g of 98% sulfuric acid while stirring. about
The mixture was added dropwise for 30 minutes, then heated in an oil bath, and polymerized in the range of 110 to 125°C, taking samples along the way and checking the degree of polymerization using GPC. After polymerization, 300 ml of distilled water was added to the reactor to dissolve it, neutralized with calcium carbonate to remove the precipitate, and then sodated with sodium carbonate to form a sodium salt. This solution was dried to give the results shown in Table 1. A quantity of brown solid was obtained.

[Table] Reference Examples b-1 to b-9 Next, regarding the component (b) of the present invention, examples thereof are shown in the second section.
Shown in the table. Note that the component (b) that can be used in the present invention is not limited to those described below.

【table】

[Table] Examples 1 to 20 Coal [component (c)] produced in Australia, 200
A material containing 76% meshwork, 6.5% ash, and 1.6% sulfur was used. To prepare the slurry, first add the ingredients (a) and (b) listed in Table 3 in water [component (d)], then add a predetermined amount of pulverized coal into the water [component (d)]. Knead by hand with a spatula for 1 minute,
Next, using a homo mixer (manufactured by Tokushu Kikako Co., Ltd.)
This was done by stirring at 3000 rpm for 15 minutes. The fluidity of the slurry was evaluated by measuring the viscosity at 25°C of the slurry prepared as described above. In addition, the stability of the slurry is determined by 20 mm in a container made of a transparent acrylic pipe with an inner diameter of 80 mm.
Pour the slurry to a depth of cm, and check the consistency of the slurry over time (10 days, 45 days, 90 days after slurry preparation).
Evaluation was made by measuring The hardness of the slurry was measured by inserting a glass rod with a diameter of 10 mm into the slurry. The evaluation criteria are as follows. Evaluation condition ◎: The glass rod penetrates to the bottom of the container under its own weight (approximately 60 g). ○: When the glass rod is pushed by hand, it penetrates to the bottom of the container. △: Even if the glass rod is pushed by hand, it does not penetrate to the bottom of the container. ×: Even if the glass rod is pressed by hand, it does not penetrate at all. The evaluation results of slurry fluidity and stability are
It is shown in Table 3.

【table】

〔Effect of the invention〕

The solid fuel slurry composition of the present invention employs the above-mentioned specific sulfonated polymer as a dispersant and a nonionic surfactant as a slurry stabilizer, thereby reducing slurry viscosity compared to conventional techniques. Therefore, the slurry has good dispersibility and fluidity, has little foaming property, and is suitable for transportation by pipeline.

Claims (1)

[Claims] 1 (a) Weight average molecular weight obtained by (co)polymerizing a sulfonated product of dicyclopentadiene: 1000~
100,000 (co)polymer, (b) The number of added moles of alkylene oxide is 4 to 800, and the content of polyoxyethylene groups in the polyether chain is 20% by weight or more. Nonionic surfactant as a component, (c) solid fuel and (d)
Contains water and has a weight ratio of component (a)/component (b).
A solid fuel slurry composition characterized in that it has a composition of 95/5 to 55/45.