JPH0367557B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD OF THE INVENTION The present invention relates to solid fuel slurry compositions containing specific dispersants. Conventional technology Traditionally, an energy structure based on petroleum has been adopted, but due to the depletion of petroleum resources in recent years, coal,
Solid fuels such as petroleum coke and pituti are being rediscovered, and various ways to use them are 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, conventional methods for transporting these solid fuels include pulverizing the solid fuel and mixing it with water to form a water slurry composition, or adding a surfactant to such a water slurry composition to produce the solid fuel. Measures have been proposed to improve the dispersibility and stability of fluorophores in water. Problems to be Solved by the Invention However, in the former water slurry composition, when the solid fuel concentration is increased, the viscosity of the composition increases and the fluidity deteriorates, while when the concentration is decreased, the stabilization of the slurry is impaired. In addition, there are problems in that combustion efficiency is deteriorated. Furthermore, even in the latter water slurry composition containing a surfactant, the dispersibility and stability of the slurry over time have not yet reached a fully satisfactory level. The present invention was made against the background of these conventional technical problems, and by employing a specific new dispersant, it is possible to give a slurry higher fluidity than conventional dispersants, and it can also last for a long time. An object of the present invention is to provide a solid fuel slurry composition that can maintain high fluidity even after being left for a long time. Means for Solving the Problems That is, the present invention provides dicyclopentadiene and α, β
- Provides a solid fuel slurry composition characterized in that solid fuel is dispersed in water using a sulfonated addition copolymer with an unsaturated dicarboxylic anhydride as a dispersant. The dispersant used in the present invention is a sulfonated product (hereinafter sometimes referred to as "sulfonated product") of an addition copolymer of dicyclopentadiene and an α,β-unsaturated dicarboxylic acid anhydride. Here, examples of the α,β-unsaturated dicarboxylic acid anhydride include maleic anhydride, citraconic anhydride, itaconic anhydride, etc., but maleic anhydride is preferable from the viewpoint of reactivity, quality, economical efficiency, etc. It is. In the present invention, the sulfonated product used as a dispersant is usually produced by producing an addition copolymer from dicyclopentadiene and an α,β-unsaturated dicarboxylic acid anhydride and then sulfonating the product, but is not limited thereto. It can also be obtained by pre-sulfonating dicyclopentadiene and then addition copolymerizing it with an α,β-unsaturated dicarboxylic acid anhydride. The dispersant of the present invention is composed of a sulfonated addition copolymer of dicyclopentadiene and α,β-unsaturated dicarboxylic acid anhydride. It is also possible to copolymerize the monomers. Such other monomers include aliphatic, alicyclic, and aromatic hydrocarbons having olefinic double bonds, unsaturated amides, unsaturated alcohols, unsaturated ethyls, unsaturated nitriles, and unsaturated carboxylic acids. esters, unsaturated sulfonic acids and their esters, or aliphatic, alicyclic, aromatic alcohols or phenols, or alcohols or diols having amino groups, ester groups, nitrile groups, or sulfonic groups. Can be used in proportions. Specific examples of other monomers include styrene, butadiene, isoprene,
Methyl methacrylate, ethyl acrylate,
Mention may be made of butyl acrylate, acrylic acid, methacrylic acid, acrylonitrile, and the like. In this way, by copolymerizing other monomers and by changing the type of other monomers used, the surface active properties of the sulfonated product and the polymerization yield of the addition copolymer can be changed. , copolymerization ratio, degree of gelation, etc., and the slurry dispersibility of the resulting composition can be further improved. Further, by appropriately selecting the type and amount of other monomers to be copolymerized depending on the type of solid fuel used, a dispersant suitable for dispersing the solid fuel can be selected. The ratio of monomer components constituting such a sulfonated product is not particularly limited, but may be α,
0.5 to 1 mol of dicyclopentadiene, preferably 0.8 to 1.5 mol of dicyclopentadiene per mol of β-unsaturated dicarboxylic acid anhydride
mol, preferably in the range of 0 to 1 mol of other monomers.
At this time, if the content of α,β-unsaturated dicarboxylic acid anhydride is too low, it will gel and it will be difficult to obtain the desired addition copolymer, and if it is too high, it will be difficult to introduce the sulfone group. occurs, and the dispersibility of the solid fuel decreases. The molecular weight of the sulfonated product is not particularly limited as long as it functions as an aqueous dispersant, but the weight average molecular weight is usually 500 to 100,000, particularly preferably 2,000 to 20,000. If the molecular weight is too small, the dispersion performance will be insufficient, and if the molecular weight is too large, it will act as a flocculant, resulting in a decrease in the dispersion performance. Next, a specific example of a method for producing such a sulfonated product is as follows. That is, an addition copolymer is first obtained by radical copolymerization of dicyclopentadiene, α,β-unsaturated dicarboxylic acid anhydride, and other monomers added as necessary according to a conventional method. It will be done. This polymerization reaction is usually carried out using a radical initiator in the presence or absence of a solvent at a temperature of 40 to 100°C for 2 to 20 hours. At this time, care must be taken because gelled dicyclopentadiene tends to decompose as the polymerization temperature increases. Furthermore, the composition of the monomers used in the reaction is appropriately selected depending on the desired addition copolymer. The radical initiator used in the polymerization may be any one commonly used in the synthesis of polycarboxylic acid polymers, and specific examples thereof include benzoyl peroxide, t-butyl peroxybivalate, etc. Peroxide type initiators such as α,α′-azobisisobutyronitrile, azobis type initiators such as α,α′-azo-α-ethylbutyronitrile, redox type initiators, persulfates, peroxides, etc. Examples include hydrogen. Although it is not necessary to use a polymerization solvent, solvents such as cyclohexane, acetone, methyl ethyl ketone, dioxane, ethyl acetate, butyl acetate, and toluene can be used in order to prevent gelation of the polymer. The addition copolymer thus obtained is then neutralized in an aqueous alkaline solution such as sodium hydroxide, potassium hydroxide, aqueous ammonia, etc., where at least a portion of the acid anhydride groups form a salt. A salt of the copolymer is obtained. Specific examples of such salts include alkali metal salts such as sodium salts, potassium salts, ammonium salts, amine salts,
Examples include alkaline earth metal salts such as calcium salts and magnesium salts, but sodium salts and ammonium salts are usually preferred from the viewpoints of performance and economy. In addition, the degree of neutralization of the sulfone group and the acid anhydride group may be appropriately selected within the range that makes the polymer salt water-soluble or water-dispersible. may be formed. Subsequently, the salt of this addition copolymer is prepared by introducing a sulfonic group into the polymerization caused by dicyclopentadiene by reacting with a sulfonating agent, typically a bisulfite. An aqueous polymer salt is synthesized. As the sulfonating agent used in the reaction, bisulfites such as sodium, potassium, and ammonium salts of bisulfite are generally used, but in some cases, sulfites are prepared in the system using sulfite gas. , it can also be subjected to a reaction. In addition, during the reaction, it is preferable to use an oxidizing agent as a reaction accelerator. Specific examples thereof include peroxides such as potassium persulfate, nitrates such as potassium nitrate, sodium nitrate, and ammonium nitrate, hydrogen peroxide, oxygen, Examples include organic peroxides. The proportion of the sulfonating agent to be used in the reaction is appropriately selected depending on the target organism, but since the reaction generally proceeds quantitatively, it is sufficient to use a stoichiometric amount or a slight excess. That is, based on dicyclopentadiene, the amount is 0.5 to 2 mol, preferably 0.8 to 1.2 mol, per 1 mol of dicyclopentadiene. Also, during the reaction
It is appropriate to control the PH to 8 or less, preferably 7 to 5; if the PH value becomes too large, the reactivity will be inhibited, and if the PH value becomes too small, the solubility of the addition copolymer salt will be poor. It becomes like this. However, as long as the pH is within the above range, the reactivity proceeds rapidly, and the reaction conditions are usually a reaction temperature of room temperature to 130 degrees Celsius and a reaction time of about 1 to 24 hours. The content of sulfone groups in the sulfonated compound used as a dispersant in the present invention varies depending on the conditions of the sulfonation reaction, the amount of addition copolymer used for the reaction, etc. at least 20 of the dicyclopentadiene units present in
It is preferred that at least mol%, preferably at least 40 mol%, be sulfonated from the viewpoint of dispersibility of the resulting composition. The cation species of the sulfonate used in the present invention is not particularly limited, but in order to make it water-soluble, hydrogen atoms, alkali metals, alkaline earth metals, ammonium, amines, etc. are preferred. Examples of the alkali metal include sodium and potassium, and examples of the amine include alkylamines such as methylamine, ethylamine, propylamine, dimethylamine, diethylamine, triethylamine, butylamine, dibutylamine, and tributylamine, ethylenediamine, diethylenetriamine, triethylenetetramine, etc. Examples of alkaline earth metals include polyamines, morpholine, piperidine, etc., and calcium, magnesium, etc. as alkaline earth metals. These cationic species can also be interchanged with other cationic species by various ion exchange techniques. An aqueous solution of the aqueous polymer salt (sulfonated product) is thus prepared, but in the present invention, a solid aqueous polymer salt can be obtained by separating and drying the aqueous polymer salt from the aqueous solution, if necessary. can. The structure of the sulfonated product used as the dispersant of the present invention can be confirmed by infrared absorption spectrum by the absorption of carboxyl groups around 1420 and 1580 cm ¹ and the absorption of sulfonic acid groups around 1045 and 1200 cm ¹ . These composition ratios can be determined by acid/alkali titration such as potential difference and conductivity. Furthermore, the structure can be confirmed by the presence of dicyclopentane rings and the like in nuclear magnetic resonance spectroscopy. When using the sulfonated product obtained in this way as a dispersant of the present invention, the weight average molecular weight is usually is 500 to 100,000, preferably 2,000 to 20,000. If the weight average molecular weight of the sulfonated product is too low, the dispersion performance will be insufficient, while if it is too large, it will act as a flocculant, resulting in a decrease in the dispersion performance. Further, the sulfonated product of the present invention can be mutually exchanged into an acid form or a salt of an alkali metal, alkaline earth metal, ammonium, amine, etc. by an ion exchange method or a neutralization reaction. Next, the solid fuels used in the present invention are coal, petroleum coke, pitch and charcoal. The coal may be lignite, subbituminous coal, bituminous coal, anthracite, or any other coal, and there is no particular restriction on the coal. 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 made from coal containing non-materials. It is extremely difficult to get wet with water compared to . Pituchi is a heavy residue obtained by distilling tar obtained from petroleum distillation and coal dry distillation, 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 used as a slurry fuel with a high calorific value. The particle size of these solid fuels may be any particle size as long as it is powder, but since the pulverized coal currently burned in thermal power plants is 70% by weight or more for 200 mesh passes, this particle size is suitable. is a rough guideline. However, the dispersant used in the present invention is not affected by the particle size and type of solid fuel, and exhibits excellent effects on any solid fuel powder. The dispersant of the present invention is added to the solid fuel slurry at a concentration of 50 to 85% by weight, although it is not particularly limited, in combination with one or more surfactants, additives, etc., which will be described later as necessary. The larger the amount of dispersant added, the lower the viscosity of the slurry, so the amount added can be selected according to the desired viscosity, and the amount of dispersant added can be selected according to the desired viscosity.
Usually, it may be 0.01 to 10% by weight, but from the viewpoint of workability and economy, 0.05 to 1% by weight is preferable. Surfactants that may be used as needed in the slurry composition of the present invention include nonionic surfactants, anionic surfactants, and the like. Examples of nonionic surfactants include alkyl polyether alcohols, alkylaryl polyether alcohols, polyoxyethylene fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and polyalkylene oxide block copolymers. Commercially available products, such as those based on diethanolamines, diethanolamines, anhydrosorbitols, glycosides, gluconamides, glycerols, and glycidols, can be used as dispersants or particle wetting agents. Examples of the anionic surfactant include dodecylbenzene sulfonate, oleate, alkylbenzene sulfonate, dialkyl sulfosuccinate, lignin sulfonate, alcohol ethoxysulfate, secondary alkanesulfonate, and α-olefin sulfonate. , tamol, 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 can be used as dispersants or wetting agents. 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 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 made and then the dispersant is added, or the solid fuel, water, and dispersant are added to a mill and the Any method can be used, such as mixing the fuel while pulverizing it. Effect 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. This results in reduced viscosity and stable dispersion of the composition. Examples Hereinafter, the present invention will be explained in more detail with reference to Examples. Note that % in the examples is based on weight. Reference Example 1 First, 200 g of ethyl acetate was charged into a three-necked flask (1) equipped with a stirrer and a thermometer, and then 132 g of dicyclopentadiene, 98 g of maleic anhydride (molar ratio 1:1), and 3 g of benzoyl peroxide were added. was added, and the mixture was sealed and reacted at a temperature of 70 to 78° C. for 8 hours while mixing under strong stirring. Then, after cooling to room temperature, the reaction mixture was taken out and added to toluene in step 3 and mixed thoroughly.
A polymer was precipitated. After separating this polymer by filtration, it was thoroughly washed with toluene and thoroughly dried.
135 g of copolymer was obtained. The weight average molecular weight of this copolymer was 4100, and the composition molar ratio of dicyclopentadiene and maleic anhydride was 1:
0.74, and the iodine value was 65. Next, 250 ml of 1N sodium hydroxide was charged into a stainless steel autoclave equipped with a stirring device and a thermometer, and 50 g of the copolymer was added to this.
Dissolve and then add 35% sodium bisulfite aqueous solution
59 g and 1 g of potassium nitrate were added, and the mixture was reacted at 90° C. for 6 hours. The PH before the reaction and after the reaction are respectively
It was 6.0 and 7.2. The surface tension of the 4% aqueous solution of the sulfonate thus obtained is 69.9dyne/
cm, which had significantly increased from 57.3 dyne/cm before the reaction. In addition, the weight average molecular weight of this substance is
It was 5380. This sulfonated product is referred to as Reference Example 1 and is shown in Table 1. Reference Examples 2 to 5 According to Reference Example 1, by appropriately changing the charging molar ratio, amount of benzoyl peroxide, reaction temperature and reaction time in the polymerization reaction, an addition copolymer having the properties shown in Table 1 was obtained, This product was sulfonated in the same manner as in Reference Example 1. The results are shown in Table 1.

[Table] Examples 1 to 5, Comparative Examples 1 to 3 Coal produced in Austria and containing 76% 200 mesh coal, 6.5% ash, and 1.6% sulfur was used. Add the dispersant listed in Table 2 (0.5% based on coal) into water, gradually add a predetermined amount of coal particles into the water, and mix at 3000 rpm with a homomixer.
A coal slurry with a concentration of 70% was prepared by stirring for 15 minutes. The viscosity of the coal slurry thus obtained was also measured at 25°C. The results are shown in Table 2. After that, the slurry was left to stand and its viscosity was measured over time to check its stability. It can be seen from Table 2 that the coal slurry composition of the present invention is excellent.

[Table] Examples 6 to 10, Comparative Examples 4 to 6 Contains 70% of 200 mesh pass, ash content of 0.65%,
Petroleum coke containing 0.30% sulfur was used. A dispersant listed in Table 3 was added to water in advance, and a predetermined amount of petroleum coke was gradually added thereto, followed by stirring at 3000 rpm for 15 minutes using a homomixer to prepare a petroleum coke water slurry. The petroleum coke concentration was 70%, and the amount of dispersant added was constant at 0.5% of the petroleum coke. The viscosity of the slurry thus obtained was measured at 25°C and the results are shown in Table 3. In addition, after the slurry was left for 30 days, the slurry viscosity was also measured.
We investigated its stability. It can be seen from Table 3 that the petroleum coke water slurry composition of the present invention is superior.

【table】

[Table] Examples 11 to 15, Comparative Examples 7 to 9 Pitch slurry was prepared in the same manner as in Example 6, except that 73% of 200 mesh pass obtained by dry-pulverizing petroleum pitch with a softening point of 120°C in a mill was used as the solid fuel. was manufactured. The results are shown in Table 4.

[Table] Effects of the Invention By selecting the specific dispersant as described above, the solid fuel slurry composition of the present invention can reduce the slurry viscosity compared to the conventional technology,
Therefore, the slurry has good viscosity dispersibility and fluidity, has little foaming property, and is suitable for transportation by pipeline.

Claims (1)

[Claims] 1. A solid fuel slurry composition characterized in that solid fuel is dispersed in water using a sulfonated addition copolymer of dicyclopentadiene and α,β-unsaturated dicarboxylic acid anhydride as a dispersant.