JP7327789B2 - Dispersant for emulsion fuel - Google Patents

Description

The present invention relates to dispersants for emulsion fuels.

Low-viscosity oil such as heavy oil is difficult to use as a fuel due to its low fluidity. Therefore, in order to promote fluidization, emulsion fuels are known in which water and oil are mixed to increase fluidity. On the other hand, as a matter of course, oil and water do not mix and have the property of being separated immediately. Therefore, in order to use it as fuel, it is essential to emulsify oil and water.

Conventionally, as means for emulsifying oil and water, emulsification mainly by organic dispersants (for example, Patent Document 1), emulsification by inorganic dispersants (for example, Patent Document 2), and emulsification by physical stirring etc., have been proposed. Organic dispersants, such as sulfates of long-chain hydrocarbon groups, are widely used as emulsifiers. Alkali metal salts and the like are used as inorganic dispersants. For emulsification by physical stirring, mechanical stirring using a mixer, stirring using ultrasonic waves, or the like is used.

However, since organic dispersants are expensive, there is a problem that they are not suitable for emulsification of a large amount of water and oil. Inorganic dispersants are inexpensive, but have the problem of low stability between emulsified water and oil, resulting in separation in a short period of time. Furthermore, physical agitation has the problem of requiring large equipment for processing large amounts of water and oil.

JP 2016-180075 A Japanese Patent Publication No. 2007-520573

Therefore, it is an object of the present invention to provide a highly stable dispersant for emulsion fuel without requiring any special equipment and without causing an increase in price.

In order to solve the above problems, an emulsified fuel dispersant of one embodiment is a dispersant for emulsified fuel that is added to a mixture of fuel oil and water to promote emulsification of the fuel oil and the water. be. The dispersant comprises an aqueous solution containing an alkali metal hydroxide, an alkali metal inorganic salt and an alkaline earth metal inorganic salt , and an organic nonionic surfactant. The dispersant is added in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the mixture.

Thus, the dispersant of one embodiment comprises an aqueous solution containing an inorganic alkali metal hydroxide, an alkali metal inorganic salt , and an alkaline earth metal inorganic salt , and an organic nonionic surfactant. contains. Thus, one embodiment of the dispersant comprising inorganic and organic surfactants exhibits high emulsion stability due to the interaction of both. In addition, since the dispersant of one embodiment contains inorganic and organic surfactants, it does not require a special device for physical emulsification, and the cost can be reduced.

In addition, the dispersant according to one embodiment may further include an affinity improver added to prevent solidification of the organic surfactant and increase the affinity between the inorganic aqueous solution and the surfactant.
This affinity improver prevents solidification of organic surfactants having a melting point near room temperature. Thus, by adding the affinity improver, the separation of the organic surfactant and the inorganic aqueous solution is avoided. Therefore, uniform mixing of the organic surfactant and the inorganic aqueous solution can be promoted, and the emulsification stability of the emulsion can be further improved.

Schematic showing the composition of a dispersant according to one embodiment Schematic diagram showing verification results by examples and comparative examples using a dispersant according to one embodiment

Embodiments of dispersants for emulsion fuels are described in detail below.
(dispersant)
A dispersant for an emulsion fuel according to one embodiment includes an aqueous solution containing an alkali metal hydroxide and an alkali metal salt (hereinafter referred to as "alkali aqueous solution") and an organic surfactant. The aqueous alkaline solution is prepared by dissolving a total of 0.01 to 10 parts by weight of alkali metal hydroxide and alkali metal salt as solutes in 100 parts by weight of water as a solvent. Purified water such as ion-exchanged water is used as the solvent water. The alkali metal hydroxide is preferably sodium hydroxide. Moreover, as the alkali metal salt, it is preferable to use one or more selected from magnesium chloride, calcium chloride, and sodium chloride.

A nonionic surfactant is preferably used as the surfactant. As the nonionic surfactant, a surfactant having a chain oxyethylene group is more preferable. In particular, the surfactant is more preferably polyoxyethylene-lauryl ether or polyoxyethylene-octylphenyl ether. In this case, the surfactant more preferably satisfies n=2 to 14, where n is the number of repeating oxyethylene groups. By setting it as such a surfactant, the hydrophilicity of the oxyethylene group can be appropriately ensured.

The amount of surfactant to be added is preferably set to 0.1 to 100 parts by weight based on 100 parts by weight of water used in the alkaline aqueous solution. If the amount of surfactant added is less than 0.1 parts by weight per 100 parts by weight of water, a sufficient effect of emulsifying water and oil in the emulsion fuel cannot be obtained. On the other hand, if the amount of surfactant added is 100 parts by weight or more with respect to 100 parts by weight of water, the emulsion fuel will gel and the fluidity will decrease. From the above, it is preferable to set the amount of the surfactant to be added to 0.1 to 100 parts by weight with respect to 100 parts by weight of the water used in the alkaline aqueous solution.

An affinity improver may be added to the dispersant. The affinity improver prevents solidification of the organic surfactant and improves the affinity between the inorganic alkaline aqueous solution and the surfactant. An organic surfactant has a melting point near room temperature. Therefore, the surfactant tends to solidify near room temperature, and when mixed with an alkaline aqueous solution, the dispersibility of the surfactant decreases or the surfactant separates. Therefore, by adding an affinity improver, the surfactant melts in the affinity improver even at around room temperature, thereby avoiding a decrease in dispersibility and separation from the alkaline aqueous solution. The affinity improver increases the solubility of the surfactant without impairing the emulsifying function of the dispersant. Affinity improvers are substances, such as alcohols or ketones, which are soluble in both water and oil and can dissolve surfactants. In one embodiment, isopropyl alcohol is used as the affinity enhancer. Thus, the affinity improver promotes uniform mixing of the organic surfactant and the inorganic alkaline aqueous solution even at around room temperature.

(Preparation of dispersant)
An example of preparation of a dispersant according to one embodiment will now be described. As dispersants, "dispersant 1" to "dispersant 6" were prepared as shown in FIG. "Dispersant 1" to "Dispersant 6" all contain deionized water, which is water, and isopropyl alcohol as an affinity improver. "Dispersant 1", "Dispersant 2", "Dispersant 5" and "Dispersant 6" are sodium hydroxide as alkali metal hydroxide and magnesium chloride hexahydrate as alkali metal salt. Contains calcium chloride dihydrate and sodium chloride. "Dispersant 3" and "Dispersant 4" do not contain alkali metal salt hydroxides and alkali metal salts.

"Dispersant 1" and "Dispersant 3" contain polyoxyethylene-lauryl ether as a nonionic surfactant. Here, Nonion K-204 manufactured by NOF Corporation is used. "Dispersant 2" and "Dispersant 4" contain polyoxyethylene-octylphenyl ether as a nonionic surfactant. "Dispersant 5" contains 2-ethylhexyl-sulfate sodium salt as an anionic surfactant. "Dispersant 6" contains tetradecylamine acetate as a cationic surfactant.

These "dispersant 1" to "dispersant 6" are water, ion-exchanged water, a predetermined amount of alkali metal hydroxide, alkali metal salt, and a surfactant dissolved in an affinity improver. Mixed using a stirrer. The stirring conditions were set at 38° C. and 200 rpm for 15 minutes.

(Example)
Next, using the prepared "dispersant 1" to "dispersant 6", the emulsifying power of water and oil was verified.
"Example 1" used "dispersant 1". "Example 2" used "dispersant 2". Furthermore, in "Comparative Example 1" to "Comparative Example 4", "Dispersant 3" to "Dispersant 6" were used, respectively. For verification of the emulsifying power, a sample of heavy oil A and ion-exchanged water at a ratio of 70:30 was used. To 100 parts by weight of this sample, 5 parts by weight of "dispersant 1" to "dispersant 6" were added to verify the emulsifying power. The sample to which the dispersant was added was stirred at high speed for 30 seconds using a homogenizer, then allowed to stand for 72 hours, and the state of separation between water and oil was confirmed. In FIG. 2, "⊚" indicates a state in which water and oil are extremely uniformly dispersed. In addition, "○" indicates a state in which water and oil are almost uniformly dispersed, "△" indicates a state in which water and oil are partially separated, and "×" indicates a state in which water and oil are completely separated. indicates

As is clear from FIG. 2, both "Example 1" using "dispersant 1" and "Example 2" using "dispersant 2" showed high uniformity even after 72 hours had passed. remained sexual. That is, in contrast to "Comparative Example 1" and "Comparative Example 2" in which a nonionic surfactant is simply added, "Dispersant 1" and "Dispersant 1" in which a nonionic surfactant is added to an alkaline aqueous solution It can be seen that Dispersant 2" has high emulsifying power and emulsification stability. In addition, in the comparison between "Example 1" and "Example 2" and "Comparative Example 3" and "Comparative Example 4", even when an alkaline aqueous solution is added, a nonionic surfactant "Dispersant 1 ” and “Dispersant 2” are superior in emulsifying power and emulsification stability than when an anionic or cationic surfactant is used.

As described above, a dispersant according to an embodiment containing an inorganic alkaline aqueous solution and an organic anionic surfactant exhibits high emulsification stability due to the mutual interaction between the two. In addition, the dispersant of one embodiment does not require special equipment for physical emulsification, and can reduce costs.
Additionally, the dispersant according to one embodiment includes isopropyl alcohol as an affinity enhancer. This isopropyl alcohol prevents the solidification of organic surfactants that have a melting point near room temperature. Therefore, uniform mixing of the organic surfactant and the inorganic aqueous solution can be promoted, and the emulsification stability of the emulsion can be further improved.

The present invention described above is not limited to the above-described embodiments, and can be applied to various embodiments without departing from the gist of the present invention.
In the above embodiment, an example in which the dispersant is used as an emulsifier for mixed fuel of water and oil has been described. However, the dispersant according to one embodiment is not limited to the emulsification of mixed fuels, and can also be applied to the treatment of oils, such as oil floating on water.

Claims (4)

A dispersant for emulsion fuel added to a mixture of fuel oil and water to facilitate emulsification of the fuel oil and the water,
an aqueous solution containing an alkali metal hydroxide and an alkali metal inorganic salt and an alkaline earth metal inorganic salt ;
and an organic nonionic surfactant,
A dispersant for emulsion fuel, which is added in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the mixture. The alkali metal hydroxide, the alkali metal inorganic salt , and the alkaline earth metal inorganic salt contained in the aqueous solution are 0.01 to 0.01 in total when the water constituting the aqueous solution is 100 parts by weight. The dispersant for emulsion fuel according to claim 1, which is 10 parts by weight. 1. The surfactant is polyoxyethylene-lauryl ether or polyoxyethylene-octylphenyl ether, wherein n=2 to 14, where n is the number of repeating oxyethylene groups. Or dispersant for emulsion fuels according to 2 above. 4. The emulsion fuel according to any one of claims 1 to 3, further comprising an affinity improver added to prevent coagulation of the surfactant and increase the affinity between the aqueous solution and the surfactant. Dispersant.

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