JPH06346071A - Emulsion fuel - Google Patents

Abstract

PURPOSE:To obtain an emulsion fuel containing an oil recovered from edible oil and fat, having excellent storage stability and giving a clean fuel. CONSTITUTION:This emulsion fuel contains (A) a mixture composed of 60-90-wt.% of a mixture of a petroleum-based fluid fuel and an oil recovered from edible oil and fat and 10-40wt.% of water and (B) 0.1-5.0wt.% (based on the component A) of a surfactant. The weight ratio of the oil mixture to water in the component A is preferably 70:30 to 85:15 and the compounding ratio of the petroleum-based fluid fuel to the recovered oil of the edible oil and fat is preferably 20:80 to 80:20.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to emulsion fuels. More specifically, it relates to an emulsion composition comprising a petroleum-based fluid fuel, water, a surfactant, and an edible oil / fat recovery oil, which provides a clean fuel with excellent storage stability.

[0002]

2. Description of the Related Art In recent years,
With increasing interest in the global environment, the cleanliness of combustion exhaust gas is increasing as a social demand. Under such circumstances, emulsification of petroleum-based fluid fuels such as light oil, kerosene, and heavy oil, as in JP-A-59-129291, JP-A-59-129292, and JP-A-4-234492, has been studied. There is. However, these emulsion fuels are unsatisfactory in that they require a large amount of expensive activator or stability. On the other hand, due to the problem of environmental pollution, among the edible oils that are said to be used several million tons annually all over the country, waste oil from fast food and confectionery makers has come to be recovered as recovered oil. It is expected that the recovery rate will further improve in the future. However, the effective use development of this recovered oil has not been made, and the effective use development of the resource is desired.

[0003]

Therefore, as a result of earnest studies, the inventors of the present invention have found that a clean oil containing, as a main component, a petroleum-based fluid fuel and an edible oil / fat recovery oil that is desired to be effectively used due to resource environmental problems. Emulsion fuel was developed.

That is, the present invention relates to a water-based emulsion fuel of petroleum-based fluid, which contains recovered oil of edible oil / fat, and more specifically, (a) a mixture of petroleum-based fluid fuel and recovered oil of edible oil / fat. Emulsion fuel (oil-in-water type) containing 60 to 90% by weight of oil and 10 to 40% by weight of water, and (b) 0.1 to 5.0% by weight of surfactant relative to the mixture. Is.

[0005] This composition is a fuel with extremely excellent stability, which does not cause separation or decomposition of the emulsion even after long-term storage due to the blending effect of the edible oil / fat recovered oil. We have found that it is a clean fuel that can greatly reduce soot and nitrogen oxides.

Although the mechanism for imparting long-term stability in the present invention is not always clear, it is presumed as follows.

An emulsion in which one of two kinds of liquids which do not dissolve in each other is finely dispersed in the other is thermodynamically because the free energy of the interface increases as the interfacial area of the two liquids increases. It is an unstable non-equilibrium system, the dispersion state changes with time, and the emulsion state tends toward elimination. It is common to use a surfactant for the purpose of reducing the free energy of the interface and improving the stability of the system, but no matter how good a surfactant is used, the free energy of the interface is not zero. It is difficult to obtain a truly stable emulsion.

Therefore, the inventors of the present invention focused on the interface between water and petroleum-based fluid fuel, and when the edible oil / fat recovery oil was added, the fatty acid molecules in the edible oil / fat recovery oil were preferentially oriented to the interface phase, and water and petroleum were recovered. It is estimated that the interfacial free energy of the system fluid fuel is reduced and the stability of the system is enhanced.

Further, the effect of reducing the concentration of soot and nitrogen oxides in the exhaust gas in the present invention is estimated as follows.

Emulsion fuel contains several tens of percent of water. This water is suddenly heated in the combustion furnace and bumps to boil off the oil existing in the vicinity. This phenomenon is called secondary atomization of oil droplets due to steam explosion. In a direct fuel injection type combustor such as a boiler or a heating furnace, oil droplets sprayed from a burner are secondary atomized by steam explosion during combustion. Due to the effect of secondary atomization due to the steam explosion and the effect of the existence of water itself, the combustion form of oil droplets changes greatly. That is, the atomization improves the contactability / mixability with oxygen, and the promotion of the water-gas reaction improves the combustibility, thereby significantly reducing the generation of soot and dust. In addition, the reduction of flame temperature due to the latent heat of vaporization of water and the short-time passage of fine particles in the high temperature region can significantly reduce thermal NO _x . The secondary atomization due to the steam explosion occurs when the emulsion fuel is burned alone, but it does not occur when the petroleum-based fluid fuel is burned alone. However, when emulsion fuel and petroleum-based fluid fuel are mixed and burned, the secondary atomization effect due to steam explosion occurs in both emulsion fuel and petroleum-based fluid fuel,
It is estimated that the reduction of soot and nitrogen oxides works synergistically.

The petroleum-based fluid fuel in the present invention may be any fluid fuel obtained by refining crude oil and has fluidity at ordinary temperature. Examples include gasoline, kerosene, light oil and heavy oil, or a mixture thereof.

The edible oil / fat recovery oil in the present invention is a used edible oil / fat recovery oil such as soybean oil, rapeseed oil, corn oil, etc., which is wasted in large amounts from fast foods, confectionery makers, and general households, and has odor and color. It has not been used effectively until now. The acid value of edible oil is generally 1 or less, but the recovered oil shows a large value of 1 to 30 due to the progress of rancidity. Regarding other physical properties, the saponification value is 50 to 250,
The iodine value shows a value of about 10 to 150 and may change slightly compared to before use. The fatty acids that make up these fats and oils are various, but they contain a large amount of C ₁₈ (C represents carbon), and the other constituent fatty acids include C ₁₂ , C ₁₄ , C ₁₆ , C ₂₀ , C ₂₂ ,
For example, C ₂₄ .

In the present invention, the weight ratio of the mixed oil of the petroleum-based fluid fuel of the emulsion fuel and the edible oil / fat recovered oil to water is
It is 60:40 to 90:10, preferably 70:30 to 85:15. When the proportion of the mixed oil is too low, the calorific value is lowered, and in some cases direct combustion becomes difficult. On the other hand, if the proportion of the mixed oil is too high, the viscosity of the emulsion increases and the fluidity decreases, and the particles coalesce or agglomerate during storage, and the storage stability decreases.

The blending ratio of the petroleum fluid fuel and the edible oil / fat recovery oil is 5:95 to 95: 5, preferably 20:80, in view of flammability.
~ 80: 20. When the amount of the petroleum-based fluid fuel is large, the amount of fuel NO _x and dust caused by the petroleum-based fluid fuel increases. Also,
If the amount of recovered oil is large, the burnout property will be improved, but the thermal NO _x due to the rise in flame temperature will increase.

As the surfactant in the present invention, one or more selected from nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants are used. Examples of the surfactant that can be used include the following.

<Nonionic Surfactant> (i) An alkylene oxide adduct of a compound having a phenolic hydroxyl group such as phenol, cresol, butylphenol, nonylphenol, dinonylphenol, dodecylphenol, paracumylphenol and bisphenol A. (Ii) An alkylene oxide adduct of a formalin condensate of a compound having a phenolic hydroxyl group such as alkylphenol, phenol, metacresol, styrenated phenol, and benzylated phenol. The average degree of condensation is 1.2-
100, preferably 2-20. (Iii) An alkylene oxide adduct of a monohydric aliphatic alcohol having 2 to 50 carbon atoms. (Iv) An alkylene oxide adduct of a monovalent aliphatic amine having 2 to 50 carbon atoms. (V) A block or random addition polymer of alkylene oxide. (Vi) Alkylene oxide adduct of polyhydric alcohol. (Vii) An alkylene oxide adduct of an ester of a polyhydric alcohol and a fatty acid having 8 to 18 carbon atoms. (viii) An alkylene oxide adduct of a polyvalent amine having a plurality of active hydrogens such as ethylenediamine, tetraethylenediamine, polyethyleneimine (molecular weight 600 to 10,000). (Ix) A product obtained by adding an alkylene oxide to a mixture of 1 mol of a triglyceride type oil and fat and 0.1 to 5 mol of a polyhydric alcohol and / or water (x) an alkoxypolyoxyalkylene fatty acid ester.

Examples of the polyhydric alcohols (vi) and (vii) include glycerin, trimethylolpropane, pentaerythritol, sorbitol, sucrose, polyglycerin, ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol and the like. It is illustrated.

<Anionic Surfactant> (I) A formalin condensate of sulfonic acid or sulfonate of an aromatic ring compound such as naphthalene, alkylnaphthalene, alkylphenol and alkylbenzene. Preferably, the average degree of condensation of formalin is 1.2 to 100.

(II) Lignin sulfonic acid, lignin sulfonate, derivatives thereof, formalin condensates of lignin sulfonic acid and sulfonic acids of aromatic compounds such as naphthalene and alkylnaphthalene, and salts thereof. Preferably, the average degree of condensation of formalin is 1.2 to 50.

(III) Polystyrene sulfonic acid or a salt thereof, a copolymer of styrene sulfonic acid and another copolymerizable monomer, and a salt thereof. Preferably the molecular weight is between 500 and 500,000.

(IV) Dicyclopentadienesulfonic acid polymer or a salt thereof. Preferably, the molecular weight of the polymer is from 500 to
It is 500,000.

(V) A copolymer of maleic anhydride or / and itaconic anhydride with another copolymerizable monomer, and an acid or salt thereof. Preferably the molecular weight is between 500 and 500,000.

(VI) Maleates of liquid polybutadiene and salts thereof. Preferably, the liquid polybutadiene has a molecular weight of 500,000 to 200,000.

(VII) The following anionic surfactant having one or two hydrophilic groups in the molecule. (a) Sulfate ester salt of an alcohol having 4 to 18 carbon atoms. (b) Alkane, alkene or / and alkylaryl sulfonic acid having 4 to 18 carbon atoms or a salt thereof. (c) Sulfates or phosphates of alkylene oxide adducts of compounds having one or more active hydrogens in the molecule, and salts thereof. (d) A sulfosuccinate which is an ester of a saturated or unsaturated fatty acid having 4 to 22 carbon atoms. (e) Alkyl diphenyl ether disulfonic acid or a salt thereof. The alkyl group is an alkyl group having 8 to 18 carbon atoms. (f) Rosin acid or a salt thereof. Tall oil mixed acid which is a mixed acid of rosin acid and higher fatty acid and its salt. (g) Alkane or alkene fatty acid having 4 to 18 carbon atoms and salts thereof. (h) An α-sulfo fatty acid ester salt represented by the following general formula.

[0025]

[Chemical 1]

However, R ₁ is an alkyl group or alkenyl group having 6 to 22 carbon atoms, R ₂ is an alkyl group having 1 to 22 carbon atoms, and M is 1
A divalent or divalent metal atom, NH ₄ , an organic amine, and n represents 1 or 2.

Regarding the compounds (I) to (VII), as salts, lower amines such as ammonium, monoethanolamine, diethanolamine, triethanolamine and triethylamine, alkali metals such as sodium, potassium, magnesium and calcium or alkalis. It is an earth metal.

<Cationic Surfactant and Amphoteric Surfactant> (I) An alkyl or / and alkenylamine salt obtained by neutralizing an alkyl or / and alkenylamine having 4 to 18 carbon atoms with an inorganic acid or an organic acid.

(II) A quaternary ammonium salt represented by the following formulas (1) to (3).

[0030]

[Chemical 2]

[0031]

[Chemical 3]

[0032]

[Chemical 4]

(III) An alkyl betaine represented by the following formula.

[0034]

[Chemical 5]

(IV) An alkylamine oxide represented by the following formula.

[0036]

[Chemical 6]

(V) An alkylalanine represented by the following formula.

[0038]

[Chemical 7]

(VI) A polyamate represented by the following formula (4) or (5).

[0040]

[Chemical 8]

(VII) A polyamine salt represented by the following formula (6) or (7).

RNHC ₃ H ₆ NHX '(6) RNH (C ₃ H ₆ NH) ₂ X' (7) (wherein R has the same meaning as described above, X'is an inorganic acid or an organic acid. (VIII) An imidazoline type amphoteric surfactant represented by the following formula.

[0043]

[Chemical 9]

(IX) A sulfobetaine-type amphoteric surfactant represented by the following formula.

[0045]

[Chemical 10]

The amount of the surfactant used is in the range of 0.1 to 5% by weight based on the mixture of the mixed oil and water, preferably
It is 0.1 to 1% by weight. If the amount used is less than this range, the emulsification of the mixed oil and the development of emulsion stability are insufficient, and if the amount used is more than this range not only is uneconomical, but also foaming during emulsification and particle size control are difficult, which is not preferable.

The blending amount of water in the emulsion fuel of the present invention is important, and it is preferable to increase or decrease it depending on the ratio of the petroleum fluid fuel in the mixed oil. In other words, if the amount of the petroleum-based fluid fuel is large, it may be adjusted to be slightly large, and if it is small, it may be adjusted to be slightly small.

In the present invention, a polyhydric alcohol and / or a polymer stabilizer may be compounded, if necessary, for the purpose of further improving the stability. Any polyhydric alcohol may be used as long as it has two or more hydroxyl groups in the molecule and is soluble in water. For example, glycerin, polyglycerin, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, oligosaccharides, sorbitol, glucose. And monosaccharides and polysaccharides. The amount of polyhydric alcohol is based on the mixture of oil and water
0.1 to 50% by weight. As the polymer stabilizer, various water-soluble polymers having a molecular weight of 10,000 or more shown in Table 1 can be blended, and the blending amount is 0.005 to 3 with respect to the mixture of the mixed oil and water.
% By weight.

[0049]

[Table 1]

In the method of blending the edible oil / fat recovered oil according to the present invention, the petroleum fluid fuel and the edible oil / fat recovered oil may be mixed or heated before the emulsion is produced, or may be added during the emulsion production.

The emulsion containing the edible oil / fat recovery oil is
Since the pH may be acidic, it is possible to add an alkaline component for neutralization. As the neutralizing agent, an alkali metal hydroxide, ammonia or amine is suitable, and the neutralizing agent may be dissolved in water before the emulsion is produced, or may be added at the time of producing the emulsion.
The amount of the neutralizing agent added is preferably such that the finished emulsion is neutral or weakly acidic to weakly alkaline.

The addition of the neutralizing agent partially saponifies the fatty acids in the recovered edible oil / fat to produce soap. This soap component acts as a surfactant and has the effect of further improving the stability of the emulsion.

[0053]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

Example 1 The following materials were used as raw materials for the production of emulsion fuel.・ C heavy oil; specific gravity 0.945, flash point 150 ℃, nitrogen content 0.21wt
%, Residual carbon content 9.0 wt% -water; ion-exchanged water-nonionic surfactant; polyoxyethylene nonyl phenyl ether, Kao Corporation Emulgen 921-anionic surfactant; naphthalene sulfonic acid formaldehyde condensate, Kao Mighty 150 Co., Ltd. ・ Oil and fat recovery oil; C ₁₈ = 81%, C ₁₆ = 10%, C ₁₄ = 2
%, Other = 7% Acid value = 5.7 Saponification value = 193.1 Iodine value = 111.8 ・ Polymer stabilizer; carboxymethyl cellulose, Daicel Chemical Industries CMC1190 ・ Neutralizer; Potassium hydroxide, Wako Pure Chemical Industries ( Co., Ltd. reagent.

The above raw materials were weighed as shown in Table 2 and heated to 50 ° C., and then the recovered edible oil / fat was dissolved in C heavy oil, and the polymer stabilizer and the neutralizer were dissolved in water. After that, while maintaining the temperature at 50 ° C, TK homomixer manufactured by Tokushu Kika Kogyo Co., Ltd. (with low viscosity stirring blade)
An emulsion was produced by using the above, the rotation speed of the stirring blade was 8000 rpm, and the stirring time was 3 minutes. After standing for 24 hours at 20 ° C. after production, the average particle size, viscosity and storage stability of the emulsion were measured.

The measuring method is as follows. Average particle size: Measured by a laser diffraction / scattering particle size distribution measuring device (LA700, manufactured by Horiba Ltd.) to obtain a median size. Viscosity: Using a B-type viscometer (model BM) manufactured by Tokyo Keiki Seisakusho, using rotor No. 3, the value was measured 1 minute after the start of rotation at 60 rpm. Stability: Using a sedimentation test tube (100 cc), the state after 1 month of standing was observed, and the presence or absence of water separation was evaluated by 3 ranks (yes, little, no).

[0057]

[Table 2]

[0058]

[Table 3]

From the stability measurement results shown in Table 3, in Experiment Nos. 1 and 2 in which the C heavy oil and the edible oil / fat recovered oil were each emulsified alone as a comparative example, water was separated on the emulsion surface after 1 month of stable standing. Can be said to be an emulsion with poor stability. On the other hand, in the systems of Experiment Nos. 3 to 8 of the present invention in which the C heavy oil and the edible oil / fat recovered oil were mixed, or in which the polymer stabilizer and / or the neutralizing agent were further mixed, the stationary stability was extremely good. Therefore, it can be said that the emulsion fuel has excellent stability without water separation after one month.

Example 2 Emulsion Nos. 3 to 8 prepared in Example 1, the same raw materials,
With the same compounding ratio, each 4000 kg of emulsion is manufactured,
A combustion test was carried out. Emulsion production was carried out by heating C heavy oil, water, surfactant, edible oil / fat recovery oil, polymer stabilizer, and neutralizer to a 5 m ³ reaction tank (tank diameter 1.9 m) after heating each to 50 ° C. The mixture was stirred for 60 minutes while maintaining 50 ° C. The stirring blade type is a Fadler blade, the blade diameter is 1.1 m, and the rotation speed is 64 rpm. PL-SL manufactured by Tokushu Kika Kogyo Co., Ltd.
It emulsified by the batch circulation system using the mold line mixer. The rotation speed of the mixer is 3600 rpm and the emulsification time is 4
It was time. After the emulsification is complete, cool to 20 ° C over 10 hours,
The emulsion was used for a combustion test. For the combustion test, a horizontal cylindrical double-wall water-cooled experimental furnace (1.2 mφ x 3.4 ml, manufactured by Nippon Furnace Industries Co., Ltd.) was used, and the amount of dust in the exhaust gas (JIS Z
-8808) and the amount of nitrogen oxides (JIS K-0104) were measured. The results are shown in Table 4. The combustion conditions are as follows. Burner; Internal mixing type (manufactured by Japan Furnace Industry Co., Ltd.) Atomized steam; Temperature = 170 ° C, flow rate = 60 liters / hr, pressure = 4.3 kg / cm ² emulsion fuel; Temperature = 50 ° C, flow rate = 150 liters /
hr, pressure = 3.8 kg / cm ² air amount; 1230 m ³ / hr As comparative examples, combustion tests of non-emulsified C heavy oil and edible oil / fat recovered oil were conducted under the same conditions.

[0061]

[Table 4]

From the results of the combustion test in Table 4, it was found that the non-emulsified C heavy oil and edible oil / fat recovered oil of Comparative Example were:
While the amount of dust and the amount of nitrogen oxides are both high, the heavy fuel oil C and the edible oil / fat recovery oil which are emulsion fuels of the present invention, or a polymer stabilizer and / or a neutralizer were further added.
In Nos. 3 to 8, both nitrogen oxides are significantly reduced compared to combustion of C heavy oil that is not emulsified and edible oil / fat recovered oil.
It can be said that it is a clean emulsion fuel.

Claims (2)

[Claims] 1. A water-emulsion fuel for petroleum-based fluids, which contains edible oil / fat recovery oil. 2. A mixture comprising (a) a mixed oil of petroleum-based fluid fuel and edible oil / fat recovered oil (60 to 90% by weight) and water (10 to 40% by weight); and (b) 0.1 to 5.0% by weight based on the mixture. Emulsion fuel (oil-in-water type) containing a surfactant.