JPH0317187A - Fuel additive and fuel composition - Google Patents

Abstract

PURPOSE:To obtain a fuel additive, composed of a solution prepared by dissolving acetylacetonate of a rare earth element in an organic solvent and having high promoting effects on combustion rate without settling and separating solid substances even in storage for a long period. CONSTITUTION:The objective additive composed of a solution prepared by dissolving acetylacetonate of one or more rare earth elements preferably selected from cerium, neodymium and lanthanum in an organic solvent, such as naphtha, kerosene, hexane, cyclohexane or toluene, so as to normally provide a concentration within the range of 1-5wt.% expressed in terms of the rare earth element. Furthermore, the acetylacetonate of the rare earth elements is obtained by simultaneously adding acetylacetone and the organic solvent to a salt of a rare earth element, e.g. hydroxide or carbonate, stirring and reacting both at 60-140 deg.C temperature.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to fuels, particularly heavy oil, coal slurry or carbon
The present invention relates to a fuel additive added as a combustion accelerator for heavy fuels such as OM, and a fuel composition containing the same.

[Prior art] Heavy fuels such as heavy oil, coal slurry, and COM contain a large amount of residual coal and have a slow ignition speed, making it difficult to achieve stable combustion and producing a large amount of unburned carbon, i.e., soot. Occur. Therefore, in order to completely burn this, it is necessary to have a high excess air ratio, resulting in low combustion efficiency.

For this reason, attempts have been made to add combustion promoters to these fuel oils so that the generation of soot and the like can be suppressed even when burned at low excess air rates. Examples of this combustion accelerator include those obtained by adsorbing naphthenic acid, etc. on fine particles of hydroxides and oxides of di- to tetravalent metals (Japanese Patent Laid-Open No. 61-15279
4), and an iron oxide in which 80% or more of the particle size is lμ or less (Japanese Patent Application Laid-Open No. 106992/1982). However, since the above-mentioned fuel additives are solids, they do not mix well with fuel oil, and if it takes a long time from addition to use, the additives will settle out. There are problems such as the effect is low unless it is used in a relatively large amount, the addition work etc. is complicated, and the efficiency of the dust collector is adversely affected.

On the other hand, it has been proposed that a basic oil-soluble cerium soap with a ratio of acid equivalent to the number of cerium atoms of 3 or less is useful as a combustion additive (Japanese Patent Laid-Open No. 1290-1290
No. 7 and Japanese Unexamined Patent Publication No. 61-225282).

However, the organic solvent solution containing this rare earth soap is
Since the viscosity is high, a method of adding glycol, alcohol, aldehyde, ketone or ether has been used (Japanese Patent Laid-Open No. 12907/1983). Although this additive has the effect of lowering the viscosity of rare earth soaps, there is a problem in that when this type of soap-containing solution is stored for a long period of time, it becomes micelles and a portion of the soap settles and separates.

[Problem to be Solved by the Invention] As a result of intensive research to solve the above problem, the present inventor found that when rare earth element acetylacetonate is used instead of rare earth soap, sedimentation separation occurs during storage. Furthermore, the viscosity of the solution can be lowered during the manufacturing process without adding additives such as glycols, alcohols, aldehydes, ketones, or ethers as mentioned above, and the effect of accelerating the burning rate is similar to that of rare earth soaps. I found that there was no difference at all. The present invention has been made based on this knowledge, and an object of the present invention is to provide a fuel additive that does not cause solid matter to be separated even when stored for a long period of time and has a high effect of accelerating the combustion rate. An object of the present invention is to provide a fuel composition comprising the following.

[Means for Solving the Problems] The present invention provides a fuel additive comprising a solution of rare earth element acetylacetonate dissolved in an organic solvent, and a fuel composition comprising the rare earth element acetylacetonate added thereto.

The rare earth elements include cerium, neodymium, lanthanum, braceodymium, samarium, promethium, eurobium, gadolinium, terbium, disbrosium,
Examples include elements such as holmium, erbium, thulium, ytterbium, and lutetium, among which cerium, neodymium, and lanthanum are particularly preferred.

These rare earth elements may be used alone, but it is particularly preferable to use a combination of two or more of cerium, neodymium, and lanthanum because the combustion promoting effect can be significantly improved. In particular, cerium, neodymium or lanthanum acetylacetonate has an elemental ratio of 3:7 to 3:7 to 3:7.
When used in the range of 7:3, the synergistic effect of both can be significantly enhanced.

Acetylacetonate of the rare earth element is prepared by adding acetylacetone and an organic solvent to the salt of the rare earth element, such as hydroxide or carbonate, at a temperature of 60 to 140°C.
It can be obtained by stirring and reacting. In addition, when producing acetylacetonate consisting of two or more rare earth elements, salts of each individual rare earth element may be mixed and used, but if the salts before separation into each element are combined It is particularly preferable to use a so-called mixed rare earth or concentrated rare earth, etc., because it is inexpensive.

The additive of the present invention is in the form of a solution dissolved in an organic solvent, and the organic solvent in this case may include aliphatic, cycloaliphatic, aromatic hydrocarbons, or mixtures thereof, such as naphtha, Petroleum ether, white spirit, mineral turbine, kerosene, light oil, hexane, hebutane, octane, nonane, decane, dodecane, tetradecane, cyclohexane, cyclohebutane, cyclohexane, cyclooctane, cyclohexene, benzene, toluene, xylene, ethylbenzene, etc. Any conventional organic solvent can be used. Particularly preferred are those with a high flash point from the viewpoint of handling, and those rich in aromatics from the viewpoint of solubility.

In addition, it is preferable for the concentration of acetylacetonate of the rare earth element to be dissolved in the organic solvent to be as high as possible for handling reasons, but the solubility varies depending on the type of organic solvent and the type of rare earth element, so take this solubility into consideration. Select as appropriate. Generally, it is preferable to prepare the organic solvent so that the concentration of the rare earth element is in the range of 1 to 5% by weight. In general, if it is less than 1% by weight, the amount added to the fuel will be large, making transportation and addition work complicated, and if it is more than 5% by weight, it may not be completely dissolved depending on the solvent, which is not very preferable.

In addition, the amount of acetylacetonate of these rare earth elements added to the fuel oil is 10 to 100 as the rare earth element.
It is selected in a timely manner within the range of 0 ppm. If the amount is less than 10 ppm, the effect of addition will not be noticeable, and if it is added more than 1000 ppm, the effect of improving the combustion rate will not be seen compared to the amount added, which is not economical and not very preferable.

The present invention as described above will be specifically explained in the following examples.

Brace Example 1 97 g of cerium hydroxide with a cerium concentration of 36.8% by weight
146 g of acetylacetone and 130 g of xylene were placed in a container, stirred at a temperature of 80°C for 30 minutes, and then heated to 140°C.
The reaction was carried out under reflux conditions at a temperature of 4 hours. After the reaction, the aqueous layer was separated and removed by standing, and 1 xylene was added to the organic layer.
70 g of the organic layer was added, and 1.2 times the amount of 70° C. warm water was added to the organic layer and washed with stirring to obtain an acetylacetonate solution having a cerium concentration of 1.06% by weight.

This solution was centrifuged at a rotational speed of 4000 rpm for 30 minutes, and the solid content was measured. As a result, the solid content was 0.
It was 1% by weight or less. Further, this solution was allowed to stand at room temperature, and after 3 and 27 days, it was centrifuged at a rotation speed of 4000 rpm to measure the solid content. As a result, the solid content was found to be 0.1% by weight or less after 3 days and 0.2% by weight after 27 days. Comparative Example 2,780 g of 5.0% by weight sodium hydroxide was added to 500 g of 2-ethylhexylic acid, and the mixture was heated and stirred at about 75° C. for 30 minutes to obtain an aqueous solution of sodium 2-ethylhexylate. To this sodium 2-edylhexylate aqueous solution, 2780 g of a cerium carbonate aqueous solution with a concentration of 5.0% by weight as cerium, 168 g of n-hexanol, and 236 g of light oil were added.
5m°C was added at the same time, a double decomposition reaction was carried out at a temperature of 75°C for 30 minutes with stirring, and the organic layer was separated by standing. 1.2 times the amount of 75°C warm water was added to this organic layer and washed with stirring to obtain a cerium 2-ethylhexylate soap solution.

This solution was centrifuged at a rotational speed of 300 rpm for 20 minutes, and the solid content was measured. As a result, the solid content was 0.1% by weight or less. Further, this solution was left at room temperature, and after 3 days and 27 days, the solution was centrifuged at a rotation speed of 3000 rpm for 20 minutes to measure the solid content. As a result, after 3 days, 0. Solids content was 3% by weight and 1.6% by weight after 27 days.

2-5, Reference 1-2, 2 Preparation of cerium acetylacetonate obtained in Example 1 and various rare earth element acetylacetonates having the compositions in Table 1 in which cerium was replaced with a mixed rare earth element in Example 1. These were mixed with C heavy oil (specific gravity O, 9580, pour point 12.5°C, residual carbon content 9.08% by weight, sulfur content 1.44
25pp as the total amount of rare earth elements in each
m, and the burning rate of the carbonaceous solid was measured.

The burning rate was determined using a differential thermal balance (Shimadzu WAECC-30).
), while flowing air through the combustion section at a flow rate of 30+nj2/min, at a heating rate of 85°C/min to 400-60°C.
The temperature was raised to 0°C and maintained at that temperature until the end of combustion, the DTA curve was measured, and the combustion part of the carbonaceous solid in the latter stage of combustion was calculated using the following Shibata et al. formula [Shibata et al., Japan Society of Mechanical Engineers paper Collection, 34260, p769 (April 1969)] σm dt σ m2In the above formula, σnicarbon particle specific surface area rf/Kgm: carbon weight Kg te: half-life time of carbon particle amount (sea ), σ is 175X10” d/kg, and m 1 / m
The time when 2=2, that is, the half-life time (s
e c) was determined from the differential thermal curve, and the burning rate was calculated from this. The results are shown in Table 1. In addition, as a reference example, the same measurement was performed when 2-ethylhexylic acid soap containing a rare earth element was added (the amount added was 25 ppm as the total amount of rare earth elements), and as a comparative example, when no rare earth element compound was added. The results are also listed in Table 1.

As is clear from the results shown in the margins below, the rare earth element acetylacetonate of the present invention has no inferiority to rare earth soap in terms of combustion rate, and is stable and does not cause solid matter to settle and separate even after long-term storage. It turns out that it is an additive.

[Effects of the Invention] The organic solvent solution containing rare earth acetylacetonate of the present invention has an extremely high effect of accelerating the combustion rate when used as a fuel additive, and moreover, it remains solid even after long-term storage. Since it does not cause sedimentation and separation and is highly stable, it is useful as a fuel additive, especially as a combustion promoter for heavy fuels.

Claims (1)

[Claims] 1. A fuel additive consisting of a solution of rare earth element acetylacetonate dissolved in an organic solvent. 2. The fuel additive according to claim 1, wherein the rare earth element is a mixture containing two or more of cerium, neodymium, or lanthanum. 3. A fuel composition containing a rare earth element acetylacetonate.