JPH11236581A - Fuel oil additive and fuel oil composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fuel oil additive which, when added to a low-sulfur fuel oil having a specified sulfur content, gives a fuel oil compsn. excellent in lubricity, separation of water, and resistance to emulsification by incorporating a monounsatd. monocarboxylic acid and a diunsatd. monocarboxylic acid in a specified wt. ratio, these acids having each a specified number of carbon atoms, into the same. SOLUTION: This additive contains a 12-22C monounsatd. monocarboxylic acid (pref. oleic acid) and a 12-22C diunsatd. monocarboxylic acid (pref. linolic acid) in a wt. ratio of (40/60)-(90/10), pref. (45/55)-(80/20), still pref. (50/50) (70/30). Pref., the sum of the amts. of these acids accounts for 50 wt.% or higher of the additive. The additive is added to a low-sulfur fuel oil having a sulfur content of 0. 2 mass % or lower, in an amt. of the additive of 20-500 ppm based on the fuel oil. If necessary, a pour-point depressant (e.g. an ethylene-vinyl acetate copolymer) is incorporated into the additive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an additive and a fuel oil composition having excellent lubricating properties, water separation properties and demulsifying properties. In particular, the present invention relates to a fuel oil additive and a fuel oil composition which are excellent in lubricity and excellent in water separation even in a low sulfur fuel oil.

[0002]

2. Description of the Related Art In the late 1960's when hydrogen treatment was introduced as a refining process for kerosene-type jet fuel oil, a problem occurred due to corrosion wear of a fuel injection pump of a jet engine due to lubricity of jet fuel. As a countermeasure, the addition of a corrosion inhibitor such as a fatty acid or a fatty acid ester was effective and employed. However, at present, measures are taken to change the pump material, and the addition of a corrosion inhibitor has been stopped. Similarly, in diesel fuel oil, glycerin or glycol is used to prevent rust.
The addition of the above partial ester with a fatty acid in combination with the fatty acid constituting the ester is disclosed in US Pat.
7,889. In addition, in order to reduce the fuel consumption of diesel engines and reduce the emission of air pollutants, it is common to add a combination of a linear carboxylic acid ester of neopentyl glycol and a linear carboxylic acid having a molecular weight of 125 to 200 in the United States. Patent 4,920,
No. 691.

[0003] In recent years, with respect to diesel fuel, along with stricter exhaust gas regulations for preserving the global environment, reduction of the sulfur content in diesel fuel oil has been promoted. The reduction in the sulfur content of diesel fuel oil has been realized by reducing sulfur-containing aromatic components such as benzothiophene by hydrogen treatment, as in the case of kerosene-type jet fuel. The sulfur-containing aromatic component contributes to the lubricity of the diesel fuel oil, and the diesel fuel oil containing a small amount of the sulfur-containing aromatic component has a reduced lubricity. For this reason, the lubricating property decreases as the sulfur content decreases, and engine troubles due to wear of the fuel injection pump occur. As a countermeasure, a diesel fuel oil to which the same fatty acid ester as that used for the kerosene-type jet fuel is added has been studied.

[0004]

However, conventional additives, such as fatty acid esters, added to improve the lubricity of the fuel injection pump are insufficient in lubricity and deteriorate water separation properties, and are satisfactory. In some cases, diesel fuel oil with a low sulfur content cannot be obtained.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on this problem, and as a result, have found that a specific proportion of carbon atoms of 12 to 24 carbon atoms is present.
By adding a monounsaturated carboxylic acid of 12 and a diunsaturated carboxylic acid having 12 to 22 carbon atoms to obtain a sulfur content of 0.2
It has been found that a low-sulfurized fuel oil having a mass percentage of not more than 10% by mass also has excellent lubricity and at the same time has excellent water separation properties.

That is, the present invention comprises a monounsaturated monocarboxylic acid having 12 to 22 carbon atoms (A) and a diunsaturated monocarboxylic acid having 12 to 22 carbon atoms (B), wherein (A) / (B)
Is a low-sulfurized fuel oil additive having a weight ratio of 40/60 to 90/10 and a sulfur content of 0.2% by mass or less.

[0007]

DETAILED DESCRIPTION OF THE INVENTION Specific examples of the monounsaturated monocarboxylic acid (A) having 12 to 22 carbon atoms include lindelic acid, lauroleic acid, tuzuic acid, fisetreic acid, myristoleic acid, zomaric acid, petroselinic acid, Oleic acid, elaidic acid, vaccenic acid, gadrenic acid, erucic acid, brassic acid and the like can be mentioned. (A) is preferably C14-20, particularly preferably oleic acid. If the carbon number is less than 12 or more than 22, the solubility in diesel fuel oil may be insufficient, or the lubricity improving ability may be insufficient.

The diunsaturated monocarboxylic acids having 12 to 22 carbon atoms (B) include 9,12-tetradecadienoic acid,
9,12-hexadecadienoic acid, linoleic acid, linoelaidic acid and the like. (B) is preferably C14-20, particularly preferably linoleic acid.

[0009] These fatty acids are obtained by refining natural oils such as coconut oil, palm oil, peanut oil, soybean oil, olive oil, castor oil, sunflower oil, rice bran oil, rapeseed oil, tallow oil, whale oil and the like. The ratio of (A) to (B) can be freely changed by using a fatty acid alone or in combination. The mass ratio between (A) and (B) is 40/60 to 90/10
, Preferably 45/55 to 80/20, more preferably 50/50 to 70/30. If the mass ratio of (A) and (B) is out of the range of 40/60 to 90/10, the lubricating properties are insufficient, and the oxidation stability is undesirably deteriorated. The total content of (A) and (B) in the additive is
It is usually at least 50%, preferably at least 60%, more preferably at least 70%. In addition, fatty acids other than (A) and (B) can be added, and the amount of addition is usually 0 to 20%, preferably 0 to 10%, and more preferably 0 to 5%.
Specific examples of fatty acids other than (A) and (B) include lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid,
Palmitic acid, margaric acid, stearic acid, isostearic acid, nonadecanoic acid, arachinic acid, behenic acid, linolenic acid and the like can be mentioned.

In the additive of the present invention, it is preferable to further add a pour point depressant (C) from the viewpoint of handling. Specific examples of (C) include ethylene-vinyl carboxylate copolymer, polyalkyl methacrylate, and alkenyl succinamide, and are preferably ethylene-vinyl carboxylate copolymer. Ethylene-
Specific examples of the vinyl carboxylate component of the vinyl carboxylate copolymer include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl neononanoate, vinyl behenate, and the like. The number average molecular weight of the ethylene-vinyl carboxylate copolymer is usually 500 to 20,000, preferably 1,000 to 10,000, more preferably 2,000 to 5,000.
000. The vinyl carboxylate content of the ethylene-vinyl carboxylate copolymer is usually 10 to 70% by mass, preferably 20 to 60% by mass, and more preferably 30 to 55% by mass.
% By mass. As a specific example of the polyalkyl methacrylate, the number of carbon atoms of the alkyl group is usually 8 to 22, preferably 10 to 20, more preferably 12 to 18, and the number average molecular weight is usually 500 to 20,000, preferably 1,000. Up to 10,000, more preferably 20
00 to 5000. As a specific example of the alkenyl succinamide, the alkenyl group usually has 8 to 22 carbon atoms, preferably 10 to 20, more preferably 12 to 1 carbon atoms.
8 The amount of (C) added to the total mass of (A) and (B) is usually 0.1 to 15% by mass, preferably 0.2 to 10% by mass, more preferably 0.3 to 8% by mass. is there. . The content of (C) in the additive is usually 0.1 to
It is 10% by weight, preferably 0.2 to 8% by weight, more preferably 0.3 to 6% by weight.

Specific examples of the low sulfur fuel oil having a sulfur content of 0.2% by weight or less in the present invention include JIS No. 1 obtained by ordinary distillation of low sulfur crude oil (for example, southern crude oil such as Minas crude oil). Light oil, JIS No. 2 light oil, JIS No. 3 light oil, JIS special No. 3 light oil; Desulfurized light oil produced from a normal crude oil through a hydrodesulfurization treatment step; This desulfurized light oil and a straight run gas oil (light oil before the hydrodesulfurization step) JIS No. 1 gas oil, JIS No. 2 gas oil, JIS No. 3 gas oil, and JIS special No. 3 gas oil produced from the gas oil fraction obtained by blending.
Particularly preferably, JIS1 manufactured using 50% by weight or more of desulfurized gas oil manufactured through a hydrodesulfurization treatment step is used.
No. light oil, JIS No. 2 light oil, JIS No. 3 light oil, JIS special 3
No. light oil.

The amount of the additive to be added to the low-sulfurized fuel oil of 0.2% by weight or less is 20 to 500 ppm, preferably 30 to 200 ppm, more preferably 40 to 150 ppm.
pm. If it is less than 20 ppm, the lubricity is insufficient, and if it exceeds 500 ppm, the addition efficiency becomes poor and the economic efficiency is impaired.

The fuel oil of the present invention may contain other known additives. These known additives include detergents (for example, ethylene oxide adduct of dibutylamine, ethylene oxide adduct of butanol), rust preventives (for example, alkenyl succinic acid-based rust inhibitor, alkenyl succinic acid ester-based inhibitor). Rust agents), antioxidants and the like.

[0014]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

The water separation property and the demulsifying property of the fuel oil composition can be evaluated by the water solubility test method of JIS K 2276 "Aero fuel oil test method". JIS K22
As described in 76, take 80 ml of the sample and 20 ml of the buffer solution in a 100 ml measuring cylinder with a stopper, shake under the prescribed conditions, and display the change in the volume of the buffer solution after standing, the state of the interface, and the separation state. 1. Evaluation was performed according to Table 2.

[0016]

[Table 1]

[0017]

[Table 2]

The lubricity of diesel fuel oil can be measured by a conventional frictional and wear evaluation table test method, for example, a test using a Falex block-on-ring friction and wear tester, BOCL
Test using E tester (ASTM D5001), SR
HFRR developed to test lubrication of diesel fuel oil using a V tester (manufactured by Optimol, Germany)
It can be evaluated by tests and the like. In particular, the HFRR test (UK P
Since the evaluation by CS Instruments Co., Ltd.) has a high correlation with the actual fuel pump wear, the evaluation was performed using this tester.

Oxidation stability test of diesel fuel oil is based on IS
The test can be performed using an OT tester, and the presence or absence of engine deposits in a real vehicle was relatively evaluated according to Table 3.

[0020]

[Table 3]

The pour point of the additive was measured according to JIS K 2269 "Testing methods for pour point of crude oil and petroleum products and cloud point of petroleum products".

Table 4 shows the composition ratios of the additives (S1 to 12) used in the examples and the additives (R1, R2) used in the comparative examples. The numerical values in Table 4 indicate mass% of the additive.

[0023]

[Table 4] O: oleic acid, L: linoleic acid, Z: zomaric acid, G: gadoleic acid LE: linoleic acid, E: ethylene-vinyl acetate copolymer having a number average molecular weight of 3,600 and a vinyl acetate content of 38% by weight, P: number Polyalkyl methacrylate having an average molecular weight of 4000 and an alkyl group having 18 carbon atoms

Examples 1 to 4 The pour points of S9 to S12 obtained in Table 4 were measured. Table 5 shows the results. Examples 5 to 22 S1 to S12 obtained in Table 4 were added to a diesel fuel oil equivalent to JIS No. 3 having a sulfur content of 0.04% by weight by 30 to 10%.
0 ppm was dissolved to prepare fuel oils of Examples 5 to 22. All of the obtained fuel oils were transparent, and no blemishes were observed. About 15 kinds of fuel oil, temperature 60 ° C,
An HFRR wear test was performed under the conditions of a stroke length of 1 mm, a frequency of 50 Hz, and a time of 75 minutes, and the friction coefficient and the size of a wear mark were measured. Further, the obtained fuel oil was evaluated for water separation property and demulsification property according to the water solubility test method described in JIS K 2776. Further, an ISOT test (110 ° C., 700 rpm, 8 hours) was performed to measure oxidation stability. In addition, a blank test using only diesel fuel oil without any addition was also performed. Table 5 shows the evaluation results.

Comparative Examples 1-2 Pour points of R1 and R2 obtained in Table 4 were measured in the same manner as in the examples. Table 5 shows the results. Comparative Examples 3 and 4 Each of R1 and R2 obtained in Table 4 was dissolved at a concentration of 100 ppm in the same manner as in the examples to prepare fuel oils of Comparative Examples 3 and 4, and a wear test by the HFRR method and JIS K
Water separation was evaluated by a water solubility test according to 2776. Further, an ISOT test (110 ° C., 700 rpm, 8
Time) and the oxidation stability was measured. Table 6 shows the results.

As is clear from Table 5, the diesel fuel composition of the present invention has a low coefficient of friction and a small wear mark, and exhibits a high wear resistance at a very low addition amount as compared with a blank containing no oil. At the same time, it is found that they have excellent water separation properties, demulsification properties, and oxidation stability.

[0027]

[Table 5]

[0028]

[Table 6]

[0029]

Industrial Applicability The fuel oil composition of the present invention has excellent lubricating properties as well as excellent water separation properties and demulsifying properties. Due to environmental problems such as acid rain, regulations such as reduction of sulfur will be strengthened in the future. However, even if it is used in the same manner as the conventional diesel fuel, engine trouble due to wear of the fuel injection pump of the diesel engine can be prevented.

Claims (6)

[Claims] 1. A monounsaturated monocarboxylic acid having 12 to 22 carbon atoms (A) and a diunsaturated monocarboxylic acid having 12 to 22 carbon atoms (B), wherein the weight ratio of (A) / (B) is 40 /
An additive for a low-sulfurized fuel oil having a sulfur content of 0.2% by mass or less, which is 60 to 90/10. 2. The additive according to claim 1, wherein (A) is oleic acid. 3. The additive according to claim 1, wherein (B) is linoleic acid. 4. The additive according to claim 1, further comprising a pour point depressant (C). 5. The additive according to claim 4, wherein the content of (C) is 0.1 to 15% by mass based on the total weight of (A) and (B). 6. A fuel oil composition comprising the additive according to claim 1, and a low sulfur fuel oil having a sulfur content of 0.2% by mass or less.