JPH111692A - Fuel oil composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the lubricity of a low-sulfur middle distillate oil capable of meeting environmental regulations and obtain a fuel oil compsn. which reduces the abrasion of a fuel oil luibricating part of a diesel engine by incorporating a fatty acid mixture contg. specific unsaid. fatty acids into a middle distillate oil having specified sulfur content and arom. content. SOLUTION: A fuel oil compsn. is prepd. by incorporating 0.001-0.5 wt.% (based on ingredient A described below) 8-30C fatty acid mixture (B) contg. at least 75 wt.% unsatd. fatty acid mixture comprising an unsatd. fatty acid (B1 ) having a double bond in the molecule and an unsatd. fatty acid (B2 ) having two double bonds in the molecule in a wt. ratio (B1 :B2 ) of (1:3)-(15:1) into a middle distillate oil (A) having a sulfur content of 0.2 wt.% or lower and an arom. content of 40 wt. % or lower. When this compsn. contains a low-temp. flowability improver usually added to a fuel oil. the lubricity of this compsn. can be improved without hindering the effect of the improver.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel oil composition having improved lubricity of a low-sulfur fuel oil, and more particularly to a fuel oil composition exhibiting excellent lubricity for a fuel oil lubricated portion of a diesel engine. It is.

[0002]

2. Description of the Related Art In a diesel engine, a system for injecting high-pressure fuel oil by a fuel injection pump is used. Therefore, an anti-wear agent for reducing wear of the injection pump has been conventionally used. For example, U.S. Pat. Nos. 2,252,889, 4,185,594, and 420,819.
As disclosed in US Patent Nos. 0 and 42044481, antiwear agents comprising fatty acid esters, unsaturated dimerized fatty acids, aliphatic amides of primary aliphatic amines or diethanolamine have been used. Was. Also, as disclosed in U.S. Pat. No. 4,248,182, anti-wear agents included in aliphatic monocarboxylic acids have been used for diesel alternative fuel oils.

[0003] However, with the recent increase in truck transportation, the sulfur content or aromatic content in light oil has had a great effect on the environment. In areas such as California and Sweden, the pollutants (SOx, NO
x, dust and smoke), which significantly limits the content of sulfur and aromatics in gas oils, which is involved in the emission of gas oil.

[0004] For example, since 1985, the United States of America has passed a law restricting the allowable sulfur content in gas oil to 0.05% by weight or less, and since 1993 the aromatic content has been reduced to 10% by weight or less. Has been added to the law. Since the same year, 0.05% by weight of sulfur in the US
The following legislation successively restricts the aromatics content to 35% by weight or less.

[0005] In Japan, a report of the Central Pollution Control Council in December 1989 reported that NOx
In the short term (1993-1994), a reduction of 20-35% by weight and in the long term (within 10 years) a reduction of 40-60% by weight are required. In order to introduce a new technology for reducing NOx, it is necessary to reduce the sulfur content. Therefore, the sulfur content in light oil was reduced to 0.2% by weight in 1992,
It has been decided to gradually reduce it to 0.05% by weight with a target of seven years.

[0006] Reduction of sulfur and aromatics in gas oil is generally carried out by catalytic hydrotreating in petroleum refining. However, the reduction of the sulfur content and the aromatic content in light oil leads to a decrease in lubricating properties of light oil, thereby causing a problem such as damage to parts such as a pump and a nozzle of an injection device of a diesel engine.

To date, for light oils having a sulfur content of at least 0.2% by weight and an aromatics content of at least 40% by weight, the problems relating to lubricity have been solved by using the aforementioned antiwear agents. However, when the sulfur content in gas oil is 0.2% by weight or less and the aromatic content is 40% by weight or less, injection pumps (especially rotary pumps and injector nozzles, governor sleeves) can be used even if an anti-wear agent is used. Engine troubles such as wear and seizure, black smoke, instability of idle rotation, engine stall, etc. occurred.

[0008] Such a phenomenon largely depends on the design of the engine, the shape and the material of the parts to be lubricated, and attempts have been made to improve the lubricating agent for low sulfur gas oil. As a lubricating agent for low sulfur gas oil,
European Patent No. 605857, JP-A-7-6
JP-A-2363, JP-T-8-505893 and JP-A-8-283753 disclose ester compounds and ether compounds, but these compounds are still insufficient for low-sulfur gas oil having poor lubricity. Effects have not been obtained.

[0009]

SUMMARY OF THE INVENTION In order to solve this problem, the present invention improves the lubricity of a low-sulfur middle distillate complying with environmental regulations and reduces wear of a fuel oil lubricated portion of a diesel engine. And a fuel oil composition.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, a low-sulfur, low-aromatic middle distillate corresponding to environmental regulations has been specified. It has been found that lubricating properties can be improved by adding a fatty acid mixture containing unsaturated fatty acids of the composition, and the present invention has been completed. That is, the present invention relates to an intermediate distillate (A component) containing 0.2% by weight or less of sulfur and 40% by weight or less of aromatic component, and unsaturated fatty acid (a) having one double bond in the molecule. And an unsaturated fatty acid (b) having two double bonds in the molecule in a weight ratio [(a) :( b)] of 1: 3 to
Fuel oil containing a fatty acid mixture having 8 to 30 carbon atoms (component B) containing 75% by weight or more of unsaturated fatty acids containing 15: 1 at a ratio of 0.001 to 0.5% by weight based on the middle distillate oil. A composition.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The fuel oil used in the present invention is a low-sulfur middle distillate refined by extreme hydrogenation in order to comply with sulfur regulations. Here, the middle distillate is the middle distillate in the distillation of petroleum, gasoline, kerosene,
Light oil and heavy oil are mentioned, and usually the boiling point range is 130 to 40.
0 ° C., preferably light oil (boiling point 180-380
° C). The middle distillate used in the present invention has a sulfur content of 0.2% by weight or less, preferably 0.12% by weight or less, particularly preferably 0.05% by weight or less, and further has an aromatics content. 40% by weight or less, preferably 35% by weight or less in aromatic content and 20% by weight or less in the middle distillate, more preferably 30% by weight or less in the middle distillate oil And at least 10% by weight of the middle distillate in the middle distillate, especially light oil.

Such a specific middle distillate is usually mixed with a straight-run gas oil, a direct desulfurized gas oil, an indirect desulfurized gas oil, a cracked gas oil, a desulfurized light gas oil, a desulfurized kerosene, etc. The one adjusted to the content and the aromatic content is used.

The fatty acid mixture having 8 to 30 carbon atoms used in the present invention contains 75% by weight or more, preferably 85% by weight or more of unsaturated fatty acids. Examples of the unsaturated fatty acid include unsaturated fatty acids having one double bond in the molecule, unsaturated fatty acids having two or more double bonds in the molecule, and preferably have 12 to 24 carbon atoms, more preferably Those having 16 to 22 carbon atoms are exemplified.

Further, the unsaturated fatty acid contained in the fatty acid mixture used in the present invention includes an unsaturated fatty acid having one double bond in the molecule (a) and an unsaturated fatty acid having two double bonds in the molecule ( b) as an essential fatty acid, and the mixing ratio of each unsaturated fatty acid [(a) :( b)] is 1: 3 to 15: 1 by weight, preferably 1: 2 to
A mixture within a certain range comprising a ratio of 7: 1, more preferably a ratio of 2: 3 to 2: 1. Further, the total amount of the unsaturated fatty acid (a) and the unsaturated fatty acid (b) contained in the unsaturated fatty acid is usually 75% by weight or more, preferably 85% by weight or more.

The unsaturated fatty acid (a) having one double bond in the molecule includes caproleic acid, undecylenic acid, myristoleic acid, palmitoleic acid, oleic acid, petroselinic acid, elaidic acid, vaccenic acid, gadolinic acid, Gondoic acid, erucic acid, brassic acid, seracoleic acid, and the like. As unsaturated fatty acids (b) having two double bonds in the molecule, sorbic acid,
Linoleic acid and the like, and unsaturated fatty acids having three or more double bonds include eleostearic acid, linolenic acid, arachidonic acid, succinic acid, nisinic acid and the like. Further, in addition to those exemplified above, unsaturated fatty acids such as ricinoleic acid and camlorenic acid having a hydroxyl group in the molecule are exemplified as the above unsaturated fatty acids.

[0016] Of these unsaturated fatty acids, one in the molecule
The case where the unsaturated fatty acid having two double bonds is oleic acid, and the case where the unsaturated fatty acid having two double bonds in the molecule is linoleic acid is particularly preferable from the viewpoint of raw material supply and cost. Other fatty acids contained in the fatty acid mixture include linear saturated fatty acids and branched fatty acids.
Straight chain saturated fatty acids include caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, myristic acid,
Palmitic acid, stearic acid, arachinic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, melicic acid and the like. Examples of the branched fatty acid include 2-ethylhexanoic acid, isononanoic acid, isotridecanoic acid, isopalmitic acid, and isostearic acid.

The fatty acid mixture used in the present invention can be prepared by mixing the above-mentioned fatty acids, or the above-mentioned fatty acids can be added to the fatty acids derived from natural fats and oils or to the purified fatty acids subjected to fractionation and hydrogenation. Can also be prepared by mixing. As fatty acids derived from natural fats and oils, coconut oil fatty acids, palm oil fatty acids, palm kernel oil fatty acids, tallow fatty acids,
Hardened tallow fatty acid, rapeseed oil fatty acid, corn oil fatty acid, olive oil fatty acid, sesame oil fatty acid, soy oil fatty acid,
Sunflower oil fatty acids, castor oil fatty acids, linseed oil fatty acids,
Examples include fish oil fatty acids, hardened fish oil fatty acids, and tall oil fatty acids.

[0018] The amount of the fatty acid mixture used in the fuel oil composition of the present invention is 0.1 to 0.1 with respect to the above-mentioned specific middle distillate.
001 to 0.5% by weight, preferably 0.002 to 0.1%
%, More preferably 0.004 to 0.02% by weight. When the addition amount exceeds 0.5% by weight, the effect of addition reaches a saturated state, and the lubricating effect sufficient for the addition amount cannot be obtained. In addition, the addition amount is 0.0
When the amount is less than 01% by weight, a sufficient lubricating effect cannot be obtained.

In the present invention, even if the fatty acid mixture is added alone, the lubricating properties of the middle distillate complying with environmental regulations can be improved. For use in cold seasons or cold regions, a low-temperature fluidity improver is usually added, but the fuel oil composition of the present invention improves lubricity without disturbing the effect of the low-temperature fluidity improver. Can be done. The fatty acid mixture of the present invention and the low-temperature fluidity improver can be contained in any ratio, but the weight ratio of the fatty acid mixture to the low-temperature fluidity improver is preferably 1:10 to 5: 1.

Examples of such a low-temperature fluidity improver include those known per se, such as a copolymer of ethylene and a saturated vinyl carboxylate, a copolymer of ethylene and methyl methacrylate, and a copolymer of ethylene and an α-olefin. Copolymer,
Graft modified product of ethylene and α-olefin copolymer, chlorinated ethylene-vinyl acetate copolymer, terpolymer of ethylene and vinyl acetate and neononanoic acid or vinyl naodecanate, alkyl ester polymer of unsaturated carboxylic acid Esters and partial esters or salts thereof synthesized from a hydroxyl-containing nitrogen-containing compound and a saturated or unsaturated fatty acid, esters synthesized from an alkylene oxide adduct of a hydroxyl-containing nitrogen-containing compound and a saturated or unsaturated fatty acid, and Partial esters (for example, behenic acid diester of 3 moles of ethylene oxide adduct of triethanolamine), esters and partial esters synthesized from polyhydric alcohols and saturated or unsaturated fatty acids, and saturated or unsaturated with polyoxyalkylene glycol Esters synthesized from fatty acid, polyhydric alcohol esters synthesized from alkyleneoxide adducts with saturated or unsaturated fatty acids and partial esters, imides and unsaturated polycarboxylic acids and primary amines /
Polymers containing an amidate as a monomer unit, amide compounds and alkylene oxide adducts thereof (such as ethylenediamine behenic diamide propylene oxide 3 mol adduct), phosphoric acid or phosphorous acid and esters of these alkylene oxide adducts (eg, Behenic acid triester of 3 moles of ethylene oxide adduct of phosphorous acid, alkenylsuccinic acid derivative (eg, amide / amide salt of cocoalkylamine of tetrapropenyl succinic acid) and chlorinated paraffin / naphthalene condensate (eg, chlorinated) Paraffin (20 to 2 carbon atoms)
8) and a Friedel-Crafts reaction product of naphthalene). These low temperature fluidity improvers are
Species can be used alone or in combination of two or more.

Among these additives, esters and partial esters synthesized from a hydroxyl group-containing nitrogen-containing compound and an alkylene oxide adduct and a saturated or unsaturated fatty acid, and a polyhydric alcohol and an alkylene oxide adduct are saturated or unsaturated. It is more preferable to use a surfactant-based low-temperature fluidity improver such as an ester or a partial ester synthesized from a saturated fatty acid, since the lubricating effect is large when used in combination.

In the fuel oil composition of the present invention, it is preferable to use a rust inhibitor and an antioxidant from the viewpoint of performance such as storage stability. As the rust inhibitor, various rust inhibitors can be used,
For example, partial esters of dicarboxylic acids and alcohols such as alkyl or alkenyl succinic acids, derivatives such as ethylene oxide adducts and amidates; carboxylic acids having a polar group such as hydroxycarboxylic acid and mercaptocarboxylic acid; dimer acid and trimer acid Polymerized acids of unsaturated fatty acids such as and their derivatives; fatty acid, alkaline earth metals of carboxylic acids such as naphthenic acid, abietic acid, alkenyl succinic acid and thiocarboxylic acid, various metal element salts such as magnesium and aluminum, amine salts and the like Carboxylates; salts of sulfonic acids such as alkali metal salts such as dinonylnaphthalenesulfonic acid and alkylbenzenesulfonic acid, alkaline earth metal salts and amine salts; polyhydric alcohols such as sorbitol and glycerin and carboxylic acids such as oleic acid of Min esters; higher aliphatic alcohols; morpholine, diethanolamine derivatives, amines such as ethylene oxide adducts of rosin; and oil-soluble surfactant having a polar group such as phosphoric acid or boric acid as the main or sub polar group. Preferred among these rust preventives are those having an ashless type ester group or amino group such as an alkyl or alkenyl succinic acid derivative. These rust preventives can be used alone or in combination of two or more.

As the antioxidant, various antioxidants can be used, for example, alkylphenol such as p-nonylphenol, 2,4-dimethyl-6-tertbutylphenol, 2,6-ditertbutylphenol, 2,2
6-ditertbutyl-p-cresol, tertbutylhydroxyanisole, 4,4′-methylenebis (2,3-ditertbutylphenol), 4,4′-
Phenolic antioxidants such as butylidenebis (3-methyl-6-tertbutylphenol), N-butyl-p-aminophenol, and hydroxyphenyl fatty acids;
N, N′-disecbutyl-p-phenylenediamine,
amine antioxidants such as α-naphthylamine, N-phenyl-α-naphthylamine, N, N′-disalicylidene-1,2-propylenediamine; derivatives such as alkyl esters and amine salts of laurylthiopropionic acid, carboxyethylthio Sulfur-based antioxidants such as derivatives of alkyl esters of succinic acid and amine salts. Of these antioxidants, preferred are alkylphenols, 2,4-dimethyl-6-tertbutylphenol, N, N'-disecbutyl-p-phenylenediamine, hydroxyphenyl fatty acids, and alkyl esters and amine salts of laurylthiopropionic acid. Is mentioned. These antioxidants can be used alone or in combination of two or more.

The fuel oil composition of the present invention can be prepared by simply adding the fatty acid mixture used in the present invention and the above-mentioned additives to be mixed as needed to the middle distillate oil. Preparation is facilitated by adding the fatty acid mixture or the like in the form of a concentrated solution with an organic solvent compatible with the middle distillate oil. Examples of such organic solvents include petroleum fractions such as naphtha, kerosene, and gas oil, aromatic hydrocarbons, and paraffinic hydrocarbons. When used after being diluted with an organic solvent, those containing 20 to 80% by weight of an additive are preferable, and those containing 35 to 75% by weight are more preferable.

The method of blending the fatty acid mixture and each additive is not particularly limited. When the low-temperature fluidity improver is blended, the fatty acid mixture and the low-temperature fluidity improver are dissolved in a suitable solvent in advance, and then mixed. Is preferably added to the middle distillate. It is preferable that the rust preventive and the antioxidant are preliminarily mixed with the fatty acid mixture and added to the middle distillate. The fuel composition of the present invention further comprises a cloud point depressant, a cetane number improver, a metal deactivator, a detergent / dispersant, a combustibility improver, a black smoke reducer, which are usually added to fuel oil,
Additives such as an antifoaming agent, a hue stabilizer, an antifreezing agent, a sludge dispersant, and a marker may be used in combination.

[0026]

The present invention will be described in more detail with reference to the following examples.

Examples 1 to 15 The middle distillate shown in Table 3 was mixed with the fatty acid mixture shown in Table 4 and other additives described below (rust inhibitor, antioxidant, low-temperature fluidity improver) in Table 1. The fuel oil composition of the present invention was prepared by blending at the ratios shown in FIGS.

The rust inhibitor B-1: Tetra Pro pyrenylpropionic succinic acid propylene glycol ester B-2: Amino ethyl oleate ethanolamine salt antioxidant C-1: 2,6-di-tert-butyl -p- cresol C- 2: 4-nonylphenol C-3: N, N'-disecbutyl-p-phenylenediamine low-temperature fluidity improver D-1: ECA8400 (manufactured by Exxon Chemical Co., Ltd.) D-2: Sanhib S101 (Nippon Yushi ( Co., Ltd.)

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

[Table 3]

[0032]

[Table 4]

The lubricating properties of the obtained fuel oil composition were evaluated using a lubrication wear tester. As a lubrication wear tester, a vibration friction wear tester (HFRR tester) was used, and as a test piece, φ10 manufactured by PCS Instruments Co., Ltd.
mm, a 3.0 mm thick disk and a φ6 mm bearing ball were used. A predetermined amount of the additive was added to the low sulfur gas oil, and lubricity was measured under the following conditions.

Testing machine: HF manufactured by PCS Instruments
R2 (Ver.3.0) Specimen material: Steel AISI for both disc and ball
E-52100 Temperature (° C): 60 soil 2 Amplitude (mm): 1.0 ± 0.03 Sample amount (ml): 2.0 ± 0.20 Operating time (min): 75 ± 0.1 Load (g) ): 200 ± 1 Frequency (Hz): 50 ± 1 Surface area of sample bath (cm ² ): 6 ± 1

The vibration of the wear mark of the upper ball was observed by microscopic observation.
Measure the diameter in the direction perpendicular to the moving direction to obtain the average diameter of the wear mark.
I did. It is further classified into the following four stages according to the shape of the wear mark.
Was. Shape of wear mark Only shallow streaks in the direction of vibration are seen. −−−−−− * Some deep streaks are seen. −−−−−−−−−−−−− ** Partially collective wear and abrasive wear are observed. −−−−− *** Cohesive wear and abrasive wear are observed in the entire area. −−−− ****

A comprehensive evaluation shown in Table 5 was also made from the average diameter and shape of the wear marks.

[0037]

[Table 5]

Further, with respect to the compositions of Examples 1, 2, 9 to 13 and 15 containing a low-temperature fluidity improver, as an evaluation of low-temperature performance, the clogging point (CFPP) was determined based on the provisions of JIS K-2288. It was measured. Table 6 shows the results.

[0039]

[Table 6]

Comparative Example 1 For each of the middle distillates shown in Table 3, the average diameter of the wear marks was measured, the shape of the wear marks was observed, and the overall evaluation was performed in the same manner as in Example 1. Further, CFPP was measured in the same manner as in Example 1. Table 7 shows the results.

[0041]

[Table 7]

Comparative Examples 2 to 7 As shown in Table 8, a known lubricant was added to the middle distillate to prepare a fuel oil composition. Regarding the resulting composition,
The average diameter of the wear mark was measured, the shape of the wear mark was observed, and the overall evaluation was performed in the same manner as in Example 1. Table 8 shows the results.

[0043]

[Table 8]

From the results of Tables 6 to 8, the fuel oil composition of the present invention has excellent lubricity while using a low sulfur middle distillate oil,
It can be seen that when the composition contains a low-temperature fluidity improver, the low-temperature fluidity improver does not impair the low-temperature performance.
It can also be seen that when combined with a surfactant-based low-temperature fluidity improver, the lubricity imparting effect is large.

[0045]

The fuel oil composition of the present invention enhances the lubricity of a low sulfur middle distillate compliant with environmental regulations and reduces the wear of the fuel oil lubrication part of a diesel engine. Further, when the composition contains a low-temperature fluidity improver, the low-temperature fluidity improver does not impair the low-temperature performance.

Claims (2)

[Claims] 1. An intermediate distillate (component A) containing 0.2% by weight or less of sulfur and 40% by weight or less of aromatics, and an unsaturated fatty acid (a) having one double bond in the molecule. And an unsaturated fatty acid having two double bonds in the molecule (b) in a weight ratio [(a) :( b)] of 1: 3 to 15: 1, in an amount of 75% by weight or more. The fatty acid mixture having 8 to 30 carbon atoms (component B) containing 0.1 to 30 parts of the middle distillate oil.
A fuel oil composition containing 001 to 0.5% by weight. 2. The fuel oil according to claim 1, wherein the unsaturated fatty acid having one double bond in the molecule is oleic acid, and the unsaturated fatty acid having two double bonds in the molecule is linoleic acid. Composition.