CN1305520A - Additive for fuel oil and fuel oil composition - Google Patents

Abstract

Disclosed is an additive for fuel oil which comprises an alkenyl succinimide compound or an alkyl succinimide compound or a boron adduct thereof, (b) an additive for distillate fuel oil wherein 90% of the lubricity enhancer is at a distillation temperature of 320 ℃ or higher, and (c) a low-temperature fluidity enhancer, and a fuel oil composition obtained by adding the above additive for fuel oil to fuel oil. Particularly, it is possible to provide a fuel oil additive having excellent performance for improving the lubricity of a fuel injection pump and the cleanliness of a fuel nozzle, and a fuel oil composition containing the fuel oil additive, in a light oil having a reduced sulfur content.

Description

Additive for fuel oil and fuel oil composition

technical field

The present invention relates to an additive for fuel oil and a fuel oil composition, and more specifically relates to an additive for fuel oil added to light oil for diesel engines used in bicycles, ships, generators, etc., and an additive for fuel oil containing the additive for fuel oil Fuel oil composition.

Background technique

In recent years, due to restrictions on exhaust gas, the sulfur content of diesel light oil has also been required to be reduced, and in October 2009, the content was limited to 0.05% by weight or less. However, it is known that when a light oil raw material is deeply desulfurized in order to achieve such a low sulfur content, the lubricating performance of the resulting light oil product decreases. In other words, it has been reported that due to this decrease in lubricating performance, the wear of various parts such as injection pumps of diesel fuel lubricated with light oil as fuel increases, resulting in problems such as poor engine rotation and poor running performance. This decrease in lubricity of gas oil is considered to be due to removal of sulfur, nitrogen, and polar compounds such as aromatics that impart lubricity when hydrodesulfurization is performed to remove sulfur from gas oil. The reduction of the lubricating performance of this light oil requires hardware to adapt to it, and fuel oil to adapt to it. This has been studied and various lubricity enhancers have been developed to be added to it.

In addition, the low sulfuration of light oil can reduce the amount of sulfuric acid patecuret in the exhaust of diesel vehicles. However, it has been reported that the discharge of patekyulet-to will also increase due to the decrease in the cleanliness of the fuel nozzles. Therefore, various cleaning agents have also been studied and added to it.

In general, the lubricity enhancers described above can improve the lubricity of the fuel injection pump, but cannot clean the fuel nozzles. On the other hand, the above cleaners clean the fuel nozzles but do little to improve the lubricity of the fuel injection pump. For example, JP-A-9-272880 discloses a low-sulfur light oil to which sorbitan fatty acid ester is added, but the fuel nozzle cannot be cleaned. In addition, JP-A-9-255973 discloses a low-sulfur light oil added with salts of carboxylic acids and aliphatic amines, etc., although it can improve the lubricity of the fuel injection pump and clean the fuel nozzles, but this The effect cannot be said to be sufficient. And Japanese Patent Application Ping 10-513208 (Exone chemical, WO96/23855, published on August 8, 1996) discloses a fuel oil composition containing no more than 0.05% by weight of sulfur, which has a 95% distillation point of 350°C A fuel oil and an additive composition comprising (a) an acylated nitrogen compound and (b) a carboxylic acid having 2 to 50 carbon atoms or an ester of the carboxylic acid and an alcohol, consisting of (a ) and (b), the additive composition formed by improving the lubricity of the fuel oil also improves its solubility in the fuel oil. Therefore, additives having excellent performance in improving the lubricity of fuel injection pumps and the cleanliness of fuel nozzles have been desired. In addition, it is also important to improve the lubricity of fuel injection pumps and the cleanliness of fuel nozzles, especially for light oils that do not undergo low-sulfurization.

The present invention is based on the above viewpoint, and its purpose is to provide a fuel oil distilled at a distillation temperature above 320° C. especially for 90% of which the sulfur content is reduced, in terms of improving the lubricity of the fuel injection pump and the cleanliness of the fuel nozzle. An additive for fuel oil having excellent performance and a fuel oil composition containing the additive for fuel oil.

Description of the invention

The inventors of the present invention have conducted intensive studies and found that the above object of the present invention can be effectively achieved by using an alkenyl succinimide compound or an alkyl succinimide compound or a boron adduct thereof as a component of an additive , thus completing the present invention.

That is, the gist of the present invention is as follows.

(1) An additive for fuel oil distilled at a distillation temperature of 320° C. or higher by 90%, containing (a) an alkenyl succinimide compound or an alkyl succinimide compound or a boron adduct thereof, and ( b) Lubricity enhancers.

(2) An additive for fuel oil distilled at a distillation temperature of 320°C or higher, containing (a) an alkenyl succinimide compound or an alkyl succinimide compound or a boron adduct thereof, (b) ) a lubricity enhancer, and (c) a low temperature fluidity enhancer.

(3) The fuel oil additive according to (1) and (2), wherein the lubricity enhancer is at least one of an unsaturated fatty acid having 4 to 22 carbon atoms, a dimer acid thereof, or an ester thereof.

(4) A fuel oil composition obtained by adding the fuel oil additive according to any one of (1) to (3) to fuel oil.

(5) The fuel oil composition according to (4), wherein the component (a) is added in an amount of 20 to 1500 ppm by weight based on the total amount of the fuel oil composition.

(6) The fuel oil composition as described in (4) or (5), wherein the addition amount of the component (b) is 5 to 300 ppm by weight based on the total amount of the fuel oil composition.

(7) The fuel oil composition according to any one of (4) to (6), wherein the component (c) is added in an amount of 50 to 500 ppm by weight based on the total amount of the fuel oil composition.

(8) The fuel oil composition according to any one of (4) to (7), wherein the fuel oil is diesel light oil.

(9) The fuel oil composition as described in (8), wherein the sulfur content in the diesel light oil is 0.001 to 0.05% by weight.

(10) The fuel oil composition as described in (4), wherein the distillation temperature of 90% of the fuel oil is 320° C. or higher.

(11) The fuel oil composition as described in (4), wherein the distillation temperature of 90% of the fuel oil is 330° C. or higher.

(12) The fuel oil composition as described in (4), wherein the distillation temperature of 90% of the fuel oil is 340° C. or higher.

(13) The fuel oil composition as described in (4), wherein the distillation temperature of 90% of the fuel oil is 350° C. or higher. BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described below.

First, an alkenyl succinimide compound or an alkyl succinimide compound, or a boron adduct thereof, which is the component (a) of the fuel oil additive constituting the first invention of the present application will be described. The alkenyl succinimide compound and the alkyl succinimide compound are, for example, a monomer of the following general formula (1) and a dimer of the general formula (2). (wherein, R ¹ , R ³ and R ⁴ are alkenyl or alkyl groups with a number average molecular weight of 300-4000, which may be the same or different, R ⁵ and R ⁶ are alkylene groups with 2-4 carbon atoms, may be the same or different, m represents an integer of 1 to 10, and n represents an integer of 0 or 1 to 10.)

In the above general formulas (1) and (2), R ¹ , R ³ and R ⁴ are preferably alkenyl or alkyl groups with a number average molecular weight of 500-2000, more preferably alkenyl groups or alkyl groups with a number average molecular weight of 500-1000 , Alkenyl such as polybutene, ethylene-propylene copolymer, and alkyl is their hydrogenation product.

In the present invention, both the above-mentioned monomers and dimers can be used.

The above-mentioned alkenyl succinimide compound and alkyl succinimide compound can usually be prepared by reacting polyalkenyl succinic anhydride obtained by reacting polyolefin with maleic anhydride or polyalkyl succinic anhydride obtained by hydrogenation with polyamine . The above-mentioned monomer or dimer can be prepared by changing the reaction ratio of polyalkenyl succinic anhydride or polyalkyl succinimide and polyamine. As the olefin monomer forming the above polyolefin, one or more kinds of α-olefins having 2 to 8 carbon atoms can be used in combination. On the other hand, polyamines such as ethylenediamine, propylenediamine, butylenediamine, pentamethylenediamine and other monomeric diamines, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylene Polyalkylenepolyamines such as ethylhexamine, bis(methylethylene)triamine, dibutylenetriamine, tributylenetetramine, and pentapentylenehexamine.

In addition, as the boron adduct of an alkenyl succinimide compound or an alkyl succinimide compound, those produced by a conventional method can be used. The preferred content of boron in this boron adduct is 0.1 to 6% by weight, more preferably 0.1 to 4% by weight.

The above-mentioned (a) component can be used singly or in combination of two or more.

Next, the component (b) constituting the first invention of the present application, the lubricity enhancer, will be described. The lubricity enhancer used in the present invention refers to additives added in order to reduce the coefficient of friction, and is not particularly limited. It is preferred to use unsaturated fatty acids with 4 to 22 carbon atoms or their dimer acids or their esters, and more preferably to use Mixtures of the above acids and their esters. The unsaturated fatty acid can be linear or branched, such as decenoic acid, dodecenoic acid, crude oleic acid (tzus acid), tetradecenoic acid, oleic acid, and decenoic acid ( kodonic acid), sinapinic acid, linoleic acid, linolenic acid, etc. Alcohols used for esterification include methanol, ethanol, oleyl alcohol, glycerin and the like. In addition, the esterified substance may be a partially esterified substance.

In addition, lubricity enhancers such as stearamide, oleamide, stearyl bis (polyethylene glycol) amide and other amide compounds, dodecylamine, stearic acid amine, stearic acid dimethylamine, cyclohexylamine, Amine compounds such as dodecyl di(diethylene glycol)amine; phenyl-α-naphthylamine, dioctylaniline, dinonylaniline, diphenyl-p-phenylenediamine, dipyridylamine, phen Thiazine, N-methylphenothiazine, N-ethylphenothiazine and other amine compounds other than the above; dibutyl disulfide, dioctyl disulfide, bis(dodecyl) disulfide disulfides such as chlorinated paraffin, chlorinated naphthalene, chlorinated alkylbenzene and other chlorinated hydrocarbons; n-butyl di-n-octyl phosphinate and other phosphinates; di-n-butylhexylphosphonic acid Phosphonate esters, di-n-butylphenyl phosphonate and other phosphonates; tributyl phosphate, tricresyl phosphate, tris(octadecenyl) phosphate, di-2-ethylhexyl phosphate, etc. Phosphate esters; 2,6-di-tert-butyl-p-cresol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis( 4-ethyl-6-tert-butylphenol), 2,5-di-tert-amylhydroquinone, 2,5-di-tert-butylhydroquinone, 4,4'-thiobis(6-tert-butyl-meta phenol), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 3,5-di-tert-butyl-4-hydroxy-benzylphosphonic acid-di Phenols such as ethyl ester, triethylene glycol di[3-(3-tert-butyl-5-methyl-5-hydroxyphenyl)propionate], etc.

The said (b) component can be used 1 type or in combination of 2 or more types.

The ratio of the above-mentioned (a) component to (b) component is preferably in a weight ratio of 90:10 to 10:90, and the fuel oil additive of the first invention can be obtained by using kerosene and a carbon number of about 8 to 10 Dilute with diluents such as aromatic solvents, and then add antioxidants, metal inert agents, microbial sterilizers, antifreeze agents, antistatic agents, anticorrosion agents, defoamers, antirust agents, combustion aids, colorants, markers It is preferable to adjust the total amount of (a) component and (b) component to 20 to 80 weight% of additives, such as an additive.

The fuel oil additive of the first invention can further improve the lubricity of the fuel oil by adding a low-temperature fluidity enhancer as the component (c) in addition to the components (a) and (b). There is no particular limitation on the low-temperature fluidity enhancer as component (c), but it is preferable to use an ester formed of a nitrogen-containing compound having a hydroxyl group and a straight-chain saturated fatty acid (JP-A-57-1790993). A polymer of one or more monomers of olefins, ethylenically unsaturated carboxylic acid alkyl esters, and saturated fatty acid vinyl esters (JP-A-58-138791). Other low temperature fluidity enhancers such as ethylene-vinyl acetate copolymers, ethylene-alkyl alkyls, polyalkyl acrylates, alkenyl succinamides and the like.

The said (c) component can be used 1 type or in combination of 2 or more types.

It is preferable that the ratio of the said (c) component is 30-150 weight part with respect to the total amount of (a) component and (b) component being 100 parts. Fuel oil additives (a), (b) and (c) are diluted with diluents such as light oil and aromatic solvents with about 8 to 10 carbon atoms, and then add antioxidants, metal inerts, microorganisms as needed Additives such as sterilizer, antifreeze, antistatic agent, anticorrosion agent, defoamer, rust inhibitor, combustion enhancer, coloring agent, marker, the total amount of (a), (b), (c) components is preferably Adjusted to 20 to 80% by weight.

The second invention of the present application is a fuel oil composition obtained by adding the above fuel oil additive to fuel oil. The fuel oil composition, such as various hydrocarbon base fuel oils, is preferably gasoline or diesel light oil in terms of performance, and particularly preferably diesel light oil. This diesel light oil satisfies the Japanese Industrial Standards (JIS K2204) in various properties, and it is particularly preferable to contain 0.001 to 0.05% by weight of sulfur. In addition, a fluid viscosity at 30°C is preferably 1.7 mm ² /s or more, and can be obtained by adjusting the sulfur content of hydrodesulfurized gas oil (DGO), hydrocracked gas oil (HCGO), or a mixture thereof to the above-mentioned range, for example. substance.

The diesel light oil composition of the present invention preferably contains a sulfur content of 0.001 to 0.05% by weight. If the sulfur content exceeds this range, the effect of the above-mentioned additives for fuel oil may be reduced.

In addition, as the distillation properties, the 90% distillation temperature is preferably 320°C or higher, more preferably 330°C or higher, more preferably 340°C or higher, and most preferably 350°C or higher. If it is lower than 320°C, the effect of the fuel oil additive will be small. .

As the hydrodesulfurized gas oil (DGO), generally, those having a boiling point in the range of 140 to 390° C. and a density of 0.80 to 0.90 can be suitably used. In addition, the above-mentioned hydrodesulfurized gas oil (DGO) generally has a sulfur content of 0.005 to 0.5% by weight, and preferably has a sulfur content of 0.05% by weight or less.

In addition, the above-mentioned hydrodesulfurized gas oil (DGO) specifically uses a hydrodesulfurization device, in the presence of a catalyst such as a Co-Mo/alumina catalyst, a Ni-Mo/alumina catalyst, etc., at 30 to 100 kg/cm ² (preferably Under the pressure of 50-70kg/cm ² ), at a temperature of 300-400°C (preferably 330-360°C), under the condition that the liquid hourly space velocity (LHSV) is 0.5-5hr ^-1 (preferably 1-2hr ^-1 ) In this case, straight-run gas oil (LGO) as a raw material oil is subjected to a desulfurization reaction, and then hydrogen sulfide and naphtha are removed by a stripper.

The above-mentioned hydrocracking gas oil (HCGO) refers to a substance obtained by hydrocracking heavy gas oil (HGO), vacuum gas oil (VGO) or a mixture thereof in the presence of a catalyst, and distilling and separating the oil generated by this decomposition. Hydrocracked gas oil (HCGO) generally has a sulfur content of 0.0001 to 0.2% by weight.

In addition, in addition to the above-mentioned light oil base material, it is possible to mix and use commonly used light oil fractions, such as straight-run light oil (LGO), by-product light oil (DSGO) obtained from heavy oil direct desulfurization equipment, and catalytic By-product light oil (LCO) from decomposition unit, desulfurized LCO (DSLCO), by-product light oil (VHLGO) from indirect desulfurization unit, dewaxed light oil (DWLGO), dewaxed desulfurized light oil (DWDGO), desulfurized Kerosene fraction (DK), etc.

The addition amount of the additive for fuel oil may be as long as the (a), (b), and (c) components are in the following amounts.

The above component (a) is preferably 20 to 1500 ppm by weight, more preferably 50 to 800 ppm by weight, based on the total amount of the composition. If it is less than 20 ppm by weight, it will be difficult to improve the cleanliness of the nozzle, and if it exceeds 1500 ppm by weight, it will not be possible to effectively improve the cleanliness of the nozzle.

The above-mentioned component (b) is preferably 5 to 300 ppm by weight, more preferably 10 to 150 ppm by weight, based on the total amount of the composition. If it is less than 5 wtppm, it will be difficult to improve the lubricity of the pump, and if it exceeds 300 wtppm, it will not be possible to effectively improve the lubricity of the pump.

The above-mentioned (c) component is preferably 50 to 500 ppm by weight, more preferably 100 to 400 ppm by weight, based on the total amount of the composition. If it is less than 50 wtppm, it is difficult to improve the lubricity of the pump due to the synergistic effect with (b) component, and if it exceeds 300 wtppm, the synergistic effect with (b) component cannot effectively improve the lubricity of the pump.

In the range that does not impair the effects of the present invention, antioxidants, metal inert agents, microbial sterilizers, antifreezing agents, antistatic agents, corrosion inhibitors, antifoaming agents, Additives such as antirust agent, combustion enhancer, coloring agent, marking substance, etc. These additives may be added separately from the above-mentioned additives for fuel oil, and are usually packaged and added together with the additive for fuel oil.

Example

The present invention will be described in more detail below in conjunction with examples, but the present invention is not limited by these examples. Embodiment 1～3; Comparative example 1, 2 and reference example 1

(1) Preparation of diesel light oil composition of the present invention

(ⅰ) Test light oil

Deeply desulfurized light oil shown in Table 1 below was used.

Table 1 project measured value test methods Density(g/cm ³ ,15℃) 0.8321 JISK2249 Flow viscosity (mm ² /s, 30℃) 4.279 JISK2283 Pour point (°C) -5.0 JISK2269 Cloud point (°C) 3.0 JISK2269 cetane number 55.1 JISK2280 Clogging temperature (°C) 1.0 JISK2288 Sulfur (weight%) 0.026 JISK2541 Distillation properties (℃) 10% by volume 50% by volume 90% by volume 222.0288.5352.0 JISK2254

(ii) Additives

The light oil composition was prepared by adding the following additives according to the ratio shown in Table 2.

(a) Succinimide of the ingredient

Add polybutene with a number average molecular weight of 960 to maleic anhydride, and then add tetraethylenepentamine to obtain polybutenyl succinimide, which has a viscosity of 32mm ² / s mineral oil to adjust the concentration to 64% by weight of the substance.

(b) lubricity enhancer of component

The main component is a mixture of unsaturated fatty acids with 18 carbon atoms, with linoleic acid, oleic acid and linoleic acid as the main components (the amount of each acid is 15 to 50% by weight, and the total amount is 90% by weight) , Diluted with an aromatic solvent having 10 carbon atoms so that the active ingredient reaches 20% by weight.

(c) low temperature fluidity enhancer of component

A mixture composed of triethanolamine (25% by weight), tribehenate (50% by weight) and ethylene-vinyl acetate copolymer (25% by weight) is diluted with an aromatic solvent with 10 carbon atoms to make The active ingredient is up to 50% by weight of the substance.

(2) Evaluation of nozzle cleanliness

For the gas oil composition prepared as described above, the following evaluation of nozzle cleanability was performed.

A 2400 cc class pre-combustion type in-line 4-cylinder diesel engine equipped with a slot nozzle was operated at a rotational speed of 2400 rpm and a torque of 12.7 kg·m (load factor 80%) for 18 hours. After the operation, in order to investigate the fouling state of the nozzle, use an air flow measuring device to measure the flow rate at the injection port when the needle valve of the nozzle is lifted by 0.00-0.6mm when the air with a pressure of 0.5kg/ ^cm2 flows through. Calculate the air flow area relative to the lift of the needle valve, compare the area before the test (new product) and after the test, and evaluate the degree of fouling of the nozzle. If the flow area maintenance rate obtained by comparing the air flow area value with respect to the needle valve lift amount before and after the test is 100%, it means that it is not contaminated at all like the new product before the test. Conversely, a 0% would indicate a complete blockage that prevents fuel from being injected. The results are shown in Table 2.

(3) Evaluation of lubrication performance

Using the HFRR (high Frequency Reciprocation Wear Rig: high-frequency reciprocating motion testing machine) device of the European Consolidation Committee CEC-F-06-T94, the load is 200g, the test oil temperature is 60°C, the vibration frequency is 50Hz, the test time is 75 minutes, and the sample size Under the condition of 2ml, wear the test hemisphere. The width of the wear marks was measured in the X (horizontal) and Y (longitudinal) directions using a microscope, and the average wear width (μm) was obtained. The results are shown in Table 2.

Table 2 Example 1 Example 2 Example 3 Comparative example 1 Comparative example 2 Reference example 1 Amount of succinimide added* 500 500 100 0 500 0 Addition of Lubricity Enhancer* 75 75 100 75 0 0 Addition amount of low temperature fluidity enhancer* 0 275 275 0 0 0 Nozzle flow area maintenance rate (%) 70 72 50 35 54 35 HFRR wear range (μm) 330 310 300 400 560 580 (Note)*ppm by weight

It can be seen from Table 2 that the nozzle flow area maintenance rate of the light oil composition added with the additive of the present invention is high, and the cleaning performance of the nozzle is improved. In addition, the wear range is small and the lubricity is improved.

Examples 4 and 5 [Effect of reducing PM in exhaust gas and effect of cleaning performance]

The emissions of PM (particulate matter, also referred to as patekure-to matter) were compared using the engines and evaluation conditions shown in Table 3 and Table 4 below. That is to say, using the fuel shown in Table 1 (Example 4) and Table 5 (Example 5) and the engine shown in Table 3, under the nozzle fouling conditions in Table 4, after running 5000 km, the nozzle in Table 4 Nozzles become clean under cleanliness recovery conditions.

Next, using the engine conditions for measuring PM emissions in Table 4 and the micro-dilution air duct system (produced by Horiba Manufacturing Co., Ltd.), the PM emissions were measured with reference to the diesel engine vehicle particulate matter test method (TRIAS-24-5-1993). The results are shown in Table 6. Comparative example 3, 4

In addition, the discharge amount of PM was measured in the same manner as in Examples 4 and 5 except that succinimide and the low-temperature fluidity enhancer were not used. The results are shown in Table 7.

Table 3 Main performance of the engines used performance content Cylinder arrangement Series 4 cylinders burning method Vortex chamber Total displacement (cc) 2982 compression ratio 21.2 Maximum torque (N·m/rpm) 289/2000 Maximum Power(Kw/rpm) 95.6/3600 Jet pump form Distributed electronic control method

Table 4 Engine evaluation conditions Nozzle fouling condition Nozzle Cleanliness Return to Operating Conditions PM emission measurement conditions Engine revolutions (rpm) 2000 2600 1500 Engine load rate (%) 80 25 80 Lubricating oil temperature (℃) 85 85 85 Engine cooling water temperature (°C) 80 80 80 Suction air temperature (℃) 25 25 25 Inhaled air humidity (℃) 50 50 50 Fuel oil temperature (℃) 25 25 25 Running time(hr) Walk up to 5000km 8 0.5/Test

Table 5 Properties of the fuel used project character test methods Density(g/cm ³ ,15℃) 0.8274 JIS-K-2249 Flow viscosity (mm ² /s, 30℃) 3.535 JIS-K-2283 cetane number 57.0 JIS-K-2280 Sulfur (wt%) 0.04 JIS-K-2541 Distillation properties (℃) 10% by volume 204.0 JIS-K-2254 50% by volume 283.0 90% by volume 330.0

Table 6 PM emissions (Example) Example 4 Example 5 Amount of succinimide added* 1000 1000 Addition of Lubricity Enhancer* 75 75 Addition amount of low temperature fluidity enhancer* 275 275 PM emission (g/kwh) 0.834 0.965 use fuel Table 1 Fuels Table 5 Fuels (Note)*ppm by weight

Table 7 PM emission (Example) Comparative example 3 Comparative example 4 Amount of succinimide added* 0 0 Addition of Lubricity Enhancer* 75 75 Addition amount of low temperature fluidity enhancer* 0 0 PM emission (g/kwh) 1.155 1.254 use fuel Table 1 Fuels Table 5 Fuels (Note)*ppm by weight

Industrial Applicability

According to the present invention, it is possible to provide an additive for fuel oil having an excellent performance in improving the lubricity of a fuel injection pump and the cleanliness of a nozzle, and an additive for fuel oil containing the light oil having a reduced sulfur content, in particular. fuel oil composition.

Claims (13)

1,90% use additive, contain (a) alkenyl succinimide compound or alkyl succinimide compound or their boron affixture at the recovered temperature distillate fuel more than 320 ℃ oil, and (b) lubricity enhancer.

2,90% use additive, contain (a) alkenyl succinimide compound or alkyl succinimide compound or their boron affixture, (b) lubricity enhancer and (c) low-temperature fluidity toughener at the recovered temperature distillate fuel more than 320 ℃ oil.

3, oil fuel additive as claimed in claim 1 or 2, lubricity enhancer are that carbonatoms is at least a in 4～22 unsaturated fatty acids or its dimeracid or their ester.

4, in oil fuel, add any fuel oil composition that described oil fuel obtains with additive in the claim 1～3.

5, fuel oil composition as claimed in claim 4 is a benchmark with the fuel oil composition total amount, and (a) addition of composition is 20～1500 ppm by weight.

6, as claim 4 or 5 described fuel oil compositions, be benchmark with the fuel oil composition total amount, (b) addition of composition is 5～300 ppm by weight.

7, as any described fuel oil composition in the claim 4～6, be benchmark with the total amount of fuel oil composition, (c) addition of composition is 50～500 ppm by weight.

8, as any described fuel oil composition in the claim 4～7, oil fuel is diesel engine light oil.

9, fuel oil composition as claimed in claim 8, the content of sulphur is 0.001～0.05 weight % in the diesel engine light oil.

10, fuel oil composition as claimed in claim 4, the recovered temperature of 90% oil fuel is more than 320 ℃.

11, fuel oil composition as claimed in claim 4, the recovered temperature of 90% oil fuel is more than 330 ℃.

12, fuel oil composition as claimed in claim 4, the recovered temperature of 90% oil fuel is more than 340 ℃.

13, fuel oil composition as claimed in claim 4, the recovered temperature of 90% oil fuel is more than 350 ℃.