JP2001303077A - Light oil composition - Google Patents

Abstract

(57) [Problem] To provide a light oil composition capable of significantly reducing particulate emissions from a diesel engine in the entire load range of the engine. SOLUTION: The composition contains at least 500 mass ppm of a cetane number improver based on the total amount of the composition, and at least one detergent selected from the group consisting of alkenyl succinic acid derivatives and amine salts of carboxylic acids, and has a cetane index of at least one. 45 or more,
90% by volume distillation temperature is 330 ° C or less, sulfur content is 5
A light oil composition having a kinematic viscosity at 30 ° C. of not more than 00 mass ppm and not less than 1.7 mm ² / s.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas oil composition having a low sulfur content, and more particularly to a gas oil composition capable of significantly reducing the amount of particulates in diesel exhaust gas over the entire engine load range. It relates to a light oil composition.

[0002]

2. Description of the Related Art As components contained in diesel exhaust gas, nitrogen oxide (hereinafter referred to as NOx) and particulate matter (hereinafter referred to as PM) are mainly regarded as problems. NOx is a substance mainly generated by the reaction of nitrogen in the air with oxygen in the engine, and includes NO, NO _{2, and the} like. PM is fine particles in the exhaust gas, and is the one obtained by discharging soot (soot) by combustion and high-boiling high-molecular unburned components contained in fuel or lubricating oil. These substances cause air pollution and acid rain, and urgent reduction measures are required. In addition, recently, aldehydes including formaldehyde and acetaldehyde have also attracted attention because of their adverse effects on human health and odor.

[0003] Since October 1997, light oil used as fuel for diesel engines has been used in SOF for automobiles.
Assuming that a post-treatment device such as a catalyst (organic solvent-soluble component oxidation catalyst) and a NOx reduction catalyst is installed, the sulfur content is reduced to 500 mass ppm or less. However, these post-processing devices have problems such as low efficiency and durability, and at present, very few devices have been put to practical use. At present, vehicles with the latest emission reduction measures are being introduced to the market, but the replacement of already sold vehicles requires a lot of time, so the fundamental solution has not been reached. In addition, more stringent emission regulations will be introduced after 2003.

[0004]

As described above, in 2003,
Because of the strict emission regulations that will be enforced after the year 2010, and because it will take a lot of time for the market to adopt the latest emission reduction technologies, the reduction of emissions Improving the quality of the product has high immediate effect and is considered to be very effective. As fuel, not only is it effective for existing diesel vehicles, but also for vehicles that have advanced emission measures such as DPF installation, effective fuel is required. There are several possible ways to improve fuel to reduce exhaust gas.However, fuels containing oxygenated compounds may have adverse effects on engine components, etc. No. Accordingly, an object of the present invention is to provide a gas oil composition capable of greatly reducing the emission of particulates contained in diesel exhaust gas over the entire load range of the engine. In particular, it is also to provide a light oil composition effective for reducing exhaust gas (particularly, reducing PM concentration) even for a vehicle equipped with a DPF.

[0005]

According to the present invention, there is provided a cetane number improver of 500 ppm by mass or more based on the total amount of the composition, and at least one detergent selected from the group consisting of alkenyl succinic acid derivatives and amine salts of carboxylic acids. And a cetane index of 45 or more and a 90% by volume distillation temperature of 330
° C or less, the sulfur content is 500 mass ppm or less, and the kinematic viscosity at 30 ° C is 1.7 mm ² / s or more.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The light oil composition of the present invention comprises a base light oil containing a cetane number improver and a detergent. First, the cetane number improver and the detergent will be described. As the cetane improver, various compounds known in the art as a cetane improver can be optionally used. For example, nitrate esters and organic peroxides can be mentioned. The cetane improver used in the present invention is preferably a nitrate ester. Examples of the nitrate include 2-chloroethyl nitrate, 2-ethoxyethyl nitrate, isopropyl nitrate,
Butyl nitrate, first amyl nitrate, second amyl nitrate, isoamyl nitrate, first hexyl nitrate, second hexyl nitrate, n-heptyl nitrate, n-octyl nitrate, 2-
Various nitrates such as ethylhexyl nitrate, cyclohexyl nitrate, and ethylene glycol dinitrate are included. Among these, an alkyl nitrate having 6 to 8 carbon atoms is preferable. As the cetane number improver, one type of compound may be used alone, or two or more types of compounds may be used in combination.

The content of the cetane number improver in the light oil composition of the present invention is 500 ppm by mass or more based on the total amount of the composition, and when it is less than 500 ppm by mass, the NOx concentration, PM concentration, aldehyde, The concentration cannot be reduced to a satisfactory level. In the light oil composition of the present invention, the content of the cetane number improver defined on the basis of the total amount of the composition is preferably 600 mass ppm or more, more preferably 700 mass ppm or more, and 800 mass Particularly preferably, it is at least 900 ppm by mass.
The upper limit of the content of the cetane number improver is not particularly limited in the present invention, but generally, the content of the cetane number improver is preferably 1400 mass ppm or less based on the total amount of the gas oil composition. , Is more preferably 1250 mass ppm or less, particularly preferably 1100 mass ppm or less, and most preferably 1000 mass ppm or less.

[0008] Commercially available products referred to as cetane number improvers are generally obtained as active ingredients that contribute to cetane number improvement, that is, the cetane number improver is diluted with an appropriate solvent. is there. When the gas oil composition of the present invention is prepared using such commercially available products, the content of the active ingredient in the gas oil composition is 500 mass p based on the total amount of the composition.
It is important that the speed is at least pm.

Detergents include alkenyl succinic acid derivatives and
And / or amine salts of carboxylic acids. The alkenyl succinic acid derivative used in the present invention has the following general formula (1) to
The compound represented by (4) is preferable.

[0010]

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(Wherein A represents an n-butyl group, a sec-butyl group or a tert-butyl group, and R ¹ , R ² , R
³ and R ⁴ each independently represent a hydrogen atom, a methyl group or an ethyl group, provided that the total number of carbon atoms in R ^{1 to} R ⁴ is 2, and R ⁵ is an alkylene group having 1 to 36 carbon atoms. And m represents an integer of 1 to 100. )

[0012]

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(Wherein A represents an n-butyl group, a sec-butyl group or a tert-butyl group; R ¹ , R ² , R
³ and R ⁴ each independently represent a hydrogen atom, a methyl group or an ethyl group, provided that the total number of carbon atoms in R ^{1 to} R ⁴ is 2, and R ⁵ is an alkylene group having 1 to 36 carbon atoms. And m represents an integer of 1 to 100, and n represents an integer of 1 to 10. )

[0014]

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(Wherein A represents an n-butyl group, a sec-butyl group or a tert-butyl group, and R ¹ , R ² , R
³ and R ⁴ each independently represent a hydrogen atom, a methyl group or an ethyl group, provided that the total number of carbon atoms in R ^{1 to} R ⁴ is 2, and R ⁵ is an alkylene group having 1 to 36 carbon atoms. Represents, m
Represents an integer of 1 to 100, and n represents an integer of 1 to 10. )

[0016]

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(Wherein A represents an n-butyl group, a sec-butyl group or a tert-butyl group, and R ¹ , R ² , R
³ and R ⁴ each independently represent a hydrogen atom, a methyl group or an ethyl group, provided that the total number of carbon atoms in R ^{1 to} R ⁴ is 2, and R ⁵ is an alkylene group having 1 to 36 carbon atoms. Represents, m
Represents an integer of 1 to 100, and n represents an integer of 1 to 10. )

The alkenyl succinic acid derivatives represented by the above general formulas (1) to (4) will be described in detail. A represents an n-butyl group, a sec-butyl group or a tert-butyl group. Tert
-A butyl group is preferred. R ^{1 to} R ⁴ each represent a hydrogen atom, a methyl group or an ethyl group. And
The total carbon number of R ^{1 to} R ⁴ is 2. In the present invention, since better detergency is obtained, when R ¹ and R ³ are both hydrogen atoms and R ² and R ⁴ are both methyl groups, or when R ¹ and R ³ are both It is preferred that the compound is a methyl group and R ² and R ⁴ are both hydrogen atoms.

R ⁵ represents an alkylene group having 1 to 36 carbon atoms. R ⁵ is preferably an alkylene group having 1 to 18 carbon atoms, more preferably an alkylene group having 1 to 6 carbon atoms, and particularly preferably an alkylene group having 1 to 4 carbon atoms. Specific examples of the alkylene group having 1 to 4 carbon atoms include a methylene group, an ethylene group, a propylene group (1-methylethylene group, a 2-methylethylene group), a trimethylene group, and a butylene group (1-ethylethylene group). , 2-ethylethylene group), 1,2-dimethylethylene group, 2,2-dimethylethylene group, 1-methyltrimethylene group, 2-methyltrimethylene group, 3-methyltrimethylene group, tetramethylene group and the like. No. Among them, R ⁵ is most preferably a methylene group, an ethylene group, a propylene group (1-methylethylene group, 2-methylethylene group) or a trimethylene group.

In the general formulas (1) to (4), m is 1 to 1.
Indicates an integer of 00. m is preferably 5 or more, more preferably 10 or more, from the viewpoint of maintaining the dispersibility in the gas oil composition and maintaining the cleanliness. In addition, in terms of the effect on the valve stick due to the increase in viscosity and the combustion chamber deposit due to the deterioration of thermal decomposition,
It is preferably 50 or less, more preferably 40 or less. n is
Represents an integer of 1 to 10. n is preferably an integer of 1 to 5, more preferably 1 to 3.

The group represented by the following formula (5) has a group represented by the following formula (6) as a structural unit.
1 shows a polymer skeleton of an alkenyl succinic acid derivative represented by any one of (1) to (4).

[0022]

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(R ¹ , R ² , R ³ , R ⁴ and m in the above formulas (5) and (6) are represented by the general formulas (1) to (4)
And the same groups and integers as those for R ¹ , R ² , R ³ , R ⁴ and m. )

In the above formulas (1) to (4) and (5), the m groups represented by the above formula (6) may be the same or different in the same molecule. That is, the above equations (1) to
The compound represented by (4) and the group represented by the above formula (5) may be a homopolymer or a copolymer. The copolymer may be any of a random copolymer, an alternating polymer, and a block copolymer.

The number average molecular weight of the alkenyl succinic acid derivative is not particularly limited, but is preferably 500 or more from the viewpoint of maintaining the dispersibility in the gas oil composition and maintaining the cleanliness. , 1000 or more, still more preferably 1500 or more, and most preferably 2000 or more. The number average molecular weight is preferably 6,000 or less from the viewpoint of the effect on the valve stick due to the increase in viscosity and the combustion chamber deposit due to the deterioration in thermal decomposition.
More preferably, it is not more than 00.

As the alkenyl succinic acid derivative of the present invention, only one compound selected from the compounds represented by formulas (1) to (4) may be used alone, or two or more compounds may be mixed. You may use it. When two or more kinds are used, a mixture of a compound represented by the general formula (2) and a compound represented by the general formula (3) is preferable. The mixing ratio (mass ratio) at that time is (2) :( 3) = 1: 99 to 9
It is preferably 9: 1, and 10:90 to 90:10
And more preferably 20:80 to 80:20, and more preferably 30:70 to 70: 3.
Most preferably, it is 0.

Next, the amine salt of a carboxylic acid as a detergent used in the present invention will be described in detail. The carboxylic acid preferably has 5 to 50 carbon atoms, more preferably has 7 to 30 carbon atoms, and particularly preferably has 9 to 20 carbon atoms.
belongs to. The carboxylic acid may be either a monocarboxylic acid or a polycarboxylic acid, but is preferably a monocarboxylic acid. The carboxylic acid may be any of a fatty acid, an alicyclic carboxylic acid, and an aromatic carboxylic acid, but is preferably a fatty acid. The fatty acid may be linear or branched, and may be saturated or unsaturated.

Specific examples of the fatty acids having 9 to 20 carbon atoms include the following. Linear or branched nonanoic acid, linear or branched decanoic acid,
Straight or branched undecanoic acid, straight or branched dodecanoic acid, straight or branched tridecanoic acid, straight or branched tetradecanoic acid, straight or branched pentadecanoic acid, straight or branched chain Hexadecanoic acid, linear or branched heptadecanoic acid, linear or branched octadecanoic acid, linear or branched nonadecanoic acid, linear or branched icosanoic acid, linear or branched nonenic acid, Linear or branched undecenoic acid, linear or branched dodecenoic acid, linear or branched tridecenoic acid, linear or branched tetradecenoic acid, linear or branched Pentadecenoic acid, linear or branched hexadecenoic acid, linear or branched heptadecenoic acid, linear or branched octadecenoic acid (including oleic acid), Nonadecenoic acid chain or branched chain, such as icosenoic acid straight or branched chain. Further, a fatty acid containing a hydroxyl group such as linoleic acid is also included. As the above carboxylic acid, one kind of carboxylic acid may be used alone, or two or more kinds of carboxylic acids may be used in combination.

The amine preferably has 1 to 30 carbon atoms. More preferably, it has 5 to 20 carbon atoms, and particularly preferably 8 to 18 carbon atoms. Examples of the amine include a monoamine, a polyamine, and an alkanolamine, and a monoamine is preferable. Examples of the monoamine include a monosubstituted amine having one hydrocarbon group, a disubstituted amine having two hydrocarbon groups, and a trisubstituted amine having three hydrocarbon groups.A monosubstituted amine is preferable. .

Examples of the monosubstituted amine include alkylamine, alkenylamine, aromatic-substituted alkylamine, cycloalkylamine, and alkylcycloalkylamine. Preference is given to alkylamines and alkenylamines. Examples of the alkylamine having 8 to 18 carbon atoms include linear or branched octylamine, linear or branched nonylamine, linear or branched decylamine, linear or branched undecylamine, and linear Or branched dodecylamine, straight or branched tridecylamine, straight or branched tetradecylamine, straight or branched pentadecylamine, straight or branched hexadecylamine, straight or Examples include branched heptadecylamine, linear or branched octadecylamine, and the like.

Examples of the alkenylamine having 8 to 18 carbon atoms include linear or branched octenylamine, linear or branched nonenylamine, linear or branched decenylamine, linear or branched undecenylamine, Linear or branched dodecenylamine, linear or branched tridecenylamine, linear or branched tetradecenylamine, linear or branched pentadecenylamine, linear or branched hexadecenylamine , Linear or branched heptadecenylamine, linear or branched octadecenylamine (including oleylamine)
And the like. As the amine, one kind of amine may be used alone, or a mixture of two or more kinds of amines may be used.

The amount of the detergent added is 20 based on the total amount of the composition.
It is preferably at least 60 ppm by mass, more preferably at least 60 ppm by mass, particularly preferably at least 80 ppm by mass.
pm or more. Even if the amount is less than 20 ppm by mass, the effect may not be exhibited. On the other hand, if the amount is too large, a corresponding effect cannot be expected, and conversely, each concentration of NOx, PM, aldehyde, etc. in the exhaust gas of the diesel engine may be increased. It is preferably at most 300 ppm by mass, more preferably at most 250 ppm by mass, particularly preferably at most 200 ppm by mass.

As in the case of the cetane number improver,
Commercially available products called detergents are generally obtained in a state where active ingredients contributing to cleaning are diluted with an appropriate solvent. When such a commercially available product is blended with the light oil composition of the present invention, the blending amount described above for the detergent means the blending amount as an active ingredient.

The gas oil composition of the present invention has a cetane index of 45 or more. If the cetane index is less than 45, the concentrations of NOx, PM, and aldehyde in the exhaust gas may increase. In the present invention, the cetane index is preferably 47 or more, more preferably 48 or more, and most preferably 50 or more.

The cetane index referred to in the present invention is JIS K
2280 means the value calculated by the "method of calculating cetane index using 8.4 variable equation" in "Petroleum products-fuel oil-test method of octane number and cetane number and method of calculating cetane index". Note that the cetane index in the above JIS standard is not applied to the case where the cetane number improver is added, but in the present invention, the cetane index of the case where the cetane number improver is added is also calculated using the above “8.4 variable equation”. Calculation method of the calculated cetane index ".

There is no particular limitation on the cetane number of the light oil composition of the present invention, but the cetane number is preferably adjusted to 45 or more by adding the above-mentioned cetane number improver. It is more preferably at least 50, and most preferably at least 50. By setting the cetane number to 45 or more, NOx, P
Each concentration of M and aldehyde can be further reduced. Here, the cetane number means a cetane number measured according to "7. Cetane number test method" in JIS K 2280 "Petroleum products-fuel oil-Octane number and cetane number test method and cetane index calculation method". .

The gas oil composition of the present invention has a 90% by volume distillation temperature (T ₉₀ ) of 330 ° C. or less. When the T ₉₀ exceeds 330 ° C., there is a possibility that PM concentration in the exhaust gas becomes high. In the present invention, T ₉₀ is preferably 325 ° C. or lower, more preferably 320 ° C. or lower,
It is particularly preferred that the temperature is 315 ° C. or lower. There is no particular restriction on the lower limit of T _90, the fuel consumption further improves, in order to increase the output of the engine, T ₉₀ is preferably at 280 ° C. or higher, more preferably 285 ° C. or higher.

The gas oil composition of the present invention is not particularly limited distillation characteristics other than T _90, it is desirable to satisfy the properties described below. Initial boiling point: 135 to 180 ° C. 10% by volume distillation temperature (T ₁₀ ): 155 to 210 ° C. 30% by volume distillation temperature (T ₃₀ ): 175 to 250 ° C. 50% by volume distillation temperature (T ₅₀ ): 190 ２270 ° C. 70% by volume distillation temperature (T ₇₀ ): 220-300 ° C. 95% by volume distillation temperature (T ₉₅ ): 290-360 ° C. Distillation end point: 320-360 ° C.

The distillation properties of the gas oil composition of the present invention will be described in more detail. If the initial boiling point of the gas oil composition is too low,
The initial boiling point is preferably 135 ° C. or higher because some light fractions are vaporized and the spray range becomes too wide, and the amount of hydrocarbons entrained in the exhaust gas may increase as unburned matter. , More preferably 140 ° C or higher, particularly preferably 145 ° C or higher. On the other hand, if the initial boiling point is too high, there is a possibility of causing a problem in low-temperature startability and low-temperature operability. Therefore, the upper limit of the initial boiling point is preferably 180 ° C, more preferably 170 ° C.

[0040] For T ₁₀ of the gas oil composition may be too low, for the same reasons as in the case initial boiling point is too low, the increase in the amount of hydrocarbons entrained in the exhaust gas is concerned, T ₁₀ 155
℃ or more, more preferably 160 ℃
Above, particularly preferably 165 ° C. or higher. On the other hand, if it is too high, there is a fear that caused a problem in cold startability and low temperature operability, it is preferable that T ₁₀ is 210 ° C. or less, more preferably 205 ° C. or less, particularly preferably at 200 ° C. or less .

If T _{30 of the} gas oil composition is too low, there is a concern that the amount of hydrocarbons entrained in the exhaust gas will increase for the same reason as described above. Therefore, it is preferable that T ₃₀ is 175 ° C. or higher, more preferably 180 ° C. or higher, particularly preferably 185 ° C. or higher. On the other hand, if it is too high, since it can cause trouble in the low temperature startability and low temperature operability, T ₃₀ is preferably at 250 ° C. or less, more preferably 230 ° C. or less, particularly preferably 210 ° C. It is as follows.

The T _{50 of the} gas oil composition is preferably 190 ° C. or higher, more preferably 195 ° C. or higher, particularly preferably 200 ° C. or higher, from the viewpoints of fuel efficiency and engine output. In reducing the PM concentration in the exhaust gas, T ₅₀ is preferably 270 ° C. or lower, more preferably 260 ° C. or lower, 250 ° C. or lower, and preferably 240 ° C. or lower, and particularly preferably 230 ° C. or lower. , Most preferably 225 ° C or lower.

[0043] Similarly as the T ₇₀ is also T ₅₀ of the gas oil composition, influence the fuel consumption and engine output. T ₇₀ is preferably 220 ° C. or more, more preferably 225 ° C. or more, and particularly preferably 230 ° C. or more, in order to further improve fuel efficiency and further increase the output of the engine. And P in the exhaust gas
In order to further reduce the M concentration, T ₇₀ is preferably 300 ° C. or lower, more preferably 290 ° C. or lower, 280 ° C. or lower,
It is preferably in the order of 270 ° C. or less, and particularly preferably 2
It is 65 ° C. or less, most preferably 260 ° C. or less.

It is desirable that the light oil composition has a T ₉₅ of 290 ° C. or higher, but in order to further reduce the PM concentration in the exhaust gas, the T ₉₅ is preferably 360 ° C. or lower, and more preferably 355 ° C. or lower. , 350 ° C or below, and 345 ° C
It is preferably in the following order, particularly preferably 342 ° C or lower, and most preferably 340 ° C or lower.

The end point of distillation of the gas oil composition is desirably 320 ° C. or higher. However, in order to further reduce the PM concentration in the exhaust gas, the distillation end point is preferably at most 360 ° C, more preferably at most 355 ° C, particularly preferably at most 355 ° C.
50 ° C. or less. Distillation properties (initial boiling point, T
₁₀ , T ₃₀ , T ₅₀ , T ₇₀ , T ₉₀ , T ₉₅ , distillation end point) are all values measured in accordance with JIS K 2254 “Petroleum Products-Distillation Test Method”.

The gas oil composition of the present invention has a sulfur content of 50
It is 0 mass ppm or less. 500 mass p sulfur content
If it exceeds pm, there is a possibility that the durability of the exhaust gas after-treatment device will be degraded or that the inside of the engine will be corroded.
In the present invention, the sulfur content is preferably 350 mass ppm or less, more preferably 200 mass ppm or less, still more preferably 150 mass ppm or less, and preferably 100 mass ppm or less. Even more preferably, it is most preferably at most 50 ppm by mass. Here, the sulfur content refers to JIS K
2541 means the sulfur content based on the total amount of the gas oil composition measured by the "sulfur content test method".

The kinematic viscosity at 30 ° C. of the light oil composition of the present invention is 1.7 mm ² / s or more. The kinematic viscosity is 1.7 m
When it is less than m ² / s, there is a concern that control of the fuel injection timing becomes difficult, and lubricity of the distribution type fuel injection pump attached to the engine is impaired. The kinematic viscosity is 1.
It is preferably at least 72 mm ² / s, and
m ² / s or more, more preferably 1.75 mm ²
/ S or more, more preferably 1.78 m
even more preferably m ² / s or more,
Most preferably, it is not less than 1.80 mm ² / s.

The upper limit of the kinematic viscosity at 30 ° C. is not particularly limited, but is preferably 3.5 mm ² / s or less, because the PM concentration in the exhaust gas can be further reduced. more preferably 0 mm ² / s or less, more preferably at most 2.5 mm ² / s, still more preferably at most 2.4 mm ² / s, is 2.2 mm ² / s or less Is most preferred. Here, the kinematic viscosity is JIS K 2283.
It means the kinematic viscosity measured by "crude oil and petroleum products-kinematic viscosity test method and viscosity index calculation method".

The density of the gas oil composition according to the present invention at 15 ° C. is not particularly limited. However, the value is preferably 802 kg / m ³ or more because the fuel consumption rate and the acceleration can be further improved. On the other hand, the upper limit of the density at 15 ° C. is the PM in the exhaust gas.
Since the concentration can be further reduced, 840 kg /
Preferably m ³ or less, still more preferably 835 kg / m ³ or less, even more preferably at 830 kg / m ³ or less, particularly preferably at 820 kg / m ³ or less, 815Kg / m ³ It is most preferred that: Here, the density refers to JIS K22
49 means the density measured by "Density Test Method for Crude Oil and Petroleum Products and Density / Mass / Volume Conversion Table".

In the gas oil composition of the present invention, the content of each of the saturated component, olefin component and aromatic component is not particularly limited, but the following composition is desirable. Saturated content: 60 to 95% by volume Olefin content: 0 to 5% by volume Aromatic content: 5 to 40% by volume The saturated content of the gas oil composition is determined by the NOx and PM in the exhaust gas. For lowering the concentration, it is preferably at least 60% by volume, more preferably at least 65% by volume,
It is particularly preferably at least 70% by volume, most preferably at least 75% by volume. On the other hand, in order to maintain good low-temperature startability and low-temperature operation, the content of the saturated component is preferably 95% by volume or less, more preferably 90% by volume or less, and particularly preferably 85% by volume or less. .

The olefin content of the gas oil composition is preferably in the range of 0 to 5% by volume, more preferably in the range of 0 to 1% by volume, from the viewpoint of the stability of the composition.

The aromatic content of the gas oil composition is preferably 5% by volume or more, more preferably 8% by volume or more, more preferably 10% by volume or more, because it is related to the fuel consumption rate and the engine output. , Even more preferably 12
% Or more, most preferably 15% or more. On the other hand, the aromatic content is determined by the NOx contained in the exhaust gas.
The content is preferably 40% by volume or less, more preferably 35% by volume or less, particularly preferably 30% by volume or less, and most preferably 25% or less because it is related to the respective concentrations of PM and PM.

In the gas oil composition of the present invention, the content of aromatics having two or more rings is preferably 3% by volume or less among the above aromatics. Thereby, each concentration of hydrocarbon (HC), NOx, and PM contained in the exhaust gas can be further reduced. This content is 2% by volume
The content is more preferably at most 1%, particularly preferably at most 1% by volume, most preferably at most 0.5% by volume. For the same reason, the content of the aromatic component having three or more rings is preferably 1% by volume or less, more preferably 0.5% by volume.
Or less, particularly preferably 0.3% by volume or less.

The saturated content, olefin content and aromatic content referred to in the present invention are JIS K 2536.
Means the volume percentage (% by volume) of the saturated component, olefin component and aromatic component measured in accordance with the fluorescent indicator adsorption method of "Petroleum product-component test method" specified in (1). The aromatic content of two or more rings is determined according to the Japan Petroleum Institute standard JIS 5S.
It means the volume% of the aromatic component having two or more rings measured by "petroleum products-hydrocarbon type test method-high performance liquid chromatography" specified in 49-97.

The light oil composition of the present invention is not particularly limited with respect to its pour point. However, the pour point of the composition is preferably −5 ° C. or lower, more preferably −10 ° C. or lower, and particularly preferably −20 ° C. or lower, from the viewpoint of low-temperature startability or low-temperature operation. -30 ° C
It is most preferred that: Here, the pour point is J
It refers to the pour point measured by IS K 2269 "Pour point of crude oil and petroleum products and cloud point test method of petroleum products".

The light oil composition of the present invention is not particularly limited with respect to its clogging point. However, the clogging point of the composition is preferably -1C or lower, more preferably -5C or lower, even more preferably -12C or lower, and preferably -19C or lower. Most preferred. Here, the clogging point means a clogging point measured according to JIS K 2288 "Light oil-clogging point test method".

The light oil composition of the present invention may contain additives other than the above-mentioned cetane number improver and detergent, if necessary. In particular, it is preferable to add a lubricity improver. As the lubricity improver, for example, one or more of carboxylic acid type, ester type, alcohol type and phenol type lubricity improvers can be arbitrarily used. Of these, carboxylic acid-based and ester-based lubricity improvers are preferred. Examples of the carboxylic acid-based lubricity improver include linoleic acid, oleic acid, salicylic acid, palmitic acid, myristic acid, hexadecenoic acid and a mixture of two or more of the above carboxylic acids. Examples of the ester-based lubricity improver include carboxylic acid esters of glycerin. The carboxylic acid constituting the carboxylic acid ester may be one kind or two or more kinds, and specific examples thereof include linoleic acid, oleic acid,
Salicylic acid, palmitic acid, myristic acid, hexadecenoic acid and the like can be mentioned.

There is no particular limitation on the amount of the lubricity improver. However, in order to bring out the effects of the compounded lubricity improver, specifically, in a diesel engine equipped with a distribution type injection pump, the increase in the driving torque of the pump during operation is suppressed and the wear of the pump is reduced. Therefore, the compounding amount of the lubricity improver is 35 mass ppm based on the total amount of the composition.
Or more, more preferably 50 mass ppm or more. And since the upper limit of the compounding amount cannot obtain the effect corresponding to the adding amount even if it is added more,
It is preferably at most 140 mass ppm, more preferably at most 105 mass ppm.

As in the case of the cetane number improver,
Commercially available products referred to as lubricity improvers are usually obtained in a state where the active ingredient contributing to the improvement of lubricity is diluted with a suitable solvent. When such a commercially available product is blended with the light oil composition of the present invention, the blending amount described above for the lubricity improver means the blending amount as an active ingredient.

To the light oil composition of the present invention, other known fuel oil additives can be added alone or in combination of several kinds in order to further enhance the performance thereof. These additives include, for example, low-temperature fluidity improvers such as ethylene-vinyl acetate copolymer and alkenyl succinamide; phenol-based and amine-based antioxidants; metal deactivators such as salicylidene derivatives; Anti-freezing agents such as polyglycol ethers; Corrosion inhibitors such as aliphatic amines and alkenyl succinates; Antistatic agents such as anionic, cationic and amphoteric surfactants; Colorants such as azo dyes; And the like. The addition amount of these additives can be arbitrarily determined, but the addition amount of each additive is usually 0.5% by mass or less, preferably 0.2% by mass or less based on the total amount of the gas oil composition. .

The light oil composition of the present invention can be produced by using a known method. Typically, in base gas oil,
It is manufactured by mixing a predetermined amount of a cetane number improver and a detergent, a lubricating oil improver and other additives as required. As the base gas oil, for example, a straight-run gas oil obtained from a normal-pressure distillation apparatus of crude oil; a straight-run heavy oil obtained from a normal-pressure distillation apparatus or a reduced-pressure gas oil obtained by subjecting a residual oil to a reduced-pressure distillation apparatus; Hydrorefined gas oil obtained by hydrorefining the resulting vacuum gas oil; hydrodesulfurized gas oil obtained by hydrodesulfurizing straight-run gas oil in one or more stages under severer conditions than ordinary hydrorefining; desulfurization Or catalytically cracked light oil obtained by catalytic cracking of undesulfurized vacuum gas oil, vacuum heavy gas oil or desulfurized heavy oil; straight kerosene obtained by atmospheric distillation of crude oil; hydrogenation obtained by hydrorefining straight kerosene Refined kerosene; one or more kinds of cracked kerosene obtained by cracking a gas oil fraction obtained by atmospheric distillation of crude oil can be used. If the sulfur content of the base gas oil exceeds 500 ppm by mass, the sulfur content is reduced to 50% by an appropriate means such as hydrorefining prior to the addition of the cetane number improver or the like.
A desulfurization treatment for reducing the content to 0 mass ppm or less is performed on the base gas oil.

[0062]

The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples.

Preparation of Light Oil Compositions Light oil compositions shown in Table 1 (Examples) and Table 2 (Comparative Examples) were prepared using detergents represented by the following formulas. The following cetane number improvers and lubricity improvers were used. Cetane number improver: 2-ethylhexyl nitrate Lubricity improver: Carboxylic acid mixture containing linoleic acid as a main component

[0064]

Embedded image Detergent 1: a compound represented by the following formula (number average molecular weight: 2500) (A: tert-butyl group, R ¹ , R ³ : hydrogen atom,
R ² , R ⁴ : methyl group, R ⁵ : trimethylene group)

[0065]

Embedded image Detergent 2: a compound represented by the following formula (number average molecular weight: 2300) (A: tert-butyl group, R ¹ , R ³ : hydrogen atom,
R ² , R ⁴ : methyl group, R ⁵ : ethylene group, n: 3)

[0066]

Embedded image Detergent 3: a compound represented by the following formula (number average molecular weight: 4500) (A: tert-butyl group, R ¹ , R ³ : hydrogen atom,
R ² , R ⁴ : methyl group, R ⁵ : ethylene group, n: 3)

[0067]

Detergent 4: a compound represented by the following formula (number average molecular weight: 2200) (A: tert-butyl group, R ¹ , R ³ : hydrogen atom,
R ² , R ⁴ R ⁵ : ethylene group, n: 3)

[0068]

Embedded image Detergent 5: Compound represented by the following formula (number average molecular weight: 4400) (A: tert-butyl group, R ¹ , R ³ : hydrogen atom,
R ² , R ⁴ : methyl group, R ⁵ : ethylene group, n: 3)

[0069]

Embedded image Detergent 6: Compound represented by the following formula (number average molecular weight: 2800) (A: tert-butyl group, R ¹ , R ³ : hydrogen atom,
R ² , R ⁴ : methyl group, R ⁵ : ethylene group, n: 3)

Detergent 7: a mono-substituted amine having a C 13-20 mixed fatty acid having oleic acid as a main component and an alkyl group having 8-16 carbon atoms and a mono-substituted amine having an alkenyl group having 8-16 carbon atoms Salt with a mixture of

Using each of the light oil compositions shown in Tables 1 and 2, (1) engine test 1, (2) engine test 2,
(3) Lubricity test and (4) Nozzle cleanliness test were performed. The test results are shown in Tables 1 and 2. (1) Engine test 1 Using the following engine A, TRIAS 24-5-19
PM and hydrocarbons (HC) in exhaust gas according to conditions of 93
And NOx were measured. PM was collected on a filter using a mini-dilution tunnel manufactured by Horiba, and the weight of the PM was measured. HC and NOx were measured by sampling directly from the exhaust pipe. (Engine specifications) Engine type: naturally-aspirated in-line 6-cylinder diesel Displacement: 7.1 L Inner diameter x stroke: 110 mm x 125 mm Compression ratio: 17.5 Maximum output: 260 ps / 2700 rpm Maximum torque: 77 kgf (754.6 N) / 2700 rpm

(2) Engine test 2 The exhaust pipe of the following engine B is led to the DPF device, and the PM and hydrocarbons (HC) in the exhaust gas discharged from the DPF device are
And NOx were measured under the conditions of TRIAS 24-5-1993. PM was collected on a filter using a mini-dilution tunnel manufactured by Horiba Ltd.
M was weighed. HC and NOx were measured by sampling directly from the exhaust pipe. (Engine specifications) Engine type: Natural-intake in-line 4-cylinder diesel Displacement: 4.985L Inner diameter x stroke: 115mm x 125mm Compression ratio: 19.5 Maximum output: 150ps / 3100rpm Maximum torque: 37kgf (362.6N) / 1600 rpm

(3) Lubricity test An HFRR test was performed under the following conditions, and the diameter of the circular scratch on the test ball after the test in the vibration direction and the diameter in the direction perpendicular to the vibration direction were measured. Was defined as a wear scar diameter (WSD). Test ball Material: ANSI 52100 Hardness: 645HV30 Surface roughness: 0.1 μm Ra or less Diameter: 6.25 nm, Test plate Material: ANSI 52100 Hardness: 180 HV30 Surface roughness: 0.1 μm Ra or less Load: 2N Test temperature: 60 ° C. Stroke: 1.0mm Frequency: 50Hz Time: 75 minutes

(4) Nozzle cleanliness test The engine A and the engine B used in the engine test 1 and the engine test 2 were used, and were continuously operated for 48 hours under the conditions of rotation 1840 rpm and torque 36.4 Nm. Was measured. The remaining nozzle flow rate indicates the ratio of the nozzle flow rate after the test to the flow rate of the new nozzle before the test. In addition,
The nozzle flow rate was measured at a needle valve lift of 0.1 mm. In this test, the larger the value of the nozzle residual flow rate ratio, the better the cleanliness.

[0075]

[Table 1]

[0076]

[Table 2]

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroaki Watanabe 8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Central Research Laboratory, Nishiishi Mitsui Co., Ltd. (72) Chikako Kaise 8, Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Prefecture Address F-term in Nippon Central Research Laboratory Co., Ltd. (reference) 4H015 AA23 AB05 AB07

Claims (1)

[Claims] 1. A cetane index containing at least 500 mass ppm of a cetane number improver based on the total amount of a composition, and at least one detergent selected from the group consisting of alkenyl succinic acid derivatives and amine salts of carboxylic acids. Is 45 or more,
90% by volume distillation temperature is 330 ° C or less, sulfur content is 5
A light oil composition having a kinematic viscosity at 30 ° C. of not more than 00 ppm by mass and not less than 1.7 mm ² / s.