JP2000144155A - Light oil composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a light oil composition having each specific cetane number improver content, cetane index, sulfur content and dynamic viscosity, or the like thereby significantly reduced in the emission of particulates in the diesel exhaust gas over the whole engine load range when combusted. SOLUTION: This light oil composition has a cetane number improver (e.g. 2-ethylhexyl nitrate) content of >=500 ppm, cetane index of >=45, 90% distillation temperature of <=330 deg.C, sulfur content of <=500 wt.%, and dynamic viscosity at 30 deg.C of >=1.7 mm2/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 capable of significantly reducing the amount of particulates in diesel exhaust gas over the entire engine load range. It relates to a composition.

[0002]

2. Description of the Related Art As components contained in diesel exhaust gas, nitrogen oxides (hereinafter referred to as NOx) and particulate matter (hereinafter referred to as PM) are 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. Diesel oil used as fuel for diesel engines since October 1997 has been
The sulfur content is reduced to 500 ppm by mass or less on the premise that a post-treatment device such as an OF catalyst (organic solvent soluble oxidation catalyst) and a NOx reduction catalyst is installed. 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, it is expected to be even more severe 20
Exhaust gas regulations after 2000 are also under consideration.

[0003]

SUMMARY OF THE INVENTION
Since the stricter exhaust emission regulations are enforced after the year, and because it takes a lot of time for the market to adopt the latest exhaust gas reduction technology, it is highly effective,
It is considered that reducing the exhaust gas by improving the quality of the fuel is very effective. There are several possible ways to improve the fuel for reducing exhaust gas.However, fuels containing oxygen-containing compounds have a concern that they may adversely affect engine parts, etc., and many problems must be solved for full-scale use. . The present invention
The present invention has been developed in view of the above circumstances, and an object thereof is to provide a gas oil composition capable of significantly reducing the emission of particulates contained in diesel exhaust gas over the entire engine load range. .

[0004]

The gas oil composition of the present invention comprises:
A cetane number improver containing 500 mass ppm or more based on the total amount of the composition, a cetane index of 45 or more, a 90% distillation temperature of 330 ° C. or less, a sulfur content of 500 mass ppm or less, and a kinematic viscosity at 30 ° C. Is 1.7 mm ² / s or more.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The cetane index of a gas oil composition is 45
It is necessary to be above. If less than 45
Indicates that the concentration of NOx, PM and aldehyde in the exhaust gas is high.
There is a risk of becoming. Therefore, in the light oil composition of the present invention,
Its cetane index must be at least 45,
It is preferably 7 or more, more preferably 48 or more.
More preferably, it is most preferably 50 or more. Departure
The cetane index referred to in the Ming is JIS K 2280 “Petroleum
Product-fuel oil-octane and cetane test methods and
Calculating Method Using 8.4 Variable Equations ”
Of the tongue index. " What
The cetane index in the above JIS standard is the cetane price
Although it is not applied to the one with the addition of the upper agent, the present invention
With the addition of the cetane improver, the cetane index
"8.4 Calculation method of cetane index using variable equation"
Represents the value calculated by Light oil set of the present invention
There is no particular limitation on the cetane number in the product. I
However, each concentration of NOx, PM and aldehyde in exhaust gas
Can be further reduced, the cetane number is 4
It is preferably 5 or more, more preferably 48 or more.
More preferably, it is most preferably 50 or more. What
The cetane number mentioned here is JIS K 2280
"Petroleum products-Fuel oil-Octane number and cetane number test methods
And cetane index calculation method ”,“ 7.
Cetane number measured in accordance with the "method". Also,
90% distillation temperature of gas oil composition (T₉₀) Below 330 ° C
It is necessary to be. If the temperature exceeds 330 ° C,
This is because the concentration of PM in the outgas may increase.
You. Therefore, in the light oil composition according to the present invention, its T₉₀Is
Must be 330 ° C or less,
Preferably, the temperature is 320 ° C. or less.
Even more preferably, it is 315 ° C or less.
No. T ₉₀There is no particular lower limit for
To improve the engine output.
T₉₀Is preferably 280 ° C or higher.
And more preferably 285 ° C. or higher.

[0006] the gas oil composition of the present invention is not particularly limited distillation characteristics other than the T _90. However, it is desirable that the following properties are satisfied. Initial boiling point: 145 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 ): 190 270 ° C. 70% by volume distillation temperature (T ₇₀ ): 220-280 ° C. 95% by volume distillation temperature (T ₉₅ ): 290-360 ° C. Distillation end point: 330-360 ° C. The initial boiling point of the gas oil composition is too low. In this case, the initial boiling point is generally 135 ° C. or higher, because some light fractions are vaporized and the spray range is too wide, and the amount of hydrocarbons entrained in the exhaust gas as unburned matter may increase. Preferably 140 ° C
It is recommended that the temperature be 145 ° C. or higher. On the other hand, if the initial boiling point is too high, there is a possibility that the low-temperature startability and the low-temperature operability may be deteriorated. Therefore, the upper limit of the initial boiling point is desirably 180 ° C, preferably 170 ° C. If T ₁₀ of the gas oil composition is too low, for the same reason as in the case initial boiling point is too low, since the increase in the amount of hydrocarbons entrained in the exhaust gas is concerned, T ₁₀ is 155 ° C. or higher, preferably 160 ° C or higher, more preferably 165 ° C
It is desirable that this is the case. On the other hand, if this is too high,
Since the low-temperature startability and there arises a problem concerned the low temperature operability, T ₁₀ is 210 ° C. or less, preferably 205 ° C. or less, and more preferably at 200 ° C. or less. If T ₃₀ of the gas oil composition is too low, for the same reasons as mentioned above, increase in the amount of hydrocarbons entrained in the exhaust gas is concerned. Thus, T ₃₀ is 175 ° C. or higher, preferably 180 ° C. or higher, more preferably at 185 ° C. or higher. On the other hand, if it is too high, the temperature is desirably 250 ° C. or lower, preferably 230 ° C. or lower, more preferably 210 ° C. or lower, since there is a possibility of causing a problem in low-temperature startability and low-temperature operation. The T ₅₀ of the gas oil composition is 190 ° C. in terms of fuel efficiency and engine output.
Or more, preferably 195 ° C. or more, more preferably 200 ° C.
It is desirable that the temperature is not less than ° C. And P in the exhaust gas
In reducing the M concentration, T ₅₀ is 270 ° C. or lower, preferably 260 ° C. or lower, more preferably 250 ° C. or lower, still more preferably 240 ° C. or lower, and even more preferably 23 ° C. or lower.
It is recommended that the temperature be 0 ° C or less, most preferably 225 ° C or less. Similar to the T ₇₀ is also T ₅₀ of the gas oil composition, influence the fuel consumption and engine output. For better fuel economy and higher engine output, T ₇₀ is generally above 220 ° C.
The temperature is preferably 225 ° C or higher, more preferably 230 ° C or higher. In order to further reduce the PM concentration in the exhaust gas, T ₇₀ is generally 300 ° C. or lower, preferably 290 ° C. or lower, more preferably 280 ° C. or lower.
The temperature is more preferably 270 ° C or lower, still more preferably 265 ° C or lower, and most preferably 260 ° C or lower. It is desirable T ₉₅ of the gas oil composition is 290 ° C. or more, in order to further reduce the PM concentration in the exhaust gas, T ₉₅ is usually 360 ° C. or less, preferably 35
5 ° C. or lower, more preferably 350 ° C. or lower, still more preferably 345 ° C. or lower, even more preferably 342 ° C. or lower, and most preferably 340 ° C. or lower. The distillation end point of the gas oil composition is desirably 320 ° C. or higher. However, in order to further reduce the PM concentration in the exhaust gas, it is desirable that the distillation end point is usually 360 ° C. or lower, preferably 355 ° C. or lower, more preferably 350 ° C. or lower. Incidentally, distillation characteristics referred to in the present invention (initial boiling _{point, T 10, T 30, T} 50,
T ₇₀ , T ₉₀ , distillation end point) are all JIS K 2254
It is a value measured by "petroleum product-distillation test method".

The sulfur content of the gas oil composition is 500 mass p.
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.
Therefore, the sulfur content of the gas oil composition according to the present invention is 50%.
It is necessary that the content be 0 ppm by mass or less. And this value is preferably 350 mass ppm or less,
0 ppm by mass or less, still more preferably 150 ppm by mass or less, and 100 ppm by mass or less.
Even more preferably at most 50 ppm by mass.
Most preferably, it is at most ppm by mass. Here, the sulfur content refers to the sulfur content based on the total amount of the gas oil composition measured by JIS K 2541 “Sulfur content test method”. The kinematic viscosity at 30 ° C. of the gas oil composition of the present invention needs to be 1.7 mm ² / s or more.
If it is less than 1.7 mm ² / s, control of the fuel injection timing may be difficult, and lubricity of the distribution type fuel injection pump attached to the engine may be impaired. Preferably this kinematic viscosity is 1.72 mm ² / s or more, more preferably 1.73 mm ² / s or more, even more preferably at 1.75 mm ² / s or more, 1.78 mm ² / S or more, even more preferably 1.80 mm ² / s or more. The upper limit of the kinematic viscosity at 30 ° C. is not particularly limited, but is 3.5 mm ² because the PM concentration in the exhaust gas can be further reduced.
/ S or less, more preferably 3.0 mm ² / s or less, still more preferably 2.5 mm ² / s or less, and even more preferably 2.4 mm ² / s or less. It is most preferably 2.2 mm ² / s or less. Here, the kinematic viscosity is JIS K
2283 "Crude oil and petroleum products-Kinematic viscosity test method and viscosity index calculation method". The density at 15 ° C. of the gas oil composition according to the present invention is not particularly limited. However, since the fuel consumption rate and acceleration can be further improved, the value is 802 kg /
It is preferably at least m ³ . On the other hand, the upper limit of the density at 15 ℃, since it is possible to reduce further the PM concentration in the exhaust gas, is preferably 840 kg / m ³ or less, more preferably 835 kg / m ³ or less, 830 kg more preferably / m ³ or less, still more preferably at 820 kg / m ³ or less, and most preferably 815Kg / m ³ or less. Here, the density refers to JIS K 2249 “Density test method for crude oil and petroleum products and density / mass / capacity conversion table”
Refers to the density measured by In the gas oil composition of the present invention, the content of each of the saturated component, the olefin component, and the aromatic component is not particularly limited, but preferably satisfies the following. Saturated content: 60 to 95% by volume Olefin content: 0 to 5% by volume Aromatic content: 5 to 40% by volume Incidentally, the saturated content of the gas oil composition is determined by NOx and PM in the exhaust gas. In reducing the respective concentrations, generally at least 60% by volume, preferably at least 65% by volume, more preferably at least 70% by volume, and most preferably at least 75% by volume.
It is desirable that this is the case. On the other hand, in order to maintain good low-temperature startability and low-temperature operability, the saturated content is usually 95% by volume or less, preferably 90% by volume or less, more preferably 85% by volume or less. The olefin content of the gas oil composition is generally 0% to 5% by volume, preferably 0% by volume, from the viewpoint of the stability of the composition.
It is desirable that the content is from 1% by volume to 1% by volume. Since the aromatic content of the gas oil composition is related to the fuel consumption rate and the engine output, it is generally 5% by volume or more, preferably 8% by volume or more, more preferably 10% by volume or more, even more preferably. It is desirable that the content be 12% by volume or more, most preferably 15% by volume or more. On the other hand, since the aromatic content is related to each concentration of NOx and PM contained in the exhaust gas, the content is generally 40% by volume or less, preferably 35% by volume or less, more preferably It is desirable that the content be 30% by volume or less, most preferably 25% or less. The saturated content, the olefin content and the aromatic content referred to in the present invention are the saturated content measured in accordance with the fluorescent indicator adsorption method of "Petroleum products-component test method" defined in JIS K 2536, It means the volume percentage (% by volume) of the olefin content and the aromatic content. There is no particular limitation on the pour point of the gas oil composition of the present invention. However, from the viewpoint of low-temperature startability or low-temperature operation, the pour point of the composition is preferably −5 ° C. or less, and −10 ° C.
Or less, still more preferably -20 ° C or less, and most preferably -30 ° C or less. Here, the pour point is defined by JIS K 2269.
It refers to the pour point measured by "Pour point of crude oil and petroleum products and cloud point test method of petroleum products". Similarly, the gas oil composition of the present invention has no particular limitation on the clogging point. However, in general, the clogging point of the composition is preferably -1 ° C or lower, more preferably -5 ° C or lower, even more preferably -12 ° C or lower, and -19 ° C or lower. Is most preferred. Here, the clogging point refers to a clogging point measured according to JIS K 2288 "Light oil-clogging point test method".

[0008] The light oil composition of the present invention needs to contain a cetane improver in an amount of 500 ppm by mass or more based on the total amount of the composition. As the cetane number improver of the present invention, various compounds known in the art as cetane number improvers can be arbitrarily used, and for example, nitrate esters and organic peroxides can be used. However, it is preferable to use a nitrate ester as the cetane number improver of the present invention. The nitrates include 2-chloroethyl nitrate, 2-ethoxyethyl nitrate, isopropyl nitrate, butyl nitrate, primary amyl nitrate, secondary amyl nitrate, isoamyl nitrate, primary hexyl nitrate, 2-hexyl nitrate, n
-Heptyl nitrate, n-octyl nitrate,
Various nitrates such as 2-ethylhexyl nitrate, cyclohexyl nitrate and ethylene glycol dinitrate are included. Among them, an alkyl nitrate having 6 to 8 carbon atoms is preferable. As the cetane number improver, one kind of a single compound may be used, or two or more kinds of compounds may be used in combination. It is to be noted that a commercially available product called a cetane number improver is usually obtained in a state where the active ingredient contributing to the improvement of the cetane number, that is, the cetane number improver is diluted with an appropriate solvent. When the light oil composition of the present invention is prepared using such commercially available products, it is important that the content of the active ingredient in the light oil composition is 500 ppm by mass or more based on the total amount of the composition. The content of the cetane number improver in the light oil composition of the present invention is 500 mass ppm based on the total amount of the composition.
If the above values are not satisfied, the NOx concentration, PM concentration, aldehyde concentration and the like of the diesel engine exhaust gas 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 It is still more preferably at least 900 ppm, most preferably at least 900 ppm by mass. Although the upper limit of the content of the cetane number improver is not particularly limited in the present invention, generally, the content of the cetane number improver is 1400 mass pp based on the total amount of the gas oil composition.
m, preferably 1250 ppm or less, more preferably 1100 ppm or less, most preferably 1000 ppm or less.

In the light oil composition of the present invention, additives other than the above-mentioned cetane number improver can be blended as required, and it is particularly preferable to blend a lubricity improver and / or a detergent. 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. Specific examples thereof include linoleic acid, oleic acid, salicylic acid, palmitic acid, myristic acid, and hexadecenoic acid. There is. 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. For this purpose, the compounding amount of the lubricity improver is preferably 35 mass ppm or more, more preferably 50 mass ppm or more based on the total amount of the composition. Since the upper limit of the compounding amount cannot obtain the effect corresponding to the adding amount even if it is added more,
0 mass ppm or less;
pm or less. As a detergent,
For example, imide compounds; alkenyl succinimides such as polybutenyl succinimide synthesized from polybutenyl succinic anhydride and ethylene polyamines; polyhydric alcohols such as pentaerythritol and polybutenyl succinic anhydride Succinic esters such as polybutenyl succinates synthesized from: copolymers such as dialkylaminoethyl methacrylate, polyethylene glycol methacrylate, and copolymers of vinylpyrrolidone with alkyl methacrylate; reaction products of carboxylic acids and amines Any one or more selected from ashless detergents can be used, and among these, the use of a reaction product of an alkenyl succinimide and a carboxylic acid with an amine is preferable. Examples of using alkenyl succinimide include those having a molecular weight of 1000 to 3
There is a case where an alkenyl succinimide having a molecular weight of about 000 is used alone, and a case where an alkenyl succinimide having a molecular weight of about 700 to 2000 and an alkenyl succinimide having a molecular weight of about 10,000 to 20,000 are mixed and used. The carboxylic acid constituting the reaction product of the carboxylic acid and the amine is 1
Or at least two kinds thereof. Specific examples thereof include fatty acids having 12 to 24 carbon atoms and 7 to 24 carbon atoms.
And the like. Fatty acids having 12 to 24 carbon atoms include, but are not limited to, linoleic acid, oleic acid, palmitic acid, myristic acid, and the like. In addition, aromatic carboxylic acids having 7 to 24 carbon atoms include:
Examples include, but are not limited to, benzoic acid, salicylic acid, and the like. The amine constituting the reaction product of the carboxylic acid and the amine may be one type or two or more types. As the amine used here, oleylamine is typical, but not limited thereto, and various amines can be used. There is no particular limitation on the amount of the detergent. However, the effect of blending the detergent,
Specifically, in order to bring out the effect of suppressing clogging of the fuel injection nozzle, the amount of the detergent is preferably at least 30 ppm by mass, more preferably at least 60 ppm by mass, based on the total amount of the composition, Even more preferably, the content is 80 ppm by mass or more. Even if an amount less than 30 ppm by mass is added, the effect may not be exhibited. On the other hand, if the amount is too large, the effect corresponding thereto cannot be expected, and conversely, there is a possibility of increasing NOx, PM, aldehyde, etc. in the exhaust gas of the diesel engine. Therefore, the amount of the detergent is 300 mass ppm. Is preferably
More preferably, it is 80 mass ppm or less. In addition,
As in the case of the cetane number improver described above, products sold on the market as lubricity improvers or detergents are obtained in a state where the active ingredients contributing to lubricity improvement or cleaning are diluted with an appropriate solvent. It is customary. When such a commercially available product is blended with the light oil composition of the present invention, the blending amount described above with respect to the lubricity improver and the detergent means the blending amount as an active ingredient.

The gas oil composition of the present invention may contain other known fuel oil additives alone for the purpose of further enhancing its performance.
Alternatively, they can be added in combination of several types. These additives include, for example, low-temperature fluidity improvers such as ethylene-vinyl acetate copolymer and alkenyl succinamide; antioxidants such as phenol and amine; metal deactivators such as salicylidene derivatives; Anti-freezing agents such as glycol ethers; Corrosion inhibitors such as aliphatic amines and alkenyl succinates; Antistatic agents such as anionic, cationic and amphoteric surfactants; Colorants such as azo dyes; Defoamers and the like can be mentioned. The addition amount of these other additives can be arbitrarily determined, but the amount of each additive is 0.5% by mass or less, preferably 0.1% by mass, based on the total amount of the gas oil composition.
It is usually less than 2% by weight.

The gas oil composition of the present invention can be produced by any method. Typically, it is manufactured by mixing a predetermined amount of a cetane number improver and, if necessary, a lubricating oil improver, a detergent, and other additives with a base gas oil. 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 a catalytic cracked gas oil obtained by catalytic cracking of undesulfurized vacuum gas oil, vacuum heavy gas oil or desulfurized heavy oil;
Straight-run kerosene obtained by atmospheric distillation of crude oil; hydrorefined kerosene obtained by hydrorefining straight-run kerosene; cracked kerosene obtained by cracking a gas oil fraction obtained by atmospheric distillation of crude oil; Species or two or more can be used. When the sulfur content of the base gas oil exceeds 500 ppm by mass, the sulfur content is adjusted to 500 mass pp by an appropriate means such as hydrorefining prior to compounding the cetane number improver and the like.
m is applied to the base gas oil.

[0012]

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. First, Table 1 shows the composition and properties of the light oil compositions used in Examples and Comparative Examples. The following additives were used. Cetane number improver: 2-ethylhexyl nitrate Lubricity improver: Carboxylic acid mixture mainly composed of linoleic acid Detergent: Reaction product of carboxylic acid mixture mainly composed of oleic acid and oleylamine Table 1 The following tests were performed using each of the light oil compositions shown in Table 1. Table 1 shows the results. (PM concentration measurement test) The PM concentration was measured in three modes simulating actual running using the following engines. PM
Was collected on a filter using a mini-dilution tunnel manufactured by Horiba, and the weight of PM was measured. Table 1 shows a relative value when the result of Comparative Example 1 is set to 100. (Engine specifications) Engine type: Natural intake type 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 / 2700 rpm (Mode Pattern 1: Mode simulating actual running assuming congestion Pattern 2: Mode simulating normal running Pattern 3: Mode simulating actual running including highway running (black smoke density Measurement test) Using the following vehicle, the density of black smoke with a free accelerator was measured. The concentration of black smoke was measured using a diesel exhaust black smoke meter manufactured by Nissan Altia Corporation. Table 1 shows a relative value when the result of Comparative Example 1 is set to 100. (Vehicle specifications) Engine type: Naturally aspirated in-line 4-cylinder diesel Displacement: 2.97 lL (Lubricity test) HFRR test method An HFRR test was performed under the following conditions, and the test ball after the test had a circular shape. The diameter of the wound in the vibration direction and the diameter in the direction perpendicular to the vibration direction were measured, and the average value was taken as the wear scar diameter (WSD). Test ball Material: ANSI 52100 Hardness: 645HV30 Surface roughness: 0.1 μmRa or less Diameter: 6.25 nm, Test plate Material: ANSI 52100 Hardness: 180HV30 Surface roughness: 0.1 μmRa or less Load: 2N Test temperature: 60 ° C. Stroke: 1.0 mm Frequency: 50 Hz Time: 75 minutes (Nozzle cleanliness test) Using a 4-cylinder engine with a displacement of 2 L, a continuous operation was performed for 48 hours under the conditions of a rotation of 1840 rpm and a torque of 36.4 Nm. The remaining flow rate 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. 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.

[0013]

[Table 1]

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masafumi Yoshimura 8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Central Research Laboratory, Nishiishi Mitsui Co., Ltd. (72) Inventor Masanori Sekimoto 8, Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Prefecture Address Nishiishi Mitsui Corporation Central Technology Research Institute (72) Inventor Hiroaki Watanabe No. 8 Chidoricho, Naka-ku, Yokohama-shi, Kanagawa Prefecture Nisseki Mitsui Corporation Central Technology Research Institute

Claims (1)

[Claims] 1. A light oil composition containing a cetane number improver, wherein the content of the cetane number improver is 5 based on the total amount of the composition.
The cetane index is 45 or more, the 90% distillation temperature is 330 ° C. or less, and the sulfur content is 5 or more.
The kinematic viscosity at 30 ° C of not more than 00 mass ppm is 1.7 m.
A light oil composition having a m ² / s or more.