JP7746076B2 - Fuel oil composition for internal combustion engines and method for producing the same - Google Patents

Description

The present invention relates to a fuel oil composition for internal combustion engines and a method for producing the same.

Class 3 heavy oil of JIS K2205:2006 (hereinafter also referred to as "C heavy oil") has a higher calorific value per unit volume than kerosene, light oil, Class A heavy oil (Class 1 heavy oil of JIS K2205:2006), etc., and can reduce the amount (volume) of fuel oil used. It is also inexpensive, and therefore is widely used as fuel oil for internal combustion engines such as marine diesel engines and as fuel oil for external combustion engines such as power generation boilers.
On the other hand, C heavy oil generally has a higher sulfur content and carbon residue than kerosene, diesel, A heavy oil, etc., and is known to have a greater environmental impact and to be more prone to sludge generation, which is likely to cause clogging of fuel oil filters. In response to this, C heavy oil compositions have been proposed that contain desulfurized fractions such as desulfurized kerosene and light cycle oil, and undesulfurized diesel fractions, with 15°C density, 50°C kinematic viscosity, carbon residue, asphaltene content, sulfur content, and aromatic content falling within specified ranges (see, for example, Patent Document 1). C heavy oil compositions that contain animal and vegetable oils, slurry oil, vacuum residual oil, etc. have also been proposed (see, for example, Patent Document 2).

Known marine fuel oils include those that meet ISO 8217 "Petroleum products - Fuels (class F) - Specification of marine fuels." Because these marine fuel oils can clog fuel oil filters, heavy oil compositions have been proposed that contain a specified amount of directly desulfurized heavy oil with specified properties, such as sulfur content, carbon residue, asphaltene content, 15°C density, and total sediment by hot filtration (ISO 10307-1) (see, for example, Patent Document 3).

JP 2013-203802 A JP 2009-227933 A JP 2014-028977 A

However, even when using an internal combustion fuel oil composition with improved oil passability as described above, when the internal combustion fuel oil composition is used in large diesel engines, such as those on large ships, the frequency of fuel oil filter blockage is likely to increase during normal use, and the frequency of blockage tends to increase even more when the composition is used after long-term storage in a fuel oil tank on the ship. Therefore, internal combustion fuel oil compositions are now required to have storage stability that maintains room-temperature oil passability, especially after long-term storage, and the required performance is becoming more stringent. Furthermore, marine diesel engines for such large ships and other vessels sometimes use a type equipped with a centrifugal separator as a pre-treatment device for the fuel oil composition, and these types of diesel engines require particularly strict storage stability.

In particular, when used in large diesel engines such as those on large ships, the operating environment of internal combustion engine fuel oil compositions changes significantly, and internal combustion engine fuel oil compositions are required to be able to adapt to these changes in the environment. In particular, it is important to have ignition performance without ignition delay and stable combustion performance (sometimes collectively referred to as "combustibility"). The C heavy oil composition described in Patent Document 2 is proposed as having excellent ignition and combustibility. However, its CCAI (Calculated Carbon Aromaticity Index) is high at 860 and 872, respectively, and does not satisfy the combustion performance required in recent years.

In recent years, preventing environmental pollution has been cited as one of the most important global issues, and as part of its air pollution prevention measures, the International Maritime Organization (IMO) has strengthened regulations requiring all ships to have a sulfur content in fuel oil of 0.5 mass% or less, down from the current 3.5 mass% or less, effective from 2020. Therefore, there is an urgent need to reduce the sulfur content of marine fuel oil compositions to 0.5 mass% or less, thereby improving environmental performance and reducing the burden on the environment. However, the sulfur contents of the C heavy oil compositions described in Patent Document 1 all exceed 2 mass%, and the sulfur content of the C heavy oil composition described in Patent Document 2 is 1.3 to 1.5 mass%, making them unsatisfactory in terms of environmental performance.

In addition to the above performance, viscosity suitability, with an appropriate kinematic viscosity, is also required. As described in Patent Document 1, one method for obtaining a product equivalent to heavy oil C is to use desulfurized diesel fractions, such as desulfurized diesel. Using desulfurized diesel fractions can reduce the sulfur content. However, using desulfurized diesel fractions results in a kinematic viscosity that is too low, making it incompatible with the operating ranges of various devices, such as pumps and flow meters, used to deliver the fuel oil composition to engines, and is also one of the factors that can cause a deterioration in lubrication performance.

Thus, conventional heavy oil C and the above-mentioned fuel oil compositions for internal combustion engines with improved oil permeability cannot be said to fully satisfy all of these performance requirements, and in applications where particularly strict storage stability performance is required, such as marine diesel engines equipped with a centrifugal separator as a pretreatment device for the fuel oil composition, it is extremely difficult to simultaneously satisfy all of these performance requirements.
Under these circumstances, an object of the present invention is to provide a fuel oil composition for internal combustion engines that meets extremely strict requirements for oil passing performance and storage stability while also satisfying other performance requirements, namely, combustion performance, environmental performance, and lubrication performance, and a method for producing the same.

After extensive research in light of the above-mentioned problems, the present inventors have discovered that the following invention can solve the problems. Specifically, the present invention provides a fuel oil composition for internal combustion engines having the following configurations, and a method for producing the same.

1. A fuel oil composition for internal combustion engines comprising a vegetable oil that satisfies both of the following ( _a1 ) and ( _a2 ), and a cracked light oil fraction that satisfies all of the following ( _b1 ) to ( _b3 ), wherein the content of the vegetable oil based on the total amount of the composition is 15.0% by volume or more and 35.0% by volume or less, and the content of the cracked light oil fraction based on the total amount of the composition is 0.20 times or more the content of the vegetable oil based on the total amount of the composition, and wherein the composition satisfies all of the following (1) to (4):
( _a1 ) Sulfur content is 0.02% by mass or less; ( _a2 ) Kinematic viscosity at 50°C is 20.0 ^mm2 /s or more and 50.0 ^mm2 /s or less; ( _b1 ) Sulfur content is 0.30% by mass or less; ( _b2 ) Kinematic viscosity at 50°C is 1.00 ^mm2 /s or more and 5.00 ^mm2 /s or less; ( _b3 ) Aromatic content is 60.0% by volume or more and 90.0% by volume or less; (1) Sulfur content is 0.40% by mass or less; (2) Kinematic viscosity at 50°C is 20.0 ^mm2 /s or more and 100.0 ^mm2 /s or less; (3) CCAI is 825 or less; (4) Latent sediment is 0.10% by mass or less. 2. The fuel oil composition for internal combustion engines according to claim 1, further comprising a directly desiccant heavy oil fraction that satisfies both of the following ( _c1 ) and ( _c2 ), and the content of the directly desiccant heavy oil fraction based on the total amount of the components is 50.0% by volume or more and 70.0% by volume or less.
( _c1 ) A sulfur content of 0.50% by mass or more and 0.60% by mass or less; ( _c2 ) A kinematic viscosity at 50°C of 100.0 ^mm2 /s or more and 200.0 ^mm2 /s or less. 3. The fuel oil composition for internal combustion engines according to 1 or 2 above, which is used in a marine diesel engine equipped with a centrifugal separator as a pretreatment device.
4. A vegetable oil that satisfies both of the following (a ₁ ) and (a ₂ ):
a cracked light oil fraction that satisfies all of the following (b ₁ ) to (b ₃ ):
The content of the vegetable oil based on the total amount of the composition is 15.0% by volume or more and 35.0% by volume or less,
The content of the cracked light oil fraction based on the total amount of the composition is 0.20 times or more the content of the vegetable oil based on the total amount of the composition.
A method for producing a fuel oil composition for internal combustion engines, which satisfies all of the following (1) to (4):
( _a1 ) Sulfur content is 0.02% by mass or less. ( _a2 ) Kinematic viscosity at 50°C is 20.0 ^mm2 /s or more and 50.0 ^mm2 /s or less. ( _b1 ) Sulfur content is 0.30% by mass or less. ( _b2 ) Kinematic viscosity at 50°C is 1.00 ^mm2 /s or more and 5.00 ^mm2 /s or less. ( _b3 ) Aromatic content is 60.0% by volume or more and 90.0% by volume or less. (1) Sulfur content is 0.40% by mass or less. (2) Kinematic viscosity at 50°C is 20.0 ^mm2 /s or more and 100.0 ^mm2 /s or less. (3) CCAI is 825 or less. (4) Latent sediment is 0.10% by mass or less. 5. 5. The method for producing a fuel oil composition for internal combustion engines according to 4 above, further comprising mixing a directly decomposed heavy oil fraction that satisfies both of the following ( _c1 ) and ( _c2 ) so that the content of the total components is 50.0% by volume or more and 70.0% by volume or less.
(c ₁ ) a sulfur content of 0.50% by mass or more and 0.60% by mass or less; (c ₂ ) a kinematic viscosity at 50°C of 100.0 mm ² /s or more and 200.0 ^{mm 2} /s or less;

The present invention provides a fuel oil composition for internal combustion engines that meets extremely strict requirements for oil passing performance and storage stability while also satisfying other performance requirements, namely combustion performance, environmental performance, and lubrication performance, as well as a method for producing the same.

Hereinafter, a fuel oil composition for internal combustion engines according to an embodiment of the present invention (hereinafter, sometimes simply referred to as "the present embodiment") will be specifically described. Note that the present invention is not limited to the following embodiment, and can be practiced with any modifications within the scope that does not impair the effects of the invention.
Furthermore, in this specification, the numerical values associated with "greater than or equal to,""less than or equal to," and "to" in describing a numerical range are numerical values that can be arbitrarily combined. For example, when a certain numerical range is described as "A to B" and "C to D," the numerical ranges "A to D" and "C to B" are also included.

[Fuel oil composition for internal combustion engines]
The fuel oil composition for internal combustion engines of this embodiment comprises a vegetable oil that satisfies both of the following ( _a1 ) and ( _a2 ), and a cracked light oil fraction that satisfies all of the following ( _b1 ) to ( _b3 ), wherein the content of the vegetable oil based on the total amount of the composition is 15.0% by volume or more and 35.0% by volume or less, and the content of the cracked light oil fraction based on the total amount of the composition is 0.20 times or more the content of the vegetable oil based on the total amount of the composition, and the fuel oil composition for internal combustion engines satisfies all of the following (1) to (4):
( _a1 ) Sulfur content is 0.02% by mass or less; ( _a2 ) Kinematic viscosity at 50°C is 20.0 ^mm2 /s or more and 50.0 ^mm2 /s or less; ( _b1 ) Sulfur content is 0.30% by mass or less; ( _b2 ) Kinematic viscosity at 50°C is 1.00 ^mm2 /s or more and 5.00 ^mm2 /s or less; ( _b3 ) Aromatic content is 60.0% by volume or more and 90.0% by volume or less; (1) Sulfur content is 0.40% by mass or less; (2) Kinematic viscosity at 50°C is 20.0 ^mm2 /s or more and 100.0 ^mm2 /s or less; (3) CCAI is 825 or less; (4) Latent sediment is 0.10% by mass or less.

(Composition and properties of fuel oil composition for internal combustion engines)
The fuel oil composition for internal combustion engines of this embodiment satisfies the composition and properties specified in the following (1) to (4).

(1) Sulfur Content The sulfur content of the fuel oil composition for internal combustion engines of this embodiment is 0.400% by mass or less. If the sulfur content exceeds 0.400% by mass, the increase in sulfur oxides in the exhaust gas increases the burden on the environment, thereby reducing environmental performance, and the increase in the acid dew point makes acid dew point corrosion more likely to occur. From the viewpoint of improving environmental performance and suppressing the occurrence of corrosion, the sulfur content is preferably 0.390% by mass or less, more preferably 0.385% by mass or less, and even more preferably 0.380% by mass or less. Furthermore, from the viewpoint of environmental performance, the lower the sulfur content, the better. As described above, the sulfur content is usually 0.010% by mass or more. Considering the ease of production of the fuel oil composition of this embodiment, the sulfur content is preferably 0.050% by mass or more, more preferably 0.100% by mass or more.
In this specification, the sulfur content is measured by selecting a measurement method depending on the content, and when the content is 0.01 to 5 mass%, it is a value measured in accordance with JIS K 2541-4:2003 (Crude oil and petroleum products - Determination of sulfur content - Part 4: Radioactive excitation method).

(2) Kinematic Viscosity at 50°C The kinematic viscosity at 50°C of the fuel oil composition for internal combustion engines of this embodiment is 20.0 ^mm2 /s or more and 100.0 ^mm2 /s or less. If the kinematic viscosity at 50°C is not within the above range, it may be difficult to conform to the operating range of various devices such as pumps and flow meters, lubricating performance may not be ensured, and the composition may not be usable as a fuel oil composition for internal combustion engines. Furthermore, there may be cases where the combustion performance is reduced, handling ease is reduced, and the heating temperature at the engine inlet is reduced.
In order to make it easier to adapt to the range of use of the above-mentioned various devices, and from the viewpoint of improving lubrication performance, combustion performance, and handleability, the kinematic viscosity at 50°C is 90.0 ^{mm 2} /s or less, more preferably 80.0 ^{mm 2} /s or less, and even more preferably 65.0 mm ² /s or less, and the lower limit is preferably 25.0 mm ² /s or more, more preferably 30.0 mm ² /s or more.
In this specification, the kinematic viscosity at 50°C is a value measured in accordance with JIS K 2283:2000 (Testing method for kinematic viscosity of crude oil and petroleum products).

(3) CCAI: Calculated Carbon Aromaticity Index
The CCAI of the fuel oil composition for internal combustion engines of this embodiment is 825 or less. If the CCAI is greater than 825, combustion performance will decrease. From the viewpoint of improving combustion performance, the CCAI is preferably 823 or less, more preferably 820 or less, and even more preferably 815 or less. The lower limit is not particularly limited, and is usually 750 or more, 775 or more, or 800 or more, from the viewpoint of combustion performance.
In this specification, CCAI is a value calculated by the calculation formula described in Annex F of ISO 8217-2012.

(4) Latent Sediment The latent sediment content of the fuel oil composition for internal combustion engines of this embodiment is 0.10% by mass or less. If the latent sediment content is greater than 0.10% by mass, storage stability decreases. From the viewpoint of improving storage stability, the latent sediment content is preferably 0.09% by mass or less, more preferably 0.08% by mass or less, and even more preferably 0.07% by mass or less. Furthermore, the lower limit is preferably as low as possible from the viewpoint of storage stability, and although there are no particular restrictions, it is usually 0.01% by mass or more.
In this specification, the total sediment potential is defined as the amount of sludge remaining on a filter paper obtained by leaving a sample (the fuel oil composition for internal combustion engines of the present embodiment) at 100°C for 24 hours and passing the sample through the filter paper, in accordance with ISO 10307-2A (Thermal Aging).

Furthermore, in addition to the properties and composition of (1) to (4) above, the internal combustion engine fuel oil composition of this embodiment preferably also satisfies at least one of the properties selected from the following (5) to (12), and it is particularly preferable that it satisfies all of the properties of (5) to (12) below.

(5) Carbon Residue The carbon residue of the fuel oil composition for internal combustion engines of this embodiment is preferably 3.0% by mass or less, more preferably 2.9% by mass or less, even more preferably 2.8% by mass or less, and even more preferably 2.7% by mass or less, and although there is no particular lower limit, it is usually 0.1% by mass or more. If the carbon residue is within the above range, the combustion performance of the fuel oil composition for internal combustion engines is improved, and the effect of reducing soot generation due to poor combustion is improved, allowing for more stable operation of the internal combustion engine.
In this specification, the carbon residue is a value measured in accordance with JIS K 2270-1:2009 (Crude oil and petroleum products - Determination of carbon residue - Part 1: Conradson method).

(6) Slope of Filtration Time The slope of the filtration time of the fuel oil composition for internal combustion engines of this embodiment is preferably 0.12 or less, more preferably 0.10 or less, and even more preferably 0.07 or less. There is no particular lower limit, and the smaller the value, the better. It is usually 0.01 or more.
The slope of the filtration time (Tn) is a value calculated based on the calculation method for the slope of the filtration time (Tn) described in the Examples.

(7) Density at 15°C The density at 15°C of the fuel oil composition for internal combustion engines of this embodiment is preferably 0.9000 g/ ^cm3 or more, more preferably 0.9100 g/ ^cm3 or more, even more preferably 0.9200 g/ ^cm3 or more, with the upper limit being preferably 0.9500 g/ ^cm3 or less, more preferably 0.9400 g/ ^cm3 or less, and even more preferably 0.9310 g/ ^cm3 or less. When the density at 15°C is within the above range, the sludge separation performance in a centrifugal separator installed as a pretreatment device before a diesel engine for a ship such as a large ship is improved, and the oil passing performance and storage stability are improved. In addition, the gross calorific value is also improved.
In this specification, the density at 15°C is a value measured in accordance with JIS K 2249-1:2011 (Crude oil and petroleum products - Determination of density - Part 1: vibration method).

(8) Flash Point The flash point of the fuel oil composition for internal combustion engines of this embodiment is preferably 70.0°C or higher, more preferably 85.0°C or higher, even more preferably 105.0°C or higher, still more preferably 115.0°C or higher, and particularly preferably 130.0°C or higher. If the flash point is within the above range, handling safety is improved. There is no particular upper limit, but it is usually 200.0°C or lower.
In this specification, the flash point is a value measured in accordance with JIS K 2265-3:2007 (Crude oil and petroleum products - Flash point test method - Part 3: Pensky-Martens closed-cell method).

(9) Pour Point The pour point of the fuel oil composition for internal combustion engines of this embodiment is preferably 30.0°C or lower, more preferably 20.0°C or lower, and even more preferably 15.0°C or lower. If the pour point is 30.0°C or lower, the flowability of the fuel oil composition in tanks, piping, etc. at low temperatures is improved. The lower the pour point, the better, and there is no particular restriction on the lower limit, but it is usually about -10.0°C or higher.
In this specification, the pour point is a value measured in accordance with JIS K 2269:1987 (Test method for pour point and cloud point of crude oil and petroleum products).

(10) Water Content The water content of the fuel oil composition for internal combustion engines of this embodiment is preferably 0.20% by volume or less, more preferably 0.15% by volume or less, and even more preferably 0.10% by volume or less. If the water content is within the above range, a decrease in storage stability (sludge formation due to an emulsion of asphaltene and water) can be suppressed, and clogging due to sludge can be prevented. Furthermore, the lower the water content, the better, and there is no particular limit, and it may be 0.0% by volume.
In this specification, the water content is a value measured in accordance with JIS K 2275-3:2015 (Crude oil and petroleum products - Determination of water content - Part 3: Karl Fischer coulometric titration method).

(11) Ash Content The ash content of the fuel oil composition for internal combustion engines of this embodiment is preferably 0.020% by mass or less, more preferably 0.015% by mass or less, and even more preferably 0.010% by mass or less. When the ash content is within the above range, storage stability and combustion performance are improved, and wear of cylinders, nozzles, etc. can be further suppressed, thereby reducing the environmental load caused by exhaust gases.
In this specification, the ash content is a value measured in accordance with JIS K 2272:1998 (Crude oil and petroleum products - Testing method for ash content and sulfated ash content).

(12) Gross Calorific Value The gross calorific value of the fuel oil composition for internal combustion engines of this embodiment is preferably 39,500 (kJ/L) or more, more preferably 40,000 (kJ/L) or more, and even more preferably 41,000 (kJ/L) or more. If the gross calorific value is within the above range, the amount of fuel oil composition used can be reduced, thereby improving fuel economy.
In this specification, the gross calorific values of vegetable oil, desulfurized diesel fraction, and cracked diesel fraction were measured in accordance with JIS K2279:2003 (Crude oil and petroleum products - Calorific value test method and calculation-based estimation method) and estimated (estimated using the calculation formula for crude oil, kerosene, diesel, A heavy oil, and B heavy oil specified in "6. Gross calorific value estimation method, 6.3 e) 1)"). In addition, the fuel oil composition, directly desulfurized diesel fraction, and cracked diesel fraction were measured in accordance with JIS K2279:2003 (Crude oil and petroleum products - Calorific value test method and calculation-based estimation method) and estimated (estimated using the calculation formula for C heavy oil specified in "6. Gross calorific value estimation method, 6.3 e) 1)".

(vegetable oil)
The fuel oil composition for internal combustion engines of this embodiment contains a vegetable oil that satisfies both of the following ( _a1 ) and ( _a2 ) in an amount of 15.0% by volume or more and 35.0% by volume or less, based on the total amount of the composition. If the vegetable oil is not contained in this amount, excellent environmental performance, oil passivation performance, and storage stability cannot be obtained in relation to the cracked light oil fraction that is used in combination with the vegetable oil.
(a ₁ ) a sulfur content of 0.02% by mass or less; (a ₂ ) a kinematic viscosity at 50°C of 20.0 mm ² /s or more and 50.0 mm ² /s or less;

The "vegetable oil" used in this embodiment refers to plant-derived oils and fats obtained by squeezing, extracting, refining, etc., lipids contained in plants, and hydrocarbon fractions derived from plant-derived oils and fats. More specifically, examples include crude oil obtained by squeezing and extracting natural vegetable oil raw materials; refined oils that have undergone various refining processes such as filtration to remove suspended impurities contained in crude oil, degumming to remove phospholipids and the like, deacidification to remove free fatty acids, bleaching to remove pigments, and dewaxing to remove wax; and processed oils and fats that have undergone processes such as hardening, fractionation, interesterification, and hydrogenation. Furthermore, triglycerides artificially synthesized by esterification of fatty acids with glycerin, the main component of vegetable oil (which typically accounts for 95 to 98% by mass of vegetable oil), may also be used.
In this embodiment, the vegetable oil may be any of the above-mentioned crude oil, refined oil, processed oils and fats, etc., but considering the quality and cost as a fuel oil composition, crude oil and refined oil are preferred, and among refined oils, refined oil in which suspended impurities contained in crude oil have been removed by filtration is preferred. In addition, the vegetable oil is likely to have the properties ( _a1 ) and ( _a2 ) described below, as well as the other properties ( _a3 ) to ( _a15 ).

Vegetable oils obtained from natural plants include those obtained from vegetable oil raw materials such as soybeans, rapeseeds, flaxseeds, safflower seeds, sunflower seeds, palm kernels, cottonseeds, grape seeds, pumpkin seeds, camellia seeds, tea seeds, borage seeds, perilla seeds, sesame seeds, perilla seeds, and cacao seeds; nuts such as coconuts, macadamia nuts, hazelnuts, walnuts, and peanuts; fruit pulp such as olives, palm kernels, and avocados; and by-products such as soybean germ, wheat germ, and corn germ, as well as rice bran.

In this embodiment, the vegetable oil can be any oil selected from the above vegetable oil raw materials without any particular limitations, and considering the ease of obtaining a vegetable oil that satisfies both ( _a1 ) and ( _a2 ) below, as well as the quality and cost as a fuel oil composition, palm oil obtained from at least one of palm kernel and palm oil, rapeseed oil, soybean oil, coconut oil, etc. are preferred. In addition, these tend to have the properties ( _a1 ) and ( _a2 ) described below, as well as the other properties ( _a3 ) to ( _a15 ).

Furthermore, vegetable oils may be named differently depending on the part of the plant from which they are made, but in this specification, they will be treated as belonging to the oil category bearing the name of the plant from which they are made, regardless of which part is used. As mentioned above, oils from which the main components (glyceride compounds) have been separated by refining may be called differently depending on the main components, but in this specification, they will be treated as belonging to the oil category bearing the name of the plant from which they are made.

For example, palm oil in the narrow sense refers to vegetable oil obtained from the fruit (flesh) of the palm tree, but vegetable oil obtained from the fruit (flesh) is also sometimes called palm oil, and vegetable oil obtained from the palm kernel (the seed part of the palm tree) is sometimes called palm kernel oil. Thus, even when palm is used as the vegetable oil raw material, the name may differ depending on which part of the palm tree is used. In this specification, both palm kernel oil and palm oil are treated as belonging to the palm oil category.
Furthermore, fractionated glyceride compounds composed of oleic acid contained in palm oil and fractionated glycerides composed of stearic acid are sometimes called palm olein and palm stearin, respectively. In this specification, these fractionated oils such as palm olein and palm stearin are also considered to belong to palm oil.

The oil components contained in these vegetable oils are glyceride compounds, and although the content cannot be generalized because it varies depending on the type of raw material of the vegetable oil, the manufacturing method, etc., it is usually 95 to 98 mass% based on the total amount of vegetable oil.
Glyceride compounds are ester compounds of saturated or unsaturated fatty acids and glycerin, and the glyceride compounds contained in vegetable oils vary depending on the vegetable oil raw material. The saturated or unsaturated fatty acids constituting the glyceride compounds are usually saturated or unsaturated fatty acids having 6 to 22 carbon atoms.

The following describes the fatty acid composition of the glyceride compounds contained in the above vegetable oils, focusing on the most preferred ones, namely palm oil, rapeseed oil, soybean oil, and coconut oil.

The glyceride compounds contained in palm oil (a vegetable oil obtained from the flesh of palm palms) cannot be generalized because they can vary depending on the origin and variety of palm, as well as the manufacturing method, but the fatty acid composition that makes up the glyceride compounds is usually 0.5 to 1.5 mass% myristic acid (carbon number 14, saturated acid), 40.0 to 50.0 mass% palmitic acid (carbon number 16, saturated acid), and palmitoleic acid. (C16, unsaturated acid) 0.1 to 1.5% by mass, stearic acid (C18, saturated acid) 1.5 to 4.0% by mass, oleic acid (C18, unsaturated acid) 35.0 to 45.0% by mass, linoleic acid (C18, unsaturated acid) 5.0 to 12.5% by mass, linolenic acid (C18, unsaturated acid) 0.5 to 1.5% by mass, and arachidic acid (C20, saturated acid) 0.01 to 1.0% by mass.
The composition of fatty acids constituting the glyceride compound contained in palm kernel oil (a vegetable oil obtained from the seeds of palm trees) is typically 1.5 to 2.5% by mass of caprylic acid (8 carbon atoms, saturated acid), 2.0 to 3.5% by mass of capric acid (10 carbon atoms, saturated acid), 45.0 to 55.0% by mass of lauric acid (12 carbon atoms, saturated acid), 10.0 to 20.0% by mass of myristic acid (14 carbon atoms, saturated acid), 5.0 to 10.0% by mass of palmitic acid (16 carbon atoms, saturated acid), 1.5 to 3.5% by mass of stearic acid (18 carbon atoms, saturated acid), 15.0 to 22.5% by mass of linoleic acid (18 carbon atoms, unsaturated acid), and 1.0 to 3.0% by mass of linolenic acid (18 carbon atoms, unsaturated acid).

The glyceride compounds contained in rapeseed oil cannot be generalized because they vary depending on the origin and variety of rapeseed (for example, native species, low erucic acid species, etc.), the manufacturing method, etc., but the composition of fatty acids that make up the glyceride compounds in native species is usually palmitic acid (16 carbon atoms, saturated acid) 2.0 to 5.0 mass%, palmitoleic acid (16 carbon atoms, unsaturated acid) 0.1 to 0.5 mass%, stearic acid (18 carbon atoms, saturated acid) 0.5 to 2.0 mass%, oleic acid (18 carbon atoms, unsaturated acid) 0.5 to 2.0 mass%, linoleic acid (18 carbon atoms, unsaturated acid) is 10.0 to 20.0 mass%, the total of linolenic acid (18 carbon atoms, unsaturated acid), octadecatetraenoic acid (18 carbon atoms, unsaturated acid) and arachidic acid (20 carbon atoms, saturated acid) is 7.5 to 12.5 mass%, gondoic acid (20 carbon atoms, unsaturated acid) is 5.0 to 12.0 mass%, behenic acid (22 carbon atoms, saturated acid) is 0.5 to 1.0 mass%, and erucic acid (22 carbon atoms, unsaturated acid) is 35.0 to 45.0 mass%.
In the case of low erucic acid species, palmitic acid (carbon number 16, saturated acid) is usually 2.5 to 7.0 mass%, palmitoleic acid (carbon number 16, unsaturated acid) is 0.1 to 0.6 mass%, stearic acid (carbon number 18, saturated acid) is 0.0 to 2.5 mass%, (carbon number 18, unsaturated acid) is 50.0 to 60.0 mass%, linoleic acid (carbon number 18, unsaturated acid) is 15.0 to 25.0 mass%, linolenic acid (carbon number 18, unsaturated acid) is 15.0 to 25.0 mass%, , unsaturated acid), octadecatetraenoic acid (18 carbon atoms, unsaturated acid), octadecatetraenoic acid (18 carbon atoms, unsaturated acid) and arachidic acid (20 carbon atoms, saturated acid) are 7.5 to 12.5 mass%, gondoic acid (20 carbon atoms, unsaturated acid) is 1.0 to 7.0 mass%, behenic acid (22 carbon atoms, saturated acid) is 0.1 to 1.0 mass%, and erucic acid (22 carbon atoms, unsaturated acid) is 3.0 to 7.5 mass%.

The glyceride compounds contained in soybean oil cannot be generalized as they can vary depending on the origin and variety of soybeans, the manufacturing method, etc., but the fatty acid composition that makes up the glyceride compounds is typically 8.0-15.0% by mass of palmitic acid (16 carbon atoms, saturated acid), 2.0-6.0% by mass of stearic acid (18 carbon atoms, saturated acid), 15.0-25.0% by mass of oleic acid (18 carbon atoms, unsaturated acid), 50.0-60.0% by mass of linoleic acid (18 carbon atoms, unsaturated acid), and 5.0-12.5% by mass of linolenic acid (18 carbon atoms, unsaturated acid).

The glyceride compounds contained in coconut oil (palm oil) cannot be generalized because they can vary depending on the origin and variety of coconut, manufacturing method, etc., but the fatty acid composition that makes up the glyceride compounds is as follows: caprylic acid (8 carbon atoms, saturated acid) 4.0-7.5% by mass, capric acid (10 carbon atoms, saturated acid) 5.0-8.0% by mass, lauric acid (12 carbon atoms, saturated acid) 47.5-55.0% by mass, myristic acid (14 carbon atoms, saturated acid) 15.0-20.0% by mass, palmitic acid (16 carbon atoms, saturated acid) 5.0-10.0% by mass, stearic acid (18 carbon atoms, saturated acid) 1.0-5.0% by mass, and oleic acid (18 carbon atoms, unsaturated acid) 0.5-2.0% by mass.

Vegetable oils that contain one or more of the above glyceride compounds artificially synthesized by the esterification reaction of fatty acids with glycerin can also be used.

The properties of vegetable oils will be explained below.
The vegetable oil used in this embodiment satisfies both of the following ( _a1 ) and ( _a2 ). By using a vegetable oil obtained from the vegetable oil raw material described above, the vegetable oil used in this embodiment is likely to have the following properties ( _a1 ) and ( _a2 ), as well as ( _a3 ) to ( _a15 ), etc.
(a ₁ ) a sulfur content of 0.02% by mass or less; (a ₂ ) a kinematic viscosity at 50°C of 20.0 mm ² /s or more and 50.0 mm ² /s or less;

( _a1 ) Sulfur content The vegetable oil used in this embodiment has a sulfur content of 0.02% by mass or less. If the sulfur content of the vegetable oil exceeds 0.02% by mass, the environmental performance of the fuel oil composition for internal combustion engines of this embodiment will be reduced in relation to the vegetable oil content and the cracked light oil fraction used in combination with the vegetable oil.
From the viewpoint of improving environmental performance, the sulfur content of the vegetable oil is preferably 0.015% by mass or less, and more preferably 0.01% by mass or less.

( _a2 ) Kinematic viscosity at 50°C The vegetable oil used in this embodiment has a kinematic viscosity at 50°C of 20.0 ^mm2 /s or more and 50.0 ^mm2 /s or less. If the vegetable oil has a kinematic viscosity outside this range, the lubrication performance and combustion performance of the fuel oil composition for internal combustion engines of this embodiment will be reduced in relation to the vegetable oil content and the cracked light oil fraction used in combination with the vegetable oil, and the composition will be less suitable for use in various equipment and will be less easy to handle.
Considering improvements in lubrication performance and combustion performance, ease of adaptation to the range of use of various equipment, and improved handleability, the kinematic viscosity of the vegetable oil at 50°C is preferably 22.0 mm ² /s or more, more preferably 25.0 mm ² /s or more, and even more preferably 27.0 mm ² /s or more, with the upper limit being preferably 50.0 mm ² /s or less, more preferably 40.0 mm ² /s or less, and even more preferably 35.0 mm ² /s or less.

Furthermore, in addition to the properties ( _a1 ) and ( _a2 ) above, the vegetable oil used in this embodiment preferably also satisfies at least one selected from the following properties ( _a3 ) to ( _a15 ), and it is particularly preferable that it satisfies all of the following properties ( _a3 ) to ( _a15 ).

( _a3 ) Carbon Residue Content The carbon residue content of the vegetable oil used in this embodiment is preferably 0.50% by mass or less, more preferably 0.40% by mass or less, and even more preferably 0.35% by mass or less. There is no particular lower limit, but it is usually 0.10% by mass or more.
When the carbon residue content is within the above range, the carbon residue content of the fuel oil composition for internal combustion engines of this embodiment tends to fall within the above preferred range in relation to the vegetable oil content and the cracked light oil fraction used in combination with the vegetable oil. As a result, the combustion performance of the fuel oil composition for internal combustion engines is improved, and the effect of reducing soot generation due to poor combustion is improved, enabling more stable operation of the internal combustion engine.

( _a4 ) Density at 15°C The density at 15°C of the vegetable oil used in this embodiment is preferably 0.9000 g/ ^cm3 or more, more preferably 0.9050 g/ ^cm3 or more, and even more preferably 9100 g/ ^cm3 or more, and the upper limit is preferably 0.9300 g/ ^cm3 or less, more preferably 0.9200 g/ ^cm3 or less.
When the density at 15°C is within the above range, the density at 15°C of the fuel oil composition for internal combustion engines of this embodiment is likely to fall within the above preferred range in relation to the vegetable oil content and the cracked light oil fraction used in combination with the vegetable oil. As a result, the sludge separation performance in a centrifugal separator installed as a pretreatment device before a diesel engine for a ship such as a large vessel is improved, and the oil passing performance and storage stability are improved. The gross calorific value is also improved.

(a ₅ ) Flash Point The flash point of the vegetable oil used in this embodiment is preferably 100.0°C or higher, more preferably 150.0°C or higher, even more preferably 200.0°C or higher, and still more preferably 240.0°C or higher.
When the flash point is within the above range, the flash point of the fuel oil composition for internal combustion engines of this embodiment is likely to fall within the above preferred range in relation to the vegetable oil content and the cracked light oil fraction used in combination with the vegetable oil, thereby improving safety in handling.

( _a6 ) Pour Point The pour point of the vegetable oil used in this embodiment is preferably 30.0° C. or lower, more preferably 27.5° C. or lower, and even more preferably 25.0° C. or lower. The lower limit of the pour point is not particularly limited, and is generally about −25.0° C. or higher.
When the pour point is 30.0°C or less, the pour point of the fuel oil composition for internal combustion engines of this embodiment tends to fall within the above-mentioned preferred range in relation to the vegetable oil content and the cracked light oil fraction used in combination with the vegetable oil, resulting in improved flowability of the fuel oil composition in tanks, piping, etc. at low temperatures.

( _a7 ) Water Content The water content of the vegetable oil used in this embodiment is preferably 0.20% by volume or less, more preferably 0.15% by volume or less, and even more preferably 0.10% by volume or less. When the water content of the vegetable oil is within the above range, the water content of the fuel oil composition for internal combustion engines of this embodiment is more likely to fall within the above preferred range in relation to the content of the vegetable oil and the cracked light oil fraction used in combination with the vegetable oil. As a result, a decrease in storage stability (sludge formation due to an emulsion of asphaltene and water) can be suppressed, and clogging due to sludge can be prevented. Furthermore, the lower the lower limit, the better, and there is no particular restriction, and it may be 0.0% by volume.

( _a8 ) Ash Content The ash content of the vegetable oil used in this embodiment is preferably 0.020% by mass or less, more preferably 0.015% by mass or less, and even more preferably 0.010% by mass or less. When the ash content is within the above range, the ash content of the fuel oil composition for internal combustion engines of this embodiment is more likely to fall within the above preferred range in relation to the vegetable oil content and the cracked light oil fraction used in combination with the vegetable oil. As a result, storage stability and combustion performance are improved, and wear of cylinders, nozzles, etc. can be further suppressed, thereby reducing the environmental load caused by exhaust gases. There is no particular restriction on the lower limit, and it may be 0.0% by mass.

( _a9 ) Nitrogen content The nitrogen content of the vegetable oil used in this embodiment is preferably 0.3% by mass or less, more preferably 0.2% by mass or less, and even more preferably 0.1% by mass or less. If the nitrogen content is 0.3% by mass or less, the content of nitrogen-containing compounds such as nitrogen oxides in the exhaust gas is reduced, thereby improving environmental performance. Furthermore, the lower the nitrogen content, the better, and although there is no particular limit, it is 0.0% by mass or more.
In this specification, the nitrogen content is a value measured by the CHN Coder method. Measurement by the CHN Coder method can be performed using, for example, an elemental analyzer such as a carbon, hydrogen, and nitrogen simultaneous quantitative analyzer.

(a ₁₀ ) Carbon Content The carbon content of the vegetable oil used in the present embodiment is not particularly limited, and is usually 74.0% by mass or more and 80.0% by mass or less.
In this specification, the carbon content is a value measured by the CHN Coder method. Measurement by the CHN Coder method can be performed using, for example, an elemental analyzer such as a carbon, hydrogen, and nitrogen simultaneous quantitative analyzer.

(a ₁₁ ) Hydrogen Content The hydrogen content of the vegetable oil used in the present embodiment is not particularly limited, and is usually 9.0% by mass or more and 14.0% by mass or less.
In this specification, the carbon content is a value measured by the CHN Coder method. Measurement by the CHN Coder method can be performed using, for example, an elemental analyzer such as a carbon, hydrogen, and nitrogen simultaneous quantitative analyzer.

( _a12 ) Oxygen content The oxygen content of the vegetable oil used in this embodiment is preferably 9.0% by mass or more, more preferably 10.0% by mass or more, and even more preferably 10.5% by mass or more. When the oxygen content is within the above range, combustion performance is improved. There is no particular upper limit, and it is usually 15.0% by mass or less.
In this specification, the oxygen content is a value calculated based on JIS M8813:2006 (Coals and cokes - Methods for elemental analysis) Appendix 5 (Calculation method of oxygen content), and is a value obtained by subtracting the above carbon content, hydrogen content, nitrogen content, sulfur content, and ash content from the total (100 mass%).

( _a13 ) Gross calorific value The gross calorific value of the vegetable oil used in this embodiment is preferably 39,500 (kJ/L) or more, more preferably 40,000 (kJ/L) or more, and even more preferably 40,500 (kJ/L) or more. When the gross calorific value is within the above range, the gross calorific value of the fuel oil composition for internal combustion engines of this embodiment is more likely to fall within the above preferred range in relation to the vegetable oil content and the cracked light oil fraction used in combination with the vegetable oil. As a result, when the gross calorific value is within the above range, the amount of fuel oil composition used can be reduced, thereby improving fuel economy.

(a ₁₄ ) Total Sediment (TSE)
The total sediment (TSE) content of the vegetable oil used in this embodiment is preferably 0.05% by mass or less, more preferably 0.03% by mass or less, and even more preferably 0.01% by mass or less. When the total sediment (TSE) content is 0.05% by mass or less, the oil passing performance and storage stability are improved. The lower the total sediment (TSE) content, the better, and although there is no particular limitation, it is 0.0% by mass or more.
Total Sediment Existence (TSE) can be measured in accordance with ISO 10307-1.

(a ₁₅ ) 90% by volume distillation temperature The 90% by volume distillation temperature of the vegetable oil used in this embodiment is not particularly limited, but is usually 310° C. or higher and 380° C. or lower. From the viewpoint of improving combustion performance, it is preferably 315° C. or higher, more preferably 320° C. or higher, and even more preferably 330° C. or higher, with the upper limit being preferably 370° C. or lower, more preferably 360° C. or lower, and even more preferably 355° C. or lower.
In this specification, the distillation properties are values measured in accordance with JIS K2254:1998 (Petroleum products - Distillation test method).

(Vegetable oil content)
In the fuel oil composition for internal combustion engines of this embodiment, the content of vegetable oil is 15.0% by volume or more and 35.0% by volume or less based on the total amount of the composition. If the vegetable oil content is outside this range, environmental performance, combustion performance, lubricity, oil passability, and storage stability will be reduced in relation to the cracked light oil fraction used in combination with the vegetable oil. From the viewpoint of improving environmental performance, combustion performance, lubricity, oil passability, and storage stability, the vegetable oil content is preferably 17.5% by volume or more, more preferably 20.0% by volume or more, even more preferably 25.0% by volume or more, and most preferably 27.5% by volume or more. The upper limit is preferably 32.5% by volume or less, more preferably 30.0% by volume or less.
In the present embodiment, the vegetable oil may be used alone or in combination of two or more. When two or more types are used in combination, the total amount thereof may be within the above content range.

(Cracked gas oil fraction)
The fuel oil composition for internal combustion engines of this embodiment contains a cracked light oil fraction that satisfies all of the following ( _b1 ) to ( _b3 ), and the content thereof, based on the total amount of the composition, is 0.20 times or more the content of the above vegetable oil, based on the total amount of the composition. The cracked light oil fraction is a light oil fraction obtained by fluid catalytic cracking of a directly desulfurized heavy oil fraction and/or a vacuum desulfurized light oil fraction.
If the cracked gas oil fraction is not contained in the above content, excellent oil passing performance and storage stability cannot be obtained in relation to the vegetable oil used in combination with the cracked gas oil fraction and its content.
(b ₁ ) a sulfur content of 0.30% by mass or less; (b ₂ ) a kinematic viscosity at 50°C of 1.00 mm ² /s or more and 5.00 mm ² /s or less; (b ₃ ) an aromatic content of 60.0% by volume or more and 90.0% by volume or less;

( _b1 ) Sulfur content The sulfur content of the cracked light oil fraction used in this embodiment is 0.30% by mass or less. If the sulfur content of the cracked light oil fraction exceeds 0.30% by mass, the environmental performance of the fuel oil composition for internal combustion engines of this embodiment will be reduced in relation to the vegetable oil used in combination with the cracked light oil fraction and its content.
From the viewpoint of improving environmental friendliness, the sulfur content of the cracked gas oil fraction is preferably 0.28 mass % or less, more preferably 0.26 mass % or less, and the lower limit is usually 0.01 mass % or more.

( _b2 ) Kinematic viscosity at 50°C The kinematic viscosity at 50°C of the cracked light oil fraction used in this embodiment is 1.00 ^mm2 /s or more and 5.00 ^mm2 /s or less. If the kinematic viscosity of the cracked light oil fraction is not within the above range, the lubrication performance and combustion performance of the internal combustion engine fuel oil composition of this embodiment will be reduced in relation to the vegetable oil used in combination with the cracked light oil fraction and its content, and the composition will be less suitable for use in various equipment and will be less easy to handle.
Considering improvements in lubrication performance and combustion performance, ease of adaptation to the range of use of various equipment, and improved handleability, the kinematic viscosity at 50°C of the cracked light oil fraction is preferably 1.25 mm ² /s or more, more preferably 1.50 mm ² /s or more, and even more preferably 1.70 mm ² /s or more, with the upper limit being preferably 3.50 mm ² /s or less, more preferably 3.00 mm ² /s or less, and even more preferably 2.60 mm ² /s or less.

( _b3 ) Aromatic content The aromatic content of the cracked light oil fraction used in this embodiment is 60.0% by volume or more and 90.0% by volume or less. If the aromatic content is outside this range, the oil passing performance and storage stability will be reduced in relation to the vegetable oil used in combination with the cracked light oil fraction and its content.
From the viewpoint of improving oil passing performance and storage stability, the aromatic content of the cracked light oil fraction is preferably 62.5% by volume or more, more preferably 65.0% by volume or more, and even more preferably 70.0% by volume or more, and the upper limit is preferably 85.0% by volume or less.

In this specification, the aromatic content, saturated content and olefin content of the cracked gas oil fraction, desulfurized gas oil fraction, straight-run gas oil fraction, vacuum gas oil fraction, desulfurized cracked gas oil fraction, straight-run gas oil fraction and hydrocracked gas oil fraction are values measured by the Petroleum Products - Hydrocarbon Type Test Method - High Performance Liquid Chromatography method (High Performance Liquid Chromatography method) specified in JPI-5S-49-2007.
The aromatic content, saturated content, resin content, and asphaltene content of the directly decomposed heavy oil fraction, cracked heavy oil fraction, atmospheric distillation residue fraction, and vacuum distillation residue fraction are values measured by the TLC/FID method specified in IP-469 (International Standard Test Methods (IP Test Methods)).

In addition to the above properties (b ₁ ) to (b ₃ ), the cracked light oil fraction used in this embodiment preferably also satisfies at least one selected from the following properties (b ₄ ) to (b ₁₇ ), and it is particularly preferable that it satisfies all of the following properties (b ₄ ) to (b ₁₇ ).

( _b4 ) Residual carbon content The residual carbon content of the cracked light oil fraction used in this embodiment is preferably 0.10 mass% or less, more preferably 0.05 mass% or less, and even more preferably 0.02 mass% or less, with no particular lower limit and usually 0.00 mass% or more.
When the carbon residue content is within the above range, the carbon residue content of the fuel oil composition for internal combustion engines of this embodiment is likely to be within the above preferred range in relation to the vegetable oil used in combination with the cracked light oil fraction and its content, which results in improved combustion performance of the fuel oil composition for internal combustion engines and an improved effect of reducing soot generation due to poor combustion, enabling more stable operation of the internal combustion engine.

( _b5 ) Density at 15°C The density at 15°C of the cracked light oil fraction used in this embodiment is preferably 0.9000 g/ ^cm3 or more, more preferably 0.9050 g/ ^cm3 or more, and even more preferably 0.9100 g/ ^cm3 or more, with the upper limit being preferably 0.9400 g/ ^cm3 or less, more preferably 0.9300 g/ ^cm3 or less, and even more preferably 0.9200 g/ ^cm3 or less.
When the density at 15°C is within the above range, the density at 15°C of the fuel oil composition for internal combustion engines of this embodiment is likely to fall within the above preferred range in relation to the vegetable oil used in combination with the cracked light oil fraction and its content. As a result, the sludge separation performance in a centrifugal separator installed as a pretreatment device before a diesel engine for a ship such as a large vessel is improved, and the oil passing performance and storage stability are improved. The gross calorific value is also improved.

(b ₆ ) Flash Point The flash point of the cracked light oil fraction used in this embodiment is preferably 60.0°C or higher, more preferably 65.0°C or higher.
When the flash point is within the above range, the flash point of the fuel oil composition for internal combustion engines of this embodiment is likely to fall within the above preferred range in relation to the vegetable oil used in combination with the cracked light oil fraction and its content, thereby improving safety in handling.

( _b7 ) Pour Point The pour point of the cracked light oil fraction used in this embodiment is preferably −15.0° C. or lower, more preferably −20.0° C. or lower, and even more preferably −25.0° C. or lower. The lower limit of the pour point is preferably as low as possible, and is not particularly limited, but is usually about −30.0° C. or higher.
When the pour point is −15.0° C. or lower, the pour point of the fuel oil composition for internal combustion engines of this embodiment tends to fall within the above-mentioned preferred range in relation to the vegetable oil used in combination with the cracked light oil fraction and its content, resulting in improved flowability of the fuel oil composition in tanks, piping, etc. at low temperatures.

( _b8 ) Water Content The water content of the cracked light oil fraction used in this embodiment is preferably 0.20% by volume or less, more preferably 0.15% by volume or less, and even more preferably 0.10% by volume or less. When the water content of the cracked light oil fraction is within the above range, the water content of the fuel oil composition for internal combustion engines of this embodiment is more likely to fall within the above preferred range in relation to the vegetable oil used in combination with the cracked light oil fraction and its content. As a result, a decrease in storage stability (sludge formation due to an emulsion of asphaltene and water) can be suppressed, and blockage due to sludge can be prevented. Furthermore, the lower the lower limit, the better, and there is no particular restriction, and it may usually be 0.0% by volume.

( _b9 ) Ash Content The ash content of the cracked light oil fraction used in this embodiment is preferably 0.020% by mass or less, more preferably 0.015% by mass or less, and even more preferably 0.010% by mass or less. When the ash content is within the above range, the ash content of the fuel oil composition for internal combustion engines of this embodiment is more likely to fall within the above preferred range in relation to the vegetable oil used in combination with the cracked light oil fraction and its content. As a result, storage stability and combustion performance are improved, and wear of cylinders, nozzles, etc. can be further suppressed, thereby reducing the environmental load caused by exhaust gases. There is no particular restriction on the lower limit, and it may be 0.0% by mass.

( _b10 ) Nitrogen Content The nitrogen content of the cracked light oil fraction used in this embodiment is preferably 0.3 mass% or less, more preferably 0.2 mass% or less, and even more preferably 0.1 mass% or less. If the nitrogen content is 0.3 mass% or less, the content of nitrogen-containing compounds such as nitrogen oxides in the exhaust gas is reduced, thereby improving environmental performance.
As for the lower limit, the lower the nitrogen content, the better, and there is no particular restriction, but it is 0.0 mass % or more.

(b ₁₁ ) Carbon Content The carbon content of the cracked gas oil fraction used in this embodiment is not particularly limited, and is usually 87.0 mass % or more and 92.0 mass % or less.

(b ₁₂ ) Hydrogen Content The hydrogen content of the cracked gas oil fraction used in this embodiment is not particularly limited, and is usually 8.0 mass % or more and 12.0 mass % or less.

(b ₁₃ ) Oxygen Content The oxygen content of the cracked gas oil fraction used in this embodiment is usually 0.1 mass % or less, and may be 0.0 mass %.

( _b14 ) Gross calorific value The gross calorific value of the cracked light oil fraction used in this embodiment is preferably 39,500 (kJ/L) or more, more preferably 40,000 (kJ/L) or more, and even more preferably 40,500 (kJ/L) or more. When the gross calorific value is within the above range, the gross calorific value of the fuel oil composition for internal combustion engines of this embodiment is more likely to fall within the above preferred range in relation to the vegetable oil used in combination with the cracked light oil fraction and its content. As a result, when the gross calorific value is within the above range, the amount of fuel oil composition used can be reduced, thereby improving fuel economy.

(b ₁₅ ) Real Sediment (TSE)
The total sediment (TSE) content of the cracked light oil fraction used in this embodiment is preferably 0.05% by mass or less, more preferably 0.03% by mass or less, and even more preferably 0.01% by mass or less. When the total sediment (TSE) content is 0.05% by mass or less, the oil passing performance and storage stability are improved. The lower the total sediment (TSE) content, the better, and although there is no particular limitation, it is 0.0% by mass or more.

(b ₁₆ ) 90% by volume distillation temperature The 90% by volume distillation temperature of the cracked light oil fraction used in this embodiment is not particularly limited, but is usually 300° C. or higher and 380° C. or lower. From the viewpoint of improving combustion performance, it is preferably 315° C. or higher, more preferably 320° C. or higher, with the upper limit being preferably 370° C. or lower, more preferably 360° C. or lower, and even more preferably 345° C. or lower.

(b ₁₇ ) Olefin content and saturates content The olefin content of the cracked gas oil fraction used in this embodiment is preferably 10.0% by volume or less, more preferably 5.0% by volume or less. There is no particular lower limit, and the smaller the better, and it is usually 1.0% by volume or more.
The saturated content is preferably 15.0% by volume or more, more preferably 20.0% by volume or more, and the upper limit is preferably 35.0% by volume or less, more preferably 30.0% by volume or less. When the contents of these components are within the above ranges, storage stability and combustion performance in particular are improved.

(Content of cracked gas oil fraction)
The content of the cracked light oil fraction contained in the fuel oil composition for internal combustion engines of this embodiment is 0.20 times or more the content of the vegetable oil based on the total amount of the composition. If it is less than 0.20 times, the oil passing performance and storage stability will be reduced depending on the vegetable oil used in combination with the cracked light oil fraction and its content. Furthermore, environmental friendliness and combustion performance may also be reduced.
From the viewpoint of improving oil passing performance, storage stability, environmental performance, and combustion performance, the content of the cracked light oil fraction is preferably 0.22 times or more, more preferably 0.25 times or more, and even more preferably 0.30 times or more of the content based on the total amount of the vegetable oil composition, with the upper limit being preferably 2.5 times or less, more preferably 2.0 times or less, even more preferably 1.5 times or less, and even more preferably 0.90 times or less.

The content of the cracked light oil fraction is not particularly limited as long as it satisfies the relationship with the vegetable oil content described above, but the absolute value is preferably 3.0% by volume or more, more preferably 5.0% by volume or more, and even more preferably 7.0% by volume or more, with the upper limit being preferably 28.0% by volume or less, more preferably 25.0% by volume or less, even more preferably 22.5% by volume or less, and even more preferably 18.0% by volume or less.

(directly desulfurized heavy oil fraction)
The fuel oil composition for internal combustion engines of this embodiment preferably contains a directly desulfurized heavy oil fraction that satisfies both of the following ( _c1 ) and ( _c2 ) in an amount of 50.0% by volume or more and 70.0% by volume or less based on the total amount of the composition. The directly desulfurized heavy oil fraction is a heavy oil fraction obtained by directly desulfurizing atmospheric distillation residue and/or vacuum distillation residue in a desulfurization unit.
( _c1 ) Sulfur content of 0.50% by mass or more and 0.60% by mass or less ( _c2 ) Kinematic viscosity at 50°C of 100.0 ^mm2 /s or more and 200.0 ^mm2 /s or less In the fuel oil composition for internal combustion engines of this embodiment, when the directly decomposed heavy oil fraction is contained in the above-mentioned amount, in relation to the above-mentioned vegetable oil and its content, and the cracked light oil fraction and its content, in addition to oil passing performance and storage stability performance, combustion performance, environmental performance and lubrication performance can be improved in a balanced manner.

( _c1 ) Sulfur content The sulfur content of the directly desulfurized heavy oil fraction used in this embodiment is preferably 0.60% by mass or less, more preferably 0.58% by mass or less, and even more preferably 0.56% by mass or less. When the sulfur content of the directly desulfurized heavy oil fraction is 0.60% by mass or less, the environmental performance of the fuel oil composition for internal combustion engines of this embodiment is likely to be improved in relation to the vegetable oil and its content, and the cracked light oil fraction and its content, which are used in combination with the directly desulfurized heavy oil fraction.
As for the lower limit, from the viewpoint of improving environmental performance, the lower the content, the better. However, taking into consideration the capacity of the direct desulfurization unit, the production volume and quality of the directly desulfurized heavy oil fraction, ease of availability, etc., the content is preferably 0.50 mass% or more, and more preferably 0.53 mass% or more.

( _c2 ) Kinematic Viscosity at 50°C The kinematic viscosity at 50°C of the directly desiccant heavy oil fraction used in this embodiment is preferably 100.0 ^mm2 /s or more, more preferably 110.0 ^mm2 /s or more, even more preferably 130.0 ^mm2 /s or more, with the upper limit being preferably 200.0 ^mm2 /s or less, more preferably 190.0 ^mm2 /s or less, and even more preferably 180.0 ^mm2 /s or less. When the kinematic viscosity of the directly desiccant heavy oil fraction is within the above range, the lubrication performance and combustion performance of the internal combustion fuel oil composition of this embodiment are improved in relation to the vegetable oil and its content, and the cracked light oil fraction and its content, which are used in combination with the directly desiccant heavy oil fraction, and the composition is more easily adapted to the range of use of various equipment, and handleability is likely to be improved.

In addition, the directly decomposed heavy oil fraction preferably used in this embodiment preferably satisfies, in addition to the above properties (c ₁ ) and (c ₂ ), at least one selected from the following properties (c ₃ ) to (c ₁₆ ), and particularly preferably satisfies all of the following properties (c ₃ ) to (c ₁₆ ).

( _c3 ) Aromatic Content The aromatic content of the directly decomposed heavy oil fraction used in this embodiment is preferably 50.0% by volume or more, more preferably 52.0% by volume or more, and the upper limit is preferably 65.0% by volume or less, more preferably 63.0% by volume or less.
When the aromatic content of the directly decomposed heavy oil fraction is within the above range, the oil passing performance and storage stability are improved in relation to the vegetable oil and its content, and the cracked light oil fraction and its content, which are used in combination with the directly decomposed heavy oil fraction. Also, the directly decomposed heavy oil fraction is easily available.

( _c4 ) Residual carbon content The residual carbon content of the directly decomposed heavy oil fraction used in this embodiment is preferably 7.0 mass% or less, more preferably 6.0 mass% or less, and even more preferably 5.0 mass% or less, with no particular lower limit and usually 2.0 mass% or more.
When the carbon residue content is within the above range, the carbon residue content of the fuel oil composition for internal combustion engines of this embodiment tends to fall within the above preferred range in relation to the vegetable oil and its content, and the cracked light oil fraction and its content, which are used in combination with the directly decomposed heavy oil fraction. As a result, the combustion performance of the fuel oil composition for internal combustion engines is improved, and the effect of reducing soot generation due to poor combustion is improved, enabling more stable operation of the internal combustion engine.

( _c5 ) Density at 15°C The density at 15°C of the directly decomposed heavy oil fraction used in this embodiment is preferably 0.9000 g/ ^cm3 or more, more preferably 0.9050 g/ ^cm3 or more, and even more preferably 0.9100 g/ ^cm3 or more, and the upper limit is preferably 0.9500 g/ ^cm3 or less, more preferably 0.9400 g/ ^cm3 or less, and even more preferably 0.9350 g/ ^cm3 or less.
When the density at 15°C is within the above range, the density at 15°C of the fuel oil composition for internal combustion engines of this embodiment tends to fall within the above preferred range in relation to the vegetable oil and its content, and the cracked light oil fraction and its content, which are used in combination with the directly decomposed heavy oil fraction. As a result, the sludge separation performance in a centrifugal separator installed as a pretreatment device before a diesel engine for a ship such as a large vessel is improved, and the oil passing performance and storage stability are also improved. The gross calorific value is also improved.

(c ₆ ) Flash Point The flash point of the directly decomposed heavy oil fraction used in this embodiment is preferably 100.0°C or higher, more preferably 150.0°C or higher, and even more preferably 180.0°C or higher.
When the flash point is within the above range, the flash point of the fuel oil composition for internal combustion engines of this embodiment tends to fall within the above preferred range in relation to the vegetable oil and its content, and the cracked light oil fraction and its content, which are used in combination with the directly decomposed heavy oil fraction, thereby improving safety in handling.

( _c7 ) Pour Point The pour point of the directly decomposed heavy oil fraction used in this embodiment is preferably 20.0°C or lower, more preferably 15.0°C or lower, and even more preferably 10.0°C or lower. The lower limit of the pour point is not particularly limited, and is usually about -10.0°C or higher.
When the pour point is 20.0°C or less, the pour point of the fuel oil composition for internal combustion engines of this embodiment tends to fall within the above-mentioned preferred range in relation to the vegetable oil and its content, and the cracked light oil fraction and its content, which are used in combination with the directly decomposed heavy oil fraction, and as a result, the flowability of the fuel oil composition in tanks, piping, etc. at low temperatures is improved.

( _c8 ) Water Content The water content of the directly decomposed heavy oil fraction used in this embodiment is preferably 0.20% by volume or less, more preferably 0.15% by volume or less, and even more preferably 0.10% by volume or less. When the water content of the directly decomposed heavy oil fraction is within the above range, the water content of the fuel oil composition for internal combustion engines of this embodiment is more likely to be within the above preferred range in relation to the vegetable oil and its content, and the cracked light oil fraction and its content, which are used in combination with the directly decomposed heavy oil fraction. As a result, a decrease in storage stability (sludge formation due to an emulsion of asphaltene and water) can be suppressed, and blockage due to sludge can be prevented.
The lower limit is preferably as small as possible, and there is no particular restriction, and it may be 0.0% by volume.

( _c9 ) Ash Content The ash content of the directly decomposed heavy oil fraction used in this embodiment is preferably 0.020% by mass or less, more preferably 0.015% by mass or less, and even more preferably 0.010% by mass or less. When the ash content is within the above range, the ash content of the internal combustion engine fuel oil composition of this embodiment is more likely to fall within the above preferred range in relation to the vegetable oil and its content, and the cracked light oil fraction and its content, used in combination with the directly decomposed heavy oil fraction. As a result, storage stability and combustion performance are improved, and wear of cylinders, nozzles, etc. can be further suppressed, thereby reducing the environmental load caused by exhaust gases. There is no particular restriction on the lower limit, and it may be 0.0% by mass.

( _c10 ) Nitrogen Content The nitrogen content of the directly decomposed heavy oil fraction used in this embodiment is preferably 0.3 mass% or less, more preferably 0.2 mass% or less, and even more preferably 0.1 mass% or less. When the nitrogen content is 0.3 mass% or less, the content of nitrogen-containing compounds such as nitrogen oxides in the exhaust gas is reduced, thereby improving environmental performance.
As for the lower limit, the lower the nitrogen content, the better, and there is no particular restriction, but it is 0.0 mass % or more.

(c ₁₁ ) Carbon Content The carbon content of the directly decomposed heavy oil fraction used in this embodiment is not particularly limited, and is usually 86.0 mass % or more and 91.0 mass % or less.

(c ₁₂ ) Hydrogen Content The hydrogen content of the directly decomposed heavy oil fraction used in this embodiment is not particularly limited, and is usually 11.0 mass % or more and 14.0 mass % or less.

(c ₁₃ ) Oxygen Content The oxygen content of the directly decomposed heavy oil fraction used in this embodiment is usually 0.1 mass % or less, and may be 0.0 mass %.

(c ₁₄ ) Gross calorific value The gross calorific value of the directly decomposed heavy oil fraction used in this embodiment is preferably 40,000 (kJ/L) or more, more preferably 40,500 (kJ/L) or more, and even more preferably 41,000 (kJ/L) or more. When the gross calorific value is within the above range, the gross calorific value of the fuel oil composition for internal combustion engines of this embodiment is more likely to fall within the above preferred range in relation to the vegetable oil and its content, and the cracked light oil fraction and its content, which are used in combination with the directly decomposed heavy oil fraction. As a result, when the gross calorific value is within the above range, the amount of fuel oil composition used can be reduced, thereby improving fuel economy.

(c ₁₅ ) Total Sediment (TSE)
The total sediment (TSE) content of the direct decomposition heavy oil fraction used in this embodiment is preferably 0.10 mass% or less, more preferably 0.07 mass% or less, and even more preferably 0.05 mass% or less. When the total sediment (TSE) content is 0.10 mass% or less, the oil passing performance and storage stability are improved.
Regarding the lower limit, the smaller the amount of total sediment (TSE) is, the better, and there is no particular limitation, but it is 0.0 mass % or more.

(c ₁₆ ) Saturates content, resin content, and asphaltene content The saturates content of the directly decomposed heavy oil fraction used in this embodiment is preferably 20.0 mass% or more and 50.0 mass% or less, more preferably 30.0 mass% or more and 40.0 mass% or less, the resin content is preferably 2.0 mass% or more and 10.0 mass% or less, more preferably 3.0 mass% or more and 7.0 mass% or less, and the asphaltene content is preferably 5.0 mass% or less, more preferably 4.0 mass% or less. There is no particular lower limit, and it is usually 1.0 mass% or more.
When the saturated content is within the above range, combustion performance is improved, and when the resin content and asphaltene content are within the above range, clogging of the fuel oil filter due to sludge generation is further suppressed, thereby improving oil passing performance, storage stability, and combustion performance.

(Content of direct desulfurized heavy oil fraction)
The content of the directly decomposed heavy oil fraction contained in the fuel oil composition for internal combustion engines of this embodiment, based on the total amount of the composition, is preferably 50.0% by volume or more, more preferably 52.0% by volume or more, and even more preferably 55.0% by volume or more, with the upper limit being preferably 70.0% by volume or less, more preferably 68.0% by volume or less, and even more preferably 65.0% by volume or less.
When the content of the directly decomposed heavy oil fraction is within the above range, in relation to the vegetable oil and its content, and the cracked light oil fraction and its content used in combination with the directly decomposed heavy oil fraction, in addition to oil passing performance and storage stability performance, combustion performance, environmental performance, and lubrication performance can be improved in a balanced manner.

(Other fractions)
The fuel oil composition for internal combustion engines of this embodiment may contain other fractions in addition to the above-mentioned vegetable oil and cracked light oil fraction, and the preferably used directly decomposed heavy oil fraction. There are no particular restrictions on the other fractions, and any fraction can be used as long as the fuel oil composition for internal combustion engines satisfies the composition and properties (1) to (4) above. From the viewpoint of achieving a balanced improvement in combustion performance, environmental performance, and lubrication performance in addition to oil passing performance and storage stability, the following light oil fractions, heavy oil fractions, etc. are preferred.

(heavy oil fraction)
The fuel oil composition for internal combustion engines of this embodiment may contain, as the heavy oil fraction of other fractions, for example, an atmospheric distillation residual oil fraction, a vacuum distillation residual oil fraction, or a cracked heavy oil fraction.
・Atmospheric distillation residual oil fraction (residual oil obtained by atmospheric distillation of crude oil using an atmospheric distillation unit)
・Vacuum distillation residual oil fraction (residual oil obtained by vacuum distilling atmospheric distillation residual oil in a vacuum distillation unit)
・Cracked heavy oil fraction (heavy oil fraction obtained by fluid catalytic cracking of directly decomposed heavy oil fraction)

(Properties of other heavy oil fractions)
The heavy oil fraction that can be used in this embodiment preferably has the following properties, for example: When the heavy oil fraction has the following properties, it is possible to improve combustion performance, environmental performance, and lubrication performance in a balanced manner, in addition to oil passing performance and storage stability.
The sulfur content is preferably 1.20% by mass or less, more preferably 1.00% by mass or less, and even more preferably 0.85% by mass or less, and the lower limit is usually 0.30% by mass or more.
The kinematic viscosity at 50°C is preferably about 30.00 mm ² /s or more, more preferably 50.00 mm ² /s or more, and even more preferably 100.0 ^{mm 2} /s or more, with the upper limit being preferably 200.0 mm ² /s or less, more preferably 195.0 mm ² /s or less.
The residual carbon content is preferably 10.0% by mass or less, more preferably 9.0% by mass or less, and even more preferably 8.0% by mass or less, and there is no particular lower limit, but it is usually 2.0% by mass or more.
The density at 15°C is preferably 1.3000 g/ ^cm3 or less, more preferably 1.2000 g/ ^cm3 or less, even more preferably 1.1000 g/ ^cm3 or less, and still more preferably 1.0500 g/ ^cm3 or less, and the lower limit is usually 0.9000 g/ ^cm3 or more.
The flash point is preferably 140.0°C or higher, more preferably 150.0°C or higher, and even more preferably 160.0°C or higher.
The pour point is preferably 25.0°C or less, more preferably 20.0°C or less, even more preferably 17.5°C or less, and even more preferably 15.0°C or less.
The water content is preferably 0.20% by volume or less, more preferably 0.15% by volume or less, and even more preferably 0.10% by volume or less.
The ash content is preferably 0.020% by mass or less, more preferably 0.015% by mass or less, and even more preferably 0.010% by mass or less.
The nitrogen content is preferably 0.3% by mass or less, more preferably 0.2% by mass or less, and even more preferably 0.1% by mass or less, the carbon content is usually 85.0% by mass or more and 91.0% by mass or less, the hydrogen content is usually 9.0% by mass or more and 14.0% by mass or less, and the oxygen content is usually 0.1% by mass or less, and may be 0.0% by mass.
The total calorific value is preferably 39,000 (kJ/L) or more, more preferably 39,500 (kJ/L) or more, and even more preferably 40,000 (kJ/L) or more.
The total sediment (TSE) content is preferably 0.10% by mass or less, more preferably 0.07% by mass or less, and even more preferably 0.05% by mass or less.
The aromatic content is preferably 50.0% by mass or more, more preferably 55.0% by mass or more, and although there is no particular upper limit, it is, for example, 75.0% by mass or less, preferably 65.0% by mass or less.
The saturated content is preferably 15.0 mass% or more and 45.0 mass% or less, more preferably 25.0 mass% or more and 40.0 mass% or less, the resin content is preferably 2.0 mass% or more and 10.0 mass% or less, more preferably 3.5 mass% or more and 6.5 mass% or less, and the asphaltene content is preferably 5.0 mass% or less and more preferably 4.0 mass% or less. There is no particular lower limit, and it is usually 1.0 mass% or more.

When heavy oil fractions from the above-mentioned other fractions are used, their content based on the total composition is preferably 1.0% by volume or more, more preferably 3.0% by volume or more, from the perspective of achieving a balanced improvement in combustion performance, environmental performance, and lubrication performance in addition to oil passing performance and storage stability, with the upper limit being preferably 15.0% by volume or less, more preferably 10.0% by volume or less, and even more preferably 9.0% by volume or less. When two or more heavy oil fractions are used, it is desirable that the total content of the heavy oil fractions be within the above range.

(Light oil fraction)
The fuel oil composition for internal combustion engines of this embodiment may contain, as the light oil fraction of other fractions, light oil fractions such as straight-run light oil fraction, vacuum light oil fraction, desulfurized light oil fraction, desulfurized cracked light oil fraction, straight-run light oil fraction, and hydrocracked light oil fraction.
・Straight-run diesel fraction (diesel fraction obtained by atmospheric distillation of crude oil in an atmospheric distillation unit)
・Vacuum diesel fraction (a diesel fraction obtained by vacuum distilling atmospheric distillation residue in a vacuum distillation unit)
Desulfurized diesel fraction (a diesel fraction obtained by desulfurizing a straight-run diesel fraction, a straight-run diesel fraction, and/or a vacuum diesel fraction)
・Desulfurized cracked diesel fraction (diesel fraction obtained by desulfurizing cracked diesel fraction)
Directly desulfurized diesel fraction (diesel fraction obtained by directly desulfurizing atmospheric distillation residue in a desulfurization unit)
- Hydrocracked diesel fraction (a diesel fraction obtained by hydrocracking vacuum diesel fraction in a hydrocracking unit)

(Properties of other diesel fractions)
The diesel fraction that can be used in this embodiment preferably has the following properties, for example: When the diesel fraction has the following properties, it is possible to improve combustion performance, environmental performance, and lubrication performance in a balanced manner, in addition to oil passing performance and storage stability.
The sulfur content is usually 0.50% by mass or less, preferably 0.30% by mass or less, and more preferably 0.10% by mass or less.
The kinematic viscosity at 50°C is preferably 5.00 mm ² /s or less, more preferably 3.00 mm ² /s or less, and even more preferably 2.50 mm ² /s or less, with the lower limit usually being 1.00 mm ² /s or more, preferably 1.50 mm ² /s or more.
The residual carbon content is preferably 0.10% by mass or less, more preferably 0.05% by mass or less, and even more preferably 0.02% by mass or less, and there is no particular lower limit, but it is usually 0.00% by mass or more.
The density at 15°C is preferably 0.8000 g/ ^cm3 or more, more preferably 0.8300 g/ ^cm3 or more, and even more preferably 0.8750 g/ ^cm3 or more, and the upper limit is preferably 0.9400 g/ ^cm3 or less, more preferably 0.9300 g/ ^cm3 or less, and even more preferably 0.9200 g/ ^cm3 or less.
The flash point is preferably 60.0°C or higher, more preferably 65.0°C or higher.
The pour point is preferably 0.0° C. or lower, more preferably −5.0° C. or lower, and even more preferably −10.0° C. or lower. The lower limit of the pour point is not particularly limited, and is generally −30.0° C. or higher.
The water content is preferably 0.20% by volume or less, more preferably 0.15% by volume or less, and even more preferably 0.10% by volume or less.
The ash content is preferably 0.020% by mass or less, more preferably 0.015% by mass or less, and even more preferably 0.010% by mass or less.
The nitrogen content is preferably 0.3% by mass or less, more preferably 0.2% by mass or less, and even more preferably 0.1% by mass or less, the carbon content is usually 85.0% by mass or more and 91.0% by mass or less, the hydrogen content is usually 9.0% by mass or more and 14.0% by mass or less, and the oxygen content is usually 0.1% by mass or less, and may be 0.0% by mass.
The total calorific value is preferably 38,000 (kJ/L) or more, more preferably 39,000 (kJ/L) or more, and even more preferably 39,500 (kJ/L) or more.
The total sediment (TSE) content is preferably 0.05% by mass or less, more preferably 0.03% by mass or less, and even more preferably 0.01% by mass or less.
The aromatic content is preferably 15.0% by mass or more, more preferably 20.0% by mass or more, and even more preferably 30.0% by volume or more. There is no particular upper limit, but it is, for example, 75.0% by mass or less.
The olefin content is preferably 10.0% by volume or less, more preferably 5.0% by volume or less, and there is no particular lower limit, but the lower the better, and it is usually 1.0% by volume or more. The saturated content is preferably 15.0% by volume or more, more preferably 20.0% by volume or more, and the upper limit is preferably 80.0% by volume or less, more preferably 70.0% by volume or less.
The 90% by volume distillation temperature is not particularly limited, but is usually 300°C or higher and 360°C or lower, preferably 315°C or higher, more preferably 320°C or higher, and the upper limit is preferably 350°C or lower, more preferably 345°C or lower.

When using diesel fractions from the above other fractions, their content based on the total composition is preferably 1.0% by volume or more, more preferably 3.0% by volume or more, from the perspective of achieving a balanced improvement in combustion performance, environmental performance, and lubrication performance in addition to oil passing performance and storage stability, with the upper limit preferably being 15.0% by volume or less, more preferably 10.0% by volume or less, and even more preferably 9.0% by volume or less. When two or more diesel fractions are used, the total content of the diesel fractions should be within the above range.

(Various additives)
To the internal combustion engine fuel oil composition of this embodiment, various additives such as antioxidants, low-temperature fluidity improvers, lubricity improvers, cetane number improvers, combustion promoters, detergents, sludge dispersants, antifungal agents, etc. may be appropriately selected and blended as needed within the range that allows the above-mentioned various properties to be maintained. Furthermore, coumarin may be blended from the viewpoint of diesel oil delivery tax.

(Application)
The fuel oil composition for internal combustion engines of this embodiment is a fuel oil composition that satisfies extremely strict requirements for oil passing performance and storage stability, while also satisfying other performance requirements, namely, combustion performance, environmental performance, and lubrication performance. Therefore, it is used as a fuel oil composition for internal combustion engines, and is particularly suitable for use in internal combustion engines such as large marine diesel engines equipped with a centrifugal separator as a pretreatment device.

[Method for producing fuel oil composition for internal combustion engines]
The method for producing a fuel oil composition for internal combustion engines of the present embodiment includes the steps of:
A vegetable oil that satisfies both of the following (a ₁ ) and (a ₂ ):
a cracked light oil fraction that satisfies all of the following (b ₁ ) to (b ₃ ):
The content of the vegetable oil based on the total amount of the composition is 15.0% by volume or more and 35.0% by volume or less,
The content of the cracked light oil fraction based on the total amount of the composition is 0.20 times or more the content of the vegetable oil based on the total amount of the composition.
The present invention provides a method for producing a fuel oil composition for internal combustion engines that satisfies all of the following requirements (1) to (4):
( _a1 ) Sulfur content is 0.02% by mass or less; ( _a2 ) Kinematic viscosity at 50°C is 20.0 ^mm2 /s or more and 50.0 ^mm2 /s or less; ( _b1 ) Sulfur content is 0.30% by mass or less; ( _b2 ) Kinematic viscosity at 50°C is 1.00 ^mm2 /s or more and 5.00 ^mm2 /s or less; ( _b3 ) Aromatic content is 60.0% by volume or more and 90.0% by volume or less; (1) Sulfur content is 0.40% by mass or less; (2) Kinematic viscosity at 50°C is 20.0 ^mm2 /s or more and 100.0 ^mm2 /s or less; (3) CCAI is 825 or less; (4) Latent sediment is 0.10% by mass or less.

The vegetable oil and cracked light oil fraction used in the production method of this embodiment are the same as the vegetable oil and cracked light oil fraction described as being contained in the fuel oil composition for internal combustion engines of this embodiment, and the content of these vegetable oil and cracked light oil fractions is also the same. It is also the same that directly decomposed heavy oil fractions are preferably used, and that other fractions such as various heavy oil fractions and various light oil fractions can also be used.

There are no particular restrictions on the order in which the vegetable oil, cracked light oil fraction, the preferably used directly decomposed heavy oil fraction, other various light oil fractions, heavy oil fractions, and various additives are mixed. For example, the vegetable oil may be mixed with the cracked light oil fraction, directly decomposed heavy oil fraction, other various light oil fractions, heavy oil fraction, and various additives added sequentially; the various additives may be mixed in advance, and then the vegetable oil, cracked light oil fraction, directly decomposed heavy oil fraction, and other various light oil fractions and heavy oil fractions are mixed; or the other various light oil fractions and heavy oil fractions may be mixed in advance, and then the vegetable oil, cracked light oil fraction, directly decomposed heavy oil fraction, and various additives are mixed.

Next, the present invention will be explained in more detail using examples, but the present invention is not limited to these examples in any way. The properties of each substrate were determined according to the following methods, as described above.

[Property measurement]
The properties of the various base materials (vegetable oil, cracked light oil fraction, directly desulfurized heavy oil fraction, desulfurized light oil fraction, and cracked heavy oil fraction) used in the Examples and Comparative Examples, as well as the properties of the fuel oil compositions of the Examples and Comparative Examples, were measured by the following methods. The properties of the various base materials are shown in Table 1. The properties of the fuel oil compositions are shown in Tables 2 and 3.
Sulfur content: Measured in accordance with JIS K 2541-4:2003 (Crude oil and petroleum products - Sulfur content test method - Part 4: Radiation excitation method).
Kinematic viscosity at 50°C: Measured in accordance with JIS K 2283:2000 (Testing method for kinematic viscosity of crude oil and petroleum products).
CCAI: Calculated using the formula described in Annex F of ISO 8217-2012.
Latent sediment: A sample (the fuel oil composition for internal combustion engines of the present embodiment) was left to stand at 100°C for 24 hours in accordance with ISO 10307-2A (Thermal Aging), and the amount of sludge remaining on the filter paper obtained by passing the sample through the filter paper was recorded.
Carbon residue: Measured in accordance with JIS K 2270-1:2009 (Crude oil and petroleum products - Determination of carbon residue - Part 1: Conradson method).
Density at 15°C: Measured in accordance with JIS K 2249-1:2011 (Crude oil and petroleum products - Determination of density - Part 1: Vibration method).
Flash point: Measured in accordance with JIS K 2265-3:2007 (Crude oil and petroleum products - Flash point test method - Part 3: Pensky-Martens closed-cell method).
Pour point: The pour point of the cracked light oil fraction was measured in accordance with JIS K2269:1987 (Test method for pour point and cloud point of crude oil and petroleum products).
Water content: Measured in accordance with JIS K 2275-3:2015 (Crude oil and petroleum products - Determination of water content - Part 3: Karl Fischer coulometric titration method).
Ash content: Measured in accordance with JIS K 2272:1998 (Crude oil and petroleum products - Testing method for ash content and sulfated ash content).
Gross calorific value: For vegetable oil, desulfurized diesel fraction, and cracked diesel fraction, the values were measured in accordance with JIS K2279:2003 (Crude oil and petroleum products - Calorific value test methods and methods for estimating by calculation) and estimated (using the formula for crude oil, kerosene, diesel, A-class fuel oil, and B-class fuel oil specified in "6. Gross calorific value estimation method, 6.3 e) 1)." Furthermore, for fuel oil composition, directly desulfurized diesel fraction, and cracked diesel fraction, the values were measured in accordance with JIS K2279:2003 (Crude oil and petroleum products - Calorific value test methods and methods for estimating by calculation) and estimated (using the formula for C-class fuel oil specified in "6. Gross calorific value estimation method, 6.3 e) 1)."
Nitrogen content, carbon content, and hydrogen content: The nitrogen content, carbon content, and hydrogen content were measured by the CHN Coder method using an elemental analyzer such as a carbon/hydrogen/nitrogen simultaneous determination apparatus.
Oxygen content: A value calculated based on JIS M8813:2006 (Coals and cokes - Elemental analysis methods) Appendix 5 (Calculation method for oxygen content), and is a value obtained by subtracting the above carbon content, hydrogen content, nitrogen content, sulfur content, and ash content from the total (100 mass%).
- Total Sediment Equivalent (TSE): Measured in accordance with ISO 10307-1.
90% by volume distillation temperature: Measured in accordance with JIS K2254:1998 (Petroleum products - Distillation test method).
Aromatic content, saturated content, and olefin content: Cracked gas oil fraction, desulfurized gas oil fraction, straight-run gas oil fraction, vacuum gas oil fraction, desulfurized cracked gas oil fraction, and straight-run gas oil fraction were measured by the Petroleum Products - Hydrocarbon Type Test Method - High Performance Liquid Chromatography method specified in JPI-5S-49-2007.
Aromatic content, saturated content, resin content, and asphaltene content: For the directly decomposed heavy oil fraction, cracked heavy oil fraction, atmospheric distillation residue fraction, and vacuum distillation residue fraction, these contents were measured by the TLC/FID method specified in IP-469 (International Standard Test Methods (IP Test Methods)).

[Performance evaluation criteria]
Each performance was evaluated on the following scales 1 to 5, and the worst evaluation was used as the overall evaluation. A rating of C indicates failure. The evaluation of each performance is shown in Table 2.

1. Oil Passage Performance The oil passage performance of the fuel oil compositions of each Example and Comparative Example was evaluated by calculating the slope of filtration time (Tn) using the following method and by the following criteria.
A: The slope of the filtration time (Tn) was 0.07 or less.
B: The slope of the filtration time (Tn) was more than 0.07 and 0.12 or less.
C: The slope of the filtration time (Tn) was more than 0.12.

(Calculation method of slope of filtration time)
For the fuel oil composition, the slope of the filtration time was calculated based on the following method.
(i) Measurement samples were collected up to the 100 mL mark in three graduated test tubes used in "JIS K2601:1998 - Crude Oil Testing Methods - 14. Water Debris Test Method 14.2 Water Debris Tester" (hereinafter also referred to as "Water Debris Tester"). Then, using the centrifuge used in the water debris tester, the samples were centrifuged at 60°C and a relative centrifugal force of 600 for 55 minutes.
(ii) Three 50 mL beakers were prepared, and the top 50 mL of the samples from the three centrifuged graduated test tubes was dispensed into each 50 mL beaker. The beakers after dispensing were weighed to the nearest 0.1 mg, and the weighed mass was designated as M ₁ (g). The dispensed samples were then heated for 15 minutes in a thermostatic bath maintained at 85±1°C.
(iii) Filter paper with pores of 20 to 25 μm (Whatman No. 4 (55 mmφ)) that has been dried in a dryer at 110°C for 20 minutes is placed in the filtration apparatus specified in the actual sediment test method of JPI-5S-60-2000 (hereinafter referred to as the filtration apparatus). An upper funnel is then placed on top and fixed in place to prevent leakage of the sample. At this time, a packing with a 28 mm diameter hole is placed on top to adjust the diameter of the filtration surface to 28 mm. A vacuum pump capable of suction at an exhaust speed of 12 L/min is then attached to the other end of the vacuum bottle. The upper funnel is also heated to 85±1°C, just like the sample.
(iv) Pour the first heated sample into the center of the filter paper, taking care not to let the sample touch the inner wall of the funnel. One minute after starting to pour the filter paper, start the vacuum pump and begin filtration. Measure the time required from the start of filtration until the sample is filtered and the entire filter paper is exposed (only the filtering surface with an inner diameter of 28 mm is sufficient), and define the measured time required for filtration as t (seconds). Also, weigh the beaker after use, and define the weighed mass as _M2 (g).
(v) After stopping the vacuum pump, repeat the same procedure as for the first sample for the second and third samples. During this time, do not perform any actions that change the measurement conditions, such as removing the tester or cleaning the equipment. Furthermore, if the sample cannot be filtered due to blockage of the filter paper, terminate the filtration process and proceed to the next step. Specifically, if filtration is not complete within 6 minutes of starting filtration, terminate the filtration process. If the filter paper is clogged, dissolve the remaining sample in toluene and remove it with a pipette or similar. Then, after washing the funnel and filter paper with n-heptane, remove the upper funnel and check the edge of the filter paper. If the color is visible up to the edge of the filter paper, the sample has leaked, so retest should be performed.
(vi) The filtration time per unit volume of fuel oil composition for each measurement was calculated using the following formula (1):
T _n =t _n /(M/d) (1)
(vii) In the above formula (1), n is the number of measurements, which is 3. Furthermore, _Tn is the filtration time per unit volume of the fuel oil composition calculated from the time required for filtration in the nth measurement (seconds/cm ³ ), _tn is the time required for filtration in the nth measurement (seconds), M is the mass of the filtered fuel oil composition (M ₁ -M ₂ ) (g), and d is the density of the fuel oil composition at 15°C (g/cm ³ ). If filtration was not possible due to clogging of the filter paper, the result was deemed "unable to calculate."
The vertical axis represents the filtration time per unit volume of the fuel oil composition, and the horizontal axis represents the number of measurements of the time required for filtration. From these plotted points, the slope of the approximate line is calculated using the least squares method, and this is taken as the slope of the filtration time (sec/cm ³ ).

2. Storage Stability The storage stability of the fuel oil compositions of each of the Examples and Comparative Examples was evaluated according to the following criteria based on the potential sediment measured by the method described above.
A. The latent sediment content was 0.07% by mass or less.
B. The potential sediment content was more than 0.07% by mass and 0.10% by mass or less.
C. The latent sediment content was more than 0.10% by mass.
3. Combustion Performance The combustion performance of the fuel oil compositions of each of the Examples and Comparative Examples was evaluated according to the following criteria based on the CCAI measured by the method described above.
A. The CCAI was 825 or less, the residual carbon content was 3.0% by mass or less, and the kinematic viscosity at 50°C was 100.0 mm ² /s or less.
B. The CCAI was 825 or less and the kinematic viscosity at 50°C was 100.0 mm ² /s or less.
C. The CCAI was greater than 825 or the kinematic viscosity at 50°C was greater than 100.0 mm ² /s.
4. Environmental Performance The environmental performance of the fuel oil compositions of the Examples and Comparative Examples was evaluated based on the sulfur content according to the following criteria.
A. The sulfur content was 0.380 mass% or less.
B. The sulfur content was more than 0.380 mass% and 0.400 mass% or less.
C. The sulfur content was more than 0.400% by mass.
5. Lubrication Performance The viscosity suitability of the fuel oil compositions of the Examples and Comparative Examples was evaluated based on the kinematic viscosity at 50°C according to the following criteria.
A. The kinematic viscosity at 50°C was 30.0 mm ² /s or more.
B. The kinematic viscosity at 50°C was 20.0 mm ² /s or more and less than 30.0 mm ² /s.
C. The kinematic viscosity at 50°C was less than 20.0 mm ² /s.

[Examples 1 to 6, Comparative Examples 1 to 6]
Various base materials having the properties and compositions shown in Table 1 were mixed in the proportions shown in Tables 2 and 3 to prepare the fuel oil compositions of Examples 1 to 6 and Comparative Examples 1 to 6.
The composition and properties of each fuel oil composition obtained, measured by the above-mentioned methods, are shown in Tables 2 and 3. Furthermore, each fuel oil composition obtained was evaluated for oil passing performance, storage stability, combustion performance, environmental performance, and viscosity suitability by the above-mentioned methods. The results are shown in Tables 2 and 3.

As shown in Table 2, the fuel oil composition for internal combustion engines of this embodiment was confirmed to be good in the evaluations of oil passing performance, storage stability, combustion performance, environmental performance, and lubrication performance. Furthermore, since the storage stability was rated A, it is clear that the composition can meet the extremely strict storage stability requirements that can withstand use in internal combustion engines such as marine diesel engines, particularly diesel engines of various ships such as large ships equipped with a centrifugal separator as a pretreatment device.
On the other hand, as shown in Table 3, it was confirmed that the fuel oil compositions of Comparative Examples 1 and 2, in which the vegetable oil content was outside the range of 15.0 to 35.0% by volume, were inferior in environmental performance and storage stability. In addition, it was confirmed that the fuel oil compositions of Comparative Examples 3 to 6, which did not contain any cracked light oil fraction, were inferior in at least one of storage stability, combustion performance, and environmental performance.

The internal combustion engine fuel oil composition of this embodiment is a fuel oil composition that meets extremely strict requirements for oil passing performance and storage stability, while also satisfying other performance requirements, namely combustion performance, environmental performance, and lubrication performance. It is suitable for use in internal combustion engines, particularly marine diesel engines, and is particularly suitable for use in marine diesel engines, such as those for large ships equipped with a centrifugal separator as a pretreatment device.

Claims (3)

A fuel oil composition for internal combustion engines comprising a vegetable oil satisfying both of the following ( _a1 ) and ( _a2 ) , a cracked light oil fraction satisfying all of the following ( _b1 ) to ( _b3 ), and a directly decomposed heavy oil fraction satisfying all of the following (c1 ₎ and (c2 ₎ , wherein the content of the vegetable oil based on the total amount of the composition is 15.0% by volume or more and 35.0% by volume or less, the content of the cracked light oil fraction based on the total amount of the composition is 0.20 times or more the content of the vegetable oil based on the total amount of the composition, and the content of the directly decomposed heavy oil fraction based on the total amount of the composition, and the composition satisfies all of the following (1) to (4):
( _a1 ) Sulfur content is 0.02% by mass or less; ( _a2 ) Kinematic viscosity at 50°C is 20.0 ^mm2 /s or more and 50.0 ^mm2 /s or less; ( _b1 ) Sulfur content is 0.30% by mass or less; ( _b2 ) Kinematic viscosity at 50°C is 1.00 ^mm2 /s or more and 5.00 ^mm2 /s or less; ( _b3 ) Aromatic content is 60.0% by volume or more and 90.0% by volume or less.
(c ₁ ) Sulfur content is 0.50% by mass or more and 0.60% by mass or less
(c ₂ ) A kinematic viscosity at 50°C of 100.0 mm ² /s or more and 200.0 mm ² /s or less
(1) Sulfur content of 0.40% by mass or less; (2) Kinematic viscosity at 50°C of 20.0 mm ² /s or more and 100.0 mm ² /s or less; (3) CCAI of 825 or less; (4) Latent sediment of 0.10% by mass or less. 2. The fuel oil composition for internal combustion engines according to claim 1 , which is used in a marine diesel engine equipped with a centrifugal separator as a pretreatment device. A vegetable oil that satisfies both of the following (a ₁ ) and (a ₂ ):
A cracked light oil fraction that satisfies all of the following (b ₁ ) to (b ₃ ):
and a directly decomposed heavy oil fraction that satisfies both of the following (c ₁ ) and (c ₂ ):
The content of the vegetable oil based on the total amount of the composition is 15.0% by volume or more and 35.0% by volume or less,
The content of the cracked light oil fraction based on the total amount of the composition is 0.20 times or more the content of the vegetable oil based on the total amount of the composition,
The directly decomposed heavy oil fraction is mixed so that the content of the directly decomposed heavy oil fraction based on the total amount of the components is 50.0% by volume or more and 70.0% by volume or less .
A method for producing a fuel oil composition for internal combustion engines, which satisfies all of the following (1) to (4):
( _a1 ) Sulfur content is 0.02% by mass or less; ( _a2 ) Kinematic viscosity at 50°C is 20.0 ^mm2 /s or more and 50.0 ^mm2 /s or less; ( _b1 ) Sulfur content is 0.30% by mass or less; ( _b2 ) Kinematic viscosity at 50°C is 1.00 ^mm2 /s or more and 5.00 ^mm2 /s or less; ( _b3 ) Aromatic content is 60.0% by volume or more and 90.0% by volume or less.
(c ₁ ) Sulfur content is 0.50% by mass or more and 0.60% by mass or less
(c ₂ ) A kinematic viscosity at 50°C of 100.0 mm ² /s or more and 200.0 mm ² /s or less
(1) Sulfur content of 0.40% by mass or less; (2) Kinematic viscosity at 50°C of 20.0 mm ² /s or more and 100.0 mm ² /s or less; (3) CCAI of 825 or less; (4) Latent sediment of 0.10% by mass or less.