JP7317735B2 - Fuel oil composition for external combustion engine and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fuel oil composition for an external combustion engine and a method for producing the same.

As fuel oil compositions for external combustion engines such as boilers, hot air heaters, and industrial furnaces, mainly kerosene (JIS K 2203), A heavy oil (JIS K 2205 class 1 heavy oil) and C heavy oil (JIS K 2205 3 types of heavy oil) are used.

Kerosene has extremely low contents of sulfur, nitrogen, and residual carbon, and has the characteristic of having a small environmental load due to its combustion. In addition, due to its excellent low-temperature fluidity, even when used in an external combustion engine equipped with a hydraulic spray burner with a low rated combustion volume and low spray oil pressure, it exhibits excellent combustibility in cold climates during the extreme cold season. Demonstrate. However, in cold regions in winter, there is a large demand for kerosene for indoor heating, etc., and special consideration is required for stable supply.
Heavy oil A is generally excellent in supply stability and has the advantage of having a higher calorific value than kerosene. However, A-heavy oil sometimes needs consideration such as facility measures in order to prevent filter clogging due to deposition of wax during the severe cold season in cold regions. Further, A heavy oil needs to be improved in combustibility when it is used in an external combustion engine equipped with a hydraulic atomizing burner having a small rated combustion amount and a low atomizing oil pressure.
C heavy oil has a higher calorific value than A heavy oil. However, due to its high viscosity, it is inconvenient to handle, such as the need for heating equipment when used. In addition, C heavy oil has low combustibility, so it cannot be used for external combustion engines equipped with hydraulic spray burners with low rated combustion and low spray oil pressure, and has high sulfur, nitrogen and residual carbon contents. It has the disadvantage of having a large environmental load.

For the purpose of contributing to the stable supply of fuel oil compositions for external combustion engines in winter, the present inventors have so far demonstrated excellent stability in long-term storage and excellent in cold regions during the severe cold season. A fuel oil composition for an external combustion engine that exhibits low-temperature fluidity, exhibits excellent combustibility even in an external combustion engine equipped with a hydraulic atomizing burner with a small rated combustion volume and a low spray oil pressure, and can be obtained at a high yield. have been proposed (see Patent Documents 1 to 3).

JP 2004-182744 A JP 2004-182745 A JP 2017-114948 A

However, there is a growing demand for further stabilization of the supply of fuel oil compositions for external combustion engines, especially in winter, and improvement in fuel consumption due to an increase in calorific value. Therefore, there is a demand for a fuel oil composition for external combustion engines that uses a wider variety of base materials and satisfies various required performances.

Therefore, the present invention is equipped with a hydraulic spray burner that has excellent stability even in long-term storage, exhibits excellent low-temperature fluidity even in cold regions during the severe cold season, and has a small rated combustion amount and a low spray oil pressure. A fuel oil composition for an external combustion engine that exhibits excellent combustibility even in an external combustion engine with a high yield, can be stably supplied with a high yield, and can contribute to improving fuel efficiency by having a high calorific value, and It aims at providing the manufacturing method.

As a result of intensive studies in view of the above problems, the inventors have found that the problems can be solved by the following inventions. That is, the present invention provides a fuel oil composition for an external combustion engine having the following constitutions and a method for producing the same.

[1] A heavy oil containing 90.0% by volume or more of a fraction obtained by hydrodesulfurizing a straight fraction obtained by atmospheric distillation of crude oil and satisfying all of the following conditions (a ₁ ) to (e ₁ ) A kerosene fraction, a paraffinic hydrocarbon that satisfies all of the following conditions (a ₂ ) to (e ₂ ), and an antioxidant, and the content of the paraffinic hydrocarbon is more than 10% by volume based on the total amount of the composition. An external combustion engine that is less than 40% by volume, has a content of the antioxidant based on the total amount of the composition of 20 mass ppm or more and 100 mass ppm or less, and satisfies all of the following conditions (1) to (6). Fuel oil composition for
(a ₁ ) initial boiling point of 140.0° C. or higher (b ₁ ) 95% by volume distillation temperature of 271.0° C. or higher and 300.0° C. or lower (c ₁ ) flash point of 40.0° C. or higher (d ₁ ) Sulfur content is 3 mass ppm or more and 10 mass ppm or less (e ₁ ) cloud point is −20.0° C. or less (a ₂ ) saturated content is 99.0% by volume or more (b ₂ ) sulfur content is 20 mass ppm or less (c ₂ ) cloud point of −50.0° C. or less (d ₂ ) kinematic viscosity at 30° C. of 5.00 mm ² /s or more and 20.0 mm ² /s or less (e ₂ ) flash point of 70.0 mm 2 /s or more; 0 ° C. or higher (1) Initial boiling point of 140.0 ° C. or higher (2) 95% by volume distillation temperature of 275.0 ° C. or higher and lower than 310.0 ° C. (3) Flash point of 40.0 ° C. or higher (4) Sulfur (5) Cloud point is -20.0 ° C. or less (6) Total calorific value is 37,000 (kJ / L) or more [2] Obtained by atmospheric distillation of crude oil A heavy _kerosene fraction containing 90.0% by volume or more of a fraction obtained by hydrodesulfurizing a straight fraction obtained by hydrodesulfurization and satisfying all of the following conditions (a ₁ ) to (e ₁ ); A paraffinic hydrocarbon and an antioxidant that satisfy all of the conditions of ~ (e ₂ ), the content of which is more than 10% by volume and less than 40% by volume based on the total amount of the paraffinic hydrocarbon composition, and the antioxidant A method for producing a fuel oil composition for an external combustion engine that satisfies all of the following conditions (1) to (6), wherein the content based on the total amount of the composition is 20 mass ppm or more and 100 mass ppm or less. .
(a ₁ ) initial boiling point of 140.0° C. or higher (b ₁ ) 95% by volume distillation temperature of 271.0° C. or higher and 300.0° C. or lower (c ₁ ) flash point of 40.0° C. or higher (d ₁ ) Sulfur content is 3 mass ppm or more and 10 mass ppm or less (e ₁ ) cloud point is −20.0° C. or less (a ₂ ) saturated content is 99.0% by volume or more (b ₂ ) sulfur content is 20 mass ppm or less (c ₂ ) cloud point of −50.0° C. or less (d ₂ ) kinematic viscosity at 30° C. of 5.00 mm ² /s or more and 20.0 mm ² /s or less (e ₂ ) flash point of 70.0 mm 2 /s or more; 0 ° C. or higher (1) Initial boiling point of 140.0 ° C. or higher (2) 95% by volume distillation temperature of 275.0 ° C. or higher and lower than 310.0 ° C. (3) Flash point of 40.0 ° C. or higher (4) Sulfur (5) Cloud point is -20.0 or less (6) Total calorific value is 37,000 (kJ / L) or more

According to the present invention, it has excellent stability even in long-term storage, exhibits excellent low-temperature fluidity even in cold regions during the severe cold season, and is equipped with a hydraulic spray burner with a small rated combustion amount and low spray oil pressure. A fuel oil composition for an external combustion engine that exhibits excellent combustibility even in a conventional external combustion engine, can be stably supplied with a high yield, and can contribute to improving fuel efficiency by having a high calorific value, and its production can provide a method.

Hereinafter, a fuel oil composition for an external combustion engine and a method for producing the same according to an embodiment of the present invention (hereinafter sometimes simply referred to as "this embodiment") will be specifically described. In this specification, the numerical values related to “less than”, “more than” and “to” regarding the description of numerical ranges are numerical values that can be arbitrarily combined, and the numerical values in the examples are used as the upper limit or lower limit. It is a numerical value that can be

[Fuel oil composition for external combustion engine]
The fuel oil composition for an external combustion engine of the present embodiment contains 90.0% by volume or more of a fraction obtained by hydrodesulfurizing a straight fraction obtained by atmospheric distillation of crude oil, and (a ₁ ) has an initial boiling point of 140.0° C. or higher, (b ₁ ) 95% by volume distillation temperature of 271.0° C. or higher and 300.0° C. or lower, (c ₁ ) flash point of 40.0° C. or higher, (d ₁ ) sulfur content A heavy kerosene fraction that satisfies both the conditions of 3 mass ppm or more and 10 mass ppm or less and (e ₁ ) a cloud point of −20.0° C. or less, and (a ₂ ) a saturated content of 99.0% by volume. (b ₂ ) sulfur content of 20 ppm by mass or less, (c ₂ ) cloud point of −50.0° C. or less, and (d ₂ ) kinematic viscosity at 30° C. of 5.00 mm ² /s or more and 20.0 mm ² / s or less and (e ₂ ) a flash point that satisfies both conditions of 70.0 ° C. or higher, and an antioxidant, and the content of the paraffinic hydrocarbon based on the total amount of the composition is It is more than 10% by volume and less than 40% by volume, the content of the antioxidant based on the total amount of the composition is 20 mass ppm or more and 100 mass ppm or less, and (1) the initial boiling point is 140.0 ° C. or more, ( 2) 95% by volume distillation temperature of 275.0° C. or more and less than 310.0° C., (3) Flash point of 40.0° C. or more, (4) Sulfur content of 3 mass ppm or more and 10 mass ppm or less, ( 5) The cloud point is -20.0 or less and (6) The total calorific value is 37,000 (kJ/L) or more.

(Composition and properties of fuel oil composition for external combustion engine)
The fuel oil composition for an external combustion engine of the present embodiment satisfies all of the composition and properties specified in (1) to (6) above. Each provision of (1) to (6) will be described in detail below.
(1) Initial boiling point The initial boiling point of the fuel oil composition for an external combustion engine of the present embodiment is 140.0°C or higher. If the initial boiling point is less than 140°C, the handling safety is lowered. From the viewpoint of improving safety in handling, it is preferably 145.0° C. or higher, more preferably 155.0° C. or higher, and from the viewpoint of improving the yield and combustibility, the upper limit is preferably 175.0. °C or less, more preferably 170.0°C or less.
In this specification, the initial boiling point, the 95% by volume distillation temperature and the end point described later are values measured according to JIS K2254: 1998 (petroleum products-distillation test method-).

(2) 95% by volume distillation temperature The 95% by volume distillation temperature of the fuel oil composition for an external combustion engine of the present embodiment is 275.0°C or higher and lower than 310.0°C. If the 95% by volume distillation temperature is not within the above range, excellent yield cannot be obtained. When the 95% by volume distillation temperature of the fuel oil composition for an external combustion engine is 275.0 ° C. or higher, it is higher than the 95% by volume distillation temperature of No. 1 kerosene (270 ° C. or lower), so the boiling point range is Since the boiling point range is wider than that of No. 1 kerosene, an excellent yield can be obtained.
The 95% by volume distillation temperature of the fuel oil composition for an external combustion engine of the present embodiment depends on the 95% by volume distillation temperature of the constituent fraction. Since the % distillation temperature is 271.0° C. or more and less than 310.0° C., the boiling point range is wider than that of No. 1 kerosene, and the yield from crude oil is higher than that of No. 1 kerosene.
From the viewpoint of improving the yield, the 95% by volume distillation temperature is preferably 277.0° C. or higher, more preferably 280.0° C. or higher, and still more preferably 290.0° C. or higher, and improving combustibility. Therefore, the upper limit is preferably 308.0° C. or less, more preferably 305.0° C. or less.

(3) Flash point The flash point of the fuel oil composition for an external combustion engine of the present embodiment is 40.0°C or higher. If the flash point is less than 40.0°C, safety in handling is lowered. From the viewpoint of improving safety in handling, the flash point is preferably 45.0°C or higher, more preferably 48.0°C or higher, and even more preferably 50.0°C or higher.
In this specification, the flash point of the fuel oil composition for an external combustion engine and the heavy kerosene fraction is JIS K 2265-1: 2007 (Crude oil and petroleum products-Flash point test method-Part 1: Tag sealing method) It is a value measured according to

(4) Sulfur Content The sulfur content of the fuel oil composition for an external combustion engine of the present embodiment is 3 mass ppm or more and 10 mass ppm or less. If the sulfur content is not within the above range, it may become difficult to maintain storage stability, and corrosion may occur due to an increase in sulfur oxides in the exhaust gas. From the viewpoint of improving storage stability and suppressing environmental load and corrosion, the sulfur content is preferably 7 ppm by mass or less, more preferably 5 ppm by mass or less, and even more preferably 4 ppm by mass or less.
As used herein, the sulfur content is a value measured according to JIS K2541-7:2003 (Crude oil and petroleum products-Sulfur content test method-Part 7: Wavelength dispersive X-ray fluorescence method).

(5) Cloud Point The cloud point of the fuel oil composition for an external combustion engine of the present embodiment is −20.0° C. or less. If the cloud point is higher than −20.0° C., the low-temperature fluidity is lowered, and the precipitated wax tends to clog the filter. It is preferably -23.0°C or less, more preferably -24.0°C from the viewpoint of suppressing filter clogging by improving low-temperature fluidity in the severe winter in cold regions and eliminating the need for equipment such as heat retention. below, and more preferably below -25.0°C. On the other hand, the lower limit is not particularly limited, but is usually -40.0°C or higher.
As used herein, the cloud point is a value measured according to JIS K2269:1987 (Determination of pour points and cloud points of crude oil and petroleum products).

(6) Total Calorific Value The total calorific value of the fuel oil composition for an external combustion engine of the present embodiment is 37,000 (kJ/L) or more. If the total calorific value is less than 37,000 (kJ/L), the fuel efficiency will decrease, making it difficult to improve the fuel efficiency. From the viewpoint of improving fuel economy, the total calorific value is preferably 37,010 (kJ/L) or more, more preferably 37,020 (kJ/L) or more. The upper limit is not particularly limited, but from the viewpoint of combustibility, it is preferably 37,100 (kJ/L) or less, more preferably 37,070 (kJ/L) or less.
In this specification, the total calorific value is measured according to JIS K2279: 2003 (Crude oil and petroleum products-calorific value test method and calculation estimation method-) and estimated ("6. Total calorific value estimation method, 6. 3 e) It is a value estimated by the calculation formula for crude oil, kerosene, light oil, A heavy oil and B heavy oil specified in 1).

Further, the fuel oil composition for an external combustion engine of the present embodiment has at least one selected from the following conditions (7) to (12) in addition to the properties and compositions of (1) to (6) above. is preferably satisfied, and it is particularly preferable to satisfy all of the following conditions (7) to (12).
(7) The result of the petroleum product reaction test is neutral (8) Moisture content is 0.01% by volume or less (9) Ash content is 0.001% by mass or less (10) Kinematic viscosity at 30 ° C. is 1.300 mm ² /s or more and 2.400 mm ² /s or less (11) Density at 15°C of 0.7985 g/cm ³ or more and 0.8020 g/cm ^{3 or} less (12) Saturation content based on the total amount of the composition is 80.0% by volume or more, Olefin content of 0.3% by volume or less, 1-ring aromatic content of 20.0% by volume or less, 2-ring aromatic content of 2.0% by volume or less, and 3- or more ring aromatic content of 1.0% by volume Below, each provision of (7) to (12) will be described in detail below.

(7) Petroleum Product Reaction Test It is preferable that the fuel oil composition for an external combustion engine of the present embodiment is neutral as a result of a petroleum product-reaction test according to JIS K 2252:1998. By being neutral, it prevents corrosion of various equipment that the fuel oil composition for an external combustion engine of the present embodiment comes into contact with, such as fuel oil tanks, pipes, diesel engines, and auxiliary equipment such as equipped pumps. Therefore, the stable operation of the external combustion engine becomes possible more easily.

(8) Moisture Content The moisture content of the fuel oil composition for an external combustion engine of the present embodiment is preferably 0.01% by volume or less. When the moisture content is within the above range, deterioration of storage stability, freezing and the like can be suppressed, and clogging of the filter can be prevented.
As used herein, the moisture content is a value measured according to JIS K 2275-3:2015 (Crude oil and petroleum products-Determination of moisture content-Part 3: Karl Fischer coulometric titration method).

(9) Ash Content The ash content of the fuel oil composition for an external combustion engine of the present embodiment is preferably 0.001% by mass or less. When the ash content is within the above range, the wear of the burner tip can be further suppressed, and the environmental load due to the exhaust gas can be reduced.
As used herein, the ash content is a value measured according to JIS K 2272:1998 (crude oil and petroleum products-ash and sulfated ash test methods-).

(10) Kinematic viscosity at 30° C. The kinematic viscosity at 30° C. of the fuel oil composition for an external combustion engine of the present embodiment is preferably 1.300 mm ² /s or more, more preferably 1.520 mm ² /s or more, and further It is preferably 1.750 mm ² /s or more, more preferably 1.850 mm ² /s or more, and the upper limit is preferably 2.400 mm ² /s or less, more preferably 2.300 mm ² /s or less, still more preferably 2.250 mm ² /s or less. When the kinematic viscosity at 30°C is within the above range, the fuel oil composition for an external combustion engine is easily adapted to the specifications of various devices such as pumps and flow meters, and the combustibility is improved.
As used herein, the kinematic viscosity at 30° C. is a value measured according to JIS K 2283:2000 (testing method for kinematic viscosity of crude oil and petroleum products).

(11) Density at 15°C The density at 15°C of the fuel oil composition for an external combustion engine of the present embodiment is preferably 0.7985 g/cm ³ or more and 0.8020 g/cm ³ or less. Within the above range, it is possible to improve the yield rate, improve the fuel consumption due to the amount of heat generated, and improve the combustibility. From the same viewpoint, it is preferably 0.7990 g/cm ³ or more, more preferably 0.7995 g/cm ³ or more, and the upper limit is preferably 0.8015 g/cm ³ or less, more preferably 0.8013 g/cm 3 . ³ or less.
As used herein, the density at 15° C. is a value measured according to JIS K 2249-1:2011 (Crude oil and petroleum products-Determination of density-Part 1: Vibration method).

(12) Composition The saturated content based on the total composition amount of the fuel oil composition for an external combustion engine of the present embodiment is preferably 80.0% by volume or more, more preferably 82.0% by volume or more, and still more preferably 84.0% by volume. It is 0% by volume or more. The olefin content is preferably 0.3% by volume or less, more preferably 0.1% by volume or less. The monocyclic aromatic content is preferably 20.0% by volume or less, more preferably 17.5% by volume or less, and even more preferably 15.0% by volume or less. The bicyclic aromatic content is preferably 2.0% by volume or less, more preferably 1.0% by volume or less, and even more preferably 0.75% by volume or less. Also, the aromatic content of three or more rings is preferably 1.0% by volume or less, more preferably 0.5% by volume or less, and even more preferably 0.3% by volume or less. When the content of these components is within the above range, the combustibility is particularly improved.
In this specification, saturated content, olefinic content, 1-ring aromatic content, 2-ring aromatic content and 3 or more ring aromatic content are specified in JPI-5S-49-2007, petroleum products-hydrocarbon type Test method—value measured by High Performance Liquid Chromatography method.

(heavy kerosene fraction)
The heavy kerosene fraction, which is the main component of the fuel oil composition for an external combustion engine of the present embodiment, is a fraction obtained by hydrodesulfurizing a straight fraction obtained by atmospheric distillation of crude oil (hereinafter referred to as "hydrodesulfurization It is a fraction that contains 90.0% by volume or more of "fraction" and satisfies all of the following conditions (a ₁ ) to (e ₁ ). If the heavy kerosene fraction is not contained, excellent low-temperature fluidity and combustibility cannot be obtained, stable supply due to high yield cannot be obtained, and fuel efficiency can be improved due to high calorific value. A fuel oil composition for an external combustion engine cannot be obtained.
(a ₁ ) initial boiling point of 140.0° C. or higher (b ₁ ) 95% by volume distillation temperature of 271.0° C. or higher and 300.0° C. or lower (c ₁ ) flash point of 40.0° C. or higher (d ₁ ) Sulfur content is 3 ppm by mass or more and 10 ppm by mass or less (e ₁ ) Cloud point is −20.0° C. or less

Hydrodesulfurization conditions for hydrodesulfurization of the straight fraction to obtain the hydrodesulfurization fraction are, for example, as follows. By setting the following hydrodesulfurization conditions, the hydrodesulfurization fraction can be obtained more easily.
Reaction temperature: 250° C. to 390° C., preferably 300° C. to 350° C. Hydrogen partial pressure: 1.0 MPa to 10.0 MPa, preferably 2.0 MPa to 5.0 MPa Hydrogen/feedstock ratio: 50 Nm ³ / kL or more and 500 Nm ³ /kL or less, preferably 100 Nm ³ /kL or more and 300 Nm ³ /kL or less,
Liquid hourly space velocity: 0.1 hr ^-1 or more and 10.0 hr ^-1 or less, preferably 1.0 hr ^-1 or more and 8.0 hr ^-1 or less

(a ₁ ) Initial boiling point The initial boiling point of the heavy kerosene fraction used in the present embodiment is 140.0°C or higher. If the initial boiling point is not within the above range, safety in handling is lowered. From the viewpoint of improving safety in handling, it is preferably 142.0° C. or higher, more preferably 145.0° C. or higher, and the upper limit is preferably 160.0 from the viewpoint of improving the yield and combustibility. °C or less, and more preferably 155.0°C or less. Further, when the initial boiling point of the heavy kerosene fraction is within the above range, the initial boiling point of the fuel oil composition for an external combustion engine of the present embodiment can be easily adjusted to 140.0°C or higher.

(b ₁ ) 95% by volume distillation temperature The 95% by volume distillation temperature of the heavy kerosene fraction used in the present embodiment is 271.0°C or higher and 300.0°C or lower. As described above, the 95% by volume distillation temperature is within the above range, and by using a heavy kerosene fraction with a wider boiling point range than kerosene, as a result, the yield of the fuel oil composition for an external combustion engine of the present embodiment can be improved. The 95% by volume distillation temperature is preferably 273.0° C. or higher, more preferably 275.0° C. or higher from the viewpoint of improving yield, and the upper limit is preferably 290.0 from the viewpoint of improving combustibility. °C or less, more preferably 280.0°C or less. Further, when the 95% by volume distillation temperature of the heavy kerosene fraction is within the above range, the 95% by volume distillation temperature of the fuel oil composition for an external combustion engine of the present embodiment is 275.0°C or higher and 310.0°C. It becomes easy to make it less than °C.

( _c1 ) Flash point The flash point of the heavy kerosene fraction used in the present embodiment is 40.0°C or higher. If the flash point is not within the above range, safety in handling is lowered. From the viewpoint of improving safety in handling, the flash point is preferably 42.0°C or higher, more preferably 44.5°C or higher. Moreover, when the flash point of the heavy kerosene fraction is within the above range, the flash point of the fuel oil composition for an external combustion engine of the present embodiment can be easily adjusted to 40.0° C. or higher.

(d ₁ ) Sulfur content The sulfur content of the heavy kerosene fraction used in the present embodiment is 3 mass ppm or more and 10 mass ppm or less. If the sulfur content is not within the above range, it may become difficult to maintain storage stability, and corrosion may occur due to an increase in sulfur oxides in the exhaust gas. From the viewpoint of improving storage stability and suppressing environmental load and corrosion, the sulfur content is preferably 8 ppm by mass or less, more preferably 6 ppm by mass or less, and the lower limit is preferably 4 ppm by mass or more. is. Moreover, when the sulfur content of the heavy kerosene fraction is within the above range, the sulfur content of the fuel oil composition for an external combustion engine of the present embodiment can easily be 3 mass ppm or more and 10 mass ppm or less.

(e ₁ ) Cloud Point The cloud point of the heavy kerosene fraction used in the present embodiment is −20.0° C. or less. If the cloud point is higher than −20.0° C., the low-temperature fluidity is lowered, and the precipitated wax tends to clog the filter. From the viewpoint of suppressing filter clogging by improving low-temperature fluidity in the harsh winter of cold regions and eliminating the need for equipment such as heat retention, the temperature is preferably -20.5 ° C. or less, and there is no particular limit as the lower limit. No, but usually -40.0°C or higher. Further, when the cloud point of the heavy kerosene fraction is within the above range, the cloud point of the fuel oil composition for an external combustion engine of the present embodiment can easily be -20.0°C or lower.

In addition, the heavy kerosene fraction used in the present embodiment, in addition to the properties and composition of (a ₁ ) to (e ₁ ) above, is at least selected from the following conditions (f ₁ ) to (h ₁ ) It is preferable to satisfy one condition, and it is particularly preferable to satisfy all of the following conditions (f ₁ ) to (h ₁ ).

(f ₁ ) Density at 15° C. The density at 15° C. of the heavy kerosene fraction used in the present embodiment is preferably 0.7890 g/cm ³ or more, more preferably 0.7920 g/cm ³ or more, and still more preferably It is 0.7940 g/cm ³ or more, and the upper limit is preferably 0.7980 g/cm ³ or less, more preferably 0.7970 g/cm ³ or less. When the density at 15° C. is within the above range, the yield is improved, fuel efficiency is improved due to the calorific value, and combustibility is also improved.

(g ₁ ) Kinematic viscosity at 30° C. The kinematic viscosity at 30° C. of the heavy kerosene fraction used in the present embodiment is preferably 1.300 mm ² /s or more, more preferably 1.400 mm ² /s or more, and further It is preferably 1.500 mm ² /s or more, and the upper limit is preferably 1.600 mm ² /s or less, more preferably 1.550 mm ² /s or less, still more preferably 1.510 mm ² /s or less. When the kinematic viscosity at 30°C is within the above range, the fuel oil composition for an external combustion engine is easily adapted to the specifications of various devices such as pumps and flow meters, and the combustibility is improved.

(h ₁ ) Composition The saturated content based on the total composition amount of the heavy kerosene fraction used in the present embodiment is preferably 70.0% by volume or more, more preferably 75.0% by volume or more, and still more preferably 78.0% by volume. It is 0% by volume or more, and the upper limit is preferably 90.0% by volume or less, more preferably 85.0% by volume or less, and even more preferably 83.0% by volume or less. The olefin content is preferably 0.3% by volume or less, more preferably 0.1% by volume or less. The 1-ring aromatic content is preferably 25.0% by volume or less, more preferably 23.0% by volume or less, and still more preferably 20.0% by volume or less, and the 2-ring aromatic content is preferably 3.0% by volume. Below, it is more preferably 2.0% by volume or less, more preferably 1.0% by volume or less, and the tricyclic aromatic content is preferably 1.0% by volume or less, more preferably 0.8% by volume or less, and further Preferably, it is 0.5% by volume or less. When the content of these components is within the above range, the combustibility is particularly improved.

(Content of hydrodesulfurization fraction in heavy kerosene fraction)
The content of the hydrodesulfurization fraction in the heavy kerosene fraction is 90.0% by volume or more. If the content of the hydrodesulfurization fraction is not within the above range, an excellent yield cannot be obtained. Especially considering obtaining a better yield, the content of the hydrodesulfurization fraction in the heavy kerosene fraction is preferably 92.0% by volume or more, more preferably 95.0% by volume or more, and 100% by volume. 0% by volume, that is, the total amount is more preferably the hydrodesulfurization fraction.

(Other Fractions that Heavy Kerosene Fractions May Contain)
In this embodiment, the heavy kerosene fraction may contain other fractions in addition to the hydrodesulfurization fraction. Other fractions that can be used in combination with the hydrodesulfurization fraction include, for example, the following fractions.
(i) A fraction obtained by hydrocracking a gas oil fraction (also referred to as a "straight-run gas oil fraction") obtained by atmospheric distillation of crude oil in an atmospheric distillation apparatus (ii) Crude oil is subjected to atmospheric distillation in an atmospheric distillation apparatus Hydrocracking the gas oil fraction (also referred to as "vacuum gas oil fraction") obtained by vacuum distillation of the residue fraction obtained by pressure distillation (also referred to as "atmospheric distillation residue") with a vacuum distillation apparatus Distilled fraction (iii) A gas oil fraction obtained by fluid catalytic cracking of the residue fraction obtained by desulfurizing the atmospheric distillation residue and / or vacuum distillation residue with a direct desulfurization device ("cracked gas oil fraction (Also referred to as “. Fractions obtained by hydrocracking (v) Aromatic solvents produced in petrochemical plants with a sulfur content of 10 mass ppm or less and a boiling point range of 140. Fraction above 0°C and below 350.0°C

(Content of heavy kerosene fraction)
The content of the heavy kerosene fraction based on the total amount of the composition is preferably more than 60% by volume, more preferably 65% by volume or more, still more preferably 72% by volume or more, and the upper limit is preferably less than 90% by volume. It is preferably 85% by volume or less, more preferably 80% by volume or less. If the content of the heavy kerosene fraction is within the above range, the low temperature fluidity is improved, the combustibility is improved, and the external combustion engine equipped with a hydraulic spray burner with a small rated combustion amount and a low spray oil pressure. It is more suitable as a fuel oil composition of No. 1, and can be supplied more stably due to a high yield, and can contribute to improvement of fuel consumption by having a higher calorific value.

(Paraffinic hydrocarbon)
The fuel oil composition for an external combustion engine of the present embodiment contains a specific paraffinic hydrocarbon that satisfies all of the following conditions (a ₂ ) to (e ₂ ), based on the total amount of the composition: more than 10% by volume and 40% by volume. % content.
(a ₂ ) Saturated content is 99.0% by volume or more (b ₂ ) Sulfur content is 20 mass ppm or less (c ₂ ) Cloud point is −50.0° C. or less (d ₂ ) Kinematic viscosity at 30° C. is 5.00 mm ² /s or more and 20.0 mm ² /s or less (e ₂ ) Flash point is 70.0° C. or more

If the content of the paraffinic hydrocarbon is less than 10% by volume, the calorific value will decrease, resulting in a decrease in fuel efficiency, making it difficult to improve fuel efficiency, and low-temperature fluidity will also decrease. On the other hand, when the content of paraffinic hydrocarbons is 40% by volume or more, the combustibility is lowered. From the viewpoint of improving fuel consumption by improving calorific value and improving low-temperature fluidity, the content of paraffinic hydrocarbon based on the total amount of the composition is preferably 15% by volume or more, more preferably 20% by volume or more. The upper limit is preferably 35% by volume or less, more preferably 30% by volume or less.

The performance of the paraffinic hydrocarbon used in this embodiment will be described below.
(a ₂ ) Saturated content The saturated content of the paraffinic hydrocarbon is required to be 99.0% by volume or more. If the saturated content of paraffinic hydrocarbons is less than 99.0% by volume, especially the low-temperature fluidity is lowered. From the viewpoint of improving low-temperature fluidity and combustibility, more stable supply by improving yield, and improving fuel efficiency by calorific value, it is preferably 99.4% by volume or more, more preferably 99.9% by volume or more, and further Preferably it is 100.0% by volume.

(b ₂ ) Sulfur Content The sulfur content of the paraffinic hydrocarbon is required to be 20 mass ppm or less. If the sulfur content is more than 20 ppm by mass, it becomes difficult to maintain storage stability, and corrosion may occur due to an increase in sulfur oxides in the exhaust gas. From the viewpoint of improving storage stability and suppressing environmental load and corrosion, the sulfur content is preferably 10 mass ppm or less, more preferably 3 mass ppm or less, and even more preferably 1 mass ppm or less. Further, when the sulfur content of the paraffinic hydrocarbon is within the above range, the sulfur content of the fuel oil composition for an external combustion engine of the present embodiment can easily be 3 mass ppm or more and 10 mass ppm or less.

(c ₂ ) Cloud Point The cloud point of the paraffinic hydrocarbon should be −50.0° C. or less. If the cloud point is higher than −50.0° C., the low-temperature fluidity is lowered and the filter is likely to be clogged by the precipitated wax, requiring equipment such as heat insulation. Further, when the cloud point of the paraffinic hydrocarbon is within the above range, the cloud point of the fuel oil composition for an external combustion engine of the present embodiment can be easily adjusted to −20.0° C. or lower.
As used herein, the cloud point is a value measured according to JIS K2269:1987 (Determination of pour point and cloud point of crude oil and petroleum products).

(d ₂ ) Kinematic Viscosity at 30° C. The kinematic viscosity of the paraffinic hydrocarbon at 30° C. is required to be 5.00 mm ² /s or more and 20.0 mm ² /s or less. If the kinematic viscosity at 30°C is greater than 20.0 mm ² /s, the combustibility will be reduced. Further, if the kinematic viscosity at 30°C is less than 5.00 mm ² /s, existing equipment (pumps, flowmeters) and the like will be difficult to use as they are. From the viewpoint of improving combustibility and making it easier to adapt the fuel oil composition for an external combustion engine to the specification range of various devices such as pumps and flow meters, the kinematic viscosity of the paraffinic hydrocarbon at 30°C is preferably 5. It is 50 mm ² /s or more, more preferably 5.70 mm ² /s or more, and the upper limit is preferably 19.9 mm ² /s or less, more preferably 19.7 mm ² /s or less.

(e ₂ ) Flash point The flash point of the paraffinic hydrocarbon is required to be 70.0°C or higher. If the flash point is less than 70.0°C, safety in handling is lowered. From the viewpoint of improving safety in handling, the flash point is preferably 80.0°C, more preferably 90.0°C or higher. Moreover, when the flash point of the paraffinic hydrocarbon is within the above range, the flash point of the fuel oil composition for an external combustion engine of the present embodiment can be easily adjusted to 40.0° C. or higher.
As used herein, the flash point of paraffinic hydrocarbons is a value measured according to JIS K 2265-3: 2007 (Crude oil and petroleum products-Flash point test method-Part 3: Pensch-Martens closed method). be.

Further, the paraffinic hydrocarbon used in the present embodiment further has the following properties and compositions (f ₂ ) to (h ₂ ) in addition to the above properties and compositions (a ₂ ) to (e ₂ ). be able to.
(f ₂ ) Density at 15° C. The density of the paraffinic hydrocarbon at 15° C. is preferably 0.8000 g/cm ³ or more, more preferably 0.8050 g/cm ³ or more, and the upper limit is preferably 0.8250 g/cm 3 . cm ³ or less, preferably 0.8200 g/cm ³ or less. When the density at 15° C. is within the above range, the yield is improved, fuel efficiency is improved due to the calorific value, and combustibility is also improved.

(g ₂ ) Initial boiling point The initial boiling point of the paraffinic hydrocarbon is preferably 200.0°C or higher, more preferably 210.0°C or higher, and still more preferably 220.0°C, from the viewpoint of improving safety in handling. It is 0° C. or higher, and the upper limit is preferably 300.0° C. or lower, more preferably 285.0° C. or lower, and still more preferably 235.0° C. or lower from the viewpoint of improving the yield and combustibility. Further, when the initial boiling point of the paraffinic hydrocarbon is within the above range, the initial boiling point of the fuel oil composition for an external combustion engine of the present embodiment can be easily adjusted to 140.0°C or higher.

(h ₂ ) End Point The end point of the paraffinic hydrocarbon is preferably 310.0° C. or higher, more preferably 320.0° C. or higher, and still more preferably 345.0° C. or higher, from the viewpoint of improving the yield. From the viewpoint of improving properties, the upper limit is preferably 360.0° C. or less, more preferably 355.0° C. or less.

(Antioxidant)
The fuel oil composition for an external combustion engine of the present embodiment contains an antioxidant in a range of 20 ppm by mass or more and 100 ppm by mass or less based on the total amount of the composition. If the above antioxidant is not contained in the above content, the storage stability may be lowered and the combustibility may be lowered. As for the upper limit, even if the content exceeds the upper limit, the addition effect is poor and it is economically disadvantageous.
The content of the antioxidant based on the total amount of the composition is preferably 25 mass ppm or more, more preferably 30 mass ppm or more, from the viewpoint of efficiently improving storage stability and improving combustibility. The value is preferably 80 mass ppm or less, more preferably 50 mass ppm or less.

The antioxidant used in the present embodiment can be used without particular limitation as long as it is commonly used in fuel oil compositions. For example, antioxidants such as phenolic antioxidants and amine antioxidants are preferably mentioned. Moreover, in this embodiment, an antioxidant can be used individually by 1 type or in combination of multiple types.

Phenolic antioxidants include 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,4-dimethyl-6-tert-butylphenol, 2,4,6 monocyclic tert-alkylphenol antioxidants such as -tri-tert-butylphenol, 2,6-di-tert-butyl-4-(N,N-dimethylaminomethyl)phenol; 4,4'-methylenebis(2 ,6-di-tert-butylphenol), 4,4′-isopropylidenebis(2,6-di-tert-butylphenol), 2,2′-methylenebis(4-methyl-6-tert-butylphenol), 4, 4'-bis(2,6-di-tert-butylphenol), 4,4'-bis(2-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol ), polycyclic tert-alkylphenol antioxidants such as 4,4′-butylidenebis(3-methyl-6-tert-butylphenol), and the like.

Amine-based antioxidants include monoalkyldiphenylamine-based antioxidants such as monooctyldiphenylamine and monononyldiphenylamine; ,4'-diheptyldiphenylamine, 4,4'-dioctyldiphenylamine, 4,4'-dinonyldiphenylamine and other dialkyldiphenylamine antioxidants; tetrabutyldiphenylamine, tetrahexyldiphenylamine, tetraoctyldiphenylamine, tetranonyldiphenylamine polyalkyldiphenylamine-based antioxidants; naphthylamine-based antioxidants such as α-naphthylamine, phenyl-α-naphthylamine and butylphenyl-α-naphthylamine;

In the present embodiment, a phenolic antioxidant having a tert-alkyl group is preferred, and a monocyclic phenolic antioxidant having a tert-alkyl group is more preferred. Among them, 2,6-di-tert-butylphenol, 2,4-dimethyl-6-tert-butylphenol and 2,6-di-tert-butyl-4-methylphenol are preferred.

(other additives)
The fuel oil composition for an external combustion engine of the present embodiment may optionally contain other additives other than the antioxidants, such as a low-temperature fluidity improver and a lubricating agent, as long as the above properties can be maintained. Various additives such as a property improver, a cetane number improver, a combustion accelerator, a detergent, a sludge dispersant, and an antifungal agent can be appropriately selected and blended. In addition, coumarin may be blended from the viewpoint of light oil collection tax.

(Application)
The fuel oil composition for an external combustion engine of the present embodiment has high storage stability, exhibits excellent low-temperature fluidity even in cold climates during the severe cold season, exhibits excellent oxidation stability, and is also excellent in combustibility. Therefore, even in an external combustion engine equipped with a hydraulic atomizing burner with a small rated combustion volume and low atomizing oil pressure, it exhibits excellent combustibility. It has a characteristic that it can contribute to fuel efficiency improvement by having Specifically, it is suitably used for external combustion engines such as steam boilers, hot water boilers, hot air heaters, absorption chiller heaters, and hot water generators.
Further, the fuel oil composition for an external combustion engine of the present embodiment has a rated combustion amount of 10.0 L/hour or less and a spray oil pressure of 0.90 MPa or less, preferably a rated combustion amount of 7 .0 L/hour or less and spray oil pressure of 0.80 MPa or less, more preferably 5.0 L/hour or less of rated combustion amount and spray oil pressure of 0.70 MPa or less for an external combustion engine equipped with a hydraulic spray burner. , the above characteristics are particularly exhibited.

[Method for producing fuel oil composition for external combustion engine]
A method for producing a fuel oil composition for an external combustion engine according to the present embodiment is a method for producing a fuel oil composition for an external combustion engine that satisfies all of the above (1) to (6), and comprises atmospheric distillation of crude oil A heavy kerosene fraction containing _90.0 % by volume or more of a fraction obtained by hydrodesulfurizing a straight fraction obtained by ( _{a 2} ) A paraffinic hydrocarbon and an antioxidant that satisfy all of the conditions of 2) to (e ₂ ) are added to the content of the paraffinic hydrocarbon composition based on the total amount of more than 10% by volume and less than 40% by volume, and the oxidation It is characterized by blending so that the content of the inhibitor based on the total amount of the composition is 20 ppm by mass or more and 100 ppm by mass or less. The fuel oil composition for an external combustion engine of this embodiment can be easily produced by the production method of this embodiment.

Specifically, it is preferable to have the following steps.
(A) A step of obtaining a fraction by hydrodesulfurizing a straight fraction obtained by atmospheric distillation of crude oil (B) A heavy kerosene fraction containing 90.0% by volume or more of the fraction obtained in the previous step , a paraffinic hydrocarbon so that the content based on the total amount of the composition is more than 10% by volume and less than 40% by volume, and an antioxidant so that the content based on the total amount of the composition is 20 ppm by mass or more and 100 ppm by mass or less. and the process of blending

In the step (A), if the fraction obtained by hydrodesulfurizing the straight fraction obtained by atmospheric distillation of crude oil has a content of 90.0% by volume or more, other fractions such as (ii) a vacuum gas oil fraction; (iii) a fraction obtained by hydrocracking the cracked gas oil fraction; and (v) an aromatic solvent produced at a petrochemical plant, which has a sulfur content of 10 mass ppm or less and a boiling point range of 140.0 ° C. or higher and 350.0 ° C. or lower. Various fractions such as fractions may be mixed.

In the step (B), the order of blending the heavy kerosene fraction, the paraffinic hydrocarbon, and the antioxidant is not particularly limited. The antioxidant may be blended after blending the hydrocarbon, or the paraffinic hydrocarbon and the antioxidant may be blended and then blended with the heavy kerosene fraction.

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The properties of each substrate were determined according to the following methods.

[Measurement of properties and composition]
Various properties and compositions of the heavy kerosene fraction, the paraffinic hydrocarbon, and the fuel oil composition for an external combustion engine of the present embodiment were measured by the following methods.
Distillation properties (initial boiling point, 95% by volume distillation temperature and end point): Measured according to JIS K2254: 1998 (petroleum products-distillation test method-).
・ Flash point of heavy kerosene fraction and fuel oil composition for external combustion engine: Measured according to JIS K 2265-1: 2007 (Crude oil and petroleum products-Flash point test method-Part 3: Tag sealing method) .
Flash point of paraffinic hydrocarbon: Measured according to JIS K 2265-3:2007 (Crude oil and petroleum products-Flash point test method-Part 3: Pensch-Martens closed method).
Sulfur content: Measured according to JIS K2541-7:2003 (Crude oil and petroleum products-Sulfur content test method-Part 7: Wavelength dispersive fluorescent X-ray method).
- Cloud point: Measured according to JIS K2269: 1987 (Testing methods for pour point and cloud point of crude oil and petroleum products).
・ Total calorific value: Measured and estimated according to JIS K2279: 2003 (Crude oil and petroleum products-calorific value test method and calculation estimation method-) ("6. Total calorific value estimation method, 6.3 e) 1) Estimated by the calculation formula for crude oil, kerosene, light oil, A heavy oil and B heavy oil specified in ".
• Petroleum product reaction test: Measured by a petroleum product-reaction test according to JIS K 2252:1998.
Moisture content: Measured in accordance with JIS K 2275-3:2015 (Crude oil and petroleum products-How to determine moisture content-Part 3: Karl Fischer coulometric titration method).
Ash content: Measured according to JIS K 2272: 1998 (Crude oil and petroleum products-Ash and sulfated ash test methods-).
- Kinematic viscosity at 30°C: Measured according to JIS K 2283:2000 (Kinematic viscosity test method for crude oil and petroleum products).
· Density at 15°C: Measured according to JIS K 2249-1: 2011 (Crude oil and petroleum products-Determination of density-Part 1: Vibration method).
・ Composition: Saturated content, olefin content, 1-ring aromatic content, 2-ring aromatic content and 3- or more ring aromatic content are specified in JPI-5S-49-2007, petroleum products-hydrocarbon type test method- It was measured by a high performance liquid chromatography method (High Performance Liquid Chromatography method).

[Evaluation criteria for performance]
Each of the following performances 1 to 4 was evaluated. If there was a C evaluation in any of the items, the overall evaluation was a C evaluation (failed).
1. Combustibility (1) Evaluation model, conditions/evaluation model; hot air warmer ("House Kaonki HK-1527", manufactured by Nepon Co., Ltd., rated combustion volume 4.9 L / hour, on-off control)
・Fuel spray pressure: 0.69 MPa (hydraulic spray burner)
・Band shutter opening: adjust exhaust gas oxygen concentration to 2.8 ± 0.2% ・Heater in front of burner for heating fuel: OFF , after burning for 500 hours, the following items were evaluated.
・Ignition: Visually, there should be no ignition delay ・Combustibility: Measure the soot concentration (Baccaraca smoke number; SN) in the exhaust gas with a Baccaracca smoke tester The lower the soot concentration (SN), the better the combustibility indicates that The SN was read in increments of 0.5 with respect to the standard (integer), with the intermediate soot concentration being 0.5.
(3) Evaluation criteria A: Visually no ignition delay, soot concentration (SN) is 0.5 or less B: Visually no ignition delay, soot concentration (SN) is more than 0.5 and 1.0 or less C: Above apart from

2. Storage stability (1) Evaluation item In accordance with ASTM D4625, after performing dark storage for 3 weeks at 43 ° C. (corresponding to storage at room temperature for about 3 months), dry sludge is measured by Zengyoren A heavy oil dry sludge measurement method. (Z.G.ST-1010).
(2) Evaluation criteria A: Dry sludge is 1 mg / 100 mL or less C: Other than the above

3. Low-temperature fluidity (1) Evaluation item The oil flow limit temperature was measured according to JPI-5S-47-96 Low-temperature fluidity test method standard for heavy oil A (actual machine simulation method). The oil flow limit temperature is the lowest oil temperature at which the filter is not clogged by wax that precipitates at low temperatures. If the oil temperature is lowered below the oil passage limit temperature, the possibility of filter blockage due to wax becomes very high.
(2) Evaluation criteria A: Limit temperature of oil passage is -25.0°C or less B: Limit temperature of oil passage is more than -25.0°C and -20.0°C or less C: Other than the above

4. Fuel efficiency improvement (1) Evaluation item The total calorific value was estimated by the above method.
(2) Evaluation Criteria Based on the total calorific value, evaluation was made according to the following criteria.
A: Total calorific value is 37,020 kJ/L or more B: Total calorific value is 37,000 kJ/L or more and less than 37,020 kJ/L C: Total calorific value is less than 37,000 kJ/L

(Manufacture of heavy kerosene fraction)
A straight-run kerosene fraction obtained by atmospheric distillation of crude oil was hydrodesulfurized at a reaction temperature (approximately 340° C.) at which the sulfur content reached 5 ppm by mass to obtain a heavy kerosene fraction. The properties and composition of the obtained heavy kerosene fraction were measured by the methods described above. The results are shown in Table 1.

[Examples 1 to 5, Comparative Examples 1 to 6]
A heavy kerosene fraction having the properties and composition shown in Table 1 and a paraffinic hydrocarbon having the properties and composition shown in Table 1 are blended so that the contents shown in Tables 2 and 3 are obtained. to prepare a mixed oil, and as an antioxidant, 2,6-di-tert-butyl-4-methylphenol is blended to 30 mass ppm with respect to 100 parts by mass of the mixed oil, fuel oil A composition was obtained. Tables 2 and 3 show the properties and evaluation results of the obtained fuel oil compositions.

As shown in Table 2, the fuel oil composition for an external combustion engine of the present embodiment has good combustibility, storage stability, low-temperature fluidity, and fuel efficiency improvement, and is It also exhibits excellent low-temperature fluidity, and exhibits excellent combustibility even in an external combustion engine equipped with a hydraulic spray burner with a low rated combustion volume and low spray oil pressure. And it was confirmed that having a higher calorific value can contribute to the improvement of fuel efficiency.
On the other hand, the compositions of Comparative Example 1, which does not contain paraffinic hydrocarbons, and Comparative Examples 2 and 4, which contain small amounts of paraffinic hydrocarbons, have small calorific values and are insufficient in terms of improving fuel efficiency. . The composition of Comparative Example 3, which has a high content of paraffinic hydrocarbons, has a high 95% by volume distillation temperature, which is insufficient in terms of combustibility. The composition of Comparative Example 5 was also unsatisfactory in terms of combustibility. In addition, the oil composition of Comparative Example 6 containing no antioxidant in Example 1 was insufficient in terms of storage stability.

The fuel oil composition for an external combustion engine of the present embodiment has excellent stability even in long-term storage, exhibits excellent low-temperature fluidity even in cold regions during the severe cold season, and has a low rated combustion amount and a low spray oil pressure. It exhibits excellent combustibility even in an external combustion engine equipped with a hydraulic spray burner, enables stable supply due to its high yield, and contributes to improved fuel efficiency due to its high calorific value. It can solve the supply shortage of kerosene and kerosene fractions, which are in great demand in winter in cold regions.
The fuel oil composition for an external combustion engine of the present embodiment is suitably used for external combustion engines such as steam boilers, hot water boilers, hot air heaters, absorption chiller heaters, and hot water generators. When used in a steam external combustion engine equipped with a hydraulic atomizing burner having a flow rate of 10.0 L/hour or less and an atomizing oil pressure of 0.90 MPa or less, the above characteristics are exhibited, and thus it is particularly preferably used.

Claims (4)

A heavy kerosene fraction that contains 90.0% by volume or more of a fraction obtained by hydrodesulfurizing a straight fraction obtained by atmospheric distillation of crude oil and that satisfies all of the following conditions (a ₁ ) to (e ₁ ): , containing a paraffinic hydrocarbon and an antioxidant that satisfy all of the following conditions (a ₂ ) to (e ₂ ), and the content of the paraffinic hydrocarbon based on the total amount of the composition is more than 10% by volume and 40% by volume. A fuel oil for an external combustion engine that is less than the above, has a content of 20 mass ppm or more and 100 mass ppm or less of the antioxidant based on the total amount of the composition, and satisfies all of the following conditions (1) to (6): Composition.
(a ₁ ) initial boiling point of 140.0° C. or higher (b ₁ ) 95% by volume distillation temperature of 271.0° C. or higher and 300.0° C. or lower (c ₁ ) flash point of 40.0° C. or higher (d ₁ ) Sulfur content is 3 mass ppm or more and 10 mass ppm or less (e ₁ ) cloud point is −20.0° C. or less (a ₂ ) saturated content is 99.0% by volume or more (b ₂ ) sulfur content is 20 mass ppm or less (c ₂ ) cloud point of −50.0° C. or less (d ₂ ) kinematic viscosity at 30° C. of 5.00 mm ² /s or more and 20.0 mm ² /s or less (e ₂ ) flash point of 70.0 mm 2 /s or more; 0 ° C. or higher (1) Initial boiling point of 140.0 ° C. or higher (2) 95% by volume distillation temperature of 275.0 ° C. or higher and lower than 310.0 ° C. (3) Flash point of 40.0 ° C. or higher (4) Sulfur content of 3 ppm by mass or more and 10 ppm by mass or less (5) Cloud point of -20.0°C or less (6) Total calorific value of 37,000 (kJ/L) or more The fuel oil composition for an external combustion engine according to claim 1, further satisfying at least one condition selected from the following conditions (7) to (12).
(7) The result of the petroleum product reaction test is neutral (8) Moisture content is 0.01% by volume or less (9) Ash content is 0.001% by mass or less (10) Kinematic viscosity at 30 ° C. is 1.300 mm ² /s or more and 2.400 mm ² /s or less (11) Density at 15°C of 0.7985 g/cm ³ or more and 0.8020 g/cm ^{3 or} less (12) Saturation content based on the total amount of the composition is 80.0% by volume or more, Olefin content of 0.3% by volume or less, 1-ring aromatic content of 20.0% by volume or less, 2-ring aromatic content of 2.0% by volume or less, and 3- or more ring aromatic content of 1.0% by volume the following 3. The fuel oil composition for an external combustion engine according to claim 1, which is used in an external combustion engine equipped with a hydraulic atomizing burner having a rated combustion rate of 10.0 L/hour or less and an atomizing oil pressure of 0.9 MPa or less. A heavy kerosene fraction that contains 90.0% by volume or more of a fraction obtained by hydrodesulfurizing a straight fraction obtained by atmospheric distillation of crude oil and that satisfies all of the following conditions (a ₁ ) to (e ₁ ): and a paraffinic hydrocarbon and an antioxidant that satisfy all of the following conditions (a ₂ ) to (e ₂ ), and the content of the paraffinic hydrocarbon based on the total amount of the composition is more than 10% by volume and 40% by volume. %, and the content of the antioxidant based on the total amount of the composition is blended so that it is 20 mass ppm or more and 100 mass ppm or less, for an external combustion engine that satisfies all of the following conditions (1) to (6). A method for producing a fuel oil composition.
(a ₁ ) initial boiling point of 140.0° C. or higher (b ₁ ) 95% by volume distillation temperature of 271.0° C. or higher and 300.0° C. or lower (c ₁ ) flash point of 40.0° C. or higher (d ₁ ) Sulfur content is 3 mass ppm or more and 10 mass ppm or less (e ₁ ) cloud point is −20.0° C. or less (a ₂ ) saturated content is 99.0% by volume or more (b ₂ ) sulfur content is 20 mass ppm or less (c ₂ ) cloud point of −50.0° C. or less (d ₂ ) kinematic viscosity at 30° C. of 5.00 mm ² /s or more and 20.0 mm ² /s or less (e ₂ ) flash point of 70.0 mm 2 /s or more; 0 ° C. or higher (1) Initial boiling point of 140.0 ° C. or higher (2) 95% by volume distillation temperature of 275.0 ° C. or higher and lower than 310.0 ° C. (3) Flash point of 40.0 ° C. or higher (4) Sulfur (5) Cloud point is -20.0 or less (6) Total calorific value is 37,000 (kJ / L) or more