Aviation fuel oil

Abstract

To provide an aviation fuel oil having a low precipitation point and excellent low-temperature fluidity even in the case of containing a specific isoparaffinic base material.SOLUTION: An aviation fuel oil comprises 1.0 to 50.0 vol% of an isoparaffinic base material with an average carbon number of 13.0 to 17.0, containing 80.0 to 100.0 vol% isoparaffins, and 50.0 to 99.0 vol% of a kerosene base material containing 6.0 to 17.0 vol% bicyclic naphthenes, 1.5 to 3.5 vol% tricyclic naphthenes, and 2.0 to 7.0 vol% naphtheno-benzenes.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to aviation fuel oil. [Background technology]

[0002] Aviation fuel oil (sometimes called "aviation turbine fuel oil") is fuel oil used in aircraft turbine engines. It is stored in the main wings of an aircraft, and when supplied to the engine, it exchanges heat with the exhaust heat from the engine to increase combustion efficiency and also plays a role in cooling the engine.

[0003] The fuel oil base stock used to make aviation fuel is usually a kerosene base stock (hydrodesulfurized kerosene base stock) obtained by hydrodesulfurizing a kerosene fraction (straight-run kerosene) obtained by atmospheric distillation of crude oil.

[0004] Meanwhile, in recent years, attention has been drawn to sustainable aviation fuel (SAF) or renewable alternative aviation fuel, which is an aviation fuel made from renewable raw materials containing a base material produced by fermenting, oil extraction, pyrolysis, etc., using organic resources derived from living organisms (biomass) as a raw material, instead of fossil fuels.

[0005] For example, Patent Document 1 (JP 2014-159597 A) describes 1+ O 1+ providing a water-soluble oxygenated hydrocarbon containing a hydrocarbon; and catalytically reacting the oxygenated hydrocarbon in the presence of a deoxygenation catalyst to produce C 1+ O 1-3 producing an oxygenate containing hydrocarbon; and catalytically reacting the oxygenate in the presence of a condensation catalyst at a condensation temperature and a condensation pressure to produce C 4+ Aviation fuel oils and the like have been proposed that use the fraction obtained by further distillation as a constituent base material after subjecting the oil to a step of producing a compound.

[0006] Furthermore, as a method for producing aviation fuel oil from biomass, a method has been proposed in which, for example, woody biomass is fed into a gasification furnace to produce synthesis gas (Syngass) consisting primarily of H2 and CO, which is then synthesized into hydrocarbons by the Fischer-Tropsch reaction (FT reaction), and further hydrogen is added to perform an isomerization reaction to produce the base material for aviation fuel oil.

[0007] Furthermore, a base material for aviation fuel containing paraffins (chain saturated hydrocarbons) as its main component (HEFA-SPK (Hydroprocessed Esters and Fatty Acids Synthetic Paraffinic Kerosene)) has become known, which is synthesized using raw materials such as waste cooking oil, oils and fats found in algae, and oils and fats obtained from common animal and vegetable oils. For example, there can be mentioned a method in which oils and fats obtained from the above-mentioned algae and seeds of plants such as jatropha and camelina are subjected to deoxygenation and hydrogenation treatment to produce a base material for aviation fuel oil containing paraffin as the main component, or a method in which various lipids derived from waste cooking oil or general oils and fats are hydrogenated to remove impurities, and the resulting paraffin fraction is isomerized and appropriately fractionated to produce a base material for aviation fuel oil containing isoparaffin as the main component.

[0008] In addition, a base material for aviation fuel oil (ATJ-SPK (Alcohol to Jet Synthetic Paraffinic Kerosene)) containing isoparaffin (branched saturated hydrocarbon) as its main component, synthesized using so-called bioalcohols such as ethanol and butanol produced by fermenting biomass, has also become known. For example, a method has become known in which ethanol produced by fermentation is dehydrated to produce ethylene, which is then polymerized and oligomerized to form a base material for aviation fuel oil, the main component of which is isoparaffin (a branched-chain saturated hydrocarbon). [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-159597 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0010] Incidentally, when an aircraft flies at altitudes near the stratosphere, it flies in low temperatures, for example, around -40°C. Therefore, it is important for the aircraft fuel oil to have low-temperature properties that prevent the freezing of water in the fuel oil and the deposition of wax, and prevent the clogging of filters, piping, etc. For this reason, aviation fuel oil is required to have excellent fluidity at -40°C and a low freezing point, and the Petroleum Association of Japan's "Uniform Standards for Shared-Use Oil Storage Facilities: ISSUE 30" stipulates that the freezing point of aviation fuel oil must be -47.0°C or lower.

[0011] Among the constituent base materials of aviation fuel oil made from renewable raw materials, those obtained through production methods involving synthesis reactions and isomerization reactions are composed mostly of isoparaffins (branched-chain saturated hydrocarbons), with a low content of n-paraffins (straight-chain saturated hydrocarbons), which tend to produce wax. In other words, when manufacturing the base material for aviation fuel oil using renewable raw materials, an isomerization process is incorporated to convert n-paraffins (straight-chain saturated hydrocarbons), which tend to produce wax, into isoparaffins (branched-chain saturated hydrocarbons), thereby obtaining a base material with a high isoparaffin content. As a method for producing such an isoparaffin-based base material, in addition to the above-mentioned method using renewable raw materials, a method for synthesizing from isobutene obtained from a petroleum refining process can also be mentioned.

[0012] However, isoparaffin-based base materials such as constituent base materials of aviation fuel oil using the above-mentioned renewable raw materials have different isoparaffin contents and isoparaffin types depending on the base material due to differences in production methods, etc.

[0013] Furthermore, isoparaffin-based base stocks, such as base stocks for aviation fuel oils made from the above-mentioned renewable raw materials, have a composition that is significantly different from that of conventional petroleum-based jet fuel base stocks, for example, they contain almost no aromatic components (aromatic hydrocarbon compounds) that affect performance such as lubricity.

[0014] For this reason, when using aviation fuel derived from the above renewable raw materials as its constituent base material, it is mandatory to mix it with conventional petroleum-based jet fuel base material, and the blending ratio of aviation fuel base material made from renewable raw materials is limited to 50% by volume or less (Guidelines for Handling Sustainable Alternative Aviation Fuels (SAF) First Edition, Petroleum Association of Japan, published August 2021).

[0015] On the other hand, the inventors have conducted studies and found that even when a petroleum-based jet fuel base stock that has been conventionally used is used as the constituent base stock of aviation fuel oil and the mixing ratio of the isoparaffin-based base stock is limited to 50% by volume or less, sufficient low-temperature properties cannot necessarily be exhibited if the average carbon number of the isoparaffin-based base stock is high.

[0016] Under these circumstances, an object of the present invention is to provide an aviation fuel oil that has a low freezing point and excellent low-temperature fluidity even when it contains a specific isoparaffin-based base oil. [Means for solving the problem]

[0017] As a result of intensive research conducted by the present inventors to solve the above technical problems, it was surprisingly found that the above technical problems can be solved by an aviation fuel oil containing 1.0 to 50.0 vol% of an isoparaffinic base oil having an average carbon number of 13.0 to 17.0 and an isoparaffin content of 80.0 to 100.0 vol%, and 50.0 to 99.0 vol% of a kerosene base oil having a bicyclic naphthenes content of 6.0 to 17.0 vol%, a tricyclic naphthenes content of 1.5 to 3.5 vol%, and a naphthenebenzenes content of 2.0 to 7.0 vol%, and the present inventors have completed the present invention based on this finding.

[0018] That is, the present invention is (1) 1.0 to 50.0% by volume of an isoparaffin-based base material having an average carbon number of 13.0 to 17.0 and an isoparaffin content of 80.0 to 100.0% by volume, 50.0 to 99.0% by volume of a kerosene base oil having a bicyclic naphthene content of 6.0 to 17.0% by volume, a tricyclic naphthene content of 1.5 to 3.5% by volume, and a naphthene benzene content of 2.0 to 7.0% by volume. Aviation fuel oil characterized by comprising (2) The aviation fuel oil according to (1) above, wherein the ratio of the total content of dicyclic naphthenes and tricyclic naphthenes in the kerosene base stock to the content of monocyclic naphthenes in the kerosene base stock is 0.5 to 1.4 by volume. This provides: [Effects of the Invention]

[0019] According to the present invention, it is possible to provide an aviation fuel oil that has a low freezing point and excellent low-temperature fluidity, even when it contains a specific isoparaffin-based base oil. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of the present invention will be described in detail. In this specification, the use of "to" to indicate a range of values ​​indicates a range that includes the values ​​stated as the upper and lower limits. When a unit is stated for only the upper limit of a range of values ​​expressed by "to," this means that the lower limit is also expressed in the same unit. In the numerical ranges described in stages in this specification, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In this specification, the content or amount of each component in a composition means, unless otherwise specified, the total content or amount of the multiple substances present in the composition when multiple substances corresponding to each component are present in the composition. As used herein, combinations of preferred embodiments are more preferred embodiments.

[0021] The aviation fuel oil according to the present invention comprises 1.0 to 50.0% by volume of an isoparaffin-based base oil having an average carbon number of 13.0 to 17.0 and an isoparaffin content of 80.0 to 100.0% by volume, 50.0 to 99.0% by volume of a kerosene base oil having a bicyclic naphthene content of 6.0 to 17.0% by volume, a tricyclic naphthene content of 1.5 to 3.5% by volume, and a naphthene benzene content of 2.0 to 7.0% by volume. It is characterized by including:

[0022] Each of the base materials constituting the aviation fuel oil according to the present invention will be described below.

[0023] The aviation fuel oil according to the present invention contains an isoparaffin-based base material as a constituent base material, and in the present application documents, the isoparaffin-based base material may be obtained using renewable raw materials, or may be obtained by further synthesizing or isomerizing a fraction obtained in a petroleum refining process.

[0024] The isoparaffinic base material constituting the aviation fuel oil according to the present invention has an average carbon number of 13.0 to 17.0, suitably 13.0 to 16.0.

[0025] The isoparaffinic base material constituting the aviation fuel oil according to the present invention is a heavy base material having an average carbon number within the above range, and therefore when blended as an aviation fuel oil base material, the freezing point is likely to be high and the low-temperature fluidity is likely to be reduced. On the other hand, although the aviation fuel oil according to the present invention contains a heavy isoparaffin base material having an average carbon number within the above range, it also contains a specific kerosene base material, which will be described later, in a specific proportion, and therefore has a low deposition point and can easily exhibit excellent low-temperature fluidity.

[0026] In the present application documents, the average carbon number of the isoparaffin-based substrate means the average value calculated from the carbon number distribution measured from the combination of GC distillation, GC-PONA analysis, and GC-MS analysis described below.

[0027] The isoparaffin-based substrate constituting the aviation fuel oil according to the present invention has an isoparaffin (branched-chain saturated hydrocarbon) content of 80.0 to 100.0% by volume, preferably 85.0 to 100.0% by volume, and more preferably 90.0 to 100.0% by volume.

[0028] In the present application documents, the content of isoparaffin in the isoparaffin-based substrate means the value obtained by subtracting the n-paraffin (linear saturated hydrocarbon) content converted per volume described below from the paraffin (alkanes (linear saturated hydrocarbons)) content described below.

[0029] The isoparaffin-based substrate constituting the aviation fuel oil according to the present invention preferably has an n-paraffin (linear saturated hydrocarbon) content of 0.0 mass% to 20.0 mass%, more preferably 0.0 mass% to 15.0 mass%, and even more preferably 0.0 mass% to 10.0 mass%.

[0030] <0000​​​​​​​​​​​ Measurement end temperature (holding time): 340℃ (14min) Oven temperature rise rate: 6℃ / min Carrier gas: He 152kPa FID combustion gas: H230mK / min, Air 400mL / min Quantitative method: Internal standard method (di-n-butyl phthalate) Sample dilution: toluene Injection method: On-column injection

[0032] The isoparaffinic base material constituting the aviation fuel oil according to the present invention preferably has a paraffin (alkanes (chain saturated hydrocarbons)) content of 84.0% to 100.0% by volume, more preferably 87.0% to 100.0% by volume, and even more preferably 90.0% to 100.0% by volume.

[0033] The isoparaffinic base material constituting the aviation fuel oil according to the present invention preferably has a naphthene (cyclic saturated hydrocarbon) content of 0.0 mass % to 5.0 volume %, more preferably 0.0 volume % to 4.0 volume %, and even more preferably 0.0 volume % to 3.0 volume %.

[0034] In the present application, the content of paraffins (alkanes (chain saturated hydrocarbons)) and the content of naphthenes (cyclic saturated hydrocarbons) in an isoparaffin-based base material refer to values ​​determined by the following method.

[0035] <Method for measuring the content of paraffins (alkanes (chain saturated hydrocarbons)) and naphthenes (cyclic saturated hydrocarbons)> (1) Using high performance liquid chromatography (HPLC), the saturated fraction (saturated hydrocarbon compounds) is separated under the following conditions. Measurement equipment: Shimadzu Corporation HPLC Column: Develosil 30-3 (4.6mm x 250mm) Mobile phase: n-hexane 1.0 mL / min 5.3 MPa Detector: CH1: UV254nm, CH2: RI Sample concentration: Dilute with n-hexane to approximately 20 vol.% Injection volume: 60μL Fractionation conditions: After elution of the saturated fraction, backflush is performed to elute the aromatic fraction all at once. (2) For the saturated fraction obtained in (1) above, an average mass spectrum is obtained using a gas chromatograph mass spectrometer (GC / MS) under the following conditions: Measuring device: Agilent GC-MS Column: DB-1HT 30m x 0.32mm I.D. x 0.10um Oven temperature: 40℃ (2 min) - (20℃ / min) - 300℃ (5 min) Run 20 min Carrier gas: He, constant pressure mode 30kPa, initial: 2.1mL / min, 52cm / sec Ionization voltage: EI 70eV Injection method: On-column injection Next, the volume ratio of alkanes and the volume ratio of naphthenes are calculated by substituting these values ​​into the calculation formula described in ASTM D 2786, and the content of alkanes and the content of naphthenes relative to the entire solution are calculated by multiplying the value of the saturated content (volume %) measured according to JPI-5S-49-07 described below by the calculated volume ratio. In addition, the factors used in calculations in ASTM D 2786 were an average carbon number of 16 and n-paraffin as the calculation factor.

[0036] The isoparaffinic base material constituting the aviation fuel oil according to the present invention preferably has a saturated content (saturated hydrocarbon compound) of 99.0% by volume to 100.0% by volume, more preferably 99.2% by volume to 100.0% by volume, and even more preferably 99.4% by volume to 100.0% by volume.

[0037] In the present application, the content of saturated components in an isoparaffin-based base material refers to a value measured by the method described in JPI-5S-49-07 "Petroleum products - Hydrocarbon type test method - High performance liquid chromatography method."

[0038] The isoparaffinic base material constituting the aviation fuel oil according to the present invention preferably has an olefin content of 0.0% to 0.5% by volume, more preferably 0.0% to 0.4% by volume, and even more preferably 0.0% to 0.3% by volume.

[0039] In the present application, the content of olefins in an isoparaffin-based base material refers to a value measured by the method described in JPI-5S-49-07 "Petroleum products - Hydrocarbon type test method - High performance liquid chromatography method."

[0040] The isoparaffinic base material constituting the aviation fuel oil according to the present invention preferably has an aromatic content (aromatic hydrocarbon compound) of 0.0% to 0.5% by volume, more preferably 0.0% to 0.4% by volume, and even more preferably 0.0% to 0.3% by volume.

[0041] In the present application, the content of aromatic components in an isoparaffin-based base material refers to a value measured by the method described in JPI-5S-49-07 "Petroleum products - Hydrocarbon type test method - High performance liquid chromatography method."

[0042] In the isoparaffin-based base material constituting the aviation fuel oil according to the present invention, the isoparaffin content and n-paraffin content are each within the above-mentioned ranges, and the majority of the content is made up of isoparaffins. Since the content of n-paraffins, which tend to generate wax, is low, the deposition point can be easily lowered when blended into aviation fuel oil.

[0043] The isoparaffinic base material constituting the aviation fuel oil according to the present invention preferably has a sulfur content of 0 ppm by mass or more and less than 10 ppm by mass, more preferably 0 ppm by mass or more and 5 ppm by mass or less, and even more preferably 0 ppm by mass or more and 1 ppm by mass or less. When the sulfur content of the isoparaffinic components constituting the aviation fuel oil according to the present invention is within the above range, the generation of sulfur oxides during combustion can be easily reduced.

[0044] In the present application, the sulfur content refers to a value measured in accordance with JIS K 2541-6:2003 "Crude oil and petroleum products - Determination of sulfur content - Part 6: Ultraviolet fluorescence method."

[0045] The isoparaffinic base material constituting the aviation fuel oil according to the present invention has a density at 15°C of 0.7300 to 0.8000 g / cm 3 and 0.7350 g / cm 3 ~0.7950g / cm 3 Preferably, it is 0.7400 g / cm 3 ~0.7900g / cm 3 It is more preferable that: When the density of the isoparaffinic base material constituting the aviation fuel oil is within the above range, a good combustion state can be easily achieved when the aviation fuel oil is burned.

[0046] In the present application, the density at 15°C means the density measured in accordance with JIS K 2249-1:2011 "Crude oil and petroleum products - Determination of density - (oscillating method)".

[0047] The isoparaffinic base material constituting the aviation fuel oil according to the present invention preferably has a distillation range of 140.0°C to 300.0°C, more preferably 145.0°C to 297.0°C, and even more preferably 150.0°C to 295.0°C. Since the distillation range of the isoparaffinic base material constituting the aviation fuel oil according to the present invention is within the above range, when the aviation fuel oil is made into an aviation fuel oil, it is possible to impart distillation properties suitable for use in aircraft. In the present application, the distillation range means the temperature range from the initial boiling point (IBP) to the final boiling point (FBP).

[0048] The isoparaffinic base material constituting the aviation fuel oil according to the present invention preferably has an initial boiling point (IBP) in atmospheric distillation of 140.0 to 205.0°C, more preferably 145.0 to 200.0°C, and even more preferably 150.0 to 195.0°C. The isoparaffinic base material constituting the aviation fuel oil according to the present invention preferably has a 50% by volume distillation temperature (T50) in atmospheric distillation of 200.0 to 270.0°C, more preferably 210.0 to 270.0°C, and even more preferably 220.0 to 270.0°C. The isoparaffinic base material constituting the aviation fuel oil according to the present invention preferably has an end point (FBP) of 270.0 to 300.0°C, more preferably 275.0 to 297.0°C, and even more preferably 280.0 to 295.0°C.

[0049] The isoparaffinic base material constituting the aviation fuel oil according to the present invention has IBP, T50 and FBP within the above ranges, so that the spray state and combustion state in an aircraft turbine engine can be maintained appropriately, and deposit formation and deterioration of exhaust gas properties can be easily suppressed. In the present application, IBP, T50 and FBP refer to the distillation temperature in atmospheric distillation measured in accordance with JIS K2254:1998 "Petroleum products - Distillation test method."

[0050] The isoparaffinic base material constituting the aviation fuel oil according to the present invention preferably has a flash point of 38.0°C or higher, more preferably 40.0°C or higher, and even more preferably 42.0°C or higher. Although there is no particular upper limit to the flash point of the isoparaffinic base material, the flash point of the isoparaffinic base material is usually 90.0°C or lower. If the flash point of the isoparaffinic base material constituting the aviation fuel oil is within the above range, handling becomes easier.

[0051] In this application, the flash point refers to a value measured according to JIS K 2265-1, Determination of Flash Point - Part 1: Tag-Sealed Method.

[0052] The isoparaffinic base material constituting the aviation fuel oil according to the present invention preferably has a freezing point of -20°C or lower, more preferably -28°C or lower, and even more preferably -39°C or lower. The lower limit of the freezing point of an isoparaffin-based base material is not particularly limited, but the measurement limit of the freezing point of an isoparaffin-based base material is -75°C. When the deposition point of the isoparaffinic base material constituting the aviation fuel oil is within the above range, deposition of wax components can be easily suppressed when the isoparaffinic base material is blended into the aviation fuel oil.

[0053] In the present application, the deposition point of an isoparaffinic base material means a value measured in accordance with the standard of ASTM D5972, unless otherwise specified.

[0054] The isoparaffinic base material constituting the aviation fuel oil according to the present invention has a kinematic viscosity at -40°C of 5 to 60 mm 2 / sec (mm 2 / s), and 5 to 40 mm 2 / sec (mm 2 / s), and 5 to 21 mm 2 / sec (mm 2 / s) is more preferable.

[0055] Since the kinematic viscosity at -40°C of the isoparaffinic base material constituting the aviation fuel oil according to the present invention is within the above range, it can be easily handled without requiring major changes to existing equipment during transportation, etc. In the present application, the kinematic viscosity at -40°C means a value measured by the method specified in ASTM D7945.

[0056] The isoparaffinic base material constituting the aviation fuel oil according to the present invention preferably has a smoke point of 25.0 mm or higher, more preferably 30.0 mm or higher, and even more preferably 35.0 mm or higher. Although there is no particular upper limit to the smoke point of the isoparaffin-based base material, the smoke point of the isoparaffin-based base material is usually 60.0 mm or less. When the smoke point of the isoparaffinic base material constituting the aviation fuel oil is within the above range, the combustibility can be easily improved when blended into the aviation fuel oil.

[0057] In the present application, the smoke point refers to a value measured according to the JIS K 2537 standard.

[0058] The isoparaffinic base material constituting the aviation fuel oil according to the present invention may be derived from biomass or may be synthesized from isobutene obtained in a petroleum refining process, and it is preferable that it is derived from biomass. When the isoparaffinic base material constituting the aviation fuel oil according to the present invention is derived from biomass, it is preferably produced using lipids as a raw material or synthesized using bioalcohol as a raw material. Specific examples of isoparaffin-based base materials produced using lipids as raw materials include those obtained by hydrogenating various lipids derived from waste cooking oil or general animal and vegetable oils, removing impurities, and then isomerizing the resulting paraffin content and subjecting it to appropriate fractional distillation. Furthermore, specific examples of isoparaffin-based base materials synthesized using bioalcohol as a raw material include those obtained by dehydrating ethanol produced by fermentation to produce ethylene, which is then polymerized to form oligomers, and then appropriately fractionated and hydrogenated. In this application, bioalcohol refers to alcohols such as ethanol and isobutanol obtained by fermenting biomass and then subjecting it to appropriate filtration.

[0059] The aviation fuel oil according to the present invention contains the above-mentioned isoparaffinic base material as a constituent base material in an amount of 1.0 to 50.0% by volume, preferably 10.0 to 45.0% by volume, and more preferably 15.0 to 40.0% by volume.

[0060] The aviation fuel oil according to the present invention contains the above-mentioned isoparaffinic base material as the main base material in the above proportion, and also contains a specific kerosene base material described below in a specific proportion, thereby easily exhibiting excellent low-temperature fluidity while suppressing the freezing point to a low level.

[0061] The aviation fuel according to the present invention contains a kerosene base stock (a base stock consisting of a kerosene fraction) as a constituent base stock.

[0062] The kerosene base material constituting the aviation fuel oil according to the present invention preferably has a monocyclic naphthene content of 14.0 to 17.0% by volume, more preferably 15.0 to 16.7% by volume, and even more preferably 15.5 to 16.5% by volume.

[0063] The composition of kerosene base oil is roughly divided into saturated and aromatic components, with the saturated components being made up of paraffins (chain saturated hydrocarbons) and naphthenes (cyclic saturated hydrocarbons). The naphthenes contained in kerosene base oils are monocyclic naphthenes, that is, cyclic structures with a basic skeleton of cyclopentane (5 carbon atoms) or cyclohexane (6 carbon atoms). Among the naphthenes contained in the kerosene base material, the monocyclic naphthenes are composed of the above-mentioned monocyclic naphthenes and monocyclic naphthenes to which an alkyl side chain is bonded. By using a kerosene base oil in which the content of monocyclic naphthenes is controlled within the above range, the aviation fuel oil according to the present invention can easily maintain a low deposition point and exhibit excellent low-temperature fluidity, even when it contains a specific isoparaffin base oil.

[0064] The kerosene base material constituting the aviation fuel oil according to the present invention has a bicyclic naphthene content of 6.0 to 17.0% by volume, The content is preferably 7.0 to 16.0% by volume, and more preferably 8.0 to 15.0% by volume.

[0065] Among the naphthenes contained in kerosene base stocks, bicyclic naphthenes have a basic structure in which two monocyclic naphthene rings are bonded together (for example, they have a decalin structure in which the rings of two cyclohexane molecules are bonded together), and are composed of these bicyclic naphthenes and bicyclic naphthenes to which alkyl side chains are bonded. Kerosene base oils contain polycyclic naphthenes, mainly bicyclic naphthenes, but because bicyclic naphthenes have a higher molecular weight and higher density than monocyclic naphthenes, they become more viscous at low temperatures, which is thought to be a factor in reducing the fluidity of aviation fuel when blended with them. By using a kerosene base oil in which the content of bicyclic naphthenes is controlled within the above range, the aviation fuel oil according to the present invention can suppress the deposition point to a low level and exhibit excellent low-temperature fluidity, even when it contains a specific isoparaffin-based base oil.

[0066] The kerosene base material constituting the aviation fuel oil according to the present invention has a tricyclic naphthenes content of 1.5 to 3.5% by volume, preferably 1.7 to 3.3% by volume, and more preferably 1.8 to 3.0% by volume.

[0067] Among the naphthenes contained in kerosene base stocks, tricyclic naphthenes have a basic structure in which three monocyclic naphthene rings are bonded together, and are composed of these tricyclic naphthenes and tricyclic naphthenes to which alkyl side chains are bonded. As described above, kerosene base oils contain mainly bicyclic naphthenes as polycyclic naphthenes, but also contain a certain amount of tricyclic naphthenes. Like bicyclic naphthenes, tricyclic naphthenes have a higher molecular weight and higher density than monocyclic naphthenes, and therefore become more viscous at low temperatures, which is thought to be a factor in reducing the flowability of aviation fuel oil when blended therewith. The aviation fuel oil according to the present invention employs a kerosene base oil in which the contents of both dicyclic naphthenes and tricyclic naphthenes are controlled within the above-mentioned ranges, thereby making it possible to suppress the deposition point to a low level and to exhibit excellent low-temperature fluidity, even when a specific isoparaffin-based base oil is contained.

[0068] The kerosene base material constituting the aviation fuel oil according to the present invention is one in which the ratio of the total content of the dicyclic naphthenes and tricyclic naphthenes to the content of monocyclic naphthenes ((total content of dicyclic naphthenes and tricyclic naphthenes) / content of monocyclic naphthenes) is preferably 0.5 to 1.4, more preferably 0.6 to 1.3, and even more preferably 0.7 to 1.2, by volume.

[0069] By using a kerosene base stock constituting the aviation fuel oil according to the present invention in which the ratio of the total content of the two-ring naphthenes and three-ring naphthenes to the content of the monocyclic naphthenes is controlled within the above range, it is possible to suppress the deposition point to a low level and exhibit excellent low-temperature fluidity, even when a specific isoparaffin-based base stock is contained.

[0070] In the present application, the content of each naphthene in the kerosene base material means a value determined by the following method, and the details of the measurement method are as described below. First, according to the method described in ASTM D 2459, saturated and aromatic components are separated from a measurement sample using high performance liquid chromatography (HPLC). Next, each fraction is measured using a gas chromatograph-flame ionization detector (GC-FID). The density of the saturated and aromatic components is considered to be the same, and the ratio of the saturated component peak area to the sum of the saturated component peak area and the aromatic component peak area is calculated as the volume ratio (volume %) of the saturated component to the entire sample. Each of the above fractions is measured using a gas chromatograph mass spectrometer (GC / MS), and the obtained values ​​for saturated content are substituted into the calculation formula described in ASTM D 2786 to calculate the volume ratios (volume %) of alkane compounds, monocyclic naphthene compounds, dicyclic naphthene compounds, tricyclic naphthene compounds, and tetracyclic naphthene compounds to the saturated content.

[0071] The kerosene base material constituting the aviation fuel oil according to the present invention preferably has an alkylbenzene content of 16.5 to 19.5% by volume, more preferably 16.7 to 19.0% by volume, and even more preferably 17.0 to 18.5% by volume.

[0072] The kerosene base material constituting the aviation fuel oil according to the present invention has a naphthenebenzene content of 2.0 to 7.0% by volume, preferably 2.5 to 6.5% by volume, and more preferably 3.0 to 6.0% by volume.

[0073] As described above, the composition of kerosene base stocks is roughly divided into saturated components and aromatic components, and the aromatic components are made up of compounds having a benzene ring, and are classified into alkylbenzenes in which an alkyl side chain is bonded to a benzene ring, naphthenebenzenes having a structure in which a benzene ring and a naphthene ring are bonded to each other, and polycyclic aromatic components in which multiple benzene rings are bonded to each other.

[0074] Of the aromatic compounds, naphthenebenzenes have a basic structure of naphthenebenzene in which benzene and naphthene rings are bonded to each other (for example, they have a tetralin structure in which benzene and cyclohexane are bonded to each other), and are composed of these naphthenebenzenes and naphthenebenzenes to which alkyl side chains are bonded.

[0075] Kerosene base oil contains mainly alkylbenzenes and naphthenebenzenes as aromatic components, but naphthenebenzenes have a higher molecular weight and higher density than alkylbenzenes, making them more viscous at low temperatures, which is thought to be a factor in reducing the fluidity of aviation fuel when blended with it. The aviation fuel oil according to the present invention uses a kerosene base oil containing alkylbenzenes within the above range or one in which the content of naphthenebenzenes is controlled within the above range, so that even when a specific isoparaffin base oil is contained, the freezing point can be kept low and excellent low-temperature fluidity can be exhibited.

[0076] In the present application, the content of each aromatic component in the kerosene base material means a value determined by the following method, and the details of the measurement method are as described below. First, according to the measurement method described in ASTM D 2459, saturated and aromatic components are separated from a measurement sample using high performance liquid chromatography (HPLC). Next, each fraction is measured using a gas chromatograph-flame ionization detector (GC-FID). The density of the saturated and aromatic components is considered to be the same, and the ratio of the peak area of ​​the aromatic component to the sum of the peak area of ​​the saturated and aromatic components is calculated as the volume ratio (volume %) of the aromatic component to the entire sample. Each of the above fractions is measured using a gas chromatograph mass spectrometer (GC / MS), and the obtained values ​​are substituted into the calculation formula for the aromatic content described in ASTM D 3239 to calculate the volume ratios (volume %) of alkylbenzenes, naphthenebenzenes, dinaphthenebenzenes, naphthalenes, acenaphthene, and dibenzofurans relative to the aromatic content.

[0077] The aviation fuel oil according to the present invention contains a kerosene base stock (a base stock consisting of a kerosene fraction) as a constituent base stock. In the present application, the kerosene base stock refers to a kerosene fraction (straight-run kerosene) obtained by atmospheric distillation of crude oil, a hydrodesulfurized kerosene obtained by further hydrodesulfurizing straight-run kerosene, or a kerosene having a sulfur content of less than 10 ppm by mass and a density at 15°C of 0.7900 to 0.8600 g / cm3 obtained from a kerosene fraction (straight-run kerosene) obtained by distilling crude oil at atmospheric pressure, a hydrodesulfurized kerosene obtained by further hydrodesulfurizing straight-run kerosene, or a kerosene having a 90% by volume distillation temperature of 320 to 360°C and a hydrogen partial pressure of 10 to 18 MPa from a feed oil containing 37 to 65% by mass of aromatic hydrocarbons. 3 and high-pressure hydrogenation treated fractions having a distillation range of 140.0°C to 320.0°C. In the aviation fuel according to the present invention, the kerosene base stock used as the constituent base stock may be a mixture of the above-mentioned kerosene base stocks. Details of the high-pressure hydrotreating fraction are as described in JP-A-2023-137574 as a high-pressure hydrotreating base material.

[0078] The kerosene base stock constituting the aviation fuel oil according to the present invention preferably has a sulfur content of less than 10 ppm by mass (not less than 0 ppm by mass and not more than 10 ppm by mass), more preferably not more than 9 ppm by mass (not less than 0 ppm by mass and not more than 9 ppm by mass), and even more preferably not more than 8 ppm by mass (not less than 0 ppm by mass and not more than 8 ppm by mass). When the sulfur content of the kerosene base material constituting the aviation fuel oil according to the present invention is within the above range, the production of sulfur oxides during combustion can be easily reduced.

[0079] The kerosene base material constituting the aviation fuel oil according to the present invention has a density at 15°C of 0.7600 g / cm 3 ~0.8600g / cm 3 Preferably, it is 0.7650 g / cm 3 ~0.8000g / cm 3 More preferably, it is 0.7700 g / cm 3 ~0.8000g / cm 3 It is more preferable that: When the density of the kerosene base material constituting the aviation fuel oil according to the present invention is within the above range, a good combustion state can be easily achieved when the aviation fuel oil is burned.

[0080] The kerosene base material constituting the aviation fuel oil according to the present invention preferably has a distillation range of 135.0°C to 320.0°C, more preferably 135.0°C to 290.0°C, even more preferably 137.0°C to 285.0°C, and even more preferably 139.0°C to 280.0°C. By having the distillation range of the kerosene base material constituting the aviation fuel oil according to the present invention fall within the above range, when blended into aviation fuel oil, it is possible to easily impart distillation properties suitable for use in aircraft. In the present application, the distillation range means the temperature range from the initial boiling point (IBP) to the final boiling point (FBP).

[0081] The kerosene base material constituting the aviation fuel oil according to the present invention preferably has an initial boiling point (IBP) in atmospheric distillation of 135.0 to 165.0°C, more preferably 140.0 to 160.0°C, and even more preferably 145.0 to 155.0°C. The kerosene base material constituting the aviation fuel oil according to the present invention preferably has a 50% by volume distillation temperature (T50) in atmospheric distillation of 170.0 to 230.0°C, more preferably 175.0 to 225.0°C, and even more preferably 180.0 to 220.0°C. The kerosene base stock constituting the aviation fuel oil according to the present invention preferably has an end point (FBP) of 230.0 to 320.0°C, preferably 230.0 to 290.0°C, more preferably 235.0 to 285.0°C, and even more preferably 240.0 to 280.0°C.

[0082] The kerosene base material constituting the aviation fuel oil according to the present invention has IBP, T50 and FBP within the above ranges, so that the atomization and combustion conditions in aircraft turbine engines can be maintained appropriately, and deposit formation and deterioration of exhaust gas properties can be easily suppressed.

[0083] The kerosene base material constituting the aviation fuel oil according to the present invention preferably has a flash point of 38°C or higher, more preferably 39°C or higher, and even more preferably 40°C or higher. There is no particular upper limit to the flash point of the kerosene base material constituting the aviation fuel oil according to the present invention, but the flash point of the kerosene base material is usually 60°C or lower. If the flash point of the kerosene base material constituting the aviation fuel falls within the above range, handling becomes easier.

[0084] The kerosene base material constituting the aviation fuel oil according to the present invention preferably has a freezing point of -47°C or lower, more preferably -49°C or lower, and even more preferably -51°C or lower. There is no particular lower limit to the freezing point of the kerosene base, but the freezing point of the kerosene base is usually −59° C. or higher. If the deposition point of the kerosene base material constituting the aviation fuel falls within the above range, deposition of wax components can be easily suppressed when blended into the aviation fuel.

[0085] In this application, unless otherwise specified, the pouring point of a kerosene base material means a value measured in accordance with the standard of ASTM D5972.

[0086] The kerosene base material constituting the aviation fuel oil according to the present invention preferably has a smoke point of 17 mm or higher, more preferably 19 mm or higher, and even more preferably 21 mm or higher. There is no particular upper limit to the smoke point of the kerosene base material that constitutes aviation fuel, but the smoke point of aviation fuel is usually 60 mm or less. By ensuring that the smoke point of the aviation fuel oil is within the above range, excellent combustibility can be maintained. If the smoke point of the kerosene base material constituting the aviation fuel oil is within the above range, the combustibility can be easily improved when blended into the aviation fuel oil.

[0087] The kerosene base material constituting the aviation fuel oil according to the present invention preferably has an induction period of 80 minutes or more, more preferably 90 minutes or more, and even more preferably 100 minutes or more. Because the kerosene base material that makes up aviation fuel has an induction period of 80 minutes or more, it exhibits excellent oxidation stability when blended into aviation fuel, suppressing the formation of sludge and deposits, and as a result, preventing clogging of engine fuel injection nozzles and a decrease in output. In the present application, the induction period refers to the induction period measured by ASTM D7545-09 "Standard Test Method for Oxidation Stability of Middle Distillate Fuels - Rapid Small Scale Oxidation Test."

[0088] In the aviation fuel oil according to the present invention, the saturated content in the kerosene base stock is preferably 75.0 to 95.0% by volume, more preferably 77.0 to 93.0% by volume, and even more preferably 79.0 to 91.0% by volume. In the aviation fuel oil according to the present invention, the saturated content in the kerosene base oil is within the above range, so that good combustibility can be easily exhibited.

[0089] In the aviation fuel oil according to the present invention, the olefin content in the kerosene base stock is preferably 0.5% by volume or less (0.0% by volume to 0.5% by volume), more preferably 0.4% by volume or less (0.0% by volume to 0.4% by volume), and even more preferably 0.3% by volume or less (0.0% by volume to 0.3% by volume). In the aviation fuel oil according to the present invention, the olefin content in the kerosene base material is within the above range, so that good oxidation stability can be exhibited.

[0090] In the aviation fuel oil according to the present invention, the aromatic content in the kerosene base stock is preferably 5.0 to 25.0% by volume, more preferably 5.0 to 24.0% by volume, and even more preferably 5.0 to 23.0% by volume. In the aviation fuel oil according to the present invention, the aromatic content in the kerosene base oil is within the above range, so that good combustibility can be easily exhibited.

[0091] The aviation fuel oil according to the present invention contains the above-mentioned kerosene base stock as a constituent base stock in an amount of 50.0 to 99.0% by volume, preferably 55.0 to 90.0% by volume, and more preferably 60.0 to 85.0% by volume.

[0092] The aviation fuel oil according to the present invention may contain various additives in addition to the above-mentioned base constituents. The additives include one or more selected from known fuel additives such as anti-icing agents, antioxidants, metal deactivators, anti-static agents, lubricity improvers, conductivity adjusters, and corrosion inhibitors. The content of additives, excluding anti-icing agents, is preferably 70 mg / L or less, more preferably 58 mg / L or less, based on the total amount of constituent base materials. The content of anti-icing agents is preferably 0.2% by volume or less, more preferably none, based on the total amount of constituent base materials.

[0093] The aviation fuel oil according to the present invention preferably has a freezing point of -47.0°C or lower, more preferably -48.5°C or lower, and even more preferably -50.0°C or lower. The lower limit of the freezing point of the aviation fuel oil according to the present invention is not particularly limited, but the freezing point is usually −75.0° C. or higher. The aviation fuel oil according to the present invention has a freezing point of −47.0° C. or lower, and therefore can easily exhibit excellent low-temperature fluidity.

[0094] The freezing point of the aviation fuel oil according to the present invention is a value measured by the method specified in ASTM D5972.

[0095] The aviation fuel oil according to the present invention has a kinematic viscosity at -40°C of 5.0 to 12.0 mmHg. 2 / sec, preferably 5.5 to 11.7 mm 2 / sec is more preferable, and 6.0 to 11.5 mm 2 / sec is even more preferable.

[0096] Since the aviation fuel oil according to the present invention has a kinematic viscosity at -40°C within the above range, it can be easily handled during transportation, etc., without requiring major modifications to existing equipment. In the present application, the kinematic viscosity at -40°C means a value measured by the method specified in ASTM D7945.

[0097] The aviation fuel according to the present invention preferably has an induction period of 70 minutes or more, more preferably 71 minutes or more, and even more preferably 72 minutes or more. Aviation fuel oil with an induction period of 70 minutes or more exhibits excellent oxidation stability and suppresses the formation of sludge and deposits, thereby preventing clogging of engine fuel injection nozzles and a decrease in power output.

[0098] The aviation fuel oil according to the present invention preferably has a flash point of 38.0 to 70.0°C, more preferably 39.0 to 69.0°C, and even more preferably 40.0 to 68.0°C. Since the flash point of the aviation fuel oil according to the present invention is within the above range, it can be handled easily and safely.

[0099] The aviation fuel oil according to the present invention can be prepared by mixing predetermined amounts of the above-mentioned isoparaffinic base stock and kerosene base stock as essential base stocks, and further mixing in known base stocks within a range that does not impair the effects of the present invention.

[0100] When the aviation fuel oil according to the present invention is prepared by mixing the above-mentioned isoparaffinic base material and kerosene base material, the order of mixing is not particularly limited.

[0101] According to the present invention, even when an isoparaffin-based base material is contained as the main base material, by containing a kerosene base material in the above-mentioned proportion, it is possible to provide an aviation fuel oil that can suppress the freezing point to a low level and easily exhibit excellent low-temperature fluidity. [Example]

[0102] The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited to these examples in any way.

[0103] (base material) The following substrates were used in the following examples and comparative examples. The properties of each substrate are shown in Table 1. Isoparaffin-based base material 1 Contains 99.0% by volume of isoparaffins and 1.0% by volume of n-paraffins, has an average carbon number of 13.4, a deposition point of -39.8°C, and a kinematic viscosity of 20.16mm³ at -40°C. 2 / seconds. Isoparaffin-based base material 2 It contains 90.0% by volume of isoparaffins and 10.0% by volume of n-paraffins, has an average carbon number of 15.9, a deposition point of -28.9°C, and a kinematic viscosity of 40mm at -40°C. 2 / seconds or more.

[0104] <Calculation method for average carbon number> The carbon number distribution in each isoparaffin-based base material was measured by the following method. (1) GC distillation Based on the ASTM D 2887 standard, the base material was subjected to GC distillation (distillation gas chromatographic analysis) under the following conditions, and the distillation properties and chart were confirmed. Measuring device: Agilent GC Column: DB-1 10m x 0.53mm Df: 2.65μm Detector: FID (Front) Oven temperature: 40℃ (0 min) - (20℃ / min) - 350℃ (4 min) Run 19.5 min Temperature: Inlet: 50℃ (0 min) - (200℃ / min) - 350℃ (Hold) Detector: 375℃ Carrier gas: N2 20.9kPa (Total Flow 42.9mL / min) (3.0psi) Make-up gas: N2 45mL / min FID combustion gas: He 30mL / min, Air 400mL / min Sample dilution: None Injection volume: 0.1μL

[0105] Using the retention time of n-C10 (n-decane) in the chart obtained by GC distillation as a reference, compounds with retention times detected before the retention time of n-C10 (n-decane) (light fraction) and compounds with retention times detected after the retention time of n-C10 (n-decane) (heavy fraction) were separated, and the total peak area detected, the total peak area of ​​the light fraction, and the total peak area of ​​the heavy fraction were calculated. Then, the ratio of the total peak area of ​​the light fraction to the total peak area detected (total peak area of ​​light fraction / total detected peak area) and the ratio of the total peak area of ​​the heavy fraction to the total detected peak area (total peak area of ​​heavy fraction / total detected peak area) were calculated. The peak area of ​​n-C10 was added to the compound (light fraction) whose retention time was detected before the retention time of n-C10 (n-decane).

[0106] (2)GC-PONA analysis Next, GC-PONA analysis was performed under the conditions shown below based on the provisions of JIS K 2536-2 to confirm the distribution of each compound. The carbon number of each compound identified by the above GC-PONA analysis was identified, and the peak area ratio (composition ratio) for each carbon number in the group of detected compounds with 12 or less carbon atoms was recalculated. (GC-PONA analysis conditions) Measuring device: Agilent GC Columns (2 sets): Columns 1 and 3: Empty columns 2m x 0.25mm ID (pre-column); Columns 2 and 4: HP-5 2m x 0.25mm ID 1.0μm + HP-1 100m x 0.25mm ID 0.5μm Detector (2 sets): FID temperature 250℃ Oven temperature: 5℃ (10 min) - (5℃ / min) → 50℃ (43 min) -(1.6℃ / min) → 100℃(0min) -(1.0℃ / min)→200℃(5min) Run198.23min Make-up gas: N2 25mL / min Carrier gas: Constant pressure Column 2 (front), column 4 (back) He FID combustion gas: He 30mL / min, Air 400mL / min Injection volume: 0.2μL

[0107] (3)GC-MS analysis GC-MS analysis was carried out under the following conditions. The sample was diluted with n-C6 (n-hexane) to 3 μL / 1.5 mL, and the distribution of each compound was confirmed under the conditions shown below. The molecular weight of each compound was confirmed from each peak, and the carbon number of each compound was identified. Then, the peak area ratio (composition ratio) for each carbon number in the group of compounds with 10 or more carbon atoms was recalculated. (GC-MS analysis conditions) Measuring device: Agilent GC-MS Column: DB-1HT 30m x 0.32mm I.D. x 0.10um Oven temperature: 40℃ (2 min) - (20℃ / min) - 300℃ (5 min) Run 20 min Carrier gas: He, constant pressure mode 30 kPa, initial: 2.1 mL / min, 52 cm / sec Ionization voltage: EI 70eV Injection method: On-column injection Injection volume 0.5μL Sample dilution: 3 μL / 1.5 mL nC6

[0108] (4) Calculation of compound content ratio by carbon number For compounds having 9 or less carbon atoms, the ratio of the total peak area of ​​the light fraction to the total peak area detected, obtained from the (1) GC distillation, was multiplied by the content ratio (composition ratio (mass ratio)) for each carbon number obtained from the (2) GC-PONA analysis to determine the content ratio (mass ratio) for each carbon number. For compounds having 10 to 12 carbon atoms, the ratio of the total peak area of ​​the light fraction to the total peak area detected from the (1) GC distillation was first multiplied by the content ratio (composition ratio (mass ratio)) of compounds having 10 to 12 carbon atoms obtained by the (2) GC-PONA analysis to determine the content ratio 1 (mass ratio) of compounds having 10 to 12 carbon atoms. In addition, the content ratio of compounds having 10 to 12 carbon atoms was also calculated from the results of the (1) GC distillation and the (3) GC-MS analysis, and the ratio of the total peak area of ​​the heavy fraction to the total peak area detected from the (1) GC distillation was multiplied by the content ratio of compounds having 10 to 12 carbon atoms obtained by the (3) GC-MS analysis to determine the content ratio 2 (mass ratio) of compounds having 10 to 12 carbon atoms. The sum of the above content ratio 1 and content ratio 2 was determined as the content ratio of the compound having 10 to 12 carbon atoms. For compounds having 13 or more carbon atoms, the ratio of the total peak area of ​​the heavy components to the total peak area detected, obtained from the (1) GC distillation, was multiplied by the content ratio (composition ratio (mass ratio)) for each carbon number obtained from the (3) GC-MS analysis to determine the content ratio (mass ratio) for each carbon number. (5) Calculation of the average carbon number Based on the content ratio for each carbon number obtained in (5) above, the average carbon number was determined by calculating the sum of each carbon number x the content ratio (mass ratio) for each carbon number.

[0109] Specifically, the average carbon number is calculated as follows. For example, suppose that the ratio of the total peak area of ​​the light components to the total peak area detected by the GC distillation (1) above is calculated to be 0.3, and the ratio of the total peak area of ​​the heavy components to the total peak area detected is calculated to be 0.7. Furthermore, it is assumed that the area ratio of the compound with 9 carbon atoms (C9) is calculated to be 0.4, the area ratio of the compound with 10 carbon atoms (C10) is calculated to be 0.4, the area ratio of the compound with 11 carbon atoms (C11) is calculated to be 0.1, and the area ratio of the compound with 12 carbon atoms (C12) is calculated to be 0.1 by the GC-PONA analysis (2). Furthermore, it is assumed that the area ratio of the compound (C10) having 10 carbon atoms is calculated to be 0.2, the area ratio of the compound (C10) having 11 carbon atoms is calculated to be 0.05, the area ratio of the compound (C12) having 12 carbon atoms is calculated to be 0.05, and the area ratio of the compound (C13) having 13 carbon atoms is calculated to be 0.7 by the GC-MS analysis in (3). In this case, the content ratio of each compound for each carbon number is calculated as follows: C9: 0.3 x 0.4 = 0.12 C10: 0.3 x 0.4 + 0.7 x 0.2 = 0.26 C11: 0.3 x 0.1 + 0.7 x 0.05 = 0.065 C12: 0.3 x 0.1 + 0.7 x 0.05 = 0.065 C13: 0.7 x 0.7 = 0.49 Therefore, in the above example, the average carbon number is calculated as follows: Average carbon number = 9 x 0.12 + 10 x 0.26 + 11 x 0.065 + 12 x 0.065 + 13 x 0.49 = 11.545 ≒ 12.0

[0110] Kerosene base material 1 to 5 A mixture of kerosene fraction (straight-run kerosene) obtained by atmospheric distillation of crude oil, kerosene fraction (hydrodesulfurized kerosene) obtained by hydrodesulfurizing straight-run kerosene, and high-pressure hydrotreated fraction, each having the composition shown in Table 1, in the blending ratios shown in Table 2, and having the physical properties shown in Table 3. <Method for measuring naphthenes and aromatics> The naphthene content and aromatic content of each base material refer to values ​​determined by the following method. (1) Using high performance liquid chromatography (HPLC), separate the saturated and aromatic components under the following conditions. Measurement equipment: Shimadzu Corporation HPLC Column: Develosil 30-3 (4.6mm x 250mm) Mobile phase: n-hexane 1.0 mL / min 5.3 MPa Detector: CH1: UV254nm, CH2: RI Sample concentration: Dilute with n-hexane to approximately 20 vol.% Injection volume: 60μL Fractionation conditions: After elution of the saturated fraction, backflush is performed to elute the aromatic fraction all at once. (2) Each fraction is measured using a gas chromatograph-flame ionization detector (GC-FID) under the conditions shown below, and the area ratio of each fraction is calculated as mass %. Measuring device: Agilent GC Column: DB-HT SimDis 5m x 0.53mm I.D. x 0.15um Oven temperature: 40℃ (1 min) - (30℃ / min) - 350℃ (2 min) Run 13.33 min Detector: FID 400℃ (H2: 40mL / min, Air: 350mL / min, Makeup: He 50mL / min) Carrier gas: He 0.45702 psi 3.51 mL / min constant flow 27.453 cm / sec Injection method: On-column injection (3) For the saturated and aromatic components obtained above, an average mass spectrum is obtained using a gas chromatograph mass spectrometer (GC / MS) under the conditions shown below. Measuring device: Agilent GC-MS Column: DB-1HT 30m x 0.32mm I.D. x 0.10um Oven temperature: 40℃ (2 min) - (20℃ / min) - 300℃ (5 min) Run 20 min Carrier gas: He, constant pressure mode 30 kPa, initial: 2.1 mL / min, 52 cm / sec Ionization potential: EI 70eV Injection method: On-column injection (4) Next, for the saturated components, the obtained values ​​are substituted into the calculation formula described in ASTM D 2786 to calculate the volume ratios (volume %) of alkane compounds, monocyclic naphthene compounds, dicyclic naphthene compounds, tricyclic naphthene compounds, and tetracyclic naphthene compounds to the saturated components. (5) Next, for the aromatic content, the obtained value is substituted into the calculation formula described in ASTM D 3239 to calculate the volume ratio (volume %) of alkylbenzenes, naphthenebenzenes, dinaphthenebenzenes, naphthalenes, acenaphthene, and dibenzofurans to the aromatic content.

[0111] [Table 1]

[0112] [Table 2]

[0113] [Table 3]

[0114] (Examples 1 to 6, Comparative Examples 1 to 4) Any one of the above isoparaffinic base stocks 1 to 2 and any one of kerosene base stocks 1 to 5 were blended in the proportions shown in Table 4 to prepare the aviation fuel oils of Examples 1 to 6 and Comparative Examples 1 to 4. The properties of each of the resulting aviation fuel oils are shown in Table 4.

[0115] [Table 4]

[0116] As can be seen from Table 4, the aviation fuel oils obtained in Examples 1 to 6 contain a specific isoparaffinic base stock having an average carbon number of 13.0 to 17.0, but because they are blended with the isoparaffinic base stock and a specific kerosene base stock in specific proportions, they have a low freezing point of -40.0°C or less and a kinematic viscosity at -40°C of 12.00mm. 2 / s or less, which shows that it has excellent low-temperature fluidity.

[0117] On the other hand, as can be seen from Table 4, the aviation fuel oils obtained in Comparative Examples 1 to 4 have an isoparaffinic base stock with an average carbon number of 13.0 to 17.0, but the kerosene base stock blended with the isoparaffinic base stock does not have any particular properties, and therefore have a high freezing point of over -40°C (Comparative Examples 1, 2, and 4) and a kinematic viscosity at -40°C of 12.00mm 2 / s (Comparative Examples 1 to 4), and it is clear that the low-temperature fluidity is poor. [Industrial Applicability]

[0118] According to the present invention, it is possible to provide an aviation fuel oil that has a low freezing point and excellent low-temperature fluidity, even when it contains a specific isoparaffin-based base oil.

Claims

1. 1.0 to 50.0% by volume of an isoparaffin-based base material having an average carbon number of 13.0 to 17.0 and an isoparaffin content of 80.0 to 100.0% by volume, 50.0 to 99.0% by volume of a kerosene base oil having a bicyclic naphthene content of 6.0 to 17.0% by volume, a tricyclic naphthene content of 1.5 to 3.5% by volume, and a naphthene benzene content of 2.0 to 7.0% by volume.

1. An aviation fuel oil comprising:

2. 2. The aviation fuel according to claim 1, wherein the ratio of the total content of dicyclic naphthenes and tricyclic naphthenes in the kerosene base stock to the content of monocyclic naphthenes in the kerosene base stock is 0.5 to 1.4 by volume.

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