JP7650738B2 - Light oil composition - Google Patents

Description

The present invention relates to a diesel fuel composition.

Generally, diesel compositions are produced by mixing hydrodesulfurized diesel, which is obtained by hydrodesulfurizing diesel fractions (straight-run diesel) obtained by atmospheric distillation of crude oil, with hydrodesulfurized kerosene, which is obtained by hydrodesulfurizing kerosene fractions (straight-run kerosene) obtained by atmospheric distillation of crude oil. By increasing the blending ratio of hydrodesulfurized kerosene, low-temperature performance is imparted that allows stable use in cold regions and during the winter (see, for example, Patent Document 1 (JP Patent Publication 7-331261)).

On the other hand, increasing the blending ratio of hydrodesulfurized kerosene tends to reduce the lubricity and heat generation of the resulting diesel composition.

Japanese Patent Application Publication No. 7-331261

Under these circumstances, the present invention aims to provide a diesel oil composition that has excellent low-temperature performance and is particularly capable of exhibiting excellent heat generation and lubricity.

The present inventors have conducted intensive research to solve the above problems, and have come up with the idea of using, instead of the hydrodesulfurized light oil, a high-pressure desulfurized cracked light oil obtained by hydrotreating a feedstock oil having a 90% by volume distillation temperature of 320.0°C to 360.0°C by atmospheric distillation and containing 35.0% by mass to 70.0% by mass of aromatic hydrocarbons at a hydrogen partial pressure of 10 MPa to 18 MPa, followed by fractional distillation.
It was expected that by blending such high-pressure desulfurized cracked gas oil, a gas oil composition with a high heating value could be obtained.

However, since the above-mentioned high-pressure desulfurized cracked diesel also has issues with low-temperature performance, when it is used as a base material for a diesel composition, it is necessary to impart the desired low-temperature performance by increasing the blending ratio of hydrodesulfurized kerosene, as described above, and even in this case, it has been found that it is difficult to obtain a diesel composition with sufficient lubricity and heat generation properties.

The inventors therefore came up with the idea of using high-pressure desulfurized cracked kerosene instead of hydrodesulfurized kerosene. This is obtained by hydrotreating a feedstock oil having a 90% volume distillation temperature of 320.0°C to 360.0°C by atmospheric distillation and containing 35.0% to 70.0% by mass of aromatic hydrocarbons at a hydrogen partial pressure of 10 MPa to 18 MPa, followed by fractional distillation.

Generally, high-pressure desulfurized cracked kerosene base stocks have a low cetane index and have been considered unsuitable as diesel base stocks for internal combustion engines, so no attempt has been made to use the high-pressure desulfurized cracked kerosene mentioned above as a diesel base stock.

The inventors conducted research into this issue and surprisingly found that the above technical problems could be solved by a diesel oil composition prepared by blending the above-mentioned high-pressure desulfurized cracked diesel and high-pressure desulfurized cracked kerosene in a specified ratio, and based on this finding, they have completed the present invention.

That is, the present invention provides
(1) A feedstock oil having a 90% by volume distillation temperature of 320.0°C to 360.0°C and containing 35.0% by mass to 70.0% by mass of aromatic hydrocarbons is hydrotreated at a hydrogen partial pressure of 10 MPa to 18 MPa, and then fractionally distilled.
(a) a density at 15°C of 0.8300 g/cm ³ to 0.8800 g/cm ³ ;
(b) a flash point of 80.0°C to 150.0°C;
(c) a pour point of 2.5°C or less;
(d) 90% by volume distillation temperature by atmospheric distillation is 320.0°C to 360.0°C;
(e) a sulfur content of less than 10 ppm by mass;
(f) Cetane index: 45.0 to 65.0
The present invention further comprises 50% to 60% by volume of high-pressure desulfurized cracked light oil,
The crude oil is obtained by subjecting a feedstock having a 90% by volume distillation temperature of 320.0°C to 360.0°C and containing 35.0% by mass to 70.0% by mass of aromatic hydrocarbons to hydrotreating at a hydrogen partial pressure of 10 to 18 MPa, followed by fractional distillation.
(g) density at 15°C of 0.8000 g/cm ³ to 0.8500 g/cm ³ ;
(h) a flash point of 40.0°C to 80.0°C;
(i) a pour point of −50.0° C. or less;
(j) 90% by volume distillation temperature by atmospheric distillation is 190.0°C to 280.0°C;
(k) a sulfur content of less than 5 ppm by mass;
(l) Cetane index: 25.0 to 50.0
A diesel fuel composition comprising 40% by volume to 50% by volume of a high-pressure desulfurized cracked kerosene,
(2) The present invention provides a diesel fuel composition as described in (1) above, in which the feedstock for the high-pressure desulfurized cracked diesel fuel or the feedstock for the high-pressure desulfurized cracked kerosene comprises one or more selected from the group consisting of light diesel oil (LCGO), catalytically cracked diesel oil (LCO) and light diesel oil (DS-LHCGO) obtained by hydrotreating heavy diesel oil.

The present invention provides a diesel oil composition that has excellent low-temperature performance and is capable of exhibiting particularly excellent heat generation and lubricity.

Hereinafter, an embodiment of the present invention will be described in detail.
In this specification, the term "to" indicating a range of values indicates a range including the values given as the upper and lower limits. When a unit is given only for the upper limit of a range of values expressed by "to", it means that the lower limit is also in the same unit.
In the present specification, any upper or lower limit value described in a numerical range may be replaced with the upper or lower limit value of another numerical range described in a numerical range.
In this specification, the content or amount of each component in a composition means, when multiple substances corresponding to each component are present in the composition, the total content or amount of those multiple substances present in the composition, unless otherwise specified.
As used herein, combinations of preferred aspects are more preferred aspects.

In this specification, unless otherwise specified, the values of the following items are values determined using the following test methods and calculations.
"Density at 15°C";
JIS K 2249 "Determination of density of crude oil and petroleum products and density, mass and volume conversion tables."
・"Kinematic viscosity at 30°C"
JIS K2283 "Crude oil and petroleum products - Kinematic viscosity test method and viscosity index calculation method."
·"flash point"
Kerosene equivalent fractions such as high pressure desulfurized cracked kerosene and hydrodesulfurized kerosene: JIS K 2265-1 "Determination of flash point - Part 1: Tag sealed method"
Diesel oil equivalent fractions such as high pressure desulfurized cracked diesel oil and hydrodesulfurized diesel oil, and diesel oil compositions: JIS K 2265-3 "Method of determining flash point - Part 3: Pensky-Martens closed-cell method"
・"Pour point"
JIS K 2269 "Test method for pour point and cloud point of crude oil and petroleum products."
・"Cloud point"
JIS K 2269 "Test method for pour point and cloud point of crude oil and petroleum products."
・"Clogging point"
JIS K 2288 "Petroleum products - Light oil - Clogging point test method".
・"Atmospheric distillation properties"
(Initial boiling point (IBP) by atmospheric distillation, 10% by volume distillation temperature by atmospheric distillation, 50% by volume distillation temperature by atmospheric distillation, 90% by volume distillation temperature by atmospheric distillation, and end point (EP) by atmospheric distillation)
JIS K2254 "Petroleum products - Determination of distillation properties - Normal pressure method"
・"Sulfur content"
JIS K 2541-6 "Crude petroleum and petroleum products - Sulfur content test method - Part 6: Ultraviolet fluorescence method".
・"Nitrogen content"
JIS K 2609 "Crude petroleum and petroleum products -- Test method for nitrogen content."
- "Aromatic hydrocarbon content"
IP548 "Determination of aromatic hydrocarbon types in middle distillates - High performance liquid chromatography method with refractive index detection".
・"Heat generation (net heat generation)"
JIS K 2279 "Crude petroleum and petroleum products - Calorific value test method and calculation method - Method for estimating net calorific value from gross calorific value".
・"Cetane index"
JIS K 2280-5 "Petroleum products - How to determine octane number, cetane number and cetane index".
- Lubricity (HFRR test wear scar diameter)
JPI-5S-50-98 "Light oil - Lubricity test method".
In the present application, the degree of friction is indicated by the humidity-corrected wear scar diameter converted to a standard water vapor pressure of 1.4 kPa (HFRR WS1.4).

The diesel fuel composition according to the present invention comprises:
The crude oil is obtained by subjecting a feedstock having a 90% by volume distillation temperature of 320.0°C to 360.0°C and containing 35.0% by mass to 70.0% by mass of aromatic hydrocarbons to hydrotreating at a hydrogen partial pressure of 10 MPa to 18 MPa, followed by fractional distillation.
(a) a density at 15°C of 0.8300 g/cm ³ to 0.8800 g/cm ³ ;
(b) a flash point of 80.0°C to 150.0°C;
(c) a pour point of 2.5°C or less;
(d) 90% by volume distillation temperature by atmospheric distillation is 320.0°C to 360.0°C;
(e) a sulfur content of less than 10 ppm by mass;
(f) Cetane index: 45.0 to 65.0
The present invention further comprises 50% to 60% by volume of high-pressure desulfurized cracked light oil,
The crude oil is obtained by subjecting a feedstock having a 90% by volume distillation temperature of 320.0°C to 360.0°C and containing 35.0% by mass to 70.0% by mass of aromatic hydrocarbons to hydrotreating at a hydrogen partial pressure of 10 to 18 MPa, followed by fractional distillation.
(g) density at 15°C of 0.8000 g/cm ³ to 0.8500 g/cm ³ ;
(h) a flash point of 40.0°C to 80.0°C;
(i) a pour point of −50.0° C. or less;
(j) 90% by volume distillation temperature by atmospheric distillation is 190.0°C to 280.0°C;
(k) a sulfur content of less than 5 ppm by mass;
(l) Cetane index: 25.0 to 50.0
The present invention is characterized in that it contains 40% by volume to 50% by volume of high-pressure desulfurized cracked kerosene.

In the diesel fuel composition according to the present invention, the feedstock oil for the high-pressure desulfurized cracked diesel fuel and the feedstock oil for the high-pressure desulfurized cracked kerosene have the common characteristics of having a 90% by volume distillation temperature by atmospheric distillation of 320.0° C. to 360.0° C. and containing 35.0% by mass to 70.0% by mass of aromatic hydrocarbons. The high-pressure desulfurized cracked diesel fuel and the high-pressure desulfurized cracked kerosene obtained using these feedstocks are obtained by subjecting the feedstock oils to hydrotreatment at a hydrogen partial pressure of 10 MPa to 18 MPa, followed by fractional distillation.
For this reason, the following will first explain the raw oils for the high-pressure desulfurized cracked light oil and the high-pressure desulfurized cracked kerosene, then explain the details of the hydrotreating process, and then explain the high-pressure desulfurized cracked light oil and the high-pressure desulfurized cracked kerosene that are obtained by fractional distillation after the hydrotreating process.

<Feedstock oil>
In the diesel fuel composition according to the present invention, the feedstock oil for the high-pressure desulfurized cracked diesel fuel or the feedstock oil for the high-pressure desulfurized cracked kerosene is composed of a base material having a 90% by volume distillation temperature by atmospheric distillation of 320.0°C to 360.0°C and containing 35.0% by mass to 70.0% by mass of aromatic hydrocarbons (hereinafter, the base material having the above properties will be referred to as "feedstock oil" as appropriate).

The 90% by volume distillation temperature (hereinafter, simply referred to as T90) of the feedstock oil by atmospheric distillation is 320.0°C to 360.0°C, preferably 330.0°C to 360.0°C, and more preferably 340.0°C to 360.0°C.
If the T90 of the feedstock oil is equal to or greater than the lower limit of the above range, the content of aromatic hydrocarbons in the feedstock oil will be high, and a large amount of compounds having naphthenic rings will be produced by hydrotreatment, which will tend to improve the calorific value of the resulting base material.
When the T90 of the feedstock is equal to or less than the upper limit of the above range, the content of aromatic hydrocarbons in the feedstock will not be too high, coke generation during the hydrotreating reaction will be suppressed, and the life of the hydrotreating catalyst will be extended.

The content of aromatic hydrocarbons in the feedstock oil is 35.0% by mass to 70.0% by mass, preferably 37.0% by mass to 65.0% by mass, more preferably 40.0% by mass to 60.0% by mass, even more preferably 45.0% by mass to 60.0% by mass, and even more preferably 50.0% by mass to 60.0% by mass.
When the content of aromatic hydrocarbons is equal to or higher than the lower limit of the above range, a large amount of compounds having naphthene rings is produced by hydrotreating, improving the calorific value of the resulting kerosene/diesel base oil.When the content of aromatic hydrocarbons is equal to or lower than the upper limit of the above range, the generation of coke during the hydrotreating reaction is suppressed, and the life of the hydrotreating catalyst is extended.

The sulfur content in the feedstock oil is preferably 3.0 mass% or less, more preferably 2.0 mass% or less. When the sulfur content is equal to or less than the above upper limit, it is not necessary to set strict operating conditions for hydrotreating, which leads to a longer catalyst life and is economically advantageous.
Since the lower the sulfur content in the feedstock oil, the more preferable it is, the lower limit of the sulfur content is not particularly limited, but is usually 0.5 mass% or more.

The nitrogen content in the feed oil is preferably 1,000 ppm by mass or less, and more preferably 800 ppm by mass or less.
When the nitrogen content is equal to or less than the upper limit, it is not necessary to set strict operating conditions during hydrotreatment, which leads to a longer catalyst life and is economically advantageous. In addition, the color of the produced kerosene base material is not adversely affected.
Since the lower the nitrogen content in the feedstock oil, the more preferable it is, the lower limit of the nitrogen content is not particularly limited, but is usually 100 ppm by mass or more.

The feedstock oil preferably contains at least one selected from the group consisting of light gas oil from thermal cracking (LCGO), light gas oil from catalytic cracking (LCO), and light gas oil from thermal cracking (DS-LHCGO) obtained by hydrotreating heavy gas oil from thermal cracking.
The above-mentioned light pyrolysis gas oil (LCGO), light catalytic cracking gas oil (LCO), and light pyrolysis gas oil (DS-LHCGO) obtained by hydrotreating heavy pyrolysis gas oil will be explained below.

(Light Gas Oil (LCGO))
Light pyrolysis oil (LCGO) is a light fraction of the cracked oil obtained by thermally cracking a vacuum distillation residue, and has a 10% by volume distillation temperature of 180.0°C to 260.0°C by atmospheric distillation and a 90% by volume distillation temperature of 310.0°C to 380.0°C by atmospheric distillation.
Since LCGO is a fraction with a high aromatic content, it can easily improve the total heating value of the resulting base stock.
The volume ratio of LCGO to the total volume of the feedstock is preferably 10% by volume to 90% by volume, more preferably 20% by volume to 80% by volume, and even more preferably 30% by volume to 70% by volume.
When the volume ratio of LCGO is equal to or greater than the lower limit of the above range, the aromatic hydrocarbon content in the feedstock oil is high, and a large amount of compounds having naphthene rings are produced by hydrotreating, which tends to improve the calorific value of the resulting base material.When the volume ratio of LCGO is equal to or less than the upper limit of the above range, the aromatic hydrocarbon content in the feedstock oil is not too high, which suppresses the generation of coke in the hydrotreating reaction and extends the life of the hydrotreating catalyst.

(Light catalytic cracking oil (LCO))
Catalytically cracked light oil (LCO) is a fraction distilled from a fluid catalytic cracking unit, and is, for example, a fraction having a 10% by volume distillation temperature of 185.0°C to 250.0°C by atmospheric distillation and a 90% by volume distillation temperature of 270.0°C to 370.0°C by atmospheric distillation.

Because LCO is a fraction with a high aromatic content, it is easy to increase the total calorific value of the resulting base material.

The volume ratio of LCO to the total volume of the feedstock oil is preferably 10 vol % to 65 vol %, more preferably 20 vol % to 65 vol %, and even more preferably 25 vol % to 65 vol %.
When the volume ratio of LCO is equal to or greater than the lower limit of the above range, the content of aromatic hydrocarbons in the feedstock oil is high, and a large amount of compounds having naphthenic rings is produced by hydrotreating, which makes it easy to improve the calorific value of the resulting base material.When the volume ratio of LCO is equal to or less than the upper limit of the above range, the content of aromatic hydrocarbons in the feedstock oil is not too high, which suppresses the generation of coke in the hydrotreating reaction and extends the life of the hydrotreating catalyst.

(Light diesel oil (DS-LHCGO) obtained by hydrotreating thermally cracked heavy diesel oil)
The light gas oil (DS-LHCGO) obtained by hydrotreating thermally cracked heavy gas oil (HCGO) is a light gas oil obtained by hydrotreating thermally cracked heavy gas oil (HCGO), which is a heavier fraction than thermally cracked light gas oil (LCGO) among gas oils obtained by thermally cracking a vacuum distillation residue.

Since DS-LHCGO is a fraction with a high aromatic content, it can easily improve the total calorific value of the resulting base material.
DS-LHCGO has a 10% by volume distillation temperature of 200.0°C to 260.0°C by atmospheric distillation and a 90% by volume distillation temperature of 300.0°C to 350.0°C by atmospheric distillation.
The volume ratio of DS-LHCGO to the total volume of the feedstock is preferably 3 to 10% by volume, more preferably 4 to 10% by volume, and even more preferably 5 to 10% by volume.
When the volume fraction of DS-LHCGO is equal to or greater than the lower limit of the above range, the content of aromatic hydrocarbons in the feedstock oil increases, and a large amount of compounds having naphthene rings is produced by hydrotreatment, making it easy to improve the calorific value of the resulting base material.
When the volume ratio of DS-LHCGO is equal to or less than the upper limit of the above range, the content of aromatic hydrocarbons in the feed oil does not become too high, coke generation in the hydrotreating reaction is suppressed, and the life of the hydrotreating catalyst is extended.

The feedstock oil preferably contains LCGO and LCO, which are fractions with a high aromatic content.
The total volume ratio of LCGO and LCO to the total volume of the feedstock oil is preferably 30% by volume to 100% by volume, more preferably 40% by volume to 98% by volume, even more preferably 50% by volume to 95% by volume, and particularly preferably 60% by volume to 95% by volume.

When the total volume ratio of LCGO and LCO is equal to or greater than the lower limit of the above range, the content of aromatic hydrocarbons in the feedstock oil increases, and a large amount of compounds having naphthene rings is produced by hydrotreatment, making it easy to improve the calorific value of the resulting base material.
When the total volume ratio of LCGO and LCO is equal to or less than the upper limit of the above range, the content of aromatic hydrocarbons in the feed oil does not become too high, coke generation in the hydrotreating reaction is suppressed, and the life of the hydrotreating catalyst is extended.

Specifically, the feedstock oil may have a volume ratio of LCGO of 30% to 60% by volume and a volume ratio of LCO of 35% to 65% by volume relative to the total volume of the feedstock oil.
When the volumetric proportions of LCGO and LCO are equal to or greater than the lower limit of the above range, the aromatic hydrocarbon content in the feedstock oil is high, and a large amount of compounds having naphthene rings are produced by hydrotreating, which makes it easy to improve the calorific value of the resulting base material.When the volumetric proportions of LCGO and LCO are equal to or less than the upper limit of the above range, the aromatic hydrocarbon content in the feedstock oil is not too high, coke generation in the hydrotreating reaction is suppressed, and the life of the hydrotreating catalyst is extended.

<Other base oil materials>
The feedstock may contain other base stocks in addition to the LCGO, LCO, and DS-LHCGO.
Other base materials constituting the feed oil include, for example, straight run diesel oil obtained by atmospheric distillation, diesel fractions obtained from an indirect desulfurization unit, and diesel fractions obtained from a direct desulfurization unit.
The volume ratio of the other base material to the total volume of the feed oil is preferably 0 to 70% by volume, more preferably 2 to 60% by volume, and even more preferably 5 to 50% by volume.

<Hydrotreatment>
The feedstock is hydrotreated at a hydrogen partial pressure of 10 MPa to 18 MPa.
The conditions of the above-mentioned hydrotreatment will be described in detail below.

(Hydrotreatment Catalyst)
As the mixture constituting the carrier of the hydrotreating catalyst, a porous inorganic oxide containing alumina can be used.
Examples of the active component constituting the hydrotreating catalyst include at least one metal element selected from Group 6 of the periodic table and at least one metal element selected from Groups 8 to 10 of the periodic table.

As the at least one metal element selected from Group 6 of the periodic table, molybdenum and tungsten are preferred. As the molybdenum compound, molybdenum trioxide, ammonium molybdate, etc. are preferred, and as the tungsten compound, tungsten trioxide, ammonium tungstate, etc. are preferred. The amount of the Group 6 metal supported is preferably 8% by mass to 20% by mass, calculated as the oxide, based on the total mass of the hydrotreating catalyst.

As the at least one metal element selected from Groups 8 to 10 of the periodic table, cobalt and nickel are preferred. As the cobalt compound, cobalt carbonate, basic cobalt carbonate, cobalt nitrate, etc. are preferred, and as the nickel compound, nickel carbonate, basic nickel carbonate, nickel nitrate, etc. are preferred. The amount of metal element of Groups 9 and 10 supported is preferably 2% by mass to 6% by mass, calculated as the oxide, of the total mass of the hydrotreating catalyst.

Among the above-mentioned active components, molybdenum-nickel catalysts, which combine molybdenum and nickel, are preferred.

It is also preferable to use the above-mentioned hydrotreating catalyst by subjecting it to hydrogen reduction treatment in a hydrogen atmosphere at 300°C to 400°C for 1 hour to 36 hours.

(Hydrotreatment conditions)
The hydrogen partial pressure during hydrotreating the feedstock is 10 MPa to 18 MPa, preferably 11 MPa to 16 MPa, and more preferably 13 MPa to 15 MPa.
When the hydrogen partial pressure is equal to or higher than the lower limit of the above range, coke generation is suppressed even when a feedstock oil having a high content of olefins or aromatic hydrocarbons is hydrotreated, and the life of the hydrotreatment catalyst is extended.
When the hydrogen partial pressure is equal to or lower than the upper limit of the above range, the cost of the hydrotreating equipment is not too high, which is economically advantageous.

When hydrotreating is carried out in a flow reactor, the hydrogen/oil ratio at the reactor inlet (hereinafter, appropriately referred to as "hydrogen/oil ratio") is, for example, 100 Nm ³ /KL to 800 Nm ³ /KL, preferably 200 Nm ³ /KL to 700 Nm ³ /KL, and more preferably 300 Nm ³ /KL to 650 Nm ³ /KL.
When the hydrogen/oil ratio is equal to or greater than the lower limit of the above range, the hydrotreating reaction proceeds sufficiently. When the hydrogen/oil ratio is equal to or less than the upper limit of the above range, hydrogen is not consumed excessively, and the processing cost can be reduced. In addition, quench hydrogen may be added according to the heat generation in the reactor.

When the hydrotreatment is carried out in a flow reactor, the liquid hourly space velocity (LHSV) is, for example, 0.1 hr ⁻¹ to 3 hr ⁻¹ , preferably 0.2 hr ⁻¹ to 2 hr ⁻¹ , and more preferably 0.25 hr ⁻¹ to 1 hr ⁻¹ .
When the liquid hourly space velocity is equal to or higher than the lower limit of the above range, the efficiency of hydrotreating is easily improved, whereas when the liquid hourly space velocity is equal to or lower than the upper limit of the above range, the contact time between the hydrotreating catalyst and the feed oil is sufficient, allowing the activity of the hydrotreating catalyst to be fully exerted.

The temperature of the catalyst layer is, for example, 300°C to 420°C, preferably 310°C to 400°C, and more preferably 310°C to 390°C.
When the temperature of the catalyst layer is equal to or higher than the lower limit of the above range, the catalytic activity of the hydrogenation catalyst is improved. When the temperature of the catalyst layer is equal to or lower than the upper limit of the above range, coloration of the hydrotreated oil and shortening of the life of the hydrotreatment catalyst are less likely to occur.

The reaction format during hydrotreating may be, for example, a fixed bed, a moving bed or a fluidized bed. The feedstock oil is introduced into this reactor and hydrotreating is carried out under the above conditions.
Most commonly, the catalyst described above is maintained in the above manner as a fixed bed and the feedstock is treated by passing downwardly through the fixed bed.

After the above-mentioned hydrogenation process, the resulting hydrogenation product can be separated by distillation (fractional distillation process) to obtain high-pressure desulfurized cracked diesel and high-pressure desulfurized cracked kerosene, each of which has specific physical properties.

For the above distillation separation, it is preferable to use a distillation apparatus. Here, a distillation apparatus refers to an apparatus that separates liquid mixtures by utilizing the difference in boiling points, and can separate a mixture that is liquid or solid at normal temperature and pressure by distillation into a liquid mixture by adjusting the temperature and pressure.

The high-pressure desulfurized cracked gas oil and the high-pressure desulfurized cracked kerosene that constitute the gas oil composition of the present invention may be obtained from the same stock oil or from different stock oils.
Furthermore, when the high-pressure desulfurized cracked light oil and the high-pressure desulfurized cracked kerosene that constitute the diesel fuel composition of the present invention are obtained from the same feedstock oil, they may be obtained under the same hydrotreating conditions or under different hydrotreating conditions.

The diesel fuel composition according to the present invention comprises:
The crude oil is obtained by subjecting a feedstock having a 90% by volume distillation temperature of 320.0°C to 360.0°C and containing 35.0% by mass to 70.0% by mass of aromatic hydrocarbons to hydrotreating at a hydrogen partial pressure of 10 MPa to 18 MPa, followed by fractional distillation.
(a) a density at 15°C of 0.8300 g/cm ³ to 0.8800 g/cm ³ ;
(b) a flash point of 80.0°C to 150.0°C;
(c) a pour point of 2.5°C or less;
(d) 90% by volume distillation temperature by atmospheric distillation is 320.0°C to 360.0°C;
(e) a sulfur content of less than 10 ppm by mass;
(f) Cetane index: 45.0 to 65.0
It includes high-pressure desulfurized cracked diesel fuel.

The high-pressure desulfurized cracked light oil constituting the light oil composition according to the present invention has (a) a density at 15°C of 0.8300 g/cm ³ to 0.8800 g/cm ³ , preferably 0.8400 g/cm ³ to 0.8800 g/cm ³ , and more preferably 0.8450 g/cm ³ to 0.8800 g/cm ³ .
By having the density of the high-pressure desulfurized cracked light oil base material that constitutes the light oil composition of the present invention fall within the above-mentioned range, when it is blended into the light oil composition, the hydrocarbon content per volume is increased, the heat generation amount is improved, and good combustion conditions can be easily achieved when the light oil composition is combusted.

The high-pressure desulfurized cracked diesel fuel constituting the diesel fuel composition according to the present invention has (b) a flash point of 80.0°C to 150.0°C, preferably 100.0°C to 150.0°C, and more preferably 120°C to 150°C.
Since the lower limit of the flash point of the high-pressure desulfurized cracked light oil is 80.0°C or higher, when the high-pressure desulfurized cracked light oil is blended into the light oil composition of the present invention, the light oil composition is likely to have a flash point of, for example, 45°C or higher, which is the flash point of No. 2 light oil in JIS K2204 "Required Quality of Light Oil", and is less likely to ignite due to ignition. The upper limit of the flash point of the high-pressure desulfurized cracked light oil is usually 150.0°C or lower.

The high-pressure desulfurized cracked gas oil constituting the gas oil composition according to the present invention has (c) a pour point of 2.5°C or lower, preferably 0.0°C or lower.
Although there is no particular lower limit for the pour point of the high-pressure desulfurized cracked gas oil, the pour point of the high-pressure desulfurized cracked gas oil is usually -10.0°C or higher.
By making the pour point of the high-pressure desulfurized cracked gas oil 2.5° C. or lower, it is possible to effectively control the low-temperature flow performance of the gas oil composition according to the present invention which contains the high-pressure desulfurized cracked gas oil.

The high-pressure desulfurized cracked gas oil constituting the gas oil composition according to the present invention preferably has a cloud point of 5°C or lower, more preferably 4°C or lower.
Since the cloud point of the high-pressure desulfurized cracked light oil that constitutes the light oil composition of the present invention is within the above range, it is possible to easily improve the low-temperature operability of diesel engines when blended into the light oil composition of the present invention.

The high-pressure desulfurized cracked diesel fuel constituting the diesel fuel composition of the present invention preferably has an initial boiling point (IBP) of 215.0°C to 290.0°C, more preferably 230.0°C to 290.0°C, and even more preferably 245.0°C to 290.0°C.

The high-pressure desulfurized cracked diesel fuel constituting the diesel fuel composition according to the present invention preferably has a 10% by volume distillation temperature (T10) by atmospheric distillation of 235.0°C to 300.0°C, more preferably 245.0°C to 300.0°C, and even more preferably 260.0°C to 300.0°C.
The high-pressure desulfurized cracked diesel fuel constituting the diesel fuel composition according to the present invention preferably has a 50% by volume distillation temperature (T50) by atmospheric distillation of 270.0°C to 320.0°C, more preferably 280.0°C to 320.0°C, and even more preferably 285.0°C to 320.0°C.
The high-pressure desulfurized cracked diesel fuel constituting the diesel fuel composition of the present invention has a 90% by volume distillation temperature (T90) by atmospheric distillation of 320.0 to 360.0°C, preferably 330.0°C to 360.0°C, and more preferably 345.0°C to 360.0°C.
The high-pressure desulfurized cracked diesel fuel constituting the diesel fuel composition according to the present invention preferably has an atmospheric distillation end point (EP) of 340.0°C to 400.0°C, more preferably 350.0°C to 390.0°C, and even more preferably 360.0°C to 390.0°C.

The high-pressure desulfurized cracked diesel fuel constituting the diesel fuel composition of the present invention has an IBP, T10, T50, T90 and EP within the above ranges, so that when blended into a diesel fuel composition, it is possible to effectively lower the cloud point while maintaining an appropriate flash point, increase the hydrocarbon content per volume, facilitate an increase in heat generation, and easily maintain good combustion characteristics.

The high-pressure desulfurized cracked diesel fuel constituting the diesel fuel composition according to the present invention preferably has (e) a sulfur content of less than 10 ppm by mass (0 ppm by mass or more and less than 10 ppm by mass), and the lower the sulfur content the more preferable.
When the sulfur content of the high-pressure desulfurized cracked gas oil constituting the gas oil composition according to the present invention is within the above range, the production of sulfur oxides during combustion can be easily reduced.

In the diesel fuel composition according to the present invention, the cetane index (f) of the high-pressure desulfurized cracked diesel fuel is preferably 45.0 to 65.0, more preferably 50.0 to 65.0, and even more preferably 55.0 to 65.0.
The high-pressure desulfurized cracked diesel oil that constitutes the diesel oil composition of the present invention has a cetane index within the above-mentioned range, and therefore when blended into a diesel engine fuel oil, it can easily improve low-temperature startability and easily suppress harmful exhaust gas emissions from the engine.

The diesel composition according to the present invention contains 50% to 60% by volume of the above-mentioned high-pressure desulfurized cracked diesel oil as a constituent base material, and preferably 55% to 60% by volume.

The diesel fuel composition of the present invention contains the high-pressure desulfurized cracked diesel fuel having the above-mentioned characteristics in the above-mentioned ratio, and when blended into the diesel fuel composition of the present invention, it easily exhibits excellent heating value and lubricity, and can easily ensure a certain level of cetane index and low-temperature performance.

The diesel composition according to the present invention is obtained by hydrotreating a feedstock oil having a 90% by volume distillation temperature of 320.0°C to 360.0°C by atmospheric distillation and containing 35.0% by mass to 70.0% by mass of aromatic hydrocarbons at a hydrogen partial pressure of 10 to 18 MPa, followed by fractional distillation.
(g) density at 15°C of 0.8000 g/cm ³ to 0.8500 g/cm ³ ;
(h) a flash point of 40.0°C to 80.0°C;
(i) a pour point of −50.0° C. or less;
(j) 90% by volume distillation temperature by atmospheric distillation is 190.0°C to 280.0°C;
(k) a sulfur content of less than 5 ppm by mass;
(l) Cetane index: 25.0 to 50.0
This includes high-pressure desulfurized cracked kerosene.

The high-pressure desulfurized cracked kerosene constituting the diesel fuel composition according to the present invention has a density at 15°C of (g) 0.8000 g/cm ³ to 0.8500 g/cm ³ , preferably 0.8100 g/cm ³ to 0.8500 g/cm ³ , and more preferably 0.8200 g/cm ³ to 0.8500 g/cm ³ .
Since the density of the high-pressure desulfurized cracked kerosene that constitutes the diesel fuel composition of the present invention is within the above-mentioned range, the hydrocarbon content per volume is increased, the heat generation amount is improved, and good combustion conditions can be easily achieved when the diesel fuel composition is combusted.

The high-pressure desulfurized cracked kerosene constituting the diesel fuel composition according to the present invention has (h) a flash point of 40.0°C to 80.0°C, preferably 45.0°C to 80.0°C, and more preferably 50.0°C to 80.0°C.
By having the flash point of the high-pressure desulfurized cracked kerosene within the above range, when it is blended into the diesel oil composition of the present invention, it is likely to have a flash point of 45°C or higher, which is the flash point of No. 2 diesel oil as specified in JIS K2204 "Required Quality of Diesel Oil", and the risk of fire due to ignition is likely to be reduced. In addition, the upper limit of the flash point of the high-pressure desulfurized cracked kerosene is usually 80.0°C or lower.

The high-pressure desulfurized cracked kerosene constituting the diesel fuel composition according to the present invention preferably has (i) a pour point of -50.0°C or lower, more preferably -55.0°C or lower.
Since the pour point of the high-pressure desulfurized cracked kerosene is −50.0° C. or lower, the low-temperature flow performance can be easily maintained in the diesel oil composition according to the present invention which contains the high-pressure desulfurized cracked kerosene.

The high-pressure desulfurized cracked kerosene constituting the diesel fuel composition of the present invention preferably has an initial boiling point (IBP) by atmospheric distillation of 120.0°C to 220.0°C, more preferably 140.0°C to 200.0°C, and even more preferably 150.0°C to 200.0°C.

The high-pressure desulfurized cracked kerosene constituting the diesel fuel composition according to the present invention preferably has a 10% by volume distillation temperature (T10) by atmospheric distillation of 170.0°C to 220.0°C, more preferably 175.0°C to 210.0°C, and even more preferably 180.0°C to 205.0°C.
The high-pressure desulfurized cracked kerosene constituting the diesel fuel composition according to the present invention preferably has a 50% by volume distillation temperature (T50) by atmospheric distillation of 170.0°C to 245.0°C, more preferably 190.0°C to 235.0°C, and even more preferably 200.0°C to 225.0°C.
The high-pressure desulfurized cracked kerosene constituting the diesel fuel composition according to the present invention has a 90% by volume distillation temperature (T90) by atmospheric distillation of 190.0 to 280.0°C, preferably 200.0°C to 270.0°C, and more preferably 210.0°C to 260.0°C.
The high-pressure desulfurized cracked kerosene constituting the diesel fuel composition according to the present invention preferably has an atmospheric distillation end point (EP) of 220.0°C to 320.0°C, more preferably 240.0°C to 300.0°C, and even more preferably 250.0°C to 290.0°C.

The high-pressure desulfurized cracked kerosene constituting the diesel fuel composition of the present invention has IBP, T10, T50, T90 and EP within the above ranges, so that the JIS standard for diesel fuel can be easily met during preparation of the diesel fuel composition of the present invention, and the hydrocarbon content per volume is increased, making it easy to improve the heating value.

The high-pressure desulfurized cracked kerosene constituting the diesel fuel composition according to the present invention preferably has a sulfur content (k) of less than 5 ppm by mass (0 ppm by mass or more and less than 5 ppm by mass), preferably 2 ppm by mass or less (0 ppm by mass or more and 2 ppm by mass or less), and more preferably 1 ppm by mass or less (0 ppm by mass or more and 1 ppm by mass or less).
When the sulfur content of the high-pressure desulfurized cracked kerosene constituting the diesel fuel composition according to the present invention is within the above range, the production of sulfur oxides during combustion can be easily reduced.

In the diesel fuel composition according to the present invention, the cetane index (l) of the high-pressure desulfurized cracked kerosene is preferably 25.0 to 50.0, more preferably 30.0 to 50.0, and even more preferably 35.0 to 50.0.
When the cetane index of the high-pressure desulfurized cracked kerosene is within the above range, it is possible to easily improve the low temperature startability as a fuel oil for diesel engines when it is blended into a light oil composition.

The diesel composition according to the present invention contains 40% to 50% by volume of the above-mentioned high-pressure desulfurized cracked kerosene as a constituent base material, and preferably 40% to 45% by volume.

The diesel fuel composition of the present invention contains high-pressure desulfurized cracked kerosene having the above-mentioned characteristics in the above-mentioned ratio, and when blended into the diesel fuel composition of the present invention, it easily exhibits excellent heating value and lubricity, and can easily ensure a certain level of cetane index and low-temperature performance.

The diesel composition according to the present invention may contain, in addition to the high-pressure desulfurized cracked diesel and the high-pressure desulfurized cracked kerosene, other base constituents to the extent that the effects of the present invention are not impaired.
The constituent base materials other than the high-pressure desulfurized cracked light oil and the high-pressure desulfurized cracked kerosene can be appropriately selected from known base materials, and examples thereof include hydrodesulfurized kerosene, synthetic light oil produced by Fischer-Tropsch synthesis, and hydrocracked light oil.
In the diesel fuel composition according to the present invention, the blending ratio of other diesel fuel base materials is limited to 0 to 10% by volume.

The diesel oil composition according to the present invention may contain various additives in addition to the above base components.
The additives include one or more selected from known fuel additives such as flow improvers, lubricity improvers, antioxidants, metal deactivators, antistatic agents, and corrosion inhibitors.

The gas oil composition according to the present invention preferably has a pour point of -7.5°C or lower.
By virtue of the pour point being within the above range, the diesel composition according to the present invention is more likely to prevent clogging of fuel filters and piping systems.

The diesel composition according to the present invention preferably has a cloud point of -3°C or lower.
Since the gas oil composition of the present invention has a cloud point within the above range, it is possible to easily improve the low temperature startability and low temperature drivability of diesel engines.

The diesel composition according to the present invention preferably has a plugging point of -6°C or lower.
If the plugging point of the diesel fuel composition according to the present invention is within the above range, the occurrence of plugging inside fuel filters and piping systems can be easily suppressed.

The diesel composition according to the present invention preferably has a calorific value of 35,500 J/mL or more.
By providing the gas oil composition of the present invention with a calorific value within the above range, the combustion efficiency during combustion in a diesel engine can be easily improved.

The diesel composition according to the present invention preferably has a cetane index of 45.0 to 65.0, and more preferably 47.0 to 65.0.
By providing the diesel fuel composition according to the present invention with a cetane index within the above range, it is possible to easily improve the low temperature startability of the diesel engine fuel oil and also to easily reduce the amount of harmful exhaust gases emitted from the engine.

The diesel oil composition according to the present invention preferably has a lubricity (HFRR test wear scar diameter) of 550 μm or less.
The diesel oil composition according to the present invention has a lubricity (HFRR test wear scar diameter) of 550 μm or less, so that stable lubricity can be easily exhibited.

The light oil composition according to the present invention preferably has a flash point of 50.0°C to 70.0°C, and more preferably 65.0°C to 70.0°C.
Since the flash point of the diesel oil composition according to the present invention is within the above range, it can be handled easily and safely.

The diesel composition of the present invention can be prepared by mixing a predetermined amount of the high-pressure desulfurized cracked diesel and high-pressure desulfurized cracked kerosene having the above-mentioned specific properties as the essential base material, and further mixing known base materials or additives within the range that does not impair the effects of the present invention.

When preparing the diesel fuel composition of the present invention by mixing the above base materials, the mixing order is not particularly limited.

The present invention provides a diesel oil composition that has excellent low-temperature performance and is capable of exhibiting particularly excellent heat generation and lubricity.

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

(Substrate)
The following substrates were used in the following examples and comparative examples. The properties of each substrate are shown in Table 1.
High-pressure desulfurized cracked diesel fuel: This is a distillate of high-pressure hydrotreated oil obtained by high-pressure hydrotreating a feedstock oil containing 44.2% by mass of aromatic hydrocarbons and having a 90% volume distillation temperature (T90) of 351.5°C by atmospheric distillation at a hydrogen partial pressure of 13 MPa.
The feedstock oil is a blend of 52 vol. % thermally cracked light gas oil (LCGO), 16 vol. % catalytically cracked light oil (LCO), 6 vol. % light gas oil (DS-LHCGO) obtained by hydrotreating thermally cracked heavy gas oil, and 26 vol. % light oil fraction (straight run gas oil) obtained by atmospheric distillation of crude oil.
High-pressure desulfurized cracked kerosene: This is a distillate of high-pressure hydrotreated oil obtained by high-pressure hydrotreating a feedstock oil containing 48.6% by mass of aromatic hydrocarbons and having a 90% volume distillation temperature (T90) of 339.0°C by atmospheric distillation at a hydrogen partial pressure of 13 MPa.
The feedstock oil is a blend of 42% by volume of thermally cracked light gas oil (LCGO), 45% by volume of catalytically cracked light gas oil (LCO), 6% by volume of light gas oil (DS-LHCGO) obtained by hydrotreating thermally cracked heavy gas oil, and 7% by volume of a light oil fraction (straight run gas oil) obtained by atmospheric distillation of crude oil.
Hydrodesulfurized diesel fuel: This is produced by hydrodesulfurizing the diesel fraction (straight run diesel fuel) obtained by atmospheric distillation of Middle Eastern crude oil.
・Hydrodesulfurized kerosene Kerosene fraction (straight run kerosene) obtained by atmospheric distillation of Middle Eastern crude oil is hydrodesulfurized.

(Examples 1 to 2, Comparative Examples 1 to 6)
The above-mentioned high-pressure desulfurized cracked light oil, high-pressure desulfurized cracked kerosene, hydrodesulfurized light oil and hydrodesulfurized kerosene were blended in the proportions shown in Table 2 below to prepare the light oil compositions of Examples 1 to 2 and Comparative Examples 1 to 6.
The properties of each of the resulting diesel compositions are shown in Table 2.

From Table 2, it can be seen that the diesel compositions obtained in Examples 1 and 2 are made by blending high-pressure desulfurized cracked diesel and high-pressure desulfurized cracked kerosene, each of which has specific properties, in specific ratios, and therefore have excellent low-temperature performance with a pour point of -7.5°C or less, a cloud point of -3°C or less, and a clogging point of -6°C or less, as well as excellent heat generation with a high net heating value of 35,880 J/ml or more, and excellent lubricity with a lubricity (HFRR test wear scar diameter) of 550 μm or less.

On the other hand, from Table 2, it can be seen that the diesel compositions obtained in Comparative Examples 1 to 6 do not contain the high-pressure desulfurized cracked diesel and high-pressure desulfurized cracked kerosene in specific proportions, each of which has specific properties, and therefore have poor low-temperature fluidity with a pour point of -5.0°C (Comparative Example 4), poor heat generation with a net heating value of 34,870 J/ml to 35,550 J/ml (Comparative Examples 1 to 3, Comparative Examples 5 to 6), and poor lubricity with a wear scar diameter of 560 μm to 575 μm (HFRR test) (Comparative Examples 1 to 3, Comparative Example 5).

The present invention provides a diesel oil composition that has excellent low-temperature performance and is capable of exhibiting particularly excellent heat generation and lubricity.

Claims (2)

The crude oil is obtained by subjecting a feedstock having a 90% by volume distillation temperature of 320.0°C to 360.0°C and containing 35.0% by mass to 70.0% by mass of aromatic hydrocarbons to hydrotreating at a hydrogen partial pressure of 10 MPa to 18 MPa, followed by fractional distillation.
(a) a density at 15°C of 0.8300 g/cm ³ to 0.8800 g/cm ³ ;
(b) a flash point of 80.0°C to 150.0°C;
(c) a pour point of 2.5°C or less;
(d) 90% by volume distillation temperature by atmospheric distillation is 320.0°C to 360.0°C;
(e) a sulfur content of less than 10 ppm by mass;
(f) Cetane index: 45.0 to 65.0
The present invention further comprises 50% to 60% by volume of high-pressure desulfurized cracked light oil,
The crude oil is obtained by subjecting a feedstock having a 90% by volume distillation temperature of 320.0°C to 360.0°C and containing 35.0% by mass to 70.0% by mass of aromatic hydrocarbons to hydrotreating at a hydrogen partial pressure of 10 to 18 MPa, followed by fractional distillation.
(g) density at 15°C of 0.8000 g/cm ³ to 0.8500 g/cm ³ ;
(h) a flash point of 40.0°C to 80.0°C;
(i) a pour point of −50.0° C. or less;
(j) 90% by volume distillation temperature by atmospheric distillation is 190.0°C to 280.0°C;
(k) a sulfur content of less than 5 ppm by mass;
(l) Cetane index: 25.0 to 50.0
A diesel fuel composition comprising 40 to 50% by volume of a high-pressure desulfurized cracked kerosene. The feedstock oil for the high-pressure desulfurized cracked gas oil or the feedstock oil for the high-pressure desulfurized cracked kerosene comprises at least one selected from the group consisting of thermally cracked light gas oil (LCGO), catalytically cracked gas oil (LCO) and light gas oil (DS-LHCGO) obtained by hydrotreating thermally cracked heavy gas oil. The diesel composition according to claim 1,