JP2008248175A - Gas oil base material and gas oil composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas oil base material prepared by using an intermediate fraction (coker gas oil) of a coker oil obtained from a coker thermal decomposition apparatus of which the use for a gas oil base material has been conventionally thought to be difficult. <P>SOLUTION: The gas oil base material, having a sulfur content of 10 ppm or lower, a cetane index of 50 or higher, a total aromatic content of 25 vol.% or lower, and an olefin content of 1 vol.% or lower, is prepared by mixing 100 pts.vol. of a straight-run gas oil with 15-40 pts.vol. of a coker gas oil which is obtained from a coker thermal decomposition apparatus and has a boiling point range of 110-400°C, a sulfur content of 3.0 mass% or lower, a total aromatic content of 35 vol.% or lower, a bicyclic or higher polycyclic aromatic content of 20 vol.% or lower, and an olefin content of 40 vol.% or lower, and flowing the resultant mixture into a gas oil desulfurization apparatus to hydrodesulfurize the mixture. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to effective utilization of coker light oil that has not been used as a conventional light oil base material, and provides a light oil composition that is excellent in storage stability and white smoke prevention performance at low temperatures.

Conventional diesel engine diesel oil (diesel diesel oil) is obtained by hydrorefining straight-run gas oil obtained from crude oil atmospheric distillation equipment, or obtained from crude oil atmospheric distillation equipment as well as hydrorefined straight-run gas oil. A straight-run kerosene or a mixture of hydrogenated products thereof has been used.
Further, in recent years, from the viewpoint of increasing production of diesel oil, contact obtained by catalytic cracking of vacuum diesel oil obtained by vacuum distillation of straight run heavy oil obtained from crude oil atmospheric distillation equipment or atmospheric distillation residue. It is known to blend a light oil obtained from a heavy fraction called cracked light oil (LCO) or a coker pyrolyzer with a light oil (see Patent Documents 1 and 2).
JP-A-6-27184 Japanese Patent Laid-Open No. 10-8070

  However, none of them are fully utilized from the viewpoint of effective use of middle distillates, such as the use of light distillate or a small blending amount. In addition, cracked diesel oil bases have a high sulfur content, and blending with diesel oil is not preferred from the viewpoint of sulfur-free diesel oil in recent years, making it difficult to use as diesel oil bases.

  Under such circumstances, the present invention conducts detailed research from a new perspective on the middle fraction of coker oil (coker gas oil) obtained from the coker pyrolysis apparatus, which was considered difficult to use as a base material for light oil. It is to provide a new light oil base material.

As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.
That is, according to the present invention, the boiling point range obtained from a coker pyrolysis apparatus is 110 to 400 ° C., the sulfur content is 3.0% by mass or less, and the total aromatic content is 35% by volume or less, based on 100 parts by volume of straight-run gas oil. A sulfur content of 10 obtained by mixing 15 to 40 parts by volume of coker diesel oil having a ring or higher polycyclic aromatic content of 20% by volume or less and an olefin content of 40% by volume or less through a gas oil desulfurization apparatus and hydrodesulfurization treatment. The present invention relates to a light oil base material having a mass ppm or less, a cetane index of 50 or more, a total aromatic content of 25% by volume or less, and an olefin content of 1% by volume or less.

The present invention also uses a hydrodesulfurization catalyst in the presence of hydrogen, a hydrogen pressure of 3 to 8 MPa, a reaction temperature of 300 to 380 ° C., a liquid space velocity (LHSV) of 0.3 to 2 h ⁻¹ , a hydrogen / oil ratio of 100. The present invention relates to the gas oil base material described above, wherein the hydrodesulfurization treatment is performed under a condition of ˜500 NL / L.

  Furthermore, the present invention comprises a gas oil composition comprising the above-mentioned gas oil base material in an amount of 60% by volume or more, having a sulfur content of 10 mass ppm or less and an HFRR wear scar diameter (WS1.4) of 460 μm or less. It is about.

Furthermore, the present invention has a flash point of 50 ° C. or higher, a distillation property 90% distillation temperature of 350 ° C. or lower, a kinematic viscosity (30 ° C.) of 2.5 mm ² / s or higher, a cetane index of 45 or higher, and a density of 750 kg. / M ³ or more and 850 kg / m ³ or less, and the lubricity improver content is 50 mg / L or more and 200 mg / L or less.

  ADVANTAGE OF THE INVENTION According to this invention, while using the coker light oil which was not utilized conventionally as a light oil base material, the light oil composition excellent in the storage stability and the white smoke prevention performance in low temperature is provided.

Hereinafter, the present invention will be described in detail.
The light oil base of the present invention has a boiling range of 110 to 400 ° C. obtained from a coker pyrolysis apparatus, a sulfur content of 3.0% by mass or less, and a total aromatic content of 35% by volume or less with respect to 100 parts by volume of straight-run gas oil. Sulfur obtained by mixing 15 to 40 parts by volume of coker gas oil having a polycyclic aromatic content of 2 or more rings of 20% by volume or less and an olefin content of 40% by volume or less through a gas oil desulfurization apparatus and hydrodesulfurizing the mixture. It is necessary that the content is 10 ppm by mass or less, the cetane index is 50 or more, the total aromatic content is 25% by volume or less, and the olefin content is 1% by volume or less.

  The straight-run gas oil according to the gas oil base of the present invention refers to a gas oil fraction obtained from a crude oil atmospheric distillation apparatus, and usually refers to a gas oil fraction having a boiling point in the range of about 140 to 350 ° C. .

  The coker light oil according to the light oil base of the present invention is a light oil distillate obtained by decomposing heavy hydrocarbons into light hydrocarbons by heating the heavy oil and causing a reaction mainly composed of radical reactions. Say minutes. Heavy oils of raw material oil include residual oil obtained from atmospheric distillation equipment (atmospheric residual oil), residual oil obtained from vacuum distillation equipment (vacuum residual oil), catalytic cracking residual oil (CLO), residual oil directly Desulfurization residue oil (RDS bottom), heavy crude oil, oil sand, bitumen and the like are preferable, but atmospheric distillation residue and vacuum distillation residue are more preferably used from the viewpoint of the efficiency of crude oil processing in refineries.

  The coker pyrolysis apparatus used for obtaining the coker gas oil according to the gas oil base of the present invention is not particularly limited, and an apparatus used in a normal pyrolysis process can be used, for example, a delayed coking process, Examples include a visbreaking process, a yurika process, and an HSC process. In addition, the pyrolysis conditions are not particularly limited, but the above heavy oil is used as a raw material and a coker pyrolysis apparatus is used and the reaction pressure is 0.04 to 0.5 MPa and the decomposition temperature is 450 to 550 ° C. Is preferred. From the viewpoint of making the light oil base material of the present invention easier to obtain, it is possible to treat at a reaction pressure of 0.15 to 0.25 MPa and a decomposition temperature of 460 to 500 ° C. using an atmospheric residue or a vacuum residue as a raw material oil. More preferred.

  The boiling range of the coker gas oil according to the light oil base material of the present invention needs to be 110 to 400 ° C. in order to make it suitable as a light oil base material, the lower limit is preferably 120 ° C. or higher, and the upper limit is 370 ° C. The following is preferable, and 360 ° C. or lower is more preferable.

The sulfur content of the coker gas oil according to the gas oil base material of the present invention is required to be 3.0% by mass or less. When the sulfur content of the coker gas oil exceeds 3.0% by mass, the sulfur content is not sufficiently lowered after hydrodesulfurization, and it may be unsuitable as a sulfur-free gas oil base material, which is not preferable.
In addition, the sulfur content here means the mass percentage (mass%) of the sulfur content based on the total amount of coker gas oil measured by JIS K2541 “Sulfur content test method”.

The total aromatic content of the coker light oil according to the light oil base material of the present invention needs to be 35% by volume or less. If the total aromatic content of the coker gas oil exceeds 35% by volume, the cetane number of the gas oil base may be lowered, which is not preferable. For this reason, 30% by volume or less is more preferable.
The total aromatic content herein is measured in accordance with the Petroleum Institute Method JPI-5S-49-97 “Hydrocarbon Type Test Method—High Performance Liquid Chromatograph Method” published by the Japan Petroleum Institute. This is the volume percentage (volume%) of the total aromatic content based on the total amount of coker gas oil.

The polycyclic aromatic content of two or more rings of the coker gas oil according to the gas oil base material of the present invention needs to be 20% by volume or less. If the polycyclic aromatic content of two or more rings of coker gas oil exceeds 20% by volume, the polycyclic aromatic content in the light oil base increases, which may lead to deterioration of exhaust gas, which is not preferable. For this reason, it is preferably 15% by volume or less, and more preferably 13% by volume or less.
The polycyclic aromatic content of two or more rings referred to here is the Petroleum Institute Method JPI-5S-49-97 “Hydrocarbon Type Test Method—High Performance Liquid Chromatograph Method” published by the Japan Petroleum Institute. The volume percentage (volume%) of the polycyclic aromatic content of two or more rings based on the total amount of coker diesel oil measured in accordance with

The olefin content of the coker gas oil according to the gas oil base of the present invention needs to be 40% by volume or less. If the olefin content of the coker gas oil exceeds 40% by volume, the heat generation in the hydrodesulfurization treatment increases, so that the reaction control becomes difficult and there is a concern of sludge generation in the raw material supply line to the reactor. For this reason, it is preferably 35% by volume or less, and more preferably 30% by volume or less.
The olefin content mentioned here is a coker gas oil measured in accordance with the Petroleum Institute Method JPI-5S-49-97 “Hydrocarbon Type Test Method—High Performance Liquid Chromatograph Method” published by the Japan Petroleum Institute. The volume percentage (volume%) of the olefin content based on the total amount.

In the hydrodesulfurization treatment according to the light oil base of the present invention, it is necessary to mix 15 to 40 parts by volume of coker light oil into the light oil desulfurization apparatus with respect to 100 parts by volume of the above-mentioned straight-run light oil. If the amount of coker light oil mixed is outside the above range, the light oil base material may not satisfy predetermined properties, which is not preferable. The mixed oil flow rate of coker gas oil is preferably 20 parts by volume or more, and more preferably 25 parts by volume or more with respect to 100 parts by volume of straight-run gas oil.
Note that the mixed oil passing here is not limited to the case where the straight run light oil and the coker light oil are mixed and passed before being introduced into the light oil desulfurization apparatus, but also includes the case where they are mixed in the light oil desulfurization apparatus.

The hydrodesulfurization treatment according to the light oil base material of the present invention uses a hydrodesulfurization catalyst in the presence of hydrogen to obtain a predetermined light oil base material, a hydrogen pressure of 2 to 13 MPa, a reaction temperature of 180 to 480 ° C., a liquid It is preferable to carry out at a space velocity (LHSV) of 0.1 to 3 h ⁻¹ and a hydrogen / oil ratio of 100 to 1500 NL / L.
The lower the reaction temperature, the more advantageous for the hydrogenation reaction, but not for the desulfurization reaction. The higher the hydrogen pressure and the hydrogen / oil ratio, the more the desulfurization and hydrogenation reactions are promoted, but there is an optimal point economically. The lower the LHSV, the more advantageous for the reaction. However, if the LHSV is too low, a very large reaction tower volume is required, resulting in an excessive capital investment. For this reason, hydrodesulfurization treatment is performed at a hydrogen pressure of 3 to 8 MPa, a reaction temperature of 300 to 380 ° C., an LHSV of 0.3 to 2 h ⁻¹ , and a hydrogen / oil ratio of 100 to 500 NL / L. Is particularly preferred.

  A general hydrodesulfurization catalyst can be applied to the hydrodesulfurization catalyst according to the present invention. As the active metal, normally, Group 6A and Group 8 metals of the periodic table are preferably used, and examples thereof include Co—Mo, Ni—Mo, Co—W, and Ni—W. As the carrier, a porous inorganic oxide mainly composed of alumina is used.

  The sulfur content of the light oil base material of the present invention is required to be 10 ppm by mass or less. From the viewpoint of reducing harmful exhaust components discharged from the engine and improving the performance of the exhaust gas aftertreatment device, 8 ppm by mass or less is required. Preferably, 5 mass ppm or less is more preferable. In addition, the sulfur content here means the mass percentage (mass%) of the sulfur content on the basis of the total amount of the light oil base material measured by JIS K2541 “Sulfur content test method”.

  The cetane index of the light oil base material of the present invention is required to be 50 or more. In order to reduce the concentration of NOx, PM and aldehydes in the exhaust gas, 53 or more is preferable, 54 or more is more preferable, 55 or more is more preferable. The cetane index here is calculated according to “Method for calculating cetane index using 8.4 variable equations” in JIS K 2280 “Petroleum products—fuel oil—octane number and cetane number test method and cetane index calculation method”. Value.

  The total aromatic content of the gas oil base of the present invention needs to be 25% by volume or less, and 20% by volume or less is preferable in order to reduce the concentration of NOx, PM and aldehydes in the exhaust gas. . The total aromatic content here is measured in accordance with the Petroleum Institute Method JPI-5S-49-97 “Hydrocarbon Type Test Method—High Performance Liquid Chromatograph Method” published by the Japan Petroleum Institute. The volume percentage (volume%) of the total aromatic content.

  The olefin content of the light oil base material of the present invention is required to be 1% by volume or less, and is preferably 0.8% by volume or less, and more preferably 0.5% by volume or less in order to improve storage stability. The olefin content referred to here is the olefin content measured in accordance with the Petroleum Institute Method JPI-5S-49-97 “Hydrocarbon Type Test Method—High Performance Liquid Chromatograph Method” published by the Japan Petroleum Institute. The capacity percentage (volume%).

The light oil composition of the present invention is a light oil composition containing 60% by volume or more of the light oil base material of the present invention and having a sulfur content of 10 mass ppm or less and an HFRR wear scar diameter (WS1.4) of 460 μm or less.
The light oil composition of the present invention preferably has a flash point of 50 ° C. or higher, a distillation property 90% distillation temperature of 350 ° C. or lower, a kinematic viscosity (30 ° C.) of 2.5 mm ² / s or higher, and cetane. A light oil composition having an index of 45 or more, a density of 750 kg / m ³ or more and 850 kg / m ³ or less, and containing 50 to 200 mg / L of a lubricity improver.

  The sulfur content of the light oil composition of the present invention needs to be 10 mass ppm or less from the viewpoint of reducing harmful exhaust components discharged from the engine and improving the performance of the exhaust gas aftertreatment device, preferably 5 mass ppm or less, More preferably, it is 3 mass ppm or less, More preferably, it is 1 mass ppm or less. In addition, the sulfur content here means the mass percentage (mass%) of the sulfur content based on the total amount of the light oil composition measured by JIS K2541 “Sulfur content test method”.

  The flash point of the light oil composition of the present invention is preferably 50 ° C. or higher. When the flash point is less than 50 ° C., it cannot be handled as a light oil composition for safety reasons. For the same reason, the flash point is preferably 54 ° C. or higher, more preferably 58 ° C. or higher. Here, the flash point indicates a value measured by JIS K 2265 “Crude oil and petroleum product flash point test method”.

  The cetane index of the light oil composition of the present invention is preferably 45 or more. When the cetane index is less than 45, the concentration of PM, aldehydes, or NOx in the exhaust gas tends to increase. For the same reason, the cetane index is preferably 48 or more, and most preferably 50 or more. The cetane index here is calculated according to “Calculation method of cetane index using 8.4 variable equation” in JIS K 2280 “Petroleum products-fuel oil-octane number and cetane number test method and cetane index calculation method”. Means the value to be Here, the cetane index in the JIS standard is generally applied to light oil to which a cetane number improver is not added, but in the present invention, the above-mentioned " Applying “8.4 Calculation Method of Cetane Index Using Variable Equation”, a value calculated by the calculation method is expressed as a cetane index.

Density at 15 ℃ of the gas oil composition of the present invention, in terms of calorific value ensuring, is preferably 750 kg / ^{m 3} or more, more preferably 760 kg / ^{m 3} or more, more preferably 770 kg / ^{m 3} or more. Further, the density, NOx, from the viewpoint of reducing the emission of PM, it is preferably 850 kg / ^{m 3} or less, more preferably 845 kg / ^{m 3} or less, more preferably 840 kg / ^{m 3} or less. In addition, the density here means the density measured by JIS K 2249 “Density test method and density / mass / capacity conversion table of crude oil and petroleum products”.

  The light oil composition of the present invention has a HFRR wear scar diameter (WS1.4) of 460 μm or less, and preferably has a lubricating performance of 430 μm or less, more preferably 410 μm or less. When the HFRR wear scar diameter (WS1.4) exceeds 460 μm, especially in a diesel engine equipped with a distribution type injection pump, the driving torque of the pump during operation and the wear of each part of the pump are increased, exhaust gas performance, fine particles The engine itself may be destroyed as well as the performance deterioration. In addition, in an electronically controlled fuel injection pump capable of high-pressure injection, there is a concern about wear on the sliding surface. In addition, HFRR wear scar diameter here (WS1.4) is a value measured by the Japan Petroleum Institute Standard JPI-5S-50-98 “Light Oil-Lubricity Test Method” issued by the Japan Petroleum Institute. means.

  Although there is no restriction | limiting in particular in aromatic content in the light oil composition of this invention, it is preferable that it is 25 volume% or less from a viewpoint of raising an environmental impact reduction effect and reducing NOx and PM, More preferably, it is 19 volume% Hereinafter, it is more preferably 18% by volume or less. The aromatic content here is measured in accordance with the Petroleum Institute Method JPI-5S-49-97 “Hydrocarbon Type Test Method—High Performance Liquid Chromatograph Method” published by the Japan Petroleum Institute. It means the volume percentage (volume%) of the aromatic content.

  The distillation property in the light oil composition of the present invention is preferably 90% distillation temperature of 350 ° C. or lower, more preferably 345 ° C. or lower, and further preferably 340 ° C. or lower. When the 90% distillation temperature (T90) exceeds the upper limit, the amount of PM and fine particles discharged tends to increase. T90 is preferably 300 ° C. or higher, more preferably 310 ° C. or higher, further preferably 315 ° C. or higher, and even more preferably 320 ° C. or higher. If T90 is less than the lower limit, the fuel efficiency improvement effect becomes insufficient and the engine output tends to decrease.

  When the initial boiling point (IBP) of the gas oil composition of the present invention is too low, there is a concern that some light fractions are vaporized, the spray range is too wide, and HC accompanying the exhaust gas as unburned components increases. IBP is preferably 140 ° C. or higher, more preferably 150 ° C. or higher, more preferably 155 ° C. or higher, and most preferably, from the viewpoint of ensuring starting performance at high temperatures and ensuring stability of engine rotation during idling. Is 160 ° C. or higher. On the other hand, when IBP is too high, there is a possibility of causing problems in low temperature startability and low temperature drivability, so IBP is preferably 230 ° C. or lower, more preferably 220 ° C. or lower, most preferably 215 ° C. or lower. It is.

  If the 10% distillation temperature (T10) of the gas oil composition of the present invention is too low, there is a concern that HC accompanying the exhaust gas may increase, as in the case where IBP is too low, and startability at high temperatures, From the viewpoint of ensuring the stability of engine rotation during idling, T10 is preferably 165 ° C or higher, more preferably 170 ° C or higher, and most preferably 175 ° C or higher. On the other hand, T10 is preferably 260 ° C. or lower, more preferably 255 ° C. or lower, and most preferably 250 ° C. or lower because T10 is too high, which may cause problems in low temperature startability and low temperature drivability. It is.

  The 50% distillation temperature (T50) of the light oil composition of the present invention is preferably 240 ° C. or higher from the viewpoints of fuel efficiency, engine output, startability at high temperatures, and stability of engine rotation during idling, and more. Preferably it is 250 degreeC or more, Most preferably, it is 260 degreeC or more. On the other hand, from the viewpoint of preventing an increase in PM discharged from the engine, T50 is preferably 310 ° C. or lower, more preferably 300 ° C. or lower, and most preferably 295 ° C. or lower.

The end point (EP) of the light oil composition of the present invention is preferably 310 ° C. or higher, more preferably 320 ° C. or higher, from the viewpoint of startability at high temperature, ensuring engine rotation stability during idling, and fuel consumption. Most preferably, it is 325 degreeC or more. On the other hand, from the viewpoint of preventing an increase in PM discharged from the engine, EP is preferably 380 ° C. or lower, more preferably 375 ° C. or lower, and further preferably 370 ° C. or lower.
Here, T90, IBP, T10, T50, and EP mean values measured in accordance with JIS K 2254 “Petroleum products—Distillation test method—Atmospheric pressure method”.

The kinematic viscosity at 30 ° C. of the light oil composition of the present invention is not particularly limited, but is preferably 2.5 mm ² / s or more, more preferably 2.7 mm ² / s or more, and 2.9 mm ^2. / S or more is more preferable. If the kinematic viscosity is less than 2.5 mm ² / s, it tends to be difficult to control the fuel injection timing on the fuel injection pump side, and the lubricity of each part of the fuel injection pump mounted on the engine is impaired. There is a fear. Moreover, kinematic viscosity at 30 ° C. of the gas oil composition of the present invention is preferably at most ^{5 mm} 2 / s, more preferably not more than 4.7 mm ² / s, or less 4.5 mm ² / s Is more preferable. If the kinematic viscosity exceeds 5 mm ² / s, the resistance inside the fuel injection system increases, the injection system becomes unstable, and the concentrations of NOx and PM in the exhaust gas increase. In addition, kinematic viscosity here means kinematic viscosity measured by JISK2283 "crude oil and petroleum products-kinematic viscosity test method and viscosity index calculation method".

The total aromatic content of the light oil composition of the present invention is preferably 25% by volume or less, and more preferably 20% by volume or less, from the viewpoints of reducing PM emissions and reducing environmental burden. The polycyclic aromatic content of two or more rings (the aromatic content of two or more rings) is preferably 3% by volume or less, more preferably 2% by volume or less, and still more preferably 1% by volume or less for the same reason.
Here, the total aromatic content and polycyclic aromatic content of two or more rings are the Petroleum Institute method JPI-5S-49-97 “Hydrocarbon type test method” published by the Japan Petroleum Institute. It refers to the volume percentage (volume%) based on the total amount of light oil composition measured in accordance with the “high performance liquid chromatographic method”.

In the light oil composition of the present invention, if necessary, an appropriate amount of a lubricity improver can be blended to improve the lubricity of the resulting light oil composition. Examples of the lubricity improver include carboxylic acids and esters. One, two or more of the system, alcohol and phenol lubricity improvers can be used arbitrarily. Among these, carboxylic acid-based and ester-based lubricity improvers are preferable.
Examples of the carboxylic acid-based lubricity improver include linoleic acid, oleic acid, salicylic acid, palmitic acid, myristic acid, hexadecenoic acid and a mixture of two or more of the above carboxylic acids.
Examples of ester-based lubricity improvers include carboxylic acid esters of glycerin. The carboxylic acid constituting the carboxylic acid ester may be one kind or two or more kinds, and specific examples thereof include linoleic acid, oleic acid, salicylic acid, palmitic acid, myristic acid, hexadecenoic acid and the like. There is.

The blending amount of the lubricity improver is preferably 50 mg / L or more and 200 mg / L or less, more preferably 75 mg / L or more and 200 mg / L or less, and still more preferably 100 mg / L or more and 150 mg / L or less. When the blending amount of the lubricity improver is within the above range, the effectiveness of the blended lubricity improving agent can be effectively extracted. For example, in a diesel engine equipped with a distributed injection pump, An increase in driving torque can be suppressed and pump wear can be reduced.
In addition, what is marketed as a lubricity improver is usually obtained in a state in which an active ingredient that contributes to improving lubricity is diluted with an appropriate solvent. When such a commercial product is blended in the light oil composition of the present invention, the content of the active ingredient in the light oil composition is preferably within the above range.

In the light oil composition of the present invention, additives other than the above-mentioned lubricity improver can be blended as necessary, and in particular, a cetane number improver and / or a detergent is preferably blended.
As the cetane number improver, various compounds known as light oil cetane number improvers can be arbitrarily used, and examples thereof include nitrate esters and organic peroxides. These cetane number improvers may be used alone or in combination of two or more.
In the present invention, it is preferable to use a nitrate ester among the cetane number improvers described above. Such nitrate esters include 2-chloroethyl nitrate, 2-ethoxyethyl nitrate, isopropyl nitrate, butyl nitrate, primary amyl nitrate, secondary amyl nitrate, isoamyl nitrate, primary hexyl nitrate, Various nitrates such as secondary hexyl nitrate, n-heptyl nitrate, n-octyl nitrate, 2-ethylhexyl nitrate, cyclohexyl nitrate, and ethylene glycol dinitrate are included. An alkyl nitrate of ˜8 is preferred.

The content of the cetane improver is preferably 500 mg / L or more, more preferably 600 mg / L or more, further preferably 700 mg / L or more, and more preferably 800 mg / L or more based on the total amount of the composition. It is particularly preferable that it is 900 mg / L or more. When the content of the cetane number improver is less than 500 mg / L, a sufficient cetane number improving effect cannot be obtained, and PM, aldehydes, and NOx in diesel engine exhaust gas tend not to be sufficiently reduced. Further, the upper limit of the content of the cetane number improver is not particularly limited, but is preferably 1400 mg / L or less, more preferably 1250 mg / L or less, based on the total amount of the light oil composition, and 1100 mg / L or less. More preferably, it is most preferably 1000 mg / L or less.
As in the case of the previous lubricity improver, a cetane improver synthesized according to a conventional method may be used, or a commercially available product may be used. In addition, what is marketed as a cetane number improver is usually obtained in a state where an active ingredient contributing to cetane number improvement (that is, cetane number improver itself) is diluted with an appropriate solvent. When preparing the light oil composition of this invention using such a commercial item, it is preferable that content of the said active ingredient in a light oil composition becomes in the above-mentioned range.

  Examples of the detergent include imide compounds; alkenyl succinimides such as polybutenyl succinimides synthesized from polybutenyl succinic anhydrides and ethylene polyamines; polyhydric alcohols such as pentaerythritol and polybutyls. Succinic acid esters such as polybutenyl succinic acid ester synthesized from tenyl succinic anhydride; copolymer polymers such as dialkylaminoethyl methacrylate, polyethylene glycol methacrylate, vinyl pyrrolidone and alkyl methacrylate copolymers, carboxylic acids and amines Ashless detergents such as reaction products of alkenyl succinic acid imide and reaction products of carboxylic acid and amine are preferred. These detergents can be used alone or in combination of two or more.

Examples of using an alkenyl succinimide include a case where an alkenyl succinimide having a molecular weight of about 1000 to 3000 is used alone, an alkenyl succinimide having a molecular weight of about 700 to 2000, and an alkenyl succinimide having a molecular weight of about 10,000 to 20000. May be used in combination.
The carboxylic acid constituting the reaction product of the carboxylic acid and the amine may be one type or two or more types. Specific examples thereof include fatty acids having 12 to 24 carbon atoms and carbon atoms having 7 to 24 carbon atoms. An aromatic carboxylic acid etc. are mentioned. Examples of the fatty acid having 12 to 24 carbon atoms include linoleic acid, oleic acid, palmitic acid, myristic acid and the like, but are not limited thereto. In addition, examples of the aromatic carboxylic acid having 7 to 24 carbon atoms include benzoic acid and salicylic acid, but are not limited thereto. Moreover, the amine which comprises the reaction product of carboxylic acid and an amine may be 1 type, or may be 2 or more types. The amine used here is typically oleylamine, but is not limited thereto, and various amines can be used.

The blending amount of the cleaning agent is not particularly limited, but in order to bring out the effect of blending the cleaning agent, specifically, the effect of suppressing the clogging of the fuel injection nozzle, the blending amount of the cleaning agent is 30 mg / L based on the total amount of the composition. It is preferable to set it as the above, It is more preferable to set it as 60 mg / L or more, It is further more preferable to set it as 80 mg / L or more. Even if an amount less than 30 mg / L is added, the effect may not appear. On the other hand, if the blending amount is too large, an effect commensurate with it cannot be expected, and conversely there is a risk of increasing NOx, PM, aldehydes, etc. in the exhaust gas of the diesel engine. L or less is preferable, and 180 mg / L or less is more preferable.
As in the case of the previous lubricity improver, what is commercially available as a detergent is usually obtained in a state where an active ingredient that contributes to cleaning is diluted with an appropriate solvent. When such a commercial product is blended in the light oil composition of the present invention, the content of the active ingredient in the light oil composition is preferably within the above range.

Further, for the purpose of further improving the performance of the light oil composition in the present invention, other known fuel oil additives (hereinafter referred to as “other additives” for convenience) to be described later are added alone or in combination of several kinds. You can also. Other additives include, for example, low-temperature fluidity improvers such as ethylene-vinyl acetate copolymer and alkenyl succinic acid amide; antioxidants such as phenols and amines; metal deactivators such as salicylidene derivatives; Anti-icing agents such as polyglycol ethers; corrosion inhibitors such as aliphatic amines and alkenyl succinic acid esters; antistatic agents such as anionic, cationic and amphoteric surfactants; colorants such as azo dyes; Antifoaming agents and the like.
The addition amount of other additives can be arbitrarily determined, but the addition amount of each additive is preferably 0.5% by mass or less, more preferably 0.2% by mass or less, based on the total amount of the light oil composition. is there.

In the light oil composition of the present invention, one kind of other light oil fraction, kerosene fraction, synthetic light oil and synthetic kerosene other than the light oil base material of the present invention is used in the category satisfying the above-described fuel characteristics required by the present invention. Or 2 or more types can be mix | blended.
Specifically, other light oil fractions are obtained by treating straight-run gas oil obtained from a crude oil atmospheric distillation unit, straight-run heavy oil or residual oil obtained from an atmospheric distillation device with a vacuum distillation unit. Gasoline diesel oil obtained by hydrotreating the above-mentioned straight-run gas oil or vacuum gas oil with a hydrorefining device depending on the sulfur content, in one or more stages under conditions severer than hydrorefining Hydrodesulfurized diesel oil obtained by hydrodesulfurization, hydrocracked diesel oil obtained by hydrocracking the above various diesel oil fractions, diesel oil fraction obtained by hydrotreating animal and vegetable oils, natural gas, asphalt For example, synthetic light oil using coal, biomass, etc. as a raw material.

  The kerosene fraction is obtained by hydrotreating a predetermined feedstock. The raw oil is mainly straight-run kerosene obtained by atmospheric distillation of crude oil, but hydrocracked kerosene produced together with hydrocracked light oil and hydrogen obtained by hydrorefining the aforementioned kerosene fraction. Refined kerosene can be used. It is also possible to use synthetic kerosene made from natural gas, asphalt, coal, biomass and the like. What was obtained by hydrotreating (desulfurization and refining) the above-mentioned raw material oil in the presence of a hydrogenation catalyst can be used as a kerosene fraction.

The hydrotreating conditions are usually a reaction temperature of 220 to 350 ° C., a hydrogen pressure of ^{1 to} 6 MPa, an LHSV of 0.1 to 10 h ⁻¹ , and a hydrogen / oil ratio of 10 to 300 NL / L. Preferably, the reaction temperature is 250 ° C. to 340 ° C., the hydrogen pressure is 2 to 5 MPa, the LHSV is ^{1 to} 10 h ⁻¹ , and the hydrogen / oil ratio is 30 to 200 NL / L, more preferably the reactivity is 270 ° C. to 330 ° C., the hydrogen pressure is 2 to 4 MPa. , LHSV 2 to 10 h ⁻¹ , hydrogen / oil ratio 50 to 200 NL / L. The lower the reaction temperature, the more advantageous for the hydrogenation reaction, but not for the desulfurization reaction. The higher the hydrogen pressure and the hydrogen / oil ratio, the more the desulfurization and hydrogenation reactions are promoted, but there is an optimal point economically. The lower the LHSV, the more advantageous for the reaction. However, if the LHSV is too low, a very large reaction tower volume is required, resulting in an excessive capital investment.

  The active metal of the catalyst used for the hydrotreatment is at least one metal selected from Group 6A metals of the periodic table. Preferably, it is at least one selected from Mo and W. The active metal may be a combination of a Group 6A metal and a Group 8 metal, specifically, a combination of Mo or W and Co or Ni. For example, Co—Mo, Co—W, Ni—Mo, Combinations such as Ni-W, Co-Ni-Mo, and Co-Ni-W can be employed.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to these Examples at all.

(Adjustment of Examples 1-4 and Comparative Examples 1-2)
The straight gas oil and the coker gas oil having the properties shown in Table 1 are reacted under hydrodesulfurization conditions 1 shown in Table 2, and the light oil base material 1 shown in Table 3 is converted into the straight oil kerosene in Table 1 and the hydrorefining conditions in Table 2. The hydrogenated refined kerosene shown in Table 3 was prepared.
The light oil bases 1 and hydrorefined kerosene shown in Table 3 were appropriately prepared to produce the light oil compositions of Examples 1 to 4 shown in Table 4.
Similarly, straight-run gas oil and catalytic cracked gas oil having the properties shown in Table 1 were reacted under hydrodesulfurization conditions 2 and 3 shown in Table 2 to prepare gas oil base material 2 and gas oil base material 3 shown in Table 3, respectively. . And the light oil base materials 2 and 3 shown in Table 3, and the hydrogenation refinement | purification kerosene were prepared suitably, and the light oil composition of Comparative Examples 1-2 shown in Table 4 was manufactured.
A commercially available ester-based lubricity improver was used as the lubricity improver, and a commercially available ethylene-vinyl acetate copolymer was mainly used as the low temperature fluidity improver.

  The blending ratio of the blended diesel oil composition and the blended diesel oil composition, density at 15 ° C., kinematic viscosity at 30 ° C., sulfur content, distillation properties, saturated content, olefin content, total aromatic content, 1 ring Table 4 shows the results of measurement of aromatic content, aromatic components of 2 or more rings, cetane index, flash point, and HFRR wear scar diameter (WS1.4).

The properties of the fuel oil were measured by the following method.
The density refers to a density measured according to JIS K 2249 “Determination method of density of crude oil and petroleum products and density / mass / capacity conversion table”.
All the distillation properties are values measured by JIS K 2254 "Petroleum products-Distillation test method".
The sulfur content refers to the mass content of the sulfur content based on the total amount of the gas oil composition measured by JIS K2541 “Sulfur content test method”.
Saturates, olefins, wholly aromatics, and 1-ring aromatics and 2-rings aromatics are Petroleum Institute Method JPI-5S-49-97 “Hydrocarbon Type Test Method” published by the Japan Petroleum Institute. It refers to the volume percentage (volume%) of each composition measured according to the “high performance liquid chromatography method”.
The kinematic viscosity refers to a kinematic viscosity measured according to JIS K 2283 “Crude oil and petroleum products—Kinematic viscosity test method and viscosity index calculation method”.
The cetane index refers to a value calculated according to “Method for calculating cetane index using 8.4 variable equation” in JIS K 2280 “Petroleum products—fuel oil—octane number and cetane number test method and cetane index calculation method”.
The flash point indicates a value measured according to JIS K 2265 “Crude oil and petroleum product flash point test method”.
The HFRR wear scar diameter (WS1.4) means a value measured by the Petroleum Institute Standard JPI-5S-50-98 “Light Oil-Lubricity Test Method” issued by the Japan Petroleum Institute.

(Oxidation stability test)
In accordance with ASTM D2274-03 “Standard Test Method for Oxidation Stability of Distillate Fuel Oil (Accelerated Method)”, the fuel sample was accelerated and deteriorated under conditions of 95 ° C. and oxygen bubbling for 16 hours (oxidation). After the stability test), it is cooled to room temperature, and the total insoluble matter is peroxidized according to the Japan Petroleum Institute Standard JPI-5S-46-96 “Peroxide Value Test Method for Kerosene”. Measure prices.
Using the light oil compositions of Examples 1 to 4 and Comparative Examples 1 to 2, the total insoluble matter and the peroxide value after the above oxidation stability test were measured.
Light oil composition Examples 1 to 4 derived from a coker gas oil base material have smaller values for both the total insoluble matter and the peroxide value after the oxidation stability test than Comparative Examples 1 and 2 derived from a catalytic cracking oil base material. It can be seen that the storage stability is excellent.

(White smoke measurement)
In a room where the environmental temperature can be controlled, 15L of fuel is supplied to the following test vehicle, the environmental temperature is set to −5 ° C., the engine is started and held at idling, and a diesel vehicle conforming to JIS D8005 White smoke was measured using a light transmission type smoke meter for exhaust smoke concentration measurement. After the engine was started, the time (seconds) until the white smoke concentration decreased to 5% due to idling was measured and defined as the 5% extinction time of white smoke. That is, as the white smoke 5% extinction time is longer, the white smoke is more difficult to disappear and the white smoke prevention performance is inferior.

(Test vehicle specifications)
Engine type: Supercharged inline 4-cylinder diesel with intercooler
Displacement: 3.0L
Fuel injection system: Common rail system
Applicable regulations: Compliant with long-term exhaust gas regulations
Exhaust gas aftertreatment device: oxidation catalyst

  Light oil composition Examples 1 to 4 derived from a coker light oil base material have less white smoke emission and excellent white smoke prevention performance at low temperatures than Comparative Examples 1 and 2 derived from a catalytic cracking oil base material. I understand.

Claims (4)

  A boiling point range of 110 to 400 ° C. obtained from a coker pyrolysis apparatus, a sulfur content of 3.0% by mass or less, a total aromatic content of 35% by volume or less, and a bicyclic or more polycyclic aroma for 100 parts by volume of straight run diesel 15 mass parts or less of coker gas oil having an olefin content of 20 volume% or less and an olefin content of 40 volume% or less, obtained by mixing and passing through a gas oil desulfurization apparatus and hydrodesulfurization treatment, sulfur content 10 mass ppm or less, cetane index A light oil base material comprising 50 or more, a total aromatic content of 25% by volume or less, and an olefin content of 1% by volume or less. In the presence of hydrogen, using a hydrodesulfurization catalyst, conditions of hydrogen pressure 3 to 8 MPa, reaction temperature 300 to 380 ° C., liquid space velocity (LHSV) 0.3 to 2 h ⁻¹ , hydrogen / oil ratio 100 to 500 NL / L 2. The light oil base material according to claim 1, wherein the hydrodesulfurization treatment is performed underneath.   A gas oil composition comprising the gas oil base material according to claim 1 or 2 in an amount of 60% by volume or more and having a sulfur content of 10 mass ppm or less and an HFRR wear scar diameter (WS1.4) of 460 µm or less. . Flash point is 50 ° C or more, distillation property 90% distillation temperature is 350 ° C or less, kinematic viscosity (30 ° C) is 2.5 mm ² / s or more, cetane index is 45 or more, density is 750 kg / m ³ or more and 850 kg / m ³ below, the gas oil composition according to claim 3 lubricity improver content is equal to or less than 50 mg / L or higher 200 mg / L.