JP4648618B2 - Light oil composition - Google Patents

Description

  The present invention relates to a light oil composition supplied to an engine equipped with an exhaust gas purification device. More specifically, the present invention relates to a light oil composition that can greatly improve the performance of an exhaust gas treatment device and can simultaneously reduce particulate matter (PM) and nitrogen oxides (NOx) discharged from an engine and a vehicle without deteriorating fuel consumption. .

  Conventionally, as the base material for light oil, straight-run gas oil obtained from crude oil atmospheric distillation equipment is hydrorefined or hydrodesulfurized, and straight-run kerosene obtained from crude oil atmospheric distillation equipment is hydrogenated. Those subjected to hydrorefining treatment or hydrodesulfurization treatment are known. Conventional gas oil compositions are produced by blending one or more of the above gas oil base and kerosene base. Moreover, additives, such as a cetane number improver and a detergent, are mix | blended with these light oil compositions as needed.

In recent years, reduction of the sulfur content and aromatic content in light oil, which is a fuel for internal combustion engines, has been demanded with the aim of improving the air environment and reducing the environmental load. At the same time, in order to cope with the global warming problem, there is a need for fuel properties that contribute to further fuel efficiency and are effective in reducing carbon dioxide. One of the solutions is biodiesel fuel (renewable energy) ( From now on, it is considered to use as an alternative fuel.
FAME is mainly a mixture of fatty acid alkyl esters made from vegetable oils and fats. It contains almost no aromatics or sulfur, and itself is an oxygen-containing compound with oxygen in the molecule. Has attracted attention as a good candidate. In addition, because many are derived from plants, it is positioned as renewable energy. Therefore, the international carbon dioxide reduction protocol concluded in 1997, the so-called Kyoto Protocol, emits carbon dioxide derived from FAME as emissions. FAME also has a policy merit in that it is a rule that is not counted.

However, depending on the composition of the fatty acid alkyl ester contained, there are those that are solid at room temperature and those that have a very heavy boiling point, so when used simply as a substitute for light oil, flow performance at low temperatures and unburned carbonization are used. Hydrogen emissions and nitrogen oxide emissions will deteriorate. Further, since FAME generally has a lower calorific value than light oil, fuel consumption per unit travel distance and unit output is inferior (see, for example, Non-Patent Document 1).
Furthermore, although the fatty acid alkyl ester itself is a chemically stable substance, the fatty acid glyceride, alkyl alcohol, and by-product glycerin mixture, which are raw materials for refining the fatty acid alkyl ester, have adverse effects on engine parts and fuel injection systems. Is a matter of great concern. Therefore, when using FAME as an alternative to light oil, it is natural to pay attention to the properties of FAME itself, but in addition to that, FAME may be used in place of light oil or mixed with light oil at a high blending ratio. There is a problem in doing so and it must be avoided (see Non-Patent Document 2, for example).
In addition, the effects on various exhaust gas aftertreatment devices that are currently required to improve exhaust gas performance have not been sufficiently studied, and in particular, when the composition ratio of exhaust gas composition differs greatly from when using ordinary light oil, oxidation is particularly important. There is a possibility that the performance of the exhaust gas purification apparatus carrying a strong noble metal catalyst will deteriorate.

  Therefore, regarding the provision of a light oil composition that can simultaneously reduce harmful exhaust components, particularly PM and NOx, maintain and improve fuel consumption, and improve the performance of exhaust gas aftertreatment devices, it can be manufactured only with existing refining methods or simply These replacements cannot be achieved at the same time by simply replacing them with alternative fuels. Furthermore, because these engine performances are closely related to other fuel properties, it is very difficult to design high-quality fuels that can simultaneously achieve these required performances at a high level, and are required as commercial fuel oils. There are no examples or knowledge based on the examination of practical manufacturing methods that satisfy the various performances.

Two others from SKOh, “An Experimental Study on Emission Characteristics in the Application of ULSD and Bio-diesel” , Preprint of Academic Lecture Meeting of the Society of Automotive Engineers of Japan, 2003, May 2003, 20035410 Masato Murayama, 5 members, “Research on the use of vegetable oil in diesel engines”, Japan Society for Automotive Engineers Autumn Showa 59 Academic Lecture Preprint, October 1984, 842071

  The present invention has been made in view of such a situation, and an object thereof is to greatly improve the performance of an exhaust gas purifying apparatus and to reduce PM and NOx discharged from an engine and a vehicle at the same time without deteriorating fuel consumption. It is to provide a composition.

As a result of intensive studies to solve the above problems, the present inventors have completed the present invention. That is, the present invention provides a saturated fatty acid alkyl ester having a fatty acid group having a fatty acid group having 6 to 16 carbon atoms and having a fatty acid group having a fatty acid group having 17 or more carbon atoms based on the total amount of the fatty acid alkyl ester mixture. The content is 10% by mass or less based on the total amount of the fatty acid alkyl ester mixture, the total acid value as the fatty acid alkyl ester mixture is 1.0 mgKOH / g or less, the sulfur content is 5 mass ppm or less, and the ester content is 1% by volume or more of fatty acid alkyl ester mixture of 97% by mass or more per gas oil composition, sulfur content of 3 mass ppm or less, aromatics content of 15% by volume or less, and bicyclic or higher aromatic content The amount is 1% by volume or less, the aromatic benzene content is 14% or less in the aromatic content, the naphthene content is 80% or more 0% by volume or more, a density at 15 ℃ is 800 kg / m ³ or more 840 kg / m ³ or less, 10% distillation temperature of 160 ° C. or higher 240 ° C. or less, the 90% distillation temperature of 280 ° C. or higher 340 ° C. or less A light oil composition supplied to an engine equipped with a post-treatment device for purifying exhaust gas, which is characterized.

Hereinafter, the present invention will be described in detail.
As a constituent of the light oil composition of the present invention, a fatty acid alkyl ester mixture having a specific property containing a specific fatty acid alkyl ester compound, that is, 4 saturated fatty acid alkyl esters having a fatty acid group having 6 to 16 carbon atoms. 10% by mass or less of a saturated fatty acid alkyl ester having a fatty acid group consisting of 17% or more by mass and 17 or more carbon atoms, a total acid value of 1.0 mgKOH / g or less, a sulfur content of 5 mass ppm or less, and an ester content of 97 A fatty acid alkyl ester mixture that is greater than or equal to mass% is required.

  As fatty acid alkyl ester mixture, glyceride compound (animal oil, vegetable oil) consisting of fatty acid derived from animal lipid part and plant seeds and glycerin (animal oil, vegetable oil), and chemistry with alkyl alcohol under alkali catalyst (sodium methylate, caustic soda, etc.) Examples thereof include a mixture of fatty acid alkyl ester compounds obtained by reacting and then separating and removing residual raw materials and by-products such as glycerin and catalysts. In the present invention, fatty acid alkyl ester compounds obtained by other chemical synthesis techniques can also be used.

Examples of the raw material of the animal lipid part include beef tallow, milk lipid (butter), pork tallow, sheep fat, whale oil, fish oil, liver oil, and the like. Then, it is desirable to use vegetable oil as a raw material.
Examples of the raw material for vegetable oil include coconut palm, palm palm, olive, Benibana, rapeseed (rapeseed flower), rice bran, sunflower, cottonseed, corn, seeds such as soybeans and sesame, and other parts.
Moreover, in this invention, the waste oil which used these animal oils and vegetable oils for consumer use, industrial use, food use etc. can also be used as a raw material after adding the removal process of miscellaneous matters.

As a typical composition of the fatty acid portion (fatty acid group) of the glyceride compound contained in these raw materials, as fatty acid, butyric acid (C ₃ H ₇ COOH) which is a saturated fatty acid having no unsaturated bond in the molecular structure , Caproic acid (C ₅ H ₁₁ COOH), caprylic acid (C ₇ H ₁₅ COOH), capric acid (C ₉ H ₁₉ COOH), lauric acid (C ₁₁ H ₂₃ COOH), myristic acid (C ₁₃ H ₂₇ COOH) , Palmitic acid (C ₁₅ H ₃₁ COOH), stearic acid (C ₁₇ H ₃₅ COOH), and oleic acid (C ₁₇ H ₃₃ COOH), which is an unsaturated fatty acid having one or more unsaturated bonds, linoleic acid (C ₁₇ H ₃₁ COOH), linolenic acid (C ₁₇ H ₂₉ COOH), ricinolenic acid (C ₁₇ H ₃₂ (OH) COOH) and the like.

  The hydrocarbon portion of these fatty acids in natural substances is generally linear, but in the present invention, a structure having a side chain, that is, an isomer is used as long as the properties defined in the present invention are satisfied. be able to. Further, in the present invention, the position of the unsaturated bond in the molecule of the unsaturated fatty acid is not limited to those generally confirmed in nature as long as the properties defined in the present invention are satisfied. The set one can also be used.

  The above-mentioned raw material oils (animal oil, vegetable oil) have one or more of these fatty acids as fatty acid groups, and the fatty acids they have differ depending on the raw material. For example, coconut oil has relatively many saturated fatty acid groups such as lauric acid and myristic acid, while soybean oil has many unsaturated fatty acid groups such as oleic acid and linoleic acid. In the present invention, the type and characteristics of these feedstocks are not limited as long as the properties defined by the present invention are satisfied.

  In the present invention, the method for producing the fatty acid alkyl ester mixture is not particularly limited. As a typical example, the above raw material oil (animal oil, vegetable oil) is used at 70 ° C. in the presence of an alkali catalyst (sodium methylate, caustic soda, etc.). A method of stirring for about 1 hour and directly reacting with an alkyl alcohol to obtain an ester compound (transesterification reaction), or a reaction of the raw material oil at a high temperature and high pressure process (50 to 60 atmospheres, 250 to 260 ° C., for 2 to 3 hours) , Non-catalyzed) to separate the fatty acid and glycerin, and react the resulting fatty acid with an alkyl alcohol in the presence of an acid catalyst (sulfuric acid, PTS, etc.) to obtain an ester compound (esterification reaction). Can be mentioned.

Examples of the alkyl alcohol compound include methanol (CH ₃ OH), ethanol (C ₂ H ₅ OH), propanol (C ₃ H ₇ OH), butanol (C ₄ H ₉ OH), hexanol (C ₅ H ₁₁ OH) and the like. These isomers can also be used, but it is preferable to use methanol and ethanol mainly from the viewpoints of economy and property stabilization upon esterification.
Examples of the methyl ester compound obtained by the above production method include butyric acid methyl ester (C ₃ H ₇ COOCH ₃ ), caproic acid methyl ester (C ₅ H ₁₁ COOCH ₃ ), caprylic acid methyl ester (C ₇ H ₁₅ COOCH ₃ ), Capric acid methyl ester (C ₉ H ₁₉ COOCH ₃ ), Lauric acid methyl ester (C ₁₁ H ₂₃ COOCH ₃ ), Myristic acid methyl ester (C ₁₃ H ₂₇ COOCH ₃ ), Palmitic acid methyl ester (C ₁₅ H ₃₁ COOCH ₃₎ ), Stearic acid methyl ester (C ₁₇ H ₃₅ COOCH ₃ ), oleic acid methyl ester (C ₁₇ H ₃₃ COOCH ₃ ), linoleic acid methyl ester (C ₁₇ H ₃₁ COOCH ₃ ), linolenic acid methyl ester (C ₁₇ H ₂₉₎ COOCH ₃ ), ricinolenic acid methyl ester (C ₁₇ H ₃₂ (OH) C OOCH ₃ ) and the like, and ethyl ester compounds include butyric acid ethyl ester (C ₃ H ₇ COOC ₂ H ₅ ), caproic acid ethyl ester (C ₅ H ₁₁ COOC ₂ H ₅ ), caprylic acid ethyl ester (C ₇ H ₁₅ COOC ₂ H ₅ ), capric acid ethyl ester (C ₉ H ₁₉ COOC ₂ H ₅ ), lauric acid ethyl ester (C ₁₁ H ₂₃ COOC ₂ H ₅ ), myristic acid ethyl ester (C ₁₃ H ₂₇ COOC ₂ H ₅₎ ), Ethyl palmitate (C ₁₅ H ₃₁ COOC ₂ H ₅ ), ethyl stearate (C ₁₇ H ₃₅ COOC ₂ H ₅ ), ethyl oleate (C ₁₇ H ₃₃ COOC ₂ H ₅ ), ethyl linoleate Ester (C ₁₇ H ₃₁ COOC ₂ H ₅ ), Linolenic acid ethyl ester (C ₁₇ H ₂₉ COOC ₂ H ₅ ), Ricinolenic acid ethyl ester (C _{1 7} H ₃₂ (OH) COOC ₂ H ₅ ) and the like.

These fatty acid alkyl ester compounds and fatty acids can be quantified using a gas chromatograph. Analytical conditions are shown below. By using a free fatty acid type column (FFAP), these substances can be easily and accurately quantified.
Column: FFAP (φ0.32mm × 25m)
Carrier gas: He (26 psi)
Detector: FID
Injection temperature: 280 ° C
Detector temperature: 300 ° C
Oven temperature: 100-260 ° C (10 minutes)
Temperature increase rate: 5 ° C./min Injection amount: 0.4 μL (methanol solution)

The fatty acid alkyl ester mixture used in the present invention is a fatty acid alkyl ester mixture containing a specific saturated fatty acid alkyl ester compound in a predetermined ratio and satisfying a predetermined property.
Specifically, among the above fatty acid alkyl ester compounds, it is necessary to contain 4% by mass or more of a saturated fatty acid alkyl ester having a fatty acid group having 6 to 16 carbon atoms based on the total amount of the fatty acid alkyl ester mixture. Here, the fatty acid group refers to a group represented by R—COO— in which a proton is removed from a fatty acid (R is an aliphatic hydrocarbon group).
Examples of saturated fatty acid alkyl esters having a fatty acid group of 6 to 16 carbon atoms include caproic acid methyl ester (C ₅ H ₁₁ COOCH ₃ ), caprylic acid methyl ester (C ₇ H ₁₅ COOCH ₃ ), methyl caprate ester _{(C 9 H 19 COOCH 3)} , methyl laurate _{(C 11 H 23 COOCH 3)} , myristic acid methyl ester _{(C 13 H 27 COOCH 3)} , palmitic acid methyl ester _{(C 15 H 31 COOCH 3)} , caproic Acid ethyl ester (C ₅ H ₁₁ COOC ₂ H ₅ ), caprylic acid ethyl ester (C ₇ H ₁₅ COOC ₂ H ₅ ), capric acid ethyl ester (C ₉ H ₁₉ COOC ₂ H ₅ ), lauric acid ethyl ester (C ₁₁ H ₂₃ COOC ₂ H ₅ ), myristic acid ethyl ester (C ₁₃ H ₂₇ COOC ₂ H ₅ ), palmitic Acid ethyl ester (C ₁₅ H ₃₁ COOC ₂ H ₅ ) and the like.

  When the amount of the saturated fatty acid alkyl ester having a fatty acid group having 6 to 16 carbon atoms is small, not only the exhaust gas performance but also the purification performance of the exhaust gas purification post-treatment device is adversely affected and the exhaust gas reduction effect is deteriorated. Therefore, the saturated fatty acid alkyl ester content ratio having a fatty acid group having 6 to 16 carbon atoms in the fatty acid alkyl ester mixture to be blended in the present invention is required to be 4% by mass or more, preferably 5% by mass or more. More preferably, it is more preferably 7% by mass or more.

Moreover, in this invention, the content rate of the saturated fatty acid alkyl ester which has a C17 or more fatty acid group among the above-mentioned fatty acid alkyl ester compounds needs to be 10 mass% or less on the basis of the total amount of the fatty acid alkyl ester mixture. is there. Examples of the saturated fatty acid alkyl ester having a fatty acid group having 17 or more carbon atoms include stearic acid methyl ester (C ₁₇ H ₃₅ COOCH ₃ ), stearic acid methyl ester (C ₁₇ H ₃₅ COOCH ₃ ), and the like.
A large amount of saturated fatty acid alkyl ester having a fatty acid group having 17 or more carbon atoms increases the content ratio of heavy and hardly decomposable compounds, which adversely affects not only the exhaust gas performance but also the purification performance of the exhaust gas after-treatment device. The exhaust gas reduction effect will deteriorate. Therefore, the content of the saturated fatty acid alkyl ester having a fatty acid group having 17 or more carbon atoms in the fatty acid alkyl ester mixture to be blended in the present invention needs to be 10% by mass or less, preferably 8% by mass or less, More preferably, it is more preferably 5% by mass or less.
The above-mentioned free fatty acid type column (FFAP) was used for the content of the saturated fatty acid alkyl ester having 6 to 16 carbon atoms and the saturated fatty acid alkyl ester having 17 or more fatty acid groups. It means the value obtained from the measurement result by gas chromatograph.

  The total acid value of the fatty acid alkyl ester mixture used in the present invention is required to be 1.0 mgKOH / g or less. Since the total acid value indicates the amount of free fatty acid in the mixture, if this value is large, there is a concern that the acidic compound may adversely affect the member and the performance of the exhaust gas aftertreatment device. Therefore, the total acid value needs to be 1.0 mgKOH / g or less, desirably 0.8 mgKOH / g or less, and more preferably 0.6 mgKOH / g or less. The total acid value as used herein means the total acid value measured according to JIS K 2501 “Petroleum products and lubricating oils—neutralization number test method”.

  Further, the sulfur content of the fatty acid alkyl ester mixture needs to be 5 mass ppm or less. If the sulfur content is high, the exhaust gas aftertreatment device installed in the engine will have a significant adverse effect, and since there is no sulfur content in the ester raw material, contamination with multiple components is considered. The amount must be 5 ppm by mass or less, preferably 4 ppm by mass or less, more preferably 3 ppm by mass or less, still more preferably 2 ppm by mass or less, and 1 ppm by mass or less. Most preferably. In addition, the sulfur content here means the mass content of the sulfur content based on the total amount of the mixture measured by JIS K2541 “Sulfur content test method”.

  The ester content of the fatty acid alkyl ester mixture needs to be 97% by mass or more. When the ester content is less than this value, compounds other than esters, such as free fatty acids, glycerin, moisture, impurities, etc., are mixed in a large amount, and not only exhaust gas performance but also stability and oxidation as a fuel The possibility of problems in degradation performance becomes extremely large. Therefore, the ester content in the fatty acid alkyl ester mixture needs to be 97% by mass or more, preferably 97.5% by mass or more, and more preferably 98% by mass or more. In addition, ester content here shows the numerical value obtained from the measurement result by the gas chromatograph using the above-mentioned free fatty acid type column (FFAP).

  Although there is no restriction | limiting in particular regarding the average molecular weight of a fatty-acid alkylester mixture, It is preferable that an average molecular weight is 500 or less. The average molecular weight means an average molecular weight obtained by multiplying the content ratio of the contained compound and the molecular weight. If this value is excessively large, the fluidity tends to deteriorate at low temperatures, so it is preferably 500 or less, more preferably 450 or less, and even more preferably 400 or less.

  Although there is no restriction | limiting in particular regarding the water content of a fatty-acid alkylester mixture, If there is much water, it will be 300 volume ppm or less from a viewpoint of stability as a fuel and a deterioration of a fuel consumption, and a hydrolysis suppression of an ester compound. It is preferably 250 ppm by volume or less, more preferably 200 ppm by volume or less, still more preferably 150 ppm by volume or less, and most preferably 100 ppm by volume or less. In addition, the water | moisture content here is the water prescribed | regulated by JISK2275 "moisture test method (crude oil and petroleum products)."

The light oil composition of the present invention contains a predetermined amount of the above-mentioned specific fatty acid alkyl ester mixture, and as the light oil composition, the sulfur content is 3 mass ppm or less, and the total aromatic content is 15 vol% or less. The aromatic content of two or more rings is 1% by volume or less, the proportion of alkylbenzene having 14 or less carbon atoms in the aromatic content is 80% or more, the content of naphthene is 30% by volume or more, and the density at 15 ° C. is 800 kg / m ^3. above 840 kg / m ³ or less, 10% distillation temperature of 160 ° C. or higher 240 ° C. or less, it is necessary 90% distillation temperature of 280 ° C. or higher 340 ° C. or less. For this purpose, it is preferable to produce the above-mentioned specific fatty acid alkyl ester mixture by mixing it with a specific fuel base material.

The fuel base material according to the present invention is a low-sulfur gas oil fraction obtained by hydrorefining and hydrotreating a petroleum-based hydrocarbon feedstock, a kerosene fraction, and a synthetic kerosene using natural gas as a raw material. , Synthetic light oil, or a mixture thereof.
The light oil fraction includes straight-run gas oil obtained from a crude oil atmospheric distillation apparatus, straight-run heavy oil obtained from an atmospheric distillation apparatus and residual oil obtained by treating the crude oil with a vacuum distillation apparatus, Catalytic cracked diesel oil or hydrocracked diesel oil obtained by catalytic cracking or hydrocracking heavy gas oil or desulfurized heavy oil, hydrorefined diesel oil or hydrodesulfurized diesel oil obtained by hydrorefining these petroleum hydrocarbons, etc. Is mentioned.

The hydrorefining of the petroleum hydrocarbon can be performed using a hydrodesulfurization apparatus common in petroleum refining. In general, the reaction is performed under the conditions of a reaction temperature of 300 to 380 ° C., a hydrogen pressure of 3 to 8 MPa, an LHSV of 0.3 to 2 h ⁻¹ , and a hydrogen / oil ratio of 100 to 500 NL / L. As a catalyst used for hydrorefining, a general hydrodesulfurization catalyst can be applied. 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. These conditions and the catalyst are not particularly limited as long as the properties of the raw material oil are satisfied.

Further, the fuel base material according to the present invention is obtained by further hydrotreating the above-described hydrorefined gas oil or hydrodesulfurized gas oil in the presence of a hydrogenation catalyst, so that the sulfur content, the aromatic content, and the naphthene content are increased. What controlled content etc. can also be used. The hydrotreating conditions are a reaction temperature of 170 to 320 ° C., a hydrogen pressure of 2 to 10 MPa, LHSV of 0.1 to 2 h ⁻¹ , and a hydrogen / oil ratio of 100 to 800 NL / L. The reaction temperature is preferably 175 to 300 ° C., the hydrogen pressure is 2.5 to 8 MPa, the LHSV is 0.2 to 1.5 h ⁻¹ , and the hydrogen / oil ratio is 150 to 600 NL / L, and more preferably the reaction temperature is 180 to 280 ° C. The hydrogen pressure is 3 to 7 MPa, the LHSV is 0.3 to 1.2 h ⁻¹ , and the hydrogen / oil ratio is 150 to 500 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.

In addition to the hydrorefined oil fraction of the light oil fraction, the fuel base material according to the present invention uses unrefined oil and / or hydrorefined oil as a raw material oil, and a reaction temperature of 220 to 350 ° C. in the presence of a hydrogenation catalyst. A low-sulfur kerosene fraction obtained by hydrogenating at 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 can be used. A general hydrodesulfurization catalyst can be applied as a catalyst used for such hydrotreatment. As the active metal, Group 6A and Group 8 metals of the periodic table are usually 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. These conditions and the catalyst are not particularly limited as long as the properties of the raw material oil are satisfied.

In the fuel base material according to the present invention, the above-mentioned hydrorefined oil kerosene fraction is hydrotreated in the presence of a hydrogenation catalyst to control the sulfur content, aromatic content, naphthene content, etc. It is also possible to use. The hydrotreating conditions are 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.
For the fuel base material according to the present invention, synthetic light oil and synthetic kerosene obtained by chemically synthesizing natural gas, asphalt content, coal and the like can be used. Chemical synthesis methods include indirect liquefaction method and direct liquefaction method, and typical synthesis methods include Fischer-Trops synthesis method. The synthetic light oil and synthetic kerosene used in the present invention are limited by these production methods. Is not to be done.

The properties of the fuel base material according to the present invention are not particularly limited as long as the light oil composition of the present invention obtained by blending a fatty acid alkyl ester mixture with the fuel base material has predetermined properties. In order to easily obtain the light oil composition, it is preferable to have the following properties.
Density at 15 ° C .: 750 to 850 kg / m ³
Kinematic viscosity at 30 ° C .: 1.4 to ⁵ mm ² / s
Distillation properties
Initial boiling point (IBP): 140-230 ° C
10% distillation temperature (T10): 150-250 ° C
50% distillation temperature (T50): 180-310 ° C
90% distillation temperature (T90): 200-370 ° C
End point (EP): 250-380 ° C
Sulfur content: 5 mass ppm or less Aromatic content: 20 vol% or less

  The light oil composition according to the present invention needs to contain 1% by volume or more of the fatty acid alkyl ester mixture having the above-mentioned properties from the viewpoint of reducing carbon dioxide and improving the performance of the exhaust gas purification apparatus, and 3% by volume or more. It is preferable to contain, and it is more preferable to contain 5 volume% or more. Further, since excessive mixing may cause adverse effects on engine members, fuel injection systems, and fuel consumption, the fatty acid alkyl ester mixture is preferably 50% by volume or less, more preferably 45% by volume or less, and 40 More preferably, it is not more than volume%.

  The sulfur content of the light oil composition according to the present invention needs to be 3 ppm by mass or less, preferably 2 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. More preferably, it is 1 mass ppm or less. In addition, the sulfur content here means the mass content of the sulfur content based on the total amount of the light oil composition measured by JIS K2541 “Sulfur content test method”.

The aromatic content of the light oil composition according to the present invention is required to be 15% by volume or less, and preferably 14% by volume or less. When the aromatic content of the light oil composition is within the above range, excessive PM emissions can be suppressed, and the properties defined in the light oil composition of the present invention can be achieved more easily and reliably. Synergy with the fatty acid alkyl ester mixture can be achieved. Here, the synergistic effect is to reduce the exhaust gas, improve the performance of the exhaust gas after-treatment device and improve the fuel consumption, that is, to solve the conflicting problems at the same time. As a result of optimizing elements such as the properties of the mixture, it means an action that can provide an improvement effect even greater than the effect of a single optimization of each element. This is due to the fact that the demerits caused by the single optimization of each element can be offset by satisfying the range of the gas oil composition.
The lower limit of the aromatic content is not particularly limited, but there is a concern about the influence on the material used for the injection pump and the like, and therefore the aromatic content is preferably 2% by volume or more, and 3 volumes. % Or more is more preferable, and 5% by volume or more is more preferable. The aromatic content here was measured in accordance with JPI-5S-49-97 “Hydrocarbon Type Test Method—High Performance Liquid Chromatograph Method” published by the Japan Petroleum Institute. Means the volume percentage (volume%) of the aromatic content.

  The aromatic content of two or more rings of the light oil composition according to the present invention needs to be 1% by volume or less, preferably 0.8% by volume or less, and 0.6% by volume or less. It is more preferable. When the content of aromatic components of two or more rings in the gas oil composition is within the above range, the properties defined in the gas oil composition of the present invention can be achieved more easily and reliably, and the fatty acid alkyl ester mixture Synergy with can be achieved. The aromatic content of two or more rings referred to here conforms to 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 of two or more rings measured.

Among the aromatic components in the gas oil composition of the present invention, the alkylbenzene content ratio composed of 14 or less carbon atoms (C14) or less needs to be 80% or more of the aromatic content. When the content of the alkylbenzene having 14 or less carbon atoms is lower than 80%, there is a large amount of heavy aromatics, so that NOx and PM may increase. Therefore, 80% or more is necessary, preferably 85% or more, more preferably 90% or more.
The alkylbenzene content ratio composed of 14 or less carbon atoms is the ratio (%) of the total peak intensity derived from alkylbenzenes having 14 or less carbon atoms to the total peak intensity derived from the total aromatics determined from mass spectrometry. is there.
For the calculation of the ratio of alkylbenzenes having 14 or less carbon atoms (single-ring aromatics), mass analysis by the FI ionization method was applied, and mass spectrometry was performed using “type analysis of lubricating base oil by mass spectrometer” (Satoshi Hamakawa, Nisseki Review, Vol. 33, No. 4, P135-142).

  The naphthene content of the gas oil composition according to the present invention needs to be 30% by volume or more, preferably 32% by volume or more, and more preferably 35% by volume or more. When the naphthene content of the light oil composition is within the above range, the properties defined in the light oil composition of the present invention can be achieved more easily and reliably, and fuel efficiency and PM reduction can be achieved at the same time. be able to. Moreover, a synergistic effect with the above-mentioned fatty acid alkyl ester mixture can be achieved. From the viewpoint of the influence on exhaust gas performance, the naphthene content is preferably 95% by volume or less, more preferably 90% by volume or less, further preferably 85% by volume or less, and 80% by volume. % Is most preferred. The naphthene content mentioned here is the volume percentage (volume%) of naphthene measured according to ASTM D2786 “Standard Test Method for Hydrocarbon Types Analysis of Gas-Oil Saturates Fractions by High Ionizing Voltage Mass Spectrometry”. Means.

The density at 15 ° C. in the light oil composition of the present invention needs to be 800 kg / m ³ or more, preferably 810 kg / m ³ or more, more preferably 820 kg / m ² from the viewpoint of fuel economy and acceleration. ³ or more. Further, the density, in terms of PM concentration decreases in the exhaust gas, it must be at 840 kg / m ³ or less, preferably 835 kg / m ³ or less, more preferably 830 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”.

  As a distillation property in the light oil composition of the present invention, the 10% distillation temperature (T10) needs to be 240 ° C. or less, preferably 235 ° C. or less, more preferably 230 ° C. or less, and further preferably 225 ° C. Hereinafter, it is most preferably 220 ° C. or lower. If the 10% distillation temperature exceeds the upper limit, the exhaust gas performance and the starting performance at low temperatures are deteriorated. The 10% distillation temperature needs to be 160 ° C. or higher, preferably 170 ° C. or higher, more preferably 180 ° C. or higher. If the 10% distillation temperature is less than the lower limit, engine output and startability at high temperatures tend to deteriorate.

As a distillation property in the light oil composition of the present invention, the 90% distillation temperature (T90) needs to be 340 ° C. or lower, preferably 335 ° C. or lower, more preferably 330 ° C. or lower. If the 90% distillation temperature exceeds the upper limit, the amount of PM and fine particles discharged tends to increase, and the above synergistic effect with the fatty acid alkyl ester mixture cannot be achieved. The 90% distillation temperature needs to be 280 ° C. or higher, preferably 285 ° C. or higher, more preferably 290 ° C. or higher, still more preferably 295 ° C. or higher, and even more preferably 300 ° C. or higher. If the 90% distillation temperature is less than the lower limit, the fuel efficiency improvement effect becomes insufficient and the engine output tends to decrease.
The 10% distillation temperature and 90% distillation temperature here mean values measured by JIS K 2254 “Petroleum product-distillation test method”.

In the light oil composition of the present invention, the distillation properties other than T10 and T90 are not particularly limited, but are preferably as follows.
Initial boiling point (IBP): 140-230 ° C
50% distillation temperature (T50): 230-310 ° C
95% distillation temperature (T95): 305-365 ° C
End point (EP): 310-380 ° C

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

  T50 of the light oil composition of the present invention is preferably 230 ° C. or higher, more preferably 240 ° C. or higher, from the viewpoint of fuel consumption rate, engine output, startability at high temperature, and stability of engine rotation during idling. More preferably, it is 250 ° C. or higher, even more preferably 255 ° C. or higher, and most preferably 260 ° C. or higher. On the other hand, T50 is preferably 310 ° C. or lower, more preferably 300 ° C. or lower, further preferably 295 ° C. or lower, and most preferably 290 ° C. or lower from the viewpoint of preventing an increase in PM discharged from the engine.

  T95 of the light oil composition of the present invention is preferably 305 ° C. or more, more preferably 315 ° C. or more, and most preferably, from the viewpoints of startability at high temperature, ensuring stability of engine rotation during idling, and fuel consumption rate. Is 320 ° C. or higher. On the other hand, from the viewpoint of preventing an increase in PM discharged from the engine, T95 is preferably 365 ° C. or less, more preferably 355 ° C. or less, and further preferably 350 ° C. or less.

The EP of the light oil composition of the present invention is preferably 310 ° C. or higher, more preferably 320 ° C. or higher, most preferably 320 ° C. or higher, from the viewpoints of startability at high temperatures, ensuring engine rotation stability during idling, and fuel consumption rate. Is 325 ° C. or higher. On the other hand, EP is preferably 380 ° C. or lower, more preferably 370 ° C. or lower, more preferably 365 ° C. or lower, even more preferably 360 ° C. or lower, and most preferably 355 from the viewpoint of preventing an increase in PM discharged from the engine. It is below ℃.
The initial boiling point, 50% distillation temperature, 95% distillation temperature, and end point mentioned here all mean values measured according to JIS K 2254 “Petroleum product-distillation test method”.

Kinematic viscosity at 30 ° C. of the gas oil composition of the present invention is preferably 2 mm ² / s or more, more preferably 2.2 mm ² / s or more, it is 2.5 mm ² / s or more More preferred. If the kinematic viscosity is less than 2 mm ² / s, the fuel injection timing control on the fuel injection pump side tends to be difficult, and the lubricity of each part of the fuel injection pump mounted on the engine may be impaired. is there. 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. When the kinematic viscosity exceeds 5 mm ² / s, the resistance in 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 cetane number in the light oil composition of the present invention is preferably 53 or more, more preferably 54 or more, and further preferably 55 or more. When the cetane number is less than 53, the concentrations of NOx, PM and aldehydes in the exhaust gas tend to be high. Further, from the viewpoint of reducing black smoke in the exhaust gas, the cetane number is preferably 80 or less, more preferably 75 or less, and further preferably 70 or less. The cetane number referred to here is a cetane number measured in accordance with “7. Cetane number test method” in JIS K 2280 “Petroleum products—Fuel oil—Octane number and cetane number test method and cetane index calculation method”. Means.

  Although there is no restriction | limiting in particular in the cetane index | exponent of the light oil composition of this invention, It is preferable to satisfy | fill 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 51 or more. The cetane index referred to in the present invention is defined by “Calculation method of 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”. It means the calculated value. 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.

The light oil composition of the present invention desirably has a lubricating performance such that the HFRR wear scar diameter (WS1.4) is preferably 410 μm or less, more preferably 380 μm or less. When the HFRR wear scar diameter (WS1.4) exceeds 410 μm, especially in a diesel engine equipped with a distribution type injection pump, it causes an increase in the driving torque of the pump during operation and an increase in wear of each part of the pump. 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.
The HFRR wear scar diameter (WS1.4) as used in the present invention is a value measured by the Petroleum Institute Standard JPI-5S-50-98 “Light Oil-Lubricity Test Method” issued by the Japan Petroleum Institute. Means.

  The clogging point (CFPP) of the light oil composition of the present invention is preferably −7 ° C. or lower. Furthermore, it is preferably −8 ° C. or lower, more preferably −9 ° C. or lower, from the viewpoint of preventing the prefilter blockage of the diesel vehicle. Here, the clogging point refers to a clogging point measured according to JIS K 2288 “Light oil—clogging point test method”.

  The water content in the present invention is preferably 200 ppm by volume or less, more preferably 180 ppm by volume or less, from the viewpoint of adverse effects on the member to the fuel tank and the like and suppression of hydrolysis of the ester compound. More preferably, it is 150 ppm by volume or less. In addition, the water | moisture content here is the water prescribed | regulated by JISK2275 "moisture test method (crude oil and petroleum products)."

  In the light oil composition of the present invention, from the viewpoint of storage stability, the total insoluble content after the oxidation stability test is preferably 2.0 mg / 100 mL or less, more preferably 1.5 mg / 100 mL or less. Preferably, it is 1.0 mg / 100 mL or less, more preferably 0.5 mg / 100 mL or less. The oxidation stability test here is conducted under conditions of 95 ° C. and oxygen bubbling for 16 hours in accordance with ASTM D2274-94. The total insoluble matter after the oxidation stability test here means a value measured in accordance with the oxidation stability test.

In the light oil composition of the present invention, the peroxide value after the oxidation stability test is preferably 50 ppm by mass or less, more preferably 40 ppm by mass or less, and further preferably from the viewpoint of storage stability and compatibility with members. Is 30 ppm by mass or less, and more preferably 20 ppm by mass or less. Here, the peroxide value means a value measured in accordance with the Petroleum Institute Standard JPI-5S-46-96.
In addition, in order to reduce the total insoluble matter and the peroxide value, additives such as an antioxidant and a metal deactivator can be appropriately added to the light oil composition of the present invention.

  Moreover, it is preferable that the pour point in the light oil composition of this invention is -7.5 degreeC or less. Furthermore, from the viewpoint of low-temperature startability or low-temperature drivability, and from the viewpoint of maintaining injection performance in the electronically controlled fuel injection pump, it is more preferably −10 ° C. or lower. Here, the pour point means a pour point measured by JIS K 2269 “Pour point of crude oil and petroleum products and cloud point test method of petroleum products”.

  The residual carbon content of 10% residual oil in the light oil composition of the present invention preferably satisfies 0.1% by mass or less. Furthermore, it is preferably 0.08% by mass or less and more preferably 0.06% by mass or less from the viewpoint of reducing fine particles and PM and maintaining the performance of the exhaust gas aftertreatment device mounted on the engine. preferable. The residual carbon content of 10% residual oil here means the residual carbon content of 10% residual oil measured by JIS K 2270 “Crude oil and petroleum products—residual carbon content test method”.

  In the light oil composition of the present invention, the ash content is preferably less than 0.01% by mass. If the ash content exceeds the upper limit, the ash becomes the core of PM during the combustion process in the engine, and the total amount of PM and the amount of nanoparticles increase. Further, even when the ash is discharged as it is, the ash is deposited on the exhaust gas post-processing device, and the performance of the post-processing device may be deteriorated. Furthermore, an adverse effect on the fuel injection system can be considered. The ash content in the present invention means a value measured by JIS K 2272 “Crude oil and petroleum product ash content and sulfate ash test method”.

Moreover, although the electrical conductivity in the light oil composition in this invention is not specifically limited, From the point of safety, it is preferable that it is 50 pS / m or more.
In order to improve the electrical conductivity, an antistatic agent or the like can be appropriately added to the light oil composition of the present invention. Here, the conductivity means a value measured in accordance with JIS K 2276 “Petroleum products—aviation fuel oil test method”.

In the light oil composition of the present invention, if necessary, an appropriate amount of a cetane number improver can be blended to improve the cetane number of the resulting light oil composition.
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 6-8 is preferred.

The content of the cetane improver is preferably 500 ppm by mass or more based on the total amount of the composition, more preferably 600 ppm by mass or more, further preferably 700 ppm by mass or more, and 800 ppm by mass or more. Even more preferably, it is most preferably 900 ppm by mass or more. When the content of the cetane number improver is less than 500 ppm by mass, a sufficient cetane number improving effect cannot be obtained, and PM, aldehydes, and further 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 mass ppm or less, more preferably 1250 mass ppm or less, based on the total amount of the light oil composition, and 1100 mass ppm or less. It is more preferable that it is 1000 mass ppm or less.
As the cetane number improver, one 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.

In the light oil composition of the present invention, additives other than the cetane number improver can be blended as necessary, and in particular, a lubricity improver and / or a detergent is preferably blended.
As the lubricity improver, for example, one or more of carboxylic acid-based, ester-based, alcohol-based, and phenol-based lubricity improvers can be arbitrarily used. 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 not particularly limited as long as the HFRR wear scar diameter (WS1.4) is within the above-mentioned preferable range, but is preferably 35 ppm by mass or more based on the total amount of the composition, and 50 ppm by mass. More preferably. 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. Further, the upper limit of the blending amount is preferably 150 mass ppm or less on the basis of the total amount of the composition, and more preferably 105 mass ppm or less because an effect commensurate with the addition amount cannot be obtained even if it is added more. preferable.

  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 clogging of the fuel injection nozzle, the blending amount of the cleaning agent is 30 mass ppm 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 mass ppm or more, It is more preferable to set it as 80 mass ppm or more. Even if an amount less than 30 ppm by mass is added, the effect may not appear. On the other hand, if the amount is too large, an effect commensurate with that cannot be expected, and conversely, NOx, PM, aldehydes, etc. in the diesel engine exhaust gas may increase, so the amount of detergent contained is 300 mass. It is preferably not more than ppm, and more preferably not more than 180 mass ppm.
As in the case of the above cetane improver, those commercially available as lubricity improvers or detergents are in a state where the active ingredients contributing to lubricity improvement or cleaning are diluted with an appropriate solvent, respectively. It is usually obtained at 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. As the above-mentioned additive, one synthesized according to a conventional method may be used, or a commercially available additive may be used. In addition, cetane number improvers, lubricity improvers, and detergents that are commercially available as well as detergents may be diluted with an appropriate solvent for the active ingredient that contributes to the intended effect of the additive. . When using the commercially available additive in which the active ingredient is diluted, it is preferable to add the commercially available additive so that the content of the active ingredient in the light oil composition falls within the above range.

  The light oil composition of the present invention is supplied to an engine equipped with an aftertreatment device for purifying exhaust gas. The light oil composition of the present invention is not subject to any restrictions depending on the type, application, and mounting conditions of the engine. Examples of typical engines to which the present invention is applied include engines mounted on automobiles, engines mounted on railways, engines mounted on construction machines, engines mounted on transfer machines, engines mounted on agricultural machinery, engines for power generation, and mounted on ships. Examples include an engine and an engine that serves as a stationary power supply source. Moreover, the light oil composition of the present invention can be applied not only for use as a single engine but also under conditions of being mounted on a vehicle or machine.

As an after-treatment device for exhaust gas purification, it oxidizes soluble organic substances (SOF) and aldehydes contained in unburned hydrocarbons (HC), carbon monoxide (CO), particulate matter (PM), etc. It has the functions of an oxidation catalyst that treats carbon dioxide and water, etc., a NOx reduction catalyst that treats nitrogen oxides (NOx) to nitrogen by a reducing action, and a function of both an oxidation catalyst and a NOx reduction catalyst. The original catalyst, mainly a diesel particulate filter (DPF) that collects PM so as to be filtered by a filter, a continuous regeneration type DPF that continuously treats the collected PM with an oxidizing action, and a continuous regeneration type DPF Examples of the various post-treatment apparatuses include a catalyst having a function of a NOx reduction catalyst as a main component. These various post-processing apparatuses can be used alone or in combination.
Many of the exhaust gas post-treatment devices described above remove and treat harmful substances in the exhaust gas by using oxidation reaction and reduction reaction. For this reason, as the catalyst used in the post-treatment apparatus, those in which various metals are supported on various carriers are used depending on the application.

  Catalysts for oxidation reactions, that is, catalysts aimed at removing HC, CO, PM, SOF, aldehyde, etc. are generally mainly precious metals (platinum (Pt), palladium (Pd), rhodium (Rh)), etc. Ingredients, Alumina powder as a carrier, and metal with the property of adsorbing and desorbing oxygen in exhaust gas (cerium (Ce), nickel (Ni), cobalt (Co), iron (Fe)) to improve activity and stabilize the carrier ) And many other oxides. In addition, for the purpose of enhancing the thermal stability of the alumina carrier and preventing poisoning due to sulfur and phosphorus, lanthanum (La), cerium (Ce), magnesium (Mg), calcium (Ca), barium (Ba), etc. In many cases, an oxide is added and fired. In many cases, these treatments are coated on the surface of a wash coat, that is, a porous material carrier, so that the reaction proceeds more.

  Generally, a catalyst for reduction reaction, that is, a catalyst mainly for removing NOx or the like, includes a zeolite system and an alumina system. Examples of the zeolite system include platinum-zeolite system, gallium-zeolite system, rare earth metal-zeolite system, iron-zeolite system, cobalt-zeolite system, and copper ion exchange zeolite system. Examples of the alumina system include copper-alumina system, cobalt-alumina system, copper-cesium-lanthanum alumina system, and combinations of active metals such as iron, nickel, manganese, platinum, palladium, and rhodium. Can be mentioned. Moreover, what uses barium as a temporary NOx adsorbent is also mentioned. Catalysts that selectively perform NOx reduction include those that carry oxides of vanadium and titanium, molybdenum, and silver.

In the present invention, the carrier for supporting the metal and the material of the filter part described above can be used for all of the materials currently under investigation. Examples of the material include cordierite, silicon carbide, porous metal, metal fiber, and the like. The present invention can also be applied to new materials that are currently under research and development.
The shape of the carrier supporting the metal and the shape of the filter portion described above can be used for all of those currently under consideration. Examples of the shape include a monolith honeycomb shape, a nonwoven fabric bellows shape, a multi-cylindrical shape, a polygon such as a quadrangle and a hexagon, a circle, and an uneven shape. The present invention can also be applied to a new shape that is currently being researched and developed.

  The number of cells per square inch (the number of holes) of the carrier supporting the metal and the filter portion is not particularly limited. However, in general, when the number of cells is extremely large, the back pressure increases, and when the number is extremely small, the ability of collecting and adsorbing exhaust gas components to be purified decreases, so this value is often restricted. In addition, although the wall thickness between cells and the size of the cell itself (cell diameter) vary depending on the number of cells and with a technical basis, the exhaust gas aftertreatment device to be combined with the light oil composition of the present invention Is not particularly limited and can be used for all.

The above-described metal-carrying carrier and the way of flowing exhaust gas in the filter section can be used for all of those currently under consideration. Examples of the flow method include a flow through type, a wall through type, and a cross flow type.
These are suitable for the usage environment, for example, exhaust gas type to be purified, exhaust gas temperature, exhaust gas component ratio, residual oxygen concentration, space velocity (SV), vehicle speed, load, outside air temperature, outside air humidity, use history of the aftertreatment device, etc. It is designed as follows. The control method, detection method, engine mounting method, and the like are also designed to be optimal according to the purpose of use.
Although the present invention can be summarized regardless of the type and specifications of the aftertreatment device for exhaust gas purification, the installation status, the usage method, etc., among the above-mentioned aftertreatment devices, DPF is related to existing products and current research. The present invention can also be applied to new products being developed.

The DPF collection and regeneration mechanism can be used for anything currently under consideration. Examples of the collection and regeneration mechanism include an exchange type, an alternating type, a forward feed type, a continuous type, and a manual type. The present invention can also be applied to a new collection and regeneration mechanism that is currently being researched and developed.
The DPF regeneration method can be used for all currently considered. Examples of the regeneration method include an electric heater method, a burner method, a catalytic combustion method, a reverse cleaning method, an oxidation catalyst method, and a fuel additive method. Also, the present invention can be applied to a new reproduction method that is currently being researched and developed.
DPF control schemes can be used for all currently under consideration. Examples of the control method include a back pressure method, a time method, an exhaust temperature method, an engine rotation speed method, an engine load method, an exhaust gas method, a deposit amount detection method, and the like, and there is a method of controlling by combining a plurality of these. Also, the present invention can be applied to a new control method that is currently under research and development.

  The light oil composition according to the present invention has an object of purifying exhaust gas in which the average supported amount of Pt per catalyst is 3 g / honeycomb · 1 L or less and at least one of Ti, Zr, La, Ce, Rh and Ba is supported. It is preferable to apply to an engine equipped with an aftertreatment device composed of an aftertreatment catalyst. In order to improve the performance of the above-mentioned exhaust gas aftertreatment device, the light oil composition of the present invention contains an appropriate amount of a saturated fatty acid methyl ester that is relatively light and excellent in decomposability, and satisfies specific properties. When the amount of Pt supported is larger than this, a sufficient performance improvement effect of the exhaust gas aftertreatment device cannot be obtained. In order to sufficiently improve the performance of the exhaust gas aftertreatment device, the amount of Pt supported per catalyst is more preferably 2.8 g / honeycomb · 1 L or less, and further preferably 2.6 g / honeycomb · 1 L or less.

The light oil composition according to the present invention has an average Pd loading per catalyst of 6 g / honeycomb 1 L or less, and is intended for exhaust gas purification in which at least one of Ti, Zr, La, Ce, Rh and Ba is supported. It is preferable to apply to an engine equipped with an aftertreatment device composed of an aftertreatment catalyst. In order to improve the performance of the above-mentioned exhaust gas aftertreatment device, the light oil composition of the present invention contains a suitable amount of a saturated fatty acid methyl ester that is relatively light and excellent in decomposability, and satisfies specific properties. When the amount of Pd supported is larger than this, a sufficient performance improvement effect of the exhaust gas aftertreatment device cannot be obtained. In order to sufficiently improve the performance of the exhaust gas aftertreatment device, the amount of Pd supported per catalyst is more preferably 5.8 g / honeycomb · 1 L or less, and further preferably 5.6 g / honeycomb · 1 L or less.
Note that, as described above, the fact that the amount of supported metal is small leads to a decrease in the manufacturing cost of the post-processing device, and thus has a great industrial significance. Be expected.

  The light oil composition of the present invention can greatly improve the performance of an exhaust gas purification device that has been difficult to realize with conventional light oil compositions, and can simultaneously reduce PM and NOx discharged from engines and vehicles without deterioration in fuel consumption. Excellent performance.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

(Examples 1-6 and Comparative Examples 1-3)
The light oil composition shown in Table 3 was prepared by blending the fatty acid alkyl ester mixture having the properties shown in Table 1 and the fuel base material shown in Table 2 (Examples 1 to 6 and Comparative Examples 1 to 3). Here, the fuel base used in Table 2 is obtained by using a low-sulfur gas oil fraction, kerosene fraction, natural gas, etc., obtained by hydrorefining and hydrotreating petroleum hydrocarbon feedstock. It was produced from synthetic kerosene and synthetic light oil.
In this case, various additives shown below were used as necessary.
(1) Cetane improver: 2-ethylhexyl nitrate
(2) Lubricity improver: Carboxylic acid mixture based on linoleic acid
(3) Detergent: reaction of oleic acid with oleic acid-based carboxylic acid mixture
Product
(4) Low temperature fluidity improver: ethylene-vinyl acetate copolymer

  The blending ratio of the fatty acid alkyl ester mixture used, and the blended diesel oil composition, density at 15 ° C., kinematic viscosity at 30 ° C., flash point, sulfur content, distillation properties, cetane number and cetane index, flow Point, clogging point, residual carbon content of 10% residual oil, ash content, moisture, total insoluble matter and peroxide value after oxidation stability test, conductivity, HFRR wear scar diameter, aromatic content, bicyclic ring Table 3 shows the results of measuring the aromatic content, the alkylbenzene content ratio of 14 or less carbon atoms, and the naphthene content.

The properties of the fuel oil were measured by the following method.
The density refers to a density at 15 ° C. measured by JIS K 2249 “Determination method of crude oil and petroleum products and density / mass / capacity conversion table”.
Kinematic viscosity refers to the kinematic viscosity at 30 ° C. measured by JIS K 2283 “Crude oil and petroleum products—Kinematic viscosity test method and viscosity 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 sulfur content refers to the mass content of the sulfur content based on the total amount of light oil composition measured by JIS K2541 “Sulfur content test method”.
All the distillation properties are values measured by JIS K 2254 "Petroleum products-Distillation test method".

The cetane number means a cetane number measured according to “7. Cetane number test method” of JIS K 2280 “Petroleum products—fuel oil—octane number and cetane number test method and cetane 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 cetane index in the JIS standard is not applied to the cetane number improver added, but the cetane index of the cetane index added with the cetane number improver also uses the above “8.4 variable equation”. It shall represent the value calculated by “Calculating method of cetane index”.

The pour point refers to a pour point measured according to JIS K 2269 “Crude point of petroleum and petroleum products and a cloud point test method of petroleum products”.
The clogging point refers to a clogging point measured by JIS K 2288 “Light oil—clogging point test method”.
The residual carbon content of 10% residual oil means the residual carbon content of 10% residual oil as measured by JIS K 2270 “Crude oil and petroleum products—residual carbon content test method”.
Ash content means a value measured by JIS K 2272 “Crude oil and petroleum product ash and sulfate ash test method”.
Moisture means the moisture specified by JIS K 2275 “Moisture test method (crude oil and petroleum products)”.

Lubricating performance and HFRR wear scar diameter (WS1.4) are the lubricating performance and HFRR measured by the Petroleum Institute Standard JPI-5S-50-98 “Light Oil-Lubricity Test Method” issued by the Japan Petroleum Institute Refers to the wear scar diameter.
The total insoluble matter after the oxidation stability test means a value measured under conditions of 95 ° C. and oxygen bubbling for 16 hours in accordance with ASTM D2274-94.
The peroxide value after the oxidation stability test is measured in accordance with ASTM D2274-94, under conditions of 95 ° C. under oxygen bubbling for 16 hours, and in accordance with the Petroleum Institute Standard JPI-5S-46-96. Means the value to be
The conductivity means a value measured in accordance with JIS K 2276 “Petroleum product-aviation fuel oil test method”.

The aromatic content and the aromatic content of two or more rings are determined by 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 that has been observed and complied with.
The alkylbenzene content ratio composed of 14 or less carbon atoms is measured in accordance with “type analysis of lubricating base oil by mass spectrometer” (Satoshi Hamakawa, Nisseki Review, Vol. 33, No. 4, P135-142). The calculation was performed based on the ratio (%) of the total peak intensity derived from alkylbenzene having 14 or less carbon atoms with respect to the total peak intensity derived from the total aromatic content determined from the mass spectrometry performed under the conditions.
The naphthene compound content means the volume percentage (volume%) of naphthene measured according to ASTM D2786 “Standard Test Method for Hydrocarbon Types Analysis of Gas-Oil Saturates Fractions by High Ionizing Voltage Mass Spectrometry”.
The total acid value means the total acid value measured according to JIS K 2501 “Petroleum products and lubricating oils—neutralization number test method”.

As shown in Table 3, the light oil compositions used in Examples and Comparative Examples are prepared by blending a specific fatty acid alkyl ester mixture at a specific blending ratio with respect to the fuel base material.
As is apparent from Table 3, in Examples 1 to 6 in which the fatty acid alkyl ester mixture that is within the range specified by the present invention was blended within the range specified by the present invention, the sulfur content 3 Mass ppm or less, aromatic content 15 volume% or less, bicyclic or higher aromatic content 1 volume% or less, alkylbenzene content of 14 or less carbon atoms in aromatic content 80% or more, naphthene content Gas oil composition having an amount of 30% by volume or more, a density at 15 ° C. of 800 kg / m ³ or more and 840 kg / m ³ or less, a 10% distillation temperature of 160 ° C. or more and 240 ° C. or less, and a 90% distillation temperature of 280 ° C. or more and 340 ° C. or less. Things could be obtained easily and reliably. On the other hand, in Comparative Examples 1, 2, and 3 in which a light oil composition was prepared without using the above-mentioned specific fatty acid alkyl ester mixture, the light oil composition targeted by the present invention was not necessarily obtained.

(Exhaust gas test)
Next, various tests shown below were performed using the light oil compositions of Examples 1 to 6 and Comparative Examples 1 to 3. All test results are shown in Tables 4-7. In addition, the data of Tables 5-7 compared in the relative value when the fuel of the comparative example 1 was set to 100 in each case.
A test method equipped with a post-treatment device for the purpose of purifying specific exhaust gas is shown below. The post-treatment device was used after being attached to the vehicle after aging equivalent to 30,000 km travel (the test fuel was a commercial diesel oil with a sulfur content of 10 mass ppm or less).

(1) Exhaust gas aftertreatment device A
Continuous regenerative DPF with an average Pt loading of 2.3g / honeycomb and 1L, and Ti, Ce, Ba, and Rh.
(2) Exhaust gas aftertreatment device B
Pd average carrying amount 3.9g / honeycomb · 1L, and oxidation catalyst carrying Zr, Ti, La in addition

(Vehicle exhaust gas test, fuel consumption test)
Using a diesel engine-equipped vehicle (vehicle 1) shown below, NOx, HC, PM, and fuel consumption were measured. PM collected the exhaust gas diluted in the whole dilution tunnel with a fluorocarbon-coated glass fiber filter and analyzed it. The test mode is a transient operation mode that simulates the actual driving shown in FIG. 1, the exhaust gas component is calculated as the emission amount (g / km) per 1 km of the test mode, and the result when the fuel of Comparative Example 1 is tested. As a result, each result was relatively compared and quantified. For fuel consumption, the fuel volume flow rate consumed during the test mode was corrected for fuel temperature, and the value (g / km) replaced with the weight value was set to 100 when the fuel of Comparative Example 1 was tested, and each result was relative. Comparison and quantification.

(Vehicle specifications): Vehicle 1
Engine type: Supercharged inline 4 cylinder diesel engine with intercooler Displacement: 3L
Compression ratio: 18.5
Maximum output: 125kW / 3400rpm
Maximum torque: 350Nm / 2400rpm
Regulatory compliance: 1997 exhaust gas regulatory compliance Vehicle weight: 1900 kg
Mission: 4AT
Exhaust gas aftertreatment device: None, aftertreatment device A, aftertreatment device B

  For reference, Table 4 shows the exhaust gas and fuel consumption measurement results when the test was performed using the fuel of Comparative Example 1 as 100 when the post-treatment device was not installed. For reference, Table 5 lists the exhaust gas and fuel consumption measurement results when the post-treatment is not installed. Compared with Table 4 where the post-treatment device is installed (Tables 6 and 7), exhaust gas and fuel consumption are shown. The improvement effect is still not enough. As shown in Table 6 and Table 7, in the case of using a light oil composition (Examples 1 to 6) containing a specific fatty acid alkyl ester mixture and a specific exhaust gas aftertreatment device (aftertreatment device A or B), the above-mentioned It can be seen that the NOx, HC, and PM reduction effects and the fuel efficiency improvement effects are further manifested. This is nothing but the light oil composition in the present invention improves the performance of the exhaust gas aftertreatment device.

The operation mode performed by the Example and the comparative example is shown.

Claims (3)

The content of saturated fatty acid alkyl ester having 6 to 16 carbon atoms is 4% by mass or more based on the total amount of fatty acid alkyl ester mixture, and the content of saturated fatty acid alkyl ester having 17 or more carbon atoms is fatty acid alkyl ester. The total acid value of the fatty acid alkyl ester mixture is 1.0 mgKOH / g or less, the sulfur content is 5 mass ppm or less, and the ester content is 97 mass% or more based on the total amount of the mixture. 1% by volume or more of fatty acid alkyl ester mixture per light oil composition, sulfur content of 3 mass ppm or less, aromatic content of 15% by volume or less, and bicyclic or higher aromatic content of 1% by volume or less In the aromatic component, the content of alkylbenzene having 14 or less carbon atoms is 80% or more, the content of naphthene is 30% by volume or more, 15 Density 800 kg / ^{m 3} or more 840 kg / ^{m 3} or less at 10% distillation temperature of 160 ° C. or higher 240 ° C. or less, and wherein the 90% distillation temperature of 280 ° C. or higher 340 ° C. or less (1) catalyst Pt average supported amount per 3g / honeycomb · 1 L or less, and a catalyst supporting at least one of Ti, Zr, La, Ce, Rh and Ba, or (2) Pd average supported amount per catalyst Is an engine equipped with an aftertreatment device for purifying exhaust gas composed of a catalyst having 6 g / honeycomb · 1 L or less and supporting at least one of Ti, Zr, La, Ce, Rh and Ba Gas oil composition to be supplied. The kinematic viscosity at 30 ° C. is 2 mm ² / s or more and 5 mm ² / s or less, the cetane number is 53 or more, the HFRR wear scar diameter (WS 1.4) is 410 μm or less, and the clogging point is −7 ° C. or less. The light oil composition according to claim 1 . The light oil composition according to claim 1 or 2 , wherein the fatty acid alkyl ester mixture is made from vegetable oil and fat and has a water content of 200 ppm by volume or less.