JP6042874B2 - Light oil composition - Google Patents

Description

  The present invention relates to a light oil composition, in particular, a light oil composition that can be used even in a very low temperature environment.

  Generally, gas oil compositions are obtained by hydrorefining or hydrodesulfurizing straight-run gas oil obtained from crude oil atmospheric distillation equipment, or hydrotreating straight-run kerosene obtained from crude oil atmospheric distillation equipment. And one or two or more of those subjected to hydrodesulfurization treatment. In particular, in order to ensure low temperature fluidity in winter, the mixing ratio of the above kerosene base and gas oil base is often controlled, and cetane number improvers, detergents, and low temperature fluidity improvement as necessary. Additives such as agents are blended.

  In recent years, Fischer-Tropsch synthetic oil (hereinafter referred to as “FT synthetic oil”) obtained by Fischer-Tropsch synthesis using carbon monoxide and hydrogen as raw materials is used as an alternative fuel for petroleum-based fuels. Use is under consideration. When diesel oil for diesel fuel is produced from FT synthetic oil, a diesel oil that does not contain sulfur is obtained. Therefore, the FT synthetic diesel oil is preferable in terms of reducing environmental impact.

  However, the above-mentioned FT synthetic oil has a relatively high content of linear saturated hydrocarbon (normal paraffin) compounds. In particular, when a heavy normal paraffin compound is contained, the FT synthetic oil itself may precipitate as a wax. Sex is pointed out. In addition, since the FT synthesis base material is a hydrocarbon mixture in which the above-mentioned normal paraffin and the saturated hydrocarbon (isoparaffin) compound having a side chain occupy the most, generally it is poor in oil solubility, and oil-soluble groups (linear alkyl) Additives of the type that dissolve in fuel oils such as light oil, depending largely on the base, etc., may be difficult to dissolve. From the above, there has been a problem that light oil derived from FT synthetic oil cannot be used in a low temperature environment.

  Various techniques have been developed to solve the above problems. For example, Patent Document 1 discloses a technique for improving fluidity in a low temperature environment by adding and mixing a lubricity improver and a low temperature fluidity improver to an FT synthetic light oil composition having a specific composition. Has been.

JP 2007-270109 A

  However, considering the use of light oil compositions in cold regions such as the Arctic and Antarctic regions, sufficient fluidity can be obtained with the FT synthetic light oil composition obtained by the technique described in Patent Document 1. There has been a possibility that there is no possibility, and further improvement in low-temperature performance has been desired.

  Moreover, when using the above-mentioned FT synthetic light oil as a fuel for a diesel engine, it is necessary to increase the kinematic viscosity at 30 ° C. in order to maintain good startability during engine combustion and rotational stability during idling, In order to improve the fluidity in a low-temperature environment, it is necessary to lower the pour point. However, since these kinematic viscosities and pour points are in a trade-off relationship, it has been difficult to achieve both with conventional techniques. Therefore, development of a technique that can improve the fluidity without reducing the kinematic viscosity even in a severe low-temperature environment is desired.

  The present invention has been developed in view of the above situation, and can exhibit excellent low-temperature performance as compared with the prior art even when oil containing a high amount of normal paraffin such as FT synthetic oil is included as a raw material. It aims at providing a light oil composition.

  As a result of earnest research on the above problems, the present inventors have attempted to optimize the composition of the light oil composition, and by adding a specific amount of a low-temperature fluidity improver to the light oil composition, It has been found that excellent fluidity in a low temperature environment can be realized without lowering the kinematic viscosity.

The present invention has been made based on such findings, and the gist thereof is as follows.
(1) The sulfur content is 1 mass ppm or less, the aromatic content is 1 mass% or less, the paraffin content having 5 to 15 carbon atoms is 40 to 70 mass%, the paraffin content having 20 to 27 carbon atoms is 7 to 16 mass%, A gas oil composition having an isoparaffin content of 50 to 75% by mass and containing 150 to 1000 ppm by mass of a low-temperature fluidity improver.

(2) The diesel oil composition as described in (1) above, wherein the pour point is −70 to −35 ° C. and the kinematic viscosity at 30 ° C. is 1.5 to 4.0 mm ² / s.

(3) The light oil composition as described in (1) above, wherein the light oil composition comprises a Fischer-Tropsch synthetic oil.

  ADVANTAGE OF THE INVENTION According to this invention, even if it is a case where oil with much normal paraffin content is used as a raw material, it becomes possible to provide the light oil composition which has the low-temperature performance excellent compared with the prior art.

Hereinafter, the present invention will be specifically described.
The gas oil composition according to the present invention has a sulfur content of 1 mass ppm or less, an aromatic content of 1 mass% or less, a C 5-15 paraffin content of 30-85 mass%, and a C 20-27 paraffin content of 3. -20 mass%, isoparaffin content is 50-75 mass%, and contains 20-1000 mass ppm of low temperature fluidity improvers.

(Sulfur content, aromatic content)
The light oil composition of the present invention has a sulfur content of 1 mass ppm or less and an aromatic content of 1 mass% or less. In order to further reduce the particulate matter discharged from the diesel engine and from the viewpoint of further improving fuel consumption, the sulfur content is 1 mass ppm or less and the aromatic content is 1 mass% or less.

(Paraffin content having 5 to 15 carbon atoms)
The gas oil composition of the present invention has a paraffin content of 5 to 15 carbon atoms of 30 to 85 mass%, preferably 40 to 70 mass%. The paraffin content having 5 to 15 carbon atoms is limited to 30% by mass or more from the viewpoint of improving startability of the diesel engine and rotational stability during idling, and 85 from the viewpoint of reducing particulate matter discharged from the diesel engine. It is limited to mass% or less.

(Paraffin content having 20 to 27 carbon atoms)
The gas oil composition of the present invention has a paraffin content of 20 to 27 carbon atoms of 3 to 20% by mass, preferably 7 to 16% by mass. The paraffin content having 20 to 27 carbon atoms needs to be 3% by mass or more in order to improve the solubility of the low-temperature fluidity improver, and 20% by mass or less in order to improve the low-temperature fluidity of the light oil composition. Is necessary.

(Isoparaffin content)
The light oil composition of the present invention has an isoparaffin content of 50 to 75% by mass, preferably 60 to 70% by mass. In order to improve startability and operability at low temperatures, the isoparaffin content needs to be 50% by mass or more, and in order to obtain a light oil composition with a high yield, the isoparaffin content is 75% by mass or less. There is a need to.

(Mass ratio of normal paraffin and isoparaffin)
The mass ratio of the normal paraffin to the isoparaffin (normal paraffin / isoparaffin) is preferably in the range of 0.3 to 1.0, more preferably 0.4 to 0.7. . This mass ratio (normal paraffin content / isoparaffin content) is set to 0.3 or more in order to improve the startability at the time of combustion and the rotational stability at idling of the diesel engine under extremely low temperature weather conditions. In order to improve the startability and operability of the oil, it is isomerized and contains isoparaffin or more, and therefore it is preferably 1.0 or less.

(Distillation properties)
The light oil composition of the present invention preferably has a 5% distillation temperature of 140 to 200 ° C, more preferably 150 to 195 ° C. In order to improve the startability of the diesel engine and the rotational stability during idling, the 5% distillation temperature should be 140 ° C or higher, and in order to improve the startability and operability at low temperatures, The exit temperature is preferably 200 ° C. or lower.
The light oil composition of the present invention preferably has a 95% distillation temperature of 300 to 340 ° C, more preferably 310 to 330 ° C. From the viewpoint of improving the fuel consumption rate of the diesel engine, the 95% distillation temperature is preferably set to 300 ° C. or higher. From the viewpoint of reducing particulate matter discharged from the diesel engine, the 95% distillation temperature is set to 340 ° C. or lower. It is preferable that

(density)
The light oil composition of the present invention preferably has a density at 15 ° C. of 0.750 to 0.780 g / cm ³ , more preferably 0.760 to 0.780 g / cm ³ . The density at 15 ° C. is 0.750 g / cm ³ or more in order to improve the fuel consumption rate of the diesel engine, and 0.780 g / cm ³ or less in order to improve the low temperature fluidity of the light oil composition.

(Cloud point)
In addition, the light oil composition of the present invention preferably has a cloud point of −35 ° C. or lower, more preferably −55 ° C. or lower so that it can withstand use under extremely low temperature weather conditions. Here, the cloud point means a cloud point measured according to JIS K 2269 “Pour point of crude oil and petroleum products and petroleum product cloud point test method”.

(Kinematic viscosity at 30 ° C)
Kinematic viscosity at 30 ° C. of the gas oil composition of the present invention is preferably from 1.5 to 4.0 mm ² / s, more preferably 2.0~3.5mm ² / s. About kinematic viscosity at 30 ° C., from the point of improving the starting stability of the diesel engine and the rotational stability during idling, 1.5 mm ² / s or more, from the point of reducing particulate matter discharged from the diesel engine, It is preferable to be 4.0 mm ² / s or less.

(Pour point)
The pour point of the light oil composition of the present invention is preferably −35 ° C. or lower. In order to improve the low temperature fluidity under extremely low temperature weather conditions, the pour point is preferably set to −35 ° C. or lower, more preferably −55 ° C. or lower.
Moreover, it is not necessary to lower the pour point more than necessary. From the viewpoint of the production cost of the light oil composition, the pour point is preferably −70 ° C. or higher, more preferably −66 ° C. or higher.

(Low temperature fluidity improver)
The light oil composition of the present invention needs to contain 150 to 1000 mass ppm of the low-temperature fluidity improver, preferably 150 to 500 mass%, more preferably 200 to 300 mass%. The content (addition amount) of the low-temperature fluidity improver is set to 150 ppm by mass or more in order to prevent the filter of the diesel vehicle from being clogged at a low temperature. It shall be below mass ppm.

  As the low-temperature kinematic viscosity improver, an ethylene-vinyl acetate copolymer and / or a low-temperature fluidity improver having a surfactant effect is used. For example, low temperature fluidity improvers having a surface active effect include copolymers of ethylene and methyl methacrylate, copolymers of ethylene and α-olefins, chlorinated methylene-vinyl acetate copolymers, unsaturated carboxylic acids. Alkyl ester polymer of acid, ester synthesized from nitrogen-containing compound having hydroxyl group and saturated fatty acid or salt thereof, ester and amide derivative synthesized from polyhydric alcohol and saturated fatty acid, synthesized from polyoxyalkylene glycol and saturated fatty acid 1 ester selected from an ester synthesized from an alkylene oxide adduct of a polyhydric alcohol or a partial ester thereof and a saturated fatty acid, a chlorinated paraffin / naphthalene condensate, an alkenyl succinic acid amide, an amine salt of sulfobenzoic acid, or the like What combined 2 or more types is mentioned

(Lubricity improver)
Moreover, it is preferable that the light oil composition of this invention contains 20-300 mg / L of lubricity improvement agents by active ingredient density | concentration, and it is more preferable that 50-200 mg / L is included. By making the addition amount of the lubricity improver within the range of 20 to 300 mg / L, the efficacy of the added lubricity improver can be effectively extracted. For example, in a diesel engine equipped with a distribution type injection pump, An increase in driving torque of the pump during operation can be suppressed, and wear of the pump can be reduced.

  As the type of the lubricity improver, a lubricity improver containing a compound having a polar group consisting of a fatty acid and / or a fatty acid ester is used. Although the detailed compound name etc. are not specifically limited, For example, 1 type, or 2 or more types of each lubricity improvement agent of a carboxylic acid type | system | group, ester type | system | group, alcohol type | system | group, and a phenol type 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. In addition, the weight average molecular weight of the active component of the lubricity improver is preferably 200 or more and 1000 or less in order to increase the solubility in the light oil composition.

(Other additives)
Further, for the purpose of further enhancing the performance of the light oil composition of 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, phenol-based and amine-based antioxidants; metal deactivators such as salicylidene derivatives; corrosion inhibitors such as aliphatic amines and alkenyl succinic acid esters; anionic-based, cationic-based, Antistatic agents such as amphoteric surfactants; coloring agents such as azo dyes; antifoaming agents such as silicones; antifreezing agents such as 2-methoxyethanol, isopropyl alcohol, and polyglycol ether.
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. It is.
In addition, this invention does not add a restriction | limiting regarding the other specification of the diesel engine to which the light oil composition of this invention is applied, a use, and a use environment.

(FT synthetic oil)
The light oil composition of the present invention preferably further contains Fischer-Tropsch synthetic oil (FT synthetic oil). As described above, since the FT synthetic oil has a relatively high content of linear saturated hydrocarbon (normal paraffin) compound, and there is a problem that the light oil derived from the FT combined oil cannot be used in a low temperature environment, the present invention. This is because the effect of is most prominent.
Moreover, in order to suppress consumption of a petroleum-type base material by utilizing FT synthetic oil from a viewpoint of the alternative fuel of petroleum, it is preferable to contain FT synthetic oil.

  The FT synthetic oil is, for example, a step of fractionating FT synthetic oil into a light fraction and a wax fraction, a step of hydroisomerizing the light fraction to obtain a hydroisomerized oil, the wax The fraction is hydrocracked to obtain hydrocracked oil, the hydroisomerized oil and the hydrocracked oil are mixed and then supplied to a product fractionator, and It is obtained by the manufacturing method including the process of adjusting the cut temperature in the said product fractionator so that a light oil composition may be obtained. The bottom oil of the product fractionator is preferably recycled and mixed with the wax fraction and then hydrocracked to obtain hydrocracked oil.

Furthermore, the light gas oil base material obtained from the product fractionating device and the heavy gas oil base material may be mixed at a predetermined ratio to produce the light oil composition of the present invention. Each of the light gas oil base and the heavy gas oil base has a sulfur content of 1 mass ppm or less and an aromatic content of 1 mass% or less. The light gas oil base has a density of 0.740 to 0.760, a 5% distillation temperature of 155 to 175 ° C, a 95% distillation temperature of 230 to 250 ° C, and a paraffin content of 5 to 15 carbon atoms of 90 to 99. .9% by mass and isoparaffin content is preferably 40 to 55% by mass. The heavy gas oil base has a density of 0.770 to 0.790, a 5% distillation temperature of 240 to 260 ° C., a 95% distillation temperature of 330 to 350 ° C., and a C 5-15 paraffin content of 15 to 35 mass% and isoparaffin content are preferably 70 to 85 mass%.
Furthermore, the base material obtained from each apparatus of a solvent or an oil refinery plant can also be suitably prepared and prepared so that the composition of the light oil composition of this invention may be satisfy | filled.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.
In addition, the analysis method of each property in an Example is as follows.
Sulfur content: Measured according to JIS K 2541 “Sulfur content test method”.
Aromatic content: Measured according to JIS K 2536-3 “How to determine aromaticity by gas chromatography”.
Distillation property: Measured according to JIS K 2254 "Petroleum products-Distillation test method".
Density: Measured according to JIS K 2249 “Crude oil and petroleum product density test method and density / mass / capacity conversion table”.
Kinematic viscosity: Measured according to JISK2283 “Crude oil and petroleum products—Kinematic viscosity test method and viscosity index calculation method”.
Flash point: Measured according to JIS K2265 “Crude oil and petroleum product flash point test method”.
Cetane index: Measured according to JIS K2280 “Calculation method of cetane index using 8.4 variable equation”.
Cloud point: Measured according to JIS K2269 “Pour point of crude oil and petroleum products and cloud point test method of petroleum products”.
Clogging point: Measured according to JISK2288 “Diesel oil—clogging point test method”.
Pour point: Measured according to JISK2269 “Pour point of crude oil and petroleum products and cloud point test method of petroleum products”.
Paraffin content, isoparaffin content: Paraffin content, paraffin content for each carbon number, and isoparaffin content were measured using GC-FID. Using a non-polar column (stainless capillary column ULTRA ALLOY-1) and FID (flame flame ionization detector) and a carrier gas (helium) flow rate of 1.0 mL / min, a predetermined temperature program (column isothermal temperature: 140 ° C to 355 ° C) The temperature was raised to 8 ° C./min at 8 ° C./min and calculated from the values measured at a sample injection temperature of 360 ° C. and a detector temperature of 360 ° C.

(Light diesel base, heavy diesel base)
A light gas oil base and a heavy gas oil base were prepared according to the following procedure.
Using the FT synthetic oil obtained by the FT synthesis reaction, the light fraction of the FT synthetic oil was hydroisomerized (LHSV1.8h-1, hydrogen partial pressure 3.0 MPa, reaction temperature 320 ° C.). Thereafter, the hydroisomerized oil thus obtained and the FT synthetic oil wax fraction were hydrocracked (LHSV1.8h-1, hydrogen partial pressure 4.0 MPa, reaction temperature 310 ° C.). The cracked oil was mixed with the bottom oil of the product fractionator (the fraction having a cut temperature of 360 ° C. or higher) while being recycled (recycle ratio 50 vol%), and then supplied to the product fractionator. And the light light oil base material and the heavy light oil base material were obtained by fractionating with the said product fractionator. The cut temperature of the light gas oil base and the heavy gas oil base is 250 ° C.
The compositions of the obtained light gas oil base 1 and heavy gas oil base 1 are shown in Table 1.

(Examples 1-4, Comparative Examples 1-2)
A light gas oil base material and a heavy gas oil base material are mixed according to the mixing ratio shown in Table 1, and a low-temperature fluidity improver (Infineum R240 manufactured by Infinium Japan Co., Ltd.) is added to give a sample by adding 200 mass ppm. A light oil composition was obtained.

About each light oil composition obtained by the said Example and comparative example, after measuring each property (however, about distilling temperature, a cloud point, flash point, and a cetane index | exponent, Example 2, Comparative example 1, and comparison Only Example 2 was measured.), The pour point and kinematic viscosity were evaluated. The results are shown in Table 1.
As a favorable condition for use under extremely low-temperature weather conditions, “preferable is a case where the pour point is −70 to −35 ° C. and the kinematic viscosity at 30 ° C. is 1.5 to 4.0 mm ² / s. (○) ”, and the case where the pour point is −66 to −55 ° C. and the kinematic viscosity at 30 ° C. is 2.0 to 3.5 mm ² / s is defined as“ particularly preferable (◎) ”. On the other hand, the case where none of the above conditions was satisfied was defined as “defective (×)”.

From the results of Table 1, it can be seen that the light oil composition obtained in each example has good quality for use under extremely low temperature weather conditions, and in particular, the examples included in the preferred range of the present invention. 1 to 3 were found to have better quality.
On the other hand, it was found that the light oil compositions obtained in the respective comparative examples precipitated wax under very low temperature weather conditions or had insufficient kinematic viscosity characteristics.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the light oil composition which has the low-temperature performance outstanding compared with the prior art, and utilizes oil with many normal paraffin content, such as FT synthetic oil, as a raw material of a light oil composition. It becomes easy and has a special effect.

Claims (3)

Sulfur content is 1 mass ppm or less, aromatic content is 1 mass% or less, paraffin content of 5 to 15 carbon atoms is 40 to 70 mass%, paraffin content of 20 to 27 carbon atoms is 7 to 16 mass%, isoparaffin content is 50-75% by mass,
A gas oil composition comprising 150 to 1000 ppm by mass of a low-temperature fluidity improver. The gas oil composition according to claim 1, wherein the pour point is -70 to -35 ° C, and the kinematic viscosity at 30 ° C is 1.5 to 4.0 mm ² / s.   The gas oil composition according to claim 1, wherein the gas oil composition comprises a Fischer-Tropsch synthetic oil.