JP2008088243A - Gas oil composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas oil blended with a fatty acid alkyl ester and showing a rapid defoaming rate. <P>SOLUTION: This gas oil composition comprises 2 to 60 vol.% fatty acid alkyl ester, 20 to 80 vol.% dewaxed gas oil and 15 to 65 vol.% kerosene based on the whole amount of the composition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light oil composition, and more particularly to a light oil composition containing a fatty acid alkyl ester and having a high defoaming rate.

In recent years, from the viewpoint of preventing global warming, reduction of carbon dioxide emissions has been demanded, and the amount of carbon dioxide emitted from automobiles is also required to be similarly reduced.
In response to this requirement, the concept of carbon neutral, that is, fuel (oil) derived from plants is considered not to increase carbon dioxide in the atmosphere in the life cycle, Carbon dioxide emitted by using it is not counted in greenhouse gas emissions. Therefore, a light oil composition containing a fatty acid alkyl ester obtained from a plant-derived compound, for example, a vegetable oil and fat, has attracted attention (for example, see Patent Document 1).

However, the present inventors have found that a light oil blended with a fatty acid alkyl ester is easy to foam, has a slow defoaming speed of the foam, and takes a long time to disappear (foaming time). .
Such light oil having a slow defoaming speed and a long defoaming time often causes a problem in handling. For example, a full stop device is attached to the oil supply nozzle of a light oil meter at a normal refueling station, and when supplying light oil to a diesel vehicle, the light oil is nearly full and a foam surface is detected. And refueling is stopped. However, with light oil with a slow defoaming speed and a long defoaming time, the foamed bubbles will not disappear, and the oil may not be supplied to the full capacity. Thus, the light oil with a slow defoaming speed may prevent proper oil supply.
Accordingly, there is a need for light oil that has a high defoaming speed, that is, a short defoaming time.

On the other hand, as a method for improving the defoaming property with respect to light oil having a low sulfur content, a method having a low aromatic content and a kinematic viscosity within a specific range has been proposed (for example, see Patent Document 2).
However, in this method, the defoaming speed is not always fast and the defoaming time is not short, and the performance of the light oil blended with the fatty acid alkyl ester has not been sufficiently studied.

JP-A-2005-23136 JP 2000-265180 A

  An object of the present invention is to provide a light oil composition containing a fatty acid alkyl ester and having a high defoaming speed under such circumstances.

  The present inventors have found that even a light oil blended with a fatty acid alkyl ester can achieve its purpose by blending a specific base material at a specific blend ratio. The present invention has been completed based on such findings.

That is, the present invention
1. A light oil composition comprising 2 to 60% by volume of a fatty acid alkyl ester, 20 to 80% by volume of dewaxed light oil, and 15 to 65% by volume of kerosene, based on the total amount of the composition;
2. The light oil composition according to claim 1, wherein the following conditions (1) to (5) are satisfied:
(1) Cetane number is 45 to 70
(2) Sulfur content is 10 mass% ppm
(3) Aromatic content is 10-25% by volume
(4) Density at 15 ° C. is 0.81 to 0.85 g / cm ³
(5) 70% distillation temperature is 250-330 ° C, 90% distillation temperature is 290-360 ° C
Is to provide.

  According to the present invention, there is provided a light oil composition having a basic performance suitable for a light oil composition (such as good engine output and fuel efficiency) and a high defoaming speed. Therefore, it is a light oil composition that has excellent performance as a diesel fuel and can be properly refueled when automatically refueling a diesel vehicle.

The light oil composition of the present invention is a composition comprising 2 to 60% by volume of a fatty acid alkyl ester, 20 to 80% by volume of dewaxed light oil, and 15 to 65% by volume of kerosene, based on the total amount of the composition. .
By satisfying the above-mentioned base material and blending ratio, ensuring sufficient fuel consumption and enjoying the basic performance of light oil such as not polluting the exhaust gas, and increasing the defoaming speed and shortening the defoaming time Can do.
The light oil composition of the present invention is composed of the above-mentioned base material, but other base materials can be blended together with the above-mentioned base material within a range not contrary to the object of the present invention. Examples of such a base material include desulfurized light oil, hydrocracked light oil, GTL (Gas To Liquid: base oil produced by isomerizing a wax produced by a mineral oil-based wax, a Fischer-Tropsch process, or the like). These light oil bases may be blended alone or in admixture of two or more. The blending amount of these base materials is preferably 40% by volume or less, more preferably 25% by volume or less, based on the total amount of the light oil composition.

The fatty acid alkyl ester used in the light oil composition of the present invention is preferably an ester obtained from a reaction between a fatty acid having 8 to 22 carbon atoms and an alkyl alcohol having 1 to 4 carbon atoms.
The fatty acid having 8 to 22 carbon atoms may be a saturated fatty acid or an unsaturated fatty acid, and may be a linear fatty acid or a fatty acid having a branched chain. Specific examples of such fatty acids include, for example, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidic acid, eicosenoic acid, arachidonic acid Eicosapentaenoic acid, behenic acid, erucic acid, docosapentaenoic acid, docosahexaenoic acid and the like.

In the fatty acid alkyl ester of the present invention, an ester using a mixed fatty acid containing two or more fatty acids having 8 to 22 carbon atoms as the fatty acid is preferable.
Such a mixed fatty acid is suitable because it can be obtained in large amounts from fats and oils such as animal oils and vegetable oils, that is, triglycerides as raw materials. Specific examples of such raw material animal oils include beef tallow, pork tallow, sheep fat, whale oil, fish oil, liver oil and the like. Specific examples of raw material vegetable oils include linseed oil, safflower oil, sunflower oil, soybean oil, corn oil. Cottonseed oil, sesame oil, olive oil, castor oil, peanut oil, coconut oil, palm kernel oil, palm oil, rapeseed oil, rice bran oil and the like. Further, waste edible oils such as these animal oils and vegetable oils can also be suitably used.

  On the other hand, specific examples of the alkyl alcohol having 1 to 4 carbon atoms forming the fatty acid alkyl ester include methanol, ethanol, propanol having a linear or branched chain, and butanol having a linear or branched chain. Among these, methanol and ethanol are preferable from the viewpoint of ease of production, and methanol is particularly preferable.

  The fatty acid alkyl ester may be obtained by subjecting the above fatty acid or fat (triglyceride) and alkyl alcohol to an esterification reaction or an ester conversion reaction in the presence of an alkali catalyst such as caustic soda, for example.

  Preferable specific examples of the fatty acid alkyl ester include the saturated or unsaturated fatty acid methyl ester having 8 to 22 carbon atoms and methyl ester of mixed fatty acid obtained from animal and vegetable oils. Among them, linseed oil, safflower oil, sunflower Methyl mixed fatty acid obtained from one or more vegetable oils selected from oil, soybean oil, corn oil, cottonseed oil, sesame oil, olive oil, castor oil, peanut oil, coconut oil, palm oil, palm kernel oil, rapeseed oil, rice bran oil Esters are preferred.

  The fatty acid alkyl ester blended in the light oil composition of the present invention preferably has a total acid value of 1.0 mgKOH / g or less. If the total acid value is 1.0 mgKOH / g or less, there is no possibility of deteriorating the properties of light oil, and there is no possibility of adversely affecting the equipment. The total acid value is a value measured according to JIS K 2501 “Petroleum products and lubricants—neutralization number test method”.

Next, a dewaxed light oil (hereinafter sometimes abbreviated as “DWGO”) used in the light oil composition of the present invention is dewaxed from a light oil base such as light light oil (LGO) to reduce the wax content. Refers to the substrate. This DWGO preferably has a pour point of −10 ° C. or lower, a cloud point of −5 ° C. or lower, and a clogging temperature of −7 ° C. or lower. If it is DWGO which has such a property, the low-temperature fluidity | liquidity of a light oil composition can be kept favorable. The pour point, cloud point, and clogging temperature are more preferably −15 ° C. or lower, −12 ° C. or lower, and −10 ° C. or lower, respectively.
The pour point, cloud point, and clogging temperature are values measured according to JIS K 2269, JIS K 2269, and JIS K 2288, respectively.

Further, DWGO preferably has a normal paraffin component having 20 or more carbon atoms (hereinafter sometimes abbreviated as “C20 ⁺ np”) of 5% by weight or less with respect to the content of normal paraffin. More preferably, it is more preferably 1.5% by weight or less. If the content of C20 ⁺ np in DWGO is in the above range, the low temperature fluidity of the light oil composition is sufficient, and the cloud point, pour point and clogging temperature are kept good. In addition, content of C20 ⁺ np is a value measured by a gas chromatography analysis method as described in detail in Examples.

Furthermore, it is preferable that the sulfur content of DWGO is 12 mass ppm or less, more preferably 10 mass ppm or less.
Further, it is preferable that a density at 15 ℃ ranges from 0.820~0.860g / cm ^3, it is further preferably in the range of 0.820~0.850g / cm ^3.
The viscosity of DWGO at 30 ° C. is preferably in the range of ² to 6 mm ² / s, and the cetane number is preferably in the range of 50 to 70.

The method for dewaxing the light oil base is not particularly limited. For example, a dewaxing catalyst such as zeolite is used, and the pressure is 30 to 70 kg / cm ² G at a temperature in the range of about 310 to 380 ° C. It can be carried out at a liquid space velocity (LHSV) of 0.0 to 2.0 Hr ⁻¹ .
DWGO can be used after dewaxing treatment and further desulfurized, and DWGO having a sulfur content of 12 ppm by mass or less can be easily obtained. In this case, the desulfurization method can be performed by a normal desulfurization treatment. For example, in the presence of a desulfurization catalyst such as a Co—Mo / alumina catalyst or a Ni—Mo / alumina catalyst, the pressure is 30 to 100 kg / cm ² G. , preferably under a pressure of ^{50~70kg / cm 2 G, 300~400 ℃} , preferably at a temperature of three hundred and thirty to three hundred sixty ° C., liquid hourly space velocity (LHSV) 0.5~5H ^-1, preferably 1～2H ^-1 It is made by carrying out deep desulfurization reaction under the conditions

As kerosene (hereinafter sometimes abbreviated as “KERO”) in the light oil composition of the present invention, straight-run kerosene or desulfurized kerosene is used. Characterization of the kerosene is preferably density at 15 ℃ ranges from 0.780~0.810g / cm ^3, it is further preferably in the range of 0.785~0.800g / cm ^3. Within this range, the output and fuel consumption can be kept good.
The sulfur content of KERO is preferably 10 mass ppm or less, more preferably 8 mass ppm or less.
Further, the viscosity of KERO at 30 ° C. is preferably in the range of 1.30 to 1.55 mm ² / s, and the cetane number is preferably in the range of 40 to 60 from the viewpoint of ignitability.

  The desulfurized kerosene is a fraction obtained by desulfurizing a straight-run kerosene fraction with a desulfurization catalyst, and kerosene having a sulfur content of 10 mass ppm or less can be obtained.

The light oil composition of the present invention preferably satisfies the following conditions (1) to (5). That is, (1) The cetane number is 45 to 70.
If the cetane number is 45 or more, there is no possibility of causing diesel knock due to abnormal combustion, and the increase of NO _x and PM in the exhaust gas can be suppressed. If the cetane number is 70 or less, black smoke is generated. Can be reduced. The cetane number is more preferably 48 to 65. The cetane number is a value measured by “Testing method for octane number and cetane number” of JIS K2280.

(2) The sulfur content (sulfur content) is 10 mass ppm or less.
If the sulfur content is 10 mass ppm or less, it is possible to suppress an increase in the amount of PM emission in the exhaust gas, and post-treatment devices such as a diesel particulate filter (DPF) and a NOx catalyst are deteriorated. Can also be prevented. The sulfur content is more preferably 5 ppm by mass or less. The sulfur content is a value measured according to “Crude oil and petroleum products—Sulfur content test method—microcoulometric titration method” in JIS K 2541-2.

(3) The aromatic content is 10 to 25% by volume.
If the aromatic content of the light oil base oil is 10% by volume or more, it is possible to avoid the occurrence of fuel leakage due to rubber swelling. Moreover, if aromatic content is 25 volume% or less, the increase in the total hydrocarbons (THC), carbon monoxide (CO), and PM (particulate matter) in exhaust gas can be suppressed. The aromatic content is more preferably 13 to 23% by volume.
The aromatic content is a value measured according to Petroleum Institute Standard JPI-5S-49-97 “Petroleum Products—Hydrocarbon Type Test Method—High Performance Liquid Chromatograph Method”.

(4) The density at 15 ° C. is 0.81 to 0.85 g / cm ³ .
If the density at 15 ° C. is 0.81 g / cm ³ or more, the fuel efficiency can be kept good, and if it is 0.85 g / cm ³ or less, the combustibility is improved and the THC in the exhaust gas is Generation of CO and PM can be suppressed. The density at 15 ° C. is more preferably 0.81 to 0.84 g / cm ³ .
The density at 15 ° C. is a value measured according to “Crude oil and petroleum products—density test method and density / mass / capacity conversion table” of JIS K 2249.

(5) The 70% distillation temperature (T70) is 250 to 330 ° C, and the 90% distillation temperature (T90) is 290 to 360 ° C.
If T70 in the distillation properties is 250 ° C. or higher and T90 is 290 ° C. or higher, there is no fear that the output will decrease, and if T70 is 330 ° C. or lower and T90 is 360 ° C. or lower, A good spray can be formed, the combustion state can be kept good, and a decrease in output and a decrease in cetane number can be avoided.
Regarding the distillation properties, it is further preferred that the 50% distillation temperature (T50) is 230 to 290 ° C.
The above T50, T70, and T90 are values obtained from the distillation properties measured based on JIS K 2254 “Petroleum product-distillation test method”.

  Various additives can be appropriately blended in the light oil composition of the present invention as necessary. Examples of such additives include fluidity improvers, lubricity improvers, detergents, antioxidants, metal deactivators, and cetane number improvers. One or more of these additives can be added. Moreover, the addition amount may be appropriately selected according to the situation, but it is usually preferable that the total amount of the additive is 5% by mass or less based on the light oil composition.

EXAMPLES Next, although an Example demonstrates this invention in detail, this invention is not restrict | limited at all by these examples. The properties and performance of the light oil composition were determined according to the following method.
[Properties and composition of light oil composition]
(1) Cetane number Measured according to JIS K 2280.
(2) Kinematic viscosity Measured according to JIS K 2283.
(3) Sulfur content It measured based on JISK2541-2.
(4) Aromatic content Measured according to the Petroleum Institute Standard JPI-5S-49-97.

(5) Distillation property Measured according to JIS K2541.
(6) Cloud point (CP)
It was measured according to JIS K 2269.
(7) Pour point (PPT)
It was measured according to JIS K 2269.
(8) Clogging point (CFPP)
It was measured according to JIS K 2288.

(9) Normal paraffin content Using a gas chromatograph GC-9A manufactured by Shimadzu Corp. and a chromatopack 3A data processor, measurement was performed under the following conditions.
Column: J &W's DB-1 Megabore column 60m (two 30m columns connected)
Column temperature: 100 to 300 ° C. (heated at 5 ° C./min)
Carrier gas; helium injector temperature; 340 ° C
Detector: Hydrogen flame ion detector (FID)
Using the above data processor, in the obtained gas chromatogram, obtain the total area (S) above the baseline and the area (Pi) above the line connecting the valleys of the normal paraffin peaks to the valleys, The normal paraffin content (mass%) of carbon number i was calculated by the formula of (Pi / S) × 100.

[Performance of light oil composition]
(10) Defoaming speed (defoaming time)
The measurement was performed according to the following procedure.
(i) Collect 60 mL of sample oil kept at 23 ± 2 ° C. in a clean 100 mL graduated graduated cylinder specified in JIS R 3505, and vortex it.
(ii) The graduated cylinder is shaken up and down for 30 seconds at an amplitude of 125 to 250 mm and twice per second.
(iii) Immediately after shaking, place the graduated cylinder on the flat table and measure the time (seconds) until the bubbles disappear and the oil level can be confirmed.
(vi) The bubble disappears and the time is the defoaming time (seconds). As the defoaming time (seconds) is shorter, the defoaming speed is faster and better.

Examples 1-10 and Comparative Examples 1-4
Using the base materials shown in Table 1, the light oil composition was prepared by mixing at the ratio shown in Table 2, and the properties, composition and performance thereof are shown in Table 2.
In Tables 1 and 2, DGO is hydrodesulfurized diesel oil, DK is desulfurized kerosene, DWGO-1 and DWGO-2 are dewaxed diesel oil, FAME-1 is a methyl ester of rapeseed oil fatty acid, and FAME-2 is palm The methyl ester of oil fatty acid is shown.

  From Table 2, the light oil compositions of Examples 1 to 10 all have a defoaming time of 30 seconds or less and a fast defoaming speed. On the other hand, the light oil compositions of Comparative Examples 1 and 2 in which the content of DWGO exceeds 80% by volume have a defoaming time of 55 seconds or more and a slow defoaming speed. Moreover, the light oil compositions of Comparative Examples 3 and 4 in which the content of DK exceeds 65% by volume have a defoaming time of 10 seconds or less and a fast defoaming speed, but T70 and T90 are low, and at 15 ° C. Since the density is small, it causes a decrease in output and fuel consumption and does not have basic performance as a light oil.

  According to the light oil composition of the present invention, a light oil composition having basic performance suitable as a light oil and having a high defoaming rate can be obtained. Therefore, it has excellent performance as a diesel fuel, and at the same time it can be properly refueled when automatically refueling a diesel vehicle.

Claims (2)

A gas oil composition comprising 2 to 60% by volume of a fatty acid alkyl ester, 20 to 80% by volume of dewaxed light oil, and 15 to 65% by volume of kerosene, based on the total amount of the composition. The light oil composition according to claim 1, wherein the following conditions (1) to (5) are satisfied.
(1) Cetane number is 45 to 70
(2) Sulfur content is 10 mass ppm or less (3) Aromatic content is 10-25% by volume
(4) Density at 15 ° C. is 0.81 to 0.85 g / cm ³
(5) 70% distillation temperature is 250-330 ° C, 90% distillation temperature is 290-360 ° C