JP6269023B2 - Lubricity improver for fuel oil and fuel oil composition - Google Patents

Description

  The present invention relates to a lubricity improver for diesel fuel oil and a fuel oil composition containing the same. Specifically, the present invention relates to a lubricant improver for diesel fuel oil that has improved handling properties by refining fatty acid crystals generated when stored in a cooled state during winter and a fuel oil composition containing the same.

  In recent years, with the increase of truck transportation, sulfur contained in light oil has been taken up as one of the causative substances of environmental problems. In Japan, diesel oil is required to have a sulfur content of 10 ppm or less by automobile exhaust gas regulations.

  Reduction of the sulfur content in light oil is usually performed by a desulfurization process by catalytic hydrotreatment in petroleum refining. However, in reducing the sulfur content in the gas oil, it is known that highly polar compounds other than the sulfur content are also removed at the time of desulfurization, and as a result, the lubricity inherent in the gas oil itself is lost. I will let you.

  In order to compensate for the lubricity of the lost diesel oil, fatty acids obtained by hydrolyzing animal and vegetable oils such as rapeseed (canola) oil and tall oil are usually used as diesel oil. For example, Patent Document 1 discloses a technique for improving the lubricity of light oil by adding a fatty acid derived from tall oil to light oil. Patent Document 2 shows that a fatty acid mixture containing an unsaturated fatty acid having a specific composition is excellent in improving the lubricity of gas oil.

US Pat. No. 3,067,152 JP-A-11-001692

  The above-mentioned fatty acid type lubricity improver usually contains a linear saturated fatty acid having about 16 to 20 carbon atoms in addition to the linear unsaturated fatty acid as the main component. This straight-chain saturated fatty acid precipitates in an additive storage tank of a refinery in winter, and causes a problem of blocking an impurity removing filter having an opening of about 100 μm installed in a pipe when added to light oil. When the filter is blocked and a predetermined amount of the lubricity improver cannot be added to the light oil, the light oil becomes insufficiently lubricated, causing seizure in a fuel injection pump of a diesel engine. In addition, when the filter opening is increased to prevent the filter from clogging, impurities that should be removed are mixed into the light oil, which causes seizure in the fuel injection pump of the diesel engine and metal wear of the sliding part. .

  For this reason, the technique which refines | miniaturizes the linear saturated fatty acid crystal which precipitates at the time of cooling is calculated | required.

  An object of the present invention is to sufficiently improve the lubricity of diesel fuel oil, refine a saturated fatty acid crystal generated when stored in a cooled state during winter, and have excellent handling properties for diesel fuel oil and It is to provide a fuel oil composition containing the same.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the fatty acid mixture having a specific composition has fine crystals, and is excellent in the effect of improving the lubricity of light oil. I found.

That is, the present invention contains 1 to 10% by mass of the following component (A), 0.4 to 4.0% by mass of component (B), and 86 to 98.6% by mass of component (C), and A lubricant improver for diesel fuel oil, wherein the mass ratio [(A) / (B)] of the component (A) to the component (B) is 90/10 to 50/50.

(A) C16-C20 linear saturated fatty acid (B) C1-C18 linear unsaturated fatty acid (C) having 1 to 3 unsaturated bonds, all of the unsaturated bonds being trans. ) A straight-chain unsaturated fatty acid having 18 carbon atoms having 1 to 3 unsaturated bonds and at least one unsaturated bond being cis-type

Preferably, in the component (B), the mass ratio [(b1) / (b2)] of the following component (b1) to the component (b2) is 70/30 to 50/50.
(B1) linear unsaturated fatty acid having one unsaturated bond (b2) linear unsaturated fatty acid having two or three unsaturated bonds

  The present invention also relates to a fuel oil composition comprising 0.001 to 0.5% by mass of the lubricant improver for diesel fuel oil.

  The lubricity improver for diesel fuel oil of the present invention can refine the linear saturated fatty acid crystals that are produced when stored in the cold state during winter, and is excellent in handling properties. The fuel oil composition containing the lubricity improver for diesel fuel oil of the present invention is excellent in lubricity even if it has a low sulfur content.

2 is a photograph showing a crystal observation result during cooling in Example 1. FIG. 6 is a photograph showing a crystal observation result during cooling in Example 2. FIG. 4 is a photograph showing a crystal observation result during cooling in Example 3. FIG. 6 is a photograph showing a crystal observation result during cooling in Example 4. FIG. 6 is a photograph showing a crystal observation result during cooling in Example 5. FIG. 6 is a photograph showing a crystal observation result during cooling in Example 6. FIG. 6 is a photograph showing a crystal observation result during cooling in Comparative Example 1. 6 is a photograph showing a crystal observation result during cooling in Comparative Example 2. 10 is a photograph showing a crystal observation result during cooling in Comparative Example 3. 10 is a photograph showing a crystal observation result during cooling in Comparative Example 4. 10 is a photograph showing a crystal observation result during cooling in Comparative Example 5. 6 is a photograph showing a crystal observation result during cooling in Comparative Example 6.

Embodiments of the present invention will be described below.
The present invention is a lubricity improver for diesel fuel oil that can refine a linear saturated fatty acid crystal generated when stored in a cooled state during winter and has excellent handling properties.

  The diesel fuel in the present invention is a middle distillate having a low sulfur content that has been refined by extreme hydrogenation in order to meet the sulfur content regulations. Here, the middle distillate oil is an intermediate spilled oil in the distillation of petroleum, and includes low-sulfur marine fuel oil such as gasoline, kerosene, light oil, heavy oil, DM class fuel oil, etc., preferably light oil. The sulfur content is 500 ppm or less, preferably 50 ppm or less, more preferably 10 ppm or less. For example, in Japan, special No. 1 light oil, No. 1 light oil, No. 2 light oil, No. 3 light oil or special No. 3 light oil are specified in the Japanese Industrial Standard (JIS K2204).

  Furthermore, in this invention, it can be used also for diesel fuels other than light oil obtained by distilling crude oil. Examples of the fuel include Fischer-Tropsch fuel obtained by converting natural gas, coal, biomass or the like into synthesis gas and obtained by a Fischer-Tropsch reaction, or further isomerized therefrom. GTL gas oil, CTL gas oil, BTL gas oil, hydrogenated oil fuel obtained by hydrogenating animal and plant oils and the like correspond to these. Other fuels that can be used in the present invention include hydrocarbons obtained from algae and the like, and also include fuels having physical properties and viscosity equivalent to those of light oil.

The lubricity improver for diesel fuel oil of the present invention contains the following (A), (B), and (C) as constituent components.
(A) C16-C20 linear saturated fatty acid (B) C1-C18 linear unsaturated fatty acid (C) Unsaturated bond having 1 to 3 unsaturated bonds, all of which are trans-type Having 1 to 3 carbon atoms and having at least one unsaturated bond in cis form, a straight-chain unsaturated fatty acid having 18 carbon atoms

  The ratio of a component (A) is 1-10 mass%. When the ratio of a component (A) is less than 1 mass%, since unsaturated fatty acid refine | purified with high purity is used, it is unpreferable from a viewpoint of cost. From this viewpoint, the proportion of the component (A) is 1% by mass or more, and more preferably 2% by mass or more. Moreover, when the ratio of a component (A) exceeds 10 mass%, there exists a possibility that the precipitation amount of a linear saturated fatty acid may increase and it may become impossible to refine a crystal | crystallization. From this viewpoint, the proportion of the component (A) is 10% by mass or less, preferably 8% by mass or less, more preferably 7% by mass or less, and particularly preferably 6% by mass or less.

  However, in this specification, the mass ratio of each component is a numerical value when the total value of the masses of the components (A), (B), and (C) is 100 mass%.

  Moreover, the ratio of a component (B) is 0.4-4.0 mass%. When the proportion of the component (B) is less than 0.4% by mass, the linear saturated fatty acid crystals may not be sufficiently refined. From this viewpoint, the proportion of the component (B) is set to 0.4% by mass or more, more preferably 0.5% by mass or more, and further preferably 0.6% by mass or more. Moreover, when the ratio of a component (B) exceeds 4.0 mass%, there exists a possibility that the crystal | crystallization of a component (B) itself may precipitate and grow, and a filter may be obstruct | occluded. From this viewpoint, the proportion of the component (B) is 4.0% by mass or less, preferably 3.5% by mass or less, more preferably 2.5% by mass or less, and particularly preferably 2.0% by mass or less. .

  The ratio of a component (C) is the remainder which subtracted the ratio of the component (A) and the ratio of the component (B) from 100 mass%, and is 86-98.6 mass%. Content of a component (C) becomes like this. Preferably it is 90 mass% or more, More preferably, it is 90.5 mass% or more, More preferably, it is 92 mass% or more. Moreover, although content of a component (C) is 98.6 mass% or less, More preferably, it is 97.5 mass% or less.

  The mass ratio [(A) / (B)] of component (A) to component (B) is 90/10 to 50/50, preferably 90/10 to 60/40, more preferably 90/10 to 10. 70/30. When the ratio of (A) exceeds 90 or the ratio of (B) exceeds 50, the crystal cannot be sufficiently refined, and the filter may be blocked.

  Component (A) is a linear saturated fatty acid having 16 to 20 carbon atoms, and may be a single or a mixture. Specific examples of the component (A) include hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecylic acid, and eicosanoic acid, preferably hexadecanoic acid and octadecanoic acid.

  Component (B) is a C18 linear unsaturated fatty acid having 1 to 3 unsaturated bonds, all of which are trans. Component (B) is, for example, trans-9-octadecenoic acid, trans-11-octadecenoic acid, trans-9, trans-12-octadecadienoic acid, trans-10, trans-12-octadecadienoic acid, trans- 9, trans-12, trans-15-octadecatrienoic acid and the like. Preferred are trans-9-octadecenoic acid, trans-9, trans-12-octadecadienoic acid, trans-9, trans-12, trans-15-octadecatrienoic acid.

  Component (C) is a C18 linear unsaturated fatty acid having 1 to 3 unsaturated bonds and at least one unsaturated bond being cis. Component (C) is, for example, cis-9-octadecenoic acid, cis-9, cis-12-octadecadienoic acid, trans-9, cis-12-octadecadienoic acid, cis-9, trans-12-octa Decadienoic acid, cis-9, cis-12, cis-15-octadecatrienoic acid, cis-6, cis-9, cis-12-octadecatrienoic acid, trans-9, cis-12, cis-15- Octadecatrienoic acid, cis-6, trans-9, cis-12-octadecatrienoic acid, cis-6, cis-9, trans-12-octadecatrienoic acid, cis-6, trans-9, trans-12 -Octadecatrienoic acid, trans-9, cis-12, trans-15-octadecatrienoic acid, trans-9, ran-12, cis-15-octadecatrienoic acid and the like, preferably cis-9-octadecenoic acid, cis-9, cis-12-octadecadienoic acid, trans-9, cis-12-octadecadienoic acid Acid, cis-9, trans-12-octadecadienoic acid, cis-9, cis-12, cis-15-octadecatrienoic acid, trans-9, cis-12, cis-15-octadecatrienoic acid, cis -6, trans-9, cis-12-octadecatrienoic acid, cis-6, cis-9, trans-12-octadecatrienoic acid, cis-6, trans-9, trans-12-octadecatrienoic acid, trans-9, cis-12, trans-15-octadecatrienoic acid, trans-9, tr Is ns-12, cis-15- octadecatrienoic acid.

Moreover, about the following (b1) and (b2) which comprise a component (B), it is preferable that the mass ratio [(b1) / (b2)] is 70 / 30-50 / 50.
(B1) linear unsaturated fatty acid having one unsaturated bond (b2) linear unsaturated fatty acid having two or three unsaturated bonds

  When [(b1) / (b2)] is within the range of 70/30 to 50/50, the linear fatty acid crystal can be further reduced.

  The fatty acid mixture used for the lubricity improver of the present invention can be prepared by mixing the above-mentioned simple fatty acids. Alternatively, the above-mentioned simple fatty acid can be mixed with a fatty acid derived from natural fats and oils, a purified fatty acid subjected to fractionation thereof, hydrogenation, or the like.

  As fatty acids derived from natural fats and oils, palm oil fatty acid, palm oil fatty acid, palm kernel oil fatty acid, beef tallow fatty acid, hardened beef tallow fatty acid, rapeseed oil fatty acid, corn oil fatty acid, olive oil fatty acid, sesame oil fatty acid, soybean oil fatty acid, rice bran oil fatty acid, Sunflower oil fatty acid, castor oil fatty acid, linseed oil fatty acid, fish oil fatty acid, hydrogenated fish oil fatty acid, tall oil fatty acid and the like.

  The addition amount of the lubricity improver of the present invention is preferably 0.001 to 0.5 mass% with respect to the fuel oil. When this addition amount exceeds 0.5 mass%, the addition effect reaches a saturated state, and it is difficult to obtain a lubricity improvement effect commensurate with the addition amount. Further, the addition amount of the lubricity improver of the present invention is more preferably 0.1% by mass or less, and further preferably 0.02% by mass or less. Moreover, it is preferable to add 0.001 mass% or more of the addition amount of the lubricity improvement agent of this invention with respect to fuel oil, and this improves lubricity improvement effect further. From this viewpoint, the amount of addition of the lubricity improver of the present invention is more preferably 0.002% by mass or more, and further preferably 0.004% by mass or more.

  The fuel oil composition of the present invention can be prepared by simply adding the fatty acid mixture used in the present invention to the above diesel fuel, but the fatty acid mixture is concentrated in an organic solvent compatible with diesel fuel. Preparation is facilitated by adding it in the form of a solution. Examples of such an organic solvent include petroleum fractions such as naphtha, kerosene, and light oil, aromatic hydrocarbons, and paraffinic hydrocarbons. When diluted with an organic solvent and used, those containing 30 to 90% by mass of the fatty acid mixture are preferred, and those containing 50 to 80% by mass are more preferred.

Next, the present invention will be described in more detail with reference to examples and comparative examples.
In Table 1, the result of having analyzed the fatty acid composition of the raw material fatty acid (FA-1 to FA-8) used for the present Example and the comparative example on condition of the following using gas chromatography is shown.

Gas Chromatographic Analysis Conditions Device: GC-2014 ATF / SPL, manufactured by Shimadzu Corporation
Column: SP-2560 100m made by SUPELCO
Column temperature: 175 ° C
Detector: FID, temperature = 250 ° C.
Injection part: split ratio (100: 1), temperature = 210 ° C.
Sample injection volume: 1 μL
Carrier gas: Helium, 1.0 mL / min Sample pretreatment

  Each raw fatty acid was methyl esterified according to the standard fat analysis method 2.4.1.2 methyl esterification method (boron trifluoride methanol method).

  By appropriately mixing FA-1 to FA-8, fatty acid mixtures having respective compositions of Examples 1 to 6 and Comparative Examples 1 to 5 shown in Tables 2 and 3 were obtained. In Comparative Example 6, rapeseed oil fatty acid was used.

In the fatty acid column, the number on the right side of “C” indicates the number of carbon atoms, and the number on the right side of “:” indicates the number of unsaturated bonds.
note)
FA-1: hexadecanoic acid FA-2: octadecanoic acid FA-3: trans-9-octadecenoic acid FA-4: cis-9-octadecenoic acid (EXTRA OLEIC 99 manufactured by NOF CORPORATION)
FA-5: cis-9, cis-12-octadecadienoic acid (EXTRA LINOLEIC 99 manufactured by NOF Corporation)
FA-7: cis-9, cis-12, cis-15-octadecatrienoic acid (EXTRA α-LINOLENIC 90 manufactured by NOF CORPORATION)
FA-6: FA-5 was obtained by the following trans isomerization reaction.
FA-8: Obtained by subjecting FA-7 to the following trans isomerization reaction.

<Trans isomerization reaction (Holde method)>
(Synthesis of FA-6)
The flask was charged with 50 g of FA-5 (cis-9, cis-12-octadecadienoic acid) and 100 g of 30% nitric acid aqueous solution and stirred at 35 ° C. Thereto, 20 g of powdered potassium nitrite was added little by little over 15 minutes to cause a trans reaction. Stirring was continued for 30 minutes after the addition of potassium nitrite. Then, it left still and the crude cis-9, cis-12-octadecadienoic acid transduction product of the upper layer was obtained. Next, the crude cis-9, cis-12-octadecadienoic acid transducted product was washed with water and dried to obtain about 40 g of linoleic acid transducted product (FA-6).

(Synthesis of FA-8)
A trans isomerization reaction was similarly carried out using FA-7 (cis-9, cis-12, cis-15-octadecatrienoic acid) instead of FA-5 used in the synthesis of FA-6, and cis About 40 g of -9, cis-12, cis-15-octadecatrienoic acid transduct (FA-8) was obtained.

<Observation of crystals precipitated under slow cooling conditions>
In Tables 2 and 3, Examples 1-6, each fatty acid mixture of Comparative Examples 1-5 and rapeseed oil fatty acid of Comparative Example 6 were observed for crystals precipitated when stored under slow cooling conditions, I took a picture. Regarding the crystal in the photograph, when the straight line was drawn from one end of the crystal to the other end, the place where the distance was the largest was taken as the maximum grain size. When the crystal reached the outside of the frame of the photograph, the distance from the end of the crystal to the frame of the photograph was measured, and the place where this distance was the largest was taken as the maximum grain size.

  At the time of slow cooling, it is allowed to stand at 20 ° C. for 1 hour, then the temperature is lowered from 20 ° C. to 10 ° C. at a rate of −10 ° C./hour, then it is lowered to 0 ° C. at a rate of −1 ° C./hour, Observations were made.

<Evaluation of lubricity improvement effect>
Lubricating improvers of Examples and Comparative Examples described in Tables 2 and 3 were each added in an amount of 0.01% by mass (100 ppm) to the base material of JIS No. 2 light oil, and lubricated using a lubricity wear tester. Sexuality was evaluated. As the lubricity wear tester, a vibration friction wear tester (HFRR tester) was used, and as a test body, a 10 mm, 3.0 mm thick disk and a φ6.0 mm bearing ball manufactured by PCS Instruments were used. Lubricity was evaluated under the following conditions.

Test machine: HFR2 manufactured by PCS Instruments
Specimen material: Steel and AISIE-52100 for both disc and ball
Temperature (° C): 60 ± 2
Amplitude (mm): 1.0 ± 0.03
Sample volume (ml): 2.0 ± 0.20
Operating time (minutes): 75 ± 0.1
Load (g): 200 ± 1
Frequency (Hz): 50 ± 1
Sample bath surface area (cm2): 6 ± 1
The average diameter of the wear marks was determined by measuring the vibration direction and perpendicular diameter of the wear marks of the upper ball by microscopic observation.

  The results of the observation of crystals precipitated under slow cooling conditions and the evaluation of the lubricity improvement effect for Examples 1 to 6 and Comparative Examples 1 to 6 described in Tables 2 and 3 by the above method, Table 4 shows.

  Moreover, about Examples 1-6 and Comparative Examples 1-6, the observation result of a crystal is shown in FIGS. 1-12, respectively. However, FIGS. 1 to 6 correspond to Examples 1 to 6, and FIGS. 7 to 12 correspond to Comparative Examples 1 to 6. Moreover, the length of the scale shown in the drawing is 100 μm, and the HFRR wear scar diameter of the unadded gas oil is 585 μm.

<Evaluation of oil permeability>
About the fatty acid mixture of Example 1 described in Table 2, Table 3, and the rapeseed oil fatty acid of the comparative example 6, oil permeability was evaluated in the following procedure.

  45 ml of each fatty acid mixture was placed in a test tube and cooled under the following slow cooling conditions. When the temperature of the sample reaches 3 ° C., the time taken for 20 ml of the sample to pass through a circular filter with a wire mesh (diameter: 12.5 mm) under a reduced pressure of 660 Torr is sucked through a filter with a mesh mesh of 100 μm. It was measured. Thereafter, every time the temperature decreased by 1 ° C., the filter passage time of the sample was measured in the same manner, and the test was terminated when the passage time exceeded 300 seconds.

  During slow cooling, leave at 20 ° C. for 1 hour, then reduce the temperature from 20 ° C. to 10 ° C. at a rate of −10 ° C./hour, then reduce the temperature to 0 ° C. at a rate of −1 ° C./hour, An oiliness test was performed. The results are shown in Table 5.

  From the results of Tables 4 and 5, it can be seen that the lubricity improver for diesel fuel oil of the present invention is capable of refining crystals precipitated under slow cooling conditions. It can also be seen that the filter is less likely to be clogged even when crystals are precipitated. And it turns out that the fuel oil composition containing the lubricity improver for diesel fuel oil of this invention is excellent in lubricity even if it is a low sulfur content.

Claims (3)

1 to 10% by mass of the following component (A), 0.4 to 4.0% by mass of component (B) and 86 to 98.6% by mass of component (C), and the component (A) A lubricity improver for diesel fuel oil, wherein the mass ratio [(A) / (B)] to the component (B) is 90/10 to 50/50.

(A) C16-C20 linear saturated fatty acid (B) C1-C18 linear unsaturated fatty acid (C) having 1 to 3 unsaturated bonds, all of the unsaturated bonds being trans. ) A straight-chain unsaturated fatty acid having 18 carbon atoms having 1 to 3 unsaturated bonds and at least one unsaturated bond being cis-type
The mass ratio [(b1) / (b2)] of the following component (b1) to the component (b2) in the component (B) is 70/30 to 50/50. Lubricant improver for diesel fuel oil.

(B1) linear unsaturated fatty acid having one unsaturated bond (b2) linear unsaturated fatty acid having two or three unsaturated bonds
  A fuel oil composition comprising 0.001 to 0.5 mass% of the lubricity improver for diesel fuel oil according to claim 1 or 2.