JP6091457B2 - Dewaxed light oil base material and light oil composition for cold regions containing the base material - Google Patents

Description

  The present invention relates to a dewaxed light oil base material having predetermined low temperature performance and excellent oxidation stability. Furthermore, the present invention relates to a light oil composition for cold districts, which is obtained by blending the dewaxed light oil base and kerosene oil base and has excellent oxidation stability.

  If there is a lot of heavy wax in light oil fuel for cold regions used in diesel engines, the wax may block the fuel filter when starting and running the engine in cold regions. In order to ensure low-temperature performance and stable running, a kerosene base material with low paraffin content has been blended in the past, but in order to deal with lubrication problems and increased demand for kerosene, especially in winter, as much as possible It is important to reduce the amount of light oil. As a base material with good low-temperature performance that replaces the kerosene base material, there is a dewaxed light oil base material that uses a straight-run light oil base material as a raw material and selectively decomposes heavy paraffins in a dewaxing device. This can be blended in light oil for cold regions as a kerosene base material. However, the deterioration of oxidation stability due to the olefin produced in the decomposition process is a problem.

  On the other hand, diesel engines are becoming more demanding to improve the oxidation stability of diesel oil than ever before due to the increased pressure of fuel injection by the common rail due to stricter exhaust gas regulations, increasing the thermal load on diesel oil. By these, in order to improve the oxidation stability of light oil, it is proposed to maintain the oxidation stability without adding antioxidant additives by making the content of aromatic component and naphthene component of light oil into a specific range (See Patent Document 1). Although the method for preparing light oil having such a composition is effective, the invention described in Patent Document 1 focuses on fluorenes and naphthenobenzenes as substances having poor oxidation stability, and their content and oxidation stability are high. It balances the naphthalene content, which is a good substance. However, there is no mention of a method for preparing a dewaxed gas oil base material having a high concentration of olefin and a gas oil composition containing the same.

JP 2006-137922 A

  An object of the present invention is to provide a dewaxed light oil base material that satisfies low temperature performance and has excellent oxidation stability by controlling the low temperature performance within a predetermined range and making the olefin content within a specific range. is there. Furthermore, by mixing a predetermined amount of dewaxed gas oil base material and straight lamp light oil base material with excellent oxidation stability, the specified low temperature performance is satisfied, sludge and deposits are not easily generated, and oxidation stability is ensured. Is to provide a low temperature gas oil composition.

  As a result of diligent research, the inventor selectively decomposes heavy paraffins with a dewaxing device to control low temperature performance within a predetermined range and limit the amount of olefin within a specific ratio. It has been found that a dewaxed light oil base material excellent in oxidation stability can be obtained. Furthermore, by ensuring good oxidative stability of the dewaxed base material, it is possible to provide a light oil composition for cold regions that can reduce the blending ratio of kerosene base material with excellent oxidative stability and improve oxidative stability. As a result, the present invention has been completed.

That is, the present invention is obtained by a production method in which a dewaxing step is combined with a later stage of the hydrodesulfurization step, and has a kinematic viscosity at 30 ° C. of 4.10 to 5.00 mm ² / s, a sulfur content of 10 mass ppm or less, an olefin content of 0.5 to 2.4% by volume, bromine number 0.5 ~3.0gBr ₂ / 100g, annealing CP is -24 ℃ ~-12 ℃, the normal paraffins of the number 27 or more carbon atoms 0. The present invention relates to a dewaxed light oil base material having a 0050-0.0120% by mass and a petrooxy induction period of 53 minutes or more.

  Further, the present invention comprises the above-mentioned dewaxed light oil base material, having a sulfur content of 10 ppm by mass or less, a cetane index of 45.0 or more, an olefin content of 0.1 to 1.0% by volume, and slowly cooled CP. The present invention relates to a light oil composition for cold regions, characterized by having a normal paraffin amount of 7.0 to 0.0 ° C. or less, a carbon number of 27 or more, 0.03 to 0.06 mass%, and a petrooxy induction period of 70 minutes or more.

  Further, the present invention provides the dewaxed light oil base based on 1 to 55% by volume based on the total amount of the light oil composition, the kerosene base based on 0 to 20% by volume based on the total amount of the light oil composition, and the light oil base based on the total amount of the light oil composition. The gas oil composition for cold regions according to the above, characterized by containing 25 to 99% by volume on a standard basis.

  The dewaxed light oil base material of the present invention has a predetermined low-temperature performance and excellent oxidation stability, so even if the blending ratio of kerosene base material with high oxidation stability, which is in high demand in winter, is reduced. In addition, a light oil composition for cold districts that ensures oxidation stability can be obtained.

The present invention is described in detail below.
The dewaxed light oil base material of the present invention is obtained by a production method in which a dewaxing step is combined with a later stage of the hydrodesulfurization step, and has a kinematic viscosity at 30 ° C. of 4.10 to 5.00 mm ² / s, sulfur content of less than 10 mass ppm, an olefin content of 0.5 to 2.4% by volume, bromine number 0.5~3.0gBr ₂ / 100g, annealing CP is -24 ℃ ~-12 ℃, carbons 27 The above normal paraffin amount is 0.0050 to 0.0120 mass%, and the petrooxy induction period is 53 minutes or more.

  The oxidation stability according to the dewaxed light oil base material of the present invention can be expressed by a petrooxy induction period. If the induction period is short, sludge and deposits are likely to be generated. As a result, the fuel injection nozzle of the engine is likely to be clogged, resulting in a reduction in output and an adverse effect of corroding a metal material such as a fuel tank. From the viewpoint of improving the oxidation stability of the light oil composition for cold regions, the base material needs to have an induction period of 53 minutes or longer, preferably 55 minutes or longer, more preferably 56 minutes or longer.

  Here, the method for measuring the petrooxy induction period referred to in the present invention will be described. The metal container containing the test fuel is sealed, and oxygen is sealed therein to a predetermined pressure. Thereafter, the sealed container is heated to a predetermined temperature, the predetermined pressure is maintained from the maximum pressure point to the point where the pressure drops by 10%, and the time from the start of heating to the 10% pressure drop point is measured, The time is defined as the petrooxy induction period.

(Measurement condition)
Apparatus: PetroXY apparatus (manufactured by Petrotest)
Oxygen filling pressure: 700 kPa (gauge pressure)
Test temperature: 140 ° C
Test fuel volume: 5mL

The kinematic viscosity at 30 ° C. of the dewaxed light oil base material of the present invention is 4.10 to 5.00 mm ² / s, preferably 4.15 to 4.80 mm ² / s, more preferably 4 from the viewpoint of fuel spraying. .20 to 4.60 mm ² / s. Here, the kinematic viscosity at 30 ° C. means a value measured by JIS K 2283 “Crude oil and petroleum products—Kinematic viscosity test method and viscosity index calculation method”.

The sulfur content of the dewaxed light oil base material of the present invention is 10 mass ppm or less, preferably 5 mass ppm or less, more preferably 1 mass ppm or less from the viewpoint of reducing particulate matter (PM) in the exhaust gas. .
In addition, in this invention, a sulfur content means the value measured by JISK2541 "Crude oil and petroleum products-sulfur content test method".

The olefin content of the dewaxed gas oil base of the present invention is 0.5 to 2.4% by volume, preferably 0.5 to 2.0% by volume, more preferably 0.5 from the viewpoint of oxidation stability. ~ 1.8% by volume.
In the present invention, the olefin content means a value measured by JPI-5S-49-97 “Petroleum products—Hydrocarbon type test method—High performance liquid chromatograph method”.

Bromine number of dewaxed gas oil base of the present invention, from the viewpoint of oxidation stability, a 0.5~3.0gBr ₂ / 100g, preferably 0.5~2.8gBr ₂ / 100g, more preferably 0 .5~2.6gBr is a ₂ / 100g.
Here, the bromine value means a value measured by JIS K 2605 “Petroleum products—Bromination test method”.

Slow cooling CP (slow cooling cloud point) of the dewaxed light oil base material of the present invention is −12 ° C. or lower, preferably −13 ° C. or lower, more preferably −14 ° C. or lower from the viewpoint of low temperature performance, and oxidation stability. In view of the above, it is −24 ° C. or higher, preferably −23 ° C. or higher, more preferably −22 ° C. or higher.
In the present invention, the slow cooling CP was obtained by slowly cooling at a rate of 0.5 ° C./min until detecting the cloud point from a temperature 10 ° C. or more higher than the cloud point, and detecting in units of 0.1 ° C. Cloud point (° C). The method of detecting the slow cooling cloud point is that the sample is irradiated with light, and the reflected light on the aluminum surface at the bottom of the sample container is reduced by a predetermined amount (reflected light of light irradiated from a height of 3 mm from the bottom of the sample liquid with a thickness of 15 mm). Is the slow cooling cloud point.

The amount of normal paraffin having 27 or more carbon atoms of the dewaxed light oil base of the present invention is 0.0120% by mass or less, preferably 0.0110% by mass or less, more preferably 0.0100% by mass or less from the viewpoint of low temperature performance. In view of oxidation stability, it is 0.0050% by mass or more, preferably 0.0055% by mass or more, more preferably 0.0060% by mass or more.
In the present invention, the amount of normal paraffin having 27 or more carbon atoms refers to a non-polar column (stainless capillary column ULTRA ALLOY-1 inner diameter 0.25 mm, length 30 m, film thickness 0.25 μm) with a flame ionization detector (FID). And a predetermined temperature program (column thermostat temperature: 140 ° C. → (8 ° C./min)→350° C. → 350 ° C. hold (1 minute), detector temperature: 360 ° C., injection part temperature: 360 ° C.) It is a normal paraffin content of 27 or more carbon atoms in the sample quantified from the activated gas chromatograph. For example, the amount of paraffin of a certain substrate can be obtained as follows. First, the amount of normal paraffin in a sample is separated and measured as a peak of each carbon number by gas chromatography. The area of the obtained normal paraffin of each carbon number is divided by the total area of all components including components other than the normal paraffin, and the content of the normal paraffin of each carbon number is determined by mass%. The gas chromatograph is an analysis technique for separating and quantitatively analyzing each composition using physical properties (boiling point, polarity, etc.) of each composition in a sample.

  By mixing a predetermined amount of the dewaxed light oil base material of the present invention with excellent oxidation stability and a kerosene base material and / or a light oil base material, it has excellent low-temperature performance and hardly generates sludge and deposits. A light oil composition for cold districts with secured properties can be obtained.

Examples of the kerosene base material used in the light oil composition for cold districts of the present invention include petroleum-based kerosene base materials.
The petroleum-based kerosene base is produced by a normal production method, for example, straight-run kerosene obtained from a crude oil atmospheric distillation apparatus; straight-run heavy oil or residual oil obtained from an atmospheric distillation apparatus Reduced-pressure kerosene obtained by applying a vacuum distillation apparatus; hydrorefined kerosene obtained by hydrorefining straight-run kerosene or reduced-pressure kerosene; straight-run kerosene or depressurized kerosene in one stage or more under severer conditions than ordinary hydrorefining Hydrodesulfurized kerosene obtained by hydrodesulfurization in stages; hydrocracked kerosene obtained by hydrocracking the above various kerosene base materials, and the like.

Moreover, as a light oil base material used for the light oil composition for cold districts of this invention, petroleum-type light oil base materials other than the above-mentioned dewaxing light oil base material are mentioned.
Such petroleum-based light oil base material is produced by a normal production method, for example, straight-run gas oil obtained from a crude oil atmospheric distillation apparatus; straight-run heavy oil or residual oil obtained from an atmospheric distillation apparatus; A vacuum gas oil obtained by subjecting oil to a vacuum distillation apparatus; a hydrorefined gas oil obtained by hydrorefining straight-run gas oil or vacuum gas oil; one-stage or a straight-run gas oil or vacuum gas oil under conditions more severe than ordinary hydrorefining Hydrodesulfurized diesel oil obtained by hydrodesulfurization in multiple stages; hydrocracked diesel oil obtained by hydrocracking the above various diesel oil bases, and the like.

  The light oil composition for cold districts of the present invention has the above dewaxed light oil base in an amount of 1 to 55% by volume based on the total amount of light oil composition, the kerosene base in an amount of 0 to 20% by volume based on the total amount of light oil composition, and a light oil base. In an amount of 25 to 99% by volume based on the total amount of the light oil composition.

Kerosene bases with good oxidation stability are hydrodesulfurized kerosene bases obtained by hydrodesulfurizing petroleum-based kerosene raw materials, or hydrogenation obtained by hydrocracking petroleum-based kerosene raw materials at high temperature and high pressure. Since it is a cracked kerosene base material, the blending ratio of the kerosene base material in the light oil composition for cold districts of the present invention is preferably 20% by volume or less, more preferably 15% by volume or less, due to high production costs and jet fuel use. 0% by volume is most preferable.
Further, the blending ratio of the dewaxed light oil base material needs to be 1% by volume or more, preferably 5% by volume or more, more preferably 10% by volume or more, and 55% by volume or less, preferably 50% by volume. It is not more than volume%, more preferably not more than 45 volume%. By setting the blending ratio of the dewaxed light oil base material of the present invention within the above range, an oxidation stability effect having an induction period of 70 minutes or more can be obtained.
Moreover, the mixture ratio of a light oil base material is 25-99 volume%, Preferably it is 30-90 volume%, More preferably, it is 35-70 volume%.

  In the present invention, the dewaxed light oil base material, kerosene base material, and light oil base material are blended in a predetermined ratio, so that the sulfur content is 10 mass ppm or less, the cetane finger is 45.0 or more, and the olefin content is 0.00. 1 to 1.0% by volume, slow cooling CP is −7.0 ° C. or less, the amount of normal paraffin having 27 or more carbon atoms is 0.03 to 0.06% by mass, and the period of induction of petrooxy is 70 minutes or more. A ground oil composition can be obtained.

  The sulfur content of the light oil composition for cold districts of the present invention is 10 mass ppm or less, preferably 5 mass ppm or less.

  The cetane index of the light oil composition for cold districts of the present invention is 45.0 or more, preferably 48.0 or more, more preferably 50.0 or more, from the viewpoint of engine startability. The cetane index here means a value measured according to JIS K 2280 “Petroleum products—fuel oil—octane number and cetane number test method and cetane index calculation method”.

  The olefin content of the light oil composition for cold districts of the present invention is 0.1 to 1.0% by volume, preferably 0.1 to 0.8% by volume, from the viewpoint of oxidation stability.

  The slow cooling CP of the light oil composition for cold districts of the present invention is −7.0 ° C. or less, preferably −8.0 ° C. or less from the viewpoint of low temperature performance.

  The amount of normal paraffin having 27 or more carbon atoms in the light oil composition for cold regions of the present invention is 0.060% by mass or less, preferably 0.055% by mass or less, more preferably 0.050% by mass or less from the viewpoint of low temperature performance. It is.

  From the viewpoint of improving oxidative stability, the induction period of the petrooxy induction period of the light oil composition for cold districts of the present invention requires 70 minutes or more, more preferably 71 minutes or more, and still more preferably 72 minutes or more.

  The light oil composition for cold regions of the present invention can contain a low-temperature fluidity improver as necessary. The type of the low-temperature fluidity improver is not particularly limited. For example, ethylene-unsaturated ester copolymer represented by ethylene-vinyl acetate copolymer, alkenyl succinic acid amide, dibehenic acid ester of polyethylene glycol Linear compounds such as phthalic acid, ethylenediaminetetraacetic acid, nitriloacetic acid and the like, or polar nitrogen compounds consisting of reaction products of hydrocarbyl-substituted amines, alkyl fumarate or alkyl itaconate-unsaturated esters One kind or two or more kinds of low-temperature fluidity improvers such as a comb polymer made of a copolymer can be used. Among these, from the viewpoint of versatility, an ethylene-vinyl acetate copolymer additive can be preferably used. When the low temperature fluidity improver is added, the addition amount is preferably 50 to 500 mg / L, and particularly preferably 50 to 300 mg / L. In addition, since a commercial product referred to as a low temperature fluidity improver may be diluted with an appropriate solvent for an active ingredient that contributes to low temperature fluidity, such a commercial product may be used as the fuel oil composition of the present invention. In the case of adding to the above, the above-mentioned addition amount means the addition amount as an active ingredient.

  The light oil composition for cold districts of the present invention can contain a lubricity improver from the viewpoint of ensuring lubricity in the injection pump. The type of the lubricity improver is not particularly limited, but one or more of the lubricity improvers such as ester, carboxylic acid, alcohol, phenol, and amine can be used. . Among these, from the viewpoint of versatility, it is preferable to use an ester-based or carboxylic acid-based lubricity improver. Furthermore, an ester-based lubricity improver is preferable from the viewpoint that the effect of addition with respect to the concentration of addition hardly reaches saturation and the WS1.4 value of HFRR can be further reduced, and the initial response of the effect of addition with respect to the concentration of addition is high. Carboxylic acid type lubricity improvers are preferred from the viewpoint that the amount of addition of can be reduced.

  Examples of the ester-based lubricity improver include glycerin carboxylic acid ester and the like. The carboxylic acid constituting the carboxylic acid ester may be one type or two or more types, and specific examples thereof include linoleic acid, oleic acid, salicylic acid, palmitic acid, myristic acid, hexadecenoic acid and the like. . Examples of the carboxylic acid-based lubricity improver include linoleic acid, oleic acid, salicylic acid, palmitic acid, myristic acid, hexadecenoic acid, and the like, and one or more of these can be used arbitrarily. is there. In addition, when a low temperature fluidity improver has a lubricity improvement effect, the low temperature fluidity improver and the lubricity improver can be combined to improve lubricity.

  When the lubricity improver is added, the addition amount is preferably 25 to 500 mg / L, more preferably 25 to 300 mg / L, and still more preferably 25 to 200 mg / L. Thus, the WS1.4 value of HFRR is preferably 500 μm or less, more preferably 460 μm or less, still more preferably 420 μm or less, and most preferably 400 μm or less. In addition, as for the commercial item called a lubricity improver, the active ingredient which contributes to lubricity is usually obtained in the state diluted with a suitable solvent. In the case where such a commercial product is added to the fuel oil composition of the present invention, the above addition amount means the addition amount as an active ingredient.

  The process for obtaining the dewaxed light oil base material of the present invention does not particularly limit the process, operating conditions, etc., and any known apparatus can be employed. A process of selectively hydrocracking normal paraffin or the like in a raw material oil using a catalyst such as Pt-H-mordenite or synthetic zeolite to obtain a light oil base material having excellent low-temperature fluidity, for example, petroleum In addition to the BP catalytic dewaxing method and the MDDW method described in the “New Oil Refining Process” of the academic society, the FIZ method and the like are known. As another dewaxing step, a method such as solvent dewaxing can also be used.

As a raw material of the dewaxed light oil base material, for example, a mixed oil of cracked light oil and straight-run gas oil, a desulfurization catalyst containing Co—Mo or Ni—Mo, a reaction temperature of 310 ° C. to 395 ° C., and LHSV of 0.5 to 2 hr ⁻¹ And desulfurized gas oil produced by performing hydrodesulfurization reaction under conditions of a hydrogen partial pressure of 3 to 7 MPa and a hydrogen / oil ratio of 168 to 320 Nm ³ / kl.

  The dewaxed light oil base material of the present invention can be produced by an ordinary dewaxing apparatus, and examples of the dewaxing reaction mode include a fixed bed, a moving bed, and a fluidized bed. In the presence of hydrogen, known conditions can be employed for the reaction temperature, liquid space velocity, pressure, hydrogen / oil ratio, and the like.

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

(Light oil base material of Examples and Comparative Examples)
Table 1 shows properties of Examples 1 to 3 and Comparative Example 1 which are various dewaxed light oil base materials obtained from the dewaxing apparatus.

(Keose oil base, light oil base and light oil composition)
Table 2 shows the properties of various hydrodesulfurized light diesel oils and various hydrodesulfurized kerosene. Table 3 shows the properties of light oil compositions obtained by mixing various hydrodesulfurized light diesel oils shown in Table 2 and various hydrodesulfurized kerosene and various dewaxed light oil base materials shown in Table 1 at a predetermined blending ratio. Shown in

From this result, it is possible to produce a dewaxed light oil base material that is less prone to generate sludge and deposits and ensures good oxidation stability. Also, by ensuring this good oxidation stability, a kerosene base with good oxidation stability is obtained. It has been found that even if the mixing ratio of the material is reduced, the oxidative stability of the light oil composition for cold regions can be improved.

Claims (3)

It is obtained by a production method in which a dewaxing step is combined with the latter stage of the hydrodesulfurization step, the kinematic viscosity at 30 ° C. is 4.10 to 5.00 mm ² / s, the sulfur content is 10 mass ppm or less, and the olefin content is 0.5. 2.4% by volume, bromine number 0.5~3.0gBr ₂ / 100g, annealing CP is -24 ℃ ~-12 ℃, normal paraffins amount having more than 27 carbon atoms is from 0.0050 to 0.0120 mass %, A dewaxed light oil base material having a petrooxy induction period of 53 minutes or more.   The dewaxed gas oil base material according to claim 1 is contained, the sulfur content is 10 mass ppm or less, the cetane index is 45.0 or more, the olefin content is 0.1 to 1.0% by volume, and the slow cooling CP is -7. A light oil composition for cold regions, characterized by having a normal paraffin amount of 0.03 or less, carbon number of 27 or more, 0.03 to 0.06% by mass and a petrooxy induction period of 70 minutes or more.   The dewaxed light oil base according to claim 1 is 1 to 55% by volume based on the total amount of light oil composition, the kerosene base is based on 0 to 20% by volume based on the total amount of light oil composition, and the light oil base is based on the total amount of light oil composition. The gas oil composition for cold districts according to claim 2, containing 25 to 99% by volume.