JP2007269926A - A-heavy oil composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an A-heavy oil composition being high in combustibility, wearing for use in a high performance engine lately developed, not causing plugging of a filter with a wax in winter, nor causing plugging of a filter with sludge at ordinary temperature. <P>SOLUTION: The A-heavy oil composition can be obtained by using a light oil fraction produced by an FT synthesis, a light oil obtained by hydrocracking an FT wax produced in the FT synthesis, a light oil made by a fluidized catalytic cracking and an extract. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an A heavy oil composition. More specifically, the present invention relates to an A heavy oil composition that has sufficient performance for recent high-performance engines, has excellent low-temperature fluidity, and is excellent in filter oil passing performance at room temperature.

A heavy oil is widely used as fuel for external combustion equipment such as boilers, diesel engine equipment fuel other than for land transportation such as small fishing boats and construction machinery, and gas turbine equipment fuel.
Various combustion equipment using heavy fuel oil A is provided with a filter having an opening of 5 to 250 μm in the fuel system for the purpose of removing foreign substances in the fuel oil. However, when such a combustion device is used in winter, the filter is likely to be clogged with wax precipitated from A heavy oil.
On the other hand, the heavy carbon oil A contains a residual carbon content-imparting base so that the 10% residual carbon content is 0.2% by mass or more in the tax law. However, there has often been a problem that the fuel filter is clogged by sludge caused by the residual carbon-added base material, making it impossible to supply the fuel. It has become. For this reason, there is an increasing demand for heavy fuel oil A that does not block the fuel filter with sludge and has excellent filter oil permeability at room temperature.

Therefore, in order to solve such problems, studies are being made to improve low-temperature performance such as low-temperature fluidity of A heavy oil, such as blending heavy oil, increasing residual oil, adding low-temperature fluidity improvers, etc. Have been proposed (see, for example, Patent Documents 1 and 2 and Non-Patent Document 1).
However, the A heavy oil obtained by the above-described methods has room for improvement in the following points, and none of them is still sufficient to be put to practical use as A heavy oil. In other words, increased blending of heavy oil leads to a deterioration in wax precipitation point (cloud point), and an increase in residual oil can cause an increase in the amount of dust in the combustion gas, as well as a deterioration in solubility with other base materials. However, there is concern about filter oil permeability associated with sludge generation at room temperature. In addition, the performance of the low temperature fluidity improver depends largely on the compatibility with the base material used, and it is difficult to obtain sufficient low temperature performance as A heavy oil simply by adding.
Japanese Patent Laid-Open No. 9-333583 JP-A-7-97581 Koji Nomura, “Science of Marine Fuel”, Naruyamado, 1994, p. 164-166

  Fuel oil A is used as boiler fuel and diesel engine fuel, but with the recent increase in output and fuel efficiency of engines used in fuel oil A, demand for higher performance has been increasing year by year. It is growing. When heavy fuel oil A is used as the fuel for these high-performance engines, there may be a problem related to combustibility such as deterioration of ignitability and increased occurrence of soot and increased frequency of cleaning in the burner and the furnace. On the other hand, since A heavy oil contains more heavy components than gasoline and kerosene, wax precipitation at low temperatures may be a problem. Wax precipitation at low temperatures may clog a filter for preventing contaminants in the fuel system, and in the worst case, fuel supply may not be possible. As a method for suppressing wax precipitation at low temperatures, a method of adding a fluidity improver is common, but under the actual severe winter conditions, a sufficient effect cannot be exhibited. Conventionally, a test based on a clogging point has been used to judge the filter clogging property at low temperatures. In this test method, the low temperature fluidity is improved by adding a fluidity improver, but in this test method, the cooling rate of the sample oil is rapidly cooled (about 40 ° C./hour). Is very different. It is known that the slower the cooling rate, the larger the precipitated wax and the clogging of the filter, and the evaluation based on the clogging point is insufficient. In general, A heavy oil excellent in low-temperature performance often has poor flammability, and A heavy oil satisfying all these performances is desired. Further, the sludge originating from the residual carbon content-imparting base often causes a problem that the filter for preventing contaminants in the fuel system is blocked even at room temperature, making it impossible to supply fuel. As a method for solving this, it is conceivable to increase the aromatic content of the A heavy oil product in order to dissolve sludge caused by the residual carbon imparting base material. However, if the aromatic content of heavy oil A is increased, the combustibility tends to deteriorate. Thus, A heavy oil that satisfies all of the low temperature performance, the combustibility, and the normal temperature oil passing performance has not been obtained. An object of the present invention is to provide an A heavy oil composition that can withstand use in recent high-performance engines, does not cause filter clogging with wax in winter, and does not cause filter clogging with sludge at room temperature. There is.

As a result of intensive research in order to solve the above problems, the present inventors have used a specific base material in combination so that it is highly combustible and does not cause clogging of the filter due to wax in winter, and at room temperature. And found that the filter is not clogged with sludge. The present invention was completed.
That is, the A heavy oil composition of the present invention is characterized by using a light oil fraction produced by FT synthesis, an FT wax hydrocracked light oil produced by FT synthesis, fluid catalytic cracking light oil and an extract.

  According to the present invention, it is highly combustible, can withstand use in recent high-performance engines, does not cause clogging of the filter due to wax in winter, and does not cause clogging of the filter due to sludge at room temperature. A heavy oil composition is obtained.

The present invention is described in further detail below.
The A heavy oil composition of the present invention comprises at least a light oil fraction produced by FT synthesis, a light oil obtained by hydrocracking FT wax produced by FT synthesis, a fluid catalytic cracking light oil, and an extract.

  The light oil fraction produced by FT synthesis as used in the present invention is a Fischer-Tropsch (FT) reaction applied to a mixed gas (also referred to as synthesis gas) mainly composed of hydrogen and carbon monoxide. It shows the liquid fraction corresponding to light oil obtained.

In the present invention, the mixed gas used as the raw material for FT synthesis is a shift reaction in which a substance containing carbon is oxidized using oxygen and / or water and / or carbon dioxide as an oxidizing agent, and water is used as necessary. To obtain a predetermined hydrogen and carbon monoxide concentration.
Substances containing carbon include natural gas, petroleum liquefied gas, methane gas, etc., gas components consisting of hydrocarbons that are gaseous at room temperature, petroleum asphalt, biomass, coal, waste such as building materials and garbage, sludge, In addition, mixed gas obtained by exposing heavy crude oil, unconventional petroleum resources, etc. that are difficult to process by ordinary methods to high temperatures is common, but mixed gas mainly composed of hydrogen and carbon monoxide As long as is obtained, the raw material is not limited.

  A metal catalyst is used for the FT reaction in the present invention. Preferably a Group 8 metal of the periodic table, for example, cobalt, ruthenium, rhodium, palladium, nickel, iron, etc., more preferably a Group 8 Group 4 metal is used as the active catalyst component. Moreover, the metal group which mixed these metals in an appropriate amount can also be used. These active metals are generally used in the form of a catalyst obtained by being supported on a support such as silica, alumina, titania or silica alumina. Further, by using these catalysts in combination with a second metal in addition to the above active metal, the catalyst performance can be improved. Examples of the second metal include zirconium, hafnium, titanium, and the like in addition to alkali metals and alkaline earth metals such as sodium, lithium, and magnesium, and a chain that serves as an index for improving the conversion rate of carbon monoxide and generating wax. It is used appropriately according to the purpose, such as an increase in growth probability (α).

The light oil obtained by hydrocracking the FT wax produced by FT synthesis in the present invention refers to a hydrocarbon mixture obtained by hydrocracking the paraffin wax produced by the FT reaction.
In the hydrocracking referred to in the present invention, a catalyst having a solid acid property on which a hydrogenation active metal is supported is generally used as a catalyst. is not.

  Supports having a solid acid property include amorphous and crystalline zeolites. Specific examples include amorphous silica-alumina, silica-magnesia, silica-zirconia, silica-titania and zeolite faujasite type, beta type, MFI type, and mordenite type. Preferred are faujasite type, beta type, MFI type, and mordenite type zeolite, and more preferred are Y type and beta type. The Y type is preferably ultra-stabilized.

As the active metal, the following two types (active metal A type and active metal B type) are preferably used.
The active metal A type is at least one metal selected from Group 6A and Group 8 metals in the periodic table. Preferably, it is at least one metal selected from Ni, Co, Mo, Pt, Pd and W. When using a noble metal catalyst composed of these metals, it can be used after pre-reduction treatment in a hydrogen stream. In general, when a gas containing hydrogen is circulated and heat of 200 ° C. or higher is applied according to a predetermined procedure, the active metal on the catalyst is reduced, and hydrogenation activity is exhibited.
The active metal B type may be a combination of these metals, and examples thereof include Pt—Pd, Co—Mo, Ni—Mo, Ni—W, and Ni—Co—Mo. Moreover, when using the catalyst which consists of these metals, it is preferable to use after pre-sulfiding.

  As the metal source, a general inorganic salt or a complex salt compound can be used, and as a supporting method, any method of a supporting method used in an ordinary hydrogenation catalyst such as an impregnation method or an ion exchange method can be used. When a plurality of metals are supported, they may be supported simultaneously using a mixed solution, or may be sequentially supported using a single solution. The metal solution may be an aqueous solution or an organic solvent.

The reaction temperature for hydrocracking is usually 200 ° C. or higher and 450 ° C. or lower, and the hydrogen pressure is usually 1 MPa or higher and 20 MPa or lower. Liquid hourly space velocity (LHSV) in the case of the active metal A type catalyst, generally not more than 0.1 h ^-1 or ^{10h -1,} when the touch active metal B type is usually 0.3h ^-1 or 3.5 h ^-1 It is as follows. The hydrogen / oil ratio is usually 50 NL / L or more and 1000 NL / L or less for an active metal A type catalyst, and is usually 150 NL / L or more and 2000 NL / L or less for an active metal B type catalyst.

The hydrocracking apparatus may have any configuration, the reaction towers may be used singly or in combination, hydrogen may be additionally injected between the reaction towers, gas-liquid separation operation, hydrogen sulfide removal equipment, hydrogenation It may have a distillation column for fractionating the product and obtaining the desired fraction.
The reaction mode of the hydrocracking apparatus can take a fixed bed system. Hydrogen can take either a countercurrent or a cocurrent flow with respect to the feedstock, and may have a plurality of reaction towers and a combination of countercurrent and cocurrent flow. The general format is downflow, and there is a gas-liquid twin parallel flow format. Hydrogen gas may be injected into the middle stage of the reaction tower as a quench for the purpose of removing reaction heat or increasing the hydrogen partial pressure.

In the present invention, a light oil fraction produced by FT synthesis and a light oil obtained by hydrocracking FT wax produced by FT synthesis are used as the A heavy oil base material. Specifically, as the distillation properties, the 50% by volume distillation temperature is 250 to 350 ° C., and the density at 15 ° C. is in the range of 750 to 800 kg / m ³ .
The light oil fraction produced by the FT synthesis and the light oil obtained by hydrocracking the FT wax produced by the FT synthesis in the present invention contain 90% by volume or more, preferably 95% by volume or more of the saturated content. If the saturated content is less than this range, it is not preferable because the ignition quality deteriorates when used as a fuel for a diesel engine.

Moreover, in the A heavy oil composition of this invention, it is essential to use a fluid catalytic cracking light oil as an A heavy oil base material.
The fluid catalytic cracking light oil in this invention refers to the light oil fraction obtained from a fluid catalytic cracking apparatus or a residue fluid catalytic cracking apparatus. Specifically, as the distillation property, a fraction having a 50% by volume distillation temperature of 200 to 300 ° C. and a density of 15 ° C. in the range of 850 to 900 kg / m ³ is used.
The fluid catalytic cracking light oil in the present invention preferably contains 50% by volume or more of an aromatic component, more preferably 60% by volume or more. When the aromatic content is less than this range, the solubility of the residual carbon imparting base material and the fluidity improver added during the winter season is not preferable.

As an A heavy oil base material constituting the A heavy oil composition of the present invention, as essential components, a light oil fraction produced by FT synthesis, a light oil obtained by hydrocracking FT wax produced by FT synthesis, and fluid catalytic cracking Although light oil is used, other A heavy oil bases can be blended within a range that does not impair the effects of the present invention.
Such A heavy oil base material includes straight-run gas oil fraction obtained from an atmospheric distillation apparatus or its desulfurized gas oil fraction, straight-run kerosene fraction or its desulfurized kerosene fraction, hydrocracked light oil, hydrocracked kerosene, residual Desulfurized deparaffinized gas oil fraction, heavy gas oil fraction, and vacuum gas oil, the residue from which normal paraffin content was removed by extraction of oil desulfurized gas oil fraction, hydrodesulfurized gas oil fraction or hydrorefined gas oil fraction Examples include light oil and fluid catalytic cracking kerosene.

The extract used in the present invention is used as a base material for imparting residual carbon content.
The extract referred to in the present invention is a highly aromatic oil produced as a by-product in the process of removing the aromatic content in the lubricating oil using a solvent such as furfural, and specifically, its property is 15 ° C. The density is 950 to 1050 kg / m ³ , the kinematic viscosity at 100 ° C. is ⁵ to 100 mm ² / s, and the sulfur content is 0.5 to 5.0 mass%.

As described above, the A heavy oil composition of the present invention contains at least a gas oil fraction produced by FT synthesis, a gas oil hydrocracked from FT wax produced by FT synthesis, fluid catalytic cracking gas oil, and an extract. is required.
Although there is no restriction | limiting in particular about the mixture ratio of each component, in order to fully demonstrate the effect, the gas oil fraction manufactured by FT synthesis and the gas oil which hydrocracked the FT wax manufactured by FT synthesis are A. It is preferable to use 20% by volume or more based on the total amount of heavy oil composition, more preferably 40% by volume or more, more preferably 60% by volume or more, and most preferably 65% by volume or more.

  In order to enhance the solubility of the residual carbon imparting base material and the fluidity improver added during the winter season, it is conceivable to increase the aromatic content of the A heavy oil product. In order to fully exert the effect, the fluid catalytic cracking light oil is preferably used in an amount of 1% by volume or more, more preferably 5% by volume or more, more preferably 10% by volume or more based on the total amount of the A heavy oil composition. Most preferably. However, since the combustibility tends to deteriorate if the aromatic content of the heavy oil A is increased, it is preferably used at 50 vol% or less, more preferably 30 vol% or less in consideration of combustibility. preferable.

Further, in order to satisfy the tax exemption condition for the residual carbon content, the extract is more preferably used in an amount of 0.5% by volume or more based on the total amount of A heavy oil composition, and more preferably 1% by volume or more. . In consideration of filter clogging at room temperature due to dry sludge, low temperature fluidity, etc., it is preferably used at 5% by volume or less, more preferably at 3% by volume or less.
Further, other residual carbon imparting base materials can be used in combination. Examples of such other residual carbon imparting base materials include normal pressure residual oil, direct desorption residual oil, vacuum residual oil, slurry oil and the like, and only one of them may be used. May be used in combination.

The cetane index of the A heavy oil composition of the present invention is not particularly limited, but the cetane index is preferably 58 or more, more preferably 60 or more, from the viewpoint of combustibility. In the present invention, the cetane index means a value obtained in accordance with JIS K 2204-1992 “light oil”. That is, it is calculated by the following formula.
[Cetane index (C) = 0.49083 + 1.06577 (X)-0.0010522 (X) ² ]
[X = 97.833 (log A) ² +2.2088 B log A + 0.01247 B ² −423.51 log A−
4.7808B + 419.59]
A: (9/5) [50% distillation temperature at 101.3 kPa (760 mmHg) (° C.)] + 32
B: API volume (50 volume% distillation temperature (° C.) at 101.3 kPa (760 mmHg) is measured according to JIS K 2254 “Petroleum products-distillation test method”, and the API degree is JIS K 2249 “crude oil and petroleum products— Calculated from the density at 15 ° C. by “density test method and density / mass / capacity conversion table”)

  The cloud point of the heavy oil composition A of the present invention is not particularly limited, but it is preferably 0 ° C. or lower from the viewpoint of reducing wax precipitation at low temperatures that clog the filter for preventing impurities in the fuel system. , −2 ° C. or lower is more preferable, −5 ° C. or lower is further preferable, and −10 ° C. or lower is most preferable.

  Although there is no restriction | limiting in particular about the pour point of the A heavy oil composition of this invention, It is preferable that it is -15 degrees C or less from the point which reduces the wax precipitation at the time of low temperature. In the present invention, the cloud point and pour point mean values obtained in accordance with JIS K 2269 “Pour point of crude oil and petroleum products and petroleum product cloud point test method”.

  The CFPP (clogging point) of the A heavy oil composition of the present invention is not particularly limited, but it is preferably −15 ° C. or lower because it is superior in terms of preventing filter clogging due to wax in winter. It is more preferably −18 ° C. or lower, and most preferably −20 ° C. or lower. In the present invention, CFPP means a value obtained in accordance with JIS K 2288 “Diesel Oil—Clogging Point Test Method”.

  The correction clogging point of the present invention is not particularly limited, but it is preferably 9 ° C. or less, more preferably −12 ° C. or less, because it is superior in terms of preventing filter clogging by wax in winter. Is more preferable. If the corrected clogging point is higher than 9 ° C., the filter clogging of the pump or burner is likely to occur in winter, which is not preferable. In addition, the correction clogging point as used in the field of this invention means the value measured by the correction method 4 described in the description of Petroleum Institute standard JPI-5S-47-96 "Low temperature fluidity test method of A heavy oil".

  The sulfur content and nitrogen content of the A heavy oil composition of the present invention are not particularly limited. However, in order to reduce harmful substances in the exhaust gas, the sulfur content is preferably 0.5% by mass or less. It is more preferably 3% by mass or less, and most preferably 0.2% by mass or less. The nitrogen content is preferably 0.02% by mass or less, more preferably 0.015% by mass or less, and most preferably 0.01% by mass or less. In the present invention, the sulfur content and the nitrogen content were obtained in accordance with JIS K 2541 “Crude oil and petroleum products—sulfur content test method” and JIS K 2609 “Crude oil and petroleum products—nitrogen content test method”, respectively. Means something that represents a value.

  The 10% residual carbon content of the A heavy oil composition of the present invention is 0.2% by weight or more, preferably 0.2 to 1.0% by weight. If it is smaller than this range, the 10% residual carbon content does not satisfy the tax exemption condition of heavy oil A, which is 0.2% by weight or more. In addition, if the 10% residual carbon content exceeds the preferable range, the hue becomes worse and the image of the product becomes worse, the dry sludge increases, the filter tends to be clogged at room temperature, and the low temperature fluidity is adversely affected. There is a fear. In the present invention, 10% carbon residue means a value obtained in accordance with JIS K 2270 “Crude oil and petroleum products—residual carbon content test method”.

Moreover, although there is no restriction | limiting about the distillation property of A heavy oil composition of this invention, Usually, what satisfy | fills the following property is preferable.
First distillation point: 130-210 ° C
10 vol% distillation temperature (T10): 180-260 ° C
50 volume% distillation temperature (T50): 250-330 degreeC
90 volume% distillation temperature (T90): 300-380 degreeC
In the present invention, the distillation property means a value obtained according to JIS K 2254 “Petroleum products—Distillation test method”.

No particular limitation is imposed on the kinematic viscosity of the heavy oil A composition of the present invention is preferably a 2~3.5mm ² / s at normal 30 ° C. in 3~5mm ² / s, 50 ℃. In this invention, kinematic viscosity means what represents the value obtained based on JISK2283 "crude oil and petroleum products-kinematic viscosity test method and viscosity index calculation method".

  Although there is no restriction | limiting in particular about the flash point of A heavy oil composition of this invention, It is preferable that it is 50-120 degreeC normally. In the present invention, the flash point means a value obtained in accordance with JIS K 2265 “Crude oil and petroleum products—flash point test method”.

Although there is no restriction | limiting in particular about the density of A heavy oil composition of this invention, Usually, it is preferable that it is 800-920 kg / m < ³ >. In the present invention, the density means a value obtained based on JIS K 2249 “Crude oil and petroleum products—density test method and density / mass / capacity conversion table”.

  Moreover, an additive can be mix | blended with the A heavy oil composition of this invention as needed. Various additives such as cetane number improvers, antioxidants, stabilizers, dispersants, metal deactivators, microbial disinfectants, auxiliary agents, antistatic agents, discriminating agents, colorants, etc. These additives can be added as appropriate. Among these, it is preferable to add a fluidity improver because it is excellent in the effect of preventing filter clogging by wax in winter. As the fluidity improver, for example, polymer-type additives such as ethylene-vinyl acetate copolymer and ethylene-α-olefin copolymer, oil-soluble dispersant-type additives, and alkersuccinic acid can be used. Moreover, although there is no restriction | limiting about the addition amount of a fluid improvement agent, it is preferable that it is 0.001-0.1 volume% on the basis of A heavy oil composition whole quantity, and is 0.01-0.05 mass%. It is more preferable.

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

[Examples 1 and 2 and Comparative Examples 1 to 3]
Each base material having the properties shown in Table 1 (gas oil fraction produced by FT synthesis and gas oil obtained by hydrocracking FT wax produced by FT synthesis, straight run gas oil, cracked gas oil, extract, atmospheric residue ) Are mixed at a volume ratio as shown in each example of Table 2, and A heavy oil compositions of Examples 1 and 2 and Comparative Examples 1 to 3 are prepared, and the properties of these adjusted compositions are shown in Table 2. did. About each sample oil (each composition), low temperature fluidity performance evaluation, flammability performance evaluation, and normal temperature oil permeability performance evaluation were performed by the following method. The results are shown in Table 3.

(Low temperature fluidity performance evaluation)
A 20 L pail can was prepared as a sample container, and a hole into which the sample suction tube was inserted was provided on the top surface of the pail can. The hole was formed at the midpoint of a straight line connecting the center of the upper surface and the point on the outer periphery. On the other hand, a copper tube having an outer diameter of 10 mm was prepared as a sample suction tube, and one end of the copper tube was connected to the inlet of a filter (Nepon Corporation, code No. 120267) via a silicon rubber tube. Moreover, the outlet of the filter was connected to a suction pump through a copper tube. As the suction pump, a pump capable of adjusting the oil flow rate within a range of 1 to 10 L / hr was used.
Next, about 15 L of a sample (A heavy oil composition) having a temperature of 20 to 25 ° C. is put in the above-mentioned pail can, and a lid with a sample suction tube is put on the hole on the upper surface of the pail can, and then the pail can and the filter are cooled to a low temperature. The pump was accommodated in a thermostat, the pump was driven, and the pump pressure was adjusted so that the oil flow rate was 9.5 ± 0.2 L / hr. As the low-temperature thermostatic bath, a thermostatic bath having a program temperature adjusting function and capable of cooling to −30 ° C. or less within a temperature system of ± 0.5 ° C. was used. After the pail can and the filter were accommodated in the low-temperature thermostatic chamber, the inside of the low-temperature thermostatic chamber was cooled with a predetermined temperature profile, and the suction pump was driven. More specifically, the sample was cooled from a temperature 8 ° C. higher than the cloud point of the sample to a predetermined temperature at a cooling rate of 1 ° C./hr. The temperature was held for 3 hours, and the oil passage limit was determined by measuring the pressure with a pressure gauge. Judgment of the oil passage limit is accepted when the differential pressure is 33 kPa (250 mmHg) or less during oil passage for 60 minutes at the holding temperature, and is rejected when it exceeds 33 kPa, and held at 1 ° C intervals until it fails. The test was repeated at a lower temperature. The highest temperature (clogging temperature) at which the judgment was rejected was used as an index for evaluating the low temperature performance. In addition, the sample was replaced with new oil for each test. A clogging temperature of −9 ° C. or lower was judged good (◯), and a temperature of −8 ° C. or higher was judged bad (×). The obtained results are shown in Table 3.

(Flammability performance evaluation)
The combustion performance was evaluated by measuring the ignition delay by the following method. Ignition delay adversely affects engine performance and exhaust gas, and is a major cause of trouble in recent high-performance engines. Using a fuel ignitability tester with a combustion chamber volume of 1 liter, fuel was injected into air at a pressure of 45 barrels and a temperature of 450 ° C., and the time from injection to ignition was measured. The results are shown in Table 2.

(Normal temperature oil permeability performance evaluation)
A 20 L pail can was prepared as a sample container, and a hole into which the sample suction tube was inserted was provided on the top surface of the pail can. The hole was formed at the midpoint of a straight line connecting the center of the upper surface and the point on the outer periphery. On the other hand, providing a copper pipe having an outer diameter of 10mm as a sample aspirating tube, one end thereof through a silicone rubber tube filter (Nippon filter Ltd. fuel filter, part number 276237, oil passing area 2.0 ± 0.1 cm ² ) Connected to the entrance. Moreover, the outlet of the filter was connected to a suction pump through a copper tube. As the suction pump, a pump capable of adjusting the oil flow rate within a range of 1 to 10 L / hr was used. Next, about 10 L of a sample (A heavy oil composition) having a temperature of 20 to 25 ° C. is put in the above-mentioned pail can, a lid with a sample suction tube is put on the hole on the top surface of the pail can, and then the pail can and the filter are cooled to a low temperature. The pump was accommodated in a thermostat, the pump was driven, and the pump pressure was adjusted so that the oil flow rate was 5.0 ± 0.2 L / hr. As the low temperature thermostat, a thermostat equipped with a program temperature control function and adjustable within a temperature accuracy of ± 0.5 ° C. was used. After the pail can and the filter were accommodated in the low-temperature thermostatic chamber, the inside of the low-temperature thermostatic chamber was cooled with a predetermined temperature profile, and the suction pump was driven. More specifically, after maintaining at an initial temperature of 20 ° C. for 2 hours, the pump is driven to start. The pressure was measured with a pressure gauge to determine the oil passage limit. The oil passage limit was determined by measuring the time required for the differential pressure to reach 26.6 kPa (200 mmHg) at the holding temperature. When oil permeability is poor, filter clogging occurs and the differential pressure rises in a short time, whereas A heavy oil with good oil permeability has a long time until the differential pressure rises. The case where it did not reach 26.6 kPa even after 60 minutes passed was judged as good (◯), and the case where it reached 26.6 kPa in less than 60 minutes was judged as bad (x). The obtained results are shown in Table 3.

  As is clear from the results of Table 3, the A heavy oil compositions of Examples 1 and 2 according to the present invention are both excellent in ignitability and excellent in combustibility, have sufficient performance for recent high performance engines, and are excellent. It can be seen that the filter has low-temperature fluidity and is excellent in filter oil passing performance at room temperature. On the other hand, Comparative Example 1 which does not contain fluid catalytic cracking light oil has poor low-temperature fluidity because the effect of the fluidity improver is not exhibited, and light oil fraction produced by FT synthesis and FT produced by FT synthesis. Comparative Example 2 containing no gas oil hydrocracked from wax has poor low-temperature fluidity and combustibility, and Comparative Example 3 containing no extract has poor room temperature oil permeability.

Claims (5)

  A heavy oil composition obtained by using a gas oil fraction produced by FT synthesis and a gas oil hydrocracked from FT wax produced by FT synthesis, fluid catalytic cracking gas oil and an extract.   50% by volume The total amount of diesel oil produced by FT synthesis with a distillation temperature of 250 to 350 ° C. and hydrocracked FT wax produced by FT synthesis is 20% by volume based on the total amount of A heavy oil composition. The A heavy oil composition according to claim 1, which is blended as described above.   The total amount of the gas oil fraction produced by FT synthesis containing 90% by volume or more of the saturated content and the gas oil hydrocracked from the FT wax produced by FT synthesis is blended by 20% by volume or more based on the total amount of the A heavy oil composition. The A heavy oil composition according to claim 1.   The A heavy oil composition according to claim 1, wherein a fluid catalytic cracking gas oil having a 50 vol% distillation temperature of 200 to 300 ° C is blended in an amount of 1 vol% or more based on the total amount of the A heavy oil composition. The A heavy oil composition according to claim 1, wherein a fluid catalytic cracking light oil containing 50% by volume or more of aromatics is blended in an amount of 1% by volume or more based on the total amount of the A heavy oil composition.