JP2006160885A - Light oil base material, light oil, and manufacturing process for these - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light oil base material which contains a reduced amount of high unit risk PAH and is obtained from readily available petroleum materials by a low energy consumption manufacturing process and light oil. <P>SOLUTION: Hydrogenation refining is conducted using at least one kind of catalyst containing a porous body containing Ni and Mo as active metal elements to manufacture the light oil base material and the light oil involving 10-20 vol% of the total aromatics, 0.5-1.5 vol% of aromatics with two or more rings, having a 90 vol% distillation temperature of 320-360°C, a sulfur content of ≤10 mass ppm and a total content of high unit risk comounds of ≤0.2 mass ppm with those compounds less than 0.1 mass ppm in content as 0 mass ppm. The high unit risk comounds are benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-c,d]pyrene and dibenzo[a,h]anthracene. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a light oil base material and light oil, and methods for producing them, and more particularly to a light oil base material and light oil with reduced polycyclic aromatics having a high unit risk, and a method for producing the light oil base material and light oil. .

  Recently, reduction of polycyclic aromatic (PAH) contained in light oil which is a fuel of a diesel engine is required. In contrast to this, a method (Method 1) for producing light oil from a raw material that does not contain an aromatic component such as Fischer-Tropsch (FT) synthetic light oil, or a nuclear hydrogenation of a petroleum-based light oil fraction, A method of removing the minute (method 2) has been studied.

  Since the above-mentioned method 1 is produced from a raw material not containing an aromatic component, it is possible to produce a light oil that does not contain PAH.

  On the other hand, the above method 2 consumes a large amount of hydrogen for nuclear hydrogenation, treats a light oil fraction in the presence of high-pressure hydrogen, and further hydrotreats a once refined light oil fraction. However, there are disadvantages such as increased capital investment and operation costs for producing light oil. However, at present, light oil is mainly produced by hydrorefining petroleum fractions. Therefore, considering the economics of using existing facilities and the balance of petroleum products that are co-products, the above method 2 is a reality. Is.

  Regarding the method 2, various techniques for reducing PAH contained in light oil have been tried. For example, Patent Document 1 below discloses a gas oil composition with a reduced PAH, but relates to a gas oil with a total PAH reduced to 2 vol% or less, and does not mention the unit risk of each PAH. As described above, most of the conventional PAH reduction techniques focus on the method of reducing the overall PAH, and focus on the unit risk of each PAH, especially the reduction of PAH with high driving severity and high unit risk. There is no known technology that focuses on balance.

  Further, Patent Document 2 below is known as a method for producing light oil with reduced PAH, but here, only the effect of reducing the entire PAH is mentioned, and in addition, the amount of hydrogen to be introduced is very large. It is difficult to drive economically because there are many.

  Furthermore, in the following Patent Document 3, after diluting a light oil fraction with oil already hydrogenated in another device and hydrotreating, only a liquid fraction is further hydrotreated using a gas-liquid separator. PAH is reduced. In addition to the technology for reducing the overall PAH, it is necessary to newly invest in equipment such as a new gas-liquid separation device on the downstream side of a normal hydrorefining device.

  On the other hand, attempts have been made to evaluate the effects on health of individual substances of PAH from the viewpoint of unit risk, and Non-Patent Document 1 described below relates to unit risks of various chemical substances. In Non-patent Document 1, among PAHs, benzo [a] anthracene, chrysene, benzo [b] fluoranthene, benzo [k] fluoranthene, benzo [a] pyrene, indeno [1,2, 3-c, d] pyrene, dibenzo [a, h] anthracene (hereinafter referred to as high unit risk compounds). On the other hand, acenaphthylene, acenaphthene, fluorene, anthracene, phenanthrene, fluoranthene, benzo [g, h, i] perylene, and pyrene are considered to have a relatively low unit risk among PAHs.

JP 2004-0697906 A JP 2001-064657 A JP 2000-198990 A New Jersey Environment Department, “UNIT RISK FACTORS FOR INHALATION” (April 2003).

  Under such circumstances, the problem to be solved by the present invention is a light oil base material and light oil in which PAH with high unit risk is reduced by a production process with low energy consumption from a petroleum-based raw material that can be sufficiently supplied, It is another object of the present invention to provide a manufacturing method thereof.

  As a result of diligent research to solve the above-mentioned problems, the present inventor has achieved unit risk reduction by hydrorefining with moderate severity on a light oil fraction not subjected to aromatic reduction treatment. The present inventors have found that high PAH can be reduced and have reached the present invention.

  That is, the light oil base material and light oil of the present invention are (1) a light oil base material and light oil in which polycyclic aromatics with a high unit risk are reduced by performing hydrorefining with moderate severity. 10 to 20% by volume of aromatics, 0.5 to 1.5% by volume of aromatics of 2 or more rings, 90% by volume, distillation temperature of 320 to 360 ° C., sulfur content of 10 massppm or less, and the total amount of high unit risk compounds It is 0.2 massppm or less. Here, the high unit risk compound is benzo [a] anthracene, chrysene, benzo [b] fluoranthene, benzo [k] fluoranthene, benzo [a] pyrene, indeno [1,2,3-c, d] pyrene, Dibenzo [a, h] anthracene, and less than 0.1 massppm is integrated as 0 massppm.

  As a criterion for setting the hydrorefining severity, the total amount of low unit risk compounds in the gas oil fraction after hydrorefining is preferably 0.1 to 1.5 mass ppm. Here, the low unit risk compound is acenaphthylene, acenaphthene, fluorene, anthracene, phenanthrene, fluoranthene, benzo [g, h, i] perylene, and less than 0.1 massppm is integrated as 0 massppm. In particular, the total aromatic content calculated by the HPLC method is preferably 13 to 18 vol%, and the pyrene content is preferably 5 to 15 mass ppm.

Moreover, the manufacturing method of the light oil base material and light oil of this invention is (2) The manufacturing method of the said light oil fraction, At least 1 type containing the porous body (NiMo catalyst) containing nickel and molybdenum as an active metal element The oil-derived gas oil fraction that has not been subjected to the aromatic reduction treatment is hydrorefined using a catalyst of the above, and the liquid space velocity (LHSV) is 0.1 to 2.0 h ⁻¹ , particularly , 0.3 to 1.5 h ⁻¹ is preferable. The fraction obtained by this method can be used as a light oil as it is, or the fraction can be used as a light oil base material and mixed with other base materials to make a light oil.

  According to the present invention, according to the above description, it is possible to reduce the unit risk of benzo [a] anthracene and the like by performing hydrorefining with an appropriate severity without completely removing the aromatic component in the petroleum-based raw material. It is possible to provide a light oil base and light oil in which high PAH is sufficiently reduced.

  The present invention is described in detail below. The light oil base material and light oil of the present invention are a light oil base material and light oil in which PAH with high unit risk is reduced by performing hydrorefining with moderate severity, and the total aromatic content is 10 to 20 vol%, 2 The aromatic content in the ring or higher is 0.5 to 1.5 vol%, the 90 vol% distillation temperature is 320 to 360 ° C, the sulfur content is 10 massppm or less, and the total amount of high unit risk compounds is 0.2 massppm or less. Features. Here, the high unit risk compound is benzo [a] anthracene, chrysene, benzo [b] fluoranthene, benzo [k] fluoranthene, benzo [a] pyrene, indeno [1,2,3-c, d] pyrene, It is dibenzo [a, h] anthracene, and the total amount of the high unit risk compound is a value obtained by integrating the amount of each high unit risk compound with 0 massppm being less than 0.1 massppm. As a criterion for setting the hydrorefining severity, the total amount of low unit risk compounds in the gas oil fraction after hydrorefining is preferably 0.1 to 1.5 mass ppm. Here, the low unit risk compound is acenaphthylene, acenaphthene, fluorene, anthracene, phenanthrene, fluoranthene, benzo [g, h, i] perylene, and the total amount of the low unit risk compound is less than 0.1 massppm and less than 0 massppm. As a value obtained by integrating the amount of each low unit risk compound. Here, the measurement method of PAH is determined for each PAH by a gas chromatograph-mass spectrometer (GC-MS). In this method, a specific component can be quantified with high sensitivity by using a selected ion detection method (SIM) that detects and measures only a component-specific selected ion.

  When hydrorefined with moderate severity, benzo [a] anthracene and the like, which are high unit risk compounds, can be reduced below the measurement limit. As described in Non-Patent Document 1, benzo [a] anthracene and the like have a unit risk about 100 times higher than that of fluorene or phenanthrene. By substantially reducing such high-unit-risk substances, the proportion of high-unit-risk compounds contained in particulate matter (PM) generated after light oil combustion, and the environmental impact of vapors that evaporate during refueling, etc. Can be reduced. If the low unit risk compounds such as fluorene and phenanthrene are excessively reduced by increasing the severity, the total aromatic content will decrease, and the rubber swellability of the fuel tank seal will decrease, resulting in a loss of fuel supply to the engine. May cause fuel leakage. In addition, PAH may be reduced when it is mildly hydrorefined. In this case, since the concentration of impurities such as sulfur is high, sulfur oxides contained in the combustion gas reduce the PM in the exhaust gas. The catalyst to be used is poisoned, and the PM removal ability of the catalyst is reduced or the catalyst life is shortened.

  The total aromatic content here can be measured by a hydrocarbon type analysis by the HPLC method (Japan Petroleum Institute Standard JPI-5S-49-97). The light oil base and light oil of the present invention have a total aromatic content measured by this method of 10 to 20 vol%, preferably 13 to 18 vol%. Moreover, the light oil base material and light oil of this invention are 0.5-1.5 vol% of aromatic content of 2 or more rings. If the aromatic content in the range shown here is not left, the rubber swelling property of the fuel tank seal cannot be maintained. Furthermore, the light oil base material and light oil of the present invention have a 90% by volume distillation temperature of 320 to 360 ° C, preferably 330 to 350 ° C. When the 90% by volume distillation temperature is less than 320 ° C, there is no effect of adding a fluidity improver, and when it is higher than 360 ° C, the amount of PAH contained in the light oil base material and light oil increases, and the combustibility As a result of this deterioration, adverse effects such as an increase in the amount of PM in the exhaust gas occur. In addition, the light oil base material and light oil of the present invention preferably have a sulfur content of 10 massppm or less, 5 massppm or less, particularly 3 massppm. When the sulfur content is 10 mass ppm or less, the life of the catalyst used for reducing PM in the exhaust gas can be extended.

Specifically, the above-mentioned moderate severity means that hydrorefining of petroleum-derived light oil fraction that has not been subjected to aromatic reduction treatment is performed using LHSV using at least one type of catalyst including NiMo catalyst. conditions 0.1~2.0h ^-1, preferably refers to be carried out in the conditions of 0.3~1.5h ^-1.

Examples of petroleum-derived light oil fractions that have not been subjected to aromatic reduction treatment include hydrocarbon oils having a sulfur content of 0.5 mass% or more and a 90 vol% distillation temperature of 390 ° C or less. It does not contain non-petroleum derived hydrocarbon oils such as synthetic light oil and vegetable oil methyl ester. Usually, the sulfur content of petroleum-derived light oil fraction (hereinafter referred to as feedstock) that has not undergone aromatic reduction treatment is 0.5 to 5 mass%, particularly 0.7 to 3 mass%. Moreover, the nitrogen content of the feedstock oil is usually 50 massppm or more, particularly 80 to 500 massppm. The density (15 ° C.) of the raw material oil is preferably 0.795 g / cm ³ or more, more preferably 0.80 to 0.92 g / cm ³ . As long as the above-described conditions are satisfied, there is no particular limitation on the origin of the hydrocarbon oil, but it is preferable to use a raw oil of a straight-run gas oil fraction alone or a feed oil mainly composed of a straight-run gas oil fraction. In addition, process oils obtained from various petroleum refining processes may be used by mixing with straight-run gas oil fractions. The straight-run gas oil fraction is obtained by atmospheric distillation of crude oil, and approximately 10% by volume distillation temperature is 150 to 280 ° C, 50% by volume distillation temperature is 240 to 320 ° C, and 90% volume distillation temperature is. 300-390 ° C. Examples of the process oil that can be mixed with the straight-run gas oil fraction to obtain a raw material oil include pyrolysis oil, catalytic cracking oil, direct desulfurization gas oil, and indirect desulfurization gas oil.

  The above pyrolytic oil is a light fraction oil obtained by a reaction mainly composed of radical reaction by applying heat to a heavy oil fraction. For example, a delayed coking method, a visbreaking method or a fluid coking method is used. This refers to the fraction obtained. Although these fractions may use the whole fraction obtained as pyrolysis oil, it is suitable to use the fraction whose distillation temperature exists in the range of 150-390 degreeC.

  The above catalytic cracked oil is a fraction obtained when catalytically cracking middle distillate and heavy fraction, especially vacuum gas oil distillate or atmospheric distillation residue with zeolitic catalyst, especially high octane gasoline production. It is a cracked gas oil fraction by-produced in the intended fluid catalytic cracker. In general, a light catalytic cracked oil having a relatively low boiling point and a heavy catalytic cracked oil having a relatively high boiling point are separately collected from this fraction. In the present invention, any of these fractions may be used, but it is preferable to use the former light catalytic cracking oil, so-called light cycle oil (LCO). The LCO generally has a 10 vol% distillation temperature of 210 to 250 ° C, a 50 vol% distillation temperature of 260 to 290 ° C, and a 90 vol% distillation temperature of 310 to 370 ° C. On the other hand, heavy catalytic cracked oil, so-called heavy cycle oil (HCO), usually has a 10 vol% distillation temperature of 280-340 ° C, a 50 vol% distillation temperature of 390-420 ° C, and a 90 vol% distillation temperature of 450. Since the temperature is higher than or equal to ° C, the HCO is further fractionated so that the 90% by volume distillation temperature of the gas oil base material and gas oil used in the production of the gas oil of the present invention is equal to or less than 390 ° C. It is preferable to mix and limit the amount mixed with the raw material oil.

  The direct desulfurized gas oil is a gas oil fraction produced as a by-product when hydrorefining atmospheric pressure residue and / or reduced pressure residue with a direct desulfurizer. The indirect desulfurized gas oil is a gas oil fraction produced as a by-product when the vacuum gas oil fraction is hydrorefined with an indirect desulfurization apparatus. Even when these direct desulfurized light oil and indirect desulfurized light oil are used as part of the feedstock, it is appropriate that the 90% by volume distillation temperature of the feedstock used in the production of the light oil and light oil base of the present invention is 390 ° C. or less. It is preferable to perform fractional distillation and limit the amount to be mixed with the raw oil.

  The hydrorefining performed in the method for producing gas oil and gas oil base of the present invention is not particularly limited in the reaction type such as batch type, flow type, fixed bed type, fluidized bed type, etc., but packed in a fixed bed flow type reactor. A form in which hydrogen and raw material oil are continuously supplied and brought into contact with the resulting hydrorefining catalyst is preferable.

The hydrorefining in the present invention is carried out under reaction conditions of a reaction temperature of 280 to 450 ° C., preferably 300 to 420 ° C., and a hydrogen pressure of 3 to 10 MPa, preferably 4 to 9 MPa. When the hydrogen pressure is lower than 3 MPa, it becomes difficult to make the sulfur content in the light oil base material and light oil with a high unit risk reduced to 10 mass ppm or less, and when it exceeds 10 MPa, the light oil base with a reduced unit risk PAH is reduced. The calorific value per unit volume of the wood and light oil becomes small, which is not preferable. The hydrorefining in the present invention is preferably performed under the reaction conditions of LHSV of 0.1 to 2 h ⁻¹ , particularly 0.3 to 1.5 h ⁻¹ . The LHSV is less than 0.1 h ^-1, a certain amount reactor for the production of gas oil bases and gas oil with reduced high PAH of unit risk is increased too, and the LHSV is more than 2h ^-1, the unit risk It is difficult to make the sulfur content of the light oil base material and light oil with high PAH reduced to 10 mass ppm or less, which is not preferable.

  Moreover, the hydrorefining in this invention is performed on the reaction conditions whose hydrogen / oil ratio is 100-1000NL / L, Preferably it is 150-500NL / L. When the hydrogen / oil ratio is less than 100 NL / L, it becomes difficult to reduce the sulfur content of the light oil base material and light oil with a high unit risk of PAH to 10 massppm or less. It is not preferable because the cost increases and it becomes difficult to produce a light oil base and light oil in which PAH with a high unit risk is economically reduced. When hydrorefining is performed in a fixed bed flow reactor, the hydrorefining catalyst may be packed in a single catalyst bed or divided into two or more catalyst beds. When dividing into two or more catalyst beds and filling the hydrorefining catalyst, it is preferable to supply quench hydrogen between the catalyst beds. When quench hydrogen is supplied between the catalyst beds, the ratio of the total amount of hydrogen and quench hydrogen supplied together with the raw material oil to the reactor inlet and the supply amount of the raw material oil is 100 to 1000 NL / L, particularly 150. It is preferable to set it to -500NL / L.

The hydrorefining catalyst used for the light oil base material and the manufacturing method of light oil which reduced PAH with high unit risk of this invention consists of at least 1 type of catalyst containing a NiMo catalyst. Here, the NiMo catalyst is a porous body containing nickel and molybdenum as active metal elements, and preferably the nickel content is 1 to 10 mass% and the molybdenum content is 2 to 30 mass%. The hydrorefining catalyst may contain elements such as phosphorus, boron, and fluorine. Further, hydrogenation containing a chelating organic compound such as ethylenediaminetetraacetic acid (EDTA), trans-1,2-cyclohexanediamine-N, N, N ′, N′-tetraacetic acid, nitrilotriacetic acid, citric acid, etc. A purified catalyst is also preferably used. The hydrorefining catalyst used in the gas oil base and gas oil production method with reduced unit risk PAH of the present invention preferably has a mesopore central pore diameter of 4 to 20 nm, more preferably 4 to 4 nm. 15 nm. The specific surface area is preferably 30 to 800 m ² / g, and more preferably 50 to 600 m ² / g. It is preferable that the hydrorefining catalyst used for the light oil base material and the manufacturing method of light oil which reduced PAH with a high unit risk of this invention is not a powder but a molded object. Here, the shape of the molded body and the molding method are not particularly limited, but a spherical or columnar shape is preferable. In the case of a spherical shape, the diameter is preferably 0.5 to 20 mm. The cross-sectional shape in the case of a columnar shape is not particularly limited, but a circular shape, a three-leaf shape, and a four-leaf shape are preferable. The dimensions of the molded body in the case of a columnar shape are preferably about 0.25 to 400 mm ² in cross-sectional area and about 0.5 to 20 mm in length. Although there is no restriction | limiting in particular in the manufacturing method of the said hydrorefining catalyst, It is preferable to manufacture by including additional elements, such as the above-mentioned active metal element and phosphorus, in a porous inorganic oxide support | carrier. Examples of porous inorganic oxides include oxides such as alumina, silica, titania, magnesia, zirconia, silica-alumina, silica-titania, silica-zirconia, silica-magnesia, silica-alumina-titania, silica-alumina-zirconia, etc. Of these, one or two or more selected from zeolites such as composite oxide, Y-type zeolite, stabilized Y-type zeolite, β-zeolite, mordenite-type zeolite and MCM-22 are preferred.

Moreover, in the light oil base material and the light oil manufacturing method with reduced PAH with high unit risk according to the present invention, one or more hydrorefining catalysts may be combined and stacked in the reaction apparatus in addition to the NiMo catalyst. . The hydrorefining catalyst combined with the NiMo catalyst is a porous material containing molybdenum and / or tungsten and cobalt and / or nickel as active metal elements, such as a CoMo catalyst, NiCoMo catalyst, NiW catalyst, preferably cobalt and The total nickel content is 1 to 10 mass%, and the molybdenum and tungsten contents are 2 to 30 mass%. The hydrorefining catalyst combined with the NiMo catalyst may contain elements such as phosphorus, boron, and fluorine. Further, hydrogenation containing a chelating organic compound such as ethylenediaminetetraacetic acid (EDTA), trans-1,2-cyclohexanediamine-N, N, N ′, N′-tetraacetic acid, nitrilotriacetic acid, citric acid, etc. A purified catalyst is also preferably used. The hydrorefining catalyst used in the gas oil base and gas oil production method with reduced unit risk PAH of the present invention preferably has a mesopore central pore diameter of 4 to 20 nm, more preferably 4 to 4 nm. 15 nm. The specific surface area is preferably 30 to 800 m ² / g, and more preferably 50 to 600 m ² / g. It is preferable that the hydrorefining catalyst used for the light oil base material and the manufacturing method of light oil which reduced PAH with a high unit risk of this invention is not a powder but a molded object. Although there is no restriction | limiting in particular in the shape of a molded object, and a shaping | molding method, A spherical shape or a columnar shape is preferable. In the case of a spherical shape, the diameter is preferably 0.5 to 20 mm. The cross-sectional shape in the case of a columnar shape is not particularly limited, but a circular shape, a three-leaf shape, and a four-leaf shape are preferable. The dimensions of the molded body in the case of a columnar shape are preferably about 0.25 to 400 mm ² in cross-sectional area and about 0.5 to 20 mm in length. Although there is no restriction | limiting in particular in the manufacturing method of the hydrorefining catalyst combined with the said NiMo catalyst, It is preferable to manufacture by adding an additive element, such as the above-mentioned active metal element and phosphorus, to a porous inorganic oxide support | carrier. Examples of porous inorganic oxides include oxides such as alumina, silica, titania, magnesia, zirconia, silica-alumina, silica-titania, silica-zirconia, silica-magnesia, silica-alumina-titania, silica-alumina-zirconia, etc. Of these, one or two or more selected from zeolites such as composite oxide, Y-type zeolite, stabilized Y-type zeolite, β-zeolite, mordenite-type zeolite and MCM-22 are preferred.

  4-position and / or 6 of dibenzothiophene (DBT) such as 4-methyldibenzothiophene (4-MDBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) contained in the light oil fraction. It is known that there is a sulfur compound having an alkyl substituent that is sterically hindered with respect to the sulfur atom at the position, and it is called a hard-to-desulfurize sulfur compound [T. Kabe, A .; Ishihara, W .; Quin, "Hydrodesulfurization and Hydrodentrogenation", Kodansha (1999)]. Therefore, when the gas oil fraction is hydrorefined, the hardly-desulfurizable sulfur compound remains selectively. On the other hand, in the desulfurization of such a hard-to-desulfurize sulfur compound, a steric hindrance due to a substituent is caused by hydrogenating the benzene ring in the DBT skeleton rather than a reaction route (direct desulfurization route) in which sulfur atoms in the DBT skeleton are directly desulfurized. It is known that it is more advantageous to use a hydrorefining catalyst that can easily take a reaction route (hydrodesulfurization route) for desulfurization after relaxing the catalyst. In addition, when the cobalt-molybdenum-based hydrorefining catalyst is compared with the nickel-molybdenum-based hydrorefining catalyst, it is known that the latter tends to take a hydrodesulfurization route. Therefore, when two or more types of hydrorefining catalysts are combined and used in a reactor, a catalyst having a smaller proportion of nickel in the total content of cobalt and nickel contained in the hydrotreating catalyst is used. It is preferable to arrange the one having a larger proportion of nickel in the total content of cobalt and nickel closer to the reactor inlet to which the feedstock is supplied, closer to the reactor outlet.

  According to the gas oil base material with reduced unit risk and reduced gas oil production method of the present invention, the obtained light oil fraction can be used as it is as light oil with reduced unit risk PAH, or another base material. It can also be used as a light oil base for preparing a light oil product with a high unit risk and reduced PAH. Other light oil bases to be mixed with the light oil base of the present invention include, for example, kerosene produced by refining crude oil, synthetic light oil derived by the Fischer-Tropsch method, hydrocracked light oil, or their Examples include base materials for blending such as semi-finished products and intermediate products. Moreover, vegetable oil methyl ester, ethers, etc. can be mix | blended as another light oil base material. When the light oil base material of the present invention and other light oil base materials are blended to prepare a light oil with a high unit risk of the present invention and reduced PAH, it can be blended as appropriate so as to obtain a light oil of a desired quality. However, the blending ratio of the other light oil base is preferably 20 mass% or less, and particularly preferably 15 mass%.

  Further, in the method for producing a light oil with reduced unit risk PAH of the present invention, low temperature fluidity improver, wear resistance improver, cetane improver, antioxidant, metal deactivator as additives. A known fuel additive such as a corrosion inhibitor may be added. As the low temperature fluidity improver, an ethylene copolymer or the like can be used. In particular, vinyl esters of saturated fatty acids such as vinyl acetate, vinyl propionate, and vinyl butyrate are preferably used. In addition, as the wear resistance improver, a long-chain (for example, C12-24) fatty acid or a fatty acid ester thereof is preferably used, and the wear resistance is sufficient with an addition amount of 10 to 500 massppm, preferably 50 to 100 massppm. Can be improved.

  Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited thereto.

The PAH measurement of the hydrorefined product oil described later was performed by the method described below.
(PAH measurement pretreatment)
After measuring a certain amount of the sample, a solution dissolved with n-heptane was injected into an alumina cartridge column. Next, the PAH component held on the alumina column was eluted with toluene, and the eluted toluene solution was made up to 1 mL with toluene to obtain a measurement solution.

(GC-MS (SIM) measurement)
PAH was quantified using the following apparatus and conditions.
GC device: Agilent 6890N type GC
Detector: Agilent 5973N type quadrupole mass spectrometer Column: Agilent HP-5MS
Liquid phase: 95% dimethylpolysiloxane-5% diphenylpolysiloxane Column size: Inner diameter 0.25 mm × 30 m, Film thickness = 0.25 micron Column oven temperature: 70 ° C. (10 minutes hold) → Temperature rise at 10 ° C./min → 300 ° C (17 minutes hold)
Inlet temperature: 290 ° C
Transfer line temperature: 290 ° C
Detector temperature: ion source temperature = 230 ° C., quadrupole temperature = 150 ° C.
Column flow rate: 0.7 mL
Carrier gas: Helium injection method: Pulsed splitless Pulse pressure at injection = 25 psi (1.5 min)
Split vent line: 50 mL (1.5 min)
SIM conditions (quantitative ions)
Acenaphthylene = 152, acenaphthene = 154, fluorene = 166, phenanthrene and anthracene = 178, fluoranthene and pyrene = 202, benzo [a] anthracene and chrysene = 228, benzo [b] fluoranthene, benzo [k] fluoranthene, benzo [a] Pyrene = 252, benzo [g, h, i] perylene, indeno [1,2,3-c, d] pyrene = 276, dibenzo [a, h] anthracene = 278.

Example 1
A fixed bed flow reactor is charged with 100 mL of a hydrorefining catalyst HOP-414 (NiMo catalyst, manufactured by ART K.K.), from room temperature to 150 ° C. while flowing hydrogen at a hydrogen pressure of 5.0 MPa and 10 L / h. The temperature was raised, and then the catalyst was presulfided by the following procedure. Sulfurizing agent (mixed with 1 mass% carbon disulfide in commercial light oil) was passed for 2 hours under the conditions of hydrogen pressure 5.0 MPa, hydrogen / oil ratio 500 NL / L, LHSV = 2.0 h ⁻¹ , 150 ° C. did. Thereafter, the supply of the sulfiding agent and hydrogen was continued under constant conditions other than temperature, the temperature was raised to 230 ° C. at 20 ° C./h, and the temperature was kept constant at 230 ° C. for 4 hours. Thereafter, the temperature was further increased to 300 ° C. at 17.5 ° C./h, and the temperature was kept constant at 300 ° C. for 4 hours. Then, the hydrorefining reaction of the following light oil fraction A (Table 1) was performed using this sulfuration-treated hydrotreating catalyst. The hydrorefining reaction was carried out at a hydrogen pressure of 8.0 MPa, a hydrogen / feed oil supply ratio of 300 NL / L, LHSV = 1.2 h ^−1, and a reaction temperature of 352 ° C. The total amount of high unit risk compounds contained in the resulting product oil was 0 mass ppm, and the sulfur content in the product oil was 1.3 mass ppm. Moreover, the total amount of the low unit risk compound contained in produced | generated oil was 1.1 massppm, and pyrene content was 8.7 massppm (Table 2).

(Example 2)
Hydrogen with the same equipment, operation procedure, raw material oil and catalyst as in Example 1 except that the hydrogen pressure was 6.5 MPa, the hydrogen / raw oil supply ratio was 350 NL / L, LHSV = 1.0 h ⁻¹ and the reaction temperature was 350 ° C. Purification reaction was performed. The total amount of high unit risk compounds contained in the resulting product oil was 0 mass ppm, and the sulfur content in the product oil was 3.7 mass ppm. Further, the total amount of low unit risk compounds contained in the product oil was 0.4 massppm, and the pyrene content was 7.0 massppm (Table 2).

(Example 3)
The hydrotreating catalyst HOP-467 (CoMo catalyst, manufactured by ART KK) and 15 m ³ of HOP-414 (NiMo catalyst, manufactured by ART KK) 45 m ³ were charged in a fixed bed flow reactor. The hydrorefining reaction of the following light oil fraction B (Table 1) was performed using the hydrotreating catalyst pre-sulfided using DMDS. The hydrorefining reaction was carried out at a reactor inlet hydrogen pressure of 6.8 MPa, a hydrogen / raw oil supply ratio of 300 Nm ³ / KL, LHSV = 1.0 h ⁻¹ , and a catalyst weight average temperature of 350 ° C. The total amount of high unit risk compounds contained in the resulting product oil was 0 massppm, and the sulfur content in the product oil was 7.4 massppm. Moreover, the total amount of the low unit risk compound contained in produced | generated oil was 0.1 massppm, and pyrene content was 10 massppm (Table 2).

(Comparative Example 1)
Fixed hydrotreating catalyst bed flow reactor HOP-467 (CoMo catalyst, manufactured by ART K. K.) was charged 40m ^3, HOP-414 (NiMo catalyst, ART K. K. Ltd.) 20 m ^3. The hydrorefining reaction of the following light oil fraction C (Table 1) was performed using the hydrotreating catalyst pre-sulfided using DMDS. The hydrorefining reaction was carried out at a reactor inlet hydrogen pressure of 5.2 MPa, a hydrogen / raw oil feed ratio of 250 Nm ³ / KL, LHSV = 2.8 h ^−1, and a catalyst weight average temperature of 370 ° C. The total amount of high unit risk compounds contained in the resulting product oil was 0.5 mass ppm, and the sulfur content in the product oil was 38 mass ppm. The total amount of low unit risk compounds contained in the product oil was 0.7 massppm, and the pyrene content was 9.8 massppm (Table 2).

(Comparative Example 2)
The hydrogen pressure is 5.0 MPa, the hydrogen / feed oil supply ratio is 200 NL / L, LHSV = 4.5 h ⁻¹ , the reactor temperature is 345 ° C., the feed oil is the following light oil fraction D (Table 1), and the catalyst is a hydrorefining catalyst. The hydrorefining reaction was performed in the same apparatus and operation procedure as in Example 1 except that HOP-467 (CoMo catalyst, manufactured by ART KK) was 100 mL. The total amount of high unit risk compounds contained in the resulting product oil was 0 mass ppm, but the sulfur content in the product oil was 511 mass ppm. The total amount of low unit risk compounds contained in the product oil was 0 massppm, and the pyrene content was 2.6 massppm (Table 2).

(Comparative Example 3)
Hydrogen pressure 5.9 MPa, hydrogen / feed oil feed ratio 170 NL / L, LHSV = 0.9 h ⁻¹ , reactor temperature 345 ° C., feedstock oil is the following light oil fraction E (Table 1), and catalyst is hydrorefining catalyst The hydrorefining reaction was performed in the same apparatus and operation procedure as in Example 1 except that Z (CoMo catalyst, Co: 3.5 mass%, Mo: 15 mass%) was 100 mL. The total amount of high unit risk compounds contained in the resulting product oil was 0.3 mass ppm, and the sulfur content in the product oil was 7.3 mass ppm. Moreover, the total amount of the low unit risk compound contained in produced | generated oil was 3.0 massppm, and pyrene content was 56 massppm (Table 2).

(Comparative Example 4)
The hydrorefining reaction was performed in the same apparatus and operation procedure as in Comparative Example 3 except that the hydrogen / raw oil supply ratio was 200 NL / L and the reactor temperature was 355 ° C. The total amount of high unit risk compounds contained in the resulting product oil was 0.9 mass ppm, and the sulfur content in the product oil was 5.8 mass ppm. Moreover, the total amount of the low unit risk compound contained in produced | generated oil was 1.1 massppm, and pyrene content was 66 massppm (Table 2).

  From Table 2 above, the gas oil in the examples has a sufficiently high unit risk PAH such as benzo [a] anthracene and the like, and has a sufficient sulfur content. It can be seen that it is low.

Claims (10)

The total aromatic content is 10 to 20 vol%, the aromatic content of two or more rings is 0.5 to 1.5 vol%, the 90 vol% distillation temperature is 320 to 360 ° C, the sulfur content is 10 massppm or less,
Benzo [a] anthracene, chrysene, benzo [b] fluoranthene, benzo [k] fluoranthene, benzo [a] pyrene, indeno [1,2,3-c, d] pyrene and dibenzo [a, as high unit risk compounds h] A light oil base material, wherein the total amount of anthracene is 0.2 massppm or less by integrating less than 0.1 massppm as 0 massppm.   The total amount of acenaphthylene, acenaphthene, fluorene, anthracene, phenanthrene, fluoranthene and benzo [g, h, i] perylene as a low unit risk compound is 0.1 to 1.5 massppm by integrating less than 0.1 massppm as 0 massppm. The light oil base material according to claim 1.   The light oil base material according to claim 1 or 2, wherein the pyrene content is 5 to 15 massppm.   The hydrorefining of petroleum-derived light oil fraction not subjected to aromatic reduction treatment is performed using at least one type of catalyst containing a porous material containing nickel and molybdenum as an active metal element. The manufacturing method of the light oil base material in any one of claim | item 1-3. The manufacturing method of the light oil base material of Claim 4 which performs the said hydrorefining on the conditions whose LHSV is 0.1-2.0h < ^-1 >. The total aromatic content is 10 to 20 vol%, the aromatic content of two or more rings is 0.5 to 1.5 vol%, the 90 vol% distillation temperature is 320 to 360 ° C, the sulfur content is 10 massppm or less,
Benzo [a] anthracene, chrysene, benzo [b] fluoranthene, benzo [k] fluoranthene, benzo [a] pyrene, indeno [1,2,3-c, d] pyrene and dibenzo [a, as high unit risk compounds h] A light oil in which the total amount of anthracene is 0.2 massppm or less by integrating less than 0.1 massppm as 0 massppm.   The total amount of acenaphthylene, acenaphthene, fluorene, anthracene, phenanthrene, fluoranthene and benzo [g, h, i] perylene as a low unit risk compound is 0.1 to 1.5 massppm by integrating less than 0.1 massppm as 0 massppm. The diesel oil according to claim 6.   The gas oil according to claim 6 or 7, wherein the pyrene content is 5 to 15 massppm.   The hydrorefining of petroleum-derived light oil fraction not subjected to aromatic reduction treatment is performed using at least one type of catalyst containing a porous material containing nickel and molybdenum as an active metal element. Item 9. A process for producing light oil according to any one of Items 6 to 8. The method for producing light oil according to claim 9, wherein the hydrorefining is performed under the condition of LHSV of 0.1 to 2.0 h- ¹ .