JP2007238870A - Method for producing hydrocarbon oil and hydrocarbon oil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a hydrocarbon oil, which obtains a hydrocarbon oil having sufficient excellent low-temperature fluidity and a kinematic viscosity of &ge;2.5mm<SP>2</SP>/s at 30&deg;C and to obtain a hydrocarbon oil obtained by the method. <P>SOLUTION: The method for producing a hydrocarbon group oil comprises fractionating a synthetic oil obtained by a Fischer-Tropsch synthesis method, obtaining an intermediate fraction comprising &ge;90 mass% of content of a fraction having 150-360&deg;C boiling point and &le;5 mass% of content of a fraction having &ge;350&deg;C boiling point and a wax component heavier than that of the intermediate fraction, bringing the intermediate fraction and the wax component into contact with a hydrogenation catalyst in the presence of hydrogen and mixing and fractionating the resulting components to give the objective hydrocarbon oil having &ge;86 mass% of content of a fraction having 150-360&deg;C boiling point and &le;5 mass% of content of a fraction having &ge;350&deg;C boiling point. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a hydrocarbon oil and a method for producing the same, and more particularly to a hydrocarbon oil useful as a diesel fuel base material and a method for producing the same.

  In recent years, clean liquid fuels that are low in sulfur content and aromatic hydrocarbon content and that are friendly to the environment have been demanded from the viewpoint of reducing environmental impact. Therefore, in the petroleum industry, a Fischer-Tropsch synthesis method (hereinafter abbreviated as “FT synthesis method”) using carbon monoxide and hydrogen as raw materials is being studied as a method for producing clean fuel. According to the FT synthesis method, a liquid fuel base material having a high paraffin content and no sulfur content can be produced.

  However, a synthetic oil obtained by the FT synthesis method (hereinafter sometimes referred to as “FT synthetic oil”) has a high normal paraffin content and contains an oxygen-containing compound such as alcohol. It is difficult to use as. More specifically, the synthetic oil has insufficient octane number for use as automobile gasoline, and low temperature fluidity for use as diesel fuel. In addition, oxygen-containing compounds such as alcohol adversely affect the oxidation stability of the fuel. Therefore, FT synthetic oil is used as a fuel base after being subjected to hydrogenation treatment to convert normal paraffin in the synthetic oil into isoparaffin or oxygen-containing compounds into other substances. Is common.

  For example, when producing diesel fuel base, kerosene base, aviation fuel base, etc., middle distillate rich in isoparaffin obtained by hydrocracking heavy wax content of FT synthetic oil or FT synthetic oil The low temperature fluidity of the fuel base material is improved by appropriately mixing the middle distillate having an increased degree of paraffin isomerization obtained by hydroisomerizing the middle distillate (for example, Patent Document 1 and 2).

International Publication No. 00/020535 Pamphlet French Patent Publication No. 2826971

By the way, it is desirable that the fuel supplied to the diesel vehicle exhibits a certain degree of kinematic viscosity at normal temperature and high temperature from the viewpoint of preventing seizure in the combustion cylinder due to malfunction of the fuel pump or running out of the oil film. For example, in the Japanese Industrial Standard JIS K2283 No. 2 diesel oil kinematic viscosity standard, the kinematic viscosity at 30 ° C. is defined as 2.5 mm ² / s or more. Therefore, the hydrocarbon oil used as the diesel fuel base material in the middle distillate obtained from the FT synthetic oil needs to have both low-temperature fluidity and kinematic viscosity sufficiently improved.

  On the other hand, cost reduction in diesel fuel production is more strongly demanded than ever, and the requirement is no exception for fuel production using the FT synthesis method. It is also necessary to efficiently produce hydrocarbon oil from FT synthetic oil.

  However, the prior arts including those in Patent Documents 1 and 2 mainly improve the low temperature fluidity of the fuel base as described above, and both the low temperature fluidity and the kinematic viscosity at 30 ° C. As a matter of fact, no effective technology for increasing the yield of hydrocarbon oil satisfying the above has been provided.

  In obtaining hydrocarbon oil, for example, a method of improving both low temperature fluidity and kinematic viscosity at 30 ° C. by narrowing the boiling point range of fractional distillation is conceivable. Since the manufacturable amount of the diesel fuel base material in the oil is lowered, the economy of the fuel production process is impaired. Moreover, if only the middle distillate obtained by hydrocracking the heavy wax content of FT synthetic oil is used as a diesel fuel base material, both low temperature fluidity and kinematic viscosity at 30 ° C. can be satisfied. In some cases, the amount of FT synthetic oil that can be produced is limited, and it is difficult to produce a sufficient amount of fuel base.

The present invention has been made in view of the above circumstances, and from FT synthetic oil, a hydrocarbon oil having sufficiently low temperature fluidity and a kinematic viscosity at 30 ° C. of 2.5 mm ² / s or higher is obtained in a high yield. It aims at providing the manufacturing method of the hydrocarbon oil which can be obtained by this, and the hydrocarbon oil obtained by this method.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have obtained a middle fraction containing a specific amount of a fraction in a specific boiling range from FT synthetic oil, and a wax content heavier than this middle fraction. The hydrocarbon oil obtained by hydrotreating these separately and then mixing, and fractionating the mixture so as to contain a specific amount of a fraction having a specific boiling range, has a flow of −7.5 ° C. or less. The present invention was completed by finding that it showed a kinematic viscosity of 2.5 mm ² / s or higher at 30 ° C. and a sufficient yield with respect to FT synthetic oil as a raw material.

  That is, the method for producing a hydrocarbon oil of the present invention fractionates synthetic oil obtained by the Fischer-Tropsch synthesis method, the content of a fraction having a boiling point of 150 to 360 ° C. is 90% by mass or more, and a boiling point of 350 ° C. An intermediate fraction having a content of the above fraction of 5% by mass or less and a wax fraction heavier than the middle fraction are obtained, and the middle fraction and the wax fraction are each hydrogenated in the presence of hydrogen. After contacting with the catalyst, mixing and fractionating, carbonization of a fraction having a boiling point of 150 to 360 ° C. is 86% by mass or more and a fraction having a boiling point of 350 ° C. or more is 5% by mass or more It is characterized by obtaining hydrogen oil.

According to the method for producing a hydrocarbon oil of the present invention, a hydrocarbon oil that is sufficiently excellent in low-temperature fluidity and has a kinematic viscosity at 30 ° C. of 2.5 mm ² / s or higher is obtained in high yield from an FT synthetic oil. be able to. Thereby, it becomes possible to manufacture an environmentally low load type diesel fuel with good economic efficiency.

  In the method for producing a hydrocarbon oil of the present invention, the content (mass%) of hydrocarbon having a boiling point of 150 ° C. or less in the middle distillate after contact with the hydrogenation catalyst is 3 to 9 mass% larger than that before contact. It is preferable that the middle distillate be hydrotreated.

  As a result, the pour point of the hydrocarbon oil can be further lowered while sufficiently securing the yield of the hydrocarbon oil.

  In the method for producing a hydrocarbon oil of the present invention, the wax content is hydrotreated so that the content of the fraction having a boiling point of 360 ° C. or less in the wax content after contact with the hydrogenation catalyst is 45 to 85 mass%. Is preferred. If the content is less than 45% by mass, the yield of the resulting hydrocarbon oil tends to decrease, or the low-temperature fluidity of the hydrocarbon oil tends to decrease. On the other hand, when the content exceeds 85% by mass, the yield of the obtained hydrocarbon oil tends to decrease.

  In the method for producing a hydrocarbon oil of the present invention, the hydrogenation catalyst brought into contact with the middle distillate and the hydrogenation catalyst brought into contact with the wax fraction each have a crystalline zeolite content of 0.1% by mass to 80.0% by mass and heat resistance. One type selected from the group consisting of a support containing 0.1 to 60.0% by weight of an amorphous metal oxide having a metal, and a metal belonging to Group VIII of the periodic table supported on the support It is preferable that the above metal is included.

In the method for producing a hydrocarbon oil of the present invention, the reaction temperature when contacting the middle distillate and the hydrogenation catalyst is 200 to 370 ° C., the hydrogen partial pressure is 1.0 to 5.0 MPa, and the liquid space velocity is 0. 3 to 3.5 h ⁻¹ , and the reaction temperature when the wax component and the hydrogenation catalyst are brought into contact is 200 to 370 ° C., the hydrogen partial pressure is 1.0 to 5.0 MPa, and the liquid space velocity is 0. It is preferable that it is 3-3.5h < ^-1 >.

Moreover, the hydrocarbon oil of the present invention is obtained by the method for producing a hydrocarbon oil of the present invention, and has a pour point of −7.5 ° C. or lower and a kinematic viscosity at 30 ° C. of 2.5 mm ² / It is characterized by being s or more. Such hydrocarbon oil has excellent quality as a diesel fuel base material and is obtained in high yield from FT synthetic oil. Therefore, according to the hydrocarbon oil of the present invention, it is possible to realize cost reduction of environmentally low load type diesel fuel.

According to the present invention, the production of a hydrocarbon oil capable of obtaining a high-yield hydrocarbon oil having excellent low-temperature fluidity and a kinematic viscosity at 30 ° C. of 2.5 mm ² / s or more from an FT synthetic oil. Methods and hydrocarbon oils obtained by such methods can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a flow diagram showing an example of a hydrocarbon oil production apparatus that implements the hydrocarbon oil production method of the present invention. A hydrocarbon oil production apparatus 100 shown in FIG. 1 includes an FT synthetic oil introduction channel 1 into which FT synthetic oil as a raw material is introduced, and a synthetic oil introduced from the FT synthetic oil introduction channel 1 into light fractions. A first distillation column 10 that fractionates into a middle distillate and a heavy wax component; a hydrotreating device 20 that hydrotreats the middle distillate supplied from the distillation column 10 through the middle distillate passage 3; A hydrotreatment device 30 for hydrotreating a heavy wax component supplied from the tower 10 through the wax fraction channel 5, a gas-liquid separation tank 22 for removing gas components from the middle distillate through the hydrotreatment device 20, hydrogen Gas-liquid separation tank 32 for removing gas components from the heavy wax component that has passed through the gasification treatment apparatus 30, and a second distillation column for fractionating the liquid components from the gas-liquid separation tank 22 and the liquid components from the gas-liquid separation tank 32 40. The gas-liquid separation tank 22 and the second distillation tower 40, and the gas-liquid separation tank 32 and the second distillation tower 40 are connected by the flow path 4 and the flow path 6, respectively.

  The first distillation column 10 is connected to a flow path 2 for taking out light wax out of the system. Further, the second distillation column 40 has a recovery channel 8 for extracting the hydrocarbon oil of the present invention obtained by fractional distillation, and a recovery channel 7 for extracting a fraction lighter than the hydrocarbon oil. And a circulation flow path 9 for supplying a wax component heavier than the hydrocarbon oil to the hydrotreating device 30 as needed to perform hydrotreating.

  Hereinafter, the hydrocarbon oil production method of the present invention will be described in detail with reference to the hydrocarbon oil production apparatus 100 of FIG.

(Fractionation of FT synthetic oil)
First, the FT synthetic oil used in the method for producing a hydrocarbon oil of the present invention is not particularly limited as long as it is produced by the FT synthesis method, but hydrocarbons having a boiling point of 150 ° C. or higher are based on the total amount of FT synthetic oil. It is preferable to contain hydrocarbons having a boiling point of 360 ° C. or more and 35% by mass or more based on the total amount of FT synthetic oil. The total amount of FT synthetic oil means the total of hydrocarbons having 5 or more carbon atoms produced by the FT synthesis method.

  In the first distillation column 10, by setting two cut points and fractionating the FT synthetic oil, the fraction below the first cut point is a light fraction, and the second cut from the first cut point is performed. The fraction up to the point can be obtained as the middle fraction, and the fraction above the second cut point can be obtained as the bottom oil (heavy wax). In the present embodiment, by appropriately setting the first cut point and the second cut point, the fraction having a boiling point of 150 to 360 ° C. is 90% by mass or more and the boiling point is 350 ° C. or more. A middle fraction having a content of 5% by mass or less and a wax content heavier than the middle fraction are obtained.

  The content of fractions having a boiling point of 150 to 360 ° C. and the content (mass%) of fractions having a boiling point of 350 ° C. or higher in the middle distillate are known, for example, by gas chromatography after sampling in the middle distillate flow path 3 It can be analyzed and obtained by the method of

  Furthermore, in this embodiment, in the first distillation column 10, it is preferable to perform fractional distillation so that the middle fraction does not substantially contain a fraction having a boiling point of 350 ° C. or higher. Moreover, it is preferable to carry out fractional distillation so that the middle fraction contains a fraction having a boiling point of 300 to 350 ° C. in an amount of 15% by mass or more.

  The first cut point and the second cut point are preferably set in the range of 135 to 170 ° C and in the range of 330 to 355 ° C, respectively, in the range of 145 to 155 ° C and 345 to 355 ° C. It is more preferable to set within the range.

  Note that the number of cut points in the first distillation column 10 is not limited to two, and can be set to three or more as long as the above middle distillate and wax can be obtained.

(Hydrotreatment of middle distillate)
In the hydrotreating apparatus 20, the middle distillate obtained in the first distillation column 10 is hydrotreated. As the hydrotreating apparatus 20, a known fixed bed reaction tower can be used. In the present embodiment, it is preferable to charge the middle distillate obtained in the first distillation column 10 by hydrotreating with a predetermined hydrotreating catalyst packed in a fixed bed flow reactor in the reaction tower. The hydrorefining here includes both hydrocracking and hydroisomerization. Decomposition means a chemical reaction accompanied by a decrease in molecular weight, and isomerization means conversion to another compound having a different carbon skeleton while maintaining the molecular weight and the number of carbon atoms constituting the molecule.

  Examples of the hydrorefining catalyst include a catalyst in which a solid acid-containing carrier is loaded with a metal belonging to Group VIII of the periodic table as an active metal.

  Suitable supports include crystalline zeolites such as ultra-stabilized Y-type (USY) zeolite, HY zeolite, mordenite and β zeolite, and amorphous metal oxides having heat resistance such as silica alumina, silica zirconia and alumina boria. What is comprised including 1 or more types of solid acids chosen from these is mentioned. Furthermore, the carrier is more preferably composed of USY zeolite and one or more solid acids selected from silica alumina, alumina boria and silica zirconia. More preferably, it is configured to include.

  USY zeolite is obtained by ultra-stabilizing Y-type zeolite by hydrothermal treatment and / or acid treatment, and in addition to the fine pore structure of 20 pores or less originally possessed by Y-type zeolite, New pores are formed in the area. When USY zeolite is used as the carrier for the hydrotreating catalyst, the average particle size is not particularly limited, but is preferably 1.0 μm or less, more preferably 0.5 μm or less. In the USY zeolite, the silica / alumina molar ratio (molar ratio of silica to alumina; hereinafter referred to as “silica / alumina ratio”) is preferably 10 to 200, more preferably 15 to 100, and 20 It is still more preferable that it is -60.

  Moreover, it is preferable that a support | carrier is comprised including 0.1 mass%-80 mass% of crystalline zeolite, and the amorphous metal oxide which has heat resistance 0.1 mass%-60 mass%. .

  The catalyst carrier can be produced by molding a mixture containing the solid acid and the binder and then firing the mixture. The blending ratio of the solid acid is preferably 1 to 70% by mass and more preferably 2 to 60% by mass based on the total amount of the carrier. Moreover, when a support | carrier is comprised including USY zeolite, it is preferable that the compounding quantity of USY zeolite is 0.1-10 mass% on the basis of the support whole quantity, and it is 0.5-5 mass%. More preferred. Furthermore, when the carrier is configured to contain USY zeolite and alumina boria, the blending ratio of USY zeolite to alumina boria (USY zeolite / alumina boria) is preferably 0.03 to 1 in terms of mass ratio. Moreover, when a support | carrier is comprised including USY zeolite and a silica alumina, it is preferable that the compounding ratio (USY zeolite / silica alumina) of USY zeolite and a silica alumina is 0.03-1.

  The binder is not particularly limited, but alumina, silica, silica alumina, titania and magnesia are preferable, and alumina is more preferable. The blending amount of the binder is preferably 20 to 98% by mass, more preferably 30 to 96% by mass based on the total amount of the carrier.

  The firing temperature of the mixture is preferably in the range of 400 to 550 ° C, more preferably in the range of 470 to 530 ° C, and still more preferably in the range of 490 to 530 ° C.

  Specific examples of the Group VIII metal include cobalt, nickel, rhodium, palladium, iridium, and platinum. Among these, it is preferable to use a metal selected from nickel, palladium, and platinum alone or in combination of two or more.

  These metals can be supported on the above-mentioned carrier by a conventional method such as impregnation or ion exchange. The amount of metal to be supported is not particularly limited, but the total amount of metal is preferably 0.1 to 3.0% by mass with respect to the support.

The hydrorefining of the middle distillate can be performed under the following reaction conditions. Examples of the hydrogen partial pressure include 0.5 to 12 MPa, but 1.0 to 5.0 MPa is preferable. The liquid hourly space velocity of the middle fraction (LHSV), including but 0.1~10.0h ^-1, 0.3~3.5h ^-1 are preferred. Although there is no restriction | limiting in particular as hydrogen / oil ratio, 50-1000NL / L is mentioned, 70-800NL / L is preferable.

In this specification, “LHSV (liquid hourly space velocity)” means the volume flow rate of the raw material oil in the standard state (25 ° C., 101325 Pa) per volume of the catalyst layer filled with the catalyst. The unit “h ⁻¹ ” indicates the reciprocal of time (hour). Further, “NL”, which is a unit of hydrogen capacity in the hydrogen / oil ratio, indicates a hydrogen capacity (L) in a normal state (0 ° C., 101325 Pa).

  Moreover, 180-400 degreeC is mentioned as reaction temperature in hydrorefining, However, 200-370 degreeC is preferable, 250-350 degreeC is more preferable, 280-350 degreeC is still more preferable. When the reaction temperature in hydrocracking exceeds 370 ° C., the side reaction that decomposes into the naphtha fraction increases and the yield of the middle fraction is extremely reduced. Since use is restricted, it is not preferable. On the other hand, when the reaction temperature is lower than 200 ° C., the alcohol component cannot be completely removed and is not preferable.

  In this embodiment, the middle distillate is such that the content (mass%) of hydrocarbons having a boiling point of 150 ° C. or lower in the middle distillate after contact with the catalyst is 3 to 9 mass% higher than that before contact. Is preferably hydrorefined.

  The content (mass%) of hydrocarbons having a boiling point of 150 ° C. or lower in the middle distillate before contact with the catalyst and the middle distillate after contact is, for example, gas chromatography obtained by sampling at the inlet and outlet of the reaction tower. Etc., and can be determined by a known method.

  In the method for producing a hydrocarbon oil of the present embodiment, while confirming the content of hydrocarbons of each carbon number in the middle distillate before contact with the catalyst and the middle distillate after contact by the above-described method, The reaction conditions in which the content (mass%) of hydrocarbons having a boiling point of 150 ° C. or less in the middle distillate after contact with the catalyst is 3 to 9 mass% higher than that before the contact are determined, and hydrorefining is performed under these conditions May be performed.

(Hydrotreatment of heavy wax)
In the hydrotreating device 30, the heavy wax component obtained in the first distillation column 10 is hydrotreated. As the hydrotreating apparatus 30, a known fixed bed reaction tower can be used. In the present embodiment, in this embodiment, a predetermined hydrocracking catalyst is charged in a fixed bed flow reactor in the reaction tower, and the wax content obtained in the first distillation tower 10 is hydrocracked. . The hydrogenation treatment of the wax mainly involves a chemical reaction accompanied by a decrease in molecular weight. Such hydrogenation treatment includes hydroisomerization.

  Examples of the hydrocracking catalyst include a catalyst in which a solid acid-containing carrier is loaded with a metal belonging to Group VIII of the periodic table as an active metal.

  Suitable supports include crystalline zeolites such as ultra-stabilized Y-type (USY) zeolite, HY zeolite, mordenite and β zeolite, and amorphous metal oxides having heat resistance such as silica alumina, silica zirconia and alumina boria. What is comprised including 1 or more types of solid acids chosen from these is mentioned. Further, the carrier is more preferably composed of USY zeolite and one or more solid acids selected from silica alumina, alumina boria and silica zirconia. More preferably, it is configured to include.

  USY zeolite is obtained by ultra-stabilizing Y-type zeolite by hydrothermal treatment and / or acid treatment, and in addition to the fine pore structure of 20 pores or less originally possessed by Y-type zeolite, New pores are formed in the area. When USY zeolite is used as the carrier for the hydrotreating catalyst, the average particle size is not particularly limited, but is preferably 1.0 μm or less, more preferably 0.5 μm or less. In the USY zeolite, the silica / alumina molar ratio (molar ratio of silica to alumina; hereinafter referred to as “silica / alumina ratio”) is preferably 10 to 200, more preferably 15 to 100, and 20 It is still more preferable that it is -60.

  Moreover, it is preferable that a support | carrier is comprised including 0.1 mass%-80 mass% of crystalline zeolite, and the amorphous metal oxide which has heat resistance 0.1 mass%-60 mass%. .

  The catalyst carrier can be produced by molding a mixture containing the solid acid and the binder and then firing the mixture. The blending ratio of the solid acid is preferably 1 to 70% by mass and more preferably 2 to 60% by mass based on the total amount of the carrier. Moreover, when a support | carrier is comprised including USY zeolite, it is preferable that the compounding quantity of USY zeolite is 0.1-10 mass% on the basis of the support whole quantity, and it is 0.5-5 mass%. More preferred. Furthermore, when the carrier is configured to contain USY zeolite and alumina boria, the blending ratio of USY zeolite to alumina boria (USY zeolite / alumina boria) is preferably 0.03 to 1 in terms of mass ratio. Moreover, when a support | carrier is comprised including USY zeolite and a silica alumina, it is preferable that the compounding ratio (USY zeolite / silica alumina) of USY zeolite and a silica alumina is 0.03-1.

  The binder is not particularly limited, but alumina, silica, silica alumina, titania and magnesia are preferable, and alumina is more preferable. The blending amount of the binder is preferably 20 to 98% by mass, more preferably 30 to 96% by mass based on the total amount of the carrier.

  The firing temperature of the mixture is preferably in the range of 400 to 550 ° C, more preferably in the range of 470 to 530 ° C, and still more preferably in the range of 490 to 530 ° C.

  Specific examples of the Group VIII metal include cobalt, nickel, rhodium, palladium, iridium, and platinum. Among these, it is preferable to use a metal selected from nickel, palladium, and platinum alone or in combination of two or more.

  These metals can be supported on the above-mentioned carrier by a conventional method such as impregnation or ion exchange. The amount of metal to be supported is not particularly limited, but the total amount of metal is preferably 0.1 to 3.0% by mass with respect to the support.

The hydrocracking of heavy wax can be performed under the following reaction conditions. Examples of the hydrogen partial pressure include 0.5 to 12 MPa, but 1.0 to 5.0 MPa is preferable. The liquid hourly space velocity of the middle fraction (LHSV), including but 0.1~10.0h ^-1, 0.3~3.5h ^-1 are preferred. Although there is no restriction | limiting in particular as hydrogen / oil ratio, 50-1000NL / L is mentioned, 70-800NL / L is preferable.

  In this embodiment, it is preferable to hydrocrack the wax so that the content of the fraction having a boiling point of 360 ° C. or less in the wax after contact with the catalyst is 45 to 85% by mass.

  The content of the fraction having a boiling point of 360 ° C. or lower in the wax content before contact with the catalyst and the wax content after contact is measured by a known method such as gas chromatography using samples sampled at the inlet and outlet of the reaction tower. Can be analyzed and determined.

  In addition, in the manufacturing method of the hydrocarbon oil of this embodiment, content of the fraction of the boiling point of 360 degrees C or less in the wax part before a catalyst and a wax part after a contact by the above-mentioned method is 45-85 mass%. The reaction conditions to be determined may be determined in advance, and the hydrogenolysis may be performed under these conditions.

(Distillation of hydrocarbon oil)
The middle distillate after hydrotreating flowing out from the hydrotreating apparatus 20 (hereinafter also referred to as “hydrotreated product”) and the wax fraction after hydrotreating flowing out from the hydrotreating apparatus 30 (hereinafter referred to as “hydrotreated product”). , In some cases referred to as “hydrocracking products”) are transferred to the second distillation column 40 through the gas-liquid separation tanks 22 and 32, respectively, and are distilled together in the second distillation column 40 to obtain a desired It is fractionated into fractions.

  In the gas-liquid separation tanks 22 and 32, the hydrorefined product and the hydrocracked product are, for example, light hydrocarbon gas composed of unreacted hydrogen gas or hydrocarbon having 4 or less carbon atoms, and carbon atoms having 5 or more carbon atoms. It is separated into a liquid hydrocarbon composition oil composed of hydrocarbons. In this case, the liquid hydrocarbon composition oil is transferred to the distillation column 40 as a hydrorefined product and a hydrocracked product. A well-known thing can be used as a gas-liquid separation tank.

  In the second distillation column 40, by setting two cut points and fractionating the hydrorefined product and the hydrocracked product, the fraction below the first cut point is divided into a light fraction, The fraction from the cut point to the second cut point can be obtained as an intermediate fraction, and the fraction above the second cut point can be obtained as tower bottom oil (the above heavy wax content). In the present embodiment, an intermediate fraction that has been fractionated so that the content of a fraction having a boiling point of 150 to 360 ° C. is 90% by mass or more and the content of a fraction having a boiling point of 350 ° C. or more is 5% by mass or more. Obtained as a hydrocarbon oil according to the present invention.

  The first cut point and the second cut point are preferably set within the range of 135 to 170 ° C and the range of 345 to 375 ° C, respectively, within the range of 145 to 155 ° C and 360 to 375 ° C. It is more preferable to set within the range.

  The number of cut points in the second distillation column 40 is not limited to two, and can be set to three or more as long as the above-described hydrocarbon oil according to the present invention is obtained.

  The middle distillate obtained above, that is, the hydrocarbon oil according to the present invention is recovered from the recovery flow path 8. A naphtha fraction that is lighter than the middle distillate is taken out of the system from the flow path 7, while a wax that is heavier than the middle distillate is supplied to the hydrotreating apparatus 30 through the circulation flow path 9. If necessary, it is hydrocracked.

According to the above-described method for producing a hydrocarbon oil of the present invention, a hydrocarbon oil having a pour point of −7.5 ° C. or lower and a kinematic viscosity at 30 ° C. of 2.5 mm ² / s or higher is high. The yield can be obtained. Such a hydrocarbon oil is suitably used as a base material for an environmentally low load diesel fuel, for example.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

<Catalyst adjustment>
(Catalyst 1)
USY zeolite having an average particle diameter of 1.1 μm (silica / alumina molar ratio: 37), silica alumina (silica / alumina molar ratio: 14) and alumina binder were mixed and kneaded at a weight ratio of 3:57:40. After forming into a cylindrical shape having a diameter of about 1.6 mm and a length of about 4 mm, the carrier was obtained by firing at 500 ° C. for 1 hour. This carrier was impregnated with an aqueous chloroplatinic acid solution to carry platinum. This was dried at 120 ° C. for 3 hours and then calcined at 500 ° C. for 1 hour to obtain Catalyst A. The supported amount of platinum was 0.8% by mass with respect to the carrier.

<Manufacture of hydrocarbon oil for diesel fuel base>
Example 1
(Fractionation of FT synthetic oil)
Product oil obtained by the FT synthesis method (FT synthetic oil) (content of hydrocarbons having a boiling point of 150 ° C. or higher: 84 mass%, content of hydrocarbons having a boiling point of 360 ° C. or higher: 42 mass%, both contents The total amount of FT synthetic oil (based on the sum of hydrocarbons having 5 or more carbon atoms) is distilled in a distillation column, a light fraction having a boiling point of 150 ° C. or less and an intermediate fraction having a boiling point of 150 to 350 ° C. (hydrocarbon having a boiling point of 150 to 360 ° C. Content of hydrocarbons having a boiling point of 350 ° C or higher, 4 mass% of hydrocarbons, a content of hydrocarbons having a boiling point of 300 to 350 ° C of 19 mass%, and a hydrocarbon content of boiling point of 150 ° C or lower of 0 mass%) The residue was separated into a heavy wax component (corresponding to a fraction having a boiling point of 350 ° C. or higher).

(Hydrogenation of middle distillate (hydrorefining))
Catalyst A (150 ml) was charged into a fixed bed flow reactor, and the middle distillate obtained above was fed from the top of the reaction tower at a rate of 300 ml / h. Hydrogenated.

  That is, hydrogen was supplied from the top of the middle fraction at a hydrogen / oil ratio of 340 NL / L, and the back pressure valve was adjusted so that the reaction tower pressure was constant at an inlet pressure of 3.0 MPa. The reaction temperature (catalyst bed weight average temperature) was adjusted so that the content of hydrocarbons having a boiling point of 150 ° C. or lower in the later middle distillate (reaction product) was 5% by mass. The reaction temperature at this time was 308 degreeC. In addition, the said content rate was confirmed by the gas chromatography measurement of the middle distillate (reaction product) after a hydrogenation process.

(Hydroprocessing of heavy wax (hydrocracking))
On the other hand, in another reaction tower, catalyst A (150 ml) was charged into a fixed bed flow-type reactor, and the heavy residue in the tower bottom was obtained at a rate of 300 ml / h from the top of the reaction tower. Then, hydrogenation was performed under the following reaction conditions in a hydrogen stream.

  That is, hydrogen was supplied from the top of the column at a hydrogen / oil ratio of 680 NL / L with respect to the wax content, and the back pressure valve was adjusted so that the reaction column pressure was constant at an inlet pressure of 4.0 MPa. The reaction temperature (catalyst bed weight average temperature) was adjusted so that the total content of decomposition products having a boiling point of 360 ° C. or less in the wax content (decomposition product) of the mixture was about 70% by mass. The reaction temperature at this time was 320 degreeC. The content was confirmed by measuring the wax content (decomposition product) after hydrogenation by gas chromatography and analyzing its distillation properties.

(Fractionation of hydrorefined products and hydrocracked products)
The middle distillate hydrofinished product and wax hydrocracked product obtained above were mixed in proportions according to their respective yields, and this mixture was fractionated in a distillation column. A fraction having a boiling point of 150 to 360 ° C. was obtained as the hydrocarbon oil for diesel fuel base material of Example 1. About the obtained hydrocarbon oil, the pour point (° C.) and the kinematic viscosity (mm ² / s) at 30 ° C. were measured. The results are shown in Table 1. The pour point was measured according to the JIS K2269 test method, and the kinematic viscosity at 30 ° C. was measured according to the JIS K2283 test method.

(Example 2)
Instead of obtaining a fraction having a boiling point of 150 to 360 ° C. as a hydrocarbon oil for a diesel fuel base material by fractionation of the hydrorefined product and hydrocracking product in Example 1, a fraction having a boiling point of 150 to 380 ° C. A hydrocarbon oil for diesel fuel base material of Example 2 was obtained in the same manner as Example 1 except that it was obtained as a hydrocarbon oil for diesel fuel base material. The obtained hydrocarbon oil was analyzed in the same manner as in Example 1. The results are shown in Table 1.

(Example 3)
Instead of obtaining a fraction having a boiling point of 150 to 360 ° C. as a hydrocarbon oil for a diesel fuel base material by fractionation of the hydrorefined product and hydrocracking product in Example 1, a fraction having a boiling point of 145 to 380 ° C. A hydrocarbon oil for diesel fuel base material of Example 3 was obtained in the same manner as in Example 1 except that it was obtained as a hydrocarbon oil for diesel fuel base material. The obtained hydrocarbon oil was analyzed in the same manner as in Example 1. The results are shown in Table 1.

Example 4
Instead of obtaining a fraction having a boiling point of 150 to 360 ° C. as a hydrocarbon oil for a diesel fuel base material by fractionation of the hydrorefined product and hydrocracking product in Example 1, a fraction having a boiling point of 140 to 385 ° C. A hydrocarbon oil for diesel fuel base material of Example 4 was obtained in the same manner as in Example 1 except that it was obtained as a hydrocarbon oil for diesel fuel base material. The obtained hydrocarbon oil was analyzed in the same manner as in Example 1. The results are shown in Table 1.

(Example 5)
In the fractionation of FT synthetic oil in Example 1, instead of a fraction having a boiling point of 150 to 350 ° C. as a middle fraction, a fraction having a boiling point of 150 to 356 ° C. (the content of hydrocarbon having a boiling point of 350 ° C. or higher is 4% by mass) The hydrocarbon oil for diesel fuel base material of Example 5 was obtained in the same manner as Example 1 except that the wax content corresponding to the fraction having a boiling point of 356 ° C. or higher was obtained as the residue wax residue at the bottom of the column. It was. The obtained hydrocarbon oil was analyzed in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 1)
In the fractionation of FT synthetic oil in Example 1, instead of a fraction having a boiling point of 150 to 350 ° C. as a middle fraction, a fraction having a boiling point of 150 to 362 ° C. (the content of hydrocarbon having a boiling point of 350 ° C. or higher is 10% by mass) And a hydrocarbon oil for a diesel fuel base material of Comparative Example 1 was obtained in the same manner as in Example 1 except that the wax content corresponding to the fraction having a boiling point of 362 ° C. or higher was obtained as the bottom residue wax content. It was. The obtained hydrocarbon oil was analyzed in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 2)
In the fractionation of FT synthetic oil in Example 1, instead of a fraction having a boiling point of 150 to 350 ° C. as a middle fraction, a fraction having a boiling point of 150 to 375 ° C. (the content of hydrocarbon having a boiling point of 350 ° C. or higher is 20% by mass) And a hydrocarbon oil for a diesel fuel base material of Comparative Example 2 was obtained in the same manner as in Example 1 except that a wax content corresponding to a fraction having a boiling point of 375 ° C. or higher was obtained as a bottom residue wax content. It was. The obtained hydrocarbon oil was analyzed in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 3)
Instead of obtaining a fraction having a boiling point of 150 to 360 ° C. as a hydrocarbon oil for a diesel fuel base material by fractionation of the hydrorefined product and hydrocracking product in Example 1, a fraction having a boiling point of 180 to 330 ° C. A hydrocarbon oil for diesel fuel base material of Comparative Example 3 was obtained in the same manner as in Example 1 except that it was obtained as a hydrocarbon oil for diesel fuel base material. The obtained hydrocarbon oil was analyzed in the same manner as in Example 1. The results are shown in Table 2.

(Comparative Example 4)
The middle distillate in Example 1 is not used, but only the hydrocracking product of the bottom residue wax is fractionated in the distillation column, and the fraction having a boiling point of 150 to 370 ° C. is used as the hydrocarbon oil for the diesel fuel base material. A hydrocarbon oil for a diesel fuel base material of Comparative Example 4 was obtained in the same manner as Example 1 except that it was obtained. The obtained hydrocarbon oil was analyzed in the same manner as in Example 1. The results are shown in Table 2.

It is a flowchart which shows an example of the hydrocarbon oil manufacturing apparatus which enforces the manufacturing method of the hydrocarbon oil of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... FT synthetic oil introduction flow path, 2, 4, 6 ... Flow path, 3 ... Middle distillate flow path, 5 ... Wax distribution flow path, 7, 8 ... Recovery flow path, 9 ... Circulation flow path, 10 ... First Distillation tower, 20, 30 ... hydrotreating apparatus, 22, 32 ... gas-liquid separation tank, 40 ... second distillation tower, 100 ... hydrocarbon oil production apparatus.

Claims (6)

Synthetic oil obtained by the Fischer-Tropsch synthesis method is fractionated, and the content of a fraction having a boiling point of 150 to 360 ° C. is 90% by mass or more and the content of a fraction having a boiling point of 350 ° C. or more is 5% by mass or less. Obtaining a middle distillate and a heavier wax than the middle distillate,
The middle fraction and the wax fraction are each brought into contact with a hydrogenation catalyst in the presence of hydrogen, mixed and fractionated, and the content of a fraction having a boiling point of 150 to 360 ° C. is 86% by mass or more, and A method for producing a hydrocarbon oil, comprising obtaining a hydrocarbon oil having a fraction having a boiling point of 350 ° C or higher of 5% by mass or more.   Hydrogenate the middle distillate so that the content (mass%) of hydrocarbons having a boiling point of 150 ° C. or less in the middle distillate after contact with the hydrogenation catalyst is 3 to 9 mass% higher than that before contact. The method for producing a hydrocarbon oil according to claim 1, wherein the hydrocarbon oil is treated.   The wax is hydrotreated so that the content of a fraction having a boiling point of 360 ° C. or less in the wax after contact with the hydrogenation catalyst is 45 to 85% by mass. The manufacturing method of hydrocarbon oil as described in any one of.   The hydrogenation catalyst to be brought into contact with the middle distillate and the hydrogenation catalyst to be brought into contact with the wax are 0.1% by mass to 80.0% by mass of crystalline zeolite and an amorphous metal oxide having heat resistance. 1% to 60.0% by mass of a carrier, and one or more metals selected from the group consisting of metals belonging to Group VIII of the Periodic Table carried on the carrier. The manufacturing method of the hydrocarbon oil of any one of Claims 1-3 characterized by the above-mentioned. The reaction temperature when contacting the middle distillate and the hydrogenation catalyst is 200 to 370 ° C., the hydrogen partial pressure is 1.0 to 5.0 MPa, and the liquid space velocity is 0.3 to 3.5 h ⁻¹ . And the reaction temperature when the wax component and the hydrogenation catalyst are brought into contact is 200 to 370 ° C., the hydrogen partial pressure is 1.0 to 5.0 MPa, and the liquid space velocity is 0.3 to 3.5 h ^−1. It is these, The manufacturing method of the hydrocarbon oil of any one of Claims 1-4 characterized by the above-mentioned. It is hydrocarbon oil obtained by the manufacturing method in any one of Claims 1-5, Comprising: A pour point is -7.5 degrees C or less, and kinematic viscosity in 30 degrees C is 2.5 mm < ² > / s or more. A hydrocarbon oil characterized by being.

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