CA3029800C

CA3029800C - Method and apparatus for producing hydrocracked oil

Info

Publication number: CA3029800C
Application number: CA3029800A
Authority: CA
Inventors: Yoichi Takahashi; Toshiaki Okui; Motoharu Murota
Original assignee: Chiyoda Corp; Kobe Steel Ltd
Current assignee: Chiyoda Corp; Kobe Steel Ltd
Priority date: 2016-07-11
Filing date: 2017-06-21
Publication date: 2021-02-02
Anticipated expiration: 2037-06-21
Also published as: BR112019000250A2; JP6715709B2; CA3029800A1; BR112019000250B1; JP2018009056A; WO2018012233A1

Abstract

This method for producing a hydrocracked oil uses a petroleum-based heavy oil containing a heavy metal component as a raw material and includes a mixing step for mixing the petroleum-based heavy oil, an iron-based catalyst and hydrogen gas, a hydrocracking step for hydrocracking the petroleum-based heavy oil in a suspended bed reactor following the mixing step, a gas-liquid separation step for subjecting the reaction product from the hydrocracking step to gas-liquid separation in a multi-stage gas-liquid separator, a circulation step for circulating to the mixing step a part of a solid/liquid phase obtained in the gas-liquid separation step and, following the circulation step, a solid-liquid separation step for subjecting a mixture comprising the remainder of the solid/liquid phase and a solvent for solid-liquid separation to solid-liquid separation in a centrifugal separator, wherein the solvent for solid-liquid separation contains more than 10 mass% of each of an aromatic light solvent and a naphtha fraction and kerosene fraction obtained using a hydrocracking method.

Description

DESCRIPTION
TITLE OF THE INVENTION: METHOD AND APPARATUS FOR PRODUCING
HYDROCRACKED OIL
TECHNICAL FIELD
[0001]
The present invention relates to a process for producing a hydrocracked oil and an apparatus for producing a hydrocracked oil.
BACKGROUND ART

[0002]
Crude oil contains various components such as low boiling-point light oil and high boiling-point heavy oil. In recent years, crude oil having a high percentage content of heavy oil (petroleum heavy oil) is increasing as the feed crude oil. On the other hand, in the oil demand aspect, demand remains high for a light oil. Accordingly, a method of producing a light oil from a petroleum heavy oil is attracting attention.

[0003]
As the technique for lightening such a heavy oil, many methods have been proposed for hydrocracking or thermally cracking a heavy oil. Hydrocracking requires a catalyst so as to lighten a heavy oil through reaction with hydrogen, but since the heavy oil contains many heavy metals such as nickel and vanadium, the catalytic activity readily decreases due to catalyst poisoning. Thermal cracking does not involve the problem of decrease in the catalytic activity, but a large amount of coke tends to be produced and the yield of the product is likely to drop.

[0004]
In order to solve such a problem in the hydrocracking or thermal cracking of heavy oil, a hydrocracking method of mixing an inexpensive disposable iron-based catalyst with a heavy oil and performing the reaction in a suspended bed (slurry bed) reactor has been proposed (see, JP-A-2001-89772). In this hydrocracking method, the catalyst used is circulated to the reactor, and the operating cost is thereby reduced.
However, in this hydrocracking method as well, the coke production amount increases depending on the type of heavy oil, and the catalytic activity may decrease.

[0005]
For the purpose of solving the problem of decrease in catalytic activity in the hydrocracking method above, a hydrocracking method of using a solvent prepared by mixing an aromatic light solvent with naphtha obtained from hydrocracking, and performing sedimentation solid-liquid separation under predetermined conditions has been , proposed (see, JP-A-2007-246719). In this hydrocracking method, coke produced in the hydrocracking step is selectively removed from a liquid-phase fluid at a low cost by =
sedimentation solid-liquid separation under predetermined conditions, and catalytic activity reduction associated with coke production is thereby suppressed.

[0006]
The aromatic light solvent mixed with the solvent above in the hydrocracking method enhances extractability of a solid matter from the liquid-phase fluid but decreases the sedimentation velocity. On the other hand, naphtha mixed with this solvent improves the sedimentability but reduces the extractability and in turn, the solid is likely to coagulate. Consequently, the hydrocracking method requires a relatively long time for sedimentation at the solid-liquid separation due to effects from the action of reducing the sedimentability by an aromatic light solvent and the action of reducing the extractability by a naphtha fraction, and it is therefore demanded to enhance the production efficiency. In addition, since the hydrocracking method requires the solid-liquid separation conditions to be set at a relatively high temperature and a high pressure, the apparatus grows in size depending on the property of raw material and the equipment cost may rise.
PRIOR ART LITERATURE
Patent Document

[0007]
Patent Document 1: JP-A-2001-89772 Patent Document 2: JP-A-2007-246719 SUMMARY OF THE INVENTION
Problems that the Invention is to Solve

[0008]
The present invention has been made under these circumstances, and an object of the present invention is to provide a process for producing a hydrocracked oil and an apparatus for producing a hydrocracked oil, ensuring that the time required for coke produced in the hydrocracking step to be selectively removed by sedimentation solid-liquid separation can be shortened and the equipment cost can be reduced.
Means for Solving the Problems

[0009]
An invention having been made to solve the problem above is a process for producing a hydrocracked oil by using, as a feed material, a petroleum heavy oil containing a heavy metal component, the process including a mixing step of mixing the petroleum heavy oil, an iron-based catalyst and a hydrogen gas, a hydrocracking step of = , hydrocracking the petroleum heavy oil in a suspended bed reactor after the mixing step, a gas-liquid separation step of subjecting a reaction product after the hydrocracking step to a gas-liquid separation in a multistage gas-liquid separator, a circulation step of circulating a part of a solid-liquid phase obtained in the gas-liquid separation step to the mixing step, and a solid-liquid separation step of performing, by means of a centrifuge, a solid-liquid separation of a mixture of a remainder of the solid-liquid phase after the circulation step and a solvent for solid-liquid separation, in which the solvent for solid-liquid separation contains a naphtha fraction and a kerosene fraction obtained by a hydrocracking method and an aromatic light solvent, each in an amount of more than 10 mass%.

[0010]
In the hydrocracked oil production process, the solvent for solid-liquid separation contains an aromatic light solvent, a naphtha fraction and a kerosene fraction, the content of each being in the range above, whereby the action of reducing the sedimentability by an aromatic light solvent and the action of reducing the extractability by a naphtha fraction can be suppressed. Consequently, in the hydrocracked oil production process, it becomes possible to increase the separability and shorten the sedimentation time in the step of performing solid-liquid separation of a mixture of the remainder of the solid-liquid phase obtained in the gas-liquid separation step and the solvent for solid-liquid separation.
Furthermore, in the hydrocracked oil production process, solid-liquid separation of the mixture above is performed by means of a centrifuge, so that upsizing of the solid-liquid separating apparatus can be suppressed without requiring relatively high temperature and high pressure conditions and the equipment cost can therefore be reduced. The "sedimentation" as used herein is a concept encompassing movement of a solid having a large specific gravity to the outer circumferential side due to centrifugal force of the centrifuge, and the "sedimentation time" means an average time required for a plurality of solids to move to the outer circumferential side of the centrifuge.

[0011]
The solvent for solid-liquid separation has a mass ratio relative to a mass of the remainder of the solid-liquid phase in the mixture of preferably 0.5 or more and 4 or less, and in the solid-liquid separation step, the mixture in the centrifuge has a temperature of C or more and 130 C or less and a residence time of 60 seconds or less. In this way, when the mass ratio of the solvent for solid-liquid separation relative to the mass of the remainder of the solid-liquid phase in the mixture is set within the range above, the effect of enhancing the separability in the solid-liquid separation step can be promoted while 35 suppressing the use amount of the solvent for solid-liquid separation.
In addition, when the temperature of the mixture in the centrifuge is set within the range above, evaporation of the kerosene fraction can be suppressed while enhancing the extractability of a heavy organic material. Furthermore, when the residence time of the mixture in the centrifuge is 0.
* =

set to be not more than the upper limit above, downsizing of the solid-liquid separating apparatus can be promoted.

[0012]
The gas-liquid separation step preferably includes a first step of subjecting the reaction product after the hydrocracking step to a gas-liquid separation in a high-pressure gas-liquid separator, a second step of subjecting a solid-liquid phase separated in the first step to a gas-liquid separation in a low-pressure gas-liquid separator, and a third step of subjecting a solid-liquid phase separated in the second step to a gas-liquid separation in a reduced-pressure gas-liquid separator. In this way, when the gas-liquid separation step includes a first step, a second step and a third step, and gas-liquid separation is performed in a plurality of gas-liquid separators providing pressure and temperature conditions getting lower in the order above, a solid-liquid phase having a large content of vacuum heavy residue can be efficiently separated.

[0013]
It is preferable that the process for producing a hydrocracked oil further includes a fractionation step of fractionating a gas phase obtained in the gas-liquid separation step and a liquid phase obtained in the solid-liquid separation step and uses, as the naphtha fraction and kerosene fraction of the solvent for solid-liquid separation, a naphtha fraction and a kerosene fraction obtained in the fractionation step. In this way, when a naphtha fraction and a kerosene fraction obtained in the fractionation step are used as the naphtha fraction and kerosene fraction of the solvent for solid-liquid separation, procurement and transport of the naphtha fraction and kerosene fraction are facilitated.

[0014]
It is preferred that the aromatic light solvent is a single component having a boiling point of 150 C or less or a mixed component thereof, the naphtha fraction has a boiling point of 80 C or more and 180 C or less, and the kerosene fraction has a boiling point of more than 180 C and 240 C or less. In this way, an aromatic light solvent, naphtha fraction and kerosene fraction having a boiling point in respective ranges above are used as the solvent for solid-liquid separation, and this makes it possible to prevent vapor pressure of the solvent for solid-liquid separation from rising and suppress an increase in the heat quantity necessary for recovering the liquid phase and the solid separated in the solid-liquid separation step, so that the effect of holding down the equipment cost and the hydrocracked oil production cost can be promoted. The "boiling point" as used herein means the boiling point at 1 atm (101,325 Pa).

[0015]
In the solid-liquid separation step, the mixture in the centrifuge preferably has a residence time of 30 seconds or less, and the centrifuge preferably has a centrifugal force of 3,000 G or less. In this way, when the residence time of the mixture in the centrifuge is a a.

set to be 30 seconds or less and the centrifugal force of the centrifuge is set to be 3,000 G
or less, upsizing of the solid-liquid separating apparatus can be more reliably suppressed and the effect of reducing the equipment cost can be promoted.

[0016]
The iron-based catalyst is preferably a limonite iron ore catalyst having an average particle diameter of 21.1m or less, and the iron-based catalyst has a mass ratio relative to a mass of the petroleum heavy oil in the mixing step of preferably 0.003 or more and 0.02 or less in terms of iron. In this way, a limonite iron ore catalyst having the above-described average particle diameter is used as the iron-based catalyst, which makes it possible to promote a hydrogenation reaction at a low cost, and the mass ratio of the iron-based catalyst relative to the mass of the petroleum heavy oil is set to fall within the range above, which makes it possible to promote the effect of increasing the yield of hydrocracked oil.
The "average particle diameter" as used herein means the particle diameter (median diameter) at a cumulative value of 50% by volume in the particle size distribution determined by the laser diffraction scattering method.

[0017]
Another invention having been made to solve the problem above is an apparatus for producing a hydrocracked oil by using, as a feed material, a petroleum heavy oil containing a heavy metal component, the apparatus including a mixing part for mixing the petroleum heavy oil, an iron-based catalyst and a hydrogen gas, a suspended bed reaction part for hydrocracking the petroleum heavy oil in a feed slurry obtained in the mixing part, a gas-liquid separation part for performing a multistage gas-liquid separation of a reaction product produced in the suspended bed reaction part, a circulation part for circulating a part of a solid-liquid phase obtained in the gas-liquid separation part to the mixing part, and a centrifugal separation part for performing a solid-liquid separation of a mixture of a remainder of the solid-liquid phase obtained in the gas-liquid separation part and a solvent for solid-liquid separation, in which the solvent for solid-liquid separation contains a naphtha fraction and a kerosene fraction obtained by a hydrocracking method and an aromatic light solvent, each in an amount of more than 10 mass%.

[0018]
In the apparatus for producing a hydrocracked oil, the solvent for solid-liquid separation contains an aromatic light solvent, a naphtha fraction and a kerosene fraction, the content of each being in the range above, whereby the action of reducing the sedimentability by an aromatic light solvent and the action of reducing the extractability by a naphtha fraction can be suppressed. Consequently, in the hydrocracked oil production apparatus, it becomes possible to elevate, in a centrifugal separation part, the separability of a mixture of the remainder of the solid-liquid phase obtained in the gas-liquid separation part and the solvent for solid-liquid separation and also shorten the sedimentation time.

A
= = 6 Furthermore, in the hydrocracked oil production apparatus, solid-liquid separation of the mixture above is performed by means of a centrifuge, so that upsizing of the solid-liquid separating apparatus can be suppressed without requiring relatively high temperature and high pressure conditions and the equipment cost can therefore be reduced.
Advantage of the Invention

[0019]
As described above, according to the hydrocracked oil production process and hydrocracked oil production apparatus of the present invention, the time required for coke produced in the hydrocracking step to be selectively removed by sedimentation solid-liquid separation can be shortened and the equipment cost can be reduced.
Brief Description of the Drawings

[0020]
[Fig. 1] Fig. 1 is a diagrammatic and schematic view illustrating the configuration of the hydrocracked oil production apparatus according to one embodiment of the present invention.
Mode for Carrying Out the Invention

[0021]
An embodiment of the hydrocracked oil production apparatus and hydrocracked oil production process according to the present invention are described below by referring to the drawings.

[0022]
[Hydrocracked Oil Production Apparatus]
The hydrocracked oil production apparatus according to the present embodiment is an apparatus for producing a hydrocracked oil by using, as a feed material, a petroleum heavy oil containing a heavy metal component. The hydrocracked oil production apparatus mainly includes a mixing part for mixing the petroleum heavy oil, an iron-based catalyst and a hydrogen gas, a suspended bed reaction part for hydrocracking the petroleum heavy oil in the feed slurry obtained in the mixing part, a gas-liquid separation part for performing multistage gas-liquid separation of the reaction product produced in the suspended bed reaction part, a circulation part for circulating part of the solid-liquid phase obtained in the gas-liquid separation part to the mixing part, and a centrifugal separation part for performing solid-liquid separation of a mixture of the remainder of the solid-liquid phase obtained in the gas-liquid separation part and a solvent for solid-liquid separation.
In addition, the hydrocracked oil production apparatus includes a gas purification part for purifying a gas from the gas phase separated in the gas-liquid separation part, and a .
. 1 . 7 fractionation part for fractionating the gas phase obtained in the gas-liquid separation part and the liquid phase obtained in the centrifugal separation part.

[0023]
The hydrocracked oil production apparatus has specifically, as illustrated in Fig. 1, a slurry preparation tank 1, a preheater 2, a first pump 3, a suspended bed reactor 4, a high-pressure gas-liquid separator 5, a low-pressure gas-liquid separator 6, a reduced-pressure gas-liquid separator 7, a mixture preparation tank 8, a second pump 9, a centrifuge 10, a third pump 11, an overflow solvent recovery unit 12, an underflow solvent recovery unit 13, a high-pressure low-temperature gas-liquid separator 14, a gas purification unit 15, and a distillation column 16.

[0024]
<Mixing Part>
The mixing part of the hydrocracked oil production apparatus has a slurry preparation tank 1, and a pipeline arranged between the slurry preparation tank 1 and a preheater 2. In the mixing part, a petroleum heavy oil A, an iron-based catalyst B and a hydrogen gas C are mixed.

[0025]
The slurry preparation tank 1 is a tank for mixing the petroleum heavy oil A
and the iron-based catalyst B to form a slurry. The slurry preparation tank I is equipped with a stirrer la.

[0026]
The preheater 2 is a heater for preheating a feed slurry D supplied to the suspended bed reactor 4.

[0027]
A first pump 3 is a pump for transferring the slurry prepared in the slurry preparation tank 1 to the preheater 2. Within the pipeline through which the slurry is transferred from the slurry preparation tank 1 to the preheater 2 by the first pump 3, a hydrogen gas C is supplied to the slurry. In this way, the slurry and the hydrogen gas C
are mixed in the pipeline, whereby a feed slurry D is formed. The feed slurry D is heated in the preheater 2 and supplied to the suspended bed reactor 4.

[0028]
<Suspended Bed Reaction Part>
The suspended bed reaction part of the hydrocracked oil production apparatus has a suspended bed reactor 4. In the suspended bed reactor 4, the petroleum heavy oil A in the feed slurry D is hydrocracked. As the suspended bed reactor 4, for example, a bubble tower-type suspended bed reactor may be used.

[0029]
<Gas-Liquid Separation Part>

. t 8 The gas-liquid separation part of the hydrocracked oil production apparatus has a high-pressure gas-liquid separator 5, a low-pressure gas-liquid separator 6, and a reduced-pressure gas-liquid separator 7. In the gas-liquid separation part, a reaction product E
produced in the suspended bed reactor 4 is subjected to multistage gas-liquid separation through the high-pressure gas-liquid separator 5, the low-pressure gas-liquid separator 6 and the reduced-pressure gas-liquid separator 7.

[0030]
In the high-pressure gas-liquid separator 5, the reaction product E produced in the suspended bed reactor 4 is separated into a gas phase and a solid-liquid phase at a high temperature and a high pressure. As the high-pressure gas-liquid separator 5, for example, a known gas-liquid separator utilizing gravity or centrifugal force may be used.
The pressure of the high-pressure gas-liquid separator 5 is, for example, 8 MPaG or more and 17 MPaG or less, and the heating temperature of the high-pressure gas-liquid separator 5 is, for example, 380 C or more and 420 C or less. The solid-liquid phase contains a heavy oil component (heavy reaction product) and a solid (coke and the iron-based catalyst B) and additionally contains a light oil component. Here, the heavy oil component is an oil component having a boiling point of 525 C or more, and the light oil component is an oil component excluding the heavy oil component and having a lower boiling point than that of the heavy oil component.

[0031]
In the low-pressure gas-liquid separator 6, the solid-liquid phase separated by means of the high-pressure gas-liquid separator 5 is separated into a gas phase and a solid-liquid phase at a high-temperature and a low pressure. As the low-pressure gas-liquid separator 6, for example, a known gas-liquid separator utilizing gravity or centrifugal force may be used. The pressure of the low-pressure gas-liquid separator 6 is, for example, 0.1 MPaG or more and 1 MPaG or less, and the heating temperature of the low-pressure gas-liquid separator 6 is, for example, 360 C or more and 400 C or less.

[0032]
In the reduced-pressure gas-liquid separator 7, the solid-liquid phase separated in the low-pressure gas-liquid separator 6 is separated into a gas phase and a solid-liquid phase F. As the reduced-pressure gas-liquid separator 7, for example, a known gas-liquid separator utilizing gravity or centrifugal force may be used. The pressure of the reduced-pressure gas-liquid separator 7 is, for example, 5 mmHG or more and 50 mmHG or less, and the heating temperature of the reduced-pressure gas-liquid separator 7 is, for example, 330 C or more and 370 C or less. The solid-liquid phase F contains a heavy oil component (heavy reaction product) and a solid and additionally contains a light oil component. The solid-liquid phase F discharged from the reduced-pressure gas-liquid = a 1 = = 9 separator 7 is in the state where the heavy oil component is dissolved in a light oil component and a solid is mixed with the oil component.

[0033]
<Circulation Part>
The circulation part of the hydrocracked oil production apparatus has a second pump 9 and a pipeline between the second pump 9 and the slurry preparation tank 1. The second pump 9 is a pump for circulating part of the solid-liquid phase F
separated in the reduced-pressure gas-liquid separator 7 to the slurry preparation tank 1 and for supplying the remainder of the solid-liquid phase F to a mixture preparation tank 8.

[0034]
The mixture preparation tank 8 is a tank for mixing the solid-liquid phase F
separated in the reduced-pressure gas-liquid separator 7 with a solvent G for solid-liquid separation to obtain a mixture H. The mixture preparation tank 8 is equipped with a stirrer 8a.

[0035]
The third pump 11 is a pump for supplying the mixture H mixed in the mixture preparation tank 8 to the centrifuge 10.

[0036]
<Centrifugal Separation Part>
The centrifugal separation part of the hydrocracked oil production apparatus has a centrifuge 10, an overflow solvent recovery unit 12, and an underflow solvent recovery unit 13.

[0037]
The centrifuge 10 performs solid-liquid separation of the mixture H by centrifugation utilizing the difference in specific gravity between solid and liquid.
Specifically, the centrifuge 10 applies a centrifugal force to the mixture H
supplied into the inside thereof by rotation of a rotor so as to accelerate the moving speed of a solid particle in the mixture H toward the outer circumferential side and move a solid matter to the outer circumferential side. In the centrifuge 10, the solid matter of the mixture H
is thus moved to the outer circumferential side, and the mixture H is thereby separated into a liquid phase and a solid matter. The solid matter of the mixture H, separated in this way to the outer circumferential side in the centrifuge 10, is discharged from a solid matter discharge outlet.
The liquid phase of the mixture H, separated to the inner side of the centrifuge 10, is discharged from a liquid phase discharge outlet. The centrifuge 10 may be sufficient if solid-liquid separation of the mixture H can be achieved, and, for example, a decanter-type centrifuge capable of mechanically discharging a sedimented solid may be used.
In addition, the centrifuge 10 may be one for processing the mixture H batchwise or one for . = µ.=
=1 10 processing it continuously, but the separation time per throughput can be more shortened by processing continuously.

[0038]
In the overflow solvent recovery unit 12, the liquid phase separated by means of the centrifuge 10 is supplied, the solvent G for solid-liquid separation is separated from the liquid phase, and the separated solvent G for solid-liquid separation is supplied to the mixture preparation tank 8 and reused. In the overflow solvent recovery unit 12, the solvent G for solid-liquid separation contained in the liquid phase is vaporized, for example, by heating, and the vaporized solvent G for solid-liquid separation is cooled, whereby the solvent G for solid-liquid separation is separated. Since the boiling point of a component contained in the solvent G for solid-liquid separation is 240 C or less as described later, for example, a drier capable of heating at 240 C or more may be used as the overflow solvent recovery unit 12. Part of the fluid after separating the solvent G for solid-liquid separation in the overflow solvent recovery unit 12 is circulated to the slurry preparation tank 1, and the remainder of the fluid is supplied to the distillation column 16.

[0039]
In the underflow solvent recovery unit 13, the solid matter separated by means of the centrifuge 10 is supplied, the solvent G for solid-liquid separation is separated from the solid matter, and the separated solvent G for solid-liquid separation is supplied to the mixture preparation tank 8 and reused. In the underflow solvent recovery unit 13, the solvent G for solid-liquid separation contained in the solid matter is vaporized, for example, by heating, and the vaporized solvent G for solid-liquid separation is cooled, whereby the solvent G for solid-liquid separation is separated. Accordingly, for example, a drier capable of heating at 240 C or more may be used as the underflow solvent recovery unit 13. The solid matter after separating the solvent G for solid-liquid separation in the underflow solvent recovery unit 13 is discharged as sludge J.

[0040]
In the high-pressure low-temperature gas-liquid separator 14, the gas phase separated by means of the high-pressure gas-liquid separator 5 is supplied, and the gas phase is further separated into a gas phase and a liquid phase. As the high-pressure low-temperature gas-liquid separator 14, for example, a known gas-liquid separator utilizing gravity or centrifugal force may be used. The gas phase separated in the high-pressure low-temperature gas-liquid separator 14 is supplied to the gas purification unit 15, and the liquid phase separated in the high-pressure low-temperature gas-liquid separator 14 is supplied to the distillation column 16 together with the gas phases separated in the low-pressure gas-liquid separator 6 and the reduced-pressure gas-liquid separator 7.

[0041]
<Gas Purification Part>

a.
, . 11 The gas purification part of the hydrocracked oil production apparatus has a gas purification unit 15. The gas purification unit 15 purifies a gas K from the gas phase separated in the high-pressure low-temperature gas-liquid separator 14. In the gas purification unit 15, for example, an unnecessary gas contained in the gas phase above is adsorbed on an adsorption column, etc. to purify a necessary component gas.
For example, in the case of purifying a hydrogen gas, adsorbent for adsorbing an unnecessary gas other than hydrogen gas, such as CO, CI-14, H20, and CO2, is packed in the adsorption column, whereby high-purity hydrogen gas can be purified. Part of the gas K
purified in the gas purification unit 15 is utilized as a fuel gas, and the remainder is used as a recycle gas for the cooling gas of the suspended bed reactor 4.

[0042]
<Fractionation Part>
The fractionation part of the hydrocracked oil production apparatus has a distillation column 16. In the distillation column 16, the gas phases separated in the low-pressure gas-liquid separator 6 and the reduced-pressure gas-liquid separator 7, the liquid phase separated in the high-pressure low-temperature gas-liquid separator 14, and the fluid after separating the solvent G for solid-liquid separation in the overflow solvent recovery unit 12 are supplied and fractionated to predetermined fractions. As the distillation column 16, for example, a known plate distillation column may be used. For example, the above-described gas phases, liquid phase and fluid are heated at about 350 C, then supplied into the distillation column 16 and turned to be a petroleum vapor in the distillation column 16, and the petroleum vapor is cooled and then separated in order from one having a low boiling point to one having a high boiling point.
Consequently, for example, as illustrated in Fig. 1, naphtha L, kerosene M, light oil N, and vacuum gas oil P
are in order separated and withdrawn. In addition, an ash-free residue Q is withdrawn from the lower part of the distillation column 16.

[0043]
(Solvent for Solid-Liquid Separation) The solvent G for solid-liquid separation, mixed with the solid-liquid phase F
in the mixture preparation tank 8, contains an aromatic light solvent, a naphtha fraction and a kerosene fraction.

[0044]
The content of the aromatic light solvent in the solvent G for solid-liquid separation is more than 10 mass%, and the lower limit of the content of the aromatic light solvent is preferably 20 mass%, more preferably 30 mass%. In addition, the content of the aromatic light solvent is preferably less than 80 mass%, and the upper limit of the content of the aromatic light solvent is preferably 60 mass%, more preferably 40 mass%.
If the content of the aromatic light solvent is less than the lower limit above, extractability to.

of a solid from the solid-liquid phase F may be reduced, failing in obtaining sufficient separability. Conversely, if the content of the aromatic light solvent exceeds the upper limit above, the sedimentation velocity may be decreased, increasing the hydrocracked oil production time, and since the aromatic light solvent is expensive, the hydrocracked oil production cost may rise.

[0045]
The content of the naphtha fraction in the solvent G for solid-liquid separation is more than 10 mass%, and the lower limit of the content of the naphtha fraction is preferably 20 mass%, more preferably 30 mass%. On the other hand, the upper limit of the content of the naphtha fraction is preferably 75 mass%, more preferably 60 mass%, still more preferably 40 mass%. If the content of the naphtha fraction is less than the lower limit above, the sedimentation velocity may be decreased, increasing the hydrocracked oil production time. Conversely, if the content of the naphtha fraction exceeds the upper limit above, extractability of a solid from the solid-liquid phase F may be reduced, making it likely to cause clogging in the lower part of the centrifuge 10 due to solids aggregation.

[0046]
The content of the kerosene fraction in the solvent G for solid-liquid separation is more than 10 mass%, and the lower limit of the content of the kerosene fraction is preferably 20 mass%, more preferably 30 mass%. On the other hand, the upper limit of the content of the kerosene fraction is preferably 75 mass%, more preferably 60 mass%, still more preferably 40 mass%. If the content of the kerosene fraction is less than the lower limit above, the action of reducing the sedimentation velocity by an aromatic light solvent may not be sufficiently suppressed, increasing the hydrocracked oil production time. Conversely, if the content of the kerosene fraction exceeds the upper limit, it is likely that the heat quantity required when recovering the solvent G for solid-liquid separation increases and in turn, the operating cost rises.

[0047]
As long as the solvent G for solid-liquid separation contains an aromatic light solvent, a naphtha fraction and a kerosene fraction each in the range above, the solvent may contain other components. The solvent G for solid-liquid separation contains an aromatic light solvent, a naphtha fraction and a kerosene fraction each in the range above, whereby the extractability of a solid from the solid-liquid phase F, sedimentability, and the handleability, recoverability, etc. of the solvent G for solid-liquid separation can be achieved in a balanced manner. Furthermore, when the contents of an aromatic light solvent, a naphtha fraction and a kerosene fraction in the solvent G for solid-liquid separation are set to be substantially the same, respective effects above can be obtained in a balanced manner. More specifically, it is particularly preferred that the solvent G for Ph = = = 13 solid-liquid separation contains aromatic light solvent, naphtha fraction and kerosene fraction in an amount of 1/3 each.

[0048]
The aromatic light solvent contained in the solvent G for solid-liquid separation is preferably a single component having a boiling point of 150 C or less or a mixed component thereof. If one having a boiling point of more than 150 C is used as the aromatic light solvent, since the temperature in the centrifuge 10 must be set high so as to enhance the extractability, the processing cost for solid-liquid separation may rise. As the aromatic light solvent having a boiling point of 150 C or less, for example, benzene, toluene and xylene may be used.

[0049]
The naphtha fraction contained in the solvent G for solid-liquid separation is preferably one having a boiling point of 80 C or more and 180 C or less, and the kerosene fraction contained in the solvent G for solid-liquid separation is preferably one having a boiling point of more than 180 C and 240 C or less. If a naphtha fraction having a boiling point of less than 80 C is used, it is likely that the vapor pressure of the solvent G
for solid-liquid separation becomes excessively high and the equipment cost rises so as to cope with the vapor pressure. If a kerosene fraction having a boiling point of more than 240 C is used, it is likely that the heat quantity required when recovering the solvent G for solid-liquid separation in the overflow solvent recovery unit 12 and the underflow solvent recovery unit 13 increases and in turn, the operating cost rises.

[0050]
[Hydrocracked Oil Production Process]
The hydrocracked oil production process according to the present embodiment is a process for producing a hydrocracked oil by using, as a feed material, a petroleum heavy oil containing a heavy metal component. The hydrocracked oil production process mainly includes a mixing step of mixing the petroleum heavy oil A, an iron-based catalyst B and a hydrogen gas C, a hydrocracking step of hydrocracking the petroleum heavy oil A
in a suspended bed reactor 4 after the mixing step, a gas-liquid separation step of subjecting the reaction product E after the hydrocracking step to gas-liquid separation in multistage gas-liquid separators 5, 6 and 7, a circulation step of circulating part of the solid-liquid phase F obtained in the gas-liquid separation step to the mixing step, and a solid-liquid separation step of performing, by means of a centrifuge 10, solid-liquid separation of a mixture H of the remainder of the solid-liquid phase F after the circulation step and a solvent G for solid-liquid separation. In addition, the hydrocracked oil production process includes a step of purifying a gas from the gas phase separated in the gas-liquid separation step, and a step of fractionating the gas phase obtained in the gas-liquid separation step and the liquid phase obtained in the solid-liquid separation step.

= . 14

[0051]
<Mixing Step>
In the mixing step, a petroleum heavy oil A, an iron-based catalyst B and a hydrogen gas C are mixed. Specifically, in a slurry preparation tank 1, a petroleum heavy oil A and an iron-based catalyst B are supplied to the slurry preparation tank 1. In the slurry preparation tank 1, the petroleum heavy oil A and the iron-based catalyst B are mixed by means of a stirrer la, and a slurry containing the petroleum heavy oil A and the iron-based catalyst B is thereby obtained. The slurry obtained by this mixing is mixed with a hydrogen gas C in a pipeline, and a feed slurry D is thereby obtained.
This feed slurry D is supplied to the suspended bed reactor 4 through the preheater 2.

[0052]
The petroleum heavy oil A is not particularly limited, but a petroleum heavy oil such as atmospheric distillation residue oil and vacuum distillation residue oil may be used.
In addition, an extra heavy oil such as naturally occurring bitumen (e.g., tar sand, oil sand) may also be used.

[0053]
The iron-based catalyst B is not particularly limited as long as it has high activity as the catalyst for a hydrocracking reaction of the petroleum heavy oil A, but it includes, for example, a limonite iron ore catalyst, pyrite, hematite, iron sulfate, and red mud.
Among these, a limonite iron ore catalyst is preferred. The limonite iron ore catalyst is highly active compared with pyrite, hematite, iron sulfate and other iron-based catalysts and is an inexpensive naturally occurring catalyst.

[0054]
The lower limit of the average particle diameter of the iron-based catalyst B
is preferably 0.1 pm, more preferably 0.3 um. On the other hand, the upper limit of the average particle diameter of the iron-based catalyst B is preferably 2 um, more preferably 1.2 um. If the average particle diameter of the iron-based catalyst B is less than the lower limit above, mechanical grinding for obtaining an iron-based catalyst B having such a small average particle diameter may take time, decreasing the processing efficiency of hydrocracking. Conversely, if the average particle diameter of the iron-based catalyst B
exceeds the upper limit above, it is likely that since the effective surface area of the iron-based catalyst B is insufficient, the catalytic activity decreases and in turn, the yield of hydrocracked oil cannot be sufficiently enhanced.

[0055]
The lower limit of the mass ratio of the iron-based catalyst B relative to the petroleum heavy oil A in the mixing step is, in terms of iron, preferably 0.003, more preferably 0.005. On the other hand, the upper limit of the mass ratio is, in terms of iron, preferably 0.02, more preferably 0.015. If the mass ratio is less than the lower limit above, the coke production amount tends to be rapidly increased, and the production of coke may not be sufficiently suppressed. Conversely, if the mass ratio exceeds the upper limit above, the processing cost for hydrocracking may rise.

[0056]
5 The temperature when the slurry mixed in the slurry preparation tank 1 is heated in the preheater 2 may be near the temperature at which the hydrocracking reaction starts.

[0057]
<Hydrocracking Step>
In the hydrocracking step, the petroleum heavy oil A in the feed slurry D is 10 hydrocracked with the hydrogen gas C in the suspended bed reactor 4. The reaction product E is obtained by this hydrocracking.

[0058]
The lower limit of the hydrocracking reaction pressure (hydrogen gas supply pressure) in the suspended bed reactor 4 is preferably 5 MPa, more preferably 7 MPa. On 15 the other hand, the upper limit of the hydrocracking reaction pressure is preferably 20 MPa, more preferably 17 MPa. If the hydrocracking reaction pressure is less than the lower limit above, since the hydrogen partial pressure drops and the coke production amount increases, the catalytic activity of the iron-based catalyst B may be reduced.
Conversely, if the hydrocracking reaction pressure exceeds the upper limit above, the reaction promoting effect of the increased pressure may not be obtained, leading to a rise of the processing cost for hydrocracking. Here, the reaction pressure can be adjusted by the amount of the hydrogen gas C supplied in the mixing step.

[0059]
The lower limit of the hydrogenation reaction temperature in the suspended bed reactor 4 is preferably 400 C, more preferably 430 C. On the other hand, the upper limit of the hydrogenation reaction temperature is preferably 480 C, more preferably 455 C. If the hydrogenation reaction temperature is less than the lower limit above, it is likely that the hydrocracking reaction is difficult to proceed and a lightened oil is not sufficiently obtained. Conversely, if the hydrogenation reaction temperature exceeds the upper limit above, the coke production amount may be readily increased due to a thermal cracking reaction, resulting in reduction of catalytic activity of the iron-based catalyst B.

[0060]
The lower limit of the hydrogenation reaction time in the suspended bed reactor 4 is preferably 30 minutes, more preferably 60 minutes. On the other hand, the upper limit of the hydrogenation reaction time is preferably 180 minutes, more preferably 120 minutes.
If the hydrogenation reaction time is less than the lower limit above, a lightened oil may not be sufficiently obtained. Conversely, if the hydrogenation reaction time exceeds the a, upper limit, it is likely that the increase in amount of a lightened oil is small relative to the increase in time and the hydrocracked oil production efficiency deteriorates.

[0061]
<Gas-Liquid Separation Step>
In the gas-liquid separation step, gas-liquid separation of the reaction product E
obtained in the suspended bed reactor 4 is performed by using a multistage gas-liquid separator. Specifically, the gas-liquid separation step includes first step, second step and third step of performing gas-liquid separation using gas-liquid separators different from each other. In the gas-liquid separation step, gas-liquid separation is performed in order of first step, second step and third step. In the first step, second step and third step, gas-liquid separation is performed by using different gas-liquid separators providing pressure and temperature conditions getting lower in the order above.

[0062]
(First Step) In the first step, the reaction product E after the hydrocracking step is subjected to gas-liquid separation by means of the high-pressure gas-liquid separator 5.

[0063]
(Second Step) In the second step, the solid-liquid phase separated by means of the high-pressure gas-liquid separator 5 in the first step is subjected to gas-liquid separation by means of the low-pressure gas-liquid separator 6.

[0064]
(Third Step) In the third step, the solid-liquid phase separated by means of the low-pressure gas-liquid separator 6 in the second step is subjected to gas-liquid separation by means of the reduced-pressure gas-liquid separator 7.

[0065]
<Circulation Step>
In the circulation step, part of the solid-liquid phase F obtained in the gas-liquid separation step is circulated to the mixing step. Specifically, part of the solid-liquid phase F separated by means of the reduced-pressure gas-liquid separator 7 in the third step of the gas-liquid separation step is supplied to the slurry preparation tank 1 through a pipeline by means of the second pump 9. The iron-based catalyst B contained in the solid-liquid phase F is thereby reused.

[0066]
In the stationary state, the lower limit of the proportion by mass of the iron-based catalyst B relative to the petroleum heavy oil A in the feed slurry D is preferably 2 mass%, more preferably 3 mass%. On the other hand, the upper limit of the proportion by mass = 17 of the iron-based catalyst B in the feed slurry D is preferably 11 mass%, more preferably 6 mass%. If the proportion by mass of the iron-based catalyst B in the feed slurry D is less than the lower limit above, it is likely that the supply amount of the iron-based catalyst B is insufficient and the yield of hydrocracked oil decreases. Conversely, if the proportion by mass of the iron-based catalyst B in the feed slurry D exceeds the upper limit, since the supply amount of the iron-based catalyst B newly supplied or the iron-based catalyst B
reused must be increased, the processing cost for hydrocracking may rise. The "stationary state" as used herein indicates a state where the total amount of the iron-based catalyst B in the suspended bed reactor 4 is out of a transient state such as apparatus startup time, and is, for example, a state where although it somewhat varies with the elapse of time, the variation rate per unit time of the total amount of the iron-based catalyst B in the suspended bed reactor 4 stays at 10 mass% or less.

[0067]
<Solid-Liquid Separation Step>
In the solid-liquid separation step, a mixture H of the remainder of the solid-liquid phase F after the circulation step and the solvent G for solid-liquid separation is subjected to solid-liquid separation by means of the centrifuge 10. Specifically, a mixture H
obtained by mixing the solid-liquid phase F and the solvent G for solid-liquid separation in the mixture preparation tank 8 is supplied to the centrifuge 10 by the third pump 11, and the centrifuge 10 performs solid-liquid separation of the mixture H. Here, in the mixture preparation tank 8, out of the solid-liquid phase F separated by means of the reduced-pressure gas-liquid separator 7, the remainder excluding a part cyclically utilized in the circulation step is supplied by the second pump 9, and the solid-liquid phase F and the solvent G for solid-liquid separation are mixed by using the stirrer 8a to produce the mixture H.

[0068]
In the solid-liquid separation step, the solvent G for solid-liquid separation is recovered from the liquid phase and solid matter separated by means of the centrifuge 10, and the recovered solvent G for solid-liquid separation is circulated to the solid-liquid separation step. Specifically, the solvent G for solid-liquid separation is separated by means of the overflow solvent recovery unit 12 from the liquid phase having been separated by the centrifuge 10, and the separated solvent G for solid-liquid separation is supplied to the mixture preparation tank 8. In addition, the solvent G for solid-liquid separation is separated by means of the underflow solvent recovery unit 13 from the solid material having been separated by the centrifuge 10, and the separated solvent G for solid-liquid separation is supplied to the mixture preparation tank 8. The solvent G
for solid-liquid separation is thereby cyclically utilized.

[0069]

r a The lower limit of the mass ratio of the solvent G for solid-liquid separation relative to the mass of the solid-liquid phase F in the mixture H is preferably 0.5, more preferably 1, still more preferably 1.5. On the other hand, the upper limit of the mass ratio is preferably 4, more preferably 3, still more preferably 2.5. If the mass ratio is less than the lower limit above, sufficient separability may not be obtained.
Conversely, if the mass ratio exceeds the upper limit above, the use amount of the solvent G for solid-liquid separation increases and it is likely that the hydrocracked oil production cost rises.

[0070]
The lower limit of the temperature of the mixture H in the centrifuge 10 in the solid-liquid separation step is preferably 40 C, more preferably 70 C. On the other hand, the upper limit of the temperature of the mixture H in the centrifuge 10 is preferably 130 C, more preferably 120 C. If the temperature of the mixture H in the centrifuge 10 is less than the lower limit above, since a heavy content does not flow and hardly dissolves, sufficient extractability may not be obtained. Conversely, if the temperature of the mixture H in the centrifuge 10 exceeds the upper limit above, since the solvent G for solid-liquid separation evaporates and the pressure in the centrifuge 10 is likely to rise, the equipment cost may increase to cope with the pressure rise.

[0071]
The upper limit of the residence time of the mixture H in the centrifuge 10 in the solid-liquid separation step is preferably 60 seconds, more preferably 45 seconds, still more preferably 30 seconds. On the other hand, the lower limit of the residence time of the mixture H is preferably 5 seconds, more preferably 10 seconds, still more preferably 20 seconds. If the residence time of the mixture H exceeds the upper limit above, the volume within the centrifuge must be made large, and the centrifuge may grow in size.
Conversely, if the residence time of the mixture H is less than the lower limit above, solid-liquid separation may not be sufficiently achieved.

[0072]
The centrifugal force of the centrifuge 10 in the solid-liquid separation step is preferably 3,000 G or less, more preferably 2,500 G or less, still more preferably 2,200 G
or less, particularly preferably 2,000 G or less. On the other hand, the centrifugal force of the centrifuge 10 is preferably 1,600 G or more. As the centrifugal force in the solid-liquid separation step is higher, the separation capacity is more enhanced, but if the centrifugal force in the solid-liquid separation step exceeds the upper limit above, the centrifugal separator 10 may grow in size, increasing the equipment cost.

[0073]
<Gas Purification Step>
In the gas purification step, a gas K is purified by the gas purification unit 15 from the gas phase separated by means of the high-pressure low-temperature gas-liquid separator 14. Here, in the high-pressure low-temperature gas-liquid separator 14, gas-liquid separation of the gas phase separated by means of the high-pressure gas-liquid separator 5 is further performed at a high pressure and a low temperature, and the separated gas phase is supplied to the gas purification unit 15.

[0074]
<Fractionation Step>
In the fractionation step, the gas phase obtained in the gas-liquid separation part and the liquid phase obtained in the solid-liquid separation step is fractionated.
Specifically, the gas phases separated in the low-pressure gas-liquid separator 6 and in the reduced-pressure gas-liquid separator 7, the liquid phase separated in the high-pressure low-temperature gas-liquid separator 14, and the liquid phase after separating the solvent G
for solid-liquid separation in the overflow solvent recovery unit 12 are supplied to the distillation column 16, and these are fractionated by the distillation column 16 into naphtha L, kerosene M, light oil N, vacuum gas oil P, ash-free residue Q, etc.

[0075]
It is preferable to use naphtha L and kerosene M obtained in the fractionation step as the naphtha and kerosene fractions of the solvent G for solid-liquid separation. In this way, when naphtha L and kerosene M obtained in the fractionation step of the hydrocracked oil production process are used as the naphtha fraction and kerosene fraction of the solvent G for solid-liquid separation, procurement and transport of the naphtha fraction and kerosene fraction are facilitated and the cost of the solvent G
for solid-liquid separation can be reduced.

[0076]
At the start of operation of the hydrocracked oil production apparatus, naphtha L
and kerosene M obtained in the fractionation step are not present and therefore, for example, naphtha L and kerosene M obtained in another hydrocracked oil production apparatus may be used as the naphtha fraction and kerosene fraction contained in the first solvent G for solid-liquid separation. It may also be possible that the operation is started without incorporating naphtha fraction and kerosene fraction as the solvent G
for solid-liquid separation and when naphtha L and kerosene M are fractionated by the hydrocracked oil production apparatus, the fractionated naphtha L and kerosene M are added to the solvent G for solid-liquid separation.

[0077]
[Advantages]
In the process for producing a hydrocracked oil, the solvent G for solid-liquid separation contains an aromatic light solvent, a naphtha fraction and a kerosene fraction, each in an amount of more than 10 mass%, whereby the action of reducing the sedimentability by an aromatic light solvent and the action of reducing the extractability by a naphtha fraction can be suppressed. Consequently, in the hydrocracked oil production process, it becomes possible to elevate the separability and shorten the sedimentation time in the solid-liquid separation step of performing solid-liquid separation of a mixture H of the remainder of the solid-liquid phase F obtained in the gas-liquid separation step and the 5 .. solvent G for solid-liquid separation. Furthermore, in the hydrocracked oil production process, solid-liquid separation of the mixture H is performed by means of a centrifuge 10, so that upsizing of the solid-liquid separating apparatus can be suppressed without requiring relatively high temperature and high pressure conditions and the equipment cost can therefore be reduced.
10 [0078]
[Other Embodiments]
The process for producing a hydrocracked oil and the apparatus for producing a hydrocracked oil of the present invention are not limited to the embodiments above.
[0079]
15 For example, in the embodiments above, a three-stage gas-liquid separator including a high-pressure gas-liquid separator 5, a low-pressure gas-liquid separator 6 and a reduced pressure gas-liquid separator 7 is used as the multistage gas-liquid separator, but it may be configured as a two-stage gas-liquid separator or may be configured as a gas-liquid separator of four or more stages. As the number of stages of the gas-liquid 20 separator is larger, the time required for gas-liquid separation increases, but the separability is likely to be enhanced.
[0080]
In the embodiments above, naphtha, kerosene, light oil, vacuum gas oil, and an ash-free residue Q are fractionated by means of a distillation column, but it is sufficient if at least naphtha and kerosene are fractionated, and oil fractions other than these may not be fractionated. In addition, other oil fractions may be fractionated.
Examples [0081]
The present invention is described in greater detail below by referring to Examples, but the present invention is not limited to these Examples.
[0082]
(Example 1) In a hydrocracked oil production apparatus of Fig. 1, a petroleum heavy oil A
containing a heavy metal component and an iron-based catalyst B were supplied to a slurry preparation tank 1, and a hydrogen gas C was supplied to the slurry mixed in the slurry preparation tank 1 to obtain a feed slurry D. The feed slurry D was preheated by a preheater 2 and then supplied to a suspended bed reactor 4. Here, a vacuum distillation = .e õ . 21 residue (hereinafter, referred to as VR) was used as the petroleum heavy oil A, and a limonite iron ore catalyst was used as the iron-based catalyst B. The addition amount of the limonite iron ore catalyst was set to, in terms of iron, 1 mass% relative to the mass of the vacuum distillation residue. The average particle diameter of the limonite iron ore catalyst was 1.05 pm. The conditions of hydrocracking reaction in the suspended bed reactor 4 were a reaction pressure of 12 MPa, a reaction temperature of 450 C, and a reaction time of 90 minutes.
[0083]
Next, the reaction product E produced in the suspended bed reactor 4 was supplied to a high-pressure gas-liquid separator 5, subjected to gas-liquid separation sequentially by the high-pressure gas-liquid separator 5, a low-pressure gas-liquid separator 6, and a reduced-pressure gas-liquid separator 7, and thereby separated into a gas phase and a solid-liquid phase. Here, the temperature conditions of each of the gas-liquid separators were a pressure of 12 MPaG and a temperature of 400 C in the high-pressure gas-liquid separator 5, a pressure of 0.3 MPaG and a temperature of 380 C in the low-pressure gas-liquid separator 6, and a pressure of 10 mmHg and a temperature of 350 C in the reduced-pressure gas-liquid separator 7. A solid-liquid phase F (VR, vacuum distillation residue) thus obtained from the lower part of the low-pressure gas-liquid separator 6 and a solvent G for solid-liquid separation were mixed, and the mixture I-I was separated into a supernatant and a precipitate (cake) by a centrifuge 10 for a 250 mL-volume centrifuge tube ("Table-Top Centrifuge 5100" of Kubota Corporation). The supernatant and the cake respectively correspond to the liquid phase and the solid matter separated by the centrifuge 10 in the embodiment above. As for the solvent G for solid-liquid separation, one containing an aromatic light solvent, a naphtha fraction and a kerosene fraction in the proportion by mass shown in Table 1 relative to the vacuum distillation residue was mixed.
Toluene was used here as the aromatic light solvent. The solid-liquid separation above was performed for 30 seconds by setting the centrifugal force of the centrifuge 10 to 2,000 G and the temperature of the mixture in the centrifuge 10 to 100 C. The method of performing solid-liquid separation in this way was designated as Example 1, and the concentration of solid matter contained in each of the supernatant and the cake, obtained by solid-liquid separation, was measured. The solid matter obtained here is asphaltene and iron-based catalyst B, which are a toluene insoluble matter. The measurement results are shown in Table 1, In Table 1, "Solvent/vacuum distillation residue mass ratio"
indicates the mass ratio of the solvent for solid-liquid separation relative to the vacuum distillation residue in the mixture. In addition, the proportion by mass in "Content in solid-liquid separation solvent" in Table 1 indicates the proportion by mass of each component in the solvent for solid-liquid separation, i.e., the blending ratio of each component in the solvent for solid-liquid separation.

,pa [0084]
(Example 2) In Example 2, solid-liquid separation was performed by the same method as in Example 1 except that a mixture prepared by using a solvent for solid-liquid separation having the same blending ratio as in Example I and mixing the solvent for solid-liquid separation to provide a mass ratio of 0.9 relative to the vacuum distillation residue was used.
[0085]
(Example 3) In Example 3, solid-liquid separation was performed by the same method as in Example 1 except that a mixture prepared by using a solvent for solid-liquid separation having the same blending ratio as in Example 1 and mixing the solvent for solid-liquid separation to provide a mass ratio of 3.6 relative to the vacuum distillation residue was used.
[0086]
(Example 4) In Example 4, solid-liquid separation was performed by the same method as in Example 1 except that one containing toluene, a naphtha fraction and a kerosene fraction in the proportion by mass shown in Table 1 relative to the vacuum distillation residue was mixed and the residence time in the centrifuge 10 in solid-liquid separation was changed to 50 seconds.
[0087]
(Example 5) In Example 5, solid-liquid separation was performed by the same method as in Example 1 except that one containing toluene, a naphtha fraction and a kerosene fraction in the proportion by mass shown in Table 1 relative to the vacuum distillation residue was mixed.
[0088]
(Example 6) In Example 6, solid-liquid separation was performed by the same method as in Example 1 except that the temperature of the mixture in the centrifuge 10 in solid-liquid separation was changed to 60 C.
[0089]
(Example 7) In Example 7, solid-liquid separation was performed by the same method as in Example 1 except that the residence time in the centrifuge 10 in solid-liquid separation was changed to 15 seconds.
[0090]

. , 23 =
(Example 8) In Example 8, solid-liquid separation was performed by the same method as in Example I except that the centrifugal force of the centrifuge 10 in solid-liquid separation was changed to 1,500 G.
[0091]
(Example 9) In Example 9, solid-liquid separation was performed by the same method as in Example 1 except that a limonite iron ore catalyst having an average particle diameter of 2.5 pm was used and the addition amount of the limonite iron ore catalyst relative to the mass of the vacuum distillation residue was changed to 2.5 mass% in terms of iron.
[0092]
(Comparative Example 1 to Comparative Example 4) In each of Comparative Example 1 to Comparative Example 4, solid-liquid separation was performed by the same method as in Example 1 except that one containing toluene, a naphtha fraction and a kerosene fraction in the proportion by mass each shown in Table 1 relative to the vacuum distillation residue was mixed.
[0093]
(Comparative Example 5) In Comparative Example 5, solid-liquid separation was performed by the same method as in Example 1 except that toluene was used as the solvent for solid-liquid separation mixed with the vacuum distillation residue.
[0094]
In each of Example 2 to Example 9 and Comparative Example 1 to Comparative Example 5, the concentration of the solid matter contained in each of the supernatant and the cake, obtained by solid-liquid separation, was measured in the same manner as in Example 1. These measurement results are shown in Table 1.

=

[0095]
[Table 1]
Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex, 5 Ex. 6 Ex. 7 Ex. 8 Ex. 9 Corn. Corn. Corn. Corn.
Corn.

Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Vacuum distillation residue (VR) wt% _ 100 100 100 100 1100 100 100 100 100 _ 100 100 100 100 100 Toluene wt% 66 30 120 140 40 66 66 66 66 180 10 10 10 200 "
)=
Naphtha fraction wt% 66 30 120 30 80 66 66 66 66 10 180 10 Kerosene fraction wt% 66 30 120 30 80 66 66 66 66 10 10 180 Solvent/vacuum distillation residue wt/wt 1.98 0.9 3.6 2 2 1.98 1.98 1.98 1.98 2 2 2 2 2 Blending mass ratio - -Toluene wt% 33 33 33 70 20 33 33 33 33 90 5 5 5 100 Naphtha Content in solid-liquid wt% 33 33 33 15 40 33 33 33 33 5 90 5 47.5 0 fraction separation solvent - -Kerosene wt% 33 33 33 15 40 33 33 33 33 5 5 90 47.5 0 fraction Average particle diameter. pin 1.05 1.05 -1.05 1.05 1.05 1.05 1.05 1.05 2.5 1.05- 1.05 1.05 1.05 1.05 Iron-based Addition amount catalyst wt% I 1 1 1 1 1 1 1 2.5 1 1 1 1 1 (as Fe on VR) - - -Solid-liquid Temperature C 100 100 100 100 100 60 100 100 100 separation Centrifugal force G 2000 2000 2000 2000 2000 2000 2000 1500 2000, 2000 2000 2000 2000 2000 conditions Residence time sec 30 30 30 50 30 30 15 30 30 30 30 _ _ _ Concentration of solid matter in wt% 0.95 1.08 0.9 1.1 1.12 1.12 1.18 1.06 1.2 1.45 10 3.6 5.4 1.43 Results supernatant Concentration of solid matter in cake wt% 45 40 45 42 40 41 40 42 40 35 15 28 , . .
[0096]
<Evaluation Results>
It is seen from the results of Table 1 that in Example Ito Example 9, the concentration of solid matter in the cake was as large as 40 mass% or more and asphaltene 5 and iron-based catalyst B could be sufficiently separated as the solid matter by the centrifuge. On the other hand, in Comparative Example 1 to Comparative Example 5, the concentration of solid matter in the cake was less than 40 mass%, and asphaltene and iron-based catalyst B could not be sufficiently separated by the centrifuge. These results confirmed that the extractability of solid matter can be enhanced by using a solvent for 10 solid-liquid separation containing toluene, a naphtha fraction and a kerosene fraction each in an amount of more than 10 mass%. Here, the concentration of solid matter in the cake was as relatively large as about 35 mass% and 36 mass% in Comparative Example 1 and Comparative Example 5. However, in Comparative Example 1 and Comparative Example 5, the content of toluene in the solvent for solid-liquid separation was extremely 15 large. Since toluene is several times as expensive as the naphtha fraction, the solvent for solid-liquid separation becomes excessively expensive in Comparative Example 1 and Comparative Example 5, and this is not practical.
[0097]
In addition, it is also seen from the results of Table 1 that since the concentration 20 of solid matter in the supernatant in Example 1 to Example 9 was as very small as 1.2 mass% or less, asphaltene and iron-based catalyst B can be sufficiently separated as the solid matter by the centrifuge in Example 1 to Example 9.
[0098]
Comparing the results of Example 1 and Example 2, although a solvent for solid-25 liquid separation with the same blending ratio of the contents of toluene, naphtha fraction and kerosene fraction being 1/3 each is used, the concentration of solid matter in the cake is higher in Example 1. This is caused because the mass ratio of the solvent for solid-liquid separation relative to the vacuum distillation residue in the solvent for solid-liquid separation was small in Example 2, compared with Example 1, and the extractability in Example 2 was reduced to be lower than in Example 1. This reveals that the separability can be more enhanced by setting the mass ratio of the solvent for solid-liquid separation to be 1.5 or more.
[0099]
Comparing the results of Example 1 and Example 3, the concentration of solid matter in the cake is equivalent between these Examples. In Example 1 and Example 3, a solvent for solid-liquid separation having the same blending ratio of toluene, naphtha fraction and kerosene fraction is used, but the mass ratio of the solvent for solid-liquid separation relative to the vacuum distillation residue in the solvent for solid-liquid = a, separation is larger in Example 3 than in Example 1. This suggests that when the mass ratio of the solvent for solid-liquid separation increases to a value close to the mass ratio in Example 3, even if it is further increased, the extractability enhancing effect is less enhanced. Accordingly, it is understood that by adjusting the mass ratio of the solvent for solid-liquid separation in the range of 4 or less, high extractability can be obtained while suppressing the use amount of the solvent for solid-liquid separation.
[0100]
Comparing the results of Example 1 and Example 4, the concentration of solid matter in the cake is higher in Example 1. In Example 1 and Example 4, the mass ratio of the solvent for solid-liquid separation relative to the vacuum distillation residue in the solvent for solid-liquid separation is substantially the same, but the blending ratio of each component in the solvent for solid-liquid separation is different. The content of toluene in the solvent for solid-liquid separation is larger in Example 4 than in Example 1 but, as described above, the concentration of solid matter in the cake is larger in Example 1.
This can be said to be because as to toluene, the effect of the action of reducing the sedimentation velocity was more greatly exerted than the action of enhancing the extractability and consequently, the concentration of solid matter in the cake of Example 4 was reduced to be lower than in Example 1. This confirmed that when the content of toluene in the solvent for solid-liquid separation is set to be 60 mass% or less and both contents of naphtha fraction and kerosene fraction are set to be 20 mass% or more, the separability can be more enhanced. In addition, it is understood that when the contents of toluene, naphtha fraction and kerosene fraction in the solvent for solid-liquid separation are made equal, the separability is likely to be enhanced.
[0101]
Comparing the results of Example 1 and Example 5, the concentration of solid matter in the cake is higher in Example 1. In Example 1 and Example 5, the mass ratio of the solvent for solid-liquid separation relative to the vacuum distillation residue in the solvent for solid-liquid separation is substantially the same, but the blending ratio of each component in the solvent for solid-liquid separation is different. The content of toluene in the solvent for solid-liquid separation is larger in Example 5 than in Example 1. This can be said to be because the content of toluene having a large effect of enhancing the extractability is small and the concentration of solid matter in the cake of Example 5 is therefore reduced to be lower than in Example 1. This confirmed that the separability can be more enhanced by setting the content of toluene in the solvent for solid-liquid separation to be 30 mass% or more.
[0102]
Comparing the results of Example 1 and Example 6, the concentration of solid matter in the cake is higher in Example 1, In Example 1 and Example 6, only the temperature of the mixture in the centrifuge is different. It can be said that the concentration of solid matter in the cake was higher in Example 1 because the temperature of the mixture in the centrifuge was lower in Example 6 and the flowability of heavy content was therefore lower. This result confirmed that the separability can be more enhanced by setting the temperature of the mixture in the centrifuge to be 70 C or more.
[0103]
Comparing the results of Example 1 and Example 7, the concentration of solid matter in the cake is higher in Example 1. In Example 1 and Example 7, only the residence time of the mixture in the centrifuge is different. It is understood from this result that the separability can be more enhanced by setting the residence time of the mixture in the centrifuge to be 20 seconds or more.
[0104]
Comparing the results of Example 1 and Example 8, the concentration of solid matter in the cake is higher in Example 1. In Example 1 and Example 8, only the centrifugal force of the centrifuge in solid-liquid separation is different.
It is understood from this result that the separability can be more enhanced by setting the centrifugal force of the centrifuge to be 1,600 G or more.
[0105]
Comparing the results of Example 1 and Example 9, the concentration of solid matter in the cake is higher in Example 1. In Example 1 and Example 9, only the average particle diameter of the limonite iron ore catalyst and the addition amount thereof relative to the vacuum distillation residue are different. It is understood from this result that extractability can be more enhanced by setting the average particle diameter of the limonite iron ore catalyst to be 2 gm or less and setting the mass ratio of the limonite iron ore catalyst relative to the mass of the vacuum distillation residue to be 0.02 or less in terms of iron.
[0106]
While the present invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the present invention.
The present application is based on a Japanese patent application No.

filed on July 11,2016.
Industrial Applicability [0107]
As demonstrated in the forgoing pages, the above-described hydrocracked oil production process and hydrocracked oil production apparatus can be suitably used as an = 28=
apparatus, etc. for producing a light oil from a petroleum heavy oil, because the time required for coke produced in the hydrocracking step to be selectively removed by sedimentation solid-liquid separation can be shortened and the equipment cost can be reduced.
Description of Reference Numerals and Signs [0108]
1 Slurry preparation tank 1 a Stirrer 2 Preheater 3 First pump 4 Suspended bed reactor 5 High-pressure gas-liquid separator 6 Low-pressure gas-liquid separator 7 Reduced-pressure gas-liquid separator 8 Mixture preparation tank 8a Stirrer 9 Second pump 10 Centrifuge 11 Third pump 12 Overflow solvent recovery unit 13 Underflow solvent recovery unit 14 High-pressure low-temperature gas-liquid separator 15 Gas purification unit 16 Distillation column A Petroleum heavy oil = Iron-based catalyst = Hydrogen gas = Feed slurry E Reaction product Solid-liquid phase = Solvent for solid-liquid separation = Mixture Sludge K Gas = Naphtha = Kerosene = Light oil = , *
. = = 29 Vacuum gas oil Ash-free residual

Claims

30

[Claim 1]
A process for producing a hydrocracked oil by using, as a feed material, a petroleum heavy oil comprising a heavy metal component, the process comprising:
a mixing step of mixing the petroleum heavy oil, an iron-based catalyst and a hydrogen gas;
a hydrocracking step of hydrocracking the petroleum heavy oil in a suspended bed reactor after the mixing step;
a gas-liquid separation step of subjecting a reaction product after the hydrocracking step to a gas-liquid separation in a multistage gas-liquid separator;
a circulation step of circulating a part of a solid-liquid phase obtained in the gas-liquid separation step to the mixing step; and a solid-liquid separation step of performing, by means of a centrifuge, a solid-liquid separation of a mixture of a remainder of the solid-liquid phase after the circulation step and a solvent for solid-liquid separation, wherein the solvent for solid-liquid separation comprises a naphtha fraction and a kerosene fraction obtained by a hydrocracking method and an aromatic light solvent, each in an amount of more than 10 mass%.
[Claim 2]
The process for producing a hydrocracked oil according to Claim 1, wherein:
the solvent for solid-liquid separation has a mass ratio relative to a mass of the remainder of the solid-liquid phase in the mixture of 0.5 or more and 4 or less; and in the solid-liquid separation step, the mixture in the centrifuge has a temperature of 40°C or more and 130°C or less and a residence time of 60 seconds or less.
[Claim 3]
The process for producing a hydrocracked oil according to Claim 1 or Claim 2, wherein the gas-liquid separation step comprises:
a first step of subjecting the reaction product after the hydrocracking step to a gas-liquid separation in a high-pressure gas-liquid separator;
a second step of subjecting a solid-liquid phase separated in the first step to a gas-liquid separation in a low-pressure gas-liquid separator; and a third step of subjecting a solid-liquid phase separated in the second step to a gas-liquid separation in a reduced-pressure gas-liquid separator.
[Claim 4]
The process for producing a hydrocracked oil according to Claim 1 or Claim 2, further comprising a fractionation step of fractionating a gas phase obtained in the gas-liquid separation step and a liquid phase obtained in the solid-liquid separation step, wherein as the naphtha fraction and kerosene fraction of the solvent for solid-liquid separation, a naphtha fraction and a kerosene fraction obtained in the fractionation step are used.
[Claim 5]
The process for producing a hydrocracked oil according to Claim 1 or Claim 2, wherein:
the aromatic light solvent is a single component having a boiling point of 150°C
or less or a mixed component thereof;
the naphtha fraction has a boiling point of 80°C or more and 180°C or less; and the kerosene fraction has a boiling point of more than 180°C and 240°C or less.
[Claim 6]
The process for producing a hydrocracked oil according to Claim 1 or Claim 2, wherein in the solid-liquid separation step, the mixture in the centrifuge has a residence time of 30 seconds or less, and the centrifuge has a centrifugal force of 3,000 G or less.
[Claim 7]
The process for producing a hydrocracked oil according to Claim 1 or Claim 2, wherein:
the iron-based catalyst is a limonite iron ore catalyst having an average particle diameter of 2µm or less; and the iron-based catalyst has a mass ratio relative to a mass of the petroleum heavy oil in the mixing step of 0.003 or more and 0.02 or less in terms of iron.
[Claim 8]
An apparatus for producing a hydrocracked oil by using, as a feed material, a petroleum heavy oil comprising a heavy metal component, the apparatus comprising:
a mixing part for mixing the petroleum heavy oil, an iron-based catalyst and a hydrogen gas;
a suspended bed reaction part for hydrocracking the petroleum heavy oil in a feed slurry obtained in the mixing part;
a gas-liquid separation part for performing a multistage gas-liquid separation of a reaction product produced in the suspended bed reaction part;
a circulation part for circulating a part of a solid-liquid phase obtained in the gas-liquid separation part to the mixing part; and a centrifugal separation part for performing a solid-liquid separation of a mixture of a remainder of the solid-liquid phase obtained in the gas-liquid separation part and a solvent for solid-liquid separation, wherein the solvent for solid-liquid separation comprises a naphtha fraction and a kerosene fraction obtained by a hydrocracking method and an aromatic light solvent, each in an amount of more than 10 mass%.