JP5421793B2 - Crude oil processing system - Google Patents

Description

  The present invention relates to a technique for treating crude oil containing a catalyst poison for a catalyst of a catalytic cracking process.

  The demand for heavy crude oil processing is increasing due to the recent increase in demand for crude oil, soaring production, and the peak of production. On the other hand, the properties of heavy crude oil have a great influence on secondary equipment that processes various fractions fractionated in a crude oil distillation unit (Cude Distillation Unit; CDU).

  For example, residual carbon contained in heavy crude oil (residual carbon whose amount is specified by the Conradson method (JIS K2270-1) is hereinafter referred to as CCR (Conradson Carbon Residue)), vanadium (V), nickel ( Ni) is a heavy oil fluid catalytic cracking unit (hereinafter referred to as “residue fluid catalytic cracking unit”) that decomposes atmospheric residue (hereinafter referred to as “AR”), which is a residual oil fraction obtained by CDU, by contacting with a catalyst. In a catalytic cracking process such as RFCCU), the coke yield and off-gas yield are increased, and the catalytic activity is decreased.

  Conventionally, catalyst poisons such as V and Ni contained in AR obtained from heavy crude oil have been removed by pretreatment equipment such as heavy oil direct desulfurization equipment (hereinafter referred to as RDSU). There are many cases where RDSU is not provided in the refinery to be processed. However, RDSU is one of the most expensive oil refining equipment, and it may be difficult from the economical point of view to construct RDSU for increasing the weight of processed crude oil.

  Here, in Patent Document 1, vanadium is liberated from the atmospheric residue oil by bringing the atmospheric residue oil distilled from CDU into contact with supercritical water or subcritical water to which an oxidizing agent is added, and iron or activated carbon. A technique for removing this vanadium with a scavenger consisting of, for example, is described. However, since the technique described in Patent Document 1 uses supercritical water or subcritical water, it requires high-temperature and high-pressure conditions and consumes an oxidizing agent and a scavenger. There is no description about the technology for removing nickel and CCR from the pressure residue oil, and there still remains a problem of lowering the activity of the catalyst used in the catalytic cracking process.

Japanese Patent Laid-Open No. 2003-277770: Claims 1, 8, and FIG.

  The present invention has been made under such circumstances. The purpose of the present invention is to process crude oil containing relatively large amounts of nickel, vanadium and residual carbon, and supplying the raw material to the subsequent catalytic cracking process. To provide a system.

The crude oil processing system according to the present invention comprises a first crude oil supplied from a first crude oil supply line, a residual oil fraction in which all or part of the first crude oil is used as a feedstock for a catalytic cracking process, and other fractions. A main distillation column for fractional distillation,
A second crude oil supplied from a second crude oil supply line and containing more catalyst poison for the catalyst used in the catalytic cracking process than the first crude oil is included in the distillation temperature range of the other fraction. A subdistillation tower for fractionating the light fraction and the remaining heavy fraction;
And a light fraction supply line for supplying the light fraction to the main distillation column for processing.

A crude oil processing system according to another invention includes a first crude oil supplied from a first crude oil supply line, a residual oil fraction in which all or part of the first crude oil is used as a feedstock for a catalytic cracking process, and other A main distillation column for fractionating
The second crude oil supplied from the second crude oil supply line and containing more catalyst poison for the catalyst used in the catalytic cracking process than the first crude oil has a content of the catalyst poison equal to or lower than a preset value. A subdistillation tower for fractionating the light fraction and the remaining heavy fraction,
And a light fraction supply line for supplying the light fraction to the main distillation column for processing.

Furthermore, each said crude oil processing system may be provided with the following characteristics.
(A) a vacuum distillation column for vacuum distillation of the heavy fraction into a vacuum gas oil fraction to be used as a feedstock for the catalytic cracking process and other vacuum residue oil fractions; and the vacuum distillation from the subdistillation column A heavy fraction supply line for supplying the heavy fraction to the tower for processing.
(B) A residual oil fraction supply line for supplying the residual oil fraction to the vacuum distillation column for processing.
(C) A residual oil fraction distilled from the main distillation column and a vacuum gas oil fraction distilled from the vacuum distillation column are mixed to obtain a raw material oil for the catalytic cracking process.
(D) The catalyst poison is selected from a catalyst poison group consisting of nickel, vanadium or residual carbon.
(E) The second crude oil contains a crude oil selected from a crude oil group consisting of Maya crude oil, Orinocotar, and oil sand bitumen.

  According to the first aspect of the present invention, the residual oil fraction is provided with the subdistillation tower capable of processing the second crude oil having a high content of the catalyst poison relative to the catalyst used in the catalytic cracking process, and is supplied to the catalytic cracking process. Since a light fraction having a temperature range that hardly mixes in the water is extracted from the second crude oil, even if the light fraction is supplied to the main distillation column that processes the first crude oil with a low content of catalyst poison, An increase in the content of the catalyst poison contained in the residual oil fraction distilled from the distillation tower can be suppressed.

In addition, according to the second invention, a subdistillation tower capable of processing the second crude oil having a high content of the catalyst poison relative to the catalyst used in the catalytic cracking process is provided, and the catalyst poison is removed from the second crude oil. Since only the light fraction with a low content is extracted, even if the light fraction is supplied to the main distillation column that processes the first crude oil with a low content of catalyst poison, the residual oil fraction distilled from the main distillation column The increase in the content of the catalyst poison contained in the minute can be suppressed.
As a result, since the crude oil can be made heavy without affecting the subsequent catalytic cracking process in either the first invention or the second invention, the range of selection of crude oil that can be processed by the crude oil processing system is increased. spread.

It is explanatory drawing which shows the structure of the crude oil processing system which concerns on embodiment. It is a characteristic view which shows an example of the change of catalyst poison content with respect to the distillation temperature of heavy crude oil.

Hereinafter, a crude oil processing system that processes crude oil containing a relatively large amount of catalyst poisons such as CCR, V, and Ni and supplies raw materials to RFCCU, for example, will be described.
FIG. 1 is an explanatory diagram showing a configuration of a crude oil processing system according to the present embodiment. This crude oil processing system includes, for example, a crude oil distillation apparatus for atmospheric distillation of light crude oil having a low content of CCR, V, and Ni. 1 and a vacuum distillation apparatus 3 that distills the AR distilled from the crude oil distillation apparatus 1 under reduced pressure, and pretreats heavy crude oil having a relatively high content of CCR, V, and Ni, and processes them in the crude oil distillation apparatus 1 A heavy crude oil pretreatment device 2 that sends a fraction that does not deteriorate the catalyst of the catalytic cracking process in the latter stage to the crude oil distillation device 1 and sends a fraction having a high catalyst poison content to the vacuum distillation device 3; I have. In the present embodiment below, the “catalyst poison content” means the content per unit weight of crude oil or AR, for example, the concentration based on weight.

  The crude oil distillation apparatus 1 is an apparatus for obtaining various intermediate products by atmospheric distillation of light crude oil having a relatively small content of CCR, V, Ni, for example. The crude oil directly supplied to the crude oil distillation apparatus 1 corresponds to the first crude oil of the present embodiment.

  The crude oil distillation apparatus 1 has a configuration in which, for example, a desalter 12, a preflash drum 13, a heating furnace 14, and an atmospheric distillation tower 11 are connected in this order from the upstream side. The desalter 12 serves to remove (desalinate) moisture, salt, and the like in the received crude oil, and the preflash drum 13 serves to remove the crude oil after desalting, for example, a lighter component such as a naphtha fraction and a heavier weight than the naphtha fraction. It is divided into masses, and the light components are supplied directly to the atmospheric distillation column 11 while the heavy components are supplied to the subsequent heating furnace 14. The heating furnace 14 has a function of heating the heavy component supplied from the preflash drum 13 to a temperature of, for example, about 300 ° C. to 380 ° C. and supplying it to the atmospheric distillation column 11.

  The pipes connecting these devices 12, 13, and 14 are provided with heaters such as a heat exchanger group so that crude oil and heavy components before being supplied to the preflash drum 13 and the heating furnace 14 are predetermined. It can be preheated to a temperature of. A series of equipment groups including the desalter 12, the preflash drum 13, the heating furnace 14, and the piping connecting them correspond to the first crude oil supply line of the present embodiment.

  The atmospheric distillation column 11 performs atmospheric distillation on the light components received from the preflash drum 13 and the heavy components received from the heating furnace 14 to obtain naphtha, kerosene, and light diesel oil (hereinafter referred to as LGO). , Heavy gas oil (hereinafter referred to as HGO) and AR, and a main distillation column of the present embodiment for fractional distillation into the overhead gas, for example, a known tray-type distillation column It is configured as. Here, in contrast to AR which is the residual oil fraction of the present invention, the overhead gas, naphtha, kerosene, LGO and HGO correspond to “other fractions” of the present invention.

  The bottom of the atmospheric distillation column 11 is connected to a pipe for supplying stripping steam for expelling light components in the oil. On the top side of the column, the overhead gas is cooled to A receiver 15 for dividing the naphtha is provided. The atmospheric distillation column 11 includes a reflac line for improving the cutting of each fraction, and a side for expelling light components in kerosene, LGO and HGO extracted from the atmospheric distillation column 11 with steam. Although a stripper and the like are provided, the illustration is omitted for convenience. The naphtha, kerosene, LGO, and HGO fractions distilled from the atmospheric distillation column 11 and cooled by a cooler are sent to a subsequent processing unit such as a desulfurization unit. On the other hand, a part of AR which is the residual oil fraction of the present embodiment taken out from the bottom of the column is transferred to the downstream RFCCU and catalytically decomposed by the catalyst, while the remaining AR is transferred to the AR transfer pipe 111 (residual oil). It is sent to the subsequent vacuum distillation apparatus 3 via the fraction supply line) and distilled under reduced pressure.

  The vacuum distillation apparatus 3 has a configuration in which, for example, a surge drum 32, a heating furnace 33, and a vacuum distillation tower 31 are connected in this order from the upstream side, and the surge drum 32 is received from the atmospheric distillation tower 11 or the like. Is temporarily stored and discharged toward the heating furnace 33, and the heating furnace 33 plays a role of heating the vacuum distillation raw material supplied from the surge drum 32 to a temperature of about 380 ° C. to 420 ° C., for example. .

  The vacuum distillation column 31 distills the raw material oil received from the heating furnace 33 in a reduced-pressure atmosphere of, for example, about 1.33 kPa to 13.3 kPa (10 mmHg to 100 mmHg), and distills from the top and middle of the vacuum distillation column 31. For example, it is configured as a plate-type distillation column that fractionates into a vacuum gas oil (Vacuum Gas Oil, hereinafter referred to as VGO) obtained by mixing the fractions obtained and a vacuum residue oil (hereinafter referred to as VR). Yes.

Similar to the atmospheric distillation column 11 described above, the bottom of the vacuum distillation column 31 is connected to a pipe for supplying stripping steam for expelling light components in the oil. The VR obtained from the bottom of the tower is, for example, a raw material for heavy oil base material, coke, and asphalt, while VGO is a raw material for RFCCU as well as the AR on the crude oil distillation apparatus 1 side. The details are described later.

  The crude oil processing system described above is provided with a heavy crude oil pretreatment device 2 for processing heavy crude oil having a relatively high content of CCR, V, Ni, for example, to obtain an RFCCU raw material. Hereinafter, the details of the heavy crude oil pretreatment device 2 will be described.

  Heavy crude oils such as Maya crude oil, Orinocotar, oil sand bitumen and other heavy oils, as shown schematically in FIG. 2, for example, have more catalyst poisons (CCR) in heavy fractions with higher distillation temperatures. , V, Ni). Therefore, for example, if only a fraction whose distillation temperature is lighter than HGO (including HGO; the same applies hereinafter) is extracted from heavy crude oil and supplied to the atmospheric distillation column 11, these light fractions are contained in the AR. It is distilled from the atmospheric distillation column 11 as a fraction lighter than HGO, with little mixing. As a result, a portion of heavy crude oil can be processed by the crude oil distillation apparatus 1 without substantially increasing the content of the RFCCCU catalyst poison in the AR. The heavy crude oil pretreatment device 2 according to the present embodiment is configured based on such a concept, and the heavy crude oil supplied to the heavy crude oil pretreatment device 2 is the second of the present embodiment. It corresponds to crude oil.

  The heavy crude oil pretreatment device 2 includes, for example, a desalter 22 that desalinates salt in heavy crude oil, a heating furnace 23 that heats the heavy crude oil after desalination to a temperature of about 200 ° C. to 370 ° C., The flasher 21 is connected in this order from the upstream side. A series of equipment groups consisting of the desalter 22, the heating furnace 23, and the pipes connecting them correspond to the second crude oil supply line of the present embodiment.

  The preflasher 21 is a distillation column that fractionates heavy crude oil received from the heating furnace 23 into, for example, a light fraction on the lighter side than HGO and a heavier heavy fraction. The preflasher 21 is not limited to a specific type, and may be a plate-type distillation column, for example, a flash distillation type distillation column. Further, the temperature condition and the pressure condition are not limited to a specific range of conditions, and it is sufficient that the light fraction and the heavy fraction can be fractionated at the target temperature. The preflasher 21 corresponds to the subdistillation tower of the present embodiment, and separates heavy crude oil into a light fraction included in the distillation temperature range of “another fraction” of the present invention and a remaining heavy fraction. Will stay.

  For example, a lighter fraction lighter than HGO distilled from the preflasher 2 is supplied to, for example, the atmospheric distillation column 11 of the crude oil distillation apparatus 1 through the light fraction supply pipe 211. Here, depending on the degree of breakage of the light fraction-heavy fraction in the preflasher 2, a part of the heavy fraction may be mixed into the light fraction side and supplied to the atmospheric distillation column 11. . Therefore, for example, the 90% distillation temperature of the light fraction is allowed to be, for example, about 10 ° C. lower than the 90% distillation temperature of HGO distilled from the atmospheric distillation column, so that the catalyst poison for the AR can be reduced. The mixing amount may be reduced. The light fraction supply pipe 211 and the pipe that joins the light fraction supply pipe 211 and supplies the light fraction to the atmospheric distillation column 11 correspond to the light fraction supply line of the present embodiment. .

  On the other hand, the heavy fraction which is the remaining fraction after the light fraction is taken out by the preflasher 21 has a distillation property equivalent to AR, for example. This heavy fraction is supplied to, for example, the surge drum 32 of the vacuum distillation apparatus 3 through the heavy fraction supply pipe 212, and is distilled under reduced pressure in the vacuum distillation tower 31 together with the AR distilled from the atmospheric distillation tower 11 side. Is done. Here, the heavy fraction distilled from the preflasher 21 side contains a large amount of catalyst poisons CCR, V, and Ni. Therefore, after mixing with AR supplied from the surge drum 32 to the vacuum distillation column 31 The vacuum distillation raw material also contains more catalyst poison than AR distilled from the atmospheric distillation column 11.

  On the other hand, as shown in FIG. 2, this reduced-pressure distillation raw material also has a characteristic that it contains more catalyst poison on the heavy side and its content is low on the light side. Therefore, in the vacuum distillation column 31, for example, VGO and VR are fractionated at a distillation temperature at which all of the contents of CCR, V, and Ni are equal to or lower than preset values, and the catalyst poison thus obtained is obtained. VGO with a small content of is mixed with, for example, a part of AR distilled from the atmospheric distillation column 11 side and supplied to the subsequent RFCCU. The VR containing a large amount of the catalyst poison is used as a raw material for heavy oil base materials, coke, and asphalt, for example. The heavy fraction supply pipe 212, the surge drum 32, the heating furnace 33, and the pipe connecting them correspond to a heavy fraction supply line.

  Each set value of CCR, V, and Ni is set as appropriate depending on, for example, a change in the mixing ratio of AR and VGO. However, the catalyst contained in the RFCCU feed oil (in this example, a mixed oil of AR and VGO) It is preferable to set the poison content to be approximately the same as that obtained when, for example, the crude oil distillation apparatus 1 alone processes the first crude oil, which is light crude oil. Here, the specific amounts of V, Ni, and CCR in the feedstock to be RFCC vary greatly depending on the RFCC processing capacity and the catalyst, so it is difficult to exemplify specific values. For example, the 90% distillation temperature of VGO is set so as to satisfy the V and Ni contents and the CCR standard (target value) in the raw material oil set in (1).

  In this way, VGO flowing out from the vacuum distillation column 31 is supplied to the RFCCU after being diluted by the AR distilled from the atmospheric distillation column 11 side. It varies depending on the content of the catalyst poison in the AR. At this time, if the content of the catalyst poison in the VGO is calculated to be equal to or less than the set value in the VGO, processing by the RFCCU is possible, but depending on the degree of disconnection between the VGO and VR, the VR side Minutes may be mixed on the VGO side. Therefore, the vacuum distillation column 31 according to the present embodiment, for example, by setting the content of the catalyst poison in the fraction at the 90% distillation temperature of VGO to be equal to or less than the set value, for example, about 10% of VR. Even if is mixed on the VGO side, the content of each catalyst poison as the RFCC raw material does not exceed a preset target value. Further, at this time, the 90% distillation temperature on the VGO side may be set with a margin so as to be lower by, for example, about 10 ° C. than the theoretical temperature.

  In addition, the raw material supply pipes of the crude oil distillation apparatus 1, heavy crude oil pretreatment apparatus 2, and vacuum distillation apparatus 3 according to the present embodiment, the discharge pipes for intermediate products, the fuel supply pipes of the heating furnaces 14, 23 and 33, etc. Are provided with control ends such as a flow rate adjusting valve, and these control ends cooperate with each other to constitute a DCS (Distributed Control System) that controls the entire crude oil processing system. Thereby, for example, the distilling temperature range of the light fraction, the heavy fraction and each intermediate product can be adjusted.

  And AR which flows out from the atmospheric distillation column 11 is sampled regularly, for example, and the distillation property, V, Ni content, and CCR are measured. For example, when the content of V and Ni in the AR and the value of CCR are equal to or higher than the preset values, for example, the heavy crude oil supplied to the heavy crude oil pretreatment device 2 becomes heavier, It shows that V, Ni, and CCR brought into the atmospheric distillation column 11 increase by minutes. Therefore, in this case, the amount of fuel supplied to the heating furnace 23 is reduced, the temperature of the heavy crude oil supplied to the preflasher 21 is lowered, and V, Ni and CCR contained in the light fraction are lowered. The amount of these poisoning components in the AR supplied directly to the RFCCU can be reduced. In addition, the distillation characteristics of AR, V, Ni content, and CCR are analyzed online, and feedback control is performed to adjust the temperature of the heavy crude oil at the outlet of the heating furnace 23 based on the detected value of the online analyzer. Of course, it is also good.

  When heavy crude oil is supplied to the heavy crude oil pretreatment device 2 having the above-described configuration, the heavy crude oil is heated to a predetermined temperature through the desalter 22 and the heating furnace 23, and is heated in the preflasher 21. It is separated into a light fraction that is lighter than HGO and contains a small amount of catalyst poison, and a remaining heavy fraction. The light fraction separated by the preflasher 21 is distilled in the atmospheric distillation column 11 and distilled as light fractions from the HGO. Therefore, the catalyst poison brought in by the heavy crude oil is in the AR. Is hardly mixed in.

  Actually, depending on the degree of breakage between the light fraction and the heavy fraction in the preflasher 21 and the degree of breakage between the HGO-AR, some amount of catalyst poison brought in by heavy crude oil is in the AR. It is also conceivable that it is mixed in However, a part of the AR is distilled under reduced pressure in the vacuum distillation apparatus 3 and is taken out as a VGO having a low content of catalyst poison, and the remaining AR is mixed with the VGO so that the content of the catalyst poison becomes a target value or less. Therefore, there is little possibility of reducing the catalytic activity of RFCCU more than before.

  At this time, AR distilled from the atmospheric distillation column 11 is regularly monitored for its distillation properties, V, Ni content, and CCR. When the V, Ni content and CCR in the AR exceed the set values due to, for example, changes in the properties of heavy crude oil, the outlet temperature of the heating furnace 23 of the heavy crude oil pretreatment device 2 is lowered, and V, Ni A fraction having a high content and a high CCR and having a relatively high distillation temperature is transferred to the heavy fraction side. Thereby, content of the catalyst poison in the light fraction supplied to the atmospheric distillation column 11 can be reduced, and content of these catalyst poisons in AR supplied directly to RFCCU can be reduced.

  On the other hand, the heavy fraction distilled from the bottom of the preflasher 21 is supplied to the vacuum distillation apparatus 3 and subjected to vacuum distillation in the vacuum distillation tower 31 together with a part of the AR from the crude oil distillation apparatus 1. The VGO having a low content of the catalyst poison and the remaining VR are fractionally distilled, and then the VGO is mixed with the remaining AR and supplied to the RFCCU. At this time, as described above, for example, the 90% distillation temperature of VGO is set so that the content of the catalyst poison in the RFCC feedstock is less than or equal to the target value. In this example, the target value is set so that the content of the catalyst poison is approximately the same as that obtained when, for example, the first crude oil, which is light crude oil, is processed alone in the crude oil distillation apparatus 1. Therefore, the degree of decrease in catalytic activity in RFCCU can be suppressed to the same level as in the past.

  The crude oil processing system according to the present embodiment has the following effects. Equipped with a preflasher 21 capable of processing heavy crude oil (second crude oil) with a high content of catalyst poisons (CCR, V, Ni) with respect to the catalyst used in RFCCU, from HGO hardly mixed into AR Since only the light light fraction is extracted from the heavy crude oil, even if the light fraction is supplied to the atmospheric distillation column 11 for processing the light crude oil (first crude oil) having a low catalyst poison content, An increase in the content of the catalyst poison contained in the residual oil fraction distilled from the atmospheric distillation column 11 can be suppressed. As a result, since the crude oil can be made heavy without affecting the subsequent RFCCU, the range of selection of crude oil that can be processed by the crude oil processing system is expanded.

  In particular, the heavy crude oil pretreatment device 2 for fractionating heavy crude oil into two fractions (light fraction and heavy fraction) has a relatively simple configuration, for example, RDSU or the like. The construction cost of the apparatus can be suppressed as compared with the case of constructing a demetalization tower that removes V and Ni in the FCCRU raw material. Further, for example, even when the crude oil to be processed is made heavy with the existing crude oil distillation apparatus 1, the crude oil processing system according to the present example continues the operation of the crude oil distillation apparatus 1 while preprocessing heavy crude oil in an adjacent area, for example. The apparatus 2 and the vacuum distillation apparatus 3 can be constructed and connected to the crude oil distillation apparatus 1 after these are completed, and the stop period of the crude oil distillation apparatus 1 can be suppressed in a short time, thereby contributing to the reduction of opportunity loss. .

  Here, in the pre-flasher 21 described above, the case where heavy crude oil is fractionated into a light fraction composed of a fraction lighter than HGO and a remaining heavy fraction is described. Light fraction-heavy The policy for fractional distillation is not limited to this example. For example, in the distillation temperature-catalyst poison content characteristic shown in FIG. 2, for example, the content of the catalyst poison at a 90% distillation temperature of the light fraction is equal to or lower than a preset value, for example, the crude oil in the crude distillation apparatus 1 is light crude oil. A fraction having a distillation temperature range that is less than or equal to the content of AR obtained when the first crude oil is treated alone may be a light fraction.

  In this case, for example, when the lighter fraction contains a heavier fraction than HGO, this fraction will be mixed in the AR, but the content of the catalyst poison in the fraction. Is known to have a lower content than AR when light crude oil is treated alone, so it does not increase the content of catalyst poisons in AR. In the case of this example as well, considering that a part of the heavy fraction is mixed in the light fraction depending on the degree of breakage between the light fraction and the heavy fraction, for example, from the 90% distillation temperature at the set value. Alternatively, a margin may be provided so that a temperature as low as about 10 ° C. becomes the 90% distillation temperature of the light fraction.

  In addition, the supply ratio of light crude oil (first crude oil) supplied to the crude oil distillation apparatus 1 side and heavy crude oil (second crude oil) supplied to the heavy crude oil pretreatment apparatus 2 side is, for example, Although it is set as appropriate depending on the size of the atmospheric distillation column 11 and the preflasher 21 and the supply amount range that can be operated, it is not limited to the case where crude oil is always supplied in parallel from both lines. For example, the supply of crude oil from one side of the crude oil supply line is stopped, and the crude oil supply line where the supply of crude oil is stopped is kept in a state where the crude oil is circulated. May be.

  The target value of the content of the catalyst poison in the RFCC feedstock is not limited to the case where it is within the range of the RFCCU feedstock property restriction. For example, the target value may be set to a stricter value (lower value) than this to further suppress the degree of catalyst deterioration of RCCU, and conversely, the target value may be relaxed (increased) to obtain VGO accordingly. The amount, in other words, the yield of RFCCU feedstock may be increased. In this case, for example, by increasing the amount of catalyst input to the RFCCU, the activity for catalyst deterioration is compensated.

  Furthermore, the crude oil processing system of the present invention does not necessarily have to be provided with the vacuum distillation column 31 capable of processing heavy fractions. The heavy fraction taken out from the preflasher 21 may be used as it is as a heavy oil base material, coke or asphalt raw material, or the heavy fraction may be transferred to another refinery equipped with RDSU for processing. At this time, for example, the total amount of AR distilled from the atmospheric distillation column 11 is the raw material oil of RFCCU.

  Furthermore, in this example, attention was paid to CCR, V, and Ni contained in crude oil as the catalyst poison of the RFCC catalyst. However, the types of catalyst poison contained in crude oil that can be processed by applying the present invention are limited to this. is not. For example, as shown in FIG. 2, if the catalyst poison has a characteristic that the content in the light fraction is small, only the fraction that is not mixed with the AR is extracted as the light fraction, or the fraction that has a small content of the catalyst poison. It is possible to apply the concept of extracting only the light fraction as a light fraction and treating it in the atmospheric distillation column 11, and the concept of extracting only the VGO having a small catalyst content in the heavy fraction and using it as the FCCU raw material.

  In addition to these, the catalytic cracking process in which the present invention can supply the raw material by the crude oil processing system is not limited to RFCC. For example, the entire amount of AR distilled from the atmospheric distillation column 11 is processed in the vacuum distillation column 31 and obtained. The obtained VGO can also be applied to an FCC process in which catalytic cracking is performed after desulfurization with an indirect desulfurization unit (HDSU). Also in this case, for example, a 90% distillation temperature of VGO is set so that the content of CCR, V, Ni in the feed oil supplied to HDSU is not more than a preset set value. For example, the content of these catalyst poisons in the desulfurized vacuum gas oil distilled from the distillation tower may be equal to or less than that in the case of treating light crude oil alone.

DESCRIPTION OF SYMBOLS 1 Crude oil distillation apparatus 11 Atmospheric distillation tower 2 Heavy crude oil pretreatment apparatus 21 Preflasher 211 Light fraction supply pipe 212 Heavy fraction supply pipe 3 Vacuum distillation apparatus 31 Vacuum distillation tower

Claims (7)

A main distillation column for fractionating the first crude oil supplied from the first crude oil supply line into a residual oil fraction, the whole or a part of which is used as a feedstock for the catalytic cracking process, and other fractions;
A second crude oil supplied from a second crude oil supply line and containing more catalyst poison for the catalyst used in the catalytic cracking process than the first crude oil is included in the distillation temperature range of the other fraction. A subdistillation tower for fractionating the light fraction and the remaining heavy fraction;
A crude oil processing system comprising: a light fraction supply line for supplying the light fraction to the main distillation column for processing. A main distillation column for fractionating the first crude oil supplied from the first crude oil supply line into a residual oil fraction, the whole or a part of which is used as a feedstock for the catalytic cracking process, and other fractions;
The second crude oil supplied from the second crude oil supply line and containing more catalyst poison for the catalyst used in the catalytic cracking process than the first crude oil has a content of the catalyst poison equal to or lower than a preset value. A subdistillation tower for fractionating the light fraction and the remaining heavy fraction,
A crude oil processing system comprising: a light fraction supply line for supplying the light fraction to the main distillation column for processing.   A vacuum distillation column that distills the heavy fraction into a vacuum gas oil fraction that is a raw oil for the catalytic cracking process, and other vacuum residue oil fractions, and a subdistillation column to the vacuum distillation column. The crude oil processing system according to claim 1, further comprising a heavy fraction supply line for supplying and processing the heavy fraction.   The crude oil processing system according to claim 3, further comprising a residual oil fraction supply line for supplying the residual oil fraction to the vacuum distillation tower for processing.   The residual oil fraction distilled from the main distillation column and the vacuum gas oil fraction distilled from the vacuum distillation column are mixed to obtain a feedstock oil for the catalytic cracking process. The described crude oil processing system.   6. The crude oil processing system according to claim 1, wherein the catalyst poison is selected from a catalyst poison group consisting of nickel, vanadium, or residual carbon.   The crude oil treatment according to any one of claims 1 to 6, wherein the second crude oil includes a crude oil selected from a crude oil group consisting of Maya crude oil, orinocotar, and oil sand bitumen. system.

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