JP6403409B2 - Production method of C heavy oil - Google Patents

Description

  The present invention relates to a method for producing C heavy oil.

  In recent years, there has been an increasing demand for C heavy oil, particularly low sulfur C heavy oil, as a fuel for thermal power generation. Conventionally, low-sulfur C heavy oil has been manufactured by a process that relies on imports or gas oil is converted into heavy oil, but has a problem of high cost. Thus, there is a demand for cost reduction by producing low sulfur C heavy oil by crude oil processing. As a method for producing low sulfur C heavy oil by crude oil treatment, crude oil with low sulfur content is treated in an atmospheric distillation column to remove light hydrocarbons (light fractions) such as naphtha, light oil and kerosene, and at normal pressure. A method of producing a low-sulfur heavy oil by producing a distillation residue (heavy fraction) and desulfurizing the low-sulfur vacuum distillation residue obtained by further treating the atmospheric distillation residue with a vacuum distillation apparatus is known. (For example, refer to Patent Document 1).

JP 2002-177796 A

  The crude oil used for the production of low sulfur C heavy oil preferably has a low sulfur content from the viewpoint of desulfurization treatment. However, crude oil with low sulfur content (LS (Low Sulfur) crude oil) has a high unit price, so it is difficult to reduce costs. Therefore, the cost can be reduced by using crude oil whose unit price is lower than that of LS crude oil. However, some crude oils with a low unit price have a sulfur content higher than that of LS crude oils, and particularly have a high chlorine concentration. For this reason, when crude oil having such properties is processed in an atmospheric distillation apparatus, the light fraction contains a large amount of high-concentration chlorine, and the equipment and piping installed at the top of the atmospheric distillation tower corrode. Such a problem may occur, resulting in a decrease in manufacturing efficiency.

  Therefore, when processing crude oil having such a high chlorine concentration, it is conceivable to lower the chlorine concentration by adding crude oil having a low chlorine concentration and a low unit price (for example, crude oil from the Middle East). However, Middle Eastern crude oil has a characteristic of high sulfur concentration. Therefore, when Middle Eastern crude oil is mixed, the sulfur content of the crude oil to be treated as a whole increases. When trying to produce low sulfur C heavy oil, the higher the sulfur content of the hydrocarbon oil treated in the desulfurizer, the higher the reaction temperature and the higher the operating temperature of the desulfurizer. However, when the reaction temperature in the desulfurization apparatus is increased, a new problem may occur that the desulfurization catalyst is easily deactivated. On the other hand, if it is attempted to suppress the catalyst deactivation and prolong the catalyst life, the processing amount of the hydrocarbon oil itself in the desulfurization apparatus is reduced, resulting in the inability to efficiently produce C heavy oil.

  An object of this invention is to provide the manufacturing method of C heavy oil which can manufacture low sulfur C heavy oil efficiently.

  The method for producing C heavy oil according to the present invention is a method for producing C heavy oil in which low sulfur C heavy oil is produced by the first crude oil and the second crude oil, and has a lower sulfur content than the first crude oil. And a second crude oil having a high chlorine concentration in the first distillation apparatus, a first crude oil and a second light fraction of the second crude oil obtained by the first distillation apparatus. And the second heavy fraction of the second crude oil obtained by processing in the first distillation apparatus is desulfurized in the desulfurization apparatus, so that the sulfur content is 0.5 wt%. And a step of obtaining the following C heavy oil.

  In this C heavy oil production method, the second crude oil is treated with the first distillation apparatus, the second heavy fraction obtained by the treatment with the first distillation apparatus is desulfurized with the desulfurization apparatus, and the sulfur content is obtained. C heavy oil whose amount is 0.5 wt% or less is produced. The second crude oil has a lower sulfur content than the first crude oil. Therefore, compared with the case of desulfurizing the crude oil mixed with the first crude oil and the second crude oil, the treatment speed can be maintained without increasing the reaction temperature of the desulfurization apparatus, so that the life of the desulfurization catalyst is extended. The processing amount of low sulfur C heavy oil can be maintained. Therefore, low sulfur C heavy oil can be efficiently produced at low cost without using LS crude oil having a low sulfur content. Moreover, in this C heavy oil manufacturing method, in the second distillation apparatus, the first crude oil and the second light fraction obtained by processing in the first distillation apparatus are mixed. Thereby, even if the chlorine concentration of the second crude oil is high, the second light fraction containing chlorine obtained by processing in the first distillation apparatus and the first crude oil having a low chlorine concentration are mixed. As a result, the chlorine concentration as a whole can be reduced. Therefore, generation | occurrence | production of the malfunction that apparatuses, such as a heat exchanger, corrode can be suppressed, and the fall of production efficiency can be suppressed. As described above, this C heavy oil production method can efficiently produce low sulfur C heavy oil.

  In one embodiment, the method includes a step of treating the first crude oil with a third distillation apparatus, and the second distillation apparatus includes a first heavy fraction of the first crude oil obtained by treatment with the third distillation apparatus. And the second light fraction of the second crude oil obtained by treatment with the first distillation apparatus, and the first light fraction of the first crude oil containing chlorine obtained by treatment with the third distillation apparatus. You may mix a minute and the light fraction containing chlorine obtained by processing with a 2nd distillation apparatus. Thereby, even when the chlorine concentration of the second crude oil is high, the first light fraction containing chlorine obtained by the treatment with the third distillation apparatus and the chlorine obtained by the treatment with the second distillation apparatus. The chlorine concentration as a whole can be reduced by mixing with a light fraction containing the second fraction (second light fraction obtained by treatment with the first distillation apparatus). Therefore, generation | occurrence | production of the malfunction that apparatuses, such as a heat exchanger, corrode can be suppressed, and the fall of production efficiency can be suppressed.

  In one embodiment, the first crude oil has a sulfur content of 1.0-4.0 wt%, a chlorine concentration of 2.0-15.0 wtppm, and the second crude oil has a sulfur content. 0.5-0.8 wt% and chlorine concentration may be 20 wtppm or more. When such crude oil is used, the above-described method for producing C heavy oil is particularly effective.

  According to the present invention, low-sulfur C heavy oil can be produced efficiently.

It is a figure which shows the structure of the manufacturing apparatus used for the manufacturing method of C heavy oil which concerns on 1st Embodiment. It is a figure which shows the structure of the manufacturing apparatus used for the manufacturing method of C heavy oil which concerns on 2nd Embodiment.

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

(First embodiment)
[Configuration of manufacturing equipment]
FIG. 1 is a diagram illustrating a configuration of a production apparatus used in the method for producing C heavy oil according to the first embodiment. In the production apparatus 1 shown in FIG. 1, C heavy oil, in particular, low sulfur C heavy oil is produced using the first crude oil and the second crude oil. Low sulfur C heavy oil is heavy oil having a sulfur content (sulfur content) of 0.5 wt% or less.

  The first crude oil is a crude oil having a sulfur content of about 1.0 to 4.0 wt% and a chlorine concentration of about 2.0 to 15.0 wtppm. The second crude oil is a crude oil having a sulfur content of about 0.5 to 0.8 wt% and a chlorine concentration of 20 wtppm or more. That is, the first crude oil has a higher sulfur content and a lower chlorine concentration than the second crude oil. In other words, the second crude oil has a lower sulfur content and a higher chlorine concentration than the first crude oil. If 1st crude oil and 2nd crude oil have said property, a crude oil type will not be limited.

  Processed crudes include, but are not limited to, for example, Alrayan crude, Arshahen crude, Alaskan North Slope crude, Arabian heavy crude, Arabian light crude, Arabian medium blend crude, Basularite crude, Dubai crude, Iranian Heavy crude oil, Kuwait crude oil, Oman crude oil, Forosan crude oil, Upper Zakum crude oil, Kafuji crude oil, Qatar Marine crude oil, Espo crude oil, etc. Among the above-mentioned treated crude oils, forosan crude oil, Arabian medium crude oil, Qatar / Marine crude oil, Espo crude oil and the like have a relatively high chlorine content.

  The low sulfur heavy oil production apparatus 1 includes a first distillation column (third distillation unit) 3, a heating furnace 5, an atmospheric distillation column (second distillation unit) 7, a vacuum distillation column 9, and a second distillation column. (First distillation apparatus) 11 and desulfurization apparatus 13 are provided. Although not shown in FIG. 1, heating furnaces are provided between the atmospheric distillation column 7 and the vacuum distillation column 9 and between the second distillation column 11 and the desulfurization apparatus 13, respectively. Yes.

  The first distillation column 3 is a pre-flush column that is provided upstream of the atmospheric distillation column 7 and extracts a light fraction such as naphtha in advance. The 1st crude oil is supplied to the 1st distillation column 3 from a tank (not shown) via the flow path L1. The first distillation column 3 heat-treats the first crude oil and fractionates it into a first light fraction and a first heavy fraction. The first distillation column 3 sends the first light fraction to the top of the atmospheric distillation column 7 through the flow path L2, and then sends it out of the system via a heat exchanger or the like. The first distillation column 3 sends the first heavy fraction to the heating furnace 5 through the flow path L3.

  The heating furnace 5 includes a first heavy fraction supplied from the first distillation column 3 via the flow path L4 and a second light fraction supplied from the second distillation tower 11 described later via the flow path L10. Heat the mixed oil with mixed minutes. As the heating furnace 5, for example, a box type, a cell type, an upright cylindrical type, or the like can be used. The heating furnace 5 sends the heated mixed oil to the atmospheric distillation tower 7 through the flow path L4.

  The atmospheric distillation column 7 processes the mixed oil supplied from the heating furnace 5 through the flow path L4 under normal pressure. The atmospheric distillation column 7 heats the mixed oil and fractionates it into each fraction described later. In the atmospheric distillation tower 7, the atmospheric distillation residue is sent to the vacuum distillation tower 9 through the flow path L6. The atmospheric distillation column 7 has a flow path L5 for sending light gas and naphtha fraction out of the system, a flow path L7 for sending kerosene fraction out of the system, and a flow path L8 for sending the light oil fraction outside the system. They are connected in this order from the tower top side to the tower bottom side. The flow path L5 merges with the flow path L2. That is, in the production apparatus 1, the light fraction containing chlorine sent from the first distillation column 3, the light gas containing chlorine sent from the atmospheric distillation column 7 and the naphtha fraction are mixed, and the atmospheric distillation column It is sent to a heat exchanger etc. installed in the tower top system of No. 7.

  The vacuum distillation column 9 processes the atmospheric distillation residue supplied from the atmospheric distillation column 7 via the flow path L6 under a reduced pressure lower than the normal pressure. The vacuum distillation tower 9 heats the atmospheric distillation residue and fractionates it. The vacuum distillation tower 9 sends the vacuum distillation residue to the outside of the system (for example, a direct desulfurization apparatus, a hydrocracking apparatus, etc.) via the flow path L9.

  Similar to the first distillation column 3, the second distillation column 11 is a pre-flash column that is provided in the preceding stage of the atmospheric distillation column 7 (heating furnace 5) and extracts a light fraction such as naphtha in advance. In the second distillation column 11, the second crude oil is supplied from a tank (not shown) via the flow path L11. The second distillation column 11 heat-treats the second crude oil and fractionates it into a second light fraction and a second heavy fraction. The second distillation column 11 sends the second light fraction to the heating furnace 5 through the flow path L10. The second distillation column 11 sends the second heavy fraction to the desulfurization device 13 through the flow path L12.

  The desulfurization device 13 desulfurizes the second heavy fraction supplied from the second distillation column 11 via the flow path L12. In the desulfurization apparatus 13, desulfurization is performed by, for example, a hydrodesulfurization method, and low sulfur heavy oil having a sulfur content of 0.5 wt% or less, preferably 0.2 wt% to 0.3 wt% is generated. The desulfurization apparatus 13 sends the produced low sulfur heavy oil out of the system through the flow path L13.

[Method for producing C heavy oil]
Then, the manufacturing method of C heavy oil by the manufacturing apparatus 1 is demonstrated. First, the first crude oil is supplied to the first distillation column 3 and processed in the first distillation column 3, and the first crude oil is fractionated into a first light fraction and a first heavy fraction. Further, the second crude oil is supplied to the second distillation column 11 and processed in the second distillation column 11, and the second crude oil is fractionated into a second light fraction and a second heavy fraction.

  The first heavy fraction sent from the first distillation column 3 and the second light fraction sent from the second distillation column 11 are heated by the heating furnace 5, and then in the atmospheric distillation column 7. It is processed. The atmospheric distillation residue obtained by being processed by the atmospheric distillation tower 7 is sent to the vacuum distillation tower 9, and then the vacuum distillation residue obtained by being processed by the vacuum distillation tower 9 is a cracker or the like. Is sent out. The light gas and naphtha fraction (naphtha, kerosene, light oil, etc.) obtained by being treated by the atmospheric distillation tower 7 and the first light fraction obtained by being treated by the first distillation tower 3 are mixed, It is sent out of the system through a heat exchanger or the like installed at the top of the atmospheric distillation column 7.

  On the other hand, the second heavy fraction of the second crude oil obtained by being processed by the second distillation column 11 is sent to the desulfurization apparatus 13. Then, the second heavy fraction is desulfurized by the desulfurization device 13 to obtain low sulfur C heavy oil. By passing through the above steps, low sulfur C heavy oil is produced.

  As described above, in the method for producing C heavy oil of the present embodiment, low sulfur C heavy oil is produced using the first crude oil and the second crude oil. The first crude oil and the second crude oil are cheaper than LS crude oil. On the other hand, the 1st crude oil and the 2nd crude oil have much sulfur content compared with LS crude oil, and especially 1st crude oil has much sulfur content.

  In the method for producing C heavy oil according to the present embodiment, the first crude oil and the second crude oil are used, the first crude oil is processed in the first distillation column 3, and the second crude oil is processed in the second distillation column 11. The second heavy fraction obtained by the treatment in the second distillation column 11 is desulfurized by the desulfurizer 13 to produce C heavy oil having a sulfur content of 0.5 wt% or less. The second crude oil has a lower sulfur content than the first crude oil. Therefore, compared with the case of desulfurizing the crude oil mixed with the first crude oil and the second crude oil, the treatment speed can be maintained without increasing the reaction temperature of the desulfurization apparatus, so that the life of the desulfurization catalyst is extended. The processing amount of low sulfur C heavy oil can be maintained. Therefore, low sulfur C heavy oil can be efficiently produced at low cost without using LS crude oil having a low sulfur content.

  The second crude oil has a characteristic that the chlorine concentration is high. When the chlorine concentration of crude oil is high, chloride corrosion occurs when the light gas and the naphtha fraction are cooled by a heat exchanger or the like at the top of the atmospheric distillation column 7, causing a problem that the equipment is damaged. Therefore, in the method for producing C heavy oil according to this embodiment, the first light fraction containing chlorine obtained by treatment in the first distillation column 3 and the light light containing chlorine obtained by treatment in the atmospheric distillation column 7 are used. The fraction is mixed. Thereby, even when the chlorine concentration of the second crude oil is high, the light fraction obtained by treatment in the first distillation column 3 and the light fraction obtained by treatment in the atmospheric distillation column 7 ( The light chlorine fraction obtained by processing in the second distillation column 11 can be mixed to reduce the chlorine concentration as a whole. Therefore, generation | occurrence | production of the malfunction that apparatuses, such as a heat exchanger, corrode can be suppressed, and the fall of production efficiency can be suppressed.

  In the present embodiment, a crude oil having a sulfur content of 1.0 to 4.0 wt% and a chlorine concentration of 2.0 to 15.0 wtppm is used as the first crude oil, and a sulfur content is used as the second crude oil. Used was crude oil having a chlorine concentration of 20 wtppm. In the case of using such crude oil, the method for producing C heavy oil of this embodiment is particularly effective.

(Second Embodiment)
[Configuration of manufacturing equipment]
Next, the second embodiment will be described. FIG. 2 is a diagram illustrating a configuration of a production apparatus used in the method for producing C heavy oil according to the second embodiment. As shown in FIG. 2, the manufacturing apparatus 1 </ b> A includes a heating furnace 5, an atmospheric distillation tower (second distillation apparatus) 7, a vacuum distillation tower 9, a second distillation tower (first distillation apparatus) 11, and desulfurization. Device 13. That is, the manufacturing apparatus 1A according to the second embodiment differs from the configuration of the manufacturing apparatus 1 according to the first embodiment in that the first distillation column 3 illustrated in FIG. 1 is not provided. Although not shown in FIG. 2, heating furnaces are provided between the atmospheric distillation column 7 and the vacuum distillation column 9 and between the second distillation column 11 and the desulfurization device 13. Yes.

  In the heating furnace 5, the first crude oil supplied from a tank (not shown) through the flow path L1 and the second light fraction supplied from the second distillation tower 11 through the flow path L10 are mixed. Heat the mixed oil. As the heating furnace 5, for example, a box type, a cell type, an upright cylindrical type, or the like can be used. The heating furnace 5 sends the heated mixed oil to the atmospheric distillation tower 7 through the flow path L4.

  The atmospheric distillation column 7 processes the mixed oil supplied from the heating furnace 5 through the flow path L4 under normal pressure. The atmospheric distillation column 7 heats the mixed oil and fractionates it into each fraction described later. In the atmospheric distillation tower 7, the atmospheric distillation residue is sent to the vacuum distillation tower 9 through the flow path L6. The atmospheric distillation column 7 has a flow path L5 for sending light gas and naphtha fraction out of the system, a flow path L7 for sending kerosene fraction out of the system, and a flow path L8 for sending the light oil fraction outside the system. They are connected in this order from the tower top side to the tower bottom side.

  The vacuum distillation column 9 processes the atmospheric distillation residue supplied from the atmospheric distillation column 7 via the flow path L6 under a reduced pressure lower than the normal pressure. The vacuum distillation tower 9 heats the atmospheric distillation residue and fractionates it. The vacuum distillation tower 9 sends the vacuum distillation residue to the outside of the system (for example, a direct desulfurization apparatus, a hydrocracking apparatus, etc.) via the flow path L9.

  The second distillation column 11 is a pre-flash column that is provided in the preceding stage of the atmospheric distillation column 7 (heating furnace 5) and extracts a light fraction such as naphtha in advance. In the second distillation column 11, the second crude oil is supplied from a tank (not shown) via the flow path L11. The second distillation column 11 heat-treats the second crude oil and fractionates it into a second light fraction and a second heavy fraction. The second distillation column 11 sends the second light fraction to the heating furnace 5 through the flow path L10. The second distillation column 11 sends the second heavy fraction to the desulfurization device 13 through the flow path L12.

  The desulfurization device 13 desulfurizes the second heavy fraction supplied from the second distillation column 11 via the flow path L12. In the desulfurization apparatus 13, desulfurization is performed by, for example, a hydrodesulfurization method to generate low sulfur heavy oil having a sulfur content of 0.5 wt% or less, preferably 0.2 wt% to 0.3 wt%. The desulfurization apparatus 13 sends the produced low sulfur heavy oil out of the system through the flow path L13.

[Method for producing C heavy oil]
Then, the manufacturing method of C heavy oil by 1 A of manufacturing apparatuses is demonstrated. First, the second crude oil is supplied to the second distillation column 11 and processed in the second distillation column 11, and the second crude oil is fractionated into a second light fraction and a second heavy fraction. The first crude oil is supplied to the heating furnace 5.

  The first crude oil and the second light fraction fed from the second distillation column 11 are heated by the heating furnace 5 and then processed in the atmospheric distillation column 7. The atmospheric distillation residue obtained by being processed by the atmospheric distillation tower 7 is sent to the vacuum distillation tower 9, and then the vacuum distillation residue obtained by being processed by the vacuum distillation tower 9 is a cracker or the like. Is sent out. The light gas and naphtha fraction (naphtha, kerosene, light oil, etc.) obtained by processing in the atmospheric distillation column 7 are removed from the system through a heat exchanger installed at the top of the atmospheric distillation column 7. Sent out.

  On the other hand, the second heavy fraction of the second crude oil obtained by being processed by the second distillation column 11 is sent to the desulfurization apparatus 13. Then, the second heavy fraction is desulfurized by the desulfurization device 13 to obtain low sulfur C heavy oil. By passing through the above steps, low sulfur C heavy oil is produced.

  As described above, in the method for producing C heavy oil of the present embodiment, the second heavy fraction obtained by treating the second crude oil with the second distillation column 11 and treating with the second distillation column 11 is obtained. Is desulfurized by the desulfurization apparatus 13 to produce C heavy oil having a sulfur content of 0.5 wt% or less. The second crude oil has a lower sulfur content than the first crude oil. Therefore, compared with the case of desulfurizing the crude oil mixed with the first crude oil and the second crude oil, the treatment speed can be maintained without increasing the reaction temperature of the desulfurization apparatus 13, thereby extending the life of the desulfurization catalyst. The amount of low sulfur C heavy oil treated can be maintained. Therefore, low sulfur C heavy oil can be efficiently produced at low cost without using LS crude oil having a low sulfur content.

  In the method for producing C heavy oil, the first crude oil and the second light fraction obtained by the treatment in the second distillation column 11 are mixed in the atmospheric distillation column 7. Thereby, even when the chlorine concentration of the second crude oil is high, the second light fraction containing chlorine obtained by processing in the second distillation column 11 and the first crude oil having a low chlorine concentration are mixed. By making it, the chlorine concentration as a whole can be reduced. Therefore, generation | occurrence | production of the malfunction that apparatuses, such as a heat exchanger, corrode can be suppressed, and the fall of production efficiency can be suppressed.

  The present invention is not limited to the above embodiment. For example, the manufacturing apparatus 1 of the said embodiment shows an example, and may be provided with another apparatus.

  In the above embodiment, the second distillation column 11 sends the second light fraction to the heating furnace 5 via the flow path L10, but the second distillation column 11 sends the second light fraction to the atmospheric distillation column. 7 may be sent directly.

  DESCRIPTION OF SYMBOLS 3 ... 1st distillation tower (3rd distillation apparatus), 7 ... Atmospheric distillation tower (2nd distillation apparatus), 11 ... 2nd distillation tower (1st distillation apparatus), 13 ... Desulfurization apparatus.

Claims (2)

A method for producing C heavy oil, in which low sulfur C heavy oil is produced from a first crude oil and a second crude oil,
The first crude oil has a sulfur content of 1.0 to 4.0 wt% and a chlorine concentration of 2.0 to 15.0 wtppm,
The second crude oil has the characteristics that the sulfur content is lower and the chlorine concentration is higher than that of the first crude oil, the sulfur content is 0.5 to 0.8 wt%, and the chlorine concentration is 20 wtppm. That's it,
Processing the second crude oil with a first distillation apparatus;
Treating the first crude oil and the second light fraction of the second crude oil obtained by treating with the first distillation apparatus with a second distillation apparatus;
Desulfurizing the second heavy fraction of the second crude oil obtained by treatment in the first distillation apparatus with a desulfurization apparatus to obtain C heavy oil having a sulfur content of 0.5 wt% or less; only including,
The first distillation apparatus is a preflash column that heat-treats the second crude oil and fractionates the second crude oil into the two light fractions and the second heavy fraction,
The method for producing C heavy oil, wherein the second distillation apparatus is an atmospheric distillation column that heats a mixed oil of the first crude oil and the second light fraction under atmospheric pressure . Processing the first crude oil with a third distillation apparatus;
The third distillation apparatus is a preflash column that heat-treats the first crude oil and fractionates the first crude oil into a first light fraction and a first heavy fraction,
The second distillation device, the third distillation apparatus in process to obtained the first oil in the first Heavy fraction and the second oil obtained by treating with the first distillation unit Of said second light fraction,
Mixing said third distillation apparatus said first crude first light fraction of containing chlorine obtained by treatment with, a light fraction containing the resulting chlorinated by treatment with the second distillation unit The method for producing C heavy oil according to claim 1, wherein:

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