WO2020174610A1

WO2020174610A1 - Regeneration method for carbon-based adsorbent and regeneration system for carbon-based adsorbent

Info

Publication number: WO2020174610A1
Application number: PCT/JP2019/007569
Authority: WO
Inventors: 洋介佐野
Original assignee: 日揮グローバル株式会社
Priority date: 2019-02-27
Filing date: 2019-02-27
Publication date: 2020-09-03

Abstract

[Problem] To provide a regeneration method for a carbon-based adsorbent and a regeneration system for a carbon-based adsorbent allowing a carbon-based adsorbent, such as active carbon, used for the purpose of eliminating impurities present in a petroleum product to be regenerated economically. [Solution] The regeneration method for carbon-based adsorbent includes: an extraction step of bringing into contact with the carbon-based adsorbent that has adsorbed an adsorption-designated component contained in an oil being processed, a regeneration oil which has a boiling point lower than the boiling point range of the adsorption-designated component and contains a hydrocarbon oil fraction including aromatics, and extracting the adsorption designated component from the carbon-based adsorbent into the regeneration oil; and a separation step of supplying the regeneration oil from after the extraction of the adsorption designated component, to a main distillation tower 5 for the purpose of subjecting a crude oil or a multi-component oil that is equivalent to the crude oil to fractional distillation, and inside the main distillation tower 5, separating the adsorption designated component from the regeneration oil.

Description

Carbon-based adsorbent regeneration method and carbon-based adsorbent regeneration system

The present invention relates to a technique for regenerating a carbon-based adsorbent that adsorbs a component to be adsorbed.

In recent years, in order to suppress environmental pollution due to atmospheric pollutants such as sulfur oxides (SOx) and nitrogen oxides (NOx), regulations on sulfur concentration in product oils such as light oils have become stricter. Under such circumstances, various measures using activated carbon having adsorption performance for various substances have been studied as means for reducing the sulfur concentration in product oil.

For example, Patent Document 1 discloses that the concentration of sulfur in light oil can be reduced by making reaction conditions (particularly temperature conditions) of a hydrodesulfurization device severe. However, when the reaction conditions are made severe, there is a problem that a part of the desulfurized and decomposed hydrocarbon is cyclized and polymerized, and the light oil is colored.

In order to solve this problem, in Patent Document 1, focusing on the fact that activated carbon can adsorb and remove a coloring substance well, the colored substance after hydrodesulfurization is brought into contact with the activated carbon to remove the coloring substance. As a result, the hydrodesulfurization equipment can be used as it is without modification, and the sulfur concentration in light oil can be reduced.

Activated carbon is a relatively expensive adsorbent, and it is desirable to economically regenerate and repeatedly use activated carbon that has adsorbed components to be adsorbed such as coloring substances. However, Patent Document 1 does not discuss a technique for regenerating activated carbon.

Further, Patent Document 2 describes that the activated carbon adsorbing the sulfur compound is contacted with an aromatic solvent such as toluene so that the sulfur compound is desorbed and the activated carbon can be regenerated. However, in Patent Document 2, it is necessary to install a dedicated distillation column for separating the sulfur compound from the aromatic solvent, which is not economically superior and has not been put into practical use.

　In this way, there is still no technology to regenerate activated carbon according to a scheme that makes it economical, and there is an urgent need to establish it.

JP-A-6-136370 Patent No. 4336308

The present invention has been made under the background as described above, and carbon capable of economically regenerating a carbon-based adsorbent such as activated carbon used for the purpose of removing impurities present in petroleum products. An object of the present invention is to provide a method for regenerating a carbon-based adsorbent and a system for regenerating a carbon-based adsorbent.

The method for regenerating a carbon-based adsorbent according to the present invention,
For a carbon-based adsorbent that has adsorbed a component to be adsorbed contained in the oil to be treated, a regenerated oil having a hydrocarbon oil fraction containing an aromatic and having a boiling point lower than the boiling range of the component to be adsorbed. And a step of extracting the components to be adsorbed to the regenerated oil from the carbon-based adsorbent,
The regenerated oil after extraction of the components to be adsorbed is supplied to a main distillation column for fractionating crude oil or a multi-component oil species equivalent to crude oil, and the regenerated oil is used to adsorb the regenerated oil in the main distillation column. A separation step of separating the components.

The method for regenerating a carbon-based adsorbent according to the present invention may have the following features.
(A) The regenerated oil may be one that is provided in a petroleum refining apparatus group that produces the oil to be processed and that is distilled from a processing apparatus for processing a raw material oil.
(B) The processing device may be the main distillation column.
(C) In the separation step, the regenerated oil may be supplied to a position lower than the height position where the regenerated oil is distilled.
(D) In the separation step, the regenerated oil may be supplied to a height position corresponding to a temperature within the boiling point range of the oil to be treated or a position lower than the height position.
(E) The oil to be treated is light oil, and the main distillation column is provided in an atmospheric distillation device or a cracking device, and crude oil or a multi-component oil species equivalent to crude oil is at least a naphtha fraction and a light oil fraction. It is a distillation column for separating into a residual oil fraction, and in the separation step, the regenerated oil is supplied to a height position where the light oil fraction is distilled, or a position lower than the distillation height position. May be.
(F) The regenerated oil is an oil produced by a catalytic reforming device that reforms the distillate oil from the atmospheric distillation device, or a naphtha fraction distilled from the main distillation column. The regenerated oil may be supplied to a height position where the light oil fraction is distilled.
(G) In the extraction step, a circulation system that circulates the regenerated oil to the carbon-based adsorbent is formed, and a smaller amount of regenerated oil than the circulation regenerated oil that circulates in the circulation system is supplied to the circulation system. What to do
The separation step may include extracting a part of the recycled recycle oil and supplying the recycle oil to the main distillation column.

Further, the carbon-based adsorbent regeneration system according to the present invention,
An adsorption tower filled with a carbon-based adsorbent that adsorbs components to be adsorbed contained in the oil to be treated,
In order to extract the components to be adsorbed from the carbon-based adsorbent, a hydrocarbon oil fraction having an aromatic content and a boiling point lower than the boiling range of the components to be adsorbed is included in the adsorption tower. A recycled oil supply line that supplies recycled oil,
From the adsorption tower, a regenerated oil extraction line for extracting the regenerated oil after extracting the components to be adsorbed,
A main distillation column for fractionating a crude oil or a multi-component oil species equivalent to crude oil, wherein the regenerated oil supplied through the regenerated oil extraction line is distilled, and the adsorption target is obtained from the regenerated oil. A main distillation column for separating the components.

The carbon-based adsorbent regeneration system according to the present invention may have the following features.
(H) a processing device provided in a petroleum refining device group for producing the oil to be processed and for processing the raw oil,
The regenerated oil supply line may supply regenerated oil distilled from the processing device to the adsorption tower.
(I) The processing device may be the main distillation column.
(J) The regenerated oil extraction line supplies the regenerated oil to a height position corresponding to a temperature within the boiling point range of the oil to be treated in the main distillation column or a position lower than the height position. May be configured.
(K) the oil to be treated is light oil,
The main distillation column is a distillation column provided in an atmospheric distillation device, or a cracking device, for separating crude oil or a multi-component oil species equivalent to crude oil into at least a naphtha fraction, a light oil fraction and a residual oil fraction. ,
The regenerated oil extraction line may be configured to supply the regenerated oil to a height position where the gas oil fraction is distilled in the main distillation column, or a position lower than the distillation height position. Good.
(L) The regenerated oil supply line uses the oil produced by the catalytic reforming device for reforming the distillate oil from the atmospheric distillation device or the naphtha fraction distilled from the main distillation column as regenerated oil for the adsorption. Supply to the tower,
The reclaimed oil withdrawal line may be configured to supply the reclaimed oil to a height position where the light oil fraction is distilled.

The present invention supplies the regenerated oil after extracting the components to be adsorbed to a main distillation column for fractionating a crude oil or a multi-component oil species equivalent to crude oil, and the adsorbed oil from the regenerated oil in the main distillation column. Since the target component is separated, the carbon-based adsorbent can be economically regenerated without giving an energy loss to the main distillation column.

1 is a configuration example of a carbon-based adsorbent regeneration system according to the present embodiment. It is an example of a desulfurization apparatus to which the method for regenerating a carbon-based adsorbent according to the present embodiment is applied. It is a structural example of the adsorption device which concerns on FIG. It is a structural example of the reproduction|regeneration system of the carbonaceous adsorbent which concerns on other embodiment.

Hereinafter, a carbon-based adsorbent regeneration system according to an embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, a carbon-based adsorbent regeneration system 1 according to the present embodiment includes an adsorption tower 2 filled with a carbon-based adsorbent that adsorbs a component to be adsorbed contained in an oil to be treated, and a carbon-based adsorbent. In order to extract the components to be adsorbed from the wood, the regenerated oil containing a hydrocarbon oil fraction containing an aromatic and having a boiling point lower than the boiling range of the components to be adsorbed is supplied to the adsorption tower 2. Reclaimed oil supply line 3, reclaimed oil withdrawal line 4 for extracting reclaimed oil after extracting components to be adsorbed from adsorption tower 2, and main distillation for fractionating crude oil or multi-component oil species equivalent to crude oil The main distillation column 5 is a tower 5, which distills the regenerated oil supplied through the regenerated oil extraction line 3 to separate the components to be adsorbed from the regenerated oil. The regeneration system 1 of the present embodiment further includes a processing device for obtaining regenerated oil, and a circulation system 6 for circulating the regenerated oil with respect to the carbon-based adsorbent.

The regeneration system 1 according to the present embodiment is a system configured across a plurality of processing devices installed in an oil refining device group (oil refining complex). Within the petroleum refining equipment group, atmospheric distillation equipment, catalytic reforming equipment for reforming distillate oil from the atmospheric distillation equipment, cracking equipment for decomposing heavy oil fractions, distillation equipment obtained in each equipment Various processing devices for processing crude oil or multi-component oil species equivalent to crude oil to finished products or semi-finished products such as a desulfurization device for desulfurizing components are installed. The regeneration system 1 according to the present embodiment is implemented by a petroleum refining apparatus group in which these various processing apparatuses are installed. The oil to be treated is manufactured by the petroleum refining equipment group. In the present embodiment, the oil to be treated is light oil.

The main distillation column 5 fractionally distills the multi-component oil species including the adsorption target component and the boiling point range of the regenerated oil as the multi-component oil species equivalent to crude oil. Specifically, a multi-component oil species equivalent to crude oil includes a multi-component oil species having a boiling point range (NBP range, NBP: Normal Boiling Point) of at least 80°C to 400°C. The multi-component oil species equivalent to crude oil may be an oil species having a lower boiling point range lower than 80°C and an upper boiling point range higher than 400°C. The main distillation column 5 of the present embodiment is a device provided in the cracking device and for distilling cracked oil. The cracking device is, for example, a fluid catalytic cracking device (FCC) or a thermal cracking device (Delayed Coker). In this case, the multi-component oil type equivalent to crude oil is cracked oil obtained by decomposing the fraction obtained by processing crude oil with various processing devices. In the present embodiment, the regenerated oil distilled from the main distillation column 5 is supplied to the adsorption column 2, and the regenerated oil after extracting the components to be adsorbed is returned to the main distillation column 5 to separate the components to be adsorbed from the regenerated oil. A case will be described. That is, in the present embodiment, the processing device for obtaining the regenerated oil is the main distillation column 5. The main distillation column 5 will be described below.

As shown in FIG. 1, the main distillation column 5 includes a column main body 5a extending in the vertical direction, and a plurality of trays 5b installed inside the column main body 5a for separating treated oil into a predetermined boiling point range. .. The tray 5b installed at the bottom in the tower body 5a is set as the first stage, and the number of stages is counted upward, such as the second stage and the third stage. The main distillation column 5 is operated such that the temperature at the bottom of the column is higher than the temperature at the top of the column, and the temperature decreases as it approaches the top of the column. That is, the main distillation column 5 separates the treated oil by gas-liquid contact reaction inside the column main body 5a, distills a light fraction of crude oil from the top side, and distills a heavy fraction from the bottom side. It is configured to let out.

The main distillation column 5 separates the feedstock oil (cracked oil) supplied from the feedstock supply line F into at least a naphtha fraction, a light oil fraction, and a residual oil fraction. In the present embodiment, the residual oil fraction is further separated into a heavy oil fraction and a bottom liquid fraction. Specifically, the main distillation column 5 distills a liquid naphtha fraction, distills a liquid gas oil fraction and a naphtha pump-around section 51 for returning a part of the naphtha fraction to the main distillation column 5. A light oil pump around part 52 for returning a part of the light oil fraction to the main distillation column 5 and a heavy oil pump around for distilling a liquid heavy oil fraction and returning the heavy oil fraction to the main distillation column 5. A part 53 and a column bottom liquid pump around part 54 for distilling a column bottom liquid fraction from the column bottom and returning the column bottom liquid to the main distillation column 5 are provided. The main distillation column 5 has excess heat energy at the bottom of the column, and this heat is used to generate steam, heat the raw material flowing through the raw material supply line F, and so on. Therefore, the main distillation column 5 includes a heat recovery unit 55 that recovers heat of the treated oil. In the present embodiment, the heavy oil pump around section 53 and the tower bottom liquid pump around section 54 are the heat recovery section 55.

The naphtha pump around section 51 is connected to the naphtha transport pump 51a for returning the naphtha fraction distilled from the main distillation column 5 to the main distillation column 5 and the naphtha transport pump 51a, and the naphtha fraction is fed to the main distillation column 5. The naphtha pump around line 51b for returning and the naphtha cooling part 51c installed in the naphtha pump around line 51b for cooling a naphtha fraction are provided. The outlet side end of the naphtha pump around line 51b is connected to the same stage as the naphtha distillation stage 51d for distilling the naphtha fraction, and the naphtha fraction cooled by the naphtha cooling part 51c is returned to the naphtha distillation stage 51d. Be done.

The light oil pump around section 52 is connected to the light oil transport pump 52a for returning the light oil fraction distilled from the main distillation column 5 to the main distillation column 5 and the light oil transport pump 52a, and the light oil fraction is fed to the main distillation column 5. A light oil pump around line 52b for returning and a light oil cooling part 52c installed on the light oil pump around line 52b for cooling the light oil fraction are provided. The outlet side end of the light oil pump around line 52b is connected to the same stage as the light oil distilling stage 52d for distilling the light oil distillate, and the light oil distillate cooled by the light oil cooling unit 52c is returned to the light oil distilling stage 52d. Be done.

The heavy oil pump around section 53 is connected to the heavy oil transport pump 53a for returning the heavy oil fraction distilled from the main distillation column 5 to the main distillation column 5, and the heavy oil transport pump 53a. A heavy oil pump around line 53b for returning the heavy oil fraction to the main distillation column 5 and a heavy oil heat recovery section 53c installed on the heavy oil pump around line 53b for recovering heat from the heavy oil fraction. With. The end portion on the outlet side of the heavy oil pump around line 53b is connected to the same stage as the heavy oil distilling stage 53d for distilling the heavy oil distillate, and the heavy oil heat recovery section 53c recovers heat. The heavy oil distillate is returned to the heavy oil distilling stage 53d.

The column bottom liquid pump around section 54 is connected to the column bottom liquid transport pump 54a for returning the column bottom liquid fraction distilled from the main distillation column 5 to the main distillation column 5, and is connected to the column bottom liquid transport pump 54a. A column bottom liquid pump around line 54b for returning the bottom liquid fraction to the main distillation column 5 and a column bottom liquid heat recovery section 54c installed in the column bottom liquid pump around line 54b for recovering heat from the column bottom liquid fraction With. The outlet side end of the column bottom liquid pump around line 54b is connected to any stage located at the first stage or higher, and the column bottom liquid fraction heat-recovered by the column bottom liquid heat recovery unit 54c is in that stage. Will be returned.

Regenerated oil is a liquid oil that has a boiling point lower than the boiling range of the components to be adsorbed and that contains a hydrocarbon oil fraction containing aromatics. That is, the regenerated oil is an aromatic-containing oil that is lighter than the component to be adsorbed. In this embodiment, the naphtha fraction distilled from the main distillation column 5 is used as the regenerated oil. The naphtha fraction contains about 60 vol% of aromatics. The regenerated oil is preferably one containing aromatics of, for example, 30 vol% or more. By using the regenerated oil containing 30 vol% or more of aromatics, the components to be adsorbed can be extracted without using a large amount of the regenerated oil, which is economical. The aromatic is preferably monocyclic or bicyclic, and may be benzene, toluene, xylene, naphthalene, methylnaphthalene or the like.

Adsorption tower 2 is filled with activated carbon as a carbon-based adsorbent. The liquid regenerated oil and activated carbon are brought into contact with each other in the adsorption tower 2 to extract the components to be adsorbed into the regenerated oil. The adsorption tower 2 of the present embodiment is installed in a desulfurization device that desulfurizes light oil. FIG. 2 is a diagram schematically showing the desulfurization device 7 in which the adsorption tower 2 is installed. The desulfurization device 7 includes a hydrodesulfurization device 72 that hydrodesulfurizes light oil, a pretreatment adsorption device 71 that is installed upstream of the hydrodesulfurization device 72, and a posttreatment adsorption device that is installed downstream of the hydrodesulfurization device 72. And a device 73. In this embodiment, for example, a case of regenerating the activated carbon filled in the pretreatment adsorption device 71 or the posttreatment adsorption device 73 will be described. The desulfurization device 7 is for desulfurizing light oil distilled from an atmospheric distillation device or the like installed in a petroleum refining device group, and activated carbon adsorbs and removes nitrogen compounds or sulfur compounds in the light oil as components to be adsorbed. To do.

As shown in FIG. 3, the pretreatment adsorption device 71 includes a plurality of adsorption towers 2, a supply line 71 a that supplies the oil to be treated (light oil) to the adsorption tower 2, and a discharge that discharges the oil to be treated from the adsorption tower 2. A line 71b, a regenerated oil supply line 3 for supplying regenerated oil to the adsorption tower 2, a regenerated oil extraction line 4 for conveying the regenerated oil discharged from the adsorption tower 2 to the main distillation column 5, and an adsorption target component After that, a decompression line 71c for drying the carbon-based adsorbent under reduced pressure is provided. Here, the pretreatment adsorption device 71 will be described as an example. The post-treatment adsorption device 73 has a device configuration substantially similar to that of the pre-treatment adsorption device 71, although the post-treatment adsorption device 73 differs in that the oil to be treated after desulfurization is treated. In this embodiment, four adsorption towers 2 are provided. While the adsorption step of the adsorption target component is being carried out in two of the four towers, the extraction step of the adsorption target component is being carried out in one of the remaining two towers, and the remaining one tower is going to the adsorption step. It is in a standby state for switching. Each step will be described later.

The regenerated oil supply line 3 supplies the naphtha fraction distilled from the main distillation column 5 to the adsorption column 2 as regenerated oil. As shown in FIG. 1, the recycled oil supply line 3 is connected to the naphtha pump around section 51. Specifically, the recycled oil supply line 3 is connected to the naphtha pump around line 51b. The regenerated oil supply line 3 supplies to the adsorption column 2 a smaller amount of regenerated oil than the naphtha fraction transported as product naphtha and the naphtha fraction returned to the main distillation column 5 as a pump around. For example, the amount of reclaimed oil is 10% or less of the naphtha fraction obtained in the main distillation column 5, and the withdrawal of reclaimed oil has a very small effect on the operation of the existing equipment. In the example shown in FIG. 3, the naphtha fraction is supplied to the third adsorption tower 23, and an extraction step of extracting nitrogen compounds from the activated carbon into the naphtha fraction is carried out in the third adsorption tower 23.

The reclaimed oil withdrawal line 4 is configured to supply the reclaimed oil to a position lower than the height position where the reclaimed oil is distilled in the main distillation column 5. In the present embodiment, the position lower than the height position at which the regenerated oil is distilled means the stage below the naphtha distillation stage 51d. For example, the amount of regenerated oil is a very small amount of 5% or less with respect to the amount of treated oil treated in the main distillation column 5, and even if the regenerated oil is supplied to the main distillation column 5, the main distillation The energy effect on the tower 5 is small.

-The components to be adsorbed are the components that make up the high boiling point region of light oil, and contaminate the product if mixed in the light fraction. Therefore, the regenerated oil extraction line 4 is configured to supply the regenerated oil to a height position corresponding to a temperature within the boiling point range of the oil to be treated in the main distillation column 5 or a position lower than the height position. ing. In the present embodiment, the regenerated oil extraction line 4 supplies the regenerated oil (naphtha fraction) to a height position corresponding to the temperature within the boiling point range of the oil to be treated, at which the light oil fraction is distilled. Is configured to. Specifically, the regenerated oil extraction line 4 is connected to the light oil pump around line 52b and returned to the light oil distilling stage 52d.

For example, the case of extracting an adsorption target component having a boiling point range of 330° C. to 370° C. with a regenerated oil having a boiling point range (NBP range) of 80° C. to 175° C. will be described. When the boiling point range of the oil to be treated containing the components to be adsorbed is, for example, 230° C. to 370° C., the regenerated oil is at a position where a fraction containing a boiling point range of 230° C. to 370° C. is refined in the main distillation column 5. (A height position corresponding to a temperature within the boiling point range of the oil to be treated), or a position at which a fraction having a boiling point range higher than this (a fraction including a boiling point range of 370° C. or higher) is purified (the height concerned) It is preferably supplied to a position lower than the position). In addition, for example, when the oil to be treated is an oil species composed of C8 to C15 (C in which a number is written together represents the number of carbons, the same applies hereinafter), and when the components to be adsorbed correspond to C14 to C15, regenerated oil Is a position in the main distillation column 5 where the C8 to C15 or C8 to C16 fraction is purified (a position corresponding to the temperature within the boiling point range of the oil to be treated) or a distillation heavier than the oil to be treated. For example, it is preferable that the oil species of, for example, C11 to C20, or a fraction heavier than the oil species is supplied to a position where it is refined (a position lower than the height position). That is, the regenerated oil is preferably supplied to a position where the fraction containing the component to be adsorbed is refined. By supplying the regenerated oil to these positions, it is possible to prevent the components to be adsorbed from mixing in a fraction lighter than itself and contaminating the fraction. The type of regenerated oil when regenerating the carbon-based adsorbent of the post-treatment adsorption device 73, the boiling point range of the adsorption target component, and the supply position of the regenerated oil after the adsorption target component is extracted are the same as those of the pre-treatment adsorption device 71. Although substantially the same, they may be different.

The height position means a predetermined position in the height direction of the main distillation column 5, and the range defined between the upper tray 5b and the lower tray 5b is the same height position. Specifically, there is no difference in the position in the height direction between the upper tray 5b and the lower tray 5b, and if the regenerated oil is supplied to this range, it means that it is supplied to the same height position. To do.

In the present embodiment, the reclaimed oil extraction line 4 is configured to supply the reclaimed oil above the heat recovery unit 55. In this embodiment, the regenerated oil extraction line 4 supplies the regenerated oil to a position (upper stage) higher than the heavy oil distilling stage 53d.

The adsorption tower 2 requires a predetermined superficial velocity in order to proceed with the extraction operation. Therefore, as shown in FIG. 1, the regeneration system 1 of the present embodiment includes a circulation system 6 that circulates the regenerated oil to the carbon-based adsorbent. In the present embodiment, a large amount of regenerated oil is circulated in the circulation system 6 to maintain the superficial velocity, and a smaller amount of regenerated oil than the circulation regenerated oil circulating in the circulation system 6 is supplied to the circulation system 6. Then, the same amount of regenerated oil as the regenerated oil supplied to the circulation system 6 is extracted from the circulated regenerated oil.

The circulation system 6 includes a surge drum 61 that receives the circulation regenerated oil, and a circulation pump 62 that supplies the circulation regenerated oil discharged from the surge drum 61 to the adsorption tower 2. The regenerated oil supply line 3 is connected to the surge drum 61 and supplies regenerated oil to the circulation system 6. Further, the regenerated oil extraction line 4 is connected to the discharge line of the circulation pump 62 and supplies the regenerated oil extracted from the circulated regenerated oil to the main distillation column 5. The circulation system 6 will be described later.

The above is the description of the carbon-based adsorbent regeneration system 1 according to the present embodiment. Next, a method of regenerating the carbon-based adsorbent according to this embodiment will be described with reference to FIGS. 1 to 3.

The method for regenerating a carbon-based adsorbent according to the present embodiment (hereinafter, may be referred to as a regenerating method) has a boiling point range of a component to be adsorbed with respect to a carbon-based adsorbent that adsorbs a component to be adsorbed contained in the oil to be treated. An extraction step of extracting a component to be adsorbed from the carbon-based adsorbent into the regenerated oil by bringing the regenerated oil containing a hydrocarbon oil fraction containing an aromatic having a lower boiling point into contact with the regenerated oil; Process of supplying the regenerated oil after extracting the crude oil to the main distillation column 5 for fractionating a crude oil or a multi-component oil species equivalent to the crude oil, and separating the components to be adsorbed from the regenerated oil in the main distillation column 5. And, including. The extraction step is performed after the adsorption step of adsorbing the components to be adsorbed contained in the oil to be treated. Here, a case where the adsorption process and the extraction process are performed by the pretreatment adsorption device 71 will be described as an example.

In FIG. 3, the thick broken line shows the fluid flow in the adsorption process, and the thick solid line shows the fluid flow in the extraction process. In FIG. 3, “O” attached to each on-off valve means an open state, and “C” means a closed state.

In the adsorption process, the first on-off valve V1 installed in the line connecting the first adsorption tower 21 in the supply line 71a for supplying the pre-desulfurization light oil to the adsorption tower 2 is in the open state. Further, the second to fourth on-off valves V2, V3, V4 installed in the supply line 71a connected to the second to fourth adsorption towers 22, 23, 24 are in the closed state. The pre-desulfurization gas oil flows through the first adsorption tower 21 into the second adsorption tower 22 in series, and is discharged from the second adsorption tower 22. The pre-desulfurization light oil discharged from the second adsorption tower 22 is sent to the hydrodesulfurization device 72 via the discharge line 71b.

While the adsorption process is performed in the first adsorption tower 21 and the second adsorption tower 22, the extraction process is performed in the third adsorption tower 23. In the extraction step, the naphtha fraction distilled from the main distillation column 5 is supplied to the third adsorption column 23 via the regenerated oil supply line 3. In the present embodiment, the naphtha fraction is supplied to the surge drum 61 and is supplied to the third adsorption tower 23 as the circulating regenerated oil. The naphtha fraction containing the adsorption target component (nitrogen compound) extracted in the third adsorption tower 23 is discharged from the third adsorption tower 23 and returned to the surge drum 61. Of the recycled recycled oil discharged from the surge drum 61, the same amount of naphtha fraction as that supplied to the surge drum 61 from the recycled oil supply line 3 is supplied to the main distillation column 5 via the recycled oil extraction line 4. Then, the separation step is performed. In this embodiment, the amount of the recycled reclaimed oil is about 5 to 15 times, preferably about 10 to 15 times the amount of the reclaimed oil withdrawn from the main distillation column 5.

In the separation step, the components to be adsorbed are separated from the regenerated oil in the main distillation column 5, and the components to be adsorbed are mixed (dropped) on the column bottom side in the column body 5a. Then, the components to be adsorbed are discharged from the main distillation column 5 as a part of the residual oil fraction and further processed.

The fourth adsorption tower 24 is in a state after the carbon-based adsorbent has been regenerated, and is in a standby state for switching to the adsorption step. In the standby state, the inside of the fourth adsorption tower 24 is depressurized by, for example, an ejector through the depressurization line 71c, and the naphtha fraction is evaporated to dry the carbon-based adsorbent.

As described above, the carbon-based adsorbent regeneration system 1 according to the present embodiment supplies the regenerated oil after extracting the components to be adsorbed to the main distillation column 5, and the regenerated oil is adsorbed from the regenerated oil in the main distillation column 5. It is configured to separate the components. Therefore, the components to be adsorbed can be separated using the existing device without installing new equipment in the oil refining device group. Further, in the present embodiment, the regenerated oil is supplied above the heat recovery unit 55. By supplying the regenerated oil above the heat recovery section 55, it is possible to separate the components to be adsorbed without affecting the heat recovery efficiency of the main distillation column 5 even when the temperature of the regenerated oil is low.

Further, in the present embodiment, the regenerated oil supply line 3 supplies the regenerated oil distilled from the main distillation column 5 to the adsorption column 2, and the regenerated oil extraction line 4 distills the regenerated oil in the main distillation column 5. The regenerated oil is supplied to a position lower than the height position. Therefore, it is possible to prevent the components to be adsorbed in the regenerated oil from being mixed with the regenerated oil and extracted from the regenerated oil supply line 3.

Further, in the present embodiment, the regenerated oil from which the components to be adsorbed is extracted is supplied to the height position corresponding to the temperature within the boiling point range of the oil to be treated or the position lower than the height position. Therefore, it is possible to prevent the components to be adsorbed from mixing in a fraction lighter than the oil to be treated, and prevent the contamination of the light components. Specifically, the regenerated oil from which the components to be adsorbed is extracted is supplied to the main distillation column 5 at a height position where the gas oil fraction is distilled. Since the light oil distilling stage 52d from which the light oil distillate distills is located above the heavy oil distilling stage 53d (heat recovery section 55), it is possible to prevent the regenerated oil from contaminating the product such as the naphtha fraction. Moreover, the components to be adsorbed can be separated from the regenerated oil without giving energy loss to the main distillation column 5.

Further, in this embodiment, the adsorption target component is extracted using the naphtha fraction as the regenerated oil. Therefore, after the extraction step, the naphtha fraction can be evaporated under a reduced pressure atmosphere, and the carbon-based adsorbent can be easily dried.

Further, in the present embodiment, the regeneration system 1 includes the circulation system 6 that circulates the regenerated oil to the carbon-based adsorbent. Therefore, a small amount of regenerated oil can be extracted from the main distillation column 5 and returned to the main distillation column 5. Therefore, the product of the main distillation column 5 is less affected, and the energy effect on the main distillation column 5 can be suppressed.

Further, in the present embodiment, regenerated oil is obtained from the main distillation column 5 in the petroleum refining apparatus group, the regenerated oil is returned to the main distillation column 5, and the components to be adsorbed are removed from the regenerated oil. Therefore, new equipment for preparing reclaimed oil and a dedicated distillation column for separating the components to be adsorbed are unnecessary. Specifically, the main distillation column 5 usually includes a naphtha pump around section and a light oil pump around section. Therefore, the regenerated oil supply line 3 and the regenerated oil extraction line 4 can be connected to these pump-around parts, and the regenerated oil can be easily extracted and returned from the main distillation column 5. Further, it is not necessary to install a nozzle for letting the regenerated oil flow into and out of the main distillation column 5. As described above, the regeneration system 1 of the present embodiment has a scheme that can be carried out in the petroleum refining equipment group without requiring additional equipment and can economically regenerate the carbon-based adsorption.

Further, in the carbon-based adsorbent regeneration system 1 according to the present embodiment, since the carbon-based adsorbent in the adsorption tower 2 installed in the desulfurization device 7 is regenerated, the operating conditions of the main distillation tower 5 (energy loss ) And the operating conditions of the desulfurization apparatus 7, the optimal oil refining apparatus group can be constructed. Specifically, light oil contains a nitrogen compound together with a sulfur compound to be desulfurized. The nitrogen compound is a reaction inhibitor of the hydrodesulfurization reaction (catalyst poison of the hydrodesulfurization catalyst) and reduces the reaction rate of the hydrodesulfurization reaction. In the desulfurization device 7 of this embodiment, the pretreatment adsorption device 71 adsorbs and removes nitrogen compounds. The post-treatment adsorption device 73 also adsorbs and removes a sulfur compound (for example, a sulfur concentration of about 50 wtppm) remaining in the desulfurized gas oil after hydrodesulfurization.

Specifically, for example, when the regulated value is 10 wtppm or less as the sulfur concentration in the product gas oil, the reaction rate decreases in the low concentration range (for example, the sulfur concentration is 50 wtppm or less). Therefore, in order to meet the regulation value, it is necessary to deal with an increase in the hydrogen circulation amount, an increase in the hydrogen consumption amount, an increase in the reaction temperature, an increase in the catalyst amount, etc., and the operating conditions of the hydrodesulfurization device 72 become severe. Become. The desulfurization device 7 removes nitrogen compounds by the pretreatment adsorption device 71 and removes sulfur compounds in the low concentration region by the posttreatment adsorption device 73 to produce low sulfur gas oil (for example, sulfur concentration less than 10 wtppm). As a result, the operating conditions can be relaxed while suppressing a decrease in the reaction rate of hydrodesulfurization. By adopting this desulfurization device 7, even when the regulation value of the sulfur concentration is lowered, it is possible to use the existing device without remodeling it on a large scale. Further, since it is not necessary to make the operating conditions of the hydrodesulfurization device 72 harsh, it is not necessary to upsize the device when newly introducing equipment, and the equipment cost can be reduced. As described above, by applying the present invention to the desulfurization device 7, the entire petroleum refining device group in which the desulfurization device 7 is installed can be optimized.

The method for regenerating the carbon-based adsorbent of the present invention is not limited to the above embodiment, and it goes without saying that various modifications can be made without departing from the scope of the present invention.

In the above embodiment, the case where the processing device for obtaining the regenerated oil is the main distillation column 5 has been described, but the present invention is not limited to this. As shown in FIG. 4, the treatment device may be a catalytic reforming device 8 that reforms the distillate oil from the atmospheric distillation device. That is, the regenerated oil may be the oil produced by the catalytic reforming device 8. The regenerated oil from which the components to be adsorbed is extracted may be supplied to the atmospheric distillation column as the main distillation column 5.

In the above embodiment, the regenerated oil from which the components to be adsorbed has been extracted has been described as being supplied to the height position where the light oil fraction distills, but the present invention is not limited to this. The regenerated oil may be supplied to the raw material supply line F, the heavy oil pump around section 53, the tower bottom liquid pump around section 54, or another height position.

Although not particularly mentioned in the above embodiment, the regenerated oil may be regenerated oil distilled from the main distillation column 5 and temporarily stored in the tank. That is, the regenerated oil may be supplied to the adsorption tower 2 via an intermediate facility such as a tank.

In the above embodiment, the case where the component to be adsorbed is a nitrogen compound or a sulfur compound has been described, but the present invention is not limited to this. For example, when the post-treatment adsorption device 73 has a function of decolorizing desulfurized gas oil, the adsorption target component may include a coloring substance.

In the above embodiment, the boiling point range of the regenerated oil, the component to be adsorbed, and the oil to be treated is exemplified, but the boiling point range of each oil/component is not limited to the exemplified temperature, but the exemplified temperature. May be higher or lower.

Although not mentioned in the present embodiment, the oil to be treated may be naphtha, lubricating oil composed of straight chain hydrocarbons, kerosene, heavy oil and the like. For example, the adsorption tower 2 may be one that removes aromatics contained in lubricating oil or the like made of straight chain hydrocarbon as the oil to be treated. In this case, the component to be adsorbed may include the aromatic. That is, the component to be adsorbed can also be referred to as a nitrogen compound, a sulfur compound, a coloring substance, or a high-boiling-point aromatic compound containing aromatic compounds.

In the above embodiment, the case where the reproduction system 1 includes the circulation system 6 has been described, but the reproduction system 1 does not have to include the circulation system 6. That is, the regenerated oil supply line 3 directly supplies the regenerated oil to the adsorption tower 2 in which the extraction step is performed, and the regenerated oil extraction line 4 directly extracts the regenerated oil after extraction from the adsorption tower 2. Good.

In the above embodiment, the case where the adsorption tower 2 is installed in the pretreatment adsorption device 71 has been described, but the present invention is not limited to this. The adsorption tower 2 may be provided in the post-treatment adsorption device 73, or may be provided in another adsorption device such as a decolorization adsorption device or a dearomatic adsorption device. The height position at which the regenerated oil is supplied in the main distillation column 5 may differ depending on the type of the adsorption device. That is, the boiling point range or the carbon number range of the component to be adsorbed or the oil to be treated is not limited to the range according to the above embodiment. The height position at which the regenerated oil is supplied (returned) in the main distillation column 5 is determined based on the properties of the oil to be actually processed and the components to be adsorbed, and may be different from the position according to the above embodiment. ..

In the above embodiment, the case where the naphtha fraction distilled from the main distillation column 5 is used as the regenerated oil has been described, but the present invention is not limited to this. The regenerated oil may be a hydrocarbon oil fraction having a boiling point lower than the boiling range of the component to be adsorbed and containing an aromatic. Therefore, it is optional from which stage of the main distillation column 5 the regenerated oil is extracted in relation to the components to be adsorbed.

In the above embodiment, the regenerated oil withdrawal line 4 is connected to the light oil pump around line 52b and returned to the light oil distilling stage 52d, but the present invention is not limited to this. The reclaimed oil extraction line 4 may be directly connected to the main distillation column 5. In short, it is sufficient that the regenerated oil is supplied to the main distillation column 5, and the position where the regenerated oil extraction line 4 is connected is arbitrary.

In the above embodiment, the main distillation column 5 is described as an example of the tray column having the tray 5a installed, but the main distillation column 5 may be a packed column.

In the above embodiment, the case where the multi-component oil type equivalent to crude oil is cracked oil has been described, but the present invention is not limited to this. The multi-component oil type equivalent to crude oil is not limited to cracked oil, and may be a multi-component oil type obtained by treating crude oil with various processing devices. That is, the main distillation column 5 is not an attached or additional distillation column installed for the purpose of separating the components to be adsorbed from the regenerated oil, but for refining crude oil into a product or a semi-finished product in a petroleum refining device group. It is a distillation column for carrying out the intermediate treatment (fractionation) of.

In the above embodiment, the case where activated carbon is used as the carbon-based adsorbent has been described, but the present invention is not limited to this. The carbon-based adsorbent may be activated coke, graphite, carbon black or the like.

DESCRIPTION OF SYMBOLS 1... Regeneration system, 2... Adsorption tower, 21... 1st adsorption tower, 22... 2nd adsorption tower, 23... 3rd adsorption tower, 24... 4th adsorption tower, 3... Regenerated oil supply line, 4... Regenerated oil removal Outlet line, 5... Main distillation column, 5a... Tower body, 5b... Tray, 51... Naphtha pump around section, 51a... Naphtha transport pump, 51b... Naphtha pump around line, 51c... Naphtha cooling section, 52... Light oil pump around section , 52a... Light oil transport pump, 52b... Light oil pump around line, 52c... Light oil cooling section, 53... Heavy oil pump around section, 53a... Heavy oil transport pump, 53b... Heavy oil pump around line, 53c... Heavy oil Oil heat recovery unit 54... Tower bottom liquid pump around unit, 54a... Tower bottom liquid transport pump, 54b... Tower bottom liquid pump around line, 54c... Tower bottom liquid heat recovery unit, 55... Heat recovery unit, 6... Circulation system , 61... Surge drum, 62... Circulation pump, 7... Desulfurization device, 71... Pretreatment adsorption device, 71a... Supply line, 71b... Discharge line, 73... Decompression line, 72... Hydrodesulfurization device, 73... Posttreatment adsorption Equipment, F... Raw material supply line

Claims

In the method of regenerating the carbon-based adsorbent,
For a carbon-based adsorbent that has adsorbed a component to be adsorbed contained in the oil to be treated, a regenerated oil having a hydrocarbon oil fraction containing an aromatic and having a boiling point lower than the boiling range of the component to be adsorbed. And a step of extracting the components to be adsorbed to the regenerated oil from the carbon-based adsorbent,
The regenerated oil after extraction of the components to be adsorbed is supplied to a main distillation column for fractionating crude oil or a multi-component oil species equivalent to crude oil, and the regenerated oil is used to adsorb the regenerated oil in the main distillation column. A method for regenerating a carbon-based adsorbent, the method including a separation step of separating components.
The method for regenerating a carbon-based adsorbent according to claim 1, wherein the regenerated oil is provided in a petroleum refining apparatus group for producing the oil to be processed and is distilled from a processing apparatus for processing a raw material oil. ..
The method for regenerating a carbon-based adsorbent according to claim 2, wherein the processing device is the main distillation column.
The method for regenerating a carbon-based adsorbent according to claim 3, wherein in the separating step, the regenerated oil is supplied to a position lower than a height position where the regenerated oil is distilled.
The carbon-based adsorption according to claim 4, wherein in the separation step, the regenerated oil is supplied to a height position corresponding to a temperature within the boiling point range of the oil to be treated or a position lower than the height position. How to recycle wood.
The oil to be treated is light oil, and the main distillation column is provided in an atmospheric distillation device or a cracking device, and at least a naphtha fraction, a light oil fraction, and a residual oil fraction are prepared from crude oil or a multi-component oil species equivalent to crude oil. It is a distillation column for separating into fractions, and in the separating step, the regenerated oil is supplied to a height position where the light oil fraction is distilled, or a position lower than the distillation height position. 1. The method for regenerating the carbon-based adsorbent according to 1.
7. The carbon-based adsorption according to claim 6, wherein the regenerated oil is a product oil of a catalytic reformer that reforms a distillate oil from the atmospheric distillation device, or a naphtha fraction distilled from the main distillation column. How to recycle wood.
In the extraction step, a circulation system that circulates the regenerated oil to the carbon-based adsorbent is formed, and a smaller amount of regenerated oil than the circulation regenerated oil that circulates in the circulation system is supplied to the circulation system. ,
The method for regenerating a carbon-based adsorbent according to claim 1, wherein in the separating step, a part of the recycled regenerated oil is extracted and supplied to the main distillation column.
In a carbon-based adsorbent regeneration system,
An adsorption tower filled with a carbon-based adsorbent that adsorbs components to be adsorbed contained in the oil to be treated,
In order to extract the adsorption target component from the carbon-based adsorbent, the adsorption tower contains a hydrocarbon oil fraction having a boiling point lower than the boiling range of the adsorption target component and containing an aromatic group. A recycled oil supply line that supplies recycled oil,
From the adsorption tower, a regenerated oil extraction line for extracting the regenerated oil after extracting the components to be adsorbed,
A main distillation column for fractionating crude oil or a multi-component oil species equivalent to crude oil, wherein the regenerated oil supplied through the regenerated oil extraction line is distilled, and the adsorption target is obtained from the regenerated oil. A carbon-based adsorbent regeneration system including a main distillation column for separating components.
The oil refining device group for producing the oil to be processed is provided with a processing device for processing the raw oil,
The system for regenerating a carbon-based adsorbent according to claim 9, wherein the regenerated oil supply line supplies the regenerated oil distilled from the processing device to the adsorption tower.
The carbon adsorbent regeneration system according to claim 10, wherein the processing device is the main distillation column.
The regenerated oil extraction line is configured to supply the regenerated oil to a height position corresponding to a temperature within the boiling point range of the oil to be treated in the main distillation column, or a position lower than the height position. The carbon-based adsorbent regeneration system according to claim 11.
The oil to be treated is light oil,
The main distillation column is a distillation column provided in an atmospheric distillation device, or a cracking device, for separating crude oil or a multi-component oil species equivalent to crude oil into at least a naphtha fraction, a light oil fraction and a residual oil fraction. ,
The reclaimed oil withdrawal line is configured to supply the reclaimed oil to a position in the main distillation column where the gas oil fraction distills or a position lower than the distilling height position. Item 10. A system for regenerating a carbon-based adsorbent according to Item 9.
The regenerated oil supply line supplies the oil produced by a catalytic reformer for reforming the distillate from the atmospheric distillation unit or the naphtha fraction distilled from the main distillation column to the adsorption column as a regenerated oil. The system for regenerating a carbon-based adsorbent according to claim 13, which is configured to: ――