JPH10195455A - Absorptive removal of trace amount of metal in liquid hydrocarbon and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for absorbing and removing a trace amount of metal contained in a liquid hydrocarbon containing asphaltene in high efficiency over a long period, and apparatus therefor. SOLUTION: At least two apparatuses in first absorption treatment zone 1 provided with porous inorganic absorbent-packed layers are parallel arranged and these apparatuses are connected in series so that either one thereof is located on upstream side and the other is located on downstream side, and a liquid hydrocarbon containing asphaltene is fed to the absorption treatment zone 1 on the upstream side to bring the hydrocarbon into contact with a porous inorganic absorption filler, and then, the liquid hydrocarbon is subjected to absorption treatment in the downstream absorption treatment zone and the hydrocarbon is subjected to absorption treatment in the absorption treatment zone on the downstream side during exchange of absorbent in absorption treatment zone on the upstream side, and the absorption treatment zone is connected so as to become downstream after finishing exchange of the absorbent, and each hydrocarbon treated with the fist absorption treatment zone 1 is fed to a second absorption treatment zone 2 packed with a porous carbonaceous material to bring the hydrocarbon into contact with the absorbent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for adsorbing and removing trace metals in liquid hydrocarbons, and more particularly, to the adsorption of trace metals, particularly mercury, in condensate oil containing asphaltene which is a kind of crude oil. It relates to a method and an apparatus suitable for removal.

[0002]

2. Description of the Related Art Mercury is present in liquid hydrocarbons such as naphtha and condensate oil as mixed base materials for petroleum products.
Catalysts used in petroleum refining processes, especially noble metal-based (Pt,
(Pd, etc.) The catalyst is poisoned and causes deterioration of the activity. Even when a hydrocarbon gas such as ethylene or propylene or a liquid hydrocarbon such as naphtha is used as a chemical raw material, mercury becomes a poison for the catalyst and the catalytic activity is impaired. Furthermore, mercury has the property of forming amalgam with many metals, and amalgam corrosion becomes a problem, especially when an aluminum-based alloy is used as a device material.

[0003] Therefore, various methods for removing mercury contained in liquid hydrocarbons have been studied, and various methods using various mercury adsorbents have been proposed. For example, as a mercury adsorbent, a carrier such as alumina loaded with sulfides of heavy metals such as molybdenum, tungsten and vanadium (for example,
See Japanese Patent Publication No. Hei 6-24623. ), And a mercury adsorbent in which a porous carrier carries sulfur. For example, sulfur-supported activated carbon obtained by mixing activated carbon and sulfur fine particles and heating to a specific temperature (see JP-A-59-7891) or activated carbon containing an organic sulfur compound (JP-A-62-114632) Gazette.) Etc. are disclosed. When such a mercury adsorbent is used, mercury reacts with the above-mentioned metal sulfide or sulfur component and is removed from liquid hydrocarbons as mercury sulfide.

[0004] However, the method for adsorbing mercury as described above usually targets naphtha, and in the case of condensate oil containing asphaltenes, the asphaltenes have a higher mercury content than the mercury content. There is a problem that mercury cannot be adsorbed because a large amount is adsorbed by the adsorbent. For this reason, it is conceivable to preliminarily adsorb and remove asphaltene in condensate oil.However, it is necessary to constantly monitor the adsorbed state of asphaltenes, and the operation becomes complicated. The problem of being damaged arises.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above problems and provides a method and an apparatus for adsorbing and removing trace metals in a liquid hydrocarbon containing asphaltene with high efficiency over a long period of time. It is to be.

[0006]

Means for Solving the Problems As a result of intensive studies in view of the above problems, the present inventors have arranged at least two first adsorption treatment zones for adsorbing asphaltene in condensate oil in parallel, The inventors have found that the above-mentioned problems can be solved by connecting the switches in series so that the upstream and the other are downstream, and performing the continuous and switching operation, and have reached the present invention.

That is, a first aspect of the present invention is a liquid hydrocarbon comprising a first adsorption treatment zone provided with a porous inorganic adsorbent packed layer and a second adsorption treatment zone provided with a porous carbon material packed bed. (1) a method for adsorbing and removing trace metals from
At least two of the first adsorption treatment zones are arranged in parallel with each other, and one of them is connected in series so that one is upstream and the other is downstream, and a small amount is connected to the first adsorption treatment zone on the upstream side. Supplying a liquid hydrocarbon containing a metal; (2) bringing the liquid hydrocarbon into contact with the porous inorganic adsorbent in the first adsorption treatment zone; and (3) adsorbing the liquid hydrocarbon from the first adsorption treatment zone. And (4) performing the adsorption treatment in the downstream first adsorption treatment zone while the adsorbent in the upstream first adsorption treatment zone is being exchanged,
(5) Next, the connection is switched so that the first treatment zone after the replacement of the adsorption treatment agent is located downstream, and (6) the liquid hydrocarbons treated in the first adsorption treatment zone are transferred to the second treatment zone. (7) A method for adsorbing and removing trace metals in liquid hydrocarbons, comprising: (7) each step of bringing the liquid hydrocarbon into contact with a porous carbonaceous material in the second adsorption processing zone.

A second aspect of the present invention is a liquid hydrocarbon comprising a first adsorption treatment zone provided with a porous inorganic adsorbent packed layer and a second adsorption treatment zone provided with a porous carbonaceous material packed bed. (1) At least two first adsorption treatment zones are arranged in parallel with each other, and one of the first adsorption treatment zones is arranged in series such that one is upstream and the other is downstream. (2) At least two units are arranged in parallel with each other so that the adsorption process can be performed in the first adsorption process zone on the downstream side during the replacement of the adsorbent in the upstream adsorption process zone. Switching pipes for supplying fluid hydrocarbons to the first adsorption treatment zone and at least two pipes between the first adsorption treatment zones arranged in parallel with each other; The lowermost stream of the treatment zone is one of the second adsorption treatment zones or parallel to each other. (4) each equipment having a switching valve connected to any one of the two or more arrangements and connected to a supply pipe for liquid hydrocarbons from the most downstream of the first adsorption treatment zone to the second adsorption treatment zone; The device for adsorption and removal of trace metals in liquid hydrocarbons consisting of:

Hereinafter, the present invention will be described in detail.

[0010] The liquid hydrocarbon used for the adsorption and removal of trace metals of the present invention is not limited as long as it is a liquid hydrocarbon in a normal state. In addition to the trace metals, sulfur compounds, nitrogen compounds and other compounds may be used. May be contained. Specific examples include condensate oil, naphtha for petrochemical raw materials, and mixed base materials of naphtha and other various petroleum products. The present invention is particularly effective for condensate oil containing asphaltenes.

The trace metals in the liquid hydrocarbon include mercury, arsenic, vanadium, nickel and the like. Among them, mercury which is most contained is effective. This mercury is contained as elemental mercury, inorganic mercury, and organic mercury. In any form, it can be adsorbed and removed in the present invention. In the present invention, the metal content in the liquid hydrocarbon is not limited, and a large amount can be almost completely removed. For example, natural gas condensate oil produced in Southeast Asia and the like usually have 10 to 50
Although it contains 00 ppb of mercury, it can be adsorbed and removed according to the present invention.

As the porous inorganic adsorbent to be filled in the first adsorption treatment zone in the present invention, one or a mixture of two or more of activated clay, silica gel, zeolite, alumina, silica alumina and the like can be mentioned. Among these, activated clay is preferred from the viewpoint of its adsorptivity and economy, particularly in the treatment of condensate oil containing asphaltenes.

Activated clay is obtained by treating acid clay, a kind of clay, with sulfuric acid or the like to further improve the activity.
Chemical composition is SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , Ca
It is composed of O, MgO, and K ₂ O, has a fine pore structure, has various catalytic actions and high adsorptivity, and is used as a carrier of the adsorbent of the present invention.

The capacity of the packed bed in the first adsorption treatment zone is preferably 5 to 30 times the capacity of the packed bed in the second adsorption treatment zone described later. This filling capacity can reduce the frequency of switching the first adsorption zone due to asphaltene adsorption in the treatment of asphaltene-containing products such as condensate oil.

Further, the shape of the first adsorption zone provided with the porous inorganic adsorption filler layer is not particularly limited, and examples thereof include a tower shape, a drum shape, and a box shape.

Examples of the porous carbonaceous material to be filled in the second adsorption treatment zone in the present invention include activated carbon, carbonized adsorbents of synthetic resins and the like, and activated carbon is preferred from the viewpoint of adsorptivity and economy.

The activated carbon used here is 100 m ² /
A carbon material having a large specific surface area of at least g and a high adsorptivity can be widely used. The raw material of the activated carbon is not particularly limited, and charcoal such as coal, coke, charcoal or coconut shell, wood, resin, and bone charcoal can be used. In addition, the activation method also uses steam or carbon dioxide.
The method may be carried out at a high temperature of 000 ° C. to 1200 ° C. or using zinc chloride, phosphoric acid, concentrated acid treatment, or the like. Usually, an activation gas having a water vapor content of 15% to 60% by volume is used. Although it is used, it is particularly preferable to activate the carbonaceous raw material in an atmosphere having a water vapor content of 15% by volume or less from the viewpoint of further improving the trace metal adsorption capacity. As a characteristic of activated carbon, specifically, the specific surface area is 10
Is preferably 0m ² / g~2500m ² / g,
In particular, 500m ² / g~1500m ² / g is more preferable. The ignition residue is preferably 10% by weight or less. By using activated carbon having these properties, the removal efficiency of trace metals can be further enhanced.

The shape of the activated carbon is not particularly limited, and may be any of powder, column, sphere, fiber, and honeycomb. Granulated coal or formed coal is used in an ordinary manner in an amount of 30 to 60 parts per 100 parts of carbon material.
It is prepared by adding a part of petroleum pitch or coal tar or the like as a binder and activating after mixing molding.

In the present invention, the activated carbon as described above may be used alone, but may be used as an adsorbent supporting alkali metal sulfide and / or alkaline earth metal sulfide.

The amount of the alkali metal sulfide and alkaline earth metal sulfide to be carried is not particularly limited, but is preferably 0.1% by weight to 30% by weight with respect to the carrier. The loading amount is 0.
If the amount is less than 1% by weight, the adsorbability of trace metals tends to decrease. If the amount exceeds 30% by weight, the adsorbability of the carrier is inhibited by these metal sulfides, and the improvement in adsorbability of trace metals slows down. The tendency appears.

Next, the method and the apparatus of the present invention will be described step by step.

In the first adsorption treatment zone provided with the porous inorganic adsorbent packed layer, at least two units are arranged in parallel with each other and filled with the same adsorbent, one of which is located upstream and the other is located downstream. Connected in series so that the liquid hydrocarbon of the raw material containing the trace metal is supplied as an upward flow or a downward flow to the first adsorption treatment zone on the upstream side and brought into contact with the porous inorganic adsorbent, Then, it is supplied to the downstream first adsorption treatment zone arranged in series and brought into contact similarly.

In addition, during the replacement of the adsorbent, the adsorption performance of the adsorbent in the first adsorption treatment zone on the upstream side is reduced, and only one or a plurality of the first adsorption treatment zones on the downstream side (in the case of three or more arrangements). The supply valve of the liquid hydrocarbon as the raw material is switched so as to perform the adsorption treatment in the step (1), and the liquid hydrocarbon is supplied in the upward flow or the downward flow. The first adsorption treatment zone on the upstream side after the replacement of the adsorbent is connected to the downstream side of the first adsorption treatment zone on the downstream side, and is again connected in series to perform adsorption treatment with two units.

Next, the liquid hydrocarbons adsorbed in the first adsorption treatment zone are supplied to the second adsorption treatment zone provided with one or more units in an upward or downward flow through a connecting pipe. The second adsorption treatment zone may be a single unit, but the supply is individually switched by operating a switching valve provided in a pipe from downstream of the first adsorption treatment zone due to a decrease in adsorption performance with two or more units. Is preferable from the viewpoint of productivity because long-term continuous operation can be performed. Further, the connection pipes of the second adsorption treatment zone are directly connected to a single second adsorption treatment zone from downstream of the first adsorption treatment zone, and are connected in parallel as in the connection of the first adsorption treatment zone. And connected so that one of them is upstream and downstream.

The contact between the liquid hydrocarbon and the trace metal adsorbent in the first adsorption treatment zone and the second adsorption treatment zone employs any of a fixed bed, a moving bed, a fluidized bed and a boiling bed. However, the fixed bed method is preferred because the structure of the adsorption zone is simple and the operation is easy.

The adsorbent fixed bed may be in the form of powder, crushed,
The adsorption zone can be installed by filling the adsorption zone with a columnar, spherical, fibrous or honeycomb-shaped adsorbent and fixing it in a conventional manner. Specifically, glass wool is laid at the bottom of the adsorption zone and silica balls are installed to prevent the adsorbent from flowing out of the adsorption zone. The trace metal-containing liquid hydrocarbon can be brought into contact with the trace metal adsorbent in the fixed bed by either flowing downward from the upper part or flowing upward from the lower part. It is preferable to flow as a downward flow from the viewpoint of stabilization.

According to the above-described steps and apparatus, in the adsorption and removal of 10 to 5000 ppb of mercury contained in trace metals of liquid hydrocarbons, particularly condensate oil containing alfalten, mainly in the first adsorption treatment zone, Alfalten is adsorbed and removed. In particular, in the first adsorption treatment zone, at least two units are arranged in series in a row, so if the asphaltene adsorption status is known in advance, it is not necessary to frequently check the asphaltene adsorption status, and it is not necessary to periodically check the asphaltene adsorption status. Then, the supply of liquid hydrocarbons to the first adsorption treatment zone may be switched between upstream and downstream between the parallel arrangements. Even if the content of asphaltenes in the raw material fluctuates and increases, backup adsorption can be performed in the first adsorption treatment zone connected in series.
Further, replacement or regeneration of the adsorbent is easy.

In the second adsorption treatment zone,
In particular, since those present together with trace metals in liquid hydrocarbons such as asphaltenes have been adsorbed and removed in advance, trace metals, particularly mercury, in liquid hydrocarbons can be adsorbed and removed with high efficiency, and productivity is good.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings.
FIG. 1 shows an embodiment in which the first adsorption processing zone and the second adsorption processing zone are combined. According to FIG. 1, asphaltene and mercury-containing liquid hydrocarbons (condensate oil) are passed from a pipe 3 through a three-way switching valve 4 through a pipe 5 to a fixed bed 6 filled with activated clay in a first adsorption treatment zone 1. The condensate oil after asphaltene adsorption treatment is supplied from the pipe 7 through the three-way switching valve 8, the pipe 9, and the three-way switching valve 10, and is disposed in parallel from the pipe 11 in the first adsorption treatment zone 1 The second adsorbent-filled fixed bed 12 is supplied as a downward flow. The second fixed bed 12 filled with the adsorbent is the fixed bed 6 filled with the first adsorbent.
And adsorbs asphaltenes and the like that have not been adsorbed by the first adsorbent-filled fixed bed 6.
The condensate oil containing mercury from which asphaltenes have been adsorbed and removed is taken out of the pipe 13 and the three-way switching valve 1
4, the water is supplied as a downward flow from a pipe 15 to a mercury adsorption fixed bed 16 in a second adsorption treatment zone filled with activated carbon. The condensate oil after the adsorption treatment in which mercury is adsorbed and removed by the activated carbon is taken out of the pipe 17.

When the adsorption performance of the fixed bed 6 filled with the first adsorbent decreases, the three-way switching valve 4 for supplying the condensate oil and the other three-way switching valves 8, 10,
By operating 14, condensate oil is supplied from the pipe 3 ′ to the second fixed bed 12 filled with the adsorbent, the condensate oil after adsorption treatment from which asphaltenes have been adsorbed and removed is taken out of the pipe 13, and the three-way switching valve 14 and the pipe 15 are connected. After that, it is supplied to the same mercury adsorption fixed bed 16 as described above.

The filler in the fixed bed filled with the first adsorbent is
The condensate oil after the exchange or the regeneration is operated by operating the three-way switching valves 8, 10 and 14, from the second adsorbent-filled fixed bed 12 via the pipes 6, 9, 11 'to the first adsorbent-filled fixed bed 6. The adsorption treatment is performed again by two of the fixed beds filled with the first adsorbent, and after the adsorption treatment, the mixture is supplied to the same mercury adsorption fixed bed 16 through the pipe 13 ′, the three-way switching valve 14, and the pipe 15 for treatment. You.

Although not shown in FIG. 1, each adsorbent in the first adsorption zone and the adsorbent in the second adsorption zone are:
In the case of a fixed bed, the condensate oil supplied to each adsorption treatment zone may be supplied as an ascending flow in addition to the forward downward flow, and may pass through each filler.

[0033]

The present invention will be described in more detail with reference to the following examples. Example Condensate oil having a mercury content of 27 ppb, asphaltene of 3 ppm and a sulfur content of 300 ppm (specific gravity 15/4 ° C.)
(0.75, initial boiling point 25 ° C, end point 330 ° C) was supplied to the following first adsorption treatment zone and second adsorption treatment zone, and mercury was adsorbed and removed under the following conditions.

First adsorption treatment zone: (1) Adsorbent filled container: glass 20 mmφ × 800 m
mx2. (2) Filler: activated clay 200 obtained by treating acid clay with sulfuric acid
ml × 2 pieces. (3) Adsorbent-filled fixed bed: A container filled with glass wool at both ends of the container and filled with the activated clay is connected in series by a tube as shown in FIG.

Second adsorption treatment zone: (1) Adsorbent filled container: glass 10 mmφ × 400 m
mx 1 piece. (2) Filler: 24 ml of activated carbon (average diameter 1.7 mm) having a specific surface area of 1,200 m ² / g. (3) Adsorbent-filled fixed bed: A container filled with activated carbon while glass wool is packed at both ends of the container is connected by a pipe at the most downstream of the container filled with activated clay as shown in FIG.

Adsorption conditions: (1) Temperature: 25 ° C. (2) Flow rate: 1 ml / min. (3) Adsorption treatment in the first adsorption treatment zone: The adsorption treatment is performed by connecting the upstream side and the downstream side of the adsorbent-filled fixed bed in series.
The supply of the condensate oil is switched from the upstream side to the downstream side every two hours, and while the activated clay in the fixed bed filled with the adsorbent on the upstream side is being replaced, the adsorption treatment is performed on the fixed bed filled with the adsorbent on the downstream side alone, and the two hours The fixed bed filled with the adsorbent on the upstream side, in which the exchange of the activated clay for the adsorbent was completed within less than, was connected to the downstream side such that the fixed bed filled with the adsorbent on the downstream side was the upstream side. This adsorption treatment operation was repeated. Next, the lowermost stream of the condensate oil that has been subjected to the adsorption treatment in the adsorbent-filled fixed bed in the first adsorption treatment zone is supplied to the inlet of the connected adsorbent-filled fixed bed in the connected second adsorption treatment zone, and the adsorption treatment is performed again. went.

For comparison, the same adsorption treatment was carried out except that the number of the adsorbent-filled containers in the first adsorption treatment zone was one and the adsorption treatment was carried out continuously without switching.

In the method using the method and apparatus of the present invention, the mercury content in the condensate oil after the adsorption treatment is 10%.
It was less than 1 ppb during the day (during the operation), but exceeded 1 ppb in 0.5 days in the comparative method and apparatus.

[0039]

According to the method and apparatus of the present invention, trace metals can be adsorbed and removed with high efficiency even in liquid hydrocarbons, particularly condensate oil containing asphaltenes, without being affected by asphaltene adsorption. In addition, since the first adsorption treatment zone can be switched, the operation of replacing the adsorbent due to a decrease in adsorption performance is not stopped, and the productivity is good.

[Brief description of the drawings]

FIG. 1 is an explanatory view illustrating an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 First adsorption treatment zone 2 Second adsorption treatment zone 6, 12 First fixed bed filled with adsorbent 16 Second fixed bed filled with adsorbent

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10G 53/08 C10G 53/08

Claims (5)

[Claims] 1. A method for adsorbing and removing trace metals in a liquid hydrocarbon comprising a first adsorption treatment zone provided with a porous inorganic adsorbent packed bed and a second adsorption treatment zone provided with a porous carbonaceous material packed bed. (1) At least two first adsorption treatment zones are arranged in parallel with each other, and one is connected in series such that one is upstream and the other is downstream, and the first adsorption treatment zone is upstream. Supplying a liquid hydrocarbon containing a trace metal to one adsorption treatment zone; (2) bringing the liquid hydrocarbon into contact with the porous inorganic adsorbent in the first adsorption treatment zone; (3)
The liquid hydrocarbons subjected to the adsorption treatment from the first adsorption treatment zone are passed through the first adsorption treatment zone on the downstream side. (4) While the adsorbent in the first adsorption treatment zone on the upstream side is being replaced, (5) Next, the connection is switched such that the first adsorption treatment zone after the replacement of the adsorbent is on the downstream side, and (6) the first adsorption treatment zone. Supplying the liquid hydrocarbon treated in the above to the second adsorption treatment zone, and (7) in the liquid hydrocarbon comprising the steps of contacting the liquid hydrocarbon with a porous carbonaceous material in the second adsorption treatment zone For removing trace metals. 2. The porous inorganic adsorbent is one or more selected from the group consisting of activated clay, silica gel, zeolite, alumina and silica alumina, and the porous carbonaceous material is activated carbon. The method for adsorptive removal of trace metals in liquid hydrocarbons according to the above. 3. The liquid hydrocarbon is a condensate oil containing asphaltenes and trace amounts of mercury.
Or the method for adsorptive removal of trace metals in liquid hydrocarbons according to item 2. 4. Adsorption and removal of trace metals in liquid hydrocarbons comprising a first adsorption treatment zone provided with a porous inorganic adsorbent packed layer and a second adsorption treatment zone provided with a porous carbonaceous material packed bed. (1) at least two first adsorption treatment zones are arranged in parallel with each other, and one of the first adsorption treatment zones is connected and connected in series such that one of the first adsorption treatment zones is upstream and the other is downstream;
(2) During the replacement of the adsorbent in the upstream adsorption treatment zone,
At least two supply pipes for supplying liquid hydrocarbons to the first adsorption treatment zone, which are arranged in parallel with each other, and at least two fuel supply lines in the parallel arrangement, so that the adsorption treatment can be performed in the first adsorption treatment zone on the downstream side. A switching valve is provided in each of the pipes disposed between the first adsorption treatment zones, and (3) the most downstream portion of the first adsorption treatment zone is provided at one end of the second adsorption treatment zone or in parallel with each other. (4) Each equipment having a switching valve connected to any one of the groups arranged in the form of a plurality of bases and connected to a supply pipe of the liquid hydrocarbon from the most downstream of the first adsorption treatment zone to the second adsorption treatment zone. For the removal and adsorption of trace metals in liquid hydrocarbons. 5. The packed bed capacity of the first adsorption treatment zone provided with the porous inorganic adsorbent packed bed is 5 to 30 times the packed bed capacity of the second adsorption treatment zone. A device to adsorb and remove trace metals in liquid hydrocarbons.