JPH10128003A - Removing method of arsenic and lead in liquid hydrocarbon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and continuously adsorb and remove arsenic and lead existing in a trace quantity in a liquid hydrocarbon by using an activated carbon having a specific pore structure as an adsorbent. SOLUTION: Arsenic and lead in the liquid hydrocarbon is removed by allowing the liquid hydrocarbon containing arsenic and/or lead to contact with the adsorbent containing the activated carbon having 10-100Å average fine pore diameter and >=30% of the whole fine pore volume in the volume of the fine pore having 20-50Å fine pore diameter. The producing method comprises allowing a carboneous raw material to contact with an activated gas consisting of 35-85vol.% gaseous nitrogen, 15-70vol.% steam, 3-30vol.% gaseous carbon dioxide and 0-2vol.% gaseous hydrogen at 700-1200 deg.C and cooling the heated activated carbon. Thus, the activated carbon having 200-25000m<2> /g surface area and 10-100Å average fine pore diameter is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing arsenic and lead in liquid hydrocarbons, and more particularly to a method for removing petroleum fractions such as naphtha used in the production of petroleum products or petrochemical products and natural oils. Arsenic and lead (in the present specification, unless otherwise specified, arsenic and lead include inorganic and organic compounds containing these elements) from gas condensate or the like using a solid adsorbent. It is about the method. Also,
TECHNICAL FIELD The present invention relates to an arsenic and lead adsorbent used for adsorbing and removing arsenic and lead in a liquid hydrocarbon.

[0002]

2. Description of the Related Art Conventionally, in a petroleum refining process, liquid hydrocarbons such as naphtha used as a mixed base material for petroleum products are subjected to catalytic reforming, hydrogenation, etc., and a noble metal catalyst such as platinum or palladium is used. It is used. If arsenic or lead is contained in the liquid hydrocarbon used as a feed oil for such a catalytic reforming process, even if the amount is very small, the noble metal-based catalyst is significantly poisoned, and the catalytic activity rapidly increases. descend. The poisoned noble metal-based catalyst cannot be regenerated, and as a result, severely hinders production activities. Also,
Even when producing hydrocarbon gas for chemical raw materials such as ethylene and propylene, the presence of arsenic or the like in the liquid hydrocarbon used as a raw material has adverse effects such as promoting coking. Therefore, it is necessary to remove arsenic and the like contained in the raw material liquid hydrocarbon used in the catalytic reforming step and the pyrolysis step using the noble metal catalyst to a predetermined amount or less.

For this reason, it has been required to establish a method for reducing the arsenic content in liquid hydrocarbons, and various removal methods have been proposed. For example, arsenic contained in liquid hydrocarbons, silica, silicon carbide, silica gel,
A method has been proposed in which copper and sulfur are brought into contact with a solid substance in which copper and sulfur are partially supported in a sulfide form on a carrier such as activated carbon to remove them (see JP-A-4-281841).
The production of the solid adsorbent was complicated, and the arsenic removal rate was still insufficient. In addition, mercury and an arsenic-containing hydrocarbon are brought into contact with a mercury collection material carrying sulfur, zinc, palladium, etc. at 175 ° C. or less, and after removing mercury, at a higher temperature and 130 ° C. or more in the presence of hydrogen. A method for removing arsenic by contacting with a nickel oxide or the like on an alumina carrier at a temperature (see JP-A-6-33074) is also disclosed. However, this method uses an expensive adsorbent, has a complicated treatment process, and has a problem in terms of cost such as requiring hydrogen. further,
An arsenic compound remover in which a copper compound and a chromium group compound are supported on activated carbon in combination has been proposed (JP-A-60-238).
See No. 144. ). In addition, a method of directly oxidizing arsenic contained in a liquid hydrocarbon using an oxidizing agent such as an organic peroxide and then separating an oxidation product is disclosed. The removal rate was not sufficient to remove trace amounts of arsenic and the like.

As a method for removing lead from a liquid hydrocarbon, a method using a sulfide such as molybdenum or nickel supported on alumina or the like (see Japanese Patent Publication No. 6-99695).
A method using an adsorbent obtained by impregnating activated carbon with cupric chloride or hydrous ferric chloride (see Japanese Patent Application Laid-Open No. 50-64228) has been proposed. There is a problem that requires. However, as in the above proposals, the production of the adsorbent is complicated, and the problem of the incorporation of the reaction product into the liquid hydrocarbon due to the falling off is also included. Further, the conventional proposal does not disclose a method for simultaneously absorbing and removing arsenic and lead.

[0005] Natural gas condensate often contains arsenic and the like, depending on the place of production. However, when arsenic and the like are removed by an adsorbent, asphaltene, carbene, and so on contained in the natural gas condensate are removed. Since the sulfur compound covers the surface of the adsorbent and closes the pores and rapidly shortens the service life, it has been difficult to continuously remove arsenic and lead coexisting with asphaltenes and the like for a long period of time.

As described above, many conventional methods for removing arsenic and lead in liquid hydrocarbons have been proposed, but each of them has some disadvantages.
There has been a long-felt need for a method of continuously removing arsenic and lead which can remove heavy metals such as arsenic in liquid hydrocarbons almost completely by a simple operation and can maintain the removal rate for a long period of time.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the problems of the conventional methods for removing arsenic and other heavy metals in liquid hydrocarbons as described above. An object of the present invention is to provide a method for removing arsenic and lead which can efficiently remove heavy metals such as arsenic and lead, maintain a high removal rate, and is simple in terms of equipment and operation.

[0008]

Means for Solving the Problems Accordingly, the present inventors have:
In order to solve the above-mentioned problems, as a result of diligent studies on methods for removing arsenic and other heavy metals in liquid hydrocarbons,
It has been found that by using activated carbon having a specific pore structure as an adsorbent, arsenic and lead present in trace amounts in liquid hydrocarbons can be efficiently and continuously adsorbed and removed. Also, the present invention is based on these findings, focusing on the fact that the adsorption performance of arsenic and lead can be further improved by supporting alkali metal sulfide and / or alkaline earth metal sulfide on the activated carbon. It was completed.

That is, the present invention provides a liquid hydrocarbon containing arsenic and / or lead having an average pore diameter of 10 ° to 1 °.
Removing arsenic and lead from the liquid hydrocarbon by contacting with an adsorbent containing activated carbon, wherein the volume of pores having a pore diameter of 20 to 50% is at least 30% of the total pore volume. It is about the method.

Further, according to a preferred embodiment of the present invention, the liquid hydrocarbon containing arsenic and / or lead has an average pore diameter of 10 ° to 100 ° and a pore diameter of 20 ° to 20 °.
A method for removing arsenic and lead by contacting activated carbon having a volume of 50 ° pores of 50% or more of the total pore volume, a liquid hydrocarbon containing arsenic and / or lead, a nitrogenous gas 35% to 85% by volume, steam 1
5% by volume to 70% by volume, carbon dioxide gas 3% by volume to 30%
Volume%, oxygen gas 0 volume% to 2 volume% and hydrogen gas 0 volume%
Activating gas consisting of 2% by volume to 700 ° C to 120%
0 After contacting at ℃ temperature, heated activated carbon cooled to The specific surface area 200m ² / g~2500m ² / g
And a method for removing arsenic and lead in a liquid hydrocarbon by contacting with activated carbon having an average pore diameter of 10 ° to 100 °.

The specificity of the present invention is that when removing arsenic and / or lead contained in a trace amount in a liquid hydrocarbon, the average pore diameter is 10 ° to 100 ° and the pore diameter is 20 °.
The use of activated carbon having a pore volume of about 50% or more of 30% or more of the total pore volume as a solid adsorbent is basically based on arsenic contained in a liquid hydrocarbon using only activated carbon without the need for a supporting component. And lead can be almost completely and simultaneously and continuously adsorbed and removed.

Hereinafter, the present invention will be described in detail.

The liquid hydrocarbon to be treated in the method for removing arsenic and lead of the present invention is not particularly limited, and any liquid hydrocarbon which contains arsenic and / or lead and which is a liquid in a normal state is particularly limited. Never be. For example, a mixed base material of naphtha and other various petroleum products, natural gas condensate, naphtha for a chemical raw material and the like can be mentioned. Specific examples include straight run naphtha, kerosene, light oil, vacuum distillate, pyrolysis gasoline, catalytic cracking naphtha, catalytic cracking light cycle oil, catalytic cracking heavy cycle oil, hydrocracking naphtha, natural gas condensate, etc. Can be. Furthermore, even if hydrocarbons that are gaseous at normal temperature and normal pressure, such as natural gas and ethylene or propylene, are pressurized and liquefied, they are subjected to the adsorption treatment in the method for removing arsenic and lead in liquid hydrocarbons of the present invention. Any method can be used as long as a hydrocarbon that is solid at room temperature can be heated to become liquid, and the method of arsenic and lead of the present invention can be applied in a liquid state. For example, liquefied natural gas (LNG), liquefied propane gas (LPG), liquefied olefins such as liquefied ethylene and liquefied propylene, and naphtha are liquid, and the arsenic and lead removal method of the present invention can be applied as it is. The liquid hydrocarbon may be a single component or a mixture of multiple components.

The chemical component of arsenic in the liquid hydrocarbon is usually R _n AsH _3-n (where R is an alkyl group, an aryl group, etc., and n is 0, 1, 2, 3) ) Or an organic compound in which hydrogen is substituted with a lower alkyl group having 1 to 4 carbon atoms or a phenyl group. As such an arsenic compound,
Specifically, arsine, monomethylarsine, dimethylarsine, trimethylarsine, monoethylarsine,
Examples include diethyl arsine, triethyl arsine, monopropyl arsine, dipropyl arsine, tripropyl arsine, monobutyl arsine, dibutyl arsine, tributyl arsine, monophenyl dimethyl arsine, diphenyl monomethyl arsine, triphenyl arsine, and the like. Also, arsenic in the form of a halogenated arsenic compound, for example, dimethyl chloroarsine or an oxidized arsenic compound, for example, trimethylarsine oxide, is present in a liquid hydrocarbon, for example, a petroleum fraction as described above. It is possible.

Such arsenic varies depending on the type of liquid hydrocarbon, but usually contains several ppb to several hundred ppb in the liquid hydrocarbon. The arsenic concentration in the liquid hydrocarbon which can be applied to the method for removing arsenic and lead in the liquid hydrocarbon of the present invention is not particularly limited, and can be processed over a wide range of concentrations. It can be completely removed.

The chemical components of lead in the liquid hydrocarbon include organic lead compounds, for example, lead 4-cyclohexylbutyrate, tetraethyl lead and the like. When lead compounds are mixed in crude oil, According to the method for removing arsenic and lead compounds of the present invention, adsorption and removal can be easily performed.

The adsorbent used in the method for removing arsenic and lead in a liquid hydrocarbon of the present invention is an activated carbon having a specific pore structure and excellent adsorption characteristics for arsenic and lead.

In the present invention, the preferred activated carbon is 10
It has a specific surface area of 0 m ² / g or more, and as characteristic values of the pore structure, (1) the average pore diameter is 10 ° to 100 °, and (2) the volume of the pores having the pore diameter of 20 ° to 50 ° is 30% or more of the total pore volume (3) 0.4 ml of total pore volume
/ G or more.

Further, the specific surface area is at least 200 m ² / g,
Preferably, it is not more than 2500 m ² / g.

A particularly preferred activated carbon has an average pore diameter of:
The volume of pores having a pore diameter of 15 ° to 70 ° and a pore diameter of 20 ° to 50 ° is 50% or more of the total pore volume. By using this activated carbon as an adsorbent, liquid Can be almost completely removed, and when lead is present, it can be removed simultaneously with arsenic. Lead can be almost completely removed from a liquid hydrocarbon containing only a lead compound.

In the present invention, the pore distribution, that is, the ratio of the volume of pores having a pore diameter of 20 ° to 50 ° to the total pore volume is 30% or more, preferably 50% or more, more preferably 70% or more. By setting, the adsorption of arsenic and lead is facilitated. By specifying the specific surface area and the average pore diameter, the adsorption can be performed more efficiently.

The total pore volume of the activated carbon used in the method for removing arsenic and lead of the present invention is the volume of all the pores of micropores, transitional pores and macropores, and is 0.4 ml / g or more, preferably Is 0.8m
1 / g to 1.5 ml / g. The specific surface area of the activated carbon is measured by the nitrogen adsorption BET method, and the average pore diameter, the pore volume, and the pore size distribution are measured, for example, by Bellsorb 28 · SA.
It can be calculated on the basis of a nitrogen gas adsorption isotherm measured by a die measuring instrument (manufactured by Nippon Bell Co., Ltd.).

As described above, the activated carbon used in the present invention has a large total pore volume and a specific pore diameter, that is, a specific range of pores of 20 ° to 50 ° is formed intensively. It is characterized by a high ratio of the pore volume, and exhibits a remarkable effect on the adsorption and removal of arsenic and lead in liquid hydrocarbons, and has not been conventionally known as activated carbon. Therefore, in order to prepare such activated carbon, it is required to suppress an excessive increase in the average pore diameter and to select activation conditions so as to obtain a specific pore distribution.

Usually, the activated carbon utilization gas contains water vapor and carbon dioxide gas. The activated carbon used in the present invention is not particularly limited in the content of carbon dioxide gas. %, Preferably 20% to 60% by volume of the activation gas.

Therefore, the activation treatment of the present invention employs a condition in which the activation rate is appropriately controlled as compared with the conventional method. By reducing the activation rate as compared with the ordinary method, as shown in Examples and Comparative Examples, the pore diameter was 20 mm.
It can be observed that the pore volume in the region of Å50 ° is increased and the adsorption performance of arsenic and lead is improved.

In the activation treatment of the activated carbon of the present invention,
The temperature of activated carbon is 300 ° C even after heating in the above activation gas
It is preferable to cool in a gas having the same composition as the activation gas until the temperature becomes below, and then take it out of the system. Here, a gas similar to the activation gas required at the time of cooling refers to a nitrogen gas, a carbon dioxide gas or a mixed gas thereof used at the time of activation, for example, a content of oxygen gas and hydrogen gas of 1% to 2% or less. Any gas may be used, and the gas used for activation and the gas used for cooling may not necessarily have the same composition.

According to the activation treatment of the carbonaceous raw material, the carbonaceous raw material is converted into a nitrogen gas at 25% to 80% by volume,
5% by volume to 70% by volume, carbon dioxide gas 3% by volume to 30%
Volume%, oxygen gas 0 volume% to 2 volume% and hydrogen gas 0 volume%
Activating gas consisting of 2% by volume to 700 ° C to 120%
After the contact at a temperature of 0 ° C., the heated activated carbon is cooled to prepare an activated carbon having the following characteristic values. That is, the activation treatment is performed in a specific surface area of 200 m ² / g to 250 m ² / g.
0 m ² / g and an average pore diameter of 10 ° to 100 °, and the above-mentioned activation conditions so as to obtain an activated carbon having a pore structure in which the volume of pores having a pore diameter of 20 ° to 50 ° is 30% or more of the total pore volume. Is appropriately adjusted.

It is not clear why the activated carbon obtained by the activation treatment using an activation gas having a relatively low water vapor content improves the arsenic adsorption performance, but the activated carbon obtained under such activation conditions is not clear. Has a highly developed structure of micropores suitable for arsenic and lead adsorption as shown in the pore size distribution, and this pore structure improves the adsorption performance for arsenic and lead in liquid hydrocarbons Can be presumed.

The raw material of the activated carbon is not particularly limited, and it is possible to use coal, coke, charcoal, bone charcoal, or charcoal such as coconut shell, wood, and phenolic resin. The carbide can be obtained as a reaction residue after heat-treating the above-described raw material to volatilize water, carbon oxide, and light hydrocarbons, and at the same time, distill a liquid tar. The carbonization temperature is lower than the activation temperature and is set at about 600C to about 800C.

The activated carbon obtained by the activation treatment of the present invention has an average pore diameter of 10 ° to 100 °, preferably 15 °.
Å70 ° and specific surface area of 200 m ² / g ／ 2500
m ² / g, and preferably 1500 m ² / g or less. Further, the total pore volume is 0.4 ml / g to 1.5 m
1 / g, preferably 0.6 ml / g to 1.3 ml / g
It is. The ignition residue is preferably 10% or less.
Activated carbon having all of these characteristic values can exert an extremely high effect on removing arsenic and lead in liquid hydrocarbons.

The shape of the activated carbon is not particularly limited.
Any of granular, crushed, columnar, spherical, fibrous, and honeycomb shapes can be selected, but granular materials are preferred in terms of pressure loss, adsorption capacity, and filling work. In addition, granulated coal or molded coal is used in accordance with a conventional method, for a carbon material 100 times 3 times.
It is prepared by adding 0 to 60 parts of petroleum pitch, coal tar, polymer or the like as a binder, activating after mixing and molding.

In the present invention, activated carbon having the above-mentioned pore characteristics may be used alone as an adsorbent. However, alkali metal sulfide and / or alkaline earth metal sulfide may be supported on the activated carbon. Adsorbents can also be used. These metal sulfides have the effect of further increasing the arsenic and lead adsorption performance of activated carbon.

The alkali metal sulfide or alkaline earth metal sulfide carried on the activated carbon is not particularly limited. Examples of the alkali metal sulfide include Li ₂ S, Na ₂ S and K ₂ S, As metal sulfides,
For example, MgS and CaS. These alkali metal sulfides and alkaline earth metal sulfides may be used alone or in combination of two or more. Among these metal sulfides, when Na ₂ S is supported, the best adsorption performance for arsenic and lead can be obtained.

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 based on the total weight of the adsorbent composition based on the activated carbon. If the supported amount does not reach 0.1% by weight, the adsorption performance tends to decrease, and the supported amount is 30% by weight.
If it exceeds 300, the adsorption performance of activated carbon is inhibited by these metal sulfides, so that the adsorption performance of arsenic and lead cannot be improved.

The activated carbon supporting alkali metal sulfide and the like used in the present invention can be produced, for example, by adding an alkali metal sulfide and an alkaline earth metal sulfide to a suitable inorganic solvent such as an aqueous solution or an aqueous ammonia solution or an organic solvent such as acetone or alcohol. And immersed in activated carbon in this solution to adsorb the metal sulfide, and then in an oven at 110 ° C. to 400 ° C.
C., preferably at 110 ° C. to 200 ° C. to prepare an adsorbent supporting alkali metal sulfide and alkaline earth metal sulfide. In addition, various methods other than the above-described immersion method may be mentioned. For example, a method in which a solution of an alkali metal sulfide and an alkaline earth metal sulfide is sprayed on activated carbon in a shower or mist may be employed. .

The atmosphere for drying after supporting the alkali metal sulfide and the alkaline earth metal sulfide is not particularly limited. For example, air, nitrogen or propane combustion gas can be used.

Even when the above-described activated carbon carrying the alkali metal sulfide and / or the alkaline earth metal sulfide obtained as described above is used for the adsorption and removal of arsenic and the like in a liquid hydrocarbon, the sulfur liquid Elution into hydrocarbons rarely occurs.

The activated carbon used in the method for removing arsenic and lead according to the present invention may be mixed with a porous solid adsorbent such as alumina, silica alumina and zeolite.

The removal of arsenic and the like in the liquid hydrocarbon of the present invention can be performed by passing the liquid hydrocarbon containing arsenic and the like through a fixed bed filled with an adsorbent in an adsorption tower. When the adsorbent is used as a fixed bed, its particle size is 0.1
5 mm to 4.75 mm, especially 0.5 mm to 1.7 mm
Is preferred.

In the method for removing arsenic and lead in a liquid hydrocarbon of the present invention, the adsorption conditions are 0.1 cm / min to 1 cm / min.
LV value (linear velocity) of 00 cm / min, preferably 50 cm / min or less, 15 ° C to 200 ° C, preferably 100 ° C
The following temperatures can be employed.

[0041]

BEST MODE FOR CARRYING OUT THE INVENTION A preferred embodiment of the present invention will be described. The method for removing arsenic and lead according to the present invention comprises the steps of:
The raw material naphtha for catalytic reforming containing 10 ppb and 5 ppb is as follows:-Average pore diameter: 10 to 50%-Volume of pores having pore diameters of 20 to 50% to total pore volume: 70% to 80%-Particles Diameter: Pass through a fixed bed filled with activated carbon of 0.4 mm to 1.7 mm at an LV value of 20 cm / min to 30 cm / min at a temperature of room temperature to 50 ° C., and from the raw material naphtha for catalytic reforming to arsenic And lead can be almost completely removed.

[0042]

The present invention will be described more specifically below with reference to examples and comparative examples. The specific surface area, pore volume and pore diameter distribution of the activated carbon were measured by the following methods.

Specific surface area: measured using a nitrogen adsorption BET method.

Pore volume and pore diameter distribution: The pore volume and pore diameter distribution of activated carbon were determined by measuring the adsorption isotherm of nitrogen gas with a measuring instrument manufactured by Nippon Bell Co., Ltd., Bellsorb 28SA after degassing the activated carbon. Then, based on this, the total pore volume and the pore size distribution of the activated carbon were calculated.

The concentrations of arsenic and lead in the liquid hydrocarbon are determined by a warm incineration and an atomic absorption spectrophotometry (based on the JPI method).
Was measured by

Example 1 A carbonized material obtained by dry distillation of a coconut shell was sized to 4 mesh to 10 mesh (1.7 mm or more and 4.75 mm or less) to obtain a raw material for granular activated carbon. Using the raw material carbide as an activation gas, propane combustion gas (gas composition: nitrogen 70% by volume, steam 2
(0 volume%, carbon dioxide gas 9.8 volume%, oxygen 0.2 volume%)
After activation at 900 ° C. until the specific surface area reached 1400 m ² / g, the mixture was cooled to 300 ° C. or lower using a gas having the same composition. The activated carbon thus obtained is crushed and
0 mesh to 32 mesh (0.5 mm or more, 1.7 m
m or less). The ignition residue of the granular activated carbon was 2.5% by weight. Table 1 shows the average pore diameter and the pore distribution of the activated carbon X. The average pore diameter is 25 °, the total pore volume is 1.3 ml / g, and the pore diameter is 20Å to 50５０.
The ratio of the pores of Å to the total pore volume was 80%.

In order to evaluate the arsenic adsorption capacity of the activated carbon X, light naphtha (specific gravity: 0.750, first density) to which triphenylarsine (AS (C ₆ H ₅ ) ₃ ) was added so that the arsenic concentration became 150 μg / kg. Retention; 120 ° C. to end point; 200
C.) 100 ml of the above-mentioned granular active substance X was filled into a glass tube having an inner diameter of 10 mm at a height of 400 mm and supplied to the upper part of an activated carbon adsorption tube manufactured at a normal temperature, at a rate of 10 ml / min (LV).
(Value: 1.2 cm / min). The following results were obtained when the arsenic concentration in the treated light naphtha obtained from the outlet of the activated carbon adsorption tube was measured.

Before treatment (μg / kg) After treatment (μg / kg) Removal rate (%) 150 10 or less 93 or more Example 2 Using light naphtha whose arsenic concentration was increased from 150 μg / kg to 1000 μg / kg An arsenic adsorption treatment was performed in the same manner as in Example 1 except for the above.

The measurement results of the arsenic concentration in light naphtha before and after the adsorption treatment are shown below.

Before treatment (μg / kg) After treatment (μg / kg) Removal rate (%) 1,000 30 97 Example 3 The same light as in Example 1 except that activated carbon A was used in place of activated carbon X Arsenic adsorption treatment was performed under the same operation and conditions as naphtha. The arsenic concentrations before and after the treatment are shown below.

Before treatment (μg / kg) After treatment (μg / kg) Removal rate (%) 150 10 or less 93 or more Example 4 Example 3 except that the arsenic concentration in light naphtha was increased to 1000 μg / kg. The arsenic adsorption treatment was performed under the same conditions as described above. The results of the performance evaluation of the activated carbon are shown below.

Before treatment (μg / kg) After treatment (μg / kg) Removal rate (%) 1,000 40 96 Example 5 The same operation as in Example 1 except that activated carbon B was used in place of activated carbon X Arsenic concentration 15
0 μg / kg of light naphtha was subjected to arsenic adsorption treatment. The arsenic concentration in the obtained treated oil did not reach 10 μg / kg.

Example 6 An adsorption treatment was carried out under the same operation and conditions as in Example 5 except that the arsenic concentration in light naphtha was increased to 1000 μg / kg.
μg / kg, and the arsenic removal rate was 98.5%.

Example 7 Arsenic was adsorbed and removed in the same manner as in Example 1 except that activated carbon C was used instead of activated carbon X.

Table 1 shows the results of the adsorption treatment.

Example 8 An adsorption treatment was carried out in the same manner as in Example 1 except that the activated carbon X was replaced with an adsorbent in which activated carbon C carried 5% by weight of Na ₂ S as sulfur.

Table 1 shows the results of the adsorption treatment.

Example 9 In order to evaluate the lead adsorption performance of activated carbon X, the lead concentration was 100
μg / kg of lead 4-cyclohexylbutyrate (C
Light naphtha to which ₂₀ H ₂₄ O ₄ pb) has been added
The above-mentioned granular activated carbon X is filled into a glass tube of 400 mm in height and supplied to the upper part of the activated carbon adsorption tube manufactured and supplied at room temperature.
100 at a speed of 0 ml / min (LV value: 1.2 cm / min)
ml. The following results were obtained by measuring the lead concentration in the treated light naphtha obtained from the outlet of the activated carbon adsorption tube.

Before treatment (μg / kg) After treatment (μg / kg) Removal rate (%) 100 10 or less 99 or more Example 10 Lead 4-cyclohexylbutyrate was added, and the lead concentration was 100 μg.
The lead adsorption treatment was performed in the same manner as in Example 1 except that light naphtha was used in which the amount / kg was increased to 600 μg / kg.

The results after the adsorption treatment are shown below. Before treatment (μg / kg) After treatment (μg / kg) Removal rate (%) 600 5 or less 99 or more Example 11 Except that activated carbon A was used in place of activated carbon X, the same operation and conditions as in Example 9 were used. Light naphtha containing lead was subjected to lead adsorption treatment. The lead concentrations before and after the adsorption treatment are shown below.

Before treatment (μg / kg) After treatment (μg / kg) Removal rate (%) 100 5 or less 95 or more Example 12 Lead 4-cyclohexylbutyrate was added to adjust the lead concentration to 600 μM.
Except that the amount was increased to g / kg, the same operation and conditions as in Example 9 were applied to the adsorption treatment of lead in light naphtha. The results of the performance evaluation of the activated carbon are shown below.

Before treatment (μg / kg) After treatment (μg / kg) Removal rate (%) 600 5 or less 99 or more Example 13 In the same manner as in Example 9 except that activated carbon B was used instead of activated carbon X A lead adsorption treatment was performed. The lead concentration in the obtained treated oil was 5 μg / kg or less, and the result was a removal rate of 95% or more.

Example 14 When the adsorption treatment was performed under the same conditions as in Example 11 except that the lead concentration in light naphtha was changed to 600 μg / kg, the amount of lead in the treated oil became 5 μg / kg or less.
The removal rate was 99% or more.

Comparative Example 1 An arsenic adsorption treatment was performed under the same operation and conditions as in Example 1 except that a molybdenum sulfide-based adsorbent was used instead of the granular activated carbon X, and the following results were obtained.

Before (μg / kg) After (μg / kg) removal rate (%) 100 20 80 Comparative Example 2 Same as Example 9 except that molybdenum sulfide-based adsorbent was used in place of granular activated carbon X When subjected to a lead adsorption treatment under the following conditions, the following results were obtained.

Before the treatment (μg / kg) After the treatment (μg / kg) Removal rate (%) 100 20 or more and 80 or less The molybdenum sulfide-based adsorbent used in Comparative Examples 1 and 2 was a particulate γ-alumina (30 %). (Mesh to 40 mesh) to support molybdenum sulfide at 10% by weight and cobalt sulfide at 5% by weight.

Comparative Example 3 Arsenic adsorption treatment was performed in the same manner as in Example 1 except that activated carbon D was used instead of activated carbon X. As a result of the adsorption treatment, the arsenic removal rate was 60%. Activated carbon D had a specific surface area of 1000 m ² / g, an average pore diameter of 30 °, and a volume of pores having a pore diameter of 20 ° to 50 ° occupying 25% of the total pore volume.

Comparative Example 4 An arsenic adsorption treatment was performed in the same manner as in Example 1 except that activated carbon E was used instead of activated carbon X.
The arsenic removal rate was 60%. Table 1 shows the characteristic values of the pore structure of the activated carbon E.

Comparative Example 5-6 Lead adsorption treatment was performed in the same manner as in Example 9 except that various activated carbons were used instead of activated carbon X as shown in Table 2. The results of the adsorption treatment are shown in the same table.

[0070]

[Table 1]

[0071]

[Table 2]

[0072]

According to the present invention, arsenic and / or lead-containing liquid hydrocarbons having a pore diameter of 10 ° to 100 ° and a volume of pores having a pore diameter of 20 ° to 50 ° are preferably 30% or more of the total pore volume. Is effective at a high removal rate of arsenic and lead by contacting an adsorbent containing activated carbon occupying 50% or more or an adsorbent carrying alkali metal sulfide and / or alkaline earth metal sulfide on the activated carbon. And can be continuously removed over a long period of time.

Claims (5)

[Claims] 1. A liquid hydrocarbon containing arsenic and / or lead having an average pore diameter of 10 ° to 100 ° and a pore diameter of 20 °
A method for removing arsenic and lead in a liquid hydrocarbon, which comprises contacting with an adsorbent containing activated carbon having a pore volume of 〜50 ° or more of 30% or more of the total pore volume. 2. The removal of arsenic and lead in a liquid hydrocarbon according to claim 1, wherein the adsorbent is obtained by supporting an alkali metal sulfide and / or an alkaline earth metal sulfide on the activated carbon. Method. 3. The removal of arsenic and lead in a liquid hydrocarbon according to claim 1, wherein the activated carbon is obtained by activating the carbonaceous raw material with an activation gas having a water vapor content of 15% by volume or more. Method. 4. The liquid carbonization according to claim 1, wherein the contact of the liquid hydrocarbon with the activated carbon is performed using a fixed bed of activated carbon having a particle size of 0.15 mm to 4.75 mm. A method for removing arsenic and lead in hydrogen. 5. A specific surface area of 200 m ² / g to 2500 m ²
/ G, average pore diameter 10 ° to 100 °, pore diameter 20 °
Arsenic and lead adsorbents in liquid hydrocarbons wherein the volume of ~ 50 ° pores is 30% or more of the total pore volume.