JP2878858B2 - Method for removing mercury and mercury compounds from hydrocarbon oil - Google Patents

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 mercury and mercury compounds in a hydrocarbon oil.

[0002]

2. Description of the Related Art It is known that condensate contained in crude oil and natural gas contains mercury and mercury compounds on the order of several tens of ppb from some localities. These mercury and mercury compounds easily produce amalgam with metal materials such as copper, and reduce the activity of the catalyst in the catalytic reaction when used as a petroleum refinery or chemical raw material, and corrode metal materials used in chemical equipment. , Causing a decrease in strength. As a method of removing mercury and a mercury compound, a method of removing the mercury by adsorption using activated carbon or a method of removing the mercury and the compound by contact with copper, aluminum, and these compounds have been attempted.

[0003]

However, in the method of adsorption removal using activated carbon, if the hydrocarbon oil is an aromatic hydrocarbon such as benzene or toluene, mercury and mercury compounds can be sufficiently removed. Can not. Also,
In the method of removing mercury and mercury compounds by contacting with copper, aluminum and their compounds, the treatment requires a high temperature, so that the apparatus is complicated and the cost is problematic. An object of the present invention is to solve the conventional problems as described above and to provide a method for efficiently removing mercury and a mercury compound from hydrocarbon oil by simple means.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have solved the above-mentioned problems. That is, the present invention comprises mixing a hydrocarbon oil containing mercury and / or a mercury compound with an organic peroxide, contacting the mixture with an acidic inorganic substance, and then containing a water-soluble organic solvent. It is intended to provide a method for removing mercury and a mercury compound in a hydrocarbon oil, which is characterized by extracting mercury and a mercury compound in a hydrocarbon oil by mixing with an aqueous solution.

Hereinafter, the present invention will be described in more detail.
The hydrocarbon oils from which mercury and mercury compounds can be removed according to the present invention are all hydrocarbon oils, and are not particularly limited. Examples thereof include hydrocarbon oils such as benzene and toluene, gasoline, kerosene, light oil, natural gas condensate, and the like. Organic peroxides that can be used in the present invention are not particularly limited, for example, cumene hydroperoxide, ditertiary butyl peroxide, benzoyl peroxide, dicumyl peroxide and the like, among which Cumene hydroperoxide is preferred. The amount of this organic peroxide added to the hydrocarbon oil is the number of available oxygen atoms contributing to oxidation, based on the number of mercury contained in the hydrocarbon oil when decomposed by contact with acidic inorganic substances. Is preferably such that oxygen having 1 to 20 times, preferably 5 to 10 times the number of atoms is produced. When the number of atoms of the organic peroxide is less than 5 times the number of atoms of mercury contained in the hydrocarbon oil, the oxidation of mercury is insufficient. The product is not preferable. The mixing of the organic peroxide and the hydrocarbon oil is carried out at 0 to 85 ° C, preferably 30 to 85 ° C.
The heating is preferably performed by heating to ６０60 ° C.

After mixing the above-mentioned organic peroxide with a hydrocarbon oil, this mixture is brought into contact with an acidic inorganic substance. Acidic inorganic substances that can be used in the present invention are not particularly limited, but acid clay, silica alumina, solid acid particles such as alumina or the like, or a mineral acid such as sulfuric acid or phosphoric acid supported thereon. Are preferred. The method of contacting the acidic inorganic substance with the mixture includes, for example, a method of filling the glass tube with the acidic inorganic substance and passing the mixture through the mixture, and a method of adding the acidic inorganic substance to the mixture and filtering the mixture. . The temperature at which the mixture is brought into contact with the acidic inorganic substance is usually 20 to 90 ° C, preferably 55 to 65 ° C.

[0007] An aqueous solution of an organic solvent, prepared by dissolving a water-soluble organic solvent in water, is added to the mixture after contact with the acidic inorganic substance to extract mercury and mercury compounds in the hydrocarbon oil. . As the organic solvent aqueous solution that can be used in the present invention, for example, an aqueous solution of an organic solvent that can be easily dissolved in water, such as being dissolved in water at 3% by volume or more, is preferable. , Ketones, glycols and the like. The concentration of the organic solvent in the aqueous solution is determined by the type of hydrocarbon oil and the concentration of mercury and mercury compounds contained therein, and is not particularly limited. Can be removed. However, as the concentration increases, the amount of the organic solvent dissolved in the hydrocarbon oil increases, and the purity of the hydrocarbon oil decreases. As a result, the organic solvent is recovered from the hydrocarbon oil and re-purified. I have to. For this reason, the concentration of the organic solvent in the aqueous solution is, for example, usually 0.01 to 1 volume, preferably 0.05 to 0.5 volume of the organic solvent per 1 volume of water.
It is 5 volumes. Examples of the method of mixing the aqueous solution of the organic solvent thus prepared and the hydrocarbon oil include, for example, a method of mixing using a separating funnel, a method of using a shaker that vibrates vertically or horizontally, and the like. it can. The degree of mixing is 300 rpm for 3 seconds to 10 minutes, preferably 1 minute.
It may take up to 3 minutes. When extraction is not completed completely by one extraction operation, mercury and mercury compounds can be almost completely removed from the hydrocarbon oil by repeating this extraction operation a plurality of times, usually two to three times. The use of a smaller amount of the organic solvent aqueous solution for the mixing is advantageous in consideration of the post-treatment of the extractant containing mercury and a mercury compound, although it is advantageous to use a smaller amount with respect to the hydrocarbon oil. Mercury and mercury compounds can be removed. As a result of examination from such a viewpoint, the organic solvent aqueous solution is mixed in 1 to 2 volumes with respect to 1 volume of the hydrocarbon oil, and then 0.3 to 2 volumes.
When mixing is repeated two or three times in one volume, the amount of the aqueous solution used is reduced, and mercury and mercury compounds can be sufficiently removed. The temperature at the time of mixing and standing separation may be any temperature at which the vapor pressure of the organic solvent aqueous solution does not abnormally increase, but is usually 0 to 80 ° C, preferably room temperature to 60 ° C. The reason why the peroxide is limited to the organic peroxide is that a decomposition product after being decomposed by contact with an acidic inorganic substance is easily dissolved in an organic solvent aqueous solution.

[0008]

EXAMPLES The present invention will be described below with reference to experimental examples and examples.
Further explanation will be given.Experimental example 1  (Preparation of hydrocarbon oil) As a hydrocarbon oil, n-heptane
40% by volume, 50% by volume of isooctane and 1 part of toluene
200 W / Vp as mercury for a mixture consisting of 0% by volume
Mercury (II) chloride to be pb, and 200 as mercury
Mercury (I) acetate was added to give W / Vppb. (Column treatment) Equipped with a Teflon cock at the bottom and
Glass column tube with an inner diameter of 10 mm equipped with a ram thermostat
Alumina (made by Wako Pure Chemical, acidic, activity 1, chromatograph
(For graphs) so that its height is 100 mm
Was. The prepared alumina column is placed in a column thermostat.
Column temperatures of 20 ° C, 35 ° C, 50 ° C and 65 ° C
And the above-prepared hydrocarbon oil was added at 2 ml /
200 ml flow from the top of the column
did. Mercury in hydrocarbon oil eluted from alumina column
The content was analyzed by the atomic absorption method. Table 1 shows the results.
Show.

[0009]

[Table 1] Table 1 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Column temperature (℃) Mercury content (W / Vppb) ━ {20 350 35 320 50 50 305 65 310} ━━━━━━━━━━━━━━━━━ Column-free treatment 400 This treatment showed a slight mercury removal effect, but the effect was still inadequate and the resulting hydrocarbon Oil could not be used as a chemical feedstock.

[0010]Experimental example 2  (Preparation of hydrocarbon oil) As a hydrocarbon oil, n-heptane
40% by volume, 50% by volume of isooctane and 1 part of toluene
200 W / Vp as mercury for a mixture consisting of 0% by volume
Mercury (II) chloride to be pb, and 200 as mercury
Mercury (I) acetate was added to give W / Vppb. (Addition of organic peroxide)
1, 3, 5, 10 and 20 times the number of mercury atoms
Amount of cumene hydroperoxide that produces as much oxygen
(70% cumene solution) was added. That is, hydrocarbon
2 × 10 per 1000 ml of oil^-3ml of 70% cumene solution
Was added. (Column treatment) Equipped with a Teflon cock at the bottom and
Glass column tube with an inner diameter of 10 mm equipped with a ram thermostat
Alumina (made by Wako Pure Chemical, acidic, activity 1, chromatograph
(For graphs) so that its height is 100 mm
Was. The prepared alumina column is placed in a column thermostat.
Keep the column temperature at 50 ° C and prepare as above.
Hydrocarbon oil at a column flow rate of 2 ml / min.
The mercury content in the eluted hydrocarbon oil flowing 200 ml
Analysis was performed by the atomic absorption method. Table 2 shows the results.

[0011]

[Table 2] Table 2 数 Number of generated oxygen atoms / number of mercury atoms Mercury content (W / Vppb) {0 305 1 280 3 240 5 190 10 170 20 20 170} ━━━━━━━━━━━━━━━━━━━━━━━━━ Untreated hydrocarbon oil 400 The effect of removing mercury was improved by adding an organic peroxide.

[0012]Experimental example 3  (Preparation of hydrocarbon oil) As a hydrocarbon oil, n-heptane
40% by volume, 50% by volume of isooctane and 1 part of toluene
200 W / Vp as mercury for a mixture consisting of 0% by volume
Mercury (II) chloride to be pb, and 200 as mercury
Mercury (I) acetate was added to give W / Vppb. (Addition of organic peroxide)
Produces five times as many oxygen atoms as mercury
Amount of cumene hydroperoxide (70% cumene
Solution), ditertiary butyl peroxide, benzoyl peroxide
And dicumyl peroxide were each added. That is,
70% cumene solution 2x per 1000ml of hydrocarbon oil
10^-3ml, ditertiary butyl peroxide 1 × 10^-3ml, excess
1.5 μg of benzoyl (solid) and dicumyl peroxide (solid)
1.5 μg was added. (Column treatment) Equipped with a Teflon cock at the bottom and
Glass column tube with an inner diameter of 10 mm equipped with a ram thermostat
Alumina (made by Wako Pure Chemical, acidic, activity 1, chromatograph
(For graphs) so that its height is 100 mm
Was. The prepared alumina column is placed in a column thermostat.
Keep the column temperature at 50 ° C and prepare as above.
Hydrocarbon oil at a column flow rate of 2 ml / min.
The mercury content in the eluted hydrocarbon oil flowing 200 ml
Analysis was performed by the atomic absorption method. Table 3 shows the results.

[0013]

[Table 3] Table 3-Organic peroxide added Mercury content (W / Vppb)キ ュ Cumene hydroperoxide 190 Ditertiary butyl peroxide 185 Benzoyl peroxide 180 Dicumyl peroxide 190 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Organic peroxide-free hydrocarbon oil 305 Add organic peroxide to hydrocarbon oil By contacting with alumina, a slight mercury compound removal effect was observed. In addition, almost the same results were obtained for all the organic peroxides.

[0014]Example 1  Hydrocarbon oil 5 eluted from the alumina column of Experimental Example 3
0 ml and 50 ml of an aqueous solution containing 30% by volume of acetone
Was placed in a separatory funnel, mixed and shaken for 3 minutes. Stationary portion
After separating, remove upper layer mainly composed of hydrocarbon oil
Then, the mercury content was analyzed by an atomic absorption method. as a result
Are shown in Table 4.

[0015]

[Table 4] ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Organic peroxide added Mercury content (W / Vppb)キ ュ Cumene hydroperoxide <10 di-tert-butyl peroxide <10 benzoyl peroxide <10 peroxide Dicumyl <10 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Organic peroxide-free hydrocarbon oil 170 From Table 4, 30% by volume It can be seen that most of the mercury was extracted into the acetone solution of.

[0016]

According to the present invention, mercury and mercury compounds can be efficiently removed from hydrocarbon oil by simple means.

Claims (1)

(57) [Claims] An aqueous solution containing a hydrocarbon oil containing mercury and / or a mercury compound and an organic peroxide, contacting the mixture with an acidic inorganic substance, and then containing a water-soluble organic solvent. A method for extracting mercury and a mercury compound in a hydrocarbon oil by mixing with water and a mercury compound in the hydrocarbon oil.