JP2878857B2 - 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, according to the present invention, a hydrocarbon oil containing mercury and / or a mercury compound is mixed with an organic peroxide, and then the fraction is distilled off at a temperature of 100 ° C. or lower to obtain a fraction. It is characterized in that mercury and a mercury compound in the hydrocarbon oil are extracted by shaking and mixing a hydrocarbon oil having a boiling point of 100 ° C. or more and an aqueous solution containing an organic solvent soluble in water by 3% by volume or more. And a method for removing mercury and mercury compounds in hydrocarbon oils.

Hereinafter, the present invention will be described in more detail.
The hydrocarbon oil from which mercury and mercury compounds can be removed according to the present invention is a hydrocarbon oil containing a distillate having a boiling point of 100 ° C. or higher, and is not particularly limited. For example,
Examples thereof include hydrocarbon oils such as toluene, gasoline, kerosene, light oil, and natural gas condensate. Also, a mixture of these with low-boiling hydrocarbon oils such as benzene and hexane may be used. In the present invention, first, an organic peroxide is added to a hydrocarbon oil, and the mixture is heated and rectified to separate a low-boiling fraction containing no mercury compound at a temperature of 100 ° C. or lower. At the same time as concentrating the mercury compound, oxidizing the mercury compound and making it easier to extract in the next operation. 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 the organic peroxide added to the hydrocarbon oil is 1 to 20 times the number of atoms of mercury contained in the hydrocarbon oil when decomposed by contact with an acidic inorganic substance.
Preferably, the amount is such that 5 to 15 times the number of atoms of oxygen is generated. When the number of atoms of available oxygen contributing to oxidation in the organic peroxide is 5 times or less the number of atoms of mercury contained in the hydrocarbon oil, the oxidation of mercury is insufficient, If it exceeds 20 times, organic oxidation products increase, which is not preferable. The reason that the peroxide is limited to the organic peroxide is that the decomposition product after the decomposition becomes a compound and a hydrocarbon compound which are easily dissolved in the organic solvent aqueous solution added thereafter. is there.

Subsequently, the mixture is rectified to separate a distillate distilled at 100 ° C. or less. Mercury and mercury compounds are hardly distilled off in this fraction. Therefore, the retained mercury and mercury compounds are concentrated and oxidized, and are easily extracted.

Next, the obtained hydrocarbon oil having a boiling point of 100 ° C. or more and an aqueous solution containing an organic solvent soluble in water by 3% by volume or more are added, and the mixture is shaken and mixed. Extract mercury and mercury compounds. The organic solvent that can be used in the present invention and is soluble in water at 3% by volume or more may satisfy the above conditions, and is not particularly limited. Examples thereof include acetone, methyl alcohol,
Examples include ethyl alcohol, isopropyl alcohol, n-propyl alcohol, tetrahydrofuran, ethylene glycol monoalkyl ether, dioxane, and the like. The concentration of an organic solvent in an aqueous solution has a boiling point of 1
It is determined by the type of hydrocarbon oil of 00 ° C or higher and the concentration of mercury and mercury compounds contained therein,
Although not particularly limited, the higher the temperature, the higher the removal of mercury and mercury compounds. But,
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 must be recovered from the hydrocarbon oil and re-refined. For these reasons, the concentration of the organic solvent in the aqueous solution is, for example, 0.1 to 5 volumes, preferably 1 to 2 volumes of the organic solvent per 1 volume of water. Examples of the method of shaking and mixing the organic solvent aqueous solution and the hydrocarbon oil thus prepared include, for example, a method of shaking and mixing using a separating funnel, and a method of using a shaker that vibrates vertically or horizontally. be able to. The degree of shaking mixing is 300 rpm for 3 seconds to 10 minutes, preferably 1 to 3 minutes.
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 shaking 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 shake-mixed with 1 to 2 volumes per 1 volume of the hydrocarbon oil, and then further mixed with 0.1 volume.
When the shaking and mixing are repeated 2 to 3 times with 3 to 1 volume, the amount of the aqueous solution used is reduced, and mercury and mercury compounds can be sufficiently removed. The temperature during shaking mixing and stationary 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.

[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) Hexane mixed with hydrocarbon oil
Product (2-methylpentane 13% by volume, 3-methylpentane
17% by volume, 55% by volume of n-hexane and methylcycline
Mixture of 15% by volume of lopentane) 40% by volume, n-heptane
30% by volume of tan, 30% by volume of isooctane and xylene
Mixture (ethylbenzene 30 vol%, p-xylene 9 vol)
%, M-xylene 42% by volume and o-xylene 19%
% By volume of the mixture).
Mercury (II), mercury phenylacetate, mercury (I) acetate, and dimer
Ethyl mercury will be 50W / Vppb each as mercury
Was added. (Addition of organic peroxide)
Produces ten times as many oxygen atoms as mercury.
An amount of cumene hydroperoxide was added. You
That is, 2 × 10 per 1000 ml of hydrocarbon oil^-3ml key
Cumene hydroperoxide was added. (Strain) Filled with a Colpac type filling to a height of 55 cm
(The number of theoretical plates is about 10), and a glass distillation tower with an inner diameter of 30 mm is used.
And the above-mentioned organic peroxide-added hydrocarbon oil 500 ml
Was distilled at a reflux ratio of 5: 1 and fractionated every 25 ml. each
The mercury content of the fraction was analyzed by atomic absorption spectroscopy. The result
The results are shown in Table 1.

[0009]

[Table 1] Table 1 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Distillation amount (hydrocarbon oil boiling point (℃) Mercury content (W / Vppb)% of the total volume) ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Initial pool point 59.5 5 63.0 <10 10 68.5 <10 15 69.0 <10 20 69.2 <10 25 69.5 <10 30 72.0 <10 35 97.5 <10 40 98.1 <10 45 98.3 <10 50 98.5 <10 55 98.5 10 60 99.0 10 65 99.3 10 70 99.5 15} １００ 100 ℃ or more 650

[0010]Example 1  Organic peroxide prepared in the same manner as in Experimental Example 1 was added.
The remaining hydrocarbon oil is rectified and the low boiling point component up to 50% by volume
Mercury in the remaining hydrocarbon oils (boiling point 98.5 ° C or less)
As a result of analyzing the content by an atomic absorption method, 395 W /
Vppb. The hydrocarbon oil after rectification has an average pore size of 0.
The solution was filtered using a 45 μm membrane filter.
Take 50 ml of the solution into a separatory funnel and add 30% methanol
Mix with 50 ml of aqueous solution and shake for 3 minutes. After standing and separating,
Analysis of mercury content of upper layer mainly composed of hydrocarbon oil
As a result, it was 35 W / Vppb. Furthermore, the carbonization of this upper layer
Take 30 ml of hydrogen oil in a separatory funnel and add 30% by volume methanol
And mixed with shaking for 3 minutes. Stationary portion
After separation, the mercury content of the upper layer, mainly
As a result of analysis, it became 10W / Vppb or less (below the detection limit).
Was.

[0011]Experimental example 2  Prepared in the same manner as in Experimental Example 1 and after adding the organic peroxide
Of 100% hydrocarbon oil and 30% by volume methanol aqueous solution
100 ml and mixed by shaking for 3 minutes. Stationary separation
After that, the mercury content of the upper layer mainly composed of hydrocarbon oil was
As a result of analysis, it was 65 W / Vppb. This hydrocarbon oil 80
ml into a separating funnel, and 30% by volume methanol aqueous solution 8
0 ml and shake mixed for 3 minutes. After standing and separating,
Analysis of the upper layer of hydrocarbon oil
As a result, it was 45 W / Vppb.

[0012]Example 2  Conde accompanied by natural gas containing 200 W / Vppb of mercury
500 ml of condensate and contained in this condensate
Effective for oxidizing 10 times the number of mercury atoms
Oxygen-producing cumene hydroperoxide
Was added. That is, per 1000 ml of condensate
2 × 10^-3Add ml of cumene hydroperoxide
did. Corpac-type filling was filled to a height of 55 cm
(The number of theoretical plates is about 10), and a glass distillation tower with an inner diameter of 30 mm is used.
And the condensate 50 containing the above organic peroxide.
0 ml was rectified at a reflux ratio of 5: 1 and the volume ratio was reduced to 52%.
The remaining (undistilled) components excluding boiling point components (100 ° C or less)
The mercury content of the densate was analyzed by atomic absorption spectrometry.
As a result, it was 370 W / Vppb. Undistilled part is average pore size
Filter using a 0.45 μm membrane filter.
Take 100 ml of the filtrate into a separatory funnel, and add 30% by volume
Mix with 100 ml of aqueous ethanol solution and mix by shaking for 3 minutes.
Was. After standing separation, the upper layer water mainly composed of hydrocarbon oil
As a result of analyzing the silver content, it was 30 W / Vppb. Further
Then, 50 ml of the upper layer hydrocarbon oil is taken in a separating funnel,
Mix with 25 ml of a 30% by volume aqueous methanol solution and shake for 3 minutes.
And mixed. After stationary separation, mainly composed of hydrocarbon oil
As a result of analyzing the mercury content of the upper layer, 10 W / Vppb or less
Below the limit).

[0013]

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

Claims (1)

(57) [Claims] 1. A mixture of a hydrocarbon oil containing mercury and / or a mercury compound and an organic peroxide, followed by rectification and separation of a distillate distilled at 100 ° C. or lower. Shaking and mixing a hydrocarbon oil at 100 ° C. or higher and an aqueous solution containing an organic solvent soluble in water at 3% by volume or more to extract mercury and a mercury compound in the hydrocarbon oil. Method for removing mercury and mercury compounds from hydrocarbon oil.