JP2947369B2 - 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 provides a hydrocarbon oil containing mercury and / or a mercury compound and an organic solvent having a higher boiling point than water.
Contacting with an aqueous solution containing ５０50% by volume, stirring and mixing, under a gauge pressure of 0.01 to 10 kg / cm ² , and
It is intended to provide a method for removing mercury and a mercury compound in a hydrocarbon oil, wherein the method is heated to 130 ° C. to extract mercury and / or a mercury compound in the hydrocarbon oil.

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.

An extract for extracting mercury and / or a mercury compound in a hydrocarbon oil is an aqueous solution containing 0.01 to 50% by volume of an organic solvent having a higher boiling point than water. Examples of the organic solvent having a higher boiling point than water include, but are not particularly limited to, ethylene glycol, trimethylene glycol, polyethylene glycol, glycerin, and partially esterified products thereof. The addition amount is usually 0.1 to 5 volumes, preferably 0.5 to 2 volumes per 1 volume of hydrocarbon oil.
It is good. By dissolving an organic solvent having a boiling point higher than the boiling point of water in water, the effect of lowering the vapor pressure during operation and the effect of increasing the distribution ratio of the mercury compound to the aqueous solution can be provided.

[0007] In the method of the present invention, a hydrocarbon oil containing mercury and / or a mercury compound is brought into contact with an extract. Extraction with water has the advantage that the higher the extraction temperature, the greater the distribution ratio of mercury compounds to water,
Increasing the temperature has the potential to increase the vapor pressure of the mercury and penetrate the hydrocarbon oil layer, thereby reducing the removal rate. There is an optimal extraction temperature to satisfy these two contradictory conditions. According to the study, when the temperature exceeds 130 ° C., the amount of mercury compound extracted from the hydrocarbon oil does not seem to increase. Furthermore, a rise in temperature leads to a rise in pressure, and the rise in pressure increases exponentially with a rise in temperature. Therefore, further maintenance of the pressure resistance of the extraction vessel is not advantageous. In the method of the present invention, the contact temperature is usually from 80 to
130 ° C, preferably 90 to 110 ° C. At a temperature lower than 80 ° C., the removal of mercury compounds becomes insufficient. At a temperature higher than 130 ° C., as described above, there is no effect on the increase in the amount of mercury extracted, which may cause deterioration of the pressure-resistant container used. It is not preferable. The pressure at the time of extraction is higher than atmospheric pressure, for example, usually 0.0 as a gauge pressure.
1 to 10 kg / cm ² , preferably 0.1 to 3 kg / cm ² is good. The 0.01 kg / cm ² less than the gauge pressure, the removal of mercury compounds becomes insufficient, also be used a gauge pressure of greater than 10 kg / cm ^2, it is necessary to increase the withstand voltage of the vessel undesirably. A mixture of a hydrocarbon oil containing mercury and / or a mercury compound and an extract is vigorously stirred under the above-mentioned predetermined temperature and pressure to bring the two liquids into contact. Examples of the method include a method in which a mixture of a hydrocarbon oil and an extract is stirred and contacted in an autoclave, or a method in which both liquids are contacted through a flow-type pressurized tank having a stirrer or filled with a filler. And the like.

After completion of the stirring and mixing, the mixture is allowed to stand and separated into an upper layer mainly composed of a hydrocarbon oil and a lower layer mainly composed of an extract. The temperature at the time of stationary separation is usually 0 to 80 ° C, preferably room temperature to 60 ° C.

[0009]

The present invention will be further described with reference to the following examples. Example 1 Mercury (II) chloride was added to a mixture of 40% by volume of n-heptane, 50% by volume of isooctane and 10% by volume of ethylbenzene as a hydrocarbon oil so as to obtain 400 W / Vppb as mercury. As an extract, 10% by volume of ethylene glycol was prepared. 300 ml of the above-prepared hydrocarbon oil was placed in an autoclave having an internal volume of 1 l and a pressure resistance of 100 kg / cm ² , and 150 ml of the extract was added thereto. While stirring and mixing using an electromagnetic induction stirrer, as shown in Table 1, Temperature and pressure. This state was maintained for 10 minutes. Thereafter, the mixture of the hydrocarbon oil and the extract was taken out of the autoclave and allowed to stand for 10 minutes to separate into an upper layer mainly composed of the hydrocarbon oil and a lower layer mainly composed of the extract. About 50 ml of the upper layer (hydrocarbon oil layer) is extracted,
After cooling to 25 ° C., the mercury content was measured by the atomic absorption method. Table 1 shows the results.

[0010]

[Table 1] ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Extraction temperature Pressure (gauge pressure) In upper layer (hydrocarbon oil layer) (° C) (kg / cm ² ) Mercury content (W / Vppb) ８０ 80 < 0.01 80 90 <0.01 65 100 0.04 40 110 0.80 25 120 1.80 20 130 2.45 30 ━━━━━━━━━━━━━━━━━━━━ ━━━━━━━━━━

Example 2 A hydrocarbon oil having the same mercury concentration as in Example 1 was prepared. As the extract, 10% by volume of ethylene glycol, diethylene glycol, triethylene glycol and glycerin were respectively prepared. The above-prepared hydrocarbon oil 30
0 ml was placed in the autoclave used in Example 1, 150 ml of each of the above extracts was added thereto, and the mixture was heated to 120 ° C. while stirring and mixing using an electromagnetic induction stirrer.
The pressure was set as shown in Table 2. This state was maintained for 10 minutes. Thereafter, the mixture of the hydrocarbon oil and the extract was taken out of the autoclave and allowed to stand for 10 minutes to separate into an upper layer mainly composed of the hydrocarbon oil and a lower layer mainly composed of the extract. About 50 ml of each of the upper layer (mercury carbonized oil layer) and the lower layer (extracted liquid layer) was extracted and cooled to 25 ° C., and the mercury content was measured by an atomic absorption method. Table 2 shows the results.

[0012]

[Table 2] Table 2 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Added pressure (gauge pressure) In upper layer Mercury in the lower layer Mercury in the lower layer Organic solvents (kg / cm ² ) Content (W / Vppb) Content (W / Vppb) ━━━━━━━━━━━━━━━━━━━━━エ チ レ ン Ethylene glycol 1.80 20 380 Diethylene glycol 1.70 25 375 Triethylene glycol 1.55 25 370 Glycerin 1.50 30 370━━━━━━━━━ ━━━━━━━━━━━━━━━━━━━━━━━━━━

EXAMPLE 3 150 ml of 10% by volume ethylene glycol was added as an extract to 300 ml of condensate containing 650 W / Vppb of mercury and containing low-boiling substances boiling below 100 ° C. and accompanied by natural gas. Stirring in an autoclave
The temperature was raised to 120 ° C. while mixing, and the pressure was increased to 2.2 kg / cm ^2.
This state was maintained for 10 minutes. Subsequently, after allowing to stand for 10 minutes, about 50 ml of each of the upper layer (condensate layer) mainly composed of condensate and the lower layer (extract layer) mainly composed of the extract is cooled, cooled to 25 ° C., and then subjected to atomic absorption spectrometry. Was used to determine the mercury content. As a result, the mercury concentration in the lower layer (extract layer) was 620 W / Vppb, and the mercury concentration in the upper layer (condensate layer) was 30 W / Vpb.
pb.

[0014]

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 hydrocarbon oil containing mercury and / or a mercury compound and an organic solvent having a boiling point higher than that of water are used in an amount of from 0.01 to
An aqueous solution containing 50% by volume is brought into contact with the solution and stirred and mixed under a gauge pressure of 0.01 to 10 kg / cm ^{2 to} 80 to 1
A method for removing mercury and a mercury compound in a hydrocarbon oil, comprising heating to 30 ° C. to extract mercury and / or a mercury compound in the hydrocarbon oil.