JPH04331287A - Method for removing mercury or mercury compound from hydrocarbon oil - Google Patents

Abstract

PURPOSE:To remove mercury or a mercury compd. contained in a hydrocarbon oil by a simple method. CONSTITUTION:Mercury or a mercury compd. contained in a hydrocarbon oil can be removed sufficient by a simple method, i.e., by shaking an aq. soln. contg. a polyhydric alcohol which has a density higher than that of water and a solubility in water of at least 3vol.% with the oil contg. mercury or the mercury compd.

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 from hydrocarbon oil.

0002

BACKGROUND OF THE INVENTION It is known that condensates contained in crude oil and natural gas contain mercury and mercury compounds on the order of tens of ppb from some sources. These mercury and mercury compounds easily form amalgams with metal materials such as copper, resulting in decreased activity of catalysts in catalytic reactions during petroleum refining processing and use as chemical raw materials, and corrosion of metal materials used in chemical equipment. , which may cause a decrease in strength, etc. As methods for removing mercury and mercury compounds, attempts have been made to remove them by adsorption using activated carbon, or by contacting them with copper, aluminum, and their compounds.

0003

[Problems to be Solved by the Invention] However, when the hydrocarbon oil is an aromatic hydrocarbon such as benzene or toluene, the adsorption removal method using activated carbon cannot sufficiently remove mercury and mercury compounds. Can not. Also, contact with copper, aluminum and their compounds can cause
Methods for removing mercury and mercury compounds require high temperatures for treatment, requiring complex equipment and causing problems in terms of cost. The present invention solves the conventional problems as described above,
The object of the present invention is to provide a method for efficiently removing mercury and mercury compounds from hydrocarbon oil using simple means.

0004

[Means for Solving the Problems] As a result of intensive studies, the present inventors were able to solve the above problems. That is, the present invention involves shaking and mixing a hydrocarbon oil with an aqueous solution containing a polyhydric alcohol that has a density greater than that of water and is soluble in water at 3% by volume or more. The present invention provides a method for removing mercury and mercury compounds from hydrocarbon oil, which is characterized by extracting mercury and mercury compounds.

[0005] The present invention will be explained in more detail below. The hydrocarbon oil from which mercury and mercury compounds can be removed by the present invention is any hydrocarbon oil, and is not particularly limited. Examples include hydrocarbon oils such as benzene and toluene, gasoline, kerosene, light oil, and natural gas condensate. The polyhydric alcohol that can be used in the present invention and has a density higher than that of water and dissolves in water by 3% by volume or more is not particularly limited as long as it satisfies the above conditions, but examples include ethylene. Polyhydric alcohols that have two or more hydroxyl groups in the molecule, such as glycol, diethylene glycol, triethylene glycol, glycerin, ethylene glycol monoethyl ether, and ethylene glycol monoacetate, and those that have etherified some of the hydroxyl groups. Compounds and compounds in which all hydroxyl groups are esterified are suitable.

[0006] The concentration of the above-mentioned polyhydric alcohols 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. The higher the temperature, the more mercury and mercury compounds can be removed. Furthermore, if the mixing ratio of polyhydric alcohol is increased, the density of the extraction layer becomes higher, which has the effect of speeding up the separation of the hydrocarbon oil and the extracted water layer when extracting mercury compounds from hydrocarbon oil. However, as the concentration increases, the amount of polyhydric alcohols dissolved in the hydrocarbon oil increases and the purity of the hydrocarbon oil decreases, resulting in the recovery of polyhydric alcohols from the hydrocarbon oil. , will have to be re-refined. For these reasons, the concentration of polyhydric alcohols in an aqueous solution is, for example, usually 0.01 to 1 volume of water.
1 volume, preferably 0.05 to 0.5 volume.

[0007] Methods of shaking and mixing the aqueous solution containing the polyhydric alcohol solution prepared in this way (polyhydric alcohol aqueous solution) and hydrocarbon oil include, for example, a method of mixing using a separatory funnel, and a method of mixing using a separating funnel, Alternatively, a method using a shaker that vibrates in the horizontal direction can be exemplified. The degree of shaking mixing is from 3 seconds to 10 minutes, preferably from 0.5 to 3
A method of mixing by shaking for a minute is sufficient. If it is not completely extracted in one extraction operation, repeat this extraction operation several times, usually 2 to 3 times.
By repeating the process three times, most of the mercury and mercury compounds can be removed from the hydrocarbon oil. It is advantageous to use a polyhydric alcohol aqueous solution used for shaking and mixing in a smaller amount than the hydrocarbon oil, considering the post-treatment of extractants containing mercury and mercury compounds, but it is better to use a larger amount. Can remove mercury and mercury compounds to a high degree. As a result of studies from this point of view, the polyhydric alcohol aqueous solution is 0.5 to 0.5 to 1 volume of hydrocarbon oil.
After shaking and mixing with 2 volumes, add 2 to 0.3 to 0.5 volumes.
By repeating shaking and mixing three times, the amount of the aqueous solution used can be reduced and mercury and mercury compounds can be sufficiently removed. The temperature during shaking mixing and static separation is usually 0 to 100°C, preferably room temperature to 80°C.

[0008]

[Examples] The present invention will be further explained below with reference to 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 toluene as a hydrocarbon oil so that the amount of mercury was 400 W/Vppb. Also, ethylene glycol was added to water at 0, 5, 10, 30 and 50% respectively.
A polyhydric alcohol aqueous solution was prepared by mixing the components in a volume % manner. 50 ml of the hydrocarbon oil prepared in this manner was placed in a separating funnel, and 50 ml of each polyhydric alcohol aqueous solution was added thereto, followed by shaking and mixing for 3 minutes. When left to stand, the mixture separated into an upper layer mainly consisting of hydrocarbon oil and a lower layer consisting of an aqueous polyhydric alcohol solution. These separated two
The layers were analyzed for mercury content by atomic absorption spectroscopy. The results of this analysis are shown in Table 1.

[0009]

[Table 1]
Table 1 ━━━━━━
━━━━━━━━━━━━━━━━━━━━━━━━
Ethylene in aqueous solution
Mercury content Glycol concentration (W/
V ppb) (capacity%)
Hydrocarbon oil layer Polyhydric alcohol aqueous solution layer ━━━━━━━━━━━━━━
━━━━━━━━━━━━━━━━
0 140
260
5
70 340
10
30 370
30
10 390
50
<10 400
In unextracted hydrocarbon oil 405
━━━━━━━━━━━━━━━━━━━━
━━━━━━━━━━

Example 2 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 toluene as a hydrocarbon oil so that the amount of mercury was 400 W/Vppb. . Further, an aqueous polyhydric alcohol solution was prepared by individually mixing ethylene glycol, diethylene glycol, triethylene glycol, and glycerin in an amount of 30% by volume relative to water. An alcohol aqueous solution was also prepared in which methanol and ethanol were individually mixed at 30% by volume. Table 2 shows the densities at 25° C. of each of the polyhydric alcohol aqueous solution and the alcohol aqueous solution.

[0011]

[Table 2]
Table 2 ━━━━━━━━━━
━━━━━━━━━━━━━━━━━━━━
mixed alcohol
Density at 25℃ (g/cm3) ━━━
━━━━━━━━━━━━━━━━━━━━━━━━━
━━ Methanol
0.933
ethanol
0.934
ethylene glycol
1.031 Diethylene glycol 1.0
35 Triethylene glycol
1.038
glycerin
1.076 Hydrocarbon oil
0.710 ━━━━━━━━━━
━━━━━━━━━━━━━━━━━━━━Pour 50 ml of the hydrocarbon oil prepared as above into a separating funnel, and add 50 ml of polyhydric alcohol aqueous solution and alcohol aqueous solution to it.
Add 0 ml each and mix by shaking for 3 minutes. When left to stand, the mixture separated into an upper layer mainly consisting of hydrocarbon oil and a lower layer consisting of an aqueous polyhydric alcohol solution or an aqueous alcohol solution. These two separated layers were analyzed for mercury content by atomic absorption spectroscopy. The results of this analysis are shown in Table 3.

0012

[Table 3]
Table 3 ━━━━━━
━━━━━━━━━━━━━━━━━━━━━━━━
mixed alcohol
Mercury content

(W/V ppb)
Hydrocarbon oil layer Alcohol aqueous layer ━
━━━━━━━━━━━━━━━━━━━━━━━━━
━━━━ Methanol
10
385 Ethanol
20
370 Ethylene glycol
10 390
diethylene glycol
15 380
Triethylene glycol 25
370 Glycerin 30
365 Hydrocarbon oil 405
━━━━━━━━━━━━━━━━━━━━━
━━━━━━━━━ Polyhydric alcohol aqueous solutions containing ethylene glycol, diethylene glycol, triethylene glycol, and glycerin separated from the hydrocarbon oil layer immediately after shaking was stopped, but alcohol aqueous solutions containing methanol and ethanol 1 to completely separate the layers
It took 0-30 seconds.

Example 3 100 ml of condensate entrained in natural gas containing 200 W/V ppb of mercury was placed in a separating funnel, 50 ml of a polyhydric alcohol aqueous solution containing 30% by volume of ethylene glycol was added to the water, and the mixture was shaken for 3 minutes. Mixed. When left to stand still, the mixture separated into an upper layer mainly consisting of hydrocarbon oil and a lower layer consisting of an aqueous polyhydric alcohol solution. The mercury content of each of the two separated layers was analyzed by atomic absorption spectroscopy, and the mercury content was found to be 30 W/Vppb in the hydrocarbon oil layer and 165 W/Vppb in the polyhydric alcohol aqueous solution layer. Furthermore, the above-mentioned mercury carbide oil layer 5 containing mercury of 30 W/Vppb
0 ml was taken into another separating funnel, 25 ml of the previously prepared aqueous polyhydric alcohol solution was added thereto, and the mixture was shaken and mixed for 3 minutes. After static separation, analysis of the mercury content in the upper layer, which mainly consists of hydrocarbon oil, showed that it was below the detection limit, that is, 1.
It became 0W/Vppb or less.

[0014]

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

Claims (1)

[Claims] Claim 1: The mercury in the hydrocarbon oil is removed by shaking and mixing a hydrocarbon oil with an aqueous solution containing a polyhydric alcohol that has a higher density than water and dissolves at least 3% by volume in the water. and a method for removing mercury and mercury compounds from hydrocarbon oil, the method comprising extracting the mercury compounds.