JP2002129172A - Method for removing mercury from liquid hydrocarbon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for continuously removing mercury from a liquid hydrocarbon containing the same at about normal temperature and pressure in a simple and easy way. SOLUTION: Mercury is removed from a liquid hydrocarbon containing the same by causing the hydrocarbon to successively pass through (A) an ionization treatment zone wherein the hydrocarbon is brought into contact with a substance capable of ionizing free mercury contained in the hydrocarbon and (B) a sulfur compound treatment zone wherein the hydrocarbon is brought into contact with a sulfur compound represented by the formula: MM'S (wherein M and M' are each hydrogen, an alkali metal or an ammonium group) (e.g. hydrogen sulfide) or a liquid containing the sulfur compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for removing mercury in a liquid hydrocarbon containing mercury.

[0002]

2. Description of the Related Art In NGL (natural gas liquid) produced from a natural gas field, that is, liquid hydrocarbons such as liquefied petroleum gas and condensate, mercury reaching 2 to several thousand ppb varies depending on the producing area. Some of them are contained, and light hydrocarbons obtained by distilling these NGLs sometimes contain mercury. If such hydrocarbons are to be used as a raw material for chemicals, the mercury contained in them will cause amalgam corrosion of aluminum used as equipment material and cause deterioration of the reforming catalyst. Development has been strongly desired. As a device for this development, JP-A-10-251667 discloses that a hydrocarbon fraction containing mercury is subjected to a hydrogenation treatment, and the hydrocarbon fraction after the hydrogenation treatment is brought into contact with a porous carbon material. A method for adsorbing and removing trace amounts of mercury in a hydrocarbon fraction by a combination of the above-mentioned hydrogenation treatment and adsorption treatment is disclosed. In this method, a reaction temperature of 1
It required conditions of 00 to 400 ° C., preferably 250 to 350 ° C., and a reaction pressure of 1 to 5 MPa, preferably 2.5 to 3.5 MPa, and high temperature and high pressure, and required energy for heating and pressurizing. Further, as the porous carbon material is a sorbent, a specific surface area of 100~2500m ² / g, preferably from 500 to 1500 ² / g, an average pore radius of 5 to 3
The volume of pores having a diameter of 0 Å and a pore radius of 50 Å or less was 0.2 to 1.2 ml / g, which required an extremely complicated process for preparing the adsorbent.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for removing mercury from a liquid hydrocarbon containing mercury continuously, easily and efficiently at about normal temperature and pressure.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have achieved the above object by sequentially supplying mercury-containing hydrocarbons to a mercury ionization treatment zone and a sulfur compound treatment zone. I found out. The present invention has been completed based on such findings. That is, in the present invention, in removing mercury from a liquid hydrocarbon containing mercury, (A) an ionization treatment zone in which the liquid hydrocarbon is brought into contact with a substance capable of ionizing single mercury contained in the liquid hydrocarbon; and (B) General formula MM'S
(Wherein, M and M ′ are the same or different and are each independently a hydrogen, an alkali metal or an ammonium group.)
And a method for removing mercury in a liquid hydrocarbon, comprising sequentially supplying the liquid hydrocarbon to a sulfur compound treatment zone contacted with a sulfur compound represented by the formula (1) or a liquid containing the sulfur compound. .

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The liquid hydrocarbon containing mercury to be treated in the present invention is not particularly limited as long as it is a liquid hydrocarbon at ordinary temperature. For example, crude oil, straight run naphtha, kerosene, light oil, vacuum distillate, atmospheric residue, natural gas condensate and the like can be mentioned, but natural gas condensate (NGL) is particularly preferable.

The form of mercury removed by the method of the present invention is
Either simple mercury or ionic mercury may be used. The concentration of mercury in the liquid hydrocarbon is not particularly limited, but is usually 2 to 1,000 W / Vppb, preferably 5 to 100 W / Vppb.
W / Vppb.

[0007] The crude oil is not particularly limited.
For example, Saudi crude oil, UAE crude oil,
Nigeria crude oil, Canadian crude oil, Mexican crude oil,
Iranian crude, Iraqi crude, Chinese crude, Kuwaiti crude, Malaysian crude, Venezuela crude, American crude, Australian crude, Russian crude, Libyan crude, Philippine crude, Indonesian crude,
These include Norwegian crude oil, Thai crude oil, Qatar crude oil, Argentine crude oil, British crude oil, Japanese crude oil and mixtures thereof. The straight-run naphtha, kerosene, light oil, reduced-pressure distillate or normal-pressure residue is not particularly limited, and examples thereof include those obtained by treating the above-mentioned crude oil by an ordinary method.

In the present invention, the liquid hydrocarbon as described above is supplied to an ionization treatment zone in which the liquid hydrocarbon is brought into contact with a substance capable of ionizing single mercury contained in the liquid hydrocarbon. Here, a substance capable of ionizing mercury alone (hereinafter, sometimes referred to as a mercury ionized substance) is, for example, iron sulfate, iron chloride, iron sulfide, iron oxide, iron nitrate, iron oxalate, or the like. Compounds (preferably trivalent iron compounds), copper compounds such as copper sulfate, copper chloride, copper oxide, copper nitrate, and copper sulfide, vanadium compounds, manganese compounds (preferably manganese dioxide), nickel compounds, hydrogen peroxide, Organic or inorganic peroxides such as peracetic acid, sludge present in crude oil tanks, and the like. These may be used alone or in combination of two or more. Here, as an example of elemental analysis of sludge present in a crude oil tank, Fe 36 wt%, Si 1.
3 wt%, Na 3600 wtppm, Al 2700
wtppm, P2200wtppm, Zn2100w
tppm, Cu 950wtppm, Ca 720wt
ppm, Mg 550wtppm, V 350wtpp
m, K350wtppm, Cr 290wtppm, M
n 230 wtppm, Ni 120 wtppm, C 3
2.0 wt%, H 3.0 wt%, N 0.9 wt%,
S is 3.0 wt% and Cl is 0.4 wt%.

The manganese compound such as manganese dioxide can be used in any form such as powder, crushed, cylindrical, spherical, fibrous, and honeycomb. Also,
It can also be used as a form supported on silica, alumina, silica-alumina, zeolite, ceramic, glass, resin or activated carbon. The loading amount is not particularly limited, but is preferably 0.1 to 30% by weight based on the carrier.

In the method of the present invention, as described above, the liquid hydrocarbon is supplied to the ionization treatment zone, and is brought into contact with the mercury ionization treatment substance to convert single mercury into ionic mercury. At this time, the reaction temperature is −50 ° C. to 100 ° C., preferably 0 ° C. to 60 ° C., and the pressure is 0 MPa to 2 MPa.

In the present invention, the hydrocarbons which have passed through the ionization zone are separated by the general formula MM'S (where M and M 'are the same or different and each independently represents a hydrogen, alkali metal or ammonium group). ) Or a liquid containing the sulfur compound (particularly an aqueous solution). General formula MM '
Examples of the sulfur compound represented by S include hydrogen sulfide,
Sodium bisulfide, potassium bisulfide, sodium sulfide,
Potassium sulfide and ammonium sulfide; Of these, hydrogen sulfide is particularly preferred. The concentration of the sulfur compound in the liquid containing the sulfur compound is not particularly limited, but is preferably 0.1 to 100,000 W /
Wppm, more preferably 1 to 1,000 W / Wpp
m.

The hydrogen sulfide can be supplied in a liquid state by applying a gas or pressure. Further, it may be supplied in the form of water or an organic solvent containing hydrogen sulfide,
It may be supplied in the form of an organic solvent mixture. The supply ratio of the sulfur compound represented by the above general formula is 1 to 10000 of the sulfur compound per 1 mol of mercury contained in the liquid hydrocarbon.
The molar ratio is suitably 100 times, preferably 100 to 5000 times. Mixing of the sulfur compound with the liquid hydrocarbon is not particularly limited, and stirring with a mixer, stirring with a line mixer, or the like can be selected. In the treatment zone using sulfur compounds, the reaction temperature is between -50 ° C and 100 ° C.
° C, preferably 0 to 60 ° C, and the pressure is 0 to 2 MPa.

After the mercury ionization treatment according to the method of the present invention, when the mercury is contacted with a sulfur compound as described above, a solid product of mercury can be obtained. The mercury solid produced is
It can be removed from liquid hydrocarbons by ordinary solid-liquid separation means such as filtration and sedimentation.

[0014]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 Mercury content: 37 W / Vppb (simple: ionic = 77)
%: 23%) of condensate A [density (g / cm ³ ,
0.7363] was supplied to an ionization tower filled with 0.3 liter of the following mercury ionization substance, and mercury was ionized under the following conditions. Reaction temperature: 25 ° C. Reaction pressure: 0.1 MPa (absolute pressure) Liquid space velocity: 10 hr ⁻¹ Mercury ionized substance: manganese dioxide As a result, the mercury content is 37 W / Vppb (simple: ionic = 0%: 100%) ) Was obtained. The condensate A thus obtained [mercury content 3
7W / Vppb (simple: ionic = 0%: 100
%)] And hydrogen sulfide were supplied to a reactor having an internal volume of 3 liters equipped with a stirrer to solidify mercury under the following conditions. Reaction temperature: 25 ° C. Reaction pressure: 0.1 MPa (absolute pressure) Residence time: 1 hr Hydrogen sulfide / mercury: 1000 (molar ratio) As a result, condensate A containing mercury as a solid was obtained. When condensate A, in which mercury is present as a solid, was continuously solid-liquid separated using a filter having a pore size of 5 μm, the mercury concentration of condensate A was 1.2 W / Vp.
pb.

Example 2 Condensate A was supplied to the mercury ionization treatment zone and treated with hydrogen sulfide in the same manner as in Example 1 to obtain condensate A in which mercury was present as a solid. The condensate A was allowed to stand in a container to precipitate a solid mercury compound, and the supernatant was collected and the mercury concentration was measured to be 1.0 W / Vppb.

Example 3 The same operation as in Example 1 was carried out except that the reaction temperature under the ionization treatment conditions in Example 1 was changed to 2 ° C., and the mercury content after the ionization treatment was 37 W / Vppb (simple form). : Ionic = 1%: 99%). Subsequently, the same hydrogen sulfide treatment as in Example 1 was performed, and the pore diameter was 5 μm.
As a result of performing solid-liquid separation with a filter, the mercury concentration in the condensate was 1.4 W / Vppb.

Example 4 The same operation as in Example 1 was carried out except that the reaction temperature under the ionization treatment conditions of Example 1 was changed to 40 ° C., and the mercury content after the ionization treatment was 37 W / Vppb (simple form). : Ionic = 0%: 100%) condensate A was obtained. Subsequently, the same hydrogen sulfide treatment as in Example 1 was performed, and the pore size was 5 μm.
As a result of solid-liquid separation with a filter of m, the mercury concentration in the condensate was 0.9 W / Vppb.

Example 5 Hydrogen sulfide / mercury under the hydrogen sulfide treatment conditions of Example 1 was 100
(Molar ratio), except that the solid-liquid separation was performed using a filter having a pore size of 5 μm, except that the mercury concentration in the condensate was 1.8 W / Vpp.
b.

Example 6 The hydrogen sulfide / mercury under the hydrogen sulfide treatment conditions of Example 1 was 100
The same operation as in Example 1 was carried out except that the molar ratio was changed to 00 (molar ratio), and solid-liquid separation was performed with a filter having a pore size of 5 μm. The mercury concentration in the condensate was 0.9 W / Vp
pb.

Example 7 A mercury content of 37 W / Vppb (simple: ionic = 77)
%: 23%) of condensate A [density (g / cm ³ ,
0.7363], and the following mercury ionization-treated substance in an internal volume of 300 m with a stirrer.
1 and the mercury was ionized under the following conditions. Reaction temperature: 25 ° C. Reaction pressure: 0.1 MPa (absolute pressure) Mercury ionization treatment substance: 0.9 wt% ferric sulfate aqueous solution Condensate A supply rate: 1.5 liter / hr Ferric sulfate aqueous solution supply rate: 1. As a result, condensate A having a mercury content of 37 W / Vppb (simple: ionic = 0%: 100%) was obtained. The condensate A thus obtained [mercury content 3
7W / Vppb (simple: ionic = 0%: 100
%)] And hydrogen sulfide were supplied to a reactor having an internal volume of 3 liters equipped with a stirrer to solidify mercury under the following conditions. Reaction temperature: 25 ° C. Reaction pressure: 0.1 MPa (absolute pressure) Residence time: 1 hr Hydrogen sulfide / mercury: 1000 (molar ratio) As a result, condensate A containing mercury as a solid was obtained. When condensate A, in which mercury exists as a solid, was continuously solid-liquid separated using a filter having a pore size of 5 μm, the mercury concentration of condensate A was 1.3 W / Vp.
pb.

[0022]

According to the present invention, mercury can be reduced from liquid hydrocarbons containing mercury to 2 W / Vppb or less at room temperature and near normal pressure continuously and easily.

Claims (8)

[Claims] 1. A method for removing mercury from a liquid hydrocarbon containing mercury, comprising: (A) an ionization treatment zone in which the liquid hydrocarbon is brought into contact with a substance capable of ionizing single mercury contained in the liquid hydrocarbon; A sulfur compound represented by the formula MM ′S (where M and M ′ are the same or different and each independently represents a hydrogen, an alkali metal or an ammonium group) or a sulfur compound to be brought into contact with a liquid containing the sulfur compound A method for removing mercury from a liquid hydrocarbon, comprising sequentially supplying the liquid hydrocarbon to a treatment zone. 2. The method for removing mercury in a liquid hydrocarbon according to claim 1, wherein the substance having an ionizing ability is an aqueous solution containing trivalent iron ions. 3. The method for removing mercury in a liquid hydrocarbon according to claim 1, wherein the substance having an ionizing ability is manganese dioxide and / or manganese dioxide supported thereon. 4. The method for removing mercury in a liquid hydrocarbon according to claim 1, wherein the sulfur compound is hydrogen sulfide. 5. An ionization treatment condition at a temperature of −50 ° C. to 10 ° C.
2. The method for removing mercury in a liquid hydrocarbon according to claim 1, wherein the temperature is 0 ° C. and the pressure is 0 to 2 MPa. 6. The sulfur compound treatment condition is a temperature of -50.degree.
2. The method for removing mercury in a liquid hydrocarbon according to claim 1, wherein the temperature is set to 00 ° C. and the pressure is set to 0 to 2 MPa. 7. In a sulfur compound treatment zone, the sulfur compound is added in an amount of 1 to 1000 with respect to mercury in a liquid hydrocarbon.
2. The method for removing mercury in a liquid hydrocarbon according to claim 1, wherein the liquid hydrocarbon is supplied in a molar ratio of 0. 8. After the sulfur compound treatment zone, (C)
2. The method for removing mercury in a liquid hydrocarbon according to claim 1, wherein the produced mercury solids are removed by solid-liquid separation.