US4915818A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Use of dilute aqueous solutions of alkali polysulfides to remove trace amounts of mercury from liquid hydrocarbons
Assignee: Mobil Oil AS
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Filing: 1988-02-25
•
Granted: 1990-04-10
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Expires: 2008-02-25
Abstract
Abstract Disclosed is a method of removing mercury from contaminated liquid hydrocarbons (natural gas condensate) by contacting them with a dilute aqueous solution of alkali metal sulfide salt and recovering the treated liquid hydrocarbon. The addition of alkali metal hydroxide enhances the phase separation of hydrocarbon and aqueous solution.
Inventors
- 👤 Tsoung Y. Yan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:08
CPC Classifications
C; C10; C10G; C10G21/00; C10G21/06; C10G21/08
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
47 words
A method for removing mercury from a mercury-contaminated liquid hydrocarbon comprising contacting it with an aqueous dilute solution of alkali metal sulfide salts and separating a liquid hydrocarbon phase substantially free of mercury from said mixture of mercury-contaminated liquid hydrocarbon and aqueous dilute alkali metal sulfide solution.
Claim 2
Independent Claim
47 words
A method for removing mercury from a mercury-contaminated liquid hydrocarbon comprising contacting it with an aqueous dilute solution of alkali metal sulfide salts and separating a liquid hydrocarbon phase substantially free of mercury from said mixture of mercury-contaminated liquid hydrocarbon and aqueous dilute alkali metal sulfide solution.
Claim 3
Independent Claim
64 words
A method for removing mercury from a mercury-contaminated liquid hydrocarbon comprising: (a) intimately contacting said liquid hydrocarbon with an aqueous solution of an alkali metal sulfide salt for a period of time sufficient for said mercury and said sulfide to react to form insoluble mercury-sulfur compounds; (b) separating said liquid hydrocarbon and said aqueous solution into separate phases; and (c) recovering said liquid hydrocarbon.
Claim 4
Independent Claim
64 words
A method for removing mercury from a mercury-contaminated liquid hydrocarbon comprising: (a) intimately contacting said liquid hydrocarbon with an aqueous solution of an alkali metal sulfide salt for a period of time sufficient for said mercury and said sulfide to react to form insoluble mercury-sulfur compounds; (b) separating said liquid hydrocarbon and said aqueous solution into separate phases; and (c) recovering said liquid hydrocarbon.
Claim 5
Dependent Claim
27 words
The method of claim 2 wherein said aqueous solution of alkali metal sulfide contains between about 1 and about 50,000 ppm of sulfur percent in said solution.
Claim 6
Dependent Claim
30 words
The method of claim 2 wherein said alkali metal sulfide is selected from the group consisting of NaHS, KHS, Na 2 S, K 2 S, sodium polysulfide, and potassium polysulfide.
Claim 7
Dependent Claim
25 words
The method of claim 2 wherein the volume ratio of alkali metal sulfide salt solution to hydrocarbon liquid is between about 0.1 and about 10.
Claim 8
Dependent Claim
17 words
The method of claim 2 wherein the temperature is between about 50° F. and about 300° F.
Claim 9
Independent Claim
87 words
A method for removing mercury from a mercury-contaminated liquid hydrocarbon comprising: (a) intimately contacting said liquid hydrocarbon with an aqueous solution of an alkali metal sulfide salt for a period of time sufficient for said mercury and said sulfide to react to form insoluble mercury-sulfur compounds; (b) intimately mixing with said aqueous sulfide solution either before or after mixing with said liquid hydrocarbon an alkali metal salt or hydroxide; (c) separating said liquid hydrocarbon and said aqueous solution into separate phases; and (d) recovering said liquid hydrocarbon.
Claim 10
Independent Claim
87 words
A method for removing mercury from a mercury-contaminated liquid hydrocarbon comprising: (a) intimately contacting said liquid hydrocarbon with an aqueous solution of an alkali metal sulfide salt for a period of time sufficient for said mercury and said sulfide to react to form insoluble mercury-sulfur compounds; (b) intimately mixing with said aqueous sulfide solution either before or after mixing with said liquid hydrocarbon an alkali metal salt or hydroxide; (c) separating said liquid hydrocarbon and said aqueous solution into separate phases; and (d) recovering said liquid hydrocarbon.
Claim 11
Dependent Claim
26 words
The process of claim 7 wherein said aqueous solution of alkali metal sulfide contains between about 1 and about 50,000 ppm of sulfur in said solution.
Claim 12
Dependent Claim
30 words
The method of claim 7 wherein said alkali metal sulfide is selected from the group consisting of NaHS, KHS, Na 2 S, K 2 S, sodium polysulfide, and potassium polysulfide.
Claim 13
Dependent Claim
23 words
The method of claim 7 wherein the volume ratio of alkali metal sulfide salt solution to hydrocarbon liquid is between 0.1 and 1.
Claim 14
Dependent Claim
17 words
The method of claim 7 wherein the temperature is between about 50° F. and about 300° F.
Claim 15
Dependent Claim
22 words
The method of claim 7 wherein the pH of the aqueous alkali metal sulfide solution is between about 7 and about 12.
Claim 16
Dependent Claim
25 words
Th method of claim 7 wherein the concentration of alkali metal hydroxide in said aqueous sulfide solution is between about 0.01 and about 0.04 percent.
Claim 17
Dependent Claim
30 words
The method of claim 7 wherein the alkali metal hydroxide is selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium or potassium carbonate, and sodium or potassium bicarbonate.
Claim 18
Dependent Claim
18 words
The method of claim 7 wherein the queous alkali metal salt or hydroxide solution is a buffered solution.
Claim 19
Dependent Claim
36 words
The method of claim 7 wherein the mixing of aqueous alkali metal salt or hydroxide solution, aqueous sulfide solution, and liquid hydrocarbon is effected by means of a centrifugal pump, static mixer, or series of orifices.
Claim 20
Dependent Claim
28 words
The method of claim 2 and adding sodium hydroxide to and maintaining between about 0.01 and about 10% concentration of alkali metal sulfide salt in said aqueous solution.
Claim 21
Independent Claim
47 words
A method for removing mercury from a liquid hydrocarbon comprising enulsifying said liquid hydrocarbon with an aqueous solution of an alkali metal polysulfide and separating a liquid hydrocarbon phase substantially free of mercury from said emulsified mixture of liquid hydrocarbon and aqueous solution of alkali metal polysulfide.
Claim 22
Independent Claim
47 words
A method for removing mercury from a liquid hydrocarbon comprising enulsifying said liquid hydrocarbon with an aqueous solution of an alkali metal polysulfide and separating a liquid hydrocarbon phase substantially free of mercury from said emulsified mixture of liquid hydrocarbon and aqueous solution of alkali metal polysulfide.
Claim 23
Dependent Claim
36 words
The method of claim 18 wherein the aqueous solution of alkali metal polysulfide is sodium polysulfide and in the resulting emulsion the aqueous solution is the continuous phase and the liquid hydrocarbon is the dispersed phase.
References Cited (Backward Citations)
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