US3876393A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and article for removing mercury from gases contaminated therewith
Assignee: Resonac Holdings Corp
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Filing: 1973-11-26
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Granted: 1975-04-08
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Expires: 1993-11-26
Abstract
Abstract Mercury is removed from gases contaminated therewith by passing the gases in contact with activated carbon which has been impregnated with sulfuric acid. Carbon impregnation by soaking in a sulfuric acid solution and drying at preferred temperatures as well as mercury adsorption at preferred temperatures is also disclosed.
Inventors
- 👤 Juichi Kasai
- 👤 Kazuo Miyazaki
- 👤 Keiji Kawasaki
- 👤 Buntaro Kawase
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 00:31
CPC Classifications
C; C22; C22B; C22B43/00; B; B01; B01D; B01D53/00; B01D53/02; Y; Y10; Y10S; Y10S95/00; Y10S95/90; Y10S95/901
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
30 words
A METHOD OF REMOVING MERCURY VAPOR FROM A GAS CONTAINING SAID VAPOR, SAID METHOD COMPRISING THE STEP OF PASSING SAID GAS IN CONTACT WITH ACTIVATED CARBON IMPREGNATED WITH SULFURIC ACID.
Claim 2
Independent Claim
30 words
A METHOD OF REMOVING MERCURY VAPOR FROM A GAS CONTAINING SAID VAPOR, SAID METHOD COMPRISING THE STEP OF PASSING SAID GAS IN CONTACT WITH ACTIVATED CARBON IMPREGNATED WITH SULFURIC ACID.
Claim 3
Dependent Claim
22 words
A method according to claim 1 wherein the gas is selected from the group consisting of air, hydrogen, nitrogen and carbon dioxide.
Claim 4
Dependent Claim
28 words
A method according to claim 1 wherein the gas is passed over the activated carbon impregnated with sulfuric acid under the conditions represented by the following general formula,
Claim 5
Dependent Claim
57 words
A method according to claim 1 wherein the adsorbed mercury is recovered by subjecting the spent activated carbon to a temperature of over 200.degree.C in a stream of super heated steam to eliminate the mercury therefrom, and by cooling the stream carrying mercury vapor to around room temperature, thus condensing the mercury metal together with the water.
Claim 6
Dependent Claim
32 words
A method according to claim 1 wherein the gas is air containing contaminants of the type produced by one of the following sources: mercury mines, non-ferrous metal smelting plants and coal fired-boilers.
Claim 7
Independent Claim
81 words
A method of removing mercury vapor from a gas containing said vapor, said method comprising the step of passing said gas in contact with a solid material comprising activated carbon impregnated with sulfuric acid which solid material has been prepared by immersing activated carbon in an aqueous solution of sulfuric acid having a sulfuric acid concentration ranging from 30 to 80 percent by weight, and drying the resulting material at a temperature ranging from 100.degree. to 200.degree.C in an air stream.
Claim 8
Independent Claim
81 words
A method of removing mercury vapor from a gas containing said vapor, said method comprising the step of passing said gas in contact with a solid material comprising activated carbon impregnated with sulfuric acid which solid material has been prepared by immersing activated carbon in an aqueous solution of sulfuric acid having a sulfuric acid concentration ranging from 30 to 80 percent by weight, and drying the resulting material at a temperature ranging from 100.degree. to 200.degree.C in an air stream.
Claim 9
Dependent Claim
22 words
A method according to claim 6, wherein the gas is selected from a group consisting of air, hydrogen, nitrogen and carbon dioxide.
Claim 10
Dependent Claim
27 words
A method according to claim 6, wherein the gas is passed over activated carbon impregnated with sulfuric acid under the conditions represented by the following general formula,
Claim 11
Independent Claim
102 words
A method of selectively removing substantially all of the mercury vapor from a gas which contains said mercury vapor, said method comprising the step of contacting the mercury vapor in said gas with a solid adsorbent which consists essentially of activated carbon impregnated with sulfuric acid to thereby adsorb said mercury vapor on said adsorbent, said adsorbent being prepared by (1) immersing activated carbon in an aqueous solution of sulfuric acid having a sulfuric acid concentration of from 30 to 80 percent by weight, and (2) drying the resulting material at a temperature of from 100.degree. to 200.degree.C in an air stream.
Claim 12
Independent Claim
102 words
A method of selectively removing substantially all of the mercury vapor from a gas which contains said mercury vapor, said method comprising the step of contacting the mercury vapor in said gas with a solid adsorbent which consists essentially of activated carbon impregnated with sulfuric acid to thereby adsorb said mercury vapor on said adsorbent, said adsorbent being prepared by (1) immersing activated carbon in an aqueous solution of sulfuric acid having a sulfuric acid concentration of from 30 to 80 percent by weight, and (2) drying the resulting material at a temperature of from 100.degree. to 200.degree.C in an air stream.
Claim 13
Dependent Claim
32 words
A method according to claim 9, wherein said contacting is performed at a temperature which is determined by the partial pressure of water vapor in said gas, according to the following formula:
Claim 14
Dependent Claim
27 words
A method according to claim 10, wherein said gas also contains, in addition to said mercury vapor, sulfur dioxide vapor, halogen vapor and vapors of compounds thereof.
Claim 15
Dependent Claim
32 words
A method according to claim 11, wherein the amount of sulfuric acid impregnated in said activated carbon is more than ten percent by weight, based on the weight of said activated carbon.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |