US3933993A
Expired / Lapsed
US
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Use of concentrated chelated iron reagent for reducing pollutant content of a fluid
Assignee: General Electric Co
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Filing: 1974-06-28
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Granted: 1976-01-20
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Expires: 1994-06-28
Abstract
Abstract A chelated iron solution of high concentration that is stable at a pH greater than 7 to at least pH 10 is disclosed. Also a process is disclosed in which this formulation is used to remove H 2 S and/or mercaptans as pollutants in a gas stream. In the case of H 2 S this chelate acts by producing sulfur therefrom in the absence of oxygen.
Inventors
- 👤 Robert M. Salemme
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:22
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/52; B01D53/485; C; C01; C01B; C01B17/00; C01B17/02; C01B17/04; C01B17/05
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
143 words
A method for reducing the pollutant content of a gas stream wherein the pollutant is at least one member of the group of hydrogen sulfide and mercaptans, comprising the steps of: a. bringing the gas stream into intimate contact with an aqueous solution having a pH from greater than 7 to about pH 10 consisting essentially of water, a chelate of ferric iron with ethylenediaminetetraacetic acid (EDTA), and a buffering agent, said solution having a ratio of EDTA to Fe of greater than 1:1, the concentration of the Fe being at least about 0.5 moles per liter of the aqueous solution, b. separating insolubles from the reacted aqueous solution, c. bringing the reacted aqueous solution substantially free of insolubles into intimate contact with an oxygenating gas and d. recirculating the regenerated aqueous solution for reaction with the gas stream as in step a).
Claim 2
Independent Claim
143 words
A method for reducing the pollutant content of a gas stream wherein the pollutant is at least one member of the group of hydrogen sulfide and mercaptans, comprising the steps of: a. bringing the gas stream into intimate contact with an aqueous solution having a pH from greater than 7 to about pH 10 consisting essentially of water, a chelate of ferric iron with ethylenediaminetetraacetic acid (EDTA), and a buffering agent, said solution having a ratio of EDTA to Fe of greater than 1:1, the concentration of the Fe being at least about 0.5 moles per liter of the aqueous solution, b. separating insolubles from the reacted aqueous solution, c. bringing the reacted aqueous solution substantially free of insolubles into intimate contact with an oxygenating gas and d. recirculating the regenerated aqueous solution for reaction with the gas stream as in step a).
Claim 3
Dependent Claim
18 words
The method for reducing pollutant content as recited in claim 1 wherein the gas stream is gasified coal.
Claim 4
Dependent Claim
23 words
The method for reducing pollutant content as recited in claim 1 wherein the pollutant is hydrogen sulfide and sulfur is the insoluble generated.
Claim 5
Dependent Claim
24 words
The method for reducing pollutant content as recited in claim 1 wherein the gas stream contains mercaptan pollutant and the insolubles are organic disulfides.
Claim 6
Dependent Claim
17 words
The method for reducing pollutant content as recited in claim 1 wherein the oxygenating gas is air.
Claim 7
Dependent Claim
24 words
The method for reducing pollutant content as recited in claim 1 wherein the pH is in the range from pH 9.0 to pH 10.0.
Claim 8
Dependent Claim
27 words
The method for reducing pollutant content as recited in claim 1 wherein the EDTA to Fe ratio is in range of from about 1.25:1 to about 1.5:1.
Claim 9
Dependent Claim
29 words
The method for reducing pollutant content as recited in claim 7 wherein the concentration of iron ranges from about 0.5 moles per liter to about 1.0 mole per liter.
Claim 10
Dependent Claim
66 words
The method for reducing pollutant content of a gas stream as recited in claim 1 wherein contact between a gas stream containing hydrogen sulfide and the aqueous solution is by countercurrent flow in a first apparatus, sulfur is removed from the reacted aqueous solution and then contact between the substantially sulfurfree reacted aqueous solution and the oxygenating gas is by countercurrent flow in a second apparatus.
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) | 1979-01-19 | 1979-07-21 | 1980-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-19 | 1983-07-21 | 1984-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-19 | 1987-07-21 | 1988-01-20 | $7700.00 | Window Closed / Lapsed |