US4300987A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas extraction
Assignee: National Research Development Corp UK
•
Filing: 1979-11-05
•
Granted: 1981-11-17
•
Expires: 1999-11-05
Abstract
Abstract An electrochemical cell used to separate gas from a gaseous mixture by reduction of said gas at the cathode and regeneration of said gas at the anode is characterized in that one or more substances formed during the cathodic reduction and/or the anodic regeneration is chemically converted, preferably by catalytic decomposition, to produce further quantities of said gas, the gas formed by both the anodic regeneration and the chemical conversion being recovered as the product. In an especially preferred embodiment a plurality of said cells are used in apparatus for extracting oxygen from the air by using a cathode comprising high surface area graphite powder which reduces oxygen to produce peroxyl ions, each cell being further provided, externally of the cathode compartment, with means for catalytically decomposing the peroxyl ions produced, suitable catalysts being CoFe2O4 or NiCo2O4.
Inventors
- 👤 Alfred C. C. Tseung
- 👤 Sameer M. Jasem
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:32
CPC Classifications
C; C01; C01B; C01B13/00; C01B13/02; C01B13/0203; C01B13/0211; C01B13/0214; C25; C25B; C25B1/00; C25B1/01; C25B1/02
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
76 words
A method in which an electrochemical cell is used to separate a gas from a gaseous mixture by reduction of said gas at the cathode and regeneration of said gas at the anode, characterised in that one or more substances formed in the cathodic reduction and/or the anodic regeneration is chemically converted to produce said gas and in that the gas formed by both the anodic regeneration and the chemical conversion is recovered as the product.
Claim 2
Independent Claim
76 words
A method in which an electrochemical cell is used to separate a gas from a gaseous mixture by reduction of said gas at the cathode and regeneration of said gas at the anode, characterised in that one or more substances formed in the cathodic reduction and/or the anodic regeneration is chemically converted to produce said gas and in that the gas formed by both the anodic regeneration and the chemical conversion is recovered as the product.
Claim 3
Dependent Claim
20 words
A method as claimed in claim 1, wherein the substance formed is chemically converted to said gas by catalytic decomposition.
Claim 4
Dependent Claim
19 words
A method as claimed in claim 2, wherein the catalyst is provided in solution or dispersion in the electrolyte.
Claim 5
Dependent Claim
19 words
A method as claimed in claim 2, wherein the catalyst is provided in the form of a solid member.
Claim 6
Dependent Claim
18 words
A method as claimed in claim 4, wherein the catalyst is absorbed or coated on a solid support.
Claim 7
Dependent Claim
15 words
A method as claimed in claim 5, wherein the solid support is porous or perforated.
Claim 8
Dependent Claim
20 words
A method as claimed in claim 2, wherein the catalyst is provided externally of the cathode compartment of the cell.
Claim 9
Dependent Claim
19 words
A method as claimed in claim 1, wherein said gas is oxygen and said gaseous mixture is ambient air.
Claim 10
Dependent Claim
29 words
A method as claimed in claim 8, wherein the oxygen in the air is cathodically reduced to produce peroxyl ions which are then catalytically decomposed to produce oxygen product.
Claim 11
Dependent Claim
19 words
A method as claimed in claim 9, wherein the cathode is made from a high surface area graphite powder.
Claim 12
Dependent Claim
25 words
A method as claimed in claim 10, wherein the powder has a surface area in the range of from 500 to 600 m 2 /g.
Claim 13
Dependent Claim
20 words
A method as claimed in claim 10, wherein the cathode is made from said graphite powder by bonding with polytetrafluoroethylene.
Claim 14
Dependent Claim
26 words
A method as claimed in claim 9, wherein the peroxyl ions are catalytically decomposed using a CoFe 2 O 4 or NiCo 2 O 4 catalyst.
Claim 15
Dependent Claim
24 words
A method as claimed in claim 13, wherein the CoFe 2 O 4 or NiCo 2 O 4 is coated on a nickel screen.
Claim 16
Dependent Claim
16 words
A method as claimed in claim 9, wherein the catalyst is a spinel oxide or silver.
Claim 17
Dependent Claim
25 words
A method as claimed in claim 8, wherein the anode is made from lithiated nickel oxide or NiCo 2 O 4 by bonding with polytetrafluoroethylene.
Claim 18
Dependent Claim
26 words
A method as claimed in claim 8, including an electrolyte present in the electrochemical cell, the electrolyte being an aqueous solution of an alkali metal hydroxide.
Claim 19
Dependent Claim
15 words
A method as claimed in claim 17, wherein the alkali metal hydroxide is potassium hydroxide.
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) | 1984-11-16 | 1985-05-18 | 1985-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-16 | 1989-05-18 | 1989-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-16 | 1993-05-18 | 1993-11-17 | $7700.00 | Window Closed / Lapsed |