US4151052A
Expired / Lapsed
US
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Process for producing sodium hypochlorite
Assignee: ThyssenKrupp Nucera Japan Ltd
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Filing: 1978-02-03
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Granted: 1979-04-24
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Expires: 1998-02-03
Abstract
Abstract A process for producing sodium hypochlorite comprising electrolyzing an aqueous solution of sodium chloride as an electrolyte solution in a non-diaphragm electrolytic cell comprising at least one unit cell in which the ratio of the actual area of the anode to the actual area of the cathode is at least about 1.5: 1. In a preferred embodiment higher concentrations of sodium hypochlorite can be attained by performing the electrolysis while cooling the electrolyte solution to about 50° C. or less.
Inventors
- 👤 Nobutaka Goto
- 👤 Hiroshi Daidoji
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:42
CPC Classifications
C; C25; C25B; C25B1/00; C25B1/01; C25B1/24; C25B1/26; C02; C02F; C02F1/00; C02F1/46; C02F1/461; C02F1/467; C02F1/4672; C02F1/4674; C02F1/46104; C02F1/46109; Y; Y02; Y02W; Y02W10/00; Y02W10/30; Y02W10/37
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
110 words
A process for producing sodium hypochlorite which comprises electrolyzing an aqueous solution of sodium chloride as an electrolyte solution in a non-diaphragm electrolytic cell comprising at least one unit cell, wherein the ratio of the actual area of the anode to the actual area of the cathode in the electrolytic cell is at least about 1.5:1 or larger, the concentration of the sodium chloride aqueous solution is about 20 g/liter to about 50 g/liter, the effective average current density at the cathode is about 20 A/dm 2 to about 80 A/dm 2 and the effective average current density at the anode is about 4 to about 60 A/dm 2 .
Claim 2
Dependent Claim
110 words
A process for producing sodium hypochlorite which comprises electrolyzing an aqueous solution of sodium chloride as an electrolyte solution in a non-diaphragm electrolytic cell comprising at least one unit cell, wherein the ratio of the actual area of the anode to the actual area of the cathode in the electrolytic cell is at least about 1.5:1 or larger, the concentration of the sodium chloride aqueous solution is about 20 g/liter to about 50 g/liter, the effective average current density at the cathode is about 20 A/dm 2 to about 80 A/dm 2 and the effective average current density at the anode is about 4 to about 60 A/dm 2 .
Claim 3
Dependent Claim
44 words
The process of claim 1, wherein the effective average current density at the cathode is about 20 A/dm 2 to about 40 A/dm 2 and the effective average current density at the anode is about 10 A/dm 2 to about 20 A/dm 2 .
Claim 4
Dependent Claim
32 words
The process of claim 2, wherein the effective average current density at the cathode is 30 A/dm 2 and the effective average current density at the anode is 15 A/dm 2 .
Claim 5
Dependent Claim
58 words
The process of claim 1, wherein the process includes cooling the electrolyte solution with at least one cooling means provided in or between the unit cells to maintain the electrolyte solution at a temperature of about 50° C. or less, whereby a sodium hypochlorite solution having an available chlorine concentration of at least about 3 g/liter is obtained.
Claim 6
Dependent Claim
19 words
The process of claim 3, wherein the temperature of the electrolyte solution is maintained at 5° to 45° C.
Claim 7
Dependent Claim
35 words
The process of claim 4, wherein the electrolyte solution is cooled by passing the electrolyte solution through cooling means provided between the unit cells of the non-diaphragm electrolytic cell comprising a plurality of unit cells.
Claim 8
Dependent Claim
34 words
The process of claim 4, wherein the electrolyte solution is cooled by a cooling device provided between the unit cells of the electrolytic cell comprising a plurality of unit cells partitioned by partitioning plates.
Claim 9
Dependent Claim
24 words
The process of claim 4, wherein the electrolyte solution is cooled by a cooling device provided along the inside surface of the unit cell.
Claim 10
Dependent Claim
34 words
The process of claim 4, wherein the electrolyte solution is cooled by a cooling device associated with the cathode, with cooling water or a cooling gas being introduced into the inside of the cathode.
Claim 11
Dependent Claim
23 words
The process of claim 1, wherein the sodium hypochlorite aqueous solution produced has an available chlorine concentration of at least about 3 g/liter.
Claim 12
Dependent Claim
35 words
The process of claim 1, wherein the following undesirable side-reactions are inherently inhibited due to the process conditions: HClO+H.sup.+ +2e→HCl+OH.sup.- ( 1) clO.sup.- +2H.sup.+ +2e→HCl+OH.sup.- ( 2) (clO.sup.- +H.sup.+ +2e→Cl.sup.- +OH.sup.-) clO.sup.- +2HClO→ClO.sub.3.sup.- +2HCl (3)
Claim 13
Dependent Claim
23 words
The process of claim 1, wherein the sodium hypochlorite aqueous solution produced has an available chlorine concentration of at least about 6 g/liter.
Claim 14
Dependent Claim
21 words
The process of claim 1, wherein the aqueous solution of sodium chloride has a pH of about 5 to about 10.
Claim 15
Dependent Claim
13 words
The process of claim 1, wherein the formation of sodium chlorate is inhibited.
Claim 16
Dependent Claim
30 words
The process of claim 1, wherein the ratio of the actual area of the anode to the actual area of the cathode in the electrolytic cell is 1.5:1 to 3:1.
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) | 1982-04-23 | 1982-10-23 | 1983-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-23 | 1986-10-23 | 1987-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-23 | 1990-10-23 | 1991-04-24 | $7700.00 | Window Closed / Lapsed |