US3884778A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrolytic production of hydrogen peroxide and alkali metal hydroxide
Assignee: Occidental Chemical Corp
•
Filing: 1974-01-02
•
Granted: 1975-05-20
•
Expires: 1994-01-02
Abstract
Abstract Hydrogen peroxide is made electrolytically in a threecompartment cell having an anion-active permselective membrane separating anode and buffer compartments and a cation-active permselective membrane separating the buffer compartment and cathode compartment, by feeding sulfuric acid to the anode compartment, alkali metal sulfate to the buffer compartment and water to the cathode compartment and withdrawing substantially sulfate-free alkali metal hydroxide solution from the cathode compartment and persulfuric acid from the anode compartment, after which the persulfuric acid is hydrolyzed to produce hydrogen peroxide and sulfuric acid. The process is particularly useful for supplying hydrogen peroxide for use in wood pulping or pulp bleaching processes, especially in conjunction with chlorine dioxide bleaching, because alkali metal sulfate resulting from chlorine dioxide manufacture can be used as a reactant in the present process, a portion of the sulfuric acid produced in the present process may be used in the manufacture of chlorine dioxide, and the alkali metal hydroxide produced by the present process is also useful in pulping wood.
Inventors
- 👤 Jeffrey D Eng
- 👤 Cyril J Harke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:12
CPC Classifications
C; C25; C25B; C25B1/00; C25B1/01; C25B1/34; C25B1/46; C25B1/28; C25B1/29
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
212 words
A method for electrolytically manufacturing hydrogen peroxide, aqueous alkali metal hydroxide and aqueous sulfuric acid which comprises electrolyzing in a cell having an anode compartment with an anode therein, a cathode compartment with a cathode therein, and a buffer compartment separating the anode and cathode compartments, an anion-active permselective membrane separating the anode and buffer compartments, and a cation-active permselective membrane separating the buffer and cathode compartments, solutions resulting from feeding sulfuric acid to the anode compartment and alkali metal sulfate to the buffer compartment, so that with the passage of direct electric current through the cell, sulfate anion selectively diffuses from the buffer compartment to the anode compartment through the anion-active permselective membrane, sodium cation selectively diffuses from the buffer compartment to the cathode compartment through the cation-active permselective membrane, sulfuric acid is oxidized at the anode to produce a sulfuric acid solution of persulfuric acid, and sodium cation is reacted with water at the cathode to produce hydrogen and a substantially alkali metal sulfate-free aqueous alkali metal hydroxide solution, withdrawing the persulfuric acid solution from the anode compartment, withdrawing the hydrogen and substantially alkali metal sulfate-free aqueous alkali metal hydroxide solution from the cathode compartment and reacting the persulfuric acid solution with water to produce hydrogen peroxide and sulfuric acid.
Claim 2
Independent Claim
212 words
A method for electrolytically manufacturing hydrogen peroxide, aqueous alkali metal hydroxide and aqueous sulfuric acid which comprises electrolyzing in a cell having an anode compartment with an anode therein, a cathode compartment with a cathode therein, and a buffer compartment separating the anode and cathode compartments, an anion-active permselective membrane separating the anode and buffer compartments, and a cation-active permselective membrane separating the buffer and cathode compartments, solutions resulting from feeding sulfuric acid to the anode compartment and alkali metal sulfate to the buffer compartment, so that with the passage of direct electric current through the cell, sulfate anion selectively diffuses from the buffer compartment to the anode compartment through the anion-active permselective membrane, sodium cation selectively diffuses from the buffer compartment to the cathode compartment through the cation-active permselective membrane, sulfuric acid is oxidized at the anode to produce a sulfuric acid solution of persulfuric acid, and sodium cation is reacted with water at the cathode to produce hydrogen and a substantially alkali metal sulfate-free aqueous alkali metal hydroxide solution, withdrawing the persulfuric acid solution from the anode compartment, withdrawing the hydrogen and substantially alkali metal sulfate-free aqueous alkali metal hydroxide solution from the cathode compartment and reacting the persulfuric acid solution with water to produce hydrogen peroxide and sulfuric acid.
Claim 3
Dependent Claim
50 words
A method according to claim 1 wherein the alkali metal sulfate is sodium sulfate, the electrolytic cell is operated at a temperature below about 60*C. and the persulfuric acid solution recovered from the anode compartment is reacted with at least about two moles of water per mole of persulfuric acid.
Claim 4
Dependent Claim
179 words
A method according to claim 2 wherein the material of the anion-active membrane is selected from the group consisting of quaternary ammonium group-substituted fluorocarbon polymers and quaternary ammonium-substituted polymers derived from heterogeneous polyvinyl chloride, the cation-active membranes are selected from the group consisting of hydrolyzed copolymers of perfluorinated olefin and a fluorosulfonated perfluorinated vinyl ether, fluorinated polymers having pendant side chains containing sulfonyl groups which are attached to carbon atoms bearing at least one fluorine atom, with sulfonyl groups on one surface being in -(SO2NH)nM form where M is H, NH4, alkali metal or alkaline earth metal and n is the valence of M, and the sulfonyls of the polymer on the other membrane surface being in -(SO3)pY form wherein Y is a cation and p is the valence of the cation and when Y is H, M is also H, or being -SO2F, and sulfostyrenated perfluorinated ethylene propylene copolymers, the sulfuric acid charged to the anode compartment is aqueous sulfuric acid containiNg about 80 percent by weight sulfuric acid, and the sodium sulfate is charged in aqueous solution.
Claim 5
Dependent Claim
207 words
A method according to claim 3 wherein the surface of the anode is of a persulfuric acid-inert noble metal, the surface of the cathode is of a material selected from the group consisting of platinum, iridium, ruthenium, rhodium, graphite, iron and steel, the hydrolyzed copolymer is derived from tetrafluoroethylene and fluorosulfonated perfluorovinyl ether of the formula FSO2CF2CF2OCF(CF3)CF2OCF CF2 and has an equivalent weight of about 900 to 1,600, the fluorinated polymer with different side materials is a perfluorinated copolymer of tetrafluoroethylene and FSO2CF2CF2OCF(CF3)CF2OCF CF2 in a molar ratio of about 7:1, M and Y are both sodium and n and p are both 1, and the sulfostyrenated perfluorinated ethylene propylene copolymer is about 16 to 18 percent styrenated and has from about two-thirds to thirteen-sixteenths of the phenyl groups therein monosulfonated, the thicknesses of the cation-active membrane and the anion-active membrane are between about 0.02 to 0.5 mm., the concentration of sulfuric acid in the sulfuric acid feed solution to the anode compartment is about 93 to 97 percent by weight, the concentration of sodium sulfate in the aqueous feed solution to the buffer compartment is about 1 to 3.5 molar and the sulfuric acid and sodium sulfate are fed to the cell at about equimolar rates.
Claim 6
Dependent Claim
103 words
A method according to claim 4 wherein the cell operates at a temperature of from about 20* to 35*C., the hydrolyzed copolymer is utilized and has an equivalent weight of from about 1,100 to 1,400, the cation-active and anion-active membranes are mounted on networks of material(s) selected from the group consisting of polytetrafluoroethylene, asbestos, perfluorinated ethylene-propylene copolymer, polypropylene, titanium, tantalum, niobium and noble metals, which have area percentage(s) of openings therein from about 8 to 80 percent and the persulfuric acid solution recovered from the anode compartment is reacted with water at a temperature of about 60* to 100*C. to produce hydrogen peroxide.
Claim 7
Dependent Claim
106 words
A method according to claim 5 wherein the cell operates at a voltage of about 2.3 to 5 volts and a current density of about 0.5 to 4 amperes per square inch of electrode surface, the anode is selected from the group consisting of platinum and platinum clad tantalum, the cathode is of mild steel or graphite having a density of about 1.68 to 1.78 grams per milliliter, the substantially sodium chloride-free hydroxide solution contains about 60 to 250 grams per liter of sodium hydroxide and the persulfuric acid solution recovered from the anode compartment is treated with steam at about 100*C. to produce hydrogen peroxide.
Claim 8
Dependent Claim
125 words
A method according to claim 6 wherein the cell operates at a voltage of about 2.5 to 4 volts, a current density of about 1 to 3 amperes per square inch of electrode surface and a temperature of about 30* to 35*C., the membranes are from about 0.1 to 0.4 mm. thick, and are mounted on a network of polytetrafluoroethylene filaments with the area percentage of openings in the network being from 10 to 70 percent, the concentration of sodium hydroxide in the aqueous hydroxide solution recovered from the cathode compartment is about 80 to 120 grams per liter, and the persulfuric acid solution recovered from the anode compartment is steam distilled to recover aqueous hydrogen peroxide as distillate and aqueous sulfuric acid as distilland.
Claim 9
Dependent Claim
95 words
A method according to claim 7 wherein the cationactive membranes are of the hydrolyzed copolymer having an equivalent weight of About 1,250, the cell operates at about 3 volts and a current density of about 2 amperes per square inch of electrode surface, the anode is of platinum, the concentration of sodium sulfate charged to the buffer compartment is about 3 molar, the hydroxide solution recovered from cathode compartment contains about 100 grams per liter of sodium hydroxide and the aqueous sulfuric acid distilland recovered is recycled as sulfuric acid feed to the anode compartment.
Claim 10
Dependent Claim
16 words
A method according to claim 8 wherein the anionactive membrane is a quaternary ammonium-substituted fluorocarbon polymer.
Claim 11
Dependent Claim
21 words
A method according to claim 8 wherein the anion-active membrane is a quaternary ammonium-substituted polymer derived from a heterogeneous polyvinyl chloride.
Claim 12
Independent Claim
198 words
A METHOD FOR ELECTROLYTICALLY MANUFACTURING PERSULFURIC ACID AND AQUEOUS ALKALI METAL HYDROXIDE FROM THE SULFURIC ACID AND ALKALI METAL SULFATE WHICH COMPRISES ELECTROLYZING IN A CELL HAVING AN ANODE COMPARTMENT WITH AN ANODE THEREIN, A CATHODE COMPARTMENT WITH A CATHODE THEREIN, AND ONE OR MORE INTERMEDIATE BUFFER COMPARTMENTS SEPARATING THE ANODE NAD CATHODE COMPARTMENTS, AN ANION-ACTIVE PERMSELECTIVE MEMBRANE SEPARATING THE ANODE AND BUFFER COMPARTMENTS, AND A CATION-ACTIVE PERMSELECTIVE MEMBRANE SEPARATING THE BUFFER AND CATHODE COMPARTMENTS, SOLUTONS RESULTING FROM FEEDING SULFURIC ACID TO THE ANODE COMPARTMENT AND ALKALI METAL SULFATE TO ONE OR MORE BUFFER COMPARTMENTS, SO THAT WITH THE PASSAGE OF DIRECT ELECTRIC CURRENT THROUGH THE CELL, SULFATE ANION SELECTIVELY DIFFUSES FROM THE BUFFER COMPARTMENT TO THE ANODE COMPARTMENT THROUGH THE ANION-ACTIVE PERMSELECTIVE MEMBRANE, SODIUM CATION SELECTIVELY DIFFUSES FROM THE BUFFER COMPARTMENT TO THE CATHODE COMPARTMENT THROUGH THE CATIONACTIVE PERMSELECTIVE MEMBRANE, SULFURIC ACID IS OXIDIZED AT THE ANODE TO PRODUCE A SULFURIC ACID SOLUTION OF PERSULFURIC ACID, AND SODIUM CATION IS REACTION WITH WATER AT THE CATHODE TO PRODUCE HYDROGEN AND QUEOUS ALKALI METAL HYDROXIDE SOLUTION, WITHDRAWING THE PERSULFURIC ACID SOLUTION FROM THE ANODE COMPARTMENT AND WITHDRAWING THE HYDROGEN AND ALKALI METAL HYDROXIDE SOLUTION FROM THE CATHODE COMPARTMENT.
Claim 13
Independent Claim
198 words
A METHOD FOR ELECTROLYTICALLY MANUFACTURING PERSULFURIC ACID AND AQUEOUS ALKALI METAL HYDROXIDE FROM THE SULFURIC ACID AND ALKALI METAL SULFATE WHICH COMPRISES ELECTROLYZING IN A CELL HAVING AN ANODE COMPARTMENT WITH AN ANODE THEREIN, A CATHODE COMPARTMENT WITH A CATHODE THEREIN, AND ONE OR MORE INTERMEDIATE BUFFER COMPARTMENTS SEPARATING THE ANODE NAD CATHODE COMPARTMENTS, AN ANION-ACTIVE PERMSELECTIVE MEMBRANE SEPARATING THE ANODE AND BUFFER COMPARTMENTS, AND A CATION-ACTIVE PERMSELECTIVE MEMBRANE SEPARATING THE BUFFER AND CATHODE COMPARTMENTS, SOLUTONS RESULTING FROM FEEDING SULFURIC ACID TO THE ANODE COMPARTMENT AND ALKALI METAL SULFATE TO ONE OR MORE BUFFER COMPARTMENTS, SO THAT WITH THE PASSAGE OF DIRECT ELECTRIC CURRENT THROUGH THE CELL, SULFATE ANION SELECTIVELY DIFFUSES FROM THE BUFFER COMPARTMENT TO THE ANODE COMPARTMENT THROUGH THE ANION-ACTIVE PERMSELECTIVE MEMBRANE, SODIUM CATION SELECTIVELY DIFFUSES FROM THE BUFFER COMPARTMENT TO THE CATHODE COMPARTMENT THROUGH THE CATIONACTIVE PERMSELECTIVE MEMBRANE, SULFURIC ACID IS OXIDIZED AT THE ANODE TO PRODUCE A SULFURIC ACID SOLUTION OF PERSULFURIC ACID, AND SODIUM CATION IS REACTION WITH WATER AT THE CATHODE TO PRODUCE HYDROGEN AND QUEOUS ALKALI METAL HYDROXIDE SOLUTION, WITHDRAWING THE PERSULFURIC ACID SOLUTION FROM THE ANODE COMPARTMENT AND WITHDRAWING THE HYDROGEN AND ALKALI METAL HYDROXIDE SOLUTION FROM THE CATHODE COMPARTMENT.
References Cited (Backward Citations)
US1299485A
Cited
US1861573A
Cited
US2234908A
Cited
US3220941A
Cited
US3135673A
Cited
US3165460A
Cited
US3344053A
Cited
US3438879A
Cited
US3694154A
Cited
US3523755A
Cited
US3681213A
Cited
US3784399A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |