US3884777A
Expired / Lapsed
US
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Electrolytic process for manufacturing chlorine dioxide, hydrogen peroxide, chlorine, alkali metal hydroxide and hydrogen
Assignee: Occidental Chemical Corp
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Filing: 1974-01-02
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Granted: 1975-05-20
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Expires: 1994-01-02
Abstract
Abstract Chlorine dioxide, hydrogen peroxide, chlorine, alkali metal hydroxide and hydrogen are produced from alkali metal chloride, alkali metal chlorate, sulfuric acid and water, utilizing an electrolytic cell having anode and cathode compartments separated by two intermediate buffer compartments, the boundaries between the anode and cathode compartments and the buffer compartments being of cation-active permselective membranes which are resistant to attack by the medium and the buffer compartments being separated by a suitable anion-active permselective membrane. On electrolysis, with sulfuric acid fed to the anode compartment, chloride and chlorate fed to the buffer compartment adjacent to the cathode compartment and water fed to the cathode compartment there are produced hydrogen and alkali metal hydroxide in the cathode compartment, chlorine dioxide and chlorine in the buffer compartment adjacent to the anode compartment and persulfuric acid in the anode compartment. The persulfuric acid is hydrolyzed to produce hydrogen peroxide. Hydrogen peroxide, alkali metal hydroxide, chlorine and chlorine dioxide are useful pulp mill chemicals especially suited for pulping wood and bleaching wood pulp.
Inventors
- 👤 Cyril J Harke
- 👤 Jeffrey D Eng
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:35
CPC Classifications
C; C25; C25B; C25B1/00; C25B1/01; C25B1/28; C25B1/24; C25B1/26; C25B1/29; C25B1/34; C25B1/46
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
262 words
A method of manufacturing chlorine dioxide, hydrogen peroxide, chlorine, hydrogen and substantially alkali metal chloride-free aqueous alkali metal hydroxide from aqueous alkali metal chloride, aqueous alkali metal chlorate, sulfuric acid and water which comprises electrolyzing in a cell haVing an anode compartment with an anode therein, a cathode compartment with a cathode therein and intermediate buffer compartments, B1 and B2, the anode compartment being separated from B1 by a cation-active permselective membrane, Mc 1, the cathode compartment being separated from B2 by a cation-active permselective membrane, Mc 2, and B1 and B2 being separated from each other by an anion-active permselective membrane, Ma, solutions resulting from feeding sulfuric acid to the anode compartment, alkali metal chloride and alkali metal chlorate to B2, and water to the cathode compartment so that with the passage of electric current through the cell hydrogen ions selectively pass from the anode compartment to B1 through Mc 1, chloride and chlorate anions selectively pass from B2 to B1 through Ma, and alkali metal cations selectively pass from B2 to the cathode compartment through Mc 2, sulfuric acid is oxidized at the anode to produce persulfuric acid in the anode compartment, chloride and chlorate ions react to produce chlorine and chlorine dioxide in B1, and water and alkali metal cation react at the cathode to produce an aqueous substantially alkali metal halide-free alkali metal hydroxide and hydrogen in the cathode compartment, recovering the persulfuric acid solutions, chlorine dioxide, chlorine, hydrogen and aqueous hydroxide produced and reacting the persulfuric acid solution with water to produce sulfuric acid and hydrogen peroxide.
Claim 2
Independent Claim
262 words
A method of manufacturing chlorine dioxide, hydrogen peroxide, chlorine, hydrogen and substantially alkali metal chloride-free aqueous alkali metal hydroxide from aqueous alkali metal chloride, aqueous alkali metal chlorate, sulfuric acid and water which comprises electrolyzing in a cell haVing an anode compartment with an anode therein, a cathode compartment with a cathode therein and intermediate buffer compartments, B1 and B2, the anode compartment being separated from B1 by a cation-active permselective membrane, Mc 1, the cathode compartment being separated from B2 by a cation-active permselective membrane, Mc 2, and B1 and B2 being separated from each other by an anion-active permselective membrane, Ma, solutions resulting from feeding sulfuric acid to the anode compartment, alkali metal chloride and alkali metal chlorate to B2, and water to the cathode compartment so that with the passage of electric current through the cell hydrogen ions selectively pass from the anode compartment to B1 through Mc 1, chloride and chlorate anions selectively pass from B2 to B1 through Ma, and alkali metal cations selectively pass from B2 to the cathode compartment through Mc 2, sulfuric acid is oxidized at the anode to produce persulfuric acid in the anode compartment, chloride and chlorate ions react to produce chlorine and chlorine dioxide in B1, and water and alkali metal cation react at the cathode to produce an aqueous substantially alkali metal halide-free alkali metal hydroxide and hydrogen in the cathode compartment, recovering the persulfuric acid solutions, chlorine dioxide, chlorine, hydrogen and aqueous hydroxide produced and reacting the persulfuric acid solution with water to produce sulfuric acid and hydrogen peroxide.
Claim 3
Dependent Claim
81 words
A method according to claim 1 wherein the alkali metal chloride, the alkali metal chlorate and the alkali metal hydroxide are sodium chloride, sodium chlorate and sodium hydroxide respectively, the Mc 1 and Mc 2 cation-active membranes are of the same cation-exchange material, the 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 2 moles of water per mol of persulfuric acid in the solution.
Claim 4
Dependent Claim
184 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 above about 80 percent thereof of sulfuric acid by weight and the sodium chloride and sodium chlorate are charged as aqueous solutions.
Claim 5
Dependent Claim
210 words
A method according to claim 3 wherein the anode is of a persulfuric acid-inert noble metal, the cathode is 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 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 membranes 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% by weight, the concentrations of sodium chlorate and sodium chloride in the feed to B2 are from about 1 N to the saturation solubility for each salt in water, and the sulfuric acid, sodium chloride and sodium chlorate are fed to the cell in molar proportioned rates of about 2:1:1.
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
68 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 of platinum or platinum on titanium, the cathode is of mild steel and the substantially sodium chloride-free hydroxide solution contains about 60 to 250 grams per liter of sodium hydroxide.
Claim 8
Dependent Claim
100 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, and the concentration of sodium hydroxide in the aqueous hydroxide solution recovered from the cathode compartment is about 80 to 120 grams per liter.
Claim 9
Dependent Claim
100 words
A method according to claim 7 wherein the cation-active 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 concentrations of sodium chlorate and sodium chloride in the feed solution to B2 are each 3 N, the hydroxide solution recovered from the cathode compartment contains about 100 grams per liter of sodium hydroxide, and the aqueous sulfuric acid distilland is recycled to the sulfuric acid feed to the anode compartment.
Claim 10
Dependent Claim
17 words
A method according to claim 8 wherein the anion-active membrane is a quaternary ammonium substituted fluorocarbon polymer.
Claim 11
Dependent Claim
22 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
299 words
A METHOD OF MANUFACTURING CHLORINE DIOXIDE, HYDROGEN PEROXIDE, CHLORINE, SUBSTANTIALLY ALKALI METAL CHLORIDE-FREE AQUEOUS ALKALI METAL HYDROXIDE AND HYDROGEN FROM ALKALI METAL CHLORIDE, ALKALI METAL CHLORATE, SULFURIC ACID AND WATER WHICH COMPRISES ELECTROLYZING WITH A DIRECT CURRENT, IN A CELL HAVING ANODE IN AN ANODE COMPARTMENT, A CATHODE IN A CATHODE COMPARTMENT AND A PLURALTY OF INTERMEDIATE BUFFER COMPARTMENTS, WITH THE ANODE COMPARTMENT BEING SEPARATED FROM A BUFFER COMPARTMENT BY A CATION-ACTIVE PERMSELECTIVE MEMBRANE, THE CATHODE COMPARTMENT BEING SEPARATED FROM A BUFFER COMPARTMENT BY A CATION-ACTIVE PERMSELECTIVE MEMBRANE AND AT LEAST ONE BUFFER COMPARTMENT BEING SEPARATED FROM ANOTHER BY AN ANION-ACTIVE PERMSELECTIVE MEMBRANE, ELECTROLYTES RESULTING FROM FEEDS OF SULFURIC ACID TO THE ANODE COMPARTMENT, ALKALI METAL CHLORIDE AND ALKALI METAL CHLORATE TO A BUFFER COMPARTMENT NEARER TO THE CATHODE COMPARTMENT THAN ANOTHER BUFFER COMPARTMENT, AND WATER TO THE CATHODE COMPARTMENT, SO THAT WITH THE PASSAGE OF DIRECT ELECTRIC CURRENT THROUGH THE CELL HYDROGEN IONS SELECTIVELY PASS FROM THE ANODE COMPARTMENT TO AN ADJACENT BUFFER COMPARTMENT THROUGH THE CATION-ACTIVE PERMSELECTIVE MEMBRANE, CHLORIDE AND CHLORATE IONS SELECTIVELY PASS FROM A BUFFER COMPARTMENT NEARER TO THE CATHODE SELECTIVELY PASS FROM A BUFFER COMPARTMENT THROUGH AN ANION-ACTIVE PERMSELECTIVE MEMBRANE, AND ALKALI METL CATIONS SELECTIVELY PASS FROM A BUFFER COMPARTMENT TO THE CATHODE COMPARTMENT THROUGH A CATION-ACTIVE PERMSELECTIVE MEMBRANE, SULFURIC ACID IS CONVERTED TO PERSULFURIC ACID IN THE ANODE COMPARTMENT, CHLORIDE AND CHLORATE IONS REACT TO PRODUCE CHLORINE AND CHLORINE DIOXIDE IN A BUFFER COMPARTMENT NEARER TO THE ANODE COMPARTMENT THAN THE BUFFER COMPARTMENT INTO WHICH CHLORIDE AND CHLORATE ARE FED, AND WATER AND ALKALI METAL CATIONS ARE CONVERTED TO AQUEOUS, SUBSTANTIALLY ALKALI METAL HALIDE-FREE ALKALI METAL HYDROXIDE AND HYDROGEN IN THE CATHODE COMPARTMENT, AND REMOVING FROM THE ELECTROLYTIC CELL THE PERSULFURIC ACID SOLUTION, CHLORINE DIOXIDE, CHLORINE, AQUEOUS ALKALI METAL HYDROXIDE AND HYDROGEN PRODUCED.
Claim 13
Independent Claim
299 words
A METHOD OF MANUFACTURING CHLORINE DIOXIDE, HYDROGEN PEROXIDE, CHLORINE, SUBSTANTIALLY ALKALI METAL CHLORIDE-FREE AQUEOUS ALKALI METAL HYDROXIDE AND HYDROGEN FROM ALKALI METAL CHLORIDE, ALKALI METAL CHLORATE, SULFURIC ACID AND WATER WHICH COMPRISES ELECTROLYZING WITH A DIRECT CURRENT, IN A CELL HAVING ANODE IN AN ANODE COMPARTMENT, A CATHODE IN A CATHODE COMPARTMENT AND A PLURALTY OF INTERMEDIATE BUFFER COMPARTMENTS, WITH THE ANODE COMPARTMENT BEING SEPARATED FROM A BUFFER COMPARTMENT BY A CATION-ACTIVE PERMSELECTIVE MEMBRANE, THE CATHODE COMPARTMENT BEING SEPARATED FROM A BUFFER COMPARTMENT BY A CATION-ACTIVE PERMSELECTIVE MEMBRANE AND AT LEAST ONE BUFFER COMPARTMENT BEING SEPARATED FROM ANOTHER BY AN ANION-ACTIVE PERMSELECTIVE MEMBRANE, ELECTROLYTES RESULTING FROM FEEDS OF SULFURIC ACID TO THE ANODE COMPARTMENT, ALKALI METAL CHLORIDE AND ALKALI METAL CHLORATE TO A BUFFER COMPARTMENT NEARER TO THE CATHODE COMPARTMENT THAN ANOTHER BUFFER COMPARTMENT, AND WATER TO THE CATHODE COMPARTMENT, SO THAT WITH THE PASSAGE OF DIRECT ELECTRIC CURRENT THROUGH THE CELL HYDROGEN IONS SELECTIVELY PASS FROM THE ANODE COMPARTMENT TO AN ADJACENT BUFFER COMPARTMENT THROUGH THE CATION-ACTIVE PERMSELECTIVE MEMBRANE, CHLORIDE AND CHLORATE IONS SELECTIVELY PASS FROM A BUFFER COMPARTMENT NEARER TO THE CATHODE SELECTIVELY PASS FROM A BUFFER COMPARTMENT THROUGH AN ANION-ACTIVE PERMSELECTIVE MEMBRANE, AND ALKALI METL CATIONS SELECTIVELY PASS FROM A BUFFER COMPARTMENT TO THE CATHODE COMPARTMENT THROUGH A CATION-ACTIVE PERMSELECTIVE MEMBRANE, SULFURIC ACID IS CONVERTED TO PERSULFURIC ACID IN THE ANODE COMPARTMENT, CHLORIDE AND CHLORATE IONS REACT TO PRODUCE CHLORINE AND CHLORINE DIOXIDE IN A BUFFER COMPARTMENT NEARER TO THE ANODE COMPARTMENT THAN THE BUFFER COMPARTMENT INTO WHICH CHLORIDE AND CHLORATE ARE FED, AND WATER AND ALKALI METAL CATIONS ARE CONVERTED TO AQUEOUS, SUBSTANTIALLY ALKALI METAL HALIDE-FREE ALKALI METAL HYDROXIDE AND HYDROGEN IN THE CATHODE COMPARTMENT, AND REMOVING FROM THE ELECTROLYTIC CELL THE PERSULFURIC ACID SOLUTION, CHLORINE DIOXIDE, CHLORINE, AQUEOUS ALKALI METAL HYDROXIDE AND HYDROGEN PRODUCED.
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) | 1978-05-19 | 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 |