Claims
- 1. An electrolytic cell for producing chlorine and an alkali metal hydroxide from an alkali metal chloride comprising:
- an anode compartment adapted to contain an anolyte containing an alkali metal chloride;
- a cathode compartment adapted to contain a catholyte containing an alkali metal hydroxide;
- an anode positioned in said anode compartment;
- a cathode positioned in said cathode compartment and spaced apart from said anode by a diaphragm;
- a porous polytetrafluoroethylene diaphragm with a thickness of from about 5 to about 100 mils, an average pore size of from about 0.1 to about 100 microns, a gas permeability of from about 1 to about 50 seconds, a liquid permeability factor of from about 1 to about 60, and a tensile strength of from about 100 to about 1000 pounds per square inch;
- a means to feed the anolyte to said anode compartment;
- a means to remove the chlorine from said anode compartment;
- a means to remove the alkali metal hydroxide from said cathode compartment;
- and a means to supply electrical energy to said anode and said cathode.
- 2. The apparatus of claim 1 wherein from about 80 to about 100 percent of the pores in said diaphragm have an area within two orders of magnitude of each other.
- 3. The apparatus of claim 1 wherein said diaphragm is about 40 to about 70 mils thick.
- 4. The apparatus of claim 1 wherein said diaphragm is from about 60 to about 90 percent porous.
- 5. The apparatus of claim 1 wherein the liquid permeability factor of said diaphragm is from about 5 to about 25.
- 6. The apparatus of claim 1 wherein the thickness of said diaphragm is about 40 to about 70 mils, the average pore size dimension is about 1 to about 20 microns, the gas permeability is from about 8 to about 20 seconds, the liquid permeability factor is from about 5 to about 25, the tensile strength is about 150 to about 700, said diaphragm is about 70 to about 80 percent porous, and about 85 to about 95 percent of the pores are of a size within two orders of magnitude from each other.
- 7. The apparatus of claim 6 wherein the tensile strength of said diaphragm is about 250 to about 600 pounds per square inch.
- 8. The apparatus of claim 1 wherein the diaphragm is porous, hydrophilic polytetrafluoroethylene.
- 9. The apparatus of claim 6 wherein the diaphragm is porous, hydrophilic polytetrafluoroethylene.
- 10. The method of claim 7 wherein the porous polytetrafluoroethylene is pretreated to provide an electrolyte wettable diaphragm.
- 11. The apparatus of claim 10 wherein the porous polytetrafluoroethylene is pretreated with an agent selected from acetone, ethyl ether or an aliphatic alcohol with 1 to 10 carbon atoms.
- 12. The apparatus of claim 10 wherein the porous polytetrafluoroethylene is pretreated with methanol or an aqueous saturated isobutyl alcohol solution.
CROSS REFERENCE TO RELATED APPLICATION
This is a continuation, of application Ser. No. 777,868 filed Mar. 15, 1977, now abandoned.
US Referenced Citations (10)
Foreign Referenced Citations (6)
Number |
Date |
Country |
681132 |
Mar 1964 |
CAX |
725704 |
Jan 1966 |
CAX |
2139646 |
Feb 1972 |
DEX |
1081046 |
Aug 1967 |
GBX |
1205943 |
Sep 1970 |
GBX |
1401290 |
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GBX |
Continuations (1)
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Number |
Date |
Country |
Parent |
777868 |
Mar 1977 |
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