Electrolysis of alkali metal halides in a three-compartment cell with a pressurized buffer compartment
US4214958A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 1979 |
| Grant date | Jul 29, 1980 |
| Priority date | — |
| Expiry date | May 14, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25B9/19
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The invention describes a pressurized, three compartment membrane cell for the electrolyzing aqueous alkali metal halides at low cell voltages and with high cathodic current efficiencies. Unitary electrode-electrolyte structures, in the form electrochemically active electrodes physically bonded to ion transporting permselective membranes divide the cell into anode, cathode and buffer compartments. The buffer compartment feed is pressurized to maintain at a positive pressure differential with respect to the anode and cathode compartment feeds. The flexible unitary electrode-membrane electrolytes are forced outwardly against electronically conductive anode and cathode current collectors to provide uniform, constant and controllable contact between the bonded electrodes and thereby minimizing ohmic losses. A three compartment cell operated in this fashion not only minimizes the voltage required to electrolyze the halide solution, but also increases the cathodic current efficiency at high caustic concentrations by providing multiple hydroxide rejection stages in a single cell process. The improvement in cathodic current efficiency is realized by forming a lower caustic concentration in…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.