Abstract
Electric current densities via different pathways and current efficiencies were evaluated in a bipolar packed bed electrode cell of 0.1m × 0.1m in cross section and 0.2m in height. The particulate electrodes were cylindrical ferrite pellets 6mm in diameter and 6mm long.
The bypass current density was dependent on electrical conductivity of electrolyte, solid holdup, cell configuration and cell voltage. The Faradaic current density under the mass transfer-controlling condition was simulated with the mass transfer coefficient in packed bed, the ratio of effective area to surface area of each pellet, solid holdup and depolarizer concentration. The overall current efficiency was expressed as a function of bypass current density, Faradaic current density and actual current efficiency. Introduction of inert gas bubbles increased the maximum current efficiency by about 15%.
