Evaluation of energy consumption for effective seawater electrolysis based on the electrodes and salinity. Issue 22 (8th May 2016) - Jung, Youmi
Abstract: This study recommended the effective condition in electrolysis of saline water considering the energy consumption. The experiments were performed using two types of electrodes, IrO2 /Ti and Pt/Ti, under various salinity conditions (4, 8, 16, 32, and 46 PSU) and current density conditions (11, 33, 55, 111, and 222 mA/cm 2 ). The electrolysis produced mainly bromine, which was measured as a total residual oxidant (TRO). Seawater electrolysis produced TRO linearly with increasing the run time and current density. Below 32 PSU, the electrolysis using the IrO2 /Ti electrode produced the TRO greater than that using the Pt/Ti electrode. The TRO formation rate of the IrO2 /Ti electrode increased following a half parabola pattern in terms of salinity, while that of the Pt/Ti electrode increased until 32 PSU, and then it decreased to 46 PSU. The measured electric power of both electrodes showed the same graph tendency with a parabolic curve as a quadratic equation. The energy consumption of the IrO2 /Ti and Pt/Ti electrodes showed a quite different tendency. Considering the energy consumption as well as the required time for TRO formation, the same range of current density (30–50 mA/cm 2 ) is recommended for the two electrodes, IrO2 /Ti and Pt/Ti electrodes, even in a different tendency of energy consumption.