POS6-1448
Development of a Gas Transport Characterization Methodology for Ion-Solvating Membranes and Adjacent Liquid Layers in High-Pressure Alkaline Water Electrolysis Systems
When and Where
Nov 30, -0001
00:00 - 00:00
Room 301 (Grand Ballroom)
Presenter(s)
Kyuwon Hwang (Kyung Hee University)
Co-Author(s)
Abstract
Conventional alkaline water electrolysis employs porous diaphragms as separators; however, their porous structure allows significant hydrogen crossover, particularly under high-pressure operation. Dense ion-solvating membranes have emerged as promising alternatives because they effectively suppress convective gas transport while maintaining ionic conduction. At the same time, advanced cell architectures such as zero-gap configurations minimize ohmic resistance by eliminating the electrolyte gap between the electrode and membrane. Although this design improves energy efficiency, it also increases hydrogen crossover by promoting gas supersaturation at the membrane–electrode interface. Quantifying the contribution of the liquid electrolyte layer to hydrogen transport is therefore essential for understanding crossover behavior in practical electrolysis systems.
In this study, a pressure decay method was employed to quantify hydrogen transport through the membrane–electrolyte system under controlled operating conditions. To account for non-ideal gas behavior at elevated pressures, the transient pressure decay was converted into time-dependent molar density using an appropriate equation of state, from which the transient gas flux and overall permeance were determined. A series resistance model was then applied to separate the overall transport resistance into membrane and liquid-layer contributions, enabling independent evaluation of each transport barrier. The proposed methodology provides a practical framework for quantifying the individual contributions of membrane and liquid-layer resistances to hydrogen transport, offering insight into hydrogen crossover mechanisms in high-pressure alkaline water electrolysis.
In this study, a pressure decay method was employed to quantify hydrogen transport through the membrane–electrolyte system under controlled operating conditions. To account for non-ideal gas behavior at elevated pressures, the transient pressure decay was converted into time-dependent molar density using an appropriate equation of state, from which the transient gas flux and overall permeance were determined. A series resistance model was then applied to separate the overall transport resistance into membrane and liquid-layer contributions, enabling independent evaluation of each transport barrier. The proposed methodology provides a practical framework for quantifying the individual contributions of membrane and liquid-layer resistances to hydrogen transport, offering insight into hydrogen crossover mechanisms in high-pressure alkaline water electrolysis.
