Cabral Roque B.A., Benachour M., Sarubbo L.A., 2026, Enhancing Hydrogen Production Efficiency in Alkaline Water Electrolysis through Biosurfactants, Ultrasound, and their Synergistic Combination, Chemical Engineering Transactions, 124, 109-114.
Alkaline water electrolysis is a key technology for low-carbon hydrogen production; however, its efficiency is constrained by gas bubble accumulation and mass transfer limitations at the electrode–electrolyte interface. This study evaluates ultrasound application and biosurfactant addition as process intensification strategies to enhance hydrogen production under mild alkaline conditions. Experiments were performed in a hermetic tubular bench-scale electrolyzer operating with 1 M KOH, stainless-steel electrodes, and a saponin-based biosurfactant. Ultrasound was applied using an immersion transducer operating at 40 kHz under pulsed and continuous regimes. A 23 factorial design with central points was employed to assess the effects of applied voltage, ultrasound condition, and biosurfactant concentration on the hydrogen volumetric flow rate. Statistical analysis based on ANOVA and response surface methodology identified applied voltage as the dominant factor, with significant quadratic effects defining optimal operating regions. Ultrasound exhibited a voltage-dependent synergistic effect by enhancing bubble detachment and mass transfer, whereas the biosurfactant showed a secondary interfacial effect within a narrow concentration range. These findings highlight ultrasound-assisted alkaline electrolysis as an effective route for performance enhancement without major modifications to electrolyzer architecture.
