3D-printed electrochemical reactor for integrated ozone generation and gas-liquid separation via PEM technology

This work presents the design, fabrication, and validation of a novel 3D-printed electrochemical reactor for integrated ozone generation and gas-liquid separation based on proton exchange membrane (PEM) technology. The system integrates two operational stages: electrochemical ozone generation via water electrolysis and gravity driven separation and collection of the produced ozone into a gaseous stream suitable for direct use as an oxidizer. The compact reactor architecture incorporates a PEM electrochemical cell in the lower section of a monolithic 3D-printed housing, enabling ozone production from water via eletrooxidation. The upper section features an internal liquid-gas separation system with curved deflector baffles that promote upward ozone transport and efficient gas disengagement. Reactor performance was evaluated under varying current intensities (1–3 A), water flowrates (340–540 mL/min), and temperatures (5–19 °C). The maximum ozone gas generation rate (0.69 mg/min) and Faradaic efficiency (3.53%) were achieved at 3 A, 540 mL/min, and 5 °C, outperforming several commercial electro-ozonizers operating under harsher conditions. Dimensional analysis yielded a Sherwood-Reynolds correlation that evidences enhanced mass transfer within the system. Additionally, a preliminary cost assessment estimated a single-unit fabrication cost of 3818.3 €, with potential reductions via industrial-scale production. These results demonstrate the reactor’s suitability for decentralized water treatment and advanced oxidation processes in low-resource settings.