REPLACING OXYGEN EVOLUTION REACTION IN WATER SPLITTING PROCESS BY PRODUCED WATER ELECTROLYSIS WITH CO-GENERATION OF GREEN HYDROGEN: FROM WASTEWATER TO THE FUTURE OF THE ENERGETIC INDUSTRY

The dual-purpose treatment of effluents with simultaneous green hydrogen (H2) generation represents an optimal synergy, addressing environmental concerns through effective pollution control while harnessing valuable clean energy resources, thereby promoting sustainable and eco-friendly industrial practices. In this way, produced waters (PW) stemming from industrial processes like oil and gas extraction, possess varying chemical compositions, elevated salinity, temperature fluctuations, and diverse contaminant profiles. Thus, a proton-exchange membrane cell (PEM) featuring a BDD anode (15 cm2) and a 316-Ni-Fe-based stainless steel mesh as the cathode (18.2 cm2), energized by a solar source of energy through a photovoltaic (PV), was used as an integrated-hybrid approach to guarantee the decontamination of the effluent at the anodic compartment, while produces green H2 at the cathodic one, both with a volume of 0.04 L. The electrolysis was performed by applying approximately 7, 13 and 26 mA cm−2 for up to 600 min. The study demonstrates that anodic oxidation achieves almost total mineralization of organics in various tested scenarios. Higher current densities are found to optimize green hydrogen generation, yielding a theoretical value of 1.27 L of dry H2 per 0.5 L of produced water (PW) treated over 10 h with favorable current efficiency (specifically 18.6 mA cm-2). Overall, PW treatment and simultaneous green H2 generation emerge as a promising solution, mitigating cost barriers associated with industrial effluents while promoting carbon-neutral energy, cleaner industries, decarbonized transportation, and resilient energy solutions.