Energies, Vol. 15, Pages 5888: Hydrogen Production by Wastewater Alkaline Electro-Oxidation (Energies)

The current work presents the electro-oxidation of olive mill and biodiesel wastewaters in an alkaline medium with the aim of hydrogen production and simultaneous reduction in the organic pollution content. The process is performed, at laboratory scale, in an own-design single cavity electrolyzer with graphite electrodes and no membrane. The system and the procedures to generate hydrogen under ambient conditions are described. The gas flow generated is analyzed through gas chromatography. The wastewater balance in the liquid electrolyte shows a reduction in the chemical oxygen demand (COD) pointing to a decrease in the organic content. The experimental results confirm the production of hydrogen with different purity levels and the simultaneous reduction inorganic contaminants. This wastewater treatment appears as a feasible process to obtain hydrogen at ambient conditions powered with renewable energy sources, resulting in a more competitive hydrogen cost.