A review of oxygen generation through renewable hydrogen production

Oxygen production as a by-product from renewable energy-based water electrolysis has great potential to support the clean energy transition. This study reviews the efficiency of electrolysis technologies, oxygen applications, and their environmental and economic impacts. Proton exchange membrane (PEM)-based systems show up to 85 % efficiencies, while transition metal catalysts increase efficiencies to 90 %. Integrating solar photovoltaic systems with electrolysis yields 80 % efficiency despite the challenges of power fluctuations. High-purity oxygen from electrolysis has broad applications, including respiratory therapy in the medical field, aeration in wastewater treatment, and more efficient combustion of fossil fuels in the energy sector, all contributing to reduced carbon emissions. In an industrial context, oxygen supports the efficiency of processes such as welding and chemical oxidation. The novelty of this study lies in the in-depth exploration of the economic opportunities and environmental impacts of oxygen as a by-product. The potential for increased revenue from oxygen could accelerate the adoption of green hydrogen technologies. Key challenges include the cost of oxygen storage and the need for more efficient liquid storage technologies. Further research is recommended to improve the modular design of electrolysis reactors and more stable integration with renewable energy systems. By overcoming these barriers, oxygen from water electrolysis could be a significant innovation for sustainability across sectors.