Mechanical Engineering for Society and Industry

During the COVID-19 pandemic, there is a shortage of oxygen in highly populated countries such as Indonesia. Oxygen can be produced by several methods, such as cryogenic distillation or pressure swing adsorption, but by-product oxygen from the electrolysis of water is uncommon. In this work, we present a case study on how oxygen produced by electrolysis, which is usually wasted, can be used for medical applications. In this case, water electrolysis is performed to produce hydrogen for gas turbine cooling in a power plant with a hydrogen gas capacity of 15 Nm³/h, corresponding to an oxygen production potential of 7.5 Nm³/h. This could potentially be replicated in many power plants in Indonesia. However, the by-product oxygen contained excessive impurities, including CO and CO₂, which were unsuitable for medical applications. The Aspen HYSYS simulation was developed to predict impurity profiles and evaluate purification performance using three adsorbents (AC, K₂CO₃/Al₂O₃, and Al₂O₃+13X). By using a lab-made adsorption column with a Zeolite 13X adsorbent, oxygen purity is increased, allowing medical-grade oxygen to be delivered. We hope that our present case study can serve as a reference for others in situations of medical oxygen shortage by utilizing by-product oxygen available in many electrolyzer units at power or other plants.