Single step production of ammonia feedstock by high temperature solid oxide electrolyser cell

• Main Author: Suparmaniam, Katiravan
• Other Authors: Chan Siew Hwa
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/168451
• Institution: Nanyang Technological University

Green ammonia would be a significant energy vector in the low carbon economy. However, issues associated with the production of green ammonia prevents it from being scalable and commercialised to a large scale. The current industrial route for ammonia synthesis is the conventional Haber-Bosch process, which is very laborious and energy intensive, and leaves substantial carbon footprint in the process of ammonia production. To greatly reduce the carbon footprint of ammonia production, a contemporary approach is proposed and evaluated in this project. This project aims to explores the efficiency and effectiveness of wet air co-electrolysis in a high temperature solid oxide electrolyser cell (SOEC) for the sustainable single step synthesis of ammonia feedstock. The electrode material is made from a mixture of SrFe0.75Mo0.25O3 (SFM), which is an electronic conductor, and Gadolinium doped ceria (GDC), which is an ionic conductor., Platinum, Pt, layer was applied on the electrode to serve as an current collector. The electrolyte is made from La0.8Sr0.2Ga0.8Mg0.2O3 (LSGM). The wet air co-electrolysis was carefully monitored and examined over various operational conditions. The exit gas from the electrolysis was analysed using Gas chromatography which showed us the ratio of H2:N2. From the performance curve, the ratio of H2:N2 could be calculated to be 2.22:1. Although the desired ratio of 3:1 of H2:N2 could be achieved at higher current based on the performance curves obtained in the experiment, the cell performance is not stable at high current. This prevents the cell from operating for prolonged duration when achieving the desired H2:N2 ratio. Thus, further research has to be done to achieve a more durable and sustainable cell which can be scaled and commercialised.