Fuel-assisted electrolysis comparison to conventional high-temperature electrolysis

Abstract Solid Oxide Fuel-assisted Electrolysis Cells (SOFEC) are a relatively recent development as far as fuel cell research is concerned. Laboratory tests predict that they have the ability of efficiently producing hydrogen and, most importantly, at a lower cost compared to conventional high temperature electrolysis. The SOFEC mode of operation is related to the conventional SOFC and SOEC. The available theoretical knowledge for those modes is presented and then applied to SOFEC. In this report the operation of SOFEC is analyzed and explained, while the experimental part aims at validating the theory through laboratory experiments, inspired by previous tests in literature. The conducted experiments focus on symmetrical button cells, with platinum being the electrode material for both the anode and the cathode. The initial tests are carried out on custom-made cells, with platinum pasted on an electrolyte substrate by hand. The equipment used, as well as the procedure of preparing the test setup are detailed. This is followed by proposed setup modifications for future application. Afterwards, the results are presented. These focus on the polarization curves for different operating modes, while comparisons between SOFEC and SOEC modes illustrate the positive impact of the assisting fuel on the performance of the electrolyzer. Hydrogen and carbon monoxide are used as fuels, while carbon dioxide is utilized for co-electrolysis with steam. Comparisons of the electrolyzer performance between different fuels are presented and explained. Finally, the results are summarized and recommendations for future research are given.Mechanical, Maritime and Materials EngineeringProcess and EnergySustainable Energy Technolog