Impact of Fluidic Oscillation on Solid Oxide Electrolysed Performance

Solid Oxide Cells (SOCs) are a leading technology for future clean power generation and chemicals production, whether operated in fuel cell (SOFC) or electrolysis (SOEC) mode, due to their high efficiencies, fuel flexibility and long projected lifetimes. Excess renewable energy produced during off-peak times can be utilised to cheaply reduce a variety of fuels, including carbon dioxide, which can then be further reacted to produce a myriad of hydrocarbon related products. Reported electrical efficiencies of SOECs are around 50% and can be increased to 80% when used in combination with recycled heat from other high temperature systems. At present, over 80% of the cost of electrolysing carbon dioxide is due to the electrical input necessary to drive an SOEC. Recent advances in cell materials and compositions have improved performance, however activation and concentration polarisation need to be addressed to advance the field further.

Here we focus on oscillation of the inlet gas flow via a Desai-Zimmerman fluidic oscillator, to facilitate the reduction of carbon dioxide to carbon monoxide. Performance improvements using a rapidly oscillating gas flow provided by a Desai-Zimmerman fluidic oscillator to minimises concentration polarisation resistance by disrupting boundary layer formation and increasing the overall efficiency are discussed. Results show remarkable improvement in performance, that could also translate to other electrolyser and fuel cell types and designs.