Significance of Micro-Scale Mass Transport Phenomena on Fuel Cells and CO₂ Sequestration

We describe micro-scale mass transport plays a key role for R&D of the two realistic countermeasures of global warming, hydrogen fuel-cell energy system and CO₂ capture and sequestration (CCS). Understanding of the phenomena based on in-situ measurements leads to the implementation and practical use of these systems. Water inside the fuel cells plays a key role for both cell performance and durability. We have been developing magnetic resonance imaging (MRI) and also soft X ray techniques as in-situ visualization methods for water transport in operational fuel cells. MRI visualization of water content in membrane achieved high spatial resolution, 5 μm, to obtain fundamental insights on water transport process in membrane of 50 μm thickness. Soft X ray has been firstly introduced to measure water transport phenomenon in gas diffusion layer. On the other hand, we clarified CO₂ distribution and its behavior by micro-focus X-ray CT and LBM simulation for CCS.