Solid Carbon Fuel Cell May Mean “Clean Coal”

Dean Sigler Fuel Cells, Sustainable Aviation Leave a Comment

For transportation, two types of fuel cells come to mind: PEMs or SOFCs.  A third variety, DCFCs, may have a place in transport systems, and may have advantages in using “dirty” fuels. PEM (Polymer Electrolyte Membrane – or Proton Exchange Membrane) cells use a solid polymer as an electrolyte and porous carbon electrodes containing a platinum or platinum alloy catalyst. They need only hydrogen, oxygen from the air, and water to operate. They are typically fueled with pure hydrogen supplied from storage tanks or reformers. SOFCs (Solid Oxide Fuel Cells) use a hard, non-porous ceramic compound as the electrolyte. SOFCs are around 60% efficient at converting fuel to electricity. In applications designed to capture and utilize the system’s waste heat (co-generation), overall fuel use efficiencies could top 85%.  They operate at high temperatures (1,000° C or 1,830° F). Both PEMs and SOFCs use hydrogen, which must be extremely pure and is therefore often produced at high costs.  What if a …

Hydrogen: Are We There Yet?

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

Probably not, but we are edging closer to when H2-powered vehicles (including small aircraft) might be as ubiquitous as Prius’s or Leafs – but there are significant barriers to overcome. Fuel cell-powered aircraft might make sense eventually from a physical and economic sense, and while new technologies show promise for EV use, hydrogen power still has barriers to overcome before we’re able to exploit the environmental benefits of hydrogen power.  The appeal of a fuel cell to burn hydrogen and leave behind only a light mist of water still dazzles, but teasingly eludes us, not so much from a technical standpoint – but from environmental and economic ones. Two Most Practical Fuel Cells for Transportation Fuel cells come in many varieties, with proton exchange membrane (PEM) and solid oxide fuel cells (SOFC) types heading the list for practical vehicle use.   PEM cells, according to Fuelcell.org, “operate at relatively low temperatures, have high power density, and can vary output quickly to …