A new kind of fuel cell
A 100 kW system would have a core of ceramic tubes, each about two inches wide and forty inches long. The system would operate at 900°C and emit only a pure stream of CO2, ready to be captured without the capital and energy cost of separation from nitrogen. Ash, sulfur, lead, mercury and other solids would not be released to the atmosphere but would be carried to landfills or re-cycled.
In the production of distributed base-load electricity, coal or biomass is fed into the base of the system. The carbon in the coal or biomass is gasified without water into carbon monoxide by the re-circulating carbon dioxide. That is: C+CO2= 2(CO). The CO then moves up the inside of the ceramic tubes. At a temperature of 900 degrees Centigrade the oxygen in the air on the outside of the cell walls is under pressure to cross the barrier and oxidize the CO on the other side. It cannot cross as an oxygen molecule but only as an oxygen ion. So the O2 picks up four electrons from the utility grid, crosses the barrier, bonds with the CO and sheds the electrons, creating the electric current. That reaction is 2(CO)+O2ion= 2(CO2)+4e.
That's simpler and twice as efficient as a 20th century coal power plant. And since the system is modular, groups of directcarbon Fuel Cell systems, each with the footprint of a forty-foot cargo container, can be grouped for generation of electricity in the megawatt range.
