Researchers at Ohio Stste University have successfully comducted a research-scale test of a new form of "clean coal" energy production which does not involve burning the coal.
The technology uses tiny beads of iron oxide to carry oxygen to coal which has been ground into a powder. The coal particles are about 100 micrometers across while the iron beads are much larger, about 1.5 to 2 millimeters across.
The coal and iron oxide are heated to high temperatures. Carbon from the coal binds with the oxygen from the iron oxide, releasing carbon dioxide, which rises into a chamber where it is captured. Hot iron and coal ash are left behind.
The reaction produces heat which can be use heat water making steam to drive a turbine.
Because the iron beads are so much bigger than the coal ash, they are easily separated out of the ash which is removed from the system. The iron beads are exposed to air, so that they become re-oxidized and can used again almost indefinitely.
Since the process is enclosed, almost all of the CO2 is captured.