Scientific American: Coal is everywhere. It can be dirty and dangerous to wrest from the ground, but we’re probably not going to run out of it anytime soon. And, unlike oil, the U.S. has a large domestic supply. As a result, some have suggested that for "energy security" transforming coal into a liquid fuel alternative for cars might make sense. To do that, coal is mixed with oxygen and steam at high temperatures and pressure to produce a gas. This gas is then reacted in the presence of a catalyst to …