"Clean Coal" is a fantasy. Even assuming that a perfectly clean stack is practical (and that's a stretch) it is far from a complete picture.

What's left are huge piles of ash. Full of heavy metals and other nasty components. Poer companies simply pile the stuff up and hope that disaster doesn't strike. But it does. A quick google search will lead you to the disasters of the TVA and Duke Power.

Coal in its totality is a dirty fuel. There are better alternatives - solar, wind and gas.