There is no such thing as "Clean Coal." Its a myth. A plan. A hope. A dream is probably most accurate.
Need evidence other than the ramblings of a geek? Try this. If burning coal was reasonably clean to begin with, would Tennessee Valley Authority (TVA) have millions of gallons of sludge left over after a coal burning plant was through burning the coal? Sludge that will contain trace amounts of lead, arsenic, magnesium and other items that can be leached into the water.
So, put clean coal right up there with "Clean" nuclear energy. Sure it's clean if you only look at a subset of the whole picture. And don't look at the entire scope where the residue left over is as bad or worse than other energy production methods.
And hey, won't it be nice to have a President that can pronounce "Nuclear" correctly? Yeah, I know that both pronunciations are now considered correct, but, I'm sorry, I'm old school. Saying it the Shrubbery way just makes you sound like an idiot.