The experimental Kemper "clean coal" power plant, which was supposed to burn coal and capture the CO2, was doomed before it was started. Executives knew their plans were likely to fail, and covered it up.

More about it.

I suspect that "clean coal" was hyped intentionally by planet roasters with the specific purpose of discouraging society from doing what really needed doing: putting an end to fossil fuel use with all due speed — while there was still time to avoid disaster.