While in the Metro Center station in Washington today, I saw an excellent series of advertisements that said "there's no such thing as clean coal." The advertising campaign featured shots an alien, a gorilla and a scantily clad woman holding up lumps of coal, plus posters with the slogan.
I'm not sure what the alien, gorilla and scantily clad woman had to do with anything. But there really is no such thing as clean coal. The phrase was invoked by candidates on both parties during the election. However, coal mining is dangerous and destructive to miners' health and the environment.
Converting coal to liquid fuels also releases a lot of CO2. The resulting fuels may burn more cleanly, but the total CO2 emissions greater than just burning gasoline or diesel. NOx and SOx emissions from coal plants can be mitigated with technology; I understand that Fuel Tech (FTEK on the NASDAQ, disclosure: I own shares of the company) has cost effective technology to mitigate these emissions and also to mitigate slag buildup in power plants. However, that cannot possibly overcome the loss of human life and environmental damage caused by coal mining, not to mention the CO2 emissions.
Aside from praying for miners worldwide, we need to be cognizant that coal plants constitute a significant share of the energy generation mix in the US, China and India. The US can reduce the percentage of coal power it uses, but elimination of coal plants is quite some time off even if maximum effort were devoted to this. In China and India, the situation is worse because coal is cheap and those countries are industrializing rapidly.