Different processes that are used to remove impurities from coal before combustion to make environmentally friendly energy are discussed. Post-combustion carbon dioxide capture technologies are currently being considered for existing supercritical coal-fired plants. The mineral-free coal, with the general term ultra-clean coal (UCC), greatly diminishes the need for cleanup technologies to remove damaging particulates and volatiles such as sodium. UCC has the potential to be fired directly in a gas turbine, achieving a cycle efficiency similar to that of natural gas. The UCC process can treat coals of sub-bituminous rank and higher and the calorific value of the UCC on an ash free basis remains unchanged. UCC is considered as a fuel for high efficiency combustion cycles and expands the potential uses for coal beyond power generation and metallurgical coke into areas currently occupied by oil.