Coal contains anywhere from 25 to 90 percent carbon, which combines with oxygen when burned to release energy. This process emits a host of noxious chemicals, such as carbon dioxide, sulfur, nitrogen oxide and mercury. Yet carbon in coal can also be used to strip oxygen from water, producing clean-burning hydrogen gas. FutureGen will liberate hydrogen by heating finely ground coal in a high-pressure, pure-oxygen environment, a process known as gasification and a turbine will burn the resulting hydrogen gas to produce electricity. As for emissions, the plant will pump the CO2 underground while the other pollutants are converted to an inert solid and buried.