Clean air act

UK researchers claim to be the first in the world to cut the level of harmful minerals in all types of coal by a factor of more than 100.

The development, carried out at the University of Nottingham, could allow clean coal production techniques to be introduced that halve carbon dioxide emissions.

Fears over the future supply of natural gas have renewed interest in making coal-fired power stations more efficient.

Existing power stations burn coal to generate steam, which is in turn used to power turbines. If this steam stage could be removed, and the combustion gases from burning coal used directly to drive the turbines, the CO2 produced for the amount of coal burnt could be reduced by 30–50 per cent.

However, this has so far not been possible as the minerals released from the burning coal would destroy the turbine blades. So the researchers have developed a method to leach these harmful minerals from the coal before using it to directly power the turbines.