Advanced Pulverised Fuel (PF) Combustion is one of the ways industry continuously strives to increase efficiencies of a conventional plant; for example, the average thermal efficiency of power stations has increased from 5% in 1900, to around 35% currently. New conventional plants achieve above 40% efficiency and with the use of specially developed high strength alloy steels, which allow the use of high pressure and high temperature steam, advanced modern plants can achieve close to 45% efficiency. Applications of new advanced materials should enable efficiencies of 55% in the future. This results in corresponding reductions in CO2 emissions as less fuel is used per unit of electricity generated.
Pulverised Fuel Combustion: This is the most widely used method for burning coal to generate electricity. Coal is milled to a powder and blown into the boiler with air. This provides the heat to produce steam, drive the turbines and generate electricity.
Emissions can be reduced by electrostatic precipitators and/or fabric filters which remove 99% of fly ash from the flue gases. Flue gas desulphurisation can remove up to 97% of sulphur oxides from flue gases, converting it into gypsum for the building trade. The combustion process of existing plants can also be modified to reduce nitrous oxide emissions by up to 70%, while selective catalytic nitrous oxide reduction, a post combustion technique, can achieve reduction of 80-90%.
