Abstract
The fine ash formed from the mineral content of pulverised fuels can be removed from the flue gas at high efficiencies by electrostatic precipitators or fabric filters. The sulphur present is converted during combustion almost stoichiometrically to sulphur oxides SOx, which can be treated by post-combustion chemistry, either dry or wet. On the other hand, oxides of nitrogen are formed by a complex interaction between fuel and atmospheric nitrogen. Control of NOx emissions can be effected both by staged combustion in the boiler, and post-combustion technology. The heavy metals except mercury are concentrated in the particulates, and are at concentrations well below environmental limits in any ash escaping the gas cleaning system. Mercury requires special attention. Organic species such as PAH and dioxins are not emitted in significant concentrations.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have