Coal-cleaning options for SO/sub 2/ emission reduction

The article discusses coal-cleaning options for reducing SO/sub 2/ emissions. Conventional PCC can reduce the potential SO/sub 2/ emission from high-sulfur coal by 20-50%, depending on the inherent properties of individual coals. SO/sub 2/ emission reduction by conventional PCC is limited by the amount of finely distributed mineral sulfur (pyrite) and organic sulfur in coal. Advanced fine-coal-cleaning technologies can be used to remove fine pyrite and sometimes organic sulfur. Coal cleaning may be used in combination with other technologies to reduce SO/sub 2/ emission. Combinations such as coal cleaning and limestone injection multistage burners (LIMB) or flue-gas desulfurization (FGD) may be more cost effective than FGD alone. The use of a multi-stream coal-preparation plant to produce deep-cleaned and middling products is another control option. The deep-cleaned coal, which is low in ash and sulfur, can be burned without further SO/sub 2/ emission control while the middling product can be burned in a boiler with a LIMB or FGD system.