It is a pollution control system for the reduction of Sox (SO2, SO3), HCl and heavy metals like mercury. It is a dry process in which a sorbent (a material used to absorb or adsorb liquids or gases) is injected into the coal-fired boiler where it interacts with various like SOx, HCl and the resultant dry waste is removed via either an electrostatic precipitator (ESP) or a fabric filter baghouse.
It offers various advantages in comparison to traditional acid gas scrubber technology such as: lower capital cost, wide range of favourable operation conditions, and much lesser time for completing installation and commissioning.
CPCB has asked coal-fired thermal plants to comply with the environmental norms by December 31, 2019 and NTPC’s power plant in Dadri is the first in the India to opt for DSI System.