Investigation on multiple benefits of wet ESP for emission control in an Indian coal fired thermal power plant

Abstract

In this article, the operation of wet electrostatic precipitators (WESP) as air pollution control device in an Indian coal fired thermal power plant has been investigated in respect of its efficacy in removing particulate laden gaseous emissions. The WESP was installed for reducing the particulate matter (PM) emission to meet the Indian stack emission standard of PM. Interestingly, the study reveals that the WESP reduced the SO2 and CO2 emissions potentially. The system, therefore, functions also simultaneously as a CO2 capture system. Since CO2 is a green house gas (GHG), operating a WESP for cleaning flue gas of a coal fired thermal power plant can be considered as a GHG emission mitigation option as well. The level of NOx emission could not be conclusively analyzed perhaps might be due to air dilution of the flue gas. It is finally suggested that the plant operators would like to operate the plant using dilute alkaline reagent replacing the water as the scrubbing medium so as to obtain multiple benefits of cleaning all acidic gases by the WESP followed by better ash management.