At present, most large coal-fired power plants are equipped with wet flue gas desulfurization (WFGD) systems downstream to an electrostatic precipitator. As the scrubbing effects of reagent solution, particulate matter can be removed simultaneously in a WFGD system. In the wet FGD process, the hot flue gas contacts normal temperature scrubbing liquid. Simultaneous mass and energy transfer takes place, causing the gas phase temperature to decrease and the liquid phase to evaporate, entering the gas phase.
Consequently, the relative humidity of flue gas can be greatly raised, allowing the flue gas after scrubbing approaches to be saturated with water vapor at a temperature of about 45–60 C. Thus it is possible to produce a supersaturated vapor phase by improving the operating conditions of the WFGD system [14,15]. Therefore, a novel process combining heterogeneous condensation of water vapor and WFGD system to separate fine particles from flue gas is presented in this paper. Supersaturation was achieved by
means of adding steam into the particle growth region, which was above the liquid phase inlet in the desulfurization tower. The condensation grown droplets are effectively removed by a wire mesh demister. The influences of the initial particle number concentration, temperature of inlet flue gas and desulfurization solution, amount of steam added, etc. on the removal efficiency were experimentally investigated.