Study on the removal of condensable particulate matter from flue gas using string-of-beads liquid

Condensable particulate matter (CPM) from coal-fired and municipal solid waste incineration flue gas is emitted as gaseous precursors that rapidly form particles in the atmosphere, representing a major challenge for air pollution control. This study proposes the use of string-of-beads liquid for CPM removal and investigates its mechanism and influencing factors. Under experimental conditions, the overall CPM removal efficiency ranged from 29.56% to 65.27%, while the energy consumption was only 1.17%-8.25% of that of conventional condensation methods. Removal efficiency of the organic fraction (CPM_o) was consistently higher than that of the inorganic fraction (CPM_i), with SO₄^2- achieving the highest removal efficiency of 78.34%. Mechanistic analysis indicates that CPM removal at high flue gas temperatures is dominated by condensation and dissolution, while dissolution becomes the primary mechanism as the temperature decreases. The developed theoretical model combining condensation and dissolution accurately predicts CPM removal. The string-of-beads liquid thus offers a low-energy, engineering-feasible approach for CPM control in coal-fired and waste incineration flue gas.