Adsorption of condensable particulate matter from coal-fired flue gas by activated carbon

Condensable particulate matter (CPM) is a special kind of primary particulate matter and is in a gaseous state before discharge. After discharge, it rapidly forms liquid or solid particles through atmospheric dilution and cooling, which are harmful to the environment and human health. However, current research on controlling CPM is lacking. Therefore, the adsorption effects of activated carbons (ACs) on CPM at different temperatures were studied using EPA Method 202. Results showed that the removal efficiency range of CPM at 90 °C by ACs could reach 19%-22%. The removal efficiency of the inorganic fraction was higher than that of the organic fraction. ACs had obvious adsorption effects on Cl^-, NH₄⁺, and Hg in CPM but had marginal adsorption effects on SO₄²⁺, NO₃^-, and other metal elements in CPM. ACs had prominent adsorption effects on extremely toxic aromatic compounds in CPM. At a flue gas temperature of 35-170 °C, the efficiency of CPM removal through AC adsorption could increase with decreasing flue gas temperature, and this effect was more obvious during the adsorption of inorganic fractions. In addition, the efficiency of CPM removal through condensation and adsorption could reach up to 51% at 35 °C when flue gas at 130 °C was used as the initial flue gas.