Factors Impacting Gaseous Mercury Speciation in Postcombustion

摘要

In the bench scale, gaseous mercury oxidization was investigated in postcombustion conditions with the experimental flue gas. The baseline experimental flue gas consisted of CO_2 and N_2. Other flue-gas constituents varied with O_2, SO_2, HCl, and NO. The measurement of mercury speciation was carried out at the downstream of the reaction tube using the Ontario Hydro method. Results showed that the possible intermediates Cl and Cl_2 from HCl are the most important factors in mercury oxidization in the experimental flue gases. More mercury oxidization occurs with a higher reaction temperature and higher HCl concentration in most of experimental flue gases with HCl addition. O_2 and NO also enhance mercury oxidization in the experimental flue gases with or without HCl and SO_2. However, the effect of SO_2 on mercury oxidization depends upon the presence of HCl.