Mercury oxidation during coal combustion by injection of vanadium pentoxide (V2O5)

Although there are many commercially available methods to capture Hg emission from coal combustion, it is still difficult to use a single method that can control Hg emission both efficiently and economically from coal combustors due to the varying coal seams, operating conditions and downstream control devices. One methodology is the use of sorbent injection at elevated temperatures; and is examined in this study. V2O5 was tested as the sorbent and was found to effectively oxidize elemental mercury (Hg0). Ultrafine V2O5 particles are formed during the combustion process resulting in a high surface area aerosol that can effectively catalyze the oxidation of Hg0. The effect of varying chlorine (Cl) concentration in coal on Hg0 oxidation was also examined. The result shows that Cl can enhance Hg0 oxidation on the V2O5 surface.