Research on reaction conditions and mechanism for simultaneous removal of NO and Hg0 over Cu[sbnd]Fe modified activated carbon at low temperature

Abstract

In this study, modified microwave coconut shell activated carbon (CuFe/MCSAC) was used to simultaneously remove NO and Hg0 in the industrial tail gas. The influences of reaction condition were investigated, such as NH3 concentration, O2 content, gas hourly space velocity (GHSV), resistance of SO2 and H2O. Under the optimal reaction conditions (600 ppm NH3, 3% O2 and 30000 h−1 GHSV), CuFe/MCSAC showed high NO conversion rate (86%), high Hg0 conversion rate (61%) and low N2O concentration (81 ppm) at 225 °C. NH3 was conducive to the removal of NO, but it had a competitive adsorption effect for Hg0. O2 promoted oxidation of NO and Hg0, and led to the formation of N2O. Low GHSV had the external diffusion effect, which affected the reaction rate. High GHSV could not provide enough reaction time. H2O and SO2 were not conducive to the selectivity of SCR reaction and oxidation of Hg0.