Catalytic reduction of NO using iron oxide impregnated biomass and lignite char for flue gas treatment

In this paper, iron oxide catalysts supported on corncob and lignite chars are used for catalytic reduction of NO in flue gas. Denitrification experiments were carried out in a fixed-bed reactor at temperatures of 100, 150, 200 and 300 °C by using simulated flue gas containing NO. Catalyst samples before and after denitrification were analyzed using Brunauer-Emmett-Teller (BET) analysis, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscope with an energy dispersive X-ray auxiliary (SEM-EDX). Results show that biomass-lignite chars impregnated with iron oxide had a high reactivity during catalytic reduction of NO. The denitrification efficiency of biomass-lignite chars impregnated with iron oxide catalyst was higher than that of un-impregnated char. The highest catalytic performance was achieved at corncob to lignite ratio of 5:5. Synergetic effects between lignite and biomass during co-gasification were attributed to the potassium migration from biomass to lignite char which improved the efficiency of NO removal. The catalysts had the highest denitrification efficiency at 300 °C and the reactions mechanism has been discussed.