The investigation of NO reduction with sawdust char in a micro fluidized bed

Some biomass has good prospects for NOx emission control. In this study, the NO reduction with a kind of sawdust (SD) char was investigated in a micro fluidized bed reaction analyzer (MFBRA). The heterogeneous reactivity of NO-SD char was studied from 4 different aspects: O2 concentrations, inlet NO concentrations, CO2 concentrations and reacting temperatures. The results showed that both O2 and CO2 had negative effects on the reduction reactivity of NO. The higher the concentration of O2 and CO2, the more unfavorable the total reduction efficiency of NO. The presence of O2 accelerated the consumption of SD char rapidly by oxidizing the carbon matrix, while the presence of CO2 competed with NO for carbon atoms and reactive intermediates C(O) through C-CO2 gasification. In addition, the reacting temperature was important for the NO-SD char reaction. When the temperature was raised from 1073 K to 1123 K and higher, the reactivity of NO reduction was significantly improved. However, the effect of inlet NO concentration on its reduction was relatively less obvious. The instantaneous reduction efficiency and total reduction efficiency only showed a certain decreasing trend with the increase of inlet NO concentration.