REMOVAL OF SO2 AND NO OVER RICE HUSK ASH (RHA)/CaO-SUPPORTED METAL OXIDES

The activity of rice husk ash (RHA)/CaO-based sorbent supported with variousmetal oxides for the removal of SO2 and NO from simulated flue gas ofcombustion process has been studied. In this study, RHA/CaO-based sorbentswere impregnated with an appropriate metal nitrates solution followed bydrying and calcinations, which resulted in the sorbent having the followingactive phases; MgO, MnO, CoO, ZnO, Al2O3, Fe2O3, and CeO2. The sorbentcatalystswere tested in a fixed bed reactor by passing mixture gas consisting of SO2 (2000 ppm), NO (500 ppm), O2 (10 %), water vapor (50%) and N2 as abalance at a total flow rate of 150 mL/min and reaction temperature of 87°C.The results showed that RHA/CaO sorbents impregnated with CeO2 displayedthe highest sorption capacity among other impregnated metal oxides for thesimultaneous removal of SO2 and NO. Infrared spectroscopic results indicatethe formation of both sulfate (SO42-) and nitrate (NO3-) species due to a catalyticrole played by CeO2.