Natural iron ore as an oxygen carrier for biomass chemical looping gasification in a fluidized bed reactor

Chemical looping gasification (CLG) of biomass was performed in a thermogravimetric analyzer (TG) reactor together with a fluidized reactor with natural iron ore oxygen carrier under inert atmosphere. TG experiments indicated that iron ore can provide oxygen source for biomass conversion in the form of lattice oxygen. In the fluidized bed experiments, the influences of reduction temperature on CLG of biomass were emphatically investigated in terms of gas distribution and solid characters. The gas yield and carbon conversion increased, but the tar content decreased in the temperature range of 1,013-1,213 K. In this temperature range, the conversion of oxygen carrier increased from 24.11 to 53.59 %. X-ray diffraction analysis shows that more FeO was generated with temperature increasing. Scanning electron microscope analysis indicates that sintering was observed at elevated temperature. An optimum mass ratio of biomass/oxygen carrier (B/O) of 0.67 was obtained with aim of achieving maximum gasification efficiency of 76.93 %.