Biomass pyrolysis/gasification using three dimensional ordered macroporous (3DOM) Fe2O3 as an oxygen carrier

Polystyrene spheres were prepared by soap free emulsion polymerization method, then three dimensional ordered macroporous (3DOM) oxides Fe2O3 were successfully prepared after impregnation and calcination using nitrates as raw materials and citric acid as complexing agent. The samples were characterized by the techniques of scanning electron microscopy (SEM), X-ray diffraction (XRD), BET and mercury porosimetry. Pyrolysis and gasification of biomass with Fe2O3 as oxygen carriers in helium atmosphere were carried out in a thermogravimetric analyzer coupled with mass spectrometry (TG-MS). The possibility of 3DOM Fe2O3 functioning as gasification agent in biomass gasification substituted for pure oxygen, oxygen-enriched air or steam were investigated. Furthermore, a comparison experiment was carried out by using analytically pure Fe2O3 to analysis the high-performance of 3DOM Fe2O3. The characterization results showed that 3DOM Fe2O3 presented 3DOM morphology and the tiers were arranged alternatively and connected through three-dimensional pore structures. 3DOM Fe2O3 prepared was pure Fe2O3 and no other impurity phases existed when contrast with the XRD pattern of analytically pure Fe2O3, TG-MS results showed that Fe2O3 contributed to biomass gasification in high temperature stage. When used 3DOM Fe2O3 as oxygen carrier, the maximum weight loss and maximum weight loss rate raised 7.1% and 0.29%/min in the gasification stage, respectively, meanwhile two generation peaks of CO, CO2, and CH4 appeared in the MS curves.