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 a three-dimensional ordered macroporous morphology, its tiers were arranged alternatively and connected through three-dimensional pore structures. By 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.